The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 1993
Filed:
Dec. 10, 1990
Shigeo Ogino, Toyokawa, JP;
Kazuaki Shiotsuka, Toyokawa, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
An image forming apparatus including a movable type developing unit carrying a plurality of developing devices for performing a developing function using a plurality of color toners. The developing unit is vertically moved along a photosensitive drum. It is detected by a sensor whether or not a selected developing device is at a first position of the level of the developing position. In carrying out a developing operation, the developing device at the first position is moved to a second position adjacent to a photosensitive drum. The following problems are detected based on the ON and OFF state of the sensor: if the developing device does not move to the second position a predetermined period of time after an instruction for moving it from the first position to the second position is issued or if the developing device does not move to the first position a predetermined period of time after an instruction for returning it from the second position to the first position is issued. Based on the detection of the above problems, the developing unit is prohibited from vertically moving and copy paper is discharged from the apparatus.