Patents by Inventor Atsushi Umeda
Atsushi Umeda 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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Publication number: 20080048533Abstract: An alternator for a vehicle has a rotor with a field wiring, a stator with a three-phase stator wiring, a regulator, and a rectifier. The regulator and rectifier are disposed away from each other with the rotor between. An alternating current is generated in the stator wiring in response to a rotation of the rotor and a field current received in the field wiring. The rectifier converts the alternating current into a direct current and outputs the direct current as an electrical energy generated in the alternator. The regulator regulates a value of the filed current to control the electrical energy. The rectifier acts as a heat generating member, but heat generated in the rectifier is hardly transmitted to the regulator disposed away from the rectifier.Type: ApplicationFiled: June 1, 2007Publication date: February 28, 2008Applicant: DENSO CORPORATIONInventors: Atsushi Umeda, Kouichi Ihata, Nobuo Isogai
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Patent number: 7252355Abstract: A print head driving circuit is provided whereby, even if the load changes, the accuracy of the driving voltage waveform supplied to the load can be maintained, and consequently, deterioration in printing quality can be prevented. Transistors Q3, Q4 connected in a push-pull configuration are connected to the upstream of a transistor Q1. If the base potential of the transistor Q1 rises above its normal level, then the emitter potential of the transistors Q3, Q4 will rise and the transistor Q3 will become non-conductive, and the transistor Q1 will also become non-conductive, but since the transistor Q4 is conductive, the current I2 will flow from the base terminal of the transistor Q1, to earth, via the transistor Q4, and hence the base potential of the transistor Q1 will fall to or below the prescribed value. As a result, it is possible to prevent the base potential of the transistor Q1 from rising up in excess of the prescribed value.Type: GrantFiled: April 6, 2004Date of Patent: August 7, 2007Assignee: Seiko Epson CorporationInventor: Atsushi Umeda
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Publication number: 20070102932Abstract: A vehicle alternator for generating electric power is driven by an engine mounted on a vehicle driven through a driving belt. The alternator has a pulley part joined to and directly receiving a driving force from the engine through the driving belt, a field magnet part located in separation from the pulley part, a rotation speed changing part placed between the pulley part and the field magnet part. The rotation speed changing part converts the number of revolutions between the pulley part and the field magnet part. The rotation speed changing part decreases a speed changing ratio āSā according to increasing of the number of revolutions of the engine, where the speed changing ratio āSā is obtained by dividing the number of revolutions of the field magnet part by the number of revolutions of the pulley part.Type: ApplicationFiled: October 13, 2006Publication date: May 10, 2007Applicant: DENSO CORPORATIONInventors: Kouichi Ihata, Atsushi Umeda, Tsutomu Shiga
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Publication number: 20070044543Abstract: A method of designing a roller bearing is disclosed upon clarifying mechanisms of damage patterns in respect of two kinds of brinelling, involved in the bearing, wherein white-banded flaking (brittle flaking) is a plastic instability phenomenon appearing under high-speed deformation accompanied by adiabatic shear deformation status with the resultant occurrence of adiabatic shear band (also called white band) inside material of the bearing. This enables all of the damage patterns to be determined upon making comparison between shear strain and shear strain rate, occurring inside the bearing, and discriminated values.Type: ApplicationFiled: July 26, 2006Publication date: March 1, 2007Applicant: DENSO CORPORATIONInventors: Atsushi Umeda, Tsutomu Shiga, Kouichi Ihata
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Publication number: 20070024248Abstract: A method of calculating torque of a Lundell-type synchronous generator is disclosed in which only power generation output current and a rotational speed are input for calculation of the amount of electric power and the amount of losses for thereby enabling calculation of power generating torque, based on a sum of the amount of electric power and the amount of losses, which is generated as an output. The present method establishes formulae enabling calculation based on only output current and the rotational speed, enabling a minimal number of inputs to shorten a calculation time interval.Type: ApplicationFiled: July 28, 2006Publication date: February 1, 2007Applicant: DENSO CORPORATIONInventors: Atsushi Umeda, Tsutomu Shiga, Kouichi Ihata
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Publication number: 20060279151Abstract: An on-vehicle alternator is disclosed having a rotor driven by an engine via a belt, a stator having armature windings to generate electromotive forces in response to rotating magnetic fluxes, a housing on which the stator is fixedly secured, a pulley fixedly supported on the rotor to transmit a belt drive force to the rotor, and bearings rotatably supporting the rotor and fixedly supported on the housing. The power generator also includes a bush, formed of a metallic member, which is accommodated in the housing. The bearing, disposed in an area closer to the pulley, is comprised of an inner race, an outer race and rolling elements, all of which are formed of metallic members, with the outer race being press fitted to the bush with a certain degree of interference.Type: ApplicationFiled: June 13, 2006Publication date: December 14, 2006Applicant: DENSO CORPORATIONInventors: Nakato Murata, Atsushi Umeda, Tsutomu Shiga
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Publication number: 20060233478Abstract: A rolling bearing is adapted for an auxiliary device driven by an internal combustion engine via a belt. The rolling bearing comprises an inner race, an outer race, and a plurality of rolling elements disposed between the inner race and the outer race for rolling capabilities. A substantially half of a tolerance value of a clearance in a radial direction of the rolling bearing falls in a negative value, under a condition where the rolling bearing is mounted in the auxiliary device.Type: ApplicationFiled: April 17, 2006Publication date: October 19, 2006Applicant: Denso CorporationInventors: Atsushi Umeda, Tsutomu Shiga, Kouichi Ihata
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Publication number: 20060223662Abstract: In an on-vehicle alternator using a serpentine drive system with a poly-V belt, a damping ratio of the alternator is rendered 0.5 or more as other auxiliary machines by considering six contributors to the damping ratio (i.e., pulley radii, a belt span, a moment of inertia, the number of belt ribs, an elasticity modulus of a single-body belt, and a hysteresis loss of a single-body belt). In one example, a pulley ratio of the alternator relative to an engine crankshaft pulley is rendered 2 or less. In another example, belt span lengths on both sides of the alternator are reduced by fixing the alternator to an on-vehicle engine using a side mounting system. The damping ratio of the alternator is thus increased to 0.5 or more, leading to a significant reduction in vibration in the serpentine drive system fixed to the on-vehicle engine.Type: ApplicationFiled: March 30, 2006Publication date: October 5, 2006Applicant: DENSO CORPORATIONInventors: Kouichi Ihata, Tsutomu Shiga, Atsushi Umeda
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Patent number: 7114791Abstract: A head driving device of a liquid jetting apparatus includes a driving element, respectively provided corresponding to plural nozzles from which a liquid droplet is jetted, a driving waveform generating circuit, generating a driving waveform to drive the driving element selectively at predetermined jetting timing, a current amplifying circuit, amplifying the driving waveform and a current amplifying element, connected in parallel with an amplifying element of the current amplifying circuit. The current amplifying element is operated when a current value of the current amplifying circuit exceeds a predetermined value.Type: GrantFiled: April 9, 2003Date of Patent: October 3, 2006Assignee: Seiko Epson CorporationInventor: Atsushi Umeda
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Publication number: 20060210206Abstract: A rolling bearing assembly according to the present invention includes an inner ring, an outer ring, a plurality of rolling elements interposed between the inner and outer rings, and a magnet provided to cause magnetic attraction between the rolling elements and at least one of the inner and outer rings. With the magnetic attraction, it is possible to avoid any collision between the rolling elements and the inner and outer rings, thereby preventing brittle flaking from occurring in the rolling bearing assembly.Type: ApplicationFiled: March 2, 2006Publication date: September 21, 2006Applicant: DENSO CORPORATIONInventors: Kouichi Ihata, Tsutomu Shiga, Atsushi Umeda
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Publication number: 20060210207Abstract: According to the present invention, a rolling bearing for supporting a rotary shaft of an automotive accessory includes an inner ring, an outer ring, a plurality of rolling elements interposed between the inner and outer rings, and grease. The grease has a withstand pressure greater than a predetermined range in which plastic deformation of at least one of surfaces of the inner and outer rings and rolling elements occurs in absence of an elastohydrodynamic lubrication film of the grease on the surface. With such a configuration, it is possible to reliably avoid plastic deformation of the inner and outer rings and rolling elements regardless of presence of elastohydrodynamic lubrication films between the inner and outer rings and the rolling elements. As a result, brittle flaking is reliably prevented from occurring in the rolling bearing.Type: ApplicationFiled: March 6, 2006Publication date: September 21, 2006Applicant: Denso CorporationInventors: Atsushi Umeda, Tsutomu Shiga, Kouichi Ihata
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Patent number: 7091644Abstract: A sequentially joined segment armature coil is provided which may be employed in an ac machine such as an ac motor or motor generator. The armature coil is equipped with three phase coils each of which is made up of a first and a second phase windings identical in number of turns. This structure permits the number of turns of the armature coil to be changed easily by changing a connection of the first and second phase winding between a series connection and a parallel connection or changing a connection of the phase coils between a star connection and a delta connection. The structure also enables terminal leads of the first and second phase windings of each of the phase coils to be collected and withdrawn outside the ac machine, thus facilitating ease of arrangement of the terminal leads.Type: GrantFiled: September 22, 2003Date of Patent: August 15, 2006Assignee: Denso CorporationInventors: Akira Fukushima, Atsushi Umeda
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Publication number: 20060103246Abstract: An automotive alternator includes a rotary shaft, a pulley, a stator, a rotor, and a magnetic fluctuation suppressor. The pulley is provided on the rotary shaft to transmit rotating power from an engine to the rotary shaft. The stator includes a stator winding. The rotor is mounted on the rotary shaft and configured to provide a first rotating magnetic field to the stator. The magnetic fluctuation suppressor includes a magnetic body and a magnetic source. The magnetic body is mounted on the rotary shaft such that the magnetic body is rotatable along with the rotary shaft at a rotational speed different from that of the rotary shaft. The magnetic source is fixed to the rotary shaft so as to create a second rotating magnetic field which induces a magnetic attraction between the magnetic body and the magnetic source, by which fluctuations in rotational movement of the rotary shaft are suppressed.Type: ApplicationFiled: November 14, 2005Publication date: May 18, 2006Applicant: DENSO CORPORATIONInventors: Atsushi Umeda, Tsutomu Shiga, Kouichi Ihata
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Patent number: 7030533Abstract: A rotary electric machine having an armature winding that includes three first phase-windings that form a ?-connection winding having output ends and three second phase-windings that are respectively connected in series to the output ends to form a star-connection three-phase winding having output ends connected to a rectifier unit.Type: GrantFiled: December 31, 2003Date of Patent: April 18, 2006Assignee: Denso CorporationInventor: Atsushi Umeda
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Publication number: 20060064197Abstract: There is provided a method and apparatus for designing a rolling bearing provided with components including rolling elements, an outer ring, and an inner ring which come into contact with each other. First, it is determined whether or not adiabatic shear bands have a potential for occurrence within at least one of the components, due to the fact that stress is applied to the components, thus causing high deformation rates in the at least one of the components to cause an unstable plastic phenomenon that brings about an adiabatic shear deformation state within the at least one of the components. Then an estimation is made such that brittle flaking resulting from the adiabatic shear bands have a potential for occurrence within the at least one of the components, when it is determined that the adiabatic shear bands have a potential for occurrence.Type: ApplicationFiled: June 15, 2005Publication date: March 23, 2006Applicant: Denso CorporationInventors: Tsutomu Shiga, Atsushi Umeda, Kouichi Ihata
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Publication number: 20060035736Abstract: The engine belt-driven system includes a plurality of auxiliaries including a vehicle generator, and a V-ribbed belt transmitting torque from a vehicle engine to said plurality of said auxiliaries. The vehicle generator is provided with a dynamic absorber having an inertia moment smaller than an inertia moment of a rotor of said vehicle generator. The dynamic absorber may be mounted to an end surface of the rotor.Type: ApplicationFiled: August 8, 2005Publication date: February 16, 2006Applicant: DENSO CORPORATIONInventors: Atsushi Umeda, Tsutomu Shiga, Kouichi Ihata
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Publication number: 20050225579Abstract: A head driving device of a liquid ejecting apparatus includes a pressure generating element, a bias voltage applying unit which applies a bias voltage to the pressure generating element, a driving voltage generating unit which generates and outputs a driving voltage to the pressure generating element for ejecting a liquid droplet from a nozzle of a liquid ejecting head, and a cutoff unit which cuts off the bias voltage applied to the pressure generating element based on an outputting of a drive stopping signal.Type: ApplicationFiled: March 31, 2005Publication date: October 13, 2005Inventor: Atsushi Umeda
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Publication number: 20050216240Abstract: In a design method for a belt transmission system, tensile forces between pulleys are calculated from a total layout of the belt transmission system, such as a spring constant of a belt, a distance between the pulleys, an initial tensile force, a driving force for the respective pulleys to be calculated from a load of the respective pulleys, and so on. A coefficient of static friction is calculated from the tensile forces at the pulling and un-pulling sides and a contact angle. Then the coefficient of the static friction is compared with a maximum coefficient of the static friction, and it is determined that no slip occurs when the coefficient of the static friction is smaller than the maximum coefficient of the static friction.Type: ApplicationFiled: March 21, 2005Publication date: September 29, 2005Applicant: DENSO CORPORATIONInventors: Tsutomu Shiga, Atsushi Umeda, Kouichi Ihata
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Patent number: 6940201Abstract: A vehicular alternator has a stator winding, in which a middle point of one phase winding is connected to a winding finish end of another phase winding in a cyclic manner among the three-phase windings. A ?-connection portion is formed by a portion between the middle points and the winding finish ends of the respective phase windings and a Y-connection portion is formed by a portion other than the ?-connection portion. The output characteristic of the vehicular alternator is variable depending on a position of the middle point.Type: GrantFiled: February 19, 2002Date of Patent: September 6, 2005Assignee: Denso CorporationInventor: Atsushi Umeda
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Publication number: 20050191018Abstract: The present invention provides a variable optical dispersion compensating module comprised of (a) an optical dispersion compensating unit having an input optical switch, an optical dispersion compensating fiber, connected to the optical switch, having a predetermined optical dispersion amount, a bypass path for bypassing the optical dispersion compensating fiber, and an output optical switch connected to the optical dispersion compensating fiber and the bypass path, (b) an optical dispersion compensating circuit with at least one of the unit connected in series, and (c) an optical attenuator provided, in the direction of an optical path, after the input optical switch or before the output optical switch of the optical dispersion compensating circuit.Type: ApplicationFiled: April 22, 2005Publication date: September 1, 2005Inventors: Nobutaka Fuke, Shiro Nakamura, Jun Ishiguro, Hiroshi Raijo, Atsushi Umeda