Method and apparatus for image forming capable of effectively reducing unevenness of density and color displacement of images

An image forming apparatus, comprising:

• at least one image carrying member configured to form a toner image on a surface thereof;
• a transfer member having a surface facing the at least one image carrying member and configured to transfer the toner image to a recording medium;
• a plurality of support rollers supporting the transfer member;
• and
• a detecting mechanism configured to detect a speed of the transfer member, comprising:
• a detection roller including at least one support roller selected from the plurality of support rollers;
• a roller shaft provided to the detection roller;
• a moving member configured to rotate with the detection roller and directly fixed to the roller shaft;
• a sensor configured to detect a moving speed of the detection roller with the moving member;
• and
• a controller configured to control a traveling speed of the transfer member to a target speed based on a detection result of the sensor,
• wherein the detection roller and the moving member are arranged such that a first radial line extending from a central axis line of the roller shaft to a maximum radius point of the detection roller is positioned at substantially a same radial angle about the central axis line as a second radial line extending from the central axis line of the roller shaft to a minimum radius point of the moving member.

An image forming apparatus, comprising:

• at least one image carrying member configured to form a toner image on a surface thereof;
• a transfer member having a surface facing the at least one image carrying member and configured to transfer the toner image to a recording medium;
• a plurality of support rollers supporting the transfer member;
• and
• a detecting mechanism configured to detect a speed of the transfer member, comprising:
• a detection roller including at least one support roller selected from the plurality of support rollers;
• a roller shaft provided to the detection roller;
• a moving member configured to rotate with the detection roller and directly fixed to the roller shaft;
• a sensor configured to detect a moving speed of the detection roller with the moving member;
• and
• a controller configured to control a traveling speed of the transfer member to a target speed based on a detection result of the sensor,
• wherein the detection roller and the moving member are arranged such that a first radial line extending from a central axis line of the roller shaft to a minimum radius point of the detection roller is positioned at substantially a same radial angle about the central axis line as a second radial line extending from the central axis line of the roller shaft to a maximum radius point of the moving member.

An image forming apparatus, comprising:

• at least one image carrying member configured to form a toner image on a surface thereof;
• a transfer member having a surface facing the at least one image carrying member and configured to transfer the toner image to a recording medium;
• a plurality of support rollers supporting the transfer member;
• and
• a detecting mechanism configured to detect a speed of the transfer member, comprising:
• a detection roller including at least one support roller selected from the plurality of support rollers;
• a roller shaft provided to the detection roller;
• a moving member configured to rotate with the detection roller and directly fixed to the roller shaft;
• a sensor configured to detect a moving speed of the detection roller with the moving member;
• and
• a controller configured to control a traveling speed of the transfer member to a target speed based on a detection result of the sensor,
• wherein a work required to raise temperature by one Celsius degree calculated from a type and amount of a material used to make the detection roller is substantially 30 Joule or more.

An image forming apparatus, comprising:

• at least one image carrying member configured to form a toner image on a surface thereof;
• a transfer member having a surface facing the at least one image carrying member and configured to transfer the toner image to a recording medium;
• a plurality of support rollers supporting the transfer member;
• and
• a detecting mechanism configured to detect a speed of the transfer member, comprising:
• a detection roller including at least one support roller selected from the plurality of support rollers;
• a roller shaft provided to the detection roller;
• a moving member configured to rotate with the detection roller and directly fixed to the roller shaft;
• a sensor configured to detect a moving speed of the detection roller with the moving member;
• and
• a controller configured to control a traveling speed of the transfer member to a target speed based on a detection result of the sensor, wherein the detection roller includes carbon fiber.