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:
Jul. 10, 2001
Filed:
Jun. 29, 1999
Shigeru Nonoyama, Aichi-ken, JP;
Shigenori Yamauchi, Nisshin, JP;
Denso Corporation, Kariya, JP;
Abstract
A capacitive physical-quantity detection apparatus includes a movable electrode (,) which is displaced in response to a physical quantity. A fixed electrode (,) opposed to the movable electrode forms a capacitor in conjunction with the movable electrode. A signal applying device (,) operates for applying a first signal between the movable electrode and the fixed electrode. The first signal is periodic, and has at least a first time period for detection of a capacity variation and a second time period for displacement of the movable electrode to implement self diagnosis. A C-V conversion circuit (,) operates for generating a voltage which depends on a variation in a capacitance of the capacitor during the first time period. A signal processing circuit (,) operates for processing the voltage generated by the C-V conversion circuit into a second signal depending on the physical quantity. A changing device (,) operates for changing the first signal in the second time period between a state for execution of self diagnosis and a state for unexecution of self diagnosis. The first signal in the state for execution of self diagnosis applies a pseudo physical quantity to the movable electrode.