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. 28, 1994
Filed:
May. 28, 1993
Sadayasu Ueno, Katsuta, JP;
Takao Sasayama, Hitachi, JP;
Seiko Suzuki, Hitachiota, JP;
Kanemasa Sato, Katsuta, JP;
Shiro Ouchi, Katsuta, JP;
Naoki Minami, Katsuta, JP;
Norio Hasegawa, Mito, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Automotive Engineering Co., Ltd., Ibaraki, JP;
Abstract
An air fuel ratio detecting arrangement using a diffusion suppressing type air fuel ratio sensor applicable to an air fuel ratio control unit for an internal combustion engine incorporating an atmospheric air pressure correction circuit in a signal processing and outputting device for correcting an output voltage signal processed therein based on a change in atmospheric air pressure which is detected when a predetermined operating condition of an internal combustion engine is satisfied. A secular change correction circuit included in the signal processing and outputting device detects a change in electromotive force of a concentration cell portion of the air fuel ratio sensor when a predetermined rich air fuel ratio is reached and corrects a reference voltage for the air fuel ratio sensor based on the detected change in electromotive force of the concentration cell portion in addition to an air calibration circuit.