JPH07311956A - Disc unit - Google Patents

Abstract

PURPOSE:To allow quick focus servo after shifting a pickup even in case of special reproduction, e.g. search operation or scanning operation, by providing a DC voltage generating circuit generating a signal of constant voltage. CONSTITUTION:In case of a special reproduction, e.g. search operation or scanning operation, a CPU 7 delivers a control signal for turning a tracking servo OFF to a servo control circuit 8 along with an access command control signal for shifting a pickup 4 from a current track to a target track on an optical disc 1. The CPU 7 delivers a switching signal 11 to a switch 10 which is thereby turned ON to feed an objective lens/objective actuator 3 with a DC voltage voltage from a DC voltage generating circuit 9 in place of a drive signal related to the tracking servo. Consequently, vibration of the objective lens 3 is not accelerated during movement of time pickup 4 and quick focus servo can be realized after shifting the pickup 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc device for playing an optical disc on which information such as music is recorded and reproducing the information.

[0002]

2. Description of the Related Art In a conventional disc device, a pickup for reading information recorded on a track of the optical disc while irradiating the optical disc with a light beam to perform focus servo and tracking servo, and the pickup is used in a radial direction of the optical disc. It is equipped with a traverse mechanism as a transport means for moving to. This traverse mechanism moves the pickup from the inner circumference to the outer circumference of the optical disk, moves to the next track while performing focus servo and tracking servo, and performs signal processing and reproduction of the read information.

In the case of normal reproduction, the pickup is made to follow the track to continuously reproduce the information on the track. In the case of special reproduction such as search operation or scan operation, the pickup is jumped from the current track to the target track. Is playing. In such special reproduction, only the focus servo is performed and the tracking servo is turned off to move the pickup.

[0004]

However, in the above-mentioned conventional disk device, in the case of special reproduction such as search operation or scan operation, since the tracking servo is turned off, the objective lens vibrates due to the acceleration applied to the pickup, The vibration continues even after moving to the target track, and if the tracking servo is turned on and the servo is pulled in, the servo operation becomes unstable and it takes time to settle.

The present invention solves such a conventional problem, and provides an excellent disk device capable of performing quick focus servo after moving the pickup even in special reproduction such as search operation and scan operation. The purpose is to provide.

[0006]

In order to achieve the above object, the present invention rotates a spindle motor for rotating an optical disk having information recorded in spiral or concentric tracks, and a spindle motor for rotating the optical disk. An objective lens that irradiates the optical disc with a light beam to obtain a reflected light beam that carries the information, an actuator that performs tracking servo by changing the attitude of the objective lens according to a drive signal, and supports the objective lens and the actuator A pickup for reading the information, and a conveying means for moving the pickup in the radial direction of the optical disc,
A disk device having a control means for issuing an access command for moving the pickup from the current track to a target track with respect to the transport means, comprising signal generation means for generating a signal of a constant voltage, the control means comprising: When the pickup is moved from the current track to the target track, a command for giving the signal of the constant voltage to the actuator is issued instead of the drive signal related to the tracking servo.

[0007]

Therefore, according to the present invention, in the case of special reproduction such as search operation or scan operation, it is possible to perform a quick focus servo after moving the pickup.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a disk device of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a disk device of the present invention. In FIG. 1, 1 is an optical disc on which information such as music is recorded, and 2 is this optical disc 1.
A spindle motor 3 for rotating and driving the objective lens is an objective lens that converges a light beam emitted from a light source (not shown) and focuses it on a track of an optical disc. By changing the attitude of the objective lens, It includes an objective lens actuator that performs focus servo and tracking servo. Reference numeral 4 denotes a pickup that supports the objective lens 3, and includes a light source that generates a light beam and a photoelectric conversion element that receives the light beam reflected by the optical disk and converts it into an electric signal.

A pickup driving motor 5 moves the pickup 4 in the radial direction of the optical disc 1, and constitutes a traverse mechanism as a conveying means together with a position detector and other mechanical parts. Reference numeral 6 is an RF circuit for amplifying the read signal obtained from the pickup 4 and for shaping the waveform, binarizing and outputting the read signal, and for outputting a focus error signal and a tracking error signal.

Reference numeral 7 is a CPU as a control means for controlling the entire apparatus, and reference numeral 8 is a servo control circuit for controlling the spindle motor 2 and the pickup drive motor 5 by a control signal from the CPU 7. The servo control circuit 8 supplies drive signals for focus servo and tracking servo to the objective lens actuator 3 based on the focus error signal and the tracking error signal from the RF circuit 6. In the case of special reproduction such as search operation or scan operation, the tracking servo is turned off, so that the line of the drive signal related to the tracking servo in the servo control circuit 8 is in an open state (high impedance).

Reference numeral 9 is a DC voltage generating circuit as a signal generating means for generating a DC voltage which is a constant voltage signal. 1
Reference numeral 0 is a switch that is turned on or off according to the switching signal, and when it is on, supplies a DC voltage to the actuator 3. Reference numeral 11 is a switching signal given from the CPU 7 to the switch 10.

Next, the operation of the disk device configured as shown in FIG. 1 will be described. In the case of special reproduction such as search operation or scan operation, the CPU 7 issues a control signal for turning off the tracking servo to the servo control circuit 8 and moves the pickup 4 from the current track of the optical disc 1 to the target track. A control signal of an access command is issued. In this case, the CPU 7 applies the switching signal 11 to the switch 10 to turn on the switch 10, and instead of the drive signal related to the tracking servo, supplies the DC voltage from the DC voltage generation circuit 9 to the actuator 3.

As a result, the objective lens 3 does not vibrate due to the acceleration during the movement of the pickup 4, and even in the special reproduction such as the search operation or the scan operation, the focus servo is quickly performed after the pickup is moved. You can

[0015]

As is apparent from the above embodiment, the present invention is applicable to special reproduction such as search operation and scan operation.
By giving a signal of a constant voltage to the actuator of the objective lens instead of the drive signal of the tracking servo, there is an effect of performing a quick focus servo after moving the pickup.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a disk device of the present invention.

[Explanation of symbols]

 1 Optical Disc 2 Spindle Motor 3 Objective Lens / Objective Lens Actuator 4 Pickup 5 Pickup Drive Motor 6 RF Circuit 7 CPU 8 Servo Control Circuit 9 DC Voltage Generation Circuit 10 Switch 11 Switching Signal

Claims (1)

[Claims] 1. An optical disc having information recorded on spiral or concentric circular tracks, a spindle motor for rotationally driving the optical disc, and a reflected light for carrying the information by irradiating a light beam on the rotating optical disc. An objective lens that obtains a beam, an actuator that performs tracking servo by changing the attitude of the objective lens according to a drive signal, a pickup that supports the objective lens and the actuator to read the information, and this pickup A disk device having a transporting unit that moves in a radial direction and a control unit that issues an access command to the transporting unit to move the pickup from a current track to a target track, the signal generating unit generating a signal of a constant voltage. Means for controlling the current track. A disk device, wherein when the pickup is moved to a target track, a command for giving a signal of the constant voltage to the actuator is issued instead of a drive signal related to the tracking servo.