Title of Invention	"AN IMPROVED EXPOSURE LIGHTHOUSE DEVICE"
Abstract	The present invention provides a an exposure lighthouse, it utilizes an elongated light source, the first slit plate that is located close to the light source and has three slits thereon each of which has a specified shape for exposing Red, Green, and Blue respectively, and the second slit plate that is disposed close to the first slit plate having a slit thereon. And the slit on the second slit plate is used to select necessary one of the slits of the first slit plate. Further, all of the light source, the first slit plate, and the second slit plate are sealed in a water jacket in which water for cooling the light source circulates. 24

Title of Invention

"AN IMPROVED EXPOSURE LIGHTHOUSE DEVICE"

Abstract

The present invention provides a an exposure lighthouse, it utilizes an elongated light source, the first slit plate that is located close to the light source and has three slits thereon each of which has a specified shape for exposing Red, Green, and Blue respectively, and the second slit plate that is disposed close to the first slit plate having a slit thereon. And the slit on the second slit plate is used to select necessary one of the slits of the first slit plate. Further, all of the light source, the first slit plate, and the second slit plate are sealed in a water jacket in which water for cooling the light source circulates. 24

Full Text	Field of the Invention The present invention relates to an inline color picture tube having dot mosaic screen and, more specifically, to an exposure lighthouse used to form a luminescent phosphor dot mosaic screen in the color picture tube. Background Of The Invention K1G.1 of the accompanying drawings illustrates a schematic partially cutaway top view and a front view of a commercial in-line color picture tube utilizing a finely perforated shadow mask. The inline color picture tube 1 illustrated here includes a highly evacuated envelope that consists of a generally rectangular dish shaped panel 2, a generally cone shaped runnel 3 that is connected to the open end of the panel I, and a generally cylindrical neck-tube 4 that is connected to the rear end of the runnel 3, and a stem 5 that seals the rear end of the neck-tube From now on, an orthogonal (X, Y, Z) coordinate system is used for the sake of convenience as described in the Figure: that is, the X-axis is parallel to the long sides of the rectangular shaped panel 2, the Y-axis is parallel to the short sides of the panel 2, and the Z-axis is coincided with the tube axis that is substantially identical to the axis of the neck tube 4. 1 he panel 2 has the inner surface on which a mosaic screen 10 of a predetermined mosaic pattern of color emissive phosphor dots, corresponding to three primary element colors (Red, (ireen, and Blue), is deposited. The panel 2 also supports a color selection electrode or a finely perforated shadow mask 20 that is made from a thin metal sheet being formed into a predetermined shape and having a multiple of apertures 21 made thereon in a predetermined pattern. The shadow mask 20 is supported in the panel 2 with supporting members that are not shown in FIG. 1 while spaced a predetermined distance inward from the mosaic screen 10. On the other hand, the neck-tube 4 supports therein an inline electron gun assembly 30 that consists of three unit electron guns 30R. 30G, and 30B corresponding to three primary clement colors (Red, Green, and Blue) and arranged in line in the X-Z plane, where the axis of the unit gun 30G that is arranged at the middle of the three unit guns is coincided with Z-axis. Electron beams are emitted from the inline electron gun assembly 30: that is, an electron beam is emitted from each of the unit electron guns 30R, 30G, and 30B, and travel toward the mosaic screen 10 with being deflected around the portion where the neck-tube 4 is connected to the tunnel 3. Typical one of the electron beams is referred with the symbol 200 mFlG.l. In order to deflect the electron beams emitted from the inline electron gun assembly 30 and to permit the beams scanning the entire useful area of the mosaic screen 10, a deflection yoke 40 having deflection coils is mounted on the exterior of the envelope around the portion where the neck-tube 4 is connected to the funnel 3. Each of three electron beams emitted from unit guns 30R, 30G, and 30B travels through fine aperture 21 in the shadow mask 20 to impinge on and to excite the color emissive phosphor dots of the mosaic screen 10. Image reproduction is accomplished by scanning the electron beams across the mosaic screen 10 in both X and Y directions in a manner that is well known to those skilled in the art. FIG.2 of the accompanying drawings illustrates the relation between the electron gun assembly 30 hence three unit electron guns 30R, 30G, and 30B thereof, shadow mask 20 hence aperture 21 thereon, and the mosaic screen 10. I he mosaic screen 10 consists of the periodic patterning of three types of phosphor dots 10R, 10G, and 10B, each of which emits light of red, green, and blue color respectively when it is excited being impinged by the electron beam Any of the two adjacent dots separate each other by a predetermined distance and there is a space in between. This space is filled with a black matrix 10X that consists of s layer of light absorbing black material. In other word, the black matrix 10X has many periodically arranged holes therein and the holes are filled with phosphors of the three colors. By projecting the electron beams through the aperture 21 of the shadow mask 20, any single electron beam impinges only upon the color emissive phosphor dots of a particular one of the primary colors (red, green, or blue). More specifically the electron beam emitted from the unit electron gun 30R, 30G, or 308 impinges only on the red emitting phosphor dot 1OR, green emitting phosphor dot 10G, or blue emitting phosphor dot 10B respectively. The degree of coincidence in the geometric positional relationship on the inner surface of the panel 2 between any of color emissive phosphor dots (30R, 30G, or 30B) and the impinging point of the corresponding single electron beam which has passed through the associated aperture 21 is generally described in a term of 'landing characteristic' or merely 'landing'. The higher the degree of coincidence the better the landing is. More specifically landing is defined by the shift of the center of the projected electron beam that has passed an aperture 21 from the center of the corresponding phosphor dot on the inner surface of the panel 2. Landing is one of the most important performance characteristics for color picture tubes to produce good pictures of good color purity and good uniformity thereon. Therefore, how to deposit each of the phosphor dots at the best location on the inner surface of the panel 2 is always an important subject for manufacturers of color picture tubes The deposition of the phosphor dots 30R. 30G. and 30B and the black matrix 10X on the inner surface of the panel 2 to form the mosaic screen 10 is generally performed by use of an exposure system I or making the mosaic screen 10, first, the black matrix IOX having holes for filling phosphor materials therein is formed on the inner surface of the panel 2. Next, the above-made holes are filled with phosphor materials to form phosphor dots. The process for depositing the phosphor dots 1OR,1OG, and 10B is similar to that for making the holes in the black material layer to form black matrix 1OX. The mosaic like patterning of phosphor dots 1OR, 10G, and 10B is completely same to the holes of the black matrix 10X. Therefore, for the sake of convenience, hereafter, the holes of the black matrix 10X are referred with the symbols 1OR, 1OG, and 10B corresponding to each of the phosphor dots filling therein. FIG.3 of the accompanying drawings illustrates a simplified schematic view of a lighthouse used for depositing mosaic screen 10 on the inner surface of the panel 2. The lighthouse has a table like mainframe 70. A panel 2 in process is put on the predetermined position of the mainframe.70. The predetermined position is defined by a plural number of positioning stopper 71, The inner surface of the panel 2 is coated preliminarily with a photo resist material IOA on its inner surface and at the same time it supports a shadow mask 20 with supporting members that are not shown in this figure. The lighthouse has a lamp house 80 having a light emitting point 85 therein. The light emitting point 85 is a point light source from where ultra violet light is emitted as the occasion demands. The lamp house 80 is mounted on a rail 131 that is fixed to the mainframe 70. With being guided by the rail 131, the lamp house 80 can change its X-coordinate without changing its Y- and Z-coordinates. The X-coordinate of the lamp house 80 is controlled by being driven with a linear actuator 132 that is fixed to the mainframe 70 and connected to the lamp house 80 with an arm 133. The Y coordinate of the light emitting point 85 is basically hold at zero. The Z coordinate of the light emitting point 85 is approximately equal to the Z-coordinate of the effective center of the deflection yoke 40: that is, the distance in Z direction between the panel 2 and the light emitting point 85 is approximately equal to the distance in the Z direction between the panel 2 and the effective center of the deflection yoke 40. A correction lens 100 is installed between the lamp house 101 and the panel 2 for giving small corrective deflection to the path of the rays. Under such arrangement the exposure process for making the black matrix 10X having holes 1OR, 1OG, and 1OB starts. At first being driven by the linear actuator 132, the X-coordinate of the light emitting point is adjusted and fixed to X=+S as shown in F1G.3R. Then, ultra violet rays are emitted from the emitting point 85: typical one of rays is described in the figure referred with the symbol 201. The rays emitted from the emitting point 85 pass through the correction lens 100. After passing through the correction lens 100, a part of the rays that pass aperture 21 impinge on the inner surface of the panel 2 and expose the photo resist material 10A to make latent images of the holes 10R as a projected pattern of the aperture 21. Next, being driven by the linear actuator 132, the X-coordinate of the light emitting point 85 is adjusted and fixed to X=0 as shown in FIG.3G, and the second exposure is given to the photo resist material 10A to make latent images of the holes 1OG. In FIG.3G (and next FIG.3B), the upper half of the lighthouse is not drawn At this time, the second collection lens is installed at the same location as the previous correction lens 100 to give a different corrective deflection to the rays than the preceded exposure The all correction lenses put here are referred with the symbol 100 hereafter. The mechanism for exchanging the correction lens is not described in the figure Next, by being driven by the linear actuator 132. the X-coordinate of the light emitting point At this time, the third correction lens is installed at the same location to give a different correction than the preceded two exposures After carrying out those three exposures, the shadow mask 20 is removed from the panel 2 and photo resist material 10A having the latent images made with the above three exposures are chemically developed to make all these exposed areas for holes1OR, 1OG, and 1OB emerged. Next, the area that is not exposed with the above exposure is dyed with a black material to form the black matrix 10X. Finally, the holes 1OR,1OG, and 1OB of black matrix 1OX are filled with color phosphors The panel 2 thus processed is, after further appropriate processing, assembled into a color picture tube with the shadow mask 20 that has been used at the time of the exposure. In order to perform a good landing characteristic, it is important for the color picture tube that the path of the ray that passes through an aperture 21 of the shadow mask 20 coincides with the path of the electron beam that passes the same aperture 21 at the time of operation. Therefore the above-used value S is so decided that it is equal to the adjacent mutual distance of the three electron beams at the effective center of the deflection yoke 40: the three beams that are emitted from three unit electron guns 30R, 30G, and 30B respectively. Further the characteristics hence shape of the correction lenses 100 are so designed that the paths of the rays coincide with the paths of the electron beams as far as possible. As the electron beams for three colors have different trajectories, three different lenses are separately used for exposing each of black matrix holes 30R, 30G, and 30B. In order to discuss the mis-landing problem, it is convenient to use the S-plane and the virtual emitting source The S-plane is defined, as shown in F1G.3R, as a hypothetical plane that is perpendicular to Z-axis and includes the light emitting point 85 The path of the exposure ray is a straight line after passing through the correction lens 100 Bv making reverse extension of this straight line, it is possible to define a virtual emitting point 86 on S-plane as the intersection of the above extension and S-plane. This point (86) is called 'realized virtual emitting point' hereafter The path of an electron beam that passes through aperture 21 of the shadow mask 20 is also a straight line near the aperture 21. Therefore by making reverse extension of this straight portion of the electron beam line it is possible to define another virtual emitting point on S-plane as the intersection of the reverse extension of the electron beam line and S-plane. This hypothetical virtual emitting point is called 'ideal virtual emitting point'. Amplifying this concept, it can be said that any point on the inner surface of the panel 2 has the corresponding ideal virtual emitting point Therefore it is possible to define mis-landing at any point on the panel 2 using the vector wise distance between the realized virtual emitting point and ideal virtual emitting point on S-plane. FIG.4 of the accompanying drawings illustrates the relation between a representative point in the inner surface of the panel 2 and the corresponding two virtual emitting points: the one is realized virtual emitting point 86 another is the ideal virtual emitting point which is referred with the symbol 87 in the drawing. Of course, when the location on the panel 2 is designated, the location of the ideal virtual emitting point depends on the color in question. Therefore, though FIG.4 illustrates just the case of red thai corresponds to F1G.3R. the result should be applied to other two colors as well. The point on the inner surface of the panel 2 is represented by P, the coordinates of which are ( X\|.. YI>). The ideal virtual emitting point 87 for P is at (X\, YI) on S-plane. It is obvious from the definition that each of the coordinates X1and Y1 is a function of the coordinates (Xp, Yp) respectively: that is. X1= X1(Xp, YP) and Y,= Y1(Xp, Yp) The correction lens 100 is employed for realizing such location (X1, Y1) of the ideal virtual emitting point 87 by reflecting the exposure ray that is emitted from the emitting point 85. However, generally speaking, it is impossible to realize the given (X1, Y1) with a correction lens having smooth surface This comes from an intrinsic property of a ray bundle that is emitted from a point-emitting source as shown in FIG 3. As far as a lenses having smooth surfaces are used, it is impossible to get complete coincidence of the realized virtual emitting point 86 with the ideal virtual emitting point 87 over the entire useful area of the mosaic screen 10 (inner surface of the panel 2). We cannot solve this problem even if we employ a lens system that consists of plural lenses. The detail of this problem has been discussed in the paper titled 'Mis-landing Pattern Eliminatable by a Smooth Surface Lesn System' (The Journal of the Institute of Television Engineers of Japan, Vol.42, No. 12, pp.82-89 (1988)). According to the above-cited paper a smooth surface lens system (that is theoretically replace-able with one smooth surface lens like 100 in FIG.3 or FIG.4) can realize patterns of the distribution of the realized virtual emitting point 86 under a mathematically expressed restriction. Let the coordinates of the realized virtual emitting point 86 that is gotten with a smooth surface lens be (XR YR). Here, coordinates (XR YR) are function of (Xp, YP): that is, XR= XR(XP, YP) and YR= YR(XP, Yp). As already discussed, mis-landing that is defined originally on the inner surface of the panel 2 can be discussed on S-plane 90. Then the mis-landing on S-plane 90 is, if it is denoted as ( X, Y). expressed as X = XR-X1, (1) Y = YK - Y1 (2) According to the paper cited above, it is possible to reduce X and Y to a certain extent, however, generally speaking it is impossible to get the complete elimination of both of them In order to solve this problem various auxiliary methods have been thought up. One method is use of a combination of a stick like elongated light source as the emitter of the exposure rays and a slit is disposed close to the light source A typical one is, for example, presented in the US Patent No 4, 983,995. Another example is shown in the Japanese Patent Publication No. HE17-153378 However even with these known arts, it is difficult to get a satisfyingly good correction with on enough realizable practical configuration. SUMMARY OF THE INVENTION The object of the present invention is to provide an exposure lighthouse device for forming phosphor dot mosaic screen of in-line colour picture tubes that can realize better correction of mis-landing with a practically realizable mechanical structure. In order to realize this demand, in one preferred mode of the invention, it utilizes an elongated light source, the first slit plate that is located close to the light source and has three slits thereon each of which has a specified shape for exposing Red, Green, and Blue respectively, and the second slit plate that is disposed close to the first slit plate having a slit thereon, and the slit on the second slit plate is used to select necessary one of the slits of the first slit plate. Further, all of the light source, the first slit plate, and the second slit plate are sealed in a water jacket in which water for cooling the light source circulates. To achieve the said objectives the present invention provides an improved exposure lighthouse device for depositing mosaic screen on colour picture tube panel consisting of black matrix layer having periodically arranged holes each of which is filled with one phosphor of Red, Green and Blue on said panel of said colour picture tube having a highly evacuated envelope and a longitudinal central axis, say Z - axis. said panel comprising a rectangular inner surface, the normal at the center thereof coinciding with the Z-axis, the long axis as X-axis, and the short axis as Y-axis, supporting a finely perforated shadow mask , and to be connected to the open end of a cone shaped funnel , the narrower end of that is connected to a cylindrical neck tube supporting an in-line electron gun with three unit electron guns in the X-Z plane and the axis of the unit electron gun that is in the middle of said three unit guns coinciding with the Z-axis, and having an elongated light source that is extended in the direction parallel to the X-axis characterized in that: - a first slit plate of a thin opaque material and placed between said light source and said panel and having three elongated slits; say a first, a second and a third slit, each of the three slits extends to the direction parallel to the Y-Z plane, - a second slit plate made of thin opaque material and placed close to said first slit plate and having an elongated slit- cover slit, that extends to the direction parallel to the Y-Z plane, a correction lens disposed between said first slit plate and said panel to correct the trajectory of the rays emitted from said light source, a selecting gear that controls the relative position between said first slit plate and said second slit plate and selects one of said first, said second, said third slit by superposing it to said cover slit to allow just a part of the rays that are emitted from the said light source and that is to fall on said slit of said first slit plate that can reach said inner surface of said panel to form holes of said black matrix layer to be filled with phosphor with any of the Red, Green & Blue colors. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 5 of the accompanying drawings illustrates a simplified total view of a preferred embodiment of a lighthouse of the present invention. The lighthouse has a table like mainframe 70. A panel 2 in process is put on the predetermined position of the mainframe 70. The predetermined position is defined by a plural number of positioning stopper 71. The inner surface of the panel 2 is coated in advance with a photo resist material 10 A and at the same time it supports a shadow mask 20 with supporting members that are not shown in this figure. The light house has a lamp house 101 having an elongated light source 110 therein. The detailed inside structure of the lamp house 101 is described later. The lamp house 101 is mounted on a sliding table 130 that can slide on a rail 131 that is fixed to the mainframe 70. Being guided by the rail 131, the lamp house 101 can change its X- coordinate without changing the Y- and Z- coordinates. A linear actuator 132 that is fixed to the mainframe 70 and connected to the lamp house 101 with an arm 133 controls the X-coordinate of the lamp house 101. There is installed also a rotary actuator 134 on the sliding table 130, the detail of that is described later too. The Y-coordinate of the light source 110 is kept substantially at zero. The Z coordinate of the light source HO: that is, the distance in Z direction between the light source 110 and the panel 2 is determined relating to the Z coordinate of the effective center of the deflection yoke 40. More practically, this distance is approximately equal to the distance in the Z direction between the effective center of the deflection yoke 40 and the panel 2 in Fig. 1. The relation between the light source 101 and the panel 2 is almost same as the one between the light emitting source and the panel known in the prior arts as Fig.3. A correction lens 100 is disposed between the lamp house 101 and the panel 2 for giving small corrective deflection to the path of the rays. FIG.6 of the accompanying drawings illustrates a part of the lighthouse of the present invention. More specifically the figure shows a preferred embodiment of the elements that are mounted on the sliding table 130 in FIG.5. There are two major elements mounted on the sliding table 130. One is the lamp house 101 The other is the rotary actuator 134. The lamp house 101 is a kind of water jacket comprising a main body 102, a cover plate 103, an transparent window plate 104, a retainer ring 105 that retains the window plate 104, and uater pipe 106 for circulating cooling water. The lamp house 101 holds also a light source 110 therein. All these elements are installed in the main body 102 keeping watertight condition using suitable sealing materials that are not shown here. The rotary actuator 134 is a kind of geared servomotor, which is connected to a driving shaft 135. Their function is described later. FIG.7 of the accompanying drawings illustrates the inside view of the lamp house 101 of FIG, 6 from which the cover plate 103 has been removed along with window plate 104 and retainer ring 105. The light source 110 is installed at the middle of the main body 102 in the direction parallel to the X-axis. The light source 110 is a stick like lamp that is actually called ' high pressure mercury arc lamp', the outer diameter, the inner diameter (the diameter of the light emitting portion), and the length of the light emitting portion of which are, for example, 5mm, 1.5mm, and 15mm respectively. The water pipe 106 is used to let water circulate in the main body 102 to cool the light source 110. There are two water pipes usually. One is for inlet and the other is for outlet. Both the pipes are planted on the same side of the light source 110 when viewed from the Z direction. The driving shaft 135 is set up through the main body 102 in parallel with the light source 110. The driving shaft 135 has a male screw 136 on the part that lies in the space surrounded by the walls of the main body 102. The male screw 136 is mated with a female screw graven in a moving block 137. The rotating actuator 134, driving shaft 135, male screw 136 and a female screw graven in moving block 137, constitute the selecting gear. The first slit plate 140 is attached to the moving block 137. With such structure, the first slit plate 140 can be driven in the cooling water filled in the main body 102 in the X direction by rotating the driving shaft 135. In order to make this move smooth a guide barrier 107 is provided in the main body 102. The first slit plate 140 is covered with the second slit plate 141 that is fixed to the main body 102 with appropriate means. Both the slit plates face closely each other. The second slit plate 141 does not obstruct the move of the first slit plate 140. Details of the mutual relation of the most important elements of FIG.7 is shown in FIG.8 of the accompanying drawings. In FIG.8, the second slit plate 141 has been lifted from the original position for convenience of explanation. Both of the first slit plate 140 and the second slit plate 141 are folded to form V-shape respectively so that the folding lines are parallel to the X axis and the distance to the light source 104 (d in FIG.8) is shortest at the bottom of the trough of the V-shape. One example of the arrangement of the first slit plate 140 is that the thickness of the plate, the angle of the v-shaped fold (a in FIG.8), and the distance between the center axis of the light source 104 and the bottom tip of the first slit plate 140 (d in FIG.8) is 0.25mm, 45degrees, and 3.2mm respectively. The first slit plate 140 has three slits 142R, 142G, and 142B thereon, each of which is elongated roughly in parallel to the Y-Z plane but, viewed from Z-direction, two of which have a small outward bent as shown in FIG.9 of the attached drawings. One example of the slit arrangement is that the bent angle of both the side slits 142R and 142B (P in FIG.9) is 3.0 degrees and the width of openings is 2.0mm. The second slit plate 141 has a slit 143 at its center, which is called 'cover slit' hereafter. The cover slit 143 is elongated in the direction parallel to the Y-Z plane and, when viewed from the Z-direction, is a rectangular. The relative position of the cover slit 143 to the light source 110 is fixed always: that is, the X-coordinate of the center of the cover slit 143 is the same as that of the middle point of the useful length of the elongated light source 110. The cover slit 143 of the second slit plate 141 has such a function that one of the slits of the lust slit plate 140 that is selectively superposed to the cover slit 143 works as a substantial slit that permits the light rays passing through Therefore, the cover slit 143 has such a size that, when it is superposed correctly to any of the slits 142R, 142G, or 142B, it produces no eclipse for the selected slit while it makes the rests blind completely Using such arrangement the exposure process for making the holes of black matrix 10X stans. FIG. 10 of the attached drawings shows how the key elements of FIG.5 are used in the present invention: that is, it shows how the three slits (142R, 142G, and 142B) of the first slit plate 140, the cover slit 143 of the second slit plate 141, and the light source 110 are arranged in the X-Z cross sectional view during the exposure process. As already described in FIG.5, a panel 2 in process is put on the predetermined position of the mainframe 70. At first being driven by the rotary actuator 134 the slit 142R is superposed to the cover slit 143. At the same time, being driven by the linear actuator 132, the X-coordinate of the center of the slit 142R is adjusted and is fixed at X=+S. as shown in FIG. 1 OR. The rays emitted from the light source 110 pass through the slit 142R of the first slit plate 140 and pass through correction lens 100 (FIG.5) to be given small corrective deflection. At this time the cover slit 143 gives no effect to the path of the rays that pass through the slit 142R. The cover slit 143 functions just as a blind shutter for the slit 142G and the slit 142B. After passing through the correction lens 100, the rays that has passed through the apertures of the shadow mask (not shown) impinges on the inner surface of the panel 2 to exposes the photo resist material to make latent images of the black matrix hole 10R. This part of the process is same as the known prior an as explained in FIG.3 except the structure and positioning of the lamp house 110. Next, being driven by the rotary actuator 134 the slit 142G is superposed to the cover slit 143. At the same time, being driven by the linear actuator 132, the X-coordinate of the center of the slit 142G is adjusted and is fixed at X--0 as shown in F1G.10G At this time, the second collection lens is installed at the same location as the previous correction lens to give a different corrective deflection to the rays than the preceded exposure And the second exposure for making the latent image for the black matrix hole 10G is performed. Finally, being driven by the rotary actuator 134 the slit 142B is superposed to the cover slit 143. At the same time, being driven with the linear actuator 132, the X-coordinate of the , filter of the slit 142G is adjusted and is fixed to X==-S as shown in FIG. 1 OB At this time, the third correction lens is installed at the same location to give a different correction than the preceded two exposures. And the third exposure for making the latent image for the black matrix hole 10B is performed The processes after carrying out those three exposures are same as known by the prior art. There are many features in the lighthouse of the present invention. Among them features in which two slit plates (140 and 141) are employed in the lamp house and both of them are installed in the water are especially significant. In order to explain this reason it is helpful to consider a basic procedure for designing the correction lens 100 and the slits in the first slit plate 140. Following are basic design steps. As the necessary correction depends on the color in question, the following explanation cites red (case of slit 142R) at first. (First step) Mis-landing that should be corrected is given by a suitable measurement. This is basically possible by making a test tube with the lighthouse shown in FIG. 3, in which, however, the correction lens 100 is not installed. At this design work, a tentative lamp house in which the slit 142R is not installed and the light source is a point source: that is, the lamp house explained as in FIG. 3 is used (Second Step) The correction lens 100 is designed so that it corrects mis-landing in just Y-direction (That is Y - 0 aver the entire screen) If the correction is limited to Y-direction. this is theoretically proven to be possible by the paper cited before. At this time it is also theoretically possible to leave (control) mis-landing in X direction on Yp = 0 arbitrarily. This is done by designing the X-Z cross section of the lens 100 appropriately. The remaining X can be expressed generally as form of a series: C02 Yp2 + C12 XpYp2 + C22 XP2Yp2 + ...... C04Yp4 + C14XpYp4+ C24 Xp2Yp" + — - ...... (3). No odd power term with respect to Y appears in this series because the CRT is symmetric with respect to Y-axis. Among the above terms, the three terms (C10Xp, C02Yp2, and C12XpYp2) are especially important from the practical view. Therefore other terms are neglected hereafter That is: .X = C10 XP + C02 YP2 + C12 XpYp2 (4). One can control the coefficients C10 with the lens, because, as mentioned above, it is theoretically possible to leave arbitrary mis-landing in X direction on YP = 0. Using this nature, the lens is so designed that it corrects not only mis-landing in Y-direction over the entire screen but also it makes C10 multiplied by L be equals to 2.5 to 5. Where L is the distance between the panel and the light emitting source. (Forth Step) The lamp house having the slit 142R and the elongated light source 110 is assumed. Then, owing to the slit 142, the X-coordinate of the emitting point of the ray that impinges on the panel varies with the coordinate (Xp, Yp) of the panel in question. The relative X-coordinate of the light emitting point with respect to the center of the slit 142R is denoted as x- The situation is shown in FIG. 10. Then I x varies depending on the point on the panel in question. We are now using this nature for correcting mis-landing. If the above x is just equal to the - X that is given from (4), then it means mis-landing in X direction is corrected. (Fifth Step) Based on this principle, the distance d is so decided that mis-landing term expressed with the term C10Xpis removed. FiG.l 1 of the accompanying drawing shows that how the above distance is decided. In the figure, for convenience of approximation, the panel 2 is represented by a plane. From the figure xis approximately expressed as x = -Xpd/L. (5) Therefore d = - x (Xp-/L). On the other hand from the first term of expression (4), I IX = C10 Xp = C10L* Xp/L, and C10L is adjusted to 2.5 to 5.0 in advance with the correction lens. Therefore, considering that x -- X, d should be the range from to 2.5 to 5.0mm. (Sixth Step) By giving appropriate bend to the first slit plate 140, correction of the mis-landing term C12XpYp2 is performed. Though detail is not explained here, the possibility of the correction is obvious from a qualitative consideration. In most cases, since the sign of the coefficient €12 is positive the bent is upward as a in FIG.8. (Seventh Step) By giving a bent to the shape of opening of the slit 142R as shown in FIG.9, it is possible to correct practically the mis-landing term Co2Yp. Though detail is not explained here, the possibility of the correction is obvious from a qualitative consideration In case of the red mis-landing, since the coefficient Co2 is always positive (This comes from the nature of the deflection yoke 40), the bent of the slit 142R is, when viewed from Z direction, +X-ward as shown in FIG 9. (Eighth Step) Design of slit 142G and 142B: The same discussion as the above slit 142R is applicable to the slits 142G and 142B. However in the slit 142G, the coefficient C02 is zero because the picture tube is symmetry with respect to the Y-axis. Therefore the slit 142G is straight when viewed from Z-direction. On the other hand mis-landing pattern for Blue (slit 142B), the coefficient C02 is, though the absolute value is the same as the case Red (slit I42R). the sign is negative. Therefore the bent of the slit 142B is -X-ward as shown in FIG 9, when viewed from the Z direction. As for the coefficients do and C12. they are practically the same as those of Red (slit 142R) It is possible to use the common d and a for the slits 142G and 142B In the above explanation it is very important that the distance between the first slit plate 140 and the light source 110 is adjusted to 2.5 to 5mm by a help of the appropriately designed correction lens. If this distance is too large, only a small fragment of the ray bundle emitted from the light ' source 110 can reach the panel 2 to result in necessity of too much exposure time. On the 'contrary if this distance is too small it becomes difficult to correct the terms of C12XpYp2 and C02Yp2. Because, in order to correct these terms with practical slit dimensions, a certain distance is necessary between the slit and the light source. For example, since the inner diameter (light emitting portion) of the light source 110 is about 1.5mm, the slit width less than 1.5mm is almost meaning less: that is. a certain distance is necessary between the slit 142 and the light source HO for its shape being meaningful. Further, too small distance is physically impossible because the first slit plate 140 touches light source and causes to break As a result, the distance 2.5 to 5 mm is a good range for the practical design of the slit plate 142. The correction lens, especially the X-Z cross section of it, should be so designed to realize this distance. On the other hand the light source must be cooled by water. As the lamp house 101 has a window plate 104 that bears the water pressure, it is concluded that the first slit plate 140 must be installed in the water. As a natural result, the second slit plate 141 should be installed in the water too. Otherwise performing the function for selecting one of three slits of the first slit plate 140 is impossible. The above conclusion leads to another conclusion that it is suitable to drive the slit plate with a rotating shaft like the driving shaft 135. With this structure the problem of sealing the water is solved easily. The three slits 142R, 142G, and 142B. which are elongated almost in Y direction, are arranged in X direction side by side wise on the first slit plate 140. The first slit plate 140 has bent lines that are parallel to the X-axis for correcting the mis-landing term C12XpYp2. This is advantageous for the slit plate 140 from being deformed unfavorably because the folding hues work as enforcing ribs for the thin material of it. With this arrangement, it is also possible to drive the slit plate 140 with the moving block 137 from one side of the light source 110 without preventing flow of the water supplied by the water pipe 106 that are arranged along another side of the light source 110 Further, it should be noted that the mutual distance between the three slits of the first slit plate 40 is the smallest at their middle portions as shown in FIG.9. If the arranging order of the slit. 142R and the slit 142B is opposite, the mutual distance is the maximum at their center. If such arrangement is employed, a larger stroke is required for the moving block 137. This is not preferable for the lamp house 101 that should be installed in a small space With the same reason the slit 142G is preferably arranged in between the slit 142R and the slit 142B The first slit plate 140 is arranged between the second slit plate 141 and the light source 110. This is meaningful for preventing the second slit plate 141 from touching the light source 110 and for securing a good flow of the cooling water around the light source 110. FIG 12 of the accompanying drawings shows another embodiment of the present invention This drawing shows the inside of the lamp house 101 as in FIG. 7. In the embodiment, though the structure is very similar to the embodiment shown in FIG.7, The first slit plate 140 is fixed to the main body 102 while the second slit plate 141 is mounted on the moving block 137. Therefore selection of the slits of the first slit plate 140 is performed with move of the second slit plate 141. In this embodiment, the mutual positional relation between the slits at both the sides and the light source 110 differs from that of the preceded embodiment shown before. Therefore though the total structure of the lighthouse is the same as the preceded embodiment, the strokes that are required to the linear actuator 132 die different from those of the preceded embodiment shown in FIG. 10. FIG. 13 of the attached drawing shows how the key elements of FIG 12 are arranged at the time of exposure R, G, and B of the drawing show the exposure for Red hole (10R in FIG.10), Green hole (10G), and Blue hole (10B) respectively as shown in FIG.10. The arrangement of the key elements is the same as the preceded embodiment except that the used portion of the light source 110 is different by color Therefore the design parameters (a. P. and d) are the same as that are used in the preceded embodiment In this embodiment, if the mutual distances of the middle points of the three slits that is measured parallel to the X axis are equal to S, it is possible to eliminate the linear actuator 137, However, too large value for this distance is not recommended. This is because, as the light intensity on the light source 110 is not necessarily uniform over the entire length, use of different portion for each color may cause unequal exposures for three colors that cause a non-uniformity of the screen of the color picture tube. The invention may be embodied in other specific forms without departing from the spirit of essential characteristics thereof. The present embodiments are therefore to be considered in all respects illustrative and not restrictive. For example, the center of the slit 142G can be out of Z-axis that is identical with the tube axis. Such technique is known as 'purity shift control' to cope with the effect of the ambient magnetic field. Another modification is giving a small continuous reciprocal move to somewhere of the lamp house. In order to make black matrix hole of a good shape it is sometimes necessary to use a light source of a special shape. In such case it is possible to give a continuous swinging move to somewhere of the lamp house or lamp house itself in the X-,Y-, and/or Z-direction. Accordingly, it should be understood that the present description intends to cover by the appended claims all modifications falling within the true spirit and scope of this invention. We claim: An improved Exposure Light House device for depositing mosaic (10)screen on a colour picture tube panel consisting of black matrix layer having periodically arranged holes each of which is filled with one phosphor of Red, Green and Blue on said panel of said colour picture tube having a highly evacuated envelope and a longitudinal central axis, say Z - axis. said panel comprising a rectangular inner surface, the normal at the center thereof coinciding with the Z-axis, the long axis as X-axis, and the short axis as Y-axis, supporting a finely perforated shadow mask(20) and to be connected to the open end of a cone shaped funnel(3)the narrower end.of that is connected to a cylindrical neck tube(4)upporting an in-line electron gun(30) with three unit electron guns in the X-Z plane and the axis of the unit electron gun that is in the middle of said three unit guns coinciding with the Z-axis, and having an elongated light source(110) that is extended in the direction parallel to the X-axis characterized in that: a first slit plate of a thin opaque material and placed between said light source and said panel and having three elongated slits; say a first, a second and a third slit , each of the three slits extends to the direction parallel to the Y-Z plane, a second slit plate made of thin opaque material and placed close to said first (140) slit plate and having an elongated slit- cover slit, that extends to the direction parallel to the Y-Z plane, a correction lens disposed between said first slit plate and said panel to correct the trajectory of the rays emitted from said light source, (110) a selecting gear that controls the relative position between said first slit plate and said second slit plate and selects one of said first , said second , said third slit by superposing it to said cover slit to allow just a part of the rays that are emitted from the said light source and that is to fall on said slit of said first slit plate that can reach said inner surface of said panel to form holes of said black matrix layer to be filled with phosphor with any of the Red, Green & Blue colors. 2. An improved Exposure Light House device as claimed in claim 1, wherein the width of said cover slit is larger than width of any of said first, said second and said third slit. 3. An improved Exposure Light House device as claimed in claim 1, wherein said first slit plate is placed between said light source and said second slit plate. 4. An improved Exposure Light House device as claimed in claim 1, wherein said selecting gear controls the position of said first plate in a manner that when one of the said first, second and third slit therein is selected by being superposed to said cover slit by said selecting gear, the selected slit takes one of the three X- coordinates for said first, said second, and said third slit respectively, and the X- coordinate of a slit is defined by the X-coordinate of the midpoint of its useful length. 5. An improved Exposure Light House device as claimed in claim 1, wherein said first, said second and said third slit are arranged in said first slit plate, in the direction parallel to the X-axis. 6. An improved Exposure Light House device as claimed in claim 1, wherein said selecting gear gives movement to said first slit plate to make one of said first, second, and third slit selectively superposed to said cover slit. 7. An improved Exposure Light House device as claimed in claim 1, wherein said selecting gear gives movement to said second slit plate to make one of said first, second, and third slit selectively superposed to said cover slit. 8. An improved Exposure Light House device as claimed in claim 7, wherein the peripheral area of said first, said second, said third slit of said first slit plate is bent along with said first, said second, and said third slit screen therein with a bending line/lines, or generating lines that are parallel to the light source. 9. An improved Exposure Light House device as claimed in claim 8, wherein said first slit plate is bent so that the distance between each of said first, said second and said third slit of said first slit plate and said light source is smallest at the mid-points of the effective length of said first, said second, and said third-slit of said first slit plate. 10. An improved Exposure Light House device as claimed in claim 6, wherein the peripheral area of said cover slit of the second slit plate is bent similarly to the peripheral area of said first, said second and said third slit of said first slit plate so that the peripheral area of said fourth slit of said second slit plate is close to said peripheral area of said first, said second, and said third slit of the said first slit plate. 11. An improved Exposure Light House device as claimed in claim 1, wherein said light source is sealed in a water jacket having transparent window to allow the rays from said light source to reach the panel while preventing the water from leaking there from, said first slit plate and said second slit plate are placed between said light source and said transparent window in said jacket, said water jacket provided with water to cool the light source. 12. An improved Exposure Light House device as claimed in claim 1, wherein said selecting gear comprises a rotating actuator, a male screw, and a female screw, said male screw and said female screw mated with each other and placed in said water jacket. 13. An improved Exposure Light House device as claimed in claim 12, wherein the shaft of said male screw is placed parallel to the X-axis and extended to outside of said water jacket and said female screw connected to either said first slit plate or said second slit plate in water, said rotating actuator controls the relative position between said first slit plate and said second slit plate by giving rotation to said shaft of said male screw from outside the said water jacket. 14. An improved Exposure Light House device as claimed in claim 4, wherein the mutual distances of the said first, said second and said third slit, viewed from Z direction, the smallest at the mid-points of the useful length thereof. 15. An improved Exposure Light House device substantially as herein described with reference to and as illustrated in the accompanying drawings.

Full Text

Field of the Invention
The present invention relates to an inline color picture tube having dot mosaic screen and, more specifically, to an exposure lighthouse used to form a luminescent phosphor dot mosaic screen in the color picture tube.
Background Of The Invention
K1G.1 of the accompanying drawings illustrates a schematic partially cutaway top view and a front view of a commercial in-line color picture tube utilizing a finely perforated shadow mask.
The inline color picture tube 1 illustrated here includes a highly evacuated envelope that consists of a generally rectangular dish shaped panel 2, a generally cone shaped runnel 3 that is connected to the open end of the panel I, and a generally cylindrical neck-tube 4 that is connected to the rear end of the runnel 3, and a stem 5 that seals the rear end of the neck-tube
From now on, an orthogonal (X, Y, Z) coordinate system is used for the sake of convenience as described in the Figure: that is, the X-axis is parallel to the long sides of the rectangular shaped panel 2, the Y-axis is parallel to the short sides of the panel 2, and the Z-axis is coincided with the tube axis that is substantially identical to the axis of the neck tube 4.
1 he panel 2 has the inner surface on which a mosaic screen 10 of a predetermined mosaic pattern of color emissive phosphor dots, corresponding to three primary element colors (Red, (ireen, and Blue), is deposited.
The panel 2 also supports a color selection electrode or a finely perforated shadow mask 20 that is made from a thin metal sheet being formed into a predetermined shape and having a multiple of apertures 21 made thereon in a predetermined pattern. The shadow mask 20 is supported in the panel 2 with supporting members that are not shown in FIG. 1 while spaced a predetermined distance inward from the mosaic screen 10.
On the other hand, the neck-tube 4 supports therein an inline electron gun assembly 30 that consists of three unit electron guns 30R. 30G, and 30B corresponding to three primary clement colors (Red, Green, and Blue) and arranged in line in the X-Z plane, where the axis

of the unit gun 30G that is arranged at the middle of the three unit guns is coincided with Z-axis.
Electron beams are emitted from the inline electron gun assembly 30: that is, an electron beam is emitted from each of the unit electron guns 30R, 30G, and 30B, and travel toward the mosaic screen 10 with being deflected around the portion where the neck-tube 4 is connected to the tunnel 3. Typical one of the electron beams is referred with the symbol 200 mFlG.l.
In order to deflect the electron beams emitted from the inline electron gun assembly 30 and to permit the beams scanning the entire useful area of the mosaic screen 10, a deflection yoke 40 having deflection coils is mounted on the exterior of the envelope around the portion where the neck-tube 4 is connected to the funnel 3.
Each of three electron beams emitted from unit guns 30R, 30G, and 30B travels through fine aperture 21 in the shadow mask 20 to impinge on and to excite the color emissive phosphor dots of the mosaic screen 10.
Image reproduction is accomplished by scanning the electron beams across the mosaic screen 10 in both X and Y directions in a manner that is well known to those skilled in the art.
FIG.2 of the accompanying drawings illustrates the relation between the electron gun assembly 30 hence three unit electron guns 30R, 30G, and 30B thereof, shadow mask 20 hence aperture 21 thereon, and the mosaic screen 10.
I he mosaic screen 10 consists of the periodic patterning of three types of phosphor dots 10R, 10G, and 10B, each of which emits light of red, green, and blue color respectively when it is excited being impinged by the electron beam Any of the two adjacent dots separate each other by a predetermined distance and there is a space in between. This space is filled with a black matrix 10X that consists of s layer of light absorbing black material. In other word, the black matrix 10X has many periodically arranged holes therein and the holes are filled with phosphors of the three colors.

By projecting the electron beams through the aperture 21 of the shadow mask 20, any single electron beam impinges only upon the color emissive phosphor dots of a particular one of the primary colors (red, green, or blue).
More specifically the electron beam emitted from the unit electron gun 30R, 30G, or 308 impinges only on the red emitting phosphor dot 1OR, green emitting phosphor dot 10G, or blue emitting phosphor dot 10B respectively.
The degree of coincidence in the geometric positional relationship on the inner surface of the panel 2 between any of color emissive phosphor dots (30R, 30G, or 30B) and the impinging point of the corresponding single electron beam which has passed through the associated aperture 21 is generally described in a term of 'landing characteristic' or merely 'landing'. The higher the degree of coincidence the better the landing is.
More specifically landing is defined by the shift of the center of the projected electron beam that has passed an aperture 21 from the center of the corresponding phosphor dot on the inner surface of the panel 2.
Landing is one of the most important performance characteristics for color picture tubes to produce good pictures of good color purity and good uniformity thereon.
Therefore, how to deposit each of the phosphor dots at the best location on the inner surface of the panel 2 is always an important subject for manufacturers of color picture tubes
The deposition of the phosphor dots 30R. 30G. and 30B and the black matrix 10X on the inner surface of the panel 2 to form the mosaic screen 10 is generally performed by use of an exposure system
I or making the mosaic screen 10, first, the black matrix IOX having holes for filling phosphor materials therein is formed on the inner surface of the panel 2. Next, the above-made holes are filled with phosphor materials to form phosphor dots.
The process for depositing the phosphor dots 1OR,1OG, and 10B is similar to that for making the holes in the black material layer to form black matrix 1OX. The mosaic like patterning of

phosphor dots 1OR, 10G, and 10B is completely same to the holes of the black matrix 10X.
Therefore, for the sake of convenience, hereafter, the holes of the black matrix 10X are referred with the symbols 1OR, 1OG, and 10B corresponding to each of the phosphor dots filling therein.
FIG.3 of the accompanying drawings illustrates a simplified schematic view of a lighthouse used for depositing mosaic screen 10 on the inner surface of the panel 2.
The lighthouse has a table like mainframe 70.
A panel 2 in process is put on the predetermined position of the mainframe.70. The predetermined position is defined by a plural number of positioning stopper 71, The inner surface of the panel 2 is coated preliminarily with a photo resist material IOA on its inner surface and at the same time it supports a shadow mask 20 with supporting members that are not shown in this figure.
The lighthouse has a lamp house 80 having a light emitting point 85 therein. The light emitting point 85 is a point light source from where ultra violet light is emitted as the occasion demands. The lamp house 80 is mounted on a rail 131 that is fixed to the mainframe 70. With being guided by the rail 131, the lamp house 80 can change its X-coordinate without changing its Y- and Z-coordinates. The X-coordinate of the lamp house 80 is controlled by being driven with a linear actuator 132 that is fixed to the mainframe 70 and connected to the lamp house 80 with an arm 133.
The Y coordinate of the light emitting point 85 is basically hold at zero.
The Z coordinate of the light emitting point 85 is approximately equal to the Z-coordinate of the effective center of the deflection yoke 40: that is, the distance in Z direction between the panel 2 and the light emitting point 85 is approximately equal to the distance in the Z direction between the panel 2 and the effective center of the deflection yoke 40.
A correction lens 100 is installed between the lamp house 101 and the panel 2 for giving

small corrective deflection to the path of the rays.
Under such arrangement the exposure process for making the black matrix 10X having holes 1OR, 1OG, and 1OB starts.
At first being driven by the linear actuator 132, the X-coordinate of the light emitting point is adjusted and fixed to X=+S as shown in F1G.3R.
Then, ultra violet rays are emitted from the emitting point 85: typical one of rays is described in the figure referred with the symbol 201.
The rays emitted from the emitting point 85 pass through the correction lens 100.
After passing through the correction lens 100, a part of the rays that pass aperture 21 impinge on the inner surface of the panel 2 and expose the photo resist material 10A to make latent images of the holes 10R as a projected pattern of the aperture 21.
Next, being driven by the linear actuator 132, the X-coordinate of the light emitting point 85 is adjusted and fixed to X=0 as shown in FIG.3G, and the second exposure is given to the photo resist material 10A to make latent images of the holes 1OG.
In FIG.3G (and next FIG.3B), the upper half of the lighthouse is not drawn
At this time, the second collection lens is installed at the same location as the previous correction lens 100 to give a different corrective deflection to the rays than the preceded exposure The all correction lenses put here are referred with the symbol 100 hereafter. The mechanism for exchanging the correction lens is not described in the figure
Next, by being driven by the linear actuator 132. the X-coordinate of the light emitting point
At this time, the third correction lens is installed at the same location to give a different correction than the preceded two exposures
After carrying out those three exposures, the shadow mask 20 is removed from the panel 2 and photo resist material 10A having the latent images made with the above three exposures are chemically developed to make all these exposed areas for holes1OR, 1OG, and 1OB emerged. Next, the area that is not exposed with the above exposure is dyed with a black material to form the black matrix 10X.
Finally, the holes 1OR,1OG, and 1OB of black matrix 1OX are filled with color phosphors The panel 2 thus processed is, after further appropriate processing, assembled into a color picture tube with the shadow mask 20 that has been used at the time of the exposure.
In order to perform a good landing characteristic, it is important for the color picture tube that the path of the ray that passes through an aperture 21 of the shadow mask 20 coincides with the path of the electron beam that passes the same aperture 21 at the time of operation.
Therefore the above-used value S is so decided that it is equal to the adjacent mutual distance of the three electron beams at the effective center of the deflection yoke 40: the three beams that are emitted from three unit electron guns 30R, 30G, and 30B respectively.
Further the characteristics hence shape of the correction lenses 100 are so designed that the paths of the rays coincide with the paths of the electron beams as far as possible. As the electron beams for three colors have different trajectories, three different lenses are separately used for exposing each of black matrix holes 30R, 30G, and 30B.
In order to discuss the mis-landing problem, it is convenient to use the S-plane and the virtual emitting source The S-plane is defined, as shown in F1G.3R, as a hypothetical plane that is perpendicular to Z-axis and includes the light emitting point 85
The path of the exposure ray is a straight line after passing through the correction lens 100 Bv making reverse extension of this straight line, it is possible to define a virtual emitting point 86 on S-plane as the intersection of the above extension and S-plane. This point (86) is called 'realized virtual emitting point' hereafter

The path of an electron beam that passes through aperture 21 of the shadow mask 20 is also a straight line near the aperture 21. Therefore by making reverse extension of this straight portion of the electron beam line it is possible to define another virtual emitting point on S-plane as the intersection of the reverse extension of the electron beam line and S-plane. This hypothetical virtual emitting point is called 'ideal virtual emitting point'.
Amplifying this concept, it can be said that any point on the inner surface of the panel 2 has the corresponding ideal virtual emitting point Therefore it is possible to define mis-landing at any point on the panel 2 using the vector wise distance between the realized virtual emitting point and ideal virtual emitting point on S-plane.
FIG.4 of the accompanying drawings illustrates the relation between a representative point in the inner surface of the panel 2 and the corresponding two virtual emitting points: the one is realized virtual emitting point 86 another is the ideal virtual emitting point which is referred with the symbol 87 in the drawing.
Of course, when the location on the panel 2 is designated, the location of the ideal virtual emitting point depends on the color in question. Therefore, though FIG.4 illustrates just the case of red thai corresponds to F1G.3R. the result should be applied to other two colors as well.
The point on the inner surface of the panel 2 is represented by P, the coordinates of which are ( X|.. YI>). The ideal virtual emitting point 87 for P is at (X\, YI) on S-plane.
It is obvious from the definition that each of the coordinates X1and Y1 is a function of the coordinates (Xp, Yp) respectively: that is. X1= X1(Xp, YP) and Y,= Y1(Xp, Yp)
The correction lens 100 is employed for realizing such location (X1, Y1) of the ideal virtual emitting point 87 by reflecting the exposure ray that is emitted from the emitting point 85.
However, generally speaking, it is impossible to realize the given (X1, Y1) with a correction lens having smooth surface

This comes from an intrinsic property of a ray bundle that is emitted from a point-emitting source as shown in FIG 3.
As far as a lenses having smooth surfaces are used, it is impossible to get complete coincidence of the realized virtual emitting point 86 with the ideal virtual emitting point 87 over the entire useful area of the mosaic screen 10 (inner surface of the panel 2). We cannot solve this problem even if we employ a lens system that consists of plural lenses. The detail of this problem has been discussed in the paper titled 'Mis-landing Pattern Eliminatable by a Smooth Surface Lesn System' (The Journal of the Institute of Television Engineers of Japan, Vol.42, No. 12, pp.82-89 (1988)).
According to the above-cited paper a smooth surface lens system (that is theoretically replace-able with one smooth surface lens like 100 in FIG.3 or FIG.4) can realize patterns of the distribution of the realized virtual emitting point 86 under a mathematically expressed restriction. Let the coordinates of the realized virtual emitting point 86 that is gotten with a smooth surface lens be (XR YR). Here, coordinates (XR YR) are function of (Xp, YP): that is, XR= XR(XP, YP) and YR= YR(XP, Yp).
As already discussed, mis-landing that is defined originally on the inner surface of the panel 2 can be discussed on S-plane 90. Then the mis-landing on S-plane 90 is, if it is denoted as ( X, Y). expressed as
X = XR-X1, (1)
Y = YK - Y1 (2)
According to the paper cited above, it is possible to reduce X and Y to a certain extent, however, generally speaking it is impossible to get the complete elimination of both of them
In order to solve this problem various auxiliary methods have been thought up. One method is use of a combination of a stick like elongated light source as the emitter of the exposure rays and a slit is disposed close to the light source A typical one is, for example, presented in the US Patent No 4, 983,995. Another example is shown in the Japanese Patent Publication No. HE17-153378
However even with these known arts, it is difficult to get a satisfyingly good correction with

on enough realizable practical configuration.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an exposure lighthouse device for forming phosphor dot mosaic screen of in-line colour picture tubes that can realize better correction of mis-landing with a practically realizable mechanical structure.
In order to realize this demand, in one preferred mode of the invention, it utilizes an elongated light source, the first slit plate that is located close to the light source and has three slits thereon each of which has a specified shape for exposing Red, Green, and Blue respectively, and the second slit plate that is disposed close to the first slit plate having a slit thereon, and the slit on the second slit plate is used to select necessary one of the slits of the first slit plate. Further, all of the light source, the first slit plate, and the second slit plate are sealed in a water jacket in which water for cooling the light source circulates.
To achieve the said objectives the present invention provides an improved exposure lighthouse device for depositing mosaic screen on colour picture tube panel consisting of black matrix layer having periodically arranged holes each of which is filled with one phosphor of Red, Green and Blue on said panel of said colour picture tube having a highly evacuated envelope and a longitudinal central axis, say Z - axis.
said panel comprising a rectangular inner surface, the normal at the center thereof coinciding with the Z-axis, the long axis as X-axis, and the short axis as Y-axis, supporting a finely perforated shadow mask , and to be connected to the open end of a cone shaped funnel , the narrower end of that is connected to a cylindrical neck tube supporting an in-line electron gun with three unit electron guns in the X-Z plane and the axis of the unit electron gun that is in the middle of said three unit guns coinciding with the Z-axis, and having an elongated light source that is extended in the direction parallel to the X-axis characterized in that:
- a first slit plate of a thin opaque material and placed between said light source
and said panel and having three elongated slits; say a first, a second and a third
slit, each of the three slits extends to the direction parallel to the Y-Z plane,
- a second slit plate made of thin opaque material and placed close to said first
slit plate and having an elongated slit- cover slit, that extends to the direction
parallel to the Y-Z plane,
a correction lens disposed between said first slit plate and said panel to correct the trajectory of the rays emitted from said light source,
a selecting gear that controls the relative position between said first slit plate and said second slit plate and selects one of said first, said second, said third slit by superposing it to said cover slit to allow just a part of the rays that are emitted from the said light source and that is to fall on said slit of said first slit plate that can reach said inner surface of said panel to form holes of said black matrix layer to be filled with phosphor with any of the Red, Green & Blue colors.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 5 of the accompanying drawings illustrates a simplified total view of a preferred embodiment of a lighthouse of the present invention.
The lighthouse has a table like mainframe 70.
A panel 2 in process is put on the predetermined position of the mainframe 70. The predetermined position is defined by a plural number of positioning stopper 71. The inner surface of the panel 2 is coated in advance with a photo resist material 10 A and at the same time it supports a shadow mask 20 with supporting members that are not shown in this figure.
The light house has a lamp house 101 having an elongated light source 110 therein. The detailed inside structure of the lamp house 101 is described later. The lamp house 101 is mounted on a sliding table 130 that can slide on a rail 131 that is fixed to the mainframe 70. Being guided by the rail 131, the lamp house 101 can change its X- coordinate without changing the Y- and Z- coordinates. A linear actuator 132 that is fixed to the mainframe 70 and connected to the lamp house 101 with an arm 133 controls the X-coordinate of the lamp house 101.

There is installed also a rotary actuator 134 on the sliding table 130, the detail of that is described later too.
The Y-coordinate of the light source 110 is kept substantially at zero.
The Z coordinate of the light source HO: that is, the distance in Z direction between the light source 110 and the panel 2 is determined relating to the Z coordinate of the effective center of the deflection yoke 40. More practically, this distance is approximately equal to the distance in the Z direction between the effective center of the deflection yoke 40 and the panel 2 in Fig. 1. The relation between the light source 101 and the panel 2 is almost same as the one between the light emitting source and the panel known in the prior arts as Fig.3.
A correction lens 100 is disposed between the lamp house 101 and the panel 2 for giving small corrective deflection to the path of the rays.
FIG.6 of the accompanying drawings illustrates a part of the lighthouse of the present invention. More specifically the figure shows a preferred embodiment of the elements that are mounted on the sliding table 130 in FIG.5.
There are two major elements mounted on the sliding table 130. One is the lamp house 101 The other is the rotary actuator 134.
The lamp house 101 is a kind of water jacket comprising a main body 102, a cover plate 103, an transparent window plate 104, a retainer ring 105 that retains the window plate 104, and uater pipe 106 for circulating cooling water. The lamp house 101 holds also a light source 110 therein. All these elements are installed in the main body 102 keeping watertight condition using suitable sealing materials that are not shown here.
The rotary actuator 134 is a kind of geared servomotor, which is connected to a driving shaft 135. Their function is described later.
FIG.7 of the accompanying drawings illustrates the inside view of the lamp house 101 of

FIG, 6 from which the cover plate 103 has been removed along with window plate 104 and retainer ring 105.
The light source 110 is installed at the middle of the main body 102 in the direction parallel to the X-axis.
The light source 110 is a stick like lamp that is actually called ' high pressure mercury arc lamp', the outer diameter, the inner diameter (the diameter of the light emitting portion), and the length of the light emitting portion of which are, for example, 5mm, 1.5mm, and 15mm respectively.
The water pipe 106 is used to let water circulate in the main body 102 to cool the light source 110. There are two water pipes usually. One is for inlet and the other is for outlet. Both the pipes are planted on the same side of the light source 110 when viewed from the Z direction.
The driving shaft 135 is set up through the main body 102 in parallel with the light source 110. The driving shaft 135 has a male screw 136 on the part that lies in the space surrounded by the walls of the main body 102. The male screw 136 is mated with a female screw graven in a moving block 137.
The rotating actuator 134, driving shaft 135, male screw 136 and a female screw graven in moving block 137, constitute the selecting gear.
The first slit plate 140 is attached to the moving block 137. With such structure, the first slit plate 140 can be driven in the cooling water filled in the main body 102 in the X direction by rotating the driving shaft 135.
In order to make this move smooth a guide barrier 107 is provided in the main body 102.
The first slit plate 140 is covered with the second slit plate 141 that is fixed to the main body 102 with appropriate means. Both the slit plates face closely each other. The second slit plate 141 does not obstruct the move of the first slit plate 140.
Details of the mutual relation of the most important elements of FIG.7 is shown in FIG.8 of the accompanying drawings.
In FIG.8, the second slit plate 141 has been lifted from the original position for convenience of explanation.

Both of the first slit plate 140 and the second slit plate 141 are folded to form V-shape respectively so that the folding lines are parallel to the X axis and the distance to the light source 104 (d in FIG.8) is shortest at the bottom of the trough of the V-shape. One example of the arrangement of the first slit plate 140 is that the thickness of the plate, the angle of the v-shaped fold (a in FIG.8), and the distance between the center axis of the light source 104 and the bottom tip of the first slit plate 140 (d in FIG.8) is 0.25mm, 45degrees, and 3.2mm respectively.
The first slit plate 140 has three slits 142R, 142G, and 142B thereon, each of which is elongated roughly in parallel to the Y-Z plane but, viewed from Z-direction, two of which have a small outward bent as shown in FIG.9 of the attached drawings. One example of the slit arrangement is that the bent angle of both the side slits 142R and 142B (P in FIG.9) is 3.0 degrees and the width of openings is 2.0mm.
The second slit plate 141 has a slit 143 at its center, which is called 'cover slit' hereafter. The cover slit 143 is elongated in the direction parallel to the Y-Z plane and, when viewed from the Z-direction, is a rectangular. The relative position of the cover slit 143 to the light source 110 is fixed always: that is, the X-coordinate of the center of the cover slit 143 is the same as that of the middle point of the useful length of the elongated light source 110.
The cover slit 143 of the second slit plate 141 has such a function that one of the slits of the lust slit plate 140 that is selectively superposed to the cover slit 143 works as a substantial slit that permits the light rays passing through
Therefore, the cover slit 143 has such a size that, when it is superposed correctly to any of the slits 142R, 142G, or 142B, it produces no eclipse for the selected slit while it makes the rests blind completely
Using such arrangement the exposure process for making the holes of black matrix 10X
stans.

FIG. 10 of the attached drawings shows how the key elements of FIG.5 are used in the present invention: that is, it shows how the three slits (142R, 142G, and 142B) of the first slit plate 140, the cover slit 143 of the second slit plate 141, and the light source 110 are arranged in the X-Z cross sectional view during the exposure process.
As already described in FIG.5, a panel 2 in process is put on the predetermined position of the mainframe 70.
At first being driven by the rotary actuator 134 the slit 142R is superposed to the cover slit 143. At the same time, being driven by the linear actuator 132, the X-coordinate of the center of the slit 142R is adjusted and is fixed at X=+S. as shown in FIG. 1 OR.
The rays emitted from the light source 110 pass through the slit 142R of the first slit plate 140 and pass through correction lens 100 (FIG.5) to be given small corrective deflection. At this time the cover slit 143 gives no effect to the path of the rays that pass through the slit 142R. The cover slit 143 functions just as a blind shutter for the slit 142G and the slit 142B.
After passing through the correction lens 100, the rays that has passed through the apertures of the shadow mask (not shown) impinges on the inner surface of the panel 2 to exposes the photo resist material to make latent images of the black matrix hole 10R. This part of the process is same as the known prior an as explained in FIG.3 except the structure and positioning of the lamp house 110.
Next, being driven by the rotary actuator 134 the slit 142G is superposed to the cover slit 143. At the same time, being driven by the linear actuator 132, the X-coordinate of the center of the slit 142G is adjusted and is fixed at X--0 as shown in F1G.10G
At this time, the second collection lens is installed at the same location as the previous correction lens to give a different corrective deflection to the rays than the preceded exposure And the second exposure for making the latent image for the black matrix hole 10G is
performed.
Finally, being driven by the rotary actuator 134 the slit 142B is superposed to the cover slit 143. At the same time, being driven with the linear actuator 132, the X-coordinate of the

, filter of the slit 142G is adjusted and is fixed to X==-S as shown in FIG. 1 OB
At this time, the third correction lens is installed at the same location to give a different correction than the preceded two exposures. And the third exposure for making the latent image for the black matrix hole 10B is performed
The processes after carrying out those three exposures are same as known by the prior art.
There are many features in the lighthouse of the present invention. Among them features in which two slit plates (140 and 141) are employed in the lamp house and both of them are installed in the water are especially significant.
In order to explain this reason it is helpful to consider a basic procedure for designing the correction lens 100 and the slits in the first slit plate 140. Following are basic design steps. As the necessary correction depends on the color in question, the following explanation cites red (case of slit 142R) at first.
(First step) Mis-landing that should be corrected is given by a suitable measurement. This is basically possible by making a test tube with the lighthouse shown in FIG. 3, in which, however, the correction lens 100 is not installed.
At this design work, a tentative lamp house in which the slit 142R is not installed and the light source is a point source: that is, the lamp house explained as in FIG. 3 is used
(Second Step) The correction lens 100 is designed so that it corrects mis-landing in just Y-direction (That is Y - 0 aver the entire screen) If the correction is limited to Y-direction. this is theoretically proven to be possible by the paper cited before. At this time it is also theoretically possible to leave (control) mis-landing in X direction on Yp = 0 arbitrarily. This is done by designing the X-Z cross section of the lens 100 appropriately.
The remaining X can be expressed generally as form of a series:
C02 Yp2 + C12 XpYp2 + C22 XP2Yp2 + ......
C04Yp4 + C14XpYp4+ C24 Xp2Yp" + — - ...... (3).

No odd power term with respect to Y appears in this series because the CRT is symmetric with respect to Y-axis.
Among the above terms, the three terms (C10Xp, C02Yp2, and C12XpYp2) are especially
important from the practical view. Therefore other terms are neglected hereafter That is:
.X = C10 XP + C02 YP2 + C12 XpYp2 (4).
One can control the coefficients C10 with the lens, because, as mentioned above, it is theoretically possible to leave arbitrary mis-landing in X direction on YP = 0. Using this nature, the lens is so designed that it corrects not only mis-landing in Y-direction over the entire screen but also it makes C10 multiplied by L be equals to 2.5 to 5. Where L is the distance between the panel and the light emitting source.
(Forth Step) The lamp house having the slit 142R and the elongated light source 110 is assumed. Then, owing to the slit 142, the X-coordinate of the emitting point of the ray that impinges on the panel varies with the coordinate (Xp, Yp) of the panel in question.
The relative X-coordinate of the light emitting point with respect to the center of the slit 142R is denoted as x- The situation is shown in FIG. 10. Then I x varies depending on the point on the panel in question. We are now using this nature for correcting mis-landing. If the above x is just equal to the - X that is given from (4), then it means mis-landing in X direction is corrected.
(Fifth Step) Based on this principle, the distance d is so decided that mis-landing term expressed with the term C10Xpis removed.
FiG.l 1 of the accompanying drawing shows that how the above distance is decided. In the figure, for convenience of approximation, the panel 2 is represented by a plane.
From the figure xis approximately expressed as
x = -Xp*d/L. (5)
Therefore d = - x *(Xp-/L).

On the other hand from the first term of expression (4), I IX = C10 Xp = C10L* Xp/L, and C10L is adjusted to 2.5 to 5.0 in advance with the correction lens. Therefore, considering that x -- X, d should be the range from to 2.5 to 5.0mm.
(Sixth Step) By giving appropriate bend to the first slit plate 140, correction of the mis-landing term C12XpYp2 is performed. Though detail is not explained here, the possibility of the correction is obvious from a qualitative consideration. In most cases, since the sign of the coefficient €12 is positive the bent is upward as a in FIG.8.
(Seventh Step) By giving a bent to the shape of opening of the slit 142R as shown in FIG.9, it is possible to correct practically the mis-landing term Co2Yp. Though detail is not explained here, the possibility of the correction is obvious from a qualitative consideration In case of the red mis-landing, since the coefficient Co2 is always positive (This comes from the nature of the deflection yoke 40), the bent of the slit 142R is, when viewed from Z direction, +X-ward as shown in FIG 9.
(Eighth Step) Design of slit 142G and 142B: The same discussion as the above slit 142R is applicable to the slits 142G and 142B. However in the slit 142G, the coefficient C02 is zero because the picture tube is symmetry with respect to the Y-axis. Therefore the slit 142G is straight when viewed from Z-direction. On the other hand mis-landing pattern for Blue (slit 142B), the coefficient C02 is, though the absolute value is the same as the case Red (slit I42R). the sign is negative. Therefore the bent of the slit 142B is -X-ward as shown in FIG 9, when viewed from the Z direction.
As for the coefficients do and C12. they are practically the same as those of Red (slit 142R) It is possible to use the common d and a for the slits 142G and 142B
In the above explanation it is very important that the distance between the first slit plate 140 and the light source 110 is adjusted to 2.5 to 5mm by a help of the appropriately designed correction lens.
If this distance is too large, only a small fragment of the ray bundle emitted from the light

'
source 110 can reach the panel 2 to result in necessity of too much exposure time. On the 'contrary if this distance is too small it becomes difficult to correct the terms of C12XpYp2 and C02Yp2. Because, in order to correct these terms with practical slit dimensions, a certain distance is necessary between the slit and the light source. For example, since the inner diameter (light emitting portion) of the light source 110 is about 1.5mm, the slit width less than 1.5mm is almost meaning less: that is. a certain distance is necessary between the slit 142 and the light source HO for its shape being meaningful. Further, too small distance is physically impossible because the first slit plate 140 touches light source and causes to break
As a result, the distance 2.5 to 5 mm is a good range for the practical design of the slit plate 142. The correction lens, especially the X-Z cross section of it, should be so designed to realize this distance.
On the other hand the light source must be cooled by water. As the lamp house 101 has a window plate 104 that bears the water pressure, it is concluded that the first slit plate 140 must be installed in the water. As a natural result, the second slit plate 141 should be installed in the water too. Otherwise performing the function for selecting one of three slits of the first slit plate 140 is impossible.
The above conclusion leads to another conclusion that it is suitable to drive the slit plate with a rotating shaft like the driving shaft 135. With this structure the problem of sealing the water is solved easily.
The three slits 142R, 142G, and 142B. which are elongated almost in Y direction, are arranged in X direction side by side wise on the first slit plate 140. The first slit plate 140 has bent lines that are parallel to the X-axis for correcting the mis-landing term C12XpYp2. This is advantageous for the slit plate 140 from being deformed unfavorably because the folding hues work as enforcing ribs for the thin material of it. With this arrangement, it is also possible to drive the slit plate 140 with the moving block 137 from one side of the light source 110 without preventing flow of the water supplied by the water pipe 106 that are arranged along another side of the light source 110
Further, it should be noted that the mutual distance between the three slits of the first slit plate

40 is the smallest at their middle portions as shown in FIG.9. If the arranging order of the slit. 142R and the slit 142B is opposite, the mutual distance is the maximum at their center. If such arrangement is employed, a larger stroke is required for the moving block 137. This is not preferable for the lamp house 101 that should be installed in a small space With the same reason the slit 142G is preferably arranged in between the slit 142R and the slit 142B
The first slit plate 140 is arranged between the second slit plate 141 and the light source 110. This is meaningful for preventing the second slit plate 141 from touching the light source 110 and for securing a good flow of the cooling water around the light source 110.
FIG 12 of the accompanying drawings shows another embodiment of the present invention This drawing shows the inside of the lamp house 101 as in FIG. 7.
In the embodiment, though the structure is very similar to the embodiment shown in FIG.7, The first slit plate 140 is fixed to the main body 102 while the second slit plate 141 is mounted on the moving block 137. Therefore selection of the slits of the first slit plate 140 is performed with move of the second slit plate 141. In this embodiment, the mutual positional relation between the slits at both the sides and the light source 110 differs from that of the preceded embodiment shown before. Therefore though the total structure of the lighthouse is the same as the preceded embodiment, the strokes that are required to the linear actuator 132 die different from those of the preceded embodiment shown in FIG. 10.
FIG. 13 of the attached drawing shows how the key elements of FIG 12 are arranged at the time of exposure R, G, and B of the drawing show the exposure for Red hole (10R in FIG.10), Green hole (10G), and Blue hole (10B) respectively as shown in FIG.10. The arrangement of the key elements is the same as the preceded embodiment except that the used portion of the light source 110 is different by color Therefore the design parameters (a. P. and d) are the same as that are used in the preceded embodiment
In this embodiment, if the mutual distances of the middle points of the three slits that is measured parallel to the X axis are equal to S, it is possible to eliminate the linear actuator 137, However, too large value for this distance is not recommended. This is because, as the light intensity on the light source 110 is not necessarily uniform over the entire length, use of

different portion for each color may cause unequal exposures for three colors that cause a non-uniformity of the screen of the color picture tube.
The invention may be embodied in other specific forms without departing from the spirit of essential characteristics thereof. The present embodiments are therefore to be considered in all respects illustrative and not restrictive.
For example, the center of the slit 142G can be out of Z-axis that is identical with the tube axis. Such technique is known as 'purity shift control' to cope with the effect of the ambient magnetic field. Another modification is giving a small continuous reciprocal move to somewhere of the lamp house. In order to make black matrix hole of a good shape it is sometimes necessary to use a light source of a special shape. In such case it is possible to give a continuous swinging move to somewhere of the lamp house or lamp house itself in the X-,Y-, and/or Z-direction.
Accordingly, it should be understood that the present description intends to cover by the appended claims all modifications falling within the true spirit and scope of this invention.

We claim:
An improved Exposure Light House device for depositing mosaic (10)screen on a colour
picture tube panel consisting of black matrix layer having periodically arranged holes each of which is filled with one phosphor of Red, Green and Blue on said panel of said colour picture tube having a highly evacuated envelope and a longitudinal central axis, say Z - axis.
said panel comprising a rectangular inner surface, the normal at the center thereof
coinciding with the Z-axis, the long axis as X-axis, and the short axis as Y-axis,
supporting a finely perforated shadow mask(20) and to be connected to the open end
of a cone shaped funnel(3)the narrower end.of that is connected to a cylindrical neck
tube(4)upporting an in-line electron gun(30) with three unit electron guns in the X-Z
plane and the axis of the unit electron gun that is in the middle of said three unit
guns coinciding with the Z-axis, and having an elongated light source(110) that is
extended in the direction parallel to the X-axis characterized in that:
a first slit plate of a thin opaque material and placed between said light source and said panel and having three elongated slits; say a first, a second and a third slit , each of the three slits extends to the direction parallel to the Y-Z plane,
a second slit plate made of thin opaque material and placed close to said first
(140) slit plate and having an elongated slit- cover slit, that extends to the direction
parallel to the Y-Z plane,
a correction lens disposed between said first slit plate and said panel to correct the trajectory of the rays emitted from said light source, (110)
a selecting gear that controls the relative position between said first slit plate and said second slit plate and selects one of said first , said second , said third slit by superposing it to said cover slit to allow just a part of the rays that are emitted from the said light source and that is to fall on said slit of said first slit plate that can reach said inner surface of said panel to form holes of said black matrix layer to be filled with phosphor with any of the Red, Green & Blue colors.
2. An improved Exposure Light House device as claimed in claim 1, wherein the
width of said cover slit is larger than width of any of said first, said second and said
third slit.
3. An improved Exposure Light House device as claimed in claim 1, wherein said first
slit plate is placed between said light source and said second slit plate.

4. An improved Exposure Light House device as claimed in claim 1, wherein said
selecting gear controls the position of said first plate in a manner that when one of
the said first, second and third slit therein is selected by being superposed to said
cover slit by said selecting gear, the selected slit takes one of the three X-
coordinates for said first, said second, and said third slit respectively, and the X-
coordinate of a slit is defined by the X-coordinate of the midpoint of its useful
length.
5. An improved Exposure Light House device as claimed in claim 1, wherein said first,
said second and said third slit are arranged in said first slit plate, in the direction
parallel to the X-axis.

6. An improved Exposure Light House device as claimed in claim 1, wherein said
selecting gear gives movement to said first slit plate to make one of said first,
second, and third slit selectively superposed to said cover slit.
7. An improved Exposure Light House device as claimed in claim 1, wherein said
selecting gear gives movement to said second slit plate to make one of said first,
second, and third slit selectively superposed to said cover slit.
8. An improved Exposure Light House device as claimed in claim 7, wherein the
peripheral area of said first, said second, said third slit of said first slit plate is bent
along with said first, said second, and said third slit screen therein with a bending
line/lines, or generating lines that are parallel to the light source.
9. An improved Exposure Light House device as claimed in claim 8, wherein said first
slit plate is bent so that the distance between each of said first, said second and said
third slit of said first slit plate and said light source is smallest at the mid-points of
the effective length of said first, said second, and said third-slit of said first slit
plate.
10. An improved Exposure Light House device as claimed in claim 6, wherein the peripheral area of said cover slit of the second slit plate is bent similarly to the peripheral area of said first, said second and said third slit of said first slit plate so that the peripheral area of said fourth slit of said second slit plate is close to said peripheral area of said first, said second, and said third slit of the said first slit plate.
11. An improved Exposure Light House device as claimed in claim 1, wherein said light source is sealed in a water jacket having transparent window to allow the rays from said light source to reach the panel while preventing the water from leaking there from, said first slit plate and said second slit plate are placed between said light source and said transparent window in said jacket, said water jacket provided with water to cool the light source.

12. An improved Exposure Light House device as claimed in claim 1, wherein said selecting gear comprises a rotating actuator, a male screw, and a female screw, said male screw and said female screw mated with each other and placed in said water jacket.
13. An improved Exposure Light House device as claimed in claim 12, wherein the shaft
of said male screw is placed parallel to the X-axis and extended to outside of said
water jacket and said female screw connected to either said first slit plate or said
second slit plate in water, said rotating actuator controls the relative position
between said first slit plate and said second slit plate by giving rotation to said shaft
of said male screw from outside the said water jacket.
14. An improved Exposure Light House device as claimed in claim 4, wherein the
mutual distances of the said first, said second and said third slit, viewed from Z
direction, the smallest at the mid-points of the useful length thereof.
15. An improved Exposure Light House device substantially as herein described with
reference to and as illustrated in the accompanying
drawings.

Documents:

614-del-2002-abstract.pdf

614-del-2002-claims.pdf

614-del-2002-correspondence-others.pdf

614-del-2002-correspondence-po.pdf

614-del-2002-description (complete).pdf

614-del-2002-form-1.pdf

614-del-2002-form-19.pdf

614-del-2002-form-2.pdf

614-del-2002-form-3.pdf

614-del-2002-gpa.pdf

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Patent Number

218007

Indian Patent Application Number

614/DEL/2002

PG Journal Number

24/2008

Publication Date

13-Jun-2008

Grant Date

31-Mar-2008

Date of Filing

06-Jun-2002

Name of Patentee

SAMATEL COLOR LIMITED,

Applicant Address

VILLAGE CHHAPRAULA, BULANDSHAHAR ROAD, GHAZIABAD-201009 (UP), INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	FUJIMURA, TAKEO	SAMTEL COLOR LIMITED, VILLAE CHHAPRAULA, BULANDSHAHAR ROAD, GHAZIABAD-201009 (UP), INDIA.

PCT International Classification Number

G09F 13/24

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA