Fujitsu Corporation

Ricoh Company, Ltd.

Fuji Xerox Co., Ltd.

Other

Atsushi Tano

Tsuneo Mizuno

Hiroki Ohta

Kunihiko Sato

Tetsu Takahashi

Hiroki Ushiroda

Toshihiro Yukawa

Tadashi Kasai

Yutaka Takahashi

Toshihiro Sugiyama

Kazuchika Saeki

Yuuji Sawai

Tomoaki Tanaka

Takehide Mizutani

Jun Shiori

Osamu Endou

Hiroyuki Inoue

Ryuuichi Minbu

Hiroshi Kera

A control unit controls a device that executes an image forming process, compares changes of each toner adhesion amount in an image-density-detection pattern image when a developing-bias control condition is changed, with respect to a toner adhesion amount in an image-density-detection pattern image in a normal status, performs a malfunction-occurrence prediction process according to the degree of each change of the densities, and displays the result.

Image forming apparatus

An image forming apparatus, in which an image forming method is performed, includes an image carrier, an optical writing unit, a developing unit developing a toner image including an output image and a forcible toner consumption image, a transfer unit including an endless moving member to transfer the toner image onto the endless moving member directly or a recording medium carried on the endless moving member, a first remover to remove residual toner from the image carrier after transfer, a toner recycling unit to convey the residual toner to the developing unit, a controller to form the forcible toner consumption image and transfer the forcible toner consumption image onto the surface of the endless moving member, and a second remover to remove the forcible toner consumption image from the endless moving member.

Image forming apparatus and image forming method performed by the image forming apparatus

A transfer device includes an endless belt, an external roller, and an internal roller. The external roller is arranged outside of the loop of the endless belt and the inner roller is arranged inside of the loop of the endless belt. The endless belt is sandwiched between the external roller and the internal roller. A surface hardness of the external roller and a surface hardness of the internal roller are 50 degrees or more in an asker C scale. A logarithm (LogR) of volume resistivity of the intermediate transfer member is 10.0 or less.

Transfer device and image forming apparatus for enhancement of an image stored on a recording medium

An image forming apparatus in which respective color visible images on tandem-arrayed plural photoconductor drums are sequentially overlay-transferred onto an intermediate transfer belt by application of a primary transfer voltage by intermediate transfer rollers, then the images are transferred at a time from the belt onto a print sheet by application of a secondary transfer voltage by a paper transfer roller. The same primary transfer voltage is applied to the respective color intermediate transfer rollers from one power source. In the intermediate transfer belt, a relative dielectric constant, a surface resistance and a volume resistance are controlled such that potential charged by initial transfer is attenuated to &#x2153; or lower than the transfer voltage before a belt position of the initial transfer arrives at a next transfer position.

The present invention relates to a color image forming device for forming toner images of a plurality of colors on a medium, and is for improving second transfer efficiency from an intermediate transfer body to the medium. The device has image forming units (-to-) for forming the toner images of the plurality of colors on at least one image bearing body (-to-) by a plurality of developing units (-to-) respectively accommodating toner of different colors; an intermediate transfer body (); primary transfer means (-to-) for primary transferring the toner images of the plurality of colors onto the intermediate transfer body sequentially for the respective colors; and secondary transfer means () for secondary transferring the toner images of the plurality of colors on the intermediate transfer body onto the medium. The image forming units form the toner images of the plurality of colors so that the potentials of toner layers transferred onto the intermediate transfer body () are progressively lower in the order in which the plurality of colors are transferred. Since the potential of the toner layer directly adhered to the intermediate transfer body is higher, the directly adhered toner layer becomes easier to be secondary-transferred, and thereby, the secondary transfer efficiency is improved and the reproducibility of the secondary color is improved.

Color image forming method and color image forming device

An image forming apparatus or method which uses plural image forming units to form visible images of different colors by making developers of different colors adhere to image holders such as photosensitive drums electrostatically. In this apparatus or method, intermediate transfer electrode members such as intermediate transfer rollers are opposite to the image holders of the image forming units with a belt transfer member between them and voltage is applied to transfer images electrostatically from the image forming units to the belt transfer member in sequence in a way that the transferred images on the belt overlap each other. Each of the intermediate transfer electrode members is located on the belt surface away from a point (transfer nip) at which a corresponding image holder contacts the belt.

Image forming apparatus and imaging method

It is an exemplified object of the present invention to provide a developer, a development device and its elements, and an image-forming device that can more stably form a high-quality image by a relatively inexpensive and easy means. A noncontact-type development method according to the present invention utilizes a nonmagnetic and single component toner having a volume average particle diameter D (&mgr;m) and an average specific charge q/m (&mgr;C/g), a development roller having a ten-point average surface roughness Rz (&mgr;m), and a blade keeping in contact with the development roller at a blade line pressure Pb (gf/cm). In order to stably form a uniform toner layer dt (&mgr;m) on the development roller, the following relationship is to be met: dt&equals;1.8&times;&lcub;q/m&times;Rz/(Pb&minus;1)&rcub; &times;D&plusmn;0.25 D, and 1.5 D&lE;dt&lE;3.5 D.

Developer, development method, development device and its elements, and image-forming device

It is an exemplified object of the present invention to provide a development device, development roller and blade used in the development device, and development roller and image-forming device having the development roller and blade, which can form a high-quality image in a cost-efficient manner. To achieve this object, the inventive development roller includes a shaft, a base material that coats a periphery of the shaft, and is made of a resistance body, and a layered coating provided on a periphery of the base material, where the layered coating includes two or more layers, a coating layer provided inside an outermost coating layer has a higher charging capability to a developing agent than at least the outermost coating layer.

Development roller and blade used in development device, and development device and image-forming device having the development roller and blade

A charge amount controlling roller serving as a charge amount controlling member is placed to face to a developing roller and is disposed on an upstream side, in a rotation direction of the developing roller, of a developing position at which a photosensitive drum and the developing roller face to each other. The charge amount controlling roller is biased with a voltage having the same polarity as that of non-latent-image portions on the photosensitive drum with respect to the developing roller, thereby reducing extraordinarily charged developing agents, or high charged, low charged, reverse charged toners otherwise causing image defects such as fogs.

Toner charge control for image defect reduction

An image forming method and an image forming apparatus achieve a high developing speed and high transferring efficiency. The method forms a latent image on the surface of an image carrier that repels a coloring liquid, attaches an affinity agent (containing fine silica grains) that has affinity for the coloring liquid, onto the latent image with the electrostatic force, and attaches the coloring liquid onto the affinity agent on the latent image, to visualize the latent image. The method efficiently transfers the visualized image having the affinity agent to a recording medium, to provide a fixed image.

Method and apparatus for forming image using an improved liquid

A liquid developing head is arranged to confront a surface of an image bearing member via a developing gap and a squeeze gap and carries out a developing by use of a developing liquid. The liquid developing head includes a housing, a developing roller, supported by the housing, supplying the developing liquid to the developing gap by rotating so that a portion of the developing roller confronting the image bearing member moves in a direction which is the same as a moving direction of the surface of the image bearing member, a squeeze roller, supported by the housing and arranged on a downstream side of the developing roller in the moving direction of the surface of the image bearing member, removing a surplus developing liquid adhered on the surface of the image bearing member at the squeeze gap by rotating so that a portion of the squeeze roller confronting the image bearing member moves in a direction opposite to the moving direction of the surface of the image bearing member, a developing liquid supply path, formed within the housing and having an ejection hole located at a portion on an upstream side of the developing gap in the moving direction of the surface of the image bearing member, supplied with the developing liquid from outside, and a developing liquid recovery path, formed within the housing, forcibly recovering the surplus developing liquid in response to a suction force applied from the outside.

Growing community of inventors

Kawasaki, Japan

Atsushi Tano