Konica Corporation

Konica Minolta Business Technologies, Inc.

Konishiroku Photo Industry Co., Ltd.

Kunio Shigeta

Satoshi Haneda

Yotaro Sato

Masakazu Fukuchi

Hisayoshi Nagase

Hiroyuki Nomori

Tadayoshi Ikeda

Akitoshi Matsubara

Toshihide Miura

Hiroshi Akita

Akihiko Itami

Jiro Takahashi

Shizuo Morita

Hiroyuki Tokimatsu

Masahiro Onodera

Seiko Itagaki

Toru Komatsu

Sachie Hosokoezawa

Sachie Hosogoezawa

Hiroshi Yamazaki

Masao Asano

Takenobu Kimura

Isao Endo

Yoko Yamamoto

Kenzi Tsuzita

Kiyoshi Kimura

Shuta Hamada

Hiroyuki Takagiwa

Shigeaki Tokutake

Seiji Yamaguchi

Hiroya Masaki

An image forming method, comprising: forming an electrostatic latent image on a rotatable organic photoreceptor; forming a developing brush with a developing agent containing a toner on a rotatable developing sleeve; and bringing the developing brush in contact with the photoreceptor at a developing region so as to visualize the electrostatic latent image into a toner image. The photoreceptor comprises a conductive support member, an intermediate layer containing a binder resin and inorganic particles which have a number average primary order particle size of 3 to 200 nm, and a photosensitive layer provided on the intermediate layer, and the rotating direction of the developing sleeve is counter to that of the photoreceptor at the developing region.

Image forming method, image forming apparatus and organic photoreceptor

A toner image is formed while a developing sleeve is rotated in a direction counter to that of an organic photoreceptor at the developing section and a developing agent contains toner which contains toner particles having a particle diameter of 0.7&#xd7;(Dp50) or less in an amount of 8 number % or less and has water content of 0.1 to 2.0 mass % under an environment of 30&#xb0; C. and 80% RH, where Dp50 represents 50% number % particle diameter of toner particles.

Image forming method and image forming apparatus

In an image forming apparatus provided with an organic photoreceptor; a developing device to bring a developing brush in contact with the organic photoreceptor so as to visualize an electrostatic latent image to toner image; a transfer device; and an agent supplying device to provide a surface energy lowering agent to the surface of the organic photoreceptor. The electrostatic latent image is visualized to the toner image while the developing sleeve is rotated in a direction counter to that of the organic photoreceptor at the developing section.

There are described an image forming method and apparatus, which enable to form an electrophotographic image having high image density and excellent color reproducibility. The method includes: applying a uniform surface potential to an organic photoreceptor; irradiating light, having a wavelength in a range of 350-500 nm, on the photoreceptor, to form a latent image on the photoreceptor; and contacting a developing blush, containing toner and carrier, with the organic photoreceptor so as to form a visible toner image. The developing sleeve bears developing agent including the toner and the carrier. An absolute value of an electric charge potential of non-exposed area on the organic photoreceptor is in a range of 250-450 Volts and the developing sleeve is rotated in a counter direction, being counter to a rotating direction of the organic photoreceptor.

A development apparatus has: a housing in which a developer supplying/collecting unit and a developer stirring unit are arranged with a circular passage for carrying developer; a developer carrying member placed at a front side of the developer supplying/collecting unit; a developer supplying/collecting section for carrying the developer; and two developer stirring sections arranged in the front-and-rear direction so as to face, wherein, a toner supplying opening is formed above a position where the two developer stirring sections face and at an upstream side in a developer carrying direction, the two developer stirring sections are rotated at the facing position to move peripheries in a forward direction, the developer carrying direction by the two developer stirring sections is substantially opposite to one by the developer supplying/collecting section, and developer carrying capability of the two developer stirring sections is set to be made equal to that of the developer supplying/collecting section.

Development apparatus and image formation apparatus

A developing device has a rotary developer carrier, a rotary developer supply and collection member, a first and second rotary developer stirring members for stirring the developer while conveying and circulating the developer between them in the direction opposite to each other and having the same developer conveyance power, and a third rotary developer stirring member having a zero conveyance power in the rotary axis direction, which are provided in a housing in parallel with each other in this order in the direction to leave a latent image carrier. A toner replenishment inlet is provided at an upper part where the second and third stirring members face each other, and on an upstream side of the second stirring member in the developer conveyance direction, and the second and third stirring members are rotated downwardly at the position where both developer stirring members face each other.

Developing device and image forming apparatus

In an image forming apparatus, an electrostatic latent image is reverse-developed by a developing device with a development bias applied, through conveying a two-component developer layer containing toner particles having a volume-average particle diameter of 3 to 5 &mgr;m by a developer carrying member rotatably provided, a developed toner image is transferred onto a recording medium or an intermediate transfer body, and untransferred toner particles remaining on an image forming body having passed a transfer region are removed by a cleaning member provided in pressure contact with the surface of the image forming body. The length in an axis direction of the image forming body of an useless toner image formed on the image forming body at the starting time and the ending time of an image formation sequence denoted by L, the total charge quantity of the toner particles making up the useless toner image is 0.04L &mgr;C or less.

Image forming apparatus including a maximum charge quantity of toner particles forming useless toner

This invention relates to an image forming apparatus which forms an image on a transfer medium using a two-component developing agent by electrophotography. An image forming apparatus according to this invention includes a potential sensor which measures the charging potential on an image forming body and a patch density sensor which detects the toner attraction amount of a patch image. In the image forming apparatus, a toner charge amount Qt (&mgr;C/g) is calculated from the potential of a patch image before and after development detected by the potential sensor and the image density of a developed patch image detected by the patch density sensor, and image formation is performed by setting image formation conditions based on the calculated toner charge amount Qt. To set the image formation conditions, a table which stores in advance an image formation condition corresponding to the toner charge amount Qt is used.

Image forming apparatus

A color image forming method in which a color toner image is formed through superposing toner images of three color toners of yellow, magenta, and cyan and a black toner, wherein each of the color toners is a flattened toner composed of particles each having an equivalent circle diameter d of 5 to 10 (&mgr;m) when viewed from a direction to make a projection area maximum, a thickness t of 1 to 4 (&mgr;m), and a flattening ratio d/t of 2 to 8 represented by a ratio of the equivalent circle diameter d to the thickness t, and the flattening ratio d/t of the particles of the color toners is larger than the flattening ratio d /t of the particles of the black toner.

Color image forming method using flattened toner

An image forming apparatus is provided for obtaining excellent developing properties using toner with small particle diameters and for forming high-quality visual images. In a developing device of an image forming apparatus, a two-component developer is used which satisfies conditions that volume mean particle diameter dt of a toner is 3&tilde;5 &mgr;m (Condition 1), volume mean particle diameter dc of a carrier is 5 dt&tilde;10 dt (Condition 2), and a weight ratio Rw of the toner and the carrier is 1.6 (dt/dc) &times;(&rgr;t/&rgr;c)&tilde;2.4 (dt/dc)&times;(&rgr;t/&rgr;c) (Condition 3, where &rgr;t and &rgr;c are density of the toner and the carrier, respectively). A main magnetic pole M of a rotary sleeve is arranged in the vicinity of the closest position of the rotary sleeve and an image forming body, and the closest distance D between the rotary sleeve and the image forming body satisfies a condition that D is 0.5 H&tilde;0.8 H for the free tip height H of a magnetic brush B of the main magnetic pole M. It is preferable that the actual supplied amount of the toner is regulated within a specific range.

Image forming apparatus with improved developing device

Fixing device and image forming apparatus therewith

In an image forming apparatus, in which toner images formed on an image forming body are formed on double sides of a transfer material, a writing of an image on the image forming body by a writing device according to image data for an intermediate transfer body is conducted before a feeding of the transfer material is started.

Image forming apparatus wherein writing of an image is conducted before feeding of a transfer material is started

The present invention concerns a duplex image forming apparatus, which can form images on both sides of a transfer sheet by employing an intermediate transfer element. The duplex image forming apparatus includes an image bearing member; a toner image forming section to form a toner image on the image bearing member; an intermediate transfer element, shaped like a belt, to bear the toner image transferred from the image bearing member and to convey a transfer sheet; a transfer sheet charging device to apply a bias voltage onto the transfer sheet at the charging position, so that the transfer sheet adheres onto the intermediate transfer element; a first transfer device to transfer the toner image onto the transfer sheet or the intermediate transfer element; a second transfer device to transfer the toner image borne on the intermediate transfer element onto the transfer sheet; and a control section to control a transfer current or a transfer voltage applied to the first transfer device.

Duplex image forming apparatus

In a fixing apparatus for fixing toner images on a transfer material upon which toner images have been placed by applying heat to the transfer material, the fixing apparatus includes: a roll-shaped rotary member for applying heat to the transfer material upon which toner images have been placed, the roll-shaped rotary member including a cylindrical ray-transmitting base member, and a ray absorbing layer for generating heat onto the transfer material upon which toner images have been placed so as to fix the toner on the transfer material, the ray absorbing layer, provided on an outer side of the ray-transmitting base member; a ray irradiating device for irradiating ray to the ray absorbing layer, the ray irradiating device provided inside the cylindrical ray-transmitting base member; bearing member for rotatably supporting the roll-shaped rotary member; flange members provided on both ends of the ray-transmitting base member; and an elastic covering member provided between the flange member and the roll-shaped rotary member for joining each member.

Apparatus for fixing toner images on a transfer material

In an image forming apparatus, a document image is read by an image scanner and image data are applied with image processing and stored in a memory. An image correction device corrects the image data with a different correcting condition depending on whether the image data are used for a toner image on the obverse side of the sheet or for a toner image on the reverse side of the sheet. A fixing device fixes the toner images on the obverse side and the reverse side of the sheet simultaneously.

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Hachioji, Japan

Kunio Shigeta