Patents by Inventor Akihiko Kuroiwa
Akihiko Kuroiwa 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: 5206469Abstract: The crash sensor of the present invention comprises a magnet, a sensing mass made of a ferromagnetic material and attractable by the magnet, a sleeve made of a paramagnetic material and restricting the movement of the sensing mass in one direction, a pair of strips that make a closed circuit by contact with the sensing mass having moved in one direction and a body fitted with the magnet and housing the sensing mass, the sleeve and the contacts; the crash sensor further comprising a magnetic shield made of a ferromagnetic material and covering the magnet and the body. The magnetic shield forms a closed-type magnetic field by covering the magnet and the body and forms an appropriate magnetic loop in the vicinity of the sensing mass, so that the crash sensor also acts as a magnetic shield to protect itself from being influenced by outside ferromagnetic bodies and makes effective use of the magnetic force of the magnet.Type: GrantFiled: July 16, 1991Date of Patent: April 27, 1993Assignee: Sensor Technology Co., Ltd.Inventors: Masaru Takeda, Akihiko Kuroiwa, Etsujiro Imanishi, Koji Minekubo, Tatsuo Munakata, Atsushi Taniguchi, Kazuyuki Kita, Masaharu Kakiya
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Patent number: 5137798Abstract: A pit-forming optical recording medium comprises a substrate supporting a film of optically deformable recording material comprising an organic dye for absorbing optical signals of modulated electromagnetic radiation applied to the film and thereby causing corresponding deformations of the film when the signal intensities exceed predetermined threshold levels. The dye is a phthalocyanine compound or mixture of phtalocyanine compounds in which each of at least five of the peripheral carbon atoms in the 1, 4, 5, 8,9, 12, 13 or 16 positions (the "3,6-positions") of the phthalocyanine nucleus, as shown in Formula I, is linked by an atom from Group VB or Group VIB of the Periodic Table to a carbon atom of an organic radical. In preferred compounds each of the eight 3,6-positions is linked by an atom from Group VB or Group VIB, especially sulphur, selenium or nitrogen, to an organic radical.Type: GrantFiled: July 5, 1990Date of Patent: August 11, 1992Assignees: Imperial Chemical Industries PLC, TDK CorporationInventors: Peter J. Duggan, Paul F. Gordon, Stephen J. Abbott, Akihiko Kuroiwa, Toshiki Aoi, Tezumbumi Kamijo
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Patent number: 5027040Abstract: In a power supply circuit for operating an electroluminescent (EL) element comprising a DC power supply, an inverter connected across the power supply, and the EL element connected to the inverter, an inductor is inserted between the inverter and the EL element wherein an AC voltage is applied from the inverter through the inductor to the EL element to emit light. Another EL operating circuit includes a DC power supply, an inverter, a transformer, and a bipolar capacitor connected in this order and an AC power output on a secondary winding of the transformer is applied to an EL element to generate light. Both the circuits enables a noticeable luminance increase and power saving.Type: GrantFiled: September 12, 1989Date of Patent: June 25, 1991Assignees: Daichi Company, Ltd., Nihon Beam Electronics Company, Ltd.Inventors: Takaaki Ikeda, Toshihiko Suga, Akihiko Kuroiwa
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Patent number: 4808902Abstract: Disclosed is a control apparatus for a brush-less motor, which can prevent commutation failure of an inverter for driving the motor. The control apparatus, according to the invention detects a counter EMF of the motor, and the detected counter EMF is applied to a PLL circuit. In the course of normal operation of the motor, an output of the PLL circuit is used for controlling the advanced control angle of a motor drive inverter. Any abnormality in the condition of the motor, such as that arising from an abrupt change in load of the motor, causes a sudden and substantial variation in the magnitude and phase of the counter EMF. Since the internal condition of the PLL circuit changes in response to this counter EMF variation, a signal generated by the PLL circuit is therefore used to detect the counter EMF variation.Type: GrantFiled: May 23, 1988Date of Patent: February 28, 1989Assignee: Kabushiki Kaisha ToshibaInventors: Masanori Miyazaki, Akihiko Kuroiwa
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Patent number: 4792739Abstract: A high-accuracy position detection apparatus comprises a position detector for detecting a position signal indicating the rotation position of a motor; a coupler for coupling the motor to the position detector with a certain eccentricity; a coupling eccentricity detector, connected to the position detector, for detecting an eccentricity signal, corresponding to a coupling eccentricity of the coupler, from the position detection signal; and a true position signal synthesizer, connected to the position detector and the coupling eccentricity detector, for combining the position signal with the eccentricity signal so as to produce a true position signal which indicates the true position of the motor and is independent of the coupling eccentricity of the coupler.Type: GrantFiled: October 6, 1987Date of Patent: December 20, 1988Assignee: Kabushiki Kaisha ToshibaInventors: Ritaka Nakamura, Akihiko Kuroiwa
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Patent number: 4771606Abstract: A helper drive apparatus for a turbine drive system in which a load is mainly driven by a turbine and a helper motor is used for assisting the drive for the load, comprising: a turbine control circuit, coupled to the turbine, for controlling output power of the turbine in accordance with a turbine power reference signal; a motor control circuit, coupled to the helper motor, for controlling output power of the helper motor in accordance with a motor power reference signal; a speed control means, coupled to the turbine, for detecting a difference between a given speed reference signal and a speed signal indicating an operation speed of the turbine, and providing a master power reference signal representing the difference; and a power sharing ratio control circuit, coupled to the speed control circuit, turbine control circuit, and motor control circuit, and being responsive to a given power sharing instruction signal, for sharing the master power reference signal to the turbine power reference signal and the motType: GrantFiled: August 20, 1987Date of Patent: September 20, 1988Assignee: Kabushiki Kaisha ToshibaInventors: Tadao Mose, Akio Hirata, Suzuo Saito, Teruo Nakagawa, Akihiko Kuroiwa
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Patent number: 4752820Abstract: An optical recording medium comprising a pair of substrates each having an electrode, the space between the substrate is filled with a high-dielectric liquid crystal to form a rewritable recording layer. The recording medium comprises radiation absorbing means to provide a change of directional orientation of the liquid crystal upon exposure to a laser beam.Type: GrantFiled: February 27, 1985Date of Patent: June 21, 1988Assignee: TDK CorporationInventors: Akihiko Kuroiwa, Shigeru Asami, Toshiki Aoi, Kazuo Takahashi, Kenryo Namba
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Patent number: 4739345Abstract: An optical recording disk wherein information is written and reproduced through the application of recording and reading laser beams is assembled by preparing a pair of circular substrates which each are provided with a plurality of studs or spikes on outer and/or inner circumferential band, forming a recording layer of dye on each substrate, and joining the substrates together through the studs by ultrasonic sealing or adhesive bonding such that the recording layers face one another via an interior space.Type: GrantFiled: March 28, 1986Date of Patent: April 19, 1988Assignee: TDK CorporationInventors: Kenryo Namba, Shigeru Asami, Toshiki Aoi, Kazuo Takahashi, Noriko Takeda, Mamoru Usami, Akihiko Kuroiwa
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Patent number: 4735889Abstract: This invention relates to an optical recording medium comprising a recording layer of a dye or dye composition on a substrate and adapted to be written and read using light such as laser or the like. The optical recording medium of the invention is characterized by further comprising a surface layer formed of a coating of a colloidal particle dispersion of a silicon base condensate on the recording layer, with improved S/N ratio as well as improved writing sensitivity and reading output of the optical recording medium.Type: GrantFiled: December 2, 1985Date of Patent: April 5, 1988Assignee: TDK CorporationInventors: Kenryo Namba, Shigeru Asami, Toshiki Aoi, Kazuo Takahashi, Akihiko Kuroiwa
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Patent number: 4713314Abstract: The invention relates to an optical recording medium for effecting writing of information by means of recording light such as laser and reproduction or reading of the recorded information by means of reproduction or reading light, and provides an optical recording medium designed to prevent any degradation of the properties by the reading light and any lowering of writing sensitivity and reading S/N ratios. The optical recording medium including a recording layer 2 on a substrate 1 is characterized in that the recording layer 2 contains a mixture of a cyanine dye with a combination of cyanine dye cation with quencher anion.Type: GrantFiled: February 4, 1986Date of Patent: December 15, 1987Assignee: TDK CorporationInventors: Kenryo Namba, Shigeru Asami, Toshiki Aoi, Kazuo Takahashi, Akihiko Kuroiwa
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Patent number: 4692855Abstract: Imprementation is presented with a view to eliminating waveform distortion in an ac power supply device using a voltage type inverter. To realize this, there is provided a control system to detect a current flowing through a capacitor for absorbing higher harmonics provided along with a smoothing reactor between the voltage type inverter and a load to compare the current detector with a sine wave reference to control the voltage type inverter by making use of the compared result. To this control system, a correction control system for follow-up control of the output voltage of the ac power supply device may be added. The correction control system is configured to detect an output voltage of the ac power supply device which lags the capacitor current by a phase angle of 90 degrees to compare the output voltage detected with another sine wave which lags the sine wave reference by a phase angle of 90 degrees to use the compared result as a voltage control signal.Type: GrantFiled: September 4, 1986Date of Patent: September 8, 1987Assignee: Kabushiki Kaisha ToshibaInventors: Akihiko Kuroiwa, Suzuo Saito
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Patent number: 4682094Abstract: In a control system for a power converter driving a synchronous motor, comprising a controllable rectifier and an inverter of a load commutation type, a speed target is passed through a variation rate limiter for limiting the variation rate to produce a speed reference varied to follow the speed target but within a limited rate. A speed controller is responsive to the speed reference and the detected speed of the motor for producing a current reference. A current control circuit is responsive to the current reference and the detected current of the rectifier for adjusting the average current through the rectifier thereby to reduce the deviation of the detected speed from the speed reference. The current control means comprises means for causing intermission of the current through the rectifier for intermission commutation of the inverter when the detected speed is below a predetermined threshold.Type: GrantFiled: November 22, 1985Date of Patent: July 21, 1987Assignee: Kabushiki Kaisha ToshibaInventor: Akihiko Kuroiwa
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Patent number: 4599718Abstract: A method for erasing a light recording medium comprising a thermoplastic resin having a number average molecular weight of 30,000 or less wherein a recording pit is refilled by using a light beam diameter greater than the pit diameter.Type: GrantFiled: March 8, 1985Date of Patent: July 8, 1986Assignee: TDK Electronics Co., Ltd.Inventors: Shiro Nakagawa, Akihiko Kuroiwa, Kenryo Nanba
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Patent number: 4516234Abstract: An optical recording system for high recording density has been found for a system which uses a heat-meltable recording medium which is melted by illuminating the same with a laser beam according to the data to be stored. The spacing between adjacent pits on the recording medium is less than the diameter of the laser beam, and then, each pit overlaps partially with the succeeding pit on the recording medium. In spite of the overlap of the pits, the recorded data can be read out by reading only the non-overlapped portion of the bank of a pit. The spacing between the pits is preferably in the range between 1/3 and 1/2 of the diameter of the laser spot so that the recording density is at least two times as high as a prior recording medium.Type: GrantFiled: June 1, 1982Date of Patent: May 7, 1985Assignee: TDK Electronics Co., Ltd.Inventors: Shiro Nakagawa, Akihiko Kuroiwa
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Patent number: 4412231Abstract: A light recording medium which has a substrate and a recording layer provided thereon and effects recording of information by selective removal or deformation of the recording layer by laser light, which is characterized by that said recording layer contains an organic dye as a light absorber, said dye is a mixed dye obtained by mixing a plurality of dyes having different light absorbing wavelengths from each other and the recording layer has a light absorptivity of 80% or more at all the wavelengths in the range of 400-900 nm in wavelength.Type: GrantFiled: March 29, 1982Date of Patent: October 25, 1983Assignee: TDK Electronics Co., Ltd.Inventors: Kenryo Namba, Akihiko Kuroiwa, Shiro Nakagawa