JP3186273B2 - Data playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing apparatus for reproducing data recorded on a disk-shaped recording medium.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram showing an example of a conventional data reproducing apparatus, and FIG. 9 is a block diagram showing a digital signal processing circuit shown in FIG. In FIG. 8, reference numeral 1 denotes a compact disc as a record carrier. The compact disk 1 is recorded with data at a constant linear velocity (hereinafter, referred to as CLV as necessary), and is rotated by a spindle motor 3 to have a constant linear velocity. Reference numeral 2 denotes an optical pickup which extracts data recorded on the compact disk 1 as an analog reproduction signal. 5
Denotes an analog waveform shaping circuit, which shapes an analog signal input from the optical pickup 2 into a binary signal, and outputs the binary data to the digital signal processing circuit 7.

A digital signal processing circuit 9 reproduces a clock from the binary data obtained by the analog waveform shaping circuit 5 and outputs the reproduced clock to the servo circuit 6. The digital signal processing circuit 9 synchronizes the digital audio data 2 with the reference clock of the internal crystal oscillation circuit.
1 and the digital data 23 are demodulated and output, and further, the disk address information 24 is output to the access control device 8. Also, the reference clock of this crystal oscillation circuit is
Output to the servo circuit 6. Reference numeral 12 denotes a D / A conversion circuit. The D / A conversion circuit 12 converts digital audio data 21 output from the digital signal processing circuit 9 into an analog audio signal, and outputs the analog audio signal.

The servo circuit 6 is a compact disk based on two types of clocks (a reference clock output from a crystal oscillation circuit and a reproduction clock reproduced from binary data) provided from a digital signal processing circuit 9. The rotation speed of the spindle motor 3 is controlled so that the linear speed of the motor 1 becomes constant. Further, the slide motor 4 and the optical pickup 2 are controlled based on an access control signal given from the access control device 8. The access control device 8 includes:
The slide motor 4 and the optical pickup 2 are controlled via the servo circuit 6 based on the disk address information 24 given from the digital signal processing circuit 9 to perform track positioning.

As shown in FIG. 9, the digital signal processing circuit 9 includes a synchronization detection circuit 41 and a PLL (Phase
(Locked Loop) circuit 42, demodulation circuit 43, crystal oscillation circuit 44, subcoding detection circuit 45, RA
M (Random Access Memory) 46
It is composed of The synchronization detection circuit 41 detects frame synchronization from the input binary data and outputs the frame synchronization to the demodulation circuit 43. The PLL circuit 42 reproduces a clock from the input binary data, and outputs the reproduced clock to the demodulation circuit 43 and the servo circuit 6. The crystal oscillation circuit 44 outputs a reference clock to the demodulation circuit 43 and the servo circuit 6.

The demodulation circuit 43 fetches a digital signal from the synchronization detection circuit 41 and uses the RAM 46 to perform CIR
C (Cross Interleaved Reed-S
demon interleaving and CIR
Error detection and correction by C are performed. Then, demodulated digital audio data 21 or digital data 23 is output. These digital audio data 21 and digital data 23 are output in synchronization with the reference clock of the crystal oscillation circuit 44 as described above. The sub-coding detection circuit 45 reproduces the disk address information 24 for performing track positioning,
Output to

[0007] A related device of this type is, for example, Japanese Patent Application Laid-Open No. 1-154369.

[0008]

Generally, as a method of recording on a disk-shaped recording medium, CLV (constant linear velocity) is used.
There is a method and a CAV (constant rotation speed) method. The CLV method can record more data than the CAV method, but the rotational speed is different between the inner and outer circumferences of the disk because the linear velocity is constant. For this reason, in the above-mentioned conventional example, it is necessary to change the rotation speed of the disk simultaneously with the movement of the optical pickup when accessing the disk, which hinders the shortening of the access time. In addition, when data is reproduced by rotating a disk recorded in the CLV format at a constant rotation speed, the data transfer speed differs between the inner and outer circumferences of the disk, so that audio and the like that require a constant transfer speed are used. Reproduction was difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances of the prior art, and has as its object to reproduce data by rotating a disk-shaped recording medium recorded by the CLV method at a constant rotational speed. To enable high-speed access, and to output data at a constant transfer rate even if data is reproduced by rotating a disk-shaped recording medium recorded by the CLV method at a constant rotational speed,
It is therefore an object of the present invention to provide a data reproducing apparatus capable of reproducing data requiring a constant transfer speed such as voice.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is as described above.
Indicates a recording medium on which data is recorded using the constant linear velocity method.
Rotating means for rotating at a constant rotation speed, and
Irradiate the recording medium rotating at a constant rotation speed
By this, the data recorded on the recording medium and
To read audio data or digital data.
Data reading means and the rotating means at a constant rotational speed.
The reading position of the data reading means on the rotating recording medium;
Position control means for controlling, and the data reading means
The data read from the recording medium is read by the data reading means.
Perform signal processing at the transfer speed according to the read position of the stage
The signal processing means and the data processed by the signal processing means
A memory for storing the audio data when the data is audio data;
Means according to the storage amount of the audio data in the memory means
The position control means controls the read position of the data read means
The audio data processed by the signal processing means.
Input control to the memory means and the sound from the memory means.
Output control to output voice data at a constant transfer rate.
Memory control means, and the data is audio data.
At a constant transfer rate output from the memory means.
The audio data is used as output data to the outside, and the data is
When the data is digital data, the signal processing means performs signal processing.
Of the transfer rate according to the read position of the read data read means.
This is achieved by using the digital data as output data to the outside .

[0011]

When a recording medium recorded by the CLV method is rotated at a constant rotation speed and data is reproduced from the recording medium, the control of the number of revolutions at the time of access becomes unnecessary, so that the access time can be greatly reduced. I can do it. Further, by absorbing the difference in the amount of data when the recording medium recorded by the CLV method is rotated at a constant rotation speed by the memory means , the data can be output at a constant transfer speed and the sound can be reproduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a data reproducing apparatus according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing a digital signal processing circuit shown in FIG. 1, which corresponds to FIG. 8 and FIG. Are given the same reference numerals. That is, FIG.
Wherein 1 is a compact disc as a record carrier,
2 is an optical pickup, 3 is a spindle motor, 4 is a slide motor, 5 is an analog waveform shaping circuit, 6 is a servo circuit, 8 is an access control device, 12 is a D / A conversion circuit, and the compact disc 1 is a CLV system. The data is recorded in. 7 is a digital signal processing circuit, 1
1 is a buffer RAM, 13 is a RAM control device, and 10 is a disk reproducing device. The disk reproducing device 10 reproduces data by rotating the compact disk 1 at a constant rotation speed.

The compact disc 1 is rotated by the spindle motor 3 not at a constant linear speed but at a constant rotational speed. The optical pickup 2 extracts data recorded on the compact disc 1 as an analog reproduction signal. The analog waveform shaping circuit 5 shapes the waveform of the analog signal input from the optical pickup 2, binarizes the analog signal, and outputs the binarized data to the digital signal processing circuit 7.
The digital signal processing circuit 7 includes an analog waveform shaping circuit 5
A clock is reproduced from the obtained binary data, digital audio data 20 and digital data 23 are demodulated and output from the reproduced clock, and disk address information 24 is output to the access control device 8. These digital voice data 20 and digital data 23
It is output in synchronization with a reproduction clock reproduced from the compact disk 1.

Since the compact disk 1 recorded by the CLV method is reproduced at a constant rotational speed, the transfer speed of the digital audio data 20 and digital data 23 differs between the inner and outer circumferences of the compact disk 1. The buffer RAM 11 is supplied with the digital audio data 20 at a normal transfer speed, that is, at a speed higher or lower than that at the time of reproduction by the CLV method. The buffer RAM 11 temporarily stores the digital audio data 20 and outputs digital audio data 21 having a constant transfer rate to the D / A conversion circuit 12.

The RAM control device 13 includes a buffer RAM 1
In addition to controlling the input / output timing and address of No. 1, a full / empty signal 26 (a signal indicating the amount of data in the buffer RAM) of the buffer RAM 11 is sent to the access control device 8. The D / A conversion circuit 12 includes a buffer RAM 1
The digital audio data 21 output from 1 is converted into an analog audio signal 22 and output. Analog audio signal 2
In order to output 2 continuously, it is necessary to rotate the spindle motor 3 so that the transfer speed of the digital audio data 20 becomes equal to or higher than that in the case of reproducing by the CLV method.

The servo circuit 6 controls the rotation speed of the spindle motor 3 to a constant speed. Further, the slide motor 4 and the optical pickup 2 are controlled based on an access control signal 25 given from the access control device 8. The access control device 8 controls the slide motor 4 and the optical pickup 2 via the servo circuit 6 based on the disk address information 24 given from the digital signal processing circuit 7 to perform track positioning. And buffer RAM
The access control is controlled by constantly monitoring the 11 full / empty signals 26 (signals indicating the amount of data in the RAM). Digital audio data 20 input to the buffer RAM 11
Since the transfer speed of the digital audio data 21 output from the buffer RAM 11 is different from that of the first embodiment, when the buffer RAM 11 becomes full, the compact disc 1 is paused, and control is performed such that data reading is resumed before the compact disk 1 becomes empty. The buffer RAM 11 keeps outputting digital audio data 21 at a constant transfer rate while repeating full / empty.

As shown in FIG. 2, the digital signal processing circuit 7 includes a synchronization detection circuit 41, a PLL circuit 42, a demodulation circuit 43, a subcoding detection circuit 45, and a RAM 46.
It is composed of The synchronization detection circuit 41 detects frame synchronization from the input binary data and outputs the frame synchronization to the demodulation circuit 43. The PLL circuit 42 reproduces a clock from the input binary data, and outputs the reproduced clock to the demodulation circuit 43. The demodulation circuit 43 takes in the digital signal from the synchronization detection circuit 41 and uses the RAM 46 to deinterleave the CIRC and detect and correct an error by the CIRC. Then, demodulated digital audio data 20 or digital data 23 is output. These digital audio data 20 and digital data 23 are
2 is output in synchronization with the reproduction clock reproduced in step 2. The subcoding detection circuit 45 reproduces the disk address information 24 for performing track positioning, and outputs this to the access control device 8.

In the first embodiment of the present invention having the above-described structure, the compact disk 1 recorded by the CLV method is used.
Can be rotated at a constant rotation speed to reproduce data, so that it is not necessary to control the number of rotations at the time of access, and as a result, high-speed access is possible. Also, by absorbing the difference in the amount of data when rotating the recording medium recorded by the CLV method at a constant rotation speed by the buffer RAM 11, data can be output at a constant transfer speed and audio can be reproduced. Becomes Further, there is an effect that the transfer speed of digital data output to the outside increases as it goes to the outer peripheral portion of the compact disc 1.

FIG. 3 is a block diagram showing a modification of the first embodiment shown in FIG. 1, and portions corresponding to FIG. 1 are denoted by the same reference numerals.

This modification differs from the first embodiment in that the buffer RAM 15 temporarily stores the digital data 23 output from the digital signal processing circuit 7.
And a RAM control device 14 for controlling the input / output timing and address of the buffer RAM 15 and the buffer RAM 11, and the other configurations are basically the same. The buffer RAM 15 temporarily stores the digital data 23 and outputs digital data 27 at a constant transfer rate to the outside.

In the modified example configured as described above, in addition to the effect of the first embodiment, since digital data is output to the outside at a constant transfer speed regardless of the reproduction track of the compact disk 1, video data and the like are output. When playing
Alternatively, it is particularly effective when a computer or the like that controls this data reproducing apparatus requires a certain transfer rate.

FIG. 4 is a block diagram showing a data reproducing apparatus according to a second embodiment of the present invention, and portions corresponding to FIG. 1 are denoted by the same reference numerals.

In FIG. 4, reference numeral 16 denotes a disk reproducing device,
17 is a servo circuit. The disc reproducing apparatus 16 divides the compact disc 1 into several zones on the inner and outer circumferences, and rotates the compact disc 1 at an appropriate rotation speed for each zone to reproduce data. This is different from the example disk reproducing device 10. Servo circuit 1
Reference numeral 7 controls the rotation speed of the spindle motor 3 to an appropriate rotation speed for each zone of the compact disk 1 based on the disk address information 24. FIG. 5 explains the relationship between the zone division example of the compact disc 1 and the rotation speed, and shows that the compact disc 1 rotates at a constant rotation speed in each zone.

In the second embodiment of the present invention thus constructed, in addition to the effects of the first embodiment, the data is reproduced by setting the rotation speed of the compact disc 1 to an appropriate rotation speed for each zone. It has the effect of being able to do so. That is, since an appropriate rotation speed can be set at both the inner peripheral portion and the outer peripheral portion of the compact disc 1, the data transfer speed at the time of reproducing the inner peripheral portion of the compact disc 1 can be increased. In addition, compact disk 1
When rotating the at a constant rotation speed, it is possible to suppress an increase in the operating frequency of each circuit at the time of reproducing the outer peripheral portion,
The burden on the waveform shaping circuit, the signal processing circuit, and the like can be reduced. In the case of a CD-ROM or the like, since access in the vicinity is usually used frequently, the access rarely spans the zone, and the access time that increases compared to the case of the first embodiment is short.

FIG. 6 is a block diagram showing a data reproducing apparatus according to a third embodiment of the present invention, and portions corresponding to FIG. 1 are denoted by the same reference numerals.

In FIG. 6, reference numeral 18 denotes a disk reproducing device,
19 is a servo circuit. The disc reproducing device 18 reproduces data by changing the rotation speed for each compact disc 1 depending on how far the outer periphery of the compact disc 1 is recorded. This is the point of the disc of the first embodiment. It is different from the playback device 10. Servo circuit 1
Numeral 9 controls the rotation speed of the spindle motor 3, and the compact disc 1 is rotated by the spindle motor 3 at a constant rotation speed according to the recording range of the outermost periphery.

When the compact disc 1 recorded by the CLV method is reproduced at a constant rotation speed, as described above, the effect of increasing the transfer rate of the data to be output to the outside as it proceeds to the outer periphery of the compact disc 1 is obtained. is there. However, if you always play at a constant rotation speed,
For example, when reproducing the compact disc 1 recorded only on the inner peripheral portion, it is not possible to increase the data transfer speed. Therefore, the compact disk 1 recorded only on the inner peripheral portion reproduces data by increasing the rotation speed according to the address of the outermost peripheral portion. The rotation speed at that time is set so that, for example, the linear velocity at the outermost track is twice as fast as that of a normal compact disc reproducing apparatus. Such a setting may be a triple speed or a quadruple speed depending on the maximum operating frequency of each circuit.

FIG. 7 illustrates the relationship between the compact discs 1 having different recording amounts and the rotational speeds thereof. The optimum rotational speed for each compact disc 1 depends on how far the compact disc 1 is recorded on the outer peripheral portion. It shows that it rotates at the speed. That is, FIG. 7A shows a compact disk 1 recorded only on the inner peripheral portion, and its rotation speed is set such that the linear velocity on the outermost track is twice as fast as that of a normal compact disk reproducing device. Set. FIG. 7B shows a compact disk 1 recorded to the outer side from FIG. 7A, and its rotation speed is also, for example, the linear velocity at the outermost track is twice as fast as that of a normal compact disk reproducing device. Set to be. FIG. 7C shows the compact disk 1 recorded to the outer peripheral portion. Similarly, for example, the linear velocity of the outermost track is set to be twice as fast as that of a normal compact disk reproducing apparatus.

In the third embodiment of the present invention having the above-described structure, in addition to the effects of the first embodiment, data is obtained by changing the rotation speed of the compact disk 1 to an appropriate speed for each compact disk 1. As a result, it is possible to achieve a high-speed access and a high-speed data transfer even with a compact disc 1 in which data is recorded only on the inner peripheral portion.

Note that the second embodiment and the third embodiment can be combined. That is, first, an optimum rotation speed for reproducing the outer peripheral portion of the compact disk 1 is determined based on how much data is recorded on the outer peripheral portion of the compact disk 1. Next, the compact disk 1 is divided into several zones on the inner and outer circumferences. What is necessary is just to divide and determine an appropriate rotation speed for each zone.

[0032]

As described above, according to the present invention,
By rotating a recording medium recorded with a constant linear velocity (CLV) method at a constant rotation speed and reproducing data from the recording medium, it becomes unnecessary to control the number of rotations at the time of access.
High-speed access becomes possible. In addition, by sequentially writing the reproduced data to the memory means and reading out the written data at a constant transfer rate, the data can be output at a constant transfer rate while the rotation speed of the recording medium is kept constant, and audio and the like can be output. Can be reproduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a data reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating the digital signal processing circuit of FIG. 1;

FIG. 3 is a block diagram showing a modification of the embodiment shown in FIG.

FIG. 4 is a block diagram showing a data reproducing apparatus according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a relationship between a zone division example of a compact disc and a rotation speed.

FIG. 6 is a block diagram showing a data reproducing apparatus according to a third embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between compact disks having different recording amounts and their rotation speeds.

FIG. 8 is a block diagram showing a data reproducing apparatus according to a conventional example.

FIG. 9 is a block diagram showing the digital signal processing circuit of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compact disk (recording medium) 2 Optical pickup 3 Spindle motor 4 Slide motor 5 Waveform shaping circuit 6,17,19 Servo circuit 7 Digital signal processing circuit 8 Access control device 10,16,18 Disk reproduction device 11,15 Buffer RAM 12 D / A conversion circuit 13,14 RAM controller

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-64-84476 (JP, A) JP-A-3-83265 (JP, A) JP-A-60-177404 (JP, A) JP-A-4- 307468 (JP, A) JP-A-59-144289 (JP, A) JP-A-63-74172 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B ^7/ 00-7 / 013 G11B 19/247 G11B 20/10 G11B 20/12 G11B 20/14

Claims (3)

(57) [Claims] A rotating means for rotating a recording medium on which data is recorded at a constant linear velocity at a constant rotational speed; and irradiating the recording medium rotated at a constant rotational speed by the rotating means with light. Data reading means for reading audio data or digital data as the data recorded on the recording medium; and controlling a reading position of the data reading means on the recording medium rotated at a constant rotation speed by the rotating means. Signal processing means for performing signal processing on the data read from the recording medium by the data reading means at a transfer rate corresponding to the reading position of the data reading means; When the data processed by the means is audio data, a memory means for storing the audio data; and a memory means for storing the audio data in the memory means. While the position control means controls the reading position of the data reading means, input control of the audio data signal-processed by the signal processing means to the memory means and transfer of the audio data from the memory means at a constant transfer rate. And memory control means for performing output control for outputting. When the data is audio data, the audio data at a constant transfer rate output from the memory means is output to the outside, and the data is digitally output. When it is data,
A data reproducing apparatus characterized in that the digital data having a transfer rate corresponding to the read position of the data reading means subjected to signal processing by the signal processing means is output to the outside. 2. The recording medium according to claim 1, wherein the entire recording area of the recording medium is divided into a plurality of zones, and the rotating means varies a rotation speed of the recording medium for each of the zones. A data reproducing apparatus characterized by maintaining a constant speed. 3. The method according to claim 1, wherein the rotation unit determines a rotation speed of the recording medium to a value corresponding to an outermost peripheral position of a data recording unit on which data of the recording medium is recorded. Data reproducing device.