JPH01178176A - Scanning operation controller for disk player - Google Patents

Abstract

PURPOSE:To easily perform the retrieval of an image by generating a position detecting signal corresponding to the radius position of the information detecting point of a pickup, and driving a slider which supports the pickup at speed corresponding to the position detecting signal. CONSTITUTION:The device is constituted in such a way that the position detecting signal corresponding to the radius position of the information detecting point of the pickup 3 is generated, and the slider 11 which supports the pickup 3 is driven at the speed corresponding to the position detecting signal. Since the number of tracks on which the information detecting point of the pickup 3 is moved in a unit time changes corresponding to the radius position, it is possible to keep the action of the image obtained by scanning a CLV disk in which a large amount of information recordable on a track of one circumference at an outer periphery compared with an inner periphery constant. In such a way, it is possible to perform the retrieval of the image easily.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a scanning operation control device in a disc player.

BACKGROUND ART The so-called scan operation is an operation in which the information detection point of the pickup alternates between a track-jumping movement (jump operation) and an operation in which the information detection point of the pickup tracks the track. Reproduction is possible.

A conventional scan operation control device for controlling such a scan operation is a device that forcibly moves the slider at a constant speed by turning off a slider servo that controls the relative position of a slider carrying a pickup in the radial direction of the recording disk. has already been devised. According to this conventional device, when the amount of deflection of the tracking actuator built into the pickup gradually increases and the actuator approaches the limit of its movable range, the tracking servo loop is opened to protect the tracking actuator. A protective means is activated to return the tracking actuator to the midpoint of its range of motion. The information detection point jumps across the track due to the action of this tracking actuator. Further, after the jump operation, the tracking servo loop is closed, the information detection point tracks the track, and the recorded information is read until the protection means is activated again.

On the other hand, recording disks include CAV disks with a constant angular velocity and CLV disks with a constant linear velocity. CA
In a V-disc, the amount of information recorded in one recording track over the entire recording surface is constant, for example, 2
A video signal for one field is recorded. On the other hand, in a CLV disc, the amount of information recorded on each recording track on the outer circumference is large; for example, on the innermost circumference, video signals for two fields are recorded, and on the outermost circumference, video signals for one frame are recorded. One video signal is recorded.

Therefore, in the conventional scan operation control device, since the moving speed of the slider is constant, the number of tracks that the pickup moves within a unit time is constant over the entire recording surface of the disk, so when scanning a CLV disk, As the pickup moves toward the outer periphery, the playback speed increases and the image moves faster, making it difficult to search for images by scanning.

SUMMARY OF THE INVENTION The present invention has been made in view of the drawbacks of the conventional devices as described above, and provides a scanning operation control device that can maintain constant movement of an image obtained during scanning of a CLv disk. The purpose is to provide

The scanning operation control device for a disk player according to the present invention is configured to generate a position detection signal according to the radial position of the information detection point of the pickup, and drive the slider supporting the pickup at a speed according to the position detection signal. ing.

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

In FIG. 1, a disk 1 is rotationally driven by a spindle motor 2, and recorded information on the disk 1 is read by a pickup 3. The pickup 3 includes a laser diode, an objective lens, a focus actuator, a tracking actuator, a photodetector, and the like. The output of the photodetector of the pickup 3 is supplied to a demodulation circuit 4 and at the same time to a focus servo circuit 5 and a tracking servo circuit 6. The focus actuator and tracking actuator in the pickup 3 are driven by the focus servo circuit 5 and the tracking servo circuit 6, and the laser light emitted from the laser diode in the pickup 3 is focused on the recording surface of the disk 1 for information detection. A light spot is formed and controlled to be located on the track. The tracking servo circuit 6 is designed to open the tracking servo loop when the absolute value of the drive signal level of the tracking actuator exceeds a predetermined value, thereby increasing the amount of deviation of the tracking actuator and causing mechanical damage. A protection circuit is provided to prevent this.

Further, the coil current supplied to the coil for driving the tracking actuator in the pickup 3 is supplied to the current detection circuit 7. A current detection signal corresponding to the coil current is output from the current detection circuit 7 and supplied to the slider servo circuit 8. In the slider servo circuit 8, the current detection signal is amplified and phase compensated. The output of the slider servo circuit 8 becomes a drive signal for the slider motor 10 via a motor drive circuit 9. This slider motor 10 drives a slider 11 on which the pickup 3 is mounted and is movable in the disk radial direction, and the tracking actuator in the pickup 3 is controlled so as to be located at the midpoint of its movable range.

In the demodulation circuit 4, the output of the pickup 3 is subjected to FM demodulation processing to reproduce a video signal. The reproduced video signal output from this demodulation circuit 4 is stored in the video memory (
(not shown) etc. at the same time as the code separation circuit 13.
is supplied to The code separation circuit 13 is configured to separate and output a frame number or time code inserted into a portion corresponding to a predetermined scanning line in a reproduced video signal. The output data of this code separation circuit 13 is transmitted to a controller 14 consisting of a microcomputer.
is supplied to The controller 14 is supplied with various commands in response to key operations on the operating section 15.

In the controller 14, the processor processes input data according to a program stored in advance in the RoM, controls the motor drive circuit 9, sends data to the D/A converter 16, etc.

The data sent from the controller 14 is converted into an analog signal in the D/A conversion circuit 16. The output of the D/A conversion circuit 16 is supplied to the motor drive circuit 9. The motor drive circuit 9 drives the slider motor 10 by the output of the slider servo circuit 8 when the input switching command is not supplied from the controller 9, and performs D/A conversion when the input switching command is supplied from the controller 14. circuit 1
The slider motor 10 is configured to be driven by the output of 6.

The operation of the processor in the microcomputer forming the controller 14 in the above configuration will be explained with reference to the flowchart in FIG.

When a ski/yan command is issued by operating a key on the operation unit 15 during execution of a main routine or the like, the processor moves to step S1 and starts sending an input switching command to the motor drive circuit 9 to perform D/A conversion. The slider motor 0 is driven by the output of the circuit 16. Next, the processor takes in data indicating the frame number or time code output from the code separation circuit 13 (step S2). Next, the processor calculates the relative position (hereinafter referred to as radial position) r of the information detection point of the pickup 3 in the radial direction on the disk 1 from the captured data (step S3). Next, the processor calculates the speed V of the slider 1 using the following formula (step S4
).

Vo·rQ V−□ (1) Here, vo is the moving speed of the slider 1 at the innermost circumference, and ro is the radius of the innermost circle.

Next, the processor sends data corresponding to V to the D/A conversion circuit 16 (step S5), and determines whether a scan command is continuously issued (step S6).
). If it is determined in step S6 that the scan command is being issued continuously, the processor moves to step S2 again, and if it is determined that the scan command is not being issued, the processor moves to step S7. stops sending the input switching command to the motor drive circuit 9,
Execution of the routine that was being executed immediately before proceeding to step S1 is resumed.

In step S4 in the above operation, a velocity V that is inversely proportional to the radial position r of the information detection point of the pickup 3 is calculated, and data corresponding to this velocity V is supplied to the D/A conversion circuit 16 in step S5. A signal inversely proportional to the radial position r is supplied from the /A conversion circuit 16 to the motor drive circuit 9. As a result, as the slider 11 moves toward the outer circumference due to the scan operation, the slider 1
1's moving speed gradually decreases in inverse proportion to the radial position r.

Now, when the slider 11 moves toward the outer circumference, the amount of deflection of the tracking actuator built into the pickup gradually increases, and when the actuator approaches the limit of its movable range, a tracking servo loop is activated to protect the tracking actuator. The protection circuit opens and the tracking actuator returns to the midpoint of its movable range. The information detection point jumps across the track due to the action of this tracking actuator.

Further, after the jump operation, the tracking servo loop is closed, the information detection point tracks the track, and the recorded information is read until the protection means is activated again.

The number of tracks to which the information detection point of the pickup 3 moves within a unit time due to the scanning operation performed as described above is:
Since the moving speed of the slider 11 gradually decreases in inverse proportion to the radial position r, it becomes inversely proportional to the radial position r. Therefore, the playback speed is constant regardless of the radial position r, the movement of the image is constant, and the screen can be easily searched.

FIG. 3 is a diagram showing another embodiment of the present invention, which includes a disk 1, a spindle motor 2, a pickup 3, a demodulation circuit 4, a focus servo circuit 5, a tracking servo circuit 6, a current detection circuit 7, and a slider servo circuit. 8, a motor drive circuit 9, a slider motor 10, a slider 11, a code separation circuit 13, a controller 14, and an operation section 15 are connected in the same manner as in the apparatus shown in FIG. However, in this example, it consists of a resistor and a slider that is in contact with the resistor and is movable on the resistor, and the position of the slider on the resistor changes depending on the position of the slider 11. A potentiometer 17 is provided which is connected to. A power supply vCc is supplied to one end of the resistor of the potentiometer 17 via a resistor R1, and the other end of this resistor is grounded via a resistor R2. Therefore, a signal corresponding to the radial position r is derived from the slider of the potentiometer 17.

The signal led to the slider of the potentiometer 17 is amplified by an inverting amplifier 19 consisting of an operational amplifier 18 and resistors R3, R, . . . R5, and then supplied to the motor drive circuit 9.

In the above configuration, the operating section 15 is similar to the device shown in FIG.
If an input switching command is supplied from the controller 14 to the motor drive circuit 9 in response to a scan command issued by key operation, the same effect as that of the device shown in FIG. 1 will work.

In the above embodiment, the direction in which the slider 11 moves is in the direction of the outer periphery, but in the device shown in FIG. In this case, an inverting amplifier that inverts the output of the inverting amplifier 19 may be separately provided so that the slider 11 can also move in the inner circumferential direction, and the same effect can be obtained in this case as well.

Effects of the Invention As detailed above, the scanning operation control device for a disc player according to the present invention generates a position detection signal according to the radial position of the information detection point of the pickup, and controls the slider carrying the pickup in response to the position detection signal. Since the drive is configured to drive at a speed that is equal to the speed of the pickup, the number of tracks that the pickup's information detection point moves within a unit time changes depending on the radial position, so the amount of information that can be recorded on one track on the outer circumference is limited. The movement of images obtained by scanning a CLV disk with a large amount of image can be made constant, and image retrieval can be facilitated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the processor in the device shown in FIG. 1, and FIG. 3 is a circuit block diagram showing another embodiment of the invention. It is. Explanation of symbols of main parts 3...Pickup 9...Motor drive circuit 13...Code separation circuit 14...Controller 17...Potentiometer 18...Inverting amplifier applicant Pioneer Corporation

Claims (1)

[Claims] a slider that carries a pickup that is movable in the radial direction of the disk and includes a tracking actuator that adjusts the relative position of the information detection point in a direction substantially orthogonal to the track of the recording disk; a tracking error signal generating means for generating a tracking error signal according to the amount of deviation; a tracking servo loop for driving the slider and the tracking actuator so as to minimize the tracking error signal; a protection means for opening the tracking servo loop to protect the tracking actuator when the tracking servo loop exceeds a value, the scanning operation control device for a disk player comprising: scanning operation control in a disk player, comprising: a position detecting means for generating a position detecting signal according to the position detecting signal; and a driving means for driving the slider at a speed corresponding to the position detecting signal in response to a command. Device.