| 摘要 |
A driving apparatus allows simple detection of the light writing characteristic of light writing means, such as a CRT, without detaching the light writing means from the liquid crystal light valve. A display apparatus uses such a photoconductive liquid crystal light valve. The driving apparatus applies a drive voltage signal from a drive voltage source across two electrodes of a photoconductive liquid crystal light valve having a liquid crystal layer, a photoconductive layer and the two electrodes arranged to sandwich the liquid crystal layer and photoconductive layer and allows a writing light to be incident upon the photoconductive layer by light writing means coupled to a writing side, and comprises detection means for detecting an impedance across the two electrodes. The apparatus generates an adjusting video signal having white and black levels, supplies the adjusting video signal as an input video signal to video signal amplifying means, and compares the levels of detection outputs of writing light intensity detection means at times of generation of the adjusting video signals of the white level and the black level, with reference levels corresponding to the white and black levels. The offset and gain of the video signal amplifying means are changed in accordance with the comparison outputs of the comparing means.
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