JPS6126280B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color bar generator.

Various test signals are used to adjust television broadcasting equipment, and color bar signals are commonly used at television broadcasting stations as test signals used on a daily basis. The color bar signal passes through a signal synthesizer called a color encoder and is converted to an NTSC signal. The color bar signal (hereinafter referred to as encoded bar signal) converted to an NTSC signal is sent to various devices within the station, such as a switcher, VTR, and color monitor, and is used to adjust each of these devices. The encoder signal is monitored by a vectorscope at the output point of each device. (Color monitors are often adjusted by the adjuster's vision.) It is normal for the waveforms of these output signals monitored using a vectorscope to appear as shown in Figure 1, and the output and input of any device are normal. It is desirable that the waveform of the output and the waveform of the output match completely.

However, each device often has its own characteristic changes, and among these, the characteristics of the VTR itself often change. Specifically, when an encoded bar signal like the one shown in Figure 1 is recorded on a VTR, the
The VTR reproduced waveform is reproduced with a phase change as shown in FIG. The amount of phase change is not uniform for each color of the color bar, and the amount of change is different for each color. For example, when a 40% chroma signal is reproduced, the color with the largest change occurs about 3 degrees, and in the case of a color bar signal, which is a 100% chroma signal, this phase change increases further. The phase of these colors is defined by the number of times between bursts.

Now, when these phase changes occur in a color television camera and a color television signal transmission system, the problem becomes which color should be used as a reference to adjust the phase between the burst and each color. Usually the angle between the burst and the yellow (12.9
In many cases, the angle is adjusted based on certain angle conditions.

The key point in adjusting the colors transmitted by broadcast stations is how close skin tones are to the burst colors. This is particularly important when signals passing from the encoder through various equipment systems are switched or superimposed.
Normally, among the colors perceived by the human eye, changes in skin color are the most noticeable in relation to memory colors, and in-house adjustments are made to minimize this change.

However, as described above, yellow is a signal with high brightness and saturation when modulated at 100%, and is a color with a large phase change, especially in VTR playback, which is different from the phase change between burst and skin color. This amount of change varies depending on the device,
Therefore, even if the angle between the burst and yellow is adjusted to a constant value, the phase change between the burst and the skin color will remain.

The present invention has been devised in view of the above, and provides a color bar generator that uses color bar signals to adjust the phase matching of encoded bar signals that have passed through various devices and systems, with a focus on skin color. It is something.

In the present invention, hues corresponding to skin colors are displayed simultaneously. If the phase control for various devices and systems using color bar signals in the station is a color television transmission system and only skin color is detected, the phase between the color signal and the burst that generates only one color with a hue that matches the skin color. However, there are actually various hues of colors, and it is meaningless unless you monitor how these colors change and adjust the phase between the skin tone and the burst. For example, if you send an encoded bar signal consisting only of skin color components and manage the phase between the burst and skin color, you will be able to see how much the other phase colors, such as yellow and green, are out of phase. I don't understand it at all.

Therefore, the present invention attempts to solve these problems by outputting a color bar signal consisting only of skin color components on the same screen instead of the usual color bar signal.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 3 to 7.

FIG. 3 shows a color bar pattern of a color bar generator according to the present invention, in which the effective vertical scanning period V is set to 3.
Vertical bars 2 of white (W), yellow (Y), cyan (C), green (G), magenta (M), red (R), and blue (B) are displayed in the upper divided row, and skin color (F) is displayed in the middle row. Skin color horizontal bar 4 of the corresponding hue, the phase reference for the I and Q channels at the bottom - I _S , Q _S , 100% white (W _S ),
A black ( _S ) reference bar 6 is formed.

The skin color horizontal bar 4 is formed with an amplitude obtained by mixing primary color bar signals of red (R), green (G), and blue (B) at a predetermined ratio over the entire effective horizontal scanning period for 1/3 of the effective vertical scanning period V. The skin color (F) or the hue corresponding thereto is displayed.

A color bar generator according to the present invention for displaying the color bar pattern shown in FIG. 3 is constructed as shown in FIG. 4.

That is, the blanking signal _SBL is introduced into the horizontal timing circuit 10, and the horizontal timing circuit 10
From this, a horizontal blanking signal S _HBL having an effective horizontal scanning period H shown in FIG. 4a is generated.

This horizontal blanking signal S _HBL is from the pulse generator 1.
2 will be introduced. In the pulse generator 12, a horizontal blanking signal S _HBL is generated as shown in FIGS. 5b to 5i.
A blue (B) signal is generated by dividing the scanning period H into seven equal parts using an astable multivibrator, which is further divided by a bistable multivibrator to obtain red (R) and green (G) signals, respectively. I _S , Q _S , W S , B _S by red (R), green (G), and blue (B ₎ signals
signal is generated. Further, as shown in FIG. 5i, red (R), green (G), and blue (B) signals having predetermined amplitudes are generated over the scanning period H.

Each signal from pulse generator 12 has an output gating circuit. The level controller 14 is supplied with each gate signal shown in FIG. 6 from the vertical timing circuit 16, and a level-controlled signal is derived in accordance with the gate signal.

The vertical timing circuit 16 generates a vertical blanking signal S _VBL having an effective vertical scanning period V shown in FIG. 6a from the blanking signal S _BL , and divides the scanning period V into three according to the pattern shown in FIG. 3. The vertical bar gate signal S _VG , skin color horizontal bar gate signal S _FG and reference horizontal bar gate signal S _SG shown in FIGS. 6b to 6d are sequentially generated. This vertical bar gate signal S _VG corresponds to the vertical scanning period (1/3V ₎ of the vertical bar 2 in _FIG . Scanning period (1/3
V) respectively.

The level controller 14 to which these gate signals S _VG , S _FG , S _SG and each signal from the pulse generator 12 are supplied is constructed as shown in FIG. That is, the signals shown in FIGS. 5b to 5i from the pulse generator 12 are respectively transmitted to NAND gates 14-1, 14-2, . . .
...14-10 is supplied to one input end. Fifth
NAND gates 14-1, 14-2, 1 to which the red (R), green (G), and blue (B) signals in Figures b to d are supplied
The other input terminal of 4-3 is the vertical bargade signal S _VG.
NAND gate 1 is commonly introduced and the red (R), green (G), and blue (B) signals shown in FIG. 5i are supplied.
The skin color horizontal bar gate signal _SFG is commonly supplied to the other input terminals of 4-4, 14-5, and 14-6.
A reference horizontal bar gate signal _SSG is commonly introduced to the other input terminals of the NAND gates 14-7, 14-8, 14-9, and 14-10 to which the _S , _Qs , _Ws , and _Bs signals are supplied. Each of these NAND gates 14-1, 14
-2,...14-10 gated signals are connected to variable resistors 14-11, 14-12,...
14-20, the levels are adjusted and derived, respectively.

Therefore, the vertical bar gate signal S _VG is output from the level controller 14 during the starting 1/3 period of the effective vertical scanning period V.
Red (R) to display the vertical bar 2 in Fig. 3,
Green (G) and blue (B) signals (Fig. 5 b to d) are derived, and in the next 1/3 period, the skin color gate signal _SFG displays the red (R) and green horizontal bars 6. (G),
A skin color signal is derived from the blue (B) signal (Fig. 5i), and the reference horizontal bar gate signal S _S is used for the last 1/3 period.
The signals -I _S , Q _S , W _S , and B _S are induced by _G , and the color bar shown in FIG. 3 is displayed.

The signal displaying the color bar of FIG. 3 is passed through a color encoder and displayed on a vectorscope as shown in FIG. 7. That is, yellow (Y), cyan (C), green (G), which correspond to each display color of the vertical bar 2,
Magenta (M), red (R), blue (B) hue vectors and hue vectors F and -I based on the skin color horizontal bar 4
The vectors _S and Q _S are displayed respectively.

As described above, according to the present invention, since the skin color horizontal bar 4 is displayed in the color bar pattern, monitoring using the normal color bar signal and monitoring using the skin color component can be performed at the same time.

In the present invention, the color bar pattern and display period are not limited to those shown in FIG. 3.

[Brief explanation of the drawing]

Figure 1 is a waveform diagram displayed on a vectorscope by a conventional color bar generator, Figure 2 is a waveform diagram displayed on a vectorscope when a conventional color bar generator signal is played back on a VTR, and Figure 3 5 is a color bar pattern diagram showing an embodiment of the display of the color bar generator according to the present invention, FIG. 4 is a circuit configuration diagram showing an embodiment of the color bar generator according to the present invention, and FIGS. FIG. 4 is a signal waveform diagram in the horizontal scanning period to explain the operation, FIGS. 6a to 6d are signal waveform diagrams in the vertical scanning period to explain the operation in FIG. FIG. 8 is a circuit diagram showing the level controller of FIG. 4. In the figure, 2...vertical bar, 4...skin tone horizontal bar, 6...
...Reference bar, 10...Horizontal timing circuit, 12
... Pulse generator, 14 ... Level controller, 16
...Vertical timing circuit.

Claims (1)

[Claims] 1 A vertical bar generation circuit that generates vertical bar signals of white, yellow, cyan, green, magenta, red, blue, etc. from the red, green, and blue signals, and a horizontal bar of a hue corresponding to skin color from the red, green, and blue signals. A color bar generator comprising a horizontal bar generation circuit that generates a signal.