(19)
(11) EP 1 498 785 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION

(48) Corrigendum issued on:
01.06.2005 Bulletin 2005/22

(43) Date of publication:
19.01.2005 Bulletin 2005/03

(21) Application number: 04016817.1

(22) Date of filing: 16.07.2004
(51) International Patent Classification (IPC)7: G03G 15/00, G03G 15/16, G03G 15/01
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR
Designated Extension States:
AL HR LT LV MK

(30) Priority: 18.07.2003 JP 2003199451
08.08.2003 JP 2003290282
30.04.2004 JP 2004136026

(71) Applicant: Ricoh Company, Ltd.
Tokyo 143-8555 (JP)

(72) Inventors:
  • Yokoyama, Masato
    Tokyo 143-8555 (JP)
  • Yokokawa, Nobuto
    Tokyo 143-8555 (JP)
  • Ando, Toshiyuki
    Tokyo 143-8555 (JP)
  • Kobayashi, Kazuhiko
    Tokyo 143-8555 (JP)
  • Shinohara, Tadashi
    Tokyo 143-8555 (JP)
  • Matsuda, Yuuji
    Tokyo 143-8555 (JP)
  • Hosokawa, Jun
    Tokyo 143-8555 (JP)
  • Miura, Yohhei
    Tokyo 143-8555 (JP)
  • Takahashi, Toshiyuki
    Tokyo 143-8555 (JP)
  • Matsuda, Hiromichi
    Tokyo 143-8555 (JP)

(74) Representative: Schwabe - Sandmair - Marx 
Stuntzstrasse 16
81677 München
81677 München (DE)

   


(54) Image forming apparatus with a speed control of a belt


(57) An image forming apparatus includes an image carrying member (3), a transfer member (4,54), support rollers (5-10), a detecting mechanism, and a controller (45). The image carrying member (3) forms a toner image on its surface facing a surface of the transfer member(4,54), supported by the support rollers (5-10), which transfers the toner image to a recording medium (P). The detecting mechanism includes a detection roller (10), a roller shaft (42), a moving member (43), and a sensor (44), and detects a speed of the transfer member (4,54). The detection roller (10) includes one support roller selected from the support rollers (5-10), and is provided with the roller shaft (42). The moving member (43) is directly fixed to the roller shaft (42) and rotates with the detection roller (10). The sensor (44) detects a moving speed of the detection roller (10) with the moving member (43). The controller (45) controls a traveling speed of the transfer member (4,54) to a target speed based on a detection result of the sensor (44).