Ricoh Company, Ltd.

Jsr Corporation

Rocoh Company, Ltd.

Hiroyuki Kishida

Toyoaki Tano

Koichi Sakata

Hitoshi Iwatsuki

Shigenori Yaguchi

Hiroshi Tohmatsu

Mariko Takii

Kenichi Mashiko

Masashi Nagayama

Toyoshi Sawada

Minoru Masuda

Kento Takeuchi

Kaede Masuko

Yukie Tanaka

Shinya Nakayama

Hiroshi Hosokawa

Yutaka Takahashi

Saori Yamada

Tohru Suganuma

Yoshihiro Murasawa

Kimitoshi Yamaguchi

Katsuya Nagaya

Kousuke Suzuki

Haruki Murata

Ran Mitsuboshi

Mitsuo Aoki

Hisashi Nakajima

Mitsuru Nakajima

Hyo Shu

Takashi Tsubouchi

Masahiro Seki

Tomomi Suzuki

Yasutada Shitara

Namie Suzuki

Masato Taikoji

Toshio Koike

Kenji Kikuchi

Shinji Tamaki

Yasuaki Iwamoto

Shunji Katoh

Kazuki Yogosawa

Yoshimichi Ishikawa

Hiroshi Ikeguchi

Michiharu Suzuki

Masahide Inoue

Shinya Nakagawa

Keinosuke Kondoh

Takuya Suganuma

Shohichi Sugimoto

Kei Niwayama

Kohsuke Miyazaki

Daisuke Shigeoka

Yumiko Yagi

Masako Horiuchi

A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a coating layer coating the core particle. The coating layer contains chargeable particles and a dispersant. The carrier has an apparent density of from 2.0 g/cmor greater but less than 2.5 g/cm.

Carrier for forming electrophotographic image, developer for forming electrophotographic image, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge

A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a coating layer coating the core particle. The coating layer contains a conductive component comprising an element A, and a coating resin comprising an element B. The element A is undetected in the coating resin by an energy dispersive X-ray spectrometer, and the element B is undetected in the conductive component by the energy dispersive X-ray spectrometer. A standard deviation of a value A/B is 0.4 or less, where the value A/B is a ratio of the element A to the element B in intensity measured by the energy dispersive X-ray spectrometer.

Carrier for forming electrophotographic image, developer, image forming method, image forming apparatus, and process cartridge

A carrier is provided that includes a core particle and a coating layer coating the core particle. The coating layer includes a resin and chargeable inorganic fine particles, and has voids. The resin has an average film thickness of 0.10 μm or larger and smaller than 0.45 μm. The coating layer has a porosity of 0.1% or higher and lower than 2.8%, when the porosity expressed by the following equation:Porosity [%]=1/2×100where, on a cross section of the coating layer, S1 represents a cross sectional area of the voids and S2 represents a cross sectional area of the resin.

Carrier, developer, image forming method, and process cartridge

A carrier can be used for forming an electrophotographic image. The carrier contains a core particle and a coating layer coating the core particle. The coating layer contains a chargeable particle. The carder has an internal void ratio of 0.0% or greater but less than 2.0%, and an apparent density of 2.0 g/cmor greater but less than 2.5 g/cm.

A carrier for developing an electrostatic latent image is provided. The carrier comprises a core particle having an internal void ratio of from 0.0% to 2.0% and a coating layer coating the core particle. The coating layer contains flat chargeable particles satisfying Formula 1 blow:1.0≤R1/R2≤3.0  Formula 1where R1 [nm] and R2 [nm] represent a major axis and a thickness, respectively, of each of the flat chargeable particles. The carrier has an apparent density of from 2.0 to 2.5 g/cm.

Carrier for developing electrostatic latent image, two-component developer, image forming apparatus, process cartridge, and image forming method

A developing apparatus includes an electrostatic latent image bearer, a developing sleeve, a case, and an air filter. The case accommodates a two-component developer and the developing sleeve. The air filter is attached to the case. The air filter has a thickness of 2 to 20 mm and has a density gradient with a pressure loss of 2 to 40 Pa at a wind speed of 10 cm/s. The air filter forms an airflow sucked into the case from a gap between the developing sleeve and the case and forms an airflow discharged from the case through the air filter. The two-component developer accommodated in the case contains a magnetic particle a surface of which is coated with a resin layer. The resin layer contains at least one type of chargeable particle.

Developing apparatus, developer for electrophotographic image formation, electrophotographic image forming method, and electrophotographic image forming apparatus

An object of the present invention is to provide an optical filter having excellent visible light-cut characteristics and near-infrared rays transmission properties at a specific wavelength that are compatible with one another even in the case where the incident angle is increased, according to reduction in height of equipment on which an optical sensor device is provided. The optical filter of the present invention includes a base material (i) including a resin layer containing a compound (Z) having an absorption maximum in the wavelength region of 700 to 930 nm, and a dielectric multilayer film formed on at least one surface of the base material (i), and has specific optical properties.

Optical filter and optical sensor device

A carrier for forming an electrophotographic image is provided. The carrier includes a core particle comprising a manganese-based ferrite particle having an apparent density of from 2.0 to 2.2 g/cmand a magnetization of from 44 to 52 emu/g in a magnetic field of 500 Oe; and a coating layer coating a surface of the core particle. The coating layer contains a carbon black, an inorganic particle A, and an inorganic particle B. The inorganic particle A and the carbon black each have a concentration gradient in a thickness direction of the coating layer. A concentration of the inorganic particle A increases toward a surface of the coating layer, and a concentration of the carbon black decreases toward the surface of the coating layer.

Carrier, developer, method, and apparatus for forming electrophotographic image, and process cartridge

A carrier for developing an electrostatic latent image includes a core material particle and a resin layer covering a surface of the core material particle. The resin layer includes a resin and at least one kind of a fine particle. At least one kind of the fine particles includes a chargeable fine particle. The chargeable fine particle has a long diameter of 400 to 900 nm. The chargeable fine particle has a shape factor SF-1 of 160 to 250.

Carrier for developing electrostatic latent image, two-component developer, developer for replenishment, image forming device, process cartridge, and image forming method

A carrier for a developer of an electrostatic latent image, the carrier including: core particles having magnetism; and a coating layer coating a surface of each of the core particles, wherein the coating layer includes two or more kinds of inorganic particles, at least one kind of inorganic particles among the two or more kinds of inorganic particles is inorganic particles A having conductivity and a peak particle diameter of from 300 nm through 1,000 nm, and surface roughness of the carrier calculated by Formula 1 below is from 1.10 m/g through 1.90 m/g,C&#x2212;F&#x2003;&#x2003;Formula 1where C is a BET specific surface area (m/g) of the carrier and F is a BET specific surface area (m/g) of the core particles.

Carrier for developer of electrostatic latent image, developer, and image forming apparatus

A carrier including a resin layer including at least one kind of particles, wherein the at least one kind of the particles are particles of barium sulfate, wherein an amount of Ba detected is 0.3 atomic % or greater in a Ba analysis through X-ray photoelectron spectroscopy (XPS) of the carrier, and wherein circle-equivalent diameters of the particles of the barium sulfate are 400 nm or greater but 900 nm or smaller.

Carrier, developer, image forming apparatus, developer stored unit, and image forming method

A developing device, including: a developer containing toner and carrier; and developer bearer configured to have surface thereof bear the developer and endlessly move, and to develop latent image over surface of latent image bearer by supplying toner in developer to latent image in developing region facing the latent image bearer, wherein carrier contains fine particles, value X in volume resistivity R (=10) (&#x3a9;&#xb7;cm) of carrier is 11.5-16.0, developer bearer includes: magnetic field generating unit including a plurality of magnetic poles; and developing sleeve having a cylindrical shape enclosing magnetic field generating unit, and configured to bear developer over outer circumferential surface of cylindrical shape by magnetic force of the magnetic field generating unit and perform surface moving by rotating relative to developing device body, and developing device includes developing sleeve voltage applying unit configured to apply AC component-containing voltage to developing sleeve.

Developing device and image forming apparatus

Provided is an electrostatic latent image developing white toner, including: a white toner including at least a binder resin, a white pigment, and a release agent; and a magnetic carrier including at least a core material, and a coating layer coating the core material and made of a coating resin and conductive particles, wherein Ra of the magnetic carrier is in a range of from 0.50 &#x3bc;m to 1.00 &#x3bc;m, and a bulk density of the magnetic carrier is in a range of from 2.08 g/cmto 2.24 g/cm.

Electrostatic latent image developing white developer, image forming method, image forming apparatus, and process cartridge

A carrier includes a core and a covering layer covering the core and including at least carbon black and a filler. The maximum height Ry of the surface of the carrier is from 4.0 &#x3bc;m to 5.0 &#x3bc;m.

Carrier, two-component developer, developer for replenishment, process cartridge, image forming apparatus, and image forming method

A carrier for developing electrostatic latent images is provided. The carrier includes a magnetic core particle and a resin layer coating a surface of the magnetic core particle. The resin layer includes a particulate material A having a volume average particle diameter (a) and a particulate material B having a volume average particle diameter (b). The volume average particle diameter (a) of the particulate material A is the largest among volume average particle diameters of all particulate materials included in the resin layer, and an inequation 100&#x2265;(a)/(b)&#x2265;5 is satisfied. The particulate material A is barium sulfate.

Carrier for developing electrostatic latent images, two-component developer, image forming apparatus, toner storing unit, and supplemental developer

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Shizuoka, Japan

Hiroyuki Kishida