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. 21, 2009
Filed:
Feb. 01, 2005
Mitsuru Yamamoto, Minato-ku, JP;
Sunao Hamamura, Minato-ku, JP;
Yasuhiro Sasaki, Minato-ku, JP;
Sakae Kitajo, Minato-ku, JP;
Mitsuru Yamamoto, Minato-ku, JP;
Sunao Hamamura, Minato-ku, JP;
Yasuhiro Sasaki, Minato-ku, JP;
Sakae Kitajo, Minato-ku, JP;
NEC Corporation, Tokyo, JP;
Abstract
A piezoelectric element of the piezoelectric pump is driven by the output signal of an amplifier that takes as input a signal that is generated by a sine wave oscillator of the same frequency that drives the piezoelectric element. The amplifier is driven by a high voltage obtained by conversion from a low-voltage power supply by a voltage-boosting converter, whereby the piezoelectric element is driven by a low-frequency sine wave of high voltage. The frequency of the sine wave oscillation is further adjusted by a signal from a first control circuit at the time of activation. In addition, the amplitude of the sine wave oscillation is adjusted by the output signal of a second control circuit that takes as input a signal from temperature sensor for sensing the temperature of the heat-generating body.