US 6,983,117 B2
Image forming apparatus configured for double sided printing
Norimasa Sohmiya, Saitama (Japan); Koji Suzuki, Kanagawa (Japan); Hideaki Mochimaru, Kanagawa (Japan); Naoki Iwata, Saitama (Japan); Kunihiko Tomita, Kanagawa (Japan); Hiroshi Yokoyama, Kanagawa (Japan); Shigeru Watanabe, Kanagawa (Japan); Chiemi Kaneko, Ibaraki (Japan); Yasukuni Omata, Kanagawa (Japan); and Hisao Murayama, Kanagawa (Japan)
Assigned to Ricoh Company, Ltd., Tokyo (Japan)
Filed on Aug. 22, 2003, as Appl. No. 10/645,614.
Claims priority of application No. 2002-243797 (JP), filed on Aug. 23, 2002; and application No. 2002-250136 (JP), filed on Aug. 29, 2002.
Prior Publication US 2004/0101332 A1, May 27, 2004
Int. Cl. G03G 15/16 (2006.01); G03G 15/20 (2006.01)
U.S. Cl. 399—307 55 Claims
OG exemplary drawing
 
1. In a method of transferring toner images to opposite surfaces of a single recording medium and fixing said toner images, an image transferring and fixing step comprising the steps of:
heating with heating means a contact position where a first belt and a second belt, endlessly moving in a same direction at least at a position where said first belt and second belt face each other, contact each other;
transferring a first toner image from an image carrier to said first belt and heating said first toner image at the contact position to thereby transfer said first toner image to said second belt;
transferring a second toner image from said image carrier to said first belt; and
heating, at the contact position, the first toner image carried on said second belt to thereby transfer said first toner image to a first surface of the recording medium and fix said first toner image and, at the same time, heating the second toner image carried on said first belt to thereby transfer said second toner image to a second surface of said recording medium and fix said second toner image;
wherein a heating temperature of said heating means is higher than a melting point or a softening point of an image forming agent, which forms the first toner image and the second toner image, by 10° C. to 30° C., and
a heating range over which said heating means heats the contact position, as measured in a direction of belt length, is so sized as to implement transfer and fixation of the first toner image and the second toner image to the recording medium at said heating temperature.