SU555564A1 - Color corrector for color video monitoring device - Google Patents

Description

(54) COLOR CORRECTOR FOR COLOR VIDEO CONTROL DEVICE

one

The invention relates to television and can be used in color video monitoring devices (COLF).

A known device for controlling white balance in a color television camera contains gain control units in red and blue transmission chains, subtraction blocks in which red and blue signals are subtracted from a green signal, memory blocks supporting red and blue transmission chains. blue colors, optimal gain, ensuring white balance, key circuits included between subtractors and memory, which are closed when an image of a white object is transmitted, since in this case In white balance, red, green, and blue signals should be equal to l.

However, the known device provides automatic adjustment of only static white balance.

A color corrector for a color video monitoring device is also known, containing three adjustable video amplifiers of red, green and blue signals, the S11 inputs of which are respectively supplied with red, green blue video signals, and the control inputs of adjustable video amplifiers are connected to the outputs of the respective comparison blocks, and the outputs are from control outputs three-beam color kinescope electrodes, the circuits of each cathode of which include load resistors connected through appropriate lines There are some video converters with the first inputs of the respective comparison units 2.

However, this device provides a white balance only in the case of reproducing a black and white image or monochrome sections of a color image.

The purpose of the invention is to improve the accuracy of maintaining white balance when playing black and white and color images.

Claims (2)

To do this, the color corrector for a color j video monitor contains three adjustable video amplifiers of the Red,; green and blue signals, the signal inputs of which are BiiflLDcarHanbi red, green and blue respectively, and the control inputs of the adjustable video amplifiers are connected to the outputs of the corresponding comparison blocks, and the outputs are with control electrodes of a three-color color kinescope, in the circuits of each cathode of which the load resistors are connected, connected through the corresponding linear type The amplifiers with the first inputs of the respective comparison units, introduced non-linear input amplifiers for the red, green and blue signals, the inputs of which are connected to the signal inputs of the respective adjustable video amplifiers, and the outputs are connected to the second inputs of the respective comparison blocks. FIG. Figure 1 shows the structural electrical circuit of the proposed device; in fig. 2 - voltage diagrams for the operation of the device. The device contains (see Fig. 1) three adjustable video amplifiers 1, 2, 3 signals of red, green and blue, to the signal inputs of which the video signals of red, green and blue are respectively supplied, and the control inputs of adjustable video amplifiers 1, 2, 3 are connected to the outputs of the respective comparison blocks 4, 5, 6, and the outputs with the control electrodes of the three-beam color kinescope 7 in the oepi of each of the cathodes of which are connected with non-resistor 8, 9, 10 connected through the respective linear video amplifiers 11, 12, 13 with the first inputs and comparing sootvetstvuyushnh blocks 4, 5, 6, a second vhoay which are respectively connected to the outputs of the nonlinear video amplifiers 14, 15, 16, the red signal, green and blue, the inputs of which are connected to the signal inputs of respective video amplifiers 1,2,3 controlled. The device works as follows. Red, green, and blue E, E, video signals. , E are fed to the segmental inputs of adjustable video amplifiers 1, 2, 3 and the inputs of nonlinear video amplifiers 14, 15, 16. The amplitude characteristics of the nonlinear video amplifiers 14, 15, 16 are nominal and represent a curve corresponding to the shape of the standard modulation characteristic of the kinescope 7 The transfer coefficients of nonlinear video amplifiers 14, 15, 16 are equal to one. Thus, when the non-linear video amplifiers 14, 15, 16 are applied to the inputs: three-linear signals of red, green and blue in time, for example, 1 V (see fkg. 2a) to the second inputs of three comparison blocks 4, 5, 6. video signals also in 1V non-linear standard form (see fig. 26), video signals taken from the load resistors 8, 9, 10 included in the cathodes of the kinescope 7 are respectively fed to the inputs of three-way video amplifiers 11, 1, 2, 13, transmission ratios of which are set in such a way that during playback uu screen kinescope 7 reference white color at the outputs of all three-way video amplifiers 11, 12, 13 razmahn signals will be equal to 1, and the form of signals will match the actual shape of the modulation characteristics of the corresponding illuminator kinescope 7 (see. FIG. 2c). Thus, the input to the input of a color video device of signals carrying information about a black and white image (Е Е Е Е-), at the inputs of each comparison unit 4, 5, 6, the sweeps of the video signals will be equal to each other, and in the event that the shape of the modulus of the primary characteristic of the corresponding 1f1 gynecore of the gynescope 7 corresponds to the standard modulation characteristic. In the case of the difference in the modular shape of the ion characteristics of one of the three projectors (the tube of the kinescope 7 from the form of the standard modulation characteristic of the output of the corresponding comparison block 4, 5 or 6, a control voltage appears (see Fig. 2d), which is supplied Single input on adjustable video amplifiers 1, 2 or 3 causes the required change in the magnitude of its transmission coefficient.When 11VCU inputs signals corresponding to a color image, if the modulation characteristic of the spotlight differs, From the standard, at each moment of the umen, at the inputs of the unit for matching the corresponding channel, the sweep of the EY video signals will be equal. The magnitude and field of the control voltage generated in this case will be such that the gain of the video amplifier of this channel changes in such a way that video output of the linear video amplifier becomes equal to the sweep of the non-linear video amplifier. Thus, when playing any color in each video channel, th line form tudnoy amplitude characteristics of video TSVKU its standard form. This ensures that the exact dynamic balance of the reference white color is automatically maintained throughout the entire range of reproducible frequencies. In addition, this increases the accuracy of color reproduction in austainable colors. Claims for chroma color for a video monitoring device, with three adjustable loudspeakers qpac, green and green signals, the signal inputs of which are respectively red, green and blue video signals, and the control inputs of adjustable video amplifiers are connected to the outputs of the corresponding qf blocks The outputs, and the outputs, with the control electrodes of the three-beam color kinescope, each of the cathodes of the kgg circuit, each include load peancTOpbi.coeaifnio through the corresponding lines e video amplifiers with the first inputs of the respective comparison units, characterized in that non-linear video amplifiers of red, green and blue signals, the inputs of which are connected to the signal inputs of the respective adjustable video amplifiers, are introduced, in order to increase the accuracy of white balance when playing black and white and color images, and the outputs are connected to the second inputs of the respective comparison units. Sources of information taken into account in the examination: 1. Patent Great istanki number 1278742, M. Kl.N 4 T, 1972. 2. Authors certificate, USSR № 488364, M.Kl.N 04 N9 / 48.1973 (prototype). g f Control Faye. 2