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. 18, 2007
Filed:
Oct. 21, 2005
Takao Kawazu, Numazu, JP;
Atsuya Takahashi, Mishima, JP;
Masataka Mochizuki, Numazu, JP;
Hiroshi Chihara, Mishima, JP;
Takao Kawazu, Numazu, JP;
Atsuya Takahashi, Mishima, JP;
Masataka Mochizuki, Numazu, JP;
Hiroshi Chihara, Mishima, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A period of a first edge, a voltage change in a first direction of a first pulse signal fed from a zero-crossing detecting circuit, is detected. A second edge, a voltage change in a second direction opposite to the first direction, is generated when a time period equal to half the period of the first edge has elapsed from the next first edge. In response to a second pulse signal generated from the first and second edges, phase control of power to be supplied to heating elements is performed by using triacs. In this manner, during power control using a signal from the zero-crossing detecting circuit as a trigger signal, is achieved stable power control which enables tracking even though the power supply frequency fluctuates, and which is impervious to the effect of the positive or negative polarity of an input power supply.