Ricoh Company, Ltd.

Bing Shu

Mitsuo Aoki

Hiroto Higuchi

Maiko Kondo

Fumihiro Sasaki

Yasuaki Iwamoto

Hiroaki Matsuda

Hiroshi Nakai

Koji Suzuki

Yasushi Koichi

Tadashi Kasai

Yutaka Takahashi

Kumi Hasegawa

Setsuo Soga

Shinya Nakayama

Toyoshi Sawada

Shinichi Kuramoto

Masashi Nagayama

Naohito Shimota

Keiko Shiraishi

Shigeru Watanabe

Yuji Suzuki

Shin Hasegawa

Minoru Masuda

Masahide Yamashita

Shinji Tamaki

Masaru Tanaka

Akihiro Itoh

Haruji Mizuishi

Hiroshi Mizusawa

Mikio Ishibashi

Yoshihiro Suguro

Hiroyuki Yoshikawa

Kazuyuki Yazaki

In an image forming apparatus configured to electrostatically transfer a toner image formed on an image carrier to a recording medium with image transferring means of the present invention, pressure is applied between the image carrier and the image transferring means. Toner is provided with relatively high hardness in accordance with the pressure beforehand. Image transfer is effected by reducing a potential difference between the image carrier and the recording medium while maintaining an electric field around the toner the same.

Image forming apparatus to prevent toner deformation

An image forming apparatus comprising: a latent image support for supporting a latent image and a developing device configured to us toner to develop the latent image on said latent image support, the estimated average halftone granularity of the toner imager after developing being 0.25 or less.

Image forming method and image forming apparatus for same

An electrophotographic image forming apparatus capable of reliably forming an image with density gradation, one which does not have a low-quality appearance. The estimated average halftone granularity of the toner image after developing but before electrostatic transfer was set at 0.25 or less. The average halftone granularity was found by measuring the granularity of a toner image at locations of different average brightness by means of newly proposed formula, and averaging the measured values for which the average brightness is 40 to 80. The estimated average halftone granularity was obtained by estimating the average halftone granularity of the toner image on a photoreceptor by means of a newly proposed method.

A toner for electrophotography contains a binder resin, a charge control agent, and a colorant. The colorant is a black iron oxide compound containing 10 to 45% by weight of titanium component calculated in terms of Ti atom in relation to Fe atom when measured by wavelength dispersive X-ray fluorescence spectrometry. Peaks at Bragg angle 2&#x3b8; of the toner to CuK&#x3b1; X-ray are peak A at 32.9 degrees &#xb1;0.3 degrees and peak B at 35.5 degrees &#xb1;0.3 degrees, and X ray intensity ratio between peaks A and B (A/B) is in the range of 0.3 to 2.0 at a scan speed of 0.5 to 4 degrees/min.

Toner for electrophotography, and image fixing process, image forming process, image forming apparatus and process cartridge using the same

A toner for forming a full color image, which includes a colorant and a binder resin including a polyester resin which is prepared by a polycondensation ester reaction in the presence of a titanium-containing catalyst selected from the group consisting of halogenated titanium, titanium diketone enolates, titanium carboxylates, titanyl carboxylates, and salts of titanyl carboxylates. A toner kit including a yellow toner, a magenta toner, a cyan toner and a black toner, wherein each of the toners is the toner mentioned above. An image forming apparatus including an image bearing member; a charger; a light irradiator; a developing device configured to develop an electrostatic latent image with a developer including the toner mentioned above; a transfer device; and a fixing device.

Dry toner, toner kit, and image forming apparatus and process cartridge using the dry toner

The image forming apparatus comprises a photoconductor, a latent electrostatic image forming unit for forming a latent electrostatic image on the photoconductor, a developing unit for developing the latent electrostatic image using a developer comprising a toner to form a visible image, a transfer unit for transferring the visible image to a recording medium, a cleaning unit for removing the developer remained on the photoconductor surface and a developer amount detection unit for detecting developer amount adhering to the photoconductor surface by a reflecting photosensor, wherein the developer stirring time per copy when one copy is made from an original, is 2 to 6 times the developer stirring time per copy when two or more copies are made from the original, wherein the toner comprises at least a binder resin and a wax, and the dynamic frictional coefficient of the toner is 0.15 to 0.45.

Image forming process and image forming apparatus

A toner including a binder resin including a crystalline polyester and a non-crystalline resin; a release agent; and a black metal-containing material having a saturation magnetization not greater than 50 emu/g. A toner container containing the toner. A fixing method including passing a support with the toner image thereon through a nip between two cylindrical rollers while applying a pressure not greater than 1&#xd7;10Pa to the two cylindrical rollers, wherein one of the cylindrical rollers which contacts the toner image has a thickness not greater than 1.0 mm. An image forming method including developing an electrostatic image with the toner to form a toner image; transferring the toner image onto a receiving material; and fixing the toner image by the fixing method mentioned above. A process cartridge including an image bearing member and a developing device using the toner.

Toner for forming image, method for developing electrostatic latent image, method for fixing toner image, image forming method and process cartridge using the toner

In an image forming apparatus, a toner image is formed on a photosensitive element and a transfer roller, which carries a transfer medium, is pressed against a photosensitive element at a pressure of from 20.4 N/cmto 200 N/cm.

Image forming apparatus and image forming method

In a copier which is an image-forming apparatus comprising a photoconductor, a developing apparatus, transfer apparatuswhich transfers a toner image formed on the photoconductorto a transfer material by heat and pressure using a transfer roller, and a fixing apparatus which fixes the toner image transferred to the transfer material, on the transfer material, a heater, temperature detection apparatusand temperature control apparatus are provided which controls the temperature to within a range of from the glass transition temperature (Tg) to the softening temperature (Tm) of the toner, and lower than the fixing temperature of the fixing apparatus

Image-forming apparatus and image-forming method

A toner for developing an electrostatic latent image, comprising a colorant, a releasing agent and a binder resin, wherein said binder resin comprises a first, non-linear resin, a second, linear resin, and a modified wax comprising a wax moiety and a vinyl polymer moiety having an ester group content of 8 to 30% by weight based on the weight of the vinyl polymer moiety.

Toner for developing electrostatic latent image, toner cartridge, developer, developer cartridge, image forming method, and image forming apparatus

A toner including toner particles including a binder resin and a release agent, wherein when the toner is molded into a plate upon application of a pressure of 478 kg/cm, the toner plate has a surface having a coefficient of static friction of from 0.20 to 0.40. An image forming apparatus including an image bearing member, an image developer to form a toner image on the image bearing member, an image transferer configured to transfer the toner image on a receiving material and a fixer configured to fix the toner image thereon, wherein the apparatus has a waiting time not longer than 15 seconds, and a maximum power consumption not greater than 1.5 KW and 30 W in an image forming state and in a standby state, respectively, wherein the toner is the toner mentioned above.

Toner, method for manufacturing the toner, and image forming method and apparatus using the toner

In a developing device having a developing zone where an image carrier and a developer carrier face each other, the developer carrier carrying a developer thereon moves at a linear velocity of 150 mm/sec or above, but below 500 mm/sec. The amount of the developer conveyed to the developing zone by the developer carrier is between 65 mg/cmand 95 mg/cm. A magnetic flux generated on the developer carrier in the developing zone by a magnetic pole has a flux density having an attenuation ratio of 40% in the direction normal to the developer carrier. The flux density in the direction normal to the developer carrier, as measured on the surface of the developer carrier, is between 100 mT and 200 mT. Magnetic grains, which constitute the developer together with toner grains, have a saturation magnetization value of 40&#xd7;10&#xd7;4 &#x3c0;Wb&#xb7;m/kg or above, but below 50&#xd7;10&#xd7;4 &#x3c0;Wb&#xb7;m/kg.

Developing device having a developer forming a magnet brush

An image forming apparatus including a photoconductor, and a developing unit having a developing sleeve for carrying a developer and a developer regulating plate for regulating the amount of the developer carried on the sleeve, wherein the developer is composed of a carrier and a toner, wherein that portion of the toner which has a particle diameter of 2.0-4.0 &#x3bc;m accounts for 30-70% of a total number thereof, and wherein the developer regulating plate is grounded so that when the developing sleeve is applied with a bias voltage, an electric field is formed between the developer regulating plate and the developing sleeve, whereby toner deposits on the developing sleeve are transferred to the developer regulating plate.

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Shizuoka, Japan

Bing Shu