JPS59158695A - Processing system of line sequential color signal - Google Patents

Abstract

PURPOSE:To reduce the scale of circuit and the cost by using different horizontal synchronizing signal on a color signal at every other horizontal scanning line in a Y-C separating type VTR to attain color discrimination without adding newly a color discriminating signal. CONSTITUTION:Signals Y, U, V are applied respectively to input terminals 1-3. Since a line sequential controller 7 is constituted so as to invert an output in the timing of the front edge of a horizontal synchronizing signal, a signal is outputted during the scanning period of an odd number order and the signal is outputted with a prescribed time of delay by a pulse delay line 36. This output makes a line sequential device 6 output the U signal. Since the horizontal synchronizing signal is superimposed on a part immediately before the V signal during the horizontal scanning period of an even number order in this way, the signal is used as a color discriminating signal of a concurrent processing device 19 at reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a line sequential color signal processing method for converting color difference signals of two glazes into i-line sequential color signals and restoring the color difference signals again.

Conventional Structures and Problems Many different recording systems have been proposed for video signal magnetic recording and reproducing apparatuses (so-called VTRs) using magnetic tapes. Among these, in broadcasting VTRs that require particularly high-quality reproduced images, the Y -C separate type VTRs are attracting attention.

By the way, Y-C minute 1? fr iVI VTR, V
In order to improve the quality, including compatible playback between TRs, a horizontal synchronization signal is superimposed on both the Y signal and C18 signal during recording, and the horizontal synchronization signal superimposed on the Y signal and C signal is superimposed on the Y signal and C signal during playback. Based on this, an operation is performed to completely correct the timing of the reproduced Y signal and C signal.

By the way, there are two color difference signals in the C signal, and the NTS
In the C system, there are I signal and C signal as color difference signals, and P
In the AL system, there are C signals and V signals as color difference signals.

In the following explanation, for convenience, the C signal and V signal will be used as color difference signals, but this is not limited to the PAL system.

Now, there are several types of Y-C separation type VTRs, typified by the FM multi-way system and line sequential system, depending on how the C signal and V signal are processed.

The present invention relates to a color discrimination signal superimposition method which is particularly effective in a Y-C separated line sequential type VTR in which a C signal and a V signal are alternately switched and recorded for each horizontal scanning line, and is shown in FIG. A conventional example is shown below.

In Figure 1, 1.2 and 3 are the Y signal and C signal, respectively.
signal and V signal input terminals, 4 and 5 are FM modulators, 6 line sequentializers, 7 are line sequential controllers, 8 is a mixer,
9 is the gate, 10 is the oscillator, 11.12.13 and 1
4 is a magnetic head, 15 is a magnetic tape, 16 and 17 are FM demodulators, 18 is a synchronization control device, 19 is a synchronizer,
20. 21 and 22 are switches, 23 , 24 , 2
5, 26 and 27 are switch terminals, 28 is an I horizontal scanning delay line (IT (delay line), 29 is a variable delay line, 30 is a delay control device, 31, 32 and 33 are output terminals, 34
is a low pass filter (LPF), and 3.5 is a bypass filter (HPF).

Here, the line serializer 6 connects the switch 20 and the switch terminal 2.
3 and 24, and the synchronizer 19 is connected to the IH delay line 2.
8 and switch 21.22 and switch terminals 25, 26.2
7, handles the Y signal, C signal, V signal, and a signal on which a horizontal synchronizing signal is superimposed, and applies them to input terminals], 2, and 3', respectively.

The line sequential control device 7 counts all the horizontal scanning periods of the Y signal, and outputs the state rHJ during odd-numbered horizontal scanning periods and outputs the state ELj during even-numbered horizontal scanning periods, for example. Based on the output of the line sequential control device 7, the line sequentializer 6 connects the switch 20 to the switch terminal 23 when the output state of the line sequential control device 7 is "H" to send the C signal to FM.
Send += to the modulator 5, and when the output state is "L", connect the switch 20 to the switch terminal 24 to output pM modulator 5
A line-sequential color signal is created by sending the entire KV signal.

This line-sequential color signal -1 is FM-modulated by an FM modulator 5 and recorded on a recording track on a magnetic tape 15 via a magnetic helix 2.

On the other hand, the output state of the gate 9-1 line sequential control device 7 is rH.
Only at the time of J, the pilot signal which is the output of the oscillator 10 is sent to the mixer 8, and the mixer 8 mixes the pylon I signal and the FM signal.
The Y signal FM modulated by the modulator 4 is mixed. Here, the pilot signal has a single frequency and is selected to have a frequency sufficiently lower than the FM wave of the Y signal. The mixed signal is recorded on the recording trunk on the magnetic tape 5 via the magnetic tape 1!11. Note that magnetic head 1] and magnetic head 1
Trace a track different from 2.

During reproduction, the mixed signal is reproduced by the magnetic head 13 tracing the same trunk as the magnetic head 11, and is supplied to an LPF (low pass filter) 34 and an HPF (bypass filter) 35.

The LPF 34 is a filter that extracts only the pilot signal from the mixed signal, and the HPF 35 is a filter that removes the pilot signal from the mixed signal and completely extracts only the FM signal of the Y signal.

The synchronization control device 18 detects the presence or absence of a pilot signal, outputs the state "H" during a period when there is a pilot signal, and outputs the state rLJ during a period when there is no pilot signal.

On the other hand, the magnetic head 14 traces the same track as the magnetic head 12, and the two-FM demodulator 17, which reproduces the FM-modulated line-sequential color signal, reproduces the line-sequential color signal based on the reproduction output of the magnetic navel 1!14. The sequential color signals are demodulated and the line sequential color signals are sent to the synchronizer 19. The synchronizer 19 separates the line-sequential color signal tones into the U signal and the V signal. When the output of the synchronization control device 18 is in the state rH(L)j, the switch 21
．． 22 is connected to the switch terminals 25, 26 (26, 27), the U (V) signal output terminal 32 (33) outputs the line sequential color signal as it is, and the V (U) signal output terminal 33
In (32), the line-sequential color signal is sent to 1H by the 1H delay line 28.
Outputs a signal delayed by the horizontal scanning period.

By the way, the Y signal F is demodulated by the M demodulator J6, and sent to the variable delay line 29 for switching. And the delay control device 3
By controlling the two variable delay lines at 0, the delay amount of the Y signal is controlled, and the Y signal of the output terminal 31 and the output terminal 32 are
The time axes of the U signals match. delay control device 30N,
For example, a control signal is sent to the variable delay line 29 so as to match the horizontal synchronizing signal position of the Y signal and the horizontal synchronizing signal position of the U signal, thereby forming a so-called Y-C timing circuit.

As mentioned above, in a Y-C separate type VTR used as a broadcasting device, when considering compatible playback between decks, it is especially important to
-C timing function is important, Y signal and C signal water:'
A Y-C timing circuit using an F synchronization signal is generally used.

Further, in the line sequential VTR, a color discrimination signal, typically a pilot signal, is required as a control signal for the synchronizer 19, as in the conventional example.

In the conventional example shown in Fig. 1, the oscillator 1
By superimposing a single frequency of 0 (pilot signal) on every other watermoon scanning line, the color discrimination signal required by the synchronizer 19 during reproduction was made. In general, conventional line-sequential color signal superimposition methods include the above example, a method in which a pilot signal is superimposed every other horizontal scanning line on the FM wave of a line-sequential color signal, and a method of superimposing a pilot signal every other horizontal scanning line on the FM wave of a line-sequential color signal. A method has been considered in which a pilot signal is superimposed at a predetermined position during the horizontal retrace period every one and a half scanning lines.

However, in such a conventional example, a means for superimposing a color discrimination signal and a means for erasing a color discrimination signal during reproduction are required, and problems such as an increase in the cost and circuit scale of these means arise.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a line-sequential color signal processing system that can perform color discrimination without adding a special color discrimination signal.

Structure of the Invention The line-sequential color signal processing method of the present invention is characterized in that, for example, the horizontal synchronization signal of the color signal required for the Y-C timing function during mutual interaction of a Y-C separated VTR is also used as a color discrimination signal. For example, a different 2 'liG force' is applied to the line-sequential color signal for each horizontal scanning period during recording.
1 power water 1 synchronization signal is all superimposed alternately, and during playback, it is used as a signal for each color of color difference signal synchronization control. Y-
It is also used as a water-'1 synchronization signal for C timing. Further, during reproduction, the above-mentioned color discrimination No. 18 is not particularly removed.

Furthermore, as another method of superimposing the color discrimination signal of the present invention,
There is a method in which a horizontal synchronizing signal is superimposed on a line-sequential color signal every other horizontal scanning period (for example, a horizontal synchronizing signal is superimposed on a line-sequential color signal only in odd-numbered horizontal scanning periods).

[Above] As a method of superimposing a horizontal synchronizing signal on every other horizontal scanning line, a method that can be considered is to thin out the horizontal synchronizing signal every one horizontal scanning period from the output signal of the conventional line sequentializer 6 shown in FIG. It will be done. However, in the present invention, as an even easier method, as the input signal of the conventional VTR shown in FIG. In addition, the line sequentializer 6. The purpose of the present invention is achieved by performing the switching of the synchronizer 19 at a timing slightly different from that of the VTR shown in FIG.

Description of the embodiment A signal in which a horizontal synchronization signal is superimposed only on the Y signal and the U signal is
FIG. 2 shows an embodiment in which a TR input signal is used. Second
In the figure, 36 and 37 pulse delay lines, 38 are a synchronization control device, and the other components are the same as those in FIG. In particular, the switching operations of the line serializer 6 and the synchronizer 9 will be explained in detail with reference to FIG.

Here, A indicates the number of the horizontal scanning period, n (n is an arbitrary integer) td indicates the n-th horizontal scanning period, and is the horizontal axis in FIG. B is the waveform of the Y signal applied to the input terminal J, C is the waveform of the U signal applied to the input terminal 2, D is the waveform of the V signal applied to the input terminal 3,
E is the output waveform of the line sequential controller 7, F is the pulse delay line 3
6, G is the line sequential color signal output from the line sequentializer 6, H is the output waveform of the synchronization controller 38, ■ is the output waveform of the pulse delay line 37, and the U signal from the J output terminal 32. K is the waveform of the V signal at the output terminal 33.

Note that the subscript i of Y, , Ui, V, in the figure indicates that the Y signal, U signal, and V signal are supplied to the input terminal 1.2.3 during the i-th horizontal scanning period. ,
Make the flow of U and V signals completely clear.

- Also, the upper side of the drawing of the signal waveforms E, F, H, and I shows that the output is in the logic state [-H], and the lower part of the drawing is the output in the logic state "L".

In FIG. 2, signal waveforms B, C, and D shown in FIG. 3 are supplied to input terminals 2 and 2.3, respectively. No horizontal synchronization signal is superimposed on the signal waveform D (ie, the ■ signal). The line sequential control device 7 is configured to invert the output at the timing of the leading edge of the horizontal synchronizing signal of waveform B of the Y signal, and for example, during an odd horizontal scanning period, the state fQ4 rHJ
As a result, the entire signal waveform E is output. The pulse delay line 36 outputs a signal waveform F obtained by delaying the signal waveform E by a certain period of time.

Here, various delay amounts of the pulse delay line 36 can be considered, but it is good if the change point of the state of the signal waveform F is located at the bank porch or front porch of the video signal. The delay amount is set to be slightly larger than the signal width, so that the changing point of the output waveform F is at the back porch.

Due to the output waveform F of the pulse delay line 36, the sixth blue sequentializer outputs the U signal when the output waveform F is rHJ, and outputs the V signal when the output waveform F is rLJ. That is, the U signal is selected for odd-numbered horizontal scanning lines, the ■ signal is selected for even-numbered horizontal scanning lines, and line-sequential color signals are created in the same manner as in the conventional example shown in FIG. 1, but as described above. Since the line sequentializer 6 is controlled by the signal delayed by the output all-pulse delay line 36 of the line sequential controller 7, the line sequentializer 6
outputs the U signal for the odd-numbered horizontal scanning period, and at the same time outputs the horizontal synchronization signal following the U signal for the odd-numbered horizontal scanning period. On the other hand, the horizontal synchronizing signal following the U signal in the even-numbered horizontal scanning period is the period in which the line sequentializer 6 is outputting the V signal, and is discarded. Therefore, as shown in signal waveform G, a signal in which a horizontal synchronizing signal is superimposed every horizontal scanning period is obtained.

The horizontal synchronization signal is
Since it is superimposed only immediately before the signal, it can be used first as a color discrimination signal for the synchronizer 19 during reproduction.

During reproduction, the outputs obtained by the magnetic heads 13 and 14 are reproduced by FM demodulators 16 and 17 to obtain a Y signal and a line-sequential color signal. The synchronization control device 36 maintains the "Hl" state for exactly one horizontal period from the timing of the leading edge of the horizontal synchronization signal included in the adjusted line-sequential color signal, and outputs the output waveform shown in FIG. Hk high output. Pulse delay line 3
7 has the same delay amount as the pulse delay line 36, and outputs an output waveform I. The synchronizer 19 outputs an output waveform I
e Used as a switching signal, the output waveform ■ is [H-1
When the switch 21 (22) is in the state, the switch terminal 25 (
26), and when the output waveform ■ is in the rLJ state, the switch 21 (22) is connected to the switch terminal 26 (27).
Connect to.

Through the above process, the output terminal 32 of the U signal and V signal
．． 33, an output signal waveform J of the U signal and an output signal waveform K of the V signal are output, respectively.

Although the above embodiment has shown a method in which a horizontal synchronizing signal is superimposed on a line-sequential color signal every one and a half scanning lines, the following method can be considered in this invention in addition to the above embodiment.

(]) A method in which the width of the horizontal synchronization signal superimposed on the line-sequential color signal is made different between the odd-numbered and even-numbered horizontal scanning periods. In the configuration of this system, signals having horizontal synchronization signals of different widths for the U signal and the V signal are used as input signals in the above embodiment.

(2) Amplitude (including polarity) of the horizontal synchronization signal superimposed on the line-sequential color signal in the odd-numbered and even-numbered horizontal scanning periods
method to make the difference. The configuration of this method is as follows: U signal and V signal.
A signal having horizontal synchronization signals of different amplitudes is used as the input signal in the above embodiment.

(3) A method in which the insertion position of the horizontal synchronization signal superimposed on the line-sequential color signal is made different between odd-numbered and even-numbered horizontal scanning periods. As a configuration of this system, a signal having a horizontal synchronizing signal inserted at different positions in the U signal and the V signal is used as the input signal in the above embodiment.

In the configuration of the invention described above, the Y-C separated line sequential type VTR
Although we have explained the above, it is of course applicable to general line sequential VTRs and line sequential television systems that do not perform Y-C separation, and is extremely effective due to the ease of superimposition of color discrimination signals. There is. Also, not only PAL system (NTS
It is clear that similar effects can be obtained with VTRs based on the C system and SECAM system.

Effects of the Invention The present invention is particularly effective in Y-C separated type line sequential VTRs, and generally Y-C separated type VTRs.
By making the horizontal synchronization signal on the color signal required for TR different every other horizontal scanning line (or by superimposing the horizontal synchronization signal only on every other horizontal scanning line), a new color discrimination signal can be added. It is possible to perform color discrimination without any
When restoring different color difference signals, it is not necessary to remove the color difference signal (11 signals) that existed in the conventional example, and the circuit size and cost increase in VTRs, etc., which were problems in the conventional example. can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional Y-C separated line sequential type VTR, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a waveform diagram of each part thereof. 1.2.3...Input terminal, 4,5...FM modulator,
6. Line sequentializer, 7. Line sequential control device, 11-14.
・Magnetic hend, 15... Magnetic deso, 16.17...
FM demodulator, ]8 ・Synchronization control device, 19...Synchronizer, 20-22...Switch, 23-27...Switch terminal, 28...]H delay line, 29...-Variable delay line ,
30・Delay control device, 31-33・Output terminal, 36°3
7. Pulse delay line, 38...Synchronization control device Fig. 1 6 Fig. 2

Claims (1)

[Claims] (]) Which of the odd-numbered and even-numbered horizontal blanking periods of a line-sequential color signal is created by alternately selecting two birch-like color difference signals of a video signal for each horizontal scanning line. A line sequential color signal processing method in which a horizontal synchronizing signal is superimposed on only one of the horizontal synchronizing signals, and the presence or absence of the horizontal synchronizing signal in each horizontal blanking period is detected to separate the line sequential color signal into two types of color difference signals. (2) A horizontal synchronizing signal is superimposed only on the horizontal blanking period of either one of the two second color difference signals, and the selection of the two types of color difference signals is switched between the front porch and the base of the horizontal synchronizing signal. By performing either one of the above at a predetermined timing! The line-sequential color signal processing method according to claim 1, wherein a horizontal synchronization signal is superimposed only on one of the fNt order color signal number and the even-numbered horizontal blanking period. (3) Superimposing different horizontal synchronization signals in the odd-numbered and even-numbered horizontal blanking periods of the line-sequential color signal created by alternately selecting two types of color difference signals for every horizontal scanning line of the video signal. , a line sequential color signal processing method in which the line sequential color signal is separated into two types of color difference signals by detecting differences in horizontal synchronization signals in each horizontal blanking period. (4) The line sequential color signal processing method according to claim (3), wherein the horizontal synchronization signal has different widths between odd-numbered horizontal blanking periods and even-numbered horizontal blanking periods. (5) The horizontal synchronization signal has an amplitude (
The line sequential color signal processing method according to claim (3), wherein the line sequential color signal processing method has different values (including v7L). (6) The line-sequential color signal processing method according to claim 2g (3), wherein the horizontal synchronization signal has different insertion positions in odd-numbered horizontal blanking periods and even-numbered horizontal blanking periods. (Claim 3) The selection of the two types of color difference signals is switched at a predetermined timing of either the front porch or the bank porch of the horizontal synchronization signal.
Line-sequential color signal processing method described in Section 1.