EP0357463A2
Expired / Lapsed
EP
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Display device
Assignee: Sharp Corp
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Filing: 1989-09-04
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Granted: —
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Expires: 2009-09-04
Abstract
Abstract Gradation display is demanded in the display device for binary display by the intensity of electric field, possessing a threshold voltage for display operation, such as liquid crystal display device. Various methods have been proposed to realize this but they have their own problems, such as necessity of advanced high precision machining and requirement of extremely high response speed. In the invention disclosed herein, display electrode and insulation layer are formed on a pair of substrates, and a display layer is placed between insulation layers to compose a display device. In this display device, plural display picture elements are set depending on the arrangement state of the display electrodes. In the display picture elements, divisions are set in insualtion layer, and different dielectric constants are set for each division. Therefore, the display device has a different impedance in every division within the display picture element, and the apparent threshold voltage of each division may be varied. As a result, gradations corresponding to the number of divisions within each display picture element may be displayed.
Inventors
- 👤 Tomoaki Kuratate
- 👤 Mitsuhiro Koden
- 👤 Hiroshi Hamada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:53
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133345; G02F1/1343; G02F1/134309; G02F1/134345; G02F1/136; G02F1/1362; G02F1/136213; G02F2203/00; G02F2203/30
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
111 words
A display device having plural arrays of unit display regions comprising: at least a pair of electric insulating substrates having conductive films for defining the unit display regions, between which is placed a display layer possessing the threshold voltage for changing over the active state/inactive state, formed on the mutually confronting surfaces thereof, and electric insulating films formed on the mutually confronting surface of the electric insulating substrates on which the conductive films are formed, wherein the ratio of the impedance of the electric insulating film of at least one electric insulating substrate to the impedance of the display layer is plural and mutually different values within each unit display region.
Claim 2
Dependent Claim
111 words
A display device having plural arrays of unit display regions comprising: at least a pair of electric insulating substrates having conductive films for defining the unit display regions, between which is placed a display layer possessing the threshold voltage for changing over the active state/inactive state, formed on the mutually confronting surfaces thereof, and electric insulating films formed on the mutually confronting surface of the electric insulating substrates on which the conductive films are formed, wherein the ratio of the impedance of the electric insulating film of at least one electric insulating substrate to the impedance of the display layer is plural and mutually different values within each unit display region.
Claim 3
Dependent Claim
34 words
A display device according to claim 1, wherein the film thickness of the electric insulating film formed between the conductive film and display layer is selected to be equal in each unit display region.
Claim 4
Dependent Claim
36 words
A display device according to claim 1, wherein the distribution state of the impedance within each unit display region is selected in different states at both sides of each electric insulating substrate holding the display layer.
Claim 5
Dependent Claim
29 words
A display device according to claim 1, wherein the distribution of impedance in each unit display region is set for at least one side of the electric insulating substrates.
Claim 6
Dependent Claim
39 words
A display device according to claim 1, wherein the distribution of impedance within the unit display region based on the electric insulating film layer formed between the conductive film and display layer is selected so as to vary continuously.
Claim 7
Dependent Claim
36 words
A display device according to claim 1, wherein the distribution of impedance on the basis of the electric insulating film layer formed between the conductive film and display layer is selected so as to vary discontinuously.
Claim 8
Dependent Claim
36 words
A display device according to claim 1, wherein plural layers of insulating film are formed between the conductive film and display layer, and shape of each insulating film is selected so as to be mutually different.
Claim 9
Dependent Claim
32 words
A display device according to claim 1 or 7, wherein any one of electric insulating film layer and insulating layer formed on the electric insulating substrate is made of an organic compound.
Claim 10
Dependent Claim
37 words
A display device according to claim 1,2,3,4,5,6,7 or 8, wherein each unit display region contains an electric insulating film formed between the conductive film and display layer and containing a portion individually possessing mutually different dielectric constant.
Claim 11
Dependent Claim
19 words
A display device according to claim 1, wherein the display layer is composed of twisted nematic liquid crystal material.
Claim 12
Dependent Claim
19 words
A display device according to claim 1, wherein the display layer is composed of supertwisted nematic liquid crystal material.
Claim 13
Dependent Claim
18 words
A display device according to claim 1, wherein the display layer is composed of ferroelectric liquid crystal material.
Claim 14
Dependent Claim
72 words
A display device wherein plural picture element regions present locally different impedance to applied display driving signals whereby the provision of a local display is made dependent upon the relationship between the electric signal applied locally to a switchable display layer and the switching threshold voltage of the display layer at such location, such locally applied signal being dependent upon the local impedance and upon the magnitude of the display device signal.
Claim 15
Dependent Claim
72 words
A display device wherein plural picture element regions present locally different impedance to applied display driving signals whereby the provision of a local display is made dependent upon the relationship between the electric signal applied locally to a switchable display layer and the switching threshold voltage of the display layer at such location, such locally applied signal being dependent upon the local impedance and upon the magnitude of the display device signal.
References Cited (Backward Citations)
No citation records indexed.
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