United States Patent an
Noda
[li] Patent Number: 5,070,362 [45] Date of Patent: Dec. 3, 1991
[54] IMAGE FORMING APPARATUS HAVING A PLURALITY OF SELECTIVELY OPERABLE DEVELOPERS
[75] Inventor: Takashi Noda, Osaka, Japan
[73] Assignee: Minolta Camera Kabushiki Kaisha, Osaka, Japan
[21] Appl. No.: 482,800
[22] Filed: Feb. 21,1990
[301 Foreign Application Priority Data
Feb. 21, 1989 [JP] Japan 1-41382
Feb. 21, 1989 [JP] Japan 1-41383
Feb. 21, 1989 [JP] Japan 1-41384
[51] Int. CI.' G03G 15/06
[52] U.S. CI. 355/206; 355/245;
355/326
[58] Field of Search 355/326, 322, 245, 246,
355/260, 205, 206, 207
[56] References Cited
U.S. PATENT DOCUMENTS
4,579,443 4/1986 Abuyama et at. .
4,620,783 11/1986 Tanaka et al. .
4,841,329 6/1989 Kasamura et al 118/645
4.841.336 6/1989 Kusumoto et al 355/245
4.841.337 6/1989 Hiratsuka 355/326 X
4,878,091 10/1989 Morita et al 355/245 X
4,891,672 1/1990 Takagi 355/245
4,941,018 7/1990 Kasamura et al 355/245
4,954,844 9/1990 Morita et al 355/326 X
4,958,191 9/1990 Yamada et al 355/245
4,963,927 10/1990 Ishihara 355/207
FOREIGN PATENT DOCUMENTS
1515654 7/1986 Japan .
Primary Examiner—R. L. Moses
Attorney, Agent, or Firm—Burns, Doane, Swecker &
Mathis
[57] ABSTRACT
A control member of image forming unit controls a driving motor so as to move a unit of combined developing devices in accordance with a developing mode or a specific operational condition which is set when the unit is moved to a toner supply position due to a shortage of toner. The control member functions so as to reserve the power cut off caused by malfunction until the unit is stopped at a predetermined position if it is still in the transit to the predetermined position.
56 Claims, 52 Drawing Sheets
