Patents by Inventor Norikazu Okada

Norikazu Okada 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: 11025793
    Abstract: A power supply controlling apparatus includes a first power supply unit that supplies DC power to a load using power supplied from a commercial power supply, a power detecting unit that detects an input voltage and an input current input from the commercial power supply to the first power supply unit, and a control unit that controls the input current to be a constant current having an upper limit current value in response to the input voltage by controlling DC power supplied to the load from the first power supply unit based on the input voltage and the input current which are detected by the power detecting unit.
    Type: Grant
    Filed: January 24, 2020
    Date of Patent: June 1, 2021
    Assignee: Ricoh Company, Ltd.
    Inventors: Junpei Hosoya, Tomoyuki Yamashita, Norikazu Okada, Takaaki Hirasawa, Shunta Yamahori
  • Publication number: 20200244832
    Abstract: A power supply controlling apparatus includes a first power supply unit that supplies DC power to a load using power supplied from a commercial power supply, a power detecting unit that detects an input voltage and an input current input from the commercial power supply to the first power supply unit, and a control unit that controls the input current to be a constant current having an upper limit current value in response to the input voltage by controlling DC power supplied to the load from the first power supply unit based on the input voltage and the input current which are detected by the power detecting unit.
    Type: Application
    Filed: January 24, 2020
    Publication date: July 30, 2020
    Applicant: Ricoh Company, Ltd.
    Inventors: Junpei HOSOYA, Tomoyuki YAMASHITA, Norikazu OKADA, Takaaki HIRASAWA, Shunta YAMAHORI
  • Publication number: 20190331769
    Abstract: An optical sensor includes a light-emitting element unit that emits a signal beam having a predetermined spread centered at a direction of emission and a light-detecting element unit that receives a signal beam reflected by an object to be measured. The light-emitting element unit has a plurality of light-emitting spots including a first light-emitting element and a second light-emitting element that are different in angle of beam spread of the signal beam from each other. Of these light-emitting elements, the second light-emitting element emits a second signal beam that is narrower in angle of beam spread than the first light-emitting element. The optical sensor combines these first and second light-emitting elements to detect the distance to the object to be measured on the basis of a signal beam received by the light-detecting element unit.
    Type: Application
    Filed: April 10, 2019
    Publication date: October 31, 2019
    Inventors: SHOHEI KAMADA, NORIKAZU OKADA
  • Publication number: 20170199272
    Abstract: An optical reflection sensor includes a light emitting element that irradiates a distance measuring target with light, a light receiving optical system that condenses reflected light from the distance measuring target, a light receiving element that receives light condensed by the light receiving optical system and outputs a photoelectric current signal corresponding to a light receiving position, and a signal processing circuit that obtains light receiving position information on the light receiving element and time-of-flight information of the light, which is a duration from when the light is emitted by the light emitting element to when the light is reflected by the distance measuring target and received by the light receiving element, on the basis of the photoelectric current signal output from the light receiving element.
    Type: Application
    Filed: May 21, 2015
    Publication date: July 13, 2017
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Takashi TAKAOKA, Norikazu OKADA, Toshiyuki TAKADA, Masaki TSUJI, Katsunori SATOH
  • Patent number: 9661169
    Abstract: An electric power supplying device includes a main power supply that supplies electric power to each component of an apparatus, an auxiliary power supply that supplies electric power to an assisted component in the apparatus, the assisted component requiring power supply during start-up time of the apparatus and having a whose start-up time being equal to or longer than a predetermined period of time, a discharging control circuit that controls the auxiliary power supply to cause the auxiliary power supply to output a voltage, the output voltage being lower than a voltage output by the main power supply and being equal to or more than a lower limit voltage of a voltage range that the assisted component is operable, and a power supply prevention circuit that prevents the auxiliary power supply from supplying power to a component other than the assisted component in the apparatus.
    Type: Grant
    Filed: May 13, 2016
    Date of Patent: May 23, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Yamashita, Atsuki Iwata, Takuma Kasai, Norikazu Okada, Homare Ehara, Tetsuya Yano, Toshimasa Aoki, Ryohta Kubokawa, Shuntaroh Nakayama, Takaaki Shirai
  • Patent number: 9640700
    Abstract: A light receiving sensor (1) includes: a photodiode (PD) which generates a photocurrent (Ipd) upon receipt of light; a transistor (Tr11) through which the photocurrent (Ipd) flows; a transistor (Tr12) which forms, together with the transistor (Tr11), a first current mirror circuit (CM1); a transistor (Tr9) whose channel type is different from that of the transistor (Tr11), and a resistor (R10) which converts, to a voltage, a current flowing through the transistors (Tr11 and Tr12). The first current mirror circuit (CM1) amplifies the photocurrent (Ipd), the transistor (Tr11) has a source connected with a gate of a MOS transistor (Tr9), and the MOS transistor (Tr9) has a threshold voltage that is set to be equal to or above a threshold voltage of the transistor (Tr11). This decreases a capacity of the photodiode (PD) and therefore allows the light receiving sensor (1) to operate at a high speed while the photodiode (PD) is biased.
    Type: Grant
    Filed: September 25, 2013
    Date of Patent: May 2, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Norikazu Okada, Kohei Yasukawa
  • Patent number: 9599506
    Abstract: A light-receiving sensor (1) includes: a photodiode (PD) for generating a photocurrent by use of a light input; and a first current source (CS), provided in parallel to the photodiode (PD), for generating a first auxiliary current by being driven by a voltage between terminals, which are a terminal (T1) and a terminal (T2). The first current source (CS) is also driven by the voltage between the terminals which voltage is obtained when no light is inputted.
    Type: Grant
    Filed: September 24, 2013
    Date of Patent: March 21, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventor: Norikazu Okada
  • Publication number: 20170045381
    Abstract: An optical encoder includes first, second, and third light receiving elements (A, B, C) that are sequentially disposed and adjacent to each other; and a detection signal generation unit (50) that outputs a detection trigger (Ts) when an output level of the second light receiving element (B) that receives incident light after the first light receiving element (A) is higher than an output level of the first light receiving element A, and outputs a non-detection trigger (Te) when an output level of the third light receiving element (C) that receives incident light after the second light receiving element (B) is higher than the output level of the second light receiving element (B).
    Type: Application
    Filed: February 20, 2015
    Publication date: February 16, 2017
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Norikazu OKADA, Masaki TSUJI, Toshiyuki TAKADA, Katsunori SATOH, Takashi TAKAOKA
  • Patent number: 9541867
    Abstract: An image forming apparatus includes a fixing device to fix an image on a recording medium by heating the recording medium, multiple heat storing devices to store heat generated at the fixing device, an electric generating element to generate power by converting the heat into power, and a switch to switch connection and disconnection between the electric generating element and at least one of the multiple heat storing devices.
    Type: Grant
    Filed: August 31, 2015
    Date of Patent: January 10, 2017
    Assignee: Rioch Company, Ltd.
    Inventors: Homare Ehara, Takaaki Shirai, Norikazu Okada, Tomoyuki Yamashita, Ryohta Kubokawa, Takuma Kasai, Keita Maejima
  • Publication number: 20160344885
    Abstract: An electric power supplying device includes a main power supply that supplies electric power to each component of an apparatus, an auxiliary power supply that supplies electric power to an assisted component in the apparatus, the assisted component requiring power supply during start-up time of the apparatus and having a whose start-up time being equal to or longer than a predetermined period of time, a discharging control circuit that controls the auxiliary power supply to cause the auxiliary power supply to output a voltage, the output voltage being lower than a voltage output by the main power supply and being equal to or more than a lower limit voltage of a voltage range that the assisted component is operable, and a power supply prevention circuit that prevents the auxiliary power supply from supplying power to a component other than the assisted component in the apparatus.
    Type: Application
    Filed: May 13, 2016
    Publication date: November 24, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Tomoyuki Yamashita, Atsuki Iwata, Takuma Kasai, Norikazu Okada, Homare Ehara, Tetsuya Yano, Toshimasa Aoki, Ryohta Kubokawa, Shuntaroh Nakayama, Takaaki Shirai
  • Publication number: 20160336799
    Abstract: A commercial AC power shutdown detecting apparatus includes a photocoupler including a light-emitting element and a light-receiving element, a lighting circuit that flows a pulsating current through the light-emitting element of the photocoupler to turn on and off light of the light-emitting element, a charging-discharging circuit including a capacitor and a resistor that charges the capacitor via the resistor when the light-emitting element is turned off, and discharges the capacitor via the light-receiving element and the a resistor when the light-emitting element is turned on, and a comparing circuit that compares a voltage value between capacitor terminals with a predetermined voltage value intermediate between a maximum voltage value between the capacitor terminals when the light-emitting element repeats turning light on and off and the consistent DC voltage value, and outputs a shutdown detection signal if the voltage value between the capacitor terminals exceeds the predetermined voltage value.
    Type: Application
    Filed: May 1, 2016
    Publication date: November 17, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Atsuki Iwata, Takuma Kasai, Norikazu Okada, Homare Ehara, Tetsuya Yano, Toshimasa Aoki, Tomoyuki Yamashita, Ryohta Kubokawa, Shuntaroh Nakayama, Takaaki Shirai
  • Patent number: 9429909
    Abstract: An image forming apparatus includes a heat-generating component, a power generation device including a thermoelectric element, a heat radiation device, a cooling device, a temperature detector that detects a temperature increase of the heat-generating component, and a controller. The heat radiation device includes a first radiator plate interposed between the heat-generating component and a surface of the thermoelectric element and a second radiator plate attached to another surface of the thermoelectric element. The cooling device cools the first radiator plate. The controller controls operations of the cooling device and the power generation device by operating the cooling device if the detected temperature increase reaches at least a predetermined threshold value, and causing the power generation device to generate power without operating the cooling device to cool the first radiator plate passively if the detected temperature increase falls below the predetermined threshold value.
    Type: Grant
    Filed: December 22, 2014
    Date of Patent: August 30, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Takaaki Shirai, Satoru Tao, Takuma Kasai, Norikazu Okada, Homare Ehara, Keita Maejima, Tomoyuki Yamashita, Ryohta Kubokawa
  • Patent number: 9389573
    Abstract: An image forming apparatus includes a heat generator configured to generate heat in the image forming apparatus; a converter including a capacitor to convert AC power supplied from an external power supply into DC power for a load unit; a thermoelectric transducer configured to convert the generated heat into DC power for the load unit; a detector configured to detect a voltage of the AC power; and a controller configured to cause the converter to continue supplying the DC power to the load unit when a first elapsed time elapsed since the detected voltage drops below a rated voltage is shorter than a first time period shorter than an upper limit of a period of time over which the capacitor is dischargeable, and cause the thermoelectric transducer to supply the DC power to the load unit when the first elapsed time exceeds the first time period.
    Type: Grant
    Filed: June 22, 2015
    Date of Patent: July 12, 2016
    Assignee: RICOH COMPANY, LIMITED
    Inventors: Norikazu Okada, Takaaki Shirai, Takuma Kasai, Keita Maejima, Tomoyuki Yamashita, Ryohta Kubokawa, Satoru Tao, Homare Ehara
  • Publication number: 20160077475
    Abstract: An image forming apparatus includes a fixing device to fix an image on a recording medium by heating the recording medium, multiple heat storing devices to store heat generated at the fixing device, an electric generating element to generate power by converting the heat into power, and a switch to switch connection and disconnection between the electric generating element and at least one of the multiple heat storing devices.
    Type: Application
    Filed: August 31, 2015
    Publication date: March 17, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Homare EHARA, Takaaki SHIRAI, Norikazu OKADA, Tomoyuki YAMASHITA, Ryohta KUBOKAWA, Takuma KASAI, Keita MAEJIMA
  • Publication number: 20150370216
    Abstract: An image forming apparatus includes a heat generator configured to generate heat in the image forming apparatus; a converter including a capacitor to convert AC power supplied from an external power supply into DC power for a load unit; a thermoelectric transducer configured to convert the generated heat into DC power for the load unit; a detector configured to detect a voltage of the AC power; and a controller configured to cause the converter to continue supplying the DC power to the load unit when a first elapsed time elapsed since the detected voltage drops below a rated voltage is shorter than a first time period shorter than an upper limit of a period of time over which the capacitor is dischargeable, and cause the thermoelectric transducer to supply the DC power to the load unit when the first elapsed time exceeds the first time period.
    Type: Application
    Filed: June 22, 2015
    Publication date: December 24, 2015
    Applicant: RICOH COMPANY, LIMITED
    Inventors: Norikazu OKADA, Takaaki SHIRAI, Takuma KASAI, Keita MAEJIMA, Tomoyuki YAMASHITA, Ryohta KUBOKAWA, Satoru TAO, Homare EHARA
  • Patent number: 9176007
    Abstract: When no light enters a photodiode, a second current mirror circuit operates. Consequently, a current that decreases a potential difference between two terminals of a light-receiving element flows into a transistor of the second current mirror circuit and an output of an optical sensor becomes low. Meanwhile, when light enters the photodiode, a transistor of the light-receiving element is turned on and the second current mirror circuit stops operating. Consequently, the current that decreases the potential difference between the two terminals of the light-receiving element is stopped in the transistor of the second current mirror circuit and the output of the optical sensor becomes high. This makes it possible to provide an optical sensor that has a circuit in which an output of a light-receiving element does not depend on a photocurrent and that is capable of operating at a high speed.
    Type: Grant
    Filed: August 30, 2012
    Date of Patent: November 3, 2015
    Assignee: SHARP KABUSHIKI KAISHA
    Inventor: Norikazu Okada
  • Publication number: 20150276474
    Abstract: A light-receiving sensor (1) includes: a photodiode (PD) for generating a photocurrent by use of a light input; and a first current source (CS), provided in parallel to the photodiode (PD), for generating a first auxiliary current by being driven by a voltage between terminals, which are a terminal (T1) and a terminal (T2). The first current source (CS) is also driven by the voltage between the terminals which voltage is obtained when no light is inputted.
    Type: Application
    Filed: September 24, 2013
    Publication date: October 1, 2015
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Norikazu Okada
  • Publication number: 20150263211
    Abstract: A light receiving sensor (1) includes: a photodiode (PD) which generates a photocurrent (Ipd) upon receipt of light; a transistor (Tr11) through which the photocurrent (Ipd) flows; a transistor (Tr12) which forms, together with the transistor (Tr11), a first current mirror circuit (CM1); a transistor (Tr9) whose channel type is different from that of the transistor (Tr11), and a resistor (R10) which converts, to a voltage, a current flowing through the transistors (Tr11 and Tr12). The first current mirror circuit (CM1) amplifies the photocurrent (Ipd), the transistor (Tr11) has a source connected with a gate of a MOS transistor (Tr9), and the MOS transistor (Tr9) has a threshold voltage that is set to be equal to or above a threshold voltage of the transistor (Tr11). This decreases a capacity of the photodiode (PD) and therefore allows the light receiving sensor (1) to operate at a high speed while the photodiode (PD) is biased.
    Type: Application
    Filed: September 25, 2013
    Publication date: September 17, 2015
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Norikazu Okada, Kohei Yasukawa
  • Patent number: 9116479
    Abstract: A fixing control device includes an image detection unit that determines presence of an image in each of areas obtained by division of an image formation region in which the image is formed, a heater selection unit that selects from heaters of a fixing device heaters at positions corresponding to areas in which the presence of the image is determined, a heating amount computation unit that computes a heating amount of a heating area heated by each of the selected heaters in a fixing region corresponding to the image formation region, a change amount computation unit that computes an amount of change of the heating amount between adjoining ones of the heating areas, and a heating amount correction unit that corrects one of the heating amounts of the adjoining heating areas so that the amount of change after the correction is less than a predetermined threshold.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: August 25, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroaki Umezawa, Shiho Shimosaka, Katsunori Kume, Koh Tokumaru, Osamu Kizaki, Noboru Sugiura, Norikazu Okada, Atsuki Iwata, Keita Maejima, Tomoyuki Yamashita
  • Patent number: 9083185
    Abstract: A power source device includes: a first voltage generating unit that includes a power storage unit storing power based on power supplied from a power source and generates a voltage to be supplied to a first load based on the power supplied from the power source; and a second voltage generating unit that generates a voltage to be supplied to a second load based on the power stored in the power storage unit when the first voltage generating unit is controlled to stop generation.
    Type: Grant
    Filed: January 23, 2013
    Date of Patent: July 14, 2015
    Assignee: RICOH COMPANY, LIMITED
    Inventor: Norikazu Okada