JPH06290533A - Synchronized recording and reproducing device - Google Patents

Abstract

PURPOSE:To record data nearly in real time and to work for a long time by dividing and recording input data in using more than one recording and reproducing device having a different transfer rate respectively. CONSTITUTION:A (p) number of low transfer rate digital audio tape recorders DATs 18 having a transfer rate (m) and a (q) number of medium transfer rate magneto-optical recording and reproducing devices MOs 19 having a transfer rate (n) are used. Then, recording data having a transfer rate (pm + qn) is divided in pm : qn by a distributor 12, and the divided ones are converted into serial data of 4 bits and 12 bits respectively by P/S converters 13 and 14. Subsequently, they are converted into formats based upon a DAT format respectively by signal processing circuits 16 and 17, and are recorded in the corresponding DATs 18 and MOs 19. By this method, since read speed of the converters 13 and 14 can be decelerated, even input data that is faster than a transfer rate of a recording and reproducing part can be recorded and reproduced in real time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous recording / reproducing apparatus suitable for application to a digital audio tape recorder or the like, and in particular uses a plurality of recording / reproducing units having different transfer rates.
The present invention relates to a synchronous recording / reproducing apparatus capable of recording data at a transfer rate higher than the transfer rate recordable by the recording / reproducing unit at a speed close to real time.

[0002]

2. Description of the Related Art The transfer rate of input data to be recorded is
If it is faster than the transfer rate that can be handled by the recording / reproducing apparatus, a memory means for normal buffer is prepared, and the transfer rate of the input data is reduced to the transfer rate that can be handled by the recording / reproducing apparatus, and recording / reproducing is performed in that state. .

For example, since the transfer rate of data output from a computer or the like is 3 Mbps or 6 Mbps, if this is recorded as a backup device (data streamer) using a digital tape recorder (DAT) or the like, Since the transfer rate that can be handled by DAT is up to approximately 1.5 Mbps, the recording data of the high transfer rate is once dropped to 1.5 Mbps and the data is recorded.

[0004]

Therefore, when a recording / reproducing apparatus having such a low transfer rate is used, it takes a long time to record data, and real-time recording processing cannot be performed.

As a recording / reproducing apparatus having a transfer rate higher than that of DAT, a magneto-optical recording / reproducing apparatus (MO) using a rewritable magneto-optical disk is known.
As is well known, this magneto-optical recording / reproducing apparatus has a recording capacity of DA.
Less than T. Therefore, the recording time cannot be sufficiently shortened even by the magneto-optical recording / reproducing apparatus alone, and since the capacity is small, it cannot be operated for a long time.

Therefore, the present invention solves the above-mentioned conventional problems, and by skillfully combining a recording / reproducing apparatus having a low transfer rate and a recording / reproducing apparatus having a medium transfer rate, the present invention can be realized in almost real time. The present invention proposes a synchronous recording / reproducing apparatus capable of achieving near data recording and operating for a long time.

[0007]

In order to solve the above-mentioned problems, the invention described in claim 1 has a recording / reproducing unit having a transfer rate m (m is an integer) and a transfer rate n (n is an integer). And has a recording / reproducing unit of m ≠ n), and (pm + qn)
The recording data with the transfer rate (p and q are integers) is p
It is characterized in that the data is divided into m: qn, the transfer rate is converted into m and n, and then dividedly recorded in synchronization with the corresponding recording / reproducing section.

According to a second aspect of the present invention, p (p is an integer) recording / reproducing units having a transfer rate of m (m is an integer), and the transfer rate is n (n is an integer, and m ≠). n) q
(Q is an integer) recording / reproducing units are provided, and the data divided and recorded in each of these recording / reproducing units is synchronously reproduced, and by combining these data, a transfer rate of (pm + qn) is obtained. It is characterized in that the possessed data is reproduced.

[0009]

According to the present invention, input data is divided and recorded by using one or more recording / reproducing units having different transfer rates. In FIG. 1, the DAT 18 is used as a recording / reproducing unit having a low transfer rate (= m), and the MO 19 is used as a recording / reproducing unit having a medium transfer rate (= n). Since m: n = 1: 3, the input data is also divided in proportion to the ratio of this transfer rate, and in the case of the 16-bit structure, it is divided into the lower 4 bits and the remaining 12 bits.

The transfer rate of DAT is approximately 1.5 Mbps.
Since the transfer rate of MO19 is about 4.6 Mbps, when using one DAT 18 and one MO19, the transfer rate of input data can be up to about 6.1 Mbps.

16-bit parallel input data with a transfer rate of 6.1 Mbps is divided into 1: 3 by the distributor 12,
These are converted into serial data (4 bits and 12 bits) by the parallel / serial converters 13 and 14, respectively.

In the parallel / serial converter 13, 1.5
The serial data is read at a Mbps clock and is output in 16-bit units, and the other parallel / serial converter 14 is read at a 4.6 Mbps clock. In this case as well, serial data in 16-bit units is output. Is output.

These are DAT in the signal processing circuits 16 and 17.
Format conversion is performed in conformity with the above format and recorded in the corresponding DAT 18 and MO 19.

If the input data is divided and recorded according to the transfer rate of the recording / reproducing section in this way, the reading speed in the parallel / serial converters 13 and 14 can be slowed down, so that it is higher than the transfer rate of the recording / reproducing section. Even fast input data can be recorded and played back in real time.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an example of the synchronous recording / reproducing apparatus according to the present invention will be described in detail with reference to the drawings. In the embodiment, the rotary DAT described above is used as the recording / reproducing unit with the transfer rate m.
Is an example of the above-mentioned rewritable MO as a recording / reproducing unit having a transfer rate n. The transfer rate of DAT is almost 1.5 Mbps (actually 1.536 Mbps),
Since the transfer rate of MO19 is approximately 4.6 Mbps (actually 4.608 Mbps), DAT18 and MO1
When 9 units are used one by one, the transfer rate of input data can be up to about 6.1 Mbps (actually 6.14 Mbps).

According to the present invention, even if input data having a transfer rate faster than any transfer rate of the recording / reproducing section can be recorded / reproduced at a speed close to real time, especially the input data is finally transferred. Rate ratio (m:
n) (m and n are integers), the transfer rate is substantially reduced, and data of a predetermined number of bits divided in this state is divided and recorded and reproduced while being synchronized using a plurality of recording / reproducing units. It was done like this.

In this way, no matter how fast the transfer rate of the input data is, if the number of recording / reproducing units to be used is increased, the input data can be recorded / reproduced at a speed close to real time.

FIG. 1 shows the structure of a recording system 10 of the synchronous recording / reproducing apparatus constructed on the basis of the above concept, and the input data supplied to the terminal 11 is shown in FIG. It is assumed that the input data is 16-bit parallel data and the transfer rate is 6.1 Mbps. Most of the data having such a transfer rate is data output from a computer or the like, and therefore the recording / reproducing apparatus in this case is used as a data streamer.

When the input data has a transfer rate of 6.1 Mbps, one DAT 18 and one MO 19 are used due to the data division ratio.

The input data supplied to the terminal 11 is distributed 1: 3 in the distributor 12. That is, the lower 4 bits AL, BL, CL, ... (AL of 16-bit parallel data A, B, C ,.
Indicates A0 to A3. Same as below) and upper 12 bits AH,
BH, CH, ... (AH indicates A4 to A15. The same applies hereinafter).

Each of the 4-bit and 12-bit parallel data distributed in two is converted into 16-bit serial data by the parallel / serial converters 13 and 14, respectively. FIG. 3 shows an example of parallel / serial conversion for the upper 12 bits. All 12 bits of the word data AH and the lower 4 bits of the next word data BH are output in units of 16 bits.

Since the transfer rate for one word of the input data is 6 Mbps as described above, the time for converting 12 bits of the two input words into serial data corresponds to 3/4 of 6 Mbps. Just MO19
The transfer rate will be 4.6 Mbps. Therefore, even if the input data is 6 Mbps per word, it can be recorded at a speed close to real time in the recording / reproducing unit slower than the transfer rate on the input side by dividing the input data.

The lower 4 bits are serial / parallel converted using a total of 4 words (see FIG. 4). Since the original input data for 4 words is used, the transfer rate of 16-bit data after serial / parallel conversion is about 1/4 of the transfer rate of input data.
Data after parallel / serial conversion can be reliably recorded using the transfer rate of AT18 (= 1.5 Mbps).

Therefore, the system controller (CPU) 15 which controls the entire apparatus has a transfer rate of 1.5 Mbps for the parallel / serial converters 13 and 14.
And a clock CK that provides 4.6 Mbps.

Serial data of 1.5 Mbps and 4.6 Mbps having a 16-bit structure are synchronously supplied to the signal processing circuits 16 and 17, respectively, and converted into a data format compliant with the data formats of DAT and MO. Additional data as shown in 5 is added. The additional data refers to sub data, header data and sync data added for the first time in the present invention.

A running time (R-TIME) as recording time information is applied to the sub data. The header data is added only in the first and last predetermined periods of the main data area as shown in FIGS. 6 and 7, respectively.

The header data is used for data detection, and the sync data is used for synchronous reproduction during reproduction. Since the DAT 18 has a frame sync f · sync, it can be synchronized with the other recording / reproducing unit on the basis of the frame sync f · sync, but the MO 19 has such a frame sync f · sync.
c does not exist. Therefore, as shown in FIGS. 6 and 7, sync data for a predetermined period is added immediately after the header.

Since the access time of the MO 19 requires about 70 msec, it is selected so that at least the access time is equal to the predetermined period T. Now 1
When 6 bits are regarded as one block, 8192 blocks are just 85 msec. Therefore, in this example, 8192 blocks, that is, 131 K bits are added as sync data after the header. As the sync data, a combination of 16-bit data that does not exist in the data recorded in the main data area or the control data is selected. In this example, the header is also inserted by the same 131K bits as the length of the sync data.

The above-mentioned signal processing circuits 16 and 17 are of a digital audio interface (DAI) structure and have a function of internally oscillating a head switching pulse, a frame sync, etc. based on input data. In FIG. 5, ATF is data for auto-tracking well known in DAT.

The serial data thus added with the predetermined additional data is recorded on the magnetic tape (not shown) loaded in the DAT 18 while maintaining the relationship with the frame sync shown in FIG. 5A (FIG. 5B). At the same time, data is recorded on the disk D (see FIG. 8) of the MO 19 in units of 16 bits in synchronization with the DAT 18.

In recording the data on the disk D, in the MO of the type in which the data is erased, the data is recorded next, and then the verify is the recording monitor,
As the disk D to be used, a raw disk (a disk on which data has not been recorded yet) is used.

This is because when the erasing / recording / verifying mode is performed, three modes must be set for each recording, so that the transfer rate is 4.6 / 3 = 1.6 Mbps as compared with the recording only mode. Because it will fall into. If the MO does not adopt such a mode, the transfer rate does not decrease, so that there is no limitation on the disk use described above.

FIG. 8 shows a reproducing system 2 in the synchronous recording / reproducing apparatus.
A specific example of 0 is shown. The control unit 15 is the same as the recording system 10. The DAT 18 has a rotary drum 21 for recording and reproduction, and the CPU 2 which controls the DAT itself inside thereof.
2a is built in. Reference numeral 23 is a basic clock generating circuit for driving the CPU 22a, and a crystal oscillator is used as an oscillating element.

In the MO 19, D is a disk, H is a data writing head, 22b is a CPU, and 25 is an optical pickup means. Further, a voltage controlled oscillator VCO24 is provided inside, the system controller 15 compares the sync data detected by DAT18 and MO19, and the basic oscillation frequency of this VCO24 is controlled based on the control signal CTL which is the comparison output. , D
AT18 and MO19 can be operated synchronously.

16-bit unit serial data reproduced synchronously from the DAT 18 (transfer rate thereof is 1.5 Mbp.
s) is supplied to the memory means 26 for time axis correction, and is read by a clock (read clock) CK whose time axis is aligned. The read clock of the memory means 26 is 1.5 MHz (specifically 1.536 MHz) shown in FIG. 9D,
The read data is converted by the serial / parallel converter 28 into parallel data (E, F, and G) in 4-bit units, and then supplied to the bit synthesizer 30 in 1-word units (H in the drawing).

On the other hand, the memory means 27 corrects the time axis of the 16-bit data reproduced synchronously from the MO 19. The read clock CK with a uniform time axis is shown in FIG. 9A.
The 16-bit serial data (shown in FIG. 9B) with the time axis corrected is 4.6 MHz (specifically, 4.608 MHz) shown in FIG. This 12-bit parallel data that has been converted (C in the same figure) is combined with the preceding 4-bit parallel data in the combiner 30.

Therefore, the serial / parallel converter 28
One word of 4-bit parallel data from
When it is L, the 12-bit parallel data output from the other serial / parallel converter 29 at the same timing becomes AH. Therefore, if both are simultaneously output from the synthesizer 30, the 16-bit parallel data will be output. A (= AH + AL) is obtained. If the bit clock given to the synthesizer 30 is a clock corresponding to 6.1 Mbps, the transfer rate of the output parallel data A becomes 6.1 Mbps, and the same data as the original transfer rate can be output.

FIG. 10 shows an example of a control flowchart for synchronous reproduction. Since the example of FIG. 8 is an example of performing the reproduction operation by synchronizing the MO 19 with the DAT 18, FIG. 10 also has such a control mode.

First, the DAT 18 side is set to the play mode and waits until the servo lock is applied. When the servo lock is applied, the header is detected (steps 41 and 42). MO1
On the 9 side, the play mode is controlled for the first time when the DAT 18 servo lock is applied, and the header is detected.
In this state, the pause mode is set (step 52).

The processing on the DAT 18 side is preceded in this way because it takes a longer time for the DAT 18 to servo lock.

When the header is detected on the DAT 18 side, MO
The pause mode on the 19 side is released (step 53),
At the same time, the sync data counting process is started (steps 44 and 54). Then, the reproduction speed control processing on the MO 19 side is performed while comparing the sync data obtained from both (steps 55 and 56), and the synchronous reproduction becomes possible by such speed control processing.

When the sync data is reproduced for a predetermined block (8192 blocks) while performing the synchronous reproduction (steps 47 and 57), the data loading process to the memory means 26 and 27 is performed (steps 48 and 58). This data loading process is performed until all the data is loaded (steps 49 and 59), and when all the data is loaded and the end ID is detected, this synchronous reproduction process ends.

In the above description, one DAT and one MO are used to divide input data having a high transfer rate for recording and reproduction, but the number of DATs used is determined by the transfer rate of the input data. If, for example, the transfer rate of the input data is 12 Mbps, D
By using two ATs (p = 2) and two MOs (q = 2), input data can be divided and recorded at a speed close to real time, so the transfer rate and the number of recording / playback units used are limited. Not something that can be done.

Although DAT and MO have been exemplified as the recording / reproducing unit having different transfer rates, other data recording / reproducing devices can be used.

[0045]

As described above, in the synchronous recording / reproducing apparatus according to the present invention, the recording / reproducing sections having different transfer rates are used to synchronously record the input data while dividing the input data according to the transfer rate. Is.

According to this, input / output data can be recorded / reproduced at a large recording capacity and at a speed close to real time by skillfully utilizing the recording / reproducing units having different transfer rates, and the recording time can be greatly increased as compared with the conventional case. Not only can it be shortened, but it also has features such as long-term operation. Therefore, the present invention is extremely suitable when applied to a data streamer that records a large amount of data having a high transfer rate such as output data of a computer.

[Brief description of drawings]

FIG. 1 is a system diagram of a main part showing a recording system in a synchronous recording / reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing an input data structure.

FIG. 3 is a diagram showing a data structure to be recorded on a tape.

FIG. 4 is a diagram showing a data structure to be recorded on a tape.

FIG. 5 is a diagram of a data format.

FIG. 6 is a diagram showing a data format in a main data area.

FIG. 7 is a diagram showing a data format in a main data area.

FIG. 8 is a system diagram of a main part showing a reproducing system in the synchronous recording / reproducing apparatus according to the present invention.

FIG. 9 is an explanatory diagram of a timing chart during synchronous reproduction.

FIG. 10 is a flowchart showing an example for synchronous reproduction.

[Explanation of symbols]

 10 recording system 12 distributor 13 and 14 parallel / serial converter 15 control unit 16 and 17 signal processing circuit 18 and 19 recording and reproducing unit (DAT, MO) 20 reproducing system 26 and 27 memory means 28 and 29 serial / parallel converter 30 synthesizer

Claims (4)

[Claims] 1. A recording / reproducing unit having a transfer rate of m (m is an integer) and a recording / reproducing unit having a transfer rate of n (n is an integer, m ≠ n), and (pm + qn) (p, Recording data having a transfer rate of q is an integer) is divided into pm: qn and the transfer rate is m.
A synchronous recording / reproducing apparatus, wherein the recording / reproducing section is divided into two parts, and converted into n, and then dividedly recorded in synchronization with the corresponding recording / reproducing section. 2. p (p is an integer) recording / reproducing units having a transfer rate of m (m is an integer) and q (q) of a transfer rate of n (n is an integer and m ≠ n). Is a whole number), and the data divided and recorded in each of these recording / reproducing sections are synchronously reproduced, and by combining these data, data having a transfer rate of (pm + qn) is obtained. A synchronous recording / reproducing apparatus characterized by being adapted to be reproduced. 3. A synchronous recording / reproducing apparatus according to claim 1, wherein a digital audio tape recorder is used as the recording / reproducing unit having a transfer rate of m. 4. The synchronous recording / reproducing apparatus according to claim 1, wherein a magneto-optical disk device is used as the recording / reproducing unit having a transfer rate of n.