JPS5830647B2 - Digital signal recording and reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital signal recording and reproducing apparatus that facilitates reproducing digital signals recorded on a recording medium.

When recording digital signals on a magnetic tape and reproducing them, with conventional technology there is a difference between the time it takes to record and process a certain amount of data and the time it takes to reproduce it.Generally, the recording processing time is longer. Few.

Therefore, when the recording side encodes a certain amount of data as a digital signal, records it on a magnetic tape, and then reproduces this recorded signal to obtain the original data, it is necessary to transfer the data from the magnetic tape to the head. Even though the reproduction has been completed, the reproduction processing device has not yet finished processing the reproduced signal, resulting in omission of reproduction of the remaining data.

For example, while measuring the disturbance noise of a servo motor,
When data from a data source is continuous, high-speed, and large-capacity, such as when recording measured data, it is not possible to stop recording midway, so conventionally, data is A method was adopted in which recording was divided into parts according to the playback processing capacity.

As a method for this divisional recording, the recording device is equipped with a high-speed storage device as a buffer memory for the amount of data that the playback processing device can process at one time (standard s, ooo bits).
There is a method of recording data on magnetic tape at a speed higher than the data speed output by the data source, and then setting an inter-record cap as a delimiter mark for each s, ooo bit, but this requires a large capacity buffer memory. There were some problems.

There is also a method of inserting and recording a block code as a block delimiter mark for each s and ooo bit of the recorded signal, but it is not possible to record the data that occurs during the time when this block code is recorded, or the data cannot be stored in a temporary buffer. When recording the data following a block code by placing it in a sofa memory, these block codes and the memorized data must be inserted and recorded properly, so the control method during recording is extremely complicated. there were.

The present invention is intended to solve the above problems, and includes forming an information track of a digital signal and a clock pulse track on a recording medium, and recording divided mark pulses on the clock pulse track at predetermined intervals. , the divided mark pulses are detected during reproduction to control running and stopping of the recording medium.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a magnetic tape 1 recorded by the recording/reproducing apparatus of the present invention, on which a data track 2 and a clock track 3 are formed.

On the data track 2, a digital signal 4 obtained by digitizing data by, for example, NRZ modulation is recorded.
In the clock track 3, a clock pulse 5 is recorded at a predetermined clock frequency, and mark signals 6a, 6b, 6c, and 6d are also recorded at predetermined intervals, for example, every 900 bytes.

Further, the data signals 4 between the mark signals 6a, 6b, 6c, and 6d are shown as blocks 4a, 4b, and 4c, respectively.

The mark signals 6a, 6b, 6c, and 6d are signals in which a pulse having a frequency twice that of the clock pulse 5 is recorded using 8 bits of the clock pulse 5, as shown in FIG.

Next, a specific example of a recording device for recording signals on the magnetic tape 1 will be described.

In FIG. 3, the information signal from the data source 7 is encoded by the data recording device 8, becomes a digital signal by NRZ modulation, for example, and is sent to the data track 2 of the magnetic tape 1 of the tape deck 9 via the head 9a. recorded.

At the same time, based on the clock pulse from the data recording device 8, the mark signal generator 10 generates, for example, 9 of the data signal.
The output clock pulse from the clock pulse generator 11 is controlled so that the frequency is doubled by 8 bits every 00 bytes, and the clock pulse containing the mark signal from the clock pulse generator 11 or the magnetic tape of the tape deck 8 is controlled. The data is recorded on the clock track 3 of No. 1 via the head 9a.

Through the above steps, the magnetic tape 1 shown in FIG. 1 can be obtained.

Note that block 4a between mark signals 6a, 6b, 6c, and 6d
, 4b, 4c is not limited to 900 bytes, but the amount that the playback processing device can process at once, that is, the standard is 8,00 bytes.
It is sufficient if it is within 0 bits.

Furthermore, the frequencies of the mark signals 6a, 6b, 6c, and 6d are not limited to twice the clock pulse 5, and pulses of any frequency can be used.

Further, the magnetic tape 1 can be a digital cassette tape, and therefore the tape deck 8 can also be a cassette tape recorder.

Next, the recording device shown in Fig. 3 (the magnetic tape 1 recorded by this
The regeneration processing device and its regeneration processing method will be explained with reference to FIG.

It is assumed that the clock pulse read head and data read head 9b of the tape deck 9 are located at point A in Figure 1.

First, the mark passing flip-flop 13 is reset by a reset signal from the control processing section 12.

Next, the forward mechanism 14 of the tape deck 9 is operated based on the forward read command signal from the control processing section 12.

As a result, the magnetic tape 1 runs in the forward direction, and the head 9
Clock pulse 5 and digital signal 4 are read out by b.

When the head 9b reads the mark signal 6a, the mark detection circuit 15 operates and sends a set signal to the mark passing flip-flop 13.

This set signal causes the mark passing flip-flop 13 to
is set and sends a mark passage signal to the control processing unit 12, and based on this, the control processing unit 12 changes the shift register 16.
At the same time, the mark passing flip-flop 13 is reset.

During this time, the data read by the head 9b is being applied to the data reading circuit 17, and this circuit 17 has started operating in response to the forward command signal.

In addition, the read clock pulse is sent to the mark detection circuit 15.
It is added to the data readout circuit 17 to detect the mark signal and is also added to the data readout circuit 17.

This data reading circuit 17 sends the data sent from the helad 9b to the shift register 16 as a serial data signal based on a clock pulse.

The data transfer signal based on the detection of the mark signal 6a causes the shift register 16 to operate, converting the serial data signal into, for example, an 8-bit parallel data signal and transmitting the signal to the control processing unit 1.
Send to 2.

The control processing unit 12 starts processing the data of the data block 4a after the mark signal 6a.

This data can be sent to, for example, another computer (not shown) and recorded on another magnetic tape or the like.

Next, when the magnetic tape 1 further travels and the mark signal 6b is detected, the mark detection circuit 15 operates, and the mark passing flip-flop 13 is set again by the set signal, and the mark passing signal is sent to the control processing section. Added to 12.

Based on this, the control processing unit 12 issues a read stop signal, and from this signal σ, the forward mechanism 14 stops and the magnetic tape 1 stops running, and the shift register 16
also stops sending data to the control processing unit 12.

When the control processing unit 12 completes the data processing of the block 4a, the head 9b passes through the mark signal 6b due to the inertia of the forward mechanism 14, enters the block 4b, and stops.

When the data processing is completed, the control processing section 12 sends a reset signal to the mark passing flip-flop 13 and sends a backward command signal to the back mechanism 18.

As a result, the magnetic tape 1 runs in the opposite direction, and the mark detection circuit 15 detects the mark signal 6b again.

Therefore, the mark passing flip-flop 13 is set and the mark passing signal is applied to the control processing section 12.

Based on this, the control processing unit 12 issues a read stop signal, whereby the back mechanism 18 is stopped, and the head 9b passes through the mark signal 6b due to inertia, enters the block 4a, and stops.

This state is the same as the state in which the head 9b is at point A on the magnetic tape 1 in FIG.

Therefore, by next pressing the start button of the tape deck 9, the control processing unit 12 sends the mark passing flip-flop 1 to the mark passing flip-flop 1.
3, a reset signal is applied to read the data of block 4b in the same order as the above-described operation from point A,
This can be handled.

Similarly, the data of each block between each mark signal can be sequentially reproduced.

In the above description, the magnetic tape 1 shown in FIG. 1 has one data track 2, but it is of course possible to form a plurality of data tracks.

The present invention forms a recording medium 11 that runs on an information track 2 on which a digital signal 4 is recorded and a clock pulse track 3 on which a clock pulse 5 is recorded, and the digital signal 4 is recorded every predetermined amount of information. Mark signals 6a to 6d having a frequency different from that of the clock pulse 5 are recorded on the clock pulse track 3 at predetermined intervals, and when the mark signal is detected during reproduction, the recording medium is stopped and the reproduction is performed. When the reproduction processing of the digital signal having the predetermined amount of information is completed, the recording medium is run in the opposite direction, and when the mark signal is detected, the recording medium 1 is stopped and reproduction is started again. The present invention relates to a digital signal recording and reproducing device characterized by the following.

Therefore, the present invention is particularly effective when recording and reproducing signals that have a large amount of recorded data and cannot be recorded on magnetic tape or the like by interrupting data generation. .

In particular, by detecting mark signals during reproduction, data can be reproduced using a simple control system without using a large-capacity buffer memory or the like.

[Brief explanation of the drawing]

FIG. 1 is a front view of a magnetic tape on which signals are recorded using the recording method according to the present invention. FIG. 2 is an enlarged view of the main part of FIG. 1, FIG. 3 is a block diagram of the recording device, and FIG. 4 is a block diagram of the reproduction processing device. Further, in the symbols used in the drawings, 1 is a magnetic tape, 2 is a data track, 3 is a clock pulse track, and 6a, 6b, 6c, and 6d are mark signals.

Claims (1)

[Claims] 1. At the time of recording, an information track for recording a digital signal and a clock pulse track for recording a clock pulse are formed on a running recording medium, and the digital signal is divided into l pieces for each predetermined amount of information, and the clock pulse is Recording mark signals having different frequencies on the clock pulse track at predetermined intervals, stopping the recording medium when the mark signal is detected during reproduction, and reproducing the reproduced digital signal having the predetermined amount of information. 2. A digital signal recording and reproducing apparatus, characterized in that the recording medium is run in the opposite direction when the mark signal is detected, and when the mark signal is detected, the recording medium is stopped and reproduction is started again.