Patent ID: 11927894
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An image forming apparatus comprising:
a first image forming portion provided with a first rotatable image bearing member on which an electrostatic latent image corresponding to image information is formed, and a first developing member contacting the first image bearing member at a developing position and configured to develop the electrostatic latent image on the first image bearing member with a first developer;
a second image forming portion provided with a second rotatable image bearing member on which an electrostatic latent image corresponding to image information is formed, and a second developing member contacting the second image bearing member and configured to develop the electrostatic latent image on the second image bearing member with a second developer;
a common driving source configured to drive the first image bearing member, the first developing member, the second image bearing member, and the second developing member;
a transfer device configured to transfer an image formed with the first developer from the first image bearing member to a transferred member at a first transfer position, and transfer an image formed with the second developer from the second image bearing member to the transferred member at a second transfer position downstream of the first transfer position with respect to a moving direction of the transferred member;
a contact-and-separation mechanism configured to cause the first developing member to contact or separate from the first image bearing member; and
a controller configured to control the contact-and-separation mechanism,
wherein in a case that the first developing member is separated from the first image bearing member when an operation in which the image is sequentially transferred to the transferred member from the first image bearing member and the second image bearing member is terminated,
the controller controls based on the image information to switch and execute a first control in which the first developing member is started to separate from the first image bearing member after an end portion of an image forming area on the first image bearing member with respect to a moving direction of a surface of the first image bearing member passes through the first transfer position, and a second control in which the first developing member is started to separate from the first image bearing member after the end portion of the image forming area on the first image bearing member with respect to the moving direction of the surface of the first image bearing member passes through the developing position and before the end portion of the image forming area reaches the first transfer position.