公开(公告)号：KR20200138226A

公开(公告)日：2020-12-09

申请号：KR20207027332

申请日：2019-03-25

Applicant: SONY CORP

Inventor： UDAGAWA TOSHIKI

IPC: H01S5/042 ,  H02H7/20 ,  H03K17/082

Abstract: [과제] 펄스구동방식으로발광소자가구동된경우에도, 발광소자에과전류가흘렀는지아닌지를적절하게판정할수 있는기술을제공하는것이다. [해결수단] 본기술에따른과전류판정회로는, 펄스발광되는발광소자의발광구간의타이밍에맞추어상기발광소자의구동전류값을취득하는샘플 & 홀드회로와, 취득된상기구동전류값과소정의판정레벨의값을비교하여상기발광소자에과전류가흘렀는지아닌지를판정하는비교회로를구비한다.

公开(公告)号：DE69033479D1

公开(公告)日：2000-04-13

申请号：DE69033479

申请日：1990-12-17

Applicant: SONY CORP

Inventor： UDAGAWA TOSHIKI ,  YOSHIMURA SHUNJI ,  OHTA MASUMI

IPC: G11B7/0045 ,  G11B7/125 ,  G11B11/105 ,  G11B20/10 ,  G11B11/10 ,  G11B7/00

Abstract: The optical recording apparatus comprises a pattern detector (31) is provided to detect a pattern of recording signal pulses. If the pulses spacing of the signal is shorter than a predetermined value, the amplitude of the subsequent signal pulses is decreased by a control signal from am amplitude limiting memory (33) so as to reduce the irradiation energy of the laser pulse. This offsets the influences of remaining heat of the recording medium due to the laser pulse corresponding to the preceding signal pulse and makes it possible to record accurately the pulse signals in a high density . @(24pp DWg.No. 4/9)@.

公开(公告)号：DE69119414T2

公开(公告)日：1997-01-02

申请号：DE69119414

申请日：1991-10-19

Applicant: SONY CORP

Inventor： FUKUMOTO ATSUSHI ,  UDAGAWA TOSHIKI ,  YOSHIMURA SHUNJI ,  ONO MASUMI ,  YASUDA KOUICHI

IPC: G11B7/004 ,  G11B7/005 ,  G11B7/125 ,  G11B7/126 ,  G11B11/105 ,  G11B19/02 ,  G11B19/04 ,  G11B33/14 ,  G11B11/10 ,  G11B7/00

Abstract: A method for reproducing signals in an optically recording medium of the type in which recording pits are erased or embossed by the temperature rise of the medium caused through projecting a light beam for reading out signals, or of the type in which the reflection factors of recording pits are changed by the temperature rise of the medium caused through projecting a light beam. The variation of the substantial size of the reproducing region because of the change of the temperature of the medium is prevented. For this prevention, for example, a temperature sensor (20) for sensing the temperature of a magnetooptical disc (11) is provided. By controlling the laser power and the external magnetic field according to the temperature sensed by this temperature sensor (20), the substantial size of the reproducing region is kept constant always.

公开(公告)号：CA2060535A1

公开(公告)日：1992-08-09

申请号：CA2060535

申请日：1992-02-03

Applicant: SONY CORP

Inventor： NAKAO ISAMU ,  FUKUMOTO ATSUSHI ,  UDAGAWA TOSHIKI ,  YOSHIMURA SHUNJI

IPC: G11B11/10 ,  G11B11/105 ,  G11B13/04

Abstract: A method and apparatus for recording and reproducing information onto and from a magneto-optic recording medium is disclosed. The magneto-optic recording medium has at least a reproducing layer and a recording layer. A recording optical head records information on the magneto-optic recording medium. A reproducing optical head has a reading light beam for reading information recorded in a region within a spot of the reading light beam by magneto-optic effect by changing a state of magnetization of the reproducing layer and at the same time irradiating the recording medium with the light beam. A wavelength of the recording light beam emitted by the recording optical head is substantially smaller than a wavelength of the reading light beam emitted by the reading optical head. A minimum ratio of the wavelength of the recording light beam to that of the reproducing light beam is 1:3.

公开(公告)号：EP0536404A4

公开(公告)日：1993-01-22

申请号：EP91917831

申请日：1991-10-19

Applicant: SONY CORP

Inventor： FUKUMOTO ATSUSHI ,  UDAGAWA TOSHIKI ,  YOSHIMURA SHUNJI ,  ONO MASUMI ,  YASUDA KOUICHI

IPC: G11B7/005 ,  G11B11/105 ,  G11B19/02

CPC classification number: G11B7/005 ,  G11B11/10515 ,  G11B11/10595 ,  G11B19/02

公开(公告)号：DE69231042D1

公开(公告)日：2000-06-15

申请号：DE69231042

申请日：1992-02-07

Applicant: SONY CORP

Inventor： OHTA MASUMI ,  NAKAO ISAMU ,  UDAGAWA TOSHIKI ,  FUKUMOTO ATSUSHI ,  YOSHIMURA SHUNJI

IPC: G11B11/105 ,  G11B19/12 ,  G11B11/10

Abstract: The present invention concerns an apparatus for recording and/or reproducing on/from a magneto-optical recording medium (10). This apparatus comprises means (62) for generating a first channel clock used to write and/or read data in and/or from a first magneto-optical recording medium (10). The first magneto-optical recording medium (10) has a recording layer (13), the reproducing layer (11) and an intermediate layer (12) for magnetically coupling the recording layer (13) the reproducing layer (11) in stationary state, in which a magnetic coupling between said recording layer (13) and said reproducing layer (11) is lost in area (14) in which the temperature is increased to be higher than a predetermined temperature by the radiation of a light upon reproducing and in which a recorded information held on said recording layer (13) is read out from said reproducing layer (11) in the radiated area (5) except the area (14) in which said magnetic coupling is lost. Furthermore, the apparatus comprises means (62) for generating a second channel clock used to write and/or read data in and/or from a second magneto-optical recording medium (10) in which a recorded information is reproduced by using substantially whole area of the radiated area (5). Moreover, the apparatus comprises a discriminating means (70) for discriminating said first magneto-optical recording medium (10) and the second magneto-optical recording medium (10) and means (40) for switching first and second channel clocks in response to a discriminating signal from said discriminating means (70).

公开(公告)号：DE69229884T2

公开(公告)日：2000-01-27

申请号：DE69229884

申请日：1992-02-14

Applicant: SONY CORP

Inventor： YOSHIMURA SHUNJI ,  UDAGAWA TOSHIKI ,  FUKUMOTO ATSUSHI

IPC: G11B11/10 ,  G11B7/007 ,  G11B11/105 ,  G11B20/12 ,  G11B27/10

Abstract: Disclosed is a method for recording and reproducing sector control information to and from a novel magneto-optical disk (31) to which the so-called erasure type data reproduction method or data-embossed type reproduction method applies. On the magneto-optical disk (31), sector control information is recorded onto a sector control information recording region (34) at a track recording density lower than that of a data recording region (33). When data is recorded on the disk (31) at a high track density, the sector control information is recorded in such a manner that the information will not exist on adjacent tracks (36) in the same rotating direction of the disk.

公开(公告)号：DE69229238T2

公开(公告)日：1999-10-14

申请号：DE69229238

申请日：1992-02-14

Applicant: SONY CORP

Inventor： YOSHIMURA SHUNJI ,  UDAGAWA TOSHIKI ,  FUKUMOTO ATSUCHI

IPC: G11B11/10 ,  G11B7/007 ,  G11B11/105 ,  G11B20/12 ,  G11B27/10

Abstract: Disclosed is a method for recording and reproducing sector control information to and from a novel magneto-optical disk (31) to which the so-called erasure type data reproduction method or data-embossed type reproduction method applies. On the magneto-optical disk (31), sector control information is recorded onto a sector control information recording region (34) at a track recording density lower than that of a data recording region (33). When data is recorded on the disk (31) at a high track density, the sector control information is recorded in such a manner that the information will not exist on adjacent tracks (36) in the same rotating direction of the disk.

公开(公告)号：DE69119418D1

公开(公告)日：1996-06-13

申请号：DE69119418

申请日：1991-10-19

Applicant: SONY CORP

Inventor： FUKUMOTO ATSUSHI ,  UDAGAWA TOSHIKI ,  YOSHIMURA SHUNJI ,  ONO MASUMI ,  YASUDA KOUICHI

IPC: G11B7/005 ,  G11B11/105 ,  G11B19/02 ,  G11B11/10

Abstract: A method for reproducing signals in an optically recording medium of the type in which recording pits are erased or embossed by the temperature rise of the medium caused through projecting a light beam for reading out signals, or of the type in which the reflection factors of recording pits are changed by the temperature rise of the medium caused through projecting a light beam. The change of the substantial size of a reproducing region because of the change of the linear velocity of the medium is prevented. For this prevention, for example, a sensing means (17) for sensing the position of the reproducing region in a radial direction of the magneto-optical disc (11) during the rotation of the disc (11) at a constant speed is provided. By controlling the laser power and the external magnetic field according to the output of the sensing means (17), the substantial size of the reproducing region is so controlled as to be constant always independently of the linear velocity in each reproducing position.

公开(公告)号：DE69018150D1

公开(公告)日：1995-05-04

申请号：DE69018150

申请日：1990-07-18

Applicant: SONY CORP

Inventor： OHSATO KIYOSHI ,  UDAGAWA TOSHIKI ,  OKADA HITOSHI

IPC: G11B7/095 ,  G11B7/09

Abstract: An optical recording and/or reproducing apparatus comprising a light beam generator (10), a photodetector (14), an optical path forming device (12,20,22,24,26,28) for causing a light beam from the light beam generator (10) to impinge upon an optical disc (D) and for guiding the light beam emanating from the optical disc (10) to the photodetector (14), and a signal generating circuit block (40) operative to obtain based on a detection output obtained from the photodetector (14) a first signal representing a tracking condition of the light beam in relation to a record track portion on the optical disc (D) and a second signal different in phase by substantially ninety degrees from the first signal and to produce a tracking error signal which satisfies the following equation: St = S1 / {K (Sl + S2 ) + S2} where St stands for the tracking error signal, S1 stands for the first signal, S2 stands for the second signal and K stands for a constant equal to or more than 1.