JPH07320397A - Reproducing device - Google Patents

Abstract

PURPOSE:To enable a reproducing device to easily perform slow reproduction by providing a control means which can control data stored in a memory means so that the data can be read out by X times for every prescribed unit quantity of data. CONSTITUTION:When data writing operations are executed against a buffer RAM 12, the same data are written in the RAM 13 by (x) times for the reproducing the data at a 1/x-time speed. When slow reproduction is started, a variable (y) for process control is first set to '0'. Then, an optical head 3 is made to access the position of a read section SCB from a disk 1 and to execute data reading. While the head 3 executes the data reading, the data read-out from the sector SCB are successively stored in the RAM 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus capable of reproducing data such as music from a recording medium such as a disc.

[0002]

2. Description of the Related Art There are known data-rewritable magneto-optical disks that allow users to record music data and the like. Among such disk media, there is a disk RAM having a seismic function improved by using a buffer RAM. Has been realized.

That is, at the time of reproduction, the audio data read from the magneto-optical disk is intermittently written into the buffer RAM at a high speed, while the audio data is continuously read from the buffer RAM at a low speed and demodulated as an audio reproduction signal. To process. At this time, data is constantly accumulated in the buffer RAM to some extent. Therefore, even if a track jump occurs due to external vibration or the like, and data reading from the magneto-optical disk is temporarily interrupted, the buffer RAM The audio data can be continuously read from, and the reproduced audio is output without interruption. Further, at the time of recording, the inputted data is once continuously written in the buffer RAM at a low speed rate, and the data is intermittently read out at a high speed rate and supplied to a recording head for recording on a disk.

A recording track in a magneto-optical disk known as a mini disk is a cluster CL (4 sectors (1 sector = 2352 bytes) of sub-data area and 32 sectors of main data area as shown in FIG. = 36 sectors-) are continuously formed, and one cluster is the minimum unit for recording. One cluster corresponds to 2 to 3 rounds of tracks. The address is recorded for each sector. The sub-sector area of 4 sectors is used as sub-data and linking area, and 32 pieces of TOC data and audio data can be recorded.
It is performed in the main data area of the sector.

The sectors are further subdivided into sound groups, and two sectors are divided into 11 sound groups. Then, in the 424-byte sound group, the data is divided into the L channel and the R channel and recorded. 11.6 per sound group
The amount of audio data corresponds to the time of msec. Further, 212 bytes which are the data area of the L channel or the R channel are called a sound frame.

When recording / reproducing data recorded in such a format on the disk via the buffer RAM, the buffer RAM stores the data in sector units. That is, the sector address and the byte address in the sector (0 to 2351 bytes) are combined to generate an access address, and writing and reading are executed.

[0007]

By the way, in the audio reproducing system such as the mini disk system, the CD player, the DAT player, the analog tape player, etc., it is desired to perform the reproduction slower than the normal reproduction speed (slow reproduction). There are cases. For example, it is convenient to be able to perform slow playback when recording the contents of a meeting and not hearing at normal speed when listening to it, or when wanting to hear the lyrics of a song.

When performing slow reproduction, a conventional player drives a recording medium such as a disc or a tape at a low speed (reproduces by reducing the disc rotation speed or reducing the tape running speed). However, in this case, it is difficult to hear the sound even if the pitch is changed or the sound quality is significantly impaired. There was a problem that was not done. Further, there is also a drawback that a circuit configuration for controlling the operating speed of the recording medium is required.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a reproducing apparatus capable of maintaining a high sound quality and realizing slow reproduction with a simple structure. To aim.

That is, in a reproducing apparatus configured to temporarily store the data read from the recording medium in the memory means and read the data from the memory means at a predetermined timing to output the data, the data read from the recording medium is read. A control means capable of controlling the same data to be stored in the memory means X times for each predetermined data amount unit and to sequentially read the data from the memory means at a predetermined timing. By providing, the reproduction output is executed at a speed of 1 / X times.

Alternatively, similarly, in a reproducing device having a memory means, the data read from the recording medium is stored in the memory means in a predetermined data amount unit, and then dummy data of the same data amount (X-1 ) The reproduction output is multiplied by 1 / X by providing a control means capable of storing the data in the memory means one by one and controlling the data to be sequentially read from the memory means at a predetermined timing. To run at the speed of.

Alternatively, similarly, in a reproducing apparatus having a memory means, the data read from the recording medium is sequentially stored in the memory means, and the data stored in the memory means is stored in units of a predetermined data amount unit. By providing control means capable of performing control such that reading is performed X times each, reproduction output is executed at a speed of 1 / X times.

[0013]

If, for example, double writing of data, storing of data and dummy data, or double reading of data is performed on the memory means, the operating speed of a recording medium such as a disk or tape does not change. , The reproduction output becomes 1/2 speed. In this case, the same data is 2 for each predetermined data amount unit.
Since the audio signal is reproduced and output once, the original reproduced audio signal does not remain as it is, but if the predetermined data amount unit is audio data of a short time of, for example, several tens of msec, there is almost no problem as reproduced audio. , It will be heard enough as the slow-speed playback sound of the original speed playback sound.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A recording / reproducing apparatus (mini disk system) using a magneto-optical disk as a recording medium will be given below as first to third embodiments of the reproducing apparatus of the present invention with reference to FIGS. explain.

<First Embodiment> FIG. 1 is a block diagram of a main part of a recording / reproducing apparatus of the embodiment. In FIG. 1, reference numeral 1 denotes a magneto-optical disk on which audio data is recorded, and the magneto-optical disk 1 is driven to rotate by a spindle motor 2. 3 is recorded / recorded on the magneto-optical disk 1.
It is an optical head that emits laser light during reproduction, provides a high level laser output for heating the recording track to the Curie temperature during recording, and a relatively high level for detecting data from reflected light by the magnetic Kerr effect during reproduction. Provides low level laser output.

For this reason, the optical head 3 is equipped with a laser diode as a laser output means, an optical system including a deflecting beam splitter, an objective lens and the like, and a detector for detecting reflected light. The objective lens 3a is held by the biaxial mechanism 4 so as to be displaceable in the disc radial direction and the direction in which the disc moves toward and away from the disc.

Reference numeral 6 denotes a magnetic head for applying a magnetic field modulated by the supplied data to the magneto-optical disk, which is arranged at a position facing the optical head 3 with the magneto-optical disk 1 interposed therebetween. The entire optical head 3 and the magnetic head 6 are movable in the disk radial direction by a sled mechanism 5.

Information detected from the magneto-optical disk 1 by the optical head 3 by the reproducing operation is supplied to the RF amplifier 7. The RF amplifier 7 calculates the supplied information by reproducing RF signals, tracking error signals, focus error signals, and absolute position information (absolute position information recorded as pregrooves (wobbling grooves) on the magneto-optical disk 1). Address information, focus monitor signal, etc. are extracted. Then, the extracted reproduction RF signal is supplied to the encoder / decoder unit 8. The tracking error signal and the focus error signal are supplied to the servo circuit 9, and the address information is supplied to the address decoder 10. Further, the absolute position information and the focus monitor signal are supplied to the system controller 11 configured by, for example, a microcomputer.

The servo circuit 9 generates various servo drive signals according to the supplied tracking error signal, focus error signal, track jump command, seek command from the system controller 11, rotational speed detection information of the spindle motor 2, etc. Shaft mechanism 4 and sled mechanism 5
To perform focus and tracking control, and control the spindle motor 2 to a constant angular velocity (CAV) or a constant linear velocity (CLV).

The reproduced RF signal is sent to the encoder / decoder unit 8
After the EFM demodulation and the decoding process such as CIRC are performed by the memory controller 12, the buffer RAM 13 is temporarily processed by the memory controller 12.
Written in. The reading of data from the magneto-optical disk 1 by the optical head 3 and the transfer of reproduced data in the system from the optical head 3 to the buffer RAM 13 are performed.
It is 1.41 Mbit / sec and is performed intermittently.

The data written in the buffer RAM 13 is read out at the timing when the reproduction data is transferred at 0.3 Mbit / sec, and is supplied to the encoder / decoder unit 14. Then, a reproduction signal process such as a decoding process for the audio compression process is performed to obtain an output digital signal.

The output digital signal is converted into an analog signal by the D / A converter 15, and the analog line output terminal 1
6A is supplied. Alternatively, it is directly supplied to the digital output terminal 16D without being converted to analog.

Here, writing / reading of data to / from the buffer RAM 13 is performed by being addressed by the memory controller 12 under the control of the write pointer and the read pointer. FIG. 2 conceptually shows an operation of writing / reading data to / from the buffer RAM 13 during reproduction, and it is assumed that addresses 0 to n are provisionally set as an area for data in the buffer RAM 13 (actually, In addition to the audio signal data, TOC data for controlling the recording / reproducing operation is also stored in the buffer RAM 13, so that a storage area other than the audio signal data is also set).

As shown in FIG. 2A, the write pointer W and the read pointer R are sequentially incremented from address 0 to address n, and the address 0 is read again after the address n. It is controlled in a so-called ring form that is reset to.

Then, when the reproducing operation is started and the data is read from the magneto-optical disk 1 and supplied to the buffer RAM 13, the write pointer W as shown in FIG. 2B.
Are sequentially incremented, and data is written to each address accordingly (actually, data is written in sector units). In addition, the read pointer R is sequentially incremented at substantially the same time (or when data is stored to some extent),
Data is read from each address and the encoder /
It is supplied to the decoder unit 14.

Here, the write pointer W is as described above.
The read pointer R is incremented at a timing of 1.41 Mbit / sec, while the read pointer R is incremented at a timing of 0.3 Mbit / sec. Therefore, at a certain point, the address indicated by the write pointer W is read out as shown in FIG. It catches up with the address indicated by the pointer R (when the read pointer R is the address x, the address of the write pointer W is x−
1). That is, the data is stored in the buffer RAM 13 in full capacity. At this time, the increment of the write pointer W is stopped, and the data reading operation from the magneto-optical disk 1 is also stopped. However, the read pointer R
Since the increment of is continuously executed, the reproduced voice output is not interrupted.

After that, only the read operation from the buffer RAM 13 is continued, and for example, as shown in FIG. 2D, at some point, the data storage amount D _R in the buffer RAM 13 falls below a predetermined amount. To do. Here, the data reading operation from the magneto-optical disk 1 and the increment of the write pointer W are restarted again, and the operation is repeated until the address of the write pointer W catches up with the address of the read pointer R. As described above, the reproduction data buffer RAM
The data write operation to 13 will be performed intermittently.

This operation relationship is shown in FIG. If the reproduction operation is started at time t ₀ , data reading from the magneto-optical disk 1 and storage in the buffer RAM are started, and immediately after that, data reading from the buffer RAM 13 and reproduction output as an acoustic signal are started ( FIG. 3 (a) (b)).
Then, assuming that the data storage amount of the buffer RAM 13 becomes full at the time point t ₁ (FIG. 3C), the data reading from the magneto-optical disk 1 and the buffer RAM 1 at that time point.
The storage operation to 3 is stopped, and thereafter it is not executed until time T ₂ when the amount of accumulated data decreases to a level at which it becomes Y _TH . Then, the data reading from the magneto-optical disk 1 and the storing operation in the buffer RAM 13 are executed from the time T ₂ to T ₃ when the data storage is full again.

By outputting the reproduced sound signal via the buffer RAM 13 as described above, the reproduced sound output is not interrupted even if the tracking is missed due to disturbance or the like, and the data accumulation remains. By accessing the correct tracking position and restarting the data reading, the operation can be continued without affecting the reproduction output. That is, the seismic resistance function can be significantly improved.

In FIG. 1, address information output from the address decoder 10 and subcode data used for control operation are supplied to the system controller 11 via the encoder / decoder section 8 and used for various control operations. Further, the lock detection signal of the PLL circuit that generates the bit clock for the recording / reproducing operation and the monitor signal of the missing state of the frame synchronization signal of the reproduction data (L and R channels) are also supplied to the system controller 11.

Further, the system controller 11 outputs a laser control signal S _LP for controlling the operation of the laser diode in the optical head 3, and controls the output of the laser diode on / off, and at the time of on control, the laser It is possible to switch between an output at the time of reproduction in which the power is at a relatively low level and an output at the time of recording in which the power is at a relatively high level.

When the recording operation is performed on the magneto-optical disk 1, the analog code is transmitted from other devices by an audio cord connected to the analog input terminal 17A or an audio optical cable connected to the digital input terminal 17D. Alternatively, a digital audio signal is supplied.

Digital data with digital input terminal 17D
The audio signal sent to is directly supplied to the encoder / decoder unit 14. The analog audio signal input from the analog input terminal 17A is converted into digital data by the A / D converter 18 and then supplied to the encoder / decoder unit 14.

The encoder / decoder unit 14 performs audio compression encoding processing on the input digital audio signal. The recording data compressed by the encoder / decoder unit 14 is once written in the buffer RAM 13 by the memory controller 12, is also read at a predetermined timing, and is sent to the encoder / decoder unit 8. Then, the encoder / decoder unit 8 performs CIRC encoding,
After being subjected to encoding processing such as EFM modulation, it is supplied to the magnetic head drive circuit 21.

The magnetic head drive circuit 21 supplies a magnetic head drive signal to the magnetic head 6 according to the encoded recording data. That is, the N or S magnetic field is applied to the magneto-optical disk 1 by the magnetic head 6. At this time, the system controller 11 also supplies a control signal to the optical head so as to output a laser beam of a recording level.

Reference numeral 19 denotes an operation input section provided with keys used for user operation, and includes playback / fast-forward / fast-reverse / AM.
There are provided operation keys for S search / stop / recording, operation keys for setting various operation modes, and operation keys for performing various editing processes. Also,
In this embodiment, operation keys for executing slow reproduction and speed setting keys (for example, setting keys for 1/2 speed, 1/3 speed, etc.) are provided. Reference numeral 20 denotes a display unit such as a liquid crystal panel, which is controlled by the system controller 11 so that the operating state, the mode state, the reproduction progress time,
The recording progress time, track number, etc. are displayed.

By the way, when the recording / reproducing operation is performed on the disc 1, the management information recorded on the disc 1, that is, P-TOC (pre-mastered TOC), U-
The TOC (user TOC) is read out, and the system controller 11 determines the address of the part to be recorded on the disc 1 and the address of the part to be reproduced according to the management information. It is held in the buffer RAM 13. Therefore, the buffer RAM
In the area 13, the recording data / playback data buffer area and the area for holding the management information are divided and set.

Then, the system controller 11 reads out these management information by executing a reproducing operation on the innermost circumference side of the disc on which the management information is recorded when the disc 1 is loaded, and stores it in the buffer RAM 13. It is possible to refer to the recording / reproducing operation for the disc 1 thereafter.

The U-TOC is edited and rewritten according to the recording and erasing of data, but the system controller 11 performs the editing process for each recording / erasing operation on the U-TOC stored in the buffer RAM 13. The TOC information is written and the U-TOC area of the disc 1 is rewritten at a predetermined timing according to the rewriting operation.

The slow reproduction operation realized in the recording / reproducing apparatus of this embodiment will be described in detail below. The slow playback process (1 / X
Double speed reproduction) is realized by the system controller 11 and the memory controller 12 controlling the operation of writing the data read from the disk 1 into the buffer RAM 13.

That is, as shown in FIG. 4, the buffer RAM 13
When the data write operation is executed for the same data, the same data is written X times in the buffer RAM 1 for the 1 / X speed reproduction operation.
3 will be written.

When the slow reproduction operation is started, the variable y for processing control is first set to 0 (F101). Then, the optical head 3 is first caused to access the position of the sector SC _n (data reading and writing to the buffer RAM 13 are performed in sector units) to be read from the disk 1 to execute data reading (F102). Then, the data of the sector SC _n is stored in the buffer RAM 13 (F103).

Here, the variable y is incremented (F10
4) Further, the write address (write pointer W described above) in the buffer RAM 13 is set to the address for storing corresponding to the next sector (F105). (Incidentally, of course, the write address is incremented for each data, but that is omitted for the sake of explanation.
(Here, the update of the write address in sector units is shown.)

Then, it is determined whether or not the variable y = X (F106). X is a constant indicating the slow reproduction speed (1 / X). For example, when the user specifies 1/2 speed, X = 2, and when 1/3 speed is specified, X = 3. In the case of reproduction at the normal speed, the processing of FIG. 4 is executed with X = 1. Hereinafter, description will be made assuming that X = 2.

Since the variable y = 1 at this point, the process returns to step F102. Since the address of the sector to be accessed on the disk 1 is not updated at this point, the same sector SC _n is read again from the disk 1. To be
Then, the data of the sector SC _n is stored in the buffer RAM.
The data is written to the address following the last time in 13 (F103), and the variable y and the write address in the buffer RAM 13 are incremented (F104, F105).

At this point, the variable y = 2, so X =
Since it is y, the process proceeds to step F107, and the address of the sector to be accessed on the disk 1 is updated to the address of the next sector. Then, at the timing of the next reading from the disk 1, the processing of FIG. 4 is executed again.

By the above processing, the buffer RAM 1
Data will be stored in 3 as shown in FIG. That is, the storage areas MA _{1 to} MA of the buffer RAM 13
_m , SC ₁ , SC ₁ , SC ₂ , SC ₂ , SC ₃ , SC
Data of the same sector is stored twice, such as ₃ ...

A buffer R for storing data in this way
Since the data read control for the AM 13 is performed as described in FIG. 2 and FIG. 3 as in the normal reproduction, one sector data is reproduced twice as the reproduction output data. It will be output one by one. As a result, this causes the audio output to be slow-speed reproduction of 1/2 speed.

This slow reproduction operation is schematically shown in FIG. Now, the audio signal as shown in FIG. 6 to some sectors SC ₁ to SC ₄ on the disc (a) is recorded (but is actually a digital data shows this in an analog manner). Here, by the above processing, the buffer RAM
When data is written in 13, the data is stored as shown in FIG.

Since each data is sequentially read from the buffer RAM 13 at normal timing, the audio signal actually reproduced and output is the signal shown in FIG. 6 (b). This signal does not become the original reproduction signal because it is duplicated in sector units, but as described in FIG. 13, one sector (5.5 sound groups) is 63.8 msec of audio data, and even if this is reproduced twice, , There is no discomfort in the sense of hearing, and it sounds as if the speed is slowed down without changing the pitch.

Of course, in the case of 1/3 speed reproduction, the above X =
Data of the same sector is buffered three times three times
It may be stored in M13. The same applies to the case of 1/4 speed, 1/5 speed, etc.

In this way, in the present embodiment, it is not necessary to lower the number of rotations of the disk, and the buffer RAM 13 is used.
The slow reproduction can be easily performed only by controlling the writing. Further, for this reason, it is possible to obtain a slow-reproduced sound which is easy to hear and whose sound quality does not deteriorate so much and whose pitch does not change.

In the process of this embodiment, the same sector is read from the disk 1 X times and the buffer RAM 13 is read.
However, the data is copied from the disk 1 only once, and data is copied after it is stored in the buffer RAM 13 or before it is stored so that the same sector data is stored X times. Good.

Further, in this embodiment, the same data is stored X times in sector units, but it may be performed in smaller data units, and the sound quality is better. For example, sound group unit (1
If it is stored X times each with 1.6 msec of audio data), slower reproduction with more natural sound quality will be achieved.
When considering the monaural system, the sound may be stored X times in units of one sound frame.

<Second Embodiment> Next, a second embodiment will be described with reference to FIG.
~ It demonstrates by FIG. The device configuration is the same as that of the first embodiment, and the description is omitted.

Also in the slow reproduction process (1 / X double speed reproduction) as the second embodiment, the system controller 11 and the memory controller 12 control the operation of writing the data read from the disk 1 into the buffer RAM 13. It is realized by doing. In this case, when the data write operation to the buffer RAM 13 is executed,
For reproduction operation at 1 / X speed, after certain sector data, (X-1) times of dummy data (for example, silent data) having the same data amount as the sector data is stored in the buffer RA.
It will be written in M13.

As shown in FIG. 7, when the slow playback operation is started, the variable y for processing control is first set to 0 (F
201). Then, the optical head 3 is caused to access the position of the sector SC _n to be read from the disk 1 to execute the data reading (F202). Then, the data of the sector SC _n is stored in the buffer RAM 13 (F203).
Here, the variable y is incremented (F204), and the write address (write pointer W described above) in the buffer RAM 13 is set to the address for storing corresponding to the next sector (F205).

Then, silent data of one sector size is written in the buffer RAM 13 as dummy data (F206), and the variable y is incremented (F207). Also, the write address in the buffer RAM 13 is set to the address for storing corresponding to the next sector (F20
8).

Here, it is determined whether or not the variable y = X (F209). When X = 2 is being executed during the 1/2 speed reproduction, y = 2 and X = y at this point, so the process proceeds to step F210. However, in the case of 1/3 speed reproduction, 1/4 speed reproduction, etc., the process returns to step F206 and dummy data is continuously written until y = 3 or y = 4.

When X = y and step F210 is reached,
The address of the sector to be accessed on disk 1,
Update to the address of the next sector. Then, when the next read timing from the disk 1 comes, the processing of FIG. 7 is executed again.

By the above processing, the buffer RAM 1
Data will be stored in 3 as shown in FIG. That is, in the case of ½ speed reproduction, the buffer RAM 13
Storage areas MA _{1 to} MA _m , SC ₁ , dummy, SC
₂ , dummy, SC ₃ , dummy, etc., the actual data is stored in the area every other sector. In the case of 1/3 speed reproduction, although not shown,
In the storage areas MA _{1 to} MA _m , SC ₁ , dummy, dummy,
SC _2, dummy, so that dummy ..., actual data is stored in the area of the two sectors worth every.

A buffer R for storing data in this way
Since the data read control for the AM 13 is performed as described above with reference to FIGS. 2 and 3 similarly to the normal reproduction, the reproduction output data at the half speed reproduction is the sector data. Will be output after one sector. As a result, this causes the audio output to be slow-speed reproduction of 1/2 speed.

This slow reproduction operation is schematically shown in FIG. Now, assuming that an audio signal as shown in FIG. 9A is recorded in a certain sector SC _{1 to} SC ₄ on the disk, if data is written in the buffer RAM 13 by the above processing, FIG. Data will be stored as in b). Since each data is read from the buffer RAM 13 at normal timing, the audio signal actually reproduced and output is the signal shown in FIG. 9B. This signal is not the original reproduction signal because the output of each sector data is output after a time period of 1 sector (63.8 msec), but even in this case, there is no particular discomfort in terms of actual hearing, and the pitch changes. It sounds as if only the speed was slowed down.

Also in this embodiment, it is not necessary to reduce the number of rotations of the disk, and the slow reproduction can be easily performed only by the write control of the buffer RAM 13. Therefore, the sound quality is not deteriorated so much and the pitch is adjusted. It is possible to obtain an easy-to-listen slow-playback sound that does not change. It should be noted that in this embodiment as well, processing may be performed in smaller data units, such that the same amount of dummy data as that unit is subsequently stored in sound group units or sound frame units. The sound quality will be better. Further, the dummy data does not have to be silent data, and may be any data as long as it is data that does not cause a sense of discomfort as a reproduction output.

<Third Embodiment> Next, a third embodiment will be described with reference to FIG.
0 to 12 will be described. The device configuration is the same as that of the first embodiment, and the description is omitted.

The slow reproduction process (1 / X double speed reproduction) as the third embodiment is a process of the operation of writing the data read from the disk 1 into the buffer RAM 13 by the system controller 11 and the memory controller 12. Is the same as that during normal reproduction, but is realized by controlling the processing when reading data from the buffer RAM 13 as follows. In this case, while the data write operation is executed by the normal processing for the buffer RAM 13, the sector data from the buffer RAM 13 is read X times repeatedly for the 1 / X speed reproduction operation. .

FIG. 10 is a flow chart of the reading process from the buffer RAM 13. As the writing process to the buffer RAM 13, which is not shown, when the slow reproduction operation is started, the disc 1 is sector-by-sector unit at a predetermined timing. Data is read out and it is sequentially buffered RAM
It is written in 13. That is, the buffer RAM 13
As shown in FIG. 11, the storage status in the storage areas MA _{1 to} MA
_{In m} , data such as SC ₁ , SC ₂ , SC _3, ... Are sequentially stored in the normal state one sector at a time.

In response to this operation, in the read process from the buffer RAM 13, when the slow reproduction operation is started, the read address (read pointer) MAnn is first set to 1 (F
301). It is to be noted that MAnn = 1 is an example for description, and in practice, MAnn is a numerical value which becomes the first read address. Subsequently, the variable y for processing control is set to 0 (F302).

Then, the data for one sector is read from the address MAnn in the buffer RAM 13 (F303),
The data is supplied to the encoder / decoder unit 14,
It will be output as voice. That is, audio output for 63.8 msec is performed. Now increment the variable y
(F304), it is determined whether or not the variable y = X (F30
Five). When X = 2 is being executed during the 1/2 speed reproduction, y = 1 at this point, so the process returns to step F303 and proceeds again. Then, one sector of data, that is, the same data as the previously read data, is read from the address MAnn (F303), and audio output for 63.8 msec is performed.

Then, the variable y is incremented (F30
4), so that y = 2 and X = y, so step
Continue to F306. Here, the read address MAnn for the buffer RAM 13 is set to the address corresponding to the next sector (F306). Then, through step F307, F302
Then, the next sector data is read with the variable y = 0 (F303). Then, in the processing of steps F303 to F305, the next sector data is also read twice consecutively.

If the read address MAnn exceeds MAm, that is, the address of the last sector in the buffer RAM 13 at the time of step F307, the reading is continued in the ring form as described with reference to FIG. Therefore, the read address MAnn is set to 1 and the processing is continued (F307 → F301).

As described above, the same sector data is read twice from the buffer RAM 13 during the 1/2 speed reproduction, and when the 1/3 speed reproduction or the 1/4 speed reproduction is performed, the same sector data is read. Is read three times or four times, the audio output is 1/2 speed, 1 /
Slow playback of 3x speed, 1 / 4x speed, etc.

This slow reproduction operation is schematically shown in FIG. Now, assuming that an audio signal as shown in FIG. 12A is recorded in a certain sector SC _{1 to} SC ₄ on the disk, writing data to the buffer RAM 13 is a normal process, so the buffer RAM 13 The data will be stored in the table as shown in FIG.

Since the data is read from the buffer RAM 13 by the above processing, the audio signal actually reproduced and output in the 1/2 speed reproduction is the signal shown in FIG. 12 (c). This signal does not serve as an original reproduction signal because the output of each sector data is output in duplicate, but in this case as well, there is no particular discomfort in terms of actual hearing, and it is heard as if only the speed is slowed without changing the pitch.

Also in this embodiment, it is not necessary to reduce the number of rotations of the disk, and the slow reproduction can be easily performed only by the read control from the buffer RAM 13. Therefore, the sound quality is not deteriorated so much and the pitch is reduced. It is possible to obtain an easy-to-listen slow-playback sound that does not change. It should be noted that in this embodiment as well, processing may be performed in smaller data amount units such as sound group units or sound frame units. For example, each sound group may be read X times.

Although the first to third embodiments have been described above, the present invention is not limited to these embodiments and various modifications can be made. In particular, the actual writing process control to the buffer RAM 13 when the slow reproduction is performed by the method of the first and second embodiments, and the buffer RAM 13 when the slow reproduction is performed by the method of the third embodiment. Needless to say, various control procedures can be considered for the actual read processing control other than those shown in the above-described flowcharts.

Further, in the embodiment, the slow reproduction is realized by the special processing of either the writing processing control or the reading processing control of the buffer RAM 13.
Alternatively, both the writing process control as in the second embodiment and the reading process control as in the third embodiment may be executed to execute slow reproduction. Playback can be performed.

In the embodiment, the example in which the present invention is applied to the mini disk system has been described.
The present invention can be applied to any type of playback device such as a T player as long as it has a buffer RAM.

[0079]

As described above, the present invention stores the data read from the recording medium in the memory means once, reads the data from the memory means at a predetermined timing, and reproduces and outputs the data. Since the slow-motion is realized by controlling the write operation or the read operation with respect to, the effect that the slow-motion can be easily performed without requiring a special circuit configuration such as lowering the rotation speed of the disk. Therefore, there is also an effect that the slow reproduction sound quality is not significantly deteriorated, and the slow reproduction sound which is easy to hear and whose pitch is not changed can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a buffer RAM operation of the embodiment.

FIG. 3 is an explanatory diagram of a buffer RAM operation of the embodiment.

FIG. 4 is a flowchart of a buffer RAM writing process of the first embodiment.

FIG. 5 is an explanatory diagram of a buffer RAM writing state according to the first embodiment.

FIG. 6 is an explanatory diagram of an operation during slow playback according to the first embodiment.

FIG. 7 is a flowchart of a buffer RAM writing process of the second embodiment.

FIG. 8 is an explanatory diagram of a buffer RAM write state of the second embodiment.

FIG. 9 is an explanatory diagram of an operation during slow playback according to the second embodiment.

FIG. 10 is a flowchart of a buffer RAM reading process according to the third embodiment.

FIG. 11 is an explanatory diagram of a buffer RAM writing state of the third embodiment.

FIG. 12 is an explanatory diagram of an operation during slow reproduction according to the third embodiment.

FIG. 13 is an explanatory diagram of a sector structure of a disc.

[Explanation of symbols]

 1 Disk 3 Optical Head 8 Encoder / Decoder Unit 11 System Controller 12 Memory Controller 13 Buffer RAM 14 Encoder / Decoder Unit 15 D / A Converter 18 A / D Converter 19 Operation Input Unit 20 Display Unit

Claims (3)

[Claims] 1. A reproducing apparatus adapted to temporarily store data read from a recording medium in a memory means, and read out the data from the memory means at a predetermined timing to reproduce and output the data. The control is such that the same data is stored in the memory means X times for each predetermined data amount unit, and the data can be sequentially read from the memory means at a predetermined timing. A reproducing device characterized by being provided with a means so that reproduction output at a speed of 1 / X times can be executed. 2. In a reproducing apparatus adapted to temporarily store data read from a recording medium in a memory means and read the data from the memory means at a predetermined timing to reproduce and output data, regarding the data read from the recording medium. After the storage in the memory unit in a predetermined data amount unit, dummy data in the same data amount unit is stored in the memory unit every (X-1) times, and from the memory unit, A reproducing apparatus characterized in that it is provided with control means capable of performing control so as to read data sequentially at a predetermined timing, and is capable of performing reproduction output at a speed of 1 / X times. 3. A reproducing apparatus adapted to temporarily store data read from a recording medium in a memory means, and read the data from the memory means at a predetermined timing to perform data reproduction output. A control means is provided which can perform control such that the data is sequentially stored in the memory means and the data stored in the memory means is read X times for each data of a predetermined data amount unit. A reproducing apparatus configured to be capable of executing reproduction output at a speed of / X times.