SU1408544A2 - Color image reproduction apparatus - Google Patents

Abstract

The invention relates to television technology. The purpose of the invention is to improve the image quality. The device contains an index color electron beam tube 1, an index signal detector 2, a phase shifter 3, indicators 4 and 5 zero, expand 6 to 9 pulses, shapers 10-13 control pulses, IL-OR 14, a divider 15 by three, the switch 16 of the chrominance signals and the EL 17 And the goal is achieved by increasing the brightness and contrast using the input of the extender 9, the former 13, the OR 14, the counter - - divider 15 and the El 17. 17. Il.

Description

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The invention relates to a television (TV) technique, in particular to the reproduction of color TV images, alphanumeric and graphic information on cathode ray tubes (CRT) of the index type, and is an improvement to the device according to the author. No. 1210235.

The aim of the invention is to increase the quality of the image by increasing

{Brightness and contrast.

I In the drawing. Represented structures on the electrical circuit of the device

4 and 5 zero. From the outputs, expand 6–9 pulses

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At the inputs of the formers 10–13 control pulses, the fronts of the generated control pulses coincide with the decay of the pulses formed by the 6–9 differentials.

the outputs of the formers 10–13 signals arrive at the inputs of the four-input element OR 14, at the output of which a sequence of pulses is formed whose temporal position is determined by the moments of intersection

Color reproduction, by a bundle of screen elements. j The color jro reproducing device contains an index color CRT 1, an index signal detector 2, a phase shifter 3, the first 4 and second 5 indicators zero, first, i6, second 7, third 8 and fourth 9 pulse extenders, first 10, second 11, the third 12 and fourth 13. control pulse shapers.

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; element OR 14, the counter - divider 15 into three, the switch 16 signals: chrominance and element And 17.; The device works as follows.

The detector 2 converts the optical {signal from the screen of the index color | CRT 1 into an electrical signal, the parameter of which (phase and period) is determined by the position of the beam on the screen. The received signal is fed to the inputs of indicators 4 and 5 zero, and to: the input of the first indicator 4, zero. The signal is fed through phase shifter 3, carrying out the phase shift of the index signal, and to the input of the second indicator 5 - directly. At the outputs of indicators 4 and 5 zero, square-wave pulses are formed, the duration of which is determined by the moments when the signals reach the zero level, i.e. equal to the duration of the positive part of the pulse signal at the input of the indicator zero. In this case, the pulses at the same outputs of the .4 and 5 zero indicators have an equal duration, but are phase shifted by an amount determined by the parameters of the phase shifter 3.

From the outputs of indicators 4 and 5, the signals arrive at the inputs of the expanders of 6–9 pulses, which carry out an adjustable proportional conversion of the duration of the pulses formed at the outputs of the indicator 30

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The accuracy of the coincidence of the cross section of the elements of the screen of the appearance of control impulses is brought about by adjusting the proportionality of the pulse duration to 6–9. Since, when the sweep changes, and traces of the velocity of movement, the beam

25, the proportionality of the signal at the zero color separation quality varies; basically, the accuracy of the combination of intersection of the elements and the instants of the control of pulses does not deteriorate.

Formed after control pulses, the counting input of the counter-divisors is three, the outputs of which are pulses of the control 16 in the sequentially divided alternation of colors on the index color screen Because for color TV it is enough to use color phosphors, then to divide the counter 15 by selecting On the output switches the sequence of signals corresponding to the alternation of phosphors with colors on the screen, index CRT 1,,

From switch 1 output

50 sequence of the element 17 arrival; on the second one, sequences are fed from the output of element 14. element 17 and are formed

55 duration and amplitude are made by the character of the video in the sequence of the screen element. Since impu

40

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, a bunch of screen elements.

0

0

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The accuracy of coincidence of the moments of intersection of the screen elements and the moments of occurrence of control pulses is set by adjusting the proportionality ratio of the pulse width conversion by the expanders 6-9. Since when changing the linearity of the sweep, and consequently, the speed of movement, the beam on the screen

5 varies in proportion to the duration of the signal at zero, the quality of separations, determined mainly by the coincidence accuracy of the moments of intersection of the screen elements and the moments of occurrence of control pulses, does not deteriorate.

The generated sequence of control pulses is fed to the counting input of the counter-divider 15 by three, the outputs of which form control pulses by the switch 16 in a sequence determined by alternating color bars on the screen of the color CRT 1. It is enough to use three color phosphors for color TV images , the division factor of the counter 15 is equal to three. At the output of the switch 1.6, a sequence of video signals is formed, corresponding to the order of alternating the luminous moat primary colors on the index color CRT screen 1,

From the switch output 16 is indicated

0, the sequence is fed to the input of the element 17, to the second input of which a sequence of pulses is fed from the output of the element 14. At the output of the element 17, pulses are generated,

5, the duration and amplitude of which are determined by the nature of the video signal and the order of alternation of the elements of the screen structure. Since the pulses are after 0

five

Since the output element OR 14 has a shorter duration. Determining the quality of color separation, then the output element AND 17 pulses correspond to the requirements for color separation, and their amplitude corresponds to the content of the video signal.

Claims (1)

Invention Formula Color image reproduction device according to autor. No. 1210235, characterized in that, in order to increase the image quality by increasing the brightness and con trust, between the second output of the second zero indicator and the control inputs of the chroma switch, the fourth connected pulse expander, the fourth driver of the control pulses, the OR element and the divider counter by three are entered, the OR element output and the chroma switch output through the input element And they are connected to the control input of an index color cathode ray tube, and the second, third and fourth inputs of the OR element are connected respectively to the outputs of the first, second third control pulse shapers constituents.