Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Kaishi

Kouichi Irihara

Yuhi Yui

Hideo Yamasa

Yukinori Andou

Takasumi Wada

Hiroshi Kubota

Atsushi Ueda

Masatsugu Nakamura

Yasuhiro Takai

Masaharu Kimura

Hisashi Yoshimura

Fumio Shimazu

Kazuya Koyama

Takashi Hayakawa

Hajime Horinaka

Yukihito Nishio

Hirokazu Tanaka

Hiroyuki Sawai

Kohji Tsurui

Kenji Tani

To provide an ink jet image forming method and an ink jet image forming device capable of forming an image of superior quality by using quickly drying ink and slowly drying ink in combination, wherein deviation which may occur in a discharge position of ink causes no reduction in the resolution of the image, black ink is adopted as the slowly drying ink, and so is white ink as one of the quickly drying ink. A white dot is formed with the white ink in a position to form a black dot on white recording paper, thereafter applying the black ink thereto. Deviation which may occur in the discharge position of the quickly drying white ink on the recording paper thus becomes almost visually unnoticeable.

Ink jet image forming method and ink jet image forming device

An image forming apparatus includes an ink tank accommodating chargeable developer ink, an ink control layer having a plurality of ink supply holes arranged in a matrix, arranged near the surface of the developer ink and having a lower portion opened in the developer ink, a potential control layer arranged above the ink control layer and having a plurality of ink passage holes arranged in the column direction of the ink supply holes, an opposing electrode arranged opposing to the potential control layer, a power supply unit for applying a potential to the developer ink and an opposing electrode to generate a prescribed potential difference between the developer ink and an opposing electrode, a surface level controller for changing surface level of the developer ink in the ink supply holes for each column of the ink supply holes, and an emission controller for controlling potential of each row of the ink supply holes in the ink passage holes of the potential control layer for controlling ink emission dot by dot.

Method and apparatus for forming an image on a recording medium wherein

Featured is an imaging forming apparatus that provides minute particles having a uniform diameter and being uniformly charged. The image forming apparatus includes a supplying member that supplies charged developing particles, a counter electrode disposed opposite to the supplying member and a control electrode disposed therebetween and including a plurality of passing holes serving as passages for the developing particles. While a potential for generating a predetermined potential difference is applied between the supplying member and the counter electrode, the potential being applied to the control electrode is changed in order to change an electric field existing between the supplying member and the counter electrode. This controls flying of the developing particles passing through the passing holes in a direction from the supplying member to the counter electrode, and thus the forming of the image. The developing particles are formed of a liquid or liquescent material, and fine-grained and charged with electricity by the supplying member. The supplying member is particularly configured or arranged so the developing particles thereon formed have a diameter to minimize particle fragmentation during flying from the supplying member towards the control electrode.

Method and apparatus for forming an image using flying developing

An ink jet head includes an electroviscous fluid chamber provided at a part of a sidewall of an ink chamber, and having electroviscous fluid sealed therein, an elastic film provided between the ink chamber and the electroviscous fluid chamber for transmitting pressure between the ink chamber and the electroviscous fluid chamber, a pair of electrodes provided at a part of a sidewall of the electroviscous fluid chamber corresponding to the ink chamber for applying an electric field to the electroviscous fluid, a pressure generation device for discharging ink from the ink chamber, and a control device for controlling ink discharge by applying a voltage to the pair of electrodes to alter the viscosity of the electroviscous fluid in response to record information.

Ink jet head utilizing electroviscous fluid for control of ink discharge

An electrophotographic printing machine is provided with a photoreceptor drum including a photosensitive layer formed on a surface of an electrically conductive base, a contact charger in contact with the photosensitive layer for charging the photosensitive layer by applying thereto a DC voltage, and a voltage drop detecting circuit for outputting a detecting signal when the voltage has dropped below a reference voltage. When a defect exists such as a pin hole on the photosensitive layer, the voltage being applied to the photosensitive layer of the contact charger drops. In this state, a detecting signal is output to a controller from the voltage drop detecting circuit. When the controller receives the detecting signal, the controller signals to stop the operation of the entire device, and signals a display to display a message indicating to exchange the photoreceptor drum. According to the electrophotographic printing machine, the image forming process will not be continued with the detective portion on the photosensitive layer. Thus, the contact charger can be prevented from breaking down.

Device for preventing breakdown of contact charger for use in

A developing device is provided with a developer vessel for storing therein a developer material composed of toner particles and carrier granules and a developer material supply section for gradually supplying a carrier developer including the carrier granules from above the developer vessel, wherein a discharge opening for discharging therethrough the developer material is formed on a side face of the developer vessel. When a tilt detection unit provided with the developing device detects the tilt of the developing device, an alarm lamp is set ON for sending a warning. In the meantime, the discharge opening is closed for preventing an excessive overflow of the developer material from the developer vessel.

Developing device with a tilt detecting function designed for a trickle

The invention is directed to an apparatus for an electrophotographic process, equipped with a charging device of a contact type using a conductive roller or brush, and the charging device used therefor. The apparatus is characterized in the following constructions: roll-shaped fiber aggregation that is rotated in contact with the photoconductive surface through a spacing member; use as applied voltage to the fiber aggregation of periodically oscillating voltage having a lower limit exceeding the surface potential of the photoconductor in the aforementioned device; a brush-type charger that is vibrated while contacted with the photoconductor surface and regulated as required; a fiber roll-type charger wherein ventilation holes are disposed on the roller substrate surface; the fiber roll-type charger with holes further including a closed container with exhausting means enclosing the charger; set-up of a product of planting fiber intervals on a fiber roller and a peripheral velocity ratio of the photoconductor to the roller such that the product is smaller the average particle size of the developer used; changing application voltage to a charger roller depending transfer-treated portion or portions otherwise on the photoconductor surface; and provision of dirt preventer, aligned with the longitudinal direction to the charging roller with conductive fiber, and shiftable between contact and spaced position.

Electrophotographic copier and charging means used therefor

An image forming apparatus shown has a developing unit and a photoconductor unit both of which are disposed in a body. The developing unit and photoconductor unit are slidably mounted adjacent to each other within the body. The mounting and positioning of the units are such as to allow the developing unit and the photoconductor unit to be successively pulled out of the body. The apparatus further includes an urging member which allows the photoconductor unit to be urged toward the developing unit. The body includes upper and lower housings and is designed so that the upper housing can be swung upward about a fulcrum on one side of the body and thereby form an opening between the upper and lower housings on the other side of the body. The apparatus is designed and the components are configured such that when the developing unit is pulled out of the body the photoconductor unit moves toward the opening and the photoconductor unit can be replaced in a large open space near the opening.

Image forming apparatus with slidably mounted developing unit and

An electrophotographic apparatus comprising a power supply, a detection means, a voltage control means, and an exposure unit control means, whereby the provision of a special discharge unit can be omitted to allow the reduction in the size and cost of the apparatus. Also, carrier attraction and toner adherence to the photoconductor can be prevented when the photoconductor is stopped after completion of an image forming operation.

Electrophotographic apparatus

An image forming apparatus has a charger; developing device; transferring device; and cleaning device which are positioned around a photoreceptor, the cleaning device and charger being integrally formed. The charger has a control unit for controlling the surface potential of the photoreceptor to be at a predetermined level in accordance with the number of rotations, or the rotating time of the photoreceptor, and/or is designed such that a predetermined voltage is applied to the cleaning device. With the above arrangement, reproduced images having constant quality can be provided for long even if the photoreceptor is repeatedly used and discharging by the charger toward the photoreceptor can be stabilized. The advantages contribute to producing small-sized and low-priced image forming apparatus.

Image forming apparatus

A process cartridge in which at least a photosensitive member and a corona charger are mounted on a casing made of resin and the corona charger includes a shield casing and a support portion for supporting a discharge wire such that the shield casing and the support portion are molded integrally with the casing, while the corona charger is subjected, substantially at the shield casing, to an electrically conductive coating.

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Nara, Japan

Kouichi Irihara