| 摘要 |
PROBLEM TO BE SOLVED: To decrease the circuit scale of a liquid crystal display unit (LCD) driving circuit. SOLUTION: Luminance data Di of one line stored in a data latch 50 are converted by a DA converter 60A into a luminance signal Bi, which is supplied to an output buffer 70A. The output buffer 70A is equipped with switch parts 71 and 74 for connection switching. When a polarity control signal POL is at "H", an odd-numbered luminance signal Bi is amplified by a noninverting amplifier 72 and applied to an odd-numbered X electrode 11<SB>i</SB>and an even-numbered luminance signal Bi+1 is amplified by an inverting amplifier 73 and applied to an even-numbered X electrode 11<SB>i+1</SB>. When the polarity control signal POL is at "L", the luminance signal Bi is amplified by the inverting amplifier 73 and applied to the X electrode 11<SB>i</SB>and the luminance signal Bi+1 is amplified by the noninverting amplifier 72 and applied to the X electrode 11<SB>i+1</SB>. The DA converter 60A does not generate a negative luminance signal Bi, so the circuit scale of this DA converter 60A can be halved. COPYRIGHT: (C)2004,JPO&NCIPI
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