Title of Invention | COLOR SORTING APPARATUS |
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Abstract | There is disclosed a color sorting apparatus for sorting objects which are relatively light, short, thin, and small in the mass and hardly sorted by any known manner. The color sorting apparatus comprises a chute 1 arranged at an angle a for permitting the objects W to run downwardly and pop off from the lower end in a predetermined direction, a cover 2 provided at a distance from the surface of the chute, to cover at least a portion of the surface of the chute, an inspecting means 3 provided at a distance from the lower end of the chute for monitoring the movement in the predetermined direction of the objects W released from the lower end of the chute in order to measure the color of the objects W, a judging means connected with the inspecting means for judging from a measurement of the color produced by the inspecting means whether or not the objects have a particular color, and a separating means 4 provided at a distance from the lower end of the chute for blowing off the object W which is judged by the judging means to have the particular color so that the object drops down along a route different from the movement in the predetermined direction. |
Full Text | BACKGROUND OF THE INVENTION 0001 1.Field of the Invention The present invention relates to a color sorting apparatus for sorting objects into goods and defectives, such as tea, green laver, and basil, which are different in size and shape. 0002 2.Description of the Related Art A color sorting apparatus for removing defectives from food products/ such as rice grains or tea leaves, which defectives are unfavorable in the color is known having a structure where the food products or objects to be sorted are slid along a wave cross sectional plate (chute), which has a row of troughs having a V or U shape in the cross section and arranged along the widthwise direction at an angle to the horizontal, and received by an inspecting means or color identifying sensor provided beneath the chute. When judged as a defective by the sensor, the object is blown off by a separating means, such as an ejector, emitting a jet of compressed air and dropped down in a passage different from the passage of the good objects. Such a conventional color sorting apparatus over which the present invention has been developed will be explained in brief referring to Figs. 6 to 8. 0003 The conventional color sorting apparatus comprises a couple of chutes C1 and C2 arranged at an angle to the horizontal for allowing objects W to be sorted to pop off in a predetermined direction, a couple of inspecting means S1 and S2 for examining the color of the objects W, a judging means J connected with the inspecting means for analyzing an output signal of the inspecting means to judge whether the objects W are good or not (See Fig. 8), and a couple of separating means V1 and V2 for sorting the objects W by emitting a jet of compressed air against a defective of the objects W determined by the judging means J, which all are mounted by unshown stays to a base frame P. The inspecting means S1 and S2 and the separating means V1 and V2 are located at a distance from the lower end of the chutes C1 and C2 respectively and above the dropping path for the objects W. As shown in Figs. 6 to 8, the chutes, the inspecting means, and the separating means are arranged at two, upper and lower, stages. Also, the chutes C1 and C2 shown in Figs. 6 to 8 are made of metallic sheets having a wave-form folded shape where a row of V cross sectional troughs are arranged along the width of the apparatus as best shown in Fig. 6B. As shown in Figs. 6 and 7, a feeding means F, namely an electromagnetic feeder, is provided above the upper end of the chute from which the objects W are scattered downwardly and uniformly throughout the each of the chute. Each pair of the inspecting means S1 and S2 and the separating means V1 and V2 are parallelly arranged at a location correspond to the each trough for operating independently. The inspecting means S1 and S2 shown in Figs. 6 to 8 are implemented by known photo-to-electric converting elements or photo sensors rowed in parallel to the width of the chutes. The inspectingmeans S1 and S2 are designed for measuring the color or tone of the objects W dropping down from the chutes and particularly include output circuits for transmitting a resultant measurement in the form of an electric signal to the judging means J. The separating means V1 and V2 include ejectors having a multiplicity of aperture therein arranged along the widthwise direction of the chutes, electromagnetic valves (not shown) communicated with the ejector apertures, and a pneumatic pump for supplying the electromagnetic valves with compressed air. The ejector apertures are directed towards the objects W dropping down from the lower end of the troughs of the chute. The electromagnetic valves are electrically connected with the corresponding photo sensors. When a defective W2 which is different in the color from the other good objects W1 is detected by the judging means J receiving and analyzing the output signal of the inspecting means S1 or S2, its detection signal is transferred to the corresponding electromagnetic valve in the separating means V1 or V2 which then opens to emit a jet of compressed air against the defective W2. Accordingly as shown in Fig. 8, the defective W2 can be removed from the dropping movement of the objects W and separated from the good products W1. However, the conventional color sorting apparatus explained referring to Figs. 6 to 8 has to modify the size and shape of the troughs of the chutes whenever the objects W to be sorted are changed to another type. Also, the apparatus allows the objects W to run down along the troughs of the chutes thus limiting the efficiency of the downward movement throughout the width of the chutes. As a result, the conventional color sorting apparatus will remain extensive along its widthwise direction for ensuring the sufficient processing capability or the effectiveness of the sorting action. 0004 For overcoming the above described drawback, an improvement has been proposed where the chute of a flat surface type extending to match the width of a feeding means or electromagnetic feeder is uniformly divided along its lower end width into sections, each section accompanied with a combination of an optoelactric inspecting means and an air nozzle for sorting the objects (See Japanese Utility Model Publication No. H07-21163). However, the improvement still has the following drawbacks. 0005 Firstly, when the objects are susceptible to static charges/ they may be stuck and hardly slid on the chute particularly in the winter dry season thus declining the efficiency of the sorting action. As the objects are slid along and on the chute with much difficulty but not at desired speeds, their good products fail to pop out to a good products receiver and may be received by a defective tray hence declining the accuracy of the sorting action. In particular, when the objects are relatively light, short, thin, and small in the mass as well as low in the bouncing coefficient or may namely be green laver, basil or leaves of tea including grainy forms of tea like "Tencha" or "deeply steamed tea leaves" which are milled or crumpled forms in bit size and in powder size, they can highly be affectedby static electricity. As a result, most of the objects statically charged may not be slid downwardly but stuck at the upper end of the chute. This may be emphasized by the objects being statically charged and conveyed to the upper end of the chute by the vibrating action of the electromagnetic feeder as the feeding means. 0006 It is an idea for solving the above described drawback to increase the sloping angle of the chute from the horizontal. When the inspecting means is a photo sensor, its focusing point is allocated near the surface of the lower end of the chute. Accordingly, the inspecting means can correctly examine the objects which are run down straight to the surface of the lower end of the chute. If the objects joggle or pop up at the lower end of the chute, they may be out of the focusing point of the inspecting means and thus misidentified. It is essential for the photo sensor examining the objects running out from the lower end of the chute that the objects to be sorted are slid directly on the surface of the chute at the lower end or focusing point, When its angle from the horizontal is sharply increased, the chute causes the objects to run down not directly on its surface but pop up and move out at higher frequency. As a result, the objects will hardly be focused with the photo sensor thus declining the accuracy of judging whether the objects are good or not. It is hence troublesome to simply increase the sloping angle of the chute from the horizontal. In the prior art shown in Figs. 6 to 8, the angle a of one chute is set to substantially 54° while the angle of another chute is about 45° (See Fig. 7). 0007 As disclosed in Japanese Patent Laid-open Publication No. 2003-275690, the inspecting means is implemented by a CCD camera for measuring the color of the objects. As the objects, such as tea leaves, running down along the chute are recorded by the CCD camera, their images in a digital form are examined for judging from the color whether the objects are good or not. The CCD camera has an imaging range allocated beneath the lower end of the chute and arranged to extend throughout the width of the chute for examining the color over the entire range. However/ the apparatus disclosed in Japanese Patent Laid-open Publication No. 2003-275690 is still unfavorable in the efficiency of downward movement of the objects about the widthwise direction of the chute, similar to that shown in Figs. 6 to 8. Even if the accuracy of examination is increased, the processing capability of the color sorting apparatus or the effectiveness of the sorting action will rarely be improved. Also, the sloping angle of the chute is increased as compared with the use of photo sensors and permits the objects to pop up and move out from the surface of the chute at more frequency. As the removal of defectives by ejection with a jet of air is not easy, therefore, the chute will be sloped to a limited angle. 0008 As apparent from the description of the prior arts, no color sorting apparatuses have successfullybeenusedinpractice where the objects are relatively light, short, thin, and small in the mass as well as low in the bouncing coefficient or may namely be green laver, basil or leaves of tea including grainy forms of tea like "Tencha" or "deeply steamed tea leaves" which are milled or crumpled forms in bit size and in powder size can be sorted at deaired accuracy. 0009 Moreover, the apparatus using the chutes of a trough shape type (described in Japanese Utility Model Publication No. H07-21163 and the prior art shown in Figs. 6 to 8) is still unfavorable for general use because the chute has to be modified in the cross sectional shape, the width of each trough, and the pitch between troughs depending on the size and shape of the objects to be sorted. 0010 SUMMARY OF THE INVENTION It is hence an object of the preeent invention to provide a color sorting apparatus which is capable of sorting particularly all types of tea leaves, which are relatively light, short, thin, and small in the mass, including grainy forms of tea like "Tencha" or "deeply steamed tea leaves" which are milled or crumpled forms in bit size and in powder size. Another object of the present invention is to provide a color sorting apparatus which is capable of sorting other objects, such as green laver or basil/ which are relatively light, short, thin, and small in the mass as well as low in the bouncing coefficient and may hardly be sorted by any prior art apparatus. 0011 It is a further object of the present invention to provide a color sorting apparatus which is higher in both the accuracy of the sorting action and the processing capability (equivalent of the effectiveness of the sorting action) . It is a still further object of the present invention to provide a color sorting apparatus which is highly favorable for general use where objects which are different in size and shape can be sorted at a single unit. 0012 We, the inventors, has found through a series of studies for overcoming the foregoing drawbacks that, in a color sorting apparatus employing a CCD camera as the inspecting means for inspecting through the image processing, the chute on which objects to be sorted are slid down is arranged of a flat shape without troughs, accompanied with a cover covering above the chute, and sloped at a higher angle to the horizontal, whereby the objects when are susceptible to static charges can be dropped smoothly as pressed downwardly by their successors even if they have temporarily been stuck on the chute. It was also found that when the objects are relatively light, short, thin, and small in the mass and frequently lifted up from the surface of the chute during their downward movement on the chute, their movement can be guided by the cover thus to run directly on the surface of the chute. 0013 For achievement of the above object, a color sorting apparatus as a first feature (1) of the present invention is provided, for sorting colored objects by color, comprising: a chute arranged at an angle to the horizontal for permitting the objects to run downwardly from upper to lower and pop off from the lower end in a predetermined direction; a cover provided at a distance from the surface of the chute to cover at least a portion of the surface of the chute; an inspect ingmeans provided at a distance from the lower end of the chute for monitoring the movement in the predetermined direction of the objects released from the lower end of the chute in order to measure the color of the objects; a judging means electrically connected with the inspecting means for judging from a measurement of the color produced by the inspecting means whether or not the objects have a particular color; and a separating means provided at a distance from the lower end of the chute for blowing off the object which is judged by the judging means to have the particular color so that the object drops down along a route different from the movement in the predetermined direction. The cover is intended for inhibiting the objects, which are relatively light, short, thin and small in the mass, and lifting up from the surface of the chute during their downward movement along and on the chute while narrowing the passage for the downward movement of the objects so that the objects can be slid down directly on the chute. More specifically, when the objects which are small in the bouncing coefficient are lifted up from the surface of the chute, their downward movement can be corrected upon striking against the cover. As a result, the objects can be slid down directly on the surface of the chute without joggling up and down. The above described structure of the apparatus of the present invention is different in the purpose, arrangement, and effectiveness from a prior art where while the objects which are slightly heavy and not small in the bouncing coefficient, such as beans, are bounced more or less and slid down along the chute after having been fed at the upper end of the chute, and their joggling energy is absorbed by an elastic material, such as vinyl film, which is disposed at a distance from the surface of the chute composed of U cross sectional troughs rowed along the width of the chute. 0014 The color sorting apparatus of the first feature (1) may be modified, as a second feature (2) of the present invention, in which the chute is a flat chute having a flat surface sized corresponding to the width for feeding the objects, and the cover is located at a distance from the flat surface of the chute, made of a sheet-like body covering at least a portion of the chute, and shaped for limiting the sloping movement of the obj ects so that the objects neatly run down along the flat surface of the chute. 0015 Also, the color sorting apparatus of the previous feature (1) or (2) may be modified, as a third feature (3) of the present invention, in which the angle of the chute from the horizontal ranges from 60° to 85°. 0016 The color sorting apparatus of any of the previous features (1) to (3) may be modified, as a fourth feature (4) of the present invention, further comprising a static eliminator provided above a means for feeding the objects at the upper end of the chute and arranged for eliminating static electricity charged on the objects. 0017 Moreover, the color sorting apparatus of any of the previous feature (1) to (4) may be modified, as a fifth feature (5) of the present invention, in which two or more of the chutes are provided from upper to lower, each the chute accompanied with the cover, the inspecting means, and the separating means. 0018 The flat chute or flat surface in the apparatus according to the present invention may include a surface which is not perfectly planer but substantially flat. For example, each of the surface of the chute and the inner side of the cover has a row of lengthwisely extending ribs at a desired shape thereof arranged in parallel to the direction of the downward movement of the objects throughout the width of the chute and the cover. Alternatively, the chute or cover is not straight in the side elevation but may be curved partially. 0019 According to the present invention, all shapes of tea leaves can be sorted including grainy forms of tea like "Tencha" or "deeply steamed tea leaves" which are milled or crumpled forms in bit size and in powder size. Also according to the present invention, objects which are relatively light, short, thin, and small in the mass as well as low in the bouncing coefficient, such as green laver or basil can be sorted. Moreover according to the present invention, objects which are different in the shape and size and sorted by any prior art manner can be sorted with much ease. 0020 According to the present invention, objects which are relatively light, short, thin, and small in the mass and hardly sorted by any prior art manner can be separated from defectives at high accuracy and hardly mixed up with the defectives, thus increasing the yield of production. 0021 According to the present invention, objects which are susceptible to static charges can be sorted at high accuracy as not being stuck up on the chute. When the static eliminator is provided about the feeding means, its action can eliminate static electricity on the objects. Therefore, the objects can slide smoothly from upper to lower along the chute and being sorted at higher accuracy. 0022 According to the present invention, as objects are fed and conveyed at higher concentration along the chute, their sorting effectiveness or the processing capability per machine size can significantly be increased. More specifically, since the objects to be sorted are uniformly distributed throughout the width of the chute, their downward movement can be improved in the efficiency. Also, when the inspecting means is a CCD camera, its action is equivalent to a row of sensors arranged without gap throughout the width of the chute hence allowing any defective running on the flat surface of the chute to be identified with ease. As combinations of the ejector apertures and their corresponding electromagnetic valves are provided along the width of the chute at equal intervals, which are equal to or greater by an integer than that an arrangement pitch of pixels in the CCD camera, their action can eject defectives of the objects at higher accuracy. The efficiency of the sorting action or the processing capability of the color sorting apparatus may be determined by, e.g., the amount or the number of objects to be sorted per hour. 0023 According to the present invention, as its chutes or troughs of each chute need not to be modified in size or shape corresponding to the objects to be sorted, the color sorting apparatus can be favorable for general use. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a primary part of a color sorting apparatus according to the present invention; Fig. 2 is a cross sectional view taken along the center of the color sorting apparatus shown in Fig. 1; Fig. 3 is a perspective view schematically showing another embodiment of the color sorting apparatus; Fig. 4 is cross sectional view taken along the center of the color sorting apparatus shown in Pig. 3; Fig. 5 illustrates modifications of the chute and the cover? Fig, 6 is a perspective view schematically showing a conventional color sorting apparatus; Pig. 7 is cross sectional view taken along the center of the conventional color sorting apparatus shown in Fig. 6; and Fig. 8 is a side view showing the theory of sorting action in the color sorting apparatus. 0024 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a color sorting apparatus according to the present invention will be described in conjunction with Figs. 1 and 2. Fig. 1 is a perspective view schematically illustrating primary parts of the color sorting apparatus of the embodiment and Fig. 2 is a cross sectional view at the center of the same. 0025 The color sorting apparatus of the embodiment is designed for sorting particular objects which may be relatively light, short, thin, and small in the mass as well as low in the bouncing coefficient or may namely be green laver, basil or leaves of tea including grainy forms of tea like "Tencha" or "deeply steamed tea leaves" which are milled or crumpled forms in bit size and in powder size. 0026 As shown in Figs. 1 and 2, the color sorting apparatus comprises a chute 1 disposed at an angle to the horizontal for scattering down the objects W to be sorted, a cover 2 provided to cover at least a portion of the upper side of the chute 1, an inspecting means 3 for inspecting the objects W from their color, a judging means 5 for analyzing an output signal from the inspecting means 3 to find defectives, and a separating means 4 for separating defectives selected by the judging means 5 with the use of a jet of compressed air, which all are commonly mounted by stays or the like to a frame base not shown of the apparatus. In particular, the inspecting means 3 and separating means 4 are spaced by a distance from the distal or lower end of the chute 1 and located above the dropping path for the objects W to be sorted. The inspecting means 3 may be a CCD camera as will be explained later in more detail. 0027 The chute lisa flat chute having a planer surface extended throughout the feeding width for the objects W. As not shown, a feeding means is provided above the proximal or upper end of the chute 1 from which the objects W are scattered downwardly and uniformly throughout the feeding width of the chute 1. In this embodiment, the sloping angle a of the chute 1 ranges preferably from 60° to 85º from the horizontal or more preferably from 65° to 75°. This allows the objects w tobe dropped smoothly as pressed downwardly by their successors even if they have temporarily been stuck on the chute 1. 0028 The cover 2 is designed for guiding the objects W, which have been lifted up from the surface of the chute 1/ with its shape narrowing the sloping down (downward) path so that the objects W can definitely slide down along and on the chute 1. More specifically, when the objects W to be sorted are light, short, thin, and small in the mass, they may be lifted up while running down from the upper end on the surface of the chute 1. The lifted objects W can thus be blocked and guided downwardly by the cover 2. As the lifted objects W are low in the bouncing coefficient, they can easily be deflected upon striking against the cover 2 before dropped straight along and on the surface of the chute 1. As apparent from Fig. 2, the distance h2 between the inner side of the cover 2 and the surface of the chute 1 is smaller than the height h1 of both side walls of the chute 1. The distance may be modified to a desired length depending on the size of the objects W. The cover 2 in this embodiment shown in Figs. 1 and 2 is made of a flat and rigid sheet extending throughout the width of the chute 1 and covering from a midway distanced from the upper end to the lower end of the chute 1. The cover 2 may preferably be made of a sheet of a metal or a plastic resin such as acryl or polycarbonate. The cover 2 is arranged at the upper region of such a shape that the distance between its inner side and the surface of the chute 1 becomes greater towards the upper end than the distance h2 at the lower region. This allows the objects W to be fed from the above onto the chute 1 with much ease and to be blocked and guided when lifted up from the surface of the chute 1 during the dropping movement. 0029 In the color sorting apparatus o£ the embodiment, the theory of detecting colors for separation is substantially known where the objects W to be sorted are released from the lower end of the chute 1, inspected over the color by the inspecting means 3 for judging from the color whether the objects W are good or not by the judging means 5, and separated the good from the bad by the separating means 4. 0030 The inspecting means 3 in the color sorting apparatus of the embodiment includes a CCD camera located just beneath the chute 1 for monitoring the inspecting area throughout the width of the chute 1. The CCD camera comprises an array of pixels extending along the widthwise direction of the chute 1. This represents a row of photo sensors aligned throughout the width of the chute 1. The CCD camera is charged in proportion to the receiving light amount for every pixel. As each of the pixels is driven by a pulsed readout signal, its color information can be obtained. As shown in Fig. 2, the output voltage signals from the pixels are received by the judging means 5 where they are compared with predetermined thresholds or a permissive range for the inspection. More particularly, the objects W staying lower or higher than the thresholds or out of the permissive range are judged as defectives W2 by the judging means 5. In response, the separating means 4 is actuated so that one of its electro-magnetic valves, turns open to blow a jet of compressed air from its ejector apertures assigned to a set of the pixels which have released in response to the voltage signal indicative of the defective W2. As a result, the defectives W2 can be blown off and separated from the good objects W1 by the action of the jet of compressed air. The defectives W2 separated are discharged along a path different from the path for the good objects Wl and received by a defective receiver of tray 6. Those steps of the sorting action can almost instantly be conducted on the order of milliseconds (ms) or microseconds (μa). 0031 As shown in Figs, 1 and 2, the separating means 4 incluudes an ejector having a row of apertures provided therein along the widthwise direction of the chute 1, a group of unshown electromagnetic valves communicated with the ejector, and an unshown pneumatic pump for feeding the compressed air to the electromagnetic valves and the ejector apertures. For ease of the action of the judging means 5, this embodiment permits the dropping range of the objects W along the width of the chute 1 to be equally divided into sections which correspondingly face the array of pixels of the CCD camera of the inspecting means 3 and the apertures in the ejector to be grouped to selectively blow off and eject the object W from each target section of the chute 1. Accordingly, the judging means 5 upon finding a defective drives one of the electromagnetic valves to separately open up its corresponding ejector apertures and blow off a jet of the compressed air for blowing off the defective. As the sloping angle of the chute 1 from the horizontal is more acute in this embodiment than that of any prior art and the objects to be sorted run down at much faster speeds, the separating means 4 is actuated almost instantly or with no delay when the judging means 5 has found a defective W2 in response to the signal from the inspecting means 3, whereby the defective W2 can be removed out from the common dropping path and separated from the good objects W1. 0032 Example 1 Another embodiment of the color sorting apparatus according to the present invention will now be described referring to Figs. 3 and 4. Fig. 3 is a schematic perspective view of the color sorting apparatus of the another embodiment and Fig. 4 is across sectional view taken along the center of the color sorting apparatus shown in Fig. 3. 0033 As shown in Figs. 3 and 4, the color sorting apparatus of the another embodiment comprises a couple of chutes 11 and 12 arranged at an angle to the horizontal for running down the objects w to be sorted, a couple of covers 21 and 22 disposed at a distance from the chutes 11 and 12 respectively for covering at least portions of their respective chutes 11 and 12, a couple of inspecting means 31 and 32 for examining the color of the objects W, a judging means 5 connected to the inspecting means, for analyzing output signals of the inspecting means 31 and 32 to judge defectives among the objects M, and a couple of separating means 41 and 42 for, when the judging means 5 detects a defective, blowing off the defective with a jet of compressed air to separate from the good objects, which all are mounted by unshown stays to a base frame 7. The inspecting means 31 and 32 and the separating means 41 and 42 are spaced by a given distance from the lower ends of the chutes 11 and 12 respectively and located above the dropping path for the objects W to be sorted. In the another embodiment, the chutes, the inspecting means, and the separating means are assembled to act at two stages. 0034 Primarily, as shown in Figs. 3 and 4, a static eliminator 9 for eliminating static electricity charged on the objects W is provided above a feeding means 8 which is namely an electromagnetic feeder for feeding the objects W to be sorted to the upper end of the first chute 11. The static eliminator 9 is designed for generating atmospheric ions by corona discharging thus to eliminate the static electricity from the objects W as its example is disclosed in Japanese Patent Laid-open Publication No. H09-63788. The static eliminator 9 in the another embodiment is of a voltage impress type. More particularly, the static eliminator 9 comprises a static electricity removing electrode assembly, an unshown AC high-voltage source, and a high-voltage cable connecting the electrode assembly with the high-voltage source, as shown in Figs. 3 and 4. As apparent from Figs. 3 and 4, the 3tatlc electricity removing electrode assembly consists mainly of a row of needle-like discharging electrodes mounted lengthwisely on an insulator of a bar-like shape and a grounding electrode unit disposed at a distance from the discharging electrodes as mounted by insulating members to both ends of the insulator. In an action of the static eliminator 9, when a high AC voltage is supplied via the high-voltage cable from the AC high-voltage source and received by the discharging electrodes, it generates a high-voltage electric field between the discharging electrodes and the grounding electrode unit. As the electric field is intensified at the distal end of each of the discharge electrodes, its corona discharging action creates atmospheric ions. The elimination of static electricity can thus be conducted by the atmospheric ions neutralizing electric charges on the objects W. Using the AC voltage at the discharging electrodes, positive ions and negative ions of atmospheric air can be generated alternately. Accordingly, the positive atmospheric ions can neutralize negative charges while the negative atmospheric ions neutralize positive charges on the objects W. 0035 In particular, the sloping angle a of the chute 11 from the horizontal is set to substantially 70 degrees while the sloping angle of the second chute 12 is slightly smaller than that of the first chute 11. This allows the objects W run down and released from the lower end of the first chute 11 to be received by an upper region of the second chute 12 without difficulty. In the conventional color sorting apparatus described previously in conjunction with Figs. 6 to 8, the objects W are released from the chute C1 at the first stage and blocked by the stopper plate T disposed above the chute C2 at the second stage. As a result, the objects W become zero at the initial speed before running down along the second stage chute C2. According to the another embodiment/ the objects W released from the first chute 11 are received directly by an upper region of the second chute 12 and their running speed remains not significantly decreased. Since the running speed of the objects W remains at a desired rate, the overall length of the second chute 12 can favorably be shortened hence contributing to the downsizing of the apparatus. 0036 Also as best shown in Fig. 4, a lamp L, such as a fluorescent lamp, and a dark color background plate M, such as a black board, are provided in a combination at the lower side of and throughout the width of each of the two chutes 11 and 12 in the another embodiment. The background plate M is disposed to confront the fluorescent light L and the CCD camera of the inspecting means 31 or 32 so that they sandwich the dropping path for the objects W from the chute 11 or 12. This allows the objects W to be highlighted as clearly distinguished from the background plate M and thus recorded at a higher image level by the CCD camera, whereby the judging action of the judging means 5 receiving and examining the output signal of the CCD camera can be improved in the accuracy and minimized in the judgment error. 0037 The covers 21 and 22 are provided for deflecting the downward movement of the objects W. More specifically, the covers 21 and 22 permit the objects W which are relatively light, short, thin, and small in the mass as well as low in the bouncing coefficient to be bounced at minimum upon the collision and thus gently received by the chutes 21 and 22 before running down further with certainty. As shown in Figs. 3 and 4, the covers 21 and 22 in the another embodiment are made of flat and rigid sheets extending throughout the width of the chutes 11 and 12 respectively and covering from a midway distanced from the upper end to the lower end of the chutes 11 and 12 respectively. The covers 21 and 22 may preferably be made of sheets of a plastic resin such as polycarbonate. Each of the covers 21 and 22 is arranged at the upper region of such a shape that the distance between its inner side and the surface of the chute 11 or 12 becomes greater towards the upper end than the distance h2 at the lower region. In the another embodiment, the distance between its inner side and the surface of the chute 11 or 12 may range from 10 mm to 15 mm depending on the size of the objects W to be sorted. 0038 The inspecting means 31 and 32 in the another embodiment are implemented by CCD cameras. The CCD camera has an array of pixels aligned without gaps along the widthwise direction thereof and thus utilized as the units in the inspecting means. This permits the ejector apertures to be arranged at equal intervals, which are smaller than the pitch along the width of the chute shown in the prior art. In the another embodiment, one CCD camera covers throughout the width, 600 mm, of the chute. 0039 Each of the separating means 41 and 42 similar to that of the previous embodiment comprises an ejector having a row of apertures provided therein along the widthwisa direction of the corresponding chute 11 or 12, a number of unshown electromagnetic valves communicated with the ejector, and an unshown pneumatic pump for feeding the compressed air to the electromagnetic valves and the ejector apertures. The apertures of the ejectors are arranged at equal intervals, which are equal to or greater by an integer than that an arrangement pitch of pixels in the CCD camera along the widthwise direction of the chute 11 or 12. Upon receiving the control signal from the judging means 5, one of the electromagnetic valves communicated with the ejector apertures is selectively actuated to open up for blowing a jet of compressed air against a defective object W to be ejected. 0040 The action of the color sorting apparatus of the another embodiment will then be explained. Firstly, the objects W to be examined are vibrated and conveyed to the upper end of the first chute 11 by the action of the feeding means or electromagnetic feeder 8. More particularly, the objects W are received at the upper end and distributed uniformly along the width of the first chute 11. Although the objects W are constantly vibrated and statically charged by the action of the electromagnetic feeder, their resultant static charges are effectively eliminated with the static eliminator 9 located above the feeding means 8. The objects W received at the upper end then run downwardly along and on the first chute 11. When the objects W which are relatively light, short, thin, and small in the mass as well as low in the bouncing coefficient are lifted up more or less from the surface of the chute 11, their downward movement can be deflected or corrected by the action of the cover 21 for running straight on the chute 11. When having been released out from the lower end of the first chute 11, the objects W are passed at a higher speed in the front of the inspecting means 3. The inspecting means or CCD camera examines the color of the objects W and its detection signal is transmitted to the judging means 5. The judging means 5 may be a microcomputer which carried out an image processing action on the detection signal received from the CCD camera for judging from their color whether the objects W are good or not. When the judging means 5 detects a defective, it actuates one of the electromagnetic valves communicated to the ejector apertures which correspond to a group of the pixels recording an image of the defective to open its passage for producing a jet of compressed air. As blown by the jet of compressed air from the ejector apertures, the defective can be separated from the other objects W. When having been judged as a defective by the inspecting means 31 and the judging means 5 during its downward movement along the first chute 11, the object W is removed out from the common path by the action of the ejector 41 and conveyed along a different path before received by a defective receiver not shown. 0041 The other objects W not judged as defectives during the downward movement along the first chute 11 are received by the second chute 12 and examined again. Similarly, when having been judged as a defective/ the object W is removed by the action of the ejector 42 and conveyed along a different path before received by the unshown defective receiver. The other objects W which are not judged aa defectives by both the inspecting means 31 and 32 are released from the lower end of the second chute 12 and received by the good products receiver. The another embodiment has two stages for sorting, permitting the objects W to be examined by the two inspecting means 31 and 32. When the object W is judged as a defective by either of the inspecting means 31 or 32, it can be blown off and separated from the other objects W by the action of the ejector. When the object w is not judged as a defective by both the inspecting means 31 and 32, it can be recovered as a good product. Accordingly, the objects W can be sorted at higher accuracy. 0042 As set forth above, the another embodiment of the present invention can sort particular objects which are hardly examined by any prior art. Also, the objects which are varied in the shape or size, as well as traditionally separable and sortable objects, can be sorted at higher accuracy. Moreover, the color sorting apparatus of the another embodiment can be improved in the processing capability per machinery size. More specifically, it was proved through testing that the color sorting apparatus of the another embodiment was capable of sorting deeply steamed tea leaves, which were hardly sorted by any prior art, at favorable accuracy, The efficiency of its sorting action was as high as 180 kg/h which was almost two times greater than a conventional average of 90 kg/h. 0043 It would understood that the present invention is not limited to the foregoing embodiments but any design modification may be made. For example, while the embodiments allows any defective to be blown off by the action of the ejector, the good objects can be ejected. Also, the good products or defectives are receivedby the receivers or recovery trays but may be transferred to the succeeding step of the production or the disposal stage by a conveying means such as a vibration conveyor or abelt conveyor. Although the objects are inspected from one side in the embodiments, they may preferably be examined from both, front and rear, sides of the apparatus. In the latter case, one pair of the inspecting means are disposed opposite to each other at both the front and rear sides about the dropping path for the objects to be inspected from two sides. The inspecting means is not limited to a CCD camera but may be a photo sensor array where a desired number of photo sensors are aligned along the wldthwise direction of the chute by a known manner. Preferably, the photo sensors may be disposed at equal intervals, which are smaller than the pitch shown in the prior art, 0044 The chutes and covers are also not limited to those in the embodiments but may be modified in the shape and size depending on the design applications. For example, the (upper) surface of the chute is not limited to a planer surface but may be arranged to configuration as denoted by a-1 or a-2 in Fig. 5A, having parallel ribs extending in the direction of movement of the objects and spaced at equal intervals of a desired width, thus ensuring smoothness in the downward movement of the objects. Alternatively, the chute may comprise a row of tubes having a four-sided shape or inverted U shape in the cross section, as denoted by a-3 or a-4 in Fig. 5A, and arranged to open at both, upper and lower, ends and extend along the downward movement of the objects. The chute may be shaped to have an outwardly or inwardly curved region at the lower end in the side elevation as denoted by 1b or 1b' in Fig. 5B. The covers are also not limited to those in the embodiments shown in Figs . 1 to 4 but may be shaped to have an inward projection, as shown in Fig. 5C, so that a narrow passage 2c or 2c' between the cover and the chute is provided at a lengthwise center or lowermost of the chute. Alternatively, the inward side of the covers is not limited to a planer surface but may be shaped with a row of inwardly projecting ribs 2d arranged at equal intervals along the widthwise direction of the chute to extend along the direction of downward movement of the objects and in parallel to each other as shown in Fig, 5D. 0045 Moreover, while the number of the chutes is, but not limited to, two at upper and lower levels in the another embodiment, it may be one or three or more. The two chutes at the upper and lower levels as illustrated in the another embodiment can permit the inspecting action to be repeated or two different inspecting actions to be conducted respectively for identifying defectives at higher accuracy. I CLAIM: 1. A color sorting apparatus for sorting colored objects by color, comprising : a chute arranged at an angle to the horizontal for permitting the objects to run downwardly from upper to lower and pop off from the lower end in a predetermined direction ; a cover provided at a distance from the surface of the chute to cover at least a portion of the surface of the chute ; an inspecting means provided at a distance from the lower end of the chute for monitoring the movement in the predetermined direction of the objects released from the lower end of the chute in order to measure the color of the objects ; a judging means electrically connected with the inspecting means for judging from a measurement of the color produced by the inspecting means whether or not the objects have a particular color; and a separating means provided at a distance from the lower end of the chute for blowing off the object which is judged by the judging means to have the particular color so that the object drops down along a route different from the movement in the predetermined direction, wherein the chute is a flat chute having a flat surface sized corresponding to the width for feeding the objects, and the cover is located at a distance from the flat surface of the chute, made of a sheet-like body covering at least a portion of the chute, and shaped for limiting the sloping movement of the objects so that the objects neatly run down along the flat surface of the chute. 2. A color sorting apparatus as claimed in claim 1, wherein the angle of the chute from the horizontal ranges from 60° to 85°. 3. A color sorting apparatus as claimed in claim 1 or 2, having a static eliminator provided above a means for feeding the objects at the upper end of the chute and arranged for eliminating static electricity charged on the objects. 4. A color sorting apparatus as claimed in any one of claims 1 to 3, wherein two or more of the chutes are provided from upper to lower, each chute accompanied with the cover, the inspecting means, and the separating means. 5. A color sorting apparatus, substantially as herein described, particularly with reference to the accompanying drawings. There is disclosed a color sorting apparatus for sorting objects which are relatively light, short, thin, and small in the mass and hardly sorted by any known manner. The color sorting apparatus comprises a chute 1 arranged at an angle a for permitting the objects W to run downwardly and pop off from the lower end in a predetermined direction, a cover 2 provided at a distance from the surface of the chute, to cover at least a portion of the surface of the chute, an inspecting means 3 provided at a distance from the lower end of the chute for monitoring the movement in the predetermined direction of the objects W released from the lower end of the chute in order to measure the color of the objects W, a judging means connected with the inspecting means for judging from a measurement of the color produced by the inspecting means whether or not the objects have a particular color, and a separating means 4 provided at a distance from the lower end of the chute for blowing off the object W which is judged by the judging means to have the particular color so that the object drops down along a route different from the movement in the predetermined direction. |
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872-KOL-2004-CORRESPONDENCE 1.1.pdf
872-KOL-2004-CORRESPONDENCE.pdf
872-kol-2004-granted-abstract.pdf
872-kol-2004-granted-claims.pdf
872-kol-2004-granted-correspondence.pdf
872-kol-2004-granted-description (complete).pdf
872-kol-2004-granted-drawings.pdf
872-kol-2004-granted-examination report.pdf
872-kol-2004-granted-form 1.pdf
872-kol-2004-granted-form 18.pdf
872-kol-2004-granted-form 2.pdf
872-kol-2004-granted-form 3.pdf
872-kol-2004-granted-form 5.pdf
872-kol-2004-granted-reply to examination report.pdf
872-kol-2004-granted-specification.pdf
Patent Number | 225989 | ||||||||
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Indian Patent Application Number | 872/KOL/2004 | ||||||||
PG Journal Number | 49/2008 | ||||||||
Publication Date | 05-Dec-2008 | ||||||||
Grant Date | 03-Dec-2008 | ||||||||
Date of Filing | 28-Dec-2004 | ||||||||
Name of Patentee | HATTORI MASARU | ||||||||
Applicant Address | 2, MIYANOGO, SHIRAKAWA, UJI-CITY, KYOTO 611-0022 | ||||||||
Inventors:
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PCT International Classification Number | B07C 5/342 | ||||||||
PCT International Application Number | N/A | ||||||||
PCT International Filing date | |||||||||
PCT Conventions:
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