KR100556478B1 - Method for judging track jump direction, method and apparatus for controliing track jump of optical record/player - Google Patents

Abstract

The present invention relates to a track jump control method and apparatus in a land / groove recording method, wherein a vibration direction of a tracking actuator is detected by a phase difference between two signals output from an optical detection element divided into two tracks during a track jump. When the desired track is reached, a brake waveform is generated in a direction opposite to the detected vibration direction of the tracking actuator, that is, a reverse phase of the tracking error signal, thereby suppressing the vibration of the tracking actuator, thereby making stable track jump without mirror signal in the land / groove recording method. Can be performed.

Track jumping

Description

Method for judging track jump direction, method and apparatus for controliing track jump of optical record / player

1 is a block diagram of a track jump control of a conventional optical recorder;

2A to 2H are waveform diagrams illustrating track jump control signals generated when a tracking actuator moves from an inner circumference to an outer circumference during a track jump in the optical recorder as shown in FIG. 1.

3A to 3H are waveform diagrams showing track jump control signals generated when a tracking actuator moves from the outer circumference to the inner circumference during a track jump in the optical recorder as shown in FIG.

4A shows an example of a photo detector divided into two in the track direction;

4B shows an example of a photo detector divided into four in the track direction and the radial direction.

4C shows an example of the amount of light detected by a photo detector divided into two in the track direction;

5 is a block diagram illustrating the structure of track jump control in the optical recorder according to the present invention.

6A to 6J are waveform diagrams illustrating track jump control signals generated when a tracking actuator moves from the inner circumference to the outer circumference during a track jump in the optical recorder as shown in FIG. 5.

7A to 7J are waveform diagrams showing track jump control signals generated when a tracking actuator moves from the outer circumference to the inner circumference during a track jump in the optical recorder as shown in FIG. 5.

Explanation of symbols for main parts of the drawings

501: comparator 502: buffer

503: inverter 504: brake drive pulse generator

505: I1 mirror generator 506: I2 mirror generator

507: edge detector 508: actuator direction detector

509: brake driving voltage generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to track jumps in optical recording and reproducing systems, and more particularly to a method and apparatus for performing track jumps in a land / groove recording scheme.

In general, in order to reach the desired point on the optical disc, the laser beam generated by the pickup must be accurately tracked from the current track to the target track and tracked on the target track. This is called search or seek.

This search operation calculates the number of tracks to the target track, and if the number of tracks to be jumped is more than hundreds to thousands of tracks, the feed motor is used to move the pickup near the desired track, and if the remaining tracks are less than several hundred tracks, the tracking actuator is used. You will find a track.

The track search using the tracking actuator is called a track jump, and is generally used to find hundreds of tracks or less.

In order to perform such a track jump, a mirror signal (track cross signal) must be detected.

In other words, the track and the track are referred to as a mirror area, and the light is totally reflected, and the signal indicating that the actuator is between the track and the track is the mirror signal.

In general, an optical recording / reproducing system generates an RF signal and a tracking error signal TE during track jump, and detects a mirror signal using the RF signal.

FIG. 1 is a conventional block diagram for generating a track jump control signal, and FIG. 2 is track jump control signals generated when track search is performed from an inner circumference to an outer circumference.

In other words, when a track jump command is input, a kick pulse (also called a jump pulse) is generated while detecting an RF signal and a tracking error signal TE through a pickup (not shown). The kick pulse pushes the objective lens of the tracking actuator in one direction.

At this time, the envelope detector 101 detects the envelope waveform from the RF signal input as shown in (a) of FIG. 2 and outputs the waveform to the waveform shaping unit 102 as shown in FIG. Slices the envelope waveform to an internal reference level and outputs the square wave as a square wave as shown in FIG. 2 (c), wherein the square wave output is a mirror signal MIRR.

That is, the area where the signal pit is located in the RF signal output during the track jump is when the size of the RF signal is the smallest, and because the mirror area is the total reflection area, when the size of the RF signal is the largest.

Meanwhile, the tracking error signal TE as shown in FIG. 2D is sliced to the internal reference level by the waveform shaping unit 103 and output as a tracking zero crossing signal TZC of a square wave as shown in FIG. . That is, the tracking zero crossing signal TZC is a signal that is turned on / off at the track cross time.

The tracking zero crossing signal TZC is detected by the edge detector 104 as shown in FIG. 2F, and the detected edge signal is provided as a clock of the flip-flop 105.

The flip-flop 105 outputs a break signal as shown in FIG. 2G by synchronizing the mirror signal MIRR with an edge signal output from the edge detector 104.

At this time, the tracking actuator is accelerated by a kick pulse and the speed drops when the brake signal is generated. The brake signal is generated to stop the actuator stably and accurately at the desired position.

However, since the actuator is vibrating, a stable track jump is performed only by rapidly suppressing the vibration of the actuator by applying a brake in a direction opposite to the vibration direction.

To this end, it is necessary to know the vibration direction of the actuator. At this time, whether the actuator proceeds from the outer circumference to the inner circumference or from the outer circumference to the inner circumference, the phase of the mirror signal does not change, but the tracking error signal is changed.

Therefore, in the related art, the vibration direction of the actuator is determined by using a phase difference between the mirror signal as shown in FIG. 2C and the tracking zero crossing signal TZC as shown in FIG. For example, if the phase of the mirror signal is 90 ° later than the tracking zero crossing signal TZC as shown in FIG. 2, it is determined that the actuator proceeds from the inner circumference to the outer circumference, and as shown in FIG. Generate a pulse.

In this case, the break position at which the break pulse is turned on becomes a track center, and the track center can be detected from the track zero crossing signal TZC.

On the other hand, Figure 3 is a track jump control signals generated when the track search from the outer circumference to the inner circumference, it is determined that the actuator proceeds from the outer circumference to the inner circumference because the phase of the mirror signal is 90 degrees faster than the tracking zero crossing signal (TZC) As shown in FIG. 3H, a pulse breaks from the inner circumference to the outer circumference.

As described above, in the pit format or the groove recording method of the CD system or the DVD system, a mirror signal is generated from the RF signal as shown in FIGS. 1 to 3 to perform a stable track jump while preventing actuator vibration.

However, in the land / groove type DVD-RAM, it is impossible to generate a track jump signal from RF. That is, in the land / groove recording method, since data is recorded in both the land and the groove, the mirror signal cannot be formed from the RF signal. Since the tracking error occurs in the same way as the groove recording method or the land / groove recording method without forming the mirror signal, the tracking actuator cannot be detected. As a result, it becomes impossible to apply an auto break, so that a stable track jump cannot be performed in the land / groove recording method.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is a track jump direction determination method, a track jump control method and apparatus of an optical recorder for stably performing track jumps in a land / groove recording optical disk. In providing.

Another object of the present invention is a track jump direction determination method and track jump control of an optical recorder which performs a stable track jump by detecting a vibration direction of a tracking actuator from a phase difference between two signals emitted from a photodetector divided into two tracks. A method and apparatus are provided.

Another object of the present invention is to detect the vibration direction of the tracking actuator from the phase difference of two signals from the photodetecting element divided into two track directions, and to generate a brake waveform in a direction opposite to the vibration direction of the actuator, thereby achieving stable track jump. Disclosed are a track jump direction determination method, a track jump control method, and an apparatus of an optical recorder.

The track jump direction determination method of the optical recorder according to the present invention for achieving the above object is, if the first and second electrical signals are output in proportion to the amount of reflected light from the two optical detection elements divided into two track directions; Detecting a rising edge of the second electrical signal; and determining a track jump direction by examining a level of the first electrical signal at the rising edge of the second electrical signal detected in the step.

The rising edge detection step may be characterized by slicing the first and second electrical signals to internal reference levels, converting them to square waves, and then detecting the rising edges of the second electrical signals converted to square waves.

The direction determining step is characterized in that the track jump proceeds from the inner circumference to the outer circumference when the first electrical signal converted into the square wave at the rising edge of the second electrical signal is low.

The direction determining step may be characterized in that the track jump proceeds from the outer circumference to the inner circumference when the first electrical signal converted into the square wave at the rising edge of the second electrical signal is high.

The first electrical signal is an electrical signal I1 output from the photodetecting device located on the inner circumference of the track direction, and the second electrical signal is an electrical signal I2 output from the photodetecting device located on the outer circumference of the track. do.

In the direction determining step, if the phase of the first electrical signal I1 is faster than the second electrical signal I2, it is determined that the track jump is progressing from the inner circumference to the outer circumference.

In the direction determining step, if the phase of the first electrical signal I1 is later than the second electrical signal I2, it is determined that the track jump is progressing from the outer circumference to the inner circumference.

The track jump control method of the optical recorder according to the present invention includes a tracking error from first and second electric signals output in proportion to the amount of reflected light from both photodetectors divided into two track directions when the tracking actuator moves by a track jump command. Detecting the signal, and slicing the first and second electrical signals to internal reference levels and converting them into square waves, and then inspecting the level of the first electrical signal at the rising edge of the second electrical signal. Determining a moving direction, and generating a brake waveform in a direction opposite to the moving direction of the tracking actuator when the desired track is reached, and driving the tracking actuator.

The phase of the brake waveform generated in the step of generating the brake waveform is inverse to the tracking error signal.
The track jump control apparatus of the optical recorder according to the present invention is a tracking error from the first and second electrical signals output in proportion to the amount of reflected light from both optical detection elements divided in two in the track direction when the tracking actuator moves by the track jump command. When detecting a signal to control the track jump,
A tracking zero crossing signal generator which slices the tracking error signal based on a track cross position to generate a tracking zero crossing signal, and then bypasses or inverts the tracking error signal;
A track jump direction detection unit for determining a moving direction of the tracking actuator by detecting a level of the first electrical signal at the rising edge of the second electrical signal after detecting the rising edge of the second electrical signal;
A brake drive pulse generator for outputting a tracking zero crossing signal bypassed or inverted according to the tracking actuator moving direction as a brake on pulse;
And a brake driving voltage generator configured to generate a brake waveform in a direction opposite to the movement direction of the tracking actuator in the break-on period of the brake on pulse to drive the tracking actuator.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

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

The present invention is to perform auto brake by detecting the vibration direction of the tracking actuator by the phase difference between the two signals output from the photodetecting element divided into two in the track direction during the track jump.

If the photo detector is divided into two in the track direction as shown in FIG. 4A, the electrical signals output in proportion to the amount of light from both photodetectors PDA and PDB become I1 and I2 and are divided into four as shown in FIG. 4B. If a + d is I1, b + c is I2.

Therefore, if the tracking actuator moves from the inner circumference to the outer circumference as shown in FIG. 4C, the phase of I2 is faster than the I1, and if the tracking actuator moves from the outer circumference to the inner circumference, I2 becomes later than I1.

Fig. 5 is a block diagram showing the construction of the optical recording and reproducing system of the present invention for generating a track jump control signal using this characteristic.

Referring to FIG. 5, a comparator 501 generating a tracking zero crossing signal TZC of a square wave by comparing the tracking error signal TE with an internal reference signal (ie, a track cross position), and the tracking zero crossing signal TZC. A buffer 502 for bypassing the signal, an inverter 503 for inverting the tracking zero crossing signal TZC, an I1 mirror generator 505 for slicing an I1 signal to an internal reference level to generate an I1 mirror signal of a square wave, An I2 mirror generator 506 that slices an I2 signal to an internal reference level to generate an I2 mirror signal of a square wave, an edge detector 507 that detects an edge of the I2 signal from an output of the I2 mirror generator 506, and Actuator direction detector 508 for determining the vibration direction of the tracking actuator from the outputs of the I1 mirror generator 505 and the edge detector 507, and the tracking zero crossing signal TZ according to the detected actuator direction. A brake drive pulse generator 508 for outputting a signal C) bypassed or inverted as a brake on pulse, and a brake waveform in a direction opposite to the detected actuator direction only during a brake on period of the brake on pulse; And a brake drive voltage generator 509.

6 are track jump control signals of the present invention generated when the track search from the inner circumference to the outer circumference, and FIG. 7 are track jump control signals of the present invention generated when the track search from the outer circumference to the circumference.

In the present invention configured as described above, the optical detector outputs an electrical signal proportional to the amount of light reflected from the optical disk. Therefore, when the photodetector is divided into two in the track direction, the tracking error signal TE is generated by I1-I2 the electrical signals I1 and I2 output from both photodetecting elements.

The phase of the tracking error signal TE is reversed when the tracking actuator proceeds from the inner circumference to the outer circumference as shown in FIG. 6A and when the tracking actuator proceeds from the outer circumference to the inner circumference as shown in FIG.

In addition, when traveling from the inner circumference to the outer circumference, as shown in (b) and (c) of FIG. 6, the phase of the I1 signal is faster than that of the I2 signal, and when traveling from the outer circumference to the inner circumference, FIGS. As shown, the phase of the I1 signal is later than the I2 signal.

Accordingly, when the track jump command is input, the above tracking error signal TE is input to the comparator 501 and the I1 signal is sent to the I1 mirror generator 505 and the I2 signal is sent to the I2 mirror generator 506. Is entered. In addition, the brake on signal is input to the brake driving pulse generator 504. The brake on signal is a signal for determining whether to perform an auto brake operation and is generated by a controller (not shown) that controls track jump.

In this case, it is assumed that the tracking actuator moves from the inner circumference to the outer circumference as shown in FIG. 6 by the track jump command and the kick pulse.

Accordingly, the comparator 501 slices the tracking error signal TE input as shown in FIG. 6A to an internal reference level (that is, the track cross position) and crosses the tracking zero of the square wave as shown in FIG. 6D. Output as signal TZC. The tracking zero crossing signal TZC is bypassed through the buffer 502 or inverted through the inverter 503 and output to the brake driving pulse generator 504.

Meanwhile, the I1 mirror generator 505 slices the I1 signal input as shown in FIG. 6B to an internal reference level to generate an I1 mirror signal as shown in FIG. 6E, and the I2 mirror generator 506. ) Slices the input I2 signal to the internal reference level as shown in FIG. 6C to generate the I2 mirror signal as shown in FIG. The edge detector 507 detects the rising edge of the I2 mirror signal from the I2 mirror signal and outputs the rising edge of the I2 mirror signal to the actuator direction detection unit 508.

The actuator direction detector 508 detects the direction of the tracking actuator according to the high / low state of the I1 mirror signal at the same position at the rising edge of the I2 mirror signal. That is, the direction of the tracking actuator is detected by sampling the I1 level at the rising edge of the I2 signal.

For example, if the I1 mirror signal is low at the rising edge of the I2 signal as shown in (e) of FIG. 6, the actuator direction detecting unit 508 determines that the tracking actuator proceeds from the inner circumference to the outer circumference. As shown in Fig. 7 (h), if the output signal is low and the I1 mirror signal is high at the rising edge of the I2 mirror signal as shown in Fig. 7E, the tracking actuator proceeds from the outer circumference to the inner circumference. Outputs

Accordingly, the brake drive pulse generator 504 bypasses the tracking zero crossing signal through the buffer 502 when a low signal is output from the actuator direction detector 508, that is, when the tracking actuator moves from the inner circumference to the outer circumference. (TZC) is selected, and a brake on pulse is output to the brake driving voltage generator 509 as shown in FIG. If the high signal is output from the actuator direction detecting unit 508, that is, if it is determined that the tracking actuator moves from the outer circumference to the inner circumference, the brake driving pulse generator 504 inverts the tracking zero crossing signal through the inverter 503. (TZC) is selected and output as a break-on pulse as shown in FIG.

The brake driving voltage generator 509 generates a brake waveform in a direction opposite to the direction of the actuator detected in the break-on period of the break-on pulse, that is, the high period. As shown in FIG. Becomes

That is, when the actuator direction signal is low as shown in (h) of FIG. 6 during the high period of the brake on pulse, the brake driving voltage generator 509 generates a brake waveform in a low state as shown in (j) of FIG. If the actuator direction signal is high as shown in (h) of FIG. 7, a brake waveform having a high state is generated as shown in (j) of FIG. 7. This break waveform eventually becomes the inverse of the tracking error signal.

Here, the brake waveform is reversed of the tracking error signal in order to stabilize the vibration of the actuator quickly. That is, the brake is applied to the vibrating actuator only when the brake waveform is applied to the opposite direction of the tracking error signal.

On the other hand, the brake driving voltage generator 509 receives the tracking zero crossing signal TZC from the comparator 501 instead of the actuator direction signal, and then the brake on pulse output from the brake driving pulse generator 504 is high. During the period, a brake waveform may be generated in a reverse phase of the input tracking zero crossing signal TZC.

At this time, in the present invention, since the center of the groove track is set to the brake position in the embodiment, the brake waveform is generated in the reverse phase of the tracking error signal in the high section of the brake on pulse to suppress the vibration of the tracking actuator.

As described above, according to the track jump direction determination method, the track jump control method and the apparatus of the optical recorder according to the present invention, the tracking actuator is a phase difference between two signals outputted from the optical detection elements divided into two tracks during the track jump. When the vibration direction is detected and a desired track is reached, a brake waveform is generated in a direction opposite to the detected vibration direction of the tracking actuator, i.e., in the inverse of the tracking error signal, thereby suppressing the vibration of the tracking actuator. This has the effect of performing a stable track jump without a signal.

Claims (17)

In the track jump direction determination method during track jump by the movement of the tracking actuator, Detecting a rising edge of the second electrical signal when the first and second electrical signals are output in proportion to the amount of reflected light from the two photodetectors divided in two in the track direction; And determining the track jump direction by examining the level of the first electric signal at the rising edge of the second electric signal detected in the step. The method of claim 1, wherein the rising edge detection step is And slicing the first and second electrical signals to internal reference levels, converting the first and second electrical signals into square waves, and detecting rising edges of the second electrical signals converted into square waves. The method of claim 1, wherein the determining of the direction The track jump direction discrimination method of the optical recorder, characterized in that the track jump proceeds from the inner circumference to the outer circumference when the first electrical signal converted into the square wave at the rising edge of the second electrical signal is low. The method of claim 1, wherein the determining of the direction A track jump direction discrimination method of an optical recorder, characterized in that it is determined that track jump is progressing from the outer circumference to the inner circumference when the first electrical signal converted into the square wave at the rising edge of the second electrical signal is high. The method of claim 1, The first electrical signal is an electrical signal I1 output from the photodetecting device located on the inner circumference of the track direction, and the second electrical signal is an electrical signal I2 output from the photodetecting device located on the outer circumference of the track. A track jump direction determination method of an optical recorder. The method of claim 5, wherein the determining of the direction And if the phase of the first electrical signal (I1) is earlier than the second electrical signal (I2), determining that the track jump is progressing from the inner circumference to the outer circumference. The method of claim 5, wherein the determining of the direction And if the phase of the first electrical signal (I1) is later than the second electrical signal (I2), determining that the track jump is progressing from the outer circumference to the inner circumference. A method of controlling a track jump by detecting a tracking error signal from first and second electrical signals output in proportion to the amount of reflected light from a two-photodetection device divided into two in the track direction when the tracking actuator moves by a track jump command, Determining the direction of movement of the tracking actuator by slicing the first and second electrical signals to internal reference levels and converting the first and second electrical signals into square waves, and then inspecting the level of the first electrical signals at the rising edges of the second electrical signals; , And driving a tracking actuator by generating a brake waveform in a direction opposite to the movement direction of the tracking actuator when the desired track is reached. The method of claim 8, And a phase of the brake waveform generated in the step of generating the brake waveform is in phase with the tracking error signal. The method of claim 8, And a brake position at which the brake waveform is generated is a track center. An apparatus for controlling a track jump by detecting a tracking error signal from first and second electrical signals output in proportion to the amount of reflected light from a two-photodetection device divided into two in the track direction when a tracking actuator moves by a track jump command. A tracking zero crossing signal generator which slices the tracking error signal based on a track cross position to generate a tracking zero crossing signal, and then bypasses or inverts the tracking error signal; A track jump direction detecting unit for determining a moving direction of the tracking actuator by detecting a level of the first electric signal at the rising edge of the second electric signal after detecting the rising edge of the second electric signal; A brake drive pulse generator for outputting a tracking zero crossing signal bypassed or inverted according to the tracking actuator moving direction as a brake on pulse; And a brake driving voltage generator configured to generate a brake waveform in a direction opposite to the movement direction of the tracking actuator in the break-on period of the brake on pulse to drive the tracking actuator. . The method of claim 11, wherein the track jump direction detection unit Whether the first and second electrical signals are sliced to internal reference levels and converted into square waves, and then the level of the first electrical signal converted into square waves is low or high at the rising edge of the second electrical signal converted into square waves. And a track jump direction according to the track jump control apparatus of the optical recorder. The method of claim 12, wherein the track jump direction detection unit The track jump control apparatus of the optical recorder, characterized in that it is determined that the track jump is progressing from the inner circumference to the outer circumference when the level of the first electrical signal is low at the rising edge of the second electrical signal. The method of claim 12, wherein the track jump direction detection unit The track jump control apparatus of the optical recording and reproducing apparatus, characterized in that it is determined that the track jump is progressing from the outer circumference to the inner circumference when the level of the first electrical signal is high at the rising edge of the second electrical signal. The method of claim 11, wherein the track jump direction detection unit And if the phase of the first electrical signal (I1) is earlier than the second electrical signal (I2), determining that the track jump is progressing from the inner circumference to the outer circumference. The method of claim 11, wherein the track jump direction detection unit And if the phase of the first electrical signal (I1) is later than the second electrical signal (I2), determining that the track jump is progressing from the outer circumference to the inner circumference. The method of claim 11, wherein the brake driving voltage generator And the phase of the brake waveform is in phase with the tracking error signal.

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