Devices and process for producing microfilm and microfiche records
US5157528A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1989 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | Jun 21, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C7/005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An updatable optical storage device, which may be in microfiche configuration, includes two electrically conductive layers (2,6) between which a layer (5) of a liquid crystal storage material and a layer (3) of a photoconductive material are sandwiched. In order to record an image on the device, the image is projected on to the photoconductive layer through one of the conductive layers, a voltage is applied between the conductive layers, and the storage material is heated at least over regions where the image is to be stored. Projection of the image is continued until the storage material has cooled. The storage material may, for example, be a liquid crystal polymer or a glassy nematic liquid crystal material. The process can be repeated any number of times to update any part or all of the iamge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.