SU711501A1 - Arrangement for shaping circles on crt screen - Google Patents

Description

The invention relates to the field of automation and computer technology and is intended for use in information display devices.

Devices are known for rendering images on a CRT screen by forming a set of simplest elements such as circles, ellipses and their arcs 1.

However, the known devices, in connection with a limited number of types of the simplest elements indicated, do not allow the formation of complex, half-tone images.

It is known a device comprising a sine-cosine generator connected to the control unit, blocks of deflection of the beam in X and Y coordinates, combined with a CRT, the corresponding code lines of the origin of coordinates X and Y 2.1.

A disadvantage of the known device is the inconsistency of the luminance of the CRT of circles of various radii on the CRT screen. In addition, the device does not allow the formation of a complex halftone image.

The purpose of the invention is to improve the quality of the device.

To do this, a summing amplifier, a comparison unit, a digital-to-analog converter, two multiplying units, a sawtooth generator, the input of which is connected to the output of the control unit, and an output with the first inputs of the multiplying units; the first input of the summing amplifier, the other inputs of which are connected to the comparison unit and digital-to-analog converters connected to the input bus, with the other inputs of the multiplying units connected s are sine-cosine generator, and the outputs are to the blocks..beam deflection along the coordinates X and Y the output of the summing amplifier is connected to the modulator of the cathode-ray tube.

The ha figure shows a structural electrical circuit of the proposed device.

five

The device for forming circles on the screen of a CRT contains a control box 1 connected to a sinus-sinus generator 2 and a sawtooth generator 3.

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the outputs of the sine-cosine generator 2 are connected respectively to the first inputs of the multiplying blocks 4, 5, the second inputs of which are connected to the sawtooth generator Zo The same output of the latter is connected to the comparison unit 6 and the summing amplifier 7 connected to the comparison block b, digital-analog converter 10 and through a modulator 8 with a CRT 9. The outputs of the multiplying blocks 4, -5 are connected respectively to the blocks 11, 12 of the deflection of the beam along the X and Y coordinates, connected to the CRT 9 and the code bus 14, 13, the origin of the X and Y. radius 15 is connected to the comparing unit 6, and the coded luminance tire 16 - with tsifrranalogovym converter 10,

The device works as follows. .

. The device forms on the screen of a CRT a complex halftone image of circles with; arbitrary radii R, coordinates X and Y of the center and brightness 5. In each cycle of accessing the device, the codes R, Xf Y,: the formed circle are received, respectively, by code 15, 14, 13, 16 on the comparison block b, the deviation blocks 11, 12 by coordinates l and y, to a digital-to-analog converter 10. By means of deflection blocks 11, 12, the beam is set. on the CRT screen to the starting point with coordinates X, At the center of the circle, which is displayed by the modulator 8 with the brightness Y-, At the same time, the control unit 1 starts the sawtooth generator 3 and the sine-cosine generator 2. The signals from the outputs of the latter arrive at the inputs of the multiplying blocks 4, 5, at the outputs of which, respectively, sine wave and cosine wave signals with linearly increasing amplitudes are formed. These signals through blocks 11, 12 of the beam deflection in coordinates l. and Y provide a spiral sweep of the beam from the starting point, (x, Y) Compensation of unevenness of the brightness resulting from the difference in length (g 2Lg) g 1,2, ..., iR) of the circles is accomplished by adding voltage, proportional to g, from the generator / sawtooth voltage 3 to one; the input of summing amplifier 7, to the second input of which a voltage is applied is proportional to a given code U of luminance.

the radius of the formed circle, the value of R, the comparison unit 6 generates a signal that turns off the output of summing amplifier 7 from the modulator. Thereby, the formation of the next circle and on the code lines 13, -14, 15, 16 is completed on the screen. The CRT of the next element is received.

The introduction of a luminance code bus, a comparison block, a digital-to-analog converter converter, two multiplication blocks, and a sawtooth voltage generator allow the formation of complex half-tone images from elements — circles that extend the functionality of the device. The introduction of the summing amplifier and the corresponding links ensures the constancy of a given brightness of the circles that make up the image.

Claims (2)

1. USSR author's certificate №440664, cl. G 06 F 3/14, 1973. 2. USSR author's certificate No. 417783, cl. G 06 P 3/14, 1972 (prototype). shh. sixteen