Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Kaishi

Hideo Yamasa

Atsushi Ueda

Yasuhiro Takai

Fumio Shimazu

Hirokazu Tanaka

Kouichi Irihara

Shirou Wakahara

Eiichi Kido

Hiromu Yoshimoto

Koichi Inui

Yuuhi Yui

Yoichi Yamamoto

Atsushi Ide

Shiro Narikawa

Hideaki Hagihara

Takasumi Wada

Hirokazu Fujita

Yukihito Nishio

Yoshinobu Okumura

Takeshi Iriuchijima

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

A doctor blade is provided in contact with frictionally charged toner in a toner tank, which regulates the amount of toner held on a toner holder. A charge control unit supplies to the doctor blade a voltage for selectively charging the toner. As a result, the amount of toner held on the toner holder is regulated, and simultaneously, the toner is charged to a specific polarity with a potential of the frictional charge or more. An electrostatic latent image is formed by the selectively charged toner. The toner is moved and transferred onto a papersheet which is sequentially transported, under the influence of an electric field generated by application of a voltage to an opposite electrode disposed opposing the toner holder. An image by the toner is thus formed on the papersheet.

Image forming apparatus selectively charging toner using doctor blade

An image forming apparatus includes a grating light valve (GLV) optical modulating device for modulating light projected by a monochromatic light source unit so that the light thus modulated is projected onto a photosensitive drum. This arrangement enables printing at a higher speed and high-quality printing using half tone. In the GLV optical modulator, a first GLV element row and a second GLV element row, each having a plurality of GLV elements provided at spaces, each space being smaller than a width of each GLV element, are provided parallel so that GLV elements constituting the first and second element rows are provided in a staggered manner.

Electrostatic printer having an array of optical modulating grating

An image forming apparatus is provided with a control electrode having a plurality of gates where negatively charged toner passes through, and the control electrode is arranged such that an electrode layer is formed on an insulating layer made of synthetic resin having electron attractiveness stronger than that of synthetic resin contained in the toner. For this reason, on the control electrode, when the toner flies to contact with the insulating layer, electrostatic force (repulsive force) acts between negative charges of the contact portion and the negative charges of the toner, and thus the charges repulse each other. Therefore, the toner does not adhere to the insulating layer. In such a manner, the adhesion of the toner to the control electrode is prevented and thus each gate is not blocked. As a result, even after long or frequent use of the control electrode, the flying of the toner by the control electrode can be stably controlled, thereby making it possible to obtain an image with excellent quality. Therefore, even if the control electrode is not maintained, namely, cleaned or replaced, an image with excellent quality can be obtained stably for a long time.

Image forming apparatus with electrostatically controlled developer

An image forming apparatus provides a photosensitive body, a main charger, an exposing unit, developing unit and a contact-transfer charger. The main charger charges the photosensitive body with a predetermined electric potential. The exposing unit applies a laser beam on the surface of the photosensitive body to form an electric latent image. The developing unit develops the electrostatic latent image to form a toner image. The contact-transfer charger transfers the toner image on an image transfer paper. The image forming apparatus further provides controller for power supplies. The controller controls the power supplies after an image forming operation in a manner to enhance the electric potential of the photosensitive body to a high level by the main charger, drop the surface potential of the photosensitive body to a low level by the contact-transfer charger and then to cut off a bias voltage of the developing unit.

Electronic image forming apparatus with reduced residual carrier and

Deteriorating developer including toner and carrier in a developer container is replaced by supplying carrier developer including carrier from a developer supply unit and discharging an amount of the deteriorated developer corresponding to the amount of the supplied carrier developer through a discharge opening formed in the developer container by opening a cover. The cover is driven by a solenoid for discharging. With this structure, even when the amount of developer in the developer container is changed and the surface level of the developer is changed, a predetermined amount of deteriorated developer is accurately discharged according to the driving of the cover. It is thus possible to control in a desired manner the replacement ratio of deteriorated developer in the developer container to new developer to be supplied. With this configuration, it is possible to maintain the charge of developer substantially uniform and good image quality of copies.

Developing device in an electrophotographic apparatus capable of

The present invention provides in a preferred embodiment a developer container having a supply and discharge shaft which is driven and rotated in a direction by a supply and discharge shaft motor, a supply screw mounted on one of the ends of the supply and discharge shaft for bringing unused developer in a developer supply container into a developer container, and a discharge screw mounted on the other end of the supply and discharge shaft for discharging the developer in the developer container through a developer discharge opening. With this structure, the ratio of replacing old developer with new developer in the developer container is controlled in the desired manner, and the charging property of the developer is maintained substantially uniform. Additionally, since the replacement efficiency of the developer is improved, the consumption of the developer is reduced. Moreover, even when a copying machine is tilted, a large amount of developer is unlikely to be discharged.

Developing device containing for storing developer having zoner and

A developer device is provided with a developer vessel for storing therein a developer material composed of toner particles and carrier granules. In the developer device, a target ratio of toner particles for a detected quantity of the developer material is computed. In the device, a toner concentration detector sensor is also provided for detecting the ratio of toner particles in the developer vessel. In order to set the detected toner ratio of toner particles equal to the target ratio, quantity of toner particles to be additionally supplied to the developer vessel is controlled. As a result, the ratio of toner particles to the developer material stored in the developer vessel can be maintained in a predetermined ratio, thereby ensuring a desirable image quality.

Developer device that gradually replaces degraded developer with fresh

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

Electronic image forming apparatus

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.

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Yamatokoriyama, Japan

Hideo Yamasa