Hitachi, Ltd.

Hitachi Koki Co., Ltd.

Nissan Motor Company Limited

Tatsuo Igawa

Takao Umeda

Tetsuya Nagata

Yasuro Hori

Yuzuru Simazaki

Takao Miyashita

Yasuo Takuma

Mamoru Okano

Takao Kumasaka

Kazuhito Masuda

Seiji Yonekura

Yoshinobu Fukano

Toru Miyasaka

Ken Sasaki

Kazuya Ooishi

Hiroji Sawada

Yoshiharu Nagae

Shigeru Matsuyama

Masayasu Anzai

Masazumi Sone

Nobuyoshi Hoshi

Ryozo Takeuchi

Fumio Nakano

Seikichi Tanno

Masato Isogai

Yasuo Kikuchi

Yukitsugu Hirota

Hiromitsu Nagae

Isamu Komatsu

Tomio Sugaya

Masato Miwa

Shigetaka Fujiwara

Osamu Namikawa

Takao Takuma

Tetuya Nagata

Kunio Fukuchi

The recording electrodes and the control electrodes of an ink jet recording head are alternately arranged on a substrate. Ink in which coloring material is distributed in a solvent is supplied to the recording electrode so that the ink can flow in the direction of the length of the recording electrode. An ink circulation part is provided for collecting surplus ink from the point of the recording electrode from which ink is discharged. As a result, an ink jet recorder, which can produce a high definition image without shifting the ink impact position on the recording medium, can be produced.

Ink-jet recording head and ink-jet recorder

An ink jet recording head has a plurality of ink-discharge electrodes and control electrodes and an opposed electrode arranged at a fixed spacing and grounded. A pulse voltage with a reversed polarity is applied to the control electrodes in synchronization with the superimposition of the pulse voltage on a bias voltage applied to the ink-discharge electrode when the ink is discharged. As a result, an ink jet recording apparatus, which can decrease the pulse voltage needed to discharge the ink, is provided with a simple configuration.

Ink jet recorder

An ink jet recording apparatus capable of obtaining a highly precise image for stabilizing an amount of ink to be flied onto a recording medium by supplying and recovering the ink, in an ink discharge unit within the recording head, due to a difference in height of positions where two ink chambers within the ink discharge unit are arranged.

Recording head and inkjet recording device having separately arranged ink chambers and ink discharge unit

By employing a developer using ferrite system carriers, a developing process can be carried out using a low brushing force by a magnetic portion having the same polarity in a developing unit in a developing roller. A relationship between a circumferential speed Up (mm/sec) of a photoconductor, a ratio K of a circumferential speed of a developing sleeve of the developing roller to the circumferential speed of the photoconductor, and a developing potential difference .DELTA.V (V) is set to 1.5.ltoreq.(K.times..DELTA.V/Up).ltoreq.2.1.

Developing apparatus and picture image forming apparatus

In a developing apparatus, a developing roller has a toner layer formed on a surface thereof, which toner layer is brought into contact with a photoconductor. A magnetic conveying roller having a magnet body is arranged rotatively close to the photoconductor. A regulating plate is provided at an outer periphery of the conveying roller.

Developing apparatus and color electrophotographic apparatus using the

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 electrostatic recording apparatus and a management system thereof wherein the recording apparatus includes a photoconductor drum having a cap provided at an opening of the drum and a photoconductor sheet wound on a portion of the drum other than the opening, with the photoconductor drum being rotated. The cap is electrified and a capacitor is provided between the cap and a terminal and charged through the cap to maintain the cap in an electrified state. A potential of the terminal is equal to a ground potential or a potential approximating the ground potential. Further, a controller is provided for discharging the electrified electric charge of the cap in response to a discharge instruction. A managing system may be provided for judging the state of the electrostatic recording apparatus.

Electrostatic recording apparatus with electrified cap and managing

A parallel circuit of a capacitor and a varistor is connected between a ground and an aluminum cap of a photosensitive drum having a photoconductor sheet wound on a surface of an aluminum drum. The capacitor is charged by a charger. A developer roll connected to a bias voltage supply is provided with a retraction mechanism and is controlled so that the developer roll is separated from the drum mechanically upon start of operation of a recording apparatus until a potential of the cap is increased to a predetermined value and a developing agent layer does not come into contact with the cap. Alternatively to retraction of the developing roll, the developing roll may be stopped to control a height of bristle of developing agent or a bias voltage of the developer may be reversed.

Electrostatic recording apparatus and managing system thereof

Image forming apparatus capable of preventing the winding on the image

A driving method is provided for an electrooptical device having scanning and signal electrodes arranged in a matrix with a plurality of picture elements formed in association with intersections of the electrodes. Voltages of high-frequency pulses are applied to both the scanning and signal electrodes, and a DC voltage pulse for setting the optical state of the electrooptical material is applied to the picture elements during a selected period for the scanning electrodes, while a high-frequency AC voltage for holding the previously set optical state of the electrooptical material is applied to the picture elements during a non-selected period for the scanning electrodes. A circuit is also provided for carrying out the method, and an electrooptical apparatus is provided employing the electrooptical device described above.

Multiplexed driving method for an electrooptical device, and circuit

An electrostatic recorder including an electrostatic latent image measuring instrument for measuring a state of an electrostatic latent image formed on a photosensitive substance, and executed a printing process until an electrostatic latent image formed on a surface of a photosensitive substance based on measured data is transferred onto a blank form as a visual image by a transfer device by adjusting control factors such as exposure, exposure time, electrostatic charge voltage, development bias, temperature and humidity. The electrostatic latent image measuring instrument is provided with distance sensors which, when a measuring electrode is disposed near to the photosensitive substance, maintains a constant distance therebetween. It is thus possible to measure an electrostatic latent image even if the photosensitive substance is eccentric. Furthermore, an arc between the measuring electrode and the photosensitive substance is prevented by utilizing a gas having a high arc starting voltage between the measuring electrode and the photosensitive substance of the electrostatic latent image measuring instrument.

Electrostatic recorder and electrostatic latent image measuring

An apparatus and method for driving an optical printer having at least one liquid crystal optical switch including a ferroelectric liquid crystal layer interposed between a pair of substrates having electrodes on confronting surfaces thereof, the at least one liquid crystal switch being disposed between a light source and a photosensitive surface, a light transmission state of the at least one liquid crystal optical switch being controlled by application of a voltage signal to the at least one liquid crystal optical switch so as to control light transmission to the photosensitive surface. A first voltage signal is applied to the liquid crystal of at least one liquid crystal optical switch in a writing period in which the light transmission state is determined in accordance with a printing signal for printing. A second voltage signal having a DC component of one polarity is applied to the liquid crystal layer in a retention period. A third voltage signal having a DC component of an opposite polarity is applied to the liquid crystal layer in a reset period in which the at least one liquid crystal optical switch is placed in a light interrupting state, and a fourth voltage signal having a DC component of the one polarity is applied to the liquid crystal layer in a period other than an excluding period which is formed of the writing period, the retention period and the reset period.

Apparatus and method for driving an optical printer having a liquid

The invention relates to a liquid crystal optical switch array in which optical switch elements are opened and closed by the time-sharing drive and to an optical printer using this optical switch array. The optical switch element comprises a ferroelectric liquid crystal having a relaxative memory effect, signal electrodes and scanning electrodes which sandwich the liquid crystal layer, and a resistor element which is formed between the scanning electrode and the liquid crystal. A line selection signal is sequentially supplied to the scanning electrodes, these scanning electrodes become substantially the open state when the selection signal is not supplied. When the scanning electrodes are open, the resistor element has a predetermined resistance value. When the selection signal is supplied to the scanning electrodes, the resistor element has a lower resistance value.

Time-sharing drive liquid crystal optical switch array and optical

A multiplexed driving method of an optical switching element employing ferroelectric liquid crystal with a negative dielectric anisotropy including signal electrodes and common signal electrodes arranged in matrix and a ferroelectric liquid crystal layer disposed therebetween so as to constitute pixels at the respective facing portions of the signal electrodes and the common signal electrodes comprising a step of applying a common writing signal voltage to one of the common signal electrode to select pixels to which information be written, simultaneously applying a common status holding AC signal voltage to the other common signal electrodes covering non-selected pixels and simultaneously applying one of two signal pulses with opposite polarities to the signal electrodes, whereby resultant information writing voltages formed in combination of the common writing signal voltage and the signal pulses, which are enough to determine the orientation of the ferroelectric liquid crystal molecules, are applied on the selected pixels and resultant AC status holding voltage formed in combination of the common status holding AC signal voltage and the signal pulses which determine the limited bias voltage for the resultant AC voltage are applied on the non-selected pixels.

Multiplexed driving method for an optical switching element employing

In a driving method of an optical switch element for controlling a quantity of transmission light between opposed electrodes by interposing a transparent, high dielectric material between the opposed electrodes and applying a positive or negative voltage between the opposed electrodes, the improvement wherein a period in which the opposed electrodes are substantially short-circuited is disposed in order to make it possible to either reduce or eliminate stored charge.

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Kitaibaraki, Japan

Tatsuo Igawa