KR20060003671A - Method for detecting optimum writing power in optical disc driver - Google Patents

Abstract

The present invention relates to a method for detecting an optimal recording power for an optical disc that is bent over an allowable range, comprising: a first step of detecting a difference in the amount of tilt detected on an inner circumference and an outer circumference of an inserted optical disc; Comparing the detected difference value with a preset reference value, and performing an OPC operation on an inner circumference and an outer circumference of the optical disc according to a comparison result to detect an optimum recording power; And a third step of performing a recording operation by using the detected optimal recording power. For an optical disk having a difference in the inner and outer circumferential tilt amounts more than a reference value, the optimum recording power detected at the inner circumference and the outer circumference side of the optical disk, respectively, is used. In the middle of the optical disc, the optimum recording power detected in the inner circumference is gradually changed, and as a result, the outer circumferential side records the optimal recording power detected in the outer circumference, so that the optimum recording quality can be obtained even for a disc that is bent above the reference value. It is a very useful invention.

PCA, OPC, Optimal Recording Power, Tilt, Outsourcing

Description

Method for detecting optimum writing power in optical disc driver             

1 is a block diagram of an embodiment of an optical disk device in which an optimal recording power detection method according to the present invention is implemented.

2 and 3 show an operation flow of an embodiment of the method for detecting the optimal recording power of the optical disk apparatus according to the present invention,

4 shows an example of the change in the optimum recording power detected in accordance with the present invention.

※ Explanation of code for main part of drawing

10: optical disc 11: spindle motor

12: sled motor 13: tilt motor

20: optical pickup 30a: digital recording signal processing unit

30b: digital reproduction signal processor 40: channel bit encoder

41: optical drive 50: R / F section

60: drive portion 61: servo portion                 

70: Micom 71: EEPROM

The present invention relates to a method for detecting optimal recording power for an optical disc that is bent over an allowable range.

In a general optical disk device, an OPC (Optimum Power Calibration) operation is performed in a PCA (Power Calibration Area) set on an inner circumferential side of the optical disk to detect an optimal recording power for an inserted optical disk, that is, a test of the PCA. If the optical disc is a high-density disc (DVD-R, DVD-RW, etc.), predetermined test data is recorded in the test area of the inner circumferential side PCA and is usually set to 6832 sectors from PSN 01E800h. The optimum recording power is detected from the reproduction characteristics of the test data.

After detection of the optimal recording power, predetermined null data is recorded in the count area of the PCA to indicate that one OPC operation has been performed.

When a recording operation is requested later, the requested recording operation is performed using the optimal recording power detected by the inner peripheral PCA.

On the other hand, disc bending may occur due to inherent factors such as manufacturing process errors or deviations in the manufacturing process, or due to acquired factors caused by inadvertent distribution and users. Since the optical axis of the light beam is not perpendicular to the disk reflecting surface, the signal-to-noise ratio (S / N) of the reproduction signal is dropped.

The deviation of the disc from the optical axis in the vertical direction is called 'tilt', and the occurrence of playback error (jitter) varies depending on the degree of tilt, especially in the case of high density discs such as DVD-R and DVD-RW. The jitter changes very sensitively depending on the amount (tilt angle).

Therefore, the curved disc is necessarily accompanied with an operation of compensating the tilt amount by adjusting the tilt compensation, that is, adjusting the angle of the optical pickup according to the detected tilt amount.

However, in the related art, even when the ROPP (Running OPC) operation for the compensation of the recording power is performed during the recording operation together with the tilt compensation on the curved disk as described above, if the tilt amount of the disk exceeds the reference value, that is, the degree of bending of the disk Is greater than the allowable range, the deviation of the recording power of the outer and outer periphery occurs greatly, and if the recording is performed on the outer side using the recording power detected on the inner side, the recording quality of the outer side may be degraded due to the lack of recording power on the outer side. There was this.

Therefore, the present invention was created to solve the above problems, by detecting the optimum recording power on the inner and outer peripheral sides of the optical disk according to the amount of tilt of the inner and outer circumference of the disk and recording by using the detected optimal recording power. It is an object of the present invention to provide an optimal recording power detection method of an optical disc apparatus that can obtain an optimum recording quality even for a disc that is bent beyond the allowable range.

According to an aspect of the present invention, there is provided a method of detecting an optimal recording power of an optical disk apparatus, the method including: detecting a difference between tilt amounts detected at an inner circumference and an outer circumference of an inserted optical disk; Comparing the detected difference value with a preset reference value, and performing an OPC operation on an inner circumference and an outer circumference of the optical disc according to a comparison result to detect an optimum recording power; And a third step of performing a recording operation using the detected optimal amount of recording power.

Hereinafter, a preferred embodiment of an optimal recording power detection method of an optical disk apparatus according to the present invention will be described with reference to the accompanying drawings.

1 is a block diagram of an embodiment of an optical disk device in which an optimal recording power detection method according to the present invention is implemented. The digital recording signal converts an input digital data into a recording format by adding an error correction code (ECC) or the like. A processing unit 30a; A channel bit encoder (40) for reconverting the data converted into the recording format into a bitstream; An optical driver 41 for outputting a light quantity driving signal according to the input signal; An optical pickup (20) for recording a signal on the optical disc (10) in accordance with the light quantity driving signal and for detecting a recording signal from the recording surface; An R / F unit 50 for generating and outputting a RECD signal indicating whether data is recorded, and for reproducing and outputting the signal detected by the optical pickup 20 as a binary signal; Adjusting the angle of the spindle motor 11 for rotating the optical disk 10, the sled motor 12 for conveying the optical pickup 20, and the angle of the optical pickup 20 relative to the optical disk 10 A drive unit 60 for driving the tilt motor 13, respectively; The drive according to the tracking error signal TE and the focusing error signal FE of the optical pickup 20, the rotational speed of the optical disk 10, and the amount of tilt detected at the inner and outer circumferences of the optical disk 10, respectively. A servo unit 61 for controlling the driving of the unit 60; A digital reproduction signal processor (30b) for restoring the binary signal to original data with its own clock synchronized with the binary signal; Non-volatile memory (EEPROM) (71) in which target beta (Target β), target gamma (Target γ), and target power (reference power) values by recording speed by disc manufacturer (disk code) are pre-stored in the form of firmware. ; And performing an OPC operation by using the stored value of the EEPROM 71, and performing an OPC operation in the inner or inner and outer circumferences according to the detected difference in the inner and outer circumference tilt amount of the optical disk 10, and performing the OPC operation. And a micom 70 for performing and controlling a recording operation using the optimum recording power detected through the above, and performing tilt compensation according to the detected tilt amount.

2 and 3 are operational flowcharts of a preferred embodiment of a method for detecting an optimal recording power of an optical disk device according to the present invention. Hereinafter, the optimal recording power of FIGS. 2 and 3 according to the present invention will be described with reference to the configuration of FIG. 1. The detection method will be described in detail.                     

First, the microcomputer 70 detects the difference between the detected inner and outer circumferential tilt amounts in a state where the tilt amount at the inner and outer circumferences of the inserted and mounted optical disk 10 is detected (S11). The detection of the tilt amount is performed in the initial disc recognition process according to the insertion and mounting of the optical disc 10.

On the other hand, when the tilt sensor for detecting the tilt angle is mounted on the upper surface of the optical pickup 20, the tilt amount can be easily detected.

When the amount of tilt in the inner and outer circumferences of the optical disc 10 is detected as described above, the microcomputer 70 moves the optical pickup 20 back to the inner circumference of the optical disc 10 and then tilts the detected inner circumference. The compensation operation is performed based on the amount, that is, the microcomputer 70 applies an appropriate driving voltage to the tilt motor 13 through the servo unit 61 and the drive unit 60, thereby providing the optical disc 10 The angle of the optical pickup 20 is adjusted so that the optical axis is perpendicular to the plane. At this time, the adjusted angle is proportional to the detected tilt amount.

The tilt compensation operation is performed for the entire area of the optical disc 10. In this case, the optical pickup at the current position is performed based on the detected tilt amount in the inner and outer circumferences without detecting the tilt amount every time. 20) to adjust the angle.

Meanwhile, the microcomputer 70 performs another OPC operation according to the detected difference between the inner and outer circumference tilt amounts, that is, the microcomputer 70 determines whether the difference between the detected inner and outer circumference tilt amounts exceeds a preset reference value. (S20), if it exceeds, it is determined that the degree of warpage of the optical disc 10 is greater than or equal to the allowable range, and each OPC operation is performed in the PCA set on the inner and outer circumference sides of the optical disc 10, When not exceeding, it is determined that the bending degree of the optical disc 10 is within an allowable range and the OPC operation is performed only in the PCA set on the inner circumferential side of the optical disc 10. The OPC operation will be described in detail below.

Before performing the OPC operation, the microcomputer 70 moves the optical pickup 20 to the test area of the PCA (the optical disk is a high-density disk (DVD-R, DVD) in order to determine the OPC start position in the PCA). -RW, etc.), the test area of the inner circumferential side PCA is usually moved to the initial position of PSN 01E800h to 6832 sectors) (S21), and then moved in the outer circumferential direction of the optical disc 10 from the moved position. The optical pickup 20 is controlled.

Accordingly, the optical pickup 20 moves in the circumferential direction from the moved position, and the R / F unit 50 generates a RECD signal from the signal detected according to the movement of the optical pickup 20. The R / F unit 50 outputs a 'high' signal as a RECD signal when the current position according to the movement of the optical pickup 20 is a data recording area. In the case of the non-data recording area, a low signal is output as the RECD signal.

The microcomputer 70 continuously monitors the generated and output RECD signal. When the RECD signal is detected as 'L' during the monitoring, the microcomputer 70 records the current position of the optical pickup 20 without data. It is determined as an area to determine this position as the OPC start position (S22), and performs the OPC operation from the determined start position, which is as follows.

First, the microcomputer 70 detects, from the EEPROM 71, the reference power stored in association with the code of the optical disc 10 and the recording speed during the OPC operation, and the detected reference power (for example, 9 mW). Is applied to the optical driver 41 for changing the recording power by a predetermined amount.

Accordingly, the optical driver 41 outputs a recording signal for test data with optical driving power corresponding to the applied control signal, and the optical pickup 20 records the output signal from the determined OPC start position. In operation S23, in one OPC operation, 15 frames are recorded with 15 recording powers.

When the recording of the test data is completed, the microcomputer 70 controls the optical pickup 20 to sequentially read the recorded test data and detects reproduction characteristics of the sequentially read data. If the optical disc 10 is a recordable disc (for example, DVD-R), the microcomputer 70 detects a beta (β) value from the reproduction RF signal (the beta value is an asymmetry of the reproduction RF signal). (Value representing Asymmetry), and when the beta value detection is completed, fitting a function of the curve by each recording power obtained the detected beta value, and then the curve obtained as described above, the code of the optical disc 10 and The optimal recording power is detected from the target beta value of the EEPROM 71 stored in association with the recording speed in the OPC operation (S24).

In the above case, if the optical disc 10 is a rewritable disc (DVD-RW), instead of the beta value, a modulation degree, which is an index indicating an amplitude size of a reproduction RF signal for the test data, is obtained. The gamma (γ) value is detected from the characteristics of the modulation degree, and the optimum recording power is detected therefrom.

After detecting the optimum recording power, the microcomputer 70 records predetermined null data in the count area of the PCA on the inner circumference side to indicate that one OPC operation has been performed.

As such, when the optimal recording power (PWO _inner ) is detected in the _inner peripheral side PCA of the optical disc 10, if the difference in the detected tilt amount exceeds the reference value, the microcomputer 70 causes the optical disc 10 to be detected. When it is determined that the degree of warp of the deflection is greater than the allowable range, the microcomputer 70 moves the optical pickup 20 to the test area of the PCA set on the outer peripheral side to perform the OPC operation on the outer peripheral side of the optical disk 10 ( S25).

After the optical pickup 20 moves, the microcomputer 70 determines the OPC start position in the test area as described above (S26), and performs the OPC operation again from the determined position (S27). Most high-density discs (DVD-R, DVD-RW, etc.) released so far have a wobble address up to PSN 265000h or higher, and full data recording is possible with PSN 261270h when recording data. Therefore, for the high-density disc, the 6832 sectors from PSN 262000 to 263AB0 are typically set as test areas of the outer PCA.

In this way, the microcomputer 70 detects the optimal recording power (PWO _outer ) from the _outer peripheral PCA of the optical disc 10 (S28), and after the detection of the optimal recording power is predetermined in the count area within the PCA. Null data is recorded to indicate that one OPC operation has been performed.

OPC performance of the outer peripheral PCA is performed only when the optical disk 10 is a DVD-based high-density disk (in the case of a high density disk, the PCA is separately assigned not only to the inner peripheral side but also to the outer peripheral lead-out area). If the optical disc 10 is a CD series in which no PCA is set on the outer circumference, OPC operation may be performed in the lead-out area of the optical disc 10, but in the case of a CD-RW, the overwrite is possible. Therefore, OPC operation can be performed in any area of the lead-out area, and in the case of CD-R, the overwrite is impossible, so that the end where hardly recording is performed in the lead-out area is used as the power measurement area for stability. It is desirable to designate and perform OPC operations.

On the other hand, when the difference in the detected tilt amount does not exceed the reference value and the microcomputer 70 determines that the degree of deflection of the optical disc 10 is within an allowable range, the microcomputer 70 determines the inner circumferential side PCA. After detecting the optimum recording power in the above, the OPC operation in the outer PCA is not performed.

As described above, when the difference between the inner and outer circumference tilt amounts of the optical disc 10 does not exceed a reference value (when the degree of warp of the optical disc 10 is within an allowable range), the microcomputer 70 has an inner circumferential side PCA. Only when the optimum recording power (PWO _inner ) is detected through the OPC operation, and the reference value is exceeded (when the degree of bending of the optical disc 10 is larger than the allowable range), the microcomputer 70 is OPC on both the inner and outer circumferential sides. It detects the optimal recording power (PWO _inner, PWO _outer ) through the operation, and stores the detected optimal recording power in the EEPROM (71) in association with the disk code of the optical disk 10, the above every time the disk is inserted It would be desirable to minimize the hassle and time spent having to perform OPC operations again.

Subsequently, upon recording request (S31, S40), the microcomputer 70 performs a recording operation based on the detected optimal recording power, in which case only the optimum recording power (inner circumferential side) of the optical disc 10 If the PWO _inner ) is detected, the microcomputer 70 records using the detected and stored PWO _inner until the end of the recording operation (S32 and S33).

However, if the optimal recording power (PWO _inner, PWO _outer ) is detected on both the inner and outer circumferences of the optical disc 10 as described above, the microcomputer 70 detects and stores the data until the end of the recording operation. The PWO _{inner and the} PWO _outer are recorded (S41 and S42), wherein the microcomputer 70 records the _inner and middle circumferences of the optical disc 10 using the detected stored PWO _inner as shown in FIG. In the middle of the optical disk 10, the PWO _inner is recorded while changing the recording power stepwise, and when the recording power is changed in stages, data is recorded from the _outer circumference of the optical disk 10 to the PWO _outer . The amount of change is determined and recorded.

On the other hand, in the above embodiment, even if the difference between the inner and outer circumference tilt amount of the optical disk 10 exceeds the reference value, if the wobble address does not exist up to PSN 263AB0 on the optical disk 10, the outer circumference may be caused by a recording failure on the outer circumference side. Since the optimum recording power cannot be detected at the side, in this case, the microcomputer 70 records using the detected stored PWO _inner without changing the recording power.

On the other hand, as described above, the microcomputer 70 performs a tilt compensation operation of adjusting the angle of the optical pickup 20 at the current position based on the detected tilt amounts of the inner and outer circumferences during the recording operation. do.

The above-described preferred embodiments of the present invention are disclosed for purposes of illustration, and those skilled in the art can improve, change, and substitute various other embodiments within the technical spirit and scope of the present invention disclosed in the appended claims below. Or addition may be possible.

In the method of detecting the optimal recording power of the optical disk apparatus according to the present invention, the optical disk having the difference in the amount of internal and external circumference tilted by the reference value is recorded using the optimal recording power detected at the inner and outer peripheral sides of the optical disk, respectively. From the middle note, the optimal recording power detected in the inner circumference is gradually changed, and as a result, the outer peripheral side is recorded with the optimal recording power detected in the outer circumference, so that even if the disc is bent above the reference value, It is a very useful invention in which recording is made and an optimal recording quality can be obtained therefrom.

Claims (6)

A first step of detecting a difference in the amount of tilt detected at the inner and outer circumferences of the inserted optical disc, respectively; Comparing the detected difference value with a preset reference value, and performing an OPC operation on an inner circumference and an outer circumference of the optical disc according to a comparison result to detect an optimum recording power; And And a third step of performing a recording operation by using the detected optimal amount of recording power. The method of claim 1, And said second step is performed when said detected difference value exceeds said reference value. The method of claim 1, The OPC operation of the second step is performed in the power measurement area (PCA) set in the inner and outer circumferences respectively when the optical disk is a DVD-based high density disk. The method of claim 3, wherein The OPC operation of the second step may include: moving an optical pickup to an initial position of a test area of the PCA; Determining whether to record data while moving the optical pickup from the initial position; And And performing the OPC operation from the current position of the optical pickup determined as unrecorded data. The method of claim 1, In the third step, recording is performed using the optimum recording power detected at the inner circumference, and the optimum recording power detected at the inner circumference is recorded in steps of a predetermined size from the middle circumference of the optical disc. An optimal recording power detection method for an optical disc apparatus, characterized by recording using an optimum recording power detected at an outer periphery. The method of claim 1, The second and third steps may further include performing a tilt compensation operation of adjusting the angle of the optical pickup such that the optical axis is perpendicular to the optical disk plane based on the detected tilt amounts in the inner and outer circumferences. An optimal recording power detection method for an optical disk device, characterized in that it comprises a.

Images