KR100563682B1 - Track movement method of eccentric disc - Google Patents

Abstract

According to the present invention, when the track movement request from the outside during the play of the eccentric disc is applied, the point of application of the signal for moving the optical pickup of the disc from the track currently being played to the requested target track is determined according to the distance between the two tracks. The present invention relates to a track moving apparatus and a method of an eccentric disk for variable setting, comprising: a spindle motor (20) for rotationally driving an mounted optical disk; An optical pickup 30 for reading out a signal recorded on the optical disk; A sled motor 40 for moving the optical pickup 30; A servo unit 90 for adjusting the position of the optical pickup 30; An R / F unit 50 for waveform shaping a high frequency signal read by the optical pickup 30; A digital signal processor (DSP) 60 for digitally processing the waveform-shaped signal; a comparator (70) for comparing the tracking error signal with an input reference level (ref.level); A traverse counter 80 for counting a traverse signal that is detected and applied; And a microcomputer (MICOM) 100 that applies a reference level (ref.level) to the comparator 71, outputs a jump pulse control signal to the servo unit 90, and controls the operation of all the components. It is configured to include, so that the time required for the track movement by the optical pickup is shortened as compared to the conventional, it is a very useful invention that more precise track movement is performed.

Description

Track moving device of eccentric disc and its method

The present invention relates to a track moving device and a method of an eccentric disc. More particularly, the present invention relates to a method for moving an optical pickup from a track currently being played to a target track requested during movement of the eccentric disc. An apparatus and method for moving track of an eccentric disc, which allow the application time of a signal to be variablely set according to the separation distance between the two tracks, so that the optical pickup can be moved more quickly and accurately to a movement requested target track.

In general, even if the track of the disc is accurately recorded at 1.6 μm pitch, as shown in the left side of FIG. 1, the center of the signal track does not coincide with the center of the disc hole. Eccentricity can occur. In addition, as shown in the right side of Fig. 1 due to the injection and hardening of the resin in the manufacturing process of the disc, distortion occurs in the signal track itself. Will occur.

When a track jump to another track is requested during the playback of the eccentric disc, the spot of the optical pickup moves from the currently playing track to the target track requested by the jump pulse applied thereto. Done. In this case, when the movement position of the optical pickup is a or c of FIGS. 2A and 2B, the optical pickup slips onto a track other than the target track to which the optical pickup is requested. The movement time to the track is relatively higher than that in the case of b of FIGS. 2A and 2B, which causes a problem in that the normal playback resume point is delayed after the track movement ends.

Accordingly, the present invention has been made to solve the above problems, and provides an apparatus and a method for moving a track of an eccentric disc, which can be moved more quickly and accurately to the target track requested when moving on a track on an eccentric disc. There is a purpose.

According to another aspect of the present invention, there is provided a track moving apparatus for an eccentric disc, comprising: detecting means for detecting a tracking error signal from the optical disc; And comparing means for comparing the level of the detected tracking error signal with a predetermined predetermined level, and movement control means for controlling the optical pickup to start moving to a target track moved at the same time as the result of the comparison. Is there.

In addition, a track movement method of an eccentric disc according to the present invention includes a first step of detecting a deviation amount from a track of an optical pickup when a track movement request is made; And a second step of determining a time point of applying the movement signal of the optical pickup based on the detected deviation amount.

In the track moving apparatus and method of the eccentric disc according to the present invention, which is constructed and constituted as described above, when the track-to-track movement of the disc optical pickup is requested during the reproduction of the eccentric disc, the detecting means first detects a tracking error signal (from the eccentric disc). Deviation amount), and then the comparison means compares the detected tracking error signal with a magnitude of a corresponding level set according to the number of tracks to be moved. As a result of the comparison, when the timing at which the tracking error signal becomes the same as the predetermined level is confirmed, the movement control means controls the optical pickup to move toward the target track from the identified timing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a track moving device and a method of an eccentric disc according to the present invention will be described in detail with reference to the accompanying drawings.

According to an exemplary embodiment of the present invention, in which the track moving device of the eccentric disk is applied, as shown in FIG. 3, the spindle for rotating the mounted optical disk is driven in accordance with the driving current output from the motor driving unit 10b. (spindle) motor 20; An optical pickup 30 for condensing the light on the signal recording surface of the rotating optical disk, and then reading the recorded digital signal by detecting the reflected light and converting the reflected light into an electrical signal; A sled motor 40 for moving the optical pickup 30 in a radial direction of the optical disk according to a driving current output from the motor driving unit 10a; Position adjustment of the optical pickup 30 by a focus error (FE) and a tracking error (TE) signal (also referred to as an amount of deviation and an amount of deviation of an optical spot) output from the optical pickup 30. Servo unit 90 for outputting a control signal for the; An R / F unit 50 for waveform shaping the analog high frequency signal read by the optical pickup 30; A digital signal processor (DSP) for digital signal processing the analog signal output from the R / F unit 50; A comparator (70) for comparing the tracking error signal with an input reference level (ref.level); A traverse counter 80 that counts the number of pulses of a predetermined period detected from the mirror surface of the track; And a reference level (ref. Level) corresponding to the number of spaced tracks up to the track requested to be moved is stored in the internal memory, and outputs a jump pulse control signal to the servo unit 90 according to the comparison result. It is configured to include a MICOM (100) for controlling the operation of the component.

4 is a flow chart of a preferred embodiment of the track movement method of an eccentric disc according to the present invention. Hereinafter, the track movement method of the present invention will be described in detail in parallel with the track movement operation of the apparatus of FIG.

First, after the eccentric disk is inserted and the spindle motor 20 is initially driven (S01), when the normal speed of the spindle motor 20 is reached by the microcomputer 100, the microcomputer 100 determines the normal speed. While maintaining and driving control of the sled motor 40, the optical pickup 30 reads a high frequency signal recorded on the optical disk while traveling along the track from the current position (S02).

At this time, the R / F unit 50 filters the high frequency signal read out from the optical pickup 30, and the digital signal processing unit 60 supplies the appropriate number of synchronization signals in the filtered high frequency signal. After checking whether it is included, a GFS (Good Frame Sync.) Signal is output to the microcomputer 100, and then the input high frequency signal is restored and reproduced from the original digital data (S03).

During such playback, if a key for requesting movement (track jumping) to another track is input (S10), the microcomputer 100 is currently playing the track based on the disc information read out during playback (track A of FIG. 6). The number of spaced tracks (BA = M) from the movement request to the target track (track B of FIG. 6) is detected (S11), and at this time, the microcomputer 100 determines a jump pulse reference according to the detected number of tracks. The level ref.level M is read from the internal memory (S12). That is, as shown in FIG. 5, if the number of spaced tracks to the requested target track is 1, a reference level 1 corresponding thereto is selected, and if the spaced track number is M, a reference level M corresponding thereto is selected and read.

The comparator 70 compares the tracking error signal detected from the optical pickup 30 with the reference level (ref.level M) read by the microcomputer 100, and then the detected tracking error signal is determined by the comparator 70. The optical pickup position that is equal to the read reference level is detected (S13). At this time, the microcomputer 100 applies a jump pulse control signal to the servo unit 90, and the servo unit 90 By applying a jump pulse (kick) to the tracking actuator (not shown) of the optical pickup 30 by the jump pulse control signal applied from the microcomputer 100, as shown in FIG. The spot of the optical pickup along the trajectory is controlled to move from the A track to the B track (S14).

Here, in the case of the long track jump, the track movement is performed by the motor driving unit 10a and the tracking actuator. In the case of the short track jump, the track movement is performed by the tracking actuator.

While the optical pickup is moved by a jump pulse (movement signal), the traverse counter 80 includes a traverse included in a high frequency signal input through the moving optical pickup 30 and the R / F unit 50. traverse) to count the number of signals. The traverse signal is a signal read out from the inter-track mirror surface of FIG. 6 by the optical pickup 30. Since the traverse signal is much larger than the high frequency signal read out from the track, the traverse counter 80 It is easy to detect and count.

Subsequently, the traverse counter 80 counts the number of traverse signals detected as described above and applies them to the microcomputer 100, and the microcomputer 100 transmits the number of tracks for which the number of the applied signals is moved ( If M), the jump pulse control signal (stop signal) is applied to the servo unit 90 by switching, so that the jump pulse (stop signal) whose phase is inverted from the movement signal is generated by the motor driving unit ( 10a) or to a tracking actuator of the optical pickup 30.

When the jump pulse (stop signal) by the servo unit 90 is applied, the microcomputer 100 drives the optical pickup 90 to control the reading of the signal from the completed target track (B track). Will resume.

On the other hand, since the disk continues to rotate even when the eccentric disk is paused during playback, the servo unit 90 restores it to the tracking actuator of the optical pickup 30 every one rotation of the disk. To apply the reverse jump pulse. At this time, according to the present invention, the reverse jump pulse application time is adjusted and applied according to the level of the detected tracking error signal so that the reverse movement of the optical pickup 30 is performed near the tracking error signal zero. Upon resuming playback of the disc, playback can be resumed from the original position previously being played back.

The track moving device and method of the eccentric disc according to the present invention constituted and constituted as described above allow the track movement to be performed at a more stable optical pickup position in the eccentric disc, as well as the time required for moving the track by optical pickup. It is a very useful invention that can be shortened compared to the prior art.

1 shows an example of an eccentric disc,

FIG. 2A shows the position of a spot following a track; FIG.

FIG. 2B is a tracking error signal generated according to the position of each spot shown in FIG. 2A;

3 is a block diagram of a track moving apparatus of an eccentric disk according to the present invention;

4 is a flowchart of a track movement method of an eccentric disc according to the present invention;

5 shows an example of generation of jump pulses applied differently according to the number of moving tracks.

FIG. 6 illustrates a spot movement trajectory according to the jump pulse application of FIG. 5.

※ Explanation of code for main part of drawing

10a, 10b: motor drive part 20: spindle motor

30: optical pickup 40: sled motor

50: R / F section 60: digital signal processing section (DSP)

70: comparator 80: traverse counter

90: servo unit 100: MICOM

Claims (2)

In the track movement method on an optical disc, Calculating a number of tracks for moving from a current track to a target track and searching for a preset jump pulse reference level corresponding to the number of tracks when the track movement is requested; And And comparing the checked jump pulse reference level with the level of the currently detected tracking error signal and starting the track movement if they match each other. The method of claim 1, The jump pulse reference level is a level value of an experimental value corresponding to the number of tracks for moving to a target track, and is set in a memory in advance.