JPH09213031A - Disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the speed of the search to a target position in a disk player such as a CD player. SOLUTION: After a pickup is moved by a thread motor, the impressing of a tracking actuator driving signal is started as a brake signal so that the tracking actuator is driven in the direction opposite to the moving direction of the pickup, and at the same time, a signal period of the tracking error signal is measured. After detecting that the period is made longer than a predetermined value (i.e., the judgement is thereby made that the speed of the pickup is sufficiently decreased), the impressing of the tracking actuator driving signal is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc playing device such as a CD (compact disc) player and an MD (mini disc) player.

[0002]

2. Description of the Related Art First, FIG. 1 shows the structure of a general CD player. Reference numeral 1 denotes a disc, and data of a digital audio signal is recorded on the disc 1 as an information string on a spiral track. In a player that reproduces such a disc, the disc is divided into a portion for tracing a track on the disc with a pickup and a portion for reproducing audio signal data read by the pickup.

As for discs other than CDs, there are discs in which data is formed on concentric circles instead of spiral tracks.

The disc reproducing apparatus is provided with a plurality of control mechanisms (focus servo system, spindle servo system, tracking servo system) for tracing the information sequence, which will be described below in order.

First, in the focus servo system for focusing the laser light emitted from the pickup 2 on the disk surface, the focus error signal obtained from the pickup 2 is amplified by the servo signal amplifier circuit 5, and the servo control circuit 7 requires it. The characteristics are equalized, the focus actuator drive circuit 4 amplifies the power, and the focus actuator (not shown) of the pickup 2 is driven to perform the focusing operation.

Next, the spindle servo system for controlling the rotation of the disk is driven by the spindle motor drive circuit 13 from the digital signal processing circuit 6 through the servo control circuit 7 according to the signal obtained in the audio signal reproducing process.
The spindle motor 14, that is, the rotation of the disk is controlled.

Further, the tracking servo system for tracing a continuous information sequence is a combination of an actuator servo system for moving the laser beam focusing lens in the pickup 2 with fine control and a thread servo system for moving the entire servo system mechanism. Is configured.

First, in the actuator servo system, the tracking error signal obtained from the pickup 2 is amplified by the servo signal amplifier circuit 5, equalized by the servo control circuit 7 to the required characteristic, and added by the addition circuit 15 from the microcomputer control circuit 9. And the signal is amplified by the tracking actuator drive circuit 10 to drive a tracking actuator (not shown) in the pickup 2 to perform a signal train supplementing operation. Although this actuator servo system is capable of fine control, it has a narrow movable range. Therefore, the sled servo system described below moves the entire tracking actuator servo system.

In the sled servo system, in the servo control circuit 7, a signal obtained by integrating the above tracking error signal and the control signal from the microcomputer control circuit 9 are added by the addition circuit 16, and the sled motor drive circuit 11 is added.
Then, the power is amplified and the sled motor 12 is driven to move the entire pickup 2.

As described above, the actuator servo system constitutes the scanning position control means for positioning (the laser beam) of the laser light emitting portion, which is the signal scanning portion inside the pickup 2, in the radial direction of the disk, and the sled servo system constitutes the pickup 2 It constitutes a moving means to the inner circumference and the outer circumference of the disk.

In the process of reproducing the information sequence recorded on the disc, first, the signal reproduced from the pickup 2 is amplified by the RF signal amplification circuit 3, decoded by the digital signal processing circuit 6, and then the digital-analog conversion circuit 8 is obtained. To output as voice output.

With the above, a device for continuing the continuous reproducing operation and accessing an arbitrary position on the disk is constructed.

[0013]

Control of a conventional CD player will be described with reference to the flowchart of FIG. 3 and the drive time chart of FIG.

A signal for driving the sled motor shown in FIG. 1 is shown as a sled drive signal (a), an error signal for tracking servo is shown as a tracking error signal (b), and driving a tracking actuator is shown as a tracking actuator drive signal (c). In addition, FIG. 5 shows signal waveforms changed by each control shown in the flowchart of FIG.
Is shown in

First, in order to move the pickup 2 to a distant position on the disk, it is necessary to traverse the number of grooves (tracks) calculated from the target position (address) and the current position (address). The measurement of the number of transverse grooves is started using the counter (S1 in FIG. 3).

After that, the tracking servo is turned off,
A thread feed voltage is applied from the microcomputer control circuit 9 of FIG. 1 to the adder circuit 16. In response to this, the sled motor drive circuit 11 supplies the sled motor 12 with the sled drive signal (a). This is shown at point (A) in FIG.

As a result, the pickup 2 moves, and the tracking error signal (b) in FIG. 1 becomes a square-wave signal whose period changes after the point (A) shown in FIG. 5 (S2).

When the required number of grooves is passed, the jump groove number counter exceeds the specified value (S3), so the microcomputer control circuit 9 stops the thread feeding voltage to the adder circuit 16 (S4). As a result, the sled motor drive circuit 1
Thread drive signal from 1 to thread motor 12 (a)
Will also be stopped. This is shown at point (B) in FIG.

Then, after waiting for a predetermined time (S5),
The microcomputer control circuit 9 turns on the tracking servo and turns on the sled servo (S6). This is shown in FIG.
Point (C).

After that, the position information of the supplemented track is read and the access is repeated to reach the final destination.

Here, as a problem of the conventional CD player, there is a waiting time from point (B) to point (C) in FIG. The reason why this is necessary is that even if the pickup 2 main body is stopped without the sled drive signal (a),
This is because the tracking actuator in the inside becomes in a vibrating state due to inertia during movement of the pickup, and waits until this vibration is stopped.

Therefore, the waiting time described above and FIG.
Since the moving speed of the pickup 2 cannot be increased in order to reduce the vibration amplitude of the tracking actuator after the point, it has been an obstacle to shortening the access time to the target position.

[0023]

In order to solve the above problems, according to the present invention, a data signal is read by scanning the information sequence from a disc-shaped recording medium in which a data signal is recorded as a concentric circle or spiral information sequence. A signal reading unit having a signal scanning unit; a scanning position control unit for positioning the signal scanning unit in the radial direction of the disk-shaped recording medium so that the signal scanning unit scans an information row; and the signal reading unit. In a disc reproducing apparatus provided with a moving unit that moves to an inner circumference and an outer circumference of the disc-shaped recording medium, the scanning position control unit is driven by the moving unit near the completion of the movement of the signal reading unit by the moving unit. A disk reproducing device provided with a control means for driving a signal scanning section in a direction opposite to the moving direction of the signal reading means is not provided. It is intended to.

Further, according to the present invention, the signal reading means has a signal scanning unit for scanning the information sequence from a disk-shaped recording medium in which the data signal is recorded as a concentric circle or spiral information sequence, and the signal reading means, Scanning position control means for positioning the signal scanning portion in the radial direction of the disc-shaped recording medium so that the signal scanning portion scans the information sequence, and the signal reading means for the inner and outer circumferences of the disc-shaped recording medium. In a disc reproducing apparatus provided with a moving means for moving, in the vicinity of the completion of the movement of the signal reading means by the moving means, a direction opposite to the moving direction of the signal reading means by the moving means by driving the scanning position control means Driving the signal scanning unit to, and detecting the period of the signal generated by the signal scanning unit traversing the information sequence, Is to St. provide a disk reproducing apparatus and a control means for stopping detecting and driving of the signal scanning portion became larger than a certain value.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

The control of the CD player of the present invention will be described in detail with reference to the flowchart of FIG. 2 and the driving time chart of FIG.

As in the prior art, the signal for driving the sled motor in FIG. 1 is the sled drive signal (a), the tracking servo error signal is the tracking error signal (b), and the tracking actuator driving signal is the tracking signal. Actuator drive signal (c)
In addition, FIG. 4 shows signal waveforms that change according to each control shown in the flowchart of FIG.

The operation before the point (B) in FIG. 2 is the same as that of the conventional CD player, and therefore a detailed description thereof will be omitted.

That is, the respective controls (S11) to (S13) in the flowchart of FIG. 2 are the same as the respective controls (S1) to (S3) shown in FIG. 3, and in the present invention, the operation after the thread feeding is stopped. It is different from the conventional CD player. Therefore, the operation after stopping the thread feeding will be described in detail.

First, after the thread feeding is stopped, FIG.
At the same time as the sled feeding is stopped, the tracking actuator signal (c) [in this case, particularly referred to as a tracking actuator brake signal] is applied from the microcomputer control circuit 9 to the addition circuit 15 at the same time as the sled feeding is stopped (FIG. 2). S14). In response to this, the tracking actuator drive circuit 10 applies the tracking actuator drive signal (c) to the pickup 2. The signal waveform at this time is shown at point (B) in FIG.

At the same time, the tracking error signal (b) is fetched into the microcomputer control circuit 9 and the measurement of its signal period is started (S15). This signal cycle is gradually lengthened by the tracking actuator brake signal, and when the cycle exceeds a preset time value, it is determined that the moving speed has become sufficiently slow (S16), and the microcomputer control circuit 9 causes the tracking actuator brake signal to move. The application of the signal to the adding circuit 15 is stopped (S17). As a result, the application of the tracking actuator brake signal from the tracking actuator drive circuit 10 to the pickup 2 is stopped. The signal waveform at this time is shown at point (C) in FIG.

Then, due to the effect of the tracking actuator brake signal, the vibration amplitude after the sled feeding is stopped becomes smaller than before, so that after a short time waiting (S1
8) Then, the tracking servo is turned on and the sled servo is turned on (S19). The signal waveform at this time is shown at point (D) in FIG.

By the above operation, the brake of the tracking actuator acts in the direction opposite to the inertia generated during the movement after the sled feeding is stopped, and the vibration amplitude becomes smaller than before, so the braking time after the sled feeding (standby) Time) can be shortened. In addition, the moving speed of the pickup at the time of thread feeding can be increased, so that the access time can be further shortened.

The method of detecting the state of crossing the information string (crossing the groove) has been described using the tracking error signal, but other signals that change between the information string and the middle thereof, such as the RF signal of FIG. 1 ( d) may be used.

In the present embodiment, it has been described that the brake is started in synchronization with the sled stop (see S14 in FIG. 2), but it is also effective to start the brake before the sled stop.

Further, although only the CD player has been described in the present embodiment, it goes without saying that the present invention can be applied to other devices that perform similar control (for example, a disc recording / reproducing device such as an MD player or a video disc player).

[0037]

As described above in detail, according to the present invention, a signal scanning for scanning a data signal from a disc-shaped recording medium in which a data signal is recorded as a concentric circle or spiral information sequence to read the data signal. Signal reading means having a portion, scanning position control means for positioning the signal scanning portion in the radial direction of the disc-shaped recording medium so that the signal scanning portion scans the information sequence, and the signal reading means for the disc. In a disk reproducing apparatus provided with a moving means for moving the inner and outer circumferences of a linear recording medium, the scanning position control means is driven near the completion of the movement of the signal reading means by the moving means to read the signal by the moving means. Since the control means for driving the signal scanning unit in the direction opposite to the moving direction of the moving means is provided, the moving speed of the moving means can be increased. Can be suppressed in a short time the vibration of the signal scanning portion after the movement of the saw takes means.

Further, according to the present invention, the signal reading means having a signal scanning unit for scanning the information signal from the disk-shaped recording medium in which the data signal is recorded as a concentric circle or spiral information string is read. A scanning position control unit for positioning the signal scanning unit in the radial direction of the disc-shaped recording medium so that the signal scanning unit scans the information sequence; and the signal reading unit for the inner circumference of the disc-shaped recording medium. And a moving means for moving to the outer circumference, in the vicinity of the completion of the movement of the signal reading means by the moving means, the moving direction of the signal reading means by the moving means by driving the scanning position control means While driving the signal scanning unit in the opposite direction,
And a control means for detecting the period of the signal generated by the signal scanning unit traversing the information string and detecting that the period becomes larger than a certain value and stopping the driving of the signal scanning unit. Therefore, it is possible to increase the moving speed of the moving unit and suppress the vibration of the signal scanning unit after the moving of the reading unit in a short time.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a configuration of a CD player.

FIG. 2 is a flowchart for explaining the operation of the CD player of the present invention.

FIG. 3 is a drive time chart for explaining the operation of the CD player of the present invention.

FIG. 4 is a flowchart for explaining the operation of a conventional CD player.

FIG. 5 is a drive time chart for explaining the operation of a conventional CD player.

[Explanation of symbols]

 1 Disc 2 Pickup 3 RF Signal Amplification Circuit 4 Focus Actuator Drive Circuit 5 Servo Signal Amplification Circuit 6 Digital Signal Processing Circuit 7 Servo Control Circuit 8 Digital-Analog Conversion Circuit 9 Microcomputer Control Circuit 10 Tracking Actuator Drive Circuit 11 Thread Motor Drive Circuit 12 Thread Motor 13 spindle motor control circuit 14 spindle motor 15 adder circuit 16 adder circuit

Claims (2)

[Claims] 1. A signal reading unit having a signal scanning unit for scanning a data signal from a disk-shaped recording medium in which a data signal is recorded as a concentric circle or spiral information sequence, and the signal scanning unit. Scanning position control means for positioning the signal scanning portion in the radial direction of the disk-shaped recording medium so as to scan the information row, and moving means for moving the signal reading means to the inner and outer circumferences of the disk-shaped recording medium. And a signal scanning unit in a direction opposite to the moving direction of the signal reading unit by the moving unit, near the completion of the movement of the signal reading unit by the moving unit. And a control means for driving the disc. 2. A signal reading unit having a signal scanning unit for scanning the information sequence from a disk-shaped recording medium on which a data signal is recorded as a concentric circle or spiral information sequence, and the signal scanning unit. Scanning position control means for positioning the signal scanning portion in the radial direction of the disk-shaped recording medium so as to scan the information row, and moving means for moving the signal reading means to the inner and outer circumferences of the disk-shaped recording medium. And a signal scanning unit in a direction opposite to the moving direction of the signal reading unit by the moving unit, near the completion of the movement of the signal reading unit by the moving unit. And the signal scanning unit detects the period of the signal generated by the signal scanning unit crossing the information sequence, and the period is larger than a certain value. And a control means for stopping the driving of the signal scanning unit upon detecting that the signal has become depleted.