公开(公告)号：DE69031958T2

公开(公告)日：1998-05-07

申请号：DE69031958

申请日：1990-11-06

Applicant: SONY CORP

Inventor： TERADA AKIO

IPC: G11B7/085 ,  G11B21/08

Abstract: In a track jump control device a scanning head (13) for scanning the recording track of a disc-shaped recording medium (11) is moved to a target track position. A signal obtained by differentiating (25) a tracking error signal (STE) is used as speed data to perform a closed loop track jump control operation to achieve direct landing on the target track. Track jump control making use of gray code information indicating the recording tracks on the recording medium (11) on a track-by-track basis is switched (30) to track jump control making use of the differentiated tracking error signal or vice versa to realize direct landing on the target track. Circuitry (22, 23) that forms a speed data signal (VGC) by detecting changes in the gray code information is operative to form a high resolution speed data signal by interpolation, in which a track pitch is divided by N, N being an integer, by a first control signal (TCNT) which is a version in binary form of the tracking error signal and a second control signal (TPOL) which is a version in binary form of a signal 90 DEG phase different from the tracking error signal.

公开(公告)号：MY123361A

公开(公告)日：2006-05-31

申请号：MYPI9801608

申请日：1998-04-10

Applicant: SONY CORP

Inventor： NAGARA TORU ,  TERADA AKIO ,  SAITO KIMIHIRO

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/126

Abstract: A LASER LIGHT POWER CONTROLLING METHOD IS PROVIDED WHICH COMPRISES THE STEPS OF IRRADIATING ONTO AN OPTICAL DISC A LASER LIGHT GENERATED BY A LASER SOURCE DRIVEN UNDER A DATA WRITE SIGNAL; DETECTING A REFLECTED PORTION OF THE LASER LIGHT IRRADIATED ONTO THE OPTICAL DISC; AND DETECTING AN UNDERSHOOT OF A DETECTION SIGNAL OF THE REFLECTED LASER LIGHT AND CONTROLLING THE POWER OF THE LASER LIGHT IN ACCORDANCE WITH THE AMOUNT OF THE DETECTED UNDERSHOOT. ALSO, A METHOD FOR WRITING DATA INTO AN OPTICAL DISC IS PROVIDED WHICH COMPRISES THE STEPS OF IRRADIATING ONTO AN OPTICAL DISC A LASER LIGHT GENERATED BY A LASER SOURCE DRIVEN UNDER A DATA WRITE SIGNAL; DETECTING A REFLECTED PORTION OF THE LASER LIGHT IRRADIATED ONTO THE OPTICAL DISC; AND DETECTING AN UNDERSHOOT OF A DETECTION SIGNAL OF THE REFLECTED LASER LIGHT AND DISCRIMINATING THE LEVEL OF THE UNDERSHOOT WITH REFERENCE TO A PREDETERMINED THRESHOLD. FURTHER, AN OPTICAL DISC RECORDING APPARATUS IS PROVIDED WHICH COMPRISES MEANS OF IRRADIATING A LASER LIGHT ONTO AN OPTICAL DISC CORRESPONDINGLY TO A DATA WRITE SIGNAL; A PHOTODETECTOR TO DETECT A REFLECTED PORTION OF THE LASER LIGHT IRRADIATED ONTO THE OPTICAL DISC; AND AN UNDERSHOOT DETECTOR TO DETECT AN UNDERSHOOT OF A DETECTION SIGNAL OF THE LASER LIGHT DETECTED BY THE PHOTODETECTOR; THE POWER OF THE LASER LIGHT BEING CONTROLLED IN ACCORDANCE WITH THE AMOUNT OF THE DETECTED UNDERSHOOT. THE OPTICAL DISC MAY BE A PHASE-CHANGE BASED ONE.(FIGURE 3)

公开(公告)号：ID20512A

公开(公告)日：1999-01-07

申请号：ID980542

申请日：1998-04-09

Applicant: SONY CORP

Inventor： NAGARA TORU ,  TERADA AKIO ,  SAITO KIMIHIRO

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/126

Abstract: A laser light power controlling method is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and controlling the power of the laser light in accordance with the amount of the detected undershoot. Also, a method for writing data into an optical disc is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and discriminating the level of the undershoot with reference to a predetermined threshold. Further, an optical disc recording apparatus is provided which comprises means of irradiating a laser light onto an optical disc correspondingly to a data write signal; a photodetector to detect a reflected portion of the laser light irradiated onto the optical disc; and an undershoot detector to detect an undershoot of a detection signal of the laser light detected by the photodetector; the power of the laser light being controlled in accordance with the amount of the detected undershoot. The optical disc may be a phase-change based one.

公开(公告)号：DE69024766T2

公开(公告)日：1996-06-27

申请号：DE69024766

申请日：1990-11-06

Applicant: SONY CORP

Inventor： TERADA AKIO

IPC: G11B7/085 ,  G11B21/08

Abstract: In a track jump control device a scanning head (13) for scanning the recording track of a disc-shaped recording medium (11) is moved to a target track position. A signal obtained by differentiating (25) a tracking error signal (STE) is used as speed data to perform a closed loop track jump control operation to achieve direct landing on the target track. Track jump control making use of gray code information indicating the recording tracks on the recording medium (11) on a track-by-track basis is switched (30) to track jump control making use of the differentiated tracking error signal or vice versa to realize direct landing on the target track. Circuitry (22, 23) that forms a speed data signal (VGC) by detecting changes in the gray code information is operative to form a high resolution speed data signal by interpolation, in which a track pitch is divided by N, N being an integer, by a first control signal (TCNT) which is a version in binary form of the tracking error signal and a second control signal (TPOL) which is a version in binary form of a signal 90 DEG phase different from the tracking error signal.

公开(公告)号：DE69024766D1

公开(公告)日：1996-02-22

申请号：DE69024766

申请日：1990-11-06

Applicant: SONY CORP

Inventor： TERADA AKIO

IPC: G11B7/085 ,  G11B21/08

Abstract: In a track jump control device a scanning head (13) for scanning the recording track of a disc-shaped recording medium (11) is moved to a target track position. A signal obtained by differentiating (25) a tracking error signal (STE) is used as speed data to perform a closed loop track jump control operation to achieve direct landing on the target track. Track jump control making use of gray code information indicating the recording tracks on the recording medium (11) on a track-by-track basis is switched (30) to track jump control making use of the differentiated tracking error signal or vice versa to realize direct landing on the target track. Circuitry (22, 23) that forms a speed data signal (VGC) by detecting changes in the gray code information is operative to form a high resolution speed data signal by interpolation, in which a track pitch is divided by N, N being an integer, by a first control signal (TCNT) which is a version in binary form of the tracking error signal and a second control signal (TPOL) which is a version in binary form of a signal 90 DEG phase different from the tracking error signal.

公开(公告)号：MY104511A

公开(公告)日：1994-04-30

申请号：MYPI19901954

申请日：1990-11-06

Applicant: SONY CORP

Inventor： TERADA AKIO

IPC: G11B7/085 ,  G11B21/12 ,  G11B21/08

Abstract: IN A TRACK JUMP CONTROL DEVICE A SCANNING HEAD (13) FOR SCANNING THE RECORDING TRACK OF A DISC-SHAPED RECORDING MEDIUM (11) IS MOVED TO A TARGET TRACK POSITION. A SIGNAL OBTAINED BY DIFFERENTIATING (25) A TRACKING ERROR SIGNAL IS USED AS SPEED DATA TO PERFORM A CLOSED LOOP TRACK LUMP CONTROL OPERATION TO ACHIEVE DIRECT LANDING ON THE TARGET TRACK. TRACK JUMP CONTROL MAKING USE GRAY CODE INFORMATION INDICATING THE RECORDING TRACKS ON THE RECORDING MEDIUM (11) ON A TRACK - BY - TRACK BASIS IS SWITCHED (30) TO TRACK JUMP CONTROL MAKING USE OF THE DIFFERENTIATED TRACKING ERROR SIGNAL OR VICE VERSA TO REALIZE DIRECT LANDING ON THE TARGET TRACK.(FIG. 5)

公开(公告)号：SG67491A1

公开(公告)日：1999-09-21

申请号：SG1998000697

申请日：1998-04-06

Applicant: SONY CORP

Inventor： NAGARA TORU ,  TERADA AKIO ,  SAITO KIMIHIRO

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/126 ,  G11B7/125

Abstract: A laser light power controlling method is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and controlling the power of the laser light in accordance with the amount of the detected undershoot. Also, a method for writing data into an optical disc is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and discriminating the level of the undershoot with reference to a predetermined threshold. Further, an optical disc recording apparatus is provided which comprises means of irradiating a laser light onto an optical disc correspondingly to a data write signal; a photodetector to detect a reflected portion of the laser light irradiated onto the optical disc; and an undershoot detector to detect an undershoot of a detection signal of the laser light detected by the photodetector; the power of the laser light being controlled in accordance with the amount of the detected undershoot. The optical disc may be a phase-change based one.

公开(公告)号：DE69031958D1

公开(公告)日：1998-02-19

申请号：DE69031958

申请日：1990-11-06

Applicant: SONY CORP

Inventor： TERADA AKIO

IPC: G11B7/085 ,  G11B21/08

Abstract: In a track jump control device a scanning head (13) for scanning the recording track of a disc-shaped recording medium (11) is moved to a target track position. A signal obtained by differentiating (25) a tracking error signal (STE) is used as speed data to perform a closed loop track jump control operation to achieve direct landing on the target track. Track jump control making use of gray code information indicating the recording tracks on the recording medium (11) on a track-by-track basis is switched (30) to track jump control making use of the differentiated tracking error signal or vice versa to realize direct landing on the target track. Circuitry (22, 23) that forms a speed data signal (VGC) by detecting changes in the gray code information is operative to form a high resolution speed data signal by interpolation, in which a track pitch is divided by N, N being an integer, by a first control signal (TCNT) which is a version in binary form of the tracking error signal and a second control signal (TPOL) which is a version in binary form of a signal 90 DEG phase different from the tracking error signal.

公开(公告)号：DE69113499T2

公开(公告)日：1996-03-07

申请号：DE69113499

申请日：1991-04-05

Applicant: SONY CORP

Inventor： TERADA AKIO

IPC: G11B7/09 ,  G11B11/105 ,  G11B7/095

Abstract: An optical disc such as a magnetooptic disc has information storage tracks each associated with a plurality of pairs of wobble pits arranged therealong. A light beam emitted from a light beam source such as a semiconductor laser is applied as a convergent light beam through an objective lens to the optical disc. A deviation of the light beam from a focused condition on the optical disc is detected as a focus error. A light beam returning from the optical disc is detected by a light detector. When the light beam returns from the wobble pits in each pair, the light detector produces a detected signal with successive peak values corresponding to the wobble pits, and the peak values are averaged. The objective lens is moved along its optical axis by an actuator based on the sum of a signal representing the focus error and a bias which maximizes the absolute value of the average of the peak values from the light detector.

公开(公告)号：DE69113499D1

公开(公告)日：1995-11-09

申请号：DE69113499

申请日：1991-04-05

Applicant: SONY CORP

Inventor： TERADA AKIO

IPC: G11B7/09 ,  G11B11/105 ,  G11B7/095

Abstract: An optical disc such as a magnetooptic disc has information storage tracks each associated with a plurality of pairs of wobble pits arranged therealong. A light beam emitted from a light beam source such as a semiconductor laser is applied as a convergent light beam through an objective lens to the optical disc. A deviation of the light beam from a focused condition on the optical disc is detected as a focus error. A light beam returning from the optical disc is detected by a light detector. When the light beam returns from the wobble pits in each pair, the light detector produces a detected signal with successive peak values corresponding to the wobble pits, and the peak values are averaged. The objective lens is moved along its optical axis by an actuator based on the sum of a signal representing the focus error and a bias which maximizes the absolute value of the average of the peak values from the light detector.