The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 29, 1986
Filed:
Apr. 12, 1984
Dayton D Eden, Dallas, TX (US);
LTV Aerospace and Defense Company, Dallas, TX (US);
Abstract
A random access memory device is disclosed which utilizes phase change materials. The memory device includes two overlapping films of a phase change material which exhibits an optically discernible phase change at any portion thereof which is subjected to a selected external stimulus and which exhibits a hysteresis effect such that any such portion is substantially unchanged after the external stimulus is removed. Various phase change materials are disclosed which respond to changes in pressure, temperature or electric field intensities to vary the transmission characteristics of a selected portion of a film of such material from substantially opaque to translucent. One of the two overlapping films is then utilized to record digital data by changing the phase of the material at selected portions thereof. A single selected portion of the second film is then rendered translucent and utilized in conjunction with a powerful light source and a photodetector to ascertain the phase of a particular portion of the first film which underlies the single selected portion of the second film.