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).

  • Publication number: 20080122380
    Abstract: A discharge lamp lighting circuit supplies an AC power for lighting a discharge lamp. The discharge lamp lighting circuit includes a power supply portion for supplying the AC power to the discharge lamp and a control portion for controlling the magnitude of the AC power. The power supply portion includes a series resonance circuit including transistors, a transformer, a capacitor and an inductor and a bridge driver for driving the transistors. The control portion controls the bridge driver so that the AC power increases intermittently. Thus, as the temperature of electrodes can be increased while suppressing the temporal average value of the supplied power within a rated power, the movement of a luminous point at the time of lighting the discharge lamp with a high frequency can be suppressed.
    Type: Application
    Filed: June 25, 2007
    Publication date: May 29, 2008
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Kotaro Matsui, Tomoyuki Ichikawa, Takuya Serita
  • Patent number: 7378802
    Abstract: A circuit includes a transformer 7 for transmitting power to a discharge lamp 10 and for supplying a starting signal to the discharge lamp. The circuit includes a direct current-alternating current converting circuit 3 for supplying an output of the transformer 7 to the discharge lamp 10 after carrying out a direct current-alternating current conversion, and a starting circuit 4 for applying the starting signal to the discharge lamp 10. A primary side of the transformer 7 has a first capacitor 11, a circuit portion 13 including a rectifying element, and a switching element 14. The transformer 7 has an auxiliary winding 7v for supplying a voltage for generating the starting signal to the starting circuit. A second capacitor 12 is interposed between the auxiliary winding and the circuit portion 13 and prevents absorption of energy by the capacitor 11 in generating the starting signal and prevents attenuation of the starting signal.
    Type: Grant
    Filed: June 5, 2006
    Date of Patent: May 27, 2008
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Tomoyuki Ichikawa, Takao Muramatsu
  • Patent number: 7374851
    Abstract: A toner which includes a toner material, wherein the toner satisfies the following formula: 0° C.??Tm?20° C. where ?Tm represents Tma (° C.)?Tmb (° C.), Tma (° C.) is ½ flown-out temperature of the toner by a capillary type flow tester, and Tmb (° C.) is ½ flown-out temperature of a melt kneaded mixture of the toner by the capillary type flow tester, and wherein Tma is from 130° C. to 200° C.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: May 20, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Masayuki Ishii, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Hideki Sugiura, Shigeru Emoto, Junichi Awamura, Masami Tomita, Takahiro Honda, Shinichiro Yagi, Tomomi Suzuki, Hiroshi Yamada, Toshiki Nanya, Hiroto Higuchi, Fumihiro Sasaki, Naohito Shimota
  • Patent number: 7368212
    Abstract: A toner for developing an electrostatic image, includes: a colorant; and a binder resin. The toner has a particle including at least one pore having a diameter of 10 nm or over, and a porosity thereof is in a range from 0.01 to 0.60.
    Type: Grant
    Filed: June 25, 2004
    Date of Patent: May 6, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Shinya Nakayama, Tomoyuki Ichikawa, Koichi Sakata, Tomoko Utsumi, Hisashi Nakajima
  • Patent number: 7368213
    Abstract: A toner containing toner particles having a core-shell structure containing a binder resin, a colorant and a release agent. The toner particles are prepared by dissolving or dispersing at least one of the binder resin and a precursor thereof in an organic solvent or a polymeric monomer and reacting the resultant in an aqueous medium for reaction, wherein the toner satisfies the following relationship: ?Tm=Tm1?Tm2>10 ° C., wherein Tm1 represents half efflux temperature of the toner and Tm2 represents half efflux temperature of a toner which is prepared by melting and kneading the toner particles and wherein a content of the release agent existing close to the surface portion of the toner particles is from 7 to 30% by volume based on an entire portion close to the surface portion of the toner particles when the content is determined by Fourier Transform Infrared Spectroscopy Attenuated Total Reflection (FTIR-ATR) method.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: May 6, 2008
    Assignee: Ricoh Company, Limited
    Inventors: Shinya Nakayama, Fumihiro Sasaki, Satoshi Mochizuki, Akihiro Kotsugai, Yasuo Asahina, Osamu Uchinokura, Hisashi Nakajima, Sonoh Matsuoka, Takuya Saito, Tomoyuki Ichikawa, Koichi Sakata
  • Publication number: 20080096116
    Abstract: The object of the invention is to provide a toner enabling excellent transferring properties, cleanability, and fixability and forming a high-precision image without substantially degraded image quality even after printed on a number of sheets of paper. The invention also provides the toner-production method, an image forming apparatus, an image forming method, and a process cartridge. To this end, the present invention provides a toner which comprises toner-base particles containing a binder resin and a filler, and inorganic fine particles, in which the filler is included in a filler-layer in the vicinity of surfaces of the toner-base particles, the number average particle diameter of the primary particles of the inorganic fine particles is 90 nm to 300 nm, and the average circularity of the toner is 0.95.
    Type: Application
    Filed: August 4, 2005
    Publication date: April 24, 2008
    Inventors: Tomoko Utsumi, Satoshi Mochizuki, Hideki Sugiura, Tomoyuki Ichikawa, Minoru Masuda, Shinya Nakayama
  • Patent number: 7356290
    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: Grant
    Filed: December 27, 2006
    Date of Patent: April 8, 2008
    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
  • Publication number: 20080065817
    Abstract: When a first reset signal is inputted, the reset control section outputs a second reset signal and an input/output control signal. The second reset signal is at a first logical level, and switches to a second logical level after a first period has passed. The input/output control signal is activated for a second period, before the first period has passed. The input/output port is connected with a controlled device and a mode identification signal generation unit which generates a mode identification signal corresponding to the controlled device. The input/output port functions as an input port only in the second period, to which the mode identification signal is inputted, and functions as an output port outside in the second period. The access control section implements switching of the operation mode and implements control of access to the controlled device on the basis of the mode identification signal from the input/output port.
    Type: Application
    Filed: July 16, 2007
    Publication date: March 13, 2008
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventor: Tomoyuki ICHIKAWA
  • Publication number: 20080061707
    Abstract: A discharge lamp lighting circuit includes a power supplying portion having a series resonant circuit including transistors and a bridge driver, a starting portion for applying a high voltage pulse to a discharge lamp to promote a lighting operation, a lighting confirming portion for generating a lighting confirmation signal Sf indicating that a lighting operation for the discharge lamp fails or is successful by the high voltage pulse, and a control portion for generating a control signal Sc to control a driving frequency of the bridge driver. The lighting confirming portion generates a lighting confirmation signal Sf based on a relationship of the magnitude between a lamp voltage equivalent signal VS and a predetermined voltage V4 at a time that a predetermined time ?t passes since the application of the high voltage pulse to the discharge lamp.
    Type: Application
    Filed: September 10, 2007
    Publication date: March 13, 2008
    Applicant: Koito Manufacturing Co., Ltd.
    Inventors: Takao Muramatsu, Tomoyuki Ichikawa
  • Publication number: 20080048575
    Abstract: A discharge lamp lighting circuit includes a power supplying portion having a series resonant circuit containing transistors and a bridge driver, and a control portion for generating a control signal Sc1 to control a driving frequency of the bridge driver. The control portion has a sample hold portion for generating a constant control signal S1, a frequency follow-up control portion for generating a control signal S2 in such a manner that a phase difference between a voltage and a current in the series resonant circuit is approximately zero, and a power control portion for generating a control signal S3 in such a manner that a magnitude of an AC power approximates a steady value. The control signal S1 is selected from a time t3 to a time t4, the control signal S2 is selected from the time t4 to a time t5, and the control signal S3 sent from the power control portion 13 is selected as the control signal Sc1 after the time t5.
    Type: Application
    Filed: August 17, 2007
    Publication date: February 28, 2008
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Takao Muramatsu, Tomoyuki Ichikawa
  • Patent number: 7332876
    Abstract: In a discharge lamp lighting apparatus, in a transient period from the time a discharge lamp is lit in a cold state to the time the discharge lamp reaches a static lighting state, the power applied to the discharge lamp is reduced over time after an initial maximum power that exceeds the rated power. A maximum power regulator circuit is provided to regulate the applied power in the transient period such that the applied power does not exceed an upper limit power line M1 or M2 that is reduced over time after the application of the initial maximum power. In this way, the application of excessive transient power is prevented from continuing longer than necessary in the event of a failure in a load, thus limiting the amount of generated heat and preventing thermal destruction.
    Type: Grant
    Filed: August 4, 2005
    Date of Patent: February 19, 2008
    Assignee: Koito Manufacturing Co., Ltd.
    Inventor: Tomoyuki Ichikawa
  • Patent number: 7323281
    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: September 29, 2006
    Date of Patent: January 29, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Masami Tomita, Tomoyuki Ichikawa
  • Publication number: 20080018263
    Abstract: A lighting circuit includes a capacitor and inductor for a resonance, and a first output, a second output, a resistor and a monitor circuit. A DC-AC converting circuit generates an AC voltage from a DC voltage. The resistor has an end connected to the second output and the other end connected to an end of a secondary winding. A monitoring output is connected to the other end of the resistor, and is provided for providing a signal for monitoring a current flowing to a discharge lamp. The end of the resistor is connected to a grounding conductor GND. The monitor circuit receives a signal from the monitoring output. The monitor circuit generates a signal for monitoring a current IL flowing to the discharge lamp.
    Type: Application
    Filed: July 19, 2007
    Publication date: January 24, 2008
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Shinji Ohta, Tomoyuki Ichikawa
  • Publication number: 20080014527
    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: July 13, 2007
    Publication date: January 17, 2008
    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: 7318989
    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: Grant
    Filed: August 3, 2006
    Date of Patent: January 15, 2008
    Assignee: Ricoh Company, Ltd.
    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
  • Publication number: 20070274740
    Abstract: A developing device includes a developing unit, a developer agitating unit, a developer conveying unit, and a toner supplementing unit. The developing unit develops an electrostatic latent image on an image carrier with a developer containing toner and carrier. The developer agitating unit agitates the developer. The developer conveying unit connects the developing unit and the developer agitating unit, and conveys the developer from the developing unit to the developer agitating unit. The toner supplementing unit is connected to the developer conveying unit, and supplements toner to the developer conveyed from the developing unit to the developer agitating unit.
    Type: Application
    Filed: May 21, 2007
    Publication date: November 29, 2007
    Inventors: Natsumi Katoh, Junichi Matsumoto, Tomoyuki Ichikawa, Nobuo Iwata
  • Publication number: 20070275318
    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: Application
    Filed: July 30, 2007
    Publication date: November 29, 2007
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Kazuhiko Umemura, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi
  • Publication number: 20070273302
    Abstract: A discharge lamp lighting circuit 1 includes an electric power supply part and a control part. The control part generates a control signal (Sc) for controlling the magnitude of electric power based on a lamp voltage (VL) of a discharge lamp. The electric power supply part supplies the electric power based on the control signal (Sc) from the control part to the discharge lamp. The control part has a differential computation part for differentiating a lamp voltage corresponding signal (VS) with respect to time and generating a first differential signal Sd1 (=dVS/dt), and an integral computation part for integrating a second differential signal (Sd2) which monotonously increases and decreases as the first differential signal (Sd1) increases and decreases with respect to time and generating a first integral signal (Si1), and generates the control signal (Sc) so that the electric power decreases with an increase in the first integral signal (Si1).
    Type: Application
    Filed: May 25, 2007
    Publication date: November 29, 2007
    Inventors: Kotaro Matsui, Tomoyuki Ichikawa
  • Publication number: 20070264053
    Abstract: A developing device for an image forming apparatus that uses developing agent supplied from a supplying device. The developing device includes a developing roller configured to bear the developing agent thereon and develop a toner image on an image bearing member. The device also includes a supply and circulation system configured to receive developing agent from the supplying device, and being configured to supply the developing agent to the developing roller and circulate the developing agent within the developing device. The system includes an agitate conveying member, and a circulation route having at least a portion that extends upward. The agitate conveying member is provided within the upwardly extending portion of the circulation route, and is configured to convey the developing agent upward through the upwardly extending portion of the circulation route.
    Type: Application
    Filed: May 15, 2007
    Publication date: November 15, 2007
    Inventors: Nobuo Iwata, Junchi Matsumoto, Tomoyuki Ichikawa, Natsumi Katoh, Tomoya Ohmura
  • Patent number: 7291990
    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: Grant
    Filed: July 10, 2006
    Date of Patent: November 6, 2007
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Tomoyuki Ichikawa, Takao Muramatsu