JPS6050668A - Magnetic recording and reproducing method - Google Patents

Abstract

PURPOSE:To execute PCM recording and reproducing over a long period by dividing one track into N areas and arranging the divided areas along the reverse direction and the forward direction of tape traveling in the recording and reproducing method for a video signal and PCM sound signal. CONSTITUTION:PCM sound areas Pn-1... are formed on about 1/7 width of a tape from one end of a track and video areas Vn-1... are formed on the residual width to execute recording and reproducing with two helical scan heads. Each video area is divided into 6 areas and one track obtains 7 PCM areas P1n-1-P7n-1 by adding an original sound area to the 6 areas. The areas P1n-1, P3n-1, P5n-1, P7n-1 are arrayed in the forward direction of the tape traveling and the areas P2m-4, P4m-4, P6m+4 are arrayed in the reverse direction. A septernary counter for inputting the start and end pulses of the tape is provided with a clear input, so that a long recording and reproducing function for the PCM sound signals can be added to an original VRT function by controlling the septernary counter so as to be an inactive state.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to high quality audio reproduction in a video table recorder (hereinafter referred to as \'i''R).

(Prior Art) Conventionally, there have been various types of audio recording and reproducing apparatuses, but there has been almost no apparatus that satisfies both the requirements of high quality, long-term recording and reproduction.

On the other hand, \i'FR, which has been proposed as -8 mm video,
Two types of high-quality audio systems are available: l'M and pulse code modulation (pcM). Of these, only one FM channel can be recorded or played back.

Ichiriki, PCMl, there will be a recording and 1 hour live broadcast on 2 channels. FIG. 1 shows a pattern recorded on a magnetic tape by 8 mm video. From one end of 1 run 2 to about 1/7 the width of the tape,
The audio of p c IVq is recorded. As the tape travels, the area where the audio is recorded becomes...Ip
H-re l, Tsure 11+IIP11+2tsuPn+:b・
... and move sequentially. The video signal is recorded on the remaining width of approximately 6/'7 of the tape, and as the tape runs, the recording area is similarly...I■III\'I
I\in+1+ ■n+2 + vn+3 + “””
And move. Note that the differential 1/1 voice signal 1) modified r/A by this PCM is 1/7 when [1]
is compressed into.

The recording time using this method is approximately 1.5 hours,111
The demand for long-term recording and playback is not met.

(Aspects of the Invention) The present invention has been made to solve the problems mentioned in "2", and provides a high-quality, low-cost product that shares the main parts of a VTR and can perform long-time recording and playback. The purpose is to provide a magnetic recording angle () and an apparatus.

(Structure of the invention) For this reason, by connecting the two helices \2),
In the magnetic recording method (11j), which records and reproduces a video signal and an audio signal modulated by I) Cl~1 on a magnetic tape, the trunk of the magnetic tape I is divided into N areas. C
The recording density of the modulated audio signal is increased by a factor of N in time, and the recording density of the modulated audio signal is increased by a factor of N in time.
) Recording or recording is performed only in one area, and the divided areas are arranged along the forward and reverse directions of the tape run 11 and sequentially recorded.

In addition, in the magnetic recording + Ii raw method described in 2.2, a recording or birth function is added in both forward and reverse directions of the magnetic tape, and the track of the magnetic tape 7'-1- is divided into N areas. , the recording density of P CM audio variations is increased temporally by N times, and the recording density of 7 + record 1 or playback is increased in one area per track during the 1st and 11th transmission of the head of Then, the divided 11 areas of 1- are arranged along the forward and reverse directions of tape running, and the areas are automatically moved to continuously record or reproduce.

(Embodiment) An embodiment of the magnetic recording/reproduction method according to the present invention in an 8 mm VTR will be described with reference to FIG. Tracks for the recording area shown in Figure 1...

~ “11-re■11I■11+1! \'n+”l+・
Divide ... into three regions. In this way,
One Tora-Tsuku is 7 in total with the original vocal range of the book.
P CM It areas are divided into P CM It areas, and these areas are sequentially divided from the original i) voice area to L'l, P2 . ..., P7
Name is 1.

Also, Pi, P3 . of each trunk-L. P.S., I-'71
If you get stuck, add T subscript 3 H2+ ”'+ 11 L l11 n+L ll along the forward running direction of the tape.
For P2.P4.P6, subscripts 1, 2, .
・,...-1,+n, +n+1. m+2+・・・・・・
・Distinguish sequentially.

To record or play back a PCM audio signal, first, PLL,
Pi2,...Pil,-4,Pi,,.

F) j11+1. P111+2. Each territory 1 in the order of...
It is done at age. Note that I) The recording density of the CM audio signal temporally increases to 7(i?), and on the other hand, the head scan interval 11.1 is 1/7 per rotation, and thus CM l °One voice can be recorded and played back temporally continuously.

When the winding and end of the magnetic tape (tape end F) is detected, the running direction of the tape is reversed and the recording is completed! Or playback is 112F'22, --, I'2. o).

]-'2. ．． ．． lゝ2+n+l, 1]2111+2
, '... are performed in each area in this order. magnetic tape 8
When the beginning (tape start) is detected, 111 and the zH+ direction of the tape are reversed.
I'31. l': (2.

..., 1J311-1. PS11. PS1. +1, 1 position (, 1 + 7°... is done in each area in the order of 4.
J, ni, 'j(II・〜l', 1゜1)5I shukui,
In each area of 'P7, the running direction of 1 (also, smoke (primary, -)) is reversed, and f1 or birth is written.

In this way, high-density, long-time recording of i18, which is the normal recording and reproducing time from beginning to end for magnetic tape, is possible.

Next, the method described in -1- is expressed as Σ) mm\: ′r [<
A circuit for realizing +muffle will be explained using Section 3 and FIG. 4.

FIG. 3 shows timing pulses when recording and reproducing the PCM I'f voice signal in each area on the magnetic tape. The throat of the helical scan consists of a pair of heads,
During recording, each head takes turns in charge of recording and playback every half rotation. The henodo inoting pulse determines the timing of this alternation; when the level of this pulse is high, one henode (CH-1) is used, and when it is low, the henode inoting pulse is used on the Ike side (CH-2). ) to record and play back. - Sword, PCM 7 proposed in 8mm video
The 'J voice recording was made during the 1712 period of this pulse, before the esso of the rising and falling edges of the henodoswitching pulse described above, and this period was
. This is the high level period of pulse A1.

In this embodiment, the period covered by each node is divided into six equal parts, and pulses A2, . . . . A7 are generated so as to sequentially increase to a high level in this period divided into six equal parts. In this way, both heads (C11-] and Cl1-2) are supplied with the pulse A1 for the original r'CM audio recording. : In total, - set of sequential pulses A] +A 2
, ...+A7, one pulse is specified,
When this pulse is at a high level, a PCM audio signal is recorded and reproduced. For example, the area F' 11 , l''+2.

..., Plll-1, P]14. F゛11. +1,1
]111-2. When you want to record and play back..., press Henodo C1
1i and C,l12t+:tit''I The pulse indicating the raw needle period is at a high level only when the pulse A1 is at a high level.When the tape end of the magnetic tape is detected, the running direction of the tape is Inverted and - SOFCII-1
The pulse indicating the period for recording and reproducing ¥1 in C11-2 is as follows:
When the pulse A2 is at a high level, it becomes a nona high level. .

Next, the above magnetic recording method 11■ Raw method;) mm\・l'
The circuit to be realized in l( will be explained using Fig. 1. Phase comparator 1, low-pass filter (Ll'l ゛) 2, variable voltage controlled oscillator (\1c(-)) 3, ] Binary counter 4 is a face-locked loop (P L 1.
). The binary/single-digit output of counter t is connected to the binary four-digit input of counter 3, and the first output of the 12 outputs of decoder 5 is a phase comparator] to compare the phase with the head switching pulse. and thus this P
L, 1. constitutes an oscillator with a period of 1/+2 of the head switching pulse, and the oscillated pulses are sequentially output to 12 outputs of the decoder 5.

The first six outputs of the decoder 5 are six pulses Δ2.C11-IJII. A3+...+A7 and 4i1
! ! jl L is sequentially connected to the second to seventh positions of the data selector 6, and the remaining six outputs are six pulses A2+A3+ for C14-2.
, A°7, and are sequentially connected to the second to seventh inputs 1-1 of the data selector. The 6th output of the decoder 5 is also connected to the 1st input of the data selector 7 as the pulse A1 for CH-2, and the 12th output of the decoder 5 is the pulse A1 of C11-1111'. As such, it is also connected to the l =I IJ input of the data selector 6. l On the other hand, a circuit for selecting each of the 7j input signals of the data selector 6.7 is configured as follows. The tape start pulse indicating the beginning of winding of the magnetic tape is input to one input of the AN I) data), and the tape end pulse indicating the end of winding of the magnetic tape is input to the AN input. I) Day 1.0+.

11 is input into one of the human power inputs. A N l) Date 2
;.

9) J is manually input to the input of 0 [(date 12), and the output of this OR gate is the amplifier down counter 1
3 tJI' connected to human power. -Power, AND date 9
．． The outputs of 11 are input to the (-)R-1]ll inputs, respectively, and the outputs of this 01(gate) are connected to the LI OWN input of the amplifier down counter. Among the digit outputs, the output of 1 廿j l'', 1 is connected to the human power of A N 1.') ge ~) 8.] 1 of 1. Also, this note 1. force is Inverter 1
/l, and then connected to the inputs of A N l', ) data, and itt).

The binary 3 finger value of the heptad counter 13 is the data selector 6.
．．゛7's λ・] Connected to the corresponding binary 3-digit selection manual.

The region Pl, r"2.
・、Shi゛77 specified. Further, this counter 13 is provided with a clear (force).

The selection circuit described in ``2'' functions as follows. counter 1
3, when the tape start pulse or tape end pulse becomes high level, either UP or G/S becomes high level, and addition, l: or i addition is performed. Pl
, P2. ..., P1 area, P1, P3 . . . which are normally recorded and played back in the forward direction. When the area of P5゜Pl is selected by the hexadecimal counter 13, the hexadecimal counter 13
The output of 1 digit 1 is at a low level, so the tape end pulse occurs at 11, ¥1. t, the hexadecimal counter is incremented, and the area P2.t is incremented. P4. P6. Each PI is selected.

Also, P2. ]? 4. F”6 area is heptad count 13
, the output of the first digit of the heptad counter is at high level, so when the tape start pulse occurs, the heptad counter is incremented and fllP3
．． P5. Pl is selected 41. ; to be done. On the other hand, when the areas PI, P2゜...P7 are recorded and played back in the opposite direction to the normal direction, the areas PI, P: (.

When P5+F'7 is selected and Tape Star 1 pulse is detected, then Pl, P2 . P4. Y-) 6 or 1
1 selection, 1 selection, and area]" 2, F' 4
, L"G are selected, and when a tape end pulse is detected, PI, F' 3 lP 5 are selected respectively. Although not shown, areas P1 and 1"7
It is also possible to easily prohibit switching to and . thus,
I”1.

1] 2. By regarding the area of P1 as continuous from the beginning of tape winding to the end of winding, long-time playback becomes possible.

The seven inputs 12 of the data selectors 6 and 7 are connected to the output of the decoder as shown in the figure, and seven consecutive oscillation pulses are sequentially input thereto. -li, In the selection input, as shown in -, a binary signal or a binary signal for selecting an area for marking or 111 generation is input manually.

The output of the data selector 6.7 is the same as the one written in A1-87. l: specifies the period for playback, but the 5 and 2 designations also specify the area to be recorded and played back at the same time. For example, 7\1 corresponds to Pl, 8°, and 7. When the clear input of the advance counter 13 is set to the active state, the output becomes a low level, and Pl is always specified in the l'cM recording/reproducing area.

Therefore, when the circuit of this embodiment is incorporated into an 8 mm VTr<, when recording and reproducing a normal video signal, when the clear input is activated, the video signal is transmitted in areas P2 to P7, and Audio (No. Fj is recorded and played back in area P1, which is the PCM recording method conventionally proposed for 8mm II VTRs.) When the clear input is made inactive, like,
This is a PCM long-time recording/playback device. In this way, one machine＼
The iTR device has a PCM length of 11. , J, it becomes possible to add the function of interpolation fJ reproduction.

(Effect of the invention) As described in 2 below, the video signal and F' CM f%
When the method according to the present invention is used in a method for recording and reproducing voice overlapping signals in a time-division manner, high-quality 1" commercials can be recorded on a VTR.
It also functions as an audio table fugue (;l can be added and ]). CM recording and playback can be performed continuously for a long time. For example, if the above embodiment is added to a device that is normally capable of recording for 1.5 hours, continuous recording for 10.5 hours becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a video area and an audio area in an 8 mm VTR. FIG. 2 is a diagram showing the range in which the divided F' CM audio signals are recorded and reproduced. Figure 3 is! It is a timing chart for playing i-sound. 4th 1 is a circuit diagram showing an embodiment according to the present invention.

Claims (1)

[Claims] (+,) Two helical scan heads modulate the video signal and pulse code change (PCM).
In a magnetic recording and reproducing method that records or reproduces audio signals on a magnetic tape, the second trunk of the magnetic tape is
The recording density of the audio signal transformed by PCM is increased by a factor of N in time.
A magnetic tape that records or plays back only in one area per track during rotation, and arranges the two divided areas along the forward and reverse directions of tape travel and sequentially records or plays back. Recording and playback method. (2) Two helical scan heads generate a video signal, an audio signal modulated by POM, and a magnetic tape.
In the magnetic recording and reproducing method for recording on a magnetic tape, the track on the magnetic tape is divided into N <:((areas), and a PCM audio signal is recorded on the magnetic tape. The density is increased temporally by N times, recording or reproduction is performed only in one area per trunk during one rotation of the above-mentioned hand, and the above-mentioned divided area is A magnetic recording and reproducing method that records or reproduces data continuously by arranging it along the direction and automatically moving the area.