JP2010129149A - Recording method of optical disk drive and optical disk drive - Google Patents

Abstract

An optical disc drive recording method and an optical disc drive that optimally suppress a deviation of a trailing end of a recorded mark by adjusting a strategy of a predetermined parameter of a recording pulse in order to improve recording quality.
When the recording speed is low, the trailing edge deviation of the mark is corrected by changing the rising edge of the cooling pulse constituting the recording pulse, the optimal strategy is determined, and the recording speed is high. In this case, by changing the falling edge of the last pulse and the rising edge of the cooling pulse constituting the recording pulse, or by changing the rising and falling edges of the last pulse and the rising edge of the cooling pulse, Correct the deviation at the trailing edge of the mark to determine the optimal strategy.
[Selection] Figure 1

Description

  The present invention relates to recording quality for recording information on an optical disc, and more specifically, to improve recording quality, by adjusting the strategy of a predetermined parameter of a recording pulse, the deviation of the trailing end of a recorded mark is recorded. The present invention relates to a recording method for an optical disc drive and an optical disc drive that optimally suppress the above.

  Information recording on an optical disk is performed by converting the recording information given from a PC (Pesonal Computer) or the like into an EFM (Eight to Future 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 is adopted in which a recording parameter (hereinafter referred to as a write strategy) unique to each optical disc to be used is determined for a reference recording waveform to maintain good recording quality.

  In the conventional rewritable optical storage disk, the correction position is fixed, so that depending on the disk and recording speed, the recording quality may be deteriorated by correcting the pulse width. In this case, only the coarse adjustment is performed and the deterioration of the recording quality is avoided by not performing the fine adjustment. As described above, when fine adjustment is not performed due to improper correction position, recorded mark and space jitter and block error rate (PIE) increase, so that the recording quality cannot be sufficiently guaranteed. .

In Patent Document 1, a table in which an optimum recording strategy is set for each identification information of an optical disk is stored in the memory of the system controller, and an average recording strategy is set for an optical disk without identification information. When recording data on an optical disc without identification information, test data is recorded with an average recording strategy and a strategy obtained by changing the average recording strategy, and a strategy in which the detection rate of the synchronization signal is equal to or higher than a predetermined value is set as an optimal strategy. There is a statement to that effect.
JP 2006-260668 A

  The present invention has been made in order to solve such a problem, and an object of the present invention is to adjust the strategy of a predetermined parameter of a recording pulse to improve the recording quality, and thereby to improve the recording quality. It is an object of the present invention to provide an optical disc drive recording method and an optical disc drive that optimally suppress the edge deviation.

  The recording method of the optical disk drive of the present invention is a recording method of an optical disk drive in which marks and spaces representing recorded information are formed on an optical disk by laser light, and information is recorded or reproduced. The method includes a step of correcting the deviation of the trailing edge of the mark, and a step of determining an optimum strategy based on the correction value at this time. Thereby, it is possible to determine the strategy of the predetermined parameter of the recording pulse that optimizes the deviation of the trailing end of the recorded mark.

  When the recording speed of the recording method of the optical disk drive of the present invention is low, the step of correcting the deviation of the trailing edge of the mark by changing the rising edge of the cooling pulse constituting the recording pulse, and the correction value at this time The step of determining the optimum strategy based on the above, and when the recording speed is high, the falling edge of the last pulse and the rising edge of the cooling pulse constituting the recording pulse are changed, or the recording pulse is constituted A step of correcting the deviation of the trailing edge of the mark by changing the rising and falling edges of the last pulse and the rising edge of the cooling pulse, and a step of determining an optimum strategy based on the correction value at this time It is characterized by including. As a result, it is possible to determine the strategy of the predetermined parameter of the recording pulse that optimizes the deviation of the trailing end of the recorded mark with respect to a specific recording speed.

  In the optical disk drive that forms marks and spaces representing recording information by laser light on an optical disk, and performs recording or reproduction of information, a write strategy calculation and control unit for performing calculation and control for determining an optimal recording strategy; Write strategy calculation, and a recording pulse adjustment unit that generates and outputs a recording pulse train of predetermined data from the control unit, and the write strategy calculation and control unit corrects deviation of the trailing edge of the mark according to the recording speed And an arithmetic process for determining an optimal strategy based on the correction value at this time. As a result, it is possible to provide an optical disc drive capable of determining a strategy of a predetermined parameter of a recording pulse in which the deviation of the trailing end of the recorded mark is optimal.

  According to the present invention, there is provided a recording method for an optical disc drive and an optical disc drive that optimally suppress a deviation of a trailing end of a recorded mark by adjusting a strategy of a predetermined parameter of a recording pulse in order to improve recording quality. Can be provided.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 7 is a basic functional block diagram of an optical disc drive for executing the method according to the present invention. In FIG. 7, an optical disk 1 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 etc.

  The ROM 220 is a non-volatile memory in which a write strategy is stored, and a write strategy corresponding to various disks is stored by a designer. The write strategy memory unit 218 is a memory that temporarily stores the write strategy parameter calculated by the write strategy calculation / control unit 216.

  Based on the strategy read from the ROM 220, the write strategy calculation / control unit 216 sets parameter data for changing the rising edge of the cooling pulse constituting the recording pulse when the recording speed is low, and the data is recorded as the recording pulse. The image is sent to the adjusting unit 226 and recorded on the optical disc 1. When the recording speed is high, the falling edge of the last pulse constituting the recording pulse and the rising edge of the cooling pulse are changed, or the rising and falling edges of the last pulse constituting the recording pulse and the cooling pulse Parameter data for changing the rising edge of the signal is set, and the data is sent to the recording pulse adjustment unit 226 to be recorded on the optical disc 1.

  When the recording speed is low, data discrimination is performed from the read data, and a deviation with respect to the rising edge change of the cooling pulse is obtained from the read data calculated by the calculation unit 212, and the deviation of the trailing edge of the mark is corrected. The optimum strategy is determined based on the correction value at this time. When the recording speed is high, the deviation from the falling edge of the last pulse and the rising edge of the cooling pulse, or the change of the rising and falling edges of the last pulse and the rising edge of the cooling pulse is obtained, and the trailing edge of the mark is obtained. The deviation is corrected, and the optimum strategy is determined based on the correction value at this time. These results are stored in the write strategy memory unit 218, and are appropriately read and used during the user's operation.

  The recording pulse adjustment unit 226 receives the write strategy calculation and pulse setting parameter data from the control unit 216, generates a recording pulse train, and outputs it to the laser driving unit 228. The laser driver 228 generates a pulse signal for driving a laser diode according to the input recording pulse, and outputs the pulse signal to the semiconductor laser in the optical pickup 200, and the semiconductor laser records predetermined data on the optical disk 1.

  The head amplifier 202 calculates an amount of reflected light based on the reflected light detected from the optical disc 1 by the optical pickup 200, generates an RF signal indicating the total amount of light, and detects a focus shift of the semiconductor laser of the optical pickup 200. And a tracking error signal which is a signal for detecting a track shift.

  The binarization circuit 204 is a reproduction signal generation circuit that forms a detection signal from the head amplifier 202 and generates a binary digital signal corresponding to the mark and space. That is, the binarization circuit 204 binarizes various signals such as analog 3T, 4T, 5T,... Output from the head amplifier 202, and constantly adjusts a threshold value for converting it to a pulse waveform. .

  The clock shift measuring unit 208 is a measuring unit that measures the variation of the strategy parameter. That is, the clock shift measuring unit 208 acquires data from the binarization circuit 204 and measures the shift between the edges of various signals and the clock edges. The pulse edge of the recording pulse train increases or decreases by a specified amount (ΔT) according to the condition, and the change amount (dT) of the mark edge actually measured at this time is measured.

  The RAM 210 is a memory that temporarily stores data measured by the clock shift measuring unit 208. That is, the RAM 210 stores a write strategy calculation, a mark edge change amount (dT) actually measured from predetermined write data set by the control unit 216, and the like.

  The data discriminating / calculating unit 212 calculates a deviation from the reference clock of each rising and falling set by the write strategy calculation and control unit 216 from the measurement data stored in the RAM 210, and each deviation is used to calculate a deviation. The associated data is output to the write strategy calculation / control unit 216. Next, the write strategy calculation described above and the calculation process performed by the control unit 216 will be described in detail.

  FIG. 1 is a timing diagram showing the relationship between a recording pulse and a mark space according to the present invention. In FIG. 1, an EFM modulation (Eight to Four Modulation) pulse is input in synchronization with a clock (CLK). The recording pulse is generated in synchronization with each mark of the EFM modulation pulse, and the mark is recorded on the optical disc by this pulse. Since the present invention is a pulse adjustment for correcting the trailing edge of the mark and making the deviation of the trailing edge close to zero, the influence of the adjustment on the leading edge of the mark must be in a negligible range.

  Types 1 to 3 show adjustment points of recording pulses for strategy adjustment. In Type 1, the top pulse (Top) and the last pulse (Tlp) are not changed, and only the rising edge of the cooling pulse (Tcl) is changed. In type 2, the falling edge of Tlp and the rising edge of Tcl are changed. In type 3, the rising and falling edges of Tlp and the rising edge of Tcl are changed.

  FIG. 2 is a rear end deviation diagram showing the relationship between types 1 and 2 and the rear end of the mark. In type 1 in FIG. 2, the rear end of the 3T mark also changes back and forth as the rising edge of Tcl changes back and forth. Similarly, in Type 2, the trailing edge of the 3T mark also changes back and forth as the falling edge of Tlp and the rising edge of Tcl change back and forth. Next, the rear end deviation of the 3T mark for types 1 and 2 will be described based on the experimental results.

  FIG. 3 is a deviation diagram showing the deviation of the 3T mark when recording is performed under type 1 conditions at a recording speed of 2X. Specifically, when Top is fixed to 0.44T, Tlp is fixed to 0.38T, and Tcl is changed in the range of (0.81 ± 0.188) T, the deviation between the front end and the rear end of the 3T mark It shows the transition. In FIG. 3, the deviation at the rear end of the 3T mark changes linearly with respect to the change in Tcl. On the other hand, the deviation of the front end of the 3T mark is almost unchanged.

  FIG. 4 is a deviation diagram showing the deviation of the 3T mark when recording is performed under type 2 conditions at a recording speed of 2X. Specifically, the change in the deviation between the front end and the rear end of the 3T mark when Top is fixed at 0.44T, Tlp is fixed at (0.38 ± 0.188) T, and Tcl is fixed at 0.81T. Yes. The Tlp falling edge and the Tcl rising edge change in the same range due to parallel movement, but since the center values are different, only the Tlp is shown on the horizontal axis.

  In FIG. 4, the deviation at the rear end of the 3T mark changes linearly with respect to the change in Tlp. However, since the deviation of the front end of the 3T mark changes in a similar manner, the influence of the rear end reaches the front end. Since this tendency is also observed in type 3 (not shown), type 1 is desirable for adjusting the recording pulse for strategy adjustment at recording speed 2X.

  FIG. 5 is a deviation diagram showing the deviation of the 3T mark when recording is performed under type 1 conditions at a recording speed of 4X. Specifically, the change in the deviation between the front end and the rear end of the 3T mark when Top is fixed to 0.63T, Tlp is fixed to 0.5T, and Tcl is changed in the range of (0 + 0.375) T is shown. Yes. In FIG. 5, the change in the deviation at the rear end of the 3T mark shows linearity, but the inclination of the change is small, which is not sufficient for adjusting the deviation.

  FIG. 6 is a deviation diagram showing the deviation of the 3T mark when recording is performed under type 2 conditions at a recording speed of 4X. Specifically, it shows the transition of the deviation between the front end and the rear end of the 3T mark when Top is fixed at 0.63T, Tlp is fixed at (0.5 ± 0.188) T, and Tcl is fixed at 0T. The Tlp falling edge and the Tcl rising edge change in the same range due to parallel movement, but since the center values are different, only the Tlp is described on the horizontal axis.

  In FIG. 6, the deviation of the rear end of the 3T mark changes linearly with respect to the change in Tlp. On the other hand, the deviation of the front end of the 3T mark is almost unchanged. Since this tendency is also observed in Type 3 (not shown), Type 2 is desirable for adjusting the recording pulse for strategy adjustment at recording speed 4X.

  As described above, according to the present invention, in the strategy adjustment for correcting the deviation of the trailing edge of the mark, the deviation of the trailing edge of the recorded mark is optimally suppressed by changing the correction position according to the recording speed. It is possible to provide an optical disk drive recording method and an optical disk drive.

FIG. 4 is a timing chart showing a relationship between a recording pulse and a mark space according to the present invention. The rear end deviation diagram showing the relationship between types 1 and 2 and the rear end of the mark. FIG. 6 is a deviation diagram showing the front end and rear end deviations of the 3T mark at the time of recording speed 2X when type 1. FIG. 6 is a deviation diagram showing the front end and rear end deviations of a 3T mark at type 2 at a recording speed of 2X. The deviation figure which shows the front end and rear end deviation of 3T mark at the time of recording speed 4X at the time of type 1. FIG. The deviation figure which shows the front end and rear end deviation of 3T mark at the time of recording speed 4X at the time of type 2. FIG. 1 is a basic functional block diagram of an optical disc drive that executes a method according to the present invention; FIG.

Explanation of symbols

1 Optical disc
2 Optical disk drive 200 Optical pickup 202 Head amplifier 204 Binarization circuit 208 Clock shift measurement unit 210 RAM
212 Data discrimination, calculation unit 216 Write strategy calculation, control unit 218 Write strategy memory unit 220 ROM
226 Recording pulse adjusting unit 228 Laser driving unit Top Top pulse Tlp Last pulse Tcl Cooling pulse CLK Clock EFM Eight to Fourteen Modulation

Claims (3)

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,
Correcting the deviation of the trailing edge of the mark according to the recording speed;
And a step of determining an optimum strategy based on the correction value at this time. When the recording speed is low, correcting the deviation of the trailing edge of the mark by changing the rising edge of the cooling pulse constituting the recording pulse;
A step of determining an optimal strategy based on the correction value at this time;
When the recording speed is high, the falling edge of the last pulse constituting the recording pulse and the rising edge of the cooling pulse are changed, or the rising and falling edges of the last pulse constituting the recording pulse Correcting the deviation of the trailing edge of the mark by changing the edge and the rising edge of the cooling pulse;
The method of claim 1, further comprising: determining an optimum strategy based on the correction value at this time. In an optical disc drive that records or reproduces information by forming marks and spaces representing recorded information on an optical disc by laser light.
Write strategy calculation and control section for performing calculation and control for determining an optimum recording strategy, and a write pulse adjustment section for generating and outputting a write pulse train of predetermined data from the write strategy calculation and control section ,
The write strategy calculation and control unit executes calculation processing for correcting deviation of the trailing edge of the mark according to recording speed, and calculation processing for determining an optimal strategy based on the correction value at this time. An optical disc drive characterized by that.

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