JPH06282857A - Track jump device - Google Patents

Abstract

PURPOSE:To execute semi-track jump by switching the operation of an acceleration pulse generation means and that of a deceleration pulse generation means according to the peak value of a tracking error signal. CONSTITUTION:This device is provided with a disk-shaped storage medium 10 with an information track, a reproduction means 1 with a tracking actuator, a tracking error detection means 2 for detecting a tracking error signal, and an acceleration/deceleration signal generation means 6 for outputting a signal for deceleration after an actuator is accelerated by a track jump command. The polarity of the tracking error signal is inverted according to the output of a toggle FF circuit 3 with a polarity inversion means 4 for inverting the polarity of the tracking error signal according to the track jump command. The maximum/minimum signals of the error signal are detected by a peak detection circuit and then the rotation of a recording medium 10 is detected by a one-rotation detection circuit 8, and then a track jump command is issued. A control circuit 9 feeds back the tracking error signal and the acceleration/ deceleration pulse signals to the tracking actuator of an optical head 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track jump device for an optical disk or magnetic disk formatted with a half track pitch.

[0002]

2. Description of the Related Art In recent years, a track jump device has attracted attention as a device that controls the basic operation of an optical disk drive.

An example of the above-mentioned conventional track jump device will be described below with reference to the drawings.

FIG. 6 is a block diagram of a conventional track jump device. In FIG. 6, reference numeral 100 denotes an optical disk medium, in which information recording tracks are spirally cut. Reference numeral 101 denotes an optical head, which is a laser light emitting element, a light receiving element, and an optical disk medium 10.
It has a tracking actuator that slightly moves the position of the laser beam irradiated onto the laser beam. Reference numeral 102 denotes a tracking error detection circuit, which is an optical disc medium 10
The position error of the laser beam emitted from the optical head with respect to an arbitrary track on 0 is detected as a tracking error signal. Reference numeral 103 is a zero-cross detection circuit, which detects a zero-cross point of the tracking error signal and outputs it as a pulse signal. A one-rotation detection circuit 104 issues a track jump command every time the optical disc medium 100 detects one revolution.
Reference numeral 105 denotes an acceleration pulse generation circuit, which is a single rotation detection circuit 1
A pulse for accelerating the tracking actuator of the optical head 101 is generated according to the output of 04. A deceleration pulse generation circuit 106 generates a pulse for decelerating the accelerated tracking actuator. A control circuit 107 receives the tracking error signal and the acceleration and deceleration pulse signals from the optical head 101.
Feedback to the tracking actuator.

The operation of the track jump device configured as described above will be described below with reference to FIGS. 6 and 7.

First, a laser beam positioned on an arbitrary track A is schematically shown in FIG. As described above, the optical disc medium 1
Since the track 00 is spirally cut, the laser beam moves to the adjacent track B when the optical disk medium 100 makes one rotation while tracking. Therefore, in order to always be located on the track A, the track B to the track A is rotated once per one rotation of the optical disk medium.
Need to be always jumping to.

The order at this time is as shown below.
First, when the one-rotation detection circuit 104 detects that the optical disk medium 100 has made one rotation, a track jump command is issued, whereby the acceleration pulse generation circuit 105 generates an acceleration pulse, which causes the tracking actuator to operate via the control circuit 107. Accelerate in the direction of track A (Fig. 7
(1)). Zero crossing detection circuit 1 when the tracking actuator accelerates and passes between tracks (between A and B)
03 detects this, and the deceleration pulse generation circuit 105 generates a pulse at this timing (FIG. 7 (2)). As a result, the tracking actuator decelerates, the velocity becomes almost 0 near the center of the track A, and the track jump ends (FIG. 7 (3)) (for example, Japanese Patent Publication No. 52-50).
098).

[0008]

However, in the above-mentioned configuration, when information is recorded at a half track pitch, that is, when information is also recorded between tracks A and B, when jumping at one track pitch, Substantially 2
There was a problem that a track jump was performed.

In view of the above problems, the present invention provides a track jump device capable of performing a track jump at a half track pitch.

[0010]

In order to solve the above problems, a track jump device of the present invention comprises polarity reversing means for reversing the polarity of the tracking error signal in response to a track jump command, and the tracking actuator accelerates. Then, an extreme value detecting means for detecting the maximum value or the minimum value of the tracking error signal is provided.

[0011]

According to the present invention, a tracking error signal having the same polarity as that of an adjacent track can be instantaneously obtained at the time of a track jump due to the above-described configuration, and further, acceleration / deceleration can be switched at a quarter track pitch by peak detection. The result is that a half-track jump can be performed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A track jump device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a track jump device according to an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes an optical disk medium spirally formatted with a half track pitch. On the optical disk medium 10, wobble mark pairs 10a and 10b and wobble mark pair 1 having different detection polarities as shown in FIG.
0c and 10d are formed alternately. Reference numeral 11 denotes an optical head, which has a laser light emitting element, a light receiving element, and a tracking actuator for minutely moving the position of the laser beam with which the optical disk medium 10 is irradiated. 1
Is a track mark detection circuit, which generates a pulse signal at the same cycle as the detection of the wobble mark pair.
Reference numeral 2 denotes a tracking error detection circuit, which includes a wobble mark pair 10a and 10b or a wobble mark pair 10c,
The tracking error signal is detected from 10d. Reference numeral 3 is a toggle flip-flop whose output state is inverted every time a pulse from the track mark detection circuit is input. An output inverting circuit 4 sequentially inverts the polarity of the tracking error signal according to the output of the toggle flip-flop 3. A peak detection circuit 5 detects the maximum (minimum) point of the tracking error signal. A one-rotation detecting circuit 8 detects that the optical disc medium 10 has made one revolution and issues a track jump command. Reference numeral 6 is an acceleration pulse generation circuit.
Generates a pulse that accelerates the tracking actuator of. A deceleration pulse generation circuit 7 generates a pulse for decelerating the accelerated tracking actuator. A control circuit 9 feeds back the tracking error signal and the acceleration and deceleration pulse signals to the tracking actuator of the optical head 11.

The operation of the track jump device configured as described above will be described below with reference to FIGS. 1, 2 and 3.

First, the track format shown in FIG. 2 will be described. The wobble mark pairs 10a and 10b and the wobble mark pairs 10c and 10d have tracking error detection polarities opposite to each other and are arranged alternately. Moreover, the total number of wobble mark pairs is characterized by being assigned an odd number per track. Now, assuming that the laser beam scans the wobble mark pair 10a, 10b on the track A, the tracking error detection circuit 2 detects the tracking error signal from these. Next, when the wobble mark pairs 10c and 10d are scanned, a tracking error signal having the opposite polarity to this is detected. However, the toggle flip-flop 3 and the polarity inversion circuit 4 alternately invert the polarity at the timing when the wobble mark pair is detected, and as a result, the tracking error signals of the same polarity are generated. This tracking error signal is fed back to the tracking actuator of the optical head 10 via the control circuit 9, and track tracking control is executed.

Since the tracks are formed in a spiral shape, the laser beam is positioned on the adjacent track B when the optical disk medium 10 makes one revolution. In order to execute the tracking still operation, it is necessary to jump to the track A at this time.

The jump method will be described below with reference to FIG. First, as is clear from FIG. 2, since the polarities of the adjacent tracks A and B are opposite to each other, the polarity of the tracking error signal is inverted (FIG. 3 (1)).

The polarity can be inverted by applying a track jump command signal issued from the one-rotation detecting circuit 8 to the toggle flip-flop 3. Next, acceleration and deceleration pulses are generated based on this track jump command signal. First, the acceleration pulse generation circuit 6 produces an acceleration pulse signal and accelerates the tracking actuator via the control circuit 9 (FIG. 3 (2)).

Further, when the laser beam passes between the tracks A and B after acceleration, the detection tracking error signal has a maximum (minimum) value. Therefore, a deceleration pulse is generated at the timing detected by the peak detection circuit 5. The generation circuit works to decelerate the tracking actuator (see Fig. 3).
(3)), and finally track A is tracked (FIG. 3 (4)).

As described above, according to this embodiment, a track jump of a half track pitch can be executed.

In this embodiment, the tracks are spiral, but they may be concentric. Further, in this embodiment, the acceleration / deceleration pulse is applied after the tracking error signal is inverted, but the polarity may be inverted after the acceleration pulse is applied. Further, the tracking follow-up control may be held or invalidated while the acceleration / deceleration pulse is applied.

The second embodiment of the present invention will be described below. FIG. 4 is a block diagram showing the main parts of the optical disc medium 10 of the track jump device according to the second embodiment of the present invention. 1
Reference numeral 0e is a spiral convex groove provided in the optical disc medium 10. The recording information is recorded on both the track A set on the convex portion of the convex groove 10e and the track B set on the concave portion sandwiched by the convex groove 10e. The operation when the optical disc medium 10 is used in the apparatus shown in FIG. 1 will be described below.

First, it is assumed that the laser beam emitted from the optical head 11 scans the track A set in the convex groove 10e. When the optical disk medium 10 rotates once,
The one-rotation detection circuit 8 issues a pulse signal, whereby a half-track jump is executed and the laser beam enters the concave track B. Here, if the half-track jump is not executed, the laser beam does not scan the concave track B, but scans the adjacent track C. Therefore, according to the present embodiment, the laser beam can sequentially scan the tracks provided on the convex portion and the concave portion, A, B, C, ...

The third embodiment of the present invention will be described below. FIG. 5 is a block diagram showing the essential parts of an optical disk medium 10 of a track jump device according to a third embodiment of the present invention. In FIG. 5, 10a, 10b and 10e, 10f are wobble mark pairs, respectively. The above wobble mark pair is first
Unlike the embodiment described above, they are arranged with the same polarity without being sequentially inverted. Therefore, the tracking detection characteristic is equivalent to that described in the second embodiment. That is, the tracks A and C correspond to the groove convex portion in FIG. 4, and the track B corresponds to the concave portion.

First, it is assumed that the laser beam emitted from the optical head 11 scans the track A defined by the wobble marks 10a and 10b. When the optical disk medium 10 makes one rotation, the one-rotation detecting circuit 8 emits a pulse signal, whereby a half track jump is executed, and the laser beam enters the track B defined by the wobble marks 10b and 10e. Here, if the half-track jump is not executed, the laser beam does not scan the track B, but scans the track C adjacent to it defined by the wobble marks 10e and 10f. Therefore, according to the present embodiment, it becomes possible to sequentially scan the tracks provided at the half track pitch as A, B, C.

[0026]

As described above, according to the present invention, the tracking error detection circuit 2 for detecting the tracking error signal from the optical disk medium 10 formatted with a half track pitch and the wobble mark pair read by the optical head 11 is described.
And an inverting circuit 4 for inverting the polarity of the tracking error signal according to a track jump command, and by switching the operation of the acceleration pulse generating means 6 and the deceleration pulse generating means at the peak of the tracking error signal, a half track The jump can be executed.

[Brief description of drawings]

FIG. 1 is a block diagram of a track jump device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an optical disk medium 10 for explaining the operation in the same embodiment.

FIG. 3 is an operation explanatory view of the track jump device in the embodiment.

FIG. 4 is a configuration diagram of a main part of a track jump device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a main part of a track jump device according to a third embodiment of the present invention.

FIG. 6 is a block diagram of a conventional track jump device.

FIG. 7 is an operation explanatory diagram of a conventional track jump device.

[Explanation of symbols]

 1 Track mark detection circuit 2 Tracking error signal detection circuit 3 Toggle flip-flop 4 Inversion circuit 5 Peak detection circuit 6 Acceleration pulse generation circuit 7 Deceleration pulse generation circuit 8 One rotation detection circuit

Claims (3)

[Claims] 1. A disk-shaped recording medium having an information track, and reproducing means having a tracking actuator.
Tracking error detection means for detecting a tracking error signal from the disc-shaped recording medium, acceleration signal generation means and deceleration signal generation means for issuing a signal for accelerating and decelerating the tracking actuator by a track jump command, and by the track jump command. Polarity inverting means for inverting the polarity of the tracking error signal is provided, and further, after the tracking actuator is accelerated, the deceleration signal generating means operates between the jump source zero cross point and the jump destination zero cross point in the tracking error signal. A track jump device characterized in that 2. An extreme value detecting means for detecting the maximum value or the minimum value of the tracking error signal is provided, and after the acceleration signal generating means operates, the deceleration signal generating means operates according to the output of the extreme value detecting means. The track jump device according to claim 1, wherein: 3. The track jump device according to claim 1, wherein the tracking mark is composed of a pair of wobble marks.