Belt device and unit device including belt device and image forming apparatus using the belt ...

38 Pages·2013·1.81 MB·English

US006324374B1
(12) United States Patent
(10) Patent N0.: US 6,324,374 B1
Sasamoto et al. (45) Date of Patent: Nov. 27, 2001
(54) BELT DEVICE AND UNIT DEVICE 5,953,559 9/1999 Obu .................................... .. 399/110
INCLUDING BELT DEVICE AND IMAGE 5,987,281 11/1999 Kurotori et a1. 399/237
FORMING APPARATUS USING THE BELT 5,987,282 11/1999 Tsukamoto et a1. 399/237
5,987,291 * 11/1999 Masuda . . . . . . . . . . . . . . . . . . .. 399/302
6,021,287 * 2/2000 Tanaka .............. ..
(75) Inventors: Tetsurou Sasamoto; Katsuaki 6,029,023 * 2/2000 Munemori et a1. .
Miyawaki; Makoto Obu; Minoru
666,,,001363814,,,454240122 ** 1530///222000000000 YMNoiasnkhaaimyniaoem teaat lea.t1. a1. .
Suzuki, all of Yokohama; Yuichi
Aoyama, Tokyo, all of (JP)
6,192,007 * 2/2001 Yamamoto etal. ................. .. 399/82
(73) Assignee: Ricoh Company, Ltd., Tokyo (JP) FOREIGN PATENT DOCUMENTS
59-192159 U 12/1984 (JP).
( * ) Notice: Subject to any disclaimer, the term of this
08160839A 9/1996 (JP).
patent is extended or adjusted under 35 09146383A 6/1997 (JP).
U.S.C. 154(b) by 0 days.
* cited by examiner
(21) Appl. N0.: 09/584,153 Primary Examiner—Sophia S. Chen
(74) Attorney, Agent, or Firm—Oblon, Spivak, McClelland,
(22) Filed: May 31, 2000
Maier & Neustadt, RC.
(30) Foreign Application Priority Data
(57) ABSTRACT
Jun. 14, 1999 (JP) ............................................... .. 11-166288
Dec. 22, 1999 (JP) 11-365318 An image forming apparatus suppresses several kinds of
Apr. 14, 2000 (JP) ............................................... .. 12-114451 inconveniences caused by unnecessary contact of a belt
formed member With opposing members and drives the
(51) Int. Cl.7 ................................................... .. G03G 15/16 belt-formed member accurately even When the belt-formed
(52) US. Cl. .......................... .. 399/298; 399/82; 399/101; member separated from a part of a plurality of opposing
399/302 members. In an image forming apparatus having a belt
(58) Field of Search ................................ .. 399/71, 82, 85, formed member supported by a plurality of supporting
399/298, 299, 302, 101, 38 rollers and a plurality of opposing members located side by
side in a line to oppose and contact the belt-formed member,
(56) References Cited a pivot mechanism is employed to temporarily separate the
belt-formed member from a part of the opposing members
U.S. PATENT DOCUMENTS
for color image formation. The image forming apparatus
5,156,308 10/1992 Aoyama ............................. .. 222/145 also includes a tension roller dive mechanism to increase a
5,248,847 9/1993 Aoyama .......... .. 399/238 relative distance betWeen the tension roller and other sup
5,652,080 7/1997 Yoshino et a1. ..... .. 430/119 porting rollers to suppress a decrease in a tension of the
5,652,948 * 7/1997 Sakaguchi et a1. 399/302 X belt-formed member during the above-described separation
5,666,616 9/1997 Yoshino et a1. ..... .. 399/240 of the belt-formed member from the plurality of opposing
5,678,149 * 10/1997 Takekoshi et a1. 399/299
members.
5,708,938 1/1998 Takeuchi et a1. 399/250
5,765,082 * 6/1998 NumaZu et a1. 399/299
5,923,930 7/1999 Tsukamoto et a1. ............... .. 399/237 16 Claims, 25 Drawing Sheets
U.S. Patent Nov. 27, 2001 Sheet 1 0f 25 US 6,324,374 B1
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