Sharp Kabushiki Kaisha Corporation

Yoshinori Mutoh

Takashi Hara

Keiichi Kikawa

Yoshiaki Akazawa

Yoritaka Tsubaki

Yoshitaka Kawase

Tadashi Iwamatsu

Hiroyuki Hirakawa

Takanori Kamoto

Nobuyuki Yoshioka

Kaoru Higuchi

Osamu Wada

Saori Yamada

Hirofumi Kanda

Yoshio Ichii

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

A method for manufacturing a capsule toner having improved preservability with no deterioration in low-temperature fixability is provided. The method for manufacturing a capsule toner includes a mixed fine resin particle adhering step of adhering mixed fine resin particles including crystalline polyester fine resin particles and amorphous fine resin particles to surfaces of toner base particles to form mixed fine resin particle-adhered particles, a spraying step of spraying a mixed solution of a liquid for plasticizing the toner base particles and the mixed fine resin particles and a crystal nucleating agent, while fluidizing the mixed fine resin particle-adhered particles, and a film-forming step of making a film of the mixed fine resin particles by impact force so that the film is a resin coating layer on the surfaces of the toner base particles.

Method for manufacturing capsule toner

There are provided a capsule toner, a two-component developer, and a capsule toner manufacturing method. The capsule toner in which a resin coating layer made of fine release-agent particles and fine resin particles is made on the surfaces of toner base particles, and thus excellent offset resistance without impairing blocking resistance can be obtained. The capsule toner includes toner base particles containing a binder resin and a colorant, and a resin coating layer made of fine release-agent particles and fine resin particles, for covering the surfaces of the toner base particles. The fine release-agent particles are dispersed in the resin coating layer.

Capsule toner, method of manufacturing the same, and two-component developer

A capsule toner capable of enhancing low temperature fixation property without impairing preservation property under a high temperature environment, a two-component developer, and an image forming apparatus are provided. The capsule toner is constituted of toner particles having toner base particles and a coating layer for coating the surface thereof. The toner base particle includes styrene-acrylic resin or polyester resin as a binder resin, and the coating layer includes styrene-acrylic resin or polyester resin. The capsule toner contains 0.05% by weight or more and 0.70% by weight or less of volatile plasticizer based on a total amount of the capsule toner.

Capsule toner, two-component developer, and image forming apparatus

A method for manufacturing a capsule toner, capable of obtaining a capsule toner including a coating layer having uniform thickness at high yield is provided. The method for manufacturing a capsule toner includes a fine resin particle adhering step of adhering fine resin particles to surfaces of toner base particles, a spraying step of spraying a spray liquid for plasticizing the toner base particles and the fine resin particles, while fluidizing the toner base particles and the fine resin particles, and a film-forming step of fluidizing the toner base particles and the fine resin particles until the fine resin particles adhered to the surfaces of the toner base particles are softened to form a film. In the spraying step, ultrasonic vibration is applied to set a number average liquid-droplet diameter of the spray liquid to less than 10 &#x3bc;m.

A toner manufacturing method is provided. The toner manufacturing method includes a step of adhering fine resin particles whose volume average particle size is 5% or more and 17% or less of a volume average particle size of toner base particles, to surfaces of the toner base particles; and a step of plasticizing the toner base particles and the fine resin particles by adding mechanical impact thereto while spraying lower alcohol, and fusing the fine resin particles to the surfaces of the toner base particles to form a plurality of projections of the fine resin particles, on the surfaces of the toner base particles. Surface coverage of the surfaces of the toner base particles with the projections is 10% or more and 50% or less.

Toner manufacturing method

A manufacturing apparatus provided with a rotary stirring section and a powder passage is used to manufacture the resin-layer coated carrier. At a fine resin particle adhering step, a magnetic base particle and a fine resin particle are inputted into the powder passage with the rotary stirring section rotating and the fine resin particle is adhered onto the surface of the magnetic base particle. At a spraying step, at least a liquid that plasticizes the fine resin particles is sprayed with spray gas from a spraying section on the magnetic base particle and the fine resin particle which are in a fluidized state in the powder passage. At a film-forming step, rotation by the rotary stirring section is continued to fluidize the magnetic base particles and the fine resin particles until the fine resin particles adhered to the magnetic base particles are softened to form a film.

Method of manufacturing resin-layer coated carrier, resin-layer coated carrier, developer, developing device, and image forming apparatus

A capsule toner achieving both low temperature fixability and hot offset resistance, and a method of manufacturing the capsule toner are provided. A capsule toner includes a toner base particle containing a binder resin and a colorant, and a resin coating layer formed on a surface of the toner base particle. The resin coating layer includes a film of plural fine resin particles having different complex viscosities. The plural fine resin particles include first fine resin particles having complex viscosity at a softening temperature of the toner base particles of 5.0&#xd7;10Pa&#xb7;s or more and 1.0&#xd7;10Pa&#xb7;s or less, and second fine resin particles having complex viscosity at a softening temperature of the toner base particles of 1.0&#xd7;10Pa&#xb7;s or more and 1.0&#xd7;10Pa&#xb7;s or less.

Capsule toner and method of manufacturing capsule toner

A toner manufacturing method, a toner obtained by the method, a one-component developer, a two-component developer, a developing device and an image forming apparatus are provided. By using a toner manufacturing apparatus including a powder passage, a spraying section for spraying a predetermined substance in the powder passage and a rotary stirring section, provided in the powder passage, and stirring particles in the powder passage to apply impact force to the particles so that the particles are fluidized in the powder passage, performed are a stirring step Sof fluidizing toner core particles with fine inorganic particles adhering to the surfaces thereof and fine resin particles in the powder passage as the powder by the rotary stirring section, and a spraying step Sof spraying a volatile liquid which softens fine resin particles as a predetermined substance by the spraying section.

Method of manufacturing toner, toner obtained by method thereof, one-component developer, two-component developer, developing device and image forming apparatus

There are provided a toner manufacturing method of manufacturing a toner which has excellent characteristics such as fluidity and preservation stability and in which a resin layer having uniform thickness is formed on a surface of tone core particle, a toner obtained by a method thereof, a one-component developer, a two-component developer, a developing device, and an image forming apparatus. By using a toner manufacturing apparatus, a stirring step Sis performed, and during rotation of a rotary shaft section, after a completion of inputting the fine resin particles into a powder passage, and within a period satisfying 1.7&#x2266;(load F&#x2212;load F)/(load F&#x2212;load F)&#x2266;5.7, a spraying step Sis started.

Method of manufacturing toner, toner obtained by method thereof, one-component developer, two-component developer, developing device, and image forming apparatus

A method for manufacturing a toner includes a pre-mixing step and a coating step. In the pre-mixing step, a secondary aggregate of the fine resin particles is disaggregated, while toner base particles and fine resin particles are mixed and stirred using a rotary stirring apparatus. Thus obtained disaggregated fine resin particles are fixed to the surface of the toner base particle. Thus, a fine resin particle-fixed toner is obtained. The rotary stirring apparatus includes a rotary stirring section, a temperature regulation section, a circulating section, and a spraying section. In the coating step, a liquid is sprayed to the fine resin particle-fixed toner with the spraying section using the rotary stirring apparatus. Thus, a film of the fine resin particles is formed. In the pre-mixing step and the coating step, temperature regulation is conducted in the temperature regulation section.

Method for manufacturing toner, toner, developer, developing device, and image forming apparatus

A method for manufacturing a toner is provided. The method for manufacturing a toner uses a rotary stirring apparatus that includes a circulating section for repeatedly performing circulation in a powder passage having a rotary stirring chamber and a circulation tube to return to the rotary stirring chamber by a rotary stirring section having a rotary disc around which rotary blades are installed and a rotary shaft, and a temperature adjusting section provided at least on a part of the powder passage for adjusting temperatures in the powder passage and of the rotary stirring section to a predetermined temperature, and includes a temperature adjusting step; a fine resin particle adhering step; a spraying step; and a film-forming step. The temperature in the powder passage is adjusted to the predetermined temperature by the temperature adjusting section at the fine resin particle adhering step, the spraying step, and the film-forming step.

A carrier of the present invention is used in a developer including a toner which includes at least a binder resin and an organic colorant, and the carrier has a core and a coating formed on the surface of the core, the coating including (i) a charge control agent for controlling a charge whose polarity is the same as a polarity of a charge controlled by a charge control agent included in the toner, and (ii) a conductive particles. The use of the carrier of the present invention enables: prevention of decrease in the charging amount of the toner which includes at least a binder resin and an organic colorant; and formation of a stable, high-resolution, high-quality image which has very few image defects such as a photographic fog.

Carrier, developer, development device, image forming apparatus and image forming method

The image forming apparatus include: a resistance detection section () for measuring a volume resistivity of a two component developer () on a surface of a developer bearing member (); a resistance memory section () for storing therein a preset volume resistivity; a resistance comparison section () for comparing the volume resistivity of the two component developer () which has been measured by the resistance detection section () with the preset volume resistivity stored in the resistance memory section (); and a control section () for carrying out a process for replacing the two component developer or carrier if the volume resistivity of the two component developer () is lower than the preset volume resistivity.

Image forming apparatus, image forming method, image forming computer program, and computer readable storage medium containing the program

In an ink-jet head device, a main tank, a sub tank and an ink-jet head are mounted in this order in a carriage, with the main tank placed at the top. The main tank, sub tank and ink-jet head are connected to one another by a three-way ink conduit. At a junction of the ink conduit is disposed a three-way switching valve, which selectively switch a path connecting the sub tank to the main tank and a path connecting the sub tank to the ink-jet head, without causing the ink-jet head and the main tank to communicate with each other. As a result, an ink-jet head device and an ink-supplying method are realized, in which the ink-jet head can maintain suitable negative pressure and in which consumption of ink is reduced.

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Osaka, Japan

Yoshinori Mutoh