Ricoh Company, Ltd.

Yasushi Koichi

Koji Suzuki

Tadashi Kasai

Mitsuo Aoki

Yutaka Takahashi

Bing Shu

Shigekazu Enoki

Kumiko Hatakeyama

Setsuo Soga

Osamu Ariizumi

Shinji Kato

Shin Hasegawa

Norimasa Sohmiya

Kazunori Karasawa

Toshiyuki Kabata

Masahide Yamashita

Hiroto Higuchi

Koichi Kato

Jun Yura

Maiko Kondo

Toshiaki Higaya

Chikara Imai

Kumi Hasegawa

Shigeru Watanabe

Shinya Nakayama

Tetsuya Fujioka

Yasuaki Iwamoto

Fumihiro Sasaki

Makoto Arai

Susumu Tatsumi

Toshitaka Yamaguchi

Kazuo Murai

Tadahiro Eda

Wakako Murakami

Yoshiyuki Tanimoto

Tsumori Satoh

Mituo Aoki

Mutuko Funaki

Haruzi Mizuishi

A transfer residual toner that has not been electrostatically transferred onto a transfer paper P at a transfer nip and remains on a surface of a photosensitive element is temporarily retained by an elastic blade of a toner retaining unit in a mechanical manner before reaching a latent image forming area. When passing through the latent image forming area, the transfer residual toner is returned onto the surface of the photosensitive member at such a timing that writing is not performed by an exposing unit on the surface of the photosensitive element.

Image forming apparatus, process cartridge, cleaning system, and image forming apparatus with cleaning system

An image forming apparatus includes an image carrier, a developing unit, a concentration sensor, a toner supplying unit, a developer supplying unit, an ejector, and a condition detector. The image carrier forms a latent image thereon. The developing unit develops the latent image formed on the image carrier with a two-component image developer including toner particles and carrier particles. The concentration sensor detects a toner ratio in the developing unit. The toner supplying unit supplies fresh toner particles to the developing unit. The developer supplying unit supplies fresh image developer to the developing unit. The ejector ejects the image developer to an outside of the developing unit. The condition detector detects a condition of the image developer used for an image forming operation to determine a supply amount of the image developer to supply to the developing unit. The condition includes a degradation level of the image developer.

Image forming apparatus including controller to detect condition of image developer

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

Image processing apparatus, process cartridge, and cleaning system with residual toner retaining unit

An image forming apparatus of includes a developing device bifunctioning as a cleaning device for collecting toner grains left on a photoconductive drum after the transfer of a toner image from the drum to a paper sheet or similar image transfer medium. In the event of toner collection, a DC voltage is applied that causes the residual toner to move from the drum toward a developing sleeve. A main-pole magnet generates, at a position where the developing sleeve faces the drum, a magnetic field of between 100 mT and 200 mT in a direction normal to the surface of the sleeve.

Image forming apparatus, process cartridge and cleaningless system

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.

An image forming apparatus includes an image carrier, a charging device configured to uniformly charge a surface of the image carrier with a charging member applied with a bias of a first polarity (e.g. a negative polarity) for charging. A latent image forming device forms a latent image on the surface of the image carrier uniformly charged. A developing device develops a latent image by depositing toner grains of the first polarity on the latent image to thereby form a corresponding toner image. A transferring device forms an electric field between the image carrier and a moving member that serves as a movable contact with the image carrier to thereby transfer the toner image from the surface of the image carrier to the moving member or to a recording member nipped between the image carrier and the moving member. A polarity controlling device sets residual toner to a second polarity (e.g. a positive polarity) opposite to the first polarity, before the residual toner left on the image carrier by the transferring device is conveyed to a corresponding position to the charging member.

Image forming apparatus controlling polarity of residual toner and process cartridge for use in the same

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

An image forming method, comprising passing a toner image-bearing sheet through a nip defined between two rollers including a heater roller to fix the toner image on the sheet, wherein the toner image is formed from a toner comprising a binder resin, and a colorant, wherein the toner image before the passage through the nip has a toner volume Vand a toner image area S, wherein the toner image after the passage through the nip has a toner volume Vand a toner image area S, and wherein a volume change Vt and an area change St defined by the formulas shown below are 30% or less and 20% or less, respectively:(%)=(1&#x2212;2)/1&#xd7;100(%)=(2&#x2212;1)/1&#xd7;100.Alternatively, the toner image before the passage through the nip has a surface roughness of 2.5 &#x3bc;m or less.

Image forming method and toner for use in the 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

An image forming method, comprising passing a toner image-bearing sheet through a nip defined between two rollers including a heater roller to fix the toner image on the sheet, wherein the toner image is formed from a toner comprising a binder resin, and a colorant, wherein the toner image before the passage through the nip has a toner volume Vand a toner image area S, wherein the toner image after the passage through the nip has a toner volume Vand a toner image area S, and wherein a volume change Vt and an area change St defined by the formulas shown below are 30% or less and 20% or less, respectively:(%)=()/(%)=()/Alternatively, the toner image before the passage through the nip has a surface roughness of 2.5 &#x3bc;m or less.

Toner, developer and image forming method using the toner

In an image forming apparatus, a voltage for a charger, a voltage for a light source for exposure or similar process condition for image formation is controlled such that a control parameter particular to image formation, e.g., the surface potential of an image carrier (light portion or dark portion) or the amount of toner deposited on the image carrier lies in a first predetermined tolerance width of a target value. Subsequently, the process condition is controlled such that the control parameter lies in a second predetermined tolerance width of the target value which is narrower than the first tolerance width. As a result, the control parameter is confined in the second tolerance width for achieving the final control accuracy.

Method and apparatus for controlling process condition for image

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Kanagawa, Japan

Yasushi Koichi