Sharp Kabushiki Kaisha Corporation

Hirofumi Kanda

Tadashi Iwamatsu

Hiroyuki Hirakawa

Yoshio Ichii

Toshihiro Tamura

Takashi Hara

Takanori Kamoto

Yoshinori Mutoh

Osamu Wada

Nobuyuki Yoshioka

The resin coated carrier is used with a toner in which an external additive having an average primary particle size of 50 nm or more is added to a toner particle, and has a carrier core and a resin coating layer on the surface of the carrier core. In the resin coated carrier, the following expression (1) is satisfied:0.5&#x2266;&#x2212;log {()/()}&#x2266;2.5&#x2003;&#x2003;(1)wherein A represents a volume resistance value (&#x3a9;/cm) of the resin coated carrier in an electric field of 1000 V/cm that is obtained by conducting a stirring test, B represents a volume resistance value (&#x3a9;/cm) of the resin coated carrier in an electric field of 1000 V/cm before the stirring test, and C represents a volume resistance value (&#x3a9;/cm) of the carrier core in an electric field of 1000 V/cm.

Resin coated carrier, two-component developer, developing device and image forming apparatus

An electron emitting element () includes a substrate (), an upper electrode (), and a fine particle layer () sandwiched between the substrate () and the upper electrode (). The fine particle layer () includes metal fine particles () with high resistance to oxidation, and insulating fine particles () larger in size than the metal fine particles (). The electron emitting element () can steadily emit electrons not only in vacuum but also in the atmosphere. Further, the electron emitting element () can work without electric discharge so that harmful substances such as ozone, NOx, or the like are scarcely generated. Accordingly, degradation of the electron emitting element () due to oxidation does not occur. Therefore, the electron emitting element () has a long life and can steadily work continuously for a long period of time even in the atmosphere.

Electron emitting element for accelerating and emitting electrons, and use of electron emitting element

A charging device () includes electrospray means for inducing electrospraying through application of a voltage to an incoming liquid (), in order to produce charged liquid droplets (). The device () charges a photoreceptor drum () by means of the liquid droplets (). Hence, the invention provides a charging device capable of reducing ozone production while preventing the charging device and the electrostatic latent image carrier from degrading or wearing out from friction between the device and the carrier and provides also an image forming device incorporating the charging device.

Charging device and image forming device using same

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Osaka, Japan

Hirofumi Kanda