Contact charging image forming apparatus having improved image transfer

An image forming apparatus, comprising:

• a photosensitive image holder;
• charging means for giving charge to a surface of said image holder through a contact charging member, which contacts with said image holder, so as to charge the surface of said image holder;
• exposing means for forming an electrostatic latent image by emitting a light to the surface of said charged image holder;
• development cleaning means for supplying a developer to the electrostatic latent image on said image holder so as to develop the electrostatic latent image and for collecting developer remaining on the surface of said image holder;
• transfer means;
• and
• voltage applying means,
• wherein said transfer means transfers a developer image on said image holder, which is obtained by the developing process by means of said development cleaning means, onto a transferred material using a voltage from said voltage applying means,
• wherein when a transferred material exists in a transfer position between said image holder and said transfer means during image forming operation, said voltage applying means applies a transfer voltage, which is used for transferring the developer image on said image holder onto the transferred material and which has an opposite polarity to that of a voltage applied to said contact charging member, to said transfer means, and when a transferred material does not exist in the transfer position during image forming operation, said voltage applying means applies a non-transfer voltage of not lower than 0V, which has opposite polarity to that of the transfer voltage, to said transfer means.

An image forming apparatus, comprising:

• a photosensitive image holder;
• charging means for giving charge to a surface of said image holder through a contact charging member, which contacts with said image holder, so as to charge the surface of said image holder;
• exposing means for forming an electrostatic latent image by emitting a light to the surface of said charged image holder;
• development cleaning means for supplying a developer to the electrostatic latent image on said image holder so as to develop the electrostatic latent image and for collecting a developer remaining on the surface of said image holder;
• transfer means for transferring a developer image on said image holder, which is obtained by the developing process by means of said development cleaning means, onto a transferred material;
• and
• control means for controlling movement of said image holder so that a contact position on said image holder with said contact charging member passes a counter position to said development cleaning means at least once at starting of the image forming operation.