Canon Kabushiki Kaisha

Takeshi Kawamura

Shinya Yamamoto

Ken Nakagawa

Hiroaki Sakai

Seiji Saito

Tomohiro Nakamori

Hikaru Osada

Kenji Kanari

Yasushi Shimizu

Masahiro Shibata

Masaru Shimura

Yasunori Chigono

Tetsuya Sano

Tatsuaki Orihara

Takahiro Uchiyama

Jun Suzuki

Bunro Noguchi

Hiroshi Takami

Hidetoshi Hanamoto

Yasuo Yoda

Junichi Ochi

Naoto Tsuchihashi

Yasunari Kobaru

Yoshiki Kudo

Shuji Moriya

Takehiro Uchiyama

Koichi Otaka

Yuzuru Tsurumi

An image forming apparatus includes a toner carrying roller for carrying a toner, an image carrying member, contacting the toner on the toner carrying roller, on which a toner image is to be formed with the toner, and an electrode portion provided at an opposing position in which the electrode portion opposes the toner carrying roller via the image carrying member interposed therebetween. The toner image is formed on the image carrying member by changing a value of a voltage, on the basis of image information, applied to the electrode portion, and the toner carried on the toner carrying roller and the image carrying member contact each other in a toner contact area. The toner is moved between the toner carrying roller and the image carrying member in a toner movement area by changing the value of the voltage applied to the electrode portion, and the toner movement area is present downstream of the toner contact area with respect to a movement direction of the image carrying member.

Image forming apparatus having toner density control

A charging apparatus includes a latent image bearing member having a charge generating layer for generating an electric charge by receiving light energy; a light source for emitting light energy for generating the electric charge in the charge generating layer; an electrode; a bias voltage applying portion for applying a bias voltage to the electrode; and an elastic member, which is insulative and transparent, for contacting the electrode to a surface of the latent image bearing member. The electric charge is generated in the charge generating layer by reception of the light energy emitted from the light source, and the surface of the latent image bearing member is electrically charged by applying the bias voltage from the bias voltage applying portion to the electrode. The electrode is provided on the elastic member and is contacted to the surface of the latent image bearing member in a contact area and does not extend to an outside of the contact area.

Charging apparatus and image forming apparatus

An image forming apparatus includes an image bearing member on which an electrostatic latent image is to be formed and a developing device for developing the electrostatic latent image by supplying a developer to the image bearing member. The developing device includes a developer container; a rotatable developer carrying member, including a first electrode member; and a developer supplying member, which includes a surface foam layer and a second electrode member. The apparatus further includes a measuring device for measuring a remaining developer amount in the developer container by detecting electrostatic capacity between the first and second electrode members and a replenishing device for replenishing the developer supplying member by rotating the developer supplying member at a speed slower than a speed during image formation. When the measured remaining developer amount is not more than a threshold, the developer is replenished, and thereafter the remaining developer amount is again measured.

Image forming apparatus including replenishing operation for developer supply member

A developing apparatus including a developing container for containing developer, the developing container having an opening portion, a developer carrying member for carrying the developer at the opening portion, a detecting member for detecting a developer amount, the detecting member detecting a capacitance between the developer carrying member and the detecting member, and a force receiving portion for receiving a force and moving the developing container between a first position in which a developing operation is performed by the developer carrying member and a second position in which the developing operation is not performed, wherein the capacitance can be detected in the second position, and the detecting member is a rotatable developer supplying member for supplying the developer to the developer carrying member, the developer supplying member including a foam layer in which the developer can enter.

Developing apparatus

A developing apparatus, including: a developing container which has an opening portion and contains a developer; a developer carrying member which carries the developer at the opening portion; and a rotatable developer supplying member which is in contact with the developer carrying member and has a surface of a foam layer, for supplying the developer to the developer carrying member, the developer supplying member detecting a capacitance between the developer carrying member and the developer supplying member, wherein a surface aeration amount L (liter/min.) of the developer supplying member satisfies 1.8&#x2266;L.

Developing apparatus and image forming apparatus including the same

An image forming apparatus including an AC high voltage power supply, a DC high voltage power supply, and a high voltage power supply apparatus, which outputs an output voltage at an output end by superposing an output of the AC high voltage power supply and an output of the DC high voltage power supply. The high voltage power supply apparatus has a positive peak detector detecting a positive peak of the voltage at an output end, and a negative peak detector detecting a negative peak of the voltage at an output end. An output voltage of at least one of the AC high voltage power supply and the DC high voltage power supply is controlled on the basis of the detection result of at least one of the positive peak detector and the negative peak detector. An output voltage of the AC high voltage power supply is controlled on the basis of the detection result of the positive peak detector, and an output voltage of the DC high voltage power supply is controlled on the basis of the detection result of the negative peak detector.

Image forming apparatus and high voltage power thereof

A developing apparatus includes a developer carrying member, disposed opposite to an image bearing member, for carrying developer which is caused to jump from the developer carrying member to the image bearing member to develop an electrostatic latent image formed on said image bearing member by creating an oscillation electric field between the image bearing member and the developer carrying member at an opposing portion where the image bearing member and the developer carrying member are opposed to each other; and a jumping developer regulation member for regulating an area in which the developer is caused to jump in the opposing portion. The jumping developer regulation member is disposed apart from the developer carried by the developer carrying member and is an insulating member or an electrically floating member.

Developing apparatus featuring an insulating or electrically floating jumping developer regulation member

An image forming apparatus includes an image bearing member; a developer carrying member, disposed opposed to the image bearing member, for carrying a developer, wherein an electric field is formed between the developer carrying member and the image bearing member during a developing operation using the developer carrying member, and the electric field including an oscillating portion in which the electric field is an oscillating electric field, wherein a supply electric field of the oscillating electric field which is effective to supply the developer to the image bearing member from the developer carrying member is variably controllable in accordance with a peripheral speed of the image bearing member.

Image forming apparatus featuring a variable oscillating electric field formed between a developer carrying member and an image bearing member during a developer operation in accordance with a peripheral speed of the image bearing member

An image forming apparatus includes an image bearing member; a charging member for electrically charging the image bearing member; developing means for developing with a developer an electrostatic latent image formed on the image bearing member, the developing means having a developer carrying member for carrying the developer, wherein a gap is formed between the developer carrying member and the image bearing member; bias voltage applying means for applying a bias voltage to the developer carrying member, wherein the bias applying means applies an AC bias when the electrostatic latent image is developed, wherein the developing means is capable of collecting the developer fro the image bearing member, and an amplitude of an AC bias voltage applied to the developer carrying member by the bias applying means when the the developer is collected, is larger than that when the the electrostatic latent image is developed.

Image forming apparatus which recovers toner by developing device

A developer apparatus includes a developer carrying member, for carrying a developer to a developing portion, the developer carrying member including an electroconductive base and a resistance layer provided thereon; a developer feeding member for being supplied with a voltage to supply the developer to the developer carrying member; wherein a surface moving speed of the developer carrying member Vp [mm/sec], a resistance R(&#x3a9;) of the developer carrying member when an electric current applied the developer carrying member is 0.04 Vp [&#x3bc;A], and a resistance R(&#x3a9;) or the developer carrying member when the electric current applied to the developer carrying member is 4 Vp [&#x3bc;A], satisfy:&#x3c;15.

The image forming apparatus includes a movable image bearing member, a charging member opposed to the image bearing member in a charging portion, a transfer member for transferring an image formed on the image bearing member to a transferred member, and a cleaning mode for applying a voltage to the transfer member, and when other area on the image bearing member differing from a surface potential changing area on the image bearing member which is changed in surface potential by the application of this voltage is located in the charging portion, applying a voltage to the charging member, thereby cleaning the transfer member and the charging member. Thereby, the cleaning of the charging member can be effected well.

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Mishima, Japan

Takeshi Kawamura