JP2000057590A - Disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk player capable of providing the optimal characteristic of a pickup servo system during playing. SOLUTION: A disk player 100 temporarily stores music data read from a minidisk 10 in a DRAM 40 by control performed by a remote controller 42. When a data quantity stored in the DRAM 42 is equal to a given value or higher, and at a timing for not writing music data in the DRAM 42, an automatic adjusting command is sent from a system controller 50 to a servo controller 36, and thus automatic readjustment is executed for an optical pickup servo system.

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 temporarily storing read audio data in a memory and reproducing the data.

[0002] It should be noted that the term "music" in this specification includes not only ordinary music produced by vocalization and musical instrument performance, but also all sounds to be recorded on a disk-type recording medium such as a compact disk. I do.

[0003]

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.

[0004] 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.

In order to read a recording signal from a disk without error, it is necessary to optimally adjust the servo characteristics of a pickup servo system. Conventionally, a manufacturer has to adjust the servo characteristics while reproducing a reference disk before shipment. Optimal adjustment of the servo characteristics was performed at the time of turning on the power or setting the disk. By performing such optimal adjustment of the servo system, good playability is ensured, and the occurrence of sound interruption or sound skipping due to disturbance such as vibration is prevented.

[0006]

However, the conventional disk reproducing apparatus described above only performs the optimal adjustment of the pickup servo system at the time of turning on the power or setting the disk. However, there is a problem that if the operating time rises due to a certain amount of reproduction time, the optimum characteristics cannot be obtained. For example, even if a disc is set at room temperature of 20 ° C. and the pickup servo system is optimally adjusted, if music or the like is reproduced for a long time, the servo system is mainly generated by self-heating by an amplifier or various drivers. May rise up to about 80 ° C. As described above, when the operating temperature changes from 20 ° C. to 80 ° C., the characteristics and the like of various actuators also change greatly, and the characteristic values also deviate from the optimum values.

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 obtaining optimum characteristics of a pickup servo system during a reproducing operation. .

[0008]

In order to solve the above-mentioned problems, a disk reproducing apparatus according to the present invention provides a pickup servo system when reading data stored in a temporary storage means and reproducing music. Has been adjusted. Specifically, the disk playback device of the present invention temporarily stores music data read from a disk-type recording medium in a temporary storage unit, and reads out the music data stored in the temporary storage unit by a storage control unit. The pickup servo system is adjusted by servo system adjustment means. The adjustment of the pickup servo system is performed while the music data is being read from the temporary storage means, so that the adjustment operation can be performed without interrupting the reproduction operation. Characteristics can be obtained.

In particular, it is preferable to provide a temperature detecting means for detecting the temperature of the pickup servo system, and to perform the above-described adjustment of the servo system when the amount of change in the detected temperature exceeds a predetermined value. Since the characteristics of the pickup servo system deviate from the optimum values due to the temperature change, the pickup servo system can be adjusted at an appropriate timing by adjusting the pickup servo system when the temperature of the pickup servo system changes.

Also, when the operation of writing the music data into the temporary storage means by the storage control means is stopped, the data amount of the music data before reading stored in the temporary storage means is equal to or more than a predetermined value. In this case, it is preferable to perform the adjustment operation by the servo system adjustment unit. Since music data is not being written, even if the operation of the optical pickup servo system is stopped, there is no substantial effect, and since the amount of data in the temporary storage means is more than a predetermined value, sound is cut off even if automatic adjustment is performed. The automatic adjustment can be performed in parallel with the normal reproduction operation without any occurrence of the above.

It is preferable that when the writing of the music data to the temporary storage means by the storage control means is completed for each music piece, an adjustment operation by the servo system adjustment means is performed. Between songs, even if the time required for automatic adjustment is long, the cueing of the next song is only slightly delayed, and there is no sound interruption or the like, which gives the user a sense of discomfort. Can be eliminated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a disc 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. 1 includes a spindle motor 12, a spindle servo circuit 14, an optical pickup 16, a sled motor 18, a sled servo circuit 20, an RF amplifier 22,
Focus servo circuit 24, servo drivers 26, 3
0, tracking servo circuit 28, detection circuit 32, A /
D converter 34, servo controller 36, digital signal processing circuit 38, DRAM 40, memory controller 4
2, ATRAC decoder 44, digital filter 46,
It includes a D / A converter 48, a system controller 50, and a temperature sensor 52.

A spindle motor 12 rotates an MD (mini-disc) 10 as a disk-type recording medium at a constant linear speed. The spindle servo circuit 14 controls the spindle motor 12 to keep the linear velocity constant.
The optical pickup 16 is for detecting a recording signal while rotating the MD 10 by the spindle motor 12, and includes a semiconductor laser, a photodiode, and a focus lens. Thread motor 1
8 moves the optical pickup 16 in the radial direction of the MD 10. The thread servo circuit 20 includes a thread motor 18
To generate a driving voltage necessary for applying a thread servo for tracking a track. RF amplifier 22
Converts the detection signal (current) of the optical pickup 16 into a voltage and outputs an RF signal.

The focus servo circuit 24 generates a focus error signal FE, and the focus error signal F
Based on E, control is performed to drive a focus actuator (not shown) provided to the optical pickup 16 to apply focus servo. The servo driver 26 drives the focus actuator by amplifying the input from the focus servo circuit 24.

The tracking servo circuit 28 generates a tracking error signal TE, and controls a tracking actuator (not shown) provided in the optical pickup 16 to apply tracking servo based on the tracking error signal TE. . Servo driver 30
Drives the tracking actuator by amplifying the input from the tracking servo circuit 28.

The detection circuit 32 detects the lower envelope of the RF signal output from the RF amplifier 22. A / D
The converter 34 converts an output signal (analog signal) of the detection circuit 32 into digital data. The servo controller 36 starts up the servo, sets an adjustment coefficient for the pickup servo system, performs automatic adjustment, and the like.

The digital signal processing circuit 38 performs synchronous detection and EFM demodulation based on the RF signal output from the RF amplifier 22, and then performs CIRC (Cross Interleave).
d Reed-Solomon Code) decodes and outputs compressed digital music data. The DRAM 40
The music data output from the digital signal processing circuit 38 is temporarily stored. The memory controller 42 includes the DRAM 4
0 for controlling the reading and writing of data to and from the digital signal processing circuit 38.
The operation of writing to the RAM 40 and the operation of reading the written music data are performed in parallel. AT
The RAC decoder 44 converts the compressed music data into an ATR
The data is expanded by the AC method and converted into normal music data. The digital filter 46 performs oversampling on the music data output from the ATRAC decoder 44 to reduce the frequency components in the band outside the signal. The D / A converter 48 converts music data input via the digital filter 46 into an analog signal and reproduces 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 14, 20, 24, 28, TOC (Table of Contents) information output from the digital signal processing circuit 38, and other sub-commands. Various controls necessary for music reproduction are performed by receiving and analyzing code data and the like. The temperature sensor 52 detects the temperature of the optical pickup 16 and sends the detection result to the system controller 50.

FIG. 2 is a diagram showing the configuration of the RF amplifier 22. As shown in FIG. 2, the RF amplifier 22 includes four current-to-voltage converters (IV) 22a, 22b, 22c, 2
2d and an adder 22e. Each of the four current-to-voltage converters 22a to 22d has an (A + C) signal input from the optical pickup 16 and a (B + D) signal.
The signal, the E signal, and the F signal are individually subjected to current-voltage conversion. The adder 16e adds the outputs of the current-voltage converters 22a and 22b to generate an RF signal.

The (A + C) signal and the (B + D) signal converted to voltage by the current-voltage converters 22a and 22b are both input to the focus servo circuit 24. Further, the E signal and the F signal converted into voltages by the current-voltage converters 22c and 22d are both input to the tracking servo circuit 28. The RF signal output from the adder 22e is input to the detection circuit 32 and the digital signal processing circuit 38.

FIG. 3 is a diagram showing the configuration of the focus servo circuit 24. As shown in FIG. 3, the focus servo circuit 24 includes variable gain amplifiers 24a, 24b, 24g,
It is configured to include subtractors 24c and 24e, an A / D converter 24d, a loop filter 24f, a loop switch 24h, a variable frequency oscillator 24i, an adder 24j, and a D / A converter 24k. The subtractor 24c converts the (B + D) signal from the signal obtained by amplifying the (A + C) signal output from the RF amplifier 22 by the variable gain amplifier 24a into the variable gain amplifier 24.
The focus error signal FE is created by subtracting the signal amplified in b. This focus error signal FE
After the A / D conversion, the offset adjustment is performed by passing the signal through a subtractor 24e, and the loop filter 24f performs low-frequency gain boost and high-frequency phase compensation. The output of the loop filter 24f is amplified by a variable gain amplifier 24g, and then amplified by a loop switch 24h.
Is input to the adder 24j via the
After the outputs of 4i are added, D / A conversion is performed. This D
The signal after the / A conversion is input to the servo driver 26.

FIG. 4 is a diagram showing the configuration of the tracking servo circuit 28. As shown in FIG. 4, the tracking servo circuit 28 includes variable gain amplifiers 28a, 28b, 28
g, subtractors 28c and 28e, A / D converter 28d, loop filter 28f, loop switch 28h, variable frequency oscillator 28i, adder 28j, and D / A converter 28k. The tracking servo circuit 28
It has the same configuration as the focus servo circuit 24 described above, and subtracts the signal obtained by amplifying the F signal by the variable gain amplifier 28b from the signal obtained by amplifying the E signal output from the RF amplifier 22 by the variable gain amplifier 28a. A signal to be output to the servo driver 30 is created by creating a tracking error signal TE and performing offset adjustment, phase compensation, and the like on the tracking error signal TE.

The above-described DRAM 40 is used as temporary storage means,
The memory control 42 corresponds to a storage control unit, the third controller 36 and the system controller 50 correspond to a servo system adjustment unit, and the temperature sensor 52 corresponds to a temperature detection unit.

The disk reproducing apparatus of the present embodiment has such a configuration, and its operation will be described next. FIG.
9 is a flowchart showing an operation procedure of a disc reproducing apparatus for automatically adjusting an optical pickup servo system at the time of setting a disc and during a reproducing operation. When the power of the disc reproducing apparatus 100 is turned on, the system controller 50
It is checked whether D10 is set (step 10).
0), if not set, a standby state is set until MD10 is set (step 101). MD10
Is set when the power is turned on, or is newly set after the power is turned on, the system controller 50 measures the current temperature t with the temperature sensor 52 and stores the measured value (step 102). ).

Next, the system controller 50 gives a servo-on / auto-adjustment command to the servo controller 36 to automatically adjust the optical pickup servo system (step 103).

FIG. 6 is a flowchart showing the operation procedure of the automatic adjustment of the optical pickup servo system which is performed under the control of the servo controller 36. Hereinafter, each step will be described in detail.

(1) Focus Offset Adjustment (Step 200) With the laser of the optical pickup 16 turned off, the A / D
The output of the converter 24d is read to determine the focus offset amount. The focus offset is zero when the current-voltage converters 22a and 22b, the variable gain amplifiers 24a and 24b, and the subtractor 24c are in a balanced state, but not zero when not in a balanced state. The servo controller 36 outputs the obtained focus offset amount as an argument to the subtractor 24e.

(2) Tracking Offset Adjustment (Step 201) A / D is performed with the laser of the optical pickup 16 turned off.
The output of the converter 28d is read to determine the tracking offset amount. The tracking offset is zero when the current-voltage converters 22c and 22d, the variable gain amplifiers 28a and 28b, and the subtractor 28c are in a balanced state, but not zero when not in a balanced state. The servo controller 36 outputs the obtained tracking offset amount as an argument to the subtractor 28e.

(3) Rough Adjustment of Focus Gain (Step 202) The laser of the optical pickup 16 is turned on, and the low frequency triangular wave is output from the variable frequency oscillator 24i while the loop switch 24h is open. Focus error signal FE
Since the S curve shown in FIG. 7A is drawn, the A / D converter 2
From the output of 4d, the voltage between the peaks (V (F in FIG. 7A)
E) _PP ) is read, and the gain of the variable gain amplifier 24g is adjusted so that this reads a predetermined reference value.

(4) Focus Servo ON (Step 2)
03) After the coarse gain adjustment, the A / D converter 24 outputs the low frequency triangular wave from the variable frequency oscillator 24i.
The change of the focus error signal FE is monitored from the output of d, the loop switch 24h is closed at a timing near the zero cross (point A in FIG. 7A), and the focus servo is turned on. Thereafter, the oscillation of the variable frequency generator 24i is stopped.

(5) Starting the spindle motor (Step 2)
04) A starting voltage is applied to the spindle servo circuit 14 to start the spindle motor 12 and start the rotation of the MD 10.

(6) Tracking Servo ON (Step 205) When the MD 10 rotates, the lower envelope of the RF signal periodically changes each time the laser beam crosses the track. Monitor the lower envelope of the RF signal input through the loop switch 28h and close the loop switch 28h at the timing of entering the negative feedback region of the tracking servo to turn on the tracking servo.

(7) Wait, Spindle Servo, and Thread Servo On (Steps 206 to 208) After waiting for several hundred ms until the MD 10 reaches near the specified rotation speed, the spindle servo is turned on, and then the thread servo is turned on.

(8) Tracking gain coarse adjustment (step 209) The loop switch 28h is opened and the tracking servo is turned off. At this time, since the tracking error signal TE repeats a periodic change as shown in FIG. 7B every time the track crosses, the change of the tracking error signal TE is read from the A / D converter 28d, and the voltage between the peaks is read. The gain of the variable gain amplifier 28g is adjusted so that (V (TE) _{PP in} FIG. 7B) becomes a predetermined reference value.

(9) Tracking Balance Adjustment (Step 210) The A / D converter 28 keeps the tracking servo off.
The change in the tracking error signal TE is read from d.
The variable gain amplifier 28a is controlled so that the upper peak level and the lower peak level (V1 and V2 in FIG. 7B) match based on the tracking offset obtained in step 201.
And the gain of 28b are adjusted.

(10) Focus Balance Adjustment (Step 211) The tracking servo is turned on, and the variable frequency oscillator 24i is turned on.
A sine wave disturbance of several hundred Hz is injected into the focus servo system. At this time, the lower envelope of the RF signal is shown in FIG.
Since the voltage changes periodically as shown in FIG. 7C, it is read from the output of the A / D converter 28d, and the voltage between adjacent peaks (V3 and V4 in FIG. 7C) is matched.
The gains of the variable gain amplifiers 24a and 24b are adjusted. Thereafter, the oscillation of the variable frequency oscillator 24i is stopped.

(11) Fine adjustment of focus gain (step 212) Among the open loop gain characteristics of the focus servo system, a sine wave disturbance having a frequency corresponding to the crossover frequency fc is injected from the variable frequency oscillator 24i into the focus servo system. The disturbance component that has been cycled is read from the output of the variable gain amplifier 24g,
The gain of the variable gain amplifier 24g is adjusted so that the level ratio between the looped disturbance component and the injected disturbance component becomes a predetermined gain value in the desired closed loop gain characteristic. After the adjustment, the oscillation of the variable frequency oscillator 24i is stopped.

(12) Fine Adjustment of Tracking Gain (Step 213) Among the open loop gain characteristics of the tracking servo system, a sine wave disturbance having a frequency corresponding to the crossing frequency fc is injected from the variable frequency oscillator 28i into the focus servo system. The looped disturbance component is read from the output of the variable gain amplifier 28g, and the variable gain amplifier 28g is controlled so that the level ratio between the looped disturbance component and the injected disturbance component becomes a predetermined gain value in the desired closed loop gain characteristic. Adjust the gain. After the adjustment, the oscillation of the variable frequency oscillator 28i is stopped.

When the automatic adjustment of the optical pickup servo system under the control of the servo controller 36 is completed, the system controller 50 sets the measured temperature t to the temperature T at the time of the automatic adjustment (step 104).
Then, it is determined whether or not the automatic adjustment performed immediately before is re-automatic adjustment based on temperature change detection (step 105).
In the case of automatic adjustment immediately after the MD 10 is set, a negative determination is made in step 105, and then the system controller 50 sets the optical pickup 16, the RF amplifier 2
2. The TOC information recorded in the lead-in of the MD 10 is read by the digital signal processing circuit 38 (step 106), and the head of the first music is searched by referring to the TOC information (step 107), and the performance is started (step 107). Step 108).

After the performance starts, the system controller 50 takes in the output of the temperature sensor 52 and measures the current temperature t (step 109). It is determined whether the temperature is within the range of 10 ° C. (step 110). When the temperature is within the range, that is, when the temperature change is within 10 ° C. as compared with the temperature T when the automatic adjustment is performed, the system controller 50 continues the performance as it is (step 111) and ends the performance. It is determined whether or not (step 112). For example, when the user instructs to stop the performance or when all the music pieces have been played, an affirmative determination is made in step 112 and the series of performance operations ends. Conversely, if the performance does not end, step 10
9, the operation after the measurement of the current temperature t is repeated.

If the current temperature t measured in step 109 is not within ± 10 ° C. of the temperature T when the automatic adjustment was performed, a negative determination is made in step 110, and , System controller 1
13 is whether or not the data amount before reading stored in the DRAM 40 is equal to or more than a predetermined value (step 113);
If it is equal to or more than the predetermined amount, it is determined whether or not the writing of music data to the DRAM 40 has been stopped (step 114).

FIG. 8 is a diagram showing a transition of the data amount before reading in the DRAM 40. In a state where track jump etc. does not occur due to large vibration or impact,
The data amount before reading in the DRAM 40 repeatedly increases and decreases between an upper limit value A determined by the capacity and a predetermined lower limit value B. By the way, in a state where the data amount decreases from the upper limit value A to the lower limit value B, the writing of the music data to the DRAM 40 is stopped. In the present embodiment, the time T corresponding to this state is set to be shorter. Utilizes automatic adjustment of the optical pickup servo system. Therefore, D
The current data amount in the RAM 40 is a predetermined value (C in FIG. 8) taking into account the time required for the automatic adjustment of the optical pickup servo system.
It is necessary to detect a state in which music data has not been written to the DRAM 40, and this state is detected in steps 113 and 114 described above.

When the amount of data before reading from the DRAM 40 is equal to or smaller than a predetermined value (a negative determination is made in step 113), or when music data is being written to the DRAM 40 (a negative determination is made in step 114). ),
It is in a standby state until these conditions are satisfied. Also,
If these conditions are met, a positive determination is made in step 114, and then the system controller 50
A re-automatic adjustment command is given to the servo controller 36 to automatically adjust the optical pickup servo system (step 103). When the automatic re-adjustment of the optical pickup servo system is performed in this way, an affirmative judgment is made in the determination process of step 105 (whether or not the re-automatic adjustment is performed).
The performance is continued (step 115).

As described above, the disc reproducing apparatus 100 of the present embodiment has the DRAM 40 for temporarily storing the music data read from the MD 10, and the DRAM 40
The automatic adjustment of the optical pickup servo system is performed again using the time during which the writing operation of the music data with respect to is stopped and only the reading operation is performed, and after the reproducing operation by the disc reproducing apparatus 100 is started. Even so,
Optimal characteristic values of the optical pickup servo system can be maintained. In particular, since the automatic adjustment is performed when the temperature change becomes large, when the characteristic value of the servo system deteriorates due to the temperature change, this characteristic value can be readjusted at an appropriate timing, and the optimum characteristic is always obtained. Value can be maintained.

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, the automatic re-adjustment of the optical pickup servo system is performed during the performance of a song, but the re-automatic adjustment may be performed using a blank portion between the songs. . FIG. 9 is a flowchart showing an operation procedure of the disk reproducing apparatus when the optical pickup servo system is automatically adjusted between music pieces. The operation procedure shown in FIG.
The operation procedure is basically the same as the operation procedure shown in FIG. 5, and steps 113 and 114 shown in FIG.
4A as well as Step 11 shown in FIG.
The difference is that step 115A is added immediately before step 5. That is, when the temperature change is large (step 1)
If the determination is negative in step 10), then the system controller 50 determines whether or not all the music data of the current music piece has been written to the DRAM 40 (step 113A), and if the writing has been completed. Has a DR
An instruction to stop reading the music data from the AM 40 when the current music piece ends is sent to the memory controller 42 (step 114A). Thereafter, returning to step 103, automatic adjustment of the optical pickup servo system is performed again. When the automatic adjustment is completed and an affirmative determination is made in the determination processing of step 105 (whether or not the automatic adjustment is performed again), the system controller 50 instructs the stop of reading of the music data from the DRAM 40 performed in step 114A. (Step 115
After A), the performance is continued (step 115). As described above, by performing the automatic re-adjustment of the optical pickup servo system using the space between the music pieces, the optimum characteristic value of the optical pickup servo system can be maintained during the reproducing operation. Also, since the space between songs is used, even if the automatic adjustment takes a long time, the performance start timing of the next song will be slightly delayed, There is almost no sense of incongruity given to people.

Further, in the above-described embodiment, the disc reproducing apparatus 100 for MD has been described.
The present invention can be applied to a disk reproducing apparatus for another disk type recording medium such as D.

[0048]

As described above, according to the present invention, when the data stored in the temporary storage means is read and the music is reproduced, the adjustment of the pickup servo system is performed, and the reproduction operation is performed. The adjustment operation can be performed without interruption, and the optimum characteristics of the pickup servo system can always be obtained even during the reproducing operation. In particular, by adjusting the servo system when the amount of change in the temperature of the pickup servo system exceeds a predetermined value, the servo system can be adjusted at an appropriate timing.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a configuration of an RF amplifier.

FIG. 3 is a diagram illustrating a configuration of a focus servo circuit.

FIG. 4 is a diagram illustrating a configuration of a tracking servo circuit.

FIG. 5 is a flowchart showing an operation procedure of a disc reproducing apparatus for automatically adjusting an optical pickup servo system at the time of setting a disc and during a reproducing operation.

FIG. 6 is a flowchart showing an operation procedure of an automatic adjustment of an optical pickup servo system performed under the control of a servo controller.

FIG. 7 is an explanatory diagram of an automatic adjustment method.

FIG. 8 is a diagram showing a transition of a data amount before reading in a DRAM.

FIG. 9 is a flowchart showing an operation procedure of the disk reproducing apparatus when the optical pickup servo system is automatically adjusted between music pieces.

[Explanation of symbols]

 Reference Signs List 16 optical pickup 22 RF amplifier 24 focus servo circuit 28 tracking servo circuit 38 digital signal processing circuit 40 DRAM 42 memory controller 44 ATRAC decoder 50 system controller 100 disk playback device

Claims (5)

[Claims] 1. A disk reproducing apparatus for reproducing music by writing and storing music data read from a disk-type recording medium in a temporary storage means, and then reading the data stored in the temporary storage means. A disk reproducing apparatus characterized in that a pickup servo system is adjusted when reproducing a disc. 2. Temporary storage means for temporarily storing music data read from a disk-type recording medium; storage control means for controlling writing and reading of music data to and from the temporary storage means; and temporary storage by the storage control means. And a servo system adjusting means for adjusting a pickup servo system when music data is being read from the means. 3. The apparatus according to claim 2, further comprising a temperature detecting means for detecting a temperature of the pickup servo system, wherein when the amount of change in the temperature detected by the temperature detecting means exceeds a predetermined value, A disc reproducing apparatus wherein an adjusting operation is performed by a system adjusting means. 4. The apparatus according to claim 2, wherein the writing operation of the music data to the temporary storage unit by the storage control unit is stopped, and the music data before the reading stored in the temporary storage unit is stopped. A disk reproducing apparatus, wherein when the data amount of music data is equal to or more than a predetermined value, the servo system adjusting means performs an adjusting operation. 5. The adjustment operation by the servo system adjustment unit according to claim 2, wherein when the writing of music data to the temporary storage unit by the storage control unit is completed for each music piece to be played. Disc playback device.