Canon Kabushiki Kaisha

Keiji Okano

Hiroshi Sato

Akira Domon

Yasushi Shimizu

Hideki Matsumoto

Satoru Motohashi

Seiji Yamaguchi

Masaki Ojima

Satoshi Sunahara

Katsuhiko Nishimura

Kouichi Suwa

Gaku Konishi

Kimio Nakahata

Masahide Kinoshita

Michihito Yamazaki

Masahiro Yoshida

Yasushi Sato

Hiroshi Satoh

Masanobu Saito

Hiroyuki Kimura

Toshio Miyamoto

Takahiro Inoue

Haruhisa Oshida

Koichi Suwa

Tatsunori Ishiyama

Motoi Katoh

Hideaki Hasegawa

Satoshi Yoshida

Tsutomu Kukimoto

Junichi Kato

Masayoshi Shimamura

Kazushige Sakurai

Hiroto Hasegawa

Yasuhide Goseki

Shinichi Tsukida

Keita Nozawa

Motoo Urawa

Takashi Hino

Noboru Kashimura

Tadashi Onimura

Yasuhi Sato

A developer regulating member abutting against a developer carrying member carrying a mono-component developer to regulate the layer thickness of the developer on the developer carrying member has a supported portion supported by a support member, and an abutting portion abutting against the developer carrying member, the surface roughness parameters of this abutting portion satisfying the following expressions (1) to (5):0.30&#x2266;&#x2266;0.170&#x2003;&#x2003;(1)Rpk&#x2266;2.0&#x2003;&#x2003;(2)Rp&#x2266;5.0&#x2003;&#x2003;(3)0.10&#x2266;(100&#x2212;)/100&#x2266;1.30&#x2003;&#x2003;(4)Rpk&#x3c;Rvk,&#x2003;&#x2003;(5)where Sm is a mean spacing [mm] of profile irregularities prescribed by JIS-B0601-1994, Rp is a maximum profile peak height [&#x3bc;m] prescribed by ISO4287-1997, Rpk is an initial wear height [&#x3bc;m] prescribed by DIN4776, Rvk is an oil retaining depth [&#x3bc;m] prescribed by DIN4776, and Mris a profile bearing length ratio 2 [%] prescribed by DIN4776.

Developer regulating member with surface roughness parameters

A memory medium is provided to a cartridge detachably mountable to an image forming apparatus. Into the memory medium, as information for performing charge control, information on the amount of usage of an image-bearing member and information on a charging alternating voltage (a threshold value for selection control of a charging peak-to-peak voltage Vpp) are written. The image forming apparatus includes a charging-bias power-supply circuit, on its body side, including AC oscillation output circuit capable of outputting two or more species of alternating peak-to-peak voltages and an AC detector for detecting an alternating current passing through the image-bearing member. Charge control is performed on the basis of a detected value detected by the AC detector and memory information for the cartridge, whereby good charge control space saving, and cost reduction of the power-supply circuit are compatibly realized.

Process cartridge comprising memory medium storing information for selecting one of a plurality of alternating voltages applied to charging member and such a memory medium

Image forming apparatus having charging member supplied with a plurality of alternating voltages and memory for storing information for selecting the voltages

A charging system includes a rotatable member to be charged, and a rotatable charging member provided with electroconductive particles thereon and forming a nip part with the member to be charged and disposed in the nip part to charge the member to be charged. When the diameter of the member to be charged is defined as LD (mm) and the diameter of the charging member is defined as LC (mm), LD&#x2266;25 and LD&#xd7;LC&#x2267;350. As a result,, in the charging system, and a process cartridge and an image-forming apparatus including such a charging system, an image-bearing member can be made small in diameter.

Charging system, process cartridge and image forming apparatus

A charging apparatus includes a charging member, contactably provided to a member to be charged, for charging the member to be charged; a voltage application device for applying alternating voltages having different peak-to-peak voltages to the charging member; and a determination device for determining a peak-to-peak voltage to be applied to the charging member with respect to a second area of the member to be charged, on the basis of a peak-to-peak voltage corresponding to a minimum current which is not less than a predetermined current of alternating currents through the member to be charged when the alternating voltages having the different peak-to-peak voltages are applied to the charging member with respect to a first area of the member to be charged.

Charging apparatus determining a peak-to-peak voltage to be applied to a charging member

A developing apparatus includes developer carrying member for carrying a developer; wherein the developer carrying member is supplied with a developing voltage comprising a superimposed DC voltage component and AC voltage component to develop an electrostatic latent image formed on an image bearing member; switching means for switching an image density of a developed image on the image bearing member; wherein when the image density of the developed image is made higher than a predetermined image density in accordance with an output of the switching means, the frequency of the AC voltage component is made higher than a predetermined frequency.

Developing apparatus

When a user changes a density adjusting value (developing contrast), and even when variations in the usage state of process characteristics (of the photosensitive body and the developing device) of the cartridge change, the amount of recording agent consumed can be suppressed to be low, and a sharp line image can be recorded. An image forming apparatus of this invention includes an edge detecting portion for detecting an edge of image data, an image data correcting portion for correcting image data inside the edge so as to decrease its density, a laser driving circuit for forming an electrostatic latent image on a photosensitive body, and a correction value determining table for acquiring an instruction value for giving an instruction to correct a density contrast, wherein a correction condition for image data changes in accordance with an instruction value.

Memory device for an image forming apparatus storing characteristics information about a process cartridge detachably attachable to the apparatus

An image forming apparatus which includes an image bearing body and a light beam scanner for exposing the image bearing body, which is charged, based on an image signal and forming an electrostatic latent image on the image bearing body. A rise time or a fall time of a light beam emitted from the light beam scanner is controlled when a pixel density of the electrostatic latent image is switched.

Image forming apparatus with pixel density based light beam control

Process cartridge, image forming apparatus, and image forming method

A developing apparatus includes a developer containing portion containing a developer having a weight average particle diameter of not more than 7 &mgr;m, a developer bearing member for bearing a developer, and an agitating member that agitates the developer contained in the developer containing portion. The agitating member is intermittently driven with respect to rotation of a developing sleeve. The agitating member is driven to rotate for one page every time the image forming apparatus performs a predetermined number of printing operations. A rod member having a crank-like shape may be used as the agitating member and both of the end portions serve as the center of rotation. By controlling the drive of the agitating member, it is possible to effectively adjust the supply of toner to the developing sleeve and prevent the density lowering phenomena caused due to inflow of a large amount of the new toner presented at the rear of the developing container. The agitating member may be positioned closest to the developing sleeve and may be arranged below the toner container. Accordingly, to these arrangements, the image density after printing a low print pattern can be prevented from being lessened to obtain a uniform image density even though a one-component magnetic developer having the weight average particle sized diameter of not more than 7 &mgr;m is used.

Developing apparatus including intermittent developer agitating feature, and image forming apparatus using same

A process cartridge includes an electrophotographic photosensitive member, a developer for developing a latent image formed on the electrophotographic photosensitive member, a developer remaining amount detecting member for detecting a remaining amount of developer in the developer, and a non-volatile memory for memorizing information corresponding to at least the print number of sheets and the developer remaining amount in such a manner that such information can be read out and re-written by an image forming apparatus. The present invention also provides and electrophotographic image forming apparatus to which such a process cartridge can be detachably mounted.

Process cartridge and image forming apparatus including a developer remaining amount detecting member

Developing apparatus and image forming apparatus having first and second voltages applied to a developing satisfying predetermined relationships

The present invention relates to a developing apparatus in which, assuming that a tangent which is in contact with said detecting member on an opening portion side of a developing container in a vertical direction is a first tangent, and a tangent which is in contact with a rotating locus of a first agitating member on an opposite side of the opening portion in a vertical direction is a second tangent, the first tangent is positioned nearer to the opening portion than the second tangent, and a lower end of said partition member is provided between the first tangent and the second tangent.

Developer apparatus featuring a developer container partition portion disposed between a detecting member and an agitating member

The present invention relates to a development density adjusting method in which development density is adjusted by varying ratio of application time of a voltage having the first voltage value to application time of a voltage having the second voltage value in one period, and difference between a potential of the developer bearing member and a potential of the electrostatic latent image, when the voltage having the first voltage value is applied to the developer bearing member.

Development density adjusting method for image forming apparatus

Growing community of inventors

Shizuoka, Japan

Keiji Okano