Fujitsu Corporation

Other

Ricoh Company, Ltd.

Masakazu Kinoshita

Yoshimichi Katagiri

Hiroshi Yamashita

Osamu Uchinokura

Masae Nakamura

Hidenori Fujioka

Takashi Yamamoto

Shinichi Kuramoto

Hachiro Tosaka

Takashi Yoshida

Hirofumi Nakayasu

Youji Houki

Tsutomu Nagatomi

Yasufumi Nakamura

Yuzo Horikoshi

Hachiroh Tosaka

Tsutomu Kawai

Shin-ichi Kuramoto

Eiji Sakurai

Kazuhiko Kido

Kazuhiko Hamazoe

Hitoshi Kusaba

Ikuya Yamabata

Yoshimi Mizoguchi

Masaki Nagaoka

Yumi Fujisaki

Kazuyuki Kishimoto

Kazuya Hamada

Masahiro Nishihata

Haruo Kuroda

Tetsuro Baba

Yuko Ohyama

Masahiro Wanou

Takeo Kojima

Morihisa Kawahara

Kouichi Kobayashi

Takeshi Tanimoto

Hitohiro Maeda

Kaneastu Uchiyama

Masakazu Kanaka

Shinichirou Yamamoto

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

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

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.

Electrophotographic image formation process and apparatus

A developing portion forms a toner image, which corresponds to a recording image, with a toner which has been electrically charged to a predetermined electrical potential. A transfer portion, to which an electric potential, different from the electric potential of the toner image, is applied, transfers the toner image onto a recording medium. A first transfer-electric-potential applying portion applies a transfer electric potential to the transfer portion. A carrying portion carries the recording medium so as to cause the recording medium to pass by the transfer portion. A second transfer-electric-potential applying portion sets the recording medium and the carrying portion to cause the recording medium and the carrying portion to have a predetermined electric potential corresponding to the transfer electric potential of the transfer portion.

Image forming apparatus

A toner developing quantity detection unit operates a plurality of electrostatic recording units to transfer Y, M, C and K color component toner marks onto a belt. A toner developing quantity correction unit detects toner developing quantities per unit area of color toners on the basis of detection signals of the color component toner marks on the belt optically detected by a sensor. The toner developing quantity correction unit corrects the toner developing quantities so as to allow the toner consuming quantities of the plurality of electrostatic recording units to be substantially the same level, on the basis of the thus detected toner developing quantities.

Printing apparatus

An image forming apparatus includes an exposure unit forming a latent image using a light from a light source, a developing unit forming a toner image by visualizing the latent image using a toner, a detector outputting a detection signal by optically detecting an amount of toner of the toner image, a memory storing an optimum value of the detection signal output from the detector with respect to a light emission time of the light source, with respect to a plurality of light emission times of the light source to thereby store a plurality optimum values, and a control unit controlling the light emission time of the light source by calculating a light emission time corresponding to a value of the detection signal output from the detector based on the plurality of light emission times stored in the memory.

Image forming apparatus with image tone adjusting function

A process for producing a wherein an aminium salt infrared light absorber and a positive charge control agent are used in combination while preventing a mutual reaction therebetween. In this toner, the physical contact of the aminium salt compound with the positive charge control agent is avoided (e.g., by separately adding them to respective two separated phases of a binder resin), or alternatively use is made of such a combination of confounds as will not cause a mutual reaction (e.g., a common anion is used).

Process for producing flash fusing color toner

A toner is disclosed wherein an aminium salt infrared light absorber and a positive charge control agent are used in combination while preventing a mutual reaction therebetween. In this toner, the physical contact of the aminium salt compound with the positive charge control agent is avoided (e.g., by separately adding them to respective two separated phases of a binder resin), or alternatively use is made of such a combination of compounds as will not cause a mutual reaction (e.g., a common anion is used).

Flash fixing color toner and process for producing the same

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Kato, Japan

Masakazu Kinoshita