Image forming apparatus, drum unit, image forming module, and method of insertion and removal of a damper into and from an image carrier drum

A drum unit, comprising:

• a cylinder;
• a shaft that extends inside and supports the cylinder;
• and
• a damper disposed inside the cylinder, wherein
• the cylinder, the shaft, and the damper are assembled such that when the shaft is pulled out from the cylinder, the damper moves in the axial direction of the cylinder together with the shaft and is removed from the cylinder;
• wherein the shaft has a protrusion in radial direction and away from a center of the shaft, the damper has a contacting portion that comes in contact with the protrusion when the shaft is pulled out from the cylinder.

A drum unit, comprising:

• a cylinder;
• a shaft that extends inside and supports the cylinder;
• and
• a damper disposed inside the cylinder, wherein
• the cylinder, the shaft, and the damper are assembled such that when the shaft is pulled out from the cylinder, the damper moves in the axial direction of the cylinder together with the shaft and is removed from the cylinder;
• wherein the mechanism is such that each end in the axial direction of the cylinder has a pair of flanges fitted respectively, the cylinder is supported by the shaft through these flanges, the damper moves in the axial direction of the cylinder and comes in contact with one of the flanges, and the flange is separated apart from the cylinder by pushing.

An image forming module, comprising:

• an image carrier drum;
• a shaft that extends inside and supports the drum;
• a damper disposed inside the drum in pressed contact with an inner wall surface of the drum and fixed to the inner wall surface due to elasticity, wherein the drum, the shaft, and the damper are assembled such that when the shaft is pulled out from the drum, the damper moves in the axial direction of the drum together with the shaft;
• and
• an image forming element that forms an image on the drum, wherein
• the image carrier drum and the image forming element are assembled together as an integrated assembly.

An image forming apparatus comprising:

• an image carrier drum;
• a shaft that extends inside and supports the drum;
• and
• a damper disposed inside the drum in pressed contact with an inner wall surface of the drum and fixed to the inner wall surface due to elasticity, wherein the drum, the shaft, and the damper are assembled such that when the shaft is pulled out from the drum, the damper moves in the axial direction of the drum together with the shaft.

An image carrier drum assembly, comprising:

• an image carrier drum;
• a shaft that extends inside and supports the image carrier drum;
• and
• a damper disposed inside the image carrier drum, wherein the damper is configured to have a tangent of loss tan δ of at least 0.5.