Canon Kabushiki Kaisha

Norio Takahashi

Katsuhiro Sakaizawa

Rie Endo

Jun Hirabayashi

Harumi Ishiyama

Kazunari Hagiwara

Shuji Moriya

Yasunori Chigono

Shinichi Nishida

Takayuki Tanaka

Takahiro Kawamoto

A developer container, which contains a developer to be supplied to a developing chamber in an electrophotographic image forming apparatus, the developer container including: a partition wall partitioning the container from the chamber; a conveying member conveying the developer to an opening in the partition wall to supply the developer to the chamber; a sealing member attached to a wall surface of the partition wall to cover the opening; an extending portion extending from the sealing member to an outside of the container, wherein, when the extending portion is pulled, the sealing member is separated into a remaining portion and a removal portion, and a free end of the remaining portion is positioned below an upper edge of the opening; and a spacing holding member disposed between the wall surface of the partition wall and the sealing member to hold a spacing between the wall surface and the sealing member.

Developer container, developing device, and process cartridge

An image forming apparatus includes a developer bearing member configured to bear a developer to develop a latent image, a developer regulating member configured to regulate an amount of the developer carried on the bearing member, a voltage application unit that can apply a plurality of direct current voltages of different values between the bearing member and the regulating member, and a current detection unit that can detect a plurality of direct currents of different values flowing in the regulating member when the voltage application unit applies the plurality of direct current voltages, wherein the image forming apparatus sets a direct current voltage value Vb applied by the voltage application unit when developing the latent image, so that the following expression is satisfied: |Vb|&#x3e;|Vbmin|, where Vbmin indicates a direct current voltage value when the direct current detected by the current detection unit is a minimum value.

Image forming apparatus and image forming system

An image forming apparatus includes an image bearing member; a developer carrying member, contactable to the image bearing member, for carrying a developer to a developing position to develop an electrostatic image formed on the image bearing member with the developer; a supplying member for supplying the developer to the developer carrying member, wherein a peripheral speed of the developer carrying member is not less than 1.05 times and not more than 1.20 times a peripheral speed of the image bearing member, and an arithmetic average roughness Ra is not less than 0.20 times and not more than 0.33 times a volume average particle size of the developer, wherein a potential applied to the supplying member is different from a potential applied to the developer carrying member toward a larger potential of a regular charge polarity of the developer.

Image forming apparatus

A developing apparatus in which a toner has a volume-average particle diameter R that is in a range of 4.0 &#x3bc;m&#x2266;R&#x2266;6.2 &#x3bc;m, a developing roller has an arithmetic mean roughness Ra (&#x3bc;m) that is not more than 0.10 times the volume-average particle diameter R of the toner, a voltage applied to a supply roller is of negative polarity, that is, a normal charging polarity of the toner, triboelectrification polarity of the supply roller with respect to the toner is negative, that is, of the normal charging polarity of the toner, and an abutment width S in which the developing roller and the supply roller abut each other is in a range of 2.5 mm&#x2266;S&#x2266;5.5 mm.

Developing apparatus and image forming apparatus

An image forming apparatus is provided, which controls an appropriate developer amount for a desired image so that an image defect such as an unclear font or a white area is prevented, resulting in a stable image formation for a long term. A developer regulating member has a resistance value varying depending on a voltage to be applied. A control device changes over the voltage to be applied to the developer regulating member during the image formation according to image information and changes a potential difference between the developer carrying member and the developer regulating member.

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.

An image forming apparatus includes an image bearing member; a charging roller cooperable with the image bearing member to form a nip therebetween, for charging the charging roller is rotatable for counterdirectional peripheral movement relative to the image bearing member at the nip; a developing unit for developing with a developer an electrostatic image formed on the image bearing member; wherein the potential of a potential changing portion of the image bearing member changes with respect to the peripheral moving direction of the image bearing member; and wherein at tA (sec) after arrival at an upstream end of the nip, of the potential changing portion, the developing unit is supplied with a voltage for collecting particles from the image bearing member to the developing unit, where tA (sec) is a sum of a time duration required for a surface of the charging roller to move from the upstream end of the nip to a downstream end of the nip and a time duration required for a surface of the image bearing member to move from the downstream end of the nip to a developing zone of the developing unit.

Image forming apparatus with image bearing member particle collection using timed voltage application to the apparatus developing unit

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

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.

Growing community of inventors

Suntou-gun, Japan

Norio Takahashi