JPH11149716A - Disc playback device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a disk reproducing apparatus in which a good reproducing operation can be extended and maintained further while electric power is saved by a method wherein a spindle motor is turned at a speed which is faster than an ordinary speed and reproduced compressed data is written intermittently into a memory means at a third speed which is faster than a first speed. SOLUTION: A spindle motor 10 is turned at a linear velocity which is, e.g. twice an ordinary linear velocity. Compressed audio data which is reproduced by a signal processing means 4 is written into a memory means 5 at a third speed which is faster than an ordinary speed. Thereby, the time in the section of the logic value H of an MEW signal which is output by a system control means 8 becomes halved as t2 /2 when the time in the section of the logic value H at an ordinary speed is designated as T2 . In addition, the time in the section of the logic value L of an SLP signal which is output by the system control means 8 is increased by T2 /2. Thereby, the time in which an optical pickup drive means 9, a reproducing amplifier 3 and the signal processing means 4 are stopped or set to a standby state can be made longer by T2 /2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable disk reproducing apparatus for reproducing recorded information from an optical disk as a recording medium.

[0002]

2. Description of the Related Art Currently, reproduction-only CDs (compact discs) and recordable / reproducible MDs (mini-discs) have been put into practical use as audio optical disks.

The characteristics of the optical disk include a relatively small diameter because high-density recording using a laser is possible, and an access speed that is particularly remarkable when compared with a tape-shaped recording medium. . In particular, MD compresses audio signals by skillfully utilizing the psychoacoustic characteristics of humans,
As a result, music of the same length as a CD can be recorded on a disk having a diameter approximately half that of a CD, and thus has gained a high reputation in terms of portability and has been rapidly spreading recently.

When a portable MD player using such an MD is put to practical use, a battery is usually used as a power source, so that continuous operation can be performed for a long time with limited power obtained from the battery. Making it possible is an important point of development. For this reason, companies have reduced power consumption by integrating the necessary circuits into as few integrated circuits as possible, for example, using circuit technology, or by keeping the operating voltage of electrical circuits as low as possible. Was. Furthermore, in recent years, the audio signal of the MD system is about 4.8.
Techniques have been put to practical use in which a circuit operation redundant to signal reproduction is stopped by skillfully utilizing the fact that the data is compressed by a factor of one.

A conventional disk reproducing apparatus using such a technique will be described below with reference to the drawings. FIG. 6 is a block diagram of a conventional disk reproducing device devised to reduce power consumption, and its operation timing diagram is shown in FIG.
Shown in In FIG. 6, 1 is an MD disc, 2
Reference numeral 3 denotes an optical pickup for reading a signal by irradiating the disk 1 with a laser beam. Reference numeral 3 denotes an EFM (8-14 modulation) for transmitting main information such as a compressed audio signal from a signal on the disk 1 read by the optical pickup 2. ) Signals, ADIP (address) signals for transmitting position information on the disk 1, and servo signals such as a focus error signal and a tracking error signal used for position control of the optical pickup 2.
A reproduction amplifier obtained by analog signal processing.
Are the EFM signal supplied from the reproduction amplifier 3 and the ADI
Signal processing means for reproducing compressed audio data and address information from the P signal by digital signal processing.

[0006] The compressed audio data reproduced by the signal processing means 4 is intermittently written into the memory means 5 at the first speed, and then, in response to a request from the decompression means 6, the second audio data which is slower than the first speed. The data is continuously read out from the memory means 5 at the speed shown in FIG. 1 and subjected to audio decompression processing by the decompression means 6 to become the original digital audio signal. Thereafter, the digital audio signal is converted to a DAC (D / A converter) 7.
Is restored to an analog audio signal, and is emitted from, for example, a speaker or headphones (not shown).

Reference numeral 9 denotes a focus servo and a tracking servo of the optical pickup 2 based on a focus error signal and a tracking error signal sent from the reproducing amplifier 3, and further, a transfer servo of the entire optical pickup 2 in a radial direction of the disk 1. An optical pickup driving unit 11 performs a spindle motor 10 based on an EFM signal or an ADIP signal sent from the signal processing unit 4.
Is a spindle motor driving means for driving the spindle motor to keep its rotation at a constant linear velocity.

Reference numeral 8 denotes a system control means, which is a difference between a writing point and a reading point of the memory means 5, that is, the memory means 5
When the remaining data amount becomes equal to or less than the first comparison value, writing of the compressed audio data from the signal processing means 4 to the memory means 5 is started, and the remaining data amount becomes the second comparison value. Then, the writing of the compressed audio data is stopped. Further, the system control means 8 controls the optical pickup drive when the read position from the disk 1 is continuous before and after intermittently starting and stopping the writing of the compressed audio data from the signal processing means 4 to the memory means 5. The optical pickup 2 is moved to the disk 1 by the means 9
Access to the optimal location.

As described above, the compressed audio data reproduced by the signal processing means 4 is stored in the memory means 5 at the first speed.
While writing intermittently to the second speed slower than the first speed
The data is continuously read out at the speed described above, and after the audio expansion processing is performed by the expansion means 6, the reproduction output is performed.

In the prior art shown in FIG. 6, unnecessary circuit operations are stopped even during a reproducing operation to reduce power consumption. The reduction method will be described with reference to FIG.
FIG. 2A shows the remaining data amount REM of the memory means 5.
FIG. 2B shows a data write command MWE output from the system control means 8 to the memory means 5, and a logic H (FIG. ₂ ) is set in a section B (time is T ₂ ) in which reproduction data is written to the memory means 5. 2 is expressed as ON), and a logic L (FIG. 2) in a section A + C (time is T ₁ + T ₃ ) in which writing is stopped.
Is represented as OFF).

The decompression means 6 continuously reads out the reproduction data from the memory means 5 in order to continuously output the audio signal. In MD, the audio signal is about 4.
Since the data is compressed to 1/8 and the REM does not underflow even if data is reproduced from the disk 1 intermittently, when the REM becomes equal to or more than the second comparison value TH, the disk 1 is compressed.
The reproduction of the data from the memory means 5 is stopped, and the writing of the reproduction data to the memory means 5 is also stopped.

Therefore, in FIG. 2A, the section A + C (the time is T ₁ +
At T ₃ ), the REM is constantly decreasing. On the other hand, when the REM becomes equal to or less than the first comparison value TL, data reproduction from the disk 1 is restarted, and writing of the reproduction data to the memory means 5 is also restarted.

Further, in the conventional example, in order to reduce power consumption, during a period in which data reproduction from the disk 1 is stopped, the optical pickup driving means 9, the reproducing amplifier 3 and the signal processing means 4 are controlled by the system control means 8 Stop command SL
The operation is stopped by P or a standby state is set. Here, stopping the operation of the optical pickup driving means 9 includes stopping the irradiation of the laser beam.

FIG. 2C shows a stop command SLP output from the system control means 8. The system control means 8 sets R
EM is monitored to compare the magnitude of TH and TL with REM, and when REM becomes equal to or less than TL, SLP is set to logic H.
(Represented as ON in FIG. 2), and then the SLP is set to logic L (represented as OFF in FIG. 2) when REM exceeds TH.

In the section C (the time is T ₃ ) where the SLP is logic L, the optical pickup driving means 9, the reproducing amplifier 3 and the signal processing means 4 are stopped or in a standby state, so that power consumption can be reduced. Immediately after REM becomes equal to or lower than TL and data reproduction from the disk 1 is resumed, it takes time in the section A (time T ₁ ) for pull-in and setting of the focus servo and the tracking servo. Therefore, the data is actually reproduced from the disk 1 and the reproduced data is written to the memory means 5 in the section B (time T ₂ ) after the servo settling operation is completed.

[0016]

However, in the conventional disk reproducing apparatus as described above, during the period when reproduction from the disk 1 is stopped during intermittent reproduction, the optical pickup driving means 9 and the reproduction amplifier 3 shown in FIG. In addition, since the signal processing unit 4 is in a power saving state by the SLP, the power consumption of the entire system can be reduced to some extent. However, it is difficult to say that sufficient power saving has not yet been achieved as a portable device. Had a point.

The present invention solves the above-mentioned conventional problems, and can achieve further power saving as compared with the conventional one, and can maintain a good reproducing operation for a longer time. Provided is a disk reproducing apparatus.

[0018]

In order to solve the above-mentioned problems, a disk reproducing apparatus according to the present invention rotates a spindle motor for rotating a disk at a speed higher than a normal linear speed, and reproduces the compressed data reproduced. By intermittently writing to the memory means at a third speed higher than the first speed,
It is characterized in that the period during which laser light irradiation is suspended is lengthened to effectively reduce the power consumption of the entire system.

As described above, further power saving can be achieved as compared with the related art, and a favorable reproducing operation can be further maintained.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk reproducing apparatus according to a first aspect of the present invention irradiates a disk, which is a recording medium rotated by a spindle motor, with laser light, and receives the reflected laser light by an optical pickup. While reproducing the compressed data recorded on the disk, and writing the compressed data to the memory means intermittently every predetermined period,
The compressed data written to the memory means is continuously read out at a speed lower than the writing speed, output after decompression processing, and at least during the intermittent interruption of the writing to the memory means, at least the laser light A disc reproducing apparatus for suspending irradiation of a disc, wherein a first rotation of a spindle motor for rotating the disc is performed.
Is the normal linear speed, the first speed in writing the reproduced compressed data to the memory means is the normal speed, and the reading speed of the compressed data from the memory means is the second speed. The spindle motor is rotated at a second linear speed higher than the first linear speed, and the reproduced compressed data is intermittently transferred to the memory means at a third speed higher than the first speed. In this case, the writing period of the laser light is shortened within the predetermined period.

According to this configuration, the spindle motor for rotating the disk is rotated at a speed higher than the normal linear speed, and the reproduced compressed data is converted to the third speed higher than the first speed.
By intermittently writing to the memory means at the speed, the period during which laser light irradiation is suspended is lengthened, and the power consumption of the entire system is effectively reduced.

According to a second aspect of the present invention, there is provided a disk reproducing apparatus including voltage detecting means for detecting an output voltage of a battery which is a power source for driving at least the optical pickup and the spindle motor according to the first aspect, and When the output voltage value of the battery detected by the means is equal to or less than a predetermined value, the spindle motor is rotated so that its linear velocity becomes lower than the second linear velocity.

According to this configuration, when the voltage value detected by the voltage detecting means is equal to or less than the predetermined value, the spindle motor is switched to a low speed and rotated, so that the reproducing operation can be maintained well even when the battery output voltage drops. I do.

According to a third aspect of the present invention, there is provided a disk reproducing apparatus comprising: an eccentricity detecting means for detecting an eccentricity amount of the disk according to the first aspect; and a runout detecting means for detecting a runout amount of the disk. When the amount of eccentricity detected by the eccentricity detecting means is equal to or more than a predetermined amount, or when the amount of surface deflection detected by the surface deflection detecting means is equal to or more than a predetermined amount, the linear velocity of the spindle motor is reduced to the second. It is configured to rotate so as to be lower than the linear velocity of No. 2.

According to this configuration, when the eccentricity detected by the eccentricity detecting means is equal to or more than a predetermined amount, or when the amount of eccentricity detected by the eccentricity detecting means is equal to or more than the predetermined amount, the spindle motor is slowed down. By switching the speed and rotating the disk, the reproducing operation is favorably maintained even when reproducing a disk having a large eccentricity or surface runout.

According to a fourth aspect of the present invention, there is provided a disk reproducing apparatus comprising an error detecting means for detecting an error in the reproduced compressed data according to the first, second or third aspect, wherein the error detecting means detects the error. At the same time as detection,
The output voltage value of the battery detected by the voltage detection means is equal to or less than a predetermined value, or the eccentricity of the disk detected by the eccentricity detection means is equal to or more than a predetermined amount, or the disk deflection detected by the surface deflection detection means is a predetermined amount. When any of the above occur,
The spindle motor is configured to rotate so that its linear velocity is lower than the second linear velocity.

According to this configuration, the voltage value detected by the voltage detecting means is equal to or less than a predetermined value, or the eccentricity detected by the eccentricity detecting means is equal to or smaller than the predetermined value when the error detecting means detects the error of the compressed data. When the surface runout amount detected by the surface runout detection means is equal to or larger than a predetermined amount, the spindle motor is switched to a low speed and rotated, whereby a reproduction error is caused by a decrease in battery output voltage. In this case, the reproducing operation can be maintained satisfactorily even in the case of a disc having a large amount of eccentricity or runout.

Hereinafter, a disk reproducing apparatus according to an embodiment of the present invention will be specifically described with reference to the drawings. (Embodiment 1) A disc reproducing apparatus according to Embodiment 1 of the present invention will be described.

FIG. 1 is an operation timing chart of the disk reproducing apparatus according to the first embodiment. The configuration diagram in the first embodiment is the same as the configuration diagram in the conventional example of FIG. Further, description of the same operation is omitted.

In FIG. 6 which is also a configuration diagram of the disk reproducing apparatus according to the first embodiment, the spindle motor driving means 11 keeps the rotation of the spindle motor 10 stable at a linear speed, for example, twice the normal linear speed. Drive as needed. The reproduction amplifier 3 performs analog signal processing in a frequency band that is twice the normal linear velocity, and the signal processing unit 4 performs digital signal processing using a clock that is twice the normal linear velocity. Therefore, the compressed audio data reproduced by the signal processing means 4 is written to the memory means 5 at the third speed which is twice the first speed.

Here, in order to rotate the spindle motor 10 at a constant linear speed twice as high as the normal linear speed, the reproducing amplifier 3 includes, for example, a constant of a band-limiting filter for band-limiting an ADIP signal (not shown). The constant of the filter for equalizing the waveform of the EFM signal is changed, and the optical pickup driving means 9
For example, the gain intersection of the focus servo and the tracking servo is changed.

In the first embodiment, the period during which unnecessary circuit operations are stopped even during the reproduction operation is lengthened, and effective power consumption is reduced. The reduction method will be described with reference to FIG. Here, the same operations as those of the conventional example shown in FIG. 2 are denoted by the same reference numerals, and the description is omitted.

In FIG. 1, the spindle motor 10 is rotated at, for example, twice the normal linear speed, and the compressed audio data reproduced by the signal processing means 4 is written into the memory means 5 at the third speed. system control means 8 the time interval BB logic H of MWE which output is halved T _2/2. The time interval CC logic L of the SLP T _2/2 increases to T ₃ to the system control unit 8 outputs
+ A T _2/2. Thus, the optical pickup driving unit 9, a period in which the or standby state and stops the operation of the reproduction amplifier 3 and the signal processing means 4 can be made longer by T _2/2.

On the other hand, by rotating the spindle motor 10 at a linear speed twice the normal linear speed, the signal processing means 4 performs digital signal processing with a double clock.
In the period BB of the logic H of the MWE, the power consumption increases almost twice, and the optimum reproduction power of the laser irradiated from the optical pickup 2 also tends to increase.

Here, the relationship between the rotational speed of the spindle motor 10 itself and the power consumption will be described. Spindle motor 10
Can be expressed by the following equation (1).

[0036]

(Equation 1)

The load torque Φ of the spindle motor 10 is expressed by Expression 2 which is the sum of the windage loss U and the iron loss V. The windage loss U is proportional to the rotation speed N.

[0038]

(Equation 2)

The current I can be expressed by equation 3 using the load torque Φ.

[0040]

(Equation 3)

The power consumption W of the spindle motor 10 is obtained by Expression 4 by substituting the load torque Φ shown by Expression 2 and the current I shown by Expression 3 into Expression 1.

[0042]

(Equation 4)

The power consumption W of the spindle motor 10 also increases as the number of revolutions N increases, and for example, when it is rotated at twice the linear speed, it increases approximately four times. As described above, by rotating the spindle motor 10 at a linear speed higher than the normal linear speed, at least the laser irradiated from the optical pickup 2, the reproducing amplifier 3, the signal processing unit 4, and the spindle motor 10 have fluctuations in power consumption. I do.

When the spindle motor 10 is rotated at the normal linear velocity shown in the conventional example, the time T ₁ of the logic H of the SLP is obtained.
+ T ₂ and the logic T time T ₃ , the power consumption of the laser radiated from the optical pickup 2 at the logic H is P ₁ , the power consumption of the reproducing amplifier 3 is P ₂ , and the power consumption of the signal processing means 4 is Assuming that P ₃ and the power consumption of the spindle motor 10 are P ₄ , the power consumption X of these four blocks as a whole is obtained by Expression 5.

[0045]

(Equation 5)

When the spindle motor 10 is rotated at, for example, a linear speed that is m times the normal speed, the time T ₁ + of the logic H of the SLP
Using T ₂ / m and the time T ₃ + T ₂ * (m−1) / m of the logic L, the power consumption of the laser irradiated from the optical pickup 2 at the logic H is increased by α ₁ , and the consumption of the reproducing amplifier 3 is increased. Assuming that the increase in power is α ₂ , the increase in power consumption of the signal processing means 4 is α ₃ , and the increase in power consumption of the spindle motor 10 is α ₄ , the power consumption Y of these four blocks as a whole is calculated by Expression 6.

[0047]

(Equation 6)

4 when the spindle motor 10 is rotated at a normal linear speed and when the spindle motor 10 is rotated at a linear speed that is m times the normal linear speed.
The power consumption difference Z of the entire block is obtained by Expression 7.

[0049]

(Equation 7)

Therefore, if the rotation speed of the spindle motor 10 is within the range of the processing speed capability of the analog signal processing performed by the reproduction amplifier 3 and the digital signal processing performed by the signal processing means 4, the power consumption difference Z It can be seen that rotating faster to the speed at which the maximum value is more effective in reducing the overall power consumption.

In the first embodiment, the spindle motor 10 is rotated at a constant linear speed at twice the normal linear speed. However, the spindle motor 10 may be rotated at a constant angular speed if the linear speed is higher than the normal linear speed. Further, in the first embodiment, in the section CC of the logic L of the SLP, the power consumption difference Z is calculated assuming that the spindle motor 10 continues to rotate, but is stopped or rotated at a low speed via the spindle motor driving means 11. It is effective in reducing power consumption. However, immediately after the SLP is switched to the logic H, it takes time to start the spindle motor 10, so that the section A required for servo settling becomes longer.

As described above, according to the first embodiment, by rotating the spindle motor 10 at a speed higher than the normal linear speed, the operations of the optical pickup driving means 9, the reproducing amplifier 3, and the signal processing means 4 are performed. Can be stopped or the period of the standby state can be lengthened, and the power consumption of the entire system can be effectively reduced. (Embodiment 2) A disk reproducing apparatus according to Embodiment 2 of the present invention will be described.

FIG. 3 is a block diagram of a disk reproducing apparatus according to the second embodiment. Components performing the same configuration and operation as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 3, reference numeral 12 denotes a battery serving as a power source of the portable MD player. Usually, the output of the battery 12 is supplied after voltage conversion (not shown) in accordance with the operating voltage of each circuit. However, at least the optical pickup driving means 9 and the spindle motor driving means 11 have large load fluctuations.
Output voltage is directly supplied to prevent a decrease in power supply efficiency. Reference numeral 13 denotes a voltage detection unit that detects the output voltage of the battery 12 and outputs a voltage detection value BAT that becomes a logic L when the output voltage falls below a predetermined comparison value.

The optical pickup 2 is driven by a DC sensitivity [μm
/ V] and acceleration sensitivity [G / V], and a necessary driving voltage is supplied from the optical pickup driving means 9 according to the driving amount. Here, if the output voltage of the battery 12 is reduced and sufficient power is not supplied to the optical pickup driving means 9, the optical pickup driving means 9 cannot drive the optical pickup 2 by a required amount, which hinders a good reproducing operation. It's coming.

Further, as the rotational speed of the spindle motor 10 increases, the rotational acceleration of the disk 1 increases. For example, when the disk 1 is rotated at twice the normal linear velocity, the rotational acceleration becomes approximately four times, and the acceleration sensitivity [G / V] Accordingly, the driving voltage required to drive the optical pickup 2 increases.

Therefore, when the output voltage of the battery 12 decreases, the optical pickup driving means 9 cannot supply a sufficient driving voltage for driving the optical pickup 2 and maintains a good reproducing operation. There is a risk of not being able to do so.

The system control means 8 receives the voltage detection value BAT output from the voltage detection means 13 and rotates the spindle motor 10 at, for example, twice the normal linear speed to reduce power consumption. When starting the playback operation,
Alternatively, when a logical L of BAT is input during the reproducing operation, a linear velocity command SPD is output to switch the spindle motor 10 to a normal linear velocity. In the SPD, logic H is a command to rotate the spindle motor 10 at twice the normal linear speed, and logic L is a command to rotate the spindle motor 10 at the normal linear speed.

When the SPD logic L is input from the system control means 8 to the spindle motor driving means 11, the spindle motor driving means 11 switches the spindle motor 10 to a normal linear speed and rotates it, and the reproducing amplifier 3 is, for example, not shown. Also, the constant and EF of the band limiting filter of the ADIP signal
The constant of the waveform equivalent filter of the M signal is changed to a value optimum for the normal linear velocity, and the optical pickup driving means 9 changes, for example, the gain intersection of the focus servo and the tracking servo to a value optimum for the normal linear velocity.

In the second embodiment, when the voltage value of the battery 12 detected by the voltage detecting means 13 is equal to or less than a predetermined value, the system control means 8 switches the spindle motor 10 to a normal linear speed to rotate. However, there is an effect if the rotation speed of the spindle motor 10 is reduced, and the spindle motor 10 may be rotated at a constant angular speed.

The battery 1 detected by the voltage detecting means 13
The rotation speed of the spindle motor 10 may be switched in multiple stages according to the voltage value of 2. As described above, according to the second embodiment, in addition to the configuration of the first embodiment, at least the voltage detection unit that detects the output voltage of the battery 12 that is the driving power source of the optical pickup 2 and the spindle motor 10 And the battery 12 detected by the voltage detecting means 13.
When the voltage value is less than or equal to the predetermined value, the system control means 8 switches the spindle motor 10 to a low speed and rotates the spindle motor 10, so that the reproducing operation can be favorably maintained even when the battery output voltage decreases. (Embodiment 3) A disc reproducing apparatus according to Embodiment 3 of the present invention will be described.

FIG. 4 is a block diagram of a disk reproducing apparatus according to the third embodiment. Components performing the same configuration and operation as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 4, reference numeral 14 denotes eccentricity detection means for detecting the amount of eccentricity of the disk 1, and reference numeral 15 denotes surface deviation detection means for detecting the amount of surface deviation of the disk 1.

Both the eccentricity detecting means 14 and the surface runout detecting means 15 detect the amount of eccentricity and the amount of surface runout using, for example, a signal by which the optical pickup driving means 9 drives the optical pickup 2. The optical pickup driving means 9 is the optical pickup 2
Are driven by a focus drive signal FOD for driving a focus servo, a tracking drive signal TRD for driving a tracking servo, and a traverse drive signal TVD for driving a servo for moving the entire optical pickup 2 in the radial direction of the disk 1. There is.

The eccentricity detecting means 14 receives the tracking drive signal TRD (not shown) as an input, and the eccentricity detecting signal HEN which becomes logic H when the amplitude of the TRD low-frequency component after the low-pass filter is equal to or larger than a predetermined comparison value. Is output. Further, the surface shake detection means 15 receives the focus drive signal FOD (not shown) as an input, and the surface shake detection signal ME which becomes logic H when the amplitude of the low-pass component of the FOD after the low-pass filter is equal to or greater than a predetermined comparison value.
N is output.

The optical pickup 2 is driven by a DC sensitivity [μm
/ V] and acceleration sensitivity [G / V], and a necessary driving voltage is supplied from the optical pickup driving means 9 according to the driving amount. Here, in order to drive the optical pickup 2 so as to follow the eccentricity and surface runout of the disk 1, the drive voltage required in accordance with the eccentricity amount and the surface runout is determined according to the DC sensitivity [μm / V]. It is supplied from the pickup driving means 9.

When the spindle motor 10 rotates faster, the rotational acceleration of the disk 1 increases. For example, when the disk 1 is rotated at twice the normal linear velocity, the rotational acceleration becomes about four times, and the rotational acceleration is increased according to the acceleration sensitivity [G / V]. The driving voltage required to drive the optical pickup 2 increases.

Further, a portable MD player usually uses a battery as a power source, and needs to be driven with limited power obtained from the battery. Therefore, if the rotation speed of the spindle motor 10 is increased, the drive voltage required to drive the optical pickup 2 so as to follow the eccentricity and the surface runout of the disk 1 cannot be supplied sufficiently.
There is a risk that a good reproduction operation cannot be maintained.

Therefore, the system control means 8 inputs the eccentricity detection value HEN output from the eccentricity detection means 14 and the surface deflection detection value MEN output from the surface deflection detection means 15 to reduce power consumption. For this reason, when the spindle motor 10 is rotated at, for example, twice the normal linear velocity to start the reproducing operation or during the reproducing operation, when either the logical L of HEN or the logical L of MEN is inputted, A linear velocity command SPD is output to switch the spindle motor 10 to a normal linear velocity. As the SPD, the logic H is a command to rotate the spindle motor 10 at twice the normal linear speed, and the logic L is a command to rotate the spindle motor 10 at the normal linear speed.

When the SPD logic L is input from the system control means 8 to the spindle motor driving means 11, the spindle motor driving means 11 switches the spindle motor 10 to the normal linear speed and rotates it. Also, the constant and EF of the band limiting filter of the ADIP signal
The constant of the waveform equivalent filter of the M signal is changed to a value optimum for the normal linear velocity, and the optical pickup driving means 9 changes, for example, the gain intersection of the focus servo and the tracking servo to a value optimum for the normal linear velocity.

In the third embodiment, the amount of eccentricity detected by the eccentricity detecting means 14 is equal to or more than a predetermined amount, or the amount of eccentricity detected by the eccentricity detecting means 15 is equal to or more than a predetermined amount. At this time, the system control means 8 switches the spindle motor 10 to the normal linear speed and rotates it. However, it is effective if the rotation speed of the spindle motor 10 is reduced, and the spindle motor 10 may be rotated at a constant angular speed.

The rotational speed of the spindle motor 10 may be switched in multiple stages according to the amount of eccentricity detected by the eccentricity detecting means 14 or the amount of surface deflection detected by the surface deviation detecting means 15.

As described above, according to the third embodiment, in addition to the configuration of the first embodiment, the eccentricity detecting means 14 for detecting the eccentricity of the disk 1 and the eccentricity of the disk 1 And the eccentricity detected by the eccentricity detecting means 14 is equal to or more than a predetermined amount, or the eccentricity detected by the eccentricity detecting means 15 is equal to or more than a predetermined amount. At this time, the system control means 8 switches the spindle motor 10 to a low speed and rotates the spindle motor 10, so that the reproducing operation can be favorably maintained even when reproducing a disk having a large amount of eccentricity or surface runout. (Embodiment 4) A disc reproducing apparatus according to Embodiment 4 of the present invention will be described.

FIG. 5 is a block diagram of a disk reproducing apparatus according to the fourth embodiment. Components that perform the same configuration and operation as those in the first, second, and third embodiments are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 5, reference numeral 16 denotes error detecting means for detecting an error in the compressed data reproduced by the signal processing means 4. The error detection means 16 performs an error correction process on the compressed data to be reproduced (not shown), and outputs an error detection signal ERR which becomes a logic H when, for example, any one of the uncorrectable compressed data is detected.

The optical pickup 2 is driven by a DC sensitivity [μm
/ V] and acceleration sensitivity [G / V], and a necessary driving voltage is supplied to the optical pickup 2 from the optical pickup driving means 9 according to the driving amount. Here, in order to drive the optical pickup 2 so as to follow the eccentricity and surface runout of the disk 1, a drive voltage required in accordance with the eccentricity amount and the surface runout amount according to the DC sensitivity [μm / V]. Drive means 9
Supplied by

When the rotation of the spindle motor 10 is increased, the rotational acceleration of the disk 1 is increased. For example, when the disk 1 is rotated at twice the normal linear velocity, the rotational acceleration becomes about 4 times, and the rotational sensitivity is increased according to the acceleration sensitivity [G / V]. The driving voltage required to drive the optical pickup 2 increases.

Further, a portable MD player usually uses a battery as a power source, and needs to be driven with limited power obtained from the battery. Therefore, when the rotation speed of the spindle motor 10 is increased, if the output voltage of the battery 12 decreases, not only the drive voltage required to drive the optical pickup 2 cannot be supplied sufficiently, but also the disc 1 Optical pickup 2 for core and surface runout
Therefore, there is a risk that a sufficient driving voltage cannot be supplied to drive the apparatus in accordance with the above, and a good reproduction operation cannot be maintained.

Therefore, the system control means 8 determines the error detection value ERR output from the error detection means 16, the voltage detection value BAT output from the voltage detection means 13, and the eccentricity output from the eccentricity detection means 14. The spindle motor 1 is supplied with the detection value HEN and the surface runout detection value MEN output from the surface runout detection means 15 to reduce power consumption.
For example, when a reproduction operation is started by rotating 0 at a linear velocity twice as fast as normal, or when a reproduction operation is being performed, a logic H of ERR is input and a logic L of BAT or HE at the same time.
When either the logic L of N or the logic L of MEN is input, a linear velocity command SPD is output to switch the spindle motor 10 to a normal linear velocity. As the SPD, the logic H is a command to rotate the spindle motor 10 at twice the normal linear speed, and the logic L is a command to rotate the spindle motor 10 at the normal linear speed.

When the SPD logic L is input from the system control means 8 to the spindle motor drive means 11, the spindle motor drive means 11 switches the spindle motor 10 to a normal linear speed and rotates it. Also, the constant and EF of the band limiting filter of the ADIP signal
The constant of the waveform equivalent filter of the M signal is changed to a value optimum for the normal linear velocity, and the optical pickup driving means 9 changes, for example, the gain intersection of the focus servo and the tracking servo to a value optimum for the normal linear velocity.

In the fourth embodiment, when the error detection means 16 detects an error in the compressed data reproduced by the signal processing means 4, the voltage value detected by the voltage detection means 13 is equal to or less than a predetermined value. When the amount of eccentricity detected by the eccentricity detecting means 14 is equal to or more than a predetermined amount, or the amount of runout detected by the runout detecting means 15 is equal to or more than a predetermined amount, the system control means 8 normally controls the spindle motor 10. Although the rotation speed is switched to the linear speed described above, it is effective if the rotation speed of the spindle motor 10 is reduced, and the rotation may be performed at a constant angular speed.

Further, according to the voltage value detected by the voltage detecting means 13, the eccentricity amount detected by the eccentricity detecting means 14, or the surface runout amount detected by the surface runout detecting means 15,
The rotation speed of the spindle motor 10 may be switched in multiple stages.

In the fourth embodiment, the system control means 8 sets the voltage value detected by the voltage detection means 13 to a predetermined value or less at the same time when the error detection means 16 detects the first error of the compressed data. When the amount of eccentricity detected by the eccentricity detecting means 14 is equal to or more than a predetermined amount, or the amount of eccentricity detected by the eccentricity detecting means 15 is equal to or more than a predetermined amount, the spindle motor 10 is rotated at a normal linear speed. However, when the error detection unit 16 detects the error of the compressed data for the first time, the retry processing is performed. When the error detection unit 16 detects the error of the compressed data again at the time of the reproduction retry, Spindle motor 1
0 may be switched to a normal linear speed and rotated, or after the reproduction retry process is repeated a plurality of times, the rotation may be switched when an error is reproduced.

As described above, according to the fourth embodiment, in addition to the configurations of the first, second and third embodiments, the error detecting means 16 for detecting an error in the reproduced compressed data is provided. When the error of the compressed data is detected by the error detecting means 16, the voltage value detected by the voltage detecting means 13 is equal to or less than a predetermined value, or the eccentricity detected by the eccentricity detecting means 14 is equal to or more than a predetermined amount, or When the amount of run-out detected by the run-out detection means 15 is equal to or more than a predetermined amount, the system control means 8 switches the spindle motor 10 to a low speed and rotates the spindle motor 10, thereby causing a reproduction error to decrease the battery output voltage. Also, even in the case of a disc having a large amount of eccentricity and surface runout, the reproducing operation can be favorably maintained.

[0083]

As described above, according to the first aspect of the present invention,
The spindle motor for rotating the disk is rotated at a speed higher than the normal linear speed, and the reproduced compressed data is
By intermittently writing data to the memory means at a third speed higher than the speed, the period during which laser light irradiation is suspended can be lengthened, and the power consumption of the entire system can be effectively reduced.

According to the second aspect of the present invention, when the voltage value detected by the voltage detecting means is equal to or less than a predetermined value, the spindle motor is switched to a low speed and rotated, so that the battery output voltage can be reduced. A good reproduction operation can be maintained.

According to the third aspect of the present invention, the eccentricity detected by the eccentricity detecting means is equal to or more than a predetermined amount, or the eccentricity detected by the eccentricity detecting means is equal to or more than a predetermined amount. At this time, by switching the spindle motor to a low speed and rotating it, the reproducing operation can be favorably maintained even when reproducing a disk having a large eccentricity or surface runout.

According to the invention of claim 4, when the error of the compressed data is detected by the error detecting means, the voltage value detected by the voltage detecting means is equal to or less than a predetermined value or the eccentricity detecting means detects the error. When the amount of eccentricity is equal to or more than a predetermined amount, or the amount of runout detected by the runout detection means is equal to or more than a predetermined amount, the spindle motor is switched to a lower speed and rotated, so that a reproduction error occurs. The reproducing operation can be maintained satisfactorily even when the voltage is reduced or when the disk is caused by a large amount of eccentricity or surface deflection.

As described above, further power saving can be achieved as compared with the related art, and a favorable reproducing operation can be further maintained.

[Brief description of the drawings]

FIG. 1 is an operation timing chart in a disk reproducing apparatus according to a first embodiment of the present invention;

FIG. 2 is an operation timing chart in a conventional disk reproducing apparatus.

FIG. 3 is a configuration diagram of a disk reproducing apparatus according to a second embodiment of the present invention;

FIG. 4 is a configuration diagram of a disk reproducing apparatus according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a disk reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram of a conventional disk reproducing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc 2 Optical pickup 3 Reproduction amplifier 4 Signal processing means 5 Memory means 6 Expansion means 7 DAC 8 System control means 9 Optical pickup driving means 10 Spindle motor 11 Spindle motor driving means 12 Voltage detecting means 13 Eccentricity detecting means 14 Surface runout detection Means 15 Error detection means

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G11B 20/18 572 G11B 20/18 572C 572F (72) Inventor Tatsuya Adachi 1006 Odakadoma, Kadoma, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] A laser beam is radiated on a disk, which is a recording medium rotated by a spindle motor, and the reflected laser beam is received by an optical pickup to reproduce compressed data recorded on the disk. While intermittently writing data to the memory means every predetermined period,
The compressed data written to the memory means is continuously read at a speed lower than the writing speed, and is output after decompression processing. At least during the intermittent interruption of the writing to the memory means, at least the laser light A disc reproducing apparatus for suspending irradiation of a disc, wherein a first rotation of a spindle motor for rotating the disc is performed.
Is the normal linear speed, the first speed of writing the reproduced compressed data to the memory means is the normal speed, and the reading speed of the compressed data from the memory means is the second speed. The spindle motor is rotated at a second linear speed higher than the first linear speed, and the reproduced compressed data is intermittently transferred to the memory means at a third speed higher than the first speed. A disk reproducing apparatus characterized in that an irradiation period of the laser beam is shortened within the predetermined period by performing writing. And a voltage detecting means for detecting an output voltage of a battery which is a power source for driving at least an optical pickup and a spindle motor, wherein an output voltage value of the battery detected by the voltage detecting means is equal to or less than a predetermined value. 2. The disk reproducing apparatus according to claim 1, wherein the spindle motor is rotated such that the linear velocity is lower than the second linear velocity. 3. An eccentricity detecting means for detecting the amount of eccentricity of a disk, and a runout detecting means for detecting an amount of runout of the disk, wherein the eccentricity detected by the eccentricity detecting means is a certain value. The spindle motor is rotated so that its linear velocity becomes slower than the second linear velocity when any of a predetermined amount or more, or the amount of surface deviation detected by the surface deviation detecting means is equal to or more than a predetermined amount. 2. The disc reproducing apparatus according to claim 1, wherein 4. An error detecting means for detecting an error in the reproduced compressed data, wherein at the same time when the error detecting means detects the error, the output voltage value of the battery detected by the voltage detecting means is equal to or less than a predetermined value. Alternatively, when the amount of eccentricity of the disk detected by the eccentricity detecting means is equal to or more than a predetermined amount, or when the amount of disk runout detected by the surface runout detecting means is equal to or more than the predetermined amount, the spindle motor is rotated at a linear velocity. 4. The disc reproducing apparatus according to claim 1, wherein the disc is rotated so as to be slower than the second linear velocity.