JPS5940790A - Recorder of color video signal - Google Patents

Abstract

PURPOSE:To prevent deterioration in signals and to simplify the circuit constitution in recording an output signal of the color video camera, by converting a chrominance signal of an output signal of a color video camera into a signal of a low carrier frequency for recording. CONSTITUTION:A rotary head 27A slides on a magnetic tape 24 at first and a video track 30A is formed by recording a recording signal for one field's share in the range of a winding angle theta. No recording current is applied to a rotary head 27B in this period. Further, the recording current is applied to the rotary head 27B only in the period of the winding angle theta at the next one rotation, the recording signal on the next one field's share is recorded as a video track 30B. The video tracks 30A, 30B are coincident with the recording pattern formed with conventional VTRs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color video signal recording device that is applied to a rotating two-head VTR integrated with a color video camera.

[Background technology and its problems] When recording using a single-tube color video camera and a portable rotary two-head VTR, although these devices have become considerably smaller and lighter, they cannot be used freely. These are still too heavy to handle. In order to make the VTR smaller and lighter, the diameter of the tape guide drum was reduced.
However, the applicant has proposed a VTR that can be played back by a normal VTR for home use.

This VTR has an integrated color video camera. FIG. 1 shows one possible configuration for recording the output signal of a color video camera.

In FIG. 1, reference numeral 1 indicates a vidicon tube, and an optical filter for color separation and an index electrode are provided on its imaging surface. The output signal of the vidicon tube 1 is supplied to a signal extraction section 2, where a luminance signal Y, a red color difference signal RY, and a blue color difference signal B-Y are extracted. The signal extraction section 2 includes a low-pass filter for separating the luminance signal Y from the output of the vidicon tube 1, an IH delay circuit and a phase detection circuit for extracting the color difference signal, and the like. This color video camera is of the electronic index phase separation type.

The color difference signals R-Y and B-Y are supplied to balanced modulation circuits 3 and 4, respectively. A subcarrier of frequency fsc (3.58 MHz in the case of NTSC system) is supplied from a terminal 5 to the balanced modulation circuit 4, and the balanced modulation circuit 5 is supplied with a subcarrier having a relative phase difference of 90° by a phase shifter 6. The subcarriers having the following information are supplied. The outputs of these balanced modulation circuits 3 and 4 are supplied to a mixing circuit 9 via a bandpass filter 7.8. In this mixing circuit 9, a burst signal from a terminal 10 is also added, and its output is supplied to a mixing circuit 11, to which a luminance signal Y and a synchronization signal from a terminal 12 are added. A composite color video signal is then obtained at the output terminal 13 of the mixing circuit 12.

This composite color video signal is supplied to a low-pass filter 14 and a band-pass filter 15, and is separated into a luminance signal and a carrier color signal. This separated luminance signal is supplied to a luminance signal recording circuit 16. Luminance signal recording circuit 16
consists of a pre-emphasis circuit, a clip circuit, a clamp circuit, an FM modulation circuit and a bypass filter,
An FM-modulated luminance signal appears at its output, and this modulated luminance signal is supplied to the mixing circuit 17.

Further, the carrier color signal separated by the bandpass filter 15 is supplied to the frequency converter 18 . A carrier signal of a low frequency is supplied to this frequency converter 18 from a carrier generation circuit 19 . A low-pass filter 20 is provided at the output of the frequency converter 18, and the output of this low-pass filter 20 is connected to the mixing circuit 17.
supplied to The output of this mixing circuit 17 is the recording amplifier 2
1- to the output terminal 22. The output terminal 22 is provided with two rotary heads via a rotary transformer (not shown).

With this rotating head, the recording signal for one field is
Recorded as a video track of the book.

In order to perform high-density recording without providing a guard band between adjacent video tracks, the gap extension direction of the rotating head that forms one adjacent video track and the rotation that forms the other video track are determined. The direction in which the head gap extends is different from that of the head.

By performing recording using two rotary heads whose gap extension directions are shifted in this manner, crosstalk from adjacent tracks can be suppressed during reproduction.

Suppression of crosstalk using this azimuth loss is effective for modulated luminance signals, but does not hold true for converted color signals with low frequencies. Therefore, the converted color signal is
Control the phase or frequency of the carrier signal for low frequency conversion,
Crosstalk from adjacent tracks is removed by a comb filter provided in the reproduction circuit.

In the configuration shown in FIG. 1, when considering signal processing for color signals, a bandpass filter γ is used.

As in 8.14.15, filtering is performed multiple times, and as in the balanced modulation circuits 3 and 4 and the frequency converter 18, frequency conversion processing is performed multiple times. This causes problems such as deterioration of frequency characteristics and phase characteristics of color signals and the generation of spurious signals, as well as an increase in the number of parts and a corresponding increase in cost.

``Object of the Invention'' The present invention aims to prevent signal deterioration and simplify the circuit configuration when recording the output signal sound of a color video camera.

"Summary of the Invention" As described above, the present invention provides a color video signal recording device that prevents crosstalk from occurring during playback with respect to both luminance signals and color signals. This converts the signal into a low carrier frequency signal for recording. The present invention is applied to control the phase of a carrier of a low frequency when converting a color signal to a low frequency.

"Embodiment of the Invention" An embodiment of the invention will be described below with reference to the drawings. First, the VTR in this example will be explained.

As will be understood from the following explanation, this VTR can form the same recording pattern as a VTR in which rotating heads are arranged at angular intervals of 180 degrees, and the diameter of the tape guide drum is 3". It is an extremely small device designed to be made as small as about 100 yen.

In FIG. 2, reference numeral 23 indicates a tape guide drum.
is wound with a winding angle θ (2700 (θ<36°). The magnetic tape 24 is wrapped around the tape guide drum 2.
3 and travels in the direction of the arrow at a predetermined speed, for example, 20 am/sec. Tape guides 25 and 26 are provided for winding the magnetic tape 24 in a predetermined relationship around the tape guide drum 23.

Magnetic tape 24 wound around tape guide drum 23
The rotating heads 27A and 27B are in sliding contact with the rotating heads 27A and 27B. The rotary heads 27A, 27B operate at a normal field frequency (NT
In case of SC method. -osec.

In the case of the CCIR method, it is rotated counterclockwise by -, sec). Although not shown, tape guide tram 2
3 is composed of a fixed upper drum and a lower drum, and a cylindrical head disk that rotates between the two, and the rotary heads 27A, 27 are opened through a window provided in the head disk.
B is made to stand out.

The rotating heads 27A and 27B have respective gaps extending in different directions, and are configured to suppress crosstalk components from adjacent tracks by azimuth loss during reproduction. Since the two rotating heads cannot be provided at the same position, they are provided at positions separated by an angular interval α. In this embodiment, the angular spacing α is equal to
The rotary head 27B is selected to be delayed by 1.5T with respect to A. This T is one modified horizontal period as expressed by the following equation.

fH' = degree ° fHT = 7 θ (fl ( is the standard horizontal scanning frequency in the NTSC system or CCIR system.) Since the rotating heads 27A and 27B need to be placed extremely close to each other, they are shown in Fig. 3. As shown, they are bonded together to form an integral structure, and the gap distance G between them is set to a predetermined value.

FIG. 4 shows a conventional helical scan type rotary two-head type V for reproducing video signals recorded according to the present invention.
It shows TR.

A magnetic tape 24 is wound around the circumferential surface of the tape guide drum 2 with a winding angle slightly larger than 1800 mm.
Two rotating heads 29A, 2 facing each other with an angular interval of
9B alternately come into sliding contact with the magnetic tape 24. The extending direction of each gap between the rotating heads 29A and 29B is the rotating head 27A.

27B. The rotating heads 29A and 29B are rotated at a frame frequency, and each reproduces a color video signal for one field. The running speed of the magnetic tape 24 is assumed to be equal to the speed in one embodiment of the present invention.

FIG. 5 shows a recording pattern formed by recording a color video signal according to an embodiment of the present invention. First, the rotary head 27A comes into sliding contact with the magnetic tape 24, and a video track 30A is formed by recording one field's worth of recording signals within the range of the winding angle θ. During this period, no recording current is supplied to the rotary head 27B.

Then, in the next rotation, the recording current is supplied only to the rotary head 27B during the period of the winding angle θ, so that the next rotation
A recording signal for one field is recorded as a video track 30B. These video tracks 30A and 30B are assumed to match the recording pattern formed by the conventional VTR having the configuration shown in FIG.

In other words, the lengths of the video tracks 30A, 30B in the extending direction and the angles formed by the extended lines of the tracks with respect to the extending direction of the magnetic tape 24 are made equal to those in the conventional case. For this purpose, the wrapping angle θ is set to a predetermined value, and the diameter of the tape guide drum 23 is set to a predetermined value.

Video signals for one field are recorded in the video trunks 30A and 30B, and video signals for NTSC and CCIR are recorded.
Considering that the common tape guide drum 23 is used in the video track 30A.

Video signals of 525 horizontal sections and 525 horizontal sections need to be recorded for 30B. In addition, the tape guide drum 2
It is necessary to record an integer multiple of horizontal sections on the magnetic tape 24 wound over 360 degrees. Therefore, 360' 525 '360' 62
5−−− x −= N −〜x−−−−=Mθ
It is assumed that the wrap angle θ satisfies both equations: 2 θ 2 . - As an example, (θ=300'). At this time, (N=315
)(M=375).

The operation of one embodiment of the present invention will be described with reference to FIG.

As mentioned above, the regular one-field period (-, -5ec
), the rotating heads 27A and 27B rotate.

When one rotary head 27A comes to a position corresponding to the beginning of the range of wrapping angle θ as a reference, 17-rJ
4i+I+ is shown in FIG. And the wrapping angle θ
While the rotary head 27A is scanning the range of 1 field (262.5 T on the time axis),
A recording signal corresponding to a video signal of 62.5T period) is supplied to this rotary head 27A as shown in FIG. 6A. If the rotating head 27A.

If 27B is at the same position, a recording signal corresponding to the video signal for the next one field is recorded from the timing indicated by 315T on the time axis.

However, as already mentioned, the rotary head 27B is provided at a position separated by an angle α from the rotary head 27A. Therefore, correspondingly, a recording signal corresponding to the video signal of the next field is recorded from a timing delayed by 1.5T from the timing of 315T.

From the next timing of 630T, the rotating head 27
A is recorded and the same operation is repeated. The field FA recorded by the rotary head 27A and the field FB recorded by the rotary head 27B are defined by the vertical synchronization signal Sv shown in FIG. 6B.

In one embodiment of the invention, a color video camera is driven by the vertical synchronization signal shown in FIG. 6B. In FIG. 7, numeral 31 indicates the effective screen of the imaging surface of the color video camera. The vertical scanning of the image pickup tube is synchronized with the vertical synchronization signal S shown in FIG. 6B, and its horizontal deflection is
) is assumed to be synchronized with the horizontal synchronization signal of the frequency.

First, in the field FA, as shown in FIG.
62.5 horizontal scans are performed, and thereafter, 54 horizontal scans (overscan) are performed outside the effective screen 31, as shown by broken lines. Then, in the field FB, as shown in FIG. 7B, horizontal scanning is started from the upper center of the effective screen 31, 262.5 horizontal scans are performed, and then, as shown by the broken line, 51 overlappings are performed. A scan is performed. Then, as shown in FIG. 7A again,
Return to the upper left end of the effective screen 31. As understood from FIG. 7, interlaced scanning is performed in the image pickup tube.

The rotary head 27B may be attached so as to advance by an angle α relative to the rotary head 27A.

In that case, as shown in FIG. 6C, the rotary head 27
Recording may be performed by the two-rotation head 27B for a period of 262.5 T from a timing 1.5 T ahead of the timing at which recording starts at A. The vertical synchronizing signal Sv at this time is shown in Figure 6. This vertical synchronization signal Sv
Vertical deflection of the image pickup tube is performed in synchronization with this.

Vertical frequency is πsec and number of horizontal scanning lines is 625 0CC
Even when an IR system color video signal is targeted, it can be recorded in the same manner as the above-mentioned NTSC system. −
As an example, the rotary head 27B is compared to the rotary head 27A.
is delayed by 1.5T (however, the value of T is specified by the horizontal frequency of the CCIR method), if
During a period of 312.5T), a signal for one field is recorded by the rotary head 27A, and then a signal for one field is recorded during a period of 312.5T).
From the timing T), the signal for one field is recorded by the two-rotation head 27BI for a period of 312.5 T.

Another value of the wrapping angle of the magnetic tape 24 is (θ=310
．． 34°). In this case.

Then, the angular interval α of the gap between the rotary heads 27A and 27B is selected to produce a time difference of mT, for example IT.

It also records and plays back CCIR color video signals.
In some VTRs, as shown in FIG. 4, two rotary heads 29A and 29B have an offset of 0.5 H with respect to 180 degrees.

At this time, the value of the angular spacing a between the rotary heads 27A and 27B is different from that described above by 0.5 T.

FIG. 8 shows the basic configuration of an embodiment of the present invention. An electromagnetic or electrostatic deflection device 32 is provided in conjunction with the vidicon tube 1 whose imaging surface is provided with a color separation filter.

Further, numeral 33 indicates a synchronization signal generation circuit.

This synchronizing signal generating circuit 33 has the configuration shown in FIG. 9 in the case of the NTSC system. The output of the clock oscillator indicated by 38 is supplied to the frequency divider circuit 39, and 2fH'=
A signal with a frequency of (fH'-1, 21H) is formed.

This signal is the frequency divider circuit 40, 41, 42.

43.

The frequency dividing ratio of the frequency dividing circuit 40 is (-''--), which is 630.
Therefore, a synchronizing signal generated at a period of 630T on the time axis in FIG. 6 appears at the output of the frequency dividing circuit 40.

The frequency dividing ratio of the frequency dividing circuit 41 is (〒〒100〉〒〉〒〉〉〒, and a synchronization signal is generated at a period of 3.16.5T from this frequency dividing circuit 41. .41
are each reset by a pulse at a predetermined timing.

Then, the output of the frequency dividing circuit 40°41 is sent to the switch circuit 44.
is alternately selected for each i S e C, and the vertical synchronizing signal S shown in FIG.
V appears.

Further, the output of the frequency divider circuit 39 is divided by 7 by the frequency divider circuit 42 to form a horizontal synchronizing signal with a frequency of fH'.
mixed with the above-mentioned vertical synchronization signal by the mixing circuit 45,
A composite synchronization signal is taken out at the output terminal 46. Furthermore, the output of the frequency dividing circuit 39) is divided into (cloth) by the frequency dividing circuit 43, and a synchronous signal of constant period of 315T is outputted to the output terminal 47.
It is taken out.

The composite synchronizing signal appearing at the output terminal 46 of the synchronizing signal generating circuit 33 is supplied to the deflection circuit 35 of the vidicon tube 1 via the variable delay circuit 34. The vidicon tube 1 performs interlaced scanning as shown in FIG. The variable delay circuit 34 has two
The gap distance G between the rotary heads 27A and 27B is
This is to correct installation errors. That is, since the rotary heads 27A and 27B are bonded together as shown in FIG. 3, even if the gap G between them deviates from the normal value, it cannot be mechanically adjusted. This dimensional error is electrically corrected by the variable delay circuit 34.

Further, a 315T constant cycle synchronization signal generated from the output terminal 471 of the synchronization signal generation circuit 33 is supplied to the servo circuit 36 as a servo reference signal. This servo circuit 36 is connected to the rotating head 27A.

The rotating head 27B is rotated so that the rotational phase of
It controls the rotational phase of 7A and 27B.

Further, the output signal of the vidicon tube 1 is supplied to the signal extraction section 2, and the luminance signal Y and color difference signals R-Y and B-Y are extracted and added to the signal processor 37. A recording signal is formed by this signal processor 37, and the recording amplifier 21
．． The signal is supplied to the rotary heads 27A and 27B via a recording switch (not shown) and a one-turn transformer (not shown), and is recorded on the magnetic tape 24. The above-mentioned signal processor 37 is supplied with a composite synchronization signal via a variable delay circuit 34.

An example of the configuration of the signal processor 37 in the case of the NTSC system is shown in FIG. A luminance signal Y to which a composite synchronization signal has been added is supplied to an input terminal 48, and color difference signals R-y and B-Y are supplied to input terminals 49 and 50, respectively.

The luminance signal Y is supplied to a luminance signal recording circuit 16.

This recording circuit 16 includes a pre-emphasis circuit 51, a clip circuit 52 . Clamp circuit 53° FM modulation circuit 54
and a bypass filter 55. At output 1 of the bypass filter 55, a modulated luminance signal appears that is FM-modulated so that the sync tip level and white peak each have a predetermined frequency, and this is transmitted to the mixing circuit 55.
6.

The color difference signals R-Y and B-Y are passed through a low-pass filter 57.
58 to balanced modulation circuits 59 and 60, respectively. The respective outputs of the balanced modulation circuits 59 and 60 are supplied to a mixing circuit 61. Further, the PLL circuit 62 has a terminal 63
The horizontal synchronizing signal from
) generates a carrier signal.

This carrier signal and a carrier signal whose phase is inverted by the inverting circuit 64 are supplied to the input terminal of the switch circuit 65. This switch circuit 65 is controlled by a switching pulse from a terminal 66. This switching pulse remains at a constant level during the field FA in which the recording signal is supplied to the rotary head 27A, and during the field FB in which the recording signal is supplied to the rotary head 27B.
The level of the tv period is inverted for each IT.

As a result, in field FA, the phase of the carrier signal is constant, and in field FB, the phase of the carrier signal is inverted for each IT. By controlling the phase of the carrier signal in this manner, crosstalk related to color signals from adjacent tracks can be removed by a comb filter provided in the reproduction circuit. The switching pulse from this terminal 66 is formed from a vertical synchronizing signal and a horizontal synchronizing signal generated by the synchronizing signal generating circuit 33.

Further, the carrier signal output from the switch circuit 65 is supplied to the balanced modulation circuit 60 , and is also phase-shifted by 90° by the phase shift circuit 67 and supplied to the balanced modulation circuit 59 . This phase shift circuit 67 is for forming a carrier color signal subjected to orthogonal two-phase modulation.

The output of the mixing circuit 61 is supplied to one input terminal of the switch circuit 68. The other input terminal of this switch circuit 68 is connected to a phase shift circuit 69 .

A burst signal with a constant phase is supplied. The switch circuit 68 is controlled by a switching pulse from a terminal 70, and the burst signal (;J added signal appears at the output of the switch circuit 68. is passed through the bandpass filter 71.

The signal is supplied to a mixing circuit 56 and mixed with the modulated luminance signal.

Then, a recording signal appears at the output terminal γ2.

In FIG. 11, the frequency spectrum 73 is related to the color difference signal RY passed through the low-pass filter 57, and the frequency spectrum 14 shown by the broken line is related to the output horn of the balanced modulation circuit 59. Of course, the frequency spectra of the color difference signal B-Y and its modulated output are also similar to those shown in FIG.

The recording signal formed by passing through the signal processor 37 shown in FIG.
Recorded by 7A and 27B.

Then, it is reproduced at 18o0 by a VTR equipped with two rotary heads 29A and 29B as shown in FIG. During this reproduction, crosstalk of luminance signal components between adjacent tracks is suppressed. In addition, the reproduced low-band carrier frequency color signal is frequency-converted to one having the standard color subcarrier frequency fSC of the NTSC system, and is then supplied to a comb-shaped filter. In other words, the comb filter is configured to subtract the IH delayed signal and the non-delayed signal, and
Crosstalk is removed by utilizing the fact that the phase of the reproduced signal from one of the adjacent tracks is inverted every horizontal section, and the phase of the reproduced signal from the other track is not inverted.

FIG. 12 shows another configuration of the signal processor 37. The luminance signal Y supplied from the input terminal 48 is converted into a modulated luminance signal by passing through the recording circuit 16 as described above, and is supplied to the mixing circuit 56 . In addition, input terminals 49 and 50
The color difference signals R-Y and B-Y supplied from each of the balanced modulation circuits 59 .
60.

A carrier signal from the terminal 75 is supplied to one balanced modulation circuit 60 after being phase-controlled in the same manner as described above. The frequency of this carrier signal is (fL+f8o). The other balanced modulation circuit 59 is supplied with a carrier signal phase-shifted by 90'. The outputs of these balanced modulation circuits 59 and 60 are mixed by a mixing circuit 61, unnecessary signal components are removed by a band pass filter 76, and a burst signal is added by a switch circuit 68.

Then, the output of the switch circuit 68 becomes the frequency converter 7
7. The frequency converter 77 has a terminal 78
A carrier signal with a frequency fsc is supplied from , and its output is passed through a low-pass filter 79 . A color signal of a low carrier frequency, fL, appears at the output of the low-pass filter 79 and is supplied to the mixing circuit 56. The recording signal appearing at the output terminal 72 is the same as that produced by the configuration shown in FIG.

The output signals of the low-pass filters 57 and 58 have a frequency spectrum in a band of about 0.5 MHz, indicated by 73 in FIG. And balanced modulation circuit 59.60
The output signal has a frequency spectrum 80 with (fL+18°) as the carrier frequency. As is clear from FIG. 13, the band of the input signal of the balanced modulation circuit 59, 60 and the band of its output signal do not overlap. Therefore, even if the input signal leaks to the output due to the imbalance of the balanced modulation circuit, it is prevented from being mixed into the output signal.

FIG. 14 shows the configuration of another example of the signal processor 37. The configuration of FIG. 14 is 1. It is applied to PAL color video signals.

The luminance signal Y of the PAL color video signal is N
It is processed in the same way as TSC recording. Color difference signal R-Y
, B-Y are respectively supplied to a balanced modulation circuit 59, 60 via filters 57, 58, and their outputs are mixed by a mixing circuit 61. Balanced modulation circuit 59.6
The low frequency carrier signal and Nost signal for 0 are different from the recording of the NTSC color video signal (
Aru.

This carrier signal is a VCO (voltage controlled oscillator) 81
It is formed by dividing the output by the first frequency by the frequency dividing circuit 82. The output of the VCO 81 is sent to the frequency dividing circuits 83 and 84.
is also supplied to the switch circuit 85, and one of these outputs is supplied to the switch circuit 85.
is selected and supplied to the phase comparator circuit 87. The frequency division ratio of the frequency divider circuit 83 is set to 353-, and the frequency division ratio of the frequency divider circuit 84 is set to 353-.The switch circuit 85 is controlled by a frame frequency switching pulse from a terminal 86, The output chi of the frequency dividing circuit 83 is selected in one field, and the output chi of the frequency dividing circuit 84 is selected in the next field.

A horizontal open signal (frequency 9') from the synchronizing signal generating circuit 33 is supplied to the phase comparator circuit 87. The output of this phase comparison circuit 87 is low (used as a control voltage for the VCO 81 via a filter 89).

In the configuration of such a PLL circuit, in the field where the output of the frequency divider circuit 83 is selected by the switch circuit 85, the oscillation frequency of vco s i is 351 f, □'
In the field where the PLL circuit is stable and the output of the frequency divider circuit 84 is selected by the switch circuit 85,
When the oscillation frequency of vco s i is 353fH', P
The LL circuit becomes stable. Therefore, the carrier signal 351 t 353 generated at the output of the frequency dividing circuit 82
.

The signal is 1 for the frequency of -fH and the frequency of Tf□.
Changes for each field.

This carrier signal is supplied to the balanced modulation circuit 60, modulated by the color difference signal B-Y, and subjected to a 90° phase shift circuit by the phase shift circuit 67. The output of the phase shift circuit 67 and its phase inverted by the inversion circuit 90 are supplied to the input terminal of the switch circuit 91. The state of this switch circuit 91 changes every horizontal interval (IT) by a switching pulse supplied from a terminal 92, and a carrier signal whose phase is inverted every one horizontal interval is obtained as its output. This carrier signal is supplied to the balanced modulation circuit 59 and modulated by the color difference signal RY. The two carrier signals supplied to the balanced modulation circuits 59 and 60 are mixed in a mixer circuit 93 and then passed through a phase shift circuit 69 to form a burst signal. This burst signal is added to the color signal by a switch circuit 68.

Furthermore, when converting to a low carrier frequency, the number of cycles of the burst signal included in the burst period becomes too small, so a signal similar to the burst signal (pseudo burst signal) is added to the horizontal synchronization signal. The switch circuit 94 is for adding this lli pseudo-burst signal, and is controlled by a switching pulse from a terminal 95, and selects the pseudo-burst signal only in the period of the horizontal synchronizing signal.

This pseudo burst signal is obtained by changing the carrier signal appearing at the output of the frequency dividing circuit 82 to a predetermined phase by a phase shift circuit 96.

FIG. 15 shows the frequency spectrum of the recording signal formed by the signal processor described above.

In FIG. 15, 97 is the frequency spectrum of the FM-modulated luminance signal, and 98A and 98B are the frequency spectra of the low-band carrier color signal. One of the two adjacent video tracks has a carrier circumference 351.

A low frequency carrier color signal (frequency spectrum 98A) with wave number fL1 (-Tf□) is recorded, and on the other side, a low frequency carrier color signal (frequency spectrum 98B) with 353 carrier frequency fL2 (-Tf,,') is recorded. recorded.

In this way, between the carrier frequencies fL1 and fL2 (
There is a frequency difference of 7fH'). therefore,
The original carrier color signal in the reproduced signal and the crosstalk from the adjacent track will have a similar frequency difference, and the 2H
Crosstalk can be removed by a comb filter consisting of a delay line and a subtractor.

FIG. 16 shows the configuration of another example of the signal processor 37. As a recording method capable of canceling crosstalk from adjacent tracks, there is a method in which the phase of a low-frequency conversion color signal is rotated by 90 degrees every horizontal section, and the directions of this phase rotation are opposite to each other between adjacent tracks. The signal processor shown in FIGS. 16 and 17 performs processing regarding this color signal.

In FIG. 16, 99 indicates a PLL circuit, and the terminal 10
By multiplying the horizontal synchronizing signal of frequency fH' from 0 by 40,
The signal is supplied to the phase shift circuit 101. This phase shift circuit 10
1, a carrier signal having a phase different by 90' is formed, and is sequentially extracted for each IT by the switch circuit 102. The direction of change in the connection state of the switch circuit 102 is opposite between adjacent tracks.

The carrier signal taken out from the switch circuit 102 is supplied to the balanced modulation circuit 60, and is also phase-shifted by 90 degrees by the phase shift circuit 67 and supplied to the balanced modulation circuit 59. The output is supplied to a mixing circuit 61, the output of the mixing circuit 61 is supplied to a switch circuit 68, a burst signal is added by the switch circuit 68, and the signal is passed through a band pass filter 11 to form an NTSC carrier color signal. Ru. Although omitted in FIG. 16, processing regarding the luminance signal Y is performed in the same manner as in the case of "double series".

The signal processor shown in FIG. 17 has a configuration for performing color signal processing using a phase shift method and recording a color image using a PAL method.

In the case of the PAL system, the phase shift of the signal having a low frequency of 40 fH' is performed only on one of the adjacent tracks. Therefore, when the connection state of the switch circuit 102 is always changed in the same direction, the output J of the switch circuit 102 and a carrier signal whose phase is not shifted are supplied to the switch circuit 103. This switch circuit 103 is controlled by a switching pulse whose level changes every field from the IN6 child 104, and the connection state is switched every field.

The low frequency carrier signal thus formed is modulated by the color difference signal B-Y. Further, this carrier signal is phase-shifted by 900 degrees and the phase is inverted for each IT, and the signal is modulated by the color difference signal RY.

Furthermore, in the configurations shown in FIGS. 16 and 17, the PL
Instead of the L circuit 99, a carrier signal or the like may be generated by a circuit shown in FIG.

In FIG. 18, reference numeral 105 indicates a crystal oscillator with an oscillation frequency of 40 fl,.
The horizontal synchronizing signal is taken out to the output terminal 0 108, and then the frequency is divided to − by the frequency dividing circuit 10.
By dividing the frequency by 9 to E, a vertical synchronizing signal is output to the output terminal 110.

"Application Example" The present invention may be applied to a case where the output of a color video camera is recorded as a SECAM color video signal using a method in which the frequency of a carrier signal is different between adjacent field periods.

In the SECAM system, carrier signals having different frequencies are FM-modulated by the color difference signals RY and BY, and the color difference signals RY and BY are combined line-sequentially. As in the case of the PAL system described above, the carrier frequency of the tracks recorded as adjacent tracks is 4f.
H' must be different. From this point of view, the following carrier signals are used as low frequency carrier signals.

First, in one field, the frequency of the carrier signal modulated by the color difference signal R-Y is 353, which in the other field is related to the color difference signal R-Y.

The frequency of the carrier signal is −T−fH, and the color difference signal B
The frequency of the carrier signal related to -Y is assumed to be 433°TfH.

Furthermore, if a single-tube color video camera outputs three color signals, red, green, and blue, these signals are mapped.
The signal may be supplied to a Jx circuit to form a luminance signal and a color difference signal. Furthermore, I and Q signals may be used as the color difference signals.

"Effects of the Invention" According to the present invention, the output of the color video camera is not supplied to the color encoder to generate a composite color video signal, but the luminance signal and color signal from the color video camera are supplied to the recording circuit, respectively. Therefore, filtering and frequency conversion processing can be reduced. therefore,
Deterioration in signal quality can be prevented, and the circuit configuration can be simplified and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram used to explain a conventional color video signal recording device, and FIGS. 2 and 3 show an arrangement of a rotary head and a specific configuration of two rotary heads according to an embodiment of the present invention. The route map and front view shown, Figure 4 is rotation 2 for reproduction.
A route map used to explain the head type VTR, FIG. 5 is a route map used to explain the recording pattern of an embodiment of the present invention, and FIG. 6 is a time chart used to explain the recording operation of the embodiment of the present invention. FIG. 7 is a route diagram used to explain the beam scanning of the vidicon tube in one embodiment of the present invention, and FIGS. 8 and 9 are block diagrams and synchronization signal generation circuits showing the basic configuration of one embodiment of the present invention. A block diagram showing the configuration of
FIGS. 10 and 11 show N in an embodiment of the present invention.
A block diagram of an example of a signal processor in the case of the TSC system and a frequency spectrum diagram used for its explanation; FIGS. 12 and 13 are block diagrams of other examples of the signal processor in the case of the NTSC system in an embodiment of the present invention. and frequency spectrum diagrams used in the explanation, Figures 14 and 15.
The figure is a block diagram of an example of a signal processor in the case of the PAL system and a frequency spectrum diagram used for its explanation.
17 and 17 are block diagrams showing main parts of one example and another example of a signal processor of a type that shifts the phase of a carrier signal, respectively, and FIG. 18 is a block diagram of a carrier signal generation circuit in a signal processor of this phase shift type. FIG. 7 is a block diagram of another example. 1... Vidicon tube, 23... Tape guide drum, 24... Magnetic tape, 27A, 27
B...Rotating head, 30A, 30B...
...Video track, 33...Synchronization signal generation circuit, 37...Signal processor, 59.60...
...Balanced modulation circuit. Figure 1 Figure 2 Figure 15 0fLIfL2f- Figure 16

Claims (1)

[Claims] A magnetic tape is wound around a tape guide drum, and first and second rotating heads whose gap extension directions are different from each other are made to alternately come into sliding contact with the magnetic tape to record an output signal from a color video camera. In such a recording device, the low frequency carrier signal is balanced modulated by the color signal of the output signal, the luminance signal of the output J signal is FM modulated, and the balanced modulated color signal and FM modulation are performed. 1. A color video signal recording apparatus which mixes the luminance signals and records them on a magnetic tape field by field using first and second rotary heads.