Canon Kabushiki Kaisha

Tomonori Matsunaga

Tetsuo Uesugi

Kentaro Yamawaki

Noriyoshi Umeda

Masaaki Matsushita

Shohei Kototani

Masaki Furutani

Masamichi Sato

Hiroomi Matsuzaki

Kunihiko Nakamura

Kenta Kamikura

Tsutomu Shimano

Kojiro Yasui

Tsuneyoshi Tominaga

Hiroki Ogino

Akane Masumoto

Tatsuo Fujisaki

Shiro Kuroki

Sara Yoshida

Toshihiko Katakura

Shinsuke Mochizuki

Yuhei Terui

Wataru Takahashi

Shinji Katagiri

Shuichi Tetsuno

Takayuki Tanaka

Junichi Matsumura

Yuichiro Hirata

Shohei Tsuda

Koji An

Go Shindo

Shohei Ishio

Hidekazu Fumita

Hiroko Yokoyama

Satoshi Otsuji

Koji Yamaguchi

Toshiyuki Karakama

Ryuta Murakami

Yasuyuki Ishii

Toshiaki Takeuchi

Jun Miura

Yoshihiro Mitsui

Kohei Matsuda

Norihito Naito

Takayuki Kanazawa

Koji Abe

Takeo Shoji

Takahiro Ikeda

Masahito Kato

Yasutaka Yagi

Shunsuke Mizukoshi

Takashi Mukai

Yasukazu Ikami

Kazunori Hashimoto

Kosuke Ikada

Koichiro Takashima

Katsuhiro Kojima

Akinobu Saito

An image forming apparatus includes a rotatable image bearing member and a rotatable developing member to carry developer made up of toner particles and carrier particles adhered to surfaces of the toner particles. Where a pressing force pressing the developing member against the image bearing member is F1, a total number of the carrier particles interposed between the toner particles and the image bearing member is N1, and an adhesion Ft between a carrier particle and a toner particle, measured when the carrier particle is pressed against the toner particle with F1/N1 that is a pressing force per unit carrier particle, and an adhesion Fdr1 between the carrier particle and the image bearing member, measured when the carrier particle is pressed against the image bearing member with F1/N1, satisfy Ft≤Fdr1.

Image forming apparatus

An image forming apparatus includes a rotatable image bearing member and a rotatable developing member to carry developer made up of toner particles and carrier particles adhered to surfaces of the toner particles. Where a pressing force pressing the developing member against the image bearing member is F, a total number of the carrier particles interposed between the toner particles and the image bearing member is N, and an adhesion Ft between a carrier particle and a toner particle, measured when the carrier particle is pressed against the toner particle with F/Nthat is a pressing force per unit carrier particle, and an adhesion Fdrbetween the carrier particle and the image bearing member, measured when the carrier particle is pressed against the image bearing member with F/N, satisfy Ft≤Fdr

A toner comprising: a toner particle including a binder resin; and an external additive, wherein the external additive includes an external additive A which is silica fine particles and an external additive B which is a fatty acid metal salt, the external additive A has a specific particle diameter, a coverage ratio of a surface of the toner particle with the external additive A is from 60% to 80%, and where an average theoretical surface area obtained from a number average particle diameter, a particle size distribution and a true density of the toner particle is denoted by C (m/g), an amount of the external additive B is denoted by D (parts by mass) and a coverage ratio of the surface of the toner particle with the external additive B is denoted by E (%), following formulas are satisfied:0.05&#x2264;&#x2264;2.00/()&#x2264;50.0.

Toner

A toner comprising: a toner particle that contains a release agent-containing toner base particle, and an organosilicon polymer on a toner base particle surface, and an external additive A, the organosilicon polymer has a T3 unit structure; the organosilicon polymer forms protruded portions on the toner base particle surface; the number-average value of the protrusion height H is from 30 nm to 300 nm; the ratio of the number-average primary particle diameter R of the external additive A to the number-average value of the protrusion height H is from 1.00 to 4.00; the number-average primary particle diameter R of the external additive A is from 30 nm to 1,200 nm; and, in an image obtained by observing the toner surface with SEM, the area percentage for the bright region area in the image with reference to the total area of the image is from 30.0% to 75.0%.

A process cartridge includes a seal member contacting an image bearing member upstream in the rotation direction of the image bearing member from a cleaning member and allowing the developer to move from upstream in the rotation direction from the contact part between the seal member and the image bearing to downstream from the contact part while regulating movement from downstream to upstream from the contact part. The developer has surface protrusions containing an organic silicon polymer, wherein either (i) the work function of the seal member is greater than the work function of the developer when the developer has a negative charging polarity and is smaller than the work function of the developer when the developer has a positive charging polarity, or (ii) the absolute value of the difference between the work function of the seal member and the work function of the developer is within a predetermined range.

Process cartridge, image forming apparatus and cleaning apparatus

Provided is a toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an external additive A and an external additive B, the external additive A is an organosilicon polymer fine particle, the number-average particle diameter of primary particles of the organosilicon polymer fine particle is from 30 to 300 nm, the external additive B is a silica fine particle, the number-average particle diameter of primary particles of the silica fine particle is from 100 to 300 nm, the fixing rate of the external additive A to the toner particle according to a water washing method is less than 30%, and the fixing rate of the external additive B to the toner particle according to the washing method is at least 30%.

A toner comprising a toner particle that contains a binder resin and a wax; in a microcompression test under a maximum load condition of 1.1&#xd7;10N, a force applied to the toner particle when a percentage deformation of the toner particle with reference to a number-average particle diameter of the toner particle at 25&#xb0; C. reaches 15% is 0.10 to 1.00 mN and the force applied to the toner particle when the percentage deformation at 45&#xb0; C. reaches 15% is 0.10 to 0.40 mN; and when the force applied to the toner particle is a variable and the percentage deformation of the toner particle is from 15 to 30%, the rate of increase in the percentage deformation of the toner particle at 25&#xb0; C. and the rate of increase in the percentage deformation of the toner particle at 45&#xb0; C. satisfy specific formula.

A image-forming apparatus includes a plurality of process cartridges each having a toner and an image bearing member, and has an intermediate transfer member, wherein the toner comprises a toner particle that contains a toner base particle and a prescribed organosilicon polymer on the surface of the toner base particle, and the organosilicon polymer forms protruded portions on the surface of the toner base particle, for the protrusions having a protrusion height H from 40 nm to 300 nm, the numerical proportion P(D/w) of protruded portions having a ratio of the protrusion diameter D to the protrusion width w in a prescribed range is at least 70 number %, and one of the plurality of process cartridges has a carbon black-containing black toner, and the weight-average particle diameter of this black toner is smaller than that of the toner present in the other process cartridges.

Image-forming apparatus

A toner comprising a toner particle that contains a toner base particle and an organosilicon polymer on a surface of the toner base particle, wherein the organosilicon polymer forms protruded portions with a prescribed structure on the surface of the toner base particle, and in the toner cross section, when the protrusion width w is the length of the segment where a protruded portion and the toner base particle form a continuous interface, the protrusion diameter D is the maximum length of a protruded portion, and the protrusion height H is the length from the peak of the protruded portion to the line along the circumference of the toner base particle surface, the numerical proportion of these protruded portions having a ratio D/w of the protrusion diameter D to the protrusion width w from 0.33 to 0.80, is a least 70 number %.

Toner comprising a surface layer of an organosilicon polymer protrusion

A developer accommodating unit for accommodating a developer for image formation includes a flexible container provided with an openingfor permitting discharge of the developer, a frame for accommodating the flexible container and for accommodating the developer to be discharged from the flexible container, and an urging memberfor urging a developer accommodating bag toward the frame for accommodating the developer accommodating bag. By this, it is possible to satisfactorily effect discharge of the developer from the flexible developer accommodating bag

Developer accommodating unit, process cartridge and electrophotographic image forming apparatus

An image forming apparatus that forms an image on a recording medium includes an image-bearing-unit support member, a developing unit support member, a plurality of light exposure units, and a light-exposure-unit operating member. The image-bearing-unit support member is movable between the inside and the outside of the image forming apparatus while supporting a plurality of image bearing units which each include an image bearing member. The developing unit support member is movable independently of the image-bearing-unit support member. The plurality of light exposure units each cause a corresponding one of the image bearing members to be exposed to light so as to form an electrostatic latent image. The light-exposure-unit operating member moves the light exposure units relative to the developing unit support member.

A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0&#xd7;10N, of from 200 MPa to 1,100 MPa.

Provided is a toner containing a colorant and a binder resin, wherein, in a wettability test of the toner with respect to a methanol/water mixed solvent, the methanol concentration when the transmittance of light at a wavelength of 780 nm is 50% is at least 5.0 volume % and not more than 30.0 volume %, and the interparticle force measured by rupturing a consolidation of the toner formed by compression of the toner with a load of 78.5 N is at least 1.0 nN and not more than 25.0 nN.

A toner comprising a toner particle that contains a binder resin and a release agent, wherein the toner particle has a surface layer that contains an organosilicon polymer and the luminance histogram of a backscattered electron image of the toner particle has two peak values Pand Pand a minimum value V between Pand P, Poriginates from the organosilicon polymer, and the luminance giving Pand Pare in specific ranges, percentages for Pand Pare each at least 0.50%, and using the luminance Bl at V as a reference point, specific relationships are satisfied by A, AV, and A, where Ais the total number of pixels at luminance from 0 to (Bl&#x2212;30 ), AV is the total number of pixels at luminance from (Bl&#x2212;29 ) to (Bl+29 ), and Ais the total number of pixels at luminance from (Bl+30 ) to 255.

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Suntou-gun, Japan

Tomonori Matsunaga