| Title of Invention | "PORTABLE WIRELESS COMMUNICATIONS UNIT AND LIGHTING CONTROL METHOD THEREOF" |
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| Abstract | A backlight for a liquid crystal display in TMDA type portable telephones is driven by PWM. A register for holding the PWM-drive pulse width setting values and a decoder for decoding counted values in a base counter for counting the basic timing of three slots for receive, idle and transmit. A lighting control circuit Scb is provided to cut off the supply of power to the backlight incandescent lamp from the secondary battery during the transmit time slot. The power cutoff period by means of the Scb signal may be extended beyond the transmit time slot depending on the voltage detected at the secondary battery terminal by means of a voltage sensor circuit. Consequently additional voltage drops in a battery can be avoided during transmission in a TMDA type portable telephone by switching off a light such as a backlight for a liquid crystal display. |
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664-del-1997-complete specification (as files).pdf
664-del-1997-complete specification (granted).pdf
664-del-1997-correspondence-others.pdf
664-del-1997-correspondence-po.pdf
664-del-1997-description (complete).pdf
| Patent Number | 215884 | ||||||||||||
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| Indian Patent Application Number | 0664/DEL/1997 | ||||||||||||
| PG Journal Number | 12/2008 | ||||||||||||
| Publication Date | 21-Mar-2008 | ||||||||||||
| Grant Date | 05-Mar-2008 | ||||||||||||
| Date of Filing | 17-Mar-1997 | ||||||||||||
| Name of Patentee | SONY CORPORATION | ||||||||||||
| Applicant Address | 7-35, KITASHINAGAWA 6 - CHOME SHINAGAWA KU TOKYO JAPAN | ||||||||||||
Inventors:
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| PCT International Classification Number | H04M 1/20 | ||||||||||||
| PCT International Application Number | N/A | ||||||||||||
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PCT Conventions:
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