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. 01, 1991
Filed:
Feb. 20, 1990
Applicant:
Inventors:
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
357 34 ; 357 30 ;
Abstract
A thin-film device having the structure of a bipolar transistor is provided. The device has three thin-films formed one on another to form emitter, base and collector regions, thereby providing a NPN or PNP structure depending on the impurities contained in these thin-films. The present bipolar thin-film device is particularly useful as a phototransistor, though use is not limited only for this. A non-transparent, insulating layer having an opening may be provided to limit the passage of light and to improve the transistor characteristics.