Image forming apparatus

An image forming apparatus comprising:

• a photosensitive drum;
• an endless belt that is disposed to face the photosensitive drum;
• a holding roller configured to hold matter attached on a surface of the belt;
• a bias control unit configured to control a bias to be applied to the holding roller;
• and
• a speed control unit configured to control a rotating speed of the holding roller,
• wherein the image forming apparatus is configured to perform:
• an image forming operation for forming an image on a recording sheet;
• and
• a collecting operation for moving the attached matter held on the holding roller onto the belt and collecting the attached matter through the belt by a collecting unit,
• wherein the bias control unit is configured to:
• during the image forming operation, apply a first bias for moving the matter attached on the surface of the belt onto the holding roller;
• and
• during the collecting operation, apply a second bias for moving the attached matter held on the holding roller onto the belt, and
• wherein the speed control unit is configured to:
• control the holding roller to rotate at a first rotating speed during the image forming operation;
• and
• in a progress of the collecting operation, control the holding roller to rotate at a second rotating speed, which is slower than the first rotating speed, at least for a first period after the bias control unit applies the second bias to the holding roller.

An image forming apparatus comprising:

• an image carrier;
• a holding roller configured to hold matter attached on a surface of the image carrier;
• a collecting unit;
• and
• a control device configured to perform:
• a bias control process of controlling a bias to be applied to the holding roller;
• a speed control process of controlling a rotating speed of the holding roller;
• and
• an operation control process of controlling the image forming apparatus to perform:
• an image forming operation for forming an image on a recording sheet;
• and
• a collecting operation for moving the attached matter held on the holding roller onto the image carrier and collecting the attached matter through the image carrier by the collecting unit,
• wherein the bias control process comprises:
• during the image forming operation, applying a first bias for moving the matter attached on the surface of the image carrier onto the holding roller;
• and
• during the collecting operation, applying a second bias for moving the attached matter held on the holding roller onto the image carrier, and
• wherein the speed control process comprises:
• controlling the holding roller to rotate at a first rotating speed during the image forming operation;
• and
• in a progress of the collecting operation, controlling the holding roller to rotate at a second rotating speed, which is slower than the first rotating speed, at least for a first period after the bias control process applies the second bias to the holding roller.