JPH04324149A - Magnetic tape recording device - Google Patents

Abstract

PURPOSE:To effectively reduce power consumption in the circuit part forming a video signal for recording or in the circuit part supplying the video signal for recording to the rotary magnetic head without increasing the number of the rotary magnetic head even in the video tape recorder having smaller diameter of the tape guide cylinder as compared with 40mm diameter, for instance, of the tape guide cylinder in the standard video tape recorder and to provide the device prepared with the interchangeability with the standard video tape recorder. CONSTITUTION:The video signal for recording based on the video signal for which time axis compressing is performed with the prescribed time compression rate is recorded in a magnetic tape 45 running on the outer peripheral surface part of a tape guide cylinder 43 by two rotary magnetic heads 41, 42. Power supply control parts 121, 122 and 123 are provided for making the state to stop the supply of the operation power for the period when the unit division signal component for which the time axis compressing was performed can not be obtained for at least one of a recording signal formation part 130 and recording amplifying parts 36, 37.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to magnetic tape recording in which a recording video signal formed based on a color television signal or the like is recorded on a magnetic tape running on the outer circumferential surface of a tape guide cylinder using a rotating magnetic head. Regarding equipment.

0002

2. Description of the Related Art A so-called video tape recorder, which is a device for recording a video signal on a magnetic tape or reproducing a video signal from a magnetic tape on which the video signal has been recorded, is
The tape guide cylinder includes a tape guide cylinder having an outer circumferential surface portion that serves as a running guide for the magnetic tape, and a rotating magnetic head disposed inside the tape guide cylinder. It is assumed that the magnetic tape runs on the outer circumferential surface of the tape guide cylinder, and in this case, the magnetic tape is wound around the outer circumferential surface of the tape guide cylinder at a preset wrapping angle. It is assumed to take on a state. The tape guide cylinder is, for example, divided in the direction of its central axis to form a fixed part and a rotating part, and the rotating part is rotated with respect to the fixed part at a preset rotation speed. The rotating magnetic head is, for example, attached to the rotating part of the tape guide cylinder and positioned between the fixed part and the rotating part of the tape guide cylinder, and rotates with the rotation of the rotating part of the tape guide cylinder. ,
The magnetic gap forming part is made to face the outer peripheral surface of the tape guide cylinder, and during each rotation period, the magnetic tape running on the outer peripheral surface of the tape guide cylinder is scanned diagonally with respect to its traveling direction. Record signals on tape or read signals from magnetic tape.

Recording of video signals on a magnetic tape using such a tape guide cylinder and rotary magnetic head involves the recording of a large number of tapes, each extending at a predetermined angle of inclination with respect to the longitudinal direction of the magnetic tape. Recording tracks are arranged in parallel, and usually one field period of a video signal is recorded on each recording track. Therefore, during a recording operation, a rotating magnetic head that scans a magnetic tape diagonally with respect to the traveling direction during one rotation period records one field period of video signals on the magnetic tape for each rotation. A recording track of a book is formed, and during a reading operation, the magnetic tape is scanned along the recording track formed on the magnetic tape every rotation to read one field period of the video signal.

[0004] Regarding such video tape recorders, many systems have been proposed with different specifications regarding the mechanism, specifications regarding signal recording and signal playback operations, specifications regarding operation control, etc., but one of them is For a standard video tape recorder that complies with The number of rotations of the rotating part in the tape guide cylinder (hereinafter referred to as cylinder rotation number), that is, the number of rotations of the rotating magnetic head is approximately 2.
There is one in which the speed is 9.97 rps, and the number of rotating magnetic heads is two, which are arranged with a rotation angle interval of 180 degrees. Such a standard video tape recorder belongs to a category in which the diameter of the tape guide cylinder is relatively small, and the tape guide cylinder and rotary magnetic head employed therein are different from the standard tape guide cylinder and the rotary magnetic head, respectively. It is considered a standard rotating magnetic head.

[0005]

[Problem to be Solved by the Invention] In order to further reduce the size and weight of the standard video tape recorder as described above, the diameter of the tape guide cylinder is made smaller than the diameter of the standard tape guide cylinder. Moreover, it has been proposed to construct a compact video tape recorder that is compatible with standard video tape recorders. For such a compact video tape recorder, from the viewpoint of compatibility with a standard video tape recorder, (1) the length of the recording track formed on the magnetic tape by the compact video tape recorder should be (2) the period for one field period of the video signal recorded on the magnetic tape is equal to the length of the recording track formed on the magnetic tape by a standard video tape recorder; It is required that two conditions be satisfied: the period should be equal to the period of one field period of the video signal.

Therefore, for a small video tape recorder, let the ratio of the diameter of the tape guide cylinder to that of a standard video tape recorder be a, the ratio of the tape winding angle be b, and the ratio of the cylinder rotation speed be c. (1) and (2)
In order to satisfy the following conditions, it is necessary that the relationship a·b=1, b/c=1 hold, and that the number of rotating magnetic heads be an even number of 4 or more. So, for example,
a = 2/3, b = c = 3/2, and the number of rotating magnetic heads was selected to be 4, thereby making the diameter of the tape guide cylinder 40 mm 2/3 ≒ 26.67 m.
m, tape wrapping angle is 180 degrees 3/2 = 270 degrees, cylinder rotation speed is 29.97 rps 3/2 ≒ 44.95
A small video tape recorder with a speed of 5 rps and four rotating magnetic heads will be constructed.

However, in a small video tape recorder constructed in this way, the number of rotating magnetic heads is
This is an increase compared to a standard video tape recorder, and it is necessary to provide four tape guide cylinders. Assembling the four independent rotating magnetic heads involves considerable difficulty, and there is a risk that the mounting accuracy of the four rotating magnetic heads may not be good. Furthermore, although mechanical downsizing can be achieved, the power consumption in, for example, the circuit section that forms the recording video signal and the circuit section that supplies the recording video signal to each of the rotating magnetic heads is relatively large.
This comes with the generally dissatisfied point that it cannot be expected to reduce the power consumption of the device as a whole. moreover,
In addition to the tape guide cylinder to which four independent rotating magnetic heads are assembled, there is also a speed changer that should be used in Cue playback mode, Review playback mode, Still playback mode, etc. It is extremely difficult to add a rotating magnetic head for reproduction, and as a result, so-called noise rescue reproduction, noiseless review reproduction, or noiseless still reproduction cannot be performed.

[0008] In view of these points, the present invention provides, for example, a tape guide cylinder with a diameter of 40 mm and a tape winding angle of 180 mm.
Even though the diameter of the tape guide cylinder is smaller than that of a standard video tape recorder in which the cylinder rotation speed is approximately 29.97 rps and the number of rotating magnetic heads is two, A circuit part that forms recording video signals without increasing the number of rotating magnetic heads, or
To form a compact video tape recorder which is said to effectively reduce power consumption in a circuit portion that supplies a recording video signal to a rotating magnetic head and is compatible with a standard video tape recorder. The purpose is to provide a magnetic tape recording device.

[0009]

[Means for Solving the Problems] In order to achieve the above-mentioned object, a magnetic tape recording device according to the present invention includes a video signal time axis processing unit that compresses the time axis of a video signal with a predetermined time compression ratio, and a video signal a recording signal forming section that forms a recording video signal in which time-domain compressed unit division signal components are intermittently linked based on the time-domain compressed video signal obtained from the time-domain processing section; and a tape guide cylinder. a rotating magnetic head that scans a magnetic tape running on the outer circumferential surface of the recording signal forming section; and a recording signal supply unit that sequentially supplies time-axis compressed unit division signal components of the recording video signal obtained from the recording signal forming section to the rotating magnetic head. In addition to the section, a power supply control section is configured to stop supplying operating power to at least one of the recording signal forming section and the recording signal supplying section during a period in which time-axis compressed unit division signal components are not obtained. It is composed of:

0010

[Operation] In the magnetic tape recording device according to the present invention configured as described above, based on the video signal which has been time-axis compressed with a predetermined time compression ratio, the time-axis compressed unit segment signal component is intermittently transmitted. A recording video signal consisting of a series of images is formed, and is recorded on a magnetic tape running on the outer circumferential surface of a tape guide cylinder by, for example, two rotating magnetic heads. , a recording signal forming unit that forms a recording video signal in which time-axis compressed unit segment signal components are intermittently connected; and a time-axis compressed unit segment in the recording video signal obtained from the recording signal forming unit. At least one of the recording signal supply units that sequentially supplies signal components to the rotating magnetic head is supplied with operating power during a period in which time-axis compressed unit segment signal components are obtained, and the time-axis compressed unit segment signal is obtained. No operating power is supplied during the period when no components are available. As a result, even when the diameter of the tape guide cylinder is made smaller than that of a standard video tape recorder, the number of rotating magnetic heads does not increase, and the recording signal forming section, recording signal supply section, etc. Compatibility with standard video tape recorders is provided while power consumption in the circuitry formed is effectively reduced.

[0011]

[Embodiment] FIG. 1 shows an example of a magnetic tape recording device according to the present invention. This example is supposed to record a color television signal conforming to the NTSC system. A video signal including a signal and a color signal is recorded on a magnetic tape together with an accompanying audio signal.

In FIG. 1, video signal input terminals 11 and 12 are supplied with a luminance signal Y and a carrier color signal C, which constitute a video signal in a color television signal based on the NTSC system, respectively. In addition, the audio signal input terminal 13
is supplied with an audio signal AU in a color television signal conforming to the NTSC system.

The luminance signal Y from the video signal input terminal 11 is digitized in an analog/digital (A/D) converter 14, and a digital luminance signal DY is obtained from the A/D converter 14 and stored in the field memory 15. supplied to Further, the carrier color signal C from the video signal input terminal 12 is digitized in the A/D converter 16, and
A digital carrier color signal DC is obtained from the /D converter 16 and supplied to the decoder 17. In the decoder 17, the digital red color difference signal DR and the digital blue color difference signal DB are individually taken out from the digital carrier color signal DC, and the digital red color difference signal DR and the digital blue color difference signal DB obtained from the decoder 17 are stored in the field memory 18, respectively. and is supplied to the field memory 19. Furthermore, the audio signal AU from the audio signal input terminal 13 is digitized by the A/D converter 20 , and the digital audio signal DA is obtained from the A/D converter 20 and supplied to the field memory 21 .

Field memories 15, 18, 19 and 2
1 are supplied with a write clock pulse PW and a read clock pulse PR sent from the timing pulse generator 22. The timing pulse generator 22 is supplied with a vertical pulse Pv synchronized with the vertical synchronization signal of the luminance signal Y supplied to the video signal input terminal 11 through the terminal 22A, and the timing pulse generator 22 receives the write clock pulse PW. is continuously transmitted as having a frequency ft, and the reading clock pulse PR is having a frequency of 4·ft/3, and the first of the two field periods forming each frame period of the luminance signal Y is From the start point synchronized with the vertical pulse Pv in the field period, for example, the period Ft・202.5/360 (where Ft represents the field period, for example, 1/60
The signal is transmitted for a period of Ft·3/4 from the time T1 after the period (seconds), and from the start point synchronized with the vertical pulse Pv in the second field period of the two field periods forming each frame period of the luminance signal Y. For example, from time T2 after the period Ft·247.5/360, the signal is transmitted for a period Ft·3/4.

Therefore, in the field memory 15, in accordance with the write clock pulse PW, the digital luminance signal DY is divided into F(n), F(n+1), F for one field period as shown by A in FIG. (n+2)
, ... are divided and written, and the written one field period F(n), F(n+1), F
(n+2), . . . are each read clock pulse P
It is read out according to R. At this time, since the frequency 4·ft/3 of the read clock pulse PR is set to 4/3 times the frequency ft of the write clock pulse PW, the digital luminance signal D read from the field memory 15
F(n), F(n+1), F( for one field period of Y
It is assumed that the time axis of each of n+2), . field memory 1.
5, as shown in B in FIG. 2, F(n) and F(n
+1), F(n+2), ... each has a time compression rate of 3/
Digital segmented time-base compressed luminance signals F(n)', F(n+2)', . . . which start from time T1 and continue for a period Ft·3/4, obtained by time-base compression with 4.
- A digital segmented time-base compressed luminance signal F(n-1)' starting from time T2 and continuing for a period Ft·3/4.
, F(n+1)', . The signal is supplied to the converter 23.

Further, in the field memories 18 and 19, the digital red color difference signal DR and the digital blue color difference signal DB are divided and written for each one field period according to the write clock pulse PW, and the written Each of the digital red color difference signal DR and the digital blue color difference signal DB for one field period is read out in accordance with the read clock pulse PR. In such a case, the frequency 4·ft/3 of the read clock pulse PR is set to 4/3 times the frequency ft of the write clock pulse PW, so that the digital red color difference signal read from the field memory 18 D.R.
It is assumed that the time axis is compressed at a time compression rate of 3/4 for each of one field period, and furthermore, the readout clock pulse PR is shortened by a period Ft·3/4 from each of time T1 and time T2. As a result, one of the digital red color difference signals DR is sent from the field memory 18.
A digital segmented time-base compressed color difference signal starting from time T1 and continuing for a period Ft·3/4, obtained by time-base compressing each field period at a time compression rate of 3/4, and a digital segmented time-base compressed color difference signal starting from time T2 and continuing for a period Ft·3/4. Digital segmented time-base compressed color difference signals lasting for a period of Ft·3/4 are sent out alternately and intermittently, and they are assumed to form a digital time-base compressed red color difference signal DR' as a whole. 24. Furthermore, since the frequency 4·ft/3 of the read clock pulse PR is set to 4/3 times the frequency ft of the write clock pulse PW, one field of the digital blue color difference signal DB read from the field memory 19 The time axis of each period is assumed to be compressed at a time compression rate of 3/4, and the read clock pulse PR is sent out for a period Ft·3/4 from each of time T1 and time T2. As a result, from the field memory 19, each of the digital blue color difference signals DB for one field period is time-axis compressed at a time compression rate of 3/4, and is obtained by time-axis compression for a period Ft·3/4 starting from time T1. The continuous digital segmented time-base compressed color difference signal and the digital segmented time-base compressed color difference signal starting from time T2 and continuing for a period Ft·3/4 are sent out alternately and intermittently, and they are digitally transmitted as a whole. The signal is supplied to the encoder 24 to form a time-base compressed blue color difference signal DB'. In the encoder 24, both the digital time-base compressed red color difference signal DR' and the digital time-base compressed blue color difference signal DB' are combined to form a digital time-base compressed carrier color signal DC' which is obtained intermittently. The digital time-base compressed carrier color signal DC′ obtained from the encoder 24 is supplied to the D/A converter 25 .

Furthermore, in the field memory 21, according to the write clock pulse PW, the digital audio signal DA is divided and written for each one field period, and the digital audio signal DA that has been written is written for one field period. Each clock pulse P for reading
It is read out according to R. In such a case, the frequency 4·ft/3 of the read clock pulse PR is set to 4/3 times the frequency ft of the write clock pulse PW, so that the digital audio signal DA read from the field memory 21 It is assumed that the time axis is compressed at a time compression rate of 3/4 for each of one field period, and furthermore, the read clock pulse PR is set at time T1 and time T1.
2, each of the digital audio signals DA for one field period is time-base compressed at a time compression rate of 3/4 and obtained from the field memory 21. A digital segmented time-base compressed audio signal starting from time T1 and continuing for a period Ft·3/4 and a time period Ft·3 starting from time T2.
The digital segmented time-base compressed audio signals that continue for 0.4 times are sent out alternately and intermittently, and they are assumed to form the digital time-base compressed audio signal DA' as a whole. supplied to

In the D/A converter 23 , the digital time axis compressed luminance signal DY' is converted into an analog signal to obtain a time axis compressed luminance signal Y', which is supplied to the luminance signal recording processor 27 . In the luminance signal recording processing unit 27, frequency modulation (FM) processing is performed based on the time axis compressed luminance signal Y', and based on the time axis compressed luminance signal Y', for example, the carrier frequency shift band is time axis compressed. A time-base compressed FM luminance signal Yf' is formed in which the leading edge of the synchronization signal of the luminance signal Y' has a frequency of 5.7 MHz and the white peak has a frequency of 7.7 MHz. Then, from the luminance signal recording processing section 27, the cut-off frequency is, for example, about 2 MH.
A time-base compressed FM luminance signal Yf' is obtained through a high-pass filter (HPF) 28 set to z, and is supplied to a signal synthesis section 29.

In the D/A converter 25, the digital time-base compressed carrier color signal DC' is converted into an analog signal to obtain a time-base compressed carrier color signal C', which is supplied to the color signal recording processor 30. In the color signal recording processing section 30, a low-pass conversion time-domain compressed color signal Cc' having a color subcarrier frequency of about 743 KHz is formed based on the time-domain compressed carrier color signal C', and Color signal recording processing section 3
0 through a bandpass filter (BPF) 31 to obtain a low-pass conversion time-base compressed color signal Cc', which is supplied to the signal synthesis section 29.

In the D/A converter 26, the digital time-base compressed audio signal DA' is converted into an analog signal to obtain a time-base compressed audio signal AU', which is supplied to the audio signal recording processor 32. In the audio signal recording processing section 32, FM processing is performed based on the time-domain compressed audio signal AU'. ±100~150
A time-domain compressed FM audio signal Af' having a frequency of approximately 1.5 MHz is formed, and a time-domain compressed FM audio signal Af' is obtained from the audio signal recording processing unit 32 through a BPF 33 whose passband center frequency is approximately 1.5 MHz. and is supplied to the signal combining section 29.

In the signal synthesis section 29, the time-domain compressed FM luminance signal Yf' from the HPF 28, the low frequency converted time-domain compressed color signal Cc' from the BPF 31, and the time-domain compressed FM audio signal Af' from the BPF 33 are processed. Frequency multiplexing is performed to form a composite recording signal Sm. As shown in A in FIG. 3, this composite recording signal Sm has a period F starting from time T1 of the time-axis compressed FM luminance signal Yf'.
one field period lasting for t·3/4, one field period starting from time T1 of the low-pass conversion time-base compressed color signal Cc′ and continuing for a period Ft·3/4;
One field period of the time-axis compressed FM audio signal Af' starting from time T1 and continuing for a period Ft·3/4 is frequency multiplexed and synthesized, starting from time T1 and continuing for a period Ft·3/4. One field period Sm(n), Sm(n+2), . field period, one field period starting from time T2 of the low-pass conversion time axis compressed color signal Cc′ and continuing for a period Ft·3/4;
And, one field period starting from time T2 and continuing for a period Ft 3/4 of the time-axis compressed FM audio signal Af' is frequency-multiplexed and synthesized to produce a period Ft 3/4 starting from time T2. 1 compressed time axis that lasts only
Field period Sm(n-1), Sm(n+1),・
...are said to be continuous alternately and intermittently,
It is supplied to the movable contact 34a of the switch 34.

The switch 34 is controlled by a switch control signal SW supplied from a control signal forming section 55, which will be described later.
The connection state between the movable contact 34a and the selection contacts 34b and 34c is controlled. As shown in B in FIG. 3, the switch control signal SW corresponds to one field period Sm(n), Sm(
n+2),...low level L during the period including each of
and Sm(n-1), Sm(n+
1), .
selects the movable contact 34a when the contact 34 takes a low level L.
b, and when the switch control signal SW takes a high level H, the movable contact 34a is connected to the selection contact 34c. As a result, from the selection contact 34b of the switch 34, Sm(n), Sm(n+2), . A first composite recording signal component Sma is derived, which is supplied to the rotary magnetic head 41 through the recording amplification section 36, and is supplied from the selection contact 34c of the switch 34 to the time signal component Sma as shown in D in FIG. Axis-compressed one field period Sm(n-1), Sm(
A second composite recording signal component Smb formed by an intermittently series of signals n+1), .

Each of the rotating magnetic heads 41 and 42 has a mutually different gap azimuth, and is attached to a rotating part of the tape guide cylinder 43.
It is disposed between the rotating part and the fixed part of the tape guide cylinder 43, rotates with the rotating part of the tape guide cylinder 43, and travels through the magnetic gap forming part on the outer circumferential surface of the tape guide cylinder 43. tape 45
The magnetic tape 45 is scanned in a direction forming a predetermined angle of intersection with the running direction of the magnetic tape 45. The rotating magnetic heads 41 and 42 are attached to the rotating part of the tape guide cylinder 43, as shown in FIG. It is meant to be.

The magnetic tape 45 is made to run by a capstan 47 which is rotationally driven by a capstan drive motor 46 and a pinch roller 48 which is in contact with the capstan 47 with the magnetic tape 45 sandwiched therebetween. It is controlled by the stun servo control circuit 49 to cause the magnetic tape 45 to take a predetermined running speed. In addition, the rotating magnetic heads 41 and 4
The rotating part of the tape guide cylinder 43 to which the tape guide cylinder 2 is attached is rotationally driven in the direction indicated by the arrow X in FIG. A rotating part in the cylinder 43,
Therefore, the rotating magnetic heads 41 and 42 are caused to have a predetermined rotation speed.

The diameter of the tape guide cylinder 43, the tape wrapping angle for the tape guide cylinder 43, and the cylinder rotation speed, that is, the rotation speed of the rotating magnetic heads 41 and 42, are as follows: a standard tape guide cylinder with a diameter of 40 mm. and two standard rotary magnetic heads, the tape winding angle for the standard tape guide cylinder is 180 degrees, and the cylinder rotation speed, that is, the rotation speed of the standard rotary magnetic head is approximately 29.97 rps. It is defined based on a standard video tape recorder, and the tape guide cylinder 4
3 is set to 2/3 of the diameter of the standard tape guide cylinder (40 mm), that is, approximately 26.67 mm, and the tape winding angle for the tape guide cylinder 43 is set to 2/3 of the diameter (40 mm) of the standard tape guide cylinder, and the tape winding angle for the tape guide cylinder 43 is the same as that for the standard tape guide cylinder. The rotation speed of the two rotating magnetic heads 41 and 42 is set to 3/2 of the angle (180 degrees), that is, 270 degrees, and the rotation speed of the two rotating magnetic heads 41 and 42 is twice the rotation speed of the standard rotating magnetic head (approximately 29.97 rps). , that is, it is set to approximately 59.94 rps. As shown in E in FIG. During the rotation period, the time axis compressed 1 in the supplied first composite recording signal component Sma
Field period Sm(n), Sm(n+2),...
The magnetic tape 45 is scanned during the period in which each of the second composite recording signal components Smb arrives, and the rotating magnetic head 42 scans the supplied second composite recording signal component Smb during each one rotation period, as shown by F in FIG. It is assumed that the magnetic tape 45 is scanned during the period in which each of Sm(n-1), Sm(n+1), . . . arrives for one field period compressed on the time axis. As a result, each time each of the rotating magnetic heads 41 and 42 scans the magnetic tape 45, one field period S which is time-base compressed in the first composite recording signal component Sma is generated.
m(n), Sm(n+2),... and the second
One field period Sm(n-1), Sm(n+1), . . . compressed on the time axis in the composite recording signal component Smb of
are alternately recorded on the magnetic tape 45 with recording tracks formed at a predetermined angle of inclination with respect to the longitudinal direction of the magnetic tape 45.

With the above settings, the ratio of the diameter of the tape guide cylinder 43 to the diameter of the standard tape guide cylinder is AA, and the ratio of the tape guide cylinder 43 to the tape winding angle of the standard tape guide cylinder is AA.
BB is the ratio of the tape winding angle for , CC is the ratio of the rotational speed of the rotating magnetic heads 41 and 42 to the rotational speed of the standard rotating magnetic head, and EE is the time compression ratio of the composite recording signal Sm. For the example shown in FIG. 1 with magnetic heads 41 and 42, in order to provide compatibility with standard video tape recorders, the length of the recording track formed on magnetic tape 45 is longer than that of a standard video tape recorder. The length of the recording track formed on the magnetic tape by a standard video tape recorder is equal to the length of the recording track formed on the magnetic tape, and the period for one field period of the composite recording signal Sm recorded on the magnetic tape 45 is equal to the length of the recording track formed on the magnetic tape by a standard video tape recorder. The condition for the period to be equal to the period of one field period of the signal is as follows: AA・BB=1 (
a) BB/(CC·EE)=1 (b) The following two relationships hold true.

[0027] Then, looking at the respective values of AA, BB, CC and EE, AA=2/3, BB=3/2, CC=2
, EE=3/4, so the above equations (a) and (b
) is established. Therefore, the example shown in FIG. 1 employs a tape guide cylinder with a smaller diameter than that of a standard video tape recorder, and the number of rotating magnetic heads is reduced to two without increasing the number of rotating magnetic heads. A color television signal consisting of a video signal including a luminance signal and a carrier color signal and an audio signal can be recorded on a magnetic tape while maintaining compatibility with a standard video tape recorder. become.

Further, the rotating portion of the tape guide cylinder 43 is provided with a magnetized portion 56, and the magnetized portion 56 is attached to the rotating magnetic heads 41 and 42 as the rotating portion of the tape guide cylinder 43 rotates. It is detected by a fixed magnetic head 57 which assumes a preset position while being rotated together. As a result, every time the magnetized portion 56 passes by, the fixed magnetic head 57 rises from the zero level to the positive level side, and then goes to the negative level side, for example, every time the rotating magnetic heads 41 and 42 rotate. A pulse signal PG that returns to zero level after falling is obtained. The pulse signal PG from the fixed magnetic head 57 is transmitted from the time when the preceding rotating magnetic head 41 of the rotating magnetic heads 41 and 42 in the rotating state finishes one scan on the magnetic tape 45 to the subsequent rotating magnetic head. This is assumed to be obtained in the middle of the period up to the time when the head 42 starts a new scan on the magnetic tape 45,
In the waveform shaping section 58, the pulse is converted into a rectangular wave pulse PGW consisting of a pair of positive level portion and negative level portion, as shown by G in FIG. 3, and is supplied to the control signal forming section 55.

The control signal forming section 55 is specifically configured as shown in FIG. 4, for example. In the specific example of the control signal forming section 55 shown in FIG. 4, the waveform shaping section 5
A rectangular wave pulse PGW from 8 is supplied to a fall detection section 101 through a terminal 100. In the falling detection section 101, the falling portion of the square wave pulse PGW, that is, the central portion of the square wave pulse PGW consisting of a pair of positive level portions and negative level portions is detected, and a detection output pulse representing that point in time is detected. PED is sent out.

The detection output pulses PED sequentially obtained from the fall detection section 101 are processed by a flip-flop circuit (F.F.
．． ) 102 as a trigger pulse, and the flip-flop circuit 102 inverts its level every time the detection output pulse PED is supplied, thereby obtaining an output signal that alternates between a high level and a low level. In relation to the composite recording signal Sm, such an output signal corresponds to one field period Sm(n), Sm(n+2), . In the composite recording signal Sm up to the leading edge of Sm(n), Sm(n+2), . . . It is assumed that the high level H is assumed in the period including each of the time axis compressed one field period Sm(n-1), Sm(n+1), . . .
It is sent out from the output terminal 103 as a switch control signal SW shown at B in FIG.

Furthermore, the detection output pulses PED sequentially obtained from the fall detection section 101 are output from four monostable multivibrators (MM, hereinafter abbreviated as monomulti) 104, 105, 106, and 107. Each is supplied as a trigger pulse. The monomulti 104 outputs a detection output pulse PED as shown by H in FIG.
The monomulti 105 sends out a rectangular wave signal PM1 that takes a high level during the period from the time when is supplied to the time when the rotating magnetic head 41 starts a new scan on the magnetic tape 45, and the monomulti 105 is shown by I in FIG. The rectangular wave signal PM2 takes a high level during the period from the time when the detection output pulse PED is supplied until the time when the rotating magnetic head 42 starts a new scan on the magnetic tape 45.
Send out. Further, the monomulti 106 has a high level during the period from the time when the detection output pulse PED is supplied to the time when the rotating magnetic head 41 finishes one scan on the magnetic tape 45, as shown by J in FIG. Sends out a rectangular wave signal PM3 that takes a monomulti 10
7 is a rectangular wave that takes a high level during the period from the time when the detection output pulse PED is supplied until the time when the rotating magnetic head 42 finishes one scan on the magnetic tape 45, as shown by K in FIG. Send signal PM4.

Square wave signal PM1 from monomulti 104
is supplied to an AND circuit 109 together with a signal SWI obtained by inverting the level of the switch control signal SW obtained from the flip-flop circuit 102 by an inverter 108. The AND circuit 109 produces an output that takes a high level when both the rectangular wave signal PM1 and the signal SWI take a high level. Therefore, the output terminal of the AND circuit 109 has a signal as shown by H in FIG. , square wave signal PM1
Pulse PM1N which is obtained when the switch control signal SW takes a low level among the high level parts in
will be extracted.

Square wave signal PM2 from monomulti 105
is supplied to the AND circuit 110 together with the switch control signal SW obtained from the flip-flop circuit 102. The AND circuit 110 produces an output that takes a high level when both the rectangular wave signal PM2 and the switch control signal SW take a high level. Like square wave signal PM
Switch control signal SW of the high level portion in 2
The pulse PM2 that is obtained when takes a high level
P will be extracted.

Square wave signal PM3 from monomulti 106
is supplied to the AND circuit 111 together with a signal SWI obtained by inverting the level of the switch control signal SW obtained from the flip-flop circuit 102 by the inverter 108. The AND circuit 111 produces an output that takes a high level when both the rectangular wave signal PM3 and the signal SWI take a high level. , square wave signal PM3
Pulse PM3N, which is obtained when the switch control signal SW of the high level part in , takes a low level.
will be extracted.

Furthermore, the rectangular wave signal PM4 from the monomulti 107 is supplied to the AND circuit 112 together with the switch control signal SW obtained from the flip-flop circuit 102. The AND circuit 112 produces an output that takes a high level when both the rectangular wave signal PM4 and the switch control signal SW take a high level. The pulse PM4P, which is obtained when the switch control signal SW takes a high level among the high level portions of the rectangular wave signal PM4, is extracted.

AND circuit 11 obtained as described above
The pulse PM3N from the AND circuit 112 and the pulse PM4P from the AND circuit 112 are passed through the OR circuit 113 to a set/reset flip-flop circuit (hereinafter referred to as S-R.F.1).
F. ) 115, and the pulse PM1N from the AND circuit 109 and the AND circuit 1
The pulse PM2P from 10 is sent through the OR circuit 114 to the S-R.F. F. It is supplied to the reset terminal (R) of 115. S-R.F. F. 115 assumes a set state in response to the falling edge of pulse PM3N or pulse PM4P, and also responds to the falling edge of pulse PM1N or pulse PM
It returns to the reset state in response to the falling edge of 2P, and its output terminal Q provides an output signal that takes a high level in the set state and a low level in the reset state. Therefore, S-R.F. F. 115, in the period from the falling edge of pulse PM3N to the falling edge of pulse PM2P and from the falling edge of pulse PM4P to the falling edge of pulse PM1N, as shown by L in FIG. A control signal CPa having a high level is obtained and sent out from the output terminal 116. This control signal CPa is the composite recording signal Sm
In the relationship, Sm (n-1), Sm
(n), Sm(n+1), Sm(n+2), .

Furthermore, the pulse PM from the AND circuit 111
3N is S-R・F. F. The pulse PM1N from the AND circuit 109 is supplied to the set terminal (S) of 117, and the pulse PM1N from the AND circuit 109 is
R.F. F. It is supplied to the reset terminal (R) of 117. S-R.F. F. 117 assumes a set state in response to the falling edge of pulse PM3N, and pulse P
Returns to the reset state in response to the falling edge of M1N,
At its output terminal Q, an output signal is obtained which takes a high level in a set state and a low level in a reset state. Therefore, S-R.F. F. 117, a pulse PM3N is generated as shown by M in FIG.
A control signal CPb that takes a high level during the period from the falling edge of pulse PM1N to the falling edge of pulse PM1N is obtained and sent from output terminal 118. Such control signal C
In relation to the composite recording signal Sm, Pb is the period between each of the time-axis compressed one field period Sm(n), Sm(n+2), . . . in the first composite recording signal component Sma. It will be considered as a high level in the period.

Furthermore, the pulse P from the AND circuit 112
M4P is S-R・F. F. The pulse PM2P from the AND circuit 110 is supplied to the set terminal (S) of 119, and the pulse PM2P from the AND circuit 110 is
-R.F. F. It is supplied to the reset terminal (R) of 119. S-R.F. F. 119 assumes the set state in response to the falling edge of pulse PM4P and returns to the reset state in response to the falling edge of pulse PM2P, and its output terminal Q takes a high level in the set state, and An output signal that takes a low level in the reset state is obtained. Therefore, S-R.F. F. 119, a pulse PM4 is generated as shown at N in FIG.
A control signal CPc that takes a high level during the period from the falling edge of P to the falling edge of pulse PM2P is obtained and sent out from output terminal 120. This control signal CPc is the second signal in relation to the composite recording signal Sm.
One field period Sm(n-1), Sm(n+1), . . . compressed on the time axis in the composite recording signal component Smb of
It will be assumed that the high level is achieved during the period between each of the following.

In this way, the switch control signal S sent out from the output terminal 103 in the control signal forming section 55
W is supplied to switch 34 as described above. In addition, the output terminals 116 and 118 in the control signal forming section 55
The control signals CPa, CPb and CPc sent from the power supply controllers 121, 122 and 123, respectively,
supplied to

[0040] The power supply control section 121 controls the encoders 24 and D.
/A conversion sections 23, 25 and 26, luminance signal recording processing section 2
7, HPF 28, signal synthesis section 29, color signal recording processing section 3
0, BPF 31 and 33, and audio signal recording processing section 3
When the control signal CPa from the control signal forming section 55 takes a low level, the recording signal forming section 130 is configured to form a composite recording signal Sm. While supplying operating power to the unit 130, the control signal CP from the control signal forming unit 55
When a takes a high level, the supply of operating power to the recording signal forming section 130 is stopped. Therefore, the recording signal forming unit 130 generates the time-axis compressed one field period Sm(n-1), Sm(n), S to form the composite recording signal Sm.
When each of m(n+1), Sm(n+2), ... is obtained, operating power is supplied and the device is placed in an operating state,
Time-axis compressed one field period Sm(n-1), Sm(n), Sm(n+1) forming the composite recording signal Sm
), Sm(n+2), . . . for one field period compressed on the time axis.
(n), Sm(n+1), Sm(n+2), . . . are not obtained, no operating power is supplied and the device is placed in a non-operating state. Thereby, the recording signal forming section 130
Time axis compressed one field period Sm(n-1),
Sm(n), Sm(n+1), Sm(n+2),...
It is assumed that a composite recording signal Sm in which each of these signals is intermittently connected can be appropriately formed, and power consumption can be effectively reduced.

The power supply control section 122 controls the recording amplification section 3 , which constitutes a recording signal supply section that supplies the first composite recording signal component Sma obtained from the switch 34 to the rotating magnetic head 41 .
6, and when the control signal CPb from the control signal forming section 55 takes a low level, the recording amplifying section 36
At the same time, when the control signal CPb from the control signal forming section 55 takes a high level, the supply of operating power to the recording amplifying section 36 is stopped. Therefore, the recording amplification unit 36 outputs Sm(n), Sm for one field period compressed in the time axis in the first composite recording signal component Sma.
When each of (n+2), . . . , Sm(n+2), . . . and the time axis is compressed for one field period Sm(n).
, Sm(n+2), . . . are not obtained, no operating power is supplied and the device is placed in a non-operating state. Thereby, the recording amplification unit 36 generates the first composite recording signal component S, which is made up of the time-axis compressed one-field period Sm(n), Sm(n+2), . . .
In addition to appropriately amplifying ma and supplying it to the rotating magnetic head 41, power consumption can be effectively reduced.

The power supply control section 123 controls the recording amplification section 3 , which constitutes a recording signal supply section that supplies the second composite recording signal component Smb obtained from the switch 34 to the rotary magnetic head 42 .
7 and when the control signal CPc from the control signal forming section 55 takes a low level, the recording amplifying section 37
At the same time, when the control signal CPc from the control signal forming section 55 takes a high level, the supply of operating power to the recording amplifying section 37 is stopped. Therefore, the recording amplification unit 37 generates one field period Sm(n-1), which is compressed in the time axis, in the second composite recording signal component Smb.
When each of Sm(n+1), . . . -1), Sm(n+1), ... for one field period S which is time axis compressed.
When m(n-1), Sm(n+1), . . . cannot be obtained, operating power is not supplied and the device is kept in a non-operating state. Thereby, the recording amplification unit 37 outputs Sm(n-1), Sm(n+1), Sm(n+1),
The second composite recording signal component Smb, which is made up of the intermittently connected signals, is appropriately amplified and supplied to the rotating magnetic head 42, and the power consumption is effectively reduced.

FIG. 5 shows a specific example of the power supply control unit 121 that controls the power supply to the recording signal forming unit 130. In the example shown in FIG.
a transistor 132 having a collector-emitter path connected in series with 31 and a collector-emitter path connected in series with resistors 133 and 134 between a positive operating power supply +Vcc and a negative operating power supply -Vcc; A transistor 135, whose collector and base are directly connected, whose bases are interconnected, forms a portion that functions as a current source. A transistor 136 is provided with a collector-emitter path connected between the collector of the transistor 135 and a ground potential point.
The base of is connected to the negative operating power supply -Vcc through resistor 137.
and is connected to terminal 13 through resistor 138.
9 has been derived.

The control signal forming section 55 is connected to the terminal 139.
The control signal CPa sent from the control signal C
When Pa takes a low level, the transistor 136 is turned off, the transistor 132 and the transistor 135 operate as a current source, and the transistor 132 supplies the recording signal forming section 130 with a signal from the positive operation power supply +Vcc to the negative operation power supply -Vcc. A constant current is supplied, and the recording signal forming section 130 is brought into a state where operating power is supplied. Further, when the control signal CPa takes a high level, the transistor 136 is turned on, and the collector of the transistor 135 and the negative operating power supply -Vcc are short-circuited through the transistor 136. As a result, the transistor 132 and the transistor 135 do not operate as current sources, and the constant current flowing from the positive operating power supply +Vcc to the negative operating power supply -Vcc is not supplied to the recording signal forming section 130, so that the recording signal forming section 130 does not operate. Power supply will be cut off.

It should be noted that each of the power control unit 122 that controls the power to the recording amplification unit 36 and the power control unit 123 that controls the power to the recording amplification unit 37 has the same specific configuration as the power control unit 121. It is said that

FIG. 6 shows a luminance signal, a carrier color signal, and an audio signal forming a color television signal from a magnetic tape 45 on which a composite recording signal Sm has been recorded using the example of the magnetic tape recording device shown in FIG. An example of a signal reproducing device for reproducing a signal is shown, and in this example, the two rotary magnetic heads 41 and 42 in the example of the magnetic tape recording device shown in FIG. 1 are used as the rotary magnetic head for reading. Therefore, the tape guide cylinder 43 is also used. Further, a fixed magnetic head 57 that detects a magnetized portion 56 provided on the tape guide cylinder 43, a waveform shaping section 58 to which a pulse signal PG from the fixed magnetic head 57 is supplied, and a rectangular wave from the waveform shaping section 58. Pulse PGW
is supplied, the switch control signal SW, the control signal CPa
, CPb, and CPc are also used as a control signal forming section 55.

In the example of the signal reproducing device shown in FIG. 6, the rotating portion of the tape guide cylinder 43 is driven to rotate in the same manner as during the recording operation, and the magnetic tape 45 is caused to run in the same manner as during the recording operation. The two rotating magnetic heads 41 and 42 having mutually different gap azimuths generate a first composite recording signal component from among the recording tracks on the magnetic tape 45 whose gap azimuths correspond during recording. Sma and second composite recording signal component Sm
b is read out alternately for one field period compressed in the time axis, and one field period Sm compressed in the time axis of the read first composite recording signal component Sma is read as shown in A in FIG. (n), Sm(n+2),
. . . and one field period Sm(n-1), Sm(n+1) of the read second composite recorded signal component Smb compressed in the time axis, as shown in B in FIG.
), . As shown in C in FIG. 7, the switch 63 supplies one field period Sm(n) of the first composite recording signal component Sma compressed in the time axis to the selection contact 63b, as shown in C in FIG. , Sm(n+2),
The selection contact 63c receives data for one field period Sm(n-1), which is time-base compressed, of the second composite recording signal component Smb.
High level H in the period including Sm(n+1),...
When the switch control signal SW takes a low level L, the movable contact 63
a is connected to the selection contact 63b, and when the switch control signal SW takes a high level H, the movable contact 63a is connected to the selection contact 63c. Thereby, the first composite recording signal component Sma obtained alternately from the reproduction amplification units 61 and 62 is compressed in the time axis for one field period, and the second composite recording signal component Sm
Each of the time-base compressed field periods of b is a series of composite recording signals S as shown in D in FIG.
m, the movable contact 6 of the switch 63
3a.

The composite recording signal Sm obtained from the movable contact 63a of the switch 63 is the time-axis compressed FM luminance signal Yf'
HPF71 compatible with low frequency conversion time axis compressed color signal Cc
BPF72 and time axis compressed FM audio signal A corresponding to '
The signal is supplied to the BPF 73 corresponding to f'. And HP
The time axis compressed FM luminance signal Yf' in the composite recording signal Sm is obtained from F71 and supplied to the luminance signal reproduction processing section 74. In the luminance signal reproduction processing section 74, the time axis compression F
Various processes including demodulation processing are performed on the M luminance signal Yf', and the luminance signal reproduction processing section 74 outputs a time-axis compressed FM signal.
A time-base compressed luminance signal Y' based on the luminance signal Yf' is obtained and supplied to the A/D converter 75. A/D converter 7
5, the time axis compressed luminance signal Y' is digitized to obtain a digital time axis compressed luminance signal DY',
It is supplied to field memory 76.

Further, the low frequency conversion time axis compressed color signal Cc' in the composite recording signal Sm is obtained from the BPF 72 and is supplied to the color signal reproduction processing section 77. In the color signal reproduction processing section 77, various processes including frequency conversion processing are performed on the low frequency conversion time axis compressed color signal Cc'. The time axis compressed carrier color signal C' based on
8. In the A/D converter 78, the time-base compressed carrier color signal C' is digitized to obtain a digital time-base compressed carrier color signal DC', which is sent to the decoder 7.
9. In the decoder 79, a digital time axis compressed red color difference signal DR' which is formed by intermittently connecting digital time axis compressed color difference signals from the digital time axis compressed carrier color signal DC' and a digital time axis compressed red color difference signal DR' which is made up of an intermittent series of digital time axis compressed color difference signals and a digital time axis compressed color difference signal DR' which is made up of an intermittent series of digital time axis compressed color difference signals A series of digital time-base compressed blue color difference signals DB' are individually extracted and sent to a decoder 79.
Digital time-base compressed red color difference signal DR' obtained from
, and digital time-base compressed blue color difference signal DB' are supplied to field memory 80 and field memory 81, respectively.

Furthermore, the composite recording signal Sm from the BPF 73
The time-base compressed FM audio signal Af' is obtained and supplied to the audio signal reproduction processing section 82. Audio signal reproduction processing section 82
, various processes including demodulation processing are performed on the time-domain compressed FM audio signal Af', and a time-domain compressed audio signal AU' based on the time-domain compressed FM audio signal Af' is obtained from the audio signal reproduction processing section 82. and is supplied to the A/D converter 83. In the A/D converter 83, the time axis compressed audio signal AU' is digitized to obtain a digital time axis compressed audio signal DA', which is stored in the field memory 8.
4.

Field memories 76, 80, 81 and 8
A write clock pulse QW and a read clock pulse QR sent from the timing pulse generator 85 are supplied to each of the clock pulses 4 and 4. A synchronizing pulse Pv' synchronized with the level change portion of the switch control signal SW is supplied to the timing pulse generator 85 through a terminal 85A, and the timing pulse generator 85 generates a write clock pulse QW at a frequency of 4·ft/ As shown in C in FIG. ',F(n
)', F(n+1)', F(n+2)', .
Continuously sends out the data as if it had the same

Thereby, in the field memory 76, in accordance with the write clock pulse QW, the digital time-base compressed luminance signal DY' is converted into the digital segmented time-base compressed luminance signal F(n) as shown in C in FIG. −
1)', F(n)', F(n+1)', F(n+2)'
, . . . and the written digital segmented time-base compressed luminance signal F(n-1)
',F(n)',F(n+1)',F(n+2)',・
... are read out in accordance with the readout clock pulse QR. At this time, the frequency ft of the read clock pulse QR is equal to the frequency 4·ft/of the write clock pulse QW.
Since it is said to be 3/4 times 3, the field memory is 76
As shown in D in FIG.
F(n)', F(n+1)', F(n+2)',...
are digital segmented luminance signals F(n-1) and F obtained by expanding their time axes at an expansion rate of 4/3, respectively.
(n), F(n+1), F(n+2), etc., and are sent out sequentially and continuously, and as a whole, the digital luminance signal D
The signal Y is supplied to the D/A converter 86 as a signal forming the signal Y.

In the D/A converter 86, the digital luminance signal DY is converted into an analog signal to obtain a luminance signal Y.
It is reproduced as the luminance signal Y at the video signal output terminal 8.
7.

Furthermore, in the field memory 80,
According to the write clock pulse QW, each of the digital segmented time-base compressed color difference signals forming the digital time-base compressed red color difference signal DR' is sequentially written, and each of the written digital segmented time-base compressed color difference signals is read out. Each of the digital segmented time-domain compressed color difference signals forming the digital time-domain compressed blue color difference signal DB' is sequentially read out in accordance with the clock pulse QR and sequentially written in the field memory 81 in accordance with the write clock pulse QW. At the same time, each of the written digital segmented time-base compressed color difference signals is sequentially read out in accordance with the readout clock pulse QR. In such a case, since the frequency ft of the read clock pulse QR is set to 3/4 times the frequency 4·ft/3 of the write clock pulse QW, the written digital division is Each of the time axis compressed color difference signals is continuously transmitted as a digital segmented color difference signal obtained by expanding the time axis at an expansion rate of 4/3, thereby obtaining a digital red color difference signal DR, and From the memory 81, each of the written digital segmented time-base compressed color difference signals is intermittently sent out as a digital segmented color-difference signal obtained by expanding the time axis at an expansion rate of 4/3, thereby producing a digital blue color. A color difference signal DB is obtained. Then, both the digital red color difference signal DR and the digital blue color difference signal DB are supplied to the encoder 88, and in the encoder 88, both the digital red color difference signal DR and the digital blue color difference signal DB are combined to form the digital carrier color signal DC.
A digital carrier color signal DC obtained from the encoder 88 is supplied to the D/A converter 89.

In the D/A converter 89, the digital carrier color signal DC is converted into an analog signal to obtain a carrier color signal C, which is outputted to the video signal output terminal 90 as a reproduced carrier color signal C.

Further, in the field memory 84, the digital time-base compressed audio signal DA' is divided and written for each one field period according to the write clock pulse QW, and the written digital time-base compressed audio signal DA' is written in accordance with the write clock pulse QW. Each of the signal DA' for one field period is read out in accordance with the read clock pulse QR. In such a case, the frequency f of the reading clock pulse QR
Since t is 3/4 times the frequency 4·ft/3 of the writing clock pulse QW, the written digital time-base compressed audio signal DA' is output from the field memory 84.
The time axis of each one field period is expanded at an expansion rate of 4/3 and is continuously transmitted as a digital segmented audio signal, which collectively constitutes the digital audio signal DA. D/A converter 9
1.

Then, in the D/A converter 91, the digital audio signal DA is converted into an analog audio signal AU.
is obtained and output to the audio signal output terminal 92 as a reproduced audio signal AU.

In this way, the signal reproducing apparatus shown in FIG. 6 which reproduces the luminance signal Y, the carrier color signal C, and the audio signal AU forming the video signal from the magnetic tape 45 is adapted to the above-mentioned standard video tape recorder. Although the tape guide cylinder 43 has a smaller diameter than the standard tape guide cylinder, two rotary magnetic heads 4 are used.
It is considered that it is sufficient to have only 1 and 42, so 2
In addition to the rotating magnetic heads 41 and 42, it is easy to provide a rotating magnetic head for variable speed playback to be used in cue playback mode, review playback mode, still playback mode, etc. It will be possible to easily perform noise rescue playback, noiseless review playback, noiseless still playback, etc.

Even in this case, the fixed magnetic head 57 that detects the magnetized portion 56 provided on the rotating part of the tape guide cylinder 43 detects a positive value from zero level every rotation of the rotating magnetic heads 41 and 42. A pulse signal PG that rises to the level side, then falls to the negative level side, and then returns to the zero level is obtained, and based on this, the waveform shaping section 5
8, a rectangular wave pulse PGW as shown in E in FIG. 7 is obtained and supplied to the control signal forming section 55. The control signal forming section 55 sends out the switch control signal SW from the output terminal 103 in the same way as the control signal forming section 55 in the example of the magnetic tape recording device shown in FIG. 118 and 120
7, control signals CPa, CPb and CPc as shown by F, G and H in FIG. 7 are sent out, respectively. Then, the switch control signal SW is supplied to the switch 34 as described above, and the control signals CPa, CPb and CPc are supplied to the power supply control units 141, 142 and 143, respectively.
supplied to

[0060] The power supply control unit 141 includes the HPF 71, BPF
72 and 73, a luminance signal reproduction processing section 74, A/D conversion sections 75, 78 and 83, a color signal reproduction processing section 77, a decoder 79, and an audio signal reproduction processing section 82. 150 and when the control signal CPa from the control signal forming section 55 takes a low level, operating power is supplied to the reproduction signal forming section 150 and the control signal CPa from the control signal forming section 55 takes a high level. When this happens, the supply of operating power to the reproduced signal forming section 150 is stopped. Therefore, the reproduced signal forming section 150 generates one time-axis compressed field period Sm(n-1), Sm(n), Sm(n+) to form the composite recording signal Sm.
1), Sm(n+2), . (n-1), Sm(n), Sm(n+1), S
Sm(n-1), Sm(n) for one field period compressed on the time axis between m(n+2), . . .
, Sm(n+1), Sm(n+2), . . . are not supplied with operating power and are kept in a non-operating state. As a result, the reproduced signal forming section 150 can appropriately form the digital time-base compressed luminance signal DY', the digital time-base compressed carrier color signal DC', and the digital time-base compressed audio signal DA', while reducing power consumption. It is assumed that the

[0061] The power supply control unit 142 controls the rotating magnetic head 41.
When the control signal CPb from the control signal forming section 55 takes a low level, power is controlled for the reproducing amplifying section 61 that receives the first composite recording signal component Sma from the control signal forming section 55, and operating power is supplied to the reproducing amplifying section 61. , control signal forming section 5
When the control signal CPb from 5 takes a high level, the supply of operating power to the regenerative amplification section 61 is stopped. Therefore,
The reproduction amplification unit 61 generates one field period Sm(n), which is compressed in the time axis, in the first composite recorded signal component Sma.
When each of Sm(n+2), . . . n), Sm(n+2), . . . for one field period compressed on the time axis.
(n), Sm(n+2), . . . are not supplied, operating power is not supplied and the device is kept in a non-operating state. Thereby, the reproduction amplification unit 61 generates the first composite recording signal component S, which is composed of the time-axis compressed one-field period Sm(n), Sm(n+2), . . . intermittently connected.
In addition to appropriately amplifying ma and supplying it to the switch 63, power consumption can be effectively reduced.

[0062] The power supply control unit 143 controls the rotating magnetic head 42.
When the control signal CPc from the control signal forming section 55 takes a low level, power is controlled for the reproducing amplifying section 62 that receives the second composite recording signal component Smb from the control signal forming section 55, and operating power is supplied to the reproducing amplifying section 62. , control signal forming section 5
When the control signal CPc from 5 takes a high level, the supply of operating power to the regenerative amplification section 62 is stopped. Therefore,
The reproduction amplification unit 62 generates one field period Sm(n-1
), Sm(n+1),... are supplied,
Operating power is supplied to the operating state, and the time-axis compressed one field period Sm(n-1), Sm(n+1), . . . in the second composite recording signal component Smb is supplied with operating power.
When Sm(n-1), Sm(n+1), . . . are not supplied for one field period compressed on the time axis, operating power is not supplied and the device is kept in a non-operating state. . As a result, the reproduction amplification unit 62 generates Sm(n-1) and Sm(n
+1), .

In the example of the magnetic tape recording device shown in FIG. 1, two rotating magnetic heads 41 and 42 are arranged such that the rotation angle interval between them is 45 degrees. The arrangement of the two rotating magnetic heads 41 and 42 is not limited to this example, and the rotational angular interval between them may be smaller or larger than 45 degrees. At that time, field memory 15,1
Digital luminance signal DY, digital red color difference signal DR, digital blue color difference signal DB from 8, 19 and 21
, and the read period during each of the first and second field periods forming each frame period of the luminance signal Y for each of the digital audio signals DA corresponds to the rotation angle interval between the rotating magnetic heads 41 and 42. Although it is changed according to
In order to avoid such a situation, the rotational angular interval between the rotating magnetic heads 41 and 42 is , is set to be smaller than the angle obtained by subtracting the tape wrapping angle from 360 degrees, and therefore, for example, is set smaller than the angle obtained by subtracting the tape wrapping angle of 270 degrees from 360 degrees, which is 90 degrees.

[0064]

As is clear from the above description, in the magnetic tape recording device according to the present invention, based on a video signal that has been time-axis compressed with a predetermined time compression ratio, time-axis compressed unit segments are A recording video signal consisting of an intermittent series of signal components is formed, and is recorded by a rotating magnetic head onto a magnetic tape running on the outer peripheral surface of a tape guide cylinder. a recording signal forming section that forms a recording video signal in which the unit division signal components are intermittently connected; Operating power is supplied to at least one of the recording signal supply units that supply the rotating magnetic head during a period in which time-axis compressed unit segment signal components are obtained, and the time-axis compressed unit segment signal components are obtained. It is assumed that operating power is not supplied during the period when there is no operation. Thereby, in the magnetic tape recording device according to the present invention, the diameter of the tape guide cylinder is, for example, 4.
0mm, the tape winding angle is 180 degrees, the cylinder rotation speed is approximately 29.97 rps, and the diameter of the tape guide cylinder is smaller than that of a standard video tape recorder, which has two rotating magnetic heads. Even in this case, the number of rotating magnetic heads will not increase, and the recording signal forming section,
The power consumption of the circuit components forming the recording signal supply section and the like can be effectively reduced, and the present invention is compatible with standard video tape recorders.

Furthermore, the magnetic tape recording device according to the present invention may have a function of reproducing video signals recorded on the magnetic tape in addition to the function of recording video signals on the magnetic tape. In this case, even though a tape guide cylinder with a smaller diameter than that of a standard video tape recorder is adopted, the number of rotating magnetic heads does not increase, so the review It is said that it is easy to add a rotary magnetic head for variable speed reproduction to be used in reproduction mode, still reproduction mode, etc., and therefore, so-called noise rescue reproduction, noiseless review reproduction, noiseless still reproduction, etc. can be easily performed. It is assumed that it can be done.

[Brief explanation of drawings]

FIG. 1 is a block connection diagram showing an example of a magnetic tape recording device according to the present invention.

FIG. 2 is a time chart for explaining the operation and other explanations of the example shown in FIG. 1;

FIG. 3 is a time chart used to explain the operation of the example shown in FIG. 1;

FIG. 4 is a block connection diagram showing a specific configuration example of a control signal forming section in the example shown in FIG. 1;

FIG. 5 is a circuit connection diagram showing a specific configuration example of a power supply control section in the example shown in FIG. 1;

FIG. 6 is a block connection diagram showing an example of a signal reproducing device for reproducing signals from a magnetic tape recorded according to the example shown in FIG. 1;

7 is a time chart used to explain the operation of an example of the signal reproducing device shown in FIG. 6; FIG.

[Explanation of symbols]

11 Video signal input terminal 12 Video signal input terminal 13 Audio signal input terminal 15 Field memory 18 Field memory 19 Field memory 21 Field memory 22 Timing pulse generation section 27 Luminance signal recording processing section 29 Signal synthesis section 30 Color signal recording processing section 32 Audio signal recording processing section 36 Recording amplification section 37 Recording amplification section 41 Rotating magnetic head 42 Rotating magnetic head 43 Tape guide cylinder 45 Magnetic tape 55 Control signal forming section 57 Fixed magnetic head 58 Waveform shaping section 121 Power control section 122 Power control unit 123 Power control section 130 Recording signal forming section

Claims (1)

[Claims] Claims: 1. A video signal time axis processing unit for time axis compressing a video signal at a predetermined time compression rate; and a time axis compressing unit based on the time axis compressed video signal obtained from the video signal time axis processing unit. a recording signal forming unit that forms a recording video signal in which the unit segmented signal components are intermittently connected;
A rotating magnetic head that scans a magnetic tape running on the outer circumferential surface of a tape guide cylinder, and a time-axis compressed unit segment signal component of a recording video signal obtained from the recording signal forming section are sequentially sent to the rotating magnetic head. A state in which the supply of operating power is stopped to the recording signal supplying section, and at least one of the recording signal forming section and the recording signal supplying section, during a period in which the time-axis compressed unit division signal component is not obtained. A magnetic tape recording device comprising: a power supply control unit that takes