JPH09115237A - Disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the rotational speed of a spindle motor to a prescribed speed in a short time without being influenced by fluctuation of a rotational load due to disk size and environmental temp. SOLUTION: The spindle motor 2 for rotatively driving an optical disk 1 corresponding to the size of the optical disk 1 is set to an accelerating rotational speed to rotate the spindle motor 2 by a CPU 8, and a current flowing into the spindle motor 2 is monitored by a current detecting circuit 10 to detect the rotational speed of the spindle motor 2. Since CVL control is performed to keep the linear velocity of a track constant by a servo control circuit 9 by a command of the CPU 8 after the spindle motor 2 reaches a prescribed rotational speed, an information reproducing operation with high accuracy is performed by the CVL control stably on the spindle motor 2 in a short time without being influenced by load fluctuation due to a disk size change and an environmental temp. change.

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 driving an optical disc on which music information or the like is recorded and reproducing the information.

[0002]

2. Description of the Related Art In a conventional disk device, an optical disk is rotatably driven by a spindle motor, a pickup focuses a beam focused by an objective lens onto an optical disk having information recorded on a track, and a reflected beam carrying information. Is received by the light receiving element and information is reproduced.

In this case, for the spindle motor,
CLV so that the linear velocity of the read track is constant
(Constant Linear Velocity
y) The control is performed, and the acceleration drive is performed for a predetermined time from the disk stopped state at the start to the rotation speed at which control is possible.

[0004]

However, in the above-mentioned conventional disk drive, it is necessary to switch the acceleration drive time of the disk according to the disk size, and further, the same time is changed due to the load fluctuation of the spindle motor due to the change of the environmental temperature. Since the rotational speed obtained by the acceleration drive is different, the acceleration drive operation of the disk becomes complicated and there is a problem that the time until the CLV servo stabilizes becomes long.

The present invention is intended to solve this problem, and its object is to make the rotation speed of a spindle motor a predetermined speed in a short time without being affected by the fluctuation of the rotation load due to the disk size and the environmental temperature. It is to provide a disk device that can be set.

[0006]

In order to achieve the above-mentioned object, the present invention provides a reflected beam carrying the above-mentioned information by projecting an irradiation beam onto an optical disc having information recorded on a track by focusing it with an objective lens. A pickup that receives light by a light receiving element, an actuator that performs focus servo and tracking servo by changing the position of the objective lens, and a focus error signal from the pickup.
An RF amplifier that extracts a tracking error signal and an RF signal, servo control means that sends a drive signal to the actuator based on the focus error signal and the tracking error signal, and the pickup is moved from a current track to a target track. A transport means, a spindle motor for rotating the optical disc, and the RF
Based on the signal, so that the linear velocity of the track is constant,
CLV servo means for controlling the spindle motor,
When an acceleration rotation speed is set in the spindle motor, the spindle motor is started, and when it is detected that the spindle motor has reached a predetermined rotation speed based on the drive current flowing in the spindle motor, the spindle motor is It has a control means for performing CLV control by the CLV servo means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below.
This will be described with reference to FIGS.

FIG. 1 is a block diagram showing the configuration of this embodiment, FIG. 2 is a flow chart showing the acceleration drive operation of the spindle motor according to this embodiment, and FIG. 3 is a load due to the disk size during the acceleration drive operation of the spindle motor. It is a characteristic view which shows the motor current characteristic corresponding to a fluctuation.

In the present embodiment, as shown in FIG. 1, an optical disc 1 on which music information and the like are recorded is arranged by a spindle motor 2 so as to be rotatable about its central axis. A spindle motor drive circuit 11 that drives the spindle motor 2 and a current detection circuit 10 that detects a current flowing through the spindle motor 2 are connected to each other.

Also, facing the recording surface of the optical disk 1,
An objective lens unit 3 including an objective lens, a focus support, and an actuator that changes a posture of the objective lens by performing a toking servo is supported and arranged by a pickup 4. The pickup 4 accommodates a light source that emits an irradiation beam and a photoelectric conversion element that receives a reflected beam from the optical disc 1 and converts it into an electric signal.

The pickup 4 has a position detector and a traverse transport mechanism, and a pickup drive motor 5 for moving the pickup 4 in the radial direction of the optical disk 1.
Is connected.

Further, the pickup 4 is connected to an RF circuit 6 for amplifying and waveform-shaping the read signal from the pickup 4, binarizing and outputting the signal, and outputting a focus error signal and a tracking error signal. The RF circuit 6 is connected to a signal processing circuit 7 that takes in a read signal from the RF circuit 6 and performs signal processing such as edge detection, CLV control signal extraction, EFM demodulation, and error correction.

On the other hand, a CPU 8 for controlling the overall operation is provided, and the CPU 8 has a servo control for controlling the operations of the actuator of the objective lens unit 3, the spindle motor 2 and the pickup drive motor 5 according to a control signal from the CPU 8. The circuit 9 is connected, and the RF circuit 6 is connected to the servo control circuit 9. Further, the signal processing circuit 7 and the current detection circuit 10 are connected to the CPU 8.

The operation of this embodiment having such a configuration will be described. The irradiation beam emitted from the light source of the pickup 4 is focused on the track of the optical disc 1 by the objective lens of the objective lens unit 3, and the reflected beam from the track is received by the photoelectric conversion element of the pickup 4 and photoelectrically converted. The read signal is input to the RF circuit 6.

The focus error signal and the tracking error signal are taken from the RF circuit 6 into the servo control circuit 9, and the servo control circuit 9 receives the focus error signal and the tracking error signal from the objective lens unit 3 based on the focus error signal and the tracking error signal. Focus servo and tracking servo drive signals are input to the actuator, and the actuator changes the attitude of the objective lens by the focus servo and tracking servo drive signals to perform focus servo and tracking servo operations.

The pickup drive motor 5 is driven based on a control signal from the servo control circuit 9, and the pickup drive motor 5 moves the pickup 4 in the radial direction of the optical disc 1 to reproduce the recorded information on the optical disc 1. Is done.

Further, based on the CLV control signal extracted from the RF signal from the RF circuit 6, the servo control circuit 9
Drive signal is input to the spindle motor drive circuit 11, and based on this drive signal, the spindle motor 2
Is driven to rotate.

When the spindle motor 2 is driven, the CPU 8 discriminates the disk size (12 cm or 8 cm), and the spindle motor is instructed by the CPU 8 until a predetermined rotation speed at which the CLV servo can be drawn is reached. A corresponding predetermined acceleration drive pulse is output from the drive circuit 11, and when the spindle motor 2 reaches a predetermined rotation speed, a command from the CPU 8 causes
The spindle motor 2 is subjected to CLV control by a drive signal based on the CLV control signal from the servo control circuit 9.

The driving operation of the spindle motor 2 will be described with reference to FIGS. In step S1 of the flowchart of FIG. 2, an acceleration command signal for the spindle motor 2 corresponding to the disk size is input from the servo control circuit 9 to the spindle motor drive circuit 11 according to a command from the CPU 8, and the spindle motor drive circuit 11 causes the spindle motor drive circuit 11 to rotate the spindle. A predetermined acceleration drive rotation is performed on the motor 2.

At this time, the current flowing through the spindle motor 2 changes as shown in FIG. 3 with respect to the disk size or load fluctuation, but with respect to the target rotation speed of the motor,
The flowing current is determined by the following relational expression (1).

I = (V−Ka · N) / R (1) (where I is the motor current, V is the motor drive voltage, Ka is the power generation constant, N is the motor speed, and R is the motor winding resistance. In step S2, the CPU 8 monitors the current flowing through the spindle motor 2 by the current detection circuit 10. When the current value corresponding to the target rotation speed is reached, the process proceeds to step S3, and the servo control circuit 9 is instructed by the CPU 8 command. Stops the output of the acceleration command signal and proceeds to step S4,
A CLV control signal is input from the servo control circuit 9 to the spindle motor drive circuit 11, and the spindle motor drive circuit 11 rotates the spindle motor 2 under CLV control.

As described above, according to the present embodiment, the CP
U8 monitors the current flowing through the spindle motor 2 according to the disk size, and the spindle motor 2 is accelerated and rotated until the current reaches the target value. When the current reaches the target value, the rotation of the spindle motor 2 is stopped. Since it is switched to CLV control, it is possible to perform stable CLV control of the spindle motor 2 in a short time and perform highly accurate information reproducing operation without being affected by load changes due to changes in disk size and environmental temperature. It will be possible.

[0023]

According to the present invention, the control means sets the acceleration rotation speed until the CLV control is reached to the spindle motor that rotationally drives the optical disc in accordance with the size of the optical disc, and the spindle motor is rotated. The current flowing through the spindle motor is monitored, and after the spin motor reaches a predetermined rotation speed, CLV control is performed by the CLV servo means so that the linear velocity of the track becomes constant. It is possible to perform stable CLV control of the spindle motor in a short time and perform a highly accurate information reproducing operation without being affected by the load fluctuation due to the change of.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing an acceleration drive operation of the spindle motor according to the same embodiment.

FIG. 3 is a characteristic diagram showing a motor current characteristic corresponding to a load change due to a disk size during acceleration drive operation of a spindle motor.

[Explanation of symbols]

 1 Optical Disc 2 Spindle Motor 3 Objective Lens Unit 4 Pickup 5 Pickup Drive Motor 6 RF Circuit 7 Signal Processing Circuit 8 CPU 9 Servo Control Circuit 10 Current Detection Circuit 11 Spindle Motor Drive Circuit

Claims (1)

[Claims] 1. A pickup for receiving a reflected beam carrying the information by a light receiving element and projecting the irradiation beam onto an optical disc on which information is recorded on a track by an objective lens, and a position of the objective lens. An actuator that performs focus servo and tracking servo by changing the focus error signal from the pickup,
An RF amplifier for extracting a tracking error signal and an RF signal, servo control means for sending a drive signal to the actuator based on the focus error signal and the tracking error signal, and moving the pickup from a current track to a target track. A carrier means, a spindle motor for rotating the optical disc, a CLV servo means for controlling the spindle motor so that the linear velocity of the track is constant based on the RF signal, and an acceleration rotation speed for the spindle motor. When the spindle motor is set and the spindle motor is started and it is detected that the spindle motor has reached a predetermined rotation speed based on the drive current flowing through the spindle motor, the spindle motor is CLV controlled by the CLV servo means. With control means A disk device characterized by: