JPS6347315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a brightness signal display device that displays brightness signals in a color composite video signal as vectors.

Prior Art and Problems Various devices are known for testing and measuring transmission systems and various devices in color television systems. For example, it is possible to simultaneously measure chromaticity and saturation in the chromaticity information of a color composite video signal using a vector scope. As for the brightness signal in the color composite video signal, there is known a method of extracting the brightness signal using a low-pass filter or the like and displaying it on the time axis.

As mentioned above, in observing a color composite video signal, the chromaticity signal and the brightness signal have been observed by separate means. Therefore, there is a drawback that observation of color composite video signals is complicated.

Purpose of the Invention The present invention separates a brightness signal and a chromaticity signal from a color composite video signal, displays the brightness signal simultaneously or separately with the chromaticity signal, and facilitates observation of the color composite video signal. This is the purpose. Examples will be described in detail below.

Embodiment of the Invention FIG. 1 is a block diagram of an embodiment of the present invention, 1 and 2 are video signal gate circuits that generate a window signal and gate a video signal using the window signal, and 3 is a video signal gate circuit that connects input terminals a to d. 4 is a brightness replacement signal generator that performs amplitude modulation to display the brightness signal; 5 is a vector scope; 6 and 7 are video signal input terminals; 8 and 9 are window signal size and This is an input terminal for a control signal that determines the position.

The video signals applied to the input terminals 6 and 7 are gated by a window signal generated based on the control signals applied to the input terminals 8 and 9, and the video signal of the portion to be measured is gated by the video signal gate circuit 1, 2 to the switching circuit 3. Input terminals a and d of the switching circuit 3 are selected when detailed measurements are to be made by comparing only the respective gated parts of the video signals from the input terminals 6 and 7, for example two Used when examining video signals in detail. In addition, the input terminals b and c of the switching circuit 3 are simply 2
This is selected when observing two video signals, and is used, for example, to compare characteristics of transmission systems using color bar signals, etc.

The output signal of the switching circuit 3 is transmitted to the vector scope 5.
It is input directly to input terminal A of , and is also input to input terminal B via brightness replacement signal generating section 4 .
The vector scope 5 displays only the chromaticity signal when it is input only to input terminal A, displays only the brightness signal when it is input only to input terminal B, and displays only the brightness signal when it is input only to input terminal A and B. At this time, the chromaticity signal and the brightness signal are displayed simultaneously by time-sharing control.

FIG. 2 is a block diagram of the brightness replacement signal generating section 4, in which 11 is a signal separation circuit that separates the brightness signal B and chromaticity signal C from the color composite video signal A applied to the input terminal 14; 13 is an amplification and amplitude limiting circuit which amplifies and limits the amplitude of the chromaticity signal C and outputs a modulated signal D; 13 is an output terminal 1 which outputs a brightness replacement signal E to which the brightness signal B and modulated signal D are added;
This is an amplitude modulation circuit that outputs to 5.

FIGS. 3A to 3H show an example of signals A to H in each part of FIG. 2, and are for the case where a color bar composite video signal is used. Figure 3 A,
In E, Y indicates yellow, C indicates cyan, G indicates green, M indicates magenta, R indicates red, and B indicates blue. When the video signal A shown in FIG. 3A is applied to the signal separation circuit 11,
The chromaticity signal C is separated into a brightness signal B shown in FIG. 3B and a chromaticity signal C shown in FIG. Signal D is output. Amplitude modulation circuit 1
3 modulates the modulated signal D with the brightness signal B, so the brightness replacement signal H shown in FIG.
5 to the input terminal B of the vectorscope 5.

Figure 4 shows the scale when displaying only the chromaticity signal of the color bar composite video signal on the vector scope, and is for displaying hue and saturation.
The positions within the R, Y, G, C, B, and M frames indicate the reference vector positions. Note that the horizontal axis, vertical axis, and circle are each provided with scales that allow the magnitude and angle of the vector to be identified.

FIG. 5 shows the scale when displaying only the brightness signal of the composite video signal of the color bar, and is for displaying the brightness amplitude for each hue, R _L , Y _L , G _L ,
The small circles on the lines C _L , B _L , and M _L indicate the reference values of the respective lightness amplitudes. Further, the horizontal axis, vertical axis, and circle are provided with scales that allow identification of the magnitude and angle of the amplitude.

The above-mentioned scales can be formed in a cathode ray tube, so-called "inner graphical", and the scale display can be changed by switching the lighting of the lamp from the outside. Alternatively, the above-mentioned scales may be formed on an acrylic resin plate, placed on the front surface of the cathode ray tube, and the display of the scales may be switched by switching on or off the lamp from the side. For example, by displaying the scales in Figures 4 and 5 at the same time, the chromaticity signal and brightness signal can be displayed simultaneously, making it easy to observe deviations from the reference value. . Also, regarding the color bar composite video signal, its chromaticity signal and brightness signal can be observed separately or simultaneously.

Effects of the Invention As explained above, the present invention separates a chromaticity signal and a brightness signal from a color composite video signal, and amplitude-modulates the chromaticity signal and an amplitude-limited modulated signal using the brightness signal as a modulating signal. It forms a brightness replacement signal and adds this brightness replacement signal to a vectorscope to display the brightness as a vector for each hue, and either or both of the color composite video signal is added to the vectorscope. It is possible to simultaneously display the chromaticity signal as a vector, and there is an advantage that the brightness signal can be observed extremely easily by adding a small amount of configuration to the vectorscope.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
The figure is a block diagram of the brightness replacement signal generating section according to the embodiment of the present invention, FIG. 3 is a waveform diagram explaining the operation, and FIGS. 4 and 5 are explanations of an example of the scale for displaying the chromaticity signal and the brightness signal. It is a diagram. 1 and 2 are video signal gate circuits, 3 is a switching circuit,
4 is a brightness substitution signal generation section, 5 is a vector scope, 6 and 7 are input terminals for video signals, 8 and 9 are input terminals for control signals, 11 is a signal separation circuit, 12 is an amplification amplitude limiting circuit, and 13 is an amplitude modulation circuit. It is a circuit.

Claims (1)

[Claims] 1. A signal separation circuit that separates a chromaticity signal and a brightness signal of a color composite video signal, an amplification amplitude limiting circuit that amplifies and limits the amplitude of the chromaticity signal separated by the signal separation circuit, and an amplification amplitude limiting circuit that an amplitude modulation circuit that uses an output as a modulated signal and amplitude-modulates the brightness signal separated by the signal separation circuit as a modulation signal; either a brightness replacement signal of the output of the amplitude modulation circuit or the color composite video signal; or a vector scope that performs vector display by adding both.