JPS6226606A - Recording method - Google Patents

Abstract

PURPOSE:To execute continuously the long time recording by rotating the rotating head, different from the speed synchronized with the cycle of one inherent unit period and recording the signal at the successively different position on the tape. CONSTITUTION:The rotating head, in which (n) pieces of head are provided, is rotated by {1+ or -1/(N - or + 1)}.360/n deg. during one unit period, the signal during one unit period is compressed to 1/N, the compressed signal is successively recorded to respective scopes where the scope wound by 360/n deg. of the rotating head of the tape is equally divided into (N - or + ) for one unit period. Thus, by rotating the head by {1+ or -1/(N - or + 1)}.360/n deg. for one unit period, the signal can be successively recorded to the adjoining scope on the tape for one unit period, and therefore, the signal can be continuously recorded over the hole surface of the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for recording, for example, a PCM audio signal using a rotating head.

[Summary of the invention]

The present invention relates to a signal recording method using a rotary head, in which the rotary head is rotated at a speed different from the original period synchronized with the period of one unit period, and signals are sequentially recorded at specific positions on a tape. It is designed to record for a long time.

[Conventional technology]

For example, there is a standard called 8mm video. According to this standard, the tape is wound around a rotating head provided with two heads, for example, over 216 degrees.
A PCM in which the audio signal for one field period is AD converted into a 36-degree range on the head entry side, and an error correction code, preamble, postamble, etc. are added, and the whole is compressed into one time. The signal is recorded. and the remaining 180
A video signal of one field is recorded within a range of 100 degrees.

By the way, in this standard, the range of 180 degrees in which a video signal is recorded becomes 36 degrees when divided into five equal parts.

Therefore, it was proposed to create a recording and reproducing device exclusively for audio signals by utilizing the device of this standard (Japanese Patent Laid-Open No. 58-2
(See Publication No. 22402).

According to this, the original video signal range (180 degrees) is divided into five equal parts ( audio signals can be recorded independently in each segment). This makes it possible to record 24 hours of audio signals using a tape capable of recording 6 times the original recording time, for example 4 hours, including the range of existing audio signals.

However, with this device, recording of an arbitrary segment reaches the end of the tape and continues until the end of the tape 'ff:
If you want to continue, you have no choice but to rewind the tape to the beginning, switch to another segment, and restart recording, or switch to reverse running mode, switch to another segment, and restart recording. Recording is not possible for several minutes or seconds. Since the above-mentioned apparatus is particularly intended for long-time recording, the occurrence of such a recording-unavailable time has a great possibility of causing inconveniences and malfunctions.

It is also possible to change the time axis and record the signals for several seconds required for reversing the running direction before and after the reversal, but this would require a complicated and expensive device such as a memory.

[Problem that the invention seeks to solve]

The conventional recording method described above has a problem in that it is not possible to record continuously for a long time.

[Means for solving problems]

The present invention uses a rotary head provided with n (2) heads to transmit a signal of a period of 1 (1 field) in 1 unit period (1 field).
↓), and this compressed signal is compressed once (180 degrees) of the rotating head of the tape for each unit period.
This is a recording method in which 11M-order recording is performed in each range obtained by dividing the range wrapped around (N king 1) into equal parts (four equal parts).

[For production]

According to this method, the rotating head is rotated in one unit period (1±
1) By rotating 360 degrees, the signal N+i
Since n is sequentially recorded in adjacent ranges on the tape every unit period, signals can be continuously recorded over the entire surface of the tape.

〔Example〕

Although the present invention is applicable to all nine recording devices using a rotating head, in the following explanation, the method of the present invention is first applied to the above-mentioned 8 mm video standard, and the video signal is recorded. A case will be described in which the entire audio signal is recorded within a 180 degree range.

In that case, the above value is n=2. N=5.

Also, one unit period is defined as one field of the video signal, and during this period, the rotating head is (1+, ) 7 = 2252
Rotate 25 degrees.

As a result, the recorded pattern on the tape becomes as shown in FIG.

In other words, in the figure, the original PC at 36 degrees is on the tape.
A recording range (1) for the M signal and a recording range (2) for the original video signal of 180 degrees are provided9, and only the range (2) of these is used in the method of the present application.

And first, in the first field, the PC of this field
If the starting edge of the M signal coincides with the scanning edge of one head (A) of the rotary head to range (2), and the PCM signal compressed to 100 is recorded from this position, this recording will be As shown in (2a) in the figure, scanning is performed within a range of 45 degrees from the starting edge of the scan.

Next, in the second field, since the rotary head is rotated 225 degrees in one field, the other head of the rotary head (
B) is at a position of 45 degrees from the start of the scan to range (2). Therefore, when a PCM signal compressed by 100 is recorded from this position, this recording is performed in the range of 45 to 90 degrees of scanning, as shown by (2b) in the figure.

Furthermore, the third. Similarly, for the fourth field, one head (A) and the other head (B) are set at 90 to 135 degrees and 135 to 18 degrees, respectively, as shown in (2c) and (2d) in the figure.
Recording is performed in the range of 0 turns.

At the beginning of the PCM signal of the fifth field, one head comes to the end of scanning to range (2), but at this time, the other head (B) comes to the beginning of scanning to range (2). This is exactly the same, except that the start end of the PCM signal of the first field described above and the header A) (B) are exchanged. Therefore, the above-described operations are repeated, and the PCM signals are continuously recorded.

This is how the PCM signal was recorded, and according to this method, the signal can be recorded continuously over the entire surface of the tape.

In this case, as is clear from the explanation of the fifth field above, the range (2a
) to (2d) and the head that records the same range in each of the next four fields, heads (A) and (B) have been swapped, and the heads are compatible with the 8 mm video standard. (If the anomalous angles of A>(B) are different, it is possible to perform high-density recording excluding the guard band.Note that recordings with the same azimuth are adjacent at the beginning and end of each range, but this part Since this is a period for signal blurring, postamble, etc., there is no effect on playback.

Furthermore, each of the above ranges (2a) to (2d) is 4
Since recording is performed only once in the field Vc, even if the tape transport speed for recording is set to 1, which is the same as for original recording such as video recording, the same recording run width as for original recording can be obtained.

Therefore, according to this method, it is possible to record audio signals for 16 hours using a tape capable of recording four hours, for example, four hours as long as the original recording time. Additionally, four hours of recording can be performed, albeit discontinuously, within the range of the existing audio signal, making the total recording time 20 hours.

In other words, although the recording time is somewhat shorter than when the recording range of the video signal is divided into five equal parts, the method of the present invention is extremely effective in that 16 hours of that range can be recorded completely continuously. .

Further, according to this method, the existing 8 mm video signal system does not require any changes at all; it is only necessary to increase the rotational speed of the rotary head by a factor of 1 and to slow down the tape transport speed to τ.

That is, in the time chart of FIG. 2, for each field period as shown in FIG. 2A, a PCM signal is formed at the end of the field as shown in FIG. 2B. On the other hand, when the rotary head is rotated to make one revolution every π seconds, the phase becomes as shown in C in the figure. In the figure
The part A is the period when the head (4) opposes the range (2), and the part low is the period when the head (B) is in contact with the range (2). From this figure, it is clear that the PCM signals of the 4th and 5th fields are recorded with the same head function B).

In this case, in order to control the rotating spatula so that it rotates once every two seconds, generate and select signals every 45 degrees from the signals shown in C in the above diagram obtained from the PG. It is only necessary to generate all the signals shown in A in the above-mentioned figure, and to supply this signal to the rotary THERM system of the RAD. In this case, the rotary head's sensor is driven synchronously as shown in the dynamic range of the system.The rotary head rotates once per second. Instead, by supplying it to the PCM signal system, a PCM signal is formed at the timing B in the above diagram.

Therefore, in this method, when reusing an existing 8mm video device, all you need to do is add a configuration to form the signal A from the signal C in the diagram above, and set the tape transport speed to 1. Continuous long-term recording can be achieved with the configuration remaining completely unchanged.

Note that the method of the present application is not limited to the case where 8 mm video is used, but can be realized using any other number of heads and compression ratio.

In that case, if high-density recording is performed using the 7 azimuth loss of the head, it can be made possible by setting the number of equally divided ranges of the tape to an integral multiple of the number of azimuth types. .

Further, according to this method, the relative speed of the head during recording is fast, so it is suitable for recording high frequency PCM signals. Also, although the tape transport speed is slow, the track width is wide, so S
/N and other characteristics are good. Furthermore, since the amount of data in one recording is, for example, one field, the memory capacity of the circuit system can be small.

Furthermore, since the tape transport speed during recording is fast, when performing so-called search playback, the proportion of the speed during search increases by the slow transport speed during recording, making extremely high-speed search playback possible.

〔Effect of the invention〕

According to this invention, since the rotating head is used to record signals in adjacent ranges on the 111th tape every unit period, it is possible to record signals continuously over the entire surface of the tape. Ta.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a tape pattern according to the present invention;
FIG. 2 is a diagram for explaining this. (1) is the PCM recording range, (2) is the video recording range, (
2m) to (2d) are equally divided ranges. Agent: Ito Hidemori Matsukuma 21.゛O (imaginary a no old; *+: J violent tape I / Figure 1

Claims (1)

[Claims] A rotary head with n heads in one unit period {
Rotate 1±[1/(N■1)]} (360/n) degrees,
The signal for one unit period is compressed to (1/N), and the range of the compressed signal to be wrapped around (360/n) degrees of the rotating head of the tape for each unit period is (N■1). ) A recording method that records sequentially in each equally divided range.