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:
Jan. 15, 1985
Filed:
Feb. 07, 1983
Applicant:
Inventor:
Koji Yamauchi, Hitachi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
219501 ; 219497 ; 219505 ; 219216 ; 323236 ;
Abstract
A temperature control device for a fixing heat source of a copying machine includes circuits for supplying power to the fixing heat source in synchronism with the zero-cross point of an a.c. signal applied from an a.c. power source. The device functions to supply the full-wave current to the heat source until a first predetermined temperature is sensed by a temperature sensor, to supply the half-wave current to the heat source until a second predetermined temperature is then sensed, and to change the duty factor of the half-wave current after attainment of the second predetermined temperature, thereby maintaining constant the temperature of the heat source with high accuracy.