Patents by Inventor Takeshi Ohkawa
Takeshi Ohkawa 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: 20230324518Abstract: Distance measurement systems and devices that optimize avalanche photodiode bias voltage are disclosed. In one example, a distance measurement system a light emitting device that emits distance measurement light, and a photodetection device that receives reflected light of the distance measurement light. The photodetection device includes a pixel array with a plurality of pixels that respectively include avalanche photodiodes that detect the reflected light; a current measurement circuit that measures a total pixel current of the pixel array; and bias voltage control that controls avalanche photodiode bias voltage using a detection result of the current measurement circuit. The light emitting device also includes light emission control circuitry that controls a light quantity of the distance measurement light using the detection result of the current measurement circuit.Type: ApplicationFiled: August 16, 2021Publication date: October 12, 2023Inventors: Takeshi Ohkawa, Akito Sekiya
-
Publication number: 20220071542Abstract: A biological information measurement apparatus according to an embodiment of the present disclosure includes one or a plurality of measurement channels to be brought into contact with a biological body, and a reference channel to be brought into contact with the biological body. The biological information measurement apparatus further includes a differential circuit that generates a biological signal corresponding to a difference between a measurement signal obtained from the measurement channel and a reference signal obtained from the reference channel, and a switch mechanism that switches contact impedance between the biological body and each of the measurement channel and the reference channel.Type: ApplicationFiled: January 8, 2020Publication date: March 10, 2022Inventors: MAO KATSUHARA, KAZUNARI YOSHIFUJI, YUKI YAGISHITA, TAKESHI OHKAWA
-
Patent number: 9141026Abstract: A developing apparatus including a layer thickness adjustment member configured to regulate a layer thickness of a two-component developer carried on a surface of a developing sleeve of a developing roller is disposed so that one end portion in a width direction faces the surface of the developing sleeve at a predetermined interval. At two end portions in a longitudinal direction of the layer thickness adjustment member, a notch open to the one end side in the width direction is provided. Since an amount of conveyance of the developer locally increases at two end portions of the developing sleeve by providing such a notch in the layer thickness adjustment member, density of an ear of a magnetic brush to be formed increases, and it is possible to exhibit the sufficient seal performance and prevent the toner from being scattered.Type: GrantFiled: December 10, 2014Date of Patent: September 22, 2015Assignee: Sharp Kabushiki KaishaInventors: Kiyofumi Morimoto, Takeshi Ohkawa
-
Publication number: 20150168865Abstract: A developing apparatus including a layer thickness adjustment member configured to regulate a layer thickness of a two-component developer carried on a surface of a developing sleeve of a developing roller is disposed so that one end portion in a width direction faces the surface of the developing sleeve at a predetermined interval. At two end portions in a longitudinal direction of the layer thickness adjustment member, a notch open to the one end side in the width direction is provided. Since an amount of conveyance of the developer locally increases at two end portions of the developing sleeve by providing such a notch in the layer thickness adjustment member, density of an ear of a magnetic brush to be formed increases, and it is possible to exhibit the sufficient seal performance and prevent the toner from being scattered.Type: ApplicationFiled: December 10, 2014Publication date: June 18, 2015Inventors: Kiyofumi MORIMOTO, Takeshi OHKAWA
-
Patent number: 8923715Abstract: An image forming apparatus includes: a developing device having a developing vessel, a developing roller and a toner supply port; a toner supply device; a toner supply detecting sensor for detecting the toner concentration inside the developing vessel; a toner concentration controller for directing toner supply; a toner empty detector; and a sheet conveyance detecting sensor. The toner concentration controller has a toner supply device control function; and a toner supply stopping function of stopping toner supply when the last sheet of image printout being executed has passed by the predetermined position in the sheet conveyance path.Type: GrantFiled: April 4, 2011Date of Patent: December 30, 2014Assignee: Sharp Kabushiki KaishaInventors: Motoyuki Itoyama, Kiyofumi Morimoto, Takeshi Ohkawa, Tomoki Minamikawa
-
Patent number: 8634730Abstract: An image forming apparatus prevents printed images from being degraded in image quality due to failure of the toner concentration to fall within a proper range, by correcting the deviations of the amount of toner consumption and the amount of toner supply depending on the individuality of each image forming apparatus and that enables exact identification of the cause of a fault associated with toner concentration, and providing an image forming method using the apparatus. A toner supply device supplies toner to a developing vessel through an opening in accordance with an instruction from a controller. The presence or absence of toner falling is detected based on the variation of the output from a magnetic permeability sensor when toner is supplied. The controller monitors the output voltage level of the magnetic permeability sensor and adjusts the input gain in accordance with the output voltage level to thereby control toner concentration.Type: GrantFiled: April 4, 2011Date of Patent: January 21, 2014Assignee: Sharp Kabushiki KaishaInventors: Kazuma Hinoue, Motoyuki Itoyama, Hideji Saikoh, Takeshi Ohkawa
-
Patent number: 8488984Abstract: An image forming apparatus includes: a developing device; a toner supply device; and a toner supply detecting sensor; and a toner concentration controller that directs toner supply. The toner concentration controller includes: a memory that stores the difference between the outputs from toner supply detecting sensor before and after toner supply; a toner supply quantity determinater that determines that the amount of toner remaining in the toner supply device is low and the amount of toner supply is low when the output difference or output ratio of the sensor is lower than a supply reference value; and an image quality adjustment controller that shortens the interval of time between adjustment of electrical potential on toner concentration correction in the above case.Type: GrantFiled: March 3, 2011Date of Patent: July 16, 2013Assignee: Sharp Kabushiki KaishaInventors: Takeshi Ohkawa, Kiyofumi Morimoto, Kohichi Takenouchi, Masayasu Narimatsu
-
Patent number: 8406641Abstract: An image forming apparatus includes a developing device having a toner supply sensor, a toner supply device supplying toner to the developing device, a toner supply controller controlling toner supply from the toner supply device to the developing device based on predetermined conditions, a toner empty determiner determining whether toner is present inside the toner supply device. In the image forming apparatus, the toner supply device includes a storage for recording multiple measured values of toner supply detected by the toner supply sensor, and the toner supply controller corrects the amount of toner supply, based on the moving average of multiple measured values of the amount of toner supply.Type: GrantFiled: October 27, 2010Date of Patent: March 26, 2013Assignee: Sharp Kabushiki KaishaInventors: Kazuma Hinoue, Motoyuki Itoyama, Masayasu Narimatsu, Kohichi Takenouchi, Hideji Saikoh, Takeshi Ohkawa, Kiyofumi Morimoto, Tomoki Minamikawa, Mitsuru Tokuyama
-
Patent number: 8295740Abstract: A developing device includes a developer tank for housing a two-component developer containing toner and magnetic carrier; a first conveying portion having a first rotary shaft rotatable about its axis and a first screw blade which surrounds the first rotary shaft and rotates together with the first rotary shaft and contains a ferromagnetic substance; a second conveying portion having a second rotary shaft rotatable about its axis and a second screw blade which surrounds the second rotary shaft and rotates together with the second rotary shaft and contains a ferromagnetic substance; a first electromagnet for magnetizing the first screw blade; and a second electromagnet for magnetizing the second screw blade.Type: GrantFiled: January 28, 2010Date of Patent: October 23, 2012Assignee: Sharp Kabushiki KaishaInventors: Takeshi Ohkawa, Mitsuru Tokuyama, Motoyuki Itoyama
-
Publication number: 20110262155Abstract: An image forming apparatus can prevent printed images from being degraded in image quality due to failure of the toner concentration to fall within a proper range, by correcting the deviations of the amount of toner consumption and the amount of toner supply depending on the individuality of each image forming apparatus and that enables exact identification of the cause of a fault associated with toner concentration, as well as providing an image forming method using the apparatus. A toner supply device supplies toner to a developing vessel through an opening in accordance with an instruction from a controller. The presence or absence of toner falling is detected based on the variation of the output from a magnetic permeability sensor when toner is supplied. The controller monitors the output voltage level of the magnetic permeability sensor and adjusts the input gain in accordance with the output voltage level to thereby control toner concentration.Type: ApplicationFiled: April 4, 2011Publication date: October 27, 2011Inventors: Kazuma Hinoue, Motoyuki Itoyama, Hideji Saikoh, Takeshi Ohkawa
-
Publication number: 20110255888Abstract: An image forming apparatus includes: a developing device having a developing vessel, a developing roller and a toner supply port; a toner supply device; a toner supply detecting sensor for detecting the toner concentration inside the developing vessel; a toner concentration controller for directing toner supply; a toner empty detector; and a sheet conveyance detecting sensor. The toner concentration controller has a toner supply device control function; and a toner supply stopping function of stopping toner supply when the last sheet of image printout being executed has passed by the predetermined position in the sheet conveyance path.Type: ApplicationFiled: April 4, 2011Publication date: October 20, 2011Inventors: Motoyuki ITOYAMA, Kiyofumi Morimoto, Takeshi Ohkawa, Tomoki Minamikawa
-
Publication number: 20110229156Abstract: An image forming apparatus includes: a developing device; a toner supply device; and a toner supply detecting sensor; and a toner concentration controller that directs toner supply. The toner concentration controller includes: a memory that stores the difference between the outputs from toner supply detecting sensor before and after toner supply; a toner supply quantity determinater that determines that the amount of toner remaining in the toner supply device is low and the amount of toner supply is low when the output difference or output ratio of the sensor is lower than a supply reference value; and an image quality adjustment controller that shortens the interval of time between adjustment of electrical potential on toner concentration correction in the above case.Type: ApplicationFiled: March 3, 2011Publication date: September 22, 2011Inventors: Takeshi OHKAWA, Kiyofumi Morimoto, Kohichi Takenouchi, Masayasu Narimatsu
-
Patent number: 7999717Abstract: A folding circuit and an analog-to-digital converter wherein a response to small signals is improved, a load on a clock signal can be reduced, and the increase of circuit area can be prevented. The circuit includes a reference voltage generating circuit that generates a plurality of differential voltages as reference voltages, and a plurality of amplification circuits that convert differential voltages between the plurality of reference voltages and an analog input voltage to differential currents, and output these differential currents. The output ends of the amplification circuits are alternately connected. Each of the amplification circuit is configured by a differential amplifier circuit having cascode output transistors (145, 146). A switch (144), which is turned on in synchronization with the control clock, is provided between the both sources of the cascode output transistors (145,146).Type: GrantFiled: September 4, 2007Date of Patent: August 16, 2011Assignee: Sony CorporationInventors: Takeshi Ohkawa, Koichi Ono, Kouji Matsuura, Yukitosi Yamashita, Junji Toyomura, Shogo Nakamura, Norifumi Kanagawa
-
Publication number: 20110123204Abstract: An image forming apparatus includes a developing device having a toner supply sensor, a toner supply device supplying toner to the developing device, a toner supply controller controlling toner supply from the toner supply device to the developing device based on predetermined conditions, a toner empty determiner determining whether toner is present inside the toner supply device. In the image forming apparatus, the toner supply device includes a storage for recoding multiple measured values of toner supply detected by the toner supply sensor, and the toner supply controller corrects the amount of toner supply, based on the moving average of multiple measured values of the amount of toner supply.Type: ApplicationFiled: October 27, 2010Publication date: May 26, 2011Inventors: Kazuma HINOUE, Motoyuki Itoyama, Masayasu Narimatsu, Kohichi Takenouchi, Hideji Saikoh, Takeshi Ohkawa, Kiyofumi Morimoto, Tomoki Minamikawa, Mitsuru Tokuyama
-
Publication number: 20110058824Abstract: An image forming apparatus includes: a developing device; a toner supply device that supplies toner to the developing device; a toner concentration controller that directs the toner supply device to perform toner supply to the developing device; and a toner empty determiner for determining that no toner is left in the toner supply device. The developing device includes a toner supply detecting sensor that detects whether toner is supplied from the toner supply device into the developer container, in the developer container. The toner concentration controller gives directions to perform the toner supply when the toner concentration of the developer in the developing device has become lower than a predetermined level. The toner empty determiner determines that the toner supply device has no toner left therein when no effect of the toner supply is detected by the toner supply detecting sensor after the toner supply is directed by the toner concentration controller.Type: ApplicationFiled: August 12, 2010Publication date: March 10, 2011Inventors: Kiyofumi Morimoto, Takeshi Ohkawa, Motoyuki Itoyama, Hideji Saikoh
-
Patent number: 7904007Abstract: A toner cartridge is a developer storage container for storing toner (developer) in a hollow cylindrical section that is driven to rotate on its axis so that the stored toner is discharged from an outlet. The cylindrical section has an inner circumferential surface provided with a plurality of liner protruding portions that extend in a direction tilted with respect to a rotation direction of the cylindrical section. Moreover, the toner cartridge includes a stirring member capable of moving in the cylindrical section so as to collide with the protruding portions. This makes it possible to stably supply a developer and to realize an inexpensive developer storage container whose size can be reduced.Type: GrantFiled: October 31, 2007Date of Patent: March 8, 2011Assignee: Sharp Kabushiki KaishaInventors: Yuichiro Takesue, Takeshi Ohkawa
-
Publication number: 20110001648Abstract: A folding circuit and an analog-to-digital converter wherein a response to small signals is improved, a load on a clock signal can be reduced, and the increase of circuit area can be prevented. The circuit includes a reference voltage generating circuit that generates a plurality of differential voltages as reference voltages, and a plurality of amplification circuits that convert differential voltages between the plurality of reference voltages and an analog input voltage to differential currents, and output these differential currents. The output ends of the amplification circuits are alternately connected. Each of the amplification circuit is configured by a differential amplifier circuit having cascode output transistors (145, 146). A switch (144), which is turned on in synchronization with the control clock, is provided between the both sources of the cascode output transistors (145,146).Type: ApplicationFiled: September 4, 2007Publication date: January 6, 2011Inventors: Takeshi Ohkawa, Koichi Ono, Kouji Matsuura, Yukitosi Yamasita, Junji Toyomura, Shogo Nakamura, Norifimi Kanagawa
-
Publication number: 20100196056Abstract: A developing device includes a developer tank for housing a two-component developer containing toner and magnetic carrier; a first conveying portion having a first rotary shaft rotatable about its axis and a first screw blade which surrounds the first rotary shaft and rotates together with the first rotary shaft and contains a ferromagnetic substance; a second conveying portion having a second rotary shaft rotatable about its axis and a second screw blade which surrounds the second rotary shaft and rotates together with the second rotary shaft and contains a ferromagnetic substance; a first electromagnet for magnetizing the first screw blade; and a second electromagnet for magnetizing the second screw blade.Type: ApplicationFiled: January 28, 2010Publication date: August 5, 2010Inventors: Takeshi OHKAWA, Mitsuru Tokuyama, Motoyuki Itoyama
-
Publication number: 20100146491Abstract: A software documentation preparing system which can prepare software documentation written in plural natural languages is provided.Type: ApplicationFiled: July 25, 2006Publication date: June 10, 2010Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCEInventors: Satoshi Hirano, Takeshi Ohkawa, Runtao Qu
-
Patent number: 7449274Abstract: A toner for electrostatic image development, which contains toner particles in which not more than 13 percent by number of the toner particles have a particle diameter of smaller than 4 ?m, not less than 20 percent by number of the toner particles have a particle diameter of 4 ?m to 6 ?m, and not more than 2.0 percent by volume of the toner particles have a particle diameter of 16 ?m or greater. The toner particles have a volume average diameter of 4 ?m to 9 ?m, and at least an external additive is added to the toner particles.Type: GrantFiled: November 1, 2005Date of Patent: November 11, 2008Assignee: Sharp Kabushiki KaishaInventors: Tatsuo Imafuku, Takahiro Bito, Eiji Tenjiku, Takeshi Satoh, Takeshi Ohkawa, Akiko Tsujimoto