Configured to enhance toner collecting efficiency and toner redepositing efficiency

An image forming apparatus comprising:

• a rotatable image carrier;
• charging means for charging a surface of said image carrier uniformly;
• latent image forming means for exposing the charged surface of said image carrier to thereby electrostatically forming a latent image;
• a developing unit for developing the latent image to produce a corresponding toner image;
• an image transfer unit for transferring the toner image to a recording medium;
• a cleaning unit for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image, wherein the toner redeposited on said image carrier is collected by said developing unit;
• and
• charge regulating means positioned downstream of said cleaning unit, but upstream of said charging means, in a direction of rotation of said image carrier, and for charging the toner moved away from said cleaning unit and charged to a polarity opposite to an original polarity deposited on the toner at the time of development to the original charge.

An image forming apparatus comprising:

• a rotatable image carrier;
• charging means for charging a surface of said image carrier uniformly;
• latent image forming means for exposing the charged surface of said image carrier to thereby electrostatically forming a latent image;
• a developing unit for developing the latent image to produce a corresponding toner image;
• an image transfer unit for transferring the toner image to a recording medium;
• a cleaning unit for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image, wherein the toner redeposited on said image carrier is collected by said developing unit;
• and
• charge regulating means positioned downstream of said cleaning unit, but upstream of said charging means, in a direction of rotation of said image carrier, and for charging the toner redeposited on said area of said image carrier to a polarity identical with an original polarity deposited on the toner at the time of development.

An image forming apparatus comprising:

• a rotatable image carrier;
• charging means for charging a surface of said image carrier uniformly;
• latent image forming means for exposing the charged surface of said image carrier to thereby electrostatically form a latent image;
• a developing unit for developing the latent image to produce a corresponding toner image;
• an image transfer unit for transferring the toner image to a recording medium;
• a cleaning member for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image, wherein the toner redeposited on said image carrier is collected by said developing unit;
• and
• control means for causing, when said cleaning member collects the toner from said image carrier, a voltage of polarity opposite to an original polarity deposited on the toner at the time of development to be applied to said cleaning member to thereby electrostatically transfer the toner of the original polarity to said cleaning member, and for causing said cleaning member to rotate in an opposite direction to said image carrier at a nip between said image carrier and said cleaning member, and for causing said cleaning member to collect the toner by less than one rotation.

An image forming apparatus comprising:

• a rotatable image carrier;
• charging means for charging a surface of said image carrier uniformly;
• latent image forming means for exposing the charged surface of said image carrier to thereby electrostatically form a latent image;
• a developing unit comprising a developer carrier for conveying a developer deposited thereon, and for developing the latent image to produce a corresponding toner image;
• and
• a cleaning member for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image, wherein the toner redeposited on said image carrier is collected by said developing unit;
• wherein an effective developing width over which said developer carrier actually develops the latent image in an axial direction thereof is greater than an axial length of said cleaning member such that said cleaning member is confined in the effective developing width.

An image forming apparatus comprising:

• a rotatable image carrier;
• charging means for charging a surface of said image carrier uniformly;
• latent image forming means for exposing the charged surface of said image carrier to thereby electrostatically form a latent image;
• a developing unit comprising a developer carrier for conveying a developer deposited thereon, and for developing the latent image to produce a corresponding toner image;
• an image transfer unit for transferring the toner image to a recording medium;
• a cleaning member for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image, wherein the toner redeposited on said image carrier is collected by said developing unit, and wherein an effective developing width over which said developer carrier actually develops the latent image in an axial direction thereof is smaller than an axial length of said cleaning member;
• and
• shifting means for shifting, when said cleaning member redeposits the toner on said image carrier, the toner on said cleaning member such that the toner lies in a range smaller than the effective developing width inclusive.

An image forming apparatus comprising:

• a rotatable image carrier;
• latent image forming means for electrostatically forming a latent image on a surface of said image carrier;
• a developing unit for developing the latent image to thereby produce a corresponding toner image;
• an image transfer unit for transferring the toner image to a recording medium;
• a cleaning unit comprising a rotatable cleaning member, and for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image, wherein an electric field is formed between said cleaning member and said image carrier to cause said cleaning member to electrostatically collect the toner from said image carrier, and then the electric field is switched in direction to cause said cleaning member to redeposit the toner in an area of the surface of said image carrier which does not effect formation of a next latent image, and wherein the toner redeposited on said image carrier is electrostatically collected by said developing unit;
• and
• control means for controlling rotation of said cleaning member such that said cleaning member moves, when collecting the toner, in an opposite direction to said image carrier at a nip between said cleaning member and said image carrier, and ends collecting the toner from an image forming area of said image carrier by less than one rotation such that a leading edge, in a direction of rotation of said cleaning member, of the toner collected by said cleaning member is brought to a position where the toner cannot be transferred to said image carrier, and for causing said cleaning member to rotate at a higher speed when collecting the toner than when redepositing the toner.

An image forming apparatus comprising:

• a rotatable image carrier;
• latent image forming means for electrostatically forming a latent image on a surface of said image carrier;
• a developing unit for developing the latent image to thereby produce a corresponding toner image;
• an image transfer unit for transferring the toner image to a recording medium;
• a cleaning unit for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image;
• and
• cleaning control means for controlling said cleaning unit such that when an intermediate between a leading and a trailing edge of an image forming area defined on said image carrier moves away from said cleaning member, a function of said cleaning member is switched from toner collection to toner redeposition.

An image forming apparatus comprising:

• a rotatable image carrier;
• latent image forming means for electrostatically forming a latent image on a surface of said image carrier;
• a developing unit for developing the latent image to thereby produce a corresponding toner image;
• an image transfer unit for transferring the toner image to a recording medium;
• and
• a cleaning roller for collecting toner left on said image carrier after transfer of the toner image, and then redepositing the toner in an area of the surface of said image carrier which does not effect formation of a next latent image;
• said cleaning roller comprising a rigid shaft rotatably supported at axially opposite ends thereof, and an elastic body mounted on said shaft, wherein said cleaning roller collects the toner from said image carrier and redeposits the toner on said image carrier with a circumference of said roller pressingly contacting the surface of said image carrier.