JP2845429B2 - Signal processing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing device effective for use in a video tape recorder and the like. 2. Description of the Related Art In general, a glass delay line (1H DL) that delays one horizontal period (1H) using glass is used as a delay device used for Y and C separation of a video signal. Hereinafter, an example of the above-described conventional signal processing device will be described with reference to the drawings. FIG. 3 shows the video signal separation of the conventional signal processing device. 1 is a video signal input, 14 is a 1H DL matching coil, and 15 is a 1H DL matching coil for time alignment. 16 is an amplification circuit, 24 and 25 are mixing circuits, 17 is a low-pass filter (LPF) that extracts a luminance signal, 18 is a luminance signal processing, 20 is an internal band-pass filter (BPF), 21 is a color signal processing, and 19 is a color signal processing. Is a recording amplifier circuit for recording on a tape. The operation of the conventional signal processing device configured as described above will be described below. First, the separation of the video signal will be described with reference to FIG. As shown in FIG. 4, the spectrum of the video signal has energy at intervals of the horizontal frequency ( _h ) around the color signal frequency ( _sc ).
The luminance signal has energy at intervals of _h , and the frequency of _sc is determined to be _h × 227.5 = 3.579545 MHz in the NTSC system, so that the chrominance signal and the luminance signal have energy shifted by _h / 2 as shown in FIG. . That is, in the NTSFC system, interleaving is maintained for each horizontal scan, and the phase of the video signal is
By 180 ° difference, Y, C
Can be separated. Next, a conventional operation will be described with reference to FIG. The video signal is applied to 1H DL14 and the output 40 is output to the matching coil 1
The adjustment is made in step 5 to correct the variation in the delay time of the 1H DL 14 and is added to the amplifier circuit 16. The amplifying circuit 16 is an amplifying circuit for obtaining the color signal 43 and the luminance signal 46 by adjusting the signal level of the signal 42 applied to the mixing circuits 24 and 25 to one video signal level. Since the output signal 43 of the mixing circuit 24 includes a signal outside the color signal band, the color signal is extracted by the BPF 20 (signal 44), and the color processing 21
To generate a reduced color signal 45 to be applied to the recording amplifier circuit 19. The luminance signal is extracted from the mixing circuit 25 and added to the LPF 17. Luminance processing of luminance signal 47 that matches the frequency characteristics of luminance signal 46
18 and processed signal of FM modulation method for recording on tape
The signal is amplified by the amplifier circuit 19 as 48 and the output of 49 is recorded on a tape. Problems to be Solved by the Invention However, in the above configuration, since the delay time of the 1H DL 14 is fixed, if the _{sc of} the video signal 1 varies, the separation performance cannot be obtained. This will be described with reference to FIG. _sc
Is 3.579545 MHz, the 1H DL time is about 63.5556 μsec, but if _sc is 100 Hz lower, it is 63.5573 μsec,
Because if 00Hz high becomes 63,5539Myusec, _sc is IH DL comb characteristic separation characteristic is attenuated not constant If it is fixed when the variation, or remain luminance signal to a color signal, the color in the luminance signal in the opposite There is a problem that a signal remains. In particular,
This is particularly noticeable when a video signal whose luminance signal is broadened to improve the horizontal resolution is input. When a luminance component remains in a color signal, a color shift occurs in an image. SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and provides a signal processing apparatus which delays a signal in accordance with the video signal even if the _{sc of} the video signal is slightly shifted. Means for Solving the Problems In order to solve the above problems, the signal processing device of the present invention includes a band pass unit that passes only the color signal frequency band of the input video signal, Delay means, a low-pass means for passing only the low-frequency output of the delay means, a phase circuit for delaying the output of the low-pass means, and an output of the phase circuit and an output of the band-pass means. Signal adding means, an amplifier circuit for inputting an output signal of the signal adding means, and an AP for inputting the output of the amplifier circuit, extracting a color subcarrier, controlling the phase of the reference color subcarrier, and outputting the control signal;
C, color processing means for performing color processing from the output of the amplification circuit and the output of the APC, luminance processing means for performing waveform processing by shaping the waveform from the input video signal and the output of the amplification circuit, and the output of the APC And a multiplier circuit for multiplying by 4. The delay time of the delay means is controlled by a signal output from the multiplier circuit. Operation According to the present invention, the delay time of the delay device is controlled according to the _sc of the video signal even if the _{sc of} the video signal is shifted, so that the comb characteristics are always optimized. Embodiment Hereinafter, a signal processing device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration diagram of a first embodiment of the present invention. In FIG. 1, 2 is a BPF for a color signal band, and 3 is 1H.
CCD and DL for DL are LPF and 5 for taking noise component from CCD.
Is a phase circuit for adjusting delay time, 6 is an amplifier circuit (AMP), 7 is a phase circuit for adjusting delay time, 9 is AMP,
Reference numeral 10 denotes luminance processing, reference numeral 12 denotes APC required for color processing, reference numeral 13 denotes color processing, reference _numeral 11 denotes an amplification circuit, reference _numeral 8 denotes a _sc multiplication circuit, and generates a clock frequency. 50 is an LPF. The operation of the signal processing device configured as described above will be described below with reference to FIGS. 1 and 2. The BPF 2 allows the input video signal to pass through only the color signal band and outputs it to the CCD 3 as delay means. Signal 27 delayed about 1H by CCD3
Since a high frequency noise component is included due to the delay caused by the CCD, the noise is removed by the LPF 4 and the color signal 28 is added to the balance volume 22 through the phase circuit 5. Signal 26 and signal 29 are
The color signals are shifted by 1H, have the same phase, the luminance signal has the opposite phase, and the signal 30 is only the color signal. On the other hand, the video signal 51 and the color signal 29 output from the phase circuit 7 are shifted by 1H, and the color signals are added in opposite phases, so that the signal 35 is only a luminance signal. Further, the APC 12 generates a signal 32 having a frequency synchronized with the _sc of the video signal, and in addition to the doubling circuit 32, generates a clock 33 of the CCD 3. Next, the delay time will be described with reference to FIG. CCD3
Delay time T2 = approx. 63.2556 μsec, LPF4 delay time T3 = approx.
0.2 μsec, delay time T4 of phase circuit 5 = T2 +
It becomes 63,55556 μsec of 1H at T3 + T4. The delay time T1 of BPF2 = 0.2 μsec, the delay time T5 of AMP6 and the phase circuit 7 =
T1 + T5 = 0.3μsec at about 0.1, while T6 = about 0.3μs at LPF50
Since the delay time is ec, the delay time of the video signal 51 and the delay time of the color signal 39 are both 0.3 μsec.
7. The balance regulators 22 and 23 reduce circuit variations. As described above, according to the present embodiment, the variation of the fsc of the video signal is calculated by using the frequency of the APC generated from the video signal passed through only the color signal band by the BPF to generate a 1HDL
By controlling the clock of the CCD for use, the performance of the Y and C separation input of the video signal can be secured by absorbing the signal. Furthermore, even when a video signal whose luminance signal band has been extended to a higher frequency for higher image quality is input, a CC for 1 HDL can be used.
The signal input to D is the signal whose band has been limited by the BPF, and the CCD output is passed through the LPF to add noise due to the CCD delay. Signal processing is easy. As described above, according to the present invention, a band-pass unit that passes only the color signal frequency band of an input video signal, a delay unit that inputs and delays the output of the band-pass unit, and a low output of the delay unit Low-pass means for passing only the band-pass frequency, a phase circuit for delaying the output of the low-pass means, a signal adding means for adding the output of the phase circuit and the output of the band-pass means, and an output signal of the signal adding means An APC that inputs the output of the amplifier circuit, extracts the color subcarrier by inputting the output of the amplifier circuit, controls the phase of the reference color subcarrier and outputs it, and the output of the amplifier circuit and the APC
Color processing means for performing color processing from the output of the APC, luminance processing means for performing waveform processing by performing waveform shaping from the input video signal and the output of the amplifier circuit, and a multiplier circuit for multiplying the output of the APC by four. The delay time of the delay means is controlled by a signal output from the multiplier circuit, so that a stable Y and C separation effect can be always obtained even for a video signal whose luminance signal extends to a wide band. it can. Furthermore, since the entire circuit system does not need to be adapted to higher frequencies, subsequent signal processing is facilitated, and the circuit configuration is also advantageous.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a block diagram showing a main part of the embodiment, FIG. 3 is a block diagram showing a conventional signal processing device, FIG. 4 is a spectrum diagram of a video signal, and FIG. 5 is a characteristic diagram showing a conventional separation solution characteristic due to variation in _sc of the video signal. 1 ... Video signal input, 2 ... BPF, 3 ... CCD, 4 ... LP
F, 5 ... Phase circuit, 6 ... AMP, 7 ... Phase circuit, 8 ...
... multiplier circuit, 9 ... AMP, 10 ... brightness processing, 11 ... recording amplification circuit, 12 ... APC, 13 ... color processing, 22 ... balanced volume, 23 ... balanced volume.

   ────────────────────────────────────────────────── ─── Continuation of front page       (56) References JP-A-52-83026 (JP, A)                 JP-A-50-40029 (JP, A)                 JP-A-60-210020 (JP, A)                 JP-A-61-49580 (JP, A)                 JP-A-50-108823 (JP, A)                 JP-A-56-158589 (JP, A)                 JP-A-61-206373 (JP, A)                 JP-A-52-10025 (JP, A)                 JP-A-57-28490 (JP, A)                 60-30685 (JP, U)

Claims (1)

(57) [Claims] Band-pass means for passing only the color signal frequency band of the input video signal, delay means for inputting and delaying the output of the band-pass means, and low-pass means for passing only the low-frequency output of the delay means. A phase circuit that delays the output of the low-pass unit, a signal addition unit that adds the output of the phase circuit and the output of the band-pass unit, and an amplification circuit that receives an output signal of the signal addition unit. An APC that receives the output of the amplifying circuit, extracts a color subcarrier, controls the phase of the reference color subcarrier and outputs the APC, and a color process that performs color processing based on the output of the amplifying circuit and the output of the APC. Means,
A luminance processing means for shaping a waveform from an input video signal and an output of the amplification circuit to perform luminance processing; and a multiplication circuit for multiplying the output of the APC by four, and a signal output from the multiplication circuit. A signal processing device for controlling a delay time of the delay means.