JPH10124980A - Disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk reproducing device capable of accurately starting the reproduction without storing the position at the time when the reproduction is interrupted. SOLUTION: The disk reproducing device 1 is constituted to include an optical pickup 14, RF amplifier 16, tracking servo circuit 20, thread servo circuit 26, thread motor 32, system controller 50 and operation part 52. When an accessory switch 54 becomes the OFF state by means of turning an engine key, or when a 'mode changer' key of the operation part 52 is depressed, the gain of a servo driver 30 in the thread servo circuit 26 is temporarily raised by the system controller 50 to control so that the mechanical center position of the optical pickup 14 coincides with the position for reading out a recorded signal, and after that, the power source for operating the disk reproducing device 1 is turned off.

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 which repeats reproduction from an interrupted point when a reproducing operation is interrupted and then resumed in an on-vehicle audio device or the like.

[0002]

2. Description of the Related Art An on-vehicle disc reproducing apparatus, for example, a compact disc player, rotates an engine key during a music reproducing operation to rotate an accessory switch (ACC switch).
Is turned off and then turned on again, music playback is continued from the point where it was interrupted. This achieves the same operability as that of a cassette deck, and allows music recorded on a compact disc to be continuously heard without complicated operations.

For example, a system controller of a compact disk player stores data in a compact disk relating to a reproduction position, and when the reproduction is resumed, the stored position is searched to allow continuous reproduction to be resumed. It becomes possible. Alternatively, it is conceivable that the reproduction is resumed from the same position when the reproduction is resumed by maintaining the position of the optical pickup when the reproduction is interrupted.

[0004]

By the way, in the conventional method of storing data in the compact disc relating to the reproduction position, it is necessary to hold the data stored in a memory or the like until the reproduction is resumed. It is necessary to use a volatile memory or to connect a backup power supply to the volatile memory, which hinders simplification of the configuration.

Further, in the conventional system in which the position of the optical pickup at the time of the reproduction interruption is maintained, there is a possibility that an error of about several seconds may occur in the reproduction time at the position where the reproduction is resumed. Will feel uncomfortable. Normally, the recording signal of a compact disc is read by tracking a track (pit train) with an optical pickup, but tracking of core runout is mainly performed by a tracking servo, and tracking of track progress is mainly performed by a thread servo. Done by
The tracking servo is a servo system that adjusts a focus position by moving a focus lens included in an optical pickup along a radial direction of a compact disk by a tracking actuator. The thread servo is a servo system that moves a slide mechanism including an optical pickup along a radial direction of a compact disc.

In the above-described disk reproducing apparatus using both the tracking servo and the thread servo, if these servo mechanisms are stopped when reproduction is interrupted, the focus lens whose position has been adjusted by the tracking actuator returns to the mechanical center position. Therefore, the reading position of the recording signal when the reproduction is restarted is shifted. Thus, simply maintaining the position of the optical pickup could not accurately resume reproduction from the interrupted position.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a disk reproducing apparatus capable of accurately starting reproduction without storing the position at which reproduction was interrupted. Is to provide.

[0008]

In order to solve the above-mentioned problems, the disk reproducing apparatus of the present invention actually increases the thread gain at a predetermined timing before the power is turned off, so that the disk-type recording medium is actually realized. The mechanical center position of the optical pickup is adjusted to the position where the above recording signal is read. Specifically, a sled motor for moving the optical pickup in the radial direction of the disk-type recording medium, a servo processing unit for generating a signal necessary for servo control of the sled motor based on the tracking error signal, and an output of the servo processing unit A servo mechanism having a servo driver for amplifying and rotating a thread motor; timing instructing means for instructing a predetermined timing before power-off; and servo control means for temporarily increasing the gain of the servo driver at the predetermined timing. It has. By temporarily increasing the gain of the servo driver before turning off the power, the optical pickup can be moved so that the mechanical center position of the optical pickup does not deviate from the reading position of the recording signal of the disk type recording medium. Therefore, the shift of the reading position of the recording signal when the reproduction is resumed is reduced, and the reproduction can be continuously resumed.

In particular, the disk reproducing apparatus of the present invention is suitable for an in-vehicle audio apparatus capable of switching to an operation mode other than the disk reproduction, and an operation mode switching instruction is given as a predetermined timing before power-off. It is possible to consider the timing at which the power supply is instructed (for example, the accessory switch is turned off) to the in-vehicle audio device by the engine key switch. In many cases, the power of this audio device is turned off by operating the engine key switch during playback of a disc in a vehicle-mounted audio device. Even in such a case, it is necessary to accurately resume continuous reproduction. Can be.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a disk reproducing apparatus to which the present invention is applied, an instruction to switch to another audio apparatus and an instruction to turn off the power are given without pressing a "stop" key during reproduction of a compact disk or the like. In this case, the gain (thread gain) of the servo driver included in the thread servo circuit is temporarily increased to control the optical pickup so that the mechanical center position of the optical pickup matches the read position of the recording signal of the compact disc at that time. It has special features. Hereinafter, a disc reproducing apparatus according to an embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a disk reproducing apparatus according to one embodiment to which the present invention is applied. As an example, a configuration of a disk reproducing apparatus included in an audio device mounted on a vehicle is shown. . The disc reproducing apparatus 1 of the present embodiment shown in FIG. 1 includes a spindle motor 12, an optical pickup 14, a focus servo circuit 18, a tracking servo circuit 20, and a spindle motor 12 for reading signals recorded on a compact disc 10 which is a disc type recording medium. A thread servo circuit 26, a thread motor 32 and a spindle servo circuit 34, and an RF amplifier 1 for performing predetermined processing on the read signal and then reproducing music.
6, digital signal processing circuit 40, shock-proof memory 42, shock-proof memory controller 44, digital filter 46, and digital-analog (D /
A) a conversion circuit 48, a system controller 50 for controlling the entire disc player 1, an operation unit 52 for a user to input various instructions, and an accessory which is turned on / off by operating an engine key (not shown). (AC
C) It comprises a switch 54 and a disk loading detection unit 36 for detecting that the compact disk 10 has been loaded by the user.

The spindle motor 12 rotates the compact disc 10 at a constant linear speed. The optical pickup 14 detects a recording signal while rotating the compact disc 10 by the spindle motor 12, and includes a semiconductor laser, a photodiode, and a focus lens. Also, this optical pickup 1
Reference numeral 4 also includes a focus actuator for moving the focus lens in a direction substantially perpendicular to the recording surface of the compact disc, and a track actuator for moving the focus lens in the radial direction of the compact disc. The RF amplifier 16 performs EFM (Eight to Fourteen Modulation) based on the detection signal of the optical pickup 14.
n) Create a signal, a focus error signal FE, a tracking error signal TE, a CLV (Constant Linear Velocity) control signal, and the like.

The focus servo circuit 18 controls the drive of the focus actuator of the optical pickup 14 based on the focus error signal FE output from the RF amplifier 16.
By moving in a direction substantially perpendicular to the recording surface of
The focal position of the irradiation light from the semiconductor laser can be adjusted.

The tracking servo circuit 20 controls the driving of the tracking actuator of the optical pickup 14 based on the tracking error signal TE output from the RF amplifier 16, and includes a tracking equalizer 22 and a servo driver 24. It is configured. The tracking equalizer 22 generates a signal necessary for tracking servo by performing phase compensation of a high-frequency component and amplification of a low-frequency component with respect to the tracking error signal TE, and outputs the output of the tracking equalizer 22 to a servo driver 24. The driving voltage of the tracking actuator of the optical pickup 14 is generated by the amplification.

The thread servo circuit 26 controls the drive of a thread motor 32 for moving the optical pickup 14 in the radial direction of the compact disk 10 based on a signal output from the tracking equalizer 22 in the tracking servo circuit 20. Yes, it includes a thread equalizer 28 and a servo driver 30.
The thread equalizer 28 includes the tracking equalizer 2
The low-pass component (mainly a direct-current component) of the signal output from 2 is passed through. The output of the thread equalizer 28 is amplified by the servo driver 30 so that
The drive voltage of the thread motor 32 is generated. The spindle servo circuit 34 controls the spindle motor 12 to rotate at a constant linear speed based on the CLV control signal output from the RF amplifier 16.

FIG. 2 is a diagram showing operation timings of the above-described tracking servo circuit and sled servo circuit, and shows a tracking error signal and a sled error signal input to the respective circuits. The tracking signal shown in FIG. 2 actually includes a high-frequency component caused by a runout of the core when the compact disc 10 is loaded, and a drive voltage including such a high-frequency component is supplied to the servo driver 24 by the servo driver 24. Then, the tracking actuator of the optical pickup 14 is driven. The thread error signal shown in FIG. 2 is a signal output from the servo driver 30 of the thread servo circuit 26, and the thread motor 32 is driven by this signal.

Normally, a certain voltage is required to drive the sled motor 32. Until the voltage value of the sled error signal becomes large to some extent, only the tracking servo by the tracking servo circuit 20 is used to determine the read position of the recording signal. Adjustments are made. When the voltage value of the thread error signal reaches a predetermined value, the thread motor 32 rotates, so that the entire optical pickup 14 moves in the radial direction of the compact disk 10. Thus, tracking servo and thread servo are performed.

The digital signal processing circuit 40 performs synchronization detection and EFM demodulation on the EFM signal output from the RF amplifier 16, and then performs CIRC (Cross Interleave).
d Reed-Solomon Code) Decodes and outputs digital music data. Shock proof memory 42
Is for temporarily storing music data output from the digital signal processing circuit 40, and is generally a DRAM.
Is used. Shockproof memory controller 4
A digital signal processing circuit 4 controls reading and writing of data from and to the shock proof memory 42.
The operation of writing the music data output from 0 to the shock proof memory 42 and the operation of reading out the written music data at a constant speed are performed in parallel.
The digital filter 46 controls the shockproof memory 4 under the control of the shockproof memory controller 44.
The oversampling is performed on the music data read out from No. 2 to reduce the frequency components in the band outside the signal. The D / A conversion circuit 48 converts the music data input via the digital filter 46 into an analog signal and reproduces the music. The reproduced analog signal is output from a speaker via an audio amplifier (not shown).

The system controller 50 outputs various servo commands to the servo circuits 18, 20, 26 and 34, TOC (Table of Contents) information output from the digital signal processing circuit 40, and other sub-commands. Various controls necessary for music reproduction are performed by receiving and analyzing code data and the like. In particular, the system controller 50 performs control to temporarily increase the gain of the servo driver 30 in the thread servo circuit 26 at a predetermined timing (described later).

The operation unit 52 is for the user to give various operation instructions, and switches the mode of reproduction of the compact disk 10, reception of radio broadcast, reproduction of a cassette tape by a cassette deck, etc., as necessary. And various operation keys including a "mode switching" key for instructing the operation. The ACC switch 54 can be turned on and off by turning an engine key.
The off state is monitored by the system controller 50.

The above-described thread equalizer 28 corresponds to a servo processing unit for generating signals necessary for servo control of the thread motor, and the thread motor 32 and the thread servo circuit 26 correspond to a servo mechanism. The operation unit 52
And the ACC switch 54 correspond to timing instruction means, and the system controller 50 corresponds to servo control means.

The disk reproducing apparatus of the present embodiment has such a 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 50 constantly monitors whether or not the compact disk 10 has been loaded (step 300). When the compact disk 10 is loaded and a predetermined detection signal is output from the disk loading detection unit 36, the system controller 50 sends an instruction to the thread servo circuit 26 to
And by sending an instruction to the spindle servo circuit 34 to rotate the spindle motor 12,
The optical pickup 14 is moved to the vicinity of the inner periphery of the compact disk 10 to read the signal recorded in the lead-in area, and the TOC information contained in the lead-in is stored in the built-in memory (step 301). Then, based on the read TOC information, the system controller 50 starts high-speed playback from the beginning of the first song recorded on the compact disc 10 (step 302). Thereafter, the recording signal is read from the compact disk 10 with various servos applied, and the digital signal processing circuit 40 performs predetermined demodulation processing and decoding processing to output music data. The music data is temporarily stored in the shock proof memory controller 44 and then read out. The music data is converted into an analog signal through the digital filter 46 and the D / A conversion circuit 48, and the music is reproduced.

After the reproduction of the music is started, the system controller 50 determines whether or not the ACC switch 54 has been turned off (step 303) and whether or not any operation key of the operation section 52 has been pressed (step 303). 304) is monitored. If any operation key is pressed,
The system controller 50 issues a "mode switch" in which the depressed operation key instructs switching from the operation of reproducing the compact disc 10 to the operation of receiving a radio broadcast by the radio receiver or the operation of reproducing the cassette tape by the cassette deck. It is checked whether it is a key (step 305).

When the driver of the vehicle turns the engine key to
When the C switch is turned off, or when the driver of the vehicle or the passenger in the passenger seat presses the “mode switching” key of the operation unit 52, the system controller 50
Sends an instruction to the servo driver 30 of the thread servo circuit 26 to increase the gain of the servo driver 30 temporarily, for example, for a predetermined time (step 30).
6) Then, the application of the operating voltage applied from the power supply circuit (not shown) to each part of the disc reproducing apparatus 1 is stopped, and the power is turned off. Gain of servo driver 30,
That is, by temporarily increasing the thread gain of the thread servo circuit 26, even if the signal reading position of the compact disk 10 is slightly deviated from the mechanical center position of the optical pickup 14, the thread motor 32 is driven to The mechanical center position of the compact disk 10 is controlled to coincide with the signal reading position of the compact disk 10. The above-mentioned “mechanical center position of the optical pickup 14” corresponds to the focal position when the power supply to the tracking actuator of the optical pickup 14 is stopped and the focus lens returns to the original position.
When the reproduction is resumed, the recording signal at this focal position is read.

If the ACC switch is kept on and none of the operation keys of the operation unit 52 is pressed, or if any of the operation keys is pressed but not the "mode switching" key, the key is pressed. After performing the processing (step 307) corresponding to the operated operation key, the system controller 50 reads the music data until the last music based on the Q channel data of the sub-code output from the digital signal processing circuit 40. It is determined whether the process has been completed (step 308). For example, since the TOC information read and stored in step 301 includes the data of the "last movement number", the system controller 50 replaces the data of the movement number whose music data is currently being read with the subcode. By extracting from the Q channel and checking whether this matches the data of the “last movement number” included in the TOC information, the above-described determination processing in step 308 is performed. If the processing has not been completed up to the last song, the process returns to step 303 (determination of whether or not the ACC switch 54 is off) and the processing is repeated.

When the reading of the music data is completed up to the last music, the system controller 50 next searches for the head position of the first music based on the TOC information stored in the built-in memory (step 309).
And repeats the high-speed reproduction from the beginning of the first music.

As described above, during the reproduction of the compact disc 10, the ACC switch 54 is turned off,
When the “mode switch” key is pressed, the system controller 50 controls to temporarily increase the gain of the servo driver 30 of the thread servo circuit 26.
Therefore, even when the mechanical center position of the optical pickup 14 and the signal reading position of the compact disc 10 are slightly shifted, the drive voltage of the servo driver 30 of the thread servo circuit 26 is required to drive the thread motor 32. It will reach a predetermined value. In other words, by temporarily increasing the gain of the servo driver 30, the mechanical center position of the optical pickup 14 is controlled so as to approach the signal reading position, and then the power is turned off. The reproduction can be resumed from a position near the signal reading position at the time of the reproduction interruption.

FIG. 4 is a diagram showing a modification of the above-described embodiment, in which a thread servo circuit 26a obtained by partially modifying the thread servo circuit 26 included in the configuration shown in FIG.
Is shown. The other configuration is shown in FIG.
Has the same configuration as that of the disc reproducing apparatus 1 shown in FIG.

The thread servo circuit 26a shown in FIG.
The drive control of the thread motor 32 is performed based on the signal output from the tracking equalizer 22 in the tracking servo circuit 20 shown in FIG. 1. The output adjustment circuit 60 is provided in addition to the above-described thread equalizer 28 and servo driver 30. And a switch 62. The output adjustment circuit 60 has a dead zone in a part of the input / output characteristics,
Only when the absolute value of the output voltage of the thread equalizer 28 exceeds a certain value, the output voltage of the thread equalizer 28 is applied to the servo driver 30 at the subsequent stage, and the absolute value of the output voltage of the thread equalizer 28 is less than a certain value. In this case, the input voltage of the servo driver 30 is set to 0V. By using this output adjustment circuit 60, it is possible to prevent a drive voltage lower than the minimum voltage at which the sled motor 32 can rotate from being applied from the servo driver 30 to the sled motor 32. Therefore, the thread motor 3
Unnecessary current does not flow in a state where the motor 2 is not rotating, and deterioration due to heat generation of the servo driver 30 and the sled motor 32 can be prevented.

The switch 62 is connected to an output adjustment circuit 60.
And the thread equalizer 28 to select which output voltage is to be applied to the servo driver 30. The connection state is switched by the system controller 50. The switch 62 is connected to the output adjustment circuit 60 during normal operation, and is connected to the thread equalizer 28 at a timing when the gain of the servo driver 30 is temporarily increased before power is turned off.

FIG. 5 is a flowchart showing the operation procedure of the disk reproducing apparatus including the thread servo circuit 26a shown in FIG. 4, and shows the operation procedure in the case where the output adjustment circuit 60 is provided. The operation procedure shown in FIG. 5 is basically the same as the operation procedure shown in FIG. 3, except that the operation of step 306a is added before step 306, and the operation of step 306b is added after step 306. . Hereinafter, portions different from FIG. 3 will be described.

The driver of the vehicle turns the engine key to turn on the AC.
When the C switch is turned off, or when the driver of the vehicle or the passenger in the passenger seat presses the “mode switching” key of the operation unit 52, the system controller 50
Switches the switch 62 in the thread servo circuit 26 to apply the output voltage of the thread equalizer 28 directly to the servo driver 30 without passing through the output adjustment circuit 60 (step 306a), and then instructs the servo driver 30 Control is performed to temporarily increase the gain by sending (step 306). After that, the system controller 50 returns the connection state of the switch 62 in the thread servo circuit 26 to the original state, and the output voltage of the output adjustment circuit 60 becomes
After the voltage is applied to 0, the application of the operating voltage applied to each part of the disk reproducing apparatus is stopped, and the power is turned off.

As described above, when the output adjusting circuit 60 is provided, when increasing the gain of the servo driver 30, the output of the thread equalizer 28 is directly input to the servo driver 30 without passing through the output adjusting circuit 60. Even if the output voltage of the thread equalizer 28 is small enough to be included in the dead zone of the output adjustment circuit 60, the output voltage is amplified by the servo driver 30 and
Can be rotated.

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, the above-described disk reproducing apparatus reproduces music recorded on the compact disk 10, but can also be applied to a disk reproducing apparatus that reproduces a mini disk (MD), a digital video disk (DVD), or the like. . 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.
In this case, since it is not necessary to consider the connection with the ACC switch 54 shown in FIG. 1, step 3 shown in FIG.
The determination of 03 (determination of whether or not the ACC switch is off) is skipped and the processing is performed.

[0036]

As described above, according to the present invention, by temporarily increasing the gain of the servo driver before turning off the power, the mechanical center position of the optical pickup and the reading position of the recording signal of the disk type recording medium are read. The optical pickup can be moved so as to eliminate the deviation, so that the deviation of the reading position of the recording signal when the reproduction is resumed is reduced, and the reproduction can be continuously resumed.

In particular, the disk reproducing apparatus of the present invention is suitable for an in-vehicle audio apparatus capable of switching to an operation mode other than the disk reproducing mode. , It is possible to accurately and continuously resume playback.

[Brief description of 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.

FIG. 2 is a diagram illustrating a relationship between a tracking error signal and a thread error signal.

FIG. 3 is a flowchart showing an operation procedure of the disc reproducing apparatus of the embodiment.

FIG. 4 is a diagram showing a partial configuration of a modified example of the disk reproducing device of the embodiment.

FIG. 5 is a flowchart showing an operation procedure of the disc reproducing apparatus shown in FIG. 4;

[Explanation of symbols]

 Reference Signs List 1 disc reproducing apparatus 10 compact disc 14 optical pickup 16 RF amplifier 20 tracking servo circuit 22 tracking equalizer 24, 30 servo driver 26 thread servo circuit 28 thread equalizer 32 thread motor 40 digital signal circuit 50 system controller 52 operating unit 54 accessory switch

Claims (3)

[Claims] 1. A disk reproduction method comprising: temporarily increasing a thread gain at a predetermined timing before a power supply is turned off so that a mechanical center position of an optical pickup is adjusted to a position where a recording signal of a disk type recording medium is read. apparatus. 2. A sled motor for moving an optical pickup for reading a recording signal in a radial direction of a disk-type recording medium; a servo processing unit for generating a signal necessary for servo control of the sled motor based on a tracking error signal; A servo mechanism having a servo driver that drives the sled motor by amplifying a signal output from the servo processing unit; timing instructing means for instructing a predetermined timing before power-off; and instructed by the timing instructing means. And servo control means for temporarily increasing the gain of the servo driver at a timing, and turning off the power after adjusting the mechanical center position of the optical pickup to a position where a recording signal of the disk-type recording medium is read. A disk reproducing device characterized by the above-mentioned. 3. The in-vehicle audio device according to claim 2, wherein the predetermined timing is a timing at which an operation mode switching instruction is given and an engine key switch. A disc playback device including at least one of timings at which a power-off instruction to the in-vehicle audio device is issued by the operation of (1).