Image forming apparatus having function for judging life of unit detachably mountable thereto, and unit detachably mountable to image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsAkihiko Uchiyama, Akihiko Takeuchi
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Abstract
An image forming apparatus including a unit detachably mountable on the image forming apparatus, the unit having a developing device for developing a latent image formed on an image bearing member, a developing bias setter for setting a developing bias so that an image developed by the developing device maintains a predetermined density, and a life determiner for determining a life of the unit in accordance with a developing bias set by the developing bias setter and a reference bias. The reference bias is set in accordance with data relating to a used amount of the unit.
Claims21
An image forming apparatus comprising:
- a unit detachably mountable on said image forming apparatus, said unit having developing means for developing a latent image formed on an image bearing member;
- developing bias setting means for setting a developing bias so that an image developed by said developing means maintains a predetermined density;
- and
- life determining means for determining the life of said unit in accordance with the developing bias set by said developing bias setting means and a reference bias,
- wherein the reference bias is set in accordance with data relating to the amount said unit is used.
A unit detachably mountable on an image forming apparatus including developing bias setting means for setting a developing bias so that an image developed by a developing means maintains a predetermined density, comprising:
- developing means for developing a latent image formed on an image bearing member;
- and
- a memory,
- wherein said memory stores data of the developing bias set by said developing bias setting means.
An image forming apparatus comprising:
- a unit detachably mountable on said image forming apparatus, said unit having developing means for developing a latent image formed on an image bearing member;
- and
- life determining means for determining the life of said unit in accordance with an image density of a test pattern formed by said developing means and a reference density;
- wherein the reference density is set in accordance with data relating to the amount said unit is used.
A unit detachably mountable on an image forming apparatus, comprising:
- developing means for developing a latent image formed on an image bearing member;
- and
- a memory;
- wherein said memory stores image density data when a gradation control is effected.
Dependencies are inferred from the claim text.