Hitachi, Ltd.

Hitachi Koki Co., Ltd.

Ricoh Company, Ltd.

Ricoh Printing Systems, Ltd.

Takao Umeda

Tatsuo Igawa

Tetsuya Nagata

Toru Miyasaka

Masayasu Anzai

Hiroyuki Mabuchi

Yasuro Hori

Yuzuru Simazaki

Isamu Komatsu

Osamu Namikawa

Katsuhiko Suzuki

Takashi Rokutanda

Teruaki Mitsuya

Yukio Otome

Yasuo Takuma

Masato Miwa

Takao Miyashita

Tadahiro Kaneko

Yoshiharu Nagae

Takashi Suzuki

Masato Isogai

Hisao Okada

Osamu Machida

Akio Tsujita

Ken Sasaki

Jun Nagata

Kazuya Ooishi

Ryoji Kojima

Michio Yokosuka

Akio Mukoh

Kozo Nakamura

Shigeru Matsuyama

Nobuyoshi Hoshi

Shunichi Oohara

Tsutomu Maekawa

Fumio Nakano

Kouji Kuwabara

Seikichi Tanno

Takao Kumasaka

Seiji Maruo

Yasuo Kikuchi

Makoto Yano

Nobuyuki Mori

Yuzuru Shimazaki

Shintaroo Hattori

Katsuya Kawai

Minoru Ohshima

Takashi Nakazawa

Kunio Satoh

Yosuke Saito

Tsukasa Ogawa

Yoshihiro Gunji

Masami Ishikawa

Ikuo Shimokobe

Kozi Kato

Tohru Miyasaka

Takao Takuma

Tetuya Nagata

Yousuke Saito

Shinji Asai

Kishiro Iwaskai

A transfer apparatus comprises a toner image supporting body and a corona transfer means, which are oppositely disposed, and a vibrating unit for exerting vibration force to the rear face of a toner supporting body, disposed opposite to the corona transfer means, wherein the vibrating unit has a cantilever structure for holding an end of a piezoelectric bimorph element in which a pair of piezoelectric bodies each having an electrode, are bonded to both sides of a conductive elastic member (a shim member). A protrusion portion is provided on the other end of the piezoelectric bimorph element.

Transfer apparatus, method of manufacturing the transfer apparatus and image forming apparatus using the transfer apparatus

In a method of manufacturing an inkjet head, a silicon dioxide (SiO) layer is produced on the surface of first silicon member formed from single-crystal silicon. Next, a glass layer formed of borosilicate glass or the like is sputtered onto the surface of the silicon dioxide (SiO) layer. A silicon oxide (SiO, x&#x3c;2) layer is then formed on the surface of a second silicon member. The first and second silicon members and are bonded together by applying heat at about 450&#xb0; C. with heaters, as a DC voltage is applied across electrode terminals. As a result, a silicon dioxide (SiO) layer is formed at the interface of the glass layer and silicon oxide (SiO, x&#x3c;2) layer, anodically bonding the two layers.

Method of manufacturing an inkjet head through the anodic bonding of silicon members

A developer transporting amount controlling member that is used in a developing apparatus is disclosed. The developing apparatus includes a recording unit having a surface that sustains an electrostatic latent image and attracts a developer, a developer transporting unit that transports the developer, and a developing unit that guides the developer to the recording unit. The recording unit, the developer transporting unit, and the developing unit have rotational center axes that are parallel to each other. The developer transporting amount controlling member includes a magnetic part and a nonmagnetic part that is harder than the magnetic part and is fixed to the developing apparatus such that a portion of the nonmagnetic part is disposed closest to the developing unit.

Developer transporting amount controlling member, developing apparatus, imaging apparatus, and method for exchanging developing unit

A developing device for use in an image forming apparatus has control means operatively responsive to receipt of an output signal of a first toner density detector means provided in a development unit for driving developing powder delivery means provided in a preliminary mixture/stirring unit to supply developing powder from a stirring chamber toward the development unit, while controlling regulator means so that introduction of the developing powder to the stirring chamber is inhibited at least within a developing powder refilling time period.

Developing device for image forming apparatus

An image forming apparatus has an image retaining body which is supported so as to be able to move endlessly, a transfer means which is installed at a specific distance away from the surface of the image retaining body or in contact with the surface of the image retaining body, and a paper guide which is installed upstream and downstream, of or at least upstream or downstream the transfer means along the moving direction of the image retaining body for guiding a sheet of paper between the image retaining body and the transfer means and for pressing the paper onto the surface of the image retaining body. The image forming apparatus is equipped with an adjusting means for adjusting the distance between the paper guide means and the transfer means along the moving direction of the image retaining body, thereby varying the length of the paper wound onto the image retaining body.

Image forming apparatus with adjusting device

A transport roll 1 consists of a metal roll 3 of 40 mm in diameter covered with a conductive PFA tube 2 of 10.sup.10 .OMEGA.cm in volume resistivity and 200 .mu.m in thickness. A DC voltage source 4 is connected to the metal roll. A sheet of paper 5 bearing toner images 6 and 7 on both sides thereof receives a drive force from a paper drive roll, and turns with the movement of the paper. The DC voltage source produces voltage VB1 of the same polarity as the charging polarity (positive) of the toner image 6 being in contact with the transport roll. The voltage VB1 is optimumly controlled so as to prevent the transport roll from being soiled with toner.

Electrostatographic printing machine

There are provided a paper separating mechanism for bringing paper into a state of non-contact with a paper carrying roll; a motor for independently driving the paper carrying roll; and a switch for changing-over the paper carrying roll driving mode between a following mode and an independent driving mode so that the driving mode is changed over to the following mode and independent driving mode at the time of printing and at the time of non-printing, respectively.

Paper carrying device in electrostatic recording apparatus

In an electrostatic printing apparatus, the residual image phenomenon conspicuously observed at low density printing can be eliminated while photo-deterioration of the photosensitive body is being suppressed to a minimum in a high speed printing process. A charging unit, a writing light source, a developing unit, a transfer unit, a first erase lamp, an AC discharging unit and a second erase lamp are arranged around a photosensitive drum. Therein, the light intensity of the erase lamp is strengthened when the density of a printed image is light and is weakened when the density of the printed image is dark. That is, by changing the light intensity of the erase lamps corresponding to a developing bias, the residual image phenomenon can be eliminated while suppressing deterioration of the photosensitive drum to a minimum.

Electrostatic printing apparatus having an erase lamp

A fixing system for fixing toner images onto an image printing system such that the image printing medium bearing the toner images on the obverse side and the reverse sides thereof is passed through a nip area between a pair of fixing rollers. In the nip area, a rotation speed of a first fixing roller, which comes into contact with a not-yet fixed toner image, which is formed on the obverse side of the image printing medium, is set to be substantially equal to a rotation speed of a second fixing roller, which comes in contact with a not-yet fixed toner image, formed on the reverse side of the image printing medium. This is accomplished by setting the diameters of the various layers of the first fixing roller to be equal to that of the second fixing roller. When the image printing medium is moved through the nip area by the fixing rollers, a moving speed of the upper side of the image printing medium is equal to that of the lower side thereof. Thus, stresses on the image printing medium are not caused, and no character blur takes place.

Apparatus for printing on both sides of an image printing medium by one

In an electrostatic both-side printing system, a first image forming unit is provided upstream of an image printing medium when viewed in the transporting direction of the image printing medium, and a second image forming unit is provided downstream of the image printing medium. A medium transporting path for transporting the image printing medium is formed between the first and the second image forming units. A first transferring unit, located facing the first image forming unit with the medium transporting path intervening therebetween, for applying no charge onto the rear side of the image printing medium, which does not face the first image forming unit. A second transferring unit being located facing the second image forming unit with the image printing medium with the medium transporting path intervening therebetween, in a state that the second transferring unit is apart from a first toner image formed on the image printing medium by the first image forming unit. In the both-side printing system thus constructed, the first and the second image forming units, and the first and the second transferring units cooperate to form first and second toner images on both sides of the image printing medium, the first and the second toner images being opposite in polarity.

Apparatus for printing images on both sides of an image printing medium

An electrostatic recording apparatus includes a background potential detector (12a, 12b, 13a and 13b) for detecting the potential (VMc) of a background region adjacent to a normal development region (having VHc) and the potential (VMd) of a background region adjacent to a reversal development region (having VLd), and a controller (25) for controlling a charge voltage, exposure intensity, and/or developing bias voltage according to the output of the background potential detector to eliminate a fogging phenomenon.

Electrostatic recording apparatus and electrostatic recording method

An electrostatic recording control method wherein there are provided a single surface potential sensor between a first and second developer units, a detector for detecting the characteristic of a factor influencing the dark attenuation characteristic of the sensitive body, comprising the steps of: irradiating the surface of a charged sensitive body with the test pattern having prescribed exposure energy by an exposure system to form a test electrostatic image on the photosensitive body; passing the test electrostatic latent image with the developing function of the first developer unit stopping to measure the surface potential of the test electrostatic latent image by the sensor; changing the control setting potential at a position where the sensor is set according to the output from the detector; comparing the potential measured by the passing step with the control setting potential changed by the changing step to control one of the voltage to be applied to the latent image forming charger and the exposure energy for forming the test pattern so that the measurement potential is a control setting potential; forming a test electrostatic latent image on the photosensitive body after the comparing step; applying a prescribed bias to the first developer unit to form the first toner image corresponding to the test electrostatic latent image; and measuring the surface potential of the first toner image to set the bias voltage of the second developer unit according to the value measured.

Electrostatic recording control method and electrostatic recording

The present invention provides a development apparatus capable of improving the development pole of a plurality of development rolls and the rotation speed thereof, thus obtaining stable printing quality. A first development roll rotatable in the opposite direction to the moving direction of photosensitive body is disposed in the upstream of it, whereas a group of second development rolls are disposed in the down stream, which development rolls are rotatable in the same direction as the moving direction of photoconductive body and have magnets of the same polarity. The first development roll and the photoconductive body define a peripheral speed ratio ranging from 0.5 to 1.5, while allowing the second development roll and the photoconductive body to define a peripheral speed ratio ranging from 0.6 to 1.5. A development control member is provided between the first development roll and the group of second development rolls. A toner density detector is provided in the downstream of the last one of the group of second development rolls which is disposed in the most significant downstream. A cross mixer and a carrier member are also provided under the first development roll and the group of second development rolls.

Development apparatus having a plurality of rolls rotated at particular

A fixing unit includes a fixing roller, a pressure roller forming a nipper in cooperation with said fixing roller, the nipper conveying a recording material on which an unfixed image is formed while nipping the recording material, a recording material pressing roller disposed at least one of upstream and downstream of said nipper in a recording material conveyance direction for pressing said recording material toward the fixing roller to form a region where the recording material is wound around the fixing roller, and a tension applying unit for applying tension to the recording material.

High-speed electrophotographic fixing unit

Growing community of inventors

Mito, Japan

Takao Umeda