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:
Apr. 11, 1995
Filed:
Aug. 18, 1993
Masahiro Ishikawa, Osaka, JP;
Yashima Electric Co., Ltd., , JP;
Abstract
A vacuum cleaner rotates a propeller fan by its suction force. The propeller fan rotates a rotor of a d.c. electric energy generator so as to generate electrical energy, and a d.c. voltage corresponding to the suction force is obtained by the generation. The vacuum cleaner employs the d.c. voltage as an operating voltage for a dust sensor and the peripheral circuitry thereof. The vacuum cleaner compares the d.c. voltage with a constant voltage output from a constant-voltage circuit by a comparing circuitry. The vacuum cleaner lowers the gain of an amplifying circuitry based upon a signal output from the comparing circuitry in correspondance to an increasing of the d.c. voltage obtained by the d.c. electric energy generator. The amplifying circuitry amplifies output of the dust sensor. The vacuum cleaner automatically determines detection sensitivity to be a proper sensitivity. The detection sensitivity is the sensitivity for detecting dust, based upon an output from the dust sensor.