Sharp Kabushiki Kaisha Corporation

Masamitsu Sakuma

Katsumi Adachi

Kiyoshi Toizumi

Taisuke Kamimura

Toshimitsu Gotoh

Tadashi Iwamatsu

Kenji Mishima

Toshimitsu Goto

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

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

A rear electrode is arranged at a location at the back of a toner transport path opposite a supply roller, and the rear electrode is moreover embedded in a support, toner-supplying voltage from rear electrode power supply being applied to rear electrode, toner-supplying electric field being formed in the vicinity or vicinities of supply roller, toner-supplying voltage from a rear electrode power supply being varied as appropriate, and intensity of toner-supplying electric field(s) being adjusted.

Developer apparatus and image forming apparatus

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

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.

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Hirakata, Japan

Masamitsu Sakuma