KR100301670B1 - Apparatus for Controlling Recording of Optical Disc And Method Thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for recording control of an optical disc which enables to set an optimum recording power and recording pulse shape before recording information on the optical disc.

The recording control apparatus of the present invention includes optical pickup means for irradiating light beams to a test area of an optical disk to record and reproduce test data, and equalizing means for amplifying an output signal of the optical pickup means to equalize a high frequency signal of a predetermined level or more; Level slicing means for slicing an output signal of the equalizing means to an arbitrary reference level to generate a square wave signal, a digitizer for converting an output signal of the optical pickup means into a digital signal, a square wave signal and a digitizer for the level slicing means And phase difference detecting means for detecting the phase difference of the digital signal, and control means for determining the optimum recording power and the shape of the recording pulse based on the phase difference signal of the phase difference detecting means.

According to the present invention, by detecting the jitter amount during the OPC process, it is possible to optimally set the optimum recording power and recording pulse shape according to the characteristics of the disc.

Description

Apparatus for Controlling Recording of Optical Disc And Method Thereof}

The present invention relates to an apparatus and method for recording control of an optical disc which enables to set an optimum recording power and recording pulse shape before recording information on the optical disc.

Optical discs are a disc medium that has begun to be generalized with the spread of compact discs (CDs). In recent years, optical discs (Digital Versatile Disc) have become more and more expected. In general, optical discs are discs for playback such as CD-ROM (CD-Read Only Memory), DVD-ROM, etc., and once-recordable discs such as CD-R (CD-Recodable), DVD-R, etc. And a disc capable of repeating recording such as a CD-Rewritable (CD-RW) and a DVD-Random Access Memory (DVD-RAM).

In general, an optical recording / reproducing apparatus uses a light beam of a small energy that irradiates a relatively large energy light beam that can change the physical properties of the information recording layer to record information on the optical disc and does not change the physical properties of the information recording layer. Information from the optical disc. To this end, an optical recording / reproducing apparatus typically uses a laser diode to drive the laser diode at a relatively high recording power to perform optical recording.

Such an optical recording / reproducing apparatus inevitably performs an Optimal Power Control (OPC) process for selecting a recording power suitable for a corresponding disc when information is recorded on a recordable optical disc. To this end, the recordable optical disc has a PCA (Power Calibration Area), which is a test area for recording power determination, in the unused area of the innermost portion.

Referring to Fig. 1, a layout diagram of a recording area of a recordable optical disc is shown.

The recordable optical disc shown in FIG. 1 is largely divided into a clamping area 10 clamped by a clamper and a recording area 20 in which data is recorded and reproduced. The recording area 20 is a PCA 22 which is used as a test area when performing OPC in the radial direction, and a PMA (Program Memory Area) 24 in which the head address of a track on which data is recorded in the user data area 28 is recorded. ), A lead-in area 26, a user data area 28 in which user data is recorded, and a lead-out area 30 located at the outermost periphery. Here, the PCA 22 is divided into a test area 22A in which test data is recorded when performing OPC and a count area 22B capable of counting the number of OPC executions, that is, the number of repeated recordings.

The optical recording / reproducing apparatus records and reproduces test data on the PCA 22 of the above-described optical disc, detects a reproduction signal (that is, a high frequency signal) proportional to the amount of reflected light, and corresponds to a parameter corresponding to vertical symmetry of the high frequency signal waveform; That is, the beta (β) value is calculated to select the optimal recording power adjusted to keep the beta constant, and the data to be recorded is recorded on the disc in accordance with the file structure. In this case, the recording power may vary due to factors such as the recording sensitivity of the disk film, the change in the recording sensitivity due to temperature, and the variation in the laser wavelength.

Referring to FIG. 2, a relationship between high frequency signal waveforms and beta values detected when test data is recorded and reproduced in the PCA during the OPC process is illustrated.

Each of the high frequency signal waveforms shown in FIG. 2 has a beta value smaller than '0' (β <0), a beta value '0' (β = 0), and a beta value larger than '0' (β). > 0). Here, the beta value β representing the up-and-down asymmetry of the high frequency signal waveform is obtained by using the top peak A1 and the bottom peak A2 based on the zero potential of the high frequency signal waveform. It is calculated by the relationship as shown in the equation.

According to Equation 1, in the case of the high frequency waveform in which the lowest value A2 is larger than the highest value A1, the beta value β is smaller than '0', and in the case of the high frequency waveform in which the highest value A1 and the lowest value A2 are the same, the beta value It can be seen that the beta value β is larger than '0' in the case of a high frequency waveform where β is equal to '0' and the minimum value A2 is smaller than the maximum value A1. Here, the recording power is adjusted to satisfy the case where the beta value β is equal to '0' (hereinafter referred to as the 'target beta') to determine the optimal recording power.

However, as described above, when OPC is performed in consideration of the beta value β, a disc using the same maker code, that is, an optical disc using the maker code, may have a target beta value due to a difference in manufacturing process conditions. OPC results are not satisfactory due to other relationships.

Accordingly, an object of the present invention is to provide an apparatus and method for controlling recording power of an optical disc capable of determining an optimal recording power using the amount of jitter.

It is another object of the present invention to provide an apparatus and method for recording power control of an optical disc capable of determining an optimal write pulse type using a jitter amount.

1 is a layout diagram of a conventional recordable optical disc.

2 is a diagram illustrating a relationship between a high frequency signal waveform and a beta value detected when test data is recorded and reproduced in the PCA during an OPC process.

3 is a block diagram showing the configuration of an optical disc recording control apparatus according to an embodiment of the present invention;

<Brief description of symbols for the main parts of the drawings>

10: clamping area 20: recording area

22: PCA (POwer Calibration Area) 22A: Test Area

22B: Count area 24: PMA (Program Memory Area)

26: lead-in area 28: user data area

30: lead-out area 32: equalizer

34: comparator 36: low pass filter

38: high pass filter 40: digitizer

42: phase difference detector 44: microcomputer

In order to achieve the above objects, the optical disc recording power control apparatus according to the present invention comprises an optical pickup means for irradiating a beam of light to a test area of an optical disc to record and reproduce test data, and amplifying an output signal of the optical pickup means to a predetermined level or more. Equalization means for equalizing high frequency signals, level slicing means for slicing the output signal of the equalizing means to an arbitrary reference level to generate a square wave signal, and a digitizer for converting the output signal of the optical pickup means into a digital signal And phase difference detecting means for detecting the phase difference between the square wave signal of the level slicing means and the digital signal of the digitizer, and control means for determining the optimum recording power and the shape of the recording pulse based on the phase difference signal of the phase difference detecting means. It is characterized by.

An optical disc recording power control method according to the present invention comprises the steps of: detecting a high frequency signal by irradiating a beam of light to a test area of an optical disc, recording and reproducing test data, and digitizing the high frequency signal to generate a first digital signal; Generating a second digital signal by equalizing and digitizing the signal, detecting a phase difference between the first and second digital signals, and controlling an optimum recording power and recording pulse shape using the phase difference. Characterized in that.

Other objects and advantages of the present invention in addition to the above object will become apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG.

3 is a block diagram illustrating a configuration of an apparatus for controlling recording power of an optical disk according to an exemplary embodiment of the present invention, wherein the apparatus for recording optical power of FIG. 3 amplifies a high frequency signal input through an input line 31 to a predetermined level or more. An equalizer 32 for equalizing a high frequency signal, a comparator 34 for converting a high frequency signal input from the equalizer 32 into a pulse signal in comparison with a slice level, and outputting the pulse signal, and the comparator 34 A low pass filter (LPF) 36 for integrating the pulse signal at the slice level and outputting the slice signal, and a high pass filter (HPF) 38 for high pass filtering the high frequency signal input through the input line 31. And compares the phase of the digital signal of the digitizer 40 with the digitizer 40 for inputting the output signal of the high pass filter 38 and converting it into a digital signal. Detect And a microcomputer 44 for determining the optimum recording power and recording pulse shape based on the phase difference signal input from the phase difference detector 42. FIG.

The recording power control apparatus of the optical disc shown in FIG. 3 determines the optimal recording power and recording pulse shape in which the jitter amount is minimal in the OPC process. In detail, in order to execute the OPC process, the optical pickup (not shown) irradiates the recording light to the PCA of the optical disc, records the test data, and then reproduces the recorded test data by irradiating the reproduced light. In this case, the area allocated to the PCA is recorded with different laser powers or 15 pulses in the ATIP section, i. Accordingly, the reproduction signal processing unit (not shown) signals the photodetection signal output from the optical pickup to generate a high frequency reproduction signal. The equalizer 32 amplifies the high frequency signal inputted from the reproduction signal processor through the input line 31 according to the magnitude, equalizes the high frequency signal of a predetermined level or more, and outputs the same to the comparator 34. The comparator 34 compares the equalized high frequency signal input from the equalizer 32 with the slice level, and converts the equalized high frequency signal into a pulse signal. The low pass filter 36 detects an average level, that is, a slice level, by outputting the pulse signal of the comparator 34 to the comparator 34. The high pass filter 38 high pass filters the high frequency signal input from the reproduction signal processor through the input line 31 and outputs the high pass filter to the digitizer 40. The digitizer 40 inputs the output signal of the high pass filter 38, converts it into a digital signal, and outputs the digital signal to the phase difference detector 42. The phase difference detector 42 detects the phase difference signal by comparing the phase of the pulse signal input from the comparator 34 and the digital signal input from the digitizer 40 and detects the phase difference signal (Anolog / Digital) port of the microcomputer 44 ( Port). The microcomputer 44 compares the phase difference signal input to the A / D port with the reference value to determine the recording power and recording pulse shape closest to the reference value as the optimal recording power and recording pulse shape, and the laser mounted to the optical pickup. The laser diode is output to a laser diode driver (not shown) for driving a diode. Accordingly, it is possible to record information by setting the optimum recording power and recording pulse shape suitable for the characteristics of the optical disc.

As described above, according to the optical disc recording control apparatus and method according to the present invention, it is possible to set the optimum recording power according to the characteristics of the disc by detecting the amount of jitter during the OPC process. In addition, according to the optical disc recording control apparatus and method according to the present invention, by detecting the jitter amount during the OPC process, it is possible to optimally set the recording pulse shape according to the recording speed and the characteristics of the disc.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

In the recording control apparatus of an optical disc, Optical pickup means for irradiating a light beam to a test area of the optical disc to record and reproduce test data; Equalizing means for amplifying the output signal of the optical pickup means and equalizing the high frequency signal with a predetermined level or more; Level slicing means for slicing an output signal of the equalizing means to an arbitrary reference level to generate a square wave shaped signal; A digitizer for converting the output signal of the optical pickup means into a digital signal; Phase difference detection means for detecting a phase difference between the square wave signal of the level slicing means and the digital signal of the digitizer; And control means for determining an optimum recording power and recording pulse shape based on the phase difference signal of said phase difference detecting means. The method of claim 1, Reproduction signal processing means for outputting a high frequency signal detected by signal processing the output signal of the optical pickup means to the equalizing means; And a high pass filter for high pass filtering the high frequency signal and outputting the high frequency signal to the digitizer. The method of claim 1, The level slicing means Comparison means for generating the square wave signal by comparing an output signal of the equalizing means with a slicing level; And an integrating means for integrating the output signal of said comparing means and outputting it at an earlier slicing level. In the recording control method of an optical disc, Irradiating a light beam to a test area of the optical disc to record and reproduce test data to detect a high frequency signal; Digitizing the high frequency signal to generate a first digital signal; Equalizing the high frequency signal and digitizing the digital signal to generate a second digital signal; Detecting a phase difference between the first and second digital signals; And controlling an optimum recording power and a recording pulse shape using the phase difference. The method of claim 4, wherein And controlling the optimum recording power and recording pulse shape by comparing the phase difference with an arbitrary reference value.