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:
Mar. 22, 2005
Filed:
Jan. 02, 2002
Satoshi Hada, Kariya, JP;
Eiichi Kurokawa, Kariya, JP;
Toshiyuki Suzuki, Handa, JP;
Tomoo Kawase, Nagoya, JP;
Satoshi Haseda, Okazaki, JP;
Satoshi Hada, Kariya, JP;
Eiichi Kurokawa, Kariya, JP;
Toshiyuki Suzuki, Handa, JP;
Tomoo Kawase, Nagoya, JP;
Satoshi Haseda, Okazaki, JP;
Denso Corporation, , JP;
Abstract
An A/F signal proportional to an oxygen concentration in the exhaust gas from an internal combustion engine is output upon application of a voltage based on an instruction from a microcomputer. At the time an element resistance is detected, a bias instruction signal Vr from the microcomputer is converted by a D/A converterto an analog signal Vb. An output voltage Vc obtained by removing high frequency components from the analog signal Vb through an LPFis input to a bias control circuit. During this time period in which the element resistance is detected, an accurate A/F signal is not output. Therefore, the A/F signal that has theretofore prevailed is held by a Sample/Hold circuitto thereby prevent the use of an erroneous A/F signal. Namely, at the time of detecting the element resistance, the detected value of the oxygen concentration is prevented from becoming abnormal. As a result, an accurate A/F control can be executed using the detected element resistance.