Canon Kabushiki Kaisha

Kenichiro Waki

Hiroyuki Suzuki

Ryo Inoue

Masahiro Itoh

Masaru Hibino

Yukio Nagase

Koichi Sato

Masahiro Inoue

Yuji Sakemi

Hiroaki Tsuchiya

Yoshiro Tomikawa

Nobuyuki Ito

Takeo Tsunemi

Keishi Ohsawa

Takehiro Takano

Yoshiaki Kobayashi

Yasushi Miura

Tatsuo Takeuchi

Nobuhiro Hayashi

Kazuhisa Kemmochi

Takeo Yamamoto

Image forming apparatus having an injection charging system and a two component contact development device

An image forming apparatus includes a charging device applies a voltage to charge an image bearing member. The charging device is provided with a charging means to which a voltage is applicable to charge said image bearing member, said charging means being provided with a magnetic particle carrying member for carrying and conveying a magnetic particle layer contacting with said image bearing member during the charging operation; a container contains magnetic particles therein; and a replacing device replaces the magnetic particles carried on the magnetic particle carrying member with the magnetic particles contained in the container. A developer develops a latent image produced on the image bearing member by the charging device using a toner to produce a toner image. A transferring device transfers the toner image from the image bearing member simultaneously with developing of the latent image without using a cleaner member after transferring by said transferring device and before charging by said charging device.

Charging device and image forming apparatus

An image forming apparatus includes image bearing member for bearing a toner image; charging member contactable to the image bearing member to electrically charge the image bearing member; wherein .delta.V=.vertline.Vdc-Vs.vertline. is different between a first area of the image bearing member which is going to be image area and second area of the image bearing member which is going to be non-image area, where Vdc is a DC component of a voltage applied to the charging member, and Vs is is a potential of the image bearing member charged by the charging member.

Image forming apparatus

An image forming apparatus includes an electrostatic image bearing member for bearing an electrostatic image; a developer carrying member for carrying developer containing toner; a voltage source for applying to said developer carrying member, an oscillating voltage of a predetermined frequency: a toner image forming device for forming a toner image on said electrostatic image bearing member using said voltage source; a transferring device for transferring the toner image onto transfer material; and a removing device for removing, using said voltage source, the toner remaining on said electrostatic image bearing member after the use of said transferring device: the voltage satisfies: ##EQU1## V.sub.pp �V!: peak-to-peak voltage of oscillating voltage V.sub.f �Hz!: frequency of oscillating voltage

Image forming apparatus which applies oscillating voltage to developer

An image forming apparatus includes at least a first image-forming unit provided with a first latent image-holding member, a first latent image-forming device, a first developing device for developing a first latent image with a first toner to form a first toner image, and a first image-transfer device for transferring the first toner image to an image-receiving member, and a second image-forming unit provided with a second latent image-holding member, a second latent image-forming device, a second developing device for developing a second latent image with a second toner to form a second toner image, and a second image-transfer device for transferring the second toner image to the image-receiving member holding the first toner image. The second developing device also serves as a cleaning device for recovering the toner remaining on the second latent image-holding member after the transfer to perform cleaning. The second latent image-holding member has a surface having a contact angle for water of not less than 85.degree..

Image-forming apparatus featuring a plurality of image forming means

An image forming apparatus has an image bearing member, charging means for uniformly charging the image bearing member, electrostatic image forming means for forming an electrostatic image on the image bearing member charged by the charging means, developing means for developing the electrostatic image on the image bearing member with a toner and also recovering any residual toner on the image bearing member, and transferring means for transferring the toner image to a transfer member conveyed. Upon re-operation after jam, at least one full rotation of the image bearing member effects the recovery of the toner on the image bearing member by the developing means with the charging by the charging means being rendered OFF.

Image forming apparatus in which residual toner is recovered by

An image forming apparatus has a plurality of image forming units for forming, on an image receiving member such as a transfer sheet, toner images of a plurality of different colors such as magenta, cyan, yellow and black. Each of the image forming units includes a photosensitive drum serving as an image carrier, a developing device for developing an electrostatic latent image carried by the image carrier to form a color toner image, and a transfer device for transferring the toner image to the image receiving member. The developing device in the image forming unit for forming on the image receiving member the toner image of an (i+1)-th color is of the type capable of simultaneously performing both development and removal of residual toner. The transfer currents T.sub.i and T.sub.i+1 employed by the transfer units which perform transfer of the toner images of an i-th color and the (i+1)-th color satisfy the following condition (1). The sphericity factor SF of the toner used in at least one of the image forming units, defined by the following equation (2) satisfies the following condition (3):

A developing method includes forming a magnetic field between an image bearing member bearing an electrostatic image and a developer carrying member carrying a developer comprising toner particles and carrier particles; and contacting chains of carrier particles formed on the developer carrying member to the image bearing member; wherein an absolute value of an intensity of a magnetic field in a movement direction of the developer carrying member over the entire portion of the developer carrying member at a position where the carrier is contacted to the image bearing member is positive.

Developing method with carrier chains contacted to image bearing member

A developing method for developing an electrostatic image on an image bearing member with a two-component developer includes the steps of bearing a developer containing toner particles and carrier particles on a developer bearing member to a contact region formed between the developer bearing member and an image bearing member bearing an electrostatic image thereon, and rubbing the image bearing member with the magnetic brush with a contact pressure equal to 0.7 gf/cm.sup.2 or less.

Magnetic brush developing method using a two-component developer

An image forming apparatus includes an image bearing member; a latent image forming device for forming on the image bearing member a dot distribution electrostatic latent image in accordance with image signals corresponding to an object image; a developing device for developing the latent image formed on the image bearing member by the latent image forming device, in a developing station and by a developer containing toner and magnetic carrier; wherein the developing device includes a developer carrying member for carrying and conveying the developer to the developing station, and a magnetic field generating device provided within the developer carrying member, for forming a magnetic brush of the developer and contacting the magnetic brush to the image bearing member; and wherein a degree .sigma.d (emu/cm.sup.3) of magnetization of the magnetic carrier by a magnetic field by the magnetic field generating means at a peak of a perpendicular magnetic field on the surface of the developer carrying member satisfies the following:

Image forming apparatus usable with a carrier having magnetization

A developing apparatus includes a guide member for guiding toner toward an image bearing member bearing an electrostatic image thereon, the guide member having a first end and a second end, a vibration generating device for applying an ultrasonic oscillation to the guide member proximate one of the first end and the second end of the guide member, and a vibration absorbing device for absorbing the ultrasonic oscillation in the guide member at the other one of the first end and the second end, wherein toner is conveyed on the guide member in a direction from the absorbing device to the vibration applying device. In one aspect, the toner is a magnetic toner, and a magnetic field is generated on the guide member at a position opposite a surface for guiding the toner.

Powder conveying device

The present invention aims to solve problems caused in forming multiple images on the same transfer sheet in response to an original by using black toner and color toner, and prevents a shade of the original from being developed by the color toner which results in the indistinct copy image. To this end, according to the present invention, an area developed by the color toner is made narrower than an area developed by the black toner.

Multi-color image forming system

An ultrasonic oscillation is applied in the neighborhood of one end of a guide member for supporting and guiding a powder, so that a transverse proceeding wave is generated in the guide member. The powder moves from the other end of the guide member toward a position of the applied ultrasonic oscillation under the action of this proceeding wave.

The present invention provides an image forming apparatus including an image bearing member; image forming devices for forming a toner image on the image bearing member, the average volume particle diameter of the toner being 3-10 .mu.m; a movable transfer sheet bearing member for bearing a transfer sheet; and a transfer member for transferring the toner image formed on the image bearing member onto the transfer sheet carried by the transfer sheet bearing member at a transfer station. The transfer member includes a fiber brush engageable by the transfer sheet bearing means at a side opposite to the image bearing member at the transfer station.

Image forming device having an electrically dielectric regulating member

The present invention provides an image forming apparatus having a shiftable image bearing member; an image forming device for forming an image on the image bearing member; and a transfer device for transferring the image formed on the image bearing member onto a transfer sheet at a transfer station, the transfer device urging the transfer sheet against the image bearing member and having a transfer electrode to which a voltage is applied; and wherein a resistance value between a surface of the transfer electrode facing the image bearing member and a portion of the transfer electrode at which the voltage is applied is greater at an upstream side of a shifting direction of the image bearing member than at a downstream side thereof, on the surface of the transfer electrode, whereby an image can be obtained without any transfer void.

Growing community of inventors

Kawasaki, Japan

Kenichiro Waki