JP2001034970A - Disk reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a disk reproducing apparatus which prevents data, to be reproduced, from being interrupted by a method wherein the abnormality of a servo system is detected as an error. SOLUTION: When a system, controller 80 detects the abnormality of a servo system it instructs the execution of a recovery processing operation with reference to a servo LSI 60 according to the existence of a vibration detection signal which is output from the servo LSI 60. When the vibration detection signal is input simultaneously with the detection of the abnormality of the servo system, the instruction of the execution of the recovery processing operation to be executed to the servo LSI 60 from the system controller 80 is limited, On the other hand, when the vibration detection signal is not input at the detection of the abnormality of the servo system, the execution of the receovery processing operation is instructed to the servo LSI 60 from the system controller 80.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk reproducing apparatus for reading out a signal recorded on a disk-type recording medium such as a compact disk and reproducing audio and the like.

[0002]

2. Description of the Related Art Audio data is recorded on a CD (compact disc), MD (mini disc), DVD (digital versatile disc) or the like in a spiral or concentric manner by small pits on a signal recording surface. The pit train (track) is tracked while the focus of the laser beam irradiated from the optical disc is adjusted to the signal recording surface, and the reflected signal at this time is detected by an optical pickup to read the recorded signal.

[0003] The signal recording surface is constantly changing due to surface runout when the disk is rotating, and the track is also constantly changing due to center runout when the disk is rotating. Therefore, in order to keep the laser beam always in focus on the signal recording surface regardless of the surface deflection of the disk, disk reproducing devices such as CD players, MD players, and DVD players have A pickup servo system consisting of a focus servo system and a tracking servo system is provided.

By providing such a pickup servo system and other servo systems (for example, a spindle servo system), a recording signal can be read from a disk without error. An abnormality may occur in the servo system. For example,
Control in various servo systems is performed by a servo LSI. However, if a power supply voltage or the like applied to the servo LSI is out of a normal range due to static electricity or voltage fluctuation, the servo LSI does not operate normally and various servo systems are not operated. Will not work effectively. Normally, when this abnormal state is detected, a return process (hereinafter, referred to as “recovery process”) is performed on the servo LSI. Specifically, the servo L
The power supply to the SI is temporarily stopped and then restarted, and then the servo LSI is reset to execute the recovery processing.

[0005]

As a method for detecting an abnormality in a servo system in the above-mentioned conventional disk reproducing apparatus, there are roughly two methods. The first method is
The time data included in the subcode is monitored, and when the updating of the time data is stopped, the abnormality of the servo system is detected. The second method is to monitor a block clock output at a period of 13.3 ms at a break of subcode data, and to detect an abnormality in the servo system when the clock becomes 8 ms or less.

[0006] By the way, as a cause of the inability to read the subcode in the conventional disk reproducing apparatus, it is conceivable that simply continuous vibration is applied in addition to the above-described abnormality of the servo system. For example, in the case of an in-vehicle disk reproducing device, when entering an unpaved road in a construction section, a large vibration may be continuously applied for 3 seconds or more. In such a case, the tracking servo or the like is temporarily disengaged until the vibration stops, so the updating of the time data included in the subcode stops,
An abnormality in the servo system is erroneously detected by the first method described above. Normally, the recovery process is performed on the servo LSI even though it is not necessary to perform the recovery process. Therefore, it takes a lot of time to resume reading data from the disk-type recording medium. (For example, about 3 seconds), and when the capacity of the memory for shock proof is small, or when the capacity of this memory is sufficient but the stored data is small, the reproduced data is interrupted and sound skipping or the like occurs. I do.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a disk reproducing apparatus capable of preventing reproduction data from being interrupted by erroneously detecting an abnormality in a servo system. To provide.

[0008]

In order to solve the above-mentioned problems, a disk reproducing apparatus of the present invention detects vibration applied to a drive system by vibration detection means, and detects abnormality of a servo system by abnormality detection means. Even if it is detected, the execution of the return process to the servo control unit is instructed by the return operation instructing unit only when the occurrence of vibration is not detected by the vibration detecting unit. For this reason,
When an error in the servo system is erroneously detected due to vibration applied to the drive system, the process does not immediately proceed to the return processing of the servo control means, and it is possible to prevent the reproduction data from being interrupted due to the erroneous detection. .

It is desirable that the above-mentioned vibration detecting means detects the occurrence of vibration based on a low-frequency component of the tracking error signal. Since the tracking error signal is used in a normal servo operation, if the presence or absence of a signal is detected based on this low frequency component,
It is not necessary to add a special configuration for detecting vibration, and it is possible to prevent the configuration from becoming complicated.

It is preferable that the abnormal state detecting means detects an abnormality of the servo system when updating of the time data included in the subcode is stopped. Sub-code reading stops due to large vibration applied to the drive system.Therefore, just judging whether or not the update of time data has been stopped, it is possible to determine whether an abnormality has occurred in the servo system or simply large vibration has been applied. It cannot be identified, and it is not possible to accurately determine only an abnormality in the servo system. But,
In the present invention, the presence or absence of vibration is detected by the vibration detecting means, so that it is possible to accurately know the cause of the stop of the update of the time data, and to determine whether the reproduction data has Disruption can be reliably prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a disk reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a disk reproducing apparatus according to an embodiment to which the present invention is applied. A disc reproducing apparatus 1 shown in FIG. 1 is included in an audio system mounted on a vehicle, and includes a spindle motor 20, an optical pickup 30, and a sled motor for reading signals recorded on a compact disc 10 which is a disc-type recording medium. 4
0, an RF amplifier 50, a servo LSI 60, a servo driver IC 70, and a system controller 80 for controlling the entire disc reproducing apparatus 1.

The spindle motor 20 rotates the compact disk 10 at a constant linear speed. The optical pickup 30 reads a recording signal while rotating the compact disc 10 by the spindle motor 20, and includes a semiconductor laser, a photodiode, and a focus lens. The optical pickup 30 also includes a focus actuator for moving the focus lens in a direction substantially perpendicular to the recording surface of the compact disc 10 and a tracking actuator for moving the focus lens in the radial direction of the compact disc 10. . The thread motor 40 moves the optical pickup 30 in the radial direction of the compact disc 10.

An RF amplifier 50 is provided with an EFM (Eight to Fourteen Modulation) based on a detection signal of the optical pickup 30.
lation) signal, a focus error signal, a tracking error signal, a CLV (Constant Linear Velocity) control signal, and the like. These signals are transmitted to the servo LSI 60
Is input to

The digital signal processing circuit 52 performs synchronization detection and EFM demodulation on the EFM signal output from the RF amplifier 50, and then performs a CIRC (Cross Interleave).
d Read-Solomon Code) Performs decoding processing. Further, the digital signal processing circuit 52 extracts the subcode data, and the extracted subcode data is sent to the system controller 80.

The servo LSI 60 outputs an EFM signal output from the RF amplifier 50 to the system controller 80. Further, the servo LSI 60 generates a focus actuator control signal necessary for controlling the driving state of the focus actuator in the optical pickup 30 based on the focus error signal output from the RF amplifier 50. Further, the servo LSI 60 performs phase compensation of a high-frequency component and amplification of a low-frequency component on a tracking error signal output from the RF amplifier 50 to control a driving state of a tracking actuator in the optical pickup 30. A necessary tracking actuator control signal is generated, and a sled motor control signal required for controlling a driving state of the sled motor 40 is generated based on a low-frequency component (mainly a DC component) of the tracking error signal. Further, the servo LSI 60
Based on the CLV control signal output from the F-amplifier 50, a spindle motor control signal required to control the driving state of the spindle motor 20 is generated. Servo L
These signals generated by the SI 60 are output to the servo driver IC 70.

The servo LSI 60 includes an RF amplifier 5
The low frequency component of the tracking error signal output from 0 is analyzed, and when the low frequency component includes abnormal vibration, a vibration detection signal is output to the system controller 80.

The servo driver IC 70 includes a servo LSI
The drive voltage of the focus actuator of the optical pickup 30 is generated based on the focus actuator control signal output from the optical pickup 30. When this drive voltage is applied to the focus actuator, the focus actuator moves the focus lens to the compact disk 10
Is moved in a direction substantially perpendicular to the recording surface, and the focal position of the irradiation light from the semiconductor laser is adjusted.

The servo driver IC 70 generates a drive voltage for the tracking actuator of the optical pickup 30 based on the tracking actuator control signal output from the servo LSI 60. When this drive voltage is applied to the tracking actuator, the tracking actuator moves the focus lens in the radial direction of the compact disc 10.

The servo driver IC 70 generates a drive voltage for the sled motor 40 based on a sled motor control signal output from the servo LSI 60. When this drive voltage is applied to the sled motor 40, the sled motor 40 moves the optical pickup 30 in the radial direction of the compact disc 10.

Further, the servo driver IC 70 generates a drive voltage for the spindle motor 20 based on a spindle motor control signal output from the servo LSI 60. When this drive voltage is applied to the spindle motor 20, the spindle motor 20
Is rotated at a constant linear speed.

The system controller 80 includes a servo LS
Various servo commands are output to the I60, and TOC (Table of C) output from the digital signal processing circuit 52 is output.
ontents) Various controls necessary for music reproduction are performed by receiving and analyzing information and other subcode data. Further, the system controller 80 monitors time data included in the subcode extracted by the digital signal processing circuit 52 to determine whether there is an abnormality in the servo system.

Further, when the system controller 80 detects an abnormality in the servo system, the system controller 80 controls the servo LSI in accordance with the presence or absence of the vibration detection signal output from the servo LSI 60.
An instruction to execute the recovery process is given to 60. More specifically, when a vibration detection signal is input at the same time when an abnormality in the servo system is detected, the execution instruction of the recovery processing performed from the system controller 80 to the servo LSI 60 is limited. That is, the spindle motor 20
It is determined that an abnormality in the servo system has been erroneously detected due to vibration applied to the drive system such as the optical pickup 30 or the like from the outside.
Is not instructed to execute recovery processing. Also,
When the vibration detection signal is not input when the abnormality of the servo system is detected, the system controller 80 instructs the servo LSI 60 to execute the recovery process. The details of the operation of the system controller 80 will be described later.

The above-described RF amplifier 50 and servo LS
I60 corresponds to vibration detection means, digital signal processing circuit 52 corresponds to abnormal state detection means, servo LSI 60 corresponds to servo control means, and system controller 80 corresponds to return operation instruction means.

The disk reproducing apparatus 1 of the present embodiment has the above-described configuration, and the operation will be described next. FIG.
5 is a flowchart showing an operation procedure of the disk reproducing device 1.

The system controller 80 constantly monitors whether or not the compact disk 10 has been loaded (step 100). For example, the presence or absence of loading is determined based on a signal input from a disk loading detecting unit (not shown). Then, when the compact disk 10 is loaded, the system controller 80 then controls the servo LSI 6
The optical pickup 30 is moved near the inner periphery of the compact disk 10 by reading the signal recorded in the lead-in area by driving the thread motor 40 and driving the spindle motor 20 by sending an instruction to 0.
The TOC information included in the lead-in is stored in a built-in memory (not shown) (step 101). Then, based on the TOC information, the system controller 80 starts reproduction from the beginning of the first music piece recorded on the compact disc 10 (step 102). Thereafter, the recording signal is read from the compact disc 10 with various servos applied, and predetermined demodulation processing and decoding processing are performed by the digital signal processing circuit 52 to generate subcode data and music data, thereby reproducing music. Is performed.

After the reproduction of music is started, the system controller 80 monitors time data included in the subcode output from the digital signal processing circuit 52, and determines whether or not the time data has been updated. (Step 103). If the time data has been updated, that is, if no abnormality has occurred in the servo system, the system controller 80 sets the music data based on the Q channel data and the like of the subcode output from the digital signal processing circuit 52. It is determined whether the reading has been completed up to the last music (step 104). For example, step 1 described above
Since the TOC information read and stored in step 01 contains the data of the "last movement number", the system controller 80 extracts the movement number data from which the music data is currently being read from the Q channel of the subcode. By checking whether or not this matches the data of the “last movement number” included in the TOC information, the above-described determination processing in step 105 is performed. If the process has not been completed up to the last song, the process returns to step 104 and the process is repeated. When the reading of the music data is completed up to the last music, the system controller 80 next searches the head position of the first music based on the TOC information stored in the internal memory (step 105), and thereafter returns to step 102. The reproduction of the first music is repeated.

When the time data included in the subcode is not updated for a predetermined time (for example, 3 seconds) (step 1)
04 (in the case of a negative determination in step S04), the system controller 80 determines whether or not vibration is externally applied to the disk reproducing apparatus 1 according to the presence or absence of a vibration detection signal output from the servo LSI 60 (step S10). 10
6). When no vibration detection signal is output from the servo LSI 60, that is, when no vibration is externally applied to the disk reproducing device 1, the system controller 8
A value of 0 determines that the update of time data has stopped due to the occurrence of an abnormality in the servo system, and instructs the servo LSI 60 to execute a recovery process (step 107). After the recovery process for the servo LSI 60 is performed in response to the execution instruction, the process returns to step 103 described above.
The process of determining whether or not the time data has been updated is repeated.

When a vibration detection signal is output from the servo LSI 60, that is, when vibration is externally applied to the disk reproducing apparatus 1, the system controller 80 determines that the servo system is not operating abnormally and that the servo system is simply operating. It is determined that the update of the time data has stopped because large vibrations that have come off are applied to the various drive systems of the disk reproducing apparatus 1, and the execution instruction of the recovery processing performed to the servo LSI 60 is limited (step 108). Then, the process returns to the above-described step 103 without issuing the execution instruction, and repeats the process of determining whether or not the time data has been updated.

As described above, the disk reproducing apparatus 1 monitors the update state of the time data included in the subcode and unconditionally sets the servo L when detecting the occurrence of a servo system abnormality.
Instead of performing the recovery processing of the SI 60, if vibration is applied at that time, it is determined that the abnormality detection is erroneous detection, and the recovery processing is not performed. Therefore, unnecessary recovery processing of the servo LSI 60 based on erroneous detection of an abnormality in the servo system can be eliminated, and interruption of music data to be reproduced can be prevented.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, when there is abnormal vibration in the low-frequency component of the tracking error signal, the servo LSI 60 determines that the disk reproducing apparatus 1 is externally vibrated. May be performed by the RF amplifier 50 instead.

Instead of judging the presence or absence of vibration based on the tracking error signal, a vibration sensor as vibration detecting means may be provided separately to directly detect vibration applied to the disc reproducing apparatus 1 from outside. Good. FIG.
FIG. 14 is a diagram showing a configuration of a modified example of the disc reproducing apparatus.
The disc reproducing apparatus 1a shown in the figure differs from the disc reproducing apparatus 1 shown in FIG. 1 in that a vibration sensor 90 is provided.

The vibration sensor 90 is provided in the disk reproducing device 1a.
The disk reproducing device 1a
When vibration is applied from outside to the controller 80, the vibration is detected and a vibration detection signal is output to the system controller 80.
The system controller 80 determines whether or not to instruct the servo LSI 60 to execute a recovery process when detecting an abnormality in the servo system, based on the presence or absence of the vibration detection signal output from the vibration sensor 90. As described above, even by using the vibration sensor 90, it is possible to accurately detect the vibration applied from the outside to the disc reproducing apparatus 1a.

In the above-described embodiment, the music recorded on the compact disk 10 is reproduced by the disk reproducing device 1. However, the disk reproduction for reproducing a mini disk (MD), a digital versatile disk (DVD), or the like is performed. The present invention may be applied to a device. Also, the disc playback device included in the in-vehicle audio device has been described as an example, but the invention can also be applied to audio devices other than in-vehicle audio devices, for example, audio devices such as home mini components.

[0034]

As described above, according to the present invention, when an abnormality in the servo system is erroneously detected due to vibration applied to the drive system, the process does not immediately proceed to the return processing of the servo control means. It is possible to prevent reproduction data from being interrupted due to erroneous detection.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a disk reproducing apparatus according to one embodiment.

FIG. 2 is a flowchart showing an operation procedure of the disc reproducing apparatus.

FIG. 3 is a diagram illustrating a configuration of a modified example of the disc reproducing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc reproducing apparatus 10 Compact disc 20 Spindle motor 30 Optical pickup 40 Thread motor 50 RF amplifier 52 Digital signal processing circuit 60 Servo LSI 70 Servo driver IC 80 System controller

Claims (3)

[Claims] 1. A disk reproducing apparatus for reproducing data read from a disk-type recording medium, comprising: a servo control means for controlling a servo system necessary for reproducing the data; and a drive controlled by the servo control means. Vibration detecting means for detecting vibration applied to the system; abnormal state detecting means for detecting an abnormality of the servo system; and vibration when the abnormal state detecting means detects an abnormality of the servo system. When the detection is not performed, the execution of the predetermined return operation is instructed to the servo control means. When the vibration is detected by the vibration detection means, the execution instruction of the return operation is restricted. A disk reproducing apparatus comprising: a return operation instructing unit. 2. The disk reproducing apparatus according to claim 1, wherein said vibration detecting means detects occurrence of vibration based on a low-frequency component of a tracking error signal. 3. The abnormal state detecting means according to claim 1, wherein the abnormal state detecting means monitors time data included in a subcode, and detects an abnormality of the servo system when updating of the time data is stopped. A disk reproducing device characterized by the above-mentioned.