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:
Dec. 12, 2000
Filed:
Aug. 31, 1998
Kazunori Jinno, Tokyo, JP;
Masahiro Ofuji, Kanagawa, JP;
NEC Home Electronics, Inc., Tokyo, JP;
Abstract
A passenger detection system including a single antenna electrode mounted on a surface of a passenger seat in an automobile. An oscillator generates an AC current having a predetermined voltage amplitude that is transmitted to the antenna electrode to produce a minute electric field around the antenna electrode. An amplitude control circuit is used to control the voltage amplitude of the output signal from the oscillator. The electrical characteristics of an object on the passenger seat alter the current and phase of the signal in the antenna electrode. A current detection circuit detects the amount of current flowing from the oscillator to the antenna electrode. In addition, a phase differential detection circuit detects a phase differential between the output signal from the oscillator and the signal on the antenna electrode. A control circuit detects the presence or absence of a passenger seated in the seat based on a current signal output from the current detection circuit and a phase differential signal output from the phase differential detection circuit. A control unit including the oscillator, the amplitude control circuit, the current detection circuit, the phase differential detection circuit and the control circuit, is contained in a single housing that is mounted under the passenger seat.