KR100510508B1 - Variable reseek offset setting method for optical disk - Google Patents

Abstract

The present invention relates to a variable setting method for an optical recording apparatus, wherein the setting method comprises: (a) when an error occurs during reproduction of the optical recording apparatus, based on a value corresponding to the current position of the optical recording apparatus during reproduction; Setting a value; And (b) performing in response to the offset value set in step (a).

Description

Variable reseek offset setting method for optical disks

The present invention relates to a reproduction method of an optical recording apparatus, and more particularly, to an offset setting method for rescanning of an optical recording apparatus.

1 is a view showing the structure of a typical CD (Compact Disc; 1). Referring to FIG. 1, the CD 1 has a front surface with letters or pictures and a shiny back side, the back side of which is covered with an aluminum film inside the surface of synthetic resin. It is engraved with a myriad of pit (small grooves) 10 along a track pitch of 1.6 micrometers. The CD 1 converts the analog voice into digital signals 0 and 1, and is engraved on the aluminum plate. The CD 1 records various voices using the presence or absence of the pit or the short and long. The total number of feet spirally connected on the back of the CD is approximately 6 billion.

2 is a view showing the structure of a general CD player 100, Figure 3 is a view showing the detailed structure of the optical pickup device shown in FIG. 2 and 3, the CD player 100 is stored in the CD (1) by converting the light reflected by the laser light on the disk in the optical pickup 150 when the CD (1) is played back into an electrical signal The data will be played back. Operation performed in the optical pickup 150 is as follows.

First, the light beam of the laser beam emitted from the semiconductor laser 140 is controlled by a collimator lens 162 to be parallel rays. The laser beam is then focused on the signal recording surface of the disk by the objective lens 170. Since the signal recording surface is made of an aluminum reflecting film as shown in Fig. 1, the emitted light causes a difference in light intensity at the concave portion with the pit and the other convex portion. In this way, the projection light and the reflected light are separated by the quarter wave plate and the beam splitter 164 and then hit the photodetector 180. The photodetector 180 converts the emitted light into electricity, and the output is changed by the intensity of the light. That is, the output changes depending on whether there is a pit.

In order to perform this optical pickup operation correctly, the laser beam must always be correctly focused on the disk signal recording surface, and the pickup must always be kept in the correct position so that the focus does not deviate from the pit rows. For this purpose, the CD player 100 uses the traversing motor 190 for tracking to focus the laser beam and maintain the correct position. With this structure, the CD player 100 can move the laser light in any pit row at a moment and focus light according to the instruction so that fast selection can be performed. do.

4 is a flowchart illustrating a rescan offset setting method of an optical recording apparatus according to the prior art, and FIG. 5 is a diagram illustrating a rescan offset value according to the prior art. First, referring to FIG. 4, in the offset setting method according to the related art, buffering / decoding of data stored in an optical recording apparatus is performed through an optical reproducing apparatus such as a CD player (step 101). Subsequently, it is determined whether a buffering / decoding error has occurred during the buffering / decoding of data stored in the optical recording device (step 102).

As a result of the determination in step 102, if a buffering / decoding error occurs, the n value indicating the number of retries for rescanning is set to 1 (step 103), and then the rescan offset value is set to nk (104). step). Here, n is the number of reruns, k is a rescan offset value, and the offset value has a constant value as shown in FIG. 5. Then, it is determined whether or not the difference between the error occurrence point (nk) and the pickup position coincides with the number of one track block at the current position (step 105).

As a result of the discrimination in step 105, when the difference between (error occurrence point-nk) and the pickup position matches the number of track blocks at the current position, the track is jumped according to the set offset value and rescanning is performed (106). step). As a result of the determination in step 105, if the difference between the target search position and the pickup position does not match the number of blocks of one track at the current position, after increasing the value of n by 1 (step 107), the process returns to step 104. Go back and set the rescan offset value again, and repeat step 105. The rescan offset value is updated or rescanned according to the determination result in step 105. The change of the rescan offset value is repeatedly performed until the difference between the target search position and the pickup position coincides with the number of blocks of one track at the current position.

As described above, when an error occurs in the buffering / decoding operation of a CD or DVD disc, a general CD or DVD disc player always applies a constant offset to resume seek as shown in FIG. 5. Will be performed. However, the offset value shown in FIG. 5 does not take into account the characteristics of a disc having a CD or DVD disc having a different number of blocks for each track. When the offset is applied to the rescan, the same error occurs at the same position. Is likely to be. In addition, since the offset value is set based on the inner circumference of the CD or DVD disc, there is a problem that it takes a long time to rescan as the outer circumference of the CD or DVD disc, and the problem that several retry attempts are repeated have.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a method for efficiently rescanning with a small number of retries by setting different offset values for rescanning of an optical recording device such as a CD or a DVD for each region. .

Another object of the present invention is to provide a computer-readable recording medium having recorded thereon a program for executing the method on a computer.

In order to achieve the above object, in the variable offset setting method according to the present invention, (a) when an error occurs during reproduction of the optical recording apparatus, rescanning is performed based on an offset value corresponding to the current position of the optical recording apparatus during reproduction. Setting an offset value; And (b) rescanning in response to the rescan offset value set in step (a).

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

6 is a diagram showing the types of optical recording devices such as CDs, and their features and functions. Referring to FIG. 6, the optical recording apparatus may be classified into a laser disc (LD), a compact disc video (CDV), a mini disc (MD), and the like in addition to a compact disc (CD). They have different sizes and functions, as shown in FIG. 6, and are characterized by different blocks per track.

Conventionally, despite the structural characteristics of the optical recording device, when an error occurs during reproduction of the optical recording device, the same offset value has been applied. However, in the present invention, the structure of the optical recording device having a different number of blocks for each track is used. Considering the feature, the offset value for rescan is variably set.

7 is a flowchart illustrating a variable offset setting method for rescanning of the optical recording apparatus according to an exemplary embodiment of the present invention. Referring to FIG. 7, in the offset setting method according to the present invention, first, buffering / decoding of data stored in an optical recording apparatus is performed through an optical reproducing apparatus such as a CD player (step 1100). Subsequently, it is determined whether a buffering / decoding error has occurred during the buffering / decoding of data stored in the optical recording device (step 1200).

As a result of the determination in step 1200, when a buffering / decoding error occurs, the buffering / decoding operation is stopped due to the error, and an n value indicating the number of re-executions for rescanning is set to 1 (step 1300). Then, a rescan offset value is set based on the offset value for each region corresponding to the current position of the CD. The rescan offset value set at this time becomes an offset value xn for each region (step 1400). Here, n represents the number of reruns for rescan.

On the other hand, when a buffering / decoding error occurs, the optical pickup flows from the position where the buffering / decoding is stopped to the outer circumferential direction, where the difference between the pick-up position and the desired target search position is one track block at the current position. Is determined in step 1500.

As a result of the determination in step 1500, when the difference between the target search position and the pickup position matches the number of blocks of one track at the current position, the track is jumped according to the set offset value and then rescanned (step 1600). . If the difference between the target search position and the pickup position does not coincide with the number of blocks of one track at the current position as a result of the determination in step 1500, after increasing the value of n by 1 (step 1700), the process returns to step 1400. Go back and set the rescan offset again, and run step 1500 again. The rescan offset value is updated or rescanned according to the determination result in step 1500. The change of the rescan offset value is repeatedly performed until the difference between the target search position and the pickup position coincides with the number of blocks of one track at the current position. However, according to the offset setting method according to the present invention, since the offset value is set differently according to the area of the CD, the number of repetitions thereof is significantly reduced compared to the method shown in FIG.

8 is a view showing an offset value for rescan according to a preferred embodiment of the present invention. Referring to FIG. 8, the variable offset setting method according to the present invention sets different offset values for respective regions of the optical recording apparatus.

8, a, b,... , e is an offset value preset for each region, and the offset value is proportional to the number of blocks per track. Therefore, the number of blocks per track is equal to the first area <second area <. <Offset values a, b,... , e is a <b <. <e has a relationship. At this time, the offset value set for each area is as follows.

For example, when the offset value of the first region is a, the rescan offset value is a × n. When the offset value of the second area is b, the rescan offset value is b × n (see step 1400 of FIG. 7). Here, n represents the number of retries, and the rescan offset value increases in proportion to the number of retries until the difference between the target search position and the pickup position matches the number of blocks of one track at the current position.

At this time, if the size of the offset value is made too large, the track jump may be performed too much. Therefore, the size of the offset value is adjusted within an appropriate range. In consideration of the setting of the offset value, the speed of the disk and the isotropic speed method of rotating the motor slowly when the head of the optical reproducing apparatus reads the outside of the CD and rapidly when reading the inside (CLV: Constant Linear) Velocity) or a constant angular velocity (CAV) that rotates at a constant rotational speed, such as a hard disk, and the time taken to adjust and rescan the offset after an error occurs. have.

In the above, as an embodiment of the present invention has been specifically described for the offset setting method when re-scanning the CD or DVD, the present invention can also be applied to various optical recording devices that store data in a digital form. .

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

As described above, according to the variable offset setting method according to the present invention, an offset value for rescanning of a CD or DVD disc is set differently for each region to match the physical characteristics of the disc. Therefore, rescanning is performed with a small number of retries, so that smooth data transmission can be performed.

1 is a view showing the structure of a typical compact disc (CD).

2 shows the structure of a typical CD player.

FIG. 3 is a diagram illustrating a detailed structure of the optical pickup device shown in FIG. 2.

4 is a flowchart illustrating a rescan offset setting method of an optical recording apparatus according to the related art.

5 is a diagram illustrating a rescan offset value according to the prior art.

6 is a diagram showing the types of optical recording devices such as CDs, and their features and functions.

7 is a flowchart illustrating a variable offset setting method for rescanning of the optical recording apparatus according to an exemplary embodiment of the present invention.

8 is a view showing an offset value for rescan according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: CD player 140: semiconductor laser

150: optical pickup 170: objective lens

180: light detector 190: traverse motor

Claims (4)

Setting an offset value for each position of the optical recording apparatus based on the number of blocks per track of the optical recording apparatus; Setting a rescan offset value based on an offset value corresponding to the current position of the optical recording device during reproduction when an error occurs during reproduction of the optical recording device; And And rescanning in response to the set rescan offset value. The method of claim 1, And the rescan offset value is equal to the product of the offset value corresponding to the current position of the optical recording device and the number of retries for the rescan. The method of claim 1, And the rescan offset value is proportional to the number of blocks per track of the optical recording device. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 1 to 3.