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:
Jul. 01, 2008
Filed:
Apr. 16, 2004
Applicants:
Kenji Tashiro, Susono, JP;
Kazutaka Hattori, Okazaki, JP;
Inventors:
Kenji Tashiro, Susono, JP;
Kazutaka Hattori, Okazaki, JP;
Assignee:
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N 27/407 (2006.01);
U.S. Cl.
CPC ...
Abstract
An oxygen sensor is employed for determining whether the exhaust air-fuel ratio is rich or lean. A voltage is applied to the oxygen sensor at device impedance calculation intervals to calculate device impedance. After device impedance calculation, a reverse voltage is applied to the oxygen sensor with a view toward promptly negating the influence of voltage application on the sensor output. Subsequently, the sensor output of the oxygen sensor is sampled at sampling time intervals until it is concluded that the device impedance calculation period is over.