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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsYasuaki Muto, Hiroshi Miyai, Akio Takimoto, Yasunori Kuratomi, Toshikazu Kawakami, Hiroshi Noguchi
Estimating the term…
In a projection type video display device comprising a light writing type spacial light modulator, disturbances brought about by a resetting pulse and appearing in a projected picture as a black belt or beat are prevented. This is accomplished by causing the resetting pulse, which is to withdraw electric charges produced by incoming writing light and accumulated in spacial light modulator, to occur within a vertical blanking period synchronized with vertical synchronization signal. Further, by changing the pulse width and the voltage of the resetting pulse in accordance with vertical synchronization frequency, pictures of a certain fixed brightness are made available against various vertical synchronization frequencies; and even with a high vertical synchronization frequency, projected pictures are never annoyed by such disturbance that is caused by a resetting pulse dislocated out of the vertical blanking period. Further, by controlling the adjustments of the writing voltage to be applied to the spacial light modulator during the writing period and the resetting voltage to be applied to the spacial light modulator during the resetting period, the spread in characteristics of the spacial light modulator is compensated to provide a certain fixed contrast and .gamma. characteristic. Furthermore, in a video display device for full-color display, writing voltage and resetting voltage can be established independently corresponding to the respective three RGB primary colors, video outputs of any desired color temperature are obtainable by adjusting the balance of light emission among the three RGB colors.
A video display device comprising:
A video display device comprising:
A video display device comprising:
Dependencies are inferred from the claim text.