EP0364307A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for displaying different shades of gray on a liquid crystal display
Assignee: Compaq Computer Corp
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Filing: 1989-10-16
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Granted: —
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Expires: 2009-10-16
Abstract
Abstract A method and apparatus are disclosed which provide a means for both spatially and temporally resolving the on/off states of a two-state display device such as a liquid crystal display to provide apparent shades of gray. A particular feature of this method is that the cycling between on and off states is not performed in a discernible pattern. Rather, a pseudo-random pattern is utilized which repeats only after many cycles. Additionally, when the method disclosed herein is utilized, adjacent pixels, when selected to display the same shade of gray, do not cycle on and off in synchronization, but rather utilize out-of-phase cycling patterns. This spatial resolution reduces perceived flicker in the display and provides a more stable image. In one embodiment, eight shades of gray are provided. The shades are generated by cycling individual pixels such that when averaged over time, they are: always off; on 20% of the time; 33% of the time; 40% of the time; 60% of the time; 67% of the time; 80% of the time; or, on at all times.
Inventors
- 👤 James H. Garrett
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 11:56
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; H; H04; H04N; H04N3/00; H04N3/10; H04N3/12; H04N3/127; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G2320/00; G09G2320/02; G09G2320/0247; G09G3/2007; G09G3/2018; G09G3/2022; G09G3/2025; G09G3/2044; G09G3/2051
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
61 words
A method for driving an LCD screen dot to simulate a single one of a plurality of up to eight different colours, comprising the steps of: c selecting one of the colours; locating the one colour in the table shown in Figure 4; and, selectively driving the screen dot ON and OFF as indicated in figure 4 for the one colour.
Claim 2
Independent Claim
61 words
A method for driving an LCD screen dot to simulate a single one of a plurality of up to eight different colours, comprising the steps of: c selecting one of the colours; locating the one colour in the table shown in Figure 4; and, selectively driving the screen dot ON and OFF as indicated in figure 4 for the one colour.
Claim 3
Independent Claim
54 words
A method of driving an LCD display to enable each pixel to simulate one of a plurality of colours, by representing the colours by different shades of a single colour, the method comprising driving the pixels such that consecutive adjacent lines of pixels do not display the same ON-OFF pattern at any one time.
Claim 4
Independent Claim
54 words
A method of driving an LCD display to enable each pixel to simulate one of a plurality of colours, by representing the colours by different shades of a single colour, the method comprising driving the pixels such that consecutive adjacent lines of pixels do not display the same ON-OFF pattern at any one time.
Claim 5
Independent Claim
54 words
A method of driving an LCD display to enable each pixel to simulate one of a plurality of colours, by representing the colours by different shades of a single colour, the method comprising driving the pixels such that any given line of pixels does not display the same ON-OFF pattern in consecutive time frames.
Claim 6
Independent Claim
54 words
A method of driving an LCD display to enable each pixel to simulate one of a plurality of colours, by representing the colours by different shades of a single colour, the method comprising driving the pixels such that any given line of pixels does not display the same ON-OFF pattern in consecutive time frames.
Claim 7
Dependent Claim
43 words
An LCD screen display including means for representing colours by different shades of a single colour, and means for driving the pixels of the display such that consecutive adjacent lines of pixels do not display the same ON-OFF pattern at any one time.
Claim 8
Dependent Claim
43 words
An LCD screen display including means for representing colours by different shades of a single colour, and means for driving the pixels of the display such that consecutive adjacent lines of pixels do not display the same ON-OFF pattern at any one time.
Claim 9
Dependent Claim
43 words
An LCD screen display including means for representing colours by different shades of a single colour, and means for driving the pixels of the display such that any given line of pixels does not display the same ON-OFF pattern in consecutive time frames.
Claim 10
Dependent Claim
43 words
An LCD screen display including means for representing colours by different shades of a single colour, and means for driving the pixels of the display such that any given line of pixels does not display the same ON-OFF pattern in consecutive time frames.
Claim 11
Dependent Claim
66 words
An LCD screen display including means for driving an LCD screen dot to simulate a single one of a plurality of up to eight different colours; means for selecting one of the colours; means for locating the one colour in the table shown in Figure 4; and, means for selectively driving the screen dot ON and OFF as indicated in figure 4 for the one colour.
Claim 12
Dependent Claim
66 words
An LCD screen display including means for driving an LCD screen dot to simulate a single one of a plurality of up to eight different colours; means for selecting one of the colours; means for locating the one colour in the table shown in Figure 4; and, means for selectively driving the screen dot ON and OFF as indicated in figure 4 for the one colour.
References Cited (Backward Citations)
No citation records indexed.
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