Ricoh Company, Ltd.

Daichi Hisakuni

Hiroshi Yamashita

Tsuneyasu Nagatomo

Keiji Makabe

Kohsuke Satoh

Minoru Masuda

Ryota Inoue

Junichi Awamura

Junichi Watanabe

Yuka Mizoguchi

Kenji Yoneda

Tomomi Harashima

Daisuke Inoue

Hiroshi Yamada

Kousuke Suzuki

Toyoshi Sawada

Masahiro Ohmori

Hidetaka Kubo

Yasuo Kamada

Akio Takei

Hiroyuki Takeda

Akira Tanaka

Kazumi Suzuki

Akihiro Kaneko

Shintaro Akiyama

Shun Kohri

Provided is an image forming apparatus including an image bearer, a developing unit configured to develop with a toner, an intermediate transfer member, and a transferring unit, wherein the intermediate transfer member is a laminate including a base layer and an elastic layer including particles at a surface thereof to form convex-concave shapes at the surface, the particles have volume resistivity of from 1&#xd7;10ohm*cm through 1&#xd7;10ohm*cm, the toner includes additive, an amount of the additive separated from the toner is from 20 percent by mass through 35 percent by mass relative to a total amount of the additive in the toner when a toner dispersion liquid in which the toner is dispersed in a dispersant is irradiated with ultrasonic wave vibration with an irradiation energy dose of 4 kJ, and the toner has a dielectric constant of 2.6 or greater but 3.9 or less.

Image forming apparatus and image forming method

An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m. The toner satisfies a relation 0.13&#x2264;X/Dn&#x2264;0.16, where X [&#x3bc;m] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00&#xd7;10N at a loading rate of 3.0&#xd7;10N/sec under an environment of 32 degrees C. and 40% RH, and Dn [&#x3bc;m] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.

A toner including: a plate-shaped pigment containing a metal as a main component; and a binder resin containing polyester resin (A) that is insoluble in THF, wherein: a weight average molecular weight (Mw) of a tetrahydrofuran (THF)-soluble component of the toner as determined by gel permeation chromatography (GPC) is 5,000 or higher but 14,000 or lower; and a glass transition temperature (Tg) of a THF-insoluble component of the toner as determined from a differential scanning colorimetry (DSC) curve at first heating in DSC is &#x2212;60&#xb0; C. or higher but 10&#xb0; C. or lower.

Toner, toner stored unit, and image forming apparatus

A toner including toner particles, each toner particle including a toner base particle, and inorganic particles, wherein the inorganic particles include particles of a fluorine-containing aluminium compound, and a liberation ratio of the inorganic particles is 10% or greater but 60% or less.

Toner, toner stored unit, developer, developer stored unit, and image forming apparatus

An image forming apparatus is provided that includes: first and second electrostatic latent image bearers; first and second electrostatic latent image forming devices; first and second developing devices configured to develop first and second electrostatic latent images with a colored toner and a special-color toner to form a colored toner image and a special-color toner image, respectively; a primary transfer device configured to transfer the colored toner image and the special-color toner image onto an intermediate image bearer in an overlapping manner to form a composite toner image; a secondary transfer device configured to transfer the composite toner image onto a recording medium; and a fixing device configured to fix the composite toner image thereon. The special-color toner comprises plate-like and/or film-like pigments. An absolute difference in volume resistivity between the special-color toner and the colored toner is 0.30 log &#x3a9; cm or less.

Image forming apparatus and toner set

A toner is provided. The toner contains a polyester resin. The toner has a glass transition temperature (Tg1st) at first temperature rising of differential scanning calorimetry (DSC) of from 45&#xb0; C. to 65&#xb0; C. The toner includes a component insoluble in tetrahydrofuran (THF) having two glass transition temperatures (Tga1st and Tgb1st) at the first temperature rising of DSC, where Tga1st is in a range of &#x2212;45&#xb0; C. to 5&#xb0; C. and Tgb1st is in a range of 45&#xb0; C. to 70&#xb0; C. The toner includes a component soluble in THF having a glass transition temperature (Tg2nd) at second temperature rising of DSC of from 40&#xb0; C. to 65&#xb0; C.

Toner, developer, and image forming device

A toner includes a base particle; and an external additive covering the base particle. The toner includes a tetrahydrofuran (THF)-insoluble component having a glass transition temperature determined from a DSC curve when heated for the second time of from &#x2212;50&#xb0; C. to 10&#xb0; C. and an average circularity not greater than 0.98, and satisfies the following relation:&#x2212;0.025&#xd7;&#x2266;1.80

Toner, developer, image forming apparatus, and process cartridge

A toner includes a base particle comprising a crystalline polyester resin; and an external additive which is a group of silica particles having a number-average particle diameter of from 0.01 &#x3bc;m to 0.11 &#x3bc;m on the surface of the toner. A number ratio of the silica particles having a circularity not less than 0.8 is 20% or more in the total number of the silica particles.

Toner, developer, and image forming apparatus

Growing community of inventors

Shizuoka, Japan

Daichi Hisakuni