SU1458978A1 - Method of reproducing color video signal on screen of single-beam index picture tube - Google Patents

Abstract

The invention relates to color television. The purpose of the invention is to reduce power consumption and increase the brightness of the reproduced video color signal. This method is based on the line-by-line scanning of the electron beam (EL) in a direction, perpendicular to the direction of the triads of phosphor stripes (TLI) of primary colors with a simultaneous delay of EL on the TLP of primary colors. A feature of this method is that, in a progressive scan, the EL signal of each of the primary colors is converted into a pulse signal, the duration of which is proportional to the amplitude of the video signal. In this case, the EL delay on the TLP of the primary colors is carried out for a time equal to the duration of the pulse signal of the corresponding primary color. In addition, the sum of the durations of the pulse signals of the primary colors within each TLP of the primary colors is a constant value. 2 Il. (L

Description

The invention relates to color television, in particular to methods of displaying a video signal of chromaticity due to the effect of a scanning electron beam on cathode monophores with different luminescence colors, and can be used to improve the efficiency and quality of color image transmission by index-type electron tubes.

The aim of the invention is to reduce power consumption and to increase the brightness of the reproduced video signal of color.

FIG. Figure 1 shows a structural electrical circuit of a device implementing the proposed method; Fig. 2 is a voltage chart.

The device contains (Fig. 1) an index kinescope 1 with an index AND and color R, G, B phosphors deposited on the screen in the form of alternating in a certain order narrow vertical stripes, a photodetector 2, a main deflecting system 3 and an additional system 4 deviations - in the form of electrostatic deflection plates, shaper 5 synchronization pulses, generator 6 sawtooth pulses, adders 7, 8 and 9, pulse-width converters 10, 11 and 12 and inverter 13.

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The device works as follows

With the help of the main deflecting system 3, the string deflection of the electron beam is successively across the phosphor bands AND, R, G,. In the index kinescope 1. Each time the electron beam crosses the index phosphor strip And a flash of light occurs, immediately converted by the photoreceiver 2 into a pulse which is amplified and transformed by shaper 5 into pulses necessary for synchronization of the device (fig. 2, a) by shaper 5. At vig. 2.6 shows a linear movement section of the electron beam carried out by the horizontal deflection coil of the main deflection system 3. Using the index sync pulse, the generator 6 of sawtooth pulses is started (Fig 2, c), which generates a sawtooth voltage with a slope that provides the opposite main deflection beam on the screen. As a result, the electron beam, having passed the index band I, stops on the surface of the screen of the index kinescope 1 for as long as the sawtooth acts. The start of the start of the generator 6 is chosen so that the beam stops at the first of the color phosphor stripes. Let it be a red phosphor R, If you do not give any signals to the other deflection plate of the additional system 4 deviations, then the electron beam will jump only on the red phosphor R and the screen of the kinescope will glow red. In this case, the duration of the delay of the beam on the red phosphor will be almost completely equal to the period of the index sync signal (except for the time when the beam passes along the index bar - this time on the sawtooth pulse corresponds to the shelf). To provide, for example, only a green glow of the screen, it is sufficient to apply a constant voltage to the second deflecting plate, shifting the beam position to the next, green, phosphor strip G. A double bias voltage will provide a blue glow of the screen. In order to obtain intermediate colors, it is necessary for further deflection plates.

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in addition to the sawtooth voltage, simultaneously with it a three-step signal with different lengths of steps. By controlling the ratio between the durations of the steps in this signal, the whole gamut of colors provided by the index kinescope 1 can be obtained. To restore the transmitted video signal of a color image, it is necessary to convert the amplitude of the signal of each primary color to the proportional duration of the corresponding three-step signal.

The video signal corresponding to the red color goes directly to the input of the pulse-width converter 10, the output of which produces a pulse of constant amplitude, the duration of which is proportional to the amplitude of the input signal (Fig. 2, d). The pulse width converter 11 is fed by the sum

The 5 red and green video signals from the output of the adder 7. The pulse-width converter 12 is fed the sum of all the video signals of the main colors from the output of the adder 8.

0 At the output of pulse-width converters 11 and 12, pulses of constant amplitude, but of longer duration, are also formed (Fig. 2, d, e). After summing the signals of all three pulse-width converters 10, 11 and 12 by adder 9 (Fig. 2, g) and inverting by the inverter 13, the resulting amount at its output appears a three-stage signal (Fig. 2, h),

Q which, when applied to the deflection plates of the additional deflection system 1 4, will provide a color modulation of the luminescence of the screen of the index kinescope 1 in accordance with the input color television signal.

The proposed method has a high modulation sensitivity, since in order to change the color of the luminescence of the screen, it is enough to deflect the electron beam to a distance equal to the distance between adjacent phosphor stripes. With an electrostatic deflection method, this will require several volts. When modulated by the beam current in a known manner, the modulating voltage reaches 50-70 volts, i.e. The sensitivity of the modulation by the proposed method is an order of magnitude.

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When using the proposed method, reducing the amount of energy expended on modulation is even greater due to the fact that the deflecting plates have only reactive load, while with the known method of beam current moduli the equivalent load resistance contains an active component equal to current electron beam.

Claims (1)

The brightness of the screen of the index kinescope is increased threefold, since the transmission of a double electron beam affects the corresponding phosphor stripes of the same color for a time three times greater than in the well-known color modulation method. And at short times the electron-beam effect on the phosphor, as is the case in this case, an increase in the duration of such effects leads to a proportional increase in the luminosity of the phosphor. Invention Formula Method of reproducing chrominance video signal on a single path screen ten g 25 589786 kinescope with vertically spaced alternating triads of luminophore bands of primary colors, based on a progressive scanning of the electron beam in the direction perpendicular to the direction of triads of luminous bands of primary colors, with simultaneous delay of the electron beam on triads of phosphor stripes of primary colors, to reduce power consumption and increase the luminance of the reproduced video signal of the chromaticity, with the G-line scanning of the electron beam in The ideosignal of each of the primary colors is converted into a pulse signal, the duration of which is proportional to the amplitude of the video signal, while the electron beam delay on the triads of the phosphor bands of the primary colors is performed for a time equal to the duration of the pulse signal of the corresponding primary color. 20 and the sum of the durations of the pulsed signals of the primary colors within each triad of the phosphor bands of the primary colors is constant. g / .BUT (rig 2