JPH08106719A - Apparatus for reproducing optical disc - Google Patents

Abstract

PURPOSE: To reproduce sound stably by attenuating the volume of sound when a focus error and a track servo are disturbed by vibrations of a speaker. CONSTITUTION: During the focus servo by a focus error signal FE, an optical pickup 1 holds a spot at a focal point. Since the pickup 1 follows the vibration of a disc surface, a position signal is changed. A pulse signal FOK is output, when the optical spot is met at the focal point. However, if the optical spot is out of focus due to the external shocks or sound of a speaker, etc., the FOK signal is turned to 0, which is detected by an MPU 9. Consequently, switches SW1, SW2 are switched and the signal is attenuated by an attenuator 12. That is, a positional servo loop is formed with an output signal (a) of a position detector 5 based on a voltage (b) so that an average voltage during the focus servo is the held voltage (b). A focus actuator is kept at an average position before the optical spot is out-focused. An audio signal is returned to the original level after maintaining an attenuated state for a fixed time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing device.

[0002]

2. Description of the Related Art In a conventional optical disc reproducing apparatus or the like, vibration of an optical pickup or an optical disc is detected as a focus error signal or a tracking error signal to control the optical pickup.

[0003]

However, when a large vibration exceeding a certain level is applied, focus control or tracking control cannot be performed, and the focus is lost or a track jump occurs.

[0004]

Therefore, the present invention comprises means for detecting that the focus control or tracking control is out of a predetermined period due to vibration from the speaker, and means for reducing the output signal level of the speaker. The vibration level applied to the optical disk reproducing section is reduced. The present invention includes a focus control means for irradiating an optical disc with a light beam and for focusing the light beam on the optical disc, and a tracking control means for causing the information track of the optical disc to follow, and a speaker for outputting sound is incorporated. In the optical disc reproducing device, the optical disc reproducing device is provided with means for reducing the output level of the speaker when the focus control by the focus control means or the tracking control by the tracking control means is deviated. Further, the present invention includes a focus control means for irradiating an optical disc with a light beam and focusing the light beam on the optical disc, and a tracking control means for causing the optical disc to follow an information track of the optical disc. In the built-in optical disk reproducing apparatus, the optical disk reproducing apparatus is provided with means for reducing the output level of the speaker when the focus control by the focus control means or the tracking control by the tracking control means is out of a predetermined period.

Further, the present invention includes a focus control means for irradiating the optical disk with a light beam and for focusing the light beam on the optical disk, and a tracking control means for following the information track of the optical disk, and outputs a sound. In an optical disk reproducing apparatus incorporating a speaker, an optical disk having means for reducing the output level of the speaker when the number of times the focus control by the focus control means or the tracking control by the tracking control means is deviated and exceeds a predetermined value. It is a playback device. Further, the present invention includes a focus control means for irradiating an optical disc with a light beam and for focusing the light beam on the optical disc, and a tracking control means for causing the optical disc to follow an information track, and a speaker for outputting a sound is incorporated. Focus control by the focus control means in the optical disc reproducing apparatus,
Alternatively, when the tracking control by the tracking control means is lost, the optical disk reproducing apparatus includes means for reducing the output level of the speaker and means for servoing the position of the actuator of the optical pickup to the original position.

[0006]

According to the present invention, out-of-focus or track skipping caused by speaker vibration is automatically reduced by a speaker output and dropped by an external condition that occurs accidentally under a specific combination condition such as a disk or optical pickup natural vibration. It is possible to prevent the out state from continuing.

Further, actuator displacement detecting means is provided to form a position servo system for the actuator.
It is possible to suppress the resonance of the actuator due to external vibrations, etc., and even if it is out of the way during the performance, it can be stably maintained within the range of the vibration of the previous disk and the servo can be recovered quickly and reliably by focusing. . Further, by doing so, the time for pulling in the focus servo can be greatly shortened and the interruption of the performance can be shortened.

[0008]

1 is a block diagram of an embodiment of a focus servo apparatus according to the present invention. The HF signal picked up by the optical pickup 1 and detected by the signal detector 2 is converted into an audio signal and amplified by the amplifier 13 via the attenuator 12 from the reproducing circuit 11 and output from the speaker 14 as an audio signal. The control of the optical pickup 1 is performed by separating and amplifying each signal by a signal detection unit 2 that extracts a servo signal or the like from the optical disc. The focus error signal FE for the focus servo is taken out and the focus servo is performed. On the other hand, a pulse signal FOK that is generated when the light spot on the disk for performing focus servo is near the in-focus point and a focus zero cross signal that changes when the focus error signal crosses the in-focus point in order to extract the timing for inserting the focus servo. Take out FZC etc. Optical pickup 1 using this FE signal via servo amplifier 3
The focus actuator 4 is driven to form a focus servo loop and maintain the in-focus point. On the other hand, the optical pickup 1 is provided with a position detector 5 for detecting the position of the focus actuator 4, detects the position of the focus actuator 4, and takes out a position signal (a) via an amplifier 6.

The position signal (a) enters the comparison amplifier 7, while the average value hold circuit 8 extracts the average voltage of the operating range of the focus actuator 4 of the optical pickup 1.
This is an average value that changes due to optical disk surface deflection and the like, and can be easily realized by an integrating circuit of a resistor R and a capacitor C. Here, SW2 is provided and normally turned on. When the switch SW2 is turned off, the average voltage before turning off is held. A switch SW1 for switching the output of the comparison amplifier 7 or the signal of the previous FE is provided to switch the servo operation. These switches SW1 and SW2 are controlled by a microprocessor (hereinafter referred to as MPU) 9.

When the switch SW1 is not provided on the FE side and the focus servo is performed by the FE signal as in the conventional case, the optical pickup 1 holds the spot at the focal point. Since it follows the surface deflection of the disk, the position signal changes as shown in FIG. Also, the FOK signal is output. When the focus is lost due to an external shock or a speaker sound, the FOK signal becomes 0 and is detected by the MPU 9, and the MPU 9 switches SW1 and SW2 based on the determination of the out-of-focus and operates the attenuator 12 to attenuate.

That is, the position servo loop is formed by the signal a from the position detector with reference to the voltage of b so that the voltage b obtained by holding the average voltage during the previous focus servo is obtained. As a result, the focus actuator is held at the average position before the defocus. Also, the audio signal returns to the original level from the attenuated state after maintaining the attenuated state for a certain period of time.

Here, if the disk is kept rotating due to inertia or the like, the actuator when the focus servo is originally performed has the output shown in FIG. 2 (a).
It is at a fixed position as shown in (b). At this time, as in FE of FIG. 2, the focus error signal FE shows an S-shaped output in the vicinity of where a and b match. Further, the FOK signal also becomes H in this vicinity. On the other hand, the FZC signal entering the MPU 9 is calibrated so as to become H when the reference potential of the positive and negative potentials is exceeded within a predetermined width.
The type of signal is taken into the MPU 9. First, when FOK becomes H as the optical disk rotates, FZC1 or FZ
Either C2 becomes H. The MPU 9 returns the switches S1 and S2 at the timing at which the FO is turned ON when the FZC input to the capture destination becomes 0. As a result, the optical pickup is position-servoed, near the midpoint of the S curve of the focus detection signal, and the servo loop can immediately restart the focus servo by the focus error signal. Although the focus control is repeatedly performed in this way, the attenuator 12 determines that the volume of the speaker is too high when the MPU 9 loses the servo, when the servo is off for a predetermined period, or when the servo is off for a predetermined number of times. Is controlled to provide a constant delay time to attenuate the volume. Speaker volume attenuation is MPU9
Therefore, the attenuator 12 is repeatedly controlled stepwise every -6 dB. In the above description, the operation of attenuating the sound volume due to the loss of control in the focus servo has been described, but the MPU 9 can count the number of times the track servo is lost and the sound volume can be attenuated as in the focus control.

When the MPU 9 determines that the focus error signal is stable for a predetermined period, the attenuator 1 described above is used.
4 is returned to the original attenuation level and sound is output. When the focus error signal is disturbed again by returning the damping level of the attenuator, the attenuator 14 is damped again to prevent the disturbance.

[0014]

According to the present invention, since the volume is attenuated when the focus error and the track servo are disturbed by the vibration of the speaker, a stable reproduced sound can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment according to the present invention.

FIG. 2 is a diagram showing a control waveform.

[Explanation of symbols]

 1 optical pickup 2 signal detector 3 servo amplifier 4 focus actuator 5 position detector 6,13 amplifier 7 comparison amplifier 8 average value hold circuit 9 microprocessor 10 oscillator 11 reproduction circuit 12 attenuator 14 speaker

Claims (4)

[Claims] 1. A speaker for outputting a sound, comprising: a focus control unit for irradiating an optical disc with a light beam and for focusing the light beam on the optical disc; and a tracking control unit for causing the optical disc to follow an information track of the optical disc. The built-in optical disk reproducing apparatus further comprises means for decreasing the output level of the speaker when the focus control by the focus control means or the tracking control by the tracking control means is deviated. apparatus. 2. A speaker for outputting a sound, comprising a focus control means for irradiating an optical disc with a light beam and for focusing the light beam on the optical disc, and a tracking control means for tracking the information track of the optical disc. The built-in optical disk reproducing apparatus further comprises means for decreasing the output level of the speaker when the focus control by the focus control means or the tracking control by the tracking control means is out of a predetermined period. apparatus. 3. A speaker for outputting a sound, comprising a focus control means for irradiating the optical disc with a light beam and for focusing the light beam on the optical disc, and a tracking control means for causing the information track of the optical disc to follow. The built-in optical disk reproducing apparatus is provided with means for counting the number of times the focus control by the focus control means or the tracking control by the tracking control means is deviated and reducing the output level of the speaker when the number of times exceeds a predetermined value. An optical disk reproducing device characterized by the above. 4. A speaker for outputting sound, comprising a focus control means for irradiating the optical disk with a light beam and for focusing the light beam on the optical disk, and a tracking control means for tracking the information track of the optical disk. In the built-in optical disk reproducing apparatus, when the focus control by the focus control means or the tracking control by the tracking control means is deviated, the position of the means for reducing the output level of the speaker and the position of the actuator of the optical pickup are returned to their original positions. An optical disk reproducing apparatus comprising means for servoing.