JP3045225B2 - Disc playback / recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magneto-optical disk (M
D) The present invention relates to a reproduction / recording apparatus, and more particularly to an improvement in driving of an optical pickup at the time of a tracking jump caused by vibration, music search, and the like.

[0002]

2. Description of the Related Art FIG. 3 is a diagram schematically illustrating a conventional magneto-optical disk reproducing apparatus. As shown in FIG. 1, a cartridge 1 containing a magneto-optical disk, a spindle motor 3 for rotating the magneto-optical disk 2, an objective lens 4 for irradiating the disk 2 with laser light and reading data, and an objective lens 4 are mounted. Then, an optical pickup 5 for focusing a beam on the signal surface of the disk 2 and tracking a row (track) of pits is provided.

The optical pickup 5 moves in the radial direction of the disk 2. This movement includes a large movement for moving a sled on which the entire optical pickup 5 including the objective lens 4 is mounted, and a fine movement for moving only the objective lens 4. There are combinations with movement. Further, a feed motor 6 for the thread is provided. The RF amplifier 7 receives a signal from the optical pickup 5,
A servo signal required to determine the position of the laser spot and an audio signal detection signal from the disk 2 are generated and processed.

[0004] A servo control circuit 8 receives a laser spot position signal from the RF amplifier 7 and controls the optical pickup 5 so that the laser spot is correctly focused on the surface of the disk 2.
And a tracking servo for controlling the optical pickup 5 in a direction crossing the track in order to accurately trace the track. The address decoder 9 demodulates a signal from the RF amplifier 7 into a signal of an address recorded in a pre-group of the disk 2, reads an absolute address, controls the rotation speed of the disk 2, and keeps the linear velocity of the reading unit constant. It works to extract the servo signal to be transmitted. EFM (Eight to Fourteen Mo
dulation) and CIRC (Cross Interleave Reed-Solomo)
n Code) decoder 10 includes an address decoder 9 and an RF decoder.
It comprises a circuit (EFM) for inputting a signal from the amplifier 7 and converting an 8-bit digital signal into a 14-bit recording format of the disk 2, and a circuit for performing error correction signal processing, and performs decoding during reproduction. The anti-vibration memory controller 11 is a multi-Mbit DRAM (Dinamic Rando
m Access Memory)
By controlling the FM and the CIRC decoder 10 to store data for several seconds and to output the stored data, even if the optical pickup 5 flies by vibration, the optical pickup 5 is returned to its original position within a few seconds, and the sound due to vibration is generated. Avoids flying.

[0005] The audio compression decoder 13 decodes a signal that has been compressed on the magneto-optical disk during reproduction, based on the auditory characteristics. The signal from the audio compression decoder 13 is converted from digital to analog by a D / A converter 14 (Digital to Analog Converter) and is taken out as an audio output signal. System controller 1
5 is a servo control circuit 18, EFM and CIRC decoder 1
0, the control of the vibration-proof memory controller 11 is performed, the control state is displayed on the display 16, and control information such as ON, OFF, and channel selection is input by the key 17.

FIG. 4 is a diagram for explaining a state of stored data stored in the semiconductor memory 13. As shown in this figure,
In a stable state without shock (vibration), memory 1
When the data is completely stored in the memory 3, the reading from the disk 2 is temporarily stopped. When the data stored in the memory 12 decreases to a certain amount, the reading of the data from the disk 2 is started. Is always near full. When the optical pickup 5 comes off the track due to a shock, the amount of data going out of the memory 12 is increased by the time required to find the original position, and the amount of reading from the disk 2 is increased as compared with the steady state.

In the disk 2, all music signals are assigned continuous addresses, so that the optical pickup 5 which is off the track due to a shock is always monitored by the address recorded on the disk 2. It is possible to quickly access the original position by performing a track jump by a moving means described later. FIG. 5 is a diagram for explaining the movement of the optical pickup 5. As shown in this figure,
In the optical pickup 5, the objective lens 4 is mounted on a sled 5A, and the objective lens 4 and the sled 5A move in a direction crossing the tracks of the disk 2. The large range of movement of the thread 5 A, the moving range of the objective lens 4, so limited on the thread 5A, is smaller. That is, the movement of the sled 5A acts as a coarse adjustment and the movement of the objective lens 4 acts as a fine adjustment for a trace that continuously tracks the track. At the start of the movement of the optical pickup 5, the objective lens 4 is located at the center of the thread 5A, and the objective lens 4 has a fixed zone on the thread 5A from the above center position, and only the objective lens 4 moves within this dead zone. Then, the movement of the thread 5A is not performed. When the objective lens 4 moves beyond the dead zone, the movement of the sled 5A starts.

The movement of the objective lens 4 and the sled 5A is performed not only at the time of tracing, but also at the time of a track jump for returning the optical pickup that has deviated from the track due to the above-mentioned shock to its original position.

[0009]

However, when the tracking of the optical pickup 5 is performed while the tracking servo is being performed, the minimum starting voltage of the sled 5A, the sled 5A, etc. There is a problem that the sled 5A often does not follow well due to the variation in the weight, so that the objective lens 4 moves too much and collides with a structure at the end of the sled 5A to be unable to track.

Accordingly, an object of the present invention is to provide a magneto-optical disk reproducing / recording apparatus in which the optical pickup 5 can move favorably during a tracking jump.

[0011]

DISCLOSURE OF THE INVENTION Disc playback / recording apparatus
Is the first to cause the objective lens to track the track on the disc.
A tracking coil that moves the lens and the objective lens
It is mounted movably, and dead zone is
When the objective lens is out of the dead zone
To start the movement of the objective lens itself and perform the second movement of the objective lens.
And the tracking error signal or positive / negative for movement.
Input voltage and flow to the motor that drives the sled.
And a thread amplifier for controlling the current that the track-di
During a search that requires a jump, during a track trace
Control means for controlling the dead zone to be smaller than
With steps. The control means may include a track jump
During a search that requires
Control is performed to increase the gain of the thread amplifier.

By this means, a track jump is required
When searching, the track
Object zone during vibration
It will not move too much and hit the end of the sled. Ma
Also, when jumping in a track,
The objective lens moves too much as the sled moves easily
Will not lose track due to collision with the thread wall
You.

Similarly, at the time of music search, fast forward and fast rewind, the objective lens does not move too much and does not collide with the structure at the end of the sled.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating movement control of the objective lens 4 and the sled 5A in the servo control circuit 8 according to the present invention. As shown in the figure, the tracking error signal supplies a drive current to a tracking coil 103 that drives the objective lens 4 via a tracking coil driver 102 via a servo control circuit 101. Here, the tracking error signal is used for tracking servo at the time of tracing, and the movement signal is mainly used for tracking jump. The movement signal from the system controller 15 is supplied to the thread amplifier 105, and a drive current is supplied to a motor that drives the thread 5 </ b> A via the thread driver 106. The system controller 15 controls the movement signal supplied in accordance with the setting of the amplifier gain G2 of the thread amplifier 105 and when the objective lens 4 is not opened when it is in the dead zone.
The system controller 15 searches for songs by key input,
Obtain fast forward and fast reverse information, EEM and CIRC decoder 1
A shock (vibration) signal and a laser spot position signal are obtained from 0, and the above-described gain setting and dead zone setting are controlled.

FIG. 2 is a flowchart for explaining the control operation of the system controller 15 of FIG. As shown in the figure, it is determined in step S1 whether there is a track jump request. In step S2, it sets the constant amplifier gain G 1 in the thread amplifier 105. In step S3, a fixed dead zone is set, and the operation in the trace mode is performed.

In step S4, when there is a jump request in step S1, that is, when a shock is received, the tracking servo is turned off and a moving signal of a positive or negative voltage is input. Setting a high amplifier gain G 2 than the amplifier gain G 1 in the thread amplifier 105 in step S5. As described above, in the jump mode, by increasing the amplifier gain of the thread amplifier 105 with respect to the trace mode, the sled 5A becomes easy to move during the operation in the jump mode, and the objective lens 4
Is outside the dead zone, the sled 5A follows quickly, so that the objective lens 4 does not move too much and hit the structure at the end of the sled 5A as in the related art, so that tracking becomes impossible. If the amplifier gain of the thread amplifier 105 is simply increased, even if the collision of the objective lens 4 can be avoided at the time of jumping, the thread 5A constantly moves in the trace mode, and the heavy thread performs fine adjustment. Gets worse. Therefore, it is necessary to switch the thread amplifier gain as described above.

Next, in step S6, the dead zone is made smaller during jumping than during tracing. For this reason, as described above, the sled 5A starts moving when the objective lens 4 goes out of the dead zone, and thus the sled 5A becomes easier to move by reducing the dead zone in the jump mode. That is, the objective lens 4 is further prevented from colliding with the end structure of the thread 5A.

In step S7, it is determined whether the optical pickup 5 has returned to the original position, and the operation in the jump mode is repeated until the optical pickup 5 returns. In step S8, when the original position is returned, the tracking servo is turned on and the jump mode ends. In setting and changing the dead zone in steps S3 and S6, the disk 2
The dead zone may be set or changed based on the address recorded above.

In the above description, the track jump in the reproduction at the time of shock has been described. However, the present invention is also applicable to a track jump such as a music search, a fast forward, and a fast rewind, and the same applies to a recording. The present invention is also applicable to a magneto-optical disk (MD) reproducing / recording device and a compact disk (CD) reproducing device.

[0020]

As described above, according to the present invention, at the time of a track jump caused by a search for a vibrating piece or the like, the sled becomes easier to move than at the time of tracing, so that the objective lens moves too much and the end of the sled 5A ends. There is no collision with the structure.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating movement control of an objective lens 4 and a thread 5A in a servo control circuit 8 according to the present invention.

FIG. 2 is a flowchart illustrating a control operation of a system controller 15 of FIG.

FIG. 3 is a diagram schematically illustrating a conventional magneto-optical disk reproducing device.

FIG. 4 is a diagram illustrating a state of stored data stored in a semiconductor memory 12;

FIG. 5 is a diagram illustrating movement of an optical pickup 5;

[Explanation of symbols]

 4 Objective lens 5 Optical pickup 5A Thread 15 System controller 105 Thread amplifier

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 7/09 G11B 7/085

Claims (2)

(57) [Claims] 1. A tracking coil for performing a first movement for tracking an objective lens on a track of a disk, the objective lens being movably mounted, a dead zone being provided in a moving range of the objective lens, and the objective lens being dead. When moving out of the zone, it starts moving by itself and the second
In a disk reproducing / recording apparatus comprising: a sled for moving the sled; and a sled amplifier for controlling the current flowing to a motor for driving the sled by inputting the tracking error signal or the positive and negative voltages for movement, a track jump is required. A disk reproducing / recording apparatus characterized by comprising control means for performing control for making the dead zone smaller at the time of a search than at the time of a track trace. 2. The control device according to claim 1, wherein the control unit performs a track jump.
At the time of the required search,
Performing control to increase the gain of the thread amplifier
The disk reproducing / recording apparatus according to claim 1, characterized in that:
Place.