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:
Jan. 07, 1992
Filed:
Jan. 19, 1990
Nobuyuki Yamamura, Hanno, JP;
Shinichi Shimomaki, Tokyo, JP;
Hideaki Shimizu, Inagi, JP;
Hiroshi Matsumoto, Tachikawa, JP;
Naoki Kato, Fussa, JP;
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
A thin-film memory element made by the technique of forming thin film and functioning as a thin-film transistor. The memory element has two gate-insulating films, and two gate electrodes formed on the gate-insulating films, respectively. The first gate-insulating film can accumulate electrical charge, whereas the second gate-insulating film cannot. The gate electrode on the first gate-insulating film is used as write/erase electrode, and the gate electrode on the second gate-insulating film is used as read electrode. Since the memory element has two electrodes, one for writing or erasing data, and the other for reading data, its threshold voltage remains unchanged. Hence, data can be read from the thin-film memory element for a virtually indefinitely long period of time.