JPH05342783A - Track jump control circuit - Google Patents

Abstract

PURPOSE:To eliminate influence of a flaw of a disk, an ID, etc., by varying a peak value of a jump pulse according to a control signal of a circuit for controlling excessive jump/insufficient jump of a track, converting the pulse, and outputting it. CONSTITUTION:A judging circuit 3 detects a tracking error signal S4 when a previous jumping by a jump pulse S7 is finished, judges whether a track is excessively jumped or insufficiently jumped, and outputs a control signal S5. A voltage varying circuit 4 varies a peak value of the pulse according to the signal S5, and outputs a signal S6. A track jump generator 5 converts the signal S6 into a jump pulse S7 of a predetermined time, and outputs it. With this configuration, a tracking error signal of a flaw, etc., of a disk during jumping is not detected, the pulse S7 is output for a predetermined time to jump the track, and hence influence of the flaw of the disk, an ID, etc., can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track jump control circuit in an optical disk device.

[0002]

2. Description of the Related Art A conventional track jump control circuit, as shown in FIG. 2, is a track position detection circuit 1 based on a tracking error signal S ₁ shown in FIG. Is always input to detect the zero-cross of the track position, and the trigger signal S ₂ of this position detection causes the track jump generation circuit 2 to change the timing of the jump trigger signal S _J.
The acceleration time of the jump pulse S ₃ is controlled, and the deceleration control is performed for the same time as this acceleration time.

In the above control circuit, when jumping from track A to track C shown in FIG. 3 (c), first, the track jump generation circuit 2 is accelerated by the jump trigger signal S _J as shown in FIG. 3 (d). The jump pulse S ₃ is started to be output at the track A point, the track position detection circuit 1 always detects the track position by the tracking error signal S ₁ , and the track jump generation circuit 2 accelerates the acceleration time as shown in FIG. 3B. The deceleration jump pulse S ₃ ′ is generated for the same time as t _1, and the track jump ends.

[0004]

The track jump control circuit in the above-mentioned conventional optical disk device is shown in FIG.
When noise occurs in the tracking error signal due to flaws on the optical disk, ID, etc. during the acceleration from track A to track B shown in FIG.
Therefore, the output of the acceleration jump pulse S ₃ at is stopped and the deceleration is started.

[0005]

A track jump control circuit in an optical disk apparatus according to the present invention comprises a judgment circuit for judging whether a track is jumping too far or not by a tracking error signal at the end of the previous jump.
A voltage variable circuit that changes the peak value of the jump pulse with a control signal of the determination circuit; and a track jump generation circuit that converts the output signal of the voltage variable circuit into jump pulses of a fixed time at the timing of the jump trigger and outputs the jump pulse. It is characterized by having.

[0006]

The track jump control circuit according to the present invention does not detect a tracking error signal during a jump and outputs a jump pulse at a fixed time to perform a track jump.

[0007]

EXAMPLES To illustrate the track jump control circuit of the present invention together with the embodiment shown in FIG. 1, determines whether or not enough tracking error signal S ₄ representing the displacement of the light spot jump is too skipping tracks for a track on the optical disk The control signal S ₅ that is the output signal of the determination circuit 3 is supplied to the voltage variable circuit 4 that changes the peak value of the jump pulse, and the output signal S ₆ of the voltage variable circuit 4 is jumped. The configuration is such that it is supplied to the track jump generation circuit 5 for converting into a pulse, the jump trigger signal S _J is input into the track jump generation circuit 5, converted into a jump pulse of a fixed time, and the jump pulse S ₇ is output.

In the track jump control circuit having the above structure, the judgment circuit 3 is caused to perform a track jump by the jump pulse S ₇ , and at the end of the jump, the tracking error signal S ₄ shown in FIG. FIG. 4B of the input signal and the output signal S ₆ of the voltage variable circuit 4.
The initial voltage V ₀ shown in FIG. 4 is converted into a jump pulse S ₇ having a constant time by the track jump generation circuit 5 at the timing of the jump trigger signal S _J , and the result is output.
A track jump is made from point A to point C shown in. The determination circuit 3 detects the tracking error signal S ₄ at the point C,
Depending on whether the voltage of the tracking signal is positive or negative, it is determined whether the voltage has jumped too much or not enough, and the control signal S ₅ is output.

Since the jump is too far in FIG. 4, in the next jump, as shown in FIG.
The voltage of the output signal S ₆ of the above is set to a voltage (V ₀ −V _X ) obtained by subtracting a certain required voltage V _X from the initial voltage V ₀ , and the track jump generation circuit 5 converts it into a jump pulse S ₇ of a constant time. Then, a track jump is performed from point A to point C shown in FIG.

Since it is a case where the jump is not sufficient in FIG. 6, in the next jump, as shown in FIG. 7B, the voltage of the output signal S ₆ of the voltage variable circuit 4 is required to be a certain _value from the initial voltage V _0. The voltage V _X is added to the voltage (V ₀ + V _X ), the track jump generation circuit 5 converts it to a jump pulse S ₇ of a fixed time and outputs it, and a track jump is made from point A to point C shown in FIG. 7. .

When a microcomputer is used in the track jump control circuit of the present invention, the tracking error signal is input to the A / D converter, the output signal is sampled by the microcomputer, and it is determined whether the jump or over jump has occurred. , It is also possible to determine the voltage value of the next jump pulse and supply it to the D / A converter of the next stage.

[0012]

According to the track-jump control circuit of the present invention, a tracking error signal such as a flaw on the disk during a jump is not detected, and a jump pulse is output at a fixed time to perform a track jump.
The influence of ID etc. disappears. It is very effective for controlling the digital servo.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a track jump control circuit of the present invention.

FIG. 2 is a block circuit diagram of a conventional track jump control circuit.

FIG. 3 is a waveform diagram illustrating a tracking jump of a conventional circuit.

FIG. 4 is a waveform diagram illustrating a tracking jump of the circuit of the present invention.

FIG. 5 is another waveform diagram for explaining the tracking jump of the circuit of the present invention.

FIG. 6 is another waveform diagram illustrating the tracking jump of the circuit of the present invention.

FIG. 7 is another waveform diagram for explaining the tracking jump of the circuit of the present invention.

[Explanation of symbols]

 1 Track position detection circuit 2, 5 Track jump generation circuit 3 Judgment circuit 4 Voltage variable circuit

Claims (1)

[Claims] 1. A discriminating circuit in an optical disc device for discriminating whether a track is jumping or not jumping based on a tracking error signal at the end of a previous jump, and a crest value of a jump pulse is changed by a control signal of the judging circuit. A track jump control circuit comprising: a voltage variable circuit for causing the voltage variable circuit to output; and a track jump generation circuit for converting an output signal of the voltage variable circuit into a jump pulse of a predetermined time at a timing of a jump trigger and outputting the jump pulse.