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:
Oct. 19, 1976
Filed:
Jan. 23, 1975
Laurence G Walker, Dover, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A non-volatile charge storage element wherein long-term charge storage occurs in the interface states of the element. Charge is stored at low applied voltages (.ltoreq. 10 volts) in short times (.ltoreq. 1 microseconds) and is stored as long as 10.sup.5 seconds or longer. The states are emptied by exposure to radiation in the visible or the near infrared regions of the spectrum. There are described, also, an information storage device employing a plurality of such elements and a solid-state camera wherein the image screen includes a plurality of such elements. Changes in the charge storage in each of the elements results in changes in the capacitance of the element; either the capacitance of the element or its charge state is sensed to indicate the state of the element for information storage purposes. In one embodiment, thin film techniques are employed and a change in transconductance is detected to sense the charge state.