JPS5923974A - Horizontal contouring circuit - Google Patents

Abstract

PURPOSE:To obtain a horizontal contouring component having no leakage of chrominance components, by obtaining the horizontal contouring signal through a BPF filter after a chromaticity signal component is removed from a digital video signal with a comb line filter. CONSTITUTION:A horizontal contouring component is obtained at a circuit, to which a vertical LPF 901 and BPF 907 constituting a comb line filter are cascade-connected. A digital video signal 110 is constituted with a 2TH delay circuit 126, to which 1TH delay circuits 402 and 403 are cascade-connected, coefficient multipliers 902-904, adder 905, and passed through a comb line filter, whose gain becomes ''1'' when its frequency (f) is nfH (fH is horizontal frequency) and ''0'' when the frequency (f) is (n+1/2)fH. The digital video signal passed through the comb line filter is passed through a BPF having a center frequency of fS/8 and pass band of + or -fS/16 constituted by 3TS delay circuits (TS is sampling period) 908 and 909, coefficient multipliers 910-912, and an adder 913, and multiplied by a horizontal contouring control signal 705, and thus, a horizontal contouring signal 709 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a digital television receiver that performs baseband video signal processing digitally, and particularly to a horizontal contour circuit.

[Techniques of the invention, t1.1 and its problems] Conventionally, all signal processing in television receivers has been done using analog signal processing (2-1.1), but in particular analog signal processing after the video stage has been (There were two problems that needed to be improved: Specifically, ζ2 is the luminance signal/chromaticity signal separation performance that appears on the screen as cross color dot interference, the T (improvement performance, synchronization performance, etc.) on each column side.On the other hand, the cost and production issues are Even if the circuit is converted to an IC, there are still many parts and adjustments required for foreign communications.

In order to solve these problems, consideration is being given to completely digitalizing the signal processing up to color signal demodulation after the video stage.

In preview receivers, horizontal contour correction is usually applied to the luminance signal. In conventional television receivers, this horizontal contour correction was accomplished by separating the horizontal contour signal component from the 1I114 degree signal and adding it to the new Celsius luminance signal.

However, since the luminance signal generally has a wide band in order to increase resolution, the horizontal contour signal separated from the luminance signal is often contaminated with chromaticity signal components. Therefore, when horizontal contour correction is performed using such a horizontal contour signal, there is a problem in that dot interference occurring in areas where color changes are large is emphasized.

[Purpose of the invention]

An object of the present invention is to provide a horizontal contour circuit that can easily obtain a horizontal contour signal with less chromaticity signal leakage by effectively utilizing the features of digital signal processing in a digital television receiver. It is to provide.

[Summary of the invention]

The present invention obtains a horizontal ring/no signal by removing the chromaticity component from a digital video signal using a comb-type filter, and then passing it through a band-pass filter to obtain a horizontal contour signal. This is how it was done. Here, the comb filter is li! The i1 wave number is f−n, f u (,
f n is horizontal frequency, n is leveling) techine is 1, f
-(n-'-Ti-) It has a frequency characteristic in which the gain becomes 0 at J'H.

[Results of invention]

According to the present invention, it is possible to obtain a horizontal contour (i) without leakage of one chromaticity value component. Therefore, when horizontal contour correction is applied, dot interference occurs in areas where there is a large color change. There is no emphasis on image quality, and the image quality is excellent.

Furthermore, in the present invention, the horizontal contour signal is directly separated and extracted from the video signal, not from the luminance signal as in the past.
The delay circuit in the comb filter for removing the chromaticity value signal component can be used in common with that of the #IiI type filter that separates the luminance signal and chrominance signal from the video signal.
41; is. This allows the horizontal contour circuit to be configured with a minimum amount of hardware, which is a great cost advantage.

[Embodiments of the invention]

FIG. 1 shows an overall block diagram of an image processing circuit 100 that demodulates an RGB signal from a baseband analog video signal by digital signal processing. In the diagrams below, the signal lines indicated by thin arrows represent analog signals or 1-bit digital signal lines, and the signal lines indicated by thick arrows represent digital signal lines digitized with multiple bits. . In addition, the digital television receiver explained as an example is NTSC
- It is assumed that both PAL signals can be demodulated using OJ functions, and this switching must be done manually. The outline of the image processing circuit 100 will be explained below with reference to FIG. 1, and then the main parts will be explained in detail.

(1) Analog video signal 1 input to the A/D conversion, clamp system, PLL circuit system, synchronization/timing system image processing circuit 100
01 is a low-pass filter (
Hereinafter, 2, referred to as LPF, enters j) 103. The LPF 103 serves to remove high-frequency noise that causes folding distortion during sampling performed by the A/I converter (hereinafter referred to as ADC) 109. I・P F J 03
The output of is inputted to the adder 1ose= via the buffer 104, added to the clamp signal 106, and then sent to the amplifier 108? It is input to A I) CJ 09 via. A
I) In C109, the input signal is sampled and digitized. Note that the amplifier 108 is the ADC1
In order to effectively utilize the dynamic range of 09,
A by adjusting the amplitude of the output signal 107 of the IJ11 calculator 105
Output to DC109.

Here, ADCJ (79 → clamp circuit 112 → D /
Controlled by A converter (hereinafter referred to as DAC) 114 → adder 105 → amplifier 108 → ADC 109 '111
1 loop is formed, which results in A, J) C109
A control 611j is performed to set the pedestal level of the digital video signal 1zo outputted from the digital video signal 1zo to a predetermined target value. In this control loop, the clamp circuit 112 (the second is the digital video signal phase 110 which is the output of the ADC 109)
Then, a burst sampling pulse 11) from a synchronization separation/timing generation circuit 122, which will be described later, is manually input.

In this clamp circuit 112, first, the digital video 48
Average value of burst part of No. 110 (pedestal level)
is calculated. Next, the culm was drawn, and the pedestal level was 5! r,: is in force.

It is output as an error signal No. 13. The error signal 113 is D
After being converted into an analog clamp signal 106 by the AC node 14, it is sent to the buffer 104 by the adder 105 as described in Oil.
is added to the output signal of As a result, adder 105
The DC component of the output video signal 107 changes, and control is performed to bring the pedestal level of this signal 107 closer to the target value (-).Then, this signal 107 is passed through the amplifier 108 for amplitude adjustment and the ADCJ (J!9). After being converted into a digital video signal 110, it is sent to a square clamp circuit 112],
An error signal 113 is calculated. Q), J2 motion f′
``From 52 onwards, Peb 'Starkrumf' will be performed.

On the other hand, sampling in the ADCJ 179 is performed at the timing of a thunking pulse (φS) output from the pressure controlled crystal oscillator (hereinafter referred to as VCXO) 115. In non-embodiments, the sampling pulse 116
(φS)σ) Frequency fS is % JS=4. rFC). (, (s a is the number of color subcarrier river waves: N'l' SC, If! - Ku 3.5) 3 M
Hz, PAL J'5e = 4.43 eight mouths lz
). In both N'l'8C and PAL signals, the hue component of color A is phase modulated by the color subcarrier.
Therefore, sampling pulse 116 (φS) and color! --The relative phase of the phase determines the demodulation axis when the color signal is demodulated, and thus determines the hue. Therefore, the phase of the sampling pulse 116 (φS) is set to 1. It is necessary to lock to the phase of This collateral is ADC 109 - phase detection circuit 1111, -+
DAC120-+V CX, 0115->ADC10
P consisting of 9 1. , L loop (2).The control procedure is as follows.

First, the digital video communication 1zo and the burst sampling pulse 111 are input to the phase detection circuit 117. In this phase detection circuit 117, the column m to st part of the digital video signal 110 is extracted by the burst extraction pulse 111.
'Y
The difference (θ-#.) from
C, which is output as No. 9 119. However, in reality, as will be described later, (21st place, 4th error, No. 119 is F+iI) (θ-θ.

). Phase error signal 1191#D
ACJ 20 converts it into an analog signal, VCXQ
It is applied to the VCXO 115 as a control voltage 12. As a result, the phase of the sine springing pulse 116 (φ8), which is the output of the VCXO 115, changes to the phase target value 117 (θ
. ). In addition, the phase target value 11
Hue control is performed by changing 7(θ.). , (Details of the PLLM path will be described later.)
- The recombination pulse 116 (φS) is
i, ll Digimol times W8 in IH processing circuit 100
P1. (FJI l'tg^(As an example, one is provided for each block.

11 concave separation/timing generation circuit 122 is manually powered by the digital bidet No. 1 7707 7, and by the operation of the seal, the pulse 111 and the horizontal/vertical J1. llProvided 123 outputs 4-ru. The burst extraction pulse 11] is generated by the clamp circuit 112 mentioned above and the near application 1 (
Supplying groove 11 to path 118, horizontal and vertical interval 171 (
R No. 123 should be manually input to the countdown circuit 124.

The countdown circuit 124 counts down the 1 ton pulse 116 (φS).
, horizontal -1), interplane (υ1 pulse 125 is created,
The horizontal/vertical synchronizing pulse 125 operates Ck 'I' via the same 1 (11 drive circuit).

The digital video signal 110 has its sample phase, pedestal level, and amplitude adjusted by t as described above, and the I? G B demodulation/if; i pieces can be input to the control system.

(2) HOB small birth/lI! 11 Trade control system 2
The 1゛H delay circuit 126 outputs the digital video signal 110.
' +1 + 11' +1, 2 'I', signal 12 delayed by I time ('l' H: L horizontal time)
Outputs 7. This U-extension signal 127 is required for each expansion operation using the U-in correlation described below. In addition, the wave number fS of the sunfling frequency is f''-・1f
sq, so N i' SC: then fs=910
．． /-H.

FAI, then f s = 1135 f L (and
The number of delay stages required for 11'++ is 910.1 each.
135 bits etc. 2. (,7'H: horizontal frequency -]
/ 'I'l; ).

The delayed signal 127 is input to an individual luminance/chromaticity signal separation circuit (hereinafter referred to as Y/C separation circuit) 12B and a Y signal processing circuit 129.

Y/C separation circuit 128#i, O'l', , 11.
A comb filter realized by calculation (line correlation calculation) using the delayed signal 127 of HI2 'I' H, and f
= , /' S, a chromaticity signal (S, shi, (: signal and ) 130 to the needle part E, and;
Delayed A word Kauka C (#i No. 13o l-ag, Arithmetic 1-
7. Shin + y Shin? ', (S1;, Y signal entry 1) 13
1). (11)-Details will be described later)

Yi J No. 131 7; and 1 mountain from Yu 1 Ro 14: □+
Input ff-+ control 155132, Y ear A
Horizontal to 3l37 (1m square, vertical 4, ll1qli, -j
Ntoranu 1 ・Each of Bright's 111 corrections ・j and others, newly)' 1go publication 133, it's out. In addition, =rntofstsodecorrectorCknee1stight1. ↑ Use Flyback Pulse 134 or 1. (For details, refer to I2-d) C-130 is input to the color control/color killer circuit 135, b, J-2 control/color-killer circuit 135 inputs the C signal 13001. The amplitude is detected and one person performs color control and color killer operations on this. The color killer signal 137 obtained by this color control/color killer circuit 135 is also input to the Y/C separation circuit 128, and when the color killer is operating, it is in the Y (J bow 13) band? In order to widen it, the first brush of the bidet is Y (No. 8 131)
Then, ζ is output
Audience/Ha1: N's color control detective; g1s t:;
(2j.

C (, 1″ bow 130 no 4. Tatsu Koide (Shikimon jj 4 old Hiki” also -!, I i, fi'i).

(Details: 1l11 is hard-run) Color control game color killer episode W6rt3s 1
′・force 0) C(, l: Bow 138 is a giant i summer J*'1 time 1・
d139 (two people;), ＼'ji'i-J from the detection circuit 18 tomoe 1 於 1h] ℃ same jJI ?艮KIM will be sent. General, A, I) C109
The sunfling phase in NTSC is ■.

QIli+11, T'A L, II, V axis ζ 2 are added 7, and the tentative tuning CfA No. 14 connected to the evf summer tuning circuit 139 is 1. Q (@ issue and II
, becomes a V signal. (II4 details will be described later) Y signal 133 and demodulated C signal 141 matrix circuit 1
42 is manually multiplied by a predetermined demodulation factor, added, and converted to ICI II 143. This 1<GB signal 143 is converted into an analog signal 145 by the DAC 144. This Iba bow 145 is RG H
I”J power circuit? is input to Cl(T) via Cl(T).

Note that switching between P A L and N i' S (' is N
T8C/ P A L cut 1! A' (This is performed by inputting the signal 146 to a predetermined circuit.

Next, what is special about the processing circuit 1000) in Figure 1 Q month 1111? pQ-like circuit (there are two, which will be explained in detail in 1).

(1゛■・1のcircuit) Figure 2 shows the position 1 output circuit 11 N', / including P L
FIG. 3 is a diagram showing a more specific implantation of the L circuit 2θ0.

1) Is the function of the L L circuit 200 the phase of the % Sanfuri Fugu Pulse 16 (φS)? The burst also needs to be locked to the 4th phase and the 1st phase target value 117 is changed by 5J (2 and the color is 41.4
:JAI +X+. $2 figure ≦2.

The phase detection circuit 118C is gated by a burst sampling pulse 11 to extract a color burst 202. The color burst 202 is input to a phase error calculation ρ26 circuit 203. An example of the Ij 14th error calculation is described in, for example, US Pat. No. 4,291,332. Figure 3 is a complete explanation of this phase error calculation. +”2...P4. The color burst 202 in FIG.
Think of it as a data string at -1 and +4.)

1JI to P4 is a surface obtained by sampling points 1'co apart from the burst phase every 90°. Therefore, it can be expressed as follows.

” 40-3= a + l) si+10P 4
n −, = a + +3 days 1n(f) +
90') P 4 n-+ = H+ ba
jn (θ - t 1-80')"4n" a +
bsin (θ+2700) (n=1~k) Target sample phase is θ. Then, the following formula holds true.

n=1 1=1(1
) The right side of the equation is a function of (θ−θ.), which can be considered as the phase error signal 204. The left side of equation (1) is 1st place 1
]1 Calculate and show 6ti to obtain the error signal 204 (7
ing. (1, data string P of color burst 202
+ l P2 '']]4k Two points, pw'17- shown on the left side of equation (1), then the place on the right side of equation (1) +
14 error signal 2θ4 is output.

In addition, in the left side of equation (1), the lEL standard sampling ring phase θ. '1iI (information is entered in the form of +anfJo, so 1
In this practical example, the phase target value 117 is θ. In it < fixed t + Ino. Use the value of °C. N '1' 8 G
In the case of (2 samples of M Bg position (if you see it, θ. Knee 57°, er 4th target A straight 1171d,
fanθn=−1,54 and /χ. In the case of PA I, the burst phase changes by 180°±45° for each line, so for example -H axis (180°)? The reference phase and deflection of the sample are 6°=±45°. Therefore, the phase target value 117 is also tanθ for each line. −±1 switching is required. This modification basically means that the sample phase of the manually generated color burst 202 is +45° or -45°.
This is done by determining whether the angle is 5°. This switching number 48 is output as a PAL identification signal 205. F
A, L identification signal 205 is V (No. 8 is +
This is a signal indicating whether the signal is modulated at 900 degrees or newly modulated at 190 degrees, and is necessary when demodulating a single color signal. Therefore, the PAL identification signal 205, together with the reference phase pulse 206 indicating the reference phase of the sample,
It is output to the color demodulation circuit 139 as a color demodulation control pulse 140. (In this example, as the reference phase of the sample,
The ■ axis is used in N i' SC, and the TJ axis is used in PAL. ) The phase error signal 204 created by the calculation shown on the left side of equation (1) is TJ P F , ? o y is input.

This L l'1" 207 determines the time constant of PLI and operation, and the time constant is usually set to about several 101' H 7f.] J 1.' The output 119 of F 207 is I) A CJ 2o? via VCXOJJ
5, and the position of the sampling pulse 116 (φS) is reduced by 1). Also ν(,': X
O115 is NTSC/PAL cut, M count → 1
46 (the 1 hour frequency from the second one is 14,3 MHz (N
'I'SC') and 177M l(y,
(1' A I,) is cut off and damaged.

θ (C'': Controls the color O by the phase 4 vote value 117).As mentioned above, in this example, the berth I/place (1st, 2nd, and When the quasi-one target sun full phase is set to 0°, the LI standard value of 414 and 117 is given by tanUo.
Instead of (2 tan (θ. doo θ,)'? Six force T is the demodulation axis is 6. However, the hue is 1 - the same in the same direction for all colors (M - only the phase changes - 1 ,.Moreover, the calculation for hue control using this method is specifically (1
) is shown by the second term on the left side of the equation.

In other words, only one multiplier is required for the circuit added to control the hue subtracted from the color burst 202.

Note that the method of changing the hue by changing the demodulation axis is the same as the method used in current analog color televisions.

There are two possible ways to control the hue: One is demodulation c (a method of changing the mutual gains of B signal 141 (I and Q, or H and V), and the other is
One is the matrix circuit 142 (the method for changing the demodulation coefficient in two degrees). Since the Mi1 type performs gain adjustment for two signals, there is a need for more hardware (multipliers) and the state of change in hue. (change beast and direction) differs depending on the hue, so it has the disadvantage that control becomes complicated.

In the latter case, the number of demodulation coefficients related to color in the matrix circuit 142 is 6 for both NTSC and PAL, so the increase in hardware and the complexity of control are even greater than in the former case.Therefore, regarding hue control, digital television Regarding the image receiving system, the method of varying the demodulation axis is considered to be the most suitable method in terms of the hard acid and ease of control described in Appendix 1) 11.

(Y/C separation circuit) Figure 1 (Y/C separation circuit)
The separation between signal 130 and Y signal 13) is 2'1. ”n
This is performed by a delay circuit 126 and a Y/C separation circuit 128, and these two circuits constitute a Y/C separation filter.

FIG. 4 is a diagram showing a specific example of the configuration of the 2'l'H delay circuit 126 and the Y/C separation circuit 128.

The digital video signal 110 is separated into a C signal 130 and a Y signal 131 using FIG.
'l? state That is, it has a periodicity of -f H and 1. f=
Model filter 4 whose gain is zero at n,/')I
01 and a C signal bandpass filter 412 having a BPF characteristic with a gain of 1 at f − and f sc are connected in cascade.

This is 11. C included in l'l'H delayed signal 405
Signal 419 is separated and extracted. C signal 419 is N i'
It is outputted as a new C signal 130 via the SC/PAL switching circuit 420. Further, this C signal 130 is input to a subtracter 425 via a C signal gate 42.

On the other hand, 1′I″H, which is the phase center of the comb filter 401,
Delay number 405 and C signal 130 are passed through adjustment delay circuit 423 to match which phase (delay amount) ℃ subtractor 42
Enter 5 Z. Then, in the subtracter 425, the Y signal 1
31 is obtained and output.

Next, the circuit of FIG. 4 will be explained in more detail.

-2 2TH delay circuit 126 is ITH delay circuit 402゜403
This is a configuration in which the following are connected in cascade. I T n delay circuit 402
, 403, the delay amount is 910 T 5 (NTSC
) and 1135'l's (I'AL) and l-tjJ. Here, T8 is the sampling period = 1゛8= '/, f
s = 1/4 f sa te. The delay signal 127 output from the 2TH delay circuit 126 is O1'n
;! i delay (M number (delayed L) 404, ITH delay signal 405.2, T H delay signal 406), which are input to the /C separation circuit 128.

In the Y/C separation circuit 128, calculations are first performed to create a comb-shaped frequency characteristic. This is input OT
H,I
is a power of 2, so the coefficient multiplier 407.40
8,409 requires only wiring operations, and in the case of page coefficients, only an inverter is added. Comb filter 4
01 frequency characteristics'] comb (f) is =-(1-fish(2πf/fH))...(2)(
z: e-no+2πfT8). Hc omb (n fH) = O5
H,,,omb((”+')frt)=
Due to the characteristics of 1, the C signal 41 is separated. The C signal band filter 412 includes 11゛S circuits 413 and 41.
4. Coefficient multiplier S units 415, 416, 417, adder 418
Consists of. As described above, the coefficient multipliers 415, 416, and 417 can be realized only by wiring operations or inverters. Frequency characteristics of C signal band filter 412 HB P
The C signal band filter 412 used here is characterized by being realized with simple hardware and has a frequency characteristic of a simple form as shown in equation (3).Moreover, This filter 412 is used in combination with the comb filter 401. Therefore, the overall Y/C separation performance is
Despite the hardware configuration, it is possible to obtain something that is practically satisfactory. C (Fj bandpass filter 412σ) output is
The signal is input to the S C/P A L 171 switching circuit 420 .

N '1' 8 C/PA 1.1; 7 replacement circuit 420
According to the contents of NTSC/PALσ1 146, if this is N 'l' 8 C mode, C signal 419
1" J1 C as it is, and in case of PAL mode, C
signal 419 with amplitude f? -24; and output or make one work. This is as follows: 1' Reason (2 J Yuru. Comb filter 410σ) 1,! i11+skin U: '4'k sex Ii
(o+nb(c) is not given by formula (2) regardless of N1'8C, PAL, "coml+ (", f
H) =IIcomb((n+')fH)=
It becomes l. In the case of NTSC signal, y4 code is f=
n, fn, C (the word is f= (II 4- =-)
, f H and are localized near 1°, respectively.

The C signal can be directly separated using the frequency ↑−° property of equation (2).

Figure 5 (a) shows the Y (^ spectrum (dotted line arrow) of NT8C (, 7), the C signal spectrum (solid line arrow), and the “c
It is a diagram showing the relationship between omb(/'. On the other hand.

In the case of PAL A, the Y signal is J°=nf11. In order to separate C (i signal (tr (g signal and v4 signal)?), (2) (if we use the frequency distortion shown in equation 21 as is, the C signal (f-Cn±L) JH ) gain is halved. Therefore, in the case of P A L 4'7, H6o
If the gain of mh(2) is doubled, the correct C signal will be separated. Fig. 5 fbl is the Y signal spectrum (dotted arrow) of the P A L signal.

IJ signal spectrum (solid arrow), V (i?i spectrum (dotted chain arrow) and 2・l-1oon1L)
(, /l) In Fig. 5(b), the gain is 2 at f = (11+2) fH, which is half the vertical high frequency component of the C signal. Therefore, there is no problem in practical use.On the other hand, for the C signal band filter 412, its frequency characteristic 1lBPF (/'l is the gain at f = fSC as shown in equation (3) in both NT8C and PAL cases. Since it is a BPF characteristic where is 1, N i' S C, F A T, (2) can be used in common. = iMii "I filter 4oz, C signal band filter 412 'r-If you consider them together, N'
I' 8 C signal case number rF, 11 r, omlJ
(7'), H13p p II), and P A J
, in the case of No. 44, 2 tIcoml+ (I)°HB
Seven P F (J') will be used (it is fine to separate the Cl group).

The specific configuration of the NTSC/PA[I] floor circuit 420,
For example, as shown in FIG.
and overflow/underflow recess 11", circuit 60
．． ? 1, N 1' 8 C/ PALLJ, consisting of
+Fj (% number 146 and 1 in 4 PAL mode)
, N'I'' 8 In the C mode, the gain switching circuit 601 maintains the C signal 419 in the NTSC mode from the predetermined art configuration C2.
4. In PAL mode, C transmits 419 to M8F.
A 111 helicopter lift will increase the field size to 24f!
r l.

and output it. The overflow/underflow prevention circuit 602 inputs the gain switching circuit 601 θ) output signal, and receives the output signal λ1. If is 2 (=1) or more, it is clamped at 2°-2-7, and -2°, and when W1 is below, it is clamped at -2°. Reason for needing this circuit 1c. II Comb (
There are places where HBpFfJl shows a gain of 1 within the video band, and especially in the 1'AL mode, it is twice as strong, so the output signal of the gain switching circuit 601 is This is because there is a possibility that the dynamic range of processing exceeds the range of -2° to (2° - 2 - 7).In other words, without the overflow/underflow lυj IF circuit 602, a signal of 2° or more is treated as negative and signals smaller than -2° are treated as 11 points.The overflow/underflow 1st stop circuit 602 has a gate configuration with n1 constant [), and the 21st point of the input signal is treated as 11 points. ) 60 J2°Pill-604f detected, each °'0".

When the value is 1", it is regarded as an overflow and ℃2°-2 is output. Also, when the 21 bits 603 and 2° bits 604 are 1" and 'Ou, it is regarded as an underflow.
2? Output.

By the method described above, tl N 'I'' 8 C and P A
The advantage of switching L is that the circuit to be added is N.
Ts C/ P A L 1. Only the IJ% circuit 420 is needed, which means that the 420th circuit can be seen at the Io~5o gates.

In Figure 41, +,EiC1N'r sC/ +''A L
g) (, 1 circuit 420 force z j') output A and C
'lu 吋1.30 outputs the color control I call/color key circuit 135-\ as well as the Cp gate 4.
2142 is also inputted.

This gate 421 is a color key circuit '1137 is J,
+ Human power fL'la from color control/color killer circuit 135 closes during color killer operation and reduces F,! , :X birth 425・-\C signal output 422
to ze[j. Therefore, in this case, you can see )' signal 13 or biden [I1 (No. 424) as it is.The color killer operation of trace+Ij is C signal 13
0 to 1 pi ``J -'', but in this example, it is also applied to Therefore, the color killer operation If;?) J, Y,
= Bandwidth restriction of f No. 131-1 is removed and the band is increased T
It has the advantage of

Y signal separation (to summarize the above explanation, video signal 424 to 117 No. 13) Y signal separation characteristics ■Y
ψ is.

It can be expressed as This Y (I No. J,? J
);i is output to the Y signal processing circuit 129 and Z.

(Y Haiku Processing Circuit) The Y signal 13 of the Y reconnaissance circuit 129 is subjected to horizontal contour, vertical contour, contrast, and bright corrections,
It is to output to the matrix circuit 142.

A specific example of purchasing the seventh meat CY signal processing circuit 129 will be shown. The Y signal processing circuit 129 is a vertical shell circuit 701. Horizontal wheel 91ζ circuit 702. Contrast circuit 703. It consists of an adder circuit 71 and a pedestal clamp circuit 713. In addition, the image quality control signal 132 is a vertical contour control signal 704, a vertical contour control signal 704, and a contrast control signal '7o6.
, including flight control signal 707 2T
The delay output from the n delay circuit 126 (P!: bow 12
7 is input to Shigenobu, horizontal ring, I+<Libi contrast circuits 701, 702, 703, and intellectual, horizontal contour, and contrast signals 701), 709, 710
is output. The gains of these signals are critical, horizontal wheel I9 and contrast control signals 704,
705, 706 to adjust the temperature.

In addition Q-device 711, 1J4: j+9・water τ11 contour and contrast 4%'r570B, 709,710 and Y
Ih No. 13 and external bright control Go No. 7
07 is added. Zoku・Rtocontrol sends ``Bright Control Signal 70'' to the direct shipment of ``Y Receiver'' 13.
7, and this is adjusted by an adder 711 and a pedestal clamp circuit 7Js. ) Is signal 131 a series of vertical contours and horizontal rings? (After each correction of contrast and brightness is performed, it is newly output as a Y signal 133 AL, MA) IJx circuit 144
to go into. Each circuit in the F1Y signal processing circuit 129 will be explained in detail.

(1) The specific configuration of the vertical i11 contour circuit claw 1μ@I contour circuit 70 is shown in Figure 8 (1-
4-0 Yuzu1tnIl'i'm Guo Signal 70B, 2'
L'H delay circuit Eg12G and vertical contour circuit 701 (two-up f'F-signal).

This is (Tari 1 white HP F 801 with a tank noir configuration)
and 1. It can be considered that P F 807 are connected in cascade. Vertical surface)-I P F 801 is 1...
This is a filter that passes components that have a large change in the vertical direction, and its output signal °8o6 includes a step ll1L coast component. Here, the vertical HPF 801 and the vertical frequency will be briefly explained. Vertical H)"l"/
I 01 );! Actual figure 4 Niokel C (No. 41)
It is exactly the same as the plum-shaped filter 401 for separating the coefficient multipliers 802 to 80, and is actually used in common with it, but is treated separately for ease of explanation.
4 and addition ('t, vessel 8θ5 is.

Coefficient multipliers 407 to 409 and υ・addition↓ in FIG.
? , corresponds to 410. The reason why these two have the same shape is because they also have cylindrical frequency components in the direction of C(-). Bending force rotation OI
<Return? The unit C is c y c l
c / p i c t u r e b i g
h t is used. (hereinafter c y , / p , h
, -(-) Figure 10 shows nl +ij rounding number F (
cy, /p, b, ), the frequency f (11Z) (hereinafter referred to as the horizontal open wave number for distinction) commonly used at 1°δ, and the relationship between the pattern and the pattern are shown schematically. Diagram C
be. The vertical frequency corresponds to the horizontal change in the pattern, and the horizontal frequency corresponds to the horizontal 1. ! The j wave number corresponds to the horizontal change in the pattern.

The horizontal leap number f and the vertical frequency F are expressed together on a two-dimensional coordinate, and this? Often called two-dimensional frequency.

Figure 11 is! Figure 810 (al, (bl, (C)
) represents the frequency components corresponding to each picture in a two-dimensional frequency format. Figure 12 shows two-dimensional 1,
'a is a diagram expressing the television number in wave number format.

The scale is written on a normalized frequency scale so that it can be expressed twice as N'I' SC and FAT. The horizontal frequency is the Nanful frequency a, fs (-4fs t;
) is normalized by vertical: α frequency, ψ number of scanning lines per field /'H/f v (/v is the field frequency).

In addition, in general, the vertical frequency F ('Y+/"p, h,) of a signal whose frequency slopes to f by 1z) = (n + a) fH
0, fV: field lap JU number). For example, the vertical frequency of the color subcarrier is tN 1' SC, and the signal is G 25 x 3! -= 234.375 (cy,
/p, l+,) and Z).

Ichiriki, horizontal 1 of color subcarrier;'a rjij-
The number is different between N 'r 8 (,: and P A L,
Both are 17. becomes. The black circles in FIG. 12 indicate the respective color subcarriers. In addition, the 12th area A indicates the approximate range of the C signal. Then: ('y rrfHP 1”
8. The characteristics of OJ will be described. Vertical) IPF80
The frequency characteristic of 1 is Ilcomb(-/
'(sz)), which can be expressed using `` for the vertical frequency, 1- and II combfF) = -(] -ctys (2r
rfv-F/fH) ) -...(31. (3)
The characteristic given by the formula is constant in the horizontal frequency direction, Q4
Monote that changes only in the direct IM wavenumber direction, this impoverishment occurs when l゛' = Q: / = O-c-so+'k r
, the in increases too much and li' == o5 XJ
Gain -1 at 2 lv. River (1 White II P F
801Q) Passage/)H area is the midpoint hold l2. in Figure 12. The area between dotted lines 12 (dotted lines 12 and 12 is F = (+, 2
5, f"y'f", dotted line A, k#, F ""
0.75.
5(J-'L,,v) corresponds to a pattern that repeats every line in terms of refueling, so the filter using the line-eye mark is F = 0.5 fH/J'V (
Characteristic of folding back at the dotted line An) (mirror symmetry)? Motsu.

In FIG. 8, the output signal 806 of the vertical HPF 801
is the C signal component included in this signal C1 (area A in Fig. 12).
I) Manually sent to LPF 807 for removal. LPF807 is 21゛s! ! Court circuit 808-811
, coefficient multipliers 812 to 816, and an adder circuit 817, and has a band of approximately 1 (Mliz)Q) when passing a low pass. Due to this characteristic, the C signal included in the signal 806 (-), including its high-frequency components, is almost completely removed.Vertical 14
By connecting P F' sθ1 and +7 P F s o y (the passband of the connected filter becomes the area indicated by A2 in FIG. 12).

This corresponds to the vertical contour signal 818. If the removal of the C signal is incomplete, dot interference occurs in areas where the color change is large by applying direct contour correction, resulting in a reduction in image quality.

Another method for obtaining the vertical contour signal is to pass the Y-h signal itself through the vertical +I PF. [7 However, generally the Y signal has a wide band17, and this is vertical)
When P F l'- is passed, the leakage of the C signal becomes significant,
Dot interference occurs and the screen stops working. One piece ``JIII
o'll has a relatively narrow band L P F 8θ7,
Vertical It P F /? θ1 non-combination, Y faith■13
1 means offshore 2 vertical 1 equipped (, ITTs 18 pieces 1 ℃
There is. Go01Ji: Direct-non-signal 818 is the east culm, vessel 81
At 9, the ℃ vertical contour control number 704 is placed, and the C221LH white ink curve is output as 708.

(2) Horizontal contour circuit FIG. 9C shows the configuration of the horizontal contour circuit 702.

Horizontal wheel ν11 signal 709 is 21'n delay circuit 126 and horizontal wheel! 1' is generated by the F15 circuit 702. This is.

Half-tooth L P F 901 and 1113 with comb-type filter configuration
It can be considered that F2O3 are connected in cascade. The vertical LPF 901 is composed of a 21' n delay circuit 126, coefficient multipliers 902 to 904, and an adder 905,
It has opposite characteristics to 801. The vertical frequency characteristic HVLPF iFl of the vertical LPF 90 is as follows: Hv Lp F(F) =-(1-coe (2πfv
・F/fH)), and this passband is at the midpoint b! in Figure 12. 12, it becomes the area of t'. (Actually, the dotted line f,
Yo.

(also present on top). The output signal 906 of the vertical 1·P I” 90 J is input to the 13 P I” 907. +1
)' F2O3 is composed of 311s delay circuits 908, 909, coefficient multipliers 910 to 912, and an adder 913C2, and has a center frequency -'! l-(N ′r sc
1, RMHz, 42.2Ml-1z for PAL),
Passing Register - LE - (0.9~lHz in N Tsc
, P A L12 has a characteristic of 1.1 MHZ). this is,
This is a filter for extracting the horizontal contour signal of a picture existing around 2 MHz. Vertical L P F2O3 and I
The passband of the filter in which t P F 907 is connected in cascade is the area indicated by As in FIG. 12, and this becomes the horizontal contour signal 914.

Normally, when obtaining a horizontal contour signal, the Y signal itself is
In many cases, the signal is passed through a BPF with an appropriate band around 2 MHz. However, the vertical frequency band of the Y signal is relatively wide, and the C signal (#iJ'lJ,
A + ) leakage increases. For this reason, by applying horizontal contour correction, the color change may be dramatic (in areas where there is a large change).
I), causing the night. Follow Matakimi 1!7 (Ill
Now, B to extract the horizontal 'IQ 17B)
Horizontal wheel 〒1 (signal 9
14 are separated. At this horizontal wheel 91ζ signal 914 and pusher 915, horizontal contour control No. 42 70
5 and gain adjusted f(, new ridge n import 1
It is output as 14I No. 709.

(3) Contrast Circuit An example of the configuration of the contrast circuit 703 is shown in FIG. The contrast circuit 703 includes an integrating circuit 1301, an average value circuit 1303, and a subtracter 1305°L I) I! 'I
307 and a multiplier 1309.

The features of contrast circuit 7θ3 are integral circuit 1, ?
07, by using the average value circuit 1303, the contrast (direct 1155r of the image signal in the g number 1308)
This is to prevent (bright signals) from leaking. Contrast for this? When fJAI is set (the inconvenience that the nib light also changes is eliminated).

Next, we will explain the operation of the contrast circuit 703. The 0 'l' H delay signal 404 output from the 2 T H reception circuit 126 is input to the Tachibana circuit 130, and it'll f4! during one horizontal period. The partial integration is performed, and the integration result 1302 is output to the average value circuit 303 during one horizontal period of the wave]. Average Ili'i circuit 1
In step 303, the integration result 7302 is converted to a predetermined target.
By calculating 1- the average value of the image part is 1301? It is calculated and output to the subtracter 1305. Average value of 77H images 1
304 corresponds to an average of 1 (degrees) within one line period.

The subtracter 1305 includes 2 'l' HiFU extension circuit 1
26, a 1'l delay signal 405 is also input manually, and the average value 1304 of the 11σ11 quadrant is subtracted from this signal. According to ℃, as a result of subtraction, the AC component of the Soi family part is 1306
is obtained. This AC component 1306 has a DC component of °C removed in the horizontal direction. For this reason, l i' I+
:+! l! The transfer characteristic from the extended signal 405 to this father part 1306 is 'C1 horizontal frequency J' in FIG.
= 0 in the part (on the vertical frequency axis) and 1 in other parts. In addition, 0 'l' H delay Ihama No. 404
Since the average value 1304 of 11') is outputted, C in the subtracter 1305 is adjusted to match the phase 2.
11'H Delaying is performed between the bow and the bow 405.

Contrast is the change in brightness over the area of the upper ring of the image, so the contrast is the change in brightness over the area of the upper ring of the image.戊1
．． It corresponds to the 14θU' component. So this low range 1
! By extracting the IL wave component at I, J) F 1307, a contrast (j number 1308 is obtained. After that, a new C contrast (1'1' is entered as B number 710).

Next, each circuit in FIG. 100 will be explained in detail. Integrating circuit 13
01 is adder 131], latch 1, ? I 2, 7
It consists of 313. The latch 1312 performs a latching operation with the sampling pulse 116, and the flyback pulse 1
34 (2) The output is cleared to zero C during the flyback period.

Therefore, by inputting the output of the adder 1311 to the latch 1312 and returning the output of the latch 1312 to the input of the adder 1311, integration (cumulative addition) is performed on the Q TitH delayed signal 404 during the °C 1 image period. latch 1312
operates with sampling pulse 116 (φS), so
The addition in the adder 131 is performed in ]'B/rjJ, and the number of additions NA during the entire integration period is NA = ('l' H - 'I' F a ) / i
''S. (1'F F3 is the flyback time).

on the other hand.

The latch 1313 latches the output signal (integration result) at the time when the latch 1312 is cleared by the flyback pulse 134, and uses this as the integration result. 1302 to the average value circuit 1303. Average value circuit 13
03 divides the input 1^ minute result 1302 by NA t1
v%1 (-"-? Multiply) L4 result
It is a road.

p NA's u'i is i' F o = 0.2・1' H
1i' n = 91 Q・TG (Ni'S(-,
), T o = 1135 ・If we perform the old calculation using Ts(L'AL).

becomes. In actual Mj calculation, the number of circuit elements is small.
Therefore, the ball τ is approximated by the following value17.

(5) In this way, if the sum of the powers of 2 is used, the coefficient multiplier 1331.
1.933.1332 only requires wiring operations, and the only hardware required is adder circuit 1334 and gate 1.
There will only be 335. Gate 1335 is N '1' S
C/11 A L VJ replacement signal 146 controlled, N
'l' 8 In C mode, to calculate equation (5), (
=2-1! The output of the coefficient multiplier 1333 is sent to the adder 1334
and in PA, T, mode, formula (6) is converted to 1sri
The output to adder 1334 is set to zero in order to do this.

In addition, the error caused by approximating "-" by equations (51 and (61) is 0.2% in A N T SC, which is not a problem in practice.
PF1307 is LPF807 shown in FIG.
(Obi Q l &i Ily, ) is used. This separates the contrast signal 1308 from the horizontal contour 904 (area As in FIG. 2) in terms of band.

In this way, the integration circuit 130 and the average value circuit 1303 are realized with relatively simple hardware, and the leakage of intoxication into the contrast ratio 130 and 8 can be eliminated.

(4) Brightness Adjustment In FIG. 7, brightness adjustment is performed by an adder 71 and a pedestal clamp circuit 713.

Horizontal/vertical control 91 (and contrast adjustment,
)゛Light? J, IL 1 coin 1) is based on the pedestal level of 14 bias;
1 and is input to Y/C separation circuit 1 along with other signals.
Added to Y signal 13) from 28, ! A signal 712 is output. However, with this alone, the output Y of the adder 711 (, the pedestal level of No. 7 712 also changes, and the DC component of the image part seen from the pedestal level is the Y signal 13)
remains the same. Therefore, the pedestal clamp circuit 71
3, the flyback pulse 134 clamps the Y signal 712 to a predetermined pedestal level during the flyback period, and the Y signal 133 is output. As a result, the average brightness of the Y signal 133 of the tij force changes by the amount of the Beblight control signal 707 relative to the average brightness of the input Y signal 131. Brightness adjustment is performed using the above steps.

(Color Control/Color Killer Circuit) An example of the configuration of the color control/color killer circuit 135 is shown in FIG. The function of this color control/color killer circuit 135 is to perform ACC control for the input C signal 130.
In addition to performing manual color control and color killer operations, it also supplies the color killer signal 137 to the Y/C separation circuit 128, and as mentioned above, when producing one color killer rabbit, the video signals 42 and ? ? ,−
The purpose is to directly output the Y signal 131 in degrees Celsius.

The color control/color killer circuit 135 includes a multiplier 140, a color killer circuit 1409, a burst scanning width detection circuit 1404, a loop filter 1408, and a subtracter 14.
It was composed of 06. The outline and characteristics of the operation will be explained below, and then each circuit will be explained.

The input C signal 130 is guided to a multiplier 1401, and the A
It is multiplied by the CC signal 1402 and controlled by the degree C amplitude jF. The C signal 1403, which is the output of the multiplier 1401, is input to the burst amplitude detection circuit 1404, and the power? - The amplitude of the burst is detected J]i. That is, a value proportional to the amplitude of the color burst is determined. The M-calculated burst width signal 1405 is input to the signal generator 14o6.

This subtracter 1406 calculates the error θj, and here a burst vibration product 1405 is used to adjust the CA and CC target values, that is, the color portion 4411ffi given from the outside. The ACC4% difference signal 14o7 is output to IJ4. This ΔCC error signal 14o7 is L P I''
: is manually input to the evening loop filter 1408. 1
This loop filter 1408 determines the ACC time constant, and the time constant is 1jjj 'F, Equation 10 'I'
Set to n. The output signal of the loop filter 14o8 is Δ
CC reconnaissance signal 14o2 enters into C multiplier 1401, f
It is carried with the C signal 130 like iji IjJj.

In this way, the Ace loop is formed by the multiplier 1401 → burst amplitude detection circuit 14o4 → subtracter 1406 → loop filter 1408 → multiplier 1401, and the input C
(The amplitude of the g signal 130 is controlled to be equal to the ΔCC target value given by the manual color control signal 136, and is output as a new C signal 138.

Q) Two points can be raised as features of this color control circuit. The first is to operate the ACC target value from the outside,
This is to perform color control, and the second
By detecting the amplitude of the color burst using the value of Ic l± 1 +IC+:Ql in the N'l'SC mode and using the value of Ic ++lc l in the P A-1, mode, ±u +V is 0 (C11CQICU , Cv (Massore OLI.

The magnitude of the burst signal is represented by the Q, U, and V axes. ) The advantage of performing color control by changing the ACC target value is that there is no need to have a multiplier for color control (for the latter).

The burst amplitude detection method is
Using the sum of the absolute values of the sample values at r,ru2+llll is necessary because of the hue control.
It is to come. In other words, the electric phase control is performed using the PLL circuit 200 shown in the second section 1 (AI by changing the second phase target value 117) C109.
This is done from C2 onwards.

The problem here is that the sampling position +11 is the change T
As a result of this, i) the sample value of the burst 11jl+ also changes, resulting in an incorrect burst amplitude value 119 being output. This λ1 changes the value of the ACC signal 1402, and accordingly the magnitude of the -CC signal J403 also changes. By changing 1, that is, 1 hue, the color saturation will also change. In order to reduce this by 1νJ, it is necessary to take measures such as correcting the value of the burst amplitude signal 14θ5 depending on the magnitude of the phase target value 117 in FIG. However, for this reason, the amount of added hardware becomes large. Therefore, in the Honjitsu Tsumugi example, as a simple method to suppress the change in color saturation caused by color 41 control to a level that does not cause any practical problems, Detect the amplitude of the color burst as described above.
+1c. 1 or IC+Ul+1c±v1.

According to this, the Demple phase can be set on the I, Q axis or IJ, V
Even when the angle is ±10° from the axis (hue variable range),
The detected burst amplitude values are 5.2%, ■, and 5, respectively.
There is no practical problem as long as the change is only by %.

Next, let's talk about color killer.

Generally, the condition for the color killer to operate is when the magnitude of the burst of the input C signal 130 is below a certain value. However, in this example.

Using the fact that the value of the ACC signal 1402 is inversely proportional to the magnitude of the input C signal 130, the ACC signal 14o2
The operating condition for the color killer is when the value of is less than or equal to a predetermined value. However.

Even for input C signal 130 of the same magnitude, A is proportional to the magnitude of manual color control signal '5136.
Because the CCC signal 1402 changes, color killer glue
In order to keep the cropping performance constant, it is necessary to make the magnitude of the manual color control signal 136 proportional to a predetermined value. For this reason, the color killer circuit 1409 is manually supplied with the ACC (Pi No.
The value of the ci signal 1402 is compared with the value of the ΔCC signal 1402.
When the value of is larger, Φ11 color killers are produced. The C signal 13 is activated by the No.
FI becomes zero, and in the Y/C separation circuit 128, the video signal 424 is directly outputted as a Y signal 131 at 7''C, widening the band of the Y signal 13 and converting it to Z.

The advantage of using the color killer with two consecutive operation threads is that it detects the size of the color burst of the input C signal 130 and uses it to set the time constant. [2] Compared to the usual method in which the color killer's operation standard is set when the output value of the LPF is less than a predetermined value, a simpler circuit is required.

(Circuit of each part in Figure 14? Using Figure 15)
Explain to Tsukuda. 15th Flash (Second, burst amplitude detection circuit 1404 includes burst extraction circuit 1soi, absolute value circuit 1502, adder 1504, latch 1505.15)
Burst vibration consisting of 06 ψ1. The 81 function of the % detection circuit 1404 is
- Color in NJ 1i4F of strike extraction pulse 11! (-S) (set for 6L'J period ℃) 1X/), integrate its absolute value, and get the result? ■Horizontal period ('
l'n)σ)1d1 to be output to the subtractor 1406. That is, the C signal 140 from the 1 multiplier 140:N
The burst sampling circuit 150 is gated with the burst sampling pulse 111. From this (2), a signal (24f) for 6 cycles of color burst is extracted and input to the absolute value circuit 1502. Absolute value circuit 1
At 502, the sign bit of the input color burst signal? Judge.

If it is ``l'', the data is inverted, and if it is 0, it is passed through, thereby calculating and outputting the absolute value of the color burst signal.This absolute value signal 1503 is sent to the adder 1.
504 and latch 1505 (2yo1) burst nyti
Note that latch 150 is integrated during pulse 111.
Five is one! Latch 11 is performed with F link parnu 116, and the output is zero outside the period of burst extraction pulse 11.
Cleared to 1. Then, the value of 8j1 (result of lees) when the latch 1505 is cleared is latched by the latch 1506 and input as W as the burst amplitude 01 1405.

The loop filter 1408 is a circuit that determines the AC]kjt constant;
7. Kaduki 1508. It is composed of a latch 1509 and an underflow/lock circuit 1510. Among these, underflow-1υ stop circuit 151θ1. f A CC signal 140
The fact that 2 becomes that value is 'p' Ii/, i.

Also, is the wiring for the 2 coefficient multiplication unit 1507? L S )l
No real hardware is required, just an n-bit shift 1- to 11+1. Note that the latch 1509 performs 1) latch operation in response to the burst extraction pulse 11;

The loop filter 1408 filters out the error signal 140.
7 is doubled, and this is added to the adder 1508 and latch 150.
9, it is accumulated (integrated) every 1゛H.Thus,
The sudden change in the error signal 1407 (high river wave component) is absorbed. In this circuit configuration, the ACC time constant is 2.
It is proportional to T. Therefore, by appropriately setting the value of n, the ACC time constant can be determined to a desired value.

The output signal from the loop filter 1408 is the ACC signal 14.
02 to the multiplier 1401.

In the color killer circuit 1409, as mentioned above, the ACC
(''AAl5O12 value and the value obtained by multiplying the value of the manual color control signal 136 by a constant (2) (1512 for the color killer threshold) by the multiplier 151) are applied to the comparator 1.
513, and if the value of ACC (No. 5 1402) is large, the color killer signal 137 is set to "0".

As a result, the C signal 138, which is the output of the gate 1514, becomes zero. On the other hand, at this time, C (, T
The C signal 422 output from the jj gate 421 also becomes zero, and the video 43 424 is output as is as the Y signal 13.

(color IV, tone circuit) FIG. 16 shows an example of the configuration of the fq adjustment circuit 139. show.

Color 1m 1. q circuit 139 is latch 1601.1602
The function of the color demodulation circuit 139 in the N T 8C mode, which is composed of a gate circuit 1613 including gates 1605 to 1607 and an Omahi inverter 1612 (gates 1608 to 161), is to extract from the input C signal 1'38. , 1 phase data at launch 1601: jt+: selectively
By F-, ■signal 1603 each/return h1. ~1 [
2. By selectively latching the data of the Q phase in the latch 1602 (1) (2), the λ signal 1604 is latched (2).

T' A 1. , mode l, J:, for each T141, by latching the data of the 0th position from C+1138 in the latch 1601" (G No. 16o.9
is demodulated. ,On the other hand, ■The signal changes every line! Since the l"l axis is reversed, even when the latch 1602 is in 1st key, the latch 1"r phase is changed by -1 for each line.
-v.

It is necessary to switch with V. This Q1 replacement PAI, Aiden) (i- is performed with the number 2θ5.Next, the actual circuit operation will be explained.

(: A3 J, 78 are input to the latches 1601 and 1602. On the other hand, the phase pulse 206 generated by the phase detection port 1118 is also input to the color 1ρ adjustment circuit 139. Eye pulse 206, N'I''S
In the C mode, the pulse at the T axis position (T1) is determined. In the PAL mode, the pulse at the T axis phase (206 is determined. The base phase pulse 206 is directly input to the latch 1601 as a latch pulse, where the C signal The data of phase 1 or 11 from among 138 is latched, and the signal is crossed (T signal 1
603 is demodulated. In addition, the spurious one-phase pulse 206 is sequentially processed by latches 1605 to 1607 to one sample phase (
90°). This causes latch 1605
-Q or ■ phase pulse from latch 1606, -1 or -U phase pulse from latch 1607, and Q from latch 1607.
or ~V (each f+ phase pulse is high output)1.
Z・. A L tel
A Q, V demodulation pulse 1614 is generated from a gate circuit J6JJl2 which uses the change signal 146, P, AJ, identification signal 205 and the output signal of the latch J6θ,5, 1607, and this is sent to the latch 16o2. Supplied. Q, V demodulation pulse 1614 is N T S C/
When the PAT-switching signal 146 is in the NT8C mode, it is a 9-phase pulse, and when it is in the I'AL mode, it is a P
This is a V-V phase pulse according to the content of the Ar identification signal 20.5. This causes the latch 160
2 outputs a Q signal or a V signal 16o4 with a rear height of 1. Note that the gate circuit 1613 has N'I'
8 C/PAL switching signal 146 is NTSC
The configuration is shown when the mode is set to Q, FAI, and the mode is set to 1, and the PAL identification signal 2o5 is set to 1 on the -v axis and 0 on the -v axis.

The demodulated C4:4 outputted from the color adjustment circuit 139 in this way
No. 141: Matrix circuit 14 along with Y signal 133
2) and put it in the prescribed matrix.
013 (Ago 142 is a cow, and it is completed.

The operation and contents of the matrix circuit 142 are N T
8 C/P A L til, switched by I switching signal 1・fO.

Although one embodiment of the civil engineering invention has been described, the specific circuit configuration is not limited to the above embodiment and may be modified in any case. Furthermore, it goes without saying that the present invention 1+, 11 (H imemi Z) television receiver is effective not only for those that receive broadcast signals, but also for so-called monitor copying machines and the like.

[Brief explanation of drawings]

Is the figure an example of the present invention? There's no point in explaining it, so here's Figure 1! li! i f 4 u + c of the entire color processing circuit; configuration diagram, m 2 is a diagram showing the configuration of the circuit, 3
The figure shows sample points of color burst, and Figure 4 shows Y
Figure 5 shows the configuration of the /C separation circuit, Figure 5 shows the privateness of the comb filter, Figure 6 shows the configuration of the N1'S CPAL switching circuit, Figure 7 shows the Y signal. The 8121st diagram showing the configuration of the processing circuit is a T diagram showing the (h configuration) of the open rectangular contour circuit.
Figure 9 is a diagram showing the configuration of the Water 311 Yukuo circuit, No. t'om
ii Image and diagram showing Kan 1 thread with 14 horizontal and vertical wave numbers, 1st
Figure 1 is a diagram to explain two-dimensional frequency, and Figure 12 is a telehysion signal? A diagram shown in two-dimensional t-number format, Figure 13 shows a contrast circuit (114th, t41Q)
Color control/color killer circuit σ) Structure D'i
, 'a' Schematic (2 diagrams), Figure 15 shows the circuit in Figure 14 in more detail, Figure 16 is a diagram showing the configuration of the color demodulation circuit. 101... Analog video No. 4g, 109...A/
l) Converter, 110°°° digital video signal. 126 delay circuit, 702...horizontal contour circuit, 7
09...Horizontal ~ Guo Yi No., 90...Comb-shaped fill (
Vertical LPF), 907...Band-pass filter. Output 11 [One agent Patent attorney Takehiko Suzue (a) f = o (Hz) F = l (cy/p, h)? ＼ Masahiro and Tsuyoshi Figure 10 (b) (c) f=fH (Hz) f=2f+ (Hz)F・2
(Cy, /p,h,) F=2 (Cy/p,h
) Figure 11

Claims (2)

[Claims] (1) After digitizing the video signal, signal processing 2
This digital television receiver includes a delay circuit that receives a digital video signal as input and outputs a plurality of delayed signals that are time-shifted by one horizontal period, and performs predetermined calculations on these delayed signals. The calculation result is d
-1, the frequency is f''=nfH (fo is the horizontal frequency, n is an integer), the gain is 1., t''=(n+
-"-) A comb-shaped filter having a frequency characteristic with a gain of O at fH, and a band-pass filter that separates a horizontal contour component from the output signal of this comb-shaped filter and outputs a horizontal contour signal. A horizontal contour circuit characterized by: (2) The horizontal contour circuit according to claim 1, wherein the delay circuit is also used as a bucket filter for separating a chromaticity signal and a luminance signal from a digital video signal.