JPH06180845A - Data reproducing device - Google Patents

Abstract

PURPOSE:To provide a data reproducing device capable of reproducing data by rotating a disk shape recording medium recorded with a CLV (constant linear velocity) system at a fixed rotational speed. CONSTITUTION:A compact disk 1 where the data are recorded with the CLV system is rotated at a fixed rotational speed, and the regenerated data are outputted from a digital signal processing circuit 7. The sound data 20 among the data outputted from the digital signal processing circuit 7 are stored in a buffer RAM 11 temporarily, and are made a fixed transfer speed to be outputted to a D/A converter circuit 12, and further, are converted to an analog sound signal by a D/A converter circuit 12 to be outputted to the outside. The digital data 23 excepting the sound are outputted to the outside from the digital signal processing circuit 7 as it is. Thus, the number of revolution control at an accessing time is unnecessitated, and high speed accessing is performed. The data are outputted at a fixed transfer speed, and the sound reproduction becomes possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing device for reproducing data recorded on a disc-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 of FIG. In FIG. 8, 1 is a compact disc as a record carrier. Data is recorded on the compact disc 1 by a constant linear velocity (hereinafter, referred to as CLV) system, and is rotated by a spindle motor 3 so as to have a constant linear velocity. An optical pickup 2 takes out the data recorded on the compact disc 1 as an analog reproduction signal. 5
Is an analog waveform shaping circuit, which shapes the analog signal input from the optical pickup 2 into a binary signal and outputs the binarized data to the digital signal processing circuit 7.

Reference numeral 9 denotes a digital signal processing circuit, which reproduces a clock from the binarized 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 with the digital audio data 2 in synchronization 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 oscillator circuit,
Output to the servo circuit 6. Reference numeral 12 is a D / A conversion circuit. The D / A conversion circuit 12 converts the digital audio data 21 output from the digital signal processing circuit 9 into an analog audio signal and outputs it.

The servo circuit 6 is a compact disc based on two kinds of clocks (a reference clock output from a crystal oscillating circuit and a reproduction clock reproduced from binarized data) supplied from the digital signal processing circuit 9. The rotation speed of the spindle motor 3 is controlled so that the linear velocity of 1 becomes constant. Further, the slide motor 4 and the optical pickup 2 are controlled based on the access control signal given from the access control device 8. The access control device 8 is
Based on the disk address information 24 given from the digital signal processing circuit 9, the slide motor 4 and the optical pickup 2 are controlled via the servo circuit 6 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, sub-coding detection circuit 45, RA
M (Random Access Memory) 46
It is composed of The synchronization detection circuit 41 detects frame synchronization from the input binarized data and outputs it to the demodulation circuit 43. The PLL circuit 42 reproduces a clock from the input binarized data and outputs the reproduced clock to the demodulation circuit 43 and the servo circuit 6. The crystal oscillation circuit 44 outputs the reference clock to the demodulation circuit 43 and the servo circuit 6.

The demodulation circuit 43 takes in the digital signal from the synchronization detection circuit 41 and uses the RAM 46 to make a CIR.
C (Cross Interleave Reed-S)
de-interleaving and CIR
The error is detected and corrected by C. Then, the demodulated digital voice data 21 or digital data 23 is output. The digital audio data 21 and the 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 disc address information 24 for performing track positioning, and reproduces the disc address information 24.
Output to.

A device related to this type of device is, for example, JP-A-1-154369.

[0008]

Generally, CLV (constant linear velocity) is used as a method for recording on a disk-shaped recording medium.
There are a system and a CAV (constant rotation speed) system. The CLV system can record more data than the CAV system, but since the linear velocity is constant, the rotation speed differs between the inner and outer circumferences of the disc. Therefore, in the above-mentioned conventional example, it is necessary to change the rotation speed of the disc at the same time as the movement of the optical pickup when the disc is accessed, which is an obstacle to shortening the access time. Further, when data is reproduced by rotating a disc recorded by the CLV system at a constant rotation speed, the data transfer speeds differ between the inner and outer circumferences of the disc, so that audio data requiring a constant transfer speed, etc. Reproduction was difficult.

The present invention has been made in view of the circumstances of the prior art as described above, and a first object thereof is to rotate a disk-shaped recording medium recorded by the CLV system at a constant rotation speed to store data. It is an object of the present invention to provide a data reproducing device that enables reproduction and realizes high-speed access.
Another object of the present invention is to enable the data to be output at a constant transfer speed even when the disk-shaped recording medium recorded by the CLV system is rotated at a constant rotation speed to reproduce the data, so that the audio It is another object of the present invention to provide a data reproducing device capable of reproducing data requiring a constant transfer rate such as the above.

[0010]

The first object of the present invention described above is to detect a digital signal read from the recording medium by rotating a disk-shaped recording medium recorded by the CLV system at a constant rotation speed. This is achieved by providing a disk reproducing device which reproduces a synchronizing signal and a clock and reproduces and outputs the data using the synchronizing signal and the clock. Further, another object of the present invention described above is
The disk reproducing device, a buffer RAM circuit for temporarily storing the data output from the disk reproducing device, and the data output from the disk reproducing device are sequentially written into the buffer RAM circuit, and the buffer RAM
It is achieved by providing a buffer RAM controller for reading data written in the circuit at a predetermined transfer rate.

[0011]

When the recording medium recorded by the CLV method is rotated at a constant rotation speed and the data is reproduced from the recording medium, the rotation speed control at the time of access becomes unnecessary, so that the access time is greatly shortened. Can be achieved. Further, the buffer RAM circuit absorbs the difference in the amount of data when the recording medium recorded by the CLV method is rotated at a constant rotation speed, so that 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 of FIG. 1, corresponding to FIGS. 8 and 9. Are given the same reference numerals. That is, FIG.
In, 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. Further, 7 is a digital signal processing circuit, 1
Reference numeral 1 is a buffer RAM, 13 is a RAM control device, and 10 is a disc reproducing device. The disc reproducing device 10 rotates the compact disc 1 at a constant rotation speed to reproduce data.

The compact disc 1 is rotated by the spindle motor 3 at a constant rotation speed instead of a constant linear speed. The optical pickup 2 takes out the data recorded on the compact disc 1 as an analog reproduction signal. The analog waveform shaping circuit 5 waveform-shapes the analog signal input from the optical pickup 2 to binarize it, and outputs the binarized data to the digital signal processing circuit 7.
The digital signal processing circuit 7 is an analog waveform shaping circuit 5
A clock is reproduced from the obtained binarized data, the digital audio data 20 and the digital data 23 are demodulated from the reproduced clock and output, and further the disk address information 24 is output to the access control device 8. The digital voice data 20 and the digital data 23 are
The data is output in synchronization with the reproduction clock reproduced from the compact disc 1.

Since the compact disc 1 recorded by the CLV system is reproduced at a constant rotation speed, the transfer rates of the digital audio data 20 and the digital data 23 are different between the inner and outer circumferences of the compact disc 1. In this way, the digital audio data 20 having a normal transfer speed, that is, a speed higher or lower than that in the case of reproduction by the CLV method is sent to the buffer RAM 11. The buffer RAM 11 temporarily stores the digital voice data 20 and outputs the digital voice data 21 having a constant transfer rate to the D / A conversion circuit 12.

The RAM controller 13 is a buffer RAM 1
In addition to controlling the input / output timing and address of 1, the full / empty signal 26 of the buffer RAM 11 (a signal indicating the amount of data in the buffer RAM) is sent to the access control device 8. The D / A conversion circuit 12 includes the buffer RAM 1
The digital voice data 21 output from 1 is converted into an analog voice 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 when reproduced by the CLV method.

The servo circuit 6 controls the rotation speed of the spindle motor 3 to a constant speed. Also, the slide motor 4 and the optical pickup 2 are controlled based on the 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 disc address information 24 given from the digital signal processing circuit 7 to perform track positioning. And the buffer RAM
11 full / empty signals 26 (signals indicating the amount of data in the RAM) are constantly monitored to control access. 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, the compact disc 1 is paused when the buffer RAM 11 is full, and the data reading is restarted before it becomes empty. The buffer RAM 11 keeps outputting the 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 sub-coding detection circuit 45, and a RAM 46.
It is composed of The synchronization detection circuit 41 detects frame synchronization from the input binarized data and outputs it to the demodulation circuit 43. The PLL circuit 42 reproduces a clock from the input binarized 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 de-interleave the CIRC and detect and correct the error by the CIRC. Then, the demodulated digital voice data 20 or digital data 23 is output. The digital voice data 20 and the digital data 23 are sent to the PLL circuit 4
It is output in synchronization with the reproduction clock reproduced in 2. The sub-coding detection circuit 45 reproduces the disc address information 24 for track positioning and outputs it to the access control device 8.

In the first embodiment of the present invention thus constructed, the compact disc 1 recorded by the CLV system is used.
Can be rotated at a constant rotation speed to reproduce the data, so that it is not necessary to control the rotation speed at the time of access, resulting in high-speed access. Further, the buffer RAM 11 absorbs the difference in the data amount when the recording medium recorded by the CLV method is rotated at a constant rotation speed, so that the data can be output at a constant transfer speed and the sound can be reproduced. Becomes Further, there is also an effect that the transfer rate of the 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 data reproducing apparatus according to the second embodiment of the present invention, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals.

The present embodiment is different from the above-mentioned first embodiment in that a buffer RAM 15 for temporarily storing the digital data 23 output from the digital signal processing circuit 7,
RAM control device 1 for controlling input / output timings and addresses of the buffer RAM 15 and the buffer RAM 11
4 is provided, and the rest of the configuration is basically the same. The buffer RAM 15 temporarily stores the digital data 23 and outputs the digital data 27 having a constant transfer rate to the outside.

In the second embodiment of the present invention thus constructed, in addition to the effects of the first embodiment, digital data is output to the outside at a constant transfer rate regardless of the reproduction track of the compact disc 1. Therefore, it is particularly effective when reproducing video data or the like, or when a computer or the like that controls the data reproducing device requires a constant transfer rate.

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

In FIG. 4, 16 is a disk reproducing device,
Reference numeral 17 is a servo circuit. The disc reproducing device 16 divides the compact disc 1 into several zones on the inner and outer sides and rotates the zones at an appropriate rotation speed to reproduce data. This point is the first embodiment. It is different from the example disk reproducing apparatus 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 disc 1 based on the disc address information 24. FIG. 5 illustrates 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 third embodiment of the present invention thus constructed, in addition to the effect of the first embodiment, data is reproduced by setting the rotation speed of the compact disc 1 to an appropriate rotation speed for each zone. There is an effect that can be. That is, since it is possible to set an appropriate rotation speed at both the inner peripheral portion and the outer peripheral portion of the compact disc 1, it is possible to increase the data transfer rate at the time of reproducing the inner peripheral portion of the compact disc 1. Also, compact disc 1
It is possible to suppress an increase in the operating frequency of each circuit at the time of reproducing the outer peripheral portion, which occurs when the is rotated at a constant rotation speed,
The load on the waveform shaping circuit, the signal processing circuit, etc. can be reduced. In the case of a CD-ROM or the like, access in the vicinity is usually used frequently, and therefore access rarely spans the zone, and the access time that increases is small compared to the case of the first embodiment.

FIG. 6 is a block diagram showing a data reproducing apparatus according to the fourth embodiment of the present invention, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals.

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

When the compact disc 1 recorded by the CLV system 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 goes to the outer periphery of the compact disc 1 is obtained. is there. However, if you just play at a constant rotation speed,
For example, when reproducing the compact disc 1 recorded only on the inner peripheral portion, the increase of the data transfer rate cannot be expected. Therefore, the compact disc 1, which is recorded only on the inner peripheral portion, reproduces data by increasing the rotation speed by the address of the outermost peripheral portion. The rotation speed at that time is set so that the linear velocity at the outermost track is, for example, twice as fast as that of a normal compact disc reproducing apparatus. Such setting may be triple speed or 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 rotation speed thereof. The optimum rotation for each compact disc 1 depends on how much the compact disc 1 is recorded on the outer peripheral portion. It shows that it rotates at speed. That is, FIG. 7A shows a compact disc 1 recorded only on the inner peripheral portion, and its rotation speed is set so that, for example, the linear velocity at the outermost peripheral track is double the speed of a normal compact disc reproducing apparatus. Set. FIG. 7B shows the compact disc 1 recorded up to the outside of FIG. 7A, and the rotation speed thereof is likewise the linear velocity at the outermost track is double the speed of a normal compact disc reproducing apparatus. To be set. FIG. 7 (c) shows a compact disc 1 recorded up to the outer peripheral portion, and similarly, for example, the linear velocity at the outermost peripheral track is set to be double the speed of a normal compact disc reproducing device.

In the fourth embodiment of the present invention thus constructed, in addition to the effect of the first embodiment, the rotation speed of the compact disc 1 is changed to an appropriate speed for each compact disc 1 and the data is stored. As a result, it is possible to reproduce, and as a result, it is possible to achieve high-speed access and high-speed data transfer even with the compact disc 1 that is recorded only on the inner peripheral portion.

It is also possible to combine the third embodiment and the fourth embodiment described above. That is, depending on how much data is recorded on the outer peripheral portion of the compact disc 1, first, the optimum rotation speed for reproducing the outer peripheral portion of the compact disc 1 is determined, and then the compact disc 1 is divided into several zones on the inner and outer sides. It may be divided, and an appropriate rotation speed may be determined for each zone.

[0032]

As described above, according to the present invention,
By rotating the recording medium recorded in the constant linear velocity (CLV) system at a constant rotation speed and reproducing the data from the recording medium, the rotation speed control at the time of access becomes unnecessary,
High-speed access is possible. Further, by sequentially writing the reproduced data to the buffer RAM circuit and reading the written data at a constant transfer speed, the data can be output at a constant transfer speed while keeping the rotation speed of the recording medium constant. It becomes possible to reproduce the data such as

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a digital signal processing circuit of FIG.

FIG. 3 is a block diagram showing a data reproducing device according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a data reproducing device according to a third 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 device according to a fourth embodiment of the present invention.

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

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

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

[Explanation of Codes] 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 reproducing device 11 , 15 Buffer RAM 12 D / A conversion circuit 13, 14 RAM controller

Claims (5)

[Claims] 1. A data reproducing apparatus for reproducing and outputting data recorded on a disk-shaped recording medium, wherein the recording medium recorded by a constant linear velocity method is rotated at a constant rotation speed to obtain the recording medium. A data reproducing device comprising a disk reproducing device for reproducing a synchronizing signal and a clock from the read digital signal and reproducing and outputting the data using the synchronizing signal and the clock. 2. A data reproducing apparatus for reproducing and outputting data recorded on a disk-shaped recording medium, wherein the recording medium recorded by a constant linear velocity method is rotated at a constant rotation speed to obtain the recording medium. And a buffer R for temporarily storing the data output from the disc reproducing device.
An AM circuit; and a buffer RAM control device for sequentially writing the data output from the disk reproducing device to the buffer RAM circuit and reading the data written in the buffer RAM circuit at a constant transfer rate. Characteristic data reproducing device. 3. A data reproducing apparatus for reproducing and outputting data recorded on a disk-shaped recording medium, comprising a rotation speed control device for dividing the disk into a plurality of zones and changing a rotation speed for each zone. And a disc reproducing device for reproducing the data from the recording medium by rotating the recording medium recorded by the constant linear velocity method at a constant rotation speed for each zone, and outputting from the disc reproducing device. Buffer R for temporarily storing the stored data
An AM circuit; and a buffer RAM control device for sequentially writing the data output from the disk reproducing device to the buffer RAM circuit and reading the data written in the buffer RAM circuit at a constant transfer rate. Characteristic data reproducing device. 4. A data reproducing apparatus for reproducing and outputting data recorded on a disk-shaped recording medium, wherein the rotation speed is determined in accordance with the rotation speed suitable for reproduction of the outermost recording section of the recording medium. A disc reproducing apparatus having a rotational speed control device, for rotating the recording medium recorded by a constant linear velocity method at a constant rotational speed to reproduce and output the data from the recording medium, and the disc reproducing apparatus. And a buffer RAM circuit for temporarily storing the data output from the disk reproducing device, the data output from the disk reproducing device are sequentially written in the buffer RAM circuit, and the data written in the buffer RAM circuit is transferred to a certain level. And a buffer RAM controller for reading at a speed. 5. A data reproducing apparatus for reproducing and outputting data recorded on a disk-shaped recording medium, wherein the rotational speed is determined according to the rotational speed suitable for reproducing the outermost recording section of the recording medium. Further, the recording medium is divided into a plurality of zones, a rotation speed control device for changing the rotation speed for each zone is provided, and the recording medium recorded in a constant linear velocity system is rotated at a constant rotation speed, A disk reproducing device for reproducing and outputting the data from the recording medium, a buffer RAM circuit for temporarily storing the data output from the disk reproducing device, and the data output from the disk reproducing device. Buffer RA
A data reproducing apparatus comprising: a buffer RAM control device which sequentially writes data in the M circuit and reads the data written in the buffer RAM circuit at a constant transfer rate.