Addressing a matrix device using electro-optical switching
First Claim
1. An addressable matrix device comprising a panel having a row and column matrix array of elements, and driving means for addressing the elements via sets of row and column address conductors of the panel, the driving means comprising a row address conductor drive circuit and a column address conductor drive circuit at least one of which comprises sequence generating means having a plurality of output stages associated with respective address conductors in a group of successive address conductors, and comprising an electro-optic switching arrangement having light sensitive means comprising a plurality of light sensitive switching elements integrated on the panel and a light emitting means comprising a plurality of light emitting elements arranged to cooperate with the light sensitive switching elements, the light sensitive switching elements being operable upon illumination to produce an output from each output stage and the light emitting elements being selectively operable to illuminate particular light sensitive switching elements in predetermined order so as to produce a sequence of outputs from the output stages, characterized in that each output stage comprises a set of two or more light sensitive switching elements each of which elements is arranged to be illuminated by a different light emitting element, in that the number of light emitting elements is at least two greater than the number of light sensitive switching elements in the set, and in that each light emitting element illuminates light sensitive switching elements associated with more than one output stage.
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Accused Products
Abstract
In an addressable matrix device, for example an active matrix liquid crystal display device comprising a panel (10) having a row and column array of addressable picture elements (12), in which the elements are addressed via sets of row and column address conductors (14,16) by row and column drive circuits (24,26) providing sequential outputs, at least one of the circuits (24,26) consists of a sequence generator (28,29) comprising an electro-optic switching arrangement having light sensitive means including light sensitive elements (42), e.g. photodiodes, integrated on the panel and controlling the outputs of individual output stages (38) and light emitting means (35) including a plurality of light emitting elements (36) cooperating with the light sensitive elements, the light emitting elements being selectively operable to produce a sequence of outputs from the output stages, for example in order to scan the row address conductors. The electro-optic switching arrangement requires comparatively few external connections to the panel and is of simple form so that high yields are obtained.
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Citations
10 Claims
- 1. An addressable matrix device comprising a panel having a row and column matrix array of elements, and driving means for addressing the elements via sets of row and column address conductors of the panel, the driving means comprising a row address conductor drive circuit and a column address conductor drive circuit at least one of which comprises sequence generating means having a plurality of output stages associated with respective address conductors in a group of successive address conductors, and comprising an electro-optic switching arrangement having light sensitive means comprising a plurality of light sensitive switching elements integrated on the panel and a light emitting means comprising a plurality of light emitting elements arranged to cooperate with the light sensitive switching elements, the light sensitive switching elements being operable upon illumination to produce an output from each output stage and the light emitting elements being selectively operable to illuminate particular light sensitive switching elements in predetermined order so as to produce a sequence of outputs from the output stages, characterized in that each output stage comprises a set of two or more light sensitive switching elements each of which elements is arranged to be illuminated by a different light emitting element, in that the number of light emitting elements is at least two greater than the number of light sensitive switching elements in the set, and in that each light emitting element illuminates light sensitive switching elements associated with more than one output stage.
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10. A liquid crystal display device comprising a matrix of picture elements arranged in rows and columns and comprising a row address conductor drive circuit and a column address conductor drive circuit at least one of which comprises a plurality of output stages associated with respective address conductors via electro-optical switching means which comprise light sensitive switching elements and light emitting elements arranged to cooperate with associated light sensitive switching elements to enable output stages individually, characterized in that each light emitting element is arranged to cooperate with light sensitive switching elements in several output stages, each output stage comprising at least two light sensitive switching elements associated with different light emitting elements, the total number of light emitting elements being at least two greater than the number of light sensitive switching elements in an output stage, and in that enabling of an output stage is dependent on the disposition of the light sensitive switching elements in an output stage relative to the light emitting elements.
Specification