JPH10199151A - Disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clarify and simplify a processing routine of pause queue reduction or pause review reduction in a disk player. SOLUTION: Data read out by a pickup 4 in reduction is written in a buffer memory 35. This read data is read out from the buffer memory 35 and an original audio signal is obtained. At this point, data indicating an elapsed time is formed, based on an address of the buffer memory 35 in reading out data, and an elapsed time is displayed on a display by data of this elapse time. When a prescribed key operation is performed, dummy data is written in the buffer memory 35 instead of data read out by the pickup 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a disk reproducing apparatus.

[0002]

2. Description of the Related Art As a recording medium for digital audio signals and the like, a small optical disk called a "mini disk" is known. This optical disc includes a read-only disc and a disc capable of recording and reproducing an audio signal by a magneto-optical method. The outline of the optical disc for recording and reproduction will be described as follows.

That is, at the time of recording, an input analog audio signal has a sampling frequency of 44.1 kHz,
A / D conversion is performed on digital audio data having a quantization bit number of 16 bits. The digital audio data is sequentially divided into blocks for a predetermined period, and the data is compressed to a size of approximately 1/5 in units of the blocks. Is done. This data compression method combines DCT and a window function in consideration of human auditory characteristics, and is called MDCT. Hereinafter, the data compression block is referred to as a “sound group”.

[0004] The compressed audio data is subjected to an encoding process for error correction and a modulation process for recording, and the processed audio data is transferred to a disk by a magnetic head and a laser beam. Is recorded on a spiral track from the inner circumference to the outer circumference.

FIG. 5 shows a format of digital audio data after compression processing among signals recorded on a disk. This audio data is distributed to clusters CN, CN + 1, CN + 2,. ing. Each cluster is composed of 36 sectors L2 to L4, S0 to S31, and L1, and the digital audio data is recorded in the sectors S0 to S31. Also, sectors L2 to L4, L1
Is called a "linking sector" and is for connection with clusters CN-1 and CN + 1 following the cluster CN. It should be noted that recording on the disc is performed in units of one cluster.

The size of each sector is 2352 bytes, and the audio sectors S0 to S31 are:
In each case, the first 20 bytes are used as the header and the remaining 23
32 bytes are divided into 5.5 blocks of 424 bytes each. This block is the above sound group. At this time, the even and odd numbered consecutive sectors are regarded as one set, and the last 0.5 sound group of the even numbered sector and the first 0.5 sound group of the odd numbered sector constitute one sound group. Is done.

[0007] One sound group has a total of 512 samples of digital audio data of stereo left and right channels in a data compressed state. Therefore, the time length of one sound group is 512 samples / 44.1 kHz ≒ 11.61 ms, and the data compression rate of each channel is 424 bytes / (16 bits × 512 samples × 2 channels)
≒ 1 / 4.8 times, resulting in about 1/5 data compression as described above.

[0008] A signal having such a format is encoded for recording and then recorded as a track on an optical disk.

The above-described reproduction of the optical disk may be performed in a complementary manner to the recording. That is, the signal is optically reproduced from the track of the disk by the optical pickup,
Data-compressed digital audio data is extracted from the reproduced signal, error correction is performed, and the error-corrected digital audio data is decompressed.
/ A conversion. By doing so, the original analog audio signal can be obtained.

[0010]

By the way, in a disk player (or a recording / reproducing apparatus) using the above optical disk, if the optical disk becomes dirty or vibrated at the time of reproduction, the signal reading from the disk fails, As a result, the digital audio data may be chipped and the reproduced sound may be interrupted.

Therefore, in an actual disc player, such interruption of sound is prevented as follows. That is, first, when a signal is read (reproduced) from a disk, the digital audio data included in the read signal, that is, the bit rate (bit speed) of the digital audio data before data expansion is determined by the data expansion For example, the bit rate is set to be equal to the bit rate of the digital audio data that follows.

When reading signals from the disk, if everything is normal, the same digital audio data is repeatedly obtained about five times every several revolutions of the disk. You just have to use the data effectively.

Further, the reproduction system of the disc player includes:
As schematically shown in FIG. 4, a ring buffer RBUF is provided. Then, the digital audio data after the error correction and before the data decompression are written into the ring buffer RBUF, and the write address AWR is set to a predetermined speed, that is, a normal time (normal ), The digital audio data is changed in the increasing direction at a speed corresponding to the bit rate of the compressed digital audio data at the time of recording.

Simultaneously with the writing, the digital audio data written in the ring buffer RBUF is read out, and the read address ARD is changed in the increasing direction. Then, the read digital audio data is expanded, and then D / A converted into an analog audio signal.

The above processing is executed by the memory controller in accordance with an instruction from the microcomputer for controlling the system. Actually, a write pointer and a read pointer are prepared, and digital audio data is written or read to or from the ring buffer RBUF from the address specified by the pointer in sector units.

Therefore, the ring buffer RBUF
Acts as a FIFO for digital audio data, in which case reading of a signal from the disk fails, and as a result, digital audio data cannot be written to the ring buffer RBUF,
Until the read address ARD catches up with the write address AWR (until the hatched area disappears), digital audio data is obtained from the ring buffer RBUF, so that there is no interruption in the reproduced sound until the catch up.

Since the signal can be read from the disk several times before the read address ARD catches up with the write address AWR, this read re-execution results in the ring buffer RBUF The digital audio data to be written into the audio data can be made complete, so that the reproduced sound can be prevented from being interrupted.

At this time, since the digital audio data included in the signal read from the disk has a bit rate that is about five times that of the digital audio data after data expansion, the write address AWR to the ring buffer RBUF and the read address The interval between the addresses ARD can be kept to a specified size in a normal state. Therefore, even if the reading of the signal from the disk fails, this can always be dealt with.

Moreover, in this case, the digital audio data before data expansion is written to the ring buffer RBUF.
Since the readout processing is performed to prevent sound breakage, the ring buffer is compared with the case where the same processing is performed using digital audio data after data expansion.
The capacity of the RBUF can be reduced to about 1/5.

Some disk players or recording / reproducing apparatuses using the above-mentioned optical disks have the following special reproducing functions.

[Pause Cue Playback] When the fast forward key is pressed in the playback pause state, the playing time displayed on the display during the pressing of the fast forward key is faster than normal playback, for example, 10 times faster. Is incremented in the positive direction. When pressing of the fast forward key is stopped, the state returns to the playback pause state at the position of the playing time at the time when the key is stopped. Note that the muting state is continued even while the fast-forward key is pressed, and the reproduction output is silent.

Therefore, when the pause state is subsequently released, the reproduction is continued from the position of the playing time when the pressing of the fast-forward key is stopped.

[Pause Review Playback] In the playback pause state, pressing the fast reverse key will cause
The displayed playing time is decremented in the reverse direction faster than during normal playback. Then, when the pressing of the fast-return key is stopped, the state returns to the reproduction pause state at the position of the playing time at the time when the key is stopped. Note that the muting state is continued even while the fast-return key is being pressed, and the reproduction output is silent.

Therefore, when the pause state is subsequently released, the reproduction is continued from the position of the performance time when the pressing of the fast reverse key is stopped.

Therefore, according to the pause cue reproduction and the pause review reproduction, when the target performance start position (time position at which the performance is desired to be started) is known in advance, the performance start position is reached at a high speed. Thus, even if the target performance start position is in the middle of a long tune, the reproduction can be immediately started from the target position.

It should be noted that the pause cue reproduction and the pause review reproduction differ only in the moving direction of the optical pickup.
Since the signal processing method is the same, both functions will be described below as representative of pause cue reproduction.

In FIG. 3, a routine 200 is an excerpt of a control procedure for realizing normal reproduction and pause cue reproduction among processing contents of the microcomputer for system control. And then at step 202,
By detecting whether the fast-forward key is pressed, it is determined whether the playback mode is the normal playback or the pause queue playback.

During normal reproduction, the process proceeds from step 202 to step 211. In this step 211, the memory controller is instructed to write digital audio data to the ring buffer RBUF. At 212, the memory controller is instructed to read digital audio data from the ring buffer RBUF.

Subsequently, in step 213, the read address ARD at that time is converted into performance time data, which is supplied to the display system to display the performance time, and then the routine 200 is terminated in step 214. At the time of reproduction, this routine 200 is repeatedly executed, and normal reproduction is continued.

On the other hand, in step 202, when the pause cue is reproduced, the processing proceeds from step 202 to step 221. In this step 221, performance time data is generated in a pseudo manner, and supplied to the display system to provide the performance time. Is displayed, and then the routine 200 ends in step 214. Then, while the fast-forward key is pressed, the routine 200 is repeatedly executed, and the pause cue reproduction is continued.

As described above, normal reproduction and pause cue reproduction (and pause review reproduction) are realized.

However, as described above and as shown in FIG. 3, during normal playback and during pause cue playback,
If the control method is completely different, a program for performing the control becomes complicated and large. Also, during the pause cue reproduction, when the performance time shifts from the end of the music to the start of the next music, another process is required, so that the program becomes more complicated and larger. As a result, the ROM consumed by the program
Problems such as an increase in size occur.

The present invention is to solve such a problem.

[0034]

According to the present invention, a pickup for reading data recorded on a disk from a disk, a buffer memory for temporarily storing the data read by the pickup, and an elapsed time of reproduction are displayed. And a display that reproduces, at the time of reproduction, writes the data read by the pickup to the buffer memory, reads the written data from the buffer memory, and obtains an original audio signal from the read data, Data indicating the elapsed time is formed based on the address of the buffer memory at the time of reading the data, the elapsed time is displayed on the display by the data of the elapsed time, and when a predetermined key operation is performed, the pickup is displayed. Instead of the data read by The Deta is to a disk reproducing apparatus to write in the buffer memory.
Therefore, most of the processing routines are standardized and systematized for normal reproduction and special reproduction.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION

[Configuration of Recording / Reproducing Apparatus] FIG. 1 shows an example of a mini-disc recording / reproducing apparatus to which the present invention is applied. Reference numeral 1 denotes the mini-disc, which is a magneto-optical disc corresponding to the format described with reference to FIG. 5 and is housed in a cartridge 1A. A pregroove is formed on the disc 1 for controlling the tracking of the light beam, and an absolute address signal is recorded in the pregroove.

Further, the disk 1 is rotated by the spindle motor 2 and its rotation is controlled by the servo control circuit 5 so that the linear velocity of the disk 1 becomes constant. A magnetic head 3 for recording is disposed on one surface of the disk 1 through a shutter opening of the cartridge 1A, and an optical pickup 4 is disposed on the other surface of the disk 1 through a shutter opening. Placed. The focus and tracking of the optical pickup 4 are controlled by a servo control circuit 5, and the head 3 and the optical pickup 4 are controlled.
Can be moved in the radial direction of the disk 1 by the feed motor 6.

A system controller 20 is provided to manage the operation of the recording / reproducing apparatus. For this reason,
This system controller 20 is constituted by a microcomputer, and has, for example, a reproduction routine 100 shown in FIG. 2 as a part of a program for managing its operation. The details of this routine 100 will be described later, but in FIG. 2, for simplicity, as in FIG.
Only parts related to the present invention, that is, parts related to normal reproduction and pause cue reproduction are extracted and shown.

Further, the system controller 20 includes:
Operation keys 10 such as an eject key, a play key, a stop key, a recording key, an erase key, and a power key are connected, and a display 30 is connected.
At 0, various kinds of information on the disk 1, for example, the playing time of the music being reproduced, the track number of the music being reproduced, and the like are displayed.

Reference numerals 31 to 42 denote recording / reproducing circuits, which are controlled by the system controller 20 and perform recording and reproduction as follows.

[Recording] At the time of recording, a stereo analog audio signal is supplied to the A / D converter 32 through the input terminal 31 and the sampling frequency is 44.1 kHz.
The A / D conversion is performed to digital audio data having a quantization bit number of 16 bits, and this digital audio data is supplied to the audio compression encoding / decoding circuit 33 and is compressed by the MDCT to a data amount of about 1/5. You.

The compressed digital audio data is temporarily written into the buffer memory 35 by the memory controller 34, and is sequentially read at a speed approximately five times the writing speed. If the data is data encoded /
The data is supplied to the decoding circuit 36 and encoded into the data having the sector structure described above.

Then, the encoded audio data is supplied to an EFM and CIRC encoding / decoding circuit 37, where an encoding process for error detection and correction is performed, and a modulation process suitable for recording, in this example, EFM (8-14 modulation) processing is performed. In this example, the code for error detection and correction is C
The interleave changed for D's CIRC is used. The encoding / decoding circuit 37
, Linking sectors L2 to L4 and L1 are added to form audio data having the above-described cluster structure.

Then, the audio data is supplied to the head 3 through the head drive circuit 38, and a magnetic field modulated by the audio data is supplied to the disk 1. At this time, the laser beam from the optical pickup 4 is applied to the disk 1, and the magnetic head 3 and the optical pickup 4 are moved in the radial direction of the disk 1 synchronously. Thus, the irradiation of light from the optical pickup 4 and the modulation magnetic field by the magnetic head 3 cause the disc 1 to emit light.
Is recorded with audio data from the drive circuit 38 by thermomagnetic recording.

Further, at the time of this recording, the detection output of the optical pickup 4 is supplied to the address decoder 40 through the RF amplifier 39, and the absolute address signal recorded in the pre-groove of the disk 1 is extracted and decoded. The absolute address signal obtained is EFM and CI
The data is supplied to the RC encoding / decoding circuit 37, inserted into the audio data, and recorded on the disk 1.

This absolute address signal is also supplied to the system controller 20, and is used for recognition of the recording position and position control. Further, the output signal of the RF amplifier 39 is supplied to the servo control circuit 5, and the servo control is performed by the pre-groove signal of the disk 1 so that the linear velocity of the disk 1 becomes constant.

[Normal Reproduction] At the time of reproduction, the servo control circuit 5 uses the pregroove signal to rotate the disk 1 at a constant linear velocity equal to that at the time of recording in the same manner as at the time of recording.

The optical pickup 4 detects the reflected light of the laser beam irradiating the target track, and supplies the detection output to the RF amplifier 39, for example, where a focus error is detected by an astigmatism method. For example, a tracking error is detected by a push-pull method. Then, these error signals are supplied to the servo control circuit 5, and the optical pickup 4 is controlled so that the focus error and the tracking error are eliminated.

Further, in the RF amplifier 39, the difference in the polarization angle of the reflected light from the target track is detected, and a reproduced signal is taken out. The reproduced signal is binarized and converted into the EFM and CIRC encode / decode circuit 3.
7 is supplied.

In the EFM and CIRC encoding / decoding circuit 37, the reproduction signal is EFM-demodulated, error-corrected, and digital audio data is taken out. The digital audio data is sent to the data encoding / decoding circuit 36. The supplied digital audio data is decoded into the original compressed digital audio data. Further, the decoded digital audio data is intermittently written to the buffer memory 35 through the memory controller 34, and is sequentially read at a speed of about 1/5 of the writing speed. At this time, the buffer memory 35 acts as the above-described ring buffer RBUF, and writing and reading are performed as described with reference to FIG.

That is, in the system controller 20, the processing of the CPU is performed in step 101 of the routine 100.
Then, in step 101, it is determined whether the playback mode is the normal playback or the pause queue playback by detecting whether the fast-forward key is pressed.

At the time of normal reproduction, the process proceeds from step 101 to step 111. In this step 111, the digital audio data from the data encoding / decoding circuit 36 is sent to the memory controller 34 in a ring buffer RBUF (buffer). Memory 3
The user is instructed to write in step 5), and then step 11
In 2, the memory controller 34 is instructed to read digital audio data from the ring buffer RBUF.

Subsequently, in step 113, the read address ARD at that time is converted into performance time data, and this data is supplied to the display 30 to display the performance time. Thereafter, the routine 100 is terminated in step 114. . At the time of reproduction, this routine 100 is repeatedly executed, and normal reproduction is continued.

At this time, the output signal of the RF amplifier 39 is supplied to the address decoder 40, the absolute address signal from the pre-groove is extracted and decoded, and the absolute address signal is encoded by the EFM and CIRC encoding / decoding.
The optical pickup 4 is supplied to the system controller 20 through the decode circuit 37 and
Is used to control the reproduction position in the radial direction of the disc. In the system controller 20, address information in sector units is also extracted from the reproduction signal, and is used for managing the reproduction position of the optical pickup 4.

Thus, the digital audio data that has been subjected to data compression is continuously read from the buffer memory 35. Then, the read digital audio data is supplied to the audio compression encoding / decoding circuit 33 through the memory controller 34 and expanded to original digital audio data, and the digital audio data is supplied to the D / A converter 41. Then, the digital signal is D / A converted into the original stereo analog signal, and the stereo analog signal is taken out to the output terminal 42.

Therefore, the digital audio data recorded on the disk 1 is reproduced as a stereo analog audio signal.

[During Pause Cue Playback (and Pause Review Playback)] In the playback pause state, the operation key 1
When a fast-forward key (or a fast-reverse key) of 0 is pressed, a pause cue is reproduced by the routine 100 during the pressed period.

That is, if the fast-forward key is pressed in the playback pause state, the process proceeds from step 102 to step 121. In step 121, for example, dummy digital audio data corresponding to silence is transmitted to a data encoding / decoding circuit. Memory controller 3 so as to write to the ring buffer RBUF (buffer memory 35) instead of the digital audio data from
4 is instructed.

Subsequently, the process proceeds to step 112, where an instruction is issued to the memory controller 34 to read digital audio data from the ring buffer RBUF.

Then, in step 113, the read address ARD at that time is converted into performance time data, which is supplied to the display 30 to display the performance time. Thereafter, the routine 100 is terminated in step 114. Then, while the fast-forward key is being pressed, the routine 100 is repeated, and the pause cue reproduction is continued.

As described above, pause cue reproduction (and pause review reproduction) is realized.

[Summary] As described above, according to the recording / reproducing apparatus, recording, normal reproduction, pause queue reproduction, and pause review reproduction are executed.
During pause cue playback and pause review playback, dummy digital audio data is written to the ring buffer RBUF instead of the original digital audio data.
Since only the data to be written to the RBUF is switched, the processing is simple, and the subsequent processing can be executed as it is, as shown in FIG.

Therefore, the processing system becomes clear and simple, and the ROM size consumed by the program can be reduced.

[Others] In the above description, the disk 1 is
Even in the case of D, the present invention can be applied by setting the track speed higher than that during recording.

[0064]

According to the present invention, the processing system of normal reproduction, pause cue reproduction and pause review reproduction becomes clear and simple, and the ROM size consumed by the program can be reduced.

[Brief description of the drawings]

FIG. 1 is a system diagram illustrating one embodiment of the present invention.

FIG. 2 is a flowchart illustrating one embodiment of the present invention.

FIG. 3 is a flowchart for explaining the present invention.

FIG. 4 is a schematic diagram for explaining the present invention.

FIG. 5 is a format diagram for explaining the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Spindle motor, 4 ... Optical pickup, 5 ... Servo control circuit, 6 ... Feed motor, 20 ...
System controller, 32A / D converter, 33 ...
Audio compression encoding / decoding circuit, 34: memory controller, 35: buffer memory, 36: data encoding / decoding circuit, 37: EFM and CIRC encoding / decoding circuit, 38: head driving circuit, 39 ...
RF amplifier, 40: address decoder, 100: reproduction routine, RBUF: ring buffer

Claims (1)

[Claims] 1. A pickup for reading data recorded on a disk from a disk, a buffer memory for temporarily storing data read by the pickup, and a display for displaying an elapsed time of reproduction. Writing the data read by the pickup into the buffer memory, reading the written data from the buffer memory, obtaining the original audio signal from the read data, and reading the buffer when reading the data. The data indicating the elapsed time is formed based on the address of the memory, and the elapsed time is displayed on the display by the data of the elapsed time. When a predetermined key operation is performed, the data read by the pickup is replaced with the data. Dummy data is stored in the buffer memory Disk reproducing apparatus to write.