Patents by Inventor Satoshi Kojima
Satoshi Kojima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20170146917Abstract: An electrostatic-image developing toner including at least a binder resin; a colorant; and a release agent, wherein an average circularity of particles having a particle diameter in a range of 0.79 times or more but less than 1.15 times as large as a most frequent diameter in a number particle size distribution of the toner is within a range of 1.010 times or more but less than 1.020 times as high as an average circularity of particles having a particle diameter of 1.15 times or more as large as the most frequent diameter.Type: ApplicationFiled: February 2, 2017Publication date: May 25, 2017Inventors: Satoshi TAKAHASHI, Yoshihiro Moriya, Ryota Inoue, Masahiko Ishikawa, Tatsuki Yamaguchi, Satoshi Kojima
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Patent number: 9618863Abstract: A toner is provided. The toner includes a binder resin, a colorant, a release agent and an external additive. The toner has an average circularity of from 0.965 to less than 0.985. The toner has BET specific surface area of less than 1.20 m2/g after liberation treatment of external additive.Type: GrantFiled: October 30, 2015Date of Patent: April 11, 2017Assignee: Ricoh Company, Ltd.Inventors: Satoshi Takahashi, Yoshihiro Moriya, Satoshi Kojima, Masahiko Ishikawa, Tatsuki Yamaguchi
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Patent number: 9588479Abstract: An image forming apparatus is provided which includes an image bearer, a charger to charge the image bearer, a latent image forming device to form an electrostatic latent image on the image bearer, a developing device to develop the electrostatic latent image with a toner, a transfer device to transfer the toner image onto a transfer medium, and a cleaning blade to remove residual toner particles remaining on the image bearer. The toner includes a binder resin and a release agent. The release agent has a longest length Lmax in the toner, which is equal to or greater than 1.1 times a maximum Feret diameter Df of the toner. The cleaning blade includes a strip-like elastic body blade having a contact part with the image bearer. The contact part includes a cured product of an ultraviolet curable composition including an acrylate or methacrylate compound having an alicyclic structure.Type: GrantFiled: March 18, 2016Date of Patent: March 7, 2017Assignee: Ricoh Company, Ltd.Inventors: Shohei Gohda, Masanobu Gondoh, Kaori Toyama, Yohta Sakon, Masahiro Ohmori, Yuka Aoyama, Yuta Nakamura, Yoshihiro Moriya, Satoshi Kojima
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Patent number: 9523931Abstract: To provide a toner, which contains silica particles containing first silica particles, and second silica particles, wherein the toner is a toner produced by depositing the silica particles on surfaces of base particles, the first silica particles have an average primary particle diameter of 75 nm to 250 nm, the second silica particles have an average primary particle diameter of 10 nm to 50 nm, a mass ratio of the first silica particles to the base particles is 0.010 to 0.040, a mass ratio of the second silica particles to the base particles is 0.005 to 0.030, a liberation ratio of the silica particles from the toner by a ultrasonic vibration method is 5% by mass to 20% by mass, and an amount of particles having primary particle diameters of 30 nm or smaller in the silica particles librated from the toner by the ultrasonic vibration method is 20% by number or less.Type: GrantFiled: January 30, 2014Date of Patent: December 20, 2016Assignee: Ricoh Company, Ltd.Inventors: Satoshi Kojima, Junichi Awamura, Tsuneyasu Nagatomo, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda
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Publication number: 20160363076Abstract: According to the present invention, by providing control whereby a rising slope or a descending slope of step-up current flowing to a step-up coil is detected, and corrections are made to step-up switching control, the step-up upper and lower limit current values of the step-up circuit can be controlled within intended current threshold values regardless of constant modifications or change in characteristics due to fluctuations of the battery power supply voltage or degradation of step-up circuit elements over time; heat emission by step-up circuit elements can be kept to a minimum; and the step-up recovery time can be adjusted to a constant value regardless of the slope of the step-up current.Type: ApplicationFiled: January 19, 2015Publication date: December 15, 2016Inventors: Satoshi KOJIMA, Takuya MAYUZUMI
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Publication number: 20160274527Abstract: An image forming apparatus is provided which includes an image bearer, a charger to charge the image bearer, a latent image forming device to form an electrostatic latent image on the image bearer, a developing device to develop the electrostatic latent image with a toner, a transfer device to transfer the toner image onto a transfer medium, and a cleaning blade to remove residual toner particles remaining on the image bearer. The toner includes a binder resin and a release agent. The release agent has a longest length Lmax in the toner, which is equal to or greater than 1.1 times a maximum Feret diameter Df of the toner. The cleaning blade includes a strip-like elastic body blade having a contact part with the image bearer. The contact part includes a cured product of an ultraviolet curable composition including an acrylate or methacrylate compound having an alicyclic structure.Type: ApplicationFiled: March 18, 2016Publication date: September 22, 2016Inventors: Shohei GOHDA, Masanobu GONDOH, Kaori TOYAMA, Yohta SAKON, Masahiro OHMORI, Yuka AOYAMA, Yuta NAKAMURA, Yoshihiro MORIYA, Satoshi KOJIMA
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Patent number: 9372416Abstract: A method for manufacturing an electrophotographic photosensitive member using plasma CVD includes steps of placing a cylindrical base member in a reactor which can be evacuated, the reactor having an electrode therein, so as to be spaced apart from the electrode, introducing a raw material gas for deposited film formation into the reactor, and applying an alternating voltage of a rectangular wave having a frequency in the range of 3 kHz to 300 kHz between the electrode and the cylindrical base member so that a potential at one of the electrode and the cylindrical base member with respect to a potential at the other becomes alternately positive and negative, to decompose the raw material gas, and forming a deposited film on the cylindrical base member. The magnitude of the potential difference between the electrode and the cylindrical base member is selectively controlled.Type: GrantFiled: September 10, 2012Date of Patent: June 21, 2016Assignee: Canon Kabushiki KaishaInventors: Satoshi Kojima, Kazunari Ooyama, Yukihiro Abe
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Publication number: 20160124332Abstract: A toner is provided. The toner includes a binder resin, a colorant, a release agent and an external additive. The toner has an average circularity of from 0.965 to less than 0.985. The toner has BET specific surface area of less than 1.20 m2/g after liberation treatment of external additive.Type: ApplicationFiled: October 30, 2015Publication date: May 5, 2016Inventors: Satoshi TAKAHASHI, Yoshihiro MORIYA, Satoshi KOJIMA, Masahiko ISHIKAWA, Tatsuki YAMAGUCHI
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Patent number: 9291931Abstract: Provided is an electrostatic charge image developing toner, including: toner base particles including a polyester resin as a binder resin; and an external additive on the surface of the toner base particles. The external additive includes silica. The silica is produced by sol-gel method, and is aspherical. The percentage of change in the specific surface area of the toner when it is stored under high-temperature, high-humidity conditions is from 25% to 45%.Type: GrantFiled: February 18, 2014Date of Patent: March 22, 2016Assignee: Ricoh Company, Ltd.Inventors: Junichi Awamura, Tsuneyasu Nagatomo, Satoshi Kojima, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda
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Publication number: 20160077455Abstract: A toner is provided. The toner includes a binder resin and a release agent. The binder resin includes a polyester resin. The toner has a single exothermic peak measured by a differential scanning calorimetry (DSC) descending in a temperature range of from 150° C. to 0° C., wherein the exothermic peak is in a temperature range of from 40° C. to 60° C. and has a half bandwidth of at most 10° C. The release agent disperse to network form in the cross-sectional images of the toner observed with a transmission electron microscope (TEM).Type: ApplicationFiled: August 27, 2015Publication date: March 17, 2016Inventors: Yoshihiro MORIYA, Masahiko Ishikawa, Satoshi Kojima, Satoshi Takahashi, Tatsuki Yamaguchi
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Patent number: 9274445Abstract: A toner set, including: a transparent toner including a binder resin a, a releasing agent a and no colorant; and one or more color toners, each including a binder resin b, a colorant b and a releasing agent b, wherein the binder resin a includes a non-crystalline resin ? and a crystalline resin ?, the binder resin b includes a non-crystalline resin ? and a crystalline resin ?, the releasing agent a has an average particle diameter as a long diameter of 0.2 ?m to 2.0 ?m, and there is a relationship of 1<A/B<1.5, where A is an area of the releasing agent a in a transparent toner cross-section from a surface thereof to a ?-depth of a volume-average particle diameter, and B is an area of the releasing agent b in a color-toner cross-section from a surface thereof to a ?-depth of a volume-average particle diameter.Type: GrantFiled: March 13, 2013Date of Patent: March 1, 2016Assignee: Ricoh Company, Ltd.Inventors: Junichi Awamura, Teruki Kusahara, Satoshi Ogawa, Daisuke Ito, Daisuke Inoue, Osamu Uchinokura, Satoshi Kojima, Tsuneyasu Nagatomo, Mamoru Hozumi, Syouko Satoh
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Patent number: 9201365Abstract: An image forming apparatus, including: photoconductor; charging unit; exposing unit; developing unit containing toner; transfer unit; and fixing unit, wherein the toner includes external additive and base particles containing binder resin, colorant, and release agent, the toner has melt viscosity at 100° C. of 500 Pa·s to 8,000 Pa·s and the release agent has melt viscosity at 100° C. of 20 mPa·s to 30 mPa·s, the fixing unit includes fixing member that has roller or belt shape and contacts toner image transferred onto recording medium, and the fixing member includes release layer on surface thereof that is to be brought into contact with the toner image transferred onto the recording medium, and wherein the release layer satisfies the following expressions: 45??c1?60, and 10??c1??c2, where ?c1 denotes receding contact angle [°] of the release agent to the release layer and ?c2 denotes receding contact angle [°] of the release agent to the toner.Type: GrantFiled: March 13, 2015Date of Patent: December 1, 2015Assignee: Ricoh Company, Ltd.Inventors: Shingo Sakashita, Satoshi Kojima, Daisuke Misawa, Hiroshi Endoh, Tomoki Murayama, Rintaro Takahashi, Chihiro Kikuchi
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Patent number: 9201325Abstract: A toner including a binder resin which contains a crystalline polyester resin and a non-crystalline polyester resin, wherein the crystalline polyester resin has at least two diffraction peaks in a range of 20°<2?<25° as detected by X-ray diffraction measurement, and has a melting point which is 60° C. or higher but lower than 80° C., and wherein the diffraction peaks each have a half width which is less than 1.0°.Type: GrantFiled: April 14, 2011Date of Patent: December 1, 2015Assignee: Ricoh Company, Ltd.Inventors: Tsuyoshi Sugimoto, Osamu Uchinokura, Satoshi Ogawa, Junichi Awamura, Satoshi Kojima, Daisuke Ito, Teruki Kusahara, Daisuke Inoue, Mamoru Hozumi, Shoko Sato
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Publication number: 20150261144Abstract: An image forming apparatus, including: photoconductor; charging unit; exposing unit; developing unit containing toner; transfer unit; and fixing unit, wherein the toner includes external additive and base particles containing binder resin, colorant, and release agent, the toner has melt viscosity at 100° C. of 500 Pa·s to 8,000 Pa·s and the release agent has melt viscosity at 100° C. of 20 mPa·s to 30 mPa·s, the fixing unit includes fixing member that has roller or belt shape and contacts toner image transferred onto recording medium, and the fixing member includes release layer on surface thereof that is to be brought into contact with the toner image transferred onto the recording medium, and wherein the release layer satisfies the following expressions: 45??c1?10, and 10??c1??c2, where ?c1 denotes receding contact angle [°] of the release agent to the release layer and ?c2 denotes receding contact angle [°] of the release agent to the toner.Type: ApplicationFiled: March 13, 2015Publication date: September 17, 2015Inventors: Shingo SAKASHITA, Satoshi KOJIMA, Daisuke MISAWA, Hiroshi ENDOH, Tomoki MURAYAMA, Rintaro TAKAHASHI, Chihiro KIKUCHI
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Patent number: 9086647Abstract: A developing device, including: a developer bearing member, which is disposed opposite to an electrostatic latent image bearing member and which bears thereon a developer for developing an electrostatic latent image formed on the electrostatic latent image bearing member and conveys the developer to a developing region, wherein the developer includes a toner and a carrier, the toner containing: a toner base containing a binder resin and a colorant; and an external additive, wherein the external additive contains coalescent particles each made up of a plurality of coalescing primary particles, and wherein a work function Wc of the carrier and a work function Ws of the developer bearing member satisfy a relationship of the following formula (1): Ws?Wc?0.4 eV??(1).Type: GrantFiled: September 10, 2013Date of Patent: July 21, 2015Assignee: Ricoh Company, Ltd.Inventors: Shingo Sakashita, Junichi Awamura, Tsuneyasu Nagatomo, Satoshi Kojima, Tomoki Murayama
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Publication number: 20150198902Abstract: Provided is a static charge image developing toner of which flowing start temperatures (Tfb) measured with a flow tester satisfy relational formulae below: Tfb(2-5)=100?[Tfb(5 Kg)/Tfb(2 Kg)]×100??(Formula 1) 2.00?Tfb(2-5)?6.50??(Formula 2) where in Formula 1 above, Tfb(2 Kg) and Tfb(5 Kg) represent flowing start temperatures of the static charge image developing toner when 1.5 g of the toner is heated at a temperature raising rate of 3° C./minute and let to flow out from a die having a diameter of 1.0 mm under loads of 2 Kg and 5 Kg respectively.Type: ApplicationFiled: December 31, 2014Publication date: July 16, 2015Inventors: Shun Saito, Osamu Uchinokura, Satoshi Ogawa, Satoshi Kojima, Rintaro Takahashi
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Patent number: 9069288Abstract: Toner housing container includes: container body mountable on toner conveying device and housing toner supplied into toner conveying device; conveying portion provided in container body and conveying toner from longer direction one end of container body to other end at which container opening portion is provided; pipe receiving port provided at container opening portion and receiving conveying pipe fixed to toner conveying device; and uplifting portion to move toner conveyed by conveying portion toward toner receiving port of conveying pipe. Toner has loose apparent density of 0.28 g/cm3 to 0.53 g/cm3. Container body includes protruding portion protruding from container body interior side of container opening portion toward one end. Uplifting portion includes uplifting wall surface extending from internal wall surface of container body toward protruding portion, and curving portion curving to conform to protruding portion.Type: GrantFiled: May 20, 2014Date of Patent: June 30, 2015Assignee: RICOH COMPANY, LTD.Inventors: Satoshi Kojima, Junichi Awamura, Tsuneyasu Nagatomo, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda, Hiroshi Hosokawa, Shunji Katoh, Shinji Tamaki, Hiroshi Ikeguchi, Kenji Kikuchi, Michiharu Suzuki
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Publication number: 20150104739Abstract: A toner, containing: toner base particles; and an external additive, the toner base particles each including a binder resin and a releasing agent, wherein the external additive includes non-spherical coalesced particles in each of which primary particles are coalesced together, and wherein the coalesced particles satisfy the following formula (1): Nx/1,000×100?30% where Nx is a number of the primary particles present alone relative to 1,000 of the coalesced particles, as observed under a scanning electron microscope after stirring 0.5 g of the coalesced particles and 49.5 g of a carrier placed in a 50 mL bottle for 10 minutes by means of a mixing and stirring device at 67 Hz.Type: ApplicationFiled: March 7, 2013Publication date: April 16, 2015Inventors: Tsuneyasu Nagatomo, Satoshi Kojima, Syouko Satoh, Kiwako Hirohara, Osamu Uchinokura, Junichi Awamura, Satoshi Ogawa, Takahiro Honda
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Patent number: 9005864Abstract: A toner including: toner base particles; and an external additive, the toner base particles each comprising a binder resin and a colorant, wherein the external additive comprises non-spherical particles and spherical particles, wherein the non-spherical particles are each a secondary particle in which spherical primary particles are coalesced together, and wherein the non-spherical particles and the spherical particles in the external additive satisfy a relationship expressed by the following formula (1): 3Ca(%)<Cb(%)??Formula (1) where Ca is greater than 10% but smaller than 20% and Cb is greater than 40% but smaller than 70%, and Ca and Cb are values given by: Ca = ( an ? ? amount ? ? of ? ? the ? ? non ? - ? spherical ? ? particles ? ? ( % ? ? by ? ? mass ) / 100 ) × ( a ? ? projected ? ? area ? ? of ? ? the ? ? non ? - ? spherical ? ? particles ? ? ( cm 2 ? / ? g ) ) ( an ? ? amount ? ? of ? ? theType: GrantFiled: March 8, 2013Date of Patent: April 14, 2015Assignee: Ricoh Company, Ltd.Inventors: Syouko Satoh, Tsuneyasu Nagatomo, Satoshi Kojima, Osamu Uchinokura, Junichi Awamura, Daisuke Ito, Satoshi Ogawa, Kiwako Hirohara, Takahiro Honda, Daisuke Inoue
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Patent number: 8956795Abstract: A toner for developing an electrostatic image, including: toner base particles each including a binder resin and a releasing agent; and inorganic fine particles, wherein the toner includes the inorganic fine particles as an external additive on a surface of the toner base particle, wherein the toner base particles have a BET specific surface area of 2.5 m2/g to 5.0 m2/g, and wherein the inorganic fine particles comprise inorganic fine particles (A) which are each a secondary particle where a plurality of primary particles are coalesced together.Type: GrantFiled: March 11, 2013Date of Patent: February 17, 2015Assignee: Ricoh Company, Ltd.Inventors: Satoshi Kojima, Tsuneyasu Nagatomo, Syouko Satoh, Osamu Uchinokura, Junichi Awamura, Satoshi Ogawa, Takahiro Honda, Daisuke Ito, Teruki Kusahara, Masaki Watanabe, Daisuke Inoue, Kiwako Hirohara