Patents by Inventor Naoyuki Takagi
Naoyuki Takagi 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: 20050264458Abstract: An antenna device includes an electrically insulating base section and a metallic first antenna element fixed to the base section. The first antenna element includes an adjusting section shaped like a ladder or a lattice, which is formed of rails confronting each other and connecting bars which couple a part of the rails. The structure discussed above allows the adjusting section to adjust frequency characteristics corresponding to the antenna element to desirable ones with ease, so that a basic tooling die can be commonly used and standardized antenna device is obtainable with ease.Type: ApplicationFiled: May 5, 2005Publication date: December 1, 2005Inventors: Naoyuki Takagi, Setsuo Takesako, Yoshinobu Nakagawa
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Publication number: 20050225488Abstract: An antenna for portable cellular telephone can adjust each of multiple antenna elements efficiently and independently to a predetermined resonance frequency. A first antenna element and second antenna element are mounted on and anchored to one common base. Terminals for feeding power to the first antenna element and the second antenna element are provided respectively. The terminals are coupled to matching circuits. This structure facilitates separate and efficient adjustment of resonance frequency of the first antenna element and the second antenna element.Type: ApplicationFiled: February 23, 2005Publication date: October 13, 2005Inventors: Yoshinobu Nakagawa, Koji Sako, Masaaki Yamabayashi, Kazumine Koshi, Naoyuki Takagi
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Publication number: 20050190107Abstract: A wireless device includes a first antenna element resonating with a first frequency, a first feeding point coupled to the first antenna element and disposed on a ground plane in the wireless device, a first matching circuit of which first end is coupled to the first feeding point, a second antenna element resonating a second frequency higher than the first frequency, a second feeding point coupled to the second antenna element and disposed on the ground plane, a second matching circuit of which one end is coupled to the second feeding point, and a radio circuit coupled via a transmission line to a common connection point shared by respective second ends of the first and second matching circuits.Type: ApplicationFiled: December 29, 2004Publication date: September 1, 2005Inventors: Naoyuki Takagi, Yuki Satoh
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Patent number: 6930641Abstract: An inverted-F type antenna and a wireless device using the same. The antenna element comprises a grounding conductor plate and a conductor at least a part of which is generally spiral in shape and is disposed above the grounding conductor plate apart from the grounding conductor plate. A stub connects one end of the antenna element with the grounding conductor plate. A feeding point locates on the antenna element at a predetermined distance from one end of the antenna element and a feeder line electrically connects the feeding point with an external circuit. The antenna element is secured on the grounding conductor plate with a support member made of a dielectric material.Type: GrantFiled: June 8, 2001Date of Patent: August 16, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masahiro Ohara, Naoyuki Takagi, Susumu Inatsugu
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Publication number: 20050128162Abstract: The present invention can be used for mobile communication and is able to provide an antenna which can assure excellent radiation characteristic, decreasing the degree of coupling between two antenna elements without using any changeover switch. The second antenna element of this antenna is nearly half in length of the wavelength of corresponding frequency, and its tip is connected to the grounding point of a ground plane.Type: ApplicationFiled: December 8, 2004Publication date: June 16, 2005Inventors: Naoyuki Takagi, Akihiko Iguchi
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Patent number: 6847590Abstract: A magneto-optical recording medium which includes a reproducing layer. When a laser beam is irradiated to the magneto-optical recording medium, a magnetic domain in a recording layer is transferred, through enlargement, to a reproducing layer increased in temperature. The magneto-optical recording medium further includes a calibration area that has a calibration magnetic domain recorded in a predetermined pattern in the recording layer. In a reproducing apparatus, a laser beam of an optical head is adjusted in output depending upon a reproduced signal obtained by reproducing the calibration magnetic domain.Type: GrantFiled: August 17, 2001Date of Patent: January 25, 2005Assignees: Sanyo Electric Co., Ltd., Hitachi Maxell, Ltd.Inventors: Atsushi Yamaguchi, Naoyuki Takagi, Yoshiharu Uchihara, Satoshi Sumi, Hiroyuki Awano, Hiroshi Shirai, Hitoshi Watanabe, Norio Ohta
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Patent number: 6697304Abstract: A magneto-optical recording medium includes a recording layer and a reproducing layer respectively formed by magnetic layers on a substrate. A record magnetic domain is formed within the recording layer by using a magnetic head, which is transferred into a reproducing layer by irradiating a laser beam upon reproduction. The physical length in recording a unit bit is taken as a unit domain length. Where the unit domain length is 1T and “1” is recorded in 1T, “1” is recorded in a former half 1T/2 and “0” is in a latter half 1T/2 by applying one period of an alternating magnetic field to the unit domain length.Type: GrantFiled: September 20, 2002Date of Patent: February 24, 2004Assignee: Sanyo Electric Co., Ltd.Inventors: Atsushi Yamaguchi, Naoyuki Takagi
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Patent number: 6650599Abstract: A reproducing apparatus reproduces a signal recorded in a magneto-optical disk. The magneto-optical disk includes a layered structure having a recording layer, an intermediate layer and a reproducing layer. Laser light is illuminated from an optical head to the magneto-optical disk in such an intensity that no magnetic domain is transferred from the recording layer to the reproducing layer only by the laser light. In this state, alternating magnetic field is applied through a magnetic head to the magneto-optical disk, thereby concurrently causing transfer and expansion of a magnetic domain to the reproducing layer. As a result, transfer of the magnetic domain is effected with expansion.Type: GrantFiled: August 7, 2001Date of Patent: November 18, 2003Assignee: Sanyo Electric Co., Ltd.Inventors: Naoyuki Takagi, Atsushi Yamaguchi, Kenichiro Mitani
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Publication number: 20030179657Abstract: A magneto-optical disk apparatus (100) includes an optical pickup (101) and a magnetic head (113). The optical pickup (101) irradiates a magneto-optical recording medium (10) with a laser beam of such intensity that a part of a reproducing layer of the magneto-optical recording medium (10) is heated to a temperature over the compensation temperature. The magnetic head (113) applies to the magneto-optical recording medium (10) a DC magnetic field having intensity weaker than the intensity at which magnetization of a transition-metal-rich area in a part of the reproducing layer heated to a temperature over the compensation temperature is inverted. The optical pickup (101) detects a magneto-optical signal varying in intensity between two levels. As a result, a signal can be reproduced correctly from the magneto-optical recording medium (10) by a magnetic domain enlargement system.Type: ApplicationFiled: September 16, 2002Publication date: September 25, 2003Inventors: Hitoshi Noguchi, Atsushi Yamaguchi, Hiroki Ishida, Naoyuki Takagi, Kenichiro Mitani
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Publication number: 20030169209Abstract: An inverted-F type antenna and a wireless device using the same. The antenna element comprises a grounding conductor plate and a conductor at least a part of which is generally spiral in shape and is disposed above the grounding conductor plate apart from the grounding conductor plate. A stub connects one end of the antenna element with the grounding conductor plate. A feeding point locates on the antenna element at a predetermined distance from one end of the antenna element and a feeder line electrically connects the feeding point with an external circuit. The antenna element is secured on the grounding conductor plate with a support member made of a dielectric material.Type: ApplicationFiled: May 6, 2003Publication date: September 11, 2003Inventors: Masahiro Ohara, Naoyuki Takagi, Susumu Inatsugu
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Publication number: 20030142592Abstract: An magneto-optical disk device (100) includes a magnetic head (11), a DC magnetic field applying device (12), an optical head (13) and a magnetic field control circuit (16). The DC magnetic field applying device (12) applies a DC magnetic field to a magneto-optical recording medium (10) through a core of the magnetic head (11). The magnetic field control circuit (16) applies the DC magnetic field of a variable intensity to the magneto-optical recording medium (10) to determine the appropriate intensity of the DC magnetic field providing an error rate not exceeding a predetermined reference value in a reproduced signal of a predetermined recording pattern detected by the optical head (13). Consequently, the signal can be accurately reproduced from the magneto-optical recording medium (10) by domain-enlarging reproduction using the DC magnetic field.Type: ApplicationFiled: December 9, 2002Publication date: July 31, 2003Inventors: Kenichiro Mitani, Naoyuki Takagi
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Publication number: 20030021192Abstract: A magneto-optical recording medium includes a recording layer and a reproducing layer respectively formed by magnetic layers on a substrate. A record magnetic domain is formed within the recording layer by using a magnetic head, which is transferred into a reproducing layer by irradiating a laser beam upon reproduction. The physical length in recording a unit bit is taken as a unit domain length. Where the unit domain length is 1T and “1” is recorded in 1T, “1” is recorded in a former half 1T/2 and “0” is in a latter half 1T/2 by applying one period of an alternating magnetic field to the unit domain length.Type: ApplicationFiled: September 20, 2002Publication date: January 30, 2003Applicant: SANYO ELECTRIC CO., LTD.Inventors: Atsushi Yamaguchi, Naoyuki Takagi
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Publication number: 20030012093Abstract: In order to reproduce signals from a double-layer optical disc having two signal recording surfaces, a focus jump that the focusing of an objective lens from the one signal recording surface to the other signal recording surface is quickly achieved, is necessary. When a focus error signal (FE) from a pickup (60, 70) reaches a predetermined threshold value (Vcomp), a deceleration signal for decelerating the objective lens (42) is supplied to an actuator (47). Preferably, a deceleration pulse voltage is lowered step by step. The deceleration pulse voltage is determined in accordance with the maximum value (DFEmax) of a differential focus error signal (DFE) generated by differentiating the focus error signal (FE). Preferably, the address seeking is done simultaneously with the focus jump. The focus jump is performed in accordance with the layer-to-layer distance which is measured beforehand. The focus jump is performed by using a lens (143) having a controllable focal distance.Type: ApplicationFiled: February 19, 2002Publication date: January 16, 2003Applicant: Sanyo Electric Co., Ltd.Inventors: Koichi Tada, Shinichi Ohe, Naoyuki Takagi, Ken Hirose, Shuichi Ichiura, Hiroshi Watanabe
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Patent number: 6501707Abstract: A magneto-optical recording medium includes a recording layer and a reproducing layer respectively formed by magnetic layers on a substrate. A record magnetic domain is formed within the recording layer by using a magnetic head, which is transferred into a reproducing layer by irradiating a laser beam upon reproduction. The physical length in recording a unit bit is taken as a unit domain length. Where the unit domain length is 1T and “1” is recorded in 1T, “1” is recorded in a former half 1T/2 and “0” is in a latter half 1T/2 by applying one period of an alternating magnetic field to the unit domain length.Type: GrantFiled: January 21, 1999Date of Patent: December 31, 2002Assignee: Sanyo Electric Co., Ltd.Inventors: Atsushi Yamaguchi, Naoyuki Takagi
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Patent number: 6492035Abstract: A magneto-optical recording medium of magnetic domain enlarging/reproducing system including a recording layer and a reproducing layer, a gate layer selectively extracting each magnetic domain within the recording layer is formed on the recording layer, a magnetic field reinforcement layer reinforcing a leakage magnetic field reaching the reproducing layer is formed on the gate layer, and a blocking layer blocking an exchange coupling force from the magnetic field reinforcement layer to the reproducing layer is formed on the magnetic field reinforcement layer.Type: GrantFiled: May 1, 2000Date of Patent: December 10, 2002Assignee: Sanyo Electric Co., Ltd.Inventors: Atsushi Yamaguchi, Naoyuki Takagi, Kenichiro Mitani, Hitoshi Noguchi
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Patent number: 6483783Abstract: A magnetic head is configured of a core and a coil wound around the core and passing current through the coil in a variable direction allows the core to have an edge generating an alternating magnetic field Hex1 and another edge generating an alternating magnetic field Hex2. Alternating magnetic fields Hex1 and Hex2 are applied to the respective edges. Furthermore, a laser beam LB1 is directed such that its optical axis L01 matches the edge receiving the alternating magnetic field Hex1, and a laser beam LB2 is directed such that its optical axis L02 matches the edge receiving the alternating magnetic field Hex2. A first magneto-optical signal detected through the alternating magnetic field Hex1 and the laser beam LB1 and a second magneto-optical signal detected through the alternating magnetic field Hex2 and the laser beam LB2 are composited together.Type: GrantFiled: November 16, 2000Date of Patent: November 19, 2002Assignee: Sanyo Electric Co., Ltd.Inventors: Kenichiro Mitani, Naoyuki Takagi, Hitoshi Noguchi, Hiroki Ishida, Atsushi Yamaguchi, Morio Nakatani
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Patent number: 6480444Abstract: In order to reproduce signals from a double-layer optical disc having two signal recording surfaces, a focus jump that the focusing of an objective lens from the one signal recording surface to the other signal recording surface is quickly achieved, is necessary. When a focus error signal (FE) from a pickup (60, 70) reaches a predetermined threshold value (Vcomp), a deceleration signal for decelerating the objective lens (42) is supplied to an actuator (47). Preferably, a deceleration pulse voltage is lowered step by step. The deceleration pulse voltage is determined in accordance with the maximum value (DFEmax) of a differential focus error signal (DFE) generated by differentiating the focus error signal (FE). Preferably, the address seeking is done simultaneously with the focus jump. The focus jump is performed in accordance with the layer-to-layer distance which is measured beforehand. The focus jump is performed by using a lens (143) having a controllable focal distance.Type: GrantFiled: February 19, 2002Date of Patent: November 12, 2002Assignees: Sanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.Inventors: Koichi Tada, Shinichi Ohe, Naoyuki Takagi, Ken Hirose, Shuichi Ichiura, Hiroshi Watanabe
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Patent number: 6477122Abstract: In order to reproduce signals from a double-layer optical disc having two signal recording surfaces, a focus jump that the focusing of an objective lens from the one signal recording surface to the other signal recording surface is quickly achieved, is necessary. When a focus error signal (FE) from a pickup (60, 70) reaches a predetermined threshold value (Vcomp), a deceleration signal for decelerating the objective lens (42) is supplied to an actuator (47). Preferably, a deceleration pulse voltage is lowered step by step. The deceleration pulse voltage is determined in accordance with the maximum value (DFEmax) of a differential focus error signal (DFE) generated by differentiating the focus error signal (FE). Preferably, the address seeking is done simultaneously with the focus jump. The focus jump is performed in accordance with the layer-to-layer distance which is measured beforehand. The focus jump is performed by using a lens (143) having a controllable focal distance.Type: GrantFiled: February 19, 2002Date of Patent: November 5, 2002Assignees: Sanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.Inventors: Koichi Tada, Shinichi Ohe, Naoyuki Takagi, Ken Hirose, Shuichi Ichiura, Hiroshi Watanabe
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Patent number: 6466527Abstract: In order to reproduce signals from a double-layer optical disc having two signal recording surfaces, a focus jump that the focusing of an objective lens from the one signal recording surface to the other signal recording surface is quickly achieved, is necessary. When a focus error signal (FE) from a pickup (60, 70) reaches a predetermined threshold value (Vcomp), a deceleration signal for decelerating the objective lens (42) is supplied to an actuator (47). Preferably, a deceleration pulse voltage is lowered step by step. The deceleration pulse voltage is determined in accordance with the maximum value (DFEmax) of a differential focus error signal (DFE) generated by differentiating the focus error signal (FE). Preferably, the address seeking is done simultaneously with the focus jump. The focus jump is performed in accordance with the layer-to-layer distance which is measured beforehand. The focus jump is performed by using a lens (143) having a controllable focal distance.Type: GrantFiled: February 19, 2002Date of Patent: October 15, 2002Assignees: Sanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.Inventors: Koichi Tada, Shinichi Ohe, Naoyuki Takagi, Ken Hirose, Shuichi Ichiura, Hiroshi Watanabe
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Patent number: 6459662Abstract: In order to reproduce signals from a double-layer optical disc having two signal recording surfaces, a focus jump that the focusing of an objective lens from the one signal recording surface to the other signal recording surface is quickly achieved, is necessary. When a focus error signal (FE) from a pickup (60, 70) reaches a predetermined threshold value (Vcomp), a deceleration signal for decelerating the objective lens (42) is supplied to an actuator (47). Preferably, a deceleration pulse voltage is lowered step by step. The deceleration pulse voltage is determined in accordance with the maximum value (DFEmax) of a differential focus error signal (DFE) generated by differentiating the focus error signal (FE). Preferably, the address seeking is done simultaneously with the focus jump. The focus jump is performed in accordance with the layer-to-layer distance which is measured beforehand. The focus jump is performed by using a lens (143) having a controllable focal distance.Type: GrantFiled: February 19, 2002Date of Patent: October 1, 2002Assignees: Sanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.Inventors: Koichi Tada, Shinichi Ohe, Naoyuki Takagi, Ken Hirose, Shuichi Ichiura, Hiroshi Watanabe