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:
Aug. 10, 1999
Filed:
Oct. 08, 1997
Masayuki Takami, Kariya, JP;
Tomomichi Mizoguchi, Nagoya, JP;
Satoshi Haseda, Okazaki, JP;
Kazuhiro Okazaki, Anjo, JP;
Denso Corporation, Kariya, JP;
Abstract
An A/F sensor is driven by a voltage applied thereto at a command issued by a microprocessor, outputting an A/F detection signal which is linearly proportional to the concentration of oxygen. The microprocessor controls the voltage applied to the A/F sensor to bring a current flowing through the A/F sensor to a predetermined value in a zone outside a predetermined air-fuel ratio detection zone. In this outside zone, the applied voltage is controlled in accordance with a characteristic different from a positive characteristic in a normal positive characteristic in a voltage-current relation. That is, in a rich zone outside the air-fuel ratio detection zone, the applied voltage is controlled so as to make the applied voltage approach a maximum value of the electromotive force of the A/F sensor. In a lean zone outside the air-fuel ratio detection zone, on the other hand, the applied voltage is controlled so as to make the applied voltage approach a minimum value of the electromotive force of the A/F sensor.