Image forming apparatus having emergency stop image processing features

An image forming apparatus comprising:

• a plurality of image bearing members;
• a plurality of image forming means for forming images on said plurality of image bearing members;
• a plurality of primary transfer means for transferring the images on said plurality of image bearing members onto an intermediate transfer member;
• secondary transfer means for transferring the images on said intermediate transfer member onto a transfer material;
• and
• control means for controlling drive operations of said plurality of image bearing members and said intermediate transfer member, and operations of said plurality of image forming means, said plurality of primary transfer means and said secondary transfer means,
• wherein an image formation emergency stop state for stopping an image forming operation is performed by stopping the drive operation of said plurality of image bearing members and said intermediate transfer member, and the operations of said plurality of image forming means, said plurality of primary transfer means and said secondary transfer means in response to an image formation emergency stop instruction, and
• wherein prior to performing an emergency stop state, said control means controls an image bearing member and said intermediate transfer member so as to drive said image bearing member and said intermediate transfer member, and controls primary transfer means so as to make said primary transfer means operative at least until an image area on said image bearing member on which an image is being formed at a time when said control means receives the image formation emergency stop instruction passes a transfer region in said primary transfer means opposing said image bearing member, and controls said secondary transfer means so as to make said secondary transfer means inoperative or controls said secondary transfer means so that an electric field opposite to that which is generated at a time of transfer operation is generated when the image area transferred onto said intermediate transfer member by the operation of said primary transfer means passes at least a transfer region in said secondary transfer means.

An image forming apparatus, comprising:

• a plurality of image bearing members;
• a plurality of image forming means for forming images on said plurality of image bearing members;
• a plurality of primary transfer means for transferring the images on said plurality of image bearing members onto an intermediate transfer member;
• secondary transfer means for transferring the images on said intermediate transfer member onto a transfer material;
• and
• control means for controlling primary transfer means to make said primary tansfer means operative at least until an image area on an image bearing member on which an image is being formed at a time when an image formation stop instruction is issued passes a transfer region in said primary transfer means opposing to said image bearing member, and controlling a movement of said intermediate transfer member so that said image area transferred to said intermediate transfer member by an operation of said primary transfer means stops at a predetermined timing.