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:
Nov. 16, 1999
Filed:
Nov. 24, 1997
Norimichi Funahashi, Nisshin, JP;
Brother Kogyo Kabushiki Kaisha, Nagoya, JP;
Abstract
A heater temperature control circuit for controlling a temperature of, for example, a heater incorporated in a laser printer for fixing a toner image on a recording material includes a voltage divider circuit delivering an output voltage divided by a thermistor changing a resistance value thereof in response to temperature changes with generation of heat by a heater and a resistance having a predetermined resistance value, and a heater control circuit comparing the output voltage of the voltage divider circuit with a reference voltage, thereby delivering a control signal for controlling an amount of heat generated by the heater on the basis of results of comparison. The heater temperature control circuit further includes a pulse width modulation circuit capable of changing a duty of an output signal thereof in response to an external instruction signal, and an integrating circuit integrating the output signal delivered from the pulse width modulation circuit, thereby delivering an integrated signal serving as the reference voltage.