Browse Prior Art Database

Electron Beam Addressable Liquid Crystal Display with Storage Capability

IP.com Disclosure Number: IPCOM000079411D
Original Publication Date: 1973-Jun-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 44K

Publishing Venue

IBM

Related People

Chang, IF: AUTHOR

Abstract

The usefulness of display devices with storage capability is obvious, particularly in large-capacity complex information display. However, available storage display devices suffer from serious limitations, particularly as pertains to low brightness and low contrast.

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Electron Beam Addressable Liquid Crystal Display with Storage Capability

The usefulness of display devices with storage capability is obvious, particularly in large-capacity complex information display. However, available storage display devices suffer from serious limitations, particularly as pertains to low brightness and low contrast.

The figure shows a display tube arrangement, whereby both a storage capability and high-contrast ratio are obtained. In addition, in accordance with the arrangement, high resolution and low-power consumption are achieved. The structure in the figure basically involves a cathode-ray tube, analogous to commercially available storage-type tubes, with the tube containing a writing gun and a pair of flood guns. In typical fashion, the writing gun and flood guns act to provide an electron Source.

The faceplate of the tube contains two parts. The inner part, facing the electron sources, includes an insulating layer (designated dielectric substrate) and a dielectric layer bistable target. Any of a variety of materials may be employed as the dielectric layer bistable target, so long as such material is dielectric in nature and produces some degree of secondary emission in response to electron bombardment.

The dielectric substrate, as shown, has a two-dimensional array of conducting pins extending therethrough from the bistable target to the liquid- crystal material in contact with the substrate. The outer part of the faceplate is a composite structure of a layer of transparent conducting material in contact with a glass faceplate. The transparent conducting layer may, for example, be tin oxide. As shown, the outer part of the tube faceplate is separated from the inner part of the tube faceplate by a space which is filled with liquid-crystal material, before sealing the parts together. Alternatively, a refillable arrangement (for liquid-crystal refill) can be made on the faceplate.

Based on the principle of bistable equilibrium potentials of an electron bombarded floating layer, local areas of the dielectric layer bistable target can be maintained at either the collector potential or the fl...