WO2002031820A1 - Unite de disque - Google Patents

Unite de disque Download PDF

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Publication number
WO2002031820A1
WO2002031820A1 PCT/JP2001/008736 JP0108736W WO0231820A1 WO 2002031820 A1 WO2002031820 A1 WO 2002031820A1 JP 0108736 W JP0108736 W JP 0108736W WO 0231820 A1 WO0231820 A1 WO 0231820A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
level
track
predetermined mark
peak
Prior art date
Application number
PCT/JP2001/008736
Other languages
English (en)
Japanese (ja)
Inventor
Koichi Tada
Tadashi Okajima
Toshihide Hamaguchi
Toshio Takahashi
Original Assignee
Sanyo Electric Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sanyo Electric Co., Ltd. filed Critical Sanyo Electric Co., Ltd.
Publication of WO2002031820A1 publication Critical patent/WO2002031820A1/fr

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/005—Reproducing
    • G11B7/0053—Reproducing non-user data, e.g. wobbled address, prepits, BCA
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/13—Optical detectors therefor
    • G11B7/131—Arrangement of detectors in a multiple array
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
    • G11B7/00718—Groove and land recording, i.e. user data recorded both in the grooves and on the lands

Definitions

  • the present invention relates to a disk drive, and more particularly to, for example, irradiating a laser beam to a disk recording medium having predetermined marks formed on a track at predetermined intervals, so that the amplitude related to the predetermined marks and the amplitude in the positive and negative directions are increased.
  • the present invention relates to a disk device that detects a predetermined mark signal that changes to a state.
  • FCMs Fluorescence Clock Marks
  • ASM Advanced Storage Magneto Optical disc
  • FCMs Fluorescence Clock Marks
  • the FCM signal is a positive / negative symmetric signal whose level changes to the positive side and the negative side. Therefore, whether the detection signal is an FCM signal or whether the detection signal is a signal that changes first from the positive side or a signal that changes first from the negative side depends on the level of the detection signal. And the slice level of the negative polarity.
  • the level of the FCM signal does not always change symmetrically.
  • the level of the FCM signal may be asymmetrical depending on the offset based on the radial tilt of the disc. If the positive and negative slice levels are always fixed, the FCM signal may not be accurately determined.
  • a main object of the present invention is to provide a novel disk drive.
  • Another object of the present invention is to provide a disk drive capable of appropriately discriminating a signal even when a signal that should change vertically symmetrically changes vertically asymmetrically. You.
  • Tracks are formed on the recording surface of the disk recording medium, and predetermined marks are formed along the tracks.
  • the predetermined mark signal detecting means detects the predetermined mark signal by irradiating a laser beam along the track.
  • the predetermined mark signal is related to the predetermined mark, and the level of this signal changes to the positive side and the negative side from the reference level.
  • the first determining means determines the first slice level on the positive electrode side based on the peak level of the predetermined mark signal
  • the second determining means determines the second slice level on the negative electrode side based on the bottom level of the predetermined mark signal.
  • the level of the predetermined mark signal is compared with the first slice level by the first comparing means, and is compared with the second slice level by the second comparing means.
  • the determining means determines the predetermined mark signal based on a comparison result by the first comparing means and the second comparing means.
  • the first slice level and the second slice level are respectively determined from the peak level and the potom level of the predetermined mark signal, even if the predetermined mark signal includes an offset, the first slice level is the peak level. The second slice level does not fall below the bottom level. For this reason, the predetermined signal can be appropriately determined from the comparison result of the first comparing means and the second comparing means.
  • a convex first track and a concave second track are formed on a recording surface of a disk recording medium.
  • the predetermined mark on the first track is formed in a concave shape
  • the predetermined mark on the second track is formed in a convex shape.
  • the determining means determines whether the predetermined mark signal starts to change from the positive electrode side or the negative electrode side based on the comparison result.
  • FIG. 1 is a block diagram showing one embodiment of the present invention
  • FIG. 2 is a perspective view of the recording surface of the disc
  • FIG. 3 (A) is a waveform diagram showing a tracking error signal
  • FIG. 3 (B) is a waveform diagram showing the TZC signal
  • FIG. 4A is a waveform diagram showing an FCM signal detected from a land track
  • FIG. 4B is a waveform diagram showing an FCM signal detected from a groove track
  • FIG. 4 (D) is a waveform diagram showing another example of the comparison signal
  • FIG. 5 is an illustrative view showing a relationship between a tracking error signal and a tracking actuator control signal
  • Figure 6 is a circuit diagram showing the configuration of the photodetector, TE signal detection circuit, FE signal detection circuit and FCM signal detection circuit;
  • FIG. 7 is a flowchart showing a part of the operation of the embodiment of FIG. 1;
  • FIG. 8 is a waveform diagram showing an example of the FCM signal. BEST MODE FOR CARRYING OUT THE INVENTION
  • an optical disk device 10 of this embodiment includes an optical pickup 12 provided with an optical lens 14.
  • the optical lens 14 is supported by the tracking activator 16 and the focus actor 18.
  • the laser light emitted from the laser diode 20 is converged by the optical lens 14 and applied to the recording surface of a magneto-optical disk 50 such as an ASMO (Advanced Storage Magneto Optical disc).
  • a magneto-optical disk 50 such as an ASMO (Advanced Storage Magneto Optical disc).
  • the magneto-optical disk 50 is mounted on a spindle 52 and is rotated by a spindle motor 54.
  • the magneto-optical disk 50 is a ZCLV (Zone Constant Linear Velocity) type disk, and the number of rotations decreases as the optical pickup 12 moves from the inner circumference to the outer circumference.
  • each track is embossed with FCM at predetermined intervals.
  • the land track is formed in a convex shape
  • the FCM on the land track is formed in a concave shape.
  • Groove track is concave
  • the FCM on the groove track is formed in a convex shape.
  • the laser light reflected from such a disk surface passes through the optical lens 14 and irradiates the photodetector 22.
  • the output of the photodetector 22 is input to an FE signal detection circuit 24 and a TE signal detection circuit 26.
  • the FE signal detection circuit 24 detects a FE (Focus Error) signal based on the output of the photodetector 22, and the TE signal detection circuit 26 detects a TE (Tracking Error) signal based on the output of the photodetector 22.
  • the detected FE signal and TE signal are supplied to a DSP (Digital Signal Processor) 4 via AZD converters 40a and 40b, respectively.
  • DSP Digital Signal Processor
  • the DSP 42 executes focus servo processing based on the FE signal, and executes tracking servo processing and thread servo processing based on the TE signal.
  • a focus actuating control signal is generated by the focus servo process
  • a tracking actuating control signal is generated by the tracking servo process
  • a thread control signal is generated by the thread servo process.
  • the focus actuating control signal is output to the focus actuating unit 18 via the DZA converter 44b, and the tracking actuating control signal is output via the DZA converter 44a. Is output to The thread control signal is converted into a PWM signal by a PWM signal generation circuit 46 and then output to a thread module 48.
  • the TE signal is also compared to a threshold in comparator 33.
  • the comparator 33 outputs a TZC (Tracking Zero Cross) signal.
  • TZC Track Zero Cross
  • the TE signal draws the waveform shown in FIG. 3A
  • the TZC signal draws the waveform shown in FIG. 3B.
  • the TZC signal rises at a zero level while the TE signal is changing from a negative level to a positive level, and falls at a zero level while the TE signal is changing from a positive level to a negative level.
  • the TZC signal output from the comparator 33 is directly supplied to the DSP 42.
  • the output of the photodetector 22 is also input to the FCM signal detection circuit 28.
  • the FCM signal detection circuit 28 generates an FCM signal based on the laser light reflected by the FCM.
  • the FCM signal is generated when the laser beam traces the FCM formed on the land track.
  • the waveform shown in Fig. 4 (A) is drawn, and when the laser beam traces the FCM formed on the groove track, the waveform shown in Fig. 4 (B) is drawn.
  • the generated FCM signal is supplied to a peak hold circuit 32 and a bottom hold circuit 34 via a VCA (Voltage Controlled Amplifier) 30.
  • the peak hold circuit 32 detects the peak level of the FCM signal
  • the bottom hold circuit 34 detects the bottom level of the FCM signal.
  • a peak hold signal having the peak level shown in FIG. 4A or 4B is output from the peak hold circuit 32, and the bottom hold signal shown in FIG. 4A or 4B is obtained.
  • a bottom hold signal having a level is output from the pottom hold circuit 34.
  • the output peak hold signal and bottom hold signal are supplied to DSP 42 via AZD converters 40c and 40d, respectively.
  • the DSP 42 generates a gain control signal for controlling the gain of the VCA 30 based on one of the peak hold signal and the bottom hold signal.
  • the generated gain control signal is provided to VCA 30 via the DZA converter 44e.
  • VCA 30 amplifies the FCM signal with a gain according to the gain control signal.
  • the DSP 42 also generates a peak slice signal for slicing the FCM signal near the peak level based on the peak hold signal, and generates a peak slice signal for slicing the FCM signal near the bottom level based on the pottom hold signal. Generate.
  • the peak slice signal is given to the comparator 36a via the DZA converter 44c, and the bottom slice signal is given to the comparator 36b via the DZA converter 44d.
  • the peak slice signal and the bottom slice signal have the peak slice level and the bottom slice level shown in FIG. 4 (A) or FIG. 4 (B), respectively.
  • the comparators 36a and 36b compare the level of the FCM signal output from the VC A30 with the peak slice level and the bottom slice level, respectively.
  • the comparator 36a inputs the peak hold signal from the minus terminal and inputs the FCM signal from the plus terminal.
  • the comparator 36b inputs the FCM signal from the negative terminal and the bottom hold signal from the positive terminal. Therefore, when the FCM signal changes as shown in Fig. 4 (A), the comparison signal shown in Fig. 4 (C) The signal is output from comparator 36a, and the comparison signal shown in Fig. 4 (D) is output from comparator 36b. On the other hand, when the FCM signal changes as shown in FIG. 4 (B), the comparison signal shown in FIG. 4 (D) is output from the comparator 36a, and the comparison signal shown in FIG. Output from
  • the determination circuit 38 determines whether the detection signal is an FCM signal and whether the detection signal is a signal that changes first from the positive side based on the phase relationship between the comparison signals output from the comparators 42 a and 42 b. Determine whether the signal changes from the negative side first. If the rise time of the output of the comparator 36a is earlier than the output of the comparator 36b by a predetermined period, it is determined that the FCM signal that changes first from the positive side is detected (that is, the current track is a land track). I do. On the other hand, if the rising timing of the output of the comparator 36a is later than the output of the comparator 36b by a predetermined period, an FCM signal that changes first from the negative side is detected (that is, the current track is Groove track). The determination result thus obtained is output to DSP42.
  • the DSP 42 inverts the polarity of the tracking work control signal when the current track is a land track.
  • the polarity of the TE signal and the tracking work overnight control signal may be the same when adjusting the tracking on the group track, but when the tracking is adjusted on the land track, the TE signal and the tracking signal may be adjusted. It is necessary to reverse the polarity of the tracking work control signal. Therefore, the DSP 42 controls the polarity of the tracking work control signal in accordance with the result of the determination by the determination circuit 38. Note that, in FIG. 5, the amplitude of the tracking work control signal is shown parallel to the horizontal axis, the outer periphery has a positive polarity, and the inner periphery has a negative polarity.
  • the photodetector 22, the FE signal detection circuit 24, the TE signal detection circuit 26, and the FCM signal detection circuit 28 are configured as shown in FIG.
  • the photodetector 22 has four detection elements 22a to 22d.
  • the outputs of the detection elements 22 a to 22 d are subjected to different calculations in the FE signal detection circuit 24, the TE signal detection circuit 26, and the FCM signal detection circuit 28. Specifically, Equation 1 is calculated in the FE signal detection circuit 24, and Equation 2 is calculated in the TE signal detection circuit 26. 1 ⁇ 1 signal detection circuit 28 Equation 3 is calculated in.
  • Equations 1 to 3 correspond to the outputs of the detection elements 22 a to 22 d, respectively.
  • the detection elements 22a and 22d detect the left half light component of the laser light in the trace direction
  • the detection elements 22b and 22c detect the right half light component of the laser light in the trace direction.
  • the DSP 42 controls the peak slice level and the bottom slice level according to the flowchart shown in FIG. Although the DSP 42 is actually formed by a logic circuit, the operation will be described with reference to a flowchart for convenience of explanation.
  • step S1 a peak hold signal is fetched from the A / D converter 40c. As a result, the peak level of the FCM signal is detected.
  • Equation 4 is calculated in step S3 to determine the peak slice level.
  • the FCM signal draws a sine curve based on 2.5 V. Therefore, "Y-2.5" indicates the amplitude on the positive side from the reference level.
  • the peak slice level is obtained by multiplying this amplitude by "K” and adding 2.5 to the multiplied value.
  • step S5 shown in FIG. 7 the peak slice signal having the calculated peak slice level is output to the comparator 36a via the DZA converter 44c.
  • step S7 a bottom hold signal is fetched from the A / D converter 40d. As a result, the bottom level of the FCM signal is detected. Bottom level detected Then, in step S9, the bottom slice level is obtained according to Equation 5.
  • step S11 the bottom slice signal having the calculated bottom slice level is output to the comparator 36b via the D / A converter 44d.
  • a convex land track and a concave group track are formed on the recording surface of the magneto-optical disk 50. Also, a concave FCM is formed on the land track, and a concave FCM is formed on the groove track.
  • the optical pickup 12 irradiates a laser beam along a land track or a group track.
  • the FCM signal detection circuit 28 detects the FCM signal based on the laser light reflected from the land track or groove track.
  • the peak hold circuit 32 detects the peak level of the FCM signal, and the DSP 42 determines the peak slice level based on the detected peak level.
  • the bottom hold circuit 34 detects the bottom level of the FCM signal, and the DSP 42 determines the bottom slice level based on the detected bottom level.
  • the level of the FCM signal is compared with the peak slice level by the comparator 36a and by the comparator 36 with the bottom slice level.
  • the determination circuit 38 determines the FCM signal based on the comparison signals output from the comparators 36a and 36b. In other words, based on the comparison signal, it is determined whether the FCM signal strength is detected and whether the detected FCM signal is a signal that changes first from the positive side or a signal that changes first from the negative side. Determine.
  • the peak slice and peak level of the FCM signal Is determined. Therefore, even if the FCM signal includes an offset, the peak slice level does not exceed the peak level, and the bottom slice level does not fall below the bottom level. Therefore, the FCM signal can be accurately determined.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Optical Head (AREA)

Abstract

L'invention concerne une unité de disque (10) comprenant un circuit de maintien de crête (32), qui détecte les niveaux de crête d'un signal FCM, et un circuit de maintien plancher (34), qui détecte les niveaux plancher d'un signal FCM. Un DPS (42) détermine un niveau de tranche de crête sur la base d'un niveau de crête détecté par le circuit de maintien de crête (32), et il détermine un niveau de tranche plancher sur la base d'un niveau plancher détecté par le circuit de maintien plancher (34). Le niveau d'un signal FCM est comparé à un niveau de tranche de crête par un comparateur (36a), et à un niveau de tranche plancher par un autre comparateur (36b). Un circuit d'évaluation (38) évalue un signal FCM sur la base de la comparaison des signaux sortant des comparateurs (36a) et (36b).
PCT/JP2001/008736 2000-10-10 2001-10-03 Unite de disque WO2002031820A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2000-309598 2000-10-10
JP2000309598A JP2002117537A (ja) 2000-10-10 2000-10-10 ディスク装置

Publications (1)

Publication Number Publication Date
WO2002031820A1 true WO2002031820A1 (fr) 2002-04-18

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PCT/JP2001/008736 WO2002031820A1 (fr) 2000-10-10 2001-10-03 Unite de disque

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WO (1) WO2002031820A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998054703A1 (fr) * 1997-05-28 1998-12-03 Sanyo Electric Co., Ltd. Support d'enregistrement et appareil de reproduction correspondant
WO1999040576A1 (fr) * 1998-02-06 1999-08-12 Sanyo Electric Co., Ltd. Disque optique
JPH11306685A (ja) * 1998-04-21 1999-11-05 Sony Corp 信号処理回路
JPH11306686A (ja) * 1998-04-21 1999-11-05 Sony Corp 信号処理回路
JP2001297532A (ja) * 2000-04-13 2001-10-26 Sharp Corp 光ディスク装置及び光ディスク装置のクロック調整方法
WO2001088907A1 (fr) * 2000-05-19 2001-11-22 Sanyo Electric Co., Ltd. Dispositif de reproduction de disque

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998054703A1 (fr) * 1997-05-28 1998-12-03 Sanyo Electric Co., Ltd. Support d'enregistrement et appareil de reproduction correspondant
WO1999040576A1 (fr) * 1998-02-06 1999-08-12 Sanyo Electric Co., Ltd. Disque optique
JPH11306685A (ja) * 1998-04-21 1999-11-05 Sony Corp 信号処理回路
JPH11306686A (ja) * 1998-04-21 1999-11-05 Sony Corp 信号処理回路
JP2001297532A (ja) * 2000-04-13 2001-10-26 Sharp Corp 光ディスク装置及び光ディスク装置のクロック調整方法
WO2001088907A1 (fr) * 2000-05-19 2001-11-22 Sanyo Electric Co., Ltd. Dispositif de reproduction de disque

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