JPH0746465B2 - Disc player device - Google Patents

Description

The present invention relates to a disc player device for reproducing a disc by rotating the disc at a constant linear velocity, and in particular devises a rotation control of a disc motor when a pickup is fast forwarded. Disk player device.

(B) Conventional Technology There is a disc player device that reproduces by rotating a disc at a constant linear velocity (CLV) in which the length of a signal track traced by a pickup per unit time is constant. A typical example of such a CLV disc player device is a CD.
2. Description of the Related Art There is known a CD player device that reproduces a standard disc (CD). In the case of the CD player device, for example, depending on whether the signal read by the pickup is larger or smaller than the shortest signal period (3T) of the recording signal in the CD system, or whether it is larger or smaller than the longest signal period (11T). A frame synchronization signal (11T-1) that determines whether the rotation is fast or slow and that indicates the end of one block of recording signal (one frame)
The disk is controlled to rotate at a constant linear velocity by a method such as determining whether or not the disk is properly rotated depending on whether or not the reference clock is counted a predetermined number of times during the period (1T) being read.

By the way, most of the disc player devices are provided with a signal search means so that a designated music number can be found and a designated section can be reproduced repeatedly. The signal search means is created, for example, based on position index data indicating position information previously recorded on the disc, and the target data according to the position of the target signal track to be searched and the reproduction according to the trace position by the pickup. A comparison is made with the position data, and the feed amount and direction of the pickup are determined according to the comparison output to perform the search. Here, in an optical disc player device that optically reads a signal by using an optical pickup such as a CD player device, when the target signal track position is apart from the trace position by the pickup to some extent, the disc is moved in the radial direction of the disc. , First, the entire pickup is fast-forwarded to perform coarse feed to move the trace position to the vicinity of the target signal track, and then the movable optical parts (objective lens etc.) in the pickup are displaced to perform the track jump of the trace position. In general, a target signal track is searched by performing a minute feed to speed up the search operation.

(C) Problem to be Solved by the Invention By the way, during the fast-forwarding of the pickup, the tracking servo that causes the read beam from the pickup to follow the signal track is removed so that the read beam crosses the signal track at high speed. Therefore, at this time, the signal recorded on the disc cannot be read. Therefore, during the fast-forwarding of the pickup, the rotation control for rotating the disc at a constant linear velocity cannot be performed, so that the rotation number of the disc shifts when the fast-forwarding signal of the pickup is performed. In this case, the number of revolutions of the disc depends on the trace position of the pickup immediately before the fast-forwarding. Is in the state of
On the contrary, when the pickup is fast-forwarded in the inner peripheral direction of the disc, the disc is rotated at a lower speed than the trace position of the pickup. Then, after the fast-forwarding of the pickup is completed and the tracking servo is turned on, the rotational speed of the disc is controlled. Therefore, if the pickup's fast-forwarding distance is large and the disc's rotational speed deviates significantly when the pickup's fast-forwarding ends, the time from the pickup's fast-forwarding until the signal is read becomes large. It became an obstacle to shortening the search time.

(D) Means for Solving the Problems The present invention has been made in view of the above-mentioned points, and a disk motor drive circuit for driving a disk motor as a drive source for rotating a disk, and a pickup as a whole have a disk diameter of the disk. A feed motor drive circuit that drives a feed motor that is a drive source that moves in a direction, and a fast feed signal that is supplied to the feed motor drive circuit to continuously drive the feed motor to perform a fast feed operation of a pickup. And a signal generating means for generating a fast-forwarding signal having a different polarity depending on the direction in which the pickup is sent, and the fast-forwarding signal generated from the signal generating means is applied to the disk motor drive circuit. So that the disc motor is decelerated when the disc is fast forwarded to the outer periphery of the disc. The disk motor is accelerated when the up-speed is fast-forwarded in the inner peripheral direction of the disk.

(E) Operation The present invention, when performing fast-forwarding to feed the entire pickup,
Focusing on the fact that the rotation direction of the feed motor for fast-forwarding is changed by using signals of different polarities to change the direction in which the pickup is fast-forwarded, the disc motor is decelerated when the pickup is fast-forwarded to the outer peripheral direction of the disc. In addition, a signal for fast-forwarding is applied to the disc motor drive circuit so that the disc motor is accelerated when the pickup is fast-forwarded in the inner circumferential direction of the disc. Close to
After the fast-forward operation is completed, signal reading is restarted in a short period of time.

(F) Embodiment FIG. 1 is a circuit block diagram showing an embodiment of the present invention.
(1) is a disk servo control means for controlling the disk to rotate at a constant linear velocity and for controlling other rotational operations of the disk. The disk rotation state is judged by using a recording signal read from the disk. Positive and negative output terminals (2) and (3) that output a pulse width modulation signal (PWM signal) whose pulse width is controlled according to
The positive output terminal (2) outputs a PWM signal for rotating the disk (positive rotation), and the negative output terminal (3) for rapidly decelerating the disk rotation.
It is designed to output a signal.

( 4 ) is a disk motor drive circuit for driving a disk motor (5) which is a drive source for rotating the disk,
The PWM signal output from the positive output terminal (2) is input to the non-inverting input terminal via the first integrating circuit ( 6 ), and the PWM signal output from the negative output terminal (3) is the second
An operational amplifier (8) which is input to the inverting input terminal through the integrating circuit ( 7 ) and supplies a drive current to the disk motor (5).
An oscillation preventing capacitor (9) and a resistor (10) connected between the output terminal of the operational amplifier (8) and the ground,
A resistor (11) for generating a voltage according to the current passed through the disk motor (5), a resistor (12) and a capacitor (1) for negatively feeding back the voltage generated at one end of the resistor (11).
3) and is configured to drive the disk motor (5) with phase compensation.

(14) is a feed servo control means for performing feed servo control for sending the entire pickup in the radial direction of the disk by sending a pickup base (not shown) to which the pickup is attached. Positive and negative outputs that output a feed servo signal for moving the pickup base to keep the objective lens near the center according to the radial deviation of the disc of the objective lens that is displaceably provided in the pickup. Terminals (15) and (16) are provided, and a feed servo signal for sending the pickup base in the outer peripheral direction of the disc is output from the positive output terminal (15),
The negative output terminal (16) outputs a feed servo signal for sending the pickup in the inner peripheral direction of the disk.

( 17 ) is a feed motor drive circuit for driving the feed motor (18) which is a drive source for moving the pickup base. The fast-forward signal output from the positive output terminal (15) of the feed servo control means (14) is The fast-forward signal output from the negative output terminal (16) of the feed servo control means (14) while being input to the non-inverting input terminal via the input resistance (19) is inverted input via the input resistance (20). An operational amplifier (21) which is input to the end and supplies a drive current to the feed motor (18), and an oscillation preventing capacitor (22) and a resistor (23) which are connected between the output end of the operational amplifier (21) and the ground. And a resistor (24) and a capacitor (25) forming a negative feedback path of the operational amplifier (21),
It is configured to drive the feed motor (18) with phase compensation.

(26) is a signal generating means for forcibly moving the pickup base when performing a signal search and generating a fast-forward signal for fast-forwarding the entire pickup in the radial direction of the disc. "H" for fast-forwarding the pickup It has positive and negative output terminals (27) and (28) for outputting a level fast-forward signal, and outputs a fast-forward signal for fast-forwarding the pickup in the outer peripheral direction of the disc from the positive output terminal (27), The negative output terminal (28) outputs a fast-forward signal for fast-forwarding the pickup in the inner circumferential direction of the disc. Then, the signal generating means (2
The fast-forward signal output from the positive output terminal (27) of 6) is supplied to the operational amplifier (21) of the feed motor drive circuit ( 17 ) via the backflow prevention diode (29) and the level setting resistor (30). Of the operational amplifier (8) of the disk motor drive circuit ( 4 ) via the backflow prevention diode (31) and level setting resistor (32). It is designed to be supplied to the inverting input terminal. On the other hand, the fast-forward signal output from the negative output terminal (28) of the signal generating means (26) is a reverse current preventing diode (33) and a level setting resistor (34).
It is configured to be supplied to the inverting input terminal of the operational amplifier (21) of the feed motor drive circuit ( 17 ) via the diode (35) for backflow prevention and the resistor (36) for level setting. Is supplied to the non-inverting input terminal of the operational amplifier (8) of the disk motor drive circuit ( 4 ).

Further, the resistance (37) connected to the positive output terminal (15) of the feed servo control means (14) is output from the positive output terminal (27) of the signal generation means (26) together with the resistance (30). It is set so that the fast-forward signal is applied to the non-inverting input terminal of the operational amplifier (21) of the feed motor drive circuit ( 17 ) at an appropriate voltage level, and the negative output terminal (16) of the feed servo control means (14) is set. The resistor (38) connected to the inverting input terminal of the op-amp (21) has an appropriate voltage level for the fast-forward signal output from the negative output terminal (28) of the signal generating means (26) together with the resistor (34). It is set to be applied.

Further, the resistance (39) connected to the positive output terminal (2) of the disk servo control means (1) is output from the negative output terminal (28) of the signal generation means (26) together with the resistance (36). It is set so that the fast-forward signal is applied to the non-inverting input terminal of the operational amplifier (8) of the disk motor drive circuit ( 4 ) at an appropriate voltage level, and the negative output terminal (3) of the disk servo control means (1) is set. The resistor (40) connected to the inverting input terminal of the operational amplifier (8) has an appropriate voltage level for the fast-forward signal output from the positive output terminal (27) of the signal generating means (26) together with the resistor (32). It is set to be applied.

Next, the operation will be described with reference to FIG.

In the disc reproducing state, the PWM signal is output from the positive output terminal (2) of the disc servo control means (1). The PWM signal is integrated by the first integrating circuit ( 6 ) and input to the non-inverting input terminal of the operational amplifier (8). Therefore, a DC signal having a voltage level obtained by smoothing the PWM signal is applied to the non-inverting input terminal of the operational amplifier (8).
It will be rotated at the number of rotations according to the pulse width of the PWM signal.

By the way, the PWM signal output from the positive output terminal (2) of the disk servo control means (1) is a predetermined line depending on the rotation state of the disk, which is judged by using a recording signal read from the disk. The pulse width is modulated so that it is rotated at speed. That is, when the reproduction progresses, the trace position by the pickup is moved in the outer peripheral direction, and it becomes necessary to decelerate the rotation of the disk, the pulse width gradually increases from the positive output terminal (2) of the disk servo control means (1). The PWM signal that becomes small comes to be output. Therefore, the voltage level of the DC signal applied to the non-inverting input terminal of the operational amplifier (8) is reduced and the drive voltage for driving the disc motor (5) is reduced, so that the rotation of the disc is decelerated. Become. On the contrary, when the trace position by the pickup is moved in the inner peripheral direction and it is necessary to accelerate the rotation of the disk, the PWM signal with a large pulse width is output from the positive output terminal (2). become. Therefore, the voltage level of the DC signal applied to the non-inverting input terminal of the operational amplifier (8) is increased and the drive voltage for driving the disk motor (5) is increased, so that the rotation of the disk is accelerated. Become.

Therefore, during reproduction of the disc, the disc can be rotated at a constant linear velocity.

On the other hand, during playback of the disc, the feed servo signals are output from the positive and negative output terminals (15) and (16) of the feed servo control means (14) in response to the displacement of the trace position of the disc by the pickup. Is output. The objective lens provided in the pickup is displaced in order to move the trace position of the pickup by following the signal track, but the positive and negative output terminals (1
The feed servo signals respectively output from 5) and (16) depend on the deviation amount of the objective lens, and are generated to return the objective lens to the mechanical center. That is, the positive or negative output terminal (15) or (16)
The feed servo signal is generated from the operational amplifier (21)
When the feed servo signal is input to the non-inverting input terminal or the inverting input terminal, the operational amplifier (21) generates an output signal having a different polarity depending on the input terminal to which the feed servo signal is input. Therefore, the feed motor (18) is rotated in different directions depending on which of the positive and negative output terminals (15) and (16) outputs the feed servo signal. Here, when the amount of deviation of the objective lens in the outer peripheral direction of the disc reaches a predetermined amount, a feed servo signal is output from the positive output terminal (15) so that the pickup base is displaced in the outer peripheral direction of the disc. When the feed motor (18) is rotated and the amount of deviation of the objective lens in the inner circumferential direction of the disc reaches a predetermined amount, a feed servo signal is output from the negative output terminal (16),
The feed motor (18) is rotated so that the pickup base is displaced in the inner peripheral direction of the disc. Therefore, the objective lens is returned to the mechanical center without shifting the trace position of the pickup, and the radial displacement of the trace position is performed.

Next, the circuit operation when the trace position of the pickup is fast-forwarded will be described.

When the amount (distance) of displacing the trace position of the pickup such as performing a signal search is equal to or larger than a predetermined amount and it is necessary to move the pickup base, the signal generating means (26 ) Positive or negative output terminal (27) or (28) outputs a fast-forward signal. Since the fast-forward signal output from the positive output terminal (27) is input to the non-inverting input terminal of the operational amplifier (21) of the feed motor drive circuit ( 17 ), the feed motor (18) is picked up by the fast-forward signal. The base is rotated so as to be displaced in the outer peripheral direction of the disk. Further, since the fast-forward signal output from the negative output terminal (28) is input to the inverting input terminal of the operational amplifier (21), the feed motor (18) uses the fast-forward signal to move the pickup base to the inner circumference of the disc. It is rotated so that it is displaced in the direction. Since the fast-forward signal output from the positive or negative output terminal (27) or (28) is output for a period corresponding to the displacement amount of the trace position, the pickup base is displaced by the required amount. .

Therefore, the trace position of the pickup can be arbitrarily fast-forwarded by the fast-forward signal generated by the signal generating means (26).

By the way, the fast-forward signal generated from the signal generating means (26) is supplied to the feed motor drive circuit ( 17 ) and also to the disk motor drive circuit ( 4 ). That is, the fast-forward signal output from the positive output terminal (27) of the signal generating means (26) is input to the inverting input terminal of the operational amplifier (8) of the disk motor drive circuit ( 4 ) via the diode (31). The fast-forward signal output from the negative output terminal (28) of the signal generating means (26) is the diode (3
It is input to the non-inverting input terminal of the operational amplifier (8) via 5). Here, when the fast-forward signal is output from the positive output terminal (27), it is when the trace position of the pickup is fast-forwarded in the outer peripheral direction of the disc.
When the fast-forward signal is output from the negative output terminal (28), the trace position of the pickup is fast-forwarded in the inner circumferential direction of the disc. Further, when a fast-forward signal is output from the positive or negative output terminal (27) or (28), a PWM signal with a constant pulse width is output from the positive output terminal (2) of the disk servo control means (1). The disc motor (5) is driven to rotate the disc at a predetermined linear velocity. Therefore, when the trace position of the pickup is fast-forwarded in the outer peripheral direction of the disc, the disc motor (5) is reduced in rotation speed by the fast-forward signal, while the disc motor (5) is fast-forwarded in the inner-peripheral direction of the disc. The rotation speed of the motor (5) is increased by the fast-forward signal.

Therefore, when the trace position is moved in the outer peripheral direction and it is necessary to decelerate the rotation of the disc in order to rotate the disc at a constant linear velocity, the rotation of the disc is decelerated by the fast-forward signal generated by the signal generating means (26). On the other hand, when the trace position is moved in the inner circumferential direction and it is necessary to accelerate the rotation of the disk in order to rotate the disk at a constant linear velocity, it is generated from the signal generating means (26). The fast-forward signal will accelerate the rotation of the disc. Then, to the extent that the rotation of the disk is decelerated by the fast-forward signal output from the positive output terminal (27) of the signal generating means (26), the inverting input of the operational amplifier (8) is made by the resistors (32) and (40). The signal level applied to the end is set and adjusted, and the signal generating means (26)
The degree to which the rotation of the disk is accelerated by the fast-forward signal output from the negative output terminal (28) of the signal level of the signal applied to the non-inverting input terminal of the operational amplifier (8) by the resistors (36) and (39). Is set and adjusted. For that reason,
Even after the pickup is fast-forwarded in either the outer peripheral direction or the inner peripheral direction of the disc, the time required for the disc to return to normal rotation is shortened.

(G) Effect of the Invention As described above, according to the present invention, the disc motor is accelerated or decelerated according to the feed direction of the pickup when the pickup is fast forwarded. Can be returned to normal rotation in a short time, and the search time for the target signal track can be shortened. In particular, according to the present invention, the fast-forward signal generated from the signal generation circuit provided for performing the fast-forward operation of the pickup is used as it is as an input signal to the disk motor drive circuit without being processed. , It is not necessary to provide a dedicated circuit to operate the input signal input to the disk motor drive circuit for accelerating and decelerating the disk motor, and it is possible to shorten the search time of the signal track with a simple circuit configuration. I can.

[Brief description of drawings]

The drawing is a circuit diagram showing an embodiment of the present invention. Description of main drawing numbers (1) …… Disk servo control means, ( 4 ) …… Disk motor drive circuit, (5) …… Disk motor, (14)
...... Feed servo control means, ( 17 ) ...... Feed motor drive circuit, (18) ...... Feed motor, (26) ...... Signal generation means.

Claims (1)

[Claims] 1. In a disc player device for rotating a disc at a constant linear velocity to read a signal recorded on the disc by a pickup, a disc motor serving as a drive source for rotating the disc, and the disc motor are driven. A disk motor drive circuit having an acceleration input terminal for inputting a control signal for accelerating the disk motor and a deceleration input terminal for inputting a control signal for decelerating the disk motor, and a drive source for moving the entire pickup in the radial direction of the disk. A feed motor, an input terminal for inputting a control signal for driving the feed motor and driving the feed motor in one direction, and an input terminal for inputting a control signal for driving the feed motor in the other direction. Feed motor drive circuit and pickup fast feed A signal generating circuit for generating the fast-forward signal so as to selectively input a fast-forward signal for performing an operation to different input terminals of the feed motor drive circuit according to the feed direction of the pickup; When a fast-forward signal is input to the feed motor drive circuit to send the pickup to the outer peripheral side of the disc, the fast-forward signal is input to the deceleration input terminal of the disc motor drive circuit, and the pickup is moved from the signal generation circuit to the inside of the disc. A disc player device, characterized in that, when a fast-forward signal is inputted to the feed motor drive circuit to be sent to the peripheral side, the fast-forward signal is inputted to an acceleration input terminal of the disc motor drive circuit.