JPS61281696A - Transmitting system and magnetic recording device for high quality television signal - Google Patents

Abstract

PURPOSE:To remove sufficiently transporting chrominance components from a luminance signal and to decrease the crosstalk of the luminance signal to the transporting chrominance components by composite-transmitting the luminance signal and the low pass transporting chrominance components and inverting the phase of the same transporting chrominance components for a pair of the horizontal scanning period respectively. CONSTITUTION:In the first horizontal scanning period, change-over switches 27, 28 and 36 are in the connecting condition reverse to switches shown in the figure. Both color difference signals outputted from an input matrix circuit 21 are respectively supplied through switches 27 and 28 and low pass filters 29a and 29b to both multiplying circuits 31 and 32 of a right-angled two phase modulating circuit 30 respectively, and in both multiplying circuits 31 and 32, a color sub-carrier having the phase difference of 90 deg. is amplitude-modulated. In case of the second horizontal scanning period, the switches 27, 28 and 36 are changed over to the connecting condition shown in the figure. From an adder circuit 35, the same chroma signal as the first horizontal scanning period is obtained.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Field of industrial application B. Overview of the invention C. Prior art D. Problem to be solved by the invention E Means for solving problem E li, 'i (Figure 1)
F Effect G Embodiment G1 Encoder (Fig. 1, Fig. 2) G2 Decoder (Fig. 1, Fig. 2) G3 Other embodiment (Fig. 3) H Effect of the invention A Industrial application field The present invention is The present invention relates to a high-definition television signal transmission system and magnetic recording device.

B. Summary of the Invention The present invention frequency-multiplexes a carrier color signal in the low range of a wideband luminance signal in the transmission and magnetic recording of high-definition television signals, and multiplexes the same carrier color signal in each of a pair of horizontal scanning periods. By inverting the phase of the signal, it is possible to easily separate the luminance signal and the carrier color signal, thereby improving the quality of one image.

C. Conventional technology High-definition television signals (hereinafter referred to as HD video signals) are based on the current standard system (NTSC system), as is well known.
The bandwidth is much wider than that of video signals. Various transmission methods have been proposed to transmit this wideband video signal with high fidelity.

Various devices have been developed.

First, while referring to FIGS. 4 to 6, the conventional method will be explained.

High-definition television VTR manufactured by the applicant (
(hereinafter abbreviated as HD-VTR) will be explained.

The standards of this HD-VTR are as follows.

(1) Video input signal Y, C,,C.

Bandwidth (MHz) 30 each (2) Video output signal Y, cw, Cw Bandwidth (MHz) 20.7.7 (3) Video signal recording mechanism rotating head mechanism 1 inch helical VTRC format and similar number of heads For video 4 (4) Video recording signal channel division method Luminance (Y) signal 2 channel division F'M chroma (C
) signal C'W I CN signal Direct FM FIG. 4 shows the configuration of the signal processing system of the HD-VTR as described above.

In FIG. 4, the luminance signal Y and both chroma signals C
W and CN are supplied to the input matrix circuit (1),
Red at 10 MHz i, as shown in Figure 5A.

While the blue primary color signals R and B are formed, as shown in FIG.
Broadband signal G1 combined with high-range luminance signal YH of zero level
is formed. Since the video bandwidth of each of the four channels of the HD-VTR is 10 MHz, the time axis of the broadband signal GW is doubled in the 1 time axis expansion circuit (2), as shown in Fig. 5C. As shown in and D, a pair of expanded signals G and G2 with one frequency bandwidth reduced are formed. At this time, one expansion signal G corresponds to the signal of the odd-numbered scanning line, and the other expansion signal G2 corresponds to the signal of the even-numbered scanning line.

The two color signals R and B and the two color signals G and G2 are respectively supplied to frequency modulators (3&) to (3d),
A carrier wave of 16-20 MHz is frequency modulated.

Frequency modulated signals with a frequency deviation of 4 MHz obtained from the modulators (3a) to (3d) are respectively sent to recording amplifiers (4).
The four recording rotary magnetic heads (
5a) to (5d) HD video signals are recorded on a magnetic tape (not shown) supplied with IIc.

The two-dimensional color signal R recorded on the magnetic tape as described above
and B, and both length signals G and G2 are output from the reproducing magnetic head (
6a) to (6d), and regenerative amplifiers (7a) to (7d) and regenerative equalizers (8a) to (8), respectively.
d) to one-frequency demodulators (9a) to (9d). The demodulated signals from the demodulators (9a) and (9b), that is, the primary color signals R and B, are jitter corrected in time axis correction circuits (10m) and (10b) and then supplied to the output matrix circuit (2). On the other hand, demodulated outputs from demodulators (9c) and (9d), ie, expanded signals G.

and G2 are supplied to the time axis compression/correction circuit α■, where the time axis is compressed, the book is removed, and the wideband signal G7 as shown in FIG. 5B is restored and output matrix. Supplied to circuit (2). This matrix circuit (
6), the luminance signal Y and both chroma signals CW and CM
is played.

D. Problems to be Solved by the Invention By the way, when recording the above-mentioned broadband signal on, for example, an A-inch tape cassette, as the recording capacity decreases, the equivalent transmission path bandwidth also decreases. , the conventional HD-VTR signaling system cannot be used.

In order to transmit the HD signal in a narrow band, frequency multiplexing of the luminance signal Y and the chroma signal C may be considered, similar to the current NTSC system. In this case, as shown in Figure 6A, the bandwidth of the NTSC luminance signal Y is 4.2.
MHz, and the bandwidth of one color eraser is 1.5 M)
fz, the 20M of the HD-VTR mentioned above.
For the luminance signal Y with a bandwidth of Hz, the bandwidth of the chroma signal C can be set to 5 MHz, as shown in FIG. Further, the color subcarrier frequency ftee is set to, for example, 15 MHz.

However, in general, the frequency multiplexing method has a problem in that crosstalk occurs between the luminance signal and the carrier color signal, and this gives a sense of instability to the image.

In addition, in the case of FM transmission such as a VTR, the noise spectrum of the modulator output is a new triangular noise as shown in Figure 6C, and the noise component in the high frequency region of the signal band is large. There is a problem in that the noise component Ne of the chroma signal multiplexed in a high frequency region increases, and the S/N of the color signal decreases.

Furthermore, if there is nonlinear distortion in the FM transmission path, the distortion between the FM carrier and the color subcarrier will enter the band and cause beat disturbance, but this phenomenon is noticeable when the frequency flIc of the color subcarrier is high. However, there is a problem that moiré fringes occur on the screen, degrading the quality of the image.

In view of the above, an object of the present invention is to provide a high-definition television signal transmission system that eliminates crosstalk between a luminance signal and a carrier color signal while reducing the bandwidth of a transmission path. be.

Another object of the present invention is to provide a magnetic recording device for high-definition television signals that can obtain images with good S/N and no moiré fringes7.

E Means for Solving Problems The first invention provides a carrier in which a relatively narrow band color signal is carried on a color subcarrier having a frequency that is less than or equal to the difference between the bandwidth of a wide band brightness signal and the brightness signal. A composite color signal is formed from the color signal, and in the n-th horizontal scanning period, a first composite color signal ( At the same time, in the n+1 horizontal scanning period, a second composite signal consisting of the luminance signal (Yn+1) of the n+1 horizontal scanning period and the carrier color signal (-Cn) of the n-th horizontal scanning period having an opposite phase is transmitted. A transmission system ENC transmitting a color signal (Yn+1-cn) and by subtraction between the first and second composite color signals within the band of the carrier color signal.

While separating the carrier color signal (Cn) of the n-th horizontal scanning period, - by subtracting and adding the separated carrier color signal (Cn) and the first and second composite color signals, the n-th and n+1-th Luminance signal during horizontal scanning period (Yn and Yn+1)
This is a high-definition television signal transmission system that has a receiving system DEC that separates the signals.

A second aspect of the present invention provides an adding means (to) to which broadband luminance signals of the n-th and (n+1)-th horizontal scanning periods are sequentially supplied;
and a color signal repetition supply means 翰 for repeatedly supplying a relatively narrow band color signal of the n-th horizontal scanning period during the n+1 horizontal scanning period, (7), @, (c) and the difference in the bandwidth of the luminance signal. One-color decoding repetition supply means (c), (c), including a color subcarrier generation means (to) that generates a color subcarrier with the following frequencies;
A carrier color signal forming means (1) is supplied with the outputs of @ and (c) to form a carrier color signal, and an output of this carrier color signal forming means (7) is supplied, and the nth horizontal roofing period and n+1th
A diagram of a phase inverting means that inverts the phase during the horizontal running period and supplies it to the adding means (goods).

F Effect According to the present invention, the bandwidth of the transmission path can be reduced, the carrier color signal is sufficiently removed from the luminance signal, and the crosstalk of the luminance signal to the carrier color signal is reduced. be done. Furthermore, in the magnetic recording device, FM demodulation noise is reduced and moiré is suppressed.

G. Embodiment Hereinafter, an embodiment of a high-definition television signal transmission system according to the present invention will be described with reference to FIGS. 1 and 2.

G1 Encoder The encoder ENC of this embodiment is shown in FIG. This first
In the figure, an HD video signal is transmitted from a signal source such as a camera (not shown) as a three-primary color signal R of red, green, and blue.
, G, and H, respectively, input terminals (20r) and (2
0g) = input matrix circuit e via (20b)
A luminance signal Y and a pair of red and blue difference signals R-Y and B-Y are formed in this human matrix circuit E. The luminance signal Y is supplied to the adder circuit (to) via the delay line (2), and the colorimetric difference signals R-Y and B-Y are each supplied to the delay line (to) whose delay time is one horizontal scanning period (IH).
A fixed contact (27 m) of one of the switching switches ■ and (to), which are supplied to (c) and (c) and are interlocked with each other.
and (28m), respectively.

The other fixed contacts (27b) and (28b) of the switch (7) are supplied with the outputs of the IH delay line (c) and 4, respectively, and the movable contacts (27e) and (28c) have a passband width of 5 M) h low pass filter (29 m
) and (29b), respectively. Note that the aforementioned delay line (2) is for compensating for the delay of the color difference signal whose passband width is limited by these low-pass filters.

(1) shows the quadrature two-phase modulation circuit as a whole, and a pair of multiplier circuits 61) and (to) included in this quadrature two-phase modulation circuit (g) include a low-pass filter (29m) and (to), respectively.
29b), the color difference signals R-Y and B-Y are respectively supplied. (to) is a color subcarrier oscillator, and from this oscillator (to), a color subcarrier whose frequency is an integer multiple of the horizontal frequency fm and has a frequency of about 8 MHz is directly supplied to one of the multiplier circuits 01). 'It is supplied to the other multiplication circuit (A) via the phase shift circuit (B). The outputs of both multiplier circuits 0 and 02 are supplied to an adder circuit (c). The output of the adder circuit (G) is connected to one fixed contact (36
a) and also via an inverter (b),
It is supplied to the other fixed contact (36b) of the switch (to). The movable contact (36c) of the switch (2) is connected to the adder circuit, and the output of the adder circuit (e) is connected to the encoder ENC.
is supplied to the output terminal (good) of

Next, the operation of the encoder ENC mentioned above will be explained.

During the first horizontal scanning period, the changeover switch (2),
It is assumed that (7) and (to) are in the opposite connection state from that shown. The colorimetric difference signals (R-Y) and (B-Y) output from the input matrix circuit Q output are passed through the switches and the low-pass filters (29m) and (29m), respectively.
29b) to both multiplier circuits 0 and (a) of the quadrature two-phase modulation circuit (1).
) and (a), color subcarriers having a phase difference of 90° are amplitude modulated. The outputs of both the multiplier circuits 01) and 01 are combined in the adder circuit 01 to form a carrier color signal (chroma signal) C1. The carrier color signal C5 and the luminance signal Y from the input matrix circuit H are frequency-multiplexed in the adder circuit (to) as shown in FIG. 2A.
A composite color signal with a bandwidth of 20 MHz is obtained from the output terminal (c).

In the second horizontal scanning period, the switch (goods), (to)
and (g) are switched to the connection state shown. At this time, the colorimetric difference signals (R-Y) 1 and (
B-Y) have reached the output side of the IH delay lines (A) and (7), and are subjected to quadrature two-phase modulation via the switch (A), @ and low-pass filters (29a) and (29b), respectively. Both multiplier circuits 0 and 02 of circuit (1) are supplied respectively.

Therefore, the same chroma signal C1 as in the first horizontal scanning period is obtained from the adder circuit (to).

The phase of this chroma signal C4 is inverted by the inverter (B) to become -C4, which is then passed through the switch (G) to the adder circuit (
(to)) and is frequency multiplexed with the luminance signal Y2 of the second horizontal scanning period supplied from the matrix circuit (c) to obtain a composite color signal as shown in FIG. 2B.

In the third horizontal scanning period, the switch (b).

(to) and (to) are again switched to the reverse connection state as shown in the figure, and in the same way as in the first horizontal scanning period, the luminance signal Y and the chroma signal C5 of positive phase in the same period are connected. Frequency multiplexing is performed to create a composite cup as shown in Figure 2C.
I get a signal.

In the fourth horizontal scanning period, the switch (b).

(c) and (to) are switched again to the connection state shown in the diagram,
In the same way as in the second horizontal period, the luminance signal Y4 and the chroma signal -C which is in opposite phase one horizontal scanning period earlier than the luminance signal Y4.
3 are frequency multiplexed to obtain a composite color signal as shown in the second diagram.

In the same manner, the luminance signals are changed to Y5. Y6. Y...
Y, . . . are sequentially transmitted every horizontal scanning period. On the other hand, the chroma signal is, for example, C5, -C5, C,, -C, .
. . , only the signals in the odd-numbered horizontal scanning periods are extracted, and their phases are inverted and transmitted in the even-numbered horizontal scanning periods.

For example, an optical fiber is used as the transmission path. In this case, as the light emitting element, a light emitting diode is used for short distance transmission, and a laser diode is used for long distance transmission.

Note that in the encoder ENC described above, the color difference signal R
-IH delay line (A) to delay B-Y
, (7) were used, but a memory may also be used, and a vertical low-pass filter using a symmetrical transversal filter may also be used.

If the latter is used, phase distortion will not occur, and folding of the frequency spectrum that occurs when only the current period of one horizontal run is extracted is prevented.

G2 Decoder The decoder DEC of this embodiment is shown in FIG. In FIG. 1, (g) shows the signal separation circuit as a whole, one input terminal (41m) is connected to the first subtraction circuit (b), and the second The other input terminal (41b) is connected to the first subtraction circuit (41b), and the delay line (4ab
) to the adder circuit. Also, the output of the first subtraction circuit (b) is supplied to the subtraction circuit (2), the addition circuit (conversion), and the third output terminal (48c) via the bandpass filter and the attenuator α. ■Addition circuit-
The output of each is the first. Second output terminal (48m),
(48b). In addition, both delay lines (43m
), (43b) are for compensating for the delay time of the bandpass filter.

The input terminals of the decoder DEC are connected to one input terminal (41m) of the signal separation circuit and directly connected to the other input terminal (41b) via the IH delay line 6D. The first output terminal of the signal separation circuit ■ (48 m
) is one fixed contact (521L) of the changeover switch (goods)
), and the second output terminal (48b) is IH
It is connected to the other fixed contact (52b) via the delay line So. The movable contact (52e) of the switch (to) is connected to the output matrix circuit. The third signal separation circuit (G)
The output terminal (48c) is directly connected to one fixed contact (55m) of the second changeover switch, and
H delay line) to the other fixed contact (55b) of the switch. Reference numeral I71 denotes a color demodulation circuit, to which a switch branch movable contact (55c) is connected, and the output of the color demodulation circuit-01 pair is supplied to the output matrix circuit (2). The output of the matrix circuit (goods), i.e. 3
The primary color signals R, G, and B are decoded at the DEC output terminal (58
r) , C58g> , (58b) are derived, respectively.

Next, the operation of the above-mentioned decoder DEC will be explained.

During the first horizontal scanning period, the changeover switch
It is assumed that f4 is in a connection state opposite to that shown in the figure. From the aforementioned encoder ENC, composite color signals as shown in FIG. 2A, B, C and D are sequentially supplied to the input terminal diagram of the decoder DEC, for example by optical fiber transmission.

As shown in FIG. 2A, when the composite color signal Y1+C1 of the first horizontal scanning period reaches one input terminal (41m) of the signal separation circuit (6) via the IH delay line 6], the other The input terminal (41b) receives a composite color signal Y2-01 during the second horizontal scanning period as shown in FIG. 2B.
is reached. In the first subtraction circuit (b), these composite color signals are subtracted to obtain a chroma signal 2C1 and vertical uncorrelated components Y1-Y2 of the luminance signal.

The output of this subtraction circuit (6) is filtered by a bandpass filter to remove frequency components outside the chroma signal band.
The amplitude is halved by

The output of the attenuator a'i) is the chroma signal separated by the signal separation circuit (g), and the vertical uncorrelated component of the luminance signal in the chroma signal band is expressed as Yl e - Y2c = Y12
As e, cl-y1□. /2. The separated chroma signal with reduced crosstalk from the luminance signal is subtracted from the composite color signal Y, +C1 of the first horizontal scanning period in the second subtraction circuit (b), and the output of the subtraction circuit - is Yl. "-Y, 2 c/2, and the chroma signal is removed, and the luminance signal of the first horizontal scanning period in which the vertical uncorrelated component is mixed in the chroma signal band is separated. Also, in the adder circuit, The composite color signal Y2-C1 of the second horizontal scanning period and the above-mentioned separated chroma signal C1-Y1□c/2 are added, and the output of the adder circuit becomes Y2+Y, 2c/2, and the chroma signal is removed. At the same time, the luminance signal of the second horizontal scanning period in which the vertical uncorrelated component is mixed in the chroma signal band is separated.

General K, since the vertical correlation is large in the low frequency region,
Vertical uncorrelated component Y of the luminance signal in the chroma signal band,
2c is generally small. The amplitude of the vertical uncorrelated components mixed in the separated chroma signal and separated luminance signal obtained by the signal separation circuit (a) is further reduced by half, and its influence can be generally ignored, so the following The description will be omitted in the explanation.

Further, in the encoder ENC described above, since the phase of the same chroma signal is inverted in each of a pair of horizontal scanning periods, the signal separation processing described above can be easily performed. Therefore, in this embodiment, there is no need for frequency interleaving, and as mentioned above, the frequency of the color subcarrier can be set to an integral multiple of the horizontal frequency.
In the case of an embodiment applied to , time axis correction becomes easy.

The separated luminance signal Y of the first horizontal scanning period obtained as described above in the signal separation circuit is supplied from the first output terminal (48 &) to the output matrix circuit via the switch Q. be done.

At this time, the third output terminal (48c) of the signal separation circuit
The separated chroma signal C1 is supplied to the color demodulation circuit through the switch (to), and the colorimetric difference signals (R-Y), , (B-Y), which are the output signals of this color demodulation circuit, are .

is supplied to the matrix circuit (goods). In the matrix circuit, this colorimetric difference signal (RY), ,
(B-Y).

and the separated luminance signal Y of the first horizontal scanning period.

Three primary color signals R4, G4. B1 is formed.

When the separation of the luminance signal and chroma signal in the first horizontal scanning period is completed, the switches □□□, (to) return to the illustrated connection state. At this time, the separated luminance signal Y2 in the second horizontal scanning period is sent to the second output terminal (48b) of the signal separation circuit (A).
and reaches the output side of the IH delay line.

Also, the same separated chroma signal C1 as in the first horizontal scanning period is transmitted from the third output terminal (48c) to the IH delay line (
has reached the output side of (to). These separated luminance signals Y
2 and the separated chroma signal C1 are respectively supplied to an output matrix circuit and a color demodulation circuit via a switch ring and a color demodulation circuit. Signal (RY).

and (BY) are obtained.

According to this embodiment, since the luminance signal and the carrier color signal are combined (frequency multiplexed), the transmission band can be used effectively. In addition, since the same chroma signal is transmitted with its phase reversed in each of a pair of horizontal scanning periods, the chroma signal can be sufficiently removed from the luminance signal, and crosstalk of the luminance signal to the chroma signal can be eliminated. This will improve the quality of the reproduced images.

G3 Other examples Nine embodiments applied to a digital VTR will be described.

The structure of another embodiment of the present invention is shown in FIG. In FIG. 3, (c) is an encoder whose detailed configuration is exactly the same as the encoder ENC shown in FIG. 1 above. From this encoder (c), a composite color signal with a bandwidth of 20 MHz as shown in FIG. 2A to D is supplied to the time axis expansion circuit (a). This time axis expansion circuit (to) is similar to the time axis expansion circuit (to) of the conventional pan-VTR shown in Fig. 4.
It is similar to 2).

A pair of expanded composite color signals (Y, +C,) and (Y2-C,) reduced to a frequency bandwidth f 10 MHz. is supplied from the time axis expansion circuit (2) to frequency modulation circuits (73m) and (73b) each having a carrier wave frequency of 16 to 20 MHz, similar to a conventional HD-VTR. At this time, the frequency of the color subcarrier is approximately 4 MHz. The outputs of the modulation circuits (73m) and (73b) are supplied to recording magnetic heads (75m) and (75b) through recording amplifiers (74m) and (74b), respectively, and two channels are recorded on the magnetic tape (not shown). recorded.

The two channels of composite color signals recorded on the magnetic tape as described above are each read by a reproducing magnetic head (76 m).
and (76b), respectively arranged in a regenerative amplifier (77m) and (77b) and a regenerative equalizer (78m).
and (78b) 'fr, the frequency demodulator (79m
) and (79b). After-rain conditioner (79m) =
The demodulated output of (79b), that is, the expanded composite color signal is A-
D converter (80m), (80b) and memory (81
The jitter is corrected in the time base correction circuit consisting of m) and (81b), and the signal is supplied to the signal separation circuit fit)K. This signal separation circuit (2) is equivalent to the signal separation circuit shown in FIG. 1 (above) except that the frequency band of the signal to be processed is different.
The digit of 10 is assumed to be 6, and detailed explanation will be omitted.

Separated luminance signals Y and Y2 from the subtraction circuit and addition circuit of the signal separation circuit are memo IJ 4113 and (to)
At the same time, the separated chroma signal C1 from the attenuator (2) is written to the memory.

Separated luminance signal Y corresponding to the first horizontal scanning period.

is read out from the memory at twice the speed of writing, thereby compressing the time and restoring a wide frequency spectrum.
The signal is supplied to the first DA converter.

Next, the switch ■ is switched to the illustrated connection state, and the separated luminance signal Y2 corresponding to the second horizontal scanning period is read out from the memory ell at twice the writing speed, and is time-compressed into a wide frequency spectrum. The signal is then supplied to the first DA converter (2) via a switch.

In this way, the analog luminance signal Y1. Y2 is output sequentially.

During this time, the separated chroma signal C4 is read from the memory twice at twice the writing speed and is time compressed to restore a wide frequency spectrum.

This compressed separated chroma signal is transmitted to the second and third D-A
First, it is commonly supplied to the converters ■ and (to) at the same timing as the separated luminance signal Y of the first horizontal scanning period, and then it is supplied at the same timing as the separated luminance signal Y2 of the second horizontal scanning period. be done.

The second D-A converter @FC is directly supplied with a clock phase-locked to the approximately 8 MHz color subcarrier from the pulse generator, and the third D-A converter @FC is supplied with a clock phase-locked to the color subcarrier of approximately 8 MHz. Since it is supplied via the phase shifter shaft, both D-A converters (b)
and (to) are analog color difference signals (R-Y), respectively.
,.

(B-Y), (R-Y)2 and (B-Y)2 are sequentially output.

The analog luminance signal Y from the first DA converter (2) is supplied to the output matrix circuit (K) via a low-pass filter (e) with a passband width of 20 MHz, and is then supplied to the second and third D/A converter (2).
- Analog color difference signal R-Y from A converter (a) and branch
and B-Y are supplied to an output matrix circuit K through low-pass filters with a passband width of 5 MHz and 2), respectively, and the three primary color signals R and G of the HD video signal are supplied to the output matrix circuit K in this matrix circuit. , B are restored.

According to the second embodiment, in addition to obtaining the same effects as in the first embodiment, since the chroma signal is transmitted in a low frequency range, FM demodulation noise is reduced and the chroma signal is is improved. Furthermore, since the color subcarrier frequency is lowered, the occurrence of moiré can be suppressed, and the quality of reproduced images is improved.

In the second embodiment described above, two-channel recording was performed using two recording heads, but it is also possible to perform one-channel recording using a broadband head. In this case, the companding process on the time axis is omitted, and the data is recorded line-sequentially as in the first embodiment.

H Effects of the Invention As detailed above, according to the present invention, a luminance signal and a low-frequency carrier color signal are transmitted in a composite manner, and the phase of the same carrier color signal is inverted in each of a pair of horizontal scanning periods. As a result, it is possible to sufficiently remove the carrier color signal from the luminance signal, and also to reduce the talk of the luminance signal to the carrier color signal, improving the quality of the reproduced image and making it possible to achieve the next highest quality TV. It is possible to obtain a transmission method for the John signal.

Further, by reducing y demodulation noise and suppressing moiré, it is possible to obtain a magnetic recording device for high-quality television signals in which the quality of reproduced images is further improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a high-definition television signal transmission system according to the first invention, FIG. 2 is a frequency spectrum of a transmission signal according to the invention, and FIG. 3 is a diagram showing an example of the transmission method according to the second invention. FIG. 4 is a block diagram showing another embodiment of a magnetic recording device for high-definition television signals according to the above-described method. FIG. 4 is a block diagram showing an example of the configuration of a conventional high-definition television VTR.
The figure shows the frequency spectrum of the transmission signal, and FIG. 6 is a diagram for explaining the present invention. The slope is the adder circuit, (c) and (c) are the IH delay lines, (1)
is a quadrature two-phase modulation circuit, (to) is a color subcarrier oscillator, (b) is an inverter, ■ is a signal separation circuit, ■ is a color demodulation circuit, ENC is a transmission system (encoder), DEC is a reception system (decoder) ). Real t! 〃1 shot ≧ Karai no.

Claims (1)

[Claims] 1. Broadband luminance signal and 1/2 of the bandwidth of the luminance signal
A composite color signal is formed from a carrier color signal in which a relatively narrow band color signal is conveyed on a color subcarrier having the following frequency, and in the n-th horizontal scanning period, the luminance signal (Y_n ) and a positive phase carrier color signal (C_n), and in the n+1 horizontal scanning period, the luminance signal (Y_n_+_1) of the n+1 horizontal scanning period and the negative phase carrier color signal (Y_n_+_1) are transmitted. a transmission system that transmits a second composite color signal (Y_n_+_1-C_n) consisting of the carrier color signal (-C_n) of the n-th horizontal scanning period;
By subtracting between the composite color signals of By subtraction and addition, the above nth
and the luminance signal (Y_n and Y_
1. A transmission system for high-definition television signals, comprising a receiving system that separates n_+_1). 2. Adding means to which broadband luminance signals of the n-th and n+1 horizontal scanning periods are sequentially supplied, and a relatively narrow-band color signal of the n-th horizontal scanning period is repeated in the n-th and n+1-th horizontal scanning periods; and a color subcarrier generation means for generating a color subcarrier having a frequency of 1/2 or less of the bandwidth of the luminance signal, and the output of the color signal repetition supply means is supplied. A transport color signal forming means for forming a transport color signal, and an output of the transport color signal forming means are supplied, and the adding means reverses the phase between the n-th horizontal scanning period and the n+1 horizontal scanning period. 1. A magnetic recording apparatus for high-quality television signals, comprising: phase inverting means for supplying a signal to a recording magnetic head; and supplying an output of the adding means to a recording magnetic head.