Canon Kabushiki Kaisha

Harumi Ishiyama

Yasunori Chigono

Jun Hirabayashi

Tadashi Furuya

Seiji Mashimo

Hideyuki Yano

Yukio Nagase

Yasushi Sato

Norio Takahashi

Akio Maruyama

Shoji Amamiya

Koichi Suzuki

Toshihiro Kikuchi

Toshiyuki Ehara

Masaya Kawada

Yomishi Toshida

Seiichi Shinohara

Kazushige Nakamura

Takeo Yamamoto

Noboru Kashimura

Nobuyuki Ito

Takahiro Hosokawa

A charging apparatus includes a charger for being supplied with an AC voltage and for electrically charging a member to be charged; a current measurer for measuring a current flowing between the charger and the member to be charged when the AC voltage is supplied to the charger; and a particular current extractor for extracting from the current a particular current having a particular frequency.

Charging apparatus

A charging apparatus includes a charging section supplied with an AC voltage and for electrically charging a member to be charged; a current measuring section for measuring a current flowing between the charging section and the member to be charged when the AC voltage is supplied to the charging section; and a particular current extraction section for extracting from the current a particular current having a particular frequency.

A charging member for charging a member to be charged, includes an elastic foam member provided at a surface of the charging member. The elastic foam member includes a plurality of cell portions with wall portion defining the cell portions. The gaps connecting the cell portions have areas which are not less than 5% and not more than 50%, for respective cells.

Charging member having an elastic foam member including cell portions whose gap ratio is 5% to 50%, charging apparatus, process cartridge, and image forming apparatus having such charging member

A charging apparatus includes a charging member for charging a member to be charged while forming a nip with the member to be charged, and electroconductive particles disposed in the nip. The charging member is supplied with a voltage of a certain polarity, a surface of the member to be charged is triboelectrically charged by a surface of the charging member so as to have a polarity opposite from that of the voltage, and the electroconductive particles are triboelectrically charged in the nip so as to have a polarity opposite from that of the voltage.

Charging apparatus, process cartridge and image forming apparatus having electroconductive particles charged in a nip between a charging member and a member to be charged

Charging apparatus, process cartridge and image forming apparatus

An electrifier for electrifying a member to be charged includes a charge rotary member that forms a first nip with the member to be charged, to charge the member to be charged, and that holds and carries charge particles to the first nip, and a nip forming member that forms a second nip with the charge rotary member, the nip forming member having a bias charge having the same polarity as the developer.

Electrifier for charging developer carrying member using charge particles, including charge rotary member and nip forming member having bias polarity the same as developer polarity

A charging apparatus includes a charging member, to which a voltage is applicable, for charging a member to be charged; the charging member including: a flexible member for forming a nip with the member to be charged, wherein the flexible member is moved with a peripheral speed difference between surfaces of the flexible member and the member to be charged at the nip; and electroconductive particles in the nip.

IMAGE FORMING APPARATUS HAVING A MEMBER TO BE CHARGED, INJECTION CHARGING MEANS HAVING AN ELASTIC MEMBER FOR PRESS-CONTACTING THE MEMBER TO BE CHARGED, AND ELECTROCONDUCTIVE PARTICLES BETWEEN THE ELASTIC MEMBER AND THE MEMBER TO BE CHARGED

A charging device, suitable for use in an electrophotographic image forming apparatus, is formed of an object to be charged, and a roller-shaped charging member disposed in contact with the object via electroconductive particles and supplied with a voltage to charge the objects. The charging member has a surface layer including an elastic foam and is moved with a surface speed difference relative to the object. The charging member has surface cavities having an average diameter of 5 to 150 &mgr;m and occupying an area percentage of 50 to 90%. An image forming apparatus and a process cartridge therefor including the charging device are also provided.

Charging device, process cartridge and image forming apparatus

A charging device for electrically charging a member to be charged includes charging particles including electroconductive particles having particles diameters in the range of 10 nm-10 &mgr;m; and a charging particles carrying member, which has a nip with the member to be charged forming a nip with said member to be charged, for carrying the charging particle to the nip; wherein said charging particles have resistances in the range of 10  &OHgr;cm; wherein (an amount, per unit area, of said charging particles carried by said charging particles carrying member)/(an average roughness Ra of a surface of said charging particles carrying member) is in the range of 0.005-1 mg/cm /&mgr;m.

Charging apparatus employing charging particles, and image forming apparatus employing such a charging apparatus

An image forming apparatus includes an image bearing member; charging means for electrically charging the image bearing member, the charging means carrying electroconductive particles and having a charging member elastially press-contacted to the image bearing member; image forming means for forming an electrostatic image by selectively dissipating electric charge on the image bearing member charged by the charging means; developing means for developing the electrostatic image on the image bearing member with toner and for supplying the electroconductive particles to the image bearing member, wherein the electroconductive particles supplied by the developing means is carried to a press-contact portion of the charging member to contribution for electric charging of the image bearing member; and changing means for changing a relation between the charging member and a supply position of the electroconductive particles of the developing means.

Image forming apparatus in which electroconductive particles are supplied to charging means from developing device by way of image bearing member

A charging apparatus includes a charging member for being supplied with a voltage to charge a member to be charged, the charging member including an elastic member for forming a nip with the member to be charged, and said elastic member having a surface provided with a plurality of projections; wherein a speed A of a surface of said charging member (mm/sec) and a speed B of a surface of the member to be charged (mm/sec) satisfy: when B&minus;A>0, said projections are inclined toward upstream with respect to a movement direction of the surface of the member to be charged in said nip, and when B&minus;A<0, the projections are inclined toward downstream with respect to a movement direction of the surface of the member to be charged in said nip.

Contact-type charging device having a plurality of projections over the surface of the charging device

A developing apparatus prevents a reduction in image density due to paper powder by providing a developing apparatus that has a developing container, a toner carrying member, and a toner container, wherein the toner container has a space portion, which is disposed below the toner carrying member and which is not substantially replenished with the toner.

Developing apparatus having foreign matter accumulating space

An image forming apparatus includes an image bearing member for bearing an electrostatic image. A developing device develops the electrostatic image on the image bearing member by toners charged with a predetermined polarity. A transfer device transfers a toner image on the image bearing member to a transferring material. An electrifying device inject-charges the image bearing member having transfer residual toners. An electrical conductive member provided and spaced apart from the image bearing member in a moving direction of the image bearing member downstream farther than the transfer means and upstream farther than the electrifying device. An electrical field forming device for forming an alternative electrical field between the electrical conductive member and the image bearing member.

Image forming apparatus for making recovery and restoration of toners by electrical conductive member

A charging member has an electrically conductive base material and a surface layer including a foaming body of a continuous bubble material.

Charging member holding charge accelerating particles in a continuous bubble

A charging apparatus includes a first charging member of being supplied with a voltage to charge a member to be charged. A first charging member has magnetic particles in the form of a magnetic brush contactable to the member to be charged. A second charging member charges a region of the member to be charged corresponding to an end portion, in a longitudinal direction of the charging member, of the magnetic particles, wherein by the second charging member, the region has a potential of the same charge polarity of the voltage when the region reaches a charging position of this first charging member.

Growing community of inventors

Numazu, Japan

Harumi Ishiyama