- 专利标题: Multiplexed display element sequential color LCD panel
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申请号: US771191申请日: 1996-12-20
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公开(公告)号: US5977942A公开(公告)日: 1999-11-02
- 发明人: Dale S. Walker , Richard M. Knox
- 申请人: Dale S. Walker , Richard M. Knox
- 申请人地址: TX Houston
- 专利权人: Compaq Computer Corporation
- 当前专利权人: Compaq Computer Corporation
- 当前专利权人地址: TX Houston
- 主分类号: G09G3/20
- IPC分类号: G09G3/20 ; G09G3/36 ; H04N5/66 ; H04N5/74 ; H04N9/30
摘要:
In a color sequential system using LCDs, the LCD must operate faster than the frame rate because red, green, and blue are done sequentially. Ferroelectric LCDs can do this, but they are not analog devices and so cannot provide analog display levels. Instead, a pulse width modulation (PWM) technique is used. In the system of the present invention, each pixel has three storage devices to hold RGB analog levels. A latch is used to load these values in parallel. Then an analog 3:1 multiplexer is used to select the proper storage device for the current sequential color. The multiplexer output goes to a comparator, which has a sawtooth waveform input at much faster than the frame rate. The comparator output changes with the sawtooth level, so that PWM control is provided for each pixel. As an alternative, standard analog LCD pixels can be sequentially switched between three color input storage devices.
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