EP0196889A2
Expired / Lapsed
EP
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Matrix-addressed liquid crystal display device
Assignee: Toshiba Corp
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Filing: 1986-03-27
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Granted: —
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Expires: 2006-03-27
Abstract
Abstract In a matrix-addressed liquid crystal display device a display (10) has a pair of substrates (30, 40) facing each other with liquid crystal cells arranged in n rows and m columns on one of the substrates (30). A switch is included in each cell in the form of a field effect transistor (20), and n address lines form a common connection for the gate electrodes of the field effect transistors (20) in each row and m signal lines form a common connection for the drain electrode or source electrode of the field effect transistors (20) in each column. A common electrode (22) is arranged on the other substrate (40) and a liquid crystal layer (23) interposed between the substrates. An address line drive circuit (11) supplies a sequential scanning signal to the n address lines, and a signal line drive circuit (12) supplies a display signal to the m signal lines. An asymmetrical display signal is produced by a polarity inversion circuit 13 so that the voltage applied across the liquid crystal leyer is controlled to be a pure AC signal with no DC component.
Inventors
- 👤 Koichi C/O Patent Division Kasahara
- 👤 Toshio C/O Patent Division Yanagisawa
- 👤 Motoji C/O Patent Division Kajimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:06
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G2320/00; G09G2320/02; G09G2320/0204; G09G2320/0219; G09G2320/0247; G09G3/3614
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
243 words
A matrix-addressed liquid crystal display device comprising: a pair of substrates (30),(40) facing each other; liquid crystal cells arranged in n rows and m columns on a first (30) of said pair of substrates including: (a) switches comprising a field effect transistor (20) with a gate, drain and source for each of said liquid crystal cells; (b) n address lines (Y (Y ) forming a common connection for said gates of said field effect transistors in each row; (c) m signal lines (X 1 ),...(X m ) forming a common connection for said drains or sources of said field effect transistors in each column; (d) a common electrode (22) arranged on the second (40) of said pair of substrates; and (e) a liquid crystal layer (23) interposed between said substrates; an address line drive circuit (11) supplying a sequential scanning signal to said n address lines; a signal line drive circuit (12) supplying a display signal to said m signal lines; polarity inversion circuit means (13) connected to said signal line drive circuit to supply to said drain or source said display signal having its polarity inverted in relation to alternate frame scanning periods; and characterized in that the voltage amplitude of said display signal of one polarity constituting the positive potential side with respect to a polarity inversion reference potential and the voltage amplitude of said display signal of the other polarity constituting the negative potential side are set at different velues.
Claim 2
Dependent Claim
243 words
A matrix-addressed liquid crystal display device comprising: a pair of substrates (30),(40) facing each other; liquid crystal cells arranged in n rows and m columns on a first (30) of said pair of substrates including: (a) switches comprising a field effect transistor (20) with a gate, drain and source for each of said liquid crystal cells; (b) n address lines (Y (Y ) forming a common connection for said gates of said field effect transistors in each row; (c) m signal lines (X 1 ),...(X m ) forming a common connection for said drains or sources of said field effect transistors in each column; (d) a common electrode (22) arranged on the second (40) of said pair of substrates; and (e) a liquid crystal layer (23) interposed between said substrates; an address line drive circuit (11) supplying a sequential scanning signal to said n address lines; a signal line drive circuit (12) supplying a display signal to said m signal lines; polarity inversion circuit means (13) connected to said signal line drive circuit to supply to said drain or source said display signal having its polarity inverted in relation to alternate frame scanning periods; and characterized in that the voltage amplitude of said display signal of one polarity constituting the positive potential side with respect to a polarity inversion reference potential and the voltage amplitude of said display signal of the other polarity constituting the negative potential side are set at different velues.
Claim 3
Dependent Claim
64 words
The matrix-addressed liquid crystal display device according to claim 1 wherein said field effect transistors comprise n channel field effect transistors, and the amplitude of said display signal of the one polarity constituting the positive potential side with respect to said polarity inversion reference potential is made smaller than the amplitude of said display signal of the other polarity constituting the negative potential side.
Claim 4
Dependent Claim
21 words
The matrix-addressed liquid crystal display device according to claim 2 wherein said n channel field effect transistor are thin film transistors.
Claim 5
Dependent Claim
33 words
The matrix-addressed liquid crystal device according to claim 1 wherein said field effect transistors are comprised of pairs of complementary field effect transistors comprised of n channel and p channel field effect transistors.
Claim 6
Dependent Claim
65 words
The matrix-addressed liquid crystal display device according to claim 1 wherein said field effect transistors comprise p channel field effect transistors, and the amplitude of the display signal voltage of the one polarity constituting the positive potential side with respect to said polarity inversion reference potential is made greater than the amplitude of the signal voltage of the other polarity constituting the negative potential side.
Claim 7
Dependent Claim
21 words
The matrix-addressed liquid crystal display device according to claim 4 wherein said p channel field effect transistors are thin film transistors.
Claim 8
Dependent Claim
37 words
The matrix-addressed liquid crystal display device according to claim 1 wherein the ratio of the display signal amplitudes at each polarity is set-so that the voltages applied to the liquid crystal layers have no DC voltage component.
Claim 9
Dependent Claim
35 words
The matrix-addressed liquid crystal display device according to claim 5 wherein the ratio of the greater to the lesser of the display signal amplitudes at each polarity is in the range of 1.5 to 3.
Claim 10
Dependent Claim
21 words
The matrix-addressed liquid crystal display device according to claim 5 wherein said source of drain is coextensive with the display electrode.
Claim 11
Dependent Claim
207 words
A matrix-addressed liquid crystal display device comprising: a liquid crystal display including: (a) a pair of opposed substrates (30,40) (b) n rows by m columns of switches on one substrate (30), each including at least one field effect transistor; (c) n address lines (Y 1 ),....(Y n ) forming a common connection for gates of the field effect transistors in each row; (d) m signal lines (X 1 ),....(X m ) forming a common connection for drains or sources of the field effect transistors in each column; (e) a common electrode (22) arranged on the second (40) of said pair of substrates; and (f) a liquid crystal layer (23) interposed between said substrates; an address line driving circuit (11) for supplying sequentially to said address lines of the display a scanning signal, a signal line driving circuit (2) for supplying a display signal to said display lines of the display; polarity inversion circuit means (13) for supplying to the signal line drive circuit (12) a display signal, the polarity of which is inverted about a reference potential during each scanning period, and characterized in that the magnitude of the supplied display signal with respect to the polarity immersion reference signal differs between successive positive and negative inversions.
Claim 12
Dependent Claim
207 words
A matrix-addressed liquid crystal display device comprising: a liquid crystal display including: (a) a pair of opposed substrates (30,40) (b) n rows by m columns of switches on one substrate (30), each including at least one field effect transistor; (c) n address lines (Y 1 ),....(Y n ) forming a common connection for gates of the field effect transistors in each row; (d) m signal lines (X 1 ),....(X m ) forming a common connection for drains or sources of the field effect transistors in each column; (e) a common electrode (22) arranged on the second (40) of said pair of substrates; and (f) a liquid crystal layer (23) interposed between said substrates; an address line driving circuit (11) for supplying sequentially to said address lines of the display a scanning signal, a signal line driving circuit (2) for supplying a display signal to said display lines of the display; polarity inversion circuit means (13) for supplying to the signal line drive circuit (12) a display signal, the polarity of which is inverted about a reference potential during each scanning period, and characterized in that the magnitude of the supplied display signal with respect to the polarity immersion reference signal differs between successive positive and negative inversions.
References Cited (Backward Citations)
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