| 摘要 |
An image display apparatus has a light valve that spatially modulates light emitted by a light source according to a gamma-corrected video signal consisting of successive video fields, by modulating the light pulse widths of individual picture elements in each field. The spatially modulated light is projected onto a screen. A light source driver changes the intensity of the light source as a function of elapsed time in each video field so as to approximately cancel the effect of the gamma correction. Only a slight reverse gamma correction is then needed to produce the correct brightness relationship between the video signal and the projected image. Consequently, fewer gradation levels are lost than in a conventional reverse gamma correction, and the picture quality in low-brightness areas of the projected image is improved.
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