JPH07311953A - Disc unit - Google Patents

Abstract

PURPOSE:To protect an objective lens against fracture or deformation due to collision against the inner wall of a housing chamber by detecting the speed of the objective lens with respect to a track and imparting a CPU with a function for decreasing the relative speed. CONSTITUTION:An optical means 3 comprises an objective lens for irradiating an optical disc 1 with an optical beam to obtain a reflected light beam carrying information, and an actuator for altering the position and attitude of the objective lens depending on a drive signal. A pickup 4 reads out information while supporting the objective lens and the actuator and moved in the radial direction of the optical disc 1 by means of a pickup drive motor 5. A CPU 8 generally controls the disc unit and delivers an access command for shifting the pickup 4 from a current track to a target track. The CPU is also provided with means or function for detecting the relative speed between the track and the objective lens when the pickup 4 is moving and decreasing the relative speed as required.

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 A conventional disk device is equipped with a pickup which irradiates an optical disk with a light beam and which is reflected by the optical disk to obtain a light beam carrying recorded information. The pickup is provided with an objective lens that converges the light beam, a housing chamber that houses the objective lens, and an actuator that changes the posture or position of the objective lens in the housing chamber according to a drive signal. This actuator is
Focus servo and tracking servo are performed by changing the posture or position of the objective lens according to the focus error signal and the tracking error signal. Furthermore, a traverse mechanism is provided as a conveying means for moving the pickup in the radial direction of the optical disc.

[0003]

However, in the above-mentioned conventional disk device, the tracking servo is turned off during special reproduction such as search operation and scan operation.
Since the displacement of the objective lens in the tracking direction is entrusted to the free vibration of the spring, while the pickup is moving at high speed, vibration disturbance is applied to the objective lens, which similarly collides with the inner wall of the storage chamber and damages or deforms it. It was

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an excellent disk device in which the objective lens does not collide with the inner wall of the accommodation chamber to be damaged or deformed. To do.

[0005]

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 changes the position and orientation of the objective lens according to a drive signal to perform focus servo and tracking servo, and the objective. A pickup that supports the lens and the actuator to read the information, a conveying unit that moves the pickup in the radial direction of the optical disk, and an access command that issues an access command to the conveying unit to move the pickup from a current track to a target track. And a control means, which is currently A direction detecting means for detecting the moving direction of the track and the objective lens while the pickup is moving from the lock to the target track, and a braking means for giving a deceleration drive signal for reducing the relative speed to the actuator. Is characterized by.

[0006]

Therefore, according to the present invention, it is possible to prevent the objective lens from colliding with the inner wall of the accommodation chamber and being damaged or deformed even when acceleration is applied to the objective lens in special reproduction such as search operation or scan operation. To do.

[0007]

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 the optical disc is an optical means for converging a light beam emitted from a light source (not shown) and focusing it on a track of an optical disk. The optical means includes an objective lens and its It includes an objective lens actuator that performs focus servo and tracking servo by changing the attitude of the objective lens. Reference numeral 4 denotes a pickup that supports the optical means 3, and incorporates 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 a read signal obtained from the pickup 4 and for binarizing the waveform to output the same, and outputting a focus error signal and a tracking error signal. Reference numeral 7 is the RF circuit.
It is a signal processing circuit for inputting a binarized signal output from the circuit and performing various processes such as edge detection, CLV control signal extraction, EFM demodulation, error detection and correction.

Reference numeral 8 denotes a CPU as a control means for controlling the entire apparatus, which issues a signal processing command to the signal processing circuit 7 and outputs a control signal for performance control based on the signal obtained from the signal processing circuit 7. To generate. 9 is this C
A servo control circuit that controls the spindle motor 2 and the pickup drive motor 5 according to a control signal from the PU 8. The servo control circuit 9 gives drive signals for focus servo and tracking servo to the optical means 3 based on the focus error signal and the tracking error signal from the RF circuit 6.

Next, the operation of the embodiment of the disk device shown in FIG. 1 will be described. In the case of special reproduction such as search operation or scan operation, the CPU 8 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, 90 obtained from the RF circuit 6
The direction in which the objective lens moves with respect to the disc can be determined by the two types of reproduction signals whose phases are shifted.

Therefore, by detecting the moving direction based on the phase relationship between the two kinds of signals, the relative moving direction and speed of the objective lens of the pickup 4 crossing the track can be detected. If this relative speed is too fast, the objective lens may collide with the inner wall of the accommodation chamber. Therefore, the CPU 8 servo-controls a command for giving a drive signal to the actuator in a direction opposite to the moving direction of the objective lens. Supply to the circuit 9. That is, the CPU 8 is provided with a speed detecting means for detecting the relative speed between the track and the objective lens and a braking means for giving a deceleration drive signal for decreasing the relative speed to the servo control circuit 9.

[0013]

As is apparent from the above embodiment, the present invention is applicable to special reproduction such as search operation and scan operation.
Even when the pickup is moved at a high speed, the moving direction of the track and the objective lens is detected by the speed detecting means, and the relative speed thereof is reduced by the braking means, so that the objective lens collides with the inner wall of the accommodation chamber. Avoid the
This has the effect of preventing damage or deformation of the objective lens.

[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 Optical Means 4 Pickup 5 Pickup Drive Motor 6 RF Circuit 7 Signal Processing Circuit 8 CPU 9 Servo Control Circuit

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 focus servo and tracking servo by changing the position and orientation of the objective lens according to a drive signal, and a pickup that supports the objective lens and the actuator to read the information, A disk device comprising: a transport unit that moves a pickup in a radial direction of the optical disc; and a control unit that issues an access command to the transport unit to move the pickup from a current track to a target track. , From current track to target track A disk device comprising: direction detecting means for detecting a moving direction of the track and the objective lens during movement of a pickup; and braking means for giving a deceleration driving signal for reducing the relative speed to the actuator.