US 7,532,834 B2
Fixing device and fixing method and image forming device
Toshiaki Kagawa, Nara (Japan); Hiroshi Kida, Yamatokoriyama (Japan); Takashi Yamanaka, Yamatokoriyama (Japan); and Tetsunori Mitsuoka, Tondabayashi (Japan)
Assigned to Sharp Kabushiki Kaisha, Osaka (Japan)
Appl. No. 10/571,939
PCT Filed Sep. 15, 2004, PCT No. PCT/JP2004/013440
§ 371(c)(1), (2), (4) Date Mar. 15, 2006,
PCT Pub. No. WO2005/029199, PCT Pub. Date Mar. 31, 2005.
Claims priority of application No. 2003-323293 (JP), filed on Sep. 16, 2003.
Prior Publication US 2007/0036571 A1, Feb. 15, 2007
Int. Cl. G03G 15/20 (2006.01)
U.S. Cl. 399—69  [219/216] 22 Claims
OG exemplary drawing
 
1. A fixing device comprising a first contacting member contacting a toner image surface and a second contacting member contacting a surface opposite to the toner image surface,
the fixing device fixing an unfixed toner image on a printing medium by causing the printing medium to pass through a contacting region (i) where the first contacting member and the second contacting member are in contact with each other and (ii) which is heated to a temperature at which fixing of toner is able to be carried out,
the fixing device further comprising:
heating means for heating the first contacting member and the second contacting member; and
control means for controlling said heating means so that a surface temperature of the second contacting member satisfies at least either of the following conditions (1) and (2), namely (1) the surface temperature of the second contacting member is not less than a lower temperature that is defined by a cold offset occurring boundary temperature of the first contacting member and (2) the surface temperature of the second contacting member is not more than an upper temperature that is defined by a hot offset occurring boundary temperature of the first contacting member, wherein
the control means controls the surface temperature of the second contacting member so that the surface temperature of the second contacting member is lower than the surface temperature of the first contacting member.