Patent ID: 8170450
Filing Date: 2012-05-01
Classification: G03G

Abstract:
1. A color electrophotographic image forming apparatus for forming an image on a recording medium, the color electrophotographic image forming apparatus comprising: a photosensitive member forming an electrostatic latent image; a rotary support member configured to support a plurality of developing devices for developing the electrostatic latent image, and to move a developing device to a developing position for developing the electrostatic latent image by rotation; a first member configured to rotate multiple times of a natural number when the rotary support member rotates once moving together with the rotary support member, a rotation of the first member being detected by a first sensor; a second member configured to move with rotation of the rotary support member, the rotary support member being detected to be positioned at a predetermined phase by a second sensor, wherein the predetermined phase is a phase in a case where one of the plurality of developing devices is at the developing position; and a controlling unit configured to detect a phase of the rotary support member by a first signal to be output from the first sensor having detected the first member, and a second signal to be output from the second sensor having detected the second member.