Patents by Inventor Shuichi Ichiura
Shuichi Ichiura 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).
-
Publication number: 20010048809Abstract: An optical disk recording/reproduction apparatus includes a semiconductor laser, an objective lens provided opposite an optical disk, an optical system for supplying a laser beam from the semiconductor laser to the objective lens, an aperture for not intercepting the laser beam in reproducing from a digital video disk and intercepting an outermost portion of the laser beam in reproducing from a compact disk, and a tracking servo mechanism for moving the objective lens in a tracking direction orthogonal to the running direction of a track of the optical disk. The aperture has an oblong opening that is longer in the tracking direction than in the track running direction.Type: ApplicationFiled: June 11, 1996Publication date: December 6, 2001Inventors: SEIJI KAJIYAMA, YOICHI TSUCHIYA, YASUYUKI KANOU, SHUICHI ICHIURA, HITOTOSHI KIMURA, TOSHIO HARADA, YASUYUKI MATSUSHITA
-
Patent number: 6321028Abstract: An optical disk recording/reproduction apparatus includes a semiconductor laser, an objective lens provided opposite an optical disk, an optical system for supplying a laser beam from the semiconductor laser to the objective lens, an aperture for not intercepting the laser beam in reproducing from a digital video disk and intercepting an outermost portion of the laser beam in reproducing from a compact disk, and a tracking servo mechanism for moving the objective lens in a tracking direction orthogonal to the running direction of a track of the optical disk. The aperture has an oblong opening that is longer in the tracking direction than in the track running direction.Type: GrantFiled: June 11, 1996Date of Patent: November 20, 2001Assignee: Sanyo Electric Co., Ltd.Inventors: Seiji Kajiyama, Yoichi Tsuchiya, Yasuyuki Kanou, Shuichi Ichiura, Hitotoshi Kimura, Toshio Harada, Yasuyuki Matsushita
-
Patent number: 6243354Abstract: An optical disk includes a track having a track pitch that is k times (0<k<1) the track pitch of a compact disk format. The track is formed by a pit having a pit length shorter than k times the pit length of the compact disk format. The track pitch P&mgr;m and shortest pit length L&mgr;m are set to satisfy the relationship of L<(A/1.6)×P where A=(V/4.3218)×3 when a standard compact disk having linear velocity of V m/second is compressed. When the recording density is to be increased to two times that of the compact disk, the track pitch is set to approximately 0.9-1.4 &mgr;m, more preferably approximately 1.1-1.3 &mgr;m, and further preferably to approximately 1.2 &mgr;m. Since the track pitch is not compressed as much as the pit length in this optical disk, generation of crosstalk can be suppressed. Also, jitter in a reproduced signal can be suppressed since the track pitch is set to 1.2 &mgr;m or in the vicinity thereof.Type: GrantFiled: April 22, 1998Date of Patent: June 5, 2001Assignee: Sanyo Electric Co., Ltd.Inventors: Hitoshi Terasaki, Shuichi Ichiura
-
Patent number: 6201777Abstract: An apparatus for discriminating optical disks has an optical pickup provided with an objective lens having an effective numerical aperture of 0.55 to 0.65, which can compatibly reproduce information from a CD and an SD. The apparatus discriminates presence/absence of waveforms of two focus error signals detected when the effective numerical aperture of the objective lens is set at 0.55 to 0.65 and 0.20 to 0.45 respectively in a process of performing focus servo control, thereby discriminating various types of optical disks from each other. Thus, optical disks having different substrate thicknesses, different track pitches, different minimum pit lengths and different reflectivity can be quickly and simply discriminated from each other.Type: GrantFiled: February 17, 1999Date of Patent: March 13, 2001Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Seiji Kajiyama, Yasuyuki Kanou, Shuichi Ichiura, Koichi Tada, Masami Shimizu, Toshio Harada
-
Patent number: 6181668Abstract: The optical pickup device includes a two wavelength semiconductor laser (23) selectively generating a laser beam having the wavelength of 635 nm and laser beam having the wavelength of 780 nm, a collimator lens (24), a hologram (25) formed on a surface of collimator lens (24), a polarizing glass (22) having an annular polarizing region (40) and an objective lens (21). Hologram (25) does not diffract the laser beam having the wavelength of 635 nm, and diffracts outward the laser beam having the wavelength of 780 nm. Therefore, virtual light source of the laser beam having the wavelength of 780 nm comes closer to the collimator lens (24) than the light source of the laser beam having the wavelength of 635 nm. Therefore, objective lens (21) focuses the laser beam having the wavelength of 635 nm on a recording surface of a transparent substrate (31) of a DVD, and focuses the laser beam having the wavelength of 780 nm on a recording surface of a transparent substrate (32) of a CD-R.Type: GrantFiled: August 28, 1998Date of Patent: January 30, 2001Assignee: Sanyo Electric Co., Ltd.Inventors: Seiji Kajiyama, Yasuyuki Kanou, Masato Yamada, Yoichi Tsuchiya, Shuichi Ichiura
-
Patent number: 6167019Abstract: An optical disc reproducing apparatus includes a semiconductor laser, an objective lens converging a laser beam from the semiconductor laser on a recording surface of an optical disc, a polarization plane rotating unit selectively rotating the plane of polarization of the laser beam according to the thickness of a substrate of the optical disc, and a polarizing filter selectively shading a peripheral portion of the laser beam having the rotated plane of polarization. In one embodiment, a numerical aperture changing unit includes a non-patterned twisted nematic liquid crystal, and the polarizing filter includes a polarizing film having a polarization characteristics at its peripheral portion.Type: GrantFiled: December 29, 1999Date of Patent: December 26, 2000Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Seiji Kajiyama, Yasuyuki Kanou, Shuichi Ichiura
-
Patent number: 6137764Abstract: An optical disc reproducing apparatus includes a semiconductor laser, an objective lens converging a laser beam from the semiconductor laser on a recording surface of an optical disc, a polarization plane rotating unit selectively rotating the plane of polarization of the laser beam according to the thickness of a substrate of the optical disc, and a polarizing filter selectively shading a peripheral portion of the laser beam having the rotated plane of polarization. In one embodiment, a numerical aperture changing unit includes a non-patterned twisted nematic liquid crystal, and the polarizing filter includes a polarizing film having a polarization characteristics at its peripheral portion.Type: GrantFiled: December 29, 1999Date of Patent: October 24, 2000Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Seiji Kajiyama, Yasuyuki Kanou, Shuichi Ichiura
-
Patent number: 6122242Abstract: An optical disc reproducing apparatus includes a semiconductor laser, an objective lens converging a laser beam from the semiconductor laser on a recording surface of an optical disc, a polarization plane rotating unit selectively rotating the plane of polarization of the laser beam according to the thickness of a substrate of the optical disc, and a polarizing filter selectively shading a peripheral portion of the laser beam having the rotated plane of polarization. In one embodiment, a numerical aperture changing unit includes a non-patterned twisted nematic liquid crystal, and the polarizing filter includes a polarizing film having a polarization characteristics at its peripheral portion.Type: GrantFiled: December 29, 1999Date of Patent: September 19, 2000Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Seiji Kajiyama, Yasuyuki Kanou, Shuichi Ichiura
-
Patent number: 6049518Abstract: An optical disc reproducing apparatus includes a semiconductor laser, an objective lens converging a laser beam from the semiconductor laser on a recording surface of an optical disc, a polarization plane rotating unit selectively rotating the plane of polarization of the laser beam according to the thickness of a substrate of the optical disc, and a polarizing filter selectively shading a peripheral portion of the laser beam having the rotated plane of polarization. In one embodiment, a numerical aperture changing unit includes a non-patterned twisted nematic liquid crystal, and the polarizing filter includes a polarizing film having a polarization characteristics at its peripheral portion.Type: GrantFiled: June 21, 1996Date of Patent: April 11, 2000Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Seiji Kajiyama, Yasuyuki Kanou, Shuichi Ichiura
-
Patent number: 6009072Abstract: An optical disc player for reproducing an optical disc having a pit width of 0.2-0.35 .mu.m, a pit depth of 100-120 nm, and a track pitch of 0.7-0.85 .mu.m. The optical disc player includes a semiconductor laser having a wavelength of 590-670 .mu.m and a laser beam projector which projects the laser beam from the laser onto the optical disc with a spot of a predetermined diameter.Type: GrantFiled: January 25, 1999Date of Patent: December 28, 1999Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Hitoshi Terasaki, Shuichi Ichiura, Toshio Ito, Yasuyuki Kano, Yoshimoto Yamaguchi, Seizo Kato, Osamu Ota
-
Patent number: 5917791Abstract: An apparatus for discriminating optical disks has an optical pickup provided with an objective lens having an effective numerical aperture of 0.55 to 0.65, which can compatibly reproduce information from a CD and an SD. The apparatus discriminates presence/absence of waveforms of two focus error signals detected when the effective numerical aperture of the objective lens is set at 0.55 to 0.65 and 0.20 to 0.45 respectively in a process of performing focus servo control, thereby discriminating various types of optical disks from each other. Thus, optical disks having different substrate thicknesses, different track pitches, different minimum pit lengths and different reflectivity can be quickly and simply discriminated from each other.Type: GrantFiled: July 30, 1996Date of Patent: June 29, 1999Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Seiji Kajiyama, Yasuyuki Kanou, Shuichi Ichiura, Koichi Tada, Masami Shimizu, Toshio Harada
-
Patent number: 5896367Abstract: A high density optical disc having a track pitch of 0.85 .mu.m, a shortest pit length of 0.49 .mu.m, a pit depth of 100 nm, and a pit width of 0.35 .mu.m is rotated at a linear velocity of 2.4-2.8 m/s such that the same is optically reproduced by a laser beam having a wavelength of 635 nm which is converged to a spot size of 0.9 .mu.m by an objective lens having a numerical aperture of 0.6. Accordingly, data is read from the optical disc at a transfer rate of 5.6 Mbps.Type: GrantFiled: October 10, 1997Date of Patent: April 20, 1999Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Hitoshi Terasaki, Shuichi Ichiura, Toshio Ito, Yasuyuki Kano, Yoshimoto Yamaguchi, Seizo Kato, Osamu Ota
-
Patent number: 5838657Abstract: An optical disc having a track pitch of 0.85 .mu.m, a shortest pit length of 0.49 .mu.m, a pit depth of 100 nm, and a pit width of 0.35 .mu.m is rotate at a linear velocity of 2.4-2.8 m/s such that the same is optically reproduced by a laser beam having a wavelength of 635 nm which is converged to a spot size of 0.9 .mu.m by an objective lens having a numerical aperture of 0.6. Accordingly, data is read from the optical disc at a transfer rate of 5.6 Mbps.Type: GrantFiled: February 8, 1996Date of Patent: November 17, 1998Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Hitoshi Terasaki, Shuichi Ichiura, Toshio Ito, Yasuyuki Kano, Yoshimoto Yamaguchi, Seizo Kato, Osamu Ota
-
Patent number: 5787061Abstract: An optical disc reproducing apparatus includes a semiconductor laser, an objective lens converging a laser beam from the semiconductor laser on a recording surface of an optical disc, a polarization plane rotating unit selectively rotating the plane of polarization of the laser beam according to the thickness of a substrate of the optical disc, and a polarizing filter selectively blocking a peripheral portion of the laser beam depending on the plane of polarization. In one embodiment, a numerical aperture changing unit includes a non-patterned twisted nematic liquid crystal, and the polarizing filter includes a polarizing film having a polarization characteristic at its peripheral portion.Type: GrantFiled: February 29, 1996Date of Patent: July 28, 1998Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Seiji Kajiyama, Yasuyuki Kanou, Shuichi Ichiura
-
Patent number: 5777970Abstract: An optical disc readout apparatus is disclosured. The apparatus adjusts an optical system which leads the laser beam output from the laser diode to the objective according to the board thickness of the optical disc, and focuses the laser beam onto the information-bearing surface of the disc by the collaboration of the adjusted optical system with the objective. The adjustment can be achieved by, for example, advancing the correction lens to the optical path of the optical system or retreating the correction lens from such optical path. An another apparatus is disclosured. The another apparatus is provided with a first optical system which leads the laser beam output from the first laser diode to the common optical system and a second optical system which leads the laser beam output from the second laser diode to the common optical system. Either the first optical system or the second optical system includes a correction lens. One of the systems is selected according to a type of the loaded disc.Type: GrantFiled: February 21, 1996Date of Patent: July 7, 1998Assignee: Sanyo Electric Co., Ltd.Inventors: Seiji Kajiyama, Yoichi Tsuchiya, Shuichi Ichiura, Tateo Toyama, Katsutoshi Hibino
-
Patent number: 5734780Abstract: In a multiplexed information receiving device of the present invention, a specific information receiving circuit separates and demodulates a received FM multiplexed signal. A specific information reconstructing circuit reconstructs program information based on a demodulated signal. A specific information recording/reproducing device carries out writing/reading operation of the program information to/from a recording medium. When an update detecting circuit detects update of specific information, and an intermission/chapter detecting circuit detects an intermission of audio and video information, a switch is driven in response to an output control signal output from a control circuit, and the specific information is output to a display device. Therefore, a person receiving the specific information such as traffic information is not made to feel uncomfortable.Type: GrantFiled: May 1, 1995Date of Patent: March 31, 1998Assignee: Sanyo Electric Co., Ltd.Inventors: Shuichi Ichiura, Nobutoshi Oki
-
Patent number: 5708635Abstract: An optical pickup device provides ultraresolving prism between a semiconductor laser and an objective lens so as to reduce light intensity at around a cross sectional center of a laser beam, thereby generating ultraresolution thereon. An optical detector is disposed at a signal detecting position where the laser beam reflected by an optical disk is converged. The optical detector has a detecting element for receiving a main lobe and a pair of detecting elements for receiving a pair of side lobes. A peak of a shielding portion of the prism is inclined to a track center of the optical disk so that the side lobes are oppositely shifted from the track center. Thus, tracking error signals are obtained on the basis of detected signals in the side lobes.Type: GrantFiled: June 18, 1996Date of Patent: January 13, 1998Assignee: Sanyo Electric Co., Ltd.Inventors: Shuichi Ichiura, Osamu Ota
-
Patent number: 5689495Abstract: An optical disc having a track pitch of 0.85 .mu.m, a shortest pit length of 0.49 .mu.m, a pit depth of 100 nm, and a pit width of 0.35 .mu.m is rotated at a linear velocity of 2.4-2.8 m/s such that the same is optically reproduced by a laser beam having a wavelength of 635 nm which is converged to a spot size of 0.9 .mu.m by an objective lens having a numerical aperture of 0.6, Accordingly, data is read from the optical disc at a transfer rate of 5.6 Mbps.Type: GrantFiled: September 9, 1996Date of Patent: November 18, 1997Assignee: Sanyo Electric Co., Ltd.Inventors: Yoichi Tsuchiya, Hitoshi Terasaki, Shuichi Ichiura, Toshio Ito, Yasuyuki Kano, Yoshimoto Yamaguchi, Seizo Kato, Osamu Ota
-
Patent number: 5659534Abstract: An apparatus is disclosed that reproduces data recorded on a recording medium having a plurality of pits formed in the medium that stores the data. The medium is designed to be compatible with an information reproducing apparatus having a lens with a first numerical aperture NA1 for focusing a laser beam of a first wavelength .lambda.1 on the recording medium. The apparatus of the present invention comprises a laser generator for generating a laser beam of a second wavelength .lambda.2 and a lens having a second numerical aperture NA2 for focusing the laser beam from the laser generator. The second wavelength .lambda.2 of the laser beam and the second numerical aperture NA2 of the lens are set to satisfy the relationship: (.lambda.2/NA2)<(.lambda.1/NA1).Type: GrantFiled: May 21, 1996Date of Patent: August 19, 1997Assignee: Sanyo Electric Co., Ltd.Inventors: Hitoshi Terasaki, Yoichi Tsuchiya, Shuichi Ichiura, Osamu Ota
-
Patent number: 5586095Abstract: An optical pickup device provides an ultraresolving prism between a semiconductor laser and an objective lens so as to reduce light intensity at around a cross sectional center of a laser beam, thereby generating ultraresolution thereon. An optical detector is disposed at a signal detecting position where the laser beam reflected by an optical disk is converged. The optical detector has a detecting element for receiving a main lobe and a pair of detecting elements for receiving a pair of side lobes. A peak of a shielding portion of the prism is inclined to a track center of the optical disk so that the side lobes are oppositely shifted from the track center. Thus, tracking error signals are obtained on the basis of detected signals in the side lobes.Type: GrantFiled: May 31, 1994Date of Patent: December 17, 1996Assignee: Sanyo Electric Co., Inc.Inventors: Shuichi Ichiura, Osamu Ota