Other

Fujitsu Corporation

Fuji Xerox Co., Ltd.

Ricoh Company, Ltd.

Masae Nakamura

Yoshimichi Katagiri

Hiroshi Yamashita

Osamu Uchinokura

Masakazu Kinoshita

Takashi Yamamoto

Shinichi Kuramoto

Hachiro Tosaka

Takashi Yoshida

Tomoaki Tanaka

Hachiroh Tosaka

Shin-ichi Kuramoto

Yoshimi Mizoguchi

Yasushige Nakamura

Satoshi Takezawa

Kazuhiko Hamazoe

A developing device for electrophotographic image has a developing mechanism having a developer carrier for carrying a developer along a preset circulating route including a developing area and a developer restricting element for restricting the developer on the developer carrier, and a developer supply mechanism having a storing unit. The storing unit is filled with a start-up developer in the vicinity of the developer carrier and a replenishing developer remoter than the start-up developer from the developer carrier. The start-up developer and the replenishing developer have different grain sizes or grain size distributions. Further, a developing method for electrophotograhic image has the steps of using the start-up developer at an initial state of use of the developing mechanism, and using the replenishing developer differed in grain size or grain size distribution from the start-up developer after an end of the initial state of use of the developing mechanism.

Developing method and developing device for electrophotographic image, and printing device using the developing device

In a method for forming a multicolored toner image in accordance with an electrophotographic process, the addition amount of external additives to a non-added toner is 1.5 to 10.0 parts by weight per 100 parts by weight of the non-added toner in each developing step, the aggregation degree of the toner is within the range of 30 to 80%, and the change ratio of the aggregation degree satisfies the relation:0.8&#x2266;(initial aggregation degree/aggregation degree after no-load revolution of developing portion for 20 hours)&#x2266;1.2. According to this method, it becomes possible to form a high-quality color image while a toner always keeps a stable degree of aggregation and a charge amount.

Color image formation method

An image formation method for forming an image is proposed, which uses an image formation apparatus capable of performing (1) multi-color image formation and printing by superimposing toner images with different colors by use of a plurality of color toners with different colors, including at least a black toner, and (2) monochrome image formation and printing, using only a black toner, with a maximum transferable amount of each color toner onto the image being in a range of 4&times;10 kg/m to 8&times;10 kg/m , wherein an image glossiness (GKC) obtained by the black toner in the maximum transferable amount thereof at the multi-color image printing, an image glossiness (GCC) obtained by each of the color toners other than the black toner in the maximum transferable amount thereof at the multi-color image printing, and an image glossiness (GKM) obtained by the black toner in the maximum transferable amount thereof at the monochrome image printing satisfy a particular relationship as described in the specification. In addition, the above toners and a printed matter prepared by this image formation method are proposed.

Image formation method, electrophotographic toners, and printed matter

A color toner for electrophotography, preferably used as a flash fixing toner which can be processed at a high speed, and exhibit excellent fixing property, high image resolution (image reproducibility) when fixed, and color reproducibility by color overlapping, and having a preferable color tone, with which a multi-color image can be formed. The color toner for electrophotography is used for the extreme bottom layer of a multi-color image comprised of laminating at least two types of toners that are selected from black toner, magenta toner, yellow toner, and cyan toner, and contains a coloring agent and an infrared ray absorbent, the color toner for electrophotography has a contrast ratio in the range of 35% to 95%.

COLOR TONER FOR ELECTROPHOTOGRAPHY, AND A COMBINED SET OF COLOR TONERS FOR ELECTROPHOTOGRAPHY USING THE SAME, COLOR DEVELOPING AGENT FOR ELECTROPHOTOGRAPHY USING THE SAME, METHOD FOR FORMING COLOR IMAGES USING THE SAME, AND DEVICE FOR FORMING COLOR IMAGES USING THE SAME

An image formation process which forms a toner image by the nonmagnetic one-component developing system by bringing an electrically conducting brush impressed with a voltage into contact with a photosensitive material to effect the uniform charging, and forming an electrostatic latent image on the photosensitive material by the exposure to the image-bearing light, wherein the toner that is used as a circularity of from 0.92 to 0.98. The nonmagnetic one-component developing system minimizes irregular electric charging that stems from the use of the electrically conducting brush. This action is obtained even in full-color developing system which effects development many times.

Image formation process and developer used therein

Disclosed is a color image forming apparatus in which a color image is formed by accumulating a visible image on an image transfer medium. The color image forming apparatus includes a plurality of forming means for forming the visible image on an image forming medium with a toner; and a plurality of transferring means for transfer the visible image onto the image transfer medium while bringing the visible image into contact with the image transfer medium. With respect to a toner amount which is transferred from each of the image forming medium onto the image transfer medium, difference between a toner deposition amount on the image transfer medium right after transferring the visible image from the image forming medium and a final toner deposition amount on the image transfer medium in the event of transfer of visible images is completed onto the image transfer medium is set such that the difference of the toner deposition amount of the visible image which is transferred by the transferring means disposed on an upstream side is larger than that on a downstream side in a direction where the visible image is successively formed.

Color image forming apparatus

In a method for forming a color image by using a contact type nonmagnetic one-component developing device, a flat sheet-like blade made of a metal flexible member and having a distal end thereof chamfered is used inside the developing device in combination with a toner having a glass transition point of 55 to 70&deg; C. and a weight average particle diameter of 6.0 to 10.0 &mgr;m, and containing up to 20 number % of particles having particle diameters of 5 &mgr;m or below, as a developer. The developing device is simple in construction, can provide high image quality and can, moreover, provide a highly reliable image formation method.

Growing community of inventors

Kawasaki, Japan

Masae Nakamura