EP0486284A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electro-optical device and driving method for the same
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1991-11-13
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Granted: —
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Expires: 2011-11-13
Abstract
Abstract A display and a driving method for the same capable of constructing clear visual images is described. In the display, a plurality of conductive pads are opposed to a back electrode with a light influencing medium, such as a liquid crystal layer, disposed therebetween. Control signals are supplied to the conductive pads through complementary transistors comprising a p-channel field effect transistor and an n-channel field effect transistor connected between VDD and VSS lines of a control circuit, which also supplies a bias voltage to the back electrode and gate control signals to the gate terminals of the p-channel field effect transistor and the n-channel field effect transistor. During operation, the bias voltage is inverted in order to invert the polarity of control signals applied across the light influencing medium.
Inventors
- 👤 Shunpei Yamazaki
- 👤 Akira Mase
- 👤 Masaaki Hiroki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 04:26
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/13624; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G3/3659; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/134345; G02F1/136245; G09G2300/00; G09G2300/08; G09G2300/0809; G09G2300/0823; G09G2330/00; G09G2330/08; G09G3/3614
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
65 words
An electro-optical device comprising: a pair of substrates; a light influencing layer disposed between said substrates; a plurality of pixels defined by conductive pads formed on an inside surface of at least one of said substrates and provided with associated switching elements; and a driving circuit for supplying control signals to said conductive pads through said switching elements; wherein said switching elements comprise complementary transistors.
Claim 2
Dependent Claim
65 words
An electro-optical device comprising: a pair of substrates; a light influencing layer disposed between said substrates; a plurality of pixels defined by conductive pads formed on an inside surface of at least one of said substrates and provided with associated switching elements; and a driving circuit for supplying control signals to said conductive pads through said switching elements; wherein said switching elements comprise complementary transistors.
Claim 3
Dependent Claim
35 words
An electro-optical device as claimed in claim 1 wherein said complementary transistors each comprise a p-channel thin-film field effect transistor and an n-channel thin-film field effect transistor which are connected together at their drain terminals.
Claim 4
Dependent Claim
39 words
An electro-optical device as claimed in claim 2 wherein said complementary transistors are connected between a first control line and a second control line supplied with a first control signal and a second control signal of different voltage level.
Claim 5
Dependent Claim
31 words
An electro-optical device as claimed in claim 2 wherein the gate terminals of said n-channel field effect transistor and said p-channel field effect transistor are connected to a third control line.
Claim 6
Dependent Claim
18 words
An electro-optical device as claimed in any preceding claim wherein said pixels are arranged in a matrix array.
Claim 7
Dependent Claim
30 words
An electro-optical device as claimed in any preceding claim wherein the photosensitivity of the channel regions of said complementary transistors is spoiled by virtue of being doped with an impurity.
Claim 8
Dependent Claim
17 words
An electro-optical device as claimed in claim 6 wherein said spoiling impurity comprises oxygen, carbon, or nitrogen.
Claim 9
Dependent Claim
25 words
An electro-optical device as claimed in any preceding claim wherein said complementary transistors comprise two pairs of complementary transistors for each pixel of said display.
Claim 10
Dependent Claim
27 words
An electro-optical device as claimed in claim 8 wherein each conductive pad comprises two individual portions which are connected with said two pairs of complementary transistors respectively.
Claim 11
Dependent Claim
19 words
An electro-optical device as claimed in any preceding claim wherein said light influencing layer is a liquid crystal layer.
Claim 12
Dependent Claim
16 words
An electro-optical device as claimed in any preceding claim wherein said electro-optical device is a display.
Claim 13
Independent Claim
171 words
A method of driving an electro-optical device comprising: a light influencing layer; a plurality of electrode pads located adjacent to said layer at one side of said layer in order to define a plurality of pixels in said layer; a back electrode adjacent to said layer at the other side of said layer in order to apply to said layer at the pixels voltages between said back electrode and said electrode pads; and a control circuit for supplying control signals to said electrode pads and said back electrode, said method comprising: applying a bias voltage to said back electrode; and applying control signals to said electrode pads in order to apply voltages between said back electrode and said electrode pads across said layer; and wherein the polarities of said bias voltage and said control signals are periodically inverted at the same time during operation of said electro-optical device in order that the effects of the voltages across said layer at each pixel substantially cancel out during operation of said electro-optical device.
Claim 14
Independent Claim
171 words
A method of driving an electro-optical device comprising: a light influencing layer; a plurality of electrode pads located adjacent to said layer at one side of said layer in order to define a plurality of pixels in said layer; a back electrode adjacent to said layer at the other side of said layer in order to apply to said layer at the pixels voltages between said back electrode and said electrode pads; and a control circuit for supplying control signals to said electrode pads and said back electrode, said method comprising: applying a bias voltage to said back electrode; and applying control signals to said electrode pads in order to apply voltages between said back electrode and said electrode pads across said layer; and wherein the polarities of said bias voltage and said control signals are periodically inverted at the same time during operation of said electro-optical device in order that the effects of the voltages across said layer at each pixel substantially cancel out during operation of said electro-optical device.
Claim 15
Dependent Claim
16 words
A method as claimed in claim 12 wherein said polarities are inverted once per several frames.
Claim 16
Dependent Claim
16 words
A method as claimed in claim 12 or 13 wherein said electro-optical device is a display.
Claim 17
Dependent Claim
21 words
A method as claimed in claim 12 or 13 or 14 wherein said light influencing layer is a liquid crystal layer.
Claim 18
Dependent Claim
18 words
A method as claimed in claim 15 wherein said liquid crystal layer is a nematic liquid crystal layer.
Claim 19
Independent Claim
46 words
A method as claimed in any of claims 12 to 16 wherein said layer is subjected to alternating voltages at all the pixels which are actuated and not actuated, the amplitude of said alternating voltages being smaller than that of the threshold voltage of said layer.
Claim 20
Dependent Claim
72 words
A liquid crystal device comprising: a pair of substrates, at least one of which is transparent; a liquid crystal layer disposed between said substrates; a plurality of conductive pads formed on an inner surface of at least one of said substrates in order to define a plurality of pixels in said liquid crystal device; and a control circuit for supplying control signals to said conductive pads through switching elements comprising complementary transistors.
Claim 21
Dependent Claim
72 words
A liquid crystal device comprising: a pair of substrates, at least one of which is transparent; a liquid crystal layer disposed between said substrates; a plurality of conductive pads formed on an inner surface of at least one of said substrates in order to define a plurality of pixels in said liquid crystal device; and a control circuit for supplying control signals to said conductive pads through switching elements comprising complementary transistors.
Claim 22
Dependent Claim
44 words
A liquid crystal device as claimed in claim 18wherein a pair of said complementary transistors are provided for each pixel and each pair comprises a p-channel field effect transistor and an n-channel field effect transistor connected at their drain terminals to a corresponding pad.
Claim 23
Dependent Claim
77 words
A liquid crystal device as claimed in claim 19 wherein said control circuit supplies first, second, and third control signals to each of said complementary transistors, said first control signal being supplied to the source terminal of said p-channel field effect transistor, said second control signal being supplied to the source terminal of said n-channel field effect transistor and said third control signal being supplied to the gate terminals of said n-channel and p-channel field effect transistors.
Claim 24
Dependent Claim
33 words
A liquid crystal device as claimed in any of claims 18 to 20 further comprising a back electrode forced on the inside surface of one of said substrates opposed to said conductive pads.
References Cited (Backward Citations)
No citation records indexed.
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