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: 7542697
    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: February 1, 2008
    Date of Patent: June 2, 2009
    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: 7531281
    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: October 31, 2007
    Date of Patent: May 12, 2009
    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: 7521164
    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 31, 2008
    Date of Patent: April 21, 2009
    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
  • Publication number: 20090080548
    Abstract: A delay indicator calculator calculates at least two of a first delay indicator indicating a delay time determined based on a correlation value having a predetermined difference from the maximum value of the correlation signal, a second delay indicator indicating a change of a delay time determined based on time during which the correlation signal has no less than a predetermined value, and a third delay indicator indicating a change of a time difference between main and delay path peaks. An estimator generates a state estimation of the transmission path based on the probabilities of the at least two delay indicator values exceeding respective reference values for a plurality of symbols.
    Type: Application
    Filed: August 18, 2008
    Publication date: March 26, 2009
    Applicant: Oki Electric Industry Co., Ltd.
    Inventor: Tomoyuki ICHIKAWA
  • Patent number: 7499321
    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: Grant
    Filed: July 16, 2007
    Date of Patent: March 3, 2009
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Tomoyuki Ichikawa
  • Patent number: 7479742
    Abstract: A discharge lamp lighting circuit 1 includes a direct current-alternating current converting circuit 3, a starting circuit 4, controlling means 15 for controlling power, switching elements 5H, 5L driven by the controlling means 15 and a series LC resonance circuit (7p, 8, 9). A frequency modulating circuit is provided for restraining acoustic resonance by modulating a frequency of driving the switching element. When a basic frequency related to the drive frequency is equal to or higher than 1 MHz, a modulation width is set to be equal to or higher than 20 kHz.
    Type: Grant
    Filed: May 16, 2006
    Date of Patent: January 20, 2009
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Kotaro Matsui, Tomoyuki Ichikawa, Soichi Yagi
  • Patent number: 7455942
    Abstract: It is an object of the present invention to provide a toner that can sustain favorable transferability and cleaning ability for prolonged periods; prevent photoconductor filming; exhibit no variation in image nonuniformity or external additive immersion induced by developer agitation at the time of use; excels in stability with flowability and charge stability over prolonged periods. Therefore, provided is the toner of which the quantity of aggregate of residual external additives found on the sieve of 635-mesh and 452 cm2 of mesh area, after 0.2 g of the toner on the sieve is blasted with air at a blow pressure of 0.2 MPa from 160 mm above the sieve while being air-suctioned at a suction force of 5 mmHg, and then air-suctioned at a suction force of 20 mmHg, is 4,500 or less and 5 or more.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: November 25, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuneyasu Nagatomo, Akihiro Kotsugai, Hiroshi Yamashita, Masayuki Ishii, Hiroto Higuchi, Osamu Uchinokura, Satoshi Mochizuki, Fumihiro Sasaki, Hisashi Nakajima, Hideki Sugiura, Yasuo Asahina, Shinya Nakayama, Koichi Sakata, Tomoyuki Ichikawa, Takuya Saito, Sonoh Matsuoka
  • Publication number: 20080268366
    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: Application
    Filed: March 31, 2008
    Publication date: October 30, 2008
    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: 7442484
    Abstract: An image forming method including: forming a toner image on a support using a toner including toner particles; and feeding the support bearing the toner image thereon through a nip between an endless toner heating member and a pressure roller to fix the toner image on the support, wherein the endless toner heating member is rotated while stretched by a fixing roller and a heat roller which includes a magnetic metal and which is heated by electromagnetic induction, and wherein the pressure roller presses the support to the endless toner heating member and the fixing roller at the nip, wherein the toner particles are prepared by a polymerizing method using a binder resin containing at least a modified polyester resin.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: October 28, 2008
    Assignee: Ricoh Company Limited
    Inventors: Osamu Uchinokura, Akihiro Kotsugai, Yasuo Asahina, Tomoyuki Ichikawa, Shinya Nakayama, Kohichi Sakata, Tomoko Utsumi, Hisashi Nakajima, Yasuaki Iwamoto, Hideki Sugiura, Satoshi Mochizuki
  • Patent number: 7439687
    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: Grant
    Filed: May 25, 2007
    Date of Patent: October 21, 2008
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Kotaro Matsui, Tomoyuki Ichikawa
  • Publication number: 20080226349
    Abstract: An image forming apparatus includes a development device for supplying a developer containing toner and carrier to an electrostatic latent image carrying member for carrying thereon an electrostatic latent image, or a process cartridge for integrally storing the development device and the electrostatic latent image carrying member. The development device includes a conveyance path for charging and conveying the developer, and a developer carrying member for developing the electrostatic latent image into a toner image with the use of the developer conveyed through the conveyance path. The conveyance path includes a first conveyance member for receiving replenished toner and generating conveyance force for conveying the replenished toner and the developer in one direction, and a second conveyance member for generating conveyance force for conveying a portion of the developer conveyed by the first conveyance member in the opposite direction to the conveyance direction of the first conveyance member.
    Type: Application
    Filed: March 14, 2008
    Publication date: September 18, 2008
    Inventors: Nobuo IWATA, Junichi Matsumoto, Tomoyuki Ichikawa, Natsumi Katoh
  • Publication number: 20080211153
    Abstract: A system for controlling an electric device comprises: a power supply for supplying electric power to an electric device; switch portion connected between the power supply and the electric device for controlling the electric power supplied to the electric device; an LC filter disposed between the switch portion and the electric device; and current detection portion for detecting an electric current supplied to the electric device.
    Type: Application
    Filed: August 30, 2007
    Publication date: September 4, 2008
    Applicants: HONDA MOTOR CO., LTD., HONDA ELESYS CO., LTD.
    Inventors: Shigenobu Sekiya, Tomoyuki Ichikawa, Naoki Iwagami
  • Patent number: 7405000
    Abstract: Provided is a resin particle comprising a resin (a) and a filler (b) contained in the particle; the particle has a volume average particle diameter of from 0.1 to 300 ?m and a shape factor of from 110 to 300; the particle has an outer shell layer (S) comprising at least a portion of the filler (b); the layer (S) is at least 0.01 ?m thick and has a thickness that is ½ or less of the maximum inscribed circle radius of the particle cross section. When used as a toner resin, it is excellent in blade cleaning properties and wide in the fixation temperature range; when employed as a paint additive or a cosmetics additive, it is excellent in masking properties; when used as paper coating additive, it is excellent in ink retention; when utilized as an abrasive, it is excellent in abrasion.
    Type: Grant
    Filed: July 14, 2004
    Date of Patent: July 29, 2008
    Assignees: Sanyo Chemical Industries, Ltd, Ricoh Company, Ltd.
    Inventors: Tadao Takikawa, Toshihiko Kinsho, Hidetoshi Noda, Shuhei Yahiro, Yutaka Yoshida, Tomoyuki Ichikawa, Satoshi Mochizuki, Yasuaki Iwamoto, Hideki Sugiura
  • Publication number: 20080164818
    Abstract: A discharge lamp lighting circuit includes a power supplying portion having a half bridge inverter for converting an output of a DC power supply into AC power, and a bridge driver for driving the half bridge inverter, and a control portion for generating a control signal S1 to control a driving frequency F of the bridge driver. The control portion has a random number generating circuit for generating a random number signal and changes the driving frequency F in accordance with the random number signal at a time interval of N/F, wherein N is an integer of one or more.
    Type: Application
    Filed: January 7, 2008
    Publication date: July 10, 2008
    Applicant: Koito Manufacturing Co., Ltd.
    Inventors: Tomoyuki Ichikawa, Kotaro Matsui, Yusuke Kasaba
  • Publication number: 20080157692
    Abstract: A discharge lamp lighting circuit is provided. The discharge lamp lighting circuit includes an inverter circuit which has two output ends; a series resonant circuit which includes a capacitor, an inductor and a transformer, coupled in series; a driving portion; and a controlling portion which provides a control signal for controlling said inverter circuit, said controlling portion including a first signal producing portion which produces a first signal indicative of a phase of a current flowing through said series resonant circuit; and a second signal producing portion which produces a second signal indicative of a phase of the AC voltage output from said inverter circuit, said controlling portion producing the control signal on the basis of a phase difference between the first and second signals, wherein one component of said series resonant circuit is coupled between one of said output ends, and a detection point.
    Type: Application
    Filed: December 21, 2007
    Publication date: July 3, 2008
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Tomoyuki ICHIKAWA, Takao MURAMATSU
  • Publication number: 20080152380
    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: February 1, 2008
    Publication date: June 26, 2008
    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: 20080150445
    Abstract: A discharge lamp lighting circuit is provided. The discharge lamp lighting circuit includes a power supplying portion which comprises an inverter circuit comprising a switching element; a series resonant circuit comprising a capacitor, and at least one of an inductor and a transformer; and a driving circuit which drives said switching element, said power supplying portion converting DC power to AC power and supplying the AC power to a discharge lamp; and a controlling portion which produces a frequency control signal for controlling a frequency of a drive signal output from said driving circuit, the controlling portion including a phase difference detecting portion which detects a phase difference between an input voltage and an input current that are supplied from said inverter circuit to said series resonant circuit; and a control signal producing portion which produces the frequency control signal in accordance with the phase difference.
    Type: Application
    Filed: December 20, 2007
    Publication date: June 26, 2008
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Tomoyuki ICHIKAWA, Takao MURAMATSU
  • Publication number: 20080138735
    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: Application
    Filed: October 31, 2007
    Publication date: June 12, 2008
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7384720
    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: December 12, 2005
    Date of Patent: June 10, 2008
    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
  • 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