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:
Jun. 21, 2011
Filed:
Nov. 27, 2006
Masamichi Hiraiwa, Aichi, JP;
Takeshi Kawai, Aichi, JP;
Satoshi Teramoto, Aichi, JP;
Shigeki Mori, Aichi, JP;
Hiroshi Inagaki, Aichi, JP;
Masamichi Hiraiwa, Aichi, JP;
Takeshi Kawai, Aichi, JP;
Satoshi Teramoto, Aichi, JP;
Shigeki Mori, Aichi, JP;
Hiroshi Inagaki, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
Using a gas detection voltage Vs output from a terminal CU, a determination is made at to whether, after startup of an air-fuel ratio detection apparatus (), a full-range air-fuel ratio sensor () has reached a semi-activated state in which a determination can be made as to whether the air-fuel ratio is on the rich or lean side based on a change in a gas detection signal Vic. After determining that the sensor has reached the semi-activated state, the signal Vic is compared with a threshold to determine whether the air-fuel ratio is on the rich or lean side. In the apparatus (), the potential difference between an outer pump electrode of a pump cell () and a reference electrode of an oxygen concentration measurement cell () is obtained via a first differential amplification circuit () as the gas detection signal Vic, the signal Vic being highly responsive to a change in air-fuel ratio of exhaust gas.