Patents by Inventor Tomoyuki Ichikawa

Tomoyuki Ichikawa 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).

  • Patent number: 7288353
    Abstract: A toner including toner particles including a binder resin, a colorant, and an inorganic particulate material present on a surface of the toner particles. The toner particles have a surface roughness (Ra) of from 1 to 30 nm, a standard deviation of the surface roughness of from 10 to 90 nm and include 1 to 20 convexities per 1 ?m, which have a height not less than 10 nm.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: October 30, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Kazuhiko Umemura, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi
  • Patent number: 7271544
    Abstract: In a lighting apparatus for an illumination light source (discharge lamp or the like), a fly-back type DC-DC converter circuit comprises a transformer and a switching element. A control circuit is provided for controlling power supplied to the illumination light source, such that operation is controlled in a current boundary mode by a control signal sent from the control circuit to the switching element. A fluctuation generator circuit is provided for giving fluctuations to a frequency at which the switching element is driven by changing the power supplied to the illumination light source with reference to a target power value associated with the power control for the illumination light source.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: September 18, 2007
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Tomoyuki Ichikawa, Tomokazu Suzuki
  • Patent number: 7261989
    Abstract: The object of the present invention is to provide a toner which has sufficiently high chargeability and less toner spent to a carrier or the like even when several tens of thousands of image sheets are output, is capable of keeping high-charge property and flowability without causing substantial background smear or toner fogging, excels in low-temperature fixing property and hot-offset property, and has a wide range of fixing temperature as well as to provide a developer, an image forming apparatus, a process cartridge, and an image forming method using the toner for developing electrostatic images. The toner of the present invention comprises a colorant, and a resin, and a fluoride compound, in which the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054.
    Type: Grant
    Filed: April 10, 2006
    Date of Patent: August 28, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Hisashi Nakajima, Tomoyuki Ichikawa, Shinya Nakayama, Masayuki Ishii, Tomoko Utsumi, Koichi Sakata
  • Patent number: 7258959
    Abstract: The object of the present invention is to provide a developer having a sharp charge amount distribution and bringing out high-quality image without substantially smearing a charging unit, developing units, a photoconductor, and an intermediate transferring member by the developer, namely, a developer capable of providing an appropriate image density and exhibiting extremely little background smear even when used over a long period of time and repeatedly used for a number of sheets of paper as well as to provide an image forming apparatus for electrophotography using the developer.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: August 21, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Kazuhiko Umemura, Hideki Sugiura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Akihiro Kotsugai, Osamu Uchinokura, Masayuki Ishii
  • Publication number: 20070166079
    Abstract: A developing apparatus using a two-component developer constituted by a magnetic carrier and a toner, and an image forming apparatus comprising the developing apparatus. A developing unit and a stirring unit are provided, and in order to suppress toner scattering that may occur after a development operation has been halted for a long time, and thereby suppress contamination of the apparatus interior, the developer in a developing machine is transferred to a stirrer serving as a developer storage unit on the exterior of the developing machine when the development operation ends.
    Type: Application
    Filed: January 11, 2007
    Publication date: July 19, 2007
    Inventors: Tomoyuki Ichikawa, Junichi Matsumoto, Nobuo Iwata, Natsumi Katoh
  • Publication number: 20070154242
    Abstract: A developing device including a development part for developing latent images to toner images. The developing device also includes an agitation part that agitates developer, and a controller, which controls an agitation strength of an agitator in the agitation part. The developer circulates between the development part and the agitation part.
    Type: Application
    Filed: December 20, 2006
    Publication date: July 5, 2007
    Inventors: Junichi Matsumoto, Natsumi Katoh, Nobuo Iwata, Tomoyuki Ichikawa
  • Publication number: 20070110480
    Abstract: The toner supply unit is provided with a preventing unit for preventing toner contamination due to toner leakage from that sealing valve. A mouth ring of the toner container is provided with the sealing valve. This valve is opened/closed by removing/inserting a nozzle.
    Type: Application
    Filed: December 27, 2006
    Publication date: May 17, 2007
    Inventors: Junichi MATSUMOTO, Nobuo Kasahara, Nobuo Iwata, Satoshi Muramatsu, Tomoyuki Ichikawa, Yoshio Hattori, Tomotoshi Nakahara, Takaaki Yanagisawa, Masumi Sato, Kouta Fujimori, Kazuhisa Sudo
  • Patent number: 7209689
    Abstract: A toner container includes a container body having a mouth-piece member positioned at a mouth of the container body. The mouth-piece member includes an opening to allow toner to be discharged from the container body, a valve configured to seal the opening and which allows a nozzle located at a setting portion of an image forming apparatus to protrude into the valve, and a least two guides provided at opposite sides of the mouth-piece member configured to engage with at least two setting guides at the setting portion of the image forming apparatus.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: April 24, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Junichi Matsumoto, Nobuo Kasahara, Nobuo Iwata, Satoshi Muramatsu, Tomoyuki Ichikawa, Yoshio Hattori, Tomotoshi Nakahara, Takaaki Yanagisawa, Masumi Sato, Kouta Fujimori, Kazuhisa Sudo
  • Patent number: 7195409
    Abstract: An apparatus, method and program produce small print including character string information in a plurality of languages together with a logo. A language converting function converts an input character string into another language. A multi-language printing function converts the input character string into a specified number and types of languages. A layout function allows specifying one piece of information of the logo, specifying one record, specifying one type of character string information and printing the specified layout as the small print inclusive of the logo and character string.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: March 27, 2007
    Assignee: King Jim Co., Ltd.
    Inventors: Nobuyuki Horii, Ko Kojima, Takanobu Kameda, Yoichi Hine, Tomoyuki Ichikawa, Sumio Honda, Toshinori Nojima, Aiko Tanaka, Takashi Yamaguchi
  • Patent number: 7196912
    Abstract: In a lighting apparatus for a discharge lamp, a mask signal against a re-arc voltage is correctly generated to detect a lamp voltage accurately in view of a support to high frequency lighting such that the detection of the lamp voltage is not affected by the re-arc voltage. The lighting apparatus for the discharge lamp comprises a DC-AC converter for receiving an input voltage from a DC power supply to convert the input voltage to an AC voltage; detecting means for detecting a lamp voltage associated with a discharge lamp or a lamp voltage and a lamp current; and a signal generator circuit for generating a mask signal for excluding a re-arc voltage, which occurs at the time the polarity is inverted, from items to be detected, in the event of a detection of the lamp voltage. The signal generator circuit detects the lamp voltage or lamp current or a voltage at an output stage of the DC-AC converter to correctly capture a polarity inversion timing to generate a mask signal against the re-arc voltage.
    Type: Grant
    Filed: September 9, 2005
    Date of Patent: March 27, 2007
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Shinji Ohta, Tomoyuki Ichikawa
  • Publication number: 20070053723
    Abstract: An image forming apparatus includes a conveying pipe configured to convey a developer and a magnetic field generation mechanism configured to generate a magnetic field inside the conveying pipe to affect the developer. The magnet is formed to have lower magnetic intensities at positions upstream and downstream from a middle position of the conveying pipe along a conveying direction of the conveying pipe than a magnetic intensity in the middle of the conveying pipe.
    Type: Application
    Filed: September 7, 2006
    Publication date: March 8, 2007
    Inventors: Nobou Iwata, Junichi Matsumoto, Tomoyuki Ichikawa, Natsumi Katoh
  • Publication number: 20070053721
    Abstract: An agent transport unit for transporting an agent from a first container to a second container includes a transport route and a pump. The transport route connects the first container and second container, and includes at least one of a first route, a second route, and a third route. The first route extends in a substantially horizontal direction, the second route extends in a substantially vertical direction, and the third route extends in a substantially inclined direction with a repose angle equal to or less than that of the agent. The pump supplies a gas flow into the transport route to transport the agent in the transport route.
    Type: Application
    Filed: September 5, 2006
    Publication date: March 8, 2007
    Inventors: Junichi Matsumoto, Nobuo Iwata, Tomoyuki Ichikawa, Natsumi Katoh
  • Publication number: 20070031748
    Abstract: To provide a toner that can provide long-term removability and high-definition images with reduced image layer thickness and densely-packed toner particles, a developer capable of forming high-quality images using the toner, a toner container for containing the toner, a process cartridge using the toner, an image forming apparatus using the toner, and an image forming method using the toner. The toner of the present invention is a toner having a substantially spherical shape with irregularities on its surface and containing at least a binder resin and a colorant, wherein a surface factor SF-1 that represents the sphericity of toner particles is 105 to 180, a surface factor SF-2 that represents the degree of surface irregularities of the toner particles is correlated with the volume-average diameter of the toner particles, and the toner particles have an inorganic oxide particle-containing layer within 1 ?m from their surfaces.
    Type: Application
    Filed: August 3, 2006
    Publication date: February 8, 2007
    Inventors: Akihiro Kotsugai, Satoshi Mochizuki, Hisashi Nakajima, Yasuo Asahina, Osamu Uchinokura, Masayuki Ishii, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto, Hideki Sugiura, Masami Tomita
  • Patent number: 7172844
    Abstract: A toner for electrophotography contains a binder resin, a colorant and a releasing agent and has a viscosity, a storage modulus (G?) and a loss modulus (G?), in which the viscosity is 1×103 Pa·s or more and a loss tangent (tan ?) as the ratio of G? to G? is 0.4 or more at temperatures from 140° C. to 170° C.
    Type: Grant
    Filed: February 24, 2004
    Date of Patent: February 6, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiko Umemura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Hideki Sugiura, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi
  • Patent number: 7169525
    Abstract: The object of the present invention is to provide a toner which is excellent in shelf stability for a long term by producing the toner through controlling the dispersion condition of the wax around the toner surface and through improving, not only the off-set resistance of the toner for rendering the fixing properties of the toner advantageous, but also the blocking resistance of the toner, wherein the toner contains a binder resin, a colorant, and a wax, wherein the amount of the wax is 3% by mass to 21% by mass, and the amount of the wax which is present in the portion of the toner particle which is in the range of from the outermost surface to the depth of 0.3 ?m in the toner particle is in a specified range, and at least a part of the wax is present as plural individual wax dispersion particles involved in the toner particles.
    Type: Grant
    Filed: July 20, 2005
    Date of Patent: January 30, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Kazuhiko Umemura, Tomoyuki Ichikawa, Shinya Nakayama, Tomoko Utsumi, Koichi Sakata
  • Publication number: 20070020546
    Abstract: A toner comprising toner particles comprising a first binder resin; a second binder resin different from said first binder resin and having a glass transition temperature of from 40 to 55 ° C.; a colorant; and a release agent, and a particulate resin material which is located on surface of the toner particles with a coverage of from 50 to 100%, and which has a glass transition temperature of from 50 to 90 ° C., wherein a weight ratio (W2/W1) between the second binder resin (W2) and the first binder resin (W1) is from 5/95 to 40/60, and wherein a ratio (G?80/G?180) between a storage modulus of the toner at 80 ° C. (G?80) and a storage modulus at 180 ° C. (G?180) is from 100 to 1,000.
    Type: Application
    Filed: September 29, 2006
    Publication date: January 25, 2007
    Inventors: Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Masami Tomita, Tomoyuki Ichikawa
  • Patent number: 7166403
    Abstract: A toner capable of making compatible a transferring property, a fixing property and a cleaning property and forming a high-precision image. The toner comprises a binder resin and a colorant and is characterized in that the average circularity of the toner is at least 0.95, a ratio (D/S) between the total projection area (S) and the contact area (D) of the toner is 15% to 40%, and the contact area (D) is a total contact area between the toner and an object surface. The toner has such a shape as to be able to contact a latent image carrier with a proper contact area, has a high transferring rate and can prevent transferring dust.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: January 23, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Ichikawa, Satoshi Mochizuki, Yasuaki Iwamoto, Hideki Sugiura, Tadao Takikawa, Toshihiko Kinsho, Hidetoshi Noda, Shuhei Yahiro
  • Publication number: 20070007913
    Abstract: A discharge lamp lighting circuit 1 is provided with a DC-AC conversion circuit 3 having a plurality of switching elements 5H, 5L and a series resonance circuit (8, 9, 7p), and control means 17 for preventing a situation in which the drive frequency of the switching element remains less than its specified minimum frequency. When the discharge lamp is lit, driving control of the switching element is carried out in a frequency range higher than the series resonance frequency. By using a driving situation detection circuit 15, a driving situation of the switching element is monitored based on a relation with a phase of a lamp current which flows through the discharge lamp. If the drive frequency of the switching element becomes less than the specified minimum frequency, the drive frequency is increased, and thereby, a lower limit of the drive frequency is automatically restricted.
    Type: Application
    Filed: July 10, 2006
    Publication date: January 11, 2007
    Inventors: Tomoyuki Ichikawa, Takao Muramatsu
  • Patent number: 7157201
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: January 2, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7157199
    Abstract: A toner comprising toner particles comprising a first binder resin; a second binder resin different from said first binder resin and having a glass transition temperature of from 40 to 55° C.; a colorant; and a release agent, and a particulate resin material which is located on surface of the toner particles with a coverage of from 50 to 100%, and which has a glass transition temperature of from 50 to 90° C., wherein a weight ratio (W2/W1) between the second binder resin (W2) and the first binder resin (W1) is from 5/95 to 40/60, and wherein a ratio (G?80/G?180) between a storage modulus of the toner at 80° C. (G?80) and a storage modulus at 180° C. (G?180) is from 100 to 1,000.
    Type: Grant
    Filed: December 1, 2003
    Date of Patent: January 2, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Masami Tomita, Tomoyuki Ichikawa