Canon Kabushiki Kaisha

Satoshi Tomiki

Takeo Yamamoto

Yoshiaki Kobayashi

Kensaku Kusaka

Jiro Kinokuni

Keishi Osawa

A developing apparatus includes a toner carrying member for carrying toner to a developing zone where the developing apparatus faces to an image bearing member; bias voltage applying means for applying to the toner carrying member a developing bias voltage for developing an electrostatic latent image formed on the image bearing member, wherein the developing bias voltage is in the form of a DC voltage biased with an AC voltage; wherein when a developing operation stops, rotation of the toner carrying member is stopped while rotating the image bearing member electrically charged, and then, the AC voltage is applied to the toner carrying member for a predetermined period, and thereafter, the AC voltage is stopped in a condition in which regular-charge toner is being urged from the toner carrying member toward the image bearing member.

Developing apparatus

An image forming apparatus includes an image bearing member for bearing a developer image; an image forming apparatus for forming the developer image borne on the image bearing member; a transferring apparatus for electrostatically transferring the developer image on the image bearing member to a transferring material in a transferring area; and a guiding member for guiding the transferring material into the transferring area. The guiding member includes an insulating member disposed on a transferring material guide surface and a conductive member disposed on a surface opposite to the transferring material guide surface. A power source capable of applying a voltage having a predetermined polarity is electrically connected to the conductive member. A projection is provided on the surface of the insulating member.

Image forming apparatus including opposed insulating and conducting transfer material guide members to prevent null transfer

An image forming apparatus with an image bearing member and a charging member for contactably charging the image bearing member. The charging member is provided within an exchangeable unit. An electric power containing an AC component is applied to the charging member, and adjustments are made to the magnitude of the AC component. When the exchangeable unit is exchanged, the magnitude of the AC component is returned to an initial value thereof, so as to extend the life of the image bearing member in situations where the exchangeable unit is exchanged and the AC component might otherwise have a magnitude inappropriate for the new unit.

Image forming apparatus capable of adjusting AC applied to charging member

A development apparatus includes a toner carrying member for carrying magnetic toner disposed opposed to an image bearing member to form a developing zone: magnetic field generating means in the toner carrying member; a toner supplying rotary member for applying the magnetic toner onto the toner carrying member and stripping the magnetic toner from the toner carrying member, comprising a surface layer of electrically conductive foam material.

Development apparatus employing toner supply roller comprising electrically conductive foamed material layer

The present invention relates to an image forming apparatus which includes an image bearing member for bearing a toner image, transfer device for electrostatically transferring the toner image on the image bearing member to a transfer material, separating and charge eliminating device for charge-eliminating the transfer material to separate the transfer material from the image bearing member, wherein the transfer device includes a transfer member forming a nip with the image bearing member and constant current control device for controlling a current to be applied on the transfer member to a predetermined value, and wherein the constant current control device effects control at a first current value from before a leading end of the transfer material reaches the nip, and switches to a second current value larger than the first current value in the vicinity of a trailing end of the transfer material in transferring operation.

Image forming apparatus having a separating and charge eliminating device for charge eliminating a recording material from the photosensitive drum

The present invention relates to an image forming apparatus in which current control means constant-current-controls a current value flowing in a transfer member so as to become constant, voltage control means constant-voltage-controls a voltage value applied to the transfer member so as to become constant, and selecting means selects a control of the transfer member during transfer to constant current control or constant voltage control in conformity with the thickness of the transfer material.

Image forming apparatus in which whether transfer member should be constant-current-controlled or constant-voltage-controlled is selected depending on thickness of transfer material

An image forming apparatus has an image bearing member, a transfer device for transferring a toner image from the image bearing member to a transfer material at a transfer station and a guide member for guiding the transfer material to the transfer station. The guide member has a notch formed at a most downstream side and, on account of the notch, a final guide point, effected by the guide member, of a transfer material having a small width in a direction perpendicular to the transfer material moving direction is positioned at an upstream side of that of a transfer material having a wide width.

Image forming apparatus

An image forming apparatus includes an image bearing member for bearing a toner image; and a transferring member for forming a nip in cooperation with the image bearing member for transferring the toner image from the image bearing member to a recording material, in the nip, wherein a voltage having a polarity opposite from a polarity; normal toner is applied to the transferring member to transfer the toner image to the recording material; wherein the between start of the voltage application to the transferring member and the arrival of the leading end of the recording material at the nip is controlled on the basis of a type of the recording material.

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Tokyo, Japan

Satoshi Tomiki