EP0271960A2
Expired / Lapsed
EP
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Matrix display devices
Assignee: Philips Electronics UK Ltd
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Filing: 1987-12-14
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Granted: —
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Expires: 2007-12-14
Abstract
Abstract A matrix display device, suitable for displaying TV pictures, has a plurality of display elements (20) arranged in a matrix array and defined by electrodes (33 and 41) on opposing substrates with, for example, liquid crystal material (32) therebetween and with the display elements being individually controllable via switching elements (40) such as thin film transistors. Each display element is sub-divided into a plurality of sub-elements using a plurality of sub-electrodes (55) on one substrate which are each connected via a series capacitor (C X ) to a switching element, the ratio of capacitances of the sub-elements to their respective series capacitors differing from one another. As applied voltage is increased, progressively more sub-elements are caused to change state providing in effect various grey scale levels. Display materials having comparatively sharp switching characteristics can be used.
Inventors
- 👤 Keith Harlow Nicholas
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 18:29
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; H; H04; H04N; H04N3/00; H04N3/10; H04N3/12; H04N3/127; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/13624; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/134345; G02F1/136213
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
127 words
A matrix display device comprising a plurality of display elements arranged in a matrix and defined by respective electrodes carried on opposed substrates between which is disposed an electrically excitable display material which, together with the electrodes, exhibits capacitance in operation, and in which the display elements are controlled by selectively applying voltage to the respective electrodes via respective switching means carried on one substrate characterised in that the display element electrodes associated with the switching means on the one substrate each comprise a plurality of separate electrodes defining sub-elements which separate electrodes are each capacitively coupled to the switching means by means of a series capacitor and in that the ratios of the capacitances of the sub-elements and their respective series capacitors differ from one another.
Claim 2
Dependent Claim
127 words
A matrix display device comprising a plurality of display elements arranged in a matrix and defined by respective electrodes carried on opposed substrates between which is disposed an electrically excitable display material which, together with the electrodes, exhibits capacitance in operation, and in which the display elements are controlled by selectively applying voltage to the respective electrodes via respective switching means carried on one substrate characterised in that the display element electrodes associated with the switching means on the one substrate each comprise a plurality of separate electrodes defining sub-elements which separate electrodes are each capacitively coupled to the switching means by means of a series capacitor and in that the ratios of the capacitances of the sub-elements and their respective series capacitors differ from one another.
Claim 3
Dependent Claim
36 words
A matrix display device according to Claim 1, characterised in that the number of the plurality of sub-elements of each display element is chosen in accordance with the number of grey scale levels to be displayed.
Claim 4
Dependent Claim
80 words
A matrix display device according to Claim 1 or Claim 2, characterised in that in addition to the plurality of sub-elements, each display element includes a further one or more sub-elements which are capacitively coupled by means of a series capacitor to the switching means with the ratios the capacitances of the further one or more sub-elements and their respective series capacitors being the same as one or respective ones of those ratios associated with the said plurality of sub-elements.
Claim 5
Dependent Claim
45 words
A matrix display device according to any one of Claims 1 to 3, characterised in that the respective areas of the said plurality of electrodes of each display element vary with respect to one another in accordance with the grey scale levels to be displayed.
Claim 6
Dependent Claim
26 words
A matrix display device according to Claim 4, characterised in that the respective areas of the electrodes of successively switched sub-elements have an approximately logarithmic relationship.
Claim 7
Dependent Claim
32 words
A matrix display device according to any one of Claims 1 to 5, characterised in that the series capacitors of each display element are arranged adjacent the edge of the display element.
Claim 8
Dependent Claim
37 words
A matrix display device according to any one of Claims 1 to 6, characterised in that the series capacitors associated with the sub-elements of each display element are connected to the output of a common switching means.
Claim 9
Dependent Claim
97 words
A matrix display device according to Claim 7, characterised in that the plurality of electrodes of each of the display elements are arranged in a planar array and are each connected to a respective conductive layer constituting part of their series capacitor adjacent to the periphery of the display element and in that the output of the switching means is connected to a conductive strip which extends over the conductive layers associated with the plurality of electrodes and is insulated therefrom, the conductive layers and the respective overlying portions of the conductive strip constituting the series capacitors.
Claim 10
Dependent Claim
27 words
A matrix display device according to Claim 8, characterised in that each of said conductive layers is formed as an extension of the electrode and integrally therewith.
Claim 11
Dependent Claim
40 words
A matrix display device according to Claim 8 or Claim 9, characterised in that each display element is substantially rectangular in shape and in that said conductive strip of each display element extends adjacent two edges of the display element.
Claim 12
Dependent Claim
50 words
A matrix display device according to any one of Claims 1 to 6, characterised in that a plurality of separate switching means are provided for each display element, the outputs of the switching means being connected to a respective one or more of the series capacitors of the display element.
Claim 13
Dependent Claim
97 words
A matrix display device according to Claim 11, characterised in that the plurality of electrodes of each of the display elements are arranged in a planar array and are each connected to a respective conductive layer constituting part of their series capacitor adjacent to the periphery of the display element and in that the outputs from the plurality of switching means are connected to respective conductors which extend over a respective one or more of said conductive layers and are insulated therefrom, the conductive layers and the respective overlying portions of the conductors constituting the series capacitors.
Claim 14
Dependent Claim
27 words
A matrix display device according to Claim 12, characterised in that the series capacitors of each display element are arranged adjacent the edge of the display element.
Claim 15
Dependent Claim
23 words
A matrix display device according to any one of Claims 1 to 13, characterised in that the display material comprises liquid crystal material.
Claim 16
Dependent Claim
23 words
A matrix display device according to any one of Claims 1 to 14, characterised in that the switching means comprise thin film transistors.
Claim 17
Dependent Claim
29 words
A matrix display device according to any one of Claims 1 to 16, characterised in that an electrode common to all display elements is carried on the other substrate.
References Cited (Backward Citations)
No citation records indexed.
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