JPH113569A - Reproducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the number of track jumps a minimum by successively detecting the data storage amount of a buffer memory and changing the reading rate from a recording medium so that the storage amount does not reach a full capacity. SOLUTION: A CPU 31 sets frequency dividing ratios of a frequency 1/M- divider 22 and a frequency 1/N-divider 24 by controlling an automatic sequencer 23 to arbitrarily control the rotational speed of a spindle motor 2. Moreover, a DSP 8 operates based on a master clock CK made to follow up the rotational speed of the motor 2. The reading rate from a disk 1 of data to be written in a buffer memory DRAM 30 can be arbitrarily changed by changing the rotational speed of the motor 2. Thus, the storage amount of the buffer memory DRAM 30 can be controlled so as to be kept at an amount close to the full capacity of the DRAM 30 by adjust the difference between the writing rate to the DRAM 30 and the reading rate from the DRAM 30 while adjusting the speed of the motor 2 in accordance with the data residual amount of the DRAM 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus compatible with a recording medium such as an optical disk.

[0002]

2. Description of the Related Art A CD (compact disk) player is widely used as a reproducing apparatus using an optical disk as a recording medium for audio signals.

In recent years, especially in a car-mounted or portable CD player, not only a mechanical damping mechanism but also a buffer memory (semiconductor memory, for example, a D-RAM) is used to improve electric vibration (vibration resistance). (ESP; Electrical Shock)
Protection) has been commercialized.

That is, data is read from the disk at a high rate, for example, by doubling the disk rotation speed, and the read data is temporarily stored in a buffer memory. The stored data is read out from the buffer memory by a normal route and output as a reproduced audio signal.

[0005] By doing so, a certain amount of data is always stored in the buffer memory, and the data cannot be temporarily read from the disk due to, for example, a track jump of the optical head caused by disturbance. However, the reproduced sound can be output without interruption.

[0006]

By the way, in the case of the ESP system, when the data read from the disk at a high rate is accumulated in the buffer memory, the data writing to the buffer memory is interrupted once. Must.

[0007] For this purpose, usually, the optical head performs one track jump (track jump for retreating one round of the reading position track) to consume the accumulated data (ie, decrease the accumulated amount due to the data read / reproduction output). Wait for.

When data writing to the buffer memory is to be resumed, the address of the last written data before one-track jump, ie, interruption of writing, is monitored, and the address is found as read data from the disk. Then, the next data is written to the buffer memory so that the continuity of the data is maintained. The address confirmation at this time is performed using so-called subcode Q data, and an operation called a frame check for monitoring the presence / absence of frame loss is also performed by using subcode Q data in data (frames) that are temporally preceding and following. .

This frame check is a process for confirming the continuity of data so that read data is continuously stored in the buffer memory. The continuity is not determined to be OK only when the difference between the subcode Q data is strictly one frame. For example, if there is a loss of several tens of frames and there is almost no effect on the reproduced sound. , And continuity OK.

In the operation of the conventional ESP system, the optical head has to wait for accumulation of read data from the disk every time the buffer memory is in the full accumulation state. One track jump is performed.

For this reason, there is a problem that the power consumption is increased due to frequent track jumps and the quality of reproduced sound is reduced due to the influence of electric noise at the time of track jumps.

On the other hand, when the reproduction output is executed via the buffer memory for the vibration proof function, it is preferable that the accumulated amount of the buffer memory is always close to full as much as possible. This is because, as the accumulated amount is larger, the time during which the reproduced sound can be output without interruption becomes longer, and there is room for re-reading the missing read data during that time.

Considering this, accumulation is interrupted when the accumulation amount becomes full, and data writing is resumed when accumulated data is consumed to a certain accumulation amount slightly less than full. It is desirable that the data storage amount of the buffer memory be maintained as close to the full capacity as possible. However, for this purpose, one track jump for writing standby must be executed frequently.

In other words, from the viewpoint of sound quality and power consumption, it is not desirable to wait for writing to the buffer memory by track jump, but on the other hand, the data stored in the buffer memory should be maintained as much as possible to improve the vibration proof function. For this reason, there is a conflicting demand to repeat writing to the buffer memory and waiting for writing at short intervals, and there is a problem that at present, suitable processing is not always realized.

In such a conventional ESP type disk reproducing apparatus, it is preferable to set the gain of the tracking servo as high as possible in order to improve the vibration proof characteristics. However, it is not preferable to increase the gain of the tracking servo from the viewpoint of improving reproduction performance and reducing power consumption.

That is, when the gain of the tracking servo is increased, the tracking servo does not come off even when receiving strong external vibration, which is preferable from the viewpoint of vibration proof characteristics. However, when the gain of the tracking servo is increased, if the disc is scratched or dust adheres to the disc, the servo signal disturbance due to the scratch or dust is picked up, and the reproduction performance deteriorates. Occurs. Also,
As the gain of the tracking servo increases, the power consumption increases accordingly.

As described above, with respect to the tracking servo, it is desired to set the gain of the tracking servo as high as possible in order to improve the anti-vibration characteristics. However, from the viewpoint of improving the reproduction performance and reducing the power consumption, the gain of the tracking servo is not increased. There are conflicting demands that they cannot be raised.

Conventionally, the rotation of the spindle motor is controlled by giving a deceleration pulse when the rotation speed of the disk is faster than a set value, and by giving an acceleration pulse when the rotation speed of the disk is slower than the set value. It is controlled so that it becomes the set value. However, when the rotation of the spindle motor is braked by the deceleration pulse, energy loss occurs and power consumption increases. Therefore, it is desired to reduce the energy loss by minimizing the application of the deceleration pulse.

Accordingly, it is an object of the present invention to provide a reproducing apparatus which can maintain the data stored in a buffer memory near a full capacity and satisfy both the quality of reproduced sound and the vibration resistance. It is in.

Another object of the present invention is to provide a reproducing apparatus capable of satisfying both servo performance and vibration resistance.

Still another object of the present invention is to provide a reproducing apparatus capable of reducing energy loss when controlling rotation of a spindle motor and improving power consumption.

[0022]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a reproducing apparatus including a reading unit capable of reading audio data from a recording medium at a variable speed, a buffer memory unit, and a reading unit. A memory control means for accumulating the read audio data in the buffer memory means, reading the audio data from the buffer memory means at a normal rate, and outputting the read audio data as reproduced audio data. Further, an accumulation amount detecting means for sequentially detecting an accumulation amount of audio data in the buffer memory means, and a detection result of the accumulation amount by the accumulation amount detecting means, and a reading means for preventing the accumulation amount from reaching the full capacity. Reading control means for changing a reading rate of audio data from a recording medium according to (1).

That is, by changing the data reading rate from the recording medium in accordance with the accumulation amount of the buffer memory means, the accumulation amount does not become full, but is maintained close to full. It is not necessary to wait for an operation of writing data read from the recording medium to the buffer memory.

Also, the clock generating means for generating a clock used for the audio data decoding processing is formed using an oscillator which changes the oscillation frequency in accordance with the reading rate of the audio data from the recording medium by the reading means. I do. That is, a so-called wide capture type PLL
A clock generation circuit is provided.

Thus, even when the data rate for reading the audio data from the recording medium is changed (for example, when the rotation speed of the spindle motor is changed), the data can be read well.

Further, according to the present invention, there is provided a reading means capable of reading audio data from a recording medium at a variable speed rate;
Tracking control means for controlling the reading means to trace along the track of the recording medium; buffer memory means; and audio data read by the reading means, stored in the buffer memory means. Memory control means for reading out audio data and outputting it as reproduced audio data, and storage amount detection means for sequentially detecting the storage area of the audio data in the buffer memory means are provided. And a reading control unit that monitors the detection result of the storage amount by the storage amount detection unit and that can change a reading rate of the audio data from the recording medium by the reading unit so that the storage amount does not reach the full capacity. And a tracking control means for changing the gain of the tracking control means according to the reading rate of the audio data.

As a result, the anti-vibration characteristics can be improved, and the deterioration of the reproduction performance and the increase in power consumption can be prevented.

According to the present invention, there is further provided a reading means capable of reading audio data from a recording medium at a variable rate,
Tracking control means for controlling the reading means to trace along the track of the recording medium; buffer memory means; and audio data read by the reading means, stored in the buffer memory means. Memory control means for reading data and outputting the data as reproduced audio data; storage amount detection means for sequentially detecting an audio data storage area in the buffer memory means;
A spindle motor for rotating the recording medium; and a rotation control unit for controlling the rotation of the spindle motor. The rotation control unit controls the rotation of the spindle motor by giving an acceleration pulse and a deceleration pulse to the spindle motor until the detection result of the storage amount by the storage amount detection unit reaches a predetermined value,
When the detection result of the accumulation amount by the accumulation amount detection means becomes equal to or more than the predetermined value and the spindle motor reaches the set speed, the rotation of the spindle motor is controlled without using the deceleration pulse.

Thus, when the buffer memory becomes equal to or larger than a predetermined amount, the rotation of the spindle motor is controlled without applying a brake. For this reason, the application of a brake to the spindle motor is minimized, and power consumption can be reduced.

[0030]

Embodiments of the present invention will be described below. Here, a reproducing apparatus (CD player) capable of reproducing an optical disk (CD) will be described as an example. The description will be made in the following order.

1. 1. Configuration of CD player 2. TOC and subcode 3. ESP operation Variable read rate operation.

5. Control for power saving FIG. 1 is a block diagram of a CD player. Information is read by the optical head 3 while the disk 1 is driven to rotate by the spindle motor 2. The optical head 3 irradiates the disk 1 with laser light, and from the reflected light,
For example, information (music signal) recorded in a pit form on the disk 1 is read.

In order to read data from the disk 1 in this manner, the optical head 3 includes a laser diode 3c as laser output means, a polarizing beam splitter,
An optical system 3d composed of a quarter-wave plate or the like, an objective lens 3a serving as a laser output terminal, a detector 3b for detecting reflected light, and the like are mounted.

The objective lens 3a is held by a two-axis mechanism 4 so as to be displaceable in a disk radial direction (tracking direction) and in a direction approaching / separating from the disk (focus direction). The disk can be moved in the radial direction.

The information detected from the disk 1 by the optical head 3 by the reproducing operation is supplied to the RF amplifier 7. The signal amplified by the RF amplifier 7 is supplied to an RF equalizer 9 in a digital signal processor (hereinafter, DSP) 8.

The RF equalizer 9 extracts a reproduced RF signal (EFM signal), a tracking error signal TE, a focus error signal FE, and the like by performing an arithmetic operation on the supplied information.

The reproduced RF signal is supplied to an asymmetry correction circuit 1
0, a signal binarized through the RF-PLL circuit 11,
That is, it is supplied to the EFM demodulation unit 13 as an EFM signal (8-14 modulation signal). The RF-PLL circuit 11 generates a reproduction clock synchronized with the EFM signal by a so-called PLL operation, and supplies the reproduction clock to the EFM demodulation unit 13 as a clock for the decoding process.

The EFM signal is subjected to EFM demodulation by an EFM demodulation unit 13, a subcode component described later is extracted, and a subcode processing unit 14 performs a subcode data decoding process. For example, subcode Q data is extracted.

The subcode data is supplied to a CPU 31 functioning as a system controller of the CD player via a CPU interface unit 19 (hereinafter, referred to as CPU-IF).

The data subjected to the EFM demodulation by the EFM demodulation unit 13 is written to the ECC-RAM 16, and the error correction unit 15 executes an error correction process as a CIRC decoding through a read / write process in the ECC-RAM 16. . So-called C1 correction and C2 correction are performed.

The data subjected to the CIRC decoding is subjected to a deinterleave process by a deinterleave circuit 17, thereby performing 16-bit quantization,
Demodulated to a so-called digital audio data format such as 44.1KHz sampling. The digital audio data DT is temporarily stored in the buffer memory 30 under the control of the memory controller 29. The data (digital audio data DT) read from the buffer memory 30 at a predetermined timing is transmitted to the D / A converter 3.
2 to the analog audio signal S _A ,
3 to a predetermined amplifying circuit section and reproduced and output as, for example, L and R audio signals.

The buffer memory 30 is composed of a D-RAM, and has a capacity to store, for example, digital audio data DT for about 3 seconds as reproduced sound. Of course, a larger capacity may be used. Also not necessarily D-RAM
It is not necessary.

By performing the reproducing operation using the buffer memory 30 as described above. An anti-vibration function (ESP function) can be obtained.

That is, the rotational speed of the disk 1 by the spindle motor 2 is adjusted, the processing by the DSP 8 from the optical head 3 is performed at a high rate, and the decoded digital audio data DT is written into the buffer memory 30.

On the other hand, reading from the buffer memory 30
The music and the like are reproduced and output at a normal speed and pitch by performing the reproduction at a normal rate under the control of the memory controller 29.

Here, due to the difference between the write bit rate and the read bit rate of the buffer memory 30, a certain amount of data is always stored in the buffer memory 30. Therefore, even if a track jump or the like occurs due to disturbance or the like, and the data reading from the disk 1 by the optical head 3 is temporarily stopped, the reading from the buffer memory 30 can be continued, and the reproduced sound is not interrupted. In this case, the optical head 3 may restart reading from an appropriate position while the reproduction by the stored data is continued.

By the way, due to the difference between the write bit rate and the read bit rate of the buffer memory 30, the amount of data stored in the buffer memory 30 may reach a full capacity at a certain point in time. Writing is interrupted when the capacity becomes full. As will be described later in detail, in the case of the present example, the transfer rate is adjusted so that the accumulated amount of the buffer memory 30 does not reach the full capacity, and writing is not interrupted (that is, writing standby by one track jump) is normally performed. To make it better. The track jump is required only when the continuity of the read data is interrupted by the frame check or when an error correction impossible state occurs, and the number of track jumps executed during reproduction is reduced as much as possible. .

As described above, as the subcode data, the subcode information recorded on the disc 1, ie, the TOC
, Address data, and the like are extracted and supplied to the CPU 31, whereby the CPU 31 can perform a frame check (a check of data continuity).

If the error cannot be corrected even by the C1 and C2 correction processing by the error correction section 15, a C2PO signal indicating the error is output.
1 is supplied. Thereby, the CPU 31 can monitor the error occurrence status. Also, from DSP8 to CPU3
1 is also supplied with a score signal, which is a signal for confirming the synchronization state of the write data to the buffer memory 30.

The tracking error signal TE and the focus error signal FE obtained by the RF equalizing section 9 are supplied to the optical system servo signal processing section 12.

The optical system servo signal processing unit 12 generates various servo drive signals according to the supplied tracking error signal TE, focus error signal FE, track jump command and access command supplied from the CPU 31 via the CPU-IF 19, and the like. generate.

The optical system servo signal processing section 12 generates a servo signal, for example, as a PWM modulation signal in accordance with the focus error signal FE, and supplies it to the servo driver 26. The servo driver 26 generates a focus drive signal based on the supplied PWM modulation signal, and applies it to the focus coil of the two-axis mechanism 4. That is, the objective lens 3a is driven in the focus direction based on the focus drive signal.

The optical servo signal processing unit 12 turns off the focus servo loop at the time of focus search and, based on the search voltage generation control from the CPU 31, controls the PWM modulation signal corresponding to the voltage value to be generated. Is supplied to the servo driver 26. The servo driver 26 applies a focus search voltage as a focus drive signal to the focus coil of the biaxial mechanism 4 based on the supplied PWM modulation signal.

The optical system servo signal processing section 12 generates a servo signal as a PWM modulation signal in accordance with the tracking error signal TE and supplies it to the servo driver 26.
The servo driver 26 generates a tracking drive signal based on the supplied PWM modulation signal, and generates a tracking drive signal.
To the tracking coil. That is, the objective lens 3a is driven in the tracking direction based on the tracking drive signal.

Further, the optical system servo signal processing section 12 generates a sled servo signal as a PWM modulation signal from the low frequency component of the tracking error signal TE and supplies it to the servo driver 26. The servo driver 26 receives the supplied P
A sled drive signal based on the WM modulation signal is generated to drive the sled mechanism 5.

As described above, in the RF-PLL circuit 11,
A reproduction RF signal (EFM signal) is injected into a PLL circuit to generate a reproduction clock synchronized with the reproduction data, and the reproduction clock is used for various processing such as EFM decoding. Become. DSP8
The spindle servo signal processing section 18 in this section compares the reproduced clock with a reference clock generated from the master clock, for example, and obtains a spindle error signal SPE as a difference between the reproduced clock and the reference clock generated from the master clock.

Normally, the spindle error signal SPE
A drive signal for driving the spindle motor is generated on the basis of the above. In this example, the DSP 8 employs a wide capture system, that is, the system PLL is locked to the rotation speed of the spindle motor 2. The signal processing in the DSP 8 is performed at the locked frequency.

For this reason, the spindle servo signal processing unit 1
The spindle error signal SPE output from 8 is band-limited by a low-pass filter 20 and then input to a voltage controlled oscillator (VCO) 21. That is, the spindle error signal SPE is used as the control voltage of the VCO 21.

Since the spindle error signal SPE changes according to the rotation speed of the spindle motor 2, the VCO 21
Performs an oscillating operation following the rotational speed of the spindle motor 2. The oscillation output of the VCO 21 is supplied to a clock generator 34, and the clock generator 34
A master clock CK of the DSP system is generated according to the output of O21. This master clock CK is R
It becomes a processing reference in the DSP 8 including the operation reference of the F-PLL circuit 11, and accordingly, the entire signal processing system of the DSP 8 performs an operation following the rotation speed of the spindle motor 2.

By operating the DSP 8 with a clock corresponding to the rotation speed of the spindle motor 2, for example, even when the spindle motor 2 is accelerating (that is, a specific CLV
Regardless of the speed), the decoding process of the read data can be performed. For example, when the disk 1 is chucked and the rotation of the spindle motor 2 is started, the data can be read immediately.

The output of the VCO 21 is a 1 / M frequency divider 22
Is supplied to the phase comparator 25. on the other hand,
The system clock from the oscillator 28, which is a crystal clock generator, is frequency-divided by the 1 / N frequency divider 24 and then supplied to the phase comparator 25. 1 / M frequency divider 22 and 1 / N
The frequency division ratio of the frequency divider 24, that is, the values of M and N are controlled by the auto sequencer 23.

The phase comparator 25 compares the output of the VCO 21 with the system clock from the oscillator 28 to generate a drive control signal for the spindle motor. The LPF / spindle driver 27 supplies drive power based on the driver control signal. Is applied to the spindle motor 2. Thus, the spindle motor 2 is controlled to a predetermined CLV speed.

Here, the 1 / M frequency divider 22 and the 1 / N frequency divider 2
By setting the frequency division ratio of 4 to a predetermined value, the rotation speed (CLV speed) of the spindle motor 2 can be controlled to an arbitrary speed such as a standard speed, 1.5 times speed, or 2 times speed.
That is, the CPU 31 can variably control the spindle rotational speed by controlling the auto sequencer 23 via the CPU-IF 19.

2. TOC and Subcode The TOC and subcode recorded in the lead-in area on the disc 1 (CD-DA; digital audio) will be described.

The minimum unit of data recorded in a CD-DA is one frame. One block (one subcoding frame) is composed of 98 frames.

The structure of one frame is as shown in FIG. 1
The frame is composed of 588 bits. The first 24 bits are used as synchronization data, and the following 14 bits are used as a subcode data area. After that, data and parity are allocated.

One frame is composed of 98 frames, and the subcode data extracted from the 98 frames are collected to form one block of subcode data as shown in FIG. .

The subcode data from the first and second frames (frame 98n + 1, frame 98n + 2) at the beginning of the 98 frames are synchronous patterns. Then, from the third frame to the 98th frame (frame 98n
+3 to frame 98n + 98), and each of 96-bit channel data, that is, P, Q, R, S, T, U, V,
W subcode data is formed.

Of these, P for managing access, etc.
Channel and Q channel are used. However, the P channel only shows a pause portion between tracks, and more detailed control is performed on the Q channel (Q ₁ to Q ₁ ).
_Q96 ). The 96-bit Q channel data is configured as shown in FIG.

First, four bits Q _{1 to} Q ₄ are used as control data, and are used for the number of audio channels, emphasis, identification of a CD-ROM, and the like.

That is, the 4-bit control data is defined as follows.

"0 ***": 2-channel audio "1 ***": 4-channel audio "* 0 **": CD-DA "* 1 **": CD-ROM "** 0 *": Digital copy not possible "** 1 *" ... Digital copy possible "*** 0" ... No pre-emphasis "*** 1" ... Pre-emphasis is available.

Next, the four bits Q _{5 to} Q ₈ are used as addresses, which are used as control bits for sub-Q data.

[0074] When the address 4 bits are "0001", if the subsequent Q ₉ sub-Q data to Q ₈₀ indicates that the audio Q data, also is "0100", followed by Q ₉ to Q ₈₀ indicates that the sub-Q data is video Q data.

Then, Q _{9 to} Q ₈₀ are used as 72-bit sub-Q data, and the remaining Q _{81 to} Q ₉₆ are used as CRC.

In the lead-in area, the sub-Q data recorded therein becomes the TOC information.

That is, the 72-bit sub Q data of Q _{9 to} Q ₈₀ in the Q channel data read from the lead-in area has information as shown in FIG. The sub-Q data has 8-bit data.

First, the track number is recorded. In the lead-in area, the track number is fixed to “00”.

Subsequently, POINT (point) is described.
MIN (minutes), SE
C (second) and FRAME (frame number) are shown.

Further, PMIN, PSEC, PFRAM
E is recorded, but PMIN, PSEC, PFRA
The meaning of ME is determined by the value of POINT.

When the value of POINT is "01" to "99", the value indicates a track number.
In IN, PSEC, and PFRAME, the start point (absolute time address) of the track of the track number is recorded as minute (PMIN), second (PSEC), and frame number (PFRAME).

When the value of POINT is "A0", PM
The track number of the first track is recorded in IN.
In addition, CD-DA, CD-I, C
A distinction is made between D-ROMs (XA specification).

When the value of POINT is "A1", PM
The track number of the last track is recorded in IN.

When the value of POINT is "A2", PM
IN, PSEC, and PFRAME indicate the start point of the lead-out area as an absolute time address.

For example, in the case of a disc on which six tracks are recorded, data is recorded as TOC based on such sub-Q data as shown in FIG. As shown in FIG. 5, the track numbers TNO are all "00".

Block NO. Indicates the number of one unit of sub-Q data read as block data of 98 frames as described above.

Each TOC data has the same contents written over three blocks.

As shown, POINT changes from "01" to
In the case of “06”, start points of tracks # 1 to # 6 are indicated as PMIN, PSEC, and PFRAME.

When POINT is "A0", PM
"01" is first shown as a track number in IN. The disc is identified by the value of PSEC, and when this disc is a CD-DA, as shown in FIG.
EC = “00”. Note that PSEC = “20” for a CD-ROM (XA specification) and “10” for a CD-I.

Then, the track number of the last track is recorded in PMIN at the position where the value of POINT is "A1", and PMIN, P is recorded at the position where the value of POINT is "A2".
SEC and PFRAME indicate the start point of the lead-out area.

From block n + 27 onwards, blocks n to n
The content of +26 is repeatedly recorded.

In tracks # 1 to #n on which data such as music is actually recorded on the disk 1, and in the lead-out area, the sub-Q data recorded there is shown in FIG.
It has the information of (b).

First, the track number is recorded. That is, for each of the tracks # 1 to #n, the value is any one of "01" to "99". In the lead-out area, the track number is "AA".

Subsequently, information for further subdividing each track is recorded as an index.

Then, as the elapsed time in the track, MI
N (minute), SEC (second), FRAME (frame number)
Is shown.

Further, AMIN, ASEC, AFRAM
As E, the absolute time address is minutes (AMIN), seconds (A
SEC) and the frame number (AFRAME).

The TOC and the subcode are formed as described above.
It is understood that MIN, ASEC, and AFRAME are recorded in units of 98 frames.

[0098] The 98 frames (1 block) are called one sub-coding frame, and 1 frame as audio data.
A second will include 75 subcoding frames. That is, the possible values of “AFRAME” as an address are “0” to “74”. It is a sub-coding frame unit that checks the continuity of data in a frame check process described later.

3. ESP Operation In the CD player of this example, the ESP function using the buffer memory 30 is executed as described above, and the processing at the time of reproduction by the CPU 31 after executing the ESP function is performed. Will be described.

In the CD player according to the present embodiment, in order to execute the ESP function at the time of reproduction of the disc 1, data is read at a required transfer rate, and a read data missing state is confirmed (frame check). This prevents a break in the reproduced sound.

Further, depending on the state of the remaining amount (accumulated amount) of the buffer memory 30, an error correction state is checked (error check) so that data in a bad state is not output as reproduced sound.

FIG. 6 is a flowchart showing the processing of the CPU 31 including the frame check and the error check.

When the disc 1 is loaded at the position of the optical head 3, that is, at the reproducible position, the CPU 31 first reads the TOC data recorded on the innermost side of the disc.

That is, the optical head 3 performs the reproducing operation of the lead-in area, and fetches the TOC data extracted by the subcode processing unit 14. By reading the TOC data, the address and the like of each track of the loaded disk 1 can be grasped, and the reproduction operation can be controlled.

After the reproduction is started, the CPU 31 executes the processing of FIG. 6 as the processing for the ESP operation.

First, as the processing of step F101, the CPU 3
Numeral 1 always monitors the amount of data stored in the buffer memory 30.

In this example, the monitoring result of the data storage amount is used for frame check, error check, and spindle motor speed setting described later.

If it is determined that there is no remaining amount as a result of checking the amount of data stored in the buffer memory 30, this means that the reproduced sound is silent, and in this case, the process proceeds from step F102 to the error process of step F103.

If there is no remaining amount, a reference value FC for frame check is set in step F104. Here, the frame check reference value FC is set according to the amount of data stored in the buffer memory 30.

Here, the reason why the frame check reference value FC is set according to the data storage amount will be described.

If the continuity in the data read from the disk 1 is interrupted due to a track jump or the like due to disturbance, the data is reread (retried) so that the continuity can be restored again, and the continuity is obtained as the reproduced sound. An operation of writing data to the buffer memory 13 is performed so as to be maintained. Therefore, during reproduction, a frame check is continuously performed to check the continuity of read data.

Here, it is preferable to check the continuity of the read data strictly if possible.
I want to minimize the consumption of data stored in the buffer memory. In other words, retrying readout due to discontinuity of continuity consumes accumulated data for that time, and therefore, the stricter the check, the more
The number of retries increases, the amount of accumulation decreases, and the vibration resistance decreases. Further, the track jump for the retry operation has the effect of deteriorating the quality of reproduced sound and increasing power consumption. Thus, the two are conflicting requirements.

If data is lost to such an extent that a break cannot be recognized as a reproduced sound, the continuity is not considered to be broken, so that retry is not executed and a decrease in vibration resistance can be avoided. However, strictly speaking, even if the level is discontinuous, the reproduced sound may be clogged and heard, so it is better to retry as much as possible to connect the sound data accurately.

Therefore, in the present invention, the continuity is maintained as strictly as possible by changing the frame check, that is, the criterion for recognizing that the continuity of data continuity has occurred, according to the capacity of the buffer memory 13. At the same time, the anti-vibration function of the buffer memory 13 is not reduced.

FIGS. 7 and 8 show examples of setting such a frame check reference value FC. When the buffer memory 30 is capable of accumulating data for 3 seconds with full capacity accumulation (remaining amount = 100%), for example, as shown in FIG. 7, the remaining amount is 50% or more (reproduction output for 1.5 seconds or more is possible). If so, the reference value FC
= 5 (sub-coding frame). If the remaining amount is still less than 50% (the reproducible output time is less than 1.5 seconds), the reference value FC is set to 40 (sub-coding frame).

The frame check reference value FC is a value such that if the data loss is within the “FC” sub-coding frame, it is not regarded as a loss. Sex check) becomes severe.

That is, when there is a margin as the remaining amount as shown in FIG. 7, the frame check is made strict by setting the reference value FC = 5. In this case, even if you retry to a certain extent,
Since the time margin is large, the vibration resistance is not significantly affected. Therefore, even if the read data is interrupted,
The continuity can be almost restored by retry.

However, when the remaining amount is small, that is, when the remaining amount is 0 to 1.5 seconds, the reference value FC is set to 40, and the strictness of the frame check is increased.

This is a case where it is considered that if the read retry is executed too many times, it is highly probable that a state of no remaining amount is reached in consideration of the vibration proof performance at that time. If so, loosen the frame check,
By not performing retry too much, it means to avoid running out of remaining power as much as possible. In other words, in this case, although a certain amount of sound, that is, a reproduced sound is allowed, priority is given to at least avoiding the sound output from becoming silent.

After setting the frame check reference value FC in step F104 of FIG. 6, it is determined in step F105 whether the remaining amount of the buffer memory 30 is full. When the state becomes full, the writing of data to the buffer memory 30 must be temporarily suspended. Therefore, the process proceeds to step F106 to set the retry mode, and thereafter, from a predetermined timing, shifts to a sound connection process of writing subsequent data.

In the case of this embodiment, the rotation speed of the spindle motor 2 is adjusted so that the data stored in the buffer memory 30 does not become full, as will be described later. Therefore, in the normal state, it is not determined that the capacity is full in step F105.

If the remaining capacity of the buffer memory 30 is not full, the sub-Q data is read in step F107, and a frame check is performed in step F108.

In the process of FIG. 6, the sub-Q data (address) previously read in step F112 is stored in the variable
Since it is stored as SUBLAST, in step F108, the current sub-Q data (address) read in step F107 is compared with the previous sub-Q data (address) stored as the variable SUBLAST.

As described above, if the continuity is not broken at all, the difference between the previous address and the current address should be one subcoding frame. However, there is almost no effect as a reproduced sound up to a loss of about 5 subcoding frames.

Therefore, in step F108, if the address difference between the previous time and the current address is within the frame check reference value FC, the continuity is regarded as OK.

That is, as shown in FIG. 8, if the current sub-Q data has an address value obtained by adding the frame check reference value FC from the previous sub-Q data SUBLAST, it is determined to be OK.

Since the frame check reference value FC is set according to the remaining amount of the buffer memory 30 as described above, the continuity check becomes strict when the remaining amount is large, and the check is performed when the remaining amount is small. Will become loose.

In step F108, the frame check reference value F
If a data loss of C or more is confirmed, it is determined that the data continuity has been broken, and the process proceeds to step F109 to perform a sound connection process (that is, read retry).

On the other hand, if continuity is determined to be OK, execution of an error check is determined in step F110.

The error check is to check the number of data for which error correction has become impossible for read data, that is, the number of C2PO occurrences. If the number of C2PO occurrences exceeds a value set as an error level, the error check is performed.
It is determined that the read data of the subcoding frame does not maintain the quality level, and the read retry is performed.

Such an error check is performed in step F1.
This is performed only when it is determined in 10 that the accumulation amount of the buffer memory 30 is 80% or more. In other words, if there is enough remaining capacity, the process proceeds to step F113. In step F113, the currently read data is read out by the normal reproduction operation, or as the operation in the retry mode described below. It is determined whether the data has been read.

If it is a normal reproduction operation, in step F114, an error level which is a reference for an error check is set to "0". This error level = 0 means C2
Only when the number of PO occurrences is “0” means that the error check is OK.

In the case of the retry mode, the check reference is changed step by step. That is, retry 1
If it is the first time, the error level is set to 0, but retry 2
If it is the first time, the error level = 5, that is, the number of C2PO occurrences is allowed up to 5.

If the retry is the third or more retry, the error level is not set, that is, substantially no error check is performed.

The reason for changing the error level stepwise in this manner is to obtain high-quality reproduction data as much as possible, and to set the buffer memory 30 in the same manner as in the case of setting according to the remaining amount of the frame check reference value. This is in order to respond to a demand that the operation is incompatible with each other to avoid the remaining amount being zero as much as possible.

In step F116, step F114 or
An error check is performed based on the error level set in F115. That is, the CPU 31 compares the number of C2POs generated in the error correction processing of the sub-coding frame with the error level,
If O has occurred, it is determined that the data quality is not maintained, and the flow advances to step F117 to shift to retry processing.

If it is determined that the frame check is OK and the error check is OK, the data (digital audio data) at that time is written to the buffer memory 30 in step F111. Then, in step F112, the current sub-Q data is assigned to a variable SUBLAST so as to be used as the previous sub-Q data in the next frame check. Then, the process returns to step F101 to repeat the same processing.

In the process of FIG. 6, steps F106, F109, F1
If the process proceeds to step 17, a retry mode process is performed. That is, when the data accumulation amount of the buffer memory 30 becomes full, and when it is determined that the data quality is not maintained by the frame check or the error check for the data. A sound connection process is performed. The sound connection process is a process of interrupting the writing of data into the buffer memory 30 and then restarting the writing of subsequent data while maintaining continuity.

In the sound connection processing, first, the optical head 3
Then, the read position on the disk is moved backward by one track by one track jump (F201). Then, the remaining amount of the buffer memory 30 is confirmed (F202). If the remaining amount is in a state of no remaining amount, this means that the reproduced sound is silence. In this case, the error processing from step F203 to step F204 is performed. move on.

If there is no remaining amount, in step F205, a frame check reference value FC is set according to the remaining amount. This is the same process as step F104 in FIG. 6 described above.

Then, in step F206, the address value is read as sub-Q data, and at this time, it is compared with the variable SUBLAST which is the previous sub-Q data. The variable SUBRAS at this time
T is the value of the address of the last data when data writing to the buffer memory 30 is interrupted.

In the read operation itself, since the read position is moved backward by one track jump in step F201, the address read in step F206 may be any address before or after the last data address. It depends on the situation.

If the read address as the sub-Q data matches the variable SUBLAST, that is, the address of the last data stored in the buffer memory 30 at that time, the next sub-coding frame ( The data from the address) is the following data. Therefore, as shown by Step F207, the steps of FIG.
Proceeding to F110, the audio data is subjected to error checking and accumulation in the buffer memory 30. That is, the mode is returned from the retry mode to the normal reproduction mode.
In this case, when the process proceeds to step F113 in FIG.
Since the data is read data due to the retry operation, step F1
At 15, the error level is set according to the number of retries.

If the address as the sub-Q data read in step F206 is an address before the variable SUBLAST, the read data is still in the buffer memory 30.
Has not reached the address of the subsequent data to be written to the. Therefore, the process proceeds to steps F207 and F208 and returns to F202. Then, data reading is continued. Then, at some point, the address as the sub-Q data read in step F207 matches the variable SUBLAST. In that case, the process proceeds to step F110 in FIG. The accumulation process is performed.

If the address as the sub-Q data read in step F206 is an address exceeding the variable SUBLAST, the process proceeds from step F208 to F209, where the address is set to the frame check reference value F from the variable SUBLAST.
It is determined whether it is within the range of C. That is, it is determined whether it is within the allowable range of FIG. Within this allowable range, some data loss (for example, within 5 frames) is allowed, and the process proceeds to step F110 in FIG.
An error check for the audio data at that time and a process of accumulating it in the buffer memory 30 are performed.

If it is determined in step F206 that the address of the data read greatly exceeds the variable SUBLAST, the read position is determined to be inappropriate, and the flow returns to step F201 to retreat by one track jump again. By repeating this as many times as necessary, the read position can be set to a position of an address before the reference value FC from the value of the variable SUBLAST, that is, an opportunity to obtain a positive result in step F207 or F209 can be created. .

By the way, also in the case of the sound connection processing, the frame check reference value FC is set according to the remaining capacity of the buffer memory 30. In other words, when the sound connection is strictly executed (only up to the loss of five sub-coding frames is allowed), only when the buffer memory 30 has room, the remaining amount is small (less than 50%) and there is no time margin. In such a case, the loss of a certain amount (40 sub-coding frames) is allowed, so that at least the situation where the reproduced sound becomes silent is avoided.

As described above, when performing reproduction for realizing the ESP function, the strictness of the frame check is set according to the remaining capacity of the buffer memory 30. An error check based on the number of C2POs is also executed, and the strictness of the error check is changed according to the remaining amount of the buffer memory 30 and the number of retries. Thus, in accordance with the situation at each point in time, priority is given to at least not generating a silent state due to data loss in the reproduced sound, and the buffer memory 30 is checked based on a double check of a frame check and an error check.
The quality of the data stored in the memory can be kept high, that is, the quality of the reproduced sound can be improved.

4. Read Rate Variable Speed Operation In addition to the ESP operation as described above, in the present example, by preventing the buffer memory 30 from reaching the full capacity, normally, there is no opportunity to proceed to step F106 in FIG. And the steps in FIG. 9 in retry mode
The number of one-track jumps, which is the operation of F201, is minimized. That is, unless the frame check or the error check is not OK, the system does not shift to the retry mode, thereby minimizing the number of track jumps and reducing the adverse effect of the track jump.

Of course, the buffer memory 30 is not allowed to reach the full capacity. On the other hand, as described above, it is preferable that the storage amount is as large as possible from the viewpoint of the vibration proof function. That is, in this example,
The amount of storage in the buffer memory 30 is not full but is kept close to full, thereby realizing a sufficient vibration proof function and high-quality reproduced sound.

As described above, the CPU 31 controls the auto sequencer 23 to control the 1 / M frequency divider 22 and the 1 / N frequency divider 2
By setting the division ratio of 4, the rotation speed of the spindle motor 2 can be controlled to an arbitrary speed. The DSP 8 operates on the basis of CK based on a master clock that follows the rotation speed of the spindle motor 2.
Data can be read irrespective of the rotational speed state of.

That is, by changing the rotation speed of the spindle motor 2, the rate at which data written to the buffer memory 30 is read from the disk 1 can be arbitrarily changed. Therefore, by adjusting the speed of the spindle motor 2 according to the remaining amount of data in the buffer memory 30, the writing rate to the buffer memory 30 and the buffer memory 30
By controlling the difference between the read rates from the data, the amount of data stored in the buffer memory 30 can be controlled so as to be maintained at a value close to full, though not full.

The processing of the CPU 31 for this will be described with reference to FIGS. FIG. 10 is a flowchart of a control process of the CPU 31 for setting the speed of the spindle motor 2. In step F301, the CPU 31 constantly checks the storage amount of the buffer memory 30. Note that this processing may be the same processing as step F101 in FIG. 6 or step F202 in FIG.

If the remaining data amount is equal to or less than 80% of the full capacity, the process proceeds from step F302 to F304 to perform control to set the speed of the spindle motor 2 to twice the standard speed.

If the remaining data amount is more than 80% and less than 90% of the full capacity, the process proceeds to steps F302, F303 and F305, and the speed of the spindle motor 2 is reduced to the standard speed. Control is performed at 1.5 times speed.

If the remaining data amount is more than 90% of the full capacity, the process proceeds to steps F302 and F30.
The process proceeds to 3, F306, and control is performed to set the speed of the spindle motor 2 to the standard speed.

FIG. 11 shows changes in the amount of storage in the buffer memory 30 realized by such processing.

[0158] In Fig. 11, the vertical axis indicates the accumulated amount, and the horizontal axis indicates the elapsed time from the start of the reproducing operation. Buffer memory 30
Assuming that the capacity is 4 Mbits, at the 100% position on the vertical axis, that is, at the full capacity, for example, reproduction data for 3 seconds is stored.

When the reproducing operation is started (after 0 second has passed), the accumulated amount of the buffer memory 30 is initially zero at first.
Is twice as fast. Then, the data decoded by the double speed reproduction operation is accumulated in the buffer memory 30. In this state, the accumulation amount of the buffer memory 30 increases as shown as a section A in FIG.

Here, the storage amount of the buffer memory 30 is 50
% (1.5 seconds), 0.75 seconds from the start of operation,
It is assumed that reproduction output is started. That is, the buffer memory 30
, Data reading at a predetermined rate is started, and is output from terminal 33 via D / A converter 32 as an audio signal.

After 0.75 seconds, the data reading from the disk 1 and the data writing to the buffer memory 30 are continuously performed at the double speed.
Data reading (1x rate) from
As shown in the section B, the increasing speed of the accumulation amount is somewhat weakened.

If the accumulation amount reaches 80% at 1.65 seconds after the accumulation amount increase in the section B is continued, the process of FIG. 10 proceeds to step F305, and the speed of the spindle motor 2 becomes Can be switched to 1.5x speed. And
The data decoded by the 1.5 times speed reproduction operation is accumulated in the buffer memory 30. In this state, the rate at which the amount of data stored in the buffer memory 30 increases is lower than that in the section B, as indicated by the section C, because the data writing rate to the buffer memory 30 decreases.

Thereafter, assuming that the accumulated amount reaches 90% at 2.25 seconds from the start of the reproducing operation, the process of FIG. 10 proceeds to step F306, and the speed of the spindle motor 2 is switched to the standard speed (1 × speed). Can be Then, the data decoded by the standard speed reproduction operation is accumulated in the buffer memory 30. In this state, the data write rate to the buffer memory 30 and the data read rate from the buffer memory 30 match, and therefore, as shown in the section D, the state in which the accumulation amount of the buffer memory 30 remains 90%. Will be maintained.

If the operation proceeds to the retry mode as a result of the frame check or the error check during the reproduction operation, the data writing to the buffer memory 30 is temporarily interrupted at that time, so that the accumulated amount decreases. However, the speed of the spindle motor 2 is switched to 1.5 times speed when the speed is reduced to 80 to 90% by the processing of FIG.
Since the speed is switched to the double speed, the accumulated amount is restored to the state of 90% again. In this state, the speed of the spindle motor 2 becomes 1x speed, and the state of the accumulated amount of 90% is maintained.

As described above, the speed of the spindle motor 2 is switched according to the amount of data stored in the buffer memory 30, and the data write rate to the buffer memory 30 is varied. Is controlled so as not to be full but close to full (90%), so that the retry operation by the full capacity does not normally occur, and therefore the number of track jumps is reduced to the minimum necessary for maintaining the data quality. Number of times.
As a result, power consumption can be saved by the track jump operation, and a decrease in sound quality due to electric noise at the time of the track jump can be minimized.

Of course, by maintaining the data storage amount of 90%, it is possible to maintain a sufficient level as the vibration proof function.

Furthermore, at most points, the spindle motor 2
Also, the rotation speed can be set to the standard speed. As a result, the power consumption of the spindle motor 2 can be reduced. In addition, it is not necessary to use a motor capable of constantly rotating at a high speed such as double speed as the spindle motor 2,
A reduction in parts cost can also be realized.

Further, in the case of the present embodiment, since the DSP 8 adopts a wide capture system in which processing is performed following the rotational speed of the spindle motor 2, the spindle motor 2
Data decoding can be performed irrespective of the speed state of. That is, for example, as shown in the example of FIG. 11, after the start of the reproduction operation (at the time of 0 second), the storage amount of the buffer memory 30 can be rapidly increased, and the audio output can be started at an early time such as 0.75 seconds. As a result, the time from the user's playback operation to the actual sound output and the time from the disc change to the playback sound output in a so-called changer type CD player can be shortened, and a CD player with good response to the user can be realized.

It is also conceivable to change the gain of the tracking servo in accordance with the rotation speed of the spindle motor 2 so that the anti-vibration characteristics and the conflicting demands of improvement in reproduction performance and reduction in power consumption can always be met. Can be

That is, it is desirable to increase the servo gain in order to improve the anti-vibration characteristics. However, if the servo gain is increased, the disk 1 may be damaged or dust may adhere to the disk 1. In addition, since the disturbance of the servo signal due to the scratches and dust is picked up, the reproduction performance is deteriorated. However, when the rotation speed of the disk 1 is increased, the change of the servo signal due to such scratches and dusts rises to a high frequency range, so that the servo gain can be increased.

Therefore, if the gain of the tracking servo is switched in accordance with the switching of the speed of the spindle motor 2 in accordance with the storage amount of the buffer memory 30, the vibration proof characteristic, the improvement of the reproducing performance and the power consumption can be improved. The conflicting demands for reduction can be met.

FIG. 12 is a flowchart in the case where the servo gain is set according to the rotation speed of the disk.

At step F401, CPU 31 constantly checks the storage amount of buffer memory 30.

If the remaining amount of data is equal to or less than 80% of the full capacity, the process proceeds to steps F402, F404, and F407 to perform control to set the speed of the spindle motor 2 to twice the standard speed, and to execute tracking servo. A process for increasing the gain by 6 dB is performed.

If the remaining data amount is more than 80% and less than 90% of the full capacity, the process proceeds to steps F402, F403, F405 and F408, and the speed of the spindle motor 2 is reduced to the standard speed. A control for increasing the speed by 1.5 times the speed is performed, and a process of increasing the gain of the tracking servo by 3.5 dB is performed.

If the remaining data amount is more than 90% of the full capacity, the process proceeds to steps F402 and F40.
3, the control proceeds to F406 and F409, and control is performed so that the speed of the spindle motor 2 is the standard speed, and the gain of the tracking servo remains unchanged.

[0177] 5. By the way, as described above, the rotation speed of the spindle motor 2 is controlled by setting the division ratio of the 1 / M frequency divider 22 and the 1 / N frequency divider 24 to a predetermined value. Controlled to any speed. To set the rotation speed of the spindle motor 2, the LPF / driver 27
And a deceleration pulse for decelerating the spindle motor 2 are output.

That is, when the rotation of the spindle motor 2 is slower than the predetermined rotation speed, the rotation speed of the spindle motor 2 is increased by the acceleration pulse.
When the rotation speed is higher than the predetermined rotation speed, the rotation of the spindle motor 2 is braked by the deceleration pulse to control the rotation of the spindle motor 2 to the predetermined rotation speed.

As described above, the spindle motor 2 uses the acceleration pulse and the deceleration pulse from the LPF / driver 27.
When the rotation control is performed, when braking is applied to the rotation of the spindle motor 2 by the deceleration pulse, an energy loss occurs and power consumption increases.

As shown in FIG. 11, the buffer memory 3
In a period in which 0 is less than 90%, that is, in the section A, the section B, and the section C, the accumulation amount of the buffer memory 30 changes, and the rotation speed of the spindle motor 2 is controlled according to the accumulation amount of the buffer memory 30. Therefore, it is necessary to control the rotation of the spindle motor 2 using the acceleration pulse and the deceleration pulse.
When the above is reached, that is, when reaching the section D, the accumulation amount of the buffer memory 30 hardly changes, and the spindle motor 2 continues to rotate at the standard speed. From this, if the amount of data stored in the buffer memory 30 exceeds a certain level and the spindle motor 2 continues to rotate at the standard speed,
It is conceivable to reduce the power consumption by causing the spindle motor 2 to rotate without outputting the deceleration pulse, that is, without turning on the brake.

FIG. 13 is a flowchart showing a process of rotating the spindle motor 2 without outputting a deceleration pulse when the data storage amount of the buffer memory 30 has exceeded a certain level.

In order to control the spindle motor 2 to rotate without outputting a deceleration pulse, a drive pulse control unit 35 is provided in front of the LPF / driver 27, as shown in FIG. The drive pulse control unit 35 switches between controlling the rotation of the spindle motor 2 using the acceleration pulse and the deceleration pulse and controlling the rotation of the spindle motor 2 without using the deceleration pulse.

In this example, when switching between the control of the rotation of the spindle motor 2 using the acceleration pulse and the deceleration pulse and the control of the rotation of the spindle motor 2 without using the deceleration pulse, the loop of the servo loop is used. The gain is also changed. The loop gain of the servo loop can be changed by, for example, changing the coefficient of the multiplier of the servo loop of the spindle servo processing unit 18.

In FIG. 13, the remaining capacity of the buffer memory 34 is checked (step F501).
Is less than 79% of the full capacity (step F5
02) The flow advances to step F503 to set the set speed to twice the standard speed. Then, the process proceeds to step F510 to determine whether the current speed is higher or lower than the set speed. If the current speed is higher than the set speed, the process proceeds to step F511, and the process proceeds to step F511.
If the current speed is lower than the set speed, the process proceeds to step F512 to accelerate at 0.25 times speed. Then, the process proceeds to step F513, where the control is performed by using the acceleration pulse and the deceleration pulse, the coefficient of the loop gain is set to the value at the time of the double speed in step F514, and the process returns to step F501. As a result, the current speed is controlled to become the set speed. When the current speed reaches the set speed, step F5
At 10, it is determined that the current speed is equal to the set speed, and the process proceeds to step F515 to determine whether the capacity of the buffer memory 30 is 95% or more. The capacity of the buffer memory 30 is 79
%, It is determined here to be "NO". Therefore, when it is determined that the current speed is equal to the set speed, the process directly returns to step F501.

As described above, when the capacity of the buffer memory 30 is 79% or less, if the current speed is lower than the set speed, the acceleration is performed 0.25 times, and if the current speed is higher than the set speed, the acceleration is 0. The rotation of the spindle motor 2 is controlled so that the speed is reduced by .25 times to become twice the standard speed. This control is performed using an acceleration pulse and a deceleration pulse, and the loop gain is set to a double speed.

When the capacity of the buffer memory 30 is 8
When the value changes from 0% to 89% (step F504), step
Proceed to F505 to set the set speed to 1.5 times the standard speed. Then, the process proceeds to step F506 to clear the control flag. This control flag is a flag used when controlling the rotation of the spindle motor 2 without using a deceleration pulse, and is set when the capacity of the buffer memory 30 becomes 95% or more of the full capacity. Then, the process proceeds to step F510 to determine whether the current speed is faster or slower than the set speed. If the current speed is faster than the set speed, 0.2
If the current speed is lower than the set speed, the vehicle is accelerated 0.25 times (step F51).
2) The control is performed by the acceleration pulse and the deceleration pulse (step F513), the loop gain coefficient is set to the value at the time of double speed (step F514), and the process returns to step F501. As a result, the current speed is controlled to become the set speed. When the current speed reaches the set speed, it is determined in step F510 that the current speed is equal to the set speed, and it is determined whether the capacity of the buffer memory 30 is 95% or more (step F515). Is 7
If it is 9% or less, the determination is "NO" here, and the process returns to step F501.

As described above, when the capacity of the buffer memory 30 is 80% to 89%, if the current speed is lower than the set speed, the acceleration is performed 0.25 times, and if the current speed is higher than the set speed, the speed is increased. The rotation of the spindle motor 2 is controlled such that the speed is reduced by 0.25 times and becomes 1.5 times the standard speed. This control is performed using the acceleration pulse and the deceleration pulse, and the loop gain is set to the value at the time of double speed.

If the capacity of the buffer memory 30 is 9
When the rate changes from 0% to 94% (step F507), step
Proceeding to F508, it is determined whether the control flag is "1". If the control flag is not "1", the flow proceeds to step F505 to set the set speed to 1.5 times speed. The process proceeds to step F510 to determine whether the current speed is higher or lower than the set speed. If the current speed is higher than the set speed, the speed is reduced by 0.25 times (step F511), and the current speed is set to the set speed. If it is slower, acceleration is performed at 0.25 times speed (step F512), and control is performed using the acceleration pulse and the deceleration pulse (step F512).
F513), the loop gain coefficient is set to the value at the time of double speed (step F514), and the process returns to step F501.
As a result, the current speed is controlled to become the set speed. When the current speed reaches the set speed, it is determined in step F510 that the current speed is equal to the set speed, and it is determined whether or not the capacity of the buffer memory 30 is 95% or more (step F515). Is 79% or less, the determination is "NO" here, and the process returns to step F501.

As described above, when the capacity of the buffer memory 30 is 90% to 94%, if the current speed is lower than the set speed, the acceleration is made 0.25 times, and if the current speed is higher than the set speed, The rotation of the spindle motor 2 is controlled so as to reduce the speed by 0.25 times to the standard speed.
This control is performed using an acceleration pulse and a deceleration pulse, and the loop gain is set to a double speed.

When the capacity of the buffer memory 30 is 9
When it becomes 5% or more, the process proceeds to step F509, and the set speed is set to the standard speed. The process proceeds to step F510 to determine whether the current speed is higher or lower than the set speed. If the current speed is higher than the set speed, the speed is reduced by 0.25 times (step F511), and the current speed is set to the set speed. If later
Acceleration is performed at 0.25 times speed (step F512), control is performed by the acceleration pulse and the deceleration pulse (step F513), and the coefficient of the loop gain is set to the value at the time of double speed (step F514). To return. As a result, the current speed is controlled to become the set speed. When the current speed reaches the set speed, it is determined in step F510 that the current speed is equal to the set speed.
It is determined whether the capacity of 0 is 95% or more (step F515). The capacity of the buffer memory 30 is 9
If it is 5% or more, "YES" is determined here. In step F515, the capacity of the buffer memory 30 is 95% of the full capacity.
If it is determined that the above is the case, the process proceeds to step F516, brake-off control is performed so as not to output a deceleration pulse, and the process proceeds to step F517, where the gain of the servo loop is set to the gain at the standard speed, and step F517 The control flag is set, and the process returns to step F501.

As described above, when the capacity of the buffer memory 30 is 95% or more, if the current speed is slower than the set speed, the acceleration is performed 0.25 times. The rotation of the spindle motor 2 is controlled so as to reduce the speed by 25 times to the standard speed. And
When the current speed becomes equal to the set speed, the rotation of the spindle motor 2 is controlled with the brake off without outputting a deceleration pulse, and the gain of the servo loop is set to the gain at the standard speed, and the control flag is set. set. As described above, by controlling the rotation of the spindle motor 2 without outputting the deceleration pulse, the power consumption can be reduced.

Once the capacity of the buffer memory 30 becomes 95% or more of the full capacity and the rotation of the spindle motor 2 is controlled without outputting a deceleration pulse, the control flag is set to "1" in step F518. . Thereafter, it is assumed that the capacity of the buffer memory 30 has dropped from 90% to 94%. In this case, it is determined in step F508 that the control flag is “1”. Accordingly, YES is determined in step F508, and the process proceeds to step F509 to continue the control for controlling the rotation of the spindle motor 2 at the standard speed without outputting the deceleration pulse.

Furthermore, the capacity of the buffer memory 30 is 89%
If it falls below, the process proceeds to step F505, the set speed is set to 1.5 times speed, the control flag is cleared in step F506, and the processing performed without outputting the deceleration pulse is canceled.

As described above, when the capacity of the buffer memory 30 increases to 95% or more, a process for controlling the rotation of the spindle motor 2 without outputting a deceleration pulse is started. On the other hand, this processing is terminated when the capacity of the buffer memory 30 falls to 89% or less. Thus, the point at which processing for controlling the rotation of the spindle motor 2 without outputting the deceleration pulse is started,
The point at which this processing is ended is different, and a dead zone is provided. This is because power is conserved by controlling as much as possible without outputting a deceleration pulse.

FIG. 15 shows a change in the capacity of the buffer memory 30 when such control as shown in FIG. 13 is performed.

The changes from the start of reproduction to the time when the accumulated amount reaches 90%, that is, in the sections A, B, and C, are the same as those shown in FIG. That is,
In the section A, data is accumulated in the buffer memory 30 by double speed reproduction. When the accumulation amount of the buffer memory 30 becomes 50%, the reproduction is started, and in the section B after the reproduction is started, the accumulation increase amount decreases. In the section C where the accumulation amount of the buffer memory 30 is 80% or more, 1.5
Double speed reproduction is performed, and data is accumulated in the buffer memory 30.

When the accumulated amount reaches 90% and the section D is reached, the reproduction is started at the standard speed. Furthermore, if the accumulated amount is 95
% (Point P1), processing for controlling the rotation of the spindle motor 2 without outputting a deceleration pulse is performed. Such processing is continued if the accumulated amount is 90% or more. When the accumulated amount becomes 89% or less (point P2), the reproduction is performed at 1.5 times speed, the accumulated amount reaches 90%, and in the section D, the reproduction is started at the standard speed, and further, the accumulated amount becomes 95% or more. When it reaches (point P3),
Processing for controlling the rotation of the spindle motor 2 without outputting a deceleration pulse is performed.

As described above, when the amount of data stored in the buffer memory 30 exceeds a certain level and the spindle motor 2 continues to rotate at the standard speed, the spindle motor 2 is rotated without outputting a deceleration pulse. , Power consumption can be reduced.

FIG. 16 compares power consumption to verify this. FIG. 16 shows that, as in this example, the rotation of the spindle motor is controlled in accordance with the accumulation amount of the buffer memory, and the spindle motor 2 is output without outputting the deceleration pulse when the data accumulation amount of the buffer memory exceeds a certain level. A comparison of the change in current consumption when rotating and reproducing, the change in current consumption when performing CLV reproduction at a standard speed, and the change in current consumption when performing ESP reproduction at a fixed speed of 2 ×. It is. As is apparent from FIG. 16, the current consumption when the CLV reproduction is performed at the standard speed and the current consumption when the ESP reproduction is performed at a fixed speed of 2 × are almost equal. This is because rotating the spindle motor at CLV consumes more power than rotating the spindle motor at double speed. As in this example,
When the rotation of the spindle motor is controlled according to the accumulation amount of the buffer memory, and when the data accumulation amount of the buffer memory exceeds a certain level, the spindle motor 2 is rotated without outputting the deceleration pulse and reproduced. In addition, current consumption can be reduced.

Although the CD player has been described as an embodiment of the present invention, various modifications are conceivable as the present invention.

For example, the rotation speed switching control of the spindle motor 2 may be more finely switched to each step. Also, the accumulated amount maintenance level is not 90%, but 95%.
%, 85%, or the like.

Various settings such as execution / non-execution of the frame check and the error check or the degree of the strictness of the check can be considered.

[0203] In the above example, a CD player storing one disc has been described. However, it is needless to say that the present invention can be applied to a changer player capable of storing a large number of discs and selectively reproducing.

[0204]

As described above, the reproducing apparatus of the present invention sequentially detects the amount of audio data stored in the buffer memory means, and reads the stored data from the recording medium by the reading means so that the stored amount does not reach the full capacity. The read rate of the audio data is changed. That is, by changing the data reading rate from the recording medium in accordance with the accumulation amount of the buffer memory means, the accumulation amount does not become full, but is kept close to full. It is not necessary to wait for an operation of writing read data to the buffer memory.

As a result, there is no need to interrupt data reading from the recording medium except for a retry operation for maintaining data quality such as continuity of data and an error situation, so that the number of track jumps is minimized ( Normally there is no need for a track jump). For this reason, power consumption due to the track jump operation is saved, and a decrease in sound quality due to electric noise at the time of the track jump is reduced, so that high-quality sound reproduction output can be realized. Also, a sufficient level can be maintained as the vibration proof function.

Furthermore, since the rotation speed of the spindle motor can be set to the standard speed at most of the time, the power consumption of the spindle motor can also be reduced, and the cost can be reduced because the high rotation capability of the spindle motor is not so required. realizable.

The clock generating means for generating a clock used for decoding the audio data may be formed using an oscillator for changing the oscillation frequency in accordance with the reading rate of the audio data from the recording medium by the reading means. To Therefore, the decoding operation can be performed by following the rotation speed of the spindle motor. Therefore, despite the fact that the rotation speed of the spindle motor is changed in order to change the data rate at the time of reading the audio data from the recording medium, it is preferable. Can be read. This makes it possible to quickly start audio output at the time of reproduction, and to provide a high-performance reproduction device with good operation response.

Further, the servo gain is set according to the number of rotations of the disk. That is, when the rotation speed of the disk is 2 ×, the surfer gain is increased by 6 dB, and when the rotation speed of the disk is 1.5 ×, the surfer gain is increased by 3.5 dB. When the rotation speed of the disk is increased, components such as scratches and dust on the disk are increased to a higher frequency range. Therefore, even if the servo gain is increased, the reproduction performance is not deteriorated. Therefore, this makes it possible to improve the vibration proof characteristics and prevent deterioration of the reproduction performance and increase in power consumption.

Further, in the present invention, the reading means includes a spindle motor for rotating the recording medium, and a rotation control means for controlling the rotation of the spindle motor, and the rotation control means detects the accumulated amount by the accumulated amount detecting means. Until the result reaches a predetermined value, an acceleration pulse and a deceleration pulse are given to the spindle motor to control the rotation of the spindle motor, and the detection result of the storage amount by the storage amount detection means becomes a predetermined value or more,
When the spindle motor reaches a set speed, the rotation of the spindle motor is controlled without using a deceleration pulse. As a result, the application of a brake to the spindle motor is minimized, and power consumption can be reduced.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of a frame structure of a CD.

FIG. 3 is an explanatory diagram of CD subcoding.

FIG. 4 is an explanatory diagram of sub-Q data of a CD.

FIG. 5 is an explanatory diagram of CD TOC data.

FIG. 6 is a flowchart of a process for an ESP function in the embodiment.

FIG. 7 is an explanatory diagram of a spindle motor speed setting operation in the embodiment.

FIG. 8 is an explanatory diagram of a spindle motor speed setting operation in the embodiment.

FIG. 9 is a flowchart of a spindle motor speed setting process in the embodiment.

FIG. 10 is a flowchart of a spindle motor speed setting process in the embodiment.

FIG. 11 is an explanatory diagram of a continuity determination criterion in the embodiment.

FIG. 12 is a flowchart of a spindle motor speed setting process and a servo gain setting process in the embodiment.

FIG. 13 is a flowchart of a power saving setting process according to the embodiment.

FIG. 14 is a block diagram of a CD player capable of setting power saving.

FIG. 15 is an explanatory diagram of a continuity determination criterion in the embodiment.

FIG. 16 is an explanatory diagram showing an effect of power saving.

[Explanation of symbols]

1 disk, 2 spindle motor, 3 optical head, 3a objective lens, 4 axis mechanism, 7 RF amplifier, 8 RF equalizer, 11 RF-PLL circuit,
13 EFM demodulator, 14 subcode processor, 15
Error correction unit, 16 ECC-RAM, 18 spindle servo signal processing unit, 20 low-pass filter, 210
SC, 22 1 / M frequency divider, 23 auto sequencer,
24 1 / N frequency divider, 25 phase comparator, 28 oscillator, 29 memory controller, 30 buffer memory, 31 CPU, 32 D / A converter, 34 clock generator

Claims (8)

[Claims] 1. A reading means capable of reading audio data from a recording medium at a variable rate, a buffer memory means, and the audio data read by the reading means is stored in the buffer memory means. A memory control means for reading out audio data at a normal rate and outputting it as reproduced audio data; an accumulation amount detection means for sequentially detecting an accumulation amount of audio data in the buffer memory means; and a detection of an accumulation amount by the accumulation amount detection means Monitor the results,
A reproduction control means for changing a reading rate of the audio data from the recording medium by the reading means so that the accumulated amount does not reach the full capacity. 2. A clock generating means for generating a clock used for audio data decoding processing is formed using an oscillator which changes an oscillation frequency according to a reading rate of audio data from a recording medium by said reading means. The playback device according to claim 1, wherein: 3. Reading means capable of reading audio data from a recording medium at a variable rate, tracking control means controlling the reading means to trace along tracks of the recording medium, and buffer memory means. Memory control means for storing the audio data read by the reading means in the buffer memory means, reading the audio data from the buffer memory means at a normal rate, and outputting the data as reproduced audio data; An accumulation amount detecting means for sequentially detecting an accumulation area of data, and monitoring a detection result of the accumulation amount by the accumulation amount detecting means,
Reading control means for changing a reading rate of audio data from a recording medium by the reading means so that the accumulated amount does not reach a full capacity; and a tracking control means in accordance with the reading rate of the audio data. And a tracking gain control means for changing the gain of the reproduction device. 4. A clock generating means for generating a clock used for audio data decoding processing is formed using an oscillator for changing an oscillation frequency according to a reading rate of audio data from a recording medium by said reading means. The reproducing apparatus according to claim 3, wherein: 5. A reading means capable of reading audio data from a recording medium at a variable rate, a tracking control means controlling the reading means to trace along a track of the recording medium, and a buffer memory means. Memory control means for storing the audio data read by the reading means in the buffer memory means, reading the audio data from the buffer memory means at a normal rate, and outputting the data as reproduced audio data; An accumulation amount detecting means for sequentially detecting an accumulation area of data, and monitoring a detection result of the accumulation amount by the accumulation amount detecting means,
Reading control means for changing a reading rate of audio data from the recording medium by the reading means so that the accumulated amount does not reach the full capacity; a spindle motor for rotating the recording medium; Rotation control means for controlling rotation, the rotation control means providing an acceleration signal and a deceleration signal to the spindle motor until the detection result of the accumulation amount by the accumulation amount detection means reaches a predetermined value, and Controlling the rotation of the motor, and performing a process of controlling the rotation of the spindle motor without using the deceleration signal when the detection result of the accumulation amount by the accumulation amount detection means is equal to or more than the predetermined value. Characteristic playback device. 6. The reproducing apparatus according to claim 5, wherein the set speed when controlling the rotation of the spindle motor without using the deceleration signal is a rotational speed at the time of standard reproduction. 7. When the detection result of the accumulation amount becomes equal to or less than a predetermined value, the processing for controlling the rotation of the spindle motor is canceled without using the deceleration signal, and the spindle motor is not used without using the deceleration signal. The predetermined value of the detection result of the accumulation amount when performing the process of controlling the rotation of the motor and the detection result of the accumulation amount when canceling the process of controlling the rotation of the spindle motor without using the deceleration signal The reproducing apparatus according to claim 5, wherein the predetermined value is different from the predetermined value. 8. A loop gain is set between a time when the acceleration signal and a deceleration signal are given to the spindle motor to control the rotation of the spindle motor and a time when the rotation of the spindle motor is controlled without using the deceleration signal. The reproducing apparatus according to claim 5, wherein the reproducing apparatus is changed.