公开(公告)号：ID26057A

公开(公告)日：2000-11-23

申请号：ID20000418

申请日：2000-05-17

Applicant: SONY CORP

Inventor： TSUTSUI KEIICHI ,  TAKESHITA YASUYUKI

IPC: G11B7/1263 ,  G11B7/125 ,  G11B11/105 ,  H01S5/0683

Abstract: A reproducing laser output can be adjusted to an optimal level. To this end, a magneto-optical disk device (1) comprises a differential amplifier (23) and a shortest recording mark identifier (3) which detect a shortest recording mark reproducing signal corresponding to a component of a shortest recording mark in a reproducing signal obtained by reproducing a magneto-optical disk (100), an envelope detector (33) which detects an amplitude level of the shortest recording mark reproducing signal, a comparator (35) which compares the amplitude level with a reference voltage outputted from the reference voltage source (34), and a drive control section (30) which adjusts the reproducing laser beam to an output level at which the amplitude level is equal to or higher than the reference voltage, based on a comparison result from the comparator (35).

公开(公告)号：MY138423A

公开(公告)日：2009-06-30

申请号：MYPI20050893

申请日：2000-05-17

Applicant: SONY CORP

Inventor： TSUTSUI KEIICHI ,  TAKESHITA YASUYUKI

IPC: G11B7/1263 ,  G11B11/00 ,  G11B7/125 ,  G11B11/105 ,  H01S5/0683

Abstract: A REPRODUCING LASER OUTPUT CAN BE ADJUSTED TO AN OPTIMAL LEVEL. TO THIS END, A MAGNETO-OPTICAL DISK DEVICE (1) INCLUDES A DIFFERENTIAL AMPLIFIER AND A SHORTEST RECORDING MARK IDENTIFIER (31) THAT DETECTS A SHORTEST RECORDING MARK REPRODUCING SIGNAL CORRESPONDING TO A COMPONENT OF A SHORTEST RECORDING MARK IN A REPRODUCING SIGNAL OBTAINED BY REPRODUCING A MAGNETO-OPTICAL DISK (100). IN ADDITION, AN ENVELOPE DETECTOR (43, 47) DETECTS AN AMPLITUDE LEVEL OF THE SHORTEST RECORDING MARK REPRODUCING SIGNAL, A COMPARATOR COMPARES THE AMPLITUDE LEVEL WITH A REFERENCE VOLTAGE OUTPUTTED FROM THE REFERENCE VOLTAGE SOURCE (34, 44, 48), AND A DRIVE CONTROL SECTION (30) ADJUSTS THE REPRODUCING LASER BEAM TO AN OUTPUT LEVEL AT WHICH THE AMPLITUDE LEVEL IS EQUAL TO OR HIGHER THAN THE REFERENCE VOLTAGE, BASED ON A COMPARISON RESULT FROM THE COMPARATOR.

公开(公告)号：AU768696B2

公开(公告)日：2004-01-08

申请号：AU3251700

申请日：2000-05-04

Applicant: SONY CORP

Inventor： TSUTSUI KEIICHI ,  TAKESHITA YASUYUKI

IPC: G11B7/1263 ,  G11B7/125 ,  G11B11/105 ,  H01S5/0683

Abstract: A reproducing laser output can be adjusted to an optimal level. To this end, a magneto-optical disk device (1) comprises a differential amplifier (23) and a shortest recording mark identifier (3) which detect a shortest recording mark reproducing signal corresponding to a component of a shortest recording mark in a reproducing signal obtained by reproducing a magneto-optical disk (100), an envelope detector (33) which detects an amplitude level of the shortest recording mark reproducing signal, a comparator (35) which compares the amplitude level with a reference voltage outputted from the reference voltage source (34), and a drive control section (30) which adjusts the reproducing laser beam to an output level at which the amplitude level is equal to or higher than the reference voltage, based on a comparison result from the comparator (35).

公开(公告)号：AU3251700A

公开(公告)日：2000-11-23

申请号：AU3251700

申请日：2000-05-04

Applicant: SONY CORP

Inventor： TSUTSUI KEIICHI ,  TAKESHITA YASUYUKI

IPC: G11B7/1263 ,  G11B7/125 ,  G11B11/105 ,  H01S5/0683

Abstract: A reproducing laser output can be adjusted to an optimal level. To this end, a magneto-optical disk device (1) comprises a differential amplifier (23) and a shortest recording mark identifier (3) which detect a shortest recording mark reproducing signal corresponding to a component of a shortest recording mark in a reproducing signal obtained by reproducing a magneto-optical disk (100), an envelope detector (33) which detects an amplitude level of the shortest recording mark reproducing signal, a comparator (35) which compares the amplitude level with a reference voltage outputted from the reference voltage source (34), and a drive control section (30) which adjusts the reproducing laser beam to an output level at which the amplitude level is equal to or higher than the reference voltage, based on a comparison result from the comparator (35).

公开(公告)号：BR0002481A

公开(公告)日：2001-01-02

申请号：BR0002481

申请日：2000-05-19

Applicant: SONY CORP

Inventor： TSUTSUI KEIICHI ,  TAKESHITA YASUYUKI

IPC: G11B7/1263 ,  G11B7/125 ,  G11B11/105 ,  H01S5/0683 ,  G11B13/04 ,  G11B13/00

Abstract: A reproducing laser output can be adjusted to an optimal level. To this end, a magneto-optical disk device (1) comprises a differential amplifier (23) and a shortest recording mark identifier (3) which detect a shortest recording mark reproducing signal corresponding to a component of a shortest recording mark in a reproducing signal obtained by reproducing a magneto-optical disk (100), an envelope detector (33) which detects an amplitude level of the shortest recording mark reproducing signal, a comparator (35) which compares the amplitude level with a reference voltage outputted from the reference voltage source (34), and a drive control section (30) which adjusts the reproducing laser beam to an output level at which the amplitude level is equal to or higher than the reference voltage, based on a comparison result from the comparator (35).

公开(公告)号：CA2308427A1

公开(公告)日：2000-11-19

申请号：CA2308427

申请日：2000-05-10

Applicant: SONY CORP

Inventor： TAKESHITA YASUYUKI ,  TSUTSUI KEIICHI

IPC: G11B7/1263 ,  G11B7/125 ,  G11B11/105 ,  H01S5/0683 ,  G11B13/04

Abstract: A reproducing laser output can be adjusted to an optimal level. To this end, a magneto-optical disk device 1 comprises a differential amplifier 23 and a shortest recording mark identifier 33 which detect a shortest recording mark reproducing signal corresponding to a component of a shortest recording mark in a reproducing signal obtained by reproducing a magneto-optical disk 100, an envelope detector 33 which detects an amplitude level of the shortest recording mark reproducing signal, a comparator 35 which compares the amplitude level with a reference voltage outputted from the reference voltage source 34, and a drive control section 30 which adjusts the reproducing laser beam to an output level at which the amplitude level is equal to or higher than the reference voltage, based on a comparison result from the comparator 35.

公开(公告)号：EP1482351A4

公开(公告)日：2009-11-25

申请号：EP03708494

申请日：2003-03-05

Applicant: SONY CORP

Inventor： TAKESHITA YASUYUKI ,  FUKUMOTO ATSUSHI ,  KAI SHINICHI

IPC: G02F1/13 ,  G02F1/133 ,  G11B7/007 ,  G11B7/095 ,  G11B7/135 ,  G11B7/125

CPC classification number: G11B7/1369 ,  G02F1/13306 ,  G02F2201/122 ,  G02F2203/50 ,  G11B7/00718 ,  G11B7/0956 ,  G11B7/13927

公开(公告)号：JPH07287885A

公开(公告)日：1995-10-31

申请号：JP8136494

申请日：1994-04-20

Applicant: SONY CORP

Inventor： ICHIMURA ISAO ,  TAKESHITA YASUYUKI

IPC: G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To realize the miniaturization and reduction of the cost of the device by unnecessitating an expensive external modulator, to directly rewrite a single layer as it is without making a recording layer a multilayer and to cancel the defect in the manufacturing of a magneto-optical medium. CONSTITUTION:A green laser light source 1 outputs a green laser beam 532nm in wavelength. A simplified external modulator 3 performs power control for keeping the power of the green laser beam constant and changeover control for changing the output of the green laser beam so as to be fitted to the recording/reproducing of an information signal. A magnetic field modulation head 9 generates modulated magnetic field complied with the information signal. Consequently, when a place arranged close to the magnetic field modulation head 9 is irradiated with the green laser beam for writing being made to be stable and a high power, the signal surface of the magneto-optical disk D is magnetized according to modulated magnetic field generated by the magnetic field modulation head 9 and the magnetic field modulated signal is are recorded on the magneto-optical disk D.

公开(公告)号：JP2004185775A

公开(公告)日：2004-07-02

申请号：JP2002354961

申请日：2002-12-06

Applicant: Sony Corp ,  ソニー株式会社

Inventor： TANAKA YASUTO ,  TAKESHITA YASUYUKI ,  SAKAMOTO TETSUHIRO ,  YOSHIMURA SHUNJI

IPC: G11B11/105

Abstract: PROBLEM TO BE SOLVED: To obtain the reproduced data with no timing shift irrespective of the influence of a leakage magnetic field or the like.
SOLUTION: A DC signal generated according to an edge detecting signal by the timing deviation of a magnetic wall movement due to the influence of a leakage magnetic field or the like is output at a level according to reproduction laser power. Then, a timing error is eliminated by the DC signal when the edge detecting signal is generated. For example, the DC signal is supplied as an offset to a secondary differential signal, or as a reference level to compare the second derivative signal, and accordingly timing deviation is corrected when the edge detecting signal is generated.
COPYRIGHT: (C)2004,JPO&NCIPI

公开(公告)号：JPH07334887A

公开(公告)日：1995-12-22

申请号：JP15036394

申请日：1994-06-08

Applicant: SONY CORP

Inventor： TAKESHITA YASUYUKI

IPC: G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To obtain an easy and accurate positioning method without using excessive optical components. CONSTITUTION:A magneto-optical disk 16 is irradiated with a beam from a light source 11, and a magneto-optical signal reflected on the magneto-optical disk 16 is detected by photodetecting means 20, 21. The signals detected by these photodetecting means 20, 21 are displayed on a display means 23, and by moving the magnetic head while observing data displayed on the display means 23, the optimum position of the magnetic head 17 is decided in accordance with the change of amplitude of the detected signal displayed on the display means 23.