JP2010118117A - Optical disk drive and recording method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk drive and a recording method of the same, setting optimum recording power based on recording power sensitivity coefficient for a recording position in accordance with identification information and recording speed of an optical disk. <P>SOLUTION: The optical disk drive includes: a storage means 20 storing recording power control information including identification information identifying an optical disk 1 and recording sensitivity coefficient indicating variation of the optimum recording power due to recording speed and a recording position in the optical disk ; an identification information detecting means 30 detecting identification information of the optical disk 1; a speed setting means 50 setting recording speed; a recording position detecting means 40 detecting a recording position; and a recording power control means 10 controlling recording power according to recording power control information read out from the storage means 30 based on each detected data detected by each detecting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to recording quality for recording information on an optical disc, and more specifically, an optical disc drive that sets an optimum recording power based on identification information of the optical disc and a recording power sensitivity coefficient for a recording position according to the recording speed. It relates to the recording method.

  Information recording on an optical disc is performed by converting recording information given from a PC (Personal Computer) or the like into an EFM (Eight to Four Modulation) signal. In addition, problems such as poor mark formation due to insufficient cooling rate occur, so that even if an EFM signal is recorded as it is, a desired mark or space cannot be formed.

  For this reason, a method has been adopted in which a recording parameter (write strategy) unique to each optical disc to be used is determined for a reference recording waveform to maintain good recording quality. Furthermore, in order to prevent reading errors and rewriting due to changes in the asymmetry (β) accompanying changes in the recording position of the optical disc, a device has been devised to obtain a desired β value by changing the recording power depending on the recording position. Yes.

β means asymmetry of a reproduction signal (RF signal) obtained by reading a mark / space when data is recorded on the optical disc. FIG. 2 is a signal waveform diagram of the read RF signal. If the peak value from the reference RFref level to the peak is A1, and the peak value to the bottom is A2, the β value is expressed by the following equation.
β (%) = [(A1−A2) / (A1 + A2)] × 100 (1)

  FIG. 3 is a recording position vs. β value diagram showing the relationship between β and a recording position with a fixed recording power in a dual disc. In FIG. 3, predetermined data is recorded at a predetermined address of the recording layer (L0) near the optical pickup of the optical disk rotating at a recording speed of X6 CLV (Constant Linear Velocity) with a fixed recording power. The β value for the recorded data is measured. The measured β value is plotted corresponding to the address 228000h of the outer peripheral portion from the address 30000h (h indicates a hexadecimal number) of the inner peripheral portion of the optical disc.

  The β value has a steep peak on the plus side indicating an excess of recording power in the vicinity of addresses 42000h to 66000h on the inner periphery of the optical disk. This is caused by the medium of the optical disk, and it is difficult to eliminate the peak by improving the servo. Further, there is a comparatively gentle peak on the minus side indicating an insufficient recording power in the vicinity of the address D2000h to 186000h in the central portion. This is due to the recording conditions (setting of recording speed and servo constant) and is likely to occur on the L0 layer side of the dual disk. The peak can be eliminated by adjusting the servo constant. It is very subtle and it is difficult to completely eliminate the peak.

  FIG. 4 is a recording position vs. β value diagram showing the relationship between the recording position and β when the recording power is controlled by skip OPC at the recording speed X6CLV. Skip OPC (Optimum Power Control) stops recording once after recording data to a specified address in order to eliminate the fluctuation of β due to the difference in in-plane recording power sensitivity of the optical disc. Is a method for correcting the recording power by repeating the recording and repeating the recording. In FIG. 4, if skip OPC is performed at a location where the variation of β is large, a large step occurs in β at the recording power correction point, and the recording quality changes greatly, which may cause a reading error.

In order to solve this problem, Japanese Patent Laid-Open No. 2004-228561 previously obtained and stored a recording power sensitivity difference in which the β value becomes a predetermined value in the radial direction of the optical disk, and when executing writing, There is a description that the recording power is corrected based on the sensitivity difference data. FIG. 5 is a recording position vs. β value diagram showing the relationship between the address and β when the recording power is controlled for each address corresponding to the change in the radial direction at the recording speed X6CLV based on Patent Document 1.
JP 2007-323687 A

  In FIG. 5, the recording power of a predetermined β is measured at seven points of radius R = 23 mm, 29 mm, 35 mm, 41 mm, 47 mm, 53 mm, 58.5 mm of the optical disk at the recording speed X6CLV, and the recording power (set by OPC) R = 23 mm) and the recording power of other radii is obtained as a recording power sensitivity coefficient. The relationship between the address corresponding to the change in the radial direction and the recording power sensitivity coefficient is obtained by performing interpolation calculation by linear approximation based on the recording sensitivity coefficient at the seven points, and associating the address with the recording power coefficient. As a result, at each address, the recording power set by OPC is multiplied by the respective coefficient, the recording power is corrected to record predetermined data, and the β value for the recorded data is measured and plotted. . According to this, it can be said that the correction effect at the recording speed X6CLV is good.

  FIG. 6 is a recording position vs. β value diagram showing the relationship between the recording position by the fixed recording power and β using the recording speed as a parameter. In FIG. 6, the β values at the recording speeds X4CLV, X6CLV, and X8ZCLV (Zone CLV) are significantly different from each other although there is a correlation. This tendency is conspicuous when recording a dual disc on L0. For this reason, it is necessary to correct the recording power in the radial direction of the optical disk for each recording speed. The speed of X8ZCLV is changed from X6 to X8 at address 78000h.

  The present invention has been made to solve such a problem, and an object of the present invention is to set an optimum recording power based on a recording sensitivity coefficient for a recording position corresponding to identification information of the optical disk and a recording speed. It is to provide a drive and a recording method thereof.

  An optical disc drive according to the present invention is an optical disc drive that forms marks and spaces representing recorded information on an optical disc by laser light, and records or reproduces information, and includes identification information for identifying an optical disc, a recording speed on the optical disc, Storage means for storing recording power control information including a recording sensitivity coefficient representing a change in optimum recording power depending on the recording position, identification information detection means for detecting identification information of the optical disc, and speed setting means for setting the recording speed A recording position detecting means for detecting the recording position, and a recording power control means for controlling the recording power in accordance with the recording power control information read from the storage means on the basis of each detection data detected by each detecting means Based on the recording sensitivity coefficient for the recording position according to the identification information of the optical disk and the recording speed. And sets the optimum recording power position. As a result, an optical disc drive capable of setting the optimum recording power at the recording position according to the identification information of the optical disc and the recording speed becomes possible.

  The recording power sensitivity coefficient of the optical disk drive of the present invention is represented by the ratio of the optimum recording power at each recording position to the optimum recording power obtained at the OPC (Optimum Power Control) setting position of the optical disk at the recording speed of the optical disk. It is characterized by that. Accordingly, the optimum recording power at the recording position can be set by integrating the recording sensitivity coefficient to the optimum recording power obtained at the OPC setting position of the optical disc.

  The recording position of the optical disk drive of the present invention is represented by a radial position of the optical pickup or a sector address. Thus, the recording position setting parameter can be appropriately selected according to the purpose.

  An optical disk drive recording method according to the present invention is a recording method for an optical disk drive in which marks and spaces representing recorded information are formed on an optical disk by laser light to record or reproduce information, and the optical disk identification information is detected. Recording power control including a step, a step of detecting a recording speed of the optical disc, a step of detecting a recording position of the optical disc, identification information, and a recording sensitivity coefficient representing a change in optimum recording power depending on the recording speed and the recording position Based on the step of reading information from the storage means, each detected detection data, the identification information of the read recording power control information and the recording sensitivity coefficient for the recording position according to the recording speed, the optimum recording of the recording position Create and output recording power correction data based on the power calculation step and the optimum recording power Characterized in that it comprises a step, a. As a result, an optical disc drive capable of setting the optimum recording power at the recording position according to the identification information of the optical disc and the recording speed becomes possible.

  According to the present invention, it is possible to provide an optical disc drive capable of setting an optimum recording power based on the identification information of the optical disc and the recording power sensitivity coefficient for the recording position corresponding to the recording speed, and a recording method therefor. .

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a basic functional block diagram of an optical disc drive for executing the method according to the present invention. In FIG. 1, an optical disc 1 set in an optical disc drive 100 is an optical recording medium on which information can be recorded, reproduced, and erased (only RW and RAM) by a semiconductor laser. For example, CD-R, CD-RW, DVD ± R, DVD-RW, DVD-RAM, and the like.

The spindle motor 2 is rotated at a predetermined recording speed by the spindle driver 60 whose speed is set by the speed setting unit 50. The optical pickup 3 writes data at the recording position set by the control unit, or reads the written data. The head amplifier 4 calculates data based on the amount of reflected light read from the optical disc 1 by the optical pickup 3 to generate an RF signal, and also a wobble signal, LPP (Land Pre-Pit) for reading the disc identification signal and sector address. ) Generate a signal. Furthermore , a focus error signal that is a signal for detecting a focus shift of the semiconductor laser of the optical pickup 3 and a tracking error signal that is a signal for detecting a track shift are generated and output.

  The identification information detection means 30 detects identification information based on the Wobble signal or LPP signal output from the head amplifier 4 and outputs the data to the recording power control means 10. The recording position detection means 40 calculates a recording position from the address information obtained by the optical pickup 3 and outputs this recording position data to the recording power control means 10.

  The speed setting means 50 outputs the set recording speed to the recording power control means 10. The storage means 20 stores in advance recording power control information including identification information for identifying an optical disc, and a recording power sensitivity coefficient representing a change in optimum recording power at which the β value becomes a predetermined value for the recording speed and recording position on the optical disc. I remember it.

  The recording power control means 10 corresponds to the identification information of the recording power control information read from the storage means 20 and the recording sensitivity coefficient corresponding to the set speeds of the identification information detection means 30, the recording position detection means 40, and the speed setting means 50. Based on this, the optimum recording power at each recording position is calculated, and data for correcting the recording power is output.

  The recording power adjustment unit 5 receives the recording power setting data for correction from the recording power control means 10 and outputs the corrected power obtained by correcting the recording power to the laser driving unit 6 built in the optical pickup 3. The laser driving unit 6 generates a pulse signal for driving the laser diode in accordance with the input correction power and outputs the pulse signal to the semiconductor laser in the optical pickup 3. The semiconductor laser records predetermined data on the optical disc 1. Next, the arithmetic processing performed by the recording power control means 10 described above will be described in detail.

  FIG. 7 is a sensitivity coefficient table showing sensitivity coefficients of recording power with respect to recording speed and radial position. Corresponding to the optical disc, the recording power at a predetermined β is measured at 7 points of the radius R of the optical disc at recording speeds X4CLV, X6CLV and X8ZCLV = 23 mm, 29 mm, 35 mm, 41 mm, 47 mm, 53 mm, 58.5 mm, The ratio of the recording power (R = 23 mm) set by OPC and the recording power of other radii is obtained and used as the recording sensitivity coefficient. The data in this table is stored in advance in the storage means 20.

  The recording power control means 10 includes identification information and recording sensitivity of the recording power control information read from the storage means 20 in response to the detection and setting data of the identification information detection means 30, the recording position detection means 40, and the speed setting means 50. The optimum recording power at each recording position is calculated based on the coefficient. At this time, in order to associate the address corresponding to the change in the radial direction and the recording sensitivity coefficient, interpolation calculation is performed by linear approximation based on the read recording sensitivity coefficient at the seven points, and the address and the recording sensitivity coefficient are correlated. . The optimum recording power at each recording position is obtained by multiplying the recording power set by OPC by the recording sensitivity coefficient at each address.

  8-10 is a recording position pair β showing the relationship between the address and β when the recording power is corrected for each address corresponding to the change in the radial direction at the recording speeds X4CLV, X6CLV and X8ZCLV based on FIG. It is a value diagram. In FIG. 8-10, it can be confirmed from the fluctuation of the β value corresponding to each recording speed that the recording power correction effect is good when the recording sensitivity coefficient suitable for the recording speed is used.

  FIG. 11 shows the addresses when the recording power is controlled using the recording sensitivity coefficient at X4 for each address and the recording power is controlled using the recording sensitivity coefficient at X6 at the recording speed X6CLV. It is a recording position versus β value diagram showing the relationship with β. In both cases, skip OPC is applied, but the step of β occurring at the skip OPC application point is smaller when the recording sensitivity coefficient at X6 is used.

  FIG. 12 is a flowchart showing the recording method of the optical disk drive of the present invention. In FIG. 12, the optical disc drive 100 starts a recording power correction operation and detects disc identification information from the optical disc 1 (step 100, step 110). Next, the recording speed is set (step 120). Recording power control information including disc identification information and a recording sensitivity coefficient representing a change in optimum recording power depending on recording speed and recording position is read from the storage means (step 130). Recording is started (step 140). The recording position of the optical disk is detected (step 150). Based on the set recording speed, the detected recording position data, and the read recording sensitivity coefficient, the optimum recording power at the current recording position is calculated (step 160). The recording power calculated in step 160 is corrected (step 170). The presence or absence of the remaining recording data is checked. If there is no remaining data, the process ends. If there is, the process returns to step 150 and repeats (steps 180 and 190).

  As described above, according to the present invention, it is possible to provide an optical disc drive for setting an optimum recording power and a recording method thereof based on the identification sensitivity of the optical disc and the recording sensitivity coefficient for the recording position according to the recording speed. Become.

1 is a basic functional block diagram of an optical disc drive that executes a method according to the present invention; FIG. The signal waveform figure of the read RF signal. The recording position vs. β value diagram showing the relationship between β and the recording position by the fixed recording power. The recording position vs. β value diagram when skip OPC is applied at a recording speed of X6 CLV. The recording position vs. β value diagram at the recording speed X6CLV based on Patent Document 1. The recording position versus β value diagram with a fixed recording power with the recording speed as a parameter. The sensitivity coefficient table | surface which shows the sensitivity coefficient of the recording power with respect to a recording speed and a radial position. FIG. 8 is a recording position vs. β value diagram by correction at a recording speed X4CLV based on FIG. 7. FIG. 8 is a plot of recording position versus β value by correction at a recording speed of X6 CLV based on FIG. FIG. 8 is a recording position versus β value diagram by correction at a recording speed X8ZCLV based on FIG. 7. The recording position versus β value diagram when using recording sensitivity coefficients at X4 and X6 at a recording speed of X6CLV. 5 is a flowchart showing a recording method of the optical disk drive of the present invention.

Explanation of symbols

1 Optical disc
2 Spindle motor
3 Optical pickup
4 Head amplifier
5 Recording pulse adjuster
6 Laser Drive Unit 10 Recording Power Control Unit 20 Storage Unit 30 Identification Information Detection Unit 40 Recording Position Detection Unit 50 Speed Setting Unit
60 Spindle driver 100 Optical disk drive
β Mark space playback signal asymmetry level RFref RF signal reference level A1 Peak value from RFref level to peak A2 Peak value from RFref level to bottom OPC Optimum Power Control
EFM Eight to Future Modulation
CLV Constant Linear Velocity

Claims (4)

An optical disc drive that records or reproduces information by forming marks and spaces representing recorded information on an optical disc by laser light,
Storage means for storing recording power control information including identification information for identifying the optical disc, and a recording sensitivity coefficient representing a change in optimum recording power depending on a recording speed and a recording position on the optical disc;
Identification information detecting means for detecting the identification information of the optical disc;
Speed setting means for setting the recording speed;
A recording position detecting means for detecting the recording position;
Recording power control means for controlling the recording power corresponding to the recording power control information read from the storage means, based on each detection data detected by each detection means,
An optical disc drive characterized in that an optimum recording power at the recording position is set based on a recording sensitivity coefficient for the recording position in accordance with the identification information and recording speed of the optical disc.   The recording power sensitivity coefficient is expressed as a ratio of the optimum recording power at each recording position to the optimum recording power obtained at the OPC (Optimum Power Control) setting position of the optical disc at the recording speed of the optical disc. The optical disk drive according to claim 1.   2. The optical disc drive according to claim 1, wherein the recording position is represented by a radial position of the optical pickup of the optical pickup or a sector address. A recording method of an optical disk drive for forming a mark and a space representing recording information on an optical disk by laser light, and recording or reproducing information,
Detecting identification information of the optical disc;
Setting the recording speed of the optical disc;
Detecting a recording position of the optical disc;
Reading from the storage means recording power control information including the identification information and a recording power sensitivity coefficient representing a change in optimum recording power depending on the recording speed and the recording position;
Calculating an optimum recording power at the recording position based on the detected data detected, the identification information of the read recording power control information, and the recording sensitivity coefficient for the recording position according to the recording speed. When,
Correcting the recording power based on the optimum recording power;
An optical disk drive recording method comprising:

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