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:
Feb. 19, 1991
Filed:
Aug. 16, 1988
Yasuyuki Matsuuchi, Osaka, JP;
Kenzo Nagata, Osaka, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
An image forming apparatus for electrophotographically producing a toner image on a recording sheet medium, a toner image fixing assembly which includes a heater unit having an operative condition to thermally fix the toner image on the recording sheet medium, a power supply circuit for electrically energizing the heater unit through a switch, a microprocessor unit for controlling the power supply circuit, the microprocessor unit being operative to supply to the power supply circuit a control signal effective to actuate the switch to cyclically close and open for a predetermined period of time for the purpose of inspecting the heater unit for any malfunction, a detecting element directly responsive to the condition of the heater unit and operative to produce a signal indicative of the detected condition of the heater unit, a malfunction detector network responsive to the signal from the detecting element, the malfunction detector network being operative to produce a malfunction signal indicating a malfunction of the heater unit when, in the presence of the control signal from the digital control network, the signal from the detecting element indicates that the heater unit is continuously in operation, and a disabling device for forcibly disabling the power supply circuit in response to the malfunction signal from the malfunction detector network.