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:
Sep. 15, 1992
Filed:
Jun. 10, 1991
Applicant:
Inventors:
Shinji Yagawara, Yokohama, JP;
Wasaburo Ohta, Yokohama, JP;
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
204424 ;
Abstract
A gas sensor senses gas using a metal oxide semiconductor whose resistance changes depending on gas adhesion on a surface of the metal oxide semiconductor. The gas sensor includes a base structure, and a gas sensitive layer formed on the base structure and made of a metal oxide semiconductor. The gas sensitive layer has a multi-layer structure which includes at least two layer portions having mutually different grain structures.