| US 7,613,419 B2 | ||
| Image forming apparatus and image forming method characterized by a particular nip time | ||
| Kazumi Suzuki, Shizuoka (Japan); Takashi Fujita, Yokohama (Japan); Hideki Kosugi, Sagamihara (Japan); Ichiro Kadota, Tokyo (Japan); Atsushi Nakafuji, Tokyo (Japan); and Hiromitsu Takagaki, Yokohama (Japan) | ||
| Assigned to Ricoh Company, Ltd., Tokyo (Japan) | ||
| Filed on Aug. 29, 2006, as Appl. No. 11/511,380. | ||
| Claims priority of application No. 2005-248650 (JP), filed on Aug. 30, 2005; and application No. 2006-145364 (JP), filed on May 25, 2006. | ||
| Prior Publication US 2007/0071511 A1, Mar. 29, 2007 | ||
| Int. Cl. G03G 15/16 (2006.01) | ||
| U.S. Cl. 399—307 | 19 Claims |
| 1. An image forming apparatus, comprising:
an image bearing member;
a latent electrostatic image forming unit configured to form a latent electrostatic image on the image bearing member;
a developing unit configured to develop the latent electrostatic image by using a toner to form a toner image;
a transfer fixing member configured to bear the toner image;
a heating unit configured to heat the toner image on the transfer fixing member; and
a pressurizing member configured to form a transfer fixing nip with the transfer fixing member,
wherein the toner image on the transfer fixing member is transferred and fixed simultaneously to a recording medium which
passes through the transfer fixing nip to record an image on the recording medium,
a nip time, which is the time it takes for the recording medium to pass through the transfer fixing nip is 30 ms or less,
the toner comprises at least a binder and the binder comprises a main peak in an area of 5,000 to 15,000 molecular weight
in a molecular weight distribution measured by GPC, a content of the component of a 30,000 or more molecular weight is 0.05%
or less and a value of weight-average molecular weight (Mw)/number average molecular weight (Mn), Mw/Mn is 2 to 6.
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