Sharp Kabushiki Kaisha Corporation

Taisuke Kamimura

Kiyoshi Toizumi

Toshimitsu Gotoh

Yasutaka Maeda

Katsumi Adachi

Hideyuki Nishimura

Tsuyoshi Miyamoto

Masamitsu Sakuma

Toshiaki Kagawa

Yasuhiro Takai

Yoichi Shimazawa

Katsuhiro Nagayama

Yukihiko Ueno

Natsuko Tanaka

Tadashi Iwamatsu

Kazuyuki Ohnishi

Atsushi Inoue

Masato Tokishige

Kenji Mishima

Kyouichi Takata

Toshimitsu Goto

Syougo Yokota

Hideaki Fujita

Tsutomu Yoshimoto

Toshihiro Tamura

Hideo Matsuda

Osamu Fujimoto

Takayuki Yamanaka

Tetsuro Toyoshima

Tetsunori Mitsuoka

Tokiyuki Okano

Kiyoshi Inamoto

Kazuhiko Furukawa

Yuichi Kazaki

Kazunori Sohda

Etsuzi Nukushina

Tetsuyuki Ueda

Keiji Yasuda

Tuyoshi Miyamoto

Etsuji Nukushina

Hisasi Atarasi

A developing device prevents deterioration of toner, i.e., prevent the toner from being damaged, or fused onto the blade, to realize a more reliable developing operation. In the developing device, an electron emitting section is provided onto the toner regulation blade in which apertures () are formed, wherein each of the apertures () is formed by electroforming to have an inner surface curved convexly to be widened outwardly to the side irradiated with an ultraviolet ray (shape A). Further, a photoelectric surface () is laminated on the surface of the electron emitting section with the apertures (). With an application of ultraviolet ray onto the electron emitting section, the resulting photoelectrons as emitted from the photoelectric surface () are guided to the toner through the apertures (). Here, for the aperture () of the shape A, a larger amount of electrons can be guided to the toner than the apertures in other shapes (B to E).

Developing device using specific charging unit for charging toner and image forming device adopting the same

Electron generating devices and LED arrays are arranged in a surrounding area of a photosensitive drum. The electron generating devices are located downstream of a cleaner and upstream of a developing unit with respect to a turning direction of the photosensitive drum with a specific gap between the electron generating devices and a surface of the photosensitive drum. The LED arrays are disposed against outer ends of the electron generating devices opposite to inner ends thereof facing the photosensitive drum. When activated by a driving circuit according to image information, individual LED elements of the LED arrays emit light, causing the electron generating devices to emit electrons in a pattern corresponding to the image information. The electrons emitted from the electron generating devices produce more electrons due to an electron avalanche phenomenon before reaching the photosensitive drum, eventually forming an electrostatic latent image on the surface of the photosensitive drum.

Image forming apparatus

Light emitted from an entire surface of a light source is passed selectively through a liquid crystal shutter. The shutter can be controlled to open/close on a pixel basis in response to image data and then selectively passed light is converted into light having a specified wavelength by a nonlinear optical element before impinging on a metal film. The metal film induces and emits its own electrons and forms an electrostatic latent image directly on a dielectric film.

Charging system

A developing device is provided with a developer conveying member in which a plurality of electrodes arranged on a substrate at a predetermined interval are coated with a surface protection layer, the developer conveying member being provided in a developing area that faces an image carrying body whose surface carries an electrostatic latent image, wherein developer is conveyed on the developer conveying member using a traveling-wave electric field that is formed by applying a polyphase voltage to the respective electrodes. The developing device is further provided with a supplying member for supplying the developer onto the developer conveying member, wherein (i) an effective electrode width Le of the respective electrodes in their width direction orthogonal to their arranging direction and (ii) a width Lt of a developer existing area on the supplying member, the width Lt being orthogonal to a direction of supplying the developer, are set so as to satisfy a relation of Lt&#x3c;Le. This prevents the developer from entering wiring pattern areas outside of the electrodes on the developer conveying member, thereby surely preventing the scattering and the sticking of the developer in the areas.

Developing device conveying toner using a traveling-wave electric field and image forming apparatus using same

On surfaces of insulating layersandof a transportation member, a protective layerhaving a volume resistivity of 10&#x3a9;&#xb7;cm to 10&#x3a9;&#xb7;cm is so laminated that a sum of thickness of the insulating layersandis less than intervals between adjacent ones of progressive wave generating electrodes. With this arrangement, it is ensured that a progressive wave electric field generated by the progressive wave generating electrodesis exposed beyond a surface of the transportation member. Even if developer T and the transportation membercontact each other, a surface potential of the transportation memberis not changed. Moreover, firm adhering of the toner T to the surface of the transportation memberis prevented. It is therefore possible to certainly transport the developer T to a development position always stably.

Developing apparatus and image forming apparatus using progressive wave electric field transport

The charging method is arranged so as to charge the toner on a developing roller by electrons as generated by the photoelectric effect from a photo-electric surface of a toner layer regulating/charging blade. An electric bias is applied across a toner layer thickness regulating/charging blade and a developing roller, and an amount of electrons discharged indicated by current flowing across the toner layer thickness regulating/charging blade and the developing roller is measured by an amplifier. When the amount of electrons discharged is detected to be 1/t of an initial amount, the amount of light to be received by the photo-electric surface of an ultraviolet ray luminescent is increased by t times to be the initial amount. According to the foregoing method, such event that the photoelectric effect is weakened due to the deterioration of the photoelectric surface can be detected with ease, and thus desirable charged state of toner can be maintained with ease.

Charging method and developing device adopting the same

According to a toner and a manufacturing method of the present invention, the toner, which is composed of a binding resin component precipitated in particle shapes with a coloring agent component dispersed in the binding resin component, is produced by dissolving the binding resin component in a supercritical fluid (a SCF), blending the coloring agent component in the SCF, and lowering solubility of the binding resin component for precipitating the binding resin component in the particle shapes. Even when the coloring agent content is increased, by the SCF, the toner can maintain dispersibility of the coloring agent component in the binding resin component precipitated in the particle shapes, meanwhile coloring power is also maintained thereby. Therefore, the toner can promote miniaturization of an image forming apparatus using the toner.

Toner and manufacturing method thereof

An image forming device includes a development section which has a blade for applying electrons generated in its photoelectric surface due to a photoelectric effect to a toner so as to charge the toner; an ultraviolet irradiator for irradiating the photoelectric surface with light; a development roller for holding the toner thus charged, and performing carriage of the toner to a photoconductive drum having an electrostatic latent image on a surface; wherein the electrostatic latent image on the photoconductive drum is developed by the charged toner. The development section further includes a control section for performing control of application of a voltage to the ultraviolet irradiator, application of a voltage to the photoelectric surface, application of a voltage to the development roller, and beginning of the carriage of the toner by the development roller, at predetermined timings, respectively.

Development device, charging method used in the development device and image forming device having the development device

A developing device comprises: a toner carrying member ( ) for carrying toner T towards a photosensitive drum, using a traveling wave electric field; a belt member ( ) which is provided so as to cover the surface of the toner carrying member ( ), the surface facing the photosensitive drum ( ); a belt drive roller ( ) which is in touch with the belt member ( ) so as to rotate the belt member ( ) around the toner carrying member ( ); and a drive assistance roller ( ) for sandwiching the belt member ( ) with the belt drive roller ( ). With this arrangement, it is possible to provide a developing device which is silent, small in size, and capable of reducing costs, and an image forming device including the developing device.

Developing device, and image forming device having the same

A developing device includes a developing roller and a toner charging roller. The toner charging roller has (a) a metallic layer which induces its electrons by receiving light irradiation, and (b) an ultraviolet irradiater which irradiates ultraviolet to the metallic layer. The toner charging roller gives the electrons to toner, so that the toner on the developing roller is charged. There is a space between the toner charging roller and the developing roller, and a grid electrode which controls a flow of the electrons is provided in the space. Thus, mechanical/thermal load given to the toner or the toner charging roller can be reduced, so that it is possible to prevent deterioration of toner and the device.

Developing device, charging method used therefor, and printing apparatus having the developing device

The developing device X includes: toner T that contacts an electrostatic latent image on a photosensitive drum D; a charging roller for charging the toner through contact; and an ultraviolet irradiator for charging the toner by shining ultraviolet light onto a sleeve of the charging roller from a position on the back of the sleeve via a roller . The sleeve of the charging roller contains material that changes its molecular structure under ultraviolet irradiation by the ultraviolet irradiator in such a manner to charge the toner. Deterioration of a charged member (toner) can be prevented, and so is fusion of the charged member with the charging means. Reliability in the developing process proves.

Developing device, printing device, and charging method through contact

A color image forming apparatus fixes a superimposed multi-color toner image, heat-fused at a heating section of an intermediate transfer belt, onto a recording material at a fixing nip section at which a pressing roller presses against the intermediate transfer belt. The fixing nip section is provided at the downstream end of the heating section in a turning direction of the intermediate transfer belt. The present apparatus can accelerate a fixing rate while maintaining stable fixing properties for a multi-layer toner image of a color image having different layer thicknesses with any kind of recording papers under any operation condition, and requires a shorter warm-up period while attaining excellent heat efficiency.

Color image forming apparatus spacially separating toner image heat-fusion from toner image transfer to a recording medium

In a fixing device, a sheet of paper carrying an image formed with pre-fixed toner is transported to a fixing nip region in which (1) a fixing roller heated by a heating roller outside of the fixing roller and (2) a pressure roller come into contact, so that the toner is melted and fixed on the sheet of paper. The heating roller is controlled so that a surface portion of the fixing roller in the vicinity of an exit of the fixing nip region constantly has a set temperature during the transport of the sheet of paper through the fixing nip region. By thus arranging a fixing device, the resultant fixing device features a short warm-up period, high thermal efficiency and uniform temperature distribution, capability of fixing color toner without application of oil, durability and safety, a simple structure and a low manufacturing cost, no curling of paper after fixation, and applicability to high-speed printing.

Fixing device having an externally-heated fixing roller

In a toner image fixing roller covered with a fluororesin layer, to evenly apply anti-offset agent to the roller surface and to increase sharpness of edge-portions of a toner image fixed on recording paper, a fixing roller consists of a core, elastic body layer and a fluororesin layer. The fluororesin layer contains filler (silicone oil or silicone powder) having affinity to anti-offset agent.

Toner image fixing member, fixing roller and fixing device

Growing community of inventors

Kitakatsuragi-gun, Japan

Taisuke Kamimura