Patents by Inventor Masayuki Muranaka
Masayuki Muranaka 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).
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Patent number: 10199967Abstract: A motor controller that controls a motor in a first control method based on a first current command value and a second control method based on a second current command value. The motor controller includes an analog-to-digital converter to generate the second current command value based on a reference signal externally input to the motor controller and a current limit generator to generate an upper limit value of the first current command value based on the second current command value.Type: GrantFiled: July 6, 2017Date of Patent: February 5, 2019Assignee: Ricoh Company, Ltd.Inventors: Norihiro Yamamoto, Haruyuki Suzuki, Masayuki Muranaka
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Patent number: 9925798Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.Type: GrantFiled: February 23, 2017Date of Patent: March 27, 2018Assignee: RICOH COMPANY, LTD.Inventors: Naoto Watanabe, Toshiaki Tokita, Kohji Sakai, Nobuaki Kubo, Masayuki Muranaka
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Publication number: 20180013363Abstract: A motor controller that controls a motor in a first control method based on a first current command value and a second control method based on a second current command value. The motor controller includes an analog-to-digital converter to generate the second current command value based on a reference signal externally input to the motor controller and a current limit generator to generate an upper limit value of the first current command value based on the second current command value.Type: ApplicationFiled: July 6, 2017Publication date: January 11, 2018Applicant: Ricoh Company, Ltd.Inventors: Norihiro YAMAMOTO, Haruyuki SUZUKI, Masayuki MURANAKA
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Publication number: 20170160667Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.Type: ApplicationFiled: February 23, 2017Publication date: June 8, 2017Inventors: Naoto WATANABE, Toshiaki TOKITA, Kohji SAKAI, Nobuaki KUBO, Masayuki MURANAKA
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Patent number: 9625711Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.Type: GrantFiled: December 18, 2012Date of Patent: April 18, 2017Assignee: RICOH COMPANY, LTD.Inventors: Naoto Watanabe, Toshiaki Tokita, Kohji Sakai, Nobuaki Kubo, Masayuki Muranaka
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Publication number: 20160065109Abstract: A position estimation device for estimating a position of a rotator of a motor includes an estimation unit configured to estimate a rotational position of the rotator of the motor using a magnetic flux estimation value of the motor, which is calculated by inputting an electric voltage instruction value to be inputted to the motor and a coil electric current value detected from the motor into a motor model in which the motor is identified; and a derivation unit configured to derive a magnetic flux deviation amount due to a distortion of a magnetic flux waveform of the motor according to the estimated rotational position. The estimation unit corrects the magnetic flux estimation value based on the derived magnetic flux deviation amount, modifies the estimated rotational position based on the corrected magnetic flux estimation value, and outputs the modified rotational position.Type: ApplicationFiled: August 12, 2015Publication date: March 3, 2016Applicant: RICOH COMPANY, LTD.Inventors: Norihiro YAMAMOTO, Haruyuki SUZUKI, Masayuki MURANAKA
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Publication number: 20160056743Abstract: A motor drive control apparatus supplies drive currents including orthogonal alternating current components to armature coils of a motor so that a magnetized rotor is rotated. The motor drive control apparatus includes a high frequency generator that generates a high frequency signal which is superimposed on one of the drive currents, a position estimator that receives position information indicating an estimated position of the rotor based on a response signal to the high frequency signal, and an amplitude controller that controls amplitudes of the drive currents according to the position information.Type: ApplicationFiled: August 6, 2015Publication date: February 25, 2016Applicant: RICOH COMPANY, LTD.Inventors: Haruyuki SUZUKI, Norihiro YAMAMOTO, Masayuki MURANAKA
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Publication number: 20160011009Abstract: A position estimation device that estimates a position of a rotor of a motor, includes a current detection unit detecting a coil current as a first detection current, the coil current being generated in accordance with a signal where a control signal, which controls a drive current that rotationally drives the motor; and a harmonic wave signal that are superimposed on each other. The device further detects a harmonic wave current, which is a response of the harmonic wave signal, as a second detection current; and has a position estimation unit estimating the position of the rotor of the motor based on the second detection current.Type: ApplicationFiled: May 22, 2015Publication date: January 14, 2016Applicant: RICOH COMPANY, LTD.Inventors: Fumihiro SHIMIZU, Norihiro YAMAMOTO, Masayuki MURANAKA
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Publication number: 20130155166Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.Type: ApplicationFiled: December 18, 2012Publication date: June 20, 2013Inventors: Naoto WATANABE, Toshiaki TOKITA, Kohji SAKAI, Nobuaki KUBO, Masayuki MURANAKA
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Patent number: 8036610Abstract: A wireless terminal using switchable first and second reception antennas to perform diversity reception of data transmitted from a base station is proposed. The terminal includes an average value calculation unit that calculates an average value of a reception level measurement result of the first reception antenna and a reception level measurement result of the second reception antenna; and a correction unit that corrects the average value calculated on the basis of a predetermined thermal noise level, a received RSSI value measurement result of the first reception antenna, and a received RSSI value measurement result of the second reception antenna.Type: GrantFiled: January 16, 2009Date of Patent: October 11, 2011Assignee: Fujitsu LimitedInventors: Takeshi Kawagishi, Tsutomu Itou, Yuki Idogawa, Masayuki Muranaka, Atsushi Manabe
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Patent number: 7653121Abstract: A disclosed power level measuring device includes a power calculator for calculating power values based on correlation values between a received signal and known signals, for each of sampling times within a predetermined period; a time divider for switching connection of input signals, responding to time slots allocated to each of plural cells; an accumulator connected to the time divider, for accumulating the power values; a detector for detecting at least one sampling time whose accumulated value is greater than a threshold; a memory connected to the time divider, for storing the power values; and an outputting unit for outputting a measured power level, based on the stored power value corresponding to the detected sampling time.Type: GrantFiled: December 28, 2004Date of Patent: January 26, 2010Assignee: Fujitsu LimitedInventors: Masayuki Muranaka, Tadamitsu Hirai, Takashi Sasaki, Masashi Kitada, Hideyuki Araki, Daisaku Yamane
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Publication number: 20090131005Abstract: A wireless terminal using switchable first and second reception antennas to perform diversity reception of data transmitted from a base station is proposed. The terminal includes an average value calculation unit that calculates an average value of a reception level measurement result of the first reception antenna and a reception level measurement result of the second reception antenna; and a correction unit that corrects the average value calculated on the basis of a predetermined thermal noise level, a received RSSI value measurement result of the first reception antenna, and a received RSSI value measurement result of the second reception antenna.Type: ApplicationFiled: January 16, 2009Publication date: May 21, 2009Inventors: Takeshi Kawagishi, Tsutomu Itou, Yuki Idogawa, Masayuki Muranaka, Atsushi Manabe
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Publication number: 20060034349Abstract: A disclosed power level measuring device includes a power calculator for calculating power values based on correlation values between a received signal and known signals, for each of sampling times within a predetermined period; a time divider for switching connection of input signals, responding to time slots allocated to each of plural cells; an accumulator connected to the time divider, for accumulating the power values; a detector for detecting at least one sampling time whose accumulated value is greater than a threshold; a memory connected to the time divider, for storing the power values; and an outputting unit for outputting a measured power level, based on the stored power value corresponding to the detected sampling time.Type: ApplicationFiled: December 28, 2004Publication date: February 16, 2006Inventors: Masayuki Muranaka, Tadamitsu Hirai, Takashi Sasaki, Masashi Kitada, Hideyuki Araki, Daisaku Yamane
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Publication number: 20050286009Abstract: A glass substrate for packing liquid crystals includes a mechanically treated surface covered by a transparent coating. This ensures that the glass substrate has a high transparence. A method for manufacturing such a glass substrate includes the steps of: (a) providing an original glass substrate including a mechanically treated surface having a plurality of dents; and (b) forming a transparent coating on the surface to fill the dents. The steps can be completed in a relatively short time, and thus the manufacturing cost is reduced. An LCD device using such glass substrates includes a plurality of liquid crystals and two glass substrates packing the liquid crystals therebetween.Type: ApplicationFiled: June 1, 2005Publication date: December 29, 2005Applicant: HON HAI Precision Industry CO., LTD.Inventors: Takeo Nakagawa, Masayuki Muranaka
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Patent number: 5513037Abstract: A rear-projection screen for a rear-projection image display comprises a Fresnel lens sheet (2) and a lenticular lens sheet (3), or a Fresnel lens sheet (2), a lenticular lens sheet (3) and a light absorbing sheet (4). The entrance surface (21) of the Fresnel lens sheet (2) or the entrance surface (41) of the light absorbing sheet (4) is formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses. The thickness of the Fresnel lens sheet (2) is approximately equal to that of the lenticular lens sheet (3). The entrance surface (31) and the exit surface (32) of the lenticular lens sheet (3) are formed by contiguously and horizontally arranging a plurality of vertically elongate lenticular lenses. Particles of a light diffusing material, which is essential to the prior art rear-projection screen, are not necessarily dispersed in the base sheet (30) of the lenticular lens sheet (3).Type: GrantFiled: November 9, 1994Date of Patent: April 30, 1996Assignee: Hitachi, Ltd.Inventors: Takahiko Yoshida, Koji Hirata, Hiroki Yoshikawa, Masayuki Muranaka, Isao Yoshizaki, Atsuo Osawa
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Patent number: 5500747Abstract: An ultra-wide angle liquid crystal projector system comprising a light source, a liquid crystal panel, a curved screen, and a projection lens for projecting in accordance with light emitted by the light source an image formed on the liquid crystal panel onto the curved screen. The projection lens has a curvature of field substantially conforming to the shape of the curved screen and an angle of projection of at least 120 degrees. The projection lens is disposed with respect to the curved screen so that a distance from an exit surface of the projection lens to the curved screen is less than 3 meters.Type: GrantFiled: August 23, 1994Date of Patent: March 19, 1996Assignees: Hitachi, Ltd., Sega Enterprises, Ltd.Inventors: Hideo Tanide, Masayuki Muranaka, Shigeru Mori, Kiyoshi Wada, Isao Yoshizaki, Naoyuki Ogura
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Patent number: 5485308Abstract: A rear-projection screen for a rear-projection image display apparatus comprises a Fresnel lens sheet, a first lenticular lens sheet, and a second lenticular lens sheet or a Fresnel lens sheet, first and second lenticular lens sheets and a light absorbing sheet. A light entrance surface of the first lenticular lens sheet or a light exit surface thereof, or both of these surfaces are formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses. A thickness of the first lenticular lens sheet is selected to be the thinner than thicknesses of the Fresnel lens sheet, the second lenticular lens sheet, and the light absorbing sheet. The entrance surface and the exit surface of the second lenticular lens sheet are formed by contiguously and horizontally arranging a plurality of vertically elongate lenticular lenses. Particles of a light diffusing material are not necessarily dispersed in the base sheet of the second lenticular lens sheet.Type: GrantFiled: February 13, 1995Date of Patent: January 16, 1996Assignee: Hitachi, Ltd.Inventors: Koji Hirata, Takahiko Yoshida, Hiroki Yoshikawa, Masayuki Muranaka, Atsuo Osawa, Yutaka Matuda
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Patent number: 5400114Abstract: A rear-projection screen for a rear-projection image display comprising a Fresnel lens sheet (2) and a lenticular lens sheet (3), or a Fresnel lens sheet (2), a lenticular lens sheet (3) and a light absorbing sheet (4). The entrance surface (21) of the Fresnel lens sheet (2) or the entrance surface (41) of the light absorbing sheet (4) is formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses. The thickness of the Fresnel lens sheet (2) is approximately equal to that of the lenticular lens sheet (3). The entrance surface (31) and the exit surface (32) of the lenticular lens sheet (3) are formed by contiguously and horizontally arranging a plurality of vertically elongate lenticular lenses. Particles of a light diffusing material, which is essential to the prior art rear-projection screen, are not necessarily dispersed in the base sheet (30) of the lenticular lens sheet (3).Type: GrantFiled: September 1, 1992Date of Patent: March 21, 1995Assignee: Hitachi, Ltd.Inventors: Takahiko Yoshida, Koji Hirata, Hiroki Yoshikawa, Masayuki Muranaka, Isao Yoshizaki, Atsuo Osawa
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Patent number: 5272540Abstract: In a projection lens device having at least two plastic lenses for magnification-projecting an original image displayed on a display screen onto a screen, one of the two plastic lens is convex at a center thereof toward the screen and concave at a periphery thereof, and the other lens has a weak positive refractive power toward the screen at a center thereof and a stronger positive refractive power at a periphery thereof. A variation of a lens power due to a change of a surrounding environment is cancelled out by the concave shape at the periphery of the one lens and the positive refractive power at the periphery of the other lens.Type: GrantFiled: September 13, 1991Date of Patent: December 21, 1993Assignee: Hitachi, Ltd.Inventors: Koji Hirata, Hiroki Yoshikawa, Tooru Numata, Kiyoshi Wada, Masayuki Muranaka, Isao Yoshizaki, Takahiko Yoshida, Shigeru Inaoka
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Patent number: 5255122Abstract: A projection lens system for a projection type television having a cathode-ray tube with a panel having a fluorescent inner surface for projecting an image onto a screen. The projection lens system includes a plurality of lens groups, the lens group positioned at a side nearest to the cathode-ray tube including, in successive order from a side toward the screen, a lens having a concave surface on the screenn side a transparent medium, and the cathode-ray tube panel having a fluorescent inner surface, the lens group attenuating at least a part of a wavelength region of the light emitted on the fluorescent surface so as to improve contrast while reducing observance of a ghost image due to multiple reflection without substantial impairment in at least one of brightness and luminance. More particularly, the attenuation is provided by the concave lens having at least one surface dyed in a predetermined color.Type: GrantFiled: December 12, 1990Date of Patent: October 19, 1993Assignee: Hitachi, Ltd.Inventors: Nobuhiro Konuma, Takahiko Yoshida, Hiroki Yoshikawa, Masayuki Muranaka, Isao Yoshizaki