Patent · US Expired

Image heating device capable of controlling activation of plural heaters

US5512993A · kind A · utility

41Cited by
5References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 1, 1994
Grant dateApr 30, 1996
Priority date
Expiry dateNov 1, 2014

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G15/2039
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Disclosed is an image heating device for a fixing device in image forming apparatus. The image heating device is provided with two heaters and an image fixing roller. The image fixing roller is heated by the two heaters, one having the heat distribution in the center and the other having the heat distribution in the end portion of the fixing roller. The heaters are alternately energized so that the power requirement is maintained limited. The energization time ratio of the heaters is suitably varied according to the sheet size in order to compensate the temperature loss in the end portions when the heating is conducted in the central portion only, or to reduce the temperature rise in the end portions, encountered when narrow sheets are consecutively passed, thereby preventing various drawbacks resulting from uneven temperature distribution on the fixing roller.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.