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:
May. 06, 2003
Filed:
Oct. 05, 2001
Hitoshi Ishikawa, Hitachinaka, JP;
Other;
Abstract
To perform with high accuracy the analog-to-digital conversion of signals of an air flow meter irrespective of fluctuation of a reference voltage of an analog-to-digital conversion circuit. A thermal type air flow meter including means for measuring an intake air flow rate by heating and controlling a heating resistor and means for performing analog-to-digital conversion of an air flow rate signal of the air flow rate measurement means, which inputs a reference voltage to the analog-to-digital conversion circuit so that the reference voltage can be converted from the analog signal to the digital signal by the analog-to-digital conversion circuit, and the air flow rate signal can be corrected in accordance with the value of the reference voltage. A/D conversion of the air flow rate signal can be executed accurately even when the voltage of the reference voltage source of the A/D converter in an electrical control unit is fluctuating.