Patents by Inventor Kunimaro Tanaka
Kunimaro Tanaka 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: 5553044Abstract: An optical recording medium and apparatus discriminates media of a direct overwrite light modulation type from media which are not of the direct overwrite light modulation type. The apparatus adapts both light power used for recording and erasing and recording method according to the medium type discriminated. A method of using both direct overwrite optical recording media at non-direct overwrite optical recording media in a single apparatus includes steps of writing control information onto a medium, including an indication of the type of overwrite operation and power levels appropriate to the medium, and adapting the recording apparatus to use the appropriate recording method and power levels for the medium type detected.Type: GrantFiled: February 15, 1994Date of Patent: September 3, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Kunimaro Tanaka
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Patent number: 5528565Abstract: A magneto-optic recording system uses a unit recording medium having on a substrate a first magnetic layer whose Curie temperature is low and also having on the first magnetic layer a second magnetic layer whose Curie temperature is high. The system heats a spot on the medium with a heating device. The system may employ two such unit recording media, each having the second magnetic layer magnetized in one direction. The two unit recording media are superposed on each other and formed integrally so as to obtain a magneto-optic recording medium in which the amount of information recorded and the recording speed are doubled. In addition, a light-emitting device and a magnetic field generator are added to the magneto-optic recording medium to obtain a compact magneto-optic recording system with a low level of power consumption.Type: GrantFiled: February 23, 1995Date of Patent: June 18, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Isao Watanabe, Koichi Takeuchi, Osamu Ito, Kyosuke Yosimoto, Kunimaro Tanaka, Kazuhiko Tsutsumi
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Patent number: 5481508Abstract: A unit recording medium, having on a substrate a first magnetic layer whose Curie temperature is low and also having on the first magnetic layer a second magnetic layer whose Curie temperature is high, is heated by a heating device. After two such unit recording media each having the second magnetic layer magnetized in one direction are fabricated, and the fabricated two unit recording media are superposed on each other and formed integrally so as to obtain a magneto-optic recording recording medium in which the amount of information recorded and the recording speed are doubled. In addition, a light-emitting device and a magnetic field generator are added to the magneto-optic recording medium to obtain a compact magneto-optic recording system with a low level of power consumption.Type: GrantFiled: May 17, 1995Date of Patent: January 2, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Isao Watanabe, Koichi Takeuchi, Osamu Ito, Kyosuke Yosimoto, Kunimaro Tanaka, Kazuhiko Tsutsumi
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Patent number: 5457674Abstract: An optical disc recording apparatus which records data with a second rotation frequency on an optical disc containing a preliminarily written recording condition in relation to a first rotation frequency. The optical disc recording apparatus preliminarily possesses recording condition in relation to the first and second rotation frequencies. The optical disc recording apparatus initially reads the recording condition in relation to the first rotation frequency, and then, in accordance with the read-out recording condition in relation to the first rotation frequency and the stored recording condition in relation to the first and second rotation frequencies, the recording apparatus computes the recording condition applicable to the optical disc in relation to the second rotation frequency. Finally, the optical disc recording apparatus records data on the optical disc by applying the computed recording condition.Type: GrantFiled: September 4, 1991Date of Patent: October 10, 1995Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Isao Watanabe, Koichi Yamada, Kyosuke Yoshimoto, Kunimaro Tanaka
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Patent number: 5369628Abstract: A magneto-optic recording medium has a cartridge provided with a magnetization direction indicating portion for indicating the direction of magnetization of a second magnetic layer. Alternatively, the direction of magnetization of the second magnetic layer is recorded in advance in the first magnetic layer. The direction of magnetization of the second magnetic layer indicated or recorded is detected and recognized. A magnetic field oriented in an opposite direction to the direction of magnetization detected is imparted to the magneto-optic recording medium. Alternatively, predetermined information is recorded in the first magnetic layer, the direction of magnetization of the second magnetic layer is detected on the basis of a signal reproducing that information, and the direction of a magnetic field to be applied to the magneto-optic recording medium is set on the basis of the direction of magnetization thus detected.Type: GrantFiled: October 2, 1990Date of Patent: November 29, 1994Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kyosuke Yoshimoto, Osamu Ito, Kunimaro Tanaka, Koichi Takeuchi, Isao Watanabe, Kazuhiko Tsutsumi
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Patent number: 5321675Abstract: A sampled servo type optical disc and its driving apparatus is disclosed, in which by cyclically repeating wobbled pits or address pits of the optical disc composed by two significant digits at every N tracks, and preformatting by patterns spaced in different intervals at every track, when the optical disc driving apparatus seeks an object track, the seek direction of the optical head can be detected by the sequence of change of the pattern, and its seek speed can be detected at high speed by the detected result of the pattern, ensuring the speed control of the optical head in response to the detected seek direction and speed.Type: GrantFiled: February 28, 1989Date of Patent: June 14, 1994Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Osamu Ito, Masaharu Ogawa, Kyosuke Yoshimoto, Kunimaro Tanaka, Teruo Furukawa, Masafumi Ototake
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Patent number: 5309415Abstract: Methods and apparatuses are disclosed for improving accuracy of recording and reproducing information onto and from a magneto-optic recording information medium. In the first method, a width of a mark formed by a relatively low intensity light beam between two kinds of light beam intensities used for recording information is made larger than a sum of a track land width and the maximum track offset of the light beam, thereby the mark formed by the relatively low intensity light beam covers the track land portion in its full width. In the first apparatus, a reflected light beam from the magneto-optic recording information medium is split into a reflected beam for information reproducing and a reflected beam for tracking and focusing servos at the reproducing, thereby the apparatus can remove part being affected by the track groove portion from the reflected light beam for information reproducing.Type: GrantFiled: July 24, 1991Date of Patent: May 3, 1994Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Koichi Takeuchi, Osamu Ito, Kyosuke Yoshimoto, Kunimaro Tanaka, Isao Watanabe, Kazuhiko Tsutsumi, Ryuichirou Arai, Yoshihiro Kiyose, Kazuhiko Nakane, Teruo Furukawa, Masayoshi Shimamoto, Yoshiyuki Nakai
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Patent number: 5272684Abstract: Methods and apparatuses are disclosed for improving accuracy of recording and reproducing information onto and from a magneto-optic recording information medium. In the first method, a width of a mark formed by a relatively low intensity light beam between two kinds of light beam intensities used for recording information is made larger than a sum of a track land width and the maximum track offset of the light beam, thereby the mark formed by the relatively low intensity light beam covers the track land portion in its full width. In the first apparatus, a reflected light beam from the magneto-optic recording information medium is split into a reflected beam for information reproducing and a reflected beam for tracking and focusing servos at the reproducing, thereby the apparatus can remove part being affected by the track groove portion from the reflected light beam for information reproducing.Type: GrantFiled: July 26, 1990Date of Patent: December 21, 1993Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Koichi Takeuchi, Osamu Ito, Kyosuke Yoshimoto, Kunimaro Tanaka, Isao Watanabe, Kazuhiko Tsutsumi, Ryuichirou Aria, Yoshihiro Kiyose, Kazuhiko Nakane, Teruo Furukawa, Masayoshi Shimamoto, Yoshiyuki Nakaki
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Patent number: 5218591Abstract: In an optical disk apparatus for recording information in pits formed on an optical disk by projecting a light beam onto the optical disk and heating an area of the optical disk corresponding to the pulse pattern of the information, the pulse pattern of the information to be recorded is discriminated, and on the basis of the discriminated pulse pattern, the timing to start on and end the emission of the light beam from the light source to the optical disk is modified, or the number of emissions and the duration of each emission is controlled so that the pattern of the pits are corrected to the shapes that ensure accurate regeneration of the information.Type: GrantFiled: July 3, 1991Date of Patent: June 8, 1993Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masayoshi Shimamoto, Kunimaro Tanaka, Isao Watanabe, Osamu Ito
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Patent number: 5197048Abstract: A magneto-optic recording medium has a cartridge provided with a magnetization direction indicating portion for indicating the direction of magnetization of a second magnetic layer. Alternatively, the direction of magnetization of the second magnetic layer is recorded in advance in the first magnetic layer. The direction of magnetization of the second magnetic layer indicated or recorded is detected and recognized. A magnetic field oriented in an opposite direction to the direction of magnetization detected is imparted to the magneto-optic recording medium. Alternatively, predetermined information is recorded in the first magnetic layer, the direction of magnetization of the second magnetic layer is detected on the basis of a signal reproducing that information, and the direction of a magnetic field to be applied to the magneto-optic recording medium is set on the basis of the direction of magnetization thus detected.Type: GrantFiled: October 3, 1991Date of Patent: March 23, 1993Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kyosuke Yoshimoto, Osamu Ito, Kunimaro Tanaka, Koichi Takeuchi, Isao Watanabe, Kazuhiko Tsutsumi
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Patent number: 5185746Abstract: An optical recording system which separates and records data on optical disks loaded respectively in a plurality of optical disk drives, check symbol of the data to be recorded being recorded on predetermined disks. Information about bad recording or lost data, which caused by the trouble of the optical disk drive, is memorized, and data to be recorded is reproduced by normally recorded and reproduced data, said check symbol and said information.Type: GrantFiled: April 13, 1990Date of Patent: February 9, 1993Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kunimaro Tanaka, Minoru Ozaki, Yoshihiro Kiyose, Osamu Ito
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Patent number: 5172364Abstract: A magneto-optic recording apparatus which has a magnetic field generator that applies a magnetic field with a constant direction to a magneto-optic recording information medium for overwriting information to improve accuracy of recording and reproducing information onto and from magneto-optic recording information medium and further has an auxiliary magnetic field generator that compensates a variation of intensity of a magnetic field generated by the magnetic field generator and applied to the magneto-optic recording information medium is disclosed as the first invention. Also, a magneto-optic recording apparatus which performs synchronous wave detection of the reflected light signals from the magneto-optic recording information medium and controls A.C.Type: GrantFiled: July 26, 1990Date of Patent: December 15, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kyosuke Yoshimoto, Osamu Ito, Kunimaro Tanaka, Koichi Takeuchi, Isao Watanabe, Kazuhiko Tsutsumi
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Patent number: 5153879Abstract: An optical recording system separates and records data on optical disks that are loaded on respective optical disk drives. On each optional disk, information identifying the disk is recorded so that the optical disk may be loaded arbitrarily into any of the optical disk drives. Each optical disk may also include check symbols for data that are recorded to enable data on defective optical disk to be properly reproduced.Type: GrantFiled: March 20, 1990Date of Patent: October 6, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kunimaro Tanaka, Minoru Ozaki, Yoshihiro Kiyose, Osamu Ito
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Patent number: 5128916Abstract: An optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits and a clock pit. The distance between one of the wobbled pits and the clock pit in each servo field is selected such that the optical disc includes at least three different types of servo field. These differnt types of servo field appear in a predetermined sequence for every one or more contiguous information tracks. A driving apparatus for driving such an optical disc has a direction detecting circuit for detecting the moving velocity of a movable portion of an optical head, and a speed detecting circuit for detecting the relative velocity of the movable portion.Type: GrantFiled: May 21, 1990Date of Patent: July 7, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Osamu Ito, Masaharu Ogawa, Kyosuke Yoshimoto, Kunimaro Tanaka, Teruo Furukawa, Yoshiki Nakajima
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Patent number: 5117412Abstract: An optical disc having a plurality of information tracks. Each information track having a data field including multiple data bytes and a servo field including a first servo byte having a pair of wobbled pits and a second servo byte having a clock pit. The byte length of at least one of the first or second servo bytes being longer than the byte lengths of the data bytes. The increased byte length providing for greater distance between the wobbled pits and the clock pit resulting in increased reliability in clock pit detection. An accessing apparatus for accessing such an optical disc including a phase-locked loop circuit with a frequency dividing ratio that varies in accordance with the various byte lengths.Type: GrantFiled: May 21, 1990Date of Patent: May 26, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Osamu Ito, Masaharu Ogawa, Kyosuke Yoshimoto, Kunimaro Tanaka, Teruo Furukawa, Yoshiki Nakajima
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Patent number: 5115424Abstract: An optical type information record carrier is disclosed which includes an arrangement wherein the depth of the guide grooves is selected to be about (2N+1).lambda./8n (N=1, 2, 3, . . . ) and the inclination angle of the wall surface of the carrier is steep enough to ensure that the information recording medium will not adhere to the wall surface of the guide grooves, or will only adhere very weakly if it does adhere. Thermal conduction at the wall surface of the guide grooves is prevented so that extension of the recording bits is restricted.Type: GrantFiled: January 23, 1989Date of Patent: May 19, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hajime Nakajima, Isao Watanabe, Kunimaro Tanaka
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Patent number: 5107483Abstract: An apparatus in accordance with the present invention sequentially fixes the wavelength of a light beam irradiated from a light source whose oscillation wavelength sequentially varies to a plurality of different wavelengths to a recording medium to required wavelengths each capable of forming a hole at absorption spectrum of the recording medium, synchronizes timing of change of the wavelength of the light source with timing of recording or regenerating each bit of information, records the optical hole formed in a manner that each bit of information corresponds to the wavelength varying in sequence, and detects the formed hole to regenerate information.Type: GrantFiled: August 12, 1988Date of Patent: April 21, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshiki Nakajima, Kunimaro Tanaka, Kyosuke Yoshimoto, Motomu Yoshimura, Mitsuo Maeda, Koichi Takeuchi, Kouichi Yamada, Masaharu Ogawa, Kazuhiko Nakane, Hajime Nakajima, Masayoshi Shimamoto, Fumio Matsuda, Minoru Ozaki
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Patent number: 5070492Abstract: The present invention relates to apparatus and method for decoding a signal reproduced from an optical disc. The optical disc has a signal format for recording data from an original signal in a data area at the optical disc. The optical disc also has recorded thereon a clock signal having the same phase as the recorded data. During reproduction of the recorded signal from the optical disc, this clock signal is utilized to generate a delayed version of the reproduced data signal. This delayed signal is used to decode the reproduced data signal obtained from the optical disc, thereby enabling a phase shift of the reproduced clock signal to there produced data signal to be eliminated by circuit processing. During the recording on the data area of the optical disc, fixing data for setting phases of data reproducing recording clock and reproducing signal to optimum phases for decoding is recorded.Type: GrantFiled: February 28, 1989Date of Patent: December 3, 1991Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masaharu Ogawa, Yoshiki Nakajima, Osamu Ito, Teruo Furukawa, Kyosuke Yoshimoto, Kunimaro Tanaka, Masafumi Ototake, Minoru Ozaki
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Patent number: 5063546Abstract: An optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits and the clock pit. The distance between one of the wobbled pits and the clock pit in each servo field is selected so that the optical disc includes at least three different types of servo field. These different types of servo field appear in a predetermined sequence for every one or more contiguous information tracks. A transducing apparatus for tranducing such an optical disc has a direction detecting circuit for detecting the moving velocity of a movable portion of an optical head, and a speed detecting circuit for detecting the relative velocity of the movable portion.Type: GrantFiled: March 11, 1988Date of Patent: November 5, 1991Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Osamu Ito, Masaharu Ogawa, Kyosuke Yoshimoto, Kunimaro Tanaka, Teruo Furukawa, Yoshiki Nakajima
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Patent number: 4835752Abstract: A device for driving and controlling an optical head by forming a spot of a light beam on an optical disk having a plurality of tracks and detecting light from the spot reflected on the optical disk by a pair of optical detectors disposed in the head.Type: GrantFiled: December 14, 1987Date of Patent: May 30, 1989Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Keiji Nakatsu, Shigeo Hayashi, Masaharu Ogawa, Osamu Itou, Isao Watanabe, Kunimaro Tanaka