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US 12,613,480 B2Granted
Image forming apparatus with charging current detector
AssigneeCanon Kabushiki Kaisha
InventorsHisashi Taniguchi, Issei Imamura, Takuya Oka
Life of this patent
Estimating the term…
Abstract
Disclosed is a controller for controlling a charging current detector to perform a detection operation to detect charging current while a surface of a photosensitive member having passed through the development portion after being charged by the charger passes through the charging portion during a non-image forming operation, and for controlling at least one of a charging voltage applicator, an exposer, and a development voltage applicator to change a development contrast based on a charging current value detected by a previous detection operation and a charging current value detected by a current detection operation.
Claims16
An image forming apparatus comprising:
- a photosensitive member configured to rotate;
- a charger configured to contact the photosensitive member to form a charging portion and charge a surface of the photosensitive member being rotated;
- a charging voltage applicator configured to apply a charging voltage to the charger;
- an exposer configured to expose the surface of the photosensitive member charged by the charger and form an electrostatic latent image on the surface of the photosensitive member;
- a development member configured to rotate, form a development portion where a developer is supplied to the surface of the photosensitive member, and form a developer image on the surface of the photosensitive member by supplying the developer charged to a predetermined polarity to the electrostatic latent image on the surface of the photosensitive member at the development portion;
- a development voltage applicator configured to apply, to the development member, a development voltage on the predetermined polarity with respect to a potential of the electrostatic latent image at the development portion;
- a charging current detector configured to detect a charging current flowing through the charging portion during the charging of the surface of the photosensitive member by the charger;
- and
- a controller configured to control the charging voltage applicator, the exposer, and the development voltage applicator,
- wherein the controller is configured to control an image forming operation in which the developer image is formed on the surface of the photosensitive member, and a non-image forming operation in which the developer image is not formed on the surface of the photosensitive member,
- wherein the controller is configured to communicate with the charging current detector during at least one detection operation for detection of the charging current while the surface of the photosensitive member having passed through the development portion after being charged by the charger passes through the charging portion during the non-image forming operation, and
- wherein the controller is configured to control at least one of the charging voltage applicator, the exposer, and the development voltage applicator to change a development contrast based on a charging current value IA detected by a detection operation that is performed before a current detection operation and a charging current value IB detected by the current detection operation, the development contrast being a difference between a voltage of the electrostatic latent image at the development portion and the development voltage.
9 more elements
An image forming apparatus comprising:
- a photosensitive member configured to rotate;
- a charger configured to contact the photosensitive member to form a charging portion and charge a surface of the photosensitive member being rotated;
- a charging voltage applicator configured to apply a charging voltage to the charger;
- an exposer configured to expose the surface of the photosensitive member charged by the charger and form an electrostatic latent image on the surface of the photosensitive member;
- a development member configured to rotate, form a development portion where a developer is supplied to the surface of the photosensitive member, and form a developer image on the surface of the photosensitive member by supplying the developer to the electrostatic latent image on the surface of the photosensitive member at the development portion;
- a speed regulator configured to change a rotation speed of the development member;
- a charging current detector configured to detect a charging current flowing through the charging portion during the charging of the surface of the photosensitive member by the charger;
- and
- a controller configured to control the charging voltage applicator and the speed regulator,
- wherein the controller is configured to control an image forming operation in which the developer image is formed on the surface of the photosensitive member, and a non-image forming operation in which the developer image is not formed on the surface of the photosensitive member,
- wherein the controller is configured to communicate with the charging current detector during at least one detection operation for detection of the charging current while the surface of the photosensitive member having passed through the development portion after being charged by the charger passes through the charging portion during the non-image forming operation, and
- wherein the controller is configured to control the speed regulator to change a circumferential speed ratio of a circumferential speed of the development member to a circumferential speed of the photosensitive member, based on a charging current value IA detected by a detection operation that is performed before a current detection operation and a charging current value IB detected by the current detection operation.
9 more elements
Dependencies are inferred from the claim text.