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. 21, 2007
Filed:
Aug. 14, 2002
Shigeo Isitani, Gunma, JP;
Yasuji Orimo, Gunma, JP;
Chiharu Katsuyama, Gunma, JP;
Futoshi Ichiyanagi, Gunma, JP;
Shigeo Isitani, Gunma, JP;
Yasuji Orimo, Gunma, JP;
Chiharu Katsuyama, Gunma, JP;
Futoshi Ichiyanagi, Gunma, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The invention relates to an air/fuel ratio detection apparatus. This apparatus includes (a) a heater portion having an elongate cylindrical shape and heating by applying electricity thereto from outside; (b) a solid electrolyte layer surrounding the heater portion and being activated by heat to conduct oxygen ions therethrough; (c) first and second electrodes in contact with the solid electrolyte layer and being away from each other such that pumping voltage is applied by the first and second electrodes to the solid electrolyte layer; (d) a reference electrode for outputting an air/fuel ratio detection signal, the reference electrode being formed on the solid electrolyte layer and being away from the first and second electrodes; and (e) a diffusion layer made of a porous material and surrounding periphery of the solid electrolyte layer to cover the first and second electrodes and the reference electrode.