Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Other

Ricoh Printing Systems, Ltd.

Tomio Sugaya

Yasuo Kikuchi

Katsuhiro Akinaga

Isao Nakajima

Takao Kumasaka

Toshitaka Ogawa

Toru Miyasaka

Takashi Suzuki

Yoshitaka Fujinuma

Hiroyuki Mabuchi

Yasuo Takuma

Tatsuo Igawa

Yasuyuki Tsuji

Shigenobu Katagiri

Yuzuru Simazaki

Kenji Asuwa

Youji Hirose

Osamu Namikawa

Kunio Satoh

Shigeo Nemoto

Yosuke Saito

Motoji Kurobane

Hidehisa Okamura

Kiyomi Tsuchiya

Sigenobu Katagiri

Hui Cheng

Masaaki Akutsu

Hirobumi Ouchi

Manabu Suzuki

Hajime Tashiro

A belt driving apparatus which inhibits a belt meandering so as to improve a printing quality and rapidly starts a printing motion at a time of starting the apparatus such as a time of turning on power or the like, and an image forming apparatus using the same. The belt driving apparatus has an endless belt, a plurality of belt tension supports for supporting the belt in a tension manner, and a steering roller supported in a tiltable manner and compensating a meandering of the belt, and the belt driving apparatus is provided with a meandering compensation sensitivity adjuster for adjusting a belt meandering compensation sensitivity of the steering roller per an angle of incline.

Belt driving apparatus and image forming apparatus using the same

In a corona discharging apparatus for use in an electrophotographic printing apparatus, a wire spring-like member having the torque limiter function is used for the cleaning member to conduct the power transmission of the screw shaft, and by releasing the load larger than a predetermined value, the deformation of the gear and deviation of the shaft are eliminated, and the lock of the motor is prevented from being generated.

Corona discharging apparatus for use in electrophotographic printing apparatus

A friction material and a braking device and an image forming apparatus using the friction material. The friction material is formed of polyamide elastomer having a bending modulus of elasticity defined to be in a range of from 100 MPa to 500 MPa.

Friction material and braking device and image forming apparatus using

In an image printer performing multi-color printing, two magnetic poles having the same polarity are provided adjacent to each other in a position facing the printing body of the second developing agent holding body provided in the second developing unit, and development is performed under a condition satisfying the following formulas;

Image printer

A developing apparatus in which a stationary multipole permanent magnet is placed in a sleeve and in which development is performed by bringing a developer, which contains at least carrier and toner particles and is held on the periphery of a sleeve by use of the magnetic force of the multipole permanent magnet, into contact with a photo-conductive body owing to the rotation of the sleeve. For securing image density and for preventing the deposition of carrier onto the photo-conductive body, two magnetic pieces, each of which is arranged lengthwise in the direction of the axis thereof and which have the same polarity, are placed in a region in the multipole permanent magnet which faces the photo-conductive body in such a manner as to adjoin in the circumferential direction of said permanent magnet. This results in generation of the distribution of a magnetic field which has two peaks of magnetic force. The position at which the second one of the two peaks of the magnetic force is formed, downstream in the direction of rotation of the sleeve, is set at the nearest point between the photo-conductive body and the sleeve. Thereby, even when development is performed by bringing the developer into light contact with the photo-conductive body, the image density can be secured. Further, the carrier can be prevented from depositing on the photo-conductive body.

Developing apparatus for an electrophotographic machine

An electrophotographic recording apparatus is provided having a reduced overall size. The space around a photosensitive member required for the developing unit to be located is minimized, more particularly, it i minimized in the lengthwise directional space. In the electrophotographic recording apparatus having a photosensitive member which moves at a predetermined speed; an exposure device for exposing the photosensitive member; a developing unit for developing an electrostatic latent image obtained by the exposure; and a transferring device for transferring a developed visible image to a recording paper sheet or the like, the developing unit is composed of developing devices, a plurality of supporting members for supporting the developing devices and an element for rotating the supporting members. The supporting members can be rotated while making a portion adjacent to a widthwise directional end of the photosensitive member to be a supporting point in a range from a state where the surface of the photosensitive member and the surface of a developing roll of each developing device run parallel to each other to a state where they are positioned substantially perpendicular to each other.

Electrophotographic recording apparatus having a plurality of developing

A method of preventing colors from being mixed in a two-color image forming apparatus. The surface of a photoreceptor is uniformly charged. A first latent electrostatic image formed on the photoreceptor surface is developed with a one-component developer so as to form a first toner image. A second latent electrostatic image formed on the photoreceptor surface is developed with a two-component developer so as to form a second toner image. The first and second toner images are simultaneously transferred onto a recording medium. In a preferred embodiment, the one-component developer is a magnetic toner, while the two-component developer is the combination of a nonmagnetic toner and a magnetic carrier. The magnetic toner and the magnetic carrier are preferably powder made of substantially the same materials.

Method of preventing colors from being mixed for a two-color image

An apparatus for printing on opposite surfaces of a strip of printing paper using two electrophotographic printing units wherein each printing operation is of high quality and thermal damage to the printing is minimized. The apparatus includes a first electrophotographic printing unit for printing on the front surface of the printing paper, a buffer unit for temporarily holding the printing paper discharged outside of the first electrophotographic printing unit, a turn unit for turning over the printing paper, and a second electrophotographic printing unit for printing the reverse surface of the printing paper. A toner having a low melting temperature is employed for each of the first and second electrophotographic printing units so that developing treatment is conducted only with the aid of a heat roll but without any use of a preheating plate. A back-up roll adapted to cooperate with the heat roll is coated with a tetrafluoroethylene-based synthetic resin. The second electrophotographic printing unit is provided with a paper presser for squeezing the printing paper against a photosensitive drum only within the printing width range. A retract mechanism is operatively connected to the paper presser.

Apparatus for printing on opposite surfaces of a strip of printing paper

In a printing sheet conveying device in which a sheet bearing a toner image is passed through a heating roll and a pressure roll, and which has means for changing the right and left contact pressures of these rolls to correct the meandering movement of the sheet when conveyance of the sheet is started; in which when conveyance of the sheet is started, the contact pressure of the rolls is made higher on one of the right and left sides than on the other side, and in a predetermined period of time the contact pressures on both sides are made equal to each other.

Sheet meandering movement preventing method

A laser printer with a thermal fixing unit comprises: a pair of heat and pressure rolls for pressing a sheet with a developed toner image therebetween to fix the toner image on the sheet; a web immersable with an oil; an oil coater for supplying the oil to the web and pressing the web against the heat roll at at least one point to make the web contact with the heat roll so that the oil is applied from the oil coater onto the surface of the heat roll through the web to thereby prevent occurrence of offset of the toner image; and at least one pressing member provided separately from the oil coater for locally urging the web against the heat roll, the pressing member being located on at least one of before and behind the oil coater.

Laser printer with thermal fixing of toner

Growing community of inventors

Ibaraki, Japan

Tomio Sugaya