Patents by Inventor Tatsuya Yamasaki
Tatsuya Yamasaki 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: 9228648Abstract: An electric linear motion actuator is provided which can set the clearance during normal braking operation of an electric brake system. The linear motion actuator includes a load sensor for detecting the magnitude of the load with which a friction pad is pressed against the brake disk, a temperature sensor for compensating for the influence of temperature on the load sensor, and an electronic control unit. The electronic control unit is adapted to calculate a target rotational angle from the position of the electric motor corresponding to the magnitude of the load detected by the load sensor to the position of the electric motor where the clearance is at a predetermined value, and control the electric motor to rotate the electric motor by the target rotational angle.Type: GrantFiled: October 23, 2012Date of Patent: January 5, 2016Assignee: NTN CorporationInventors: Tatsuya Yamasaki, Yui Masuda, Makoto Muramatsu, Masaaki Eguchi, Yuki Saoyama
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Patent number: 9188183Abstract: An electric linear motion actuator includes planetary rollers mounted between the radially inner surface of an outer ring member and the radially outer surface of a rotary shaft, and a carrier rotatable about the rotary shaft and including radially movable roller shafts rotatably supporting the respective planetary rollers. Elastic rings each having circumferentially separate ends are each wrapped around the roller shafts to radially inwardly bias the roller shafts, thereby bringing the respective planetary rollers into elastic contact with the radially outer surface of the rotary shaft. Each elastic ring is prevented from rotating relative to the roller shafts, thereby preventing one of the roller shafts from being axially aligned with the gap between the circumferential separate ends, causing the elastic ring to be radially compressed and thus making it impossible for the elastic rings to radially bias the roller shafts.Type: GrantFiled: August 31, 2011Date of Patent: November 17, 2015Assignee: NTN CORPORATIONInventors: Makoto Yasui, Makoto Muramatsu, Masaaki Eguchi, Tatsuya Yamasaki, Tomomi Goto
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Patent number: 9182021Abstract: A disk brake system includes a disk, brake pads, and a linear motion actuator including an electric motor, a rotary shaft coupled to the motor through a reduction gear mechanism, planetary rollers formed with helical grooves in their outer surfaces, and an outer ring member having a helical rib engaged in the helical grooves. The outer ring is coupled to one of the brake pads. When the rotary shaft is rotated by the motor, the outer ring member is moved axially through the planetary rollers, and the brake pads are pressed against the disk. The linear motion actuator further includes a locking mechanism including engaging holes formed in an intermediate gear of the reduction gear mechanism at equal intervals, a locking pin, and a linear solenoid for moving the locking pin until the pin engages in one of the engaging holes, thus locking the motor.Type: GrantFiled: October 17, 2011Date of Patent: November 10, 2015Assignee: NTN CORPORATIONInventors: Makoto Muramatsu, Tatsuya Yamasaki, Masaaki Eguchi, Tomomi Goto
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Publication number: 20150316112Abstract: An electric linear motion actuator includes an outer ring member provided around a central shaft, and a plurality of planetary rollers disposed between the central shaft and the outer ring member. One of the central shaft and the outer ring member serves as an input member which is rotatable and immovable in the axial direction and rotated by an electric motor, while the other serves as an output member which is rotationally stationary and movable in the axial direction. The input member has a peripheral surface formed with a plurality of annular ribs which are equal in pitch. Each planetary roller has a radially outer surface formed with annular grooves which are equal in pitch to the annular ribs and in which the annular ribs are engaged. The output member has a peripheral surface formed with a helical rib which is equal in pitch to the annular grooves of the planetary rollers.Type: ApplicationFiled: August 27, 2013Publication date: November 5, 2015Applicant: NTN CORPORATIONInventor: Tatsuya YAMASAKI
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Patent number: 9145940Abstract: An electric brake system is proposed which includes an electric linear motion actuator and can generate the required braking force with high accuracy. A load sensor (30) is provided in a motion converting mechanism of the actuator which converts the rotary motion of a rotary shaft (4) to which the rotation of an electric motor (2) is transmitted to linear motion of an outer ring member (5) as an output member. The load sensor (30) detects the pushing force with which the outer ring member (5) linearly drives a driven member. With this arrangement, if the driven member is a braking member of an electric brake system, it is possible to directly detect the braking force applied by the driven member and thus to accurately generate the required braking force.Type: GrantFiled: April 27, 2011Date of Patent: September 29, 2015Assignee: NTN CorporationInventors: Makoto Muramatsu, Tatsuya Yamasaki, Masaaki Eguchi, Tomomi Goto
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Patent number: 9091335Abstract: In an electric linear motion actuator for transmitting torque of a rotary shaft (4) to planetary rollers (7) and thus to a linearly driven output member constituted by an outer race member (5), axial movement of a carrier (6) supporting the planetary rollers (7) is restricted, and the outer race member (5) is axially slidably fitted in a radially inner surface of a cylindrical portion (1a) of a housing (1) and is rotationally fixedly coupled to an object to be driven via keys (25) The planetary rollers (7) have their radially inner surfaces rotatably supported, on respective support pins (6c) of the carrier (6), and are radially inwardly biased by radial compression ring springs (21) wound around the support pins (6c) so as to envelop the support pins. The planetary rollers (7) are thus pressed against the radially outer surface of the rotary shaft (4).Type: GrantFiled: July 30, 2013Date of Patent: July 28, 2015Assignee: NTN CorporationInventor: Tatsuya Yamasaki
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Patent number: 9076494Abstract: An optical pickup, including a housing, and an optical element mounted on the housing, wherein the optical element is fixed onto wall surfaces of the housing via adhesive agents on both sides of a certain single surface of the optical element, the optical pickup, further including a protrusion portion on the other side of a surface with the optical element positioned therebetween, the surface being orthogonal to the wall surfaces of the housing, the protrusion portion protruding from the housing, the front end of the protrusion portion protruding than the adhesive agents in a direction away from the wall surfaces.Type: GrantFiled: October 2, 2013Date of Patent: July 7, 2015Assignee: HITACHI MEDIA ELECTRONICS CO., LTD.Inventors: Tatsuya Yamasaki, Kenji Kiya, Katsuhiko Kimura
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Publication number: 20150117172Abstract: An optical pickup includes a pair of first tracking coils near the center of the lens holder in the tracking direction on one side of the holder; a pair of first magnets facing the first tracking coils and near the outer sides of the holder in the tracking direction; a pair of second tracking coils near the outer sides of the holder on another side of the holder; and a pair of second magnets facing the second tracking coils and near the center of the holder. The vertical electromagnetic force F in each of the first tracking coils is larger than the vertical electromagnetic force f in each of the second tracking coils. A distance K between the action center of the force F and the support center of the movable part is shorter than a distance k between the action center of the force f and the support center.Type: ApplicationFiled: October 30, 2014Publication date: April 30, 2015Inventors: Tatsuya YAMASAKI, Katsuhiko KIMURA, Ryuichiro MIZUNO
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Patent number: 8893162Abstract: In an optical disc drive, a degradation of traveling performance of an optical pickup under hard acceleration or hard deceleration in a random access operation or the like results in a degradation of recording/reproducing performance. Groove structure is provided between two gears of a guide feed provided in an optical pickup, and the groove forms bending structure. Thus, the engagement state between a screw gear and the gears of the guide feed is stabilized. This makes it possible to prevent tooth jumping and step-out from occurring in the gears during the traveling of the optical pickup, achieving stable traveling. In consequence, the recoding/reproducing performance of the optical disc drive can be improved.Type: GrantFiled: February 8, 2011Date of Patent: November 18, 2014Assignees: Hitachi Consumer Electronics Co., Ltd., Hitachi-LG Data Storage, Inc.Inventors: Yoshiaki Yamauchi, Tatsuya Yamasaki, Nozomu Harada, Sojiro Kirihara, Ikuo Nishida
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Publication number: 20140320960Abstract: In a method for manufacturing a polarizing film comprising a polarizer, a first transparent protective film provided on one surface of the polarizer with an adhesive layer interposed therebetween, and a second transparent protective film provided on another surface of the polarizer with an adhesive layer interposed therebetween, the adhesive layers are obtained by first using active energy rays to carry out irradiation by way of the first transparent protective film and then using the active energy rays to carry out irradiation by way of the second transparent protective film to cure the active energy ray-curable adhesive composition.Type: ApplicationFiled: March 12, 2014Publication date: October 30, 2014Applicant: NITTO DENKO CORPORATIONInventors: Takeshi Saito, Masashi Shinagawa, Tetsurou Ikeda, Tatsuya Yamasaki, Toshiki Oomine, Shunsuke Shuto, Kentarou Kunishima, Makoto Tsuchinaga
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Patent number: 8854577Abstract: The present invention provides a polarizer protective film capable of suppressing blocking that occurs in taking up the film. The polarizer protective film of the present invention includes a (meth)acrylic resin film and an easy-adhesion layer formed of an easy-adhesive composition including a urethane resin and fine particles. The fine particles include preferably colloidal silica.Type: GrantFiled: June 1, 2009Date of Patent: October 7, 2014Assignees: Nitto Denko Corporation, Nippon Shokubai Co., Ltd.Inventors: Tatsuya Yamasaki, Takeshi Saitou, Hiroyuki Takao, Youichirou Sugino, Yuuji Yamashita
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Publication number: 20140290402Abstract: An electric linear motion actuator capable of accurately controlling the axial position of an outer ring member is provided. A plurality of planetary rollers are kept in rolling contact with the cylindrical surface formed on the outer periphery of a rotary shaft. Helical ribs formed on the inner periphery of the outer ring member are engaged in circumferential grooves formed on the outer periphery of each of the planetary rollers. A carrier retains the plurality of planetary rollers. A revolution sensor detects the rotation angle of the carrier.Type: ApplicationFiled: October 31, 2012Publication date: October 2, 2014Applicant: NTN CORPORATIONInventors: Tatsuya Yamasaki, Yui Masuda, Makoto Muramatsu, Masaaki Eguchi, Yuki Saoyama
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Publication number: 20140283635Abstract: A magnetic load sensor unit for use in a linear motion actuator is provided which is less likely to suffer from hysteresis errors during use while being mounted in the linear motion actuator, and which can reduce the axial length of the linear motion actuator. The magnetic load sensor unit is configured to detect the magnitude of an axial load applied to an object from the linear motion actuator. The sensor unit includes a flange member configured to be deflected when a reaction force to the axial load is received through a thrust bearing, a magnetic target which generates magnetic fields; and a magnetic sensor arranged such that its position relative to the magnetic target changes when the flange member is deflected. The flange member has an axial end surface in which a groove is formed with which rolling elements of the thrust bearing are in rolling contact.Type: ApplicationFiled: October 2, 2012Publication date: September 25, 2014Applicant: NTN CORPORATIONInventors: Yui Masuda, Tatsuya Yamasaki, Makoto Muramatsu
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Publication number: 20140262634Abstract: An electric linear motion actuator is provided which can set the clearance during normal braking operation of an electric brake system. The linear motion actuator includes a load sensor for detecting the magnitude of the load with which a friction pad is pressed against the brake disk, a temperature sensor for compensating for the influence of temperature on the load sensor, and an electronic control unit. The electronic control unit is adapted to calculate a target rotational angle from the position of the electric motor corresponding to the magnitude of the load detected by the load sensor to the position of the electric motor where the clearance is at a predetermined value, and control the electric motor to rotate the electric motor by the target rotational angle.Type: ApplicationFiled: October 23, 2012Publication date: September 18, 2014Applicant: NTN CorporationInventors: Tatsuya Yamasaki, Yui Masuda, Makoto Muramatsu, Masaaki Eguchi, Yuki Saoyama
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Patent number: 8827051Abstract: An actuator has planetary rollers disposed between a rotor shaft of an electric motor and an outer ring member fixed around the rotor shaft. The planetary rollers are rotated about the axis of the rotor shaft and about their own axes, thereby converting rotary motion of the rotor shaft to linear motion of the planetary rollers A helical groove is formed in the radially outer surface of each planetary roller in which a helical rib formed on the radially inner surface of the outer ring member is received. The helical groove has a pitch equal to that of the helical rib and a lead angle different from that of the helical rib. The amount of the linear motion of the planetary rollers relative to the amount of the rotary motion of the rotor shaft is determined by the difference in lead angle between the helical groove and the helical rib.Type: GrantFiled: December 7, 2011Date of Patent: September 9, 2014Assignee: NTN CorporationInventor: Tatsuya Yamasaki
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Patent number: 8794395Abstract: In an electric linear motion actuator, it is proposed to uniformly distribute external thrust loads to respective planetary rollers while the planetary rollers are revolving around a rotary shaft while rotating about their respective axes with a helical rib of an outer ring member in engagement with circumferential grooves of the respective planetary rollers. The planetary rollers have bearing support surfaces on which thrust bearings are supported, respectively. The distance from the bearing support surface of each planetary roller to a predetermined reference position of each circumferential groove (6a) of the planetary roller is different from the corresponding distances for the other planetary rollers, whereby with the planetary rollers supported by the respective thrust bearings, the axial position of each circumferential groove coincides with the axial position of the portion of the helical rib of the outer ring member that is engaged in the circumferential groove.Type: GrantFiled: September 13, 2010Date of Patent: August 5, 2014Assignee: NTN CorporationInventors: Tatsuya Yamasaki, Masaaki Eguchi
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Publication number: 20140182980Abstract: To provide an electric brake device in an automotive vehicle, which a freezing that takes place while the automotive vehicle is parked can be assuredly avoided with a simplified mechanism. The electric brake device includes an electric motor (2), a braking force application mechanism (4), a lock mechanism (5), a temperature sensor (6) for measuring an ambient temperature of the automotive vehicle, and a freezing preventive power supply unit (7). The freezing preventive power supply unit (7) initiates the supply of an electric power to the electric motor (2) or a drive source (30) of the lock mechanism (5) in the event that while the braking force application mechanism (4) applies a braking force and the lock mechanism (5) is held in a locked condition the temperature sensor (6) detects a preset temperature of the electric brake device immediately before freezing.Type: ApplicationFiled: August 7, 2012Publication date: July 3, 2014Applicant: NTN CORPORATIONInventors: Makoto Muramatsu, Yuuki Saoyama, Tatsuya Yamasaki, Masaaki Eguchi, Yui Masuda
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Publication number: 20140101678Abstract: An optical pickup, including a housing, and an optical element mounted on the housing, wherein the optical element is fixed onto wall surfaces of the housing via adhesive agents on both sides of a certain single surface of the optical element, the optical pickup, further including a protrusion portion on the other side of a surface with the optical element positioned therebetween, the surface being orthogonal to the wall surfaces of the housing, the protrusion portion protruding from the housing, the front end of the protrusion portion protruding than the adhesive agents in a direction away from the wall surfaces.Type: ApplicationFiled: October 2, 2013Publication date: April 10, 2014Applicant: Hitachi Media Electronics Co., Ltd.Inventors: Tatsuya YAMASAKI, Kenji KIYA, Katsuhiko KIMURA
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Patent number: 8596426Abstract: In an electric linear motion actuator, planetary rollers 7 rotatably supported on their radially inner surfaces by respective support pins 6b are radially inwardly biased by radially compressible ring springs 18 enveloping the support pins 6b, thereby biasing and pressing the respective planetary rollers 7 against the radially outer surface of a rotary shaft 4. Thus, it is possible to stably transmit torque of the rotary shaft 4 to the respective planetary rollers 7 without applying a preload to the planetary rollers 7 with a negative gap between the radially outer surface of the rotary shaft 4 and the radially inner surface of the outer ring member 5.Type: GrantFiled: February 17, 2009Date of Patent: December 3, 2013Assignee: NTN CorporationInventors: Tatsuya Yamasaki, Masaaki Eguchi, Katsuhisa Yamaguchi, Tomoaki Makino
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Publication number: 20130312555Abstract: In an electric linear motion actuator for transmitting torque of a rotary shaft (4) to planetary rollers (7) and thus to a linearly driven output member constituted by an outer race member (5), axial movement of a carrier (6) supporting the planetary rollers (7) is restricted, and the outer race member (5) is axially slidably fitted in a radially inner surface of a cylindrical portion (1a) of a housing (1) and is rotationally fixedly coupled to an object to be driven via keys (25) The planetary rollers (7) have their radially inner surfaces rotatably supported, on respective support pins (6c) of the carrier (6), and are radially inwardly biased by radial compression ring springs (21) wound around the support pins (6c) so as to envelop the support pins. The planetary rollers (7) are thus pressed against the radially outer surface of the rotary shaft (4).Type: ApplicationFiled: July 30, 2013Publication date: November 28, 2013Applicant: NTN CorporationInventor: Tatsuya YAMASAKI