JPH05217287A - Disk reproducing device - Google Patents

Abstract

PURPOSE:To reduce an installation area of plural RAMs and to reduce the cost and the size of the device. CONSTITUTION:Storage areas of a RAM 6 are divided into plural storage areas and a RAM controlling circuit 8 controls the writings and the readings of voice data, TOC data, error flags and subdata into these plural storage areas. Thus, there is no need to provide respective dedicated plural RAMs and plural kinds of data writing and reading are performed to a single RAM.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus for reproducing, for example, audio data recorded on an optical disc.

[0002]

2. Description of the Related Art In recent years, optical disks have come to be widely used as recording media because high-speed access and semi-permanent storage of data are possible, and audio data recorded on this optical disk is reproduced. There is known a disc reproducing device called a so-called CD player.

The entire recording area of the optical disc is divided into a data recording area and a lead-in area, the audio data is recorded in the data recording area, and recording of the audio data recorded in the data recording area is started. Address, recording end address, absolute time, etc.
Contents) Data is recorded in the lead-in area.

Before reproducing the audio data recorded in the data recording area, the disk reproducing apparatus reproduces the TOC data indicating the recorded contents of the audio data from the lead-in area in advance, and temporarily reproduces it in the TOC memory. Remember.
Then, when the reproduction of the audio data is designated, the TOC data of the designated audio data is read from the TOC memory, access is performed based on the read TOC data, and the designated audio data is reproduced.

The audio data recorded in the data recording area is subjected to an encoding process for error correction, and the error correction process is performed at the time of such reproduction. When it is determined that an error has occurred in the audio data as a result of performing the above, the error flag is set. This error flag is stored in an error flag memory provided separately from the voice data memory and the TOC memory. Then, the audio data in which the error has occurred is corrected to correct audio data according to the error flag stored in the error flag memory and is output.

Here, if a disturbance such as a vibration is applied during the reproduction of the audio data, an unexpected track jump or the like occurs and a sound skip occurs. To prevent the above skipping,
By providing a mechanism that absorbs vibrations and prevents the vibrations from being transmitted to the reproduction system, the sound skipping can be prevented. However, the provision of such a mechanism undesirably increases the size of the device itself. ..

Therefore, a large-capacity RAM for storing the audio data reproduced from the optical disk is provided, and the reproduced audio data is once stored in the RAM and read out, thereby increasing the size of the device itself. Without
Even if an unexpected track jump or the like occurs due to the disturbance such as the vibration, the audio data stored in the RAM can be read and output while the correction is performed, so that no sound skip occurs. The audio data can be continuously output.

[0008]

However, the conventional disk reproducing apparatus has a plurality of memories such as a dedicated TOC memory for storing the TOC data and a dedicated error flag memory for storing the error flag. Was needed. Therefore, the installation area for installing the plurality of memories becomes large, and it is not possible to cope with the downsizing of the device, and the cost is increased.

If a large-capacity RAM for storing the audio data is provided in order to prevent the skipping of sound, the problems of the installation area and the like become more remarkable.

The present invention has been made in view of the above-mentioned problems, and in addition to recording data, data relating to the recording data such as TOC data is stored in one memory and data processing is performed. It is an object of the present invention to provide a disc reproducing apparatus that can reduce the installation area and cost and can respond to downsizing of equipment.

[0011]

DISCLOSURE OF THE INVENTION A disc reproducing apparatus according to the present invention reproduces record data recorded on an optical disc, writes it once in a storage unit, and reads out and outputs the record data once written in this storage unit. In such a disc reproducing apparatus, the storage means is divided into a recording data area which is an area for writing and reading the recording data and an auxiliary data area for writing and reading auxiliary data corresponding to the recording data. The above problem is solved by having storage control means for controlling writing and reading of recording data to and from the recording data area and writing and reading of auxiliary data to and from the auxiliary data area.

[0012]

In the disc reproducing apparatus according to the present invention, the storage control means writes and reads the recording data area, which is an area for writing and reading the recording data, and the auxiliary data corresponding to the recording data. Storage means for the recording data and the auxiliary data respectively by controlling the writing and reading of the recording data to and from the recording data area and the writing and reading of the auxiliary data to and from the auxiliary data area. It is possible to process a plurality of data with one storage means without providing the above.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a disc reproducing apparatus according to the present invention will be described below with reference to the drawings. The disc reproducing apparatus according to the present embodiment can be configured as a disc recording / reproducing apparatus by being configured with a recording system for recording audio data as shown in FIG. 1, for example.

In the disc recording / reproducing apparatus, in the recording mode for recording the voice data, which is the record data, on the optical disc, the voice data is once written in the storage means, and the voice data once written in the storage means is read out every predetermined amount. The recording data recorded on the optical disc is reproduced at a predetermined amount in the reproduction mode in which the audio data recorded on the optical disc is reproduced, and the audio data recorded on the optical disc is reproduced in the storage unit. So-called intermittent recording / reproduction is performed such that audio data once written is continuously read and output.

As a specific configuration, as shown in FIG. 1, the optical disc 1 on which the audio data and so-called TOC (Table of Contents) data showing the recorded contents of the audio data are recorded and reproduced, and the optical disc 1 are described. For example, a spindle motor 2 that is rotationally driven at a constant linear velocity, and an A / D converter 4 that digitizes an audio signal supplied through the input terminal 3 in the recording mode to form audio data.
In the recording mode, the audio data supplied from the A / D converter 4 has ATRAC data compression processing.
An ATRAC encoder / decoder 5 which performs an encoding process and performs an ATRAC decoding process, which is a data decompression process, on the reproduced audio data in the reproduction mode.
And a RAM 6 which is the storage means.

In the disk recording / reproducing apparatus, the storage area of the RAM 6 is an audio data area for writing and reading the audio data and an area for writing and reading auxiliary data corresponding to the audio data. A TOC data recording area for recording certain TOC data, an error flag recording area, which will be described later, which is error information of the audio data obtained in a reproduction mode, and sub-data recording such as character data and image data corresponding to the audio data. The RAM 6 is divided into areas.
From the audio data area, TOC data recording area, sub-data recording area audio data, TOC data, sub-data writing and reading, and the audio data write address value and read address value to the audio data area. It has a RAM control circuit 8 which is a storage control means for calculating the remaining amount of the empty area in the voice data area and controlling the writing and reading of the error flag in the error flag recording area based on the calculation result. ing.

Further, in the recording mode, the disc reproducing apparatus performs encoding processing (parity addition and interleaving processing) for error correction, EFM (8-14 modulation) processing, etc. on the audio data to reproduce the audio data. In the mode, the encoder / decoder 9 that performs decoding processing for error correction and EFM demodulation processing on the audio data.
In the recording mode, a magnetic head drive circuit 11 that drives the magnetic head 10 in accordance with audio data from the encoder / decoder 9, and an optical system that irradiates a laser beam to a portion to which a magnetic field is applied by the magnetic head 10. The head 12 and R for performing the extraction of the focus error signal and the tracking error signal from the output of the optical head 12
An F circuit 13, a servo control circuit 16 for controlling the rotation of the spindle motor 2 and an access control for the magnetic head 10 and the optical head 12, and the ATR in the reproduction mode.
The audio data from the AC encoder / decoder 5 is converted into an analog signal to form an audio signal, and the D / A converter 14 outputs the audio signal via an output terminal 15.

The optical disc 1 has, for example, as shown in FIG. 2, a reproduction-only area A ₁₀ and a recording / reproduction area A ₂₀ provided outside the reproduction-only area A ₁₀ . The reproduction-only area A ₁₀ is an area in which desired data is recorded by the manufacturer, and includes a data recording area A ₁₁ in which data such as performance information is recorded, and a lead-in area A ₁₂ provided on the inner peripheral side thereof. have. In the reproduction-only area A ₁₀ , digital data is recorded as the presence or absence of pits corresponding to “1” and “0”. In addition, the lead-in area A
_{In the 12} , recording start address information and recording end address information are recorded in order for all performance information as TOC data indicating the recording position and recording content of the data recording area A ₁₁ .

The recording / reproducing area A ₂₀ of the optical disc 1 is
A magneto-optical recording area for the user to arbitrarily rewrite data, a data recording area A ₂₁ in which data such as performance information is recorded, and a lead-in area A ₂₂ provided on the inner peripheral side thereof. have.

The disk recording / reproducing apparatus according to this embodiment is
As shown in FIG. 3, the recording of each data in the reproduction-only area A ₁₀ and the recording / reproduction area A ₂₀ is performed in one cluster consisting of 32 sectors of main data, 3 sectors of linking, and 1 sector of sub-data, totaling 36 sectors. It is supposed to be done every time. Specifically, in the lead-in area A ₂₂ , the TOC data indicating the recording position and the recording contents of the recording data recorded in the data recording area A ₂₁ is recorded, and the sector number 00 As shown in FIG. 4, for example, one sector consists of a sync signal of 12 bytes, header information of 8 bytes, and a data area of 2332 bytes, which is 2357 bytes in total. In the data area, 8 bytes are used for each recording data, and the recording data number (song number), upper byte of start cluster, lower byte of start cluster, start sector, sector number 00, etc. are recorded. It

The RAM control circuit 8 includes an audio data write address generator 20 for forming an audio data write address for writing audio data in the audio data recording area of the RAM 6 as shown in FIG. 5, and the audio data. The audio data read address generator 21 forming an audio data read address for reading the audio data written in the recording area, and the RAM 6 from the audio data write address and the audio data read address.
A memory remaining amount calculator 22 for calculating the remaining amount of free space in the audio data area, and selecting and outputting the audio data write address when writing the audio data, and reading the audio data read when reading the audio data. A selector 23 for selecting and outputting an address, and the selector 2
When the audio data write address 3 is selected, the error flag address generator 24 that outputs the address of the error flag, the sub data address generator 25 that generates the address of the sub data, and the system controller 7 It has a system controller read / write address generator 26 for generating read and write addresses.

In the recording mode, the RAM control circuit 8 writes / reads the audio data supplied via the FIFO (First In First Out) 28 into the RAM 6 and outputs the audio data via the FIFO 28b, and the reproduction. In the mode, the audio data supplied through the FIFO 28b is written in and read out from the RAM 6 and the F
The buffer 30 outputs the data via the IFO 28a.
The error flag corresponding to the audio data output from the buffer b is written in and read from the RAM 6 and the buffer 30a
And a RAM interface 19 for outputting via.

Next, the operation of the disc recording / reproducing apparatus according to the present embodiment in the recording mode for recording desired audio data in the recording / reproducing area A ₂₀ of the optical disc 1 will be described. This recording mode is designated by turning on a recording key (not shown). When the recording key is turned on, the optical disc 1 is rotated by the spindle motor 2 so that the linear velocity is constant, and a desired audio signal which is an analog signal is input to the input terminal 3.
Is supplied to the A / D converter 4 via. The spindle motor 2 is controlled by the servo control circuit 16 so as to always rotate constantly.

The A / D converter 4 quantizes the audio signal and 2CH × 16 bit × 44.1 kHz≈1.4.
Audio data having a data rate of Mbit / sec is formed and supplied to the ATRAC encoder / decoder 5.

The above ATRAC encoder / decoder 5
Operates as an encoder in this recording mode, and the audio signal is quantized by the A / D converter 4.
For voice data at a data rate of 4 Mbit / sec, a maximum of about 20 msec of data is taken as one block,
The waveform on the time axis is analyzed by so-called orthogonal transformation into about 1,000 components on the frequency axis, and the frequency components that are important for hearing are extracted in order to form audio data at a data rate of 300 kbit / sec. That is, the above 1.4 Mbi
1/5 of audio data with a data rate of t / sec is 30
A process of compressing audio data (hereinafter referred to as compressed data) having a data rate of 0 kbit / sec is performed, and the data transfer rate is converted from 75 sectors / sec in the standard CD-DA format to 15 sectors / sec. Output.

Here, the recording area of the RAM 6 is the R area.
By the AM control circuit 8, for example, as shown in FIG. 6, an audio data recording area 40 which is an area for recording the audio data.
An error flag recording area 41 for recording the error flag, a TOC data recording area 42 for recording the TOC data, and a sub data recording area 43 for recording the sub data. It is divided. Since the error flag recording area 41 is an area for writing or reading an error flag formed in a reproduction mode described later, it is not used in this recording mode.

As a concrete division ratio, for example, when the size of the entire recording area of the RAM 6 is "N",
The size of the voice data recording area 40 is “N-NU”,
The size of the error flag recording area 41 is “NU-1 /
8 (N-NU) ≧ NL ”, and the size of the TOC data recording area is divided into“ NL-NP ”.

The RAM 6 is used as a buffer memory for temporarily storing the compressed data supplied from the ATRAC encoder / decoder 5, and the RAM 6 is used for writing and reading the data. It is controlled by the circuit 8.

The compressed data supplied from the ATRAC encoder / decoder 5 has its data transfer rate reduced to ⅕ of the standard data transfer rate of 75 sectors / second, that is, 15 sectors / second, This compressed data is continuously written in the RAM 6. It is sufficient for this compressed data to record one sector for every five sectors, but such recording for every five sectors is practically impossible. Therefore, continuous sector recording as described later is performed. This recording is
The cluster is used as a recording unit and burst-wise at a data transfer rate of 75 sectors / second. That is, in the RAM 6, 15 (= 75) depending on the bit compression rate.
/ 5) Compressed data continuously written at a low transfer rate of sector / second is read out in burst at the transfer rate of 75 sector / second. The overall data transfer rate of the read and recorded data including the recording stop period is as low as 15 sectors / second described above.
The instantaneous data transfer rate within the time of the recording operation performed in a burst is the above-mentioned 75 sectors / second.

As shown in FIG. 7, the RAM control circuit 8 continuously increments the write pointer W of the RAM 6 at a transfer rate of 15 sectors / second to store the compressed data in the RAM 6 at 15 sectors / second. When the data amount of the compressed data stored in the RAM 6 exceeds a predetermined amount K, the read pointer R of the RAM 6 is incremented in bursts at a transfer rate of 75 sectors / second. Then, memory control is performed so that the compressed data is read from the RAM 6 in a burst at a transfer rate of 75 sectors / second by a predetermined amount K.

By the memory control by the RAM control circuit 8, the RAM is transferred from the ATRAC encoder / decoder 5 at a transfer rate of, for example, 15 sectors / second.
6 and the data amount of the compressed data stored in the RAM 6 becomes a predetermined amount K or more, the RA
Since the compressed data is read as a recording data from M6 in bursts at a transfer rate of 75 sectors / second by a predetermined amount K, the input data is stored in the RAM 6 while always ensuring a data writing region of a predetermined amount or more. RA
It is possible to write continuously to M6.

The system controller 7 uses the RA
The recording position on the recording track of the optical disc 1 is controlled so that the recording data read out in burst from M6 is recorded in a continuous state on the recording track of the optical disc 1. In this case, as described above, since the RAM 6 is always secured with a data writing area of a predetermined amount or more, the system controller 7 detects that a track jump or the like has occurred due to disturbance or the like, and records on the optical disc 1. Even if the operation is interrupted, the above RAM
Input data can be continuously written in a data write area of a predetermined amount or more by the memory control of the control circuit 8, and a recovery processing operation can be performed during that time, and the input data can be continuously recorded on the recording track of the optical disc 1. You can

The writing and reading of compressed data to and from the RAM 6 will be described in detail below.
The compressed data from the TRAC encoder / decoder 5 is
Via the terminal 27a of the RAM control circuit 8 shown in FIG.
It is supplied to the FO 28a. When the RAM 6 is a 4-bit RAM, the FIFO 28a stores the compressed data in 4 bits.
Bytes are accumulated and output (RAM6 is 8 bits R
In the case of AM, the compressed data of 4 bytes is accumulated and output. ). The compressed data output every 4 bytes is transferred to the RAM via the RAM interface 19.
6 is supplied. As described above, the audio data write address generator 20 outputs the audio data write address designating the write address of the compressed data, and the audio data write address is sent to the RAM via the selector 23. It is supplied to the RAM 6 through the interface 19.

As a result, the compressed data output from the FIFO 28a every 4 bytes is written on the audio data recording area 40 by the audio data write address.

The compressed data contains sub-data corresponding to the compressed data. The sub-data address is obtained by the system controller 7 detecting the address of the audio data recording area 40 in which the compressed data is written and supplying the detected data to the sub-data address generator 25. It is written in the sub data recording area 43 by the sub data write address output from the generator 25.

The TOC data indicating the recording contents of the audio data recorded in the audio data recording area 40 is formed by the system controller 7 in accordance with the audio data recorded on the optical disk 1, and the system controller read / write address is generated. It is written in the TOC data recording area 42 by the system controller write address from the device 26.

The compressed data written in the audio data recording area 40 is read by the audio data read address output from the audio data read address generator 21 and supplied through the selector 23 and the RAM interface 19. The compressed data read from the audio data recording area 40 is stored in the FIFO 28b for 4 bytes and output. The compressed data output from the FIFO 28b every 4 bytes is supplied to the encoder / decoder 9 via the terminal 27b.

The sub data written in the sub data recording area 43 is read by the sub data read address supplied from the sub data address generator 25 through the RAM interface 19.
The sub data read from the sub data recording area 43 is supplied to the encoder / decoder 9 via the FIFO 28b and the terminal 27b.

The TOC data written in the TOC data recording area 42 is supplied from the system controller read / write address generator 26 via the RAM interface 19 after the recording of the compressed data on the optical disc 1 is completed. It is read by the system controller read address. The TOC data read from the TOC data recording area 42 is the FI
It is supplied to the encoder / decoder 9 through the FO 28b and the terminal 27b.

As described above, the entire recording area of the RAM 6 is the audio data recording area 40 and the error flag recording area 4
Audio data from the audio data write address generator 20 is divided into a plurality of recording areas such as the TOC data recording area 42 and the sub data recording area 43, and the compressed data is written in the audio data recording area 40. The sub-data recording area 43 is controlled by the write address and the read is controlled by the audio data read address from the audio data read address generator 21.
The writing and reading of sub data to and from the sub data address generator 24 are controlled by the sub data write address and the sub data read address from the sub data address generator 24.
By controlling the writing and reading of TOC data to and from the C data recording area 42 by the system controller write address and the system controller read address from the system controller read / write address generator 26, a plurality of types of data are respectively stored in one RAM. It may be possible to write or read.

Therefore, it is not necessary to provide a RAM for writing and reading the above data, and the R
Since only one AM needs to be provided, the cost can be reduced, the installation area of the RAM can be reduced, and the size of the device can be reduced.

The encoder / decoder 9 has the RA
Encoding processing (parity addition and interleaving processing) for error correction, EFM encoding processing, and the like are performed on the compressed data supplied in burst from M6 as described above. The compressed data encoded by the encoder / decoder 9 is supplied to the magnetic head drive circuit 11.

The magnetic head drive circuit 11 drives the magnetic head 10 so that magnetic field modulation according to the compressed data is applied to the optical disc 1.

Here, the optical head 12 has a laser light source 31 such as a laser diode as shown in FIG.
Optical components such as a collimator lens 32, a beam splitter 33, an objective lens 34, and a polarization beam splitter 35, and first and second photodetectors 36 and 37 for detecting the light separated by the polarization beam splitter 35.
It is composed of a first signal synthesizer 38 for adding and synthesizing the detection outputs of the photodetectors 36 and 37, a first signal synthesizer 39 for subtracting and synthesizing the detection outputs, and the like, with the optical disc 1 interposed therebetween. It is provided at a position facing the magnetic head 16.

In the recording mode, the optical head 12 drives the magnetic head 10 by the magnetic head drive circuit 11 to apply a modulation magnetic field according to the recording data to the target track of the optical disc 1 with a laser beam. Irradiate. As a result, desired audio data is thermomagnetically recorded in the data recording area A ₂₁ of the optical disc 1.

The optical head 12 detects the reflected light of the laser light applied to the target track in the recording mode and in the reproducing mode described later,
For example, a so-called astigmatism method is used to detect a focus error, and a so-called push-pull method is used to detect a tracking error. The changeover switch 40 provided on the optical head 12 is
The system controller 7 controls the switching, and in the recording mode, the selection terminal 40a is controlled to select the selected terminal 40c. This allows
In this recording mode, the photo detectors 36, 3 are
First signal combiner 3 that adds and combines the detection outputs from 7
The combined signal from 8 is supplied to the RF circuit 13 shown in FIG.

The RF circuit 13 includes the optical head 12
The focus error signal and the tracking error signal are extracted from the output of the above and supplied to the servo control circuit 16, and the reproduced signal is binarized to obtain the encoder / decoder 9 described above.
Supply to.

The servo control circuit 16 is composed of, for example, a focus servo control circuit, a tracking servo control circuit, a spindle motor servo control circuit, a sled servo control circuit, and the like. The focus servo control circuit controls the focus of the optical system of the optical head 12 so that the focus error signal becomes zero. Further, the tracking servo control circuit controls the tracking of the optical system of the optical head 12 so that the tracking error signal becomes zero. Further, the spindle motor servo control circuit controls the spindle motor 2 so that the optical disc 1 is rotationally driven at the constant angular velocity or the constant linear velocity. Further, the sled servo control circuit moves the optical head 12 and the magnetic head 10 to a target track position of the optical disc 1 designated by the system controller 7.

The servo control circuit 16 performing such various control operations supplies the system controller 7 with information indicating the operating state of each part controlled by the servo control circuit 16.

The system controller 7 controls the respective control circuits according to the information indicating the operating states of the respective parts, whereby the optical head 12 and the magnetic head 10 are controlled.
Manages the recording position on the recording track that is being traced, and also manages the reproducing position on the recording track in the reproduction mode described later.

The system controller 7 records the TOC data table of the RAM 6 in the TOC data table including the TOC data indicating the recording position of the data recording area A ₂₁ of the recording / reproducing area A ₂₀ during the recording of the audio data. A control is performed in which the data is automatically formed in the area 42 and is read out at the end of recording the audio data and recorded in the lead-in area A ₂₂ .

Next, the reproduction-only area A of the optical disc 1
The operation of the disc recording / reproducing apparatus in the reproducing mode for reproducing the audio data continuously recorded on the recording tracks of ₁₀ and the recording / reproducing area A ₂₀ will be described. When the optical disc 1 is set in the disc recording / reproducing apparatus, the system controller 7 previously rotationally drives the optical disc 1 at a constant linear velocity to reproduce the data area A ₁₁ of the reproduction-only area A ₁₀ of the optical disk 1. In order to manage the position, the TOC data is controlled to be reproduced from the lead-in area A ₁₂ of the reproduction-only area A ₁₀ . The TOC data reproduced from the lead-in area A ₁₂ of the reproduction-only area A ₁₀ is written in the TOC data recording area 42 of the RAM 6 by the RAM control circuit 8.

Further, the system controller 7 manages the reproducing position of the recording / reproducing area A ₂₀ with respect to the data area A ₂₁ , and the lead-in area A of the recording / reproducing area A _20.
Control to reproduce TOC data from ₂₂ . The T reproduced from the lead-in area A ₂₂ of the recording / reproducing area A ₂₀
The OC data is also stored in the RAM 6 by the RAM control circuit 8.
Of the TOC data recording area 42.

Then, the process waits for the designation of the playback mode by turning on the playback key (not shown).

Next, when the reproduction key is turned on to specify the reproduction mode, the system controller 7
The spindle motor 17 is rotationally driven at a constant linear velocity to rotationally drive the optical disc 1, and the TOC data corresponding to the designated audio data written in the TOC data recording area 42 is read out.
The optical head 12 is controlled to move to the position where the designated audio data is recorded according to the C data.

The optical head 12 is the optical disc 1 described above.
When the data is reproduced from the reproduction-only area A _{10, the} reproduction signal can be obtained by detecting the change in the amount of the reflected light of the laser light from the target track, and the respective detection outputs by the photodetectors 36 and 37 can be obtained as described above. The reproduction signal added and synthesized by the signal synthesizer 38 of No. 1 is supplied to the RF circuit 19 through the changeover switch 40. Also,
When data is reproduced from the recording / reproducing area A ₂₀ of the optical disc 1, a reproduction signal can be obtained by detecting a difference in polarization angle (Kerr rotation angle) of the reflected light of the laser light from the target track. 36,3
A reproduction signal obtained by subtracting and synthesizing each detection output of 7 by the second signal synthesizer 39 is output through the changeover switch 40.

The reproduction signal output through the changeover switch 40 is binarized by the RF circuit 13 and supplied to the encoder / decoder 9.

The encoder / decoder 9 operates as a decoder in the reproduction mode, and the RF circuit 13 is operated.
The above-described decoding processing for error correction, EFM decoding processing, etc., is performed on the reproduced output binarized by the above, and the above-mentioned compressed data is reproduced at a transfer rate of 75 sectors / second. Output as playback data. This reproduction data is once written and read in the RAM 6 by the RAM control circuit 8.

The RAM 6 is controlled by the RAM control circuit 8 to write and read data, and the reproduction data supplied from the encoder / decoder 9 at a transfer rate of 75 sectors / second is transferred at a transfer rate of 75 sectors / second. It is written in burst. Also, this RAM 6 is
The reproduction data written in burst at the transfer rate of 75 sectors / second is continuously read out at the transfer rate of 15 sectors / second.

The RAM control circuit 8 controls the memory so that the reproduction data is written in the RAM 22 at a transfer rate of 75 sectors / second, and the written reproduction data is continuously read out at a transfer rate of 15 sectors / second. And the reproduction data written in burst from the RAM 6 by the memory control is performed.
The playback position is controlled so as to continuously play back from the recording track. The reproduction position is controlled by managing the reproduction position of the reproduction data that is burst-read from the RAM 6 by the system controller 7 and using a servo control signal to specify the reproduction position on the recording track of the optical disc 1. This is done by supplying to the circuit 16.

That is, the RAM control circuit 8 shown in FIG.
As shown in 0, the write pointer W of the RAM 6 is set to 7
The reproduction data is written to the RAM 6 at a transfer rate of 75 sectors / second while being incremented at a transfer rate of 5 sectors / second, and the read pointer R of the RAM 6 is continuously incremented at a transfer rate of 15 sectors / second. And the reproduced data from the RAM 6 to the 15 sectors /
Continuously read at a transfer rate of 2 seconds, stop writing when the write pointer W catches up with the read pointer R, and write when the data amount of the reproduction data stored in the RAM 6 becomes a predetermined amount L or less. As is done, the write pointer W of the RAM 6 is burst-wise incremented at a transfer rate of 75 sectors / second for memory control.

By the memory control by the RAM control circuit 8 as described above, the compressed data reproduced from the recording track of the optical disk 1 is burst-written to the RAM 6 at a transfer rate of 75 sectors / sec, and the RAM 6 compresses the data. Since the data is continuously read out as reproduction data at a transfer rate of 75 sectors / second, the RAM
It is possible to continuously read the reproduction data from the RAM 6 while always securing a data reading area of a predetermined amount L or more in the RAM 6. Also, the reproduction data read out in bursts from the optical disc 1 can be reproduced continuously from the recording track of the optical disc 1 by controlling the reproduction position on the recording track of the optical disc 1 by the system controller 7. Can be done. Moreover, as described above, since the RAM 6 always has a data reading area of a predetermined amount L or more, the system controller 5 detects that a track jump or the like has occurred due to disturbance or the like, and reproduces the optical disk 1. Even when the operation is interrupted, it is possible to read the reproduction data from the data reading area of the predetermined amount K or more and continue the output of the analog signal, and to perform the restoration processing operation during that time.

If it is determined that an error has occurred in the reproduction data by performing error correction processing on the reproduction data reproduced from the optical disc 1 by the encoder / decoder 9, an error indicating this is indicated. A flag is set, and it is output together with the reproduction data.

The above-mentioned reproduced data is stored in the terminal 3 shown in FIG.
4 to the FIFO 28b. FIFO above
When the RAM 6 is, for example, a 4-bit RAM, 28b accumulates the reproduced data for 4 bytes and outputs it every 4 bytes (the RAM 6 is, for example, an 8-bit RAM).
Is output every 8 bytes. ). The reproduction data output every 4 bytes is the RAM specified by the audio data write address output from the audio data write address generator 20 through the selector 23.
6 is written in the voice data recording area 40.

The memory remaining capacity calculator 22 calculates the remaining capacity of the empty area of the audio data recording area 40 from the audio data write address and the audio data read address. That is, when the pointer of the audio data read address is R _P , the pointer of the audio data write address is W _P, and R _P > W _P , the remaining amount M _{R of the} empty area is shown in FIG. Thus, M _R = R _P −W _P −1.

[0066] Also, in the case of R _P ≦ W _P, the remaining M _R of the free space, as shown in FIG. _{8 (b), M R =} (R P -NU) + (N-W P -1 ) Becomes. The memory remaining amount calculator 22 outputs the calculation result to the R through the RAM interface 19.
Supply to AM6.

On the other hand, the error flag is formed at a rate of 1 bit with respect to the reproduced data of 4 bytes, and the terminal 2
4 bits are stored in the buffer 30b via 9b (when the RAM 6 is an 8-bit RAM, the error flag stored in the buffer 30b is 8 bits). When the selector 23 selects the audio data write address supplied from the audio data write address generator 20, the audio data write address is supplied to the RAM interface 19 and the error flag address generator 24. Is also supplied.

The error flag address generator 24 is
When the voice data write address is supplied, the R
The storage capacity of the entire recording area of the AM 6 is "N", the storage capacity of the audio data recording area 40 is "N-NU", and the storage capacity of the error flag recording area 41 is NU-1 / 8 (NN).
U) ≧ NL, the audio data write address supplied from the audio data write address generator 20 through the selector 23 is MA, and the error flag address C
A is calculated using the formula CA = NL + 1/8 (MA-NU). Then, the error flag address (CA) as the calculation result is supplied to the RAM 6 via the RAM interface 19.

As a result, after the 4-byte reproduction data is written in the voice data recording area 40 according to the voice data write address, the 4-bit error flag corresponding to the 4-byte voice data is set to the above-mentioned error flag. The error is read according to the remaining amount of the empty area of the audio data recording area 40 which is read from the buffer 30b and calculated based on the above-described calculation formula and the error flag address output from the error flag address generator 24. It is written in the flag recording area 41.

The reproduction data recorded in the audio data recording area 40 is recorded in the audio data read address generator 2.
According to the audio data read address output from 1 through the selector 23, the data is read through the RAM interface 19 and stored in the FIFO 28a for 4 bytes. When the 4-byte reproduction data is accumulated in the FIFO 28a, an error flag (4 bits) corresponding to the reproduction data accumulated in the FIFO 28a is read from the error flag recording area 41, and the buffer 30
is supplied to a. The error flag supplied to the buffer 30a is transferred from the FIFO 28a to the terminal 27.
With the playback data that is output for each byte via a,
Each bit is output via the terminal 29a.

The reproduction data and the error flag are supplied to the ATRAC encoder / decoder 5.

As described above, the recording area of the RAM 6 is provided with the audio data recording area 40 which is an area for recording the reproduction data and the error flag recording area 41 which is an area for storing the error flag to calculate the remaining memory amount. Bowl 22
Then, the remaining amount of free space in the voice data recording area 40 is calculated, and the error flag address generator 24 calculates based on the calculated remaining amount of free space and the recording state of voice data in the voice data recording area. By controlling the writing and reading of the error flag with the generated error flag address, the RAM for writing and reading the audio data can be shared as the RAM for writing and reading the error flag. A dedicated RAM for recording the error flag can be omitted, which can contribute to a reduction in the installation area and the size of the device, and the cost can be reduced.

Further, since the error flag is written in the same RAM 6 as the reproduction data, it is possible to easily obtain error mapping information for confirming the generation condition of the error data.

The ATRAC encoder / decoder 5
Operates as a decoder in this playback mode, and in the operation mode designated by the system controller 7, for example, expands the compressed data five times to 75
Audio data, which is digital data having a transfer rate of sectors / second, is formed and supplied to the D / A converter 14.

The D / A converter 14 is the ATRAC
The audio data supplied from the encoder / decoder 5 is converted into an analog signal to form an audio signal, which is output via the output terminal 15.

As is clear from the above description, the disk recording / reproducing apparatus according to the present embodiment has the RAM control circuit 8 described above.
Thus, the storage area of the RAM 6 is divided into an audio data recording area 40, an error flag recording area 41, a TOC data recording area 42 and a sub data recording area 43, and the compressed data is written to the audio data recording area 40. Controlled by the audio data write address from the audio data write address generator 20, reading is controlled by the audio data read address from the audio data read address generator 21, and writing and writing of sub data to the sub data recording area 43 is performed. The reading is controlled by the sub data write address and the sub data read address from the sub data address generator 24, and the TOC
Writing and reading TOC data to and from the data recording area 42 is controlled by the system controller write address and the system controller read address from the system controller read / write address generator 26, thereby writing a plurality of types of data in one RAM. It can also be read.

Therefore, it is not necessary to provide a RAM for writing and reading the above data, and the R
Since only one AM needs to be provided, the cost can be reduced, the installation area of the RAM can be reduced, and the size of the device can be reduced.

In the above description of the embodiments, the disc reproducing apparatus according to the present invention is configured as a disc recording / reproducing apparatus together with a recording system. However, it is needless to say that this may be only the disc reproducing apparatus of the reproducing system. Is.

[0079]

In the disc reproducing apparatus according to the present invention, the storage control means causes the storage means to write and read the recording data area, which is an area for writing and reading the recording data, and the auxiliary data corresponding to the recording data. The recording data and the auxiliary data are divided into the auxiliary data areas and the recording data is written to and read from the recording data area and the auxiliary data is written to and read from the auxiliary data area. It is possible to process a plurality of data with one storage unit without providing a storage unit.

Therefore, it is not necessary to provide a storage means for each of the recorded data and the attached data, the number of parts can be reduced and the installation area can be reduced, and the cost can be reduced, and the equipment can be reduced. Can contribute to downsizing.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a disc recording / reproducing apparatus in which a disc reproducing apparatus according to the present invention is configured with a recording system.

FIG. 2 is a schematic plan view for explaining the structure of an optical disc provided in the disc recording / reproducing apparatus.

FIG. 3 is a diagram showing a recording state of recording data of one cluster recorded on the optical disc.

FIG. 4 is a diagram showing a specific recording mode of TOC data recorded on the optical disc.

FIG. 5 is an R provided in the disc recording / reproducing apparatus.
It is a block diagram of an AM control circuit.

FIG. 6 is an R provided in the disc recording / reproducing apparatus.
It is a schematic diagram which shows the state which divided the recording area of AM.

FIG. 7 is a diagram showing a memory state for explaining memory control in the recording mode of the disc recording / reproducing apparatus.

FIG. 8 is a schematic diagram for explaining calculation of a remaining amount of an empty area of a voice data recording area of the RAM.

FIG. 9 is a block diagram of an optical head provided in the disk recording / reproducing apparatus of the above embodiment.

FIG. 10 is a diagram showing a memory state for explaining memory control in the reproduction mode of the disc recording / reproducing apparatus of the embodiment.

[Explanation of symbols]

1 ・ ・ ・ Optical disc 2 ・ ・ ・ ・ ・ ・ ・ ・ Spindle motor 3 ・ ・ ・ ・ ・ ・ ・ ・ Display 4 ・ ・ ・ ・ ・ ・ ・ ・ A / D converter 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ATRAC encoder / decoder 6 ・ ・ ・ ・ ・ ・ ・ ・ RAM 7 ・ ・ ・ ・ ・ ・ ・ ・ System controller 8 ・ ・ ・ ・ ・・ ・ ・ RAM control circuit 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Encoder / decoder 10 ・ ・ ・ ・ ・ Magnetic head 11 ・ ・ ・ ・ ・ ・ ・ Magnetic head drive circuit 12 ・ ・・ ・ ・ ・ ・ ・ ・ ・ Optical head 13 ・ ・ ・ ・ ・ ・ ・ ・ RF circuit 14 ・ ・ ・ ・ ・ ・ D / A converter 16 ・ ・ ・ ・ ・ ・ Servo control circuit 19 --- RAM interface 20 --- voice data write address generator 21 --- Voice data read address generator 22 .... Remaining memory calculator 23 ..... Selector 24 ..... Error flag address generator 25 .. ........ Sub data address generator 26 ..... System controller read / write address generator 28a, 28b ..... FIFO 30a, 30b ..... Buffer

Claims (1)

[Claims] 1. A disc reproducing apparatus for reproducing recorded data recorded on an optical disc, temporarily writing it in a storage means, and reading and outputting the recorded data once written in the storage means. Divided into a recording data area, which is an area for writing and reading the recording data, and an auxiliary data area, for writing and reading auxiliary data corresponding to the recording data, and writing and reading the recording data to and from the recording data area. And a disk reproducing device comprising storage control means for controlling writing and reading of the attached data to and from the attached data area.