KR20090021779A - Method and apparatus of discriminating optical disc and method and apparatus of reproducing optical disc - Google Patents

Abstract

An optical disc discriminating method is provided to prevent the error of the disk discrimination from being generated by calculating an intrinsic slice level revising a reference slice level according to sensitivity of an actuator. An optical disc discriminating method comprises: a step for storing a reference slice level; a step for measuring sensitivity of an actuator; a step(S80) for calculating an intrinsic slice level revising a reference slice level according to the sensitivity of the actuator; and a step for determining an optical disc type according to the intrinsic slice level.

Description

Optical Disc Discrimination Method and Discrimination Device, Optical Disc Playback Method and Reproducing Device {METHOD AND APPARATUS OF DISCRIMINATING OPTICAL DISC AND METHOD AND APPARATUS OF REPRODUCING OPTICAL DISC}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc discrimination method and a discriminating device, and an optical disc reproducing method and a reproducing apparatus, and more particularly, to determine a disc type by discrepancy in sensitivity of an actuator provided in a pickup. An optical disc discrimination method and apparatus for preventing an error from occurring and a method and apparatus for reproducing an optical disc.

In an optical disc reproducing apparatus capable of reproducing various optical discs such as a compact disc (CD) or a digital versatile disc (DVD), in order to reproduce a specific type of optical disc data, the type of disc loaded in the optical disc reproducing apparatus is determined before the data is reproduced. It is necessary to do

Among the methods for determining the type of optical disc, there is a method using the fact that the distance between the recording layer of the optical disc and the distance from the surface of the optical disc differs depending on the type of the optical disc.

This method determines the type of optical disc on the basis of the signal generated on the surface of the optical disc and the recording layer. That is, since the distance between the surface and the recording layer in each optical disc is different, a difference occurs in the time at which a signal generated at each surface of the optical disc and the recording layer arrives, thereby determining the type of the optical disc.

However, this method has a problem in that the criterion for discriminating the optical disk is changed according to the sensitivity of the actuator. That is, since the lens moving speed, which is a variable for measuring the time interval of the signal, depends on the sensitivity of the actuator, a difference occurs in the time interval of the signal measured for the same optical disc for each actuator. Therefore, an error may occur in determining the optical disk according to the sensitivity of the actuator.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to prevent an error due to a sensitivity deviation of an actuator when determining the type of an optical disc in an optical disc reproducing apparatus.

In order to achieve the above object, the optical disc discrimination method according to the present invention comprises the steps of: storing the reference slice level, measuring the sensitivity of the actuator, calculating a unique slice level correcting the reference slice level according to the sensitivity of the actuator And determining the type of optical disc according to the unique slice level.

Measuring the sensitivity of the actuator may include measuring an average sensitivity for the plurality of actuators, measuring an inherent sensitivity for the actuator, and calculating a sensitivity for the actuator based on the average sensitivity.

Measuring average sensitivity and intrinsic sensitivity may include detecting time intervals of surface and write focus error signals for the same reference disk.

The optical disc discrimination method according to the present invention can discriminate two different types of optical discs. In this case, the two different types of optical discs may be two types of optical discs selected from CD, DVD, and BD.

The reference slice level may include a first reference slice level and a second slice level for determining three different types of optical disks, and the unique slice level may include a first unique slice level corresponding to the first reference slice level and a first slice level. And a second unique slice level corresponding to the two reference slice levels. In this case, three different types of optical discs may be CD, DVD, and BD.

On the other hand, the optical disc discrimination apparatus according to the present invention includes a memory for storing the reference slice level, a sensitivity measuring unit for measuring the sensitivity of the actuator, and a control unit for calculating the unique slice level of correcting the reference slice level according to the sensitivity of the actuator.

Meanwhile, the optical disk reproducing method according to the present invention comprises the steps of storing a reference slice level, measuring the sensitivity of the actuator, calculating a unique slice level correcting the reference slice level according to the sensitivity of the actuator, and according to the unique slice level Determining the type of optical disc.

On the other hand, the optical disk reproducing apparatus according to the present invention includes a memory for storing the reference slice level, a sensitivity measuring unit for measuring the sensitivity of the actuator, and a control unit for calculating the unique slice level of correcting the reference slice level according to the sensitivity of the actuator .

An optical disc discrimination method and discrimination apparatus and an optical disc reproducing method and reproducing apparatus according to the present invention have an effect of preventing an error in disc discrimination caused by a sensitivity deviation of an actuator.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

1 is a flowchart showing an optical disc discriminating method according to a first embodiment of the present invention. In the method for discriminating an optical disk according to the present embodiment, a method for discriminating two types of optical disks will be described. At this time, CD and DVD will be described as two types of optical disks. However, the present invention is not limited thereto, and the present invention is applicable to various types of optical discs in addition to CDs and DVDs.

In the following description, the use of a DVD laser diode used for recording or reproducing DVD for disc determination is described, but the present invention is not limited thereto.

In the method for discriminating an optical disk according to the present embodiment, a unique slice level for determining the type of an optical disk using a specific reference disk, for example, a specific DVD, that is, a slice level in consideration of the sensitivity of an actuator is set and inserted using the same. Determine the type of disk. This will be described in detail below.

First, when a specific disk is inserted (S10), it is determined whether the inserted disk is a reference disk (S20). In this case, it is assumed that the reference disk is a DVD having a total thickness of 1.2 mm and a distance between the recording layer and the beam incident surface, that is, the surface of the disk is 0.6 mm.

When the inserted disc is a reference disc, a signal for determining the type of optical disc is detected from the recording layer and the surface of the disc. In the present embodiment, such a signal uses a focus error signal for focusing control. Specifically, when the inserted disc is the reference disc, the focus error signal reflected from the surface of the disc and the recording layer is detected through the focus up / down (S30).

Next, the time interval between the focus error signal detected on the surface and the focus error signal detected on the recording layer is measured (S40).

2A is a schematic cross-sectional view for explaining the case where the inserted disc is the DVD 100, and FIG. 2B is a graph illustrating a focus error signal detected by the DVD 100. As shown in FIG. Referring to FIG. 2A, the thickness of the DVD 100 is 1.2 mm, the distance between the recording layer 14 and the surface 12 is 0.6 mm, and the recording layer 14 is located in the middle of the entire disk thickness.

Accordingly, when focusing the lens holder 10, the time interval between the signal S-curve1 reflected from the surface 12 and the signal S-curve2 reflected from the recording layer 14 becomes T1. In other words, T1 is the moving speed of the distance (0.6 mm) / lens 16.

At this time, the moving speed of the lens 16 is changed according to the sensitivity of the actuator. That is, when the sensitivity of the actuator is sensitive, the moving speed of the lens 16 is high, and when the sensitivity of the actuator is insensitive, the moving speed of the lens 16 is low. Therefore, the time interval of the focus error signal is smaller as the sensitivity of the actuator is sensitive.

Next, the time interval of the previously stored average focus error signal is read (S50). In this case, the time interval of the average focus error signal means an average of values measured using the same reference disk for a plurality of actuators.

Next, a correction coefficient α for detecting the intrinsic slice level S1 for the actuator is detected (S60). For example, when the average focus error signal interval previously measured and stored is 20 ms, and the focus error signal interval for the actuator measured above is 18 ms, the correction coefficient α for detecting the intrinsic slice level S1 is 18 ms. /20=0.9

Next, the stored reference slice level S is read in advance (S70). In this case, the reference slice level S may be set by measuring the focus error signal intervals for the reference CD and DVD with a plurality of actuators and calculating an average of the average values of the focus error signal intervals for the measured CD and DVD, respectively. Can be.

For example, if the average of the focus error signal intervals measured using a plurality of actuators for a particular CD is 40 ms and the average of the focus error signal intervals measured by the plurality of actuators for a specific DVD is 20 ms, the reference slice The level S is 30 ms which is an average of these.

Next, a unique slice level S1 is calculated from the correction coefficient α and the reference slice level S (S80) and stored (S90). For example, assuming that the correction coefficient α is 0.9 and the reference slice level S is 30 ms as described above, the intrinsic slice level S1 is a product of the correction coefficient α and the reference slice level S. Can be represented. In other words, the unique slice level S1 is 27 ms.

This case corresponds to a case where the sensitivity of the actuator is more sensitive than the average, so that the value of the intrinsic slice level S1 becomes small. On the other hand, as described above, the inserted reference disc is determined as a DVD (S100).

Next, when the inserted disc is not the reference disc, the type of the inserted disc is determined using the unique slice level S1 set and stored using the reference disc.

First, a focus error signal is detected through focus up / down (S110) with respect to the inserted disc. Next, the focus error signal interval T2 for the inserted disc is measured (S120).

Hereinafter, the case where the inserted disc is a CD will be described as an example. 3A is a schematic cross-sectional view for explaining the discrimination of a CD, and FIG. 3B is a graph illustrating a focus error signal detected in the CD.

As shown, the CD 200 has a distance of 1.2 mm between the surface 18 and the recording layer 20, with the recording layer 20 on the opposite side of the disk surface 18. As shown in FIG. Accordingly, when the lens holder 10 focuses, the Scurve1 signal reflected from the disk surface 18 and the S-curve2 signal reflected from the recording layer 20 of the disk take T2 time. That is, the time T2 is the moving speed of the distance (1.2 mm) / lens 16.

At this time, the distance between the surface 18 of the CD 200 and the recording layer 20 is twice the distance between the surface of the DVD and the recording layer. Therefore, when the inserted disc is the CD 200, the measured focus error signal interval is approximately twice that of the DVD.

Next, the measured and stored unique slice level S1 is read (S130), and the measured focus error signal interval T2 is compared with the unique slice level S1 (S140).

In this case, when the measured focus error signal interval is larger than the intrinsic slice level S1, the inserted disc is determined as the CD 200 (S150). On the other hand, if the measured focus error signal interval is smaller than the intrinsic slice level S1, the inserted disc is discriminated by the DVD 100 (S100).

At this time, since the intrinsic slice level S1 reflects the sensitivity deviation of the actuator, the disc type is prevented from being misidentified by the sensitivity deviation of the actuator.

Although CDs and DVDs are exemplified above as the types of discs determined in the present embodiment, the present invention is not limited thereto, and various types of optical discs can be determined by the method of determining an optical disc according to the present invention. Do.

Hereinafter, a method of discriminating an optical disc according to a second embodiment of the present invention will be described in detail. The discriminating method according to this embodiment discriminates three types of optical disks.

4 is a flowchart showing a method of discriminating an optical disc according to a second embodiment of the present invention. In the method for discriminating an optical disc according to the present embodiment, a method for discriminating three types of optical discs will be described. Hereinafter, CD, DVD and BD will be described as three types of optical disks. However, the present invention is not limited thereto, and the present invention can also be applied to various other optical discs.

In the following, the use of a DVD laser diode used for recording or reproducing DVD is described, but the present invention is not limited thereto.

First, it is determined whether or not the reference disk is inserted, and the unique slice levels SA and SB are set when the reference disk is inserted, and the type of the disk is determined when the reference disk is not.

When the inserted disc is a reference disc, a signal for determining the type of optical disc is detected from the recording layer and the surface of the disc. In this embodiment, this signal uses a focus error signal for focusing control.

Specifically, when the disc is inserted (S200), and it is determined whether the inserted disc is the reference disc (S210), and if it is determined that the reference disc, the focus on the surface and the recording layer of the disc through the focus up / down (S220) Detect the reflected focus error signal.

Next, the time interval T1 between the focus error signal detected on the surface and the focus error signal detected on the recording layer is measured (S230).

Next, the time interval of the previously stored average focus error signal is read (S240). The time interval of the average focus error signal can be obtained from the values measured using the same reference disk for the plurality of actuators.

Next, a correction coefficient α for detecting the intrinsic slice level S1 for the actuator is detected (S250). For example, when the average focus error signal interval previously measured and stored is 20 ms, and the focus error signal interval for the actuator measured above is 18 ms, the correction coefficient α for detecting the intrinsic slice level S1 is 18 ms. /20=0.9

Next, the stored reference slice levels SA and SB are read in advance (S260). At this time, in the present embodiment, two reference slice levels SA and SB are stored to discriminate three types of optical discs, and thus two unique slice levels SA1 and SB1 are set.

In this case, the reference slice levels SA and SB measure the focus error signal intervals for the reference CD, DVD, and BD with a plurality of actuators, respectively, and the average value of each of the measured focus error signal intervals for the CD, DVD, and BD. It can be set by obtaining the average of.

For example, the average of the focus error signal intervals measured by multiple actuators for a CD is 40 ms, the average of the focus error signal intervals measured by multiple actuators for a DVD is 20 ms, and measured by multiple actuators for a BD. Assume that the average of the focused focus error signal intervals is 3.3 ms.

At this time, the first reference slice level SA for distinguishing the CD from the DVD is 30 ms. The second reference slice level SB for distinguishing between BD and DVD is 11.65 ms.

Next, the unique slice levels SA1 and SB2 are calculated from the correction coefficient α and the reference slice levels SA and SB (S280) and stored.

In this case, as illustrated above, when the correction coefficient α is 0.9, the first intrinsic slice level SA1 that distinguishes the CD and the DVD from the first reference slice level SA is 27 ms. Further, the second unique slice level SB1 that distinguishes BD and DVD from the second reference slice level SB is 10.485 ms.

At this time, as is assumed, the reference disc is determined to be a DVD (S290).

Next, when the inserted disc is not the reference disc, the type of the inserted disc is determined using the stored unique slice levels SA1 and SB1.

First, a focus error signal is detected through the focus up / down on the inserted disc. Next, the focus error signal interval for the inserted disc is measured (S310).

Hereinafter, the case where the inserted disc is a BD (Blue-ray Disc) will be described as an example. 5A is a schematic cross-sectional view for explaining the discrimination of a BD disc, and FIG. 5B is a graph illustrating a focus error signal detected in a BD disc.

As shown, the BD 300 has a distance of 0.1 mm between the surface and the recording layer, so that the recording layer 28 is located near the disk surface 26. Accordingly, when the lens holder 10 focuses, the Scurve1 signal reflected from the disk surface 26 and the S-curve2 signal reflected from the recording layer 28 of the disk take T3 time. That is, time T3 becomes the moving speed of the distance (1.2 mm) / lens 16.

Therefore, the time interval of the focus error signal is measured long in the order of CD, DVD, BD.

Next, the measured and stored unique slice levels SA1 and SB1 are read (S320), and the measured focus error signal interval T3 is compared with the unique slice levels SA1 and SB1.

First, when the measured focus error signal interval T3 is compared with the first eigen slice level SA1 (S330) and the measured focus error signal interval T3 is larger than the first eigen slice level SA1, an inserted disc Is determined as a CD (S340).

In addition, the measured focus error signal interval T3 is compared with the second inherent slice level SB1 (S350), and the measured focus error signal interval T3 is smaller than the second inherent slice level SA1, and the second inherent slice level SA1 is determined. If the slice level is larger than the SB1, the inserted disc is determined by the DVD 100 (S360).

In addition, when the measured focus error signal interval is smaller than the second inherent slice level SB1, the inserted disc is determined as a BD (S370).

As described above, the optical disc discrimination method according to the present embodiment can prevent the error of the discrimination caused by the sensitivity deviation of the actuator with respect to the three types of optical discs.

6 is a block diagram of an optical disc reproducing apparatus according to an embodiment of the present invention. The optical disc reproducing apparatus according to the present embodiment is equipped with laser diodes of various wavelengths and is configured to enable reproduction of various optical discs.

Referring to FIG. 6, an optical disc reproducing apparatus according to an exemplary embodiment of the present invention includes an optical pickup 30, an R / F unit 32, a sled motor 34, a spindle motor 36, a driver 38, and a servo. The unit 40 includes a digital signal processor 42, a microcomputer 44, a memory 46, and a phase encoder 48.

The optical pickup 30 reads recording data on the optical disc 400. The R / F unit 32 filters the signals detected by the optical pickup 30 and outputs them as binary signals.

The sled motor 34 is responsible for horizontal movement of the optical pickup 30, and the spindle motor 36 rotates the optical disc 400. The driver 38 drives the sled motor 34 and the spindle motor 36. The servo unit 40 controls the driving of the driver 38 from the tracking error and focus error signals of the optical pickup 30 and the rotational speed of the optical disc 400.

The digital signal processor 42 restores the binary signal to the original data with its own clock phase-locked to the binary signal from the R / F unit 32.

The microcomputer 44 continuously counts pulse signals generated and output from the digital signal processor 42, and variably controls the rotational speed of the optical disk therefrom.

In addition, when the disc is inserted, the microcomputer 44 determines whether the reference disc is a reference disc, and when the disc is determined as the reference disc, the focus error signal detected by the optical pickup 30 and the average focus error signal interval stored in the memory 46. From this, the correction value for setting the unique slice level S1 is calculated. In addition, the intrinsic slice level S1 is calculated from the calculated correction value and the reference slice level S stored in the memory 46, and is transmitted to and stored in the memory 46.

In addition, when the inserted optical disc 400 is not the reference disc, the microcomputer 44 compares the focus error signal detected by the optical pickup 30 with the inherent slice level S1 stored in the memory 46 and the optical disc 400. Type).

The memory 46 stores the above-mentioned reference slice level S and the average focus error signal interval for the reference disk and provides it to the microcomputer 44 when the optical disk is discriminated. In addition, the memory 46 stores the unique slice level S1 calculated by the microcomputer 44 and provides it to the microcomputer 44 in determining the optical disk.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings, and the present invention is also provided. Naturally, it belongs to the range of.

1 is a flowchart showing an optical disc discriminating method according to a first embodiment of the present invention.

2A is a schematic cross-sectional view for explaining the discrimination of a DVD disk.

2B is a graph illustrating a focus error signal detected on a DVD disc.

3A is a schematic cross-sectional view for explaining the discrimination of a CD disk.

3B is a graph illustrating a focus error signal detected on a CD disc.

4 is a flowchart showing a method of discriminating an optical disc according to a second embodiment of the present invention.

5A is a schematic cross-sectional view for explaining the discrimination of a BD disc.

5B is a graph illustrating a focus error signal detected in a BD disc.

6 is a schematic diagram showing an optical disk reproducing apparatus according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

30: Optical pickup 32: R / F part

34: sled motor 36: spindle motor

38: driver 40: servo

42: digital signal processor 44: microcomputer

46: memory 48: phase encoder

Claims (14)

Storing a reference slice level; Measuring the sensitivity of the actuator; Calculating an inherent slice level by correcting the reference slice level according to the sensitivity of the actuator; And Determining an optical disc type according to the unique slice level Optical disc determination method comprising a. According to claim 1, Measuring the sensitivity of the actuator, Measuring an average sensitivity for the plurality of actuators; Measuring the intrinsic sensitivity to the actuator; And Calculating a sensitivity for the actuator based on the average sensitivity Optical disc determination method comprising a. The method of claim 2, The measuring of the average sensitivity and the intrinsic sensitivity comprises detecting time intervals of surface and recording focus error signals for the same reference disk. According to claim 1, An optical disc discrimination method for discriminating two different types of optical discs. The method of claim 4, wherein And said two different types of optical discs are two types of optical discs selected from CD, DVD and BD. According to claim 1, The reference slice level includes a first reference slice level and a second slice level for determining three different types of optical disks, And the unique slice level comprises a first unique slice level corresponding to the first reference slice level and a second unique slice level corresponding to the second reference slice level. The method of claim 6, And said three different types of optical discs are CD, DVD and BD. A memory for storing a reference slice level; A sensitivity measuring unit for measuring the sensitivity of the actuator; And A controller for calculating an inherent slice level by correcting the reference slice level according to the sensitivity of the actuator Optical disc determination device comprising a. The method of claim 8, An optical disc discrimination apparatus for discriminating two different types of optical discs. The method of claim 9, And said two different types of optical discs are two types of optical discs selected from CD, DVD and BD. The method of claim 8, The reference slice level includes a first reference slice level and a second slice level for determining three different types of optical disks, And the unique slice level includes a first unique slice level corresponding to the first reference slice level and a second unique slice level corresponding to the second reference slice level. The method of claim 11, wherein And said three different types of optical discs are CD, DVD and BD. Storing a reference slice level; Measuring the sensitivity of the actuator; Calculating an inherent slice level by correcting the reference slice level according to the sensitivity of the actuator; And Determining an optical disc type according to the unique slice level Optical disc playback method comprising a. A memory for storing a reference slice level; A sensitivity measuring unit for measuring the sensitivity of the actuator; And A controller for calculating an inherent slice level by correcting the reference slice level according to the sensitivity of the actuator Optical disc playback device comprising a.

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