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:
Nov. 03, 1998
Filed:
Dec. 13, 1996
Applicant:
Inventors:
Takehiko Kowatari, Chiyoda-machi, JP;
Nobukatsu Arai, Ushiku, JP;
Kaoru Uchiyama, Omiya-machi, JP;
Chihiro Kobayashi, Naka-machi, JP;
Shinya Igarashi, Naka-machi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01M / ;
U.S. Cl.
CPC ...
701103 ; 731182 ; 340439 ; 340451 ;
Abstract
A digital signal obtained by A/D converting an output of a thermal type air flow meter is supplied along two paths. After a time constant is obtained in one path, inverse-transformation is performed to obtain an error together with an output of the other path. The inverse-transformed signal is linearized on the basis of the characteristic of the thermal type air flow meter, and a direction of flow is determined.