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:
May. 07, 1991
Filed:
Nov. 13, 1989
Shinji Yagawara, Yokohama, JP;
Wasaburo Ohta, Yokohama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A gas detecting device includes a substrate and a plurality of overhang portions made from an electric insulation material and disposed in a space over the substrate. A gas sensitive film is made from a metallic oxide semiconductor material and is mounted on each of the overhang portions. A pair of detecting leads is connected to the gas sensitive film. A heater lead for heating the gas sensitive film is mounted on each of the overhang portions. The gas sensitive film of at least one of the plurality of overhang portions has a composition ratio of metal to oxygen different from that of the other gas sensitive films whereby a specified gas can be selectively detected on the basis of the response of the plurality of metallic oxide semiconductors to the gas.