Minolta Company, Ltd.

Konica Minolta Business Technologies, Inc.

Konica-minolta Holdings, Inc.

Chikara Tsutsui

Masahiro Anno

Minoru Nakamura

Katsunori Kurose

Hiroyuki Fukuda

Junji Murauchi

Tetsuya Kagawa

Hiroaki Takada

Yoshitaka Sekiguchi

Junji Machida

Masahide Inoue

Takeshi Arai

Takayuki Takai

Kazuhiro Saito

Takuya Okada

Hiroshi Goto

Tetsuo Sano

Tomoyuki Imura

Takuya Sasaki

Yoshihiro Mikuriya

Ryuji Inoue

Masafumi Uchida

Shuichi Nakagawa

Takao Yamanouchi

Megumi Aoki

Yoichi Fujieda

Masaaki Takama

Mikihiko Sukeno

Choichiro Tanigawa

Junju Machida

Senyu Taira

A toner for hybrid development, comprising toner particles containing at least a binder resin and a colorant and being charged when made in friction-contact with a carrier; reverse polarity particles that are charged to polarity reversed to the charged polarity of the toner particles when made in friction-contact with the carrier, and have a number-average primary particle size in a range from 95 to 850 nm; and same polarity particles that are charged into the same polarity as the charged polarity of the toner particles when made in friction-contact with the carrier, and have a number-average primary particle size in a range from 80 to 800 nm and a shape factor in a range from 100 to 160; a developer for hybrid development containing the above toner and a carrier; and an image-forming apparatus provided with the developer for hybrid development.

Toner for hybrid development, developer for hybrid development and image-forming apparatus

A developing device is provided with a developer transporting member for transporting a developer containing a toner and a carrier; a toner transporting member opposite to the developer transporting member and opposite to an electrostatic latent image carrying member; a first electric field forming device, which is composed of a power source for the developer transporting member and a power source for the toner transporting member, for shifting the toner in the developer held onto the developer transporting member to the toner transporting member; and a second electric field forming device for shifting the toner held onto the toner transporting member to an electrostatic latent image on the carrying member. Operation of the first electric field forming device is controlled based on an electric current flowing in the developer transporting member power source, which is detected by a detecting block.

Developing device, and controlling method thereof

A developing device is provided with a first transporting member for transporting a developer containing a toner and a carrier; a second transporting member opposite to the first transporting member to interpose a first spatial region therebetween and opposite to an electrostatic latent image carrying member to interpose a second spatial region therebetween; a first electric field forming device, composed of first and second power sources, for shifting the toner in the developer held onto the first transporting member to the second transporting member; and a second electric field forming device, composed of the second power source, for shifting the toner held onto the second transporting member to an electrostatic latent image on the carrying member. The operation of the second electric field forming device is controlled based on electric currents flowing in the first and second power sources, which are detected by first and second detecting blocks, respectively.

A housing of a developing apparatus is provided with a conveying member in a developer supplying and recovering portion, and with two agitating members rotating from the below to the above in portions opposed to each other in a developer agitating portion. A guide is provided in an inner bottom surface of the housing between two agitating members. A braking portion suppressing a discharge of a developer is provided in a downstream side of the developer agitating portion in a developer conveying direction of the second agitating member, and a discharge portion is provided in a downstream side of a disc of the braking portion.

Developing apparatus and image forming apparatus provided with the same

A housing of a developing apparatus is provided with a conveying member and two agitating members. A guide is provided in an inner bottom surface of the housing between two agitating members. A guide is formed into a mountain shape with wide foot portion in a cross sectional shape which is orthogonal to an axial direction of rotating shafts of the agitating members. The guide is arranged in such a manner that a gap between respective outermost portions of two agitating members, and an inner bottom surface of the housing and the guide becomes equal to or more than 1.5 mm and less than 3 mm. Further, each of two agitating members rotates in a direction from the below to the above at a position of the guide.

A housing of a developing apparatus is provided with a conveying member and first and second agitating members. A guide is provided in an inner bottom surface of the housing between the first and second agitating members. The guide has a mountain shape with a wide foot portion in a cross sectional shape which is orthogonal to an axial direction of rotating shafts of the first and second agitating members. The first and second agitating are arranged in such a manner that gaps between respective outermost portions thereof and the inner bottom surface of the housing and the guide become equal to or more than 1.5 mm and less than 3 mm. A discharge portion is provided on a downstream side of a developer agitating portion in a developer conveying direction of the first and second agitating members.

Developing apparatus with agitating portion and image forming apparatus provided with the same

A housing of a developing apparatus is provided with a conveying member in a developer supplying and recovering portion, and with first and second agitating members rotating from the below to the above in portions opposed to each other in a developer agitating portion. A guide is provided in an inner bottom surface of the housing between the first and second agitating members. A discharge portion provided with a developer discharge port is provided on a downstream side of the developer agitating portion in a developer conveying direction of the first agitating member. A suitable amount of developer can be circulated while conveying a part of an excess amount of developer in a circulating conveying path to the discharge portion and discharging from the developer discharge port. Packing and leaking of the developer within the developing apparatus and breakage of the developing apparatus can be prevented and also a good image can be obtained even if high printing images are continuously provided.

Developing apparatus including guide for preventing packing and leaking of developer and image forming apparatus provided with the same

A developing apparatus for visualizing an electrostatic latent image on an electrostatic latent image bearing member by using a developer including toner and carrier particles, has a developer including toner and carrier particles, a first transport member, a second transport member positioned to oppose to the first transport member across a first region and to the electrostatic latent image bearing member across a second region. A first electric field forming unit forms a first electric field between the first and second transport members to move the toner particles from the first transport member to the second transport member. A second electric field forming unit forms a second electric field between the second transport member and the electrostatic latent image bearing member to move the toner particles from the second transport member to the electrostatic latent image bearing member and thereby to visualize an electrostatic latent image on the image into a visible image. The developer further includes charging particles releasably retained on surfaces of the toner particles. Once released from the toner particles and then held on surfaces of the carrier particles, the third particles function to provide an electric charge of the first polarity to the toner particles by the contact therewith.

Developing apparatus image forming apparatus, and method of charging a developer using charging particles

A toner used for an image forming method comprises steps of: limiting an amount of toner on a surface of a toner carrier by allowing a toner layer limiting member to be pressed to the surface of the toner carrier; and developing an electrostatic latent image formed on an electrostatic latent image carrier using the toner carried and transferred by the toner carrier, based on a non-magnetic single component development system, wherein the toner comprises toner particles having a volume average particle diameter of 3 to 9 &#x3bc;m, an arithmetic mean value of shape factor of 1.1 to 1.5, a coefficient of variation of shape factor of 16% or less, a ratio of rounded toner particle of 50% by number or more and a coefficient of variation of number particle diameter distribution of 26% or less, and a conveyance index of 2.0 to 10.0.

Toner and image forming method

The present invention relates to a toner for developing an electrostatic latent image comprising a binder resin, a colorant, a first wax, and a second wax whose kind is different from that of the first wax, wherein the toner is prepared by a kneading-grinding method and integrated domains of the first wax and the second wax are dispersed in the binder resin.

Toner for developing electrostatic latent image

The present invention relates to toners for full color image-forming machine with specific external additives (kind, BET specific surface area etc.) added externally in combination to toner particles prepared by a wet granulation method, and a fixing method suitable for the toner.

Toner containing specific external additive for full color-copying machine and fixing method of the same

The present invention relates to a mono-component developing device, which develops an electrostatic latent image formed on an electrostatic latent image-supporting member with a toner having a weight-average particle size of from 4 to 10 &mgr;m, a compression rate of not more than 32% and an angle of repose of not more than 38&deg;, and a toner used for the mono-component developing device. Even in the case when a comparatively great stress is imposed on the toner particles, the toner of the present invention maintains superior fluidity and makes it possible to provide a high-quality image.

Mono-component developing device, toner for the same and image forming apparatus

Developing system for forming a full-color image

Toner set and full-color image-forming method suitable for use of the toner set

A production method of toner particles has steps of mixing a binder resin and a colorant, melting and kneading the mixture, pulverizing the kneaded material, and classifying the pulverized materials to give a colored resin particles. Then the colored resin particles are mixed with silica particles having an average primary particle size of 16 to 28 nm with the number of particles (A) that are less than 15 nm in particle size, the number of particles (B) that are between 15 and 30 nm in particle size and the number of particles (C) that are larger than 30 nm in particle size having the relation of (B)/(A)>4 and (B)/(C)>4. To obtain toner particles, the resultant mixture is heat-treated to make the colored resin particles spherical and to make the silica particles fixed on the surface of the colored resin particles.

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Nishinomiya, Japan

Chikara Tsutsui