Image forming apparatus

An image forming apparatus wherein a developer remaining on a photosensitive member after an image transfer process is removed by developing means, said apparatus comprising:

• an electrophotographic photosensitive member;
• a contact charger including an electrode contacted to said photosensitive member to electrically charge said photosensitive member, said contact charging means being supplied with a bias voltage form a charging bias voltage source;
• an exposure device for exposing said photosensitive member to form an electrostatic latent image thereon after said photosensitive member is electrically charged by said charger;
• a developing device for supplying the developer from a developer carrying member to a latent image portion of said photosensitive member to develop said photosensitive member and simultaneously removing the developer remaining on said photosensitive member after the transfer process and conveyed to a downstream of said contact charger on said photosensitive member, to said developer carrying member by a potential difference between said developer carrying member supplied with a developing bias and a latent image of said photosensitive member;
• and
• a control circuit for controlling said charging bias and a developing bias, during a preparatory pre-rotation process of said photosensitive member for preparation for an image forming operation, to maintain a potential difference between said photosensitive member and said developer carrying member at a level lower than that during normal image forming operation, by surface potentials of said developer carrying member supplied with the developing bias and of said photosensitive member charged by said charger.

An image forming apparatus wherein a developer remaining on a photosensitive member after an image transfer process is removed by developing means, said apparatus comprising:

• an electrophotographic photosensitive member;
• a contact charging means including an electrode contacted to said photosensitive member to electrically charge said photosensitive member, said contact charging means being supplied with a bias voltage form a charging bias voltage source;
• exposure means for exposing said photosensitive member to form an electrostatic latent image thereon after said photosensitive member is electrically charged by said charging means;
• developing means for supplying the developer from a developer carrying member to a latent image portion of said photosensitive member to develop said photosensitive member and simultaneously removing spherical developer particles remaining on said photosensitive member after the transfer process and conveyed to a downstream of said contact charging means on said photosensitive member, to said developer carrying member by a potential difference between said developer carrying member supplied with a developing bias and a latent image of said photosensitive member;
• and
• control means for controlling said charging bias and a developing bias, during a preparatory pre-rotation process of said photosensitive member for preparation for an image forming operation, to maintain a potential difference between said photosensitive member and said developer carrying member at a level lower than that during normal image forming operation, by surface potentials of said developer carrying member supplied with the developing bias and of said photosensitive member charged by said charging means.

An image forming apparatus wherein a developer remaining on a photosensitive member after an image transfer process is removed by developing means, said apparatus comprising:

• an electrophotographic photosensitive member;
• a contact charging means including an electrode contacted to said photosensitive member to electrically charge said photosensitive member, said contact charging means being supplied with a bias voltage form a charging bias voltage source;
• exposure means for exposing said photosensitive member to form an electrostatic latent image thereon after said photosensitive member is electrically charged by said charging means;
• developing means for supplying the developer from a developer carrying member to a latent image portion of said photosensitive member to develop said photosensitive member and simultaneously removing the developer remaining on said photosensitive member after the transfer process and conveyed to a downstream of said contact charging means on said photosensitive member, to said developer carrying member by a potential difference between said developer carrying member supplied with a developing bias and a latent image of said photosensitive member;
• control means for controlling said charging bias and a developing bias, during a preparatory pre-rotation process of said photosensitive member for preparation for an image forming operation, to maintain a potential difference between said photosensitive member and said developer carrying member at a level lower than that during normal image forming operation, by surface potentials of said developer carrying member supplied with the developing bias and of said photosensitive member charged by said charging means;
• and
• transferring means for transferring the developer from said photosensitive member while contacting to a transfer material.