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. 24, 1993
Filed:
Mar. 19, 1992
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01N / ;
U.S. Cl.
CPC ...
60274 ; 60276 ; 60277 ; 60285 ; 731181 ; 123691 ;
Abstract
A conversion efficiency of a catalyst is estimated by a correlation function concerning output signals of upper and down stream side air fuel ratio sensors. The conversion efficiency is measured by comparing the correlation function and a complement value of the correlation function with a comparing standard value.