KR20000074560A - Method For Controlling Seek On Optical Disc - Google Patents

Abstract

PURPOSE: A method of controlling search of an optical disk is provided to convert time information in a lead-in area to be continuous with the time information in a data area, thereby rapidly performing data searching process. CONSTITUTION: A method of controlling search of an optical disk comprises the steps of: extracting time information on an optical disk and converting the time information in a lead-in area to be continuous with the time information in a data area; calculating a frame number on an optional track placed at the most inner side of the optical disk; detecting the time information corresponding to every jump starting position and every jump ending position when searching data; jumping to an outer side of the optical disk in a desired track number unit to enter into the data area if the jump ending position is placed in the lead-in area; backing up the time information corresponding to a last jumping position in the lead-in area; and calculating an initial track number in the data area between a starting portion of the data area adjacent to the lead-in area and an entering position of the data area.

Description

Method for Controlling Seek On Optical Disc

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data searching method of an optical disc, and more particularly, to a method of searching an optical disc for searching data with continuous time information in a lead-in area and a data area.

In general, an optical disc such as a CD (Compact Disc) and a DVD (Digital Versatile Disc) is irradiated with a laser beam on a recording surface so that information is recorded or reproduced. Such optical discs are classified into read-only and rewritable media. In the former case, there are ROM types such as CD-ROM and DVD-ROM. In the latter case, the write once read many (WORM) type, the rewritable type, and the RAM are based on the number of rewritable times. It is divided into types.

In an optical disc, in order to record or reproduce data, the objective lens must be moved to a target point by a data search process.

An optical disk driver is a means for moving an objective lens, which includes a tracking actuator for moving a bobbin on which an objective lens is mounted, an optical pickup provided with an objective lens and a tracking actuator, and an optical pickup for moving an optical pickup. Sled motor is provided.

Data search is performed in the order of Rough Search Mode, Fine Search Mode, and 1 Track Jump. In rough search mode, the sled motor is driven in the moving range beyond the moving range of the tracking actuator, and the optical pickup is moved to the starting point of the fine search by monitoring the tracking traverse signal detected as the track is traversed. do. In the fine search mode, the starting point is determined by the rough search mode, and the tracking actuator is driven to move the objective lens to the final target point. When the objective lens approaches the target point by the fine search mode, the objective lens jumps by one track from the current point to the target point by the tracking actuator to find the target point.

However, in rough search mode, the jump is performed using the sled motor, so the accuracy cannot be greater than that of the sled motor. The resolution of a sled motor ranges from as little as 64 tracks to as many as 80 tracks per sled clock. In rough search mode, a search error may occur by adding up to one sled clock that can occur at departure and up to one sled clock that can occur upon arrival. This means that a search error of up to 160 tracks may occur when searching for data based on 0 minutes: 0 seconds: 0 frames MSF0 in the time information recorded on the optical disc.

Referring to FIG. 1, the optical disc includes a lead-in area 1 located at the innermost circumference, a lead-out area 3 located at the outermost circumference, and a lead-in area 1 located at the outermost circumference. And a data area 2 located between the lead-out area 3 and the lead-out area 3. In the lead-in area 1, disc specification information and disc content information are recorded. In the data area 2, audio / video data and the like are recorded. The data search is mainly performed in the above-described rough search mode, fine search mode and one track by the sled servo or the tracking servo to move to the target point on the data area 2 when recording or reproducing data in the data area 2. Jump is done in order. In the lead-in area 1 and the data area 2, time information indicating a moving distance during data search is recorded in minutes: seconds: frames (MSF). Here, the frame usually represents 1/75 seconds.

By the way, the time information recorded in the lead-in area 1 and the data area 2 is recorded so as not to be continuous with each other as shown in FIG. Referring to Fig. 2, 0 minutes: 0 seconds: 0 frames MSF0 are recorded in the track closest to the lead-in area 1 in the data area 2, and increase toward the outer circumference side. In the lead-in area 1, time information is recorded differently for each optical disc. Normally, the time information recorded in the lead-in area 1 becomes discontinuous with the time information recorded in the data area 2. In other words, in the lead-in area 1, the start time and the end time change continuously, but the end time is not continuous with the start time of the data area 2, and the amount of discontinuity varies for each optical disk.

As described above, the discontinuous time information of the lead-in area 1 and the data area 2 is mainly recorded or reproduced in the data area 2, and the lead-in area 1 and the data area 2 Is based on distinguishing them.

As described above, since the search error of up to 160 tracks may occur in the rough search mode, when the data search is performed from the outer circumference side to the inner circumference side of the optical disc to perform a target search on the data area, Up to 160 tracks can be entered into the lead-in area 1 from the target point.

In the conventional data search method, when the objective lens enters the lead-in area 1 during the data search in the rough search mode, the objective lens is jumped to the data area 2, and then time information read from the data area 2 is read. By moving the objective lens to the target point. Accordingly, when entering the lead-in area during data search, the search time is long because it takes time to come out of the data area 2 and to find a target point at the arrival point on the data area 2. In addition, if the target point is adjacent to the lead-in area 1, the probability that the objective lens enters the lead-in area is increased, so that the process of returning to the data area 2 and the process of finding the target point are repeated so that the search time is increased. This takes an excessive amount. In addition, according to the conventional data search method, as described above, the search on the inner circumferential side of the optical disc becomes unstable, so that the servo for data search becomes unstable on the inner circumferential side.

Accordingly, an object of the present invention is to provide a search control method for an optical disc, which performs data searching using continuous time information even when the lead-in area is invaded during data search.

1 is a diagram showing a general data area structure of an optical disc.

FIG. 2 is a diagram showing discontinuity of time information recorded in each of the data area and lead-in area shown in FIG. 1; FIG.

3 is a block diagram schematically showing an apparatus for controlling search of an optical disc according to an embodiment of the present invention;

4 is a flowchart showing step by step a control procedure of a search control method for an optical disc according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating the number of tracks and time information calculated in the search control method of FIG. 4. FIG.

FIG. 6 is a diagram illustrating conversion of time information in a lead-in area in the search control method of FIG. 4. FIG.

FIG. 7 is a flowchart illustrating a control procedure of a data search control method in a case where the time information in the lead-in area is converted in the search control method of FIG. 4 and then re-enter the lead-in area in the data search. FIG.

<Description of Symbols for Main Parts of Drawings>

1: lead-in area 2: data area

3: lead-out area 11: mechanical part

12: search execution unit 13: time information processing unit

14: data extraction and decoding unit 15: time information extraction unit

In order to achieve the above object, the search control method for an optical disc according to the present invention includes extracting time information on the optical disc and converting time information of the lead-in area into time information of the data area to search for data.

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

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 7.

Referring to FIG. 3, the search execution unit 12 and the time information processing unit 14 connected in series with the input terminal of the mechanism unit 11, the data extraction and decoding unit 14 connected to the output terminal of the mechanism unit 11, The search control apparatus for an optical disc according to the present invention includes a time information extracting unit 15 connected in common to the search executing unit 12 and the time information processing unit 13, and connected to the data extracting and decoding unit 14. Is shown. The mechanism part 11 includes an optical pickup in which the objective lens is operably installed, a tracking actuator for driving the objective lens, and a sled motor and a sled gear for moving the entire optical pickup in the radial direction of the optical disc. The mechanism unit 11 drives the sled motor in the rough search mode by the drive signal supplied from the search execution unit 12 to move the entire optical pickup in the radial direction of the optical disc, and drives the tracking actuator in the fine search mode. To move the objective lens. The data extraction and decoding section 14 decodes the data supplied from the optical pickup of the mechanism section 11 and supplies it to the time information extraction section 15. Then, the time information extracting unit 15 determines the area currently accessed based on the track number information TNO included in the data from the data extracting and decoding unit 14. The time information extracting unit 15 extracts the time information MSF from the data supplied from the data extracting and decoding unit 14 and determines that the currently accessed area is the data region 2. Will be supplied. On the contrary, if it is determined that the currently accessed area is the lead-in area 1, the time information extracting unit 15 extracts time information MSF from the data supplied from the data extracting and decoding unit 14 to extract the time information MSF. 13). The time information processor 13 may be configured to detect the time information detected by the data area 2 even when the optical pickup or the objective lens enters the lead-in area 1 while the optical pickup or the objective lens jumps to the target point during data search. The time information of the lead line region 1 is converted into continuous time information in the time information of the data region 2 so that the data search can be continued with the continuous time information. The search execution unit 12 is a sled motor or tracking so that the objective lens or the optical pickup can be moved to a target point of data search based on the time information supplied from the time information extraction unit 15 or the time information processing unit 13. It will drive the actuator.

4 is a flowchart showing step by step a control procedure of a search control method for an optical disc according to an embodiment of the present invention.

First, the number of frames f on any one track is calculated in the innermost circumference on the data area 2 of the optical disc, i.e., in the data area corresponding to time information of 0 minutes. The frame number f can be calculated as a function of speed (seconds / distance), time information (MSF) and track pitch (1.6 μm in the case of CD). (Step S1) from a microcomputer (not shown) When a search command is issued, data search is started in the rough search mode in the innermost or other data area on the data area 2. (Step S2) In this case, the data search is performed to calculate the movement amount to the target point. The time information is detected at the search start position on the data area 2, and the time information is detected at the jump end position after the jump. (Step S3) The object is determined by the number of tracks TNO included in the detected time information. When the stop position is determined to be the lead-in area 1 after the movement of the lens (step S4), that is, when the objective lens enters the lead-in area 1, the objective lens is jumped toward the outer circumference by N tracks. Here, since the number f of frames present in each of the tracks on the inner circumferential side of the optical disc is about the same, the N tracks are the number of frames f × N frames. At each jump, time information is detected at the jump start position and the jump end position to determine the current position. The time information LMSF detected at the last jump start position in the lead-in area 1 is stored in memory (not shown). N track jump is performed after the data is backed up. (2) It is determined whether it is included in (S7 step).

In step S7, when the current position after the jump is determined as the data area 2, the time information of the lead-in area 1 using the time information LMSF of the last jump start position in the back-up lead-in area 1 is used. Is converted into time information continuous to the time information of the data area 2. This will be described in detail with reference to FIGS. 5 and 6.

When the N track jumps from the lead-in area 1 to the data area 2, as shown in FIG. 5, a 0 minute: 0 second: 0 frame MSF0 corresponding to the start point of the data area 2 is passed. The time information processing unit 13 calculates the number of tracks n between the last jump start positions in the lead-in area 1 at a point corresponding to 0 minutes: 0 seconds: 0 frames MSF0. Here, the track number n may be calculated as a function of speed (seconds / distance), time information (MSF), and track pitch. That is, since the track number n knows the time information corresponding to the last jump start position in the lead-in area 1, and knows the time information corresponding to the current position in the data area 2, It can be calculated considering the difference, speed and track pitch. The number of tracks m between the last jump start position of the lead-in area 1 and the start position of the data area 2 is obtained by subtracting the track number n calculated above from the jump stroke, that is, N tracks. The time information processor 13 converts the number of tracks m between the last jump start position of the lead-in area 1 and the start position of the data area 2 into time. When the time thus calculated is added to the time information LMSF corresponding to the last jump start position in the lead-in area 1, the updated last time information ULMSF is obtained. The time information processing unit 13 maps the updated last time information ULMSF to 99 minutes: 59 seconds: 74 frames to coordinate transformation and stores the conversion amount dMSF at the time of coordinate transformation in a memory (S8). And step S9). Thus, the time corresponding to the start position of the last jump in the lead-in area 1 is converted into 99 minutes: 59 seconds: 74 frames, so that the time information (MSF0) corresponding to the start position of the data area 2 is converted. And discontinuous with a time difference of more than 99 minutes. By removing this discontinuity, the time information processing unit 13 adds 10 minutes to the time information in the data area 2 so that the time information between the lead-in area 1 and the data area 2 is continuous. 99 minutes is subtracted from the time information in 1). Then, at the boundary between the lead-in area 1 and the data area 2, the time information is continuous from 9 minutes: 59 seconds: 74 frames to 10 minutes: 0 seconds: 0 frames. It continues with the time information in the area 2. The time information in the lead-in area 1 converted in this manner is supplied to the search execution unit 12. Then, the search execution unit 12 drives the sled motor based on the time information of the lead-in area 1 that is continuous to the time information in the data area 2, so that the objective lens and the light are moved to the target point in the data area 2. The pickup is moved (step S10).

In this way, when the optical pickup accesses the data area of the optical disk after moving to the target point and searches for data again, the lead-in area 1 may be re-entered. In this case, the present invention detects the time information in the lead-in area 1 and compares the current position with the time information LMSF detected at the last jump start position in the lead-in area 1 backed up in step S5. It is determined whether or not the time information in the lead-in area 1 is updated.

This will be described with reference to the flowchart of FIG. 7.

Referring to FIG. 7, when a search command is generated, data search is started, and time information is detected at a search start position on the data area 2 during data search to calculate the amount of movement to a target point, and jumping after jumping is completed. The time information is detected at the position (steps S11 and S12). The track number information TNO of the time information detected at the stop position determines whether the current position is included in the lead-in area 1 (step S13). If the current position is determined as the lead-in area 1 by the track number information TNO detected after the jump, the time information LMSF backed up in step S5 and the time information detected at the current position in the lead-in area 1 By comparing the CCMSF, the backed up time information LMSF is updated with the time information CCMSF detected at the current position (steps S14 and S15) and in the same manner as in steps S7 to S9 of FIG. Change the coordinate transformation amount (dMSF) After reconverting the time information in the lead-in area 1 into continuous time information with the time information in the data area 2, data search is continued based on the converted time information to find the target track. (Steps S17 and S18) On the other hand, if the time information CCMSF detected at the current position in the lead-in area after the jump in steps S13 and S14 is equal to or smaller than the time information LMSF backed up in step S5, then in step S9. The data search is continued based on the time information in the converted lead-in area 1.

As described above, the search control method of the optical disc according to the present invention converts the time information in the lead-in area so that the time information in the lead-in area is continuous with the time information in the data area. The data is searched using. In contrast to the conventional data search method, when entering the lead-in area during the data search, the target area is found by repeating the process of re-searching the data, which can jump to the data area. Data search is performed by recognizing a part of and performing data search. Accordingly, the data search control method of the present invention can reduce the data search time even when entering the lead-in area during data search. In addition, in the present invention, the data search can be performed without being greatly affected by the resolution error of the sled motor. Meanwhile, in the related art, when the data is searched from the inner circumferential side of the optical disk due to the low resolution of the sled motor, the objective lens often enters the lead-in area. Therefore, a program or a control means is provided to prevent the data. While the hardware is complicated, the data search control program and the hardware are simplified by searching the data by recognizing the lead-in area as the data area in the present invention.

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 (4)

An optical disc comprising a lead-in area in which disc specification information and disc content information are recorded, and a data area in which user data is recorded; Extracting time information on the optical disc and converting time information of the lead-in area into time information of the data area to search for data. The method of claim 1, Calculating the number of frames on any track existing on the innermost circumferential side of the optical disc; Detecting time information corresponding to each jump start position and every jump end position during data search; When the jump end position is determined as the lead-in area, jumping to the outer peripheral side of the optical disc by a predetermined number of tracks to enter the data area; Backing up time information corresponding to the last jump position in the lead-in area; Calculating a data area initial track number between a start position of the data area adjacent to the lead-in area and an entry position in the data area; Calculating the last track number of lead-in areas between the last jump position and the start position of the data area by subtracting the initial track number of the data area from the predetermined track number; Converting the last track number of the lead-in area into time; Updating the time information at the last jump position by adding the time to the time information at the last jump position; And converting time information in the lead-in area into time information having continuity with the time information in the data area based on the time information at the last jump position. Way. The method of claim 2, Converting the time information in the lead-in area based on the time information at the updated last jump position; Mapping the time information at the updated last jump position to 99 minutes: 59 seconds and 74 frames; Subtracting the time at the mapped last jump position by 99 minutes and adding the time information in the data area by 10 minutes to convert the mapped last jump position; Calculating and storing a conversion amount between the converted last jump position and the updated last jump position; And searching for data based on time information corresponding to the converted last jump position. The method of claim 2 or 3, And re-converting the time information in the lead-in area by recalculating the conversion amount if the time information detected by re-entry into the lead-in area during the data search is different from the last jump position backed up. Search control method of the optical disk.