SU798790A1 - Device for displaying graphic information on crt screen - Google Patents

Description

frame and frame sweeps connected to the deflection system of the cathode ray tube, which is connected to the video driver 2.

However, this signal mapping as a series of points is a significant disadvantage of this and other lime devices. The signals of random form with steep edges are displayed in them as separate points, which makes it difficult to observe the signal and degrades the image quality.

The purpose of the invention is to improve image clarity.

This goal is achieved by introducing a second comparison circuit, two OR elements, a one-shot, an exclusive OR element, and a second register connected to the synchronization unit, the first register, and a second comparison circuit connected to the counter, the first comparison scheme, and an exclusive OR element. connected to the first OR element, connected to the Video Shaper and the one-shot connected to the second OR element connected to two comparison circuits.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 image formation process.

The device contains receiving registers 1 and 2, circuits 3 and 4 comparing counter 5, generator 6 clock pulses, element exclusive OR 7, first element OR 8, one-shot 9, second element OR 10, driver 11 video signal, CRT 12, generator 13 horizontal scan (GSR generator 14 frame scan (GKR and block 15 synchronization.

On the register information entry

InocTynaieT is the code of the displayed signal, the output of register 1 is connected to the first input of the comparison circuit 3 and to the information input of the register 2. The output of the register 2 is connected to the first input of the comparison circuit 4. The input of the counter 5 of the position of the beam in the row is connected to the output of the clock generator 6, and the output of the counter to the second inputs of the circuits 3 and 4 of the comparison. The outputs of the comparison circuits 3 and 4 are connected to the inputs of the exclusive OR element 7 and also to the inputs of the element OR 8. The output of the element 8 is connected to the input of the one-vibrator 9, the output of which is connected to one input of the element OR 10, and to the second input of this element - the output of the exclusive element OR 7. The output element OR 10 is connected to the input of the imaging unit 11 of the video signal, and the output of the imaging unit

II- to the CRT modulator 12. The outputs of the horizontal 13 and frame 14 sweepers are connected to the CRT deflection system 12. The outputs of the synchronization unit 15 are connected to the clock inputs of registers 1 and 2 of the clock generator 6, counter 5, generators 13 and 14. Synchronization unit controlled by external signals

The device works as follows.

With each display clock, synchronization unit 15 generates pulses that trigger generator 13, clock generator 6 and counter 5. In addition, the current value of the displayed code D, is placed in the first receiving register 1, and the previous code value from the first receiving register 1, where it was in the preceding display cycle, transmitted to the second reception register 2. Codes D and go to comparison circuits 3 and 4, respectively. The second inputs of these circuits receive the position code of the beam in row a from counter 5. At the beginning of the display cycle d O.

Circuits 3 and 4 are built in such a way that the signals at their outputs are 1 if d 5-DI I or d xD Denote the output signals of circuits 3 and 4 by K and K ,. Therefore, K 1 at, and K 1 at) -. The exclusive OR element 7 generates a signal when K i. Thus, the signal at its output appears only in the interval (; D. or (D, -;. D), depending on which value or D is greater. For each the value of d corresponds to a certain position of the beam in the row (signal amplitude), the signal at the output of the element exclusive OR 7 operates only in the interval (l) -;.

From the output of the element, the exclusive OR 7 signal is fed through the second element OR 10 to the video signal shaper 11, and the video signal from its output is fed to the CRT modulator 12, illuminating the part between the D.J and D values. This is how the image of a rising or falling signal is formed. At D D., the signals at the outputs of the circuits 3 and 4 of the comparison appear almost simultaneously (B

 dr) and the K 4 K state is not

occurs, which causes the image to disappear. This case corresponds to the horizontal section on the graph of the displayed signal. To prevent these areas from falling out of the image, the device includes the first element OR 8, the one-shot 9, the second element OR 10.

Claims (2)

When in this case, the counter 5 reaches the smaller of the D or D values from the output of the corresponding comparison circuit 3 or 4 through the first element OR 8, the signal enters the one-oscillator 9, which produces a pulse with a duration of one period of the frequency of the generator 6 clock pulses ticked). This pulse through the second element OR 10, regardless of the signal of the exclusive OR element 7, enters the video signal shaper 11 giving the illumination of a point on the screen of the CRT 12. If the exclusive OR element also produces a signal (K f K), then this pulse will be nested in the interval (; .) and will not be overlaid on the screen. The synchronization unit 15 stops the counter 5 at the end of the forward stroke of the line and resets it to zero until the beginning of the new cycle (line). The frequency of the clock pulses of the generator 6 is chosen from the relation "N where N is the size of the displayed code; line sweep time. The pulse duration of the one-shot horizontal sweep for the period of the line should be AXid, where o1d is the beam diameter. At the same time, the junction point of two adjacent image segments is partially overlapped by the scanning beam and the seam is not very noticeable. The figure in FIG. 2. Thus, the proposed device makes it possible to form an image on the screen of a CRT in the form of a continuous line with very insignificant elemental costs, which allows using such devices even in small systems. Additional advantages of the device to be provided are the possibility of simply increasing the number of channels by switching on a parallel required number of devices (some of the nodes are used in all channels) and low requirements for the speed of the circuits. In the device, the thickness of the beam is greater than the distance between the rows. Due to this, the junction points of the segments overlap and the steps in the signal image are almost imperceptible. An apparatus for displaying graphic information on a screen of a cathode ray tube comprising a synchronization unit connected to a first receiving register connected to the first comparison circuit, a clock generator, a counter connected to the first comparison circuit and a clock generator, and horizontal and frame scan generators connected to the deflection system of the electron-beam tube, which is connected to the video signal conditioner, characterized in that, in order to improve the image bones, the second comparison scheme, two OR elements, one-shot, exclusive OR element and the second register connected to the synchronization unit, the first register and the second comparison scheme connected to the counter, the first comparison scheme and the exclusive OR element connected to the first OR element connected to the video signal conditioner and the one-shot connected to the second OR element connected to two comparison circuits. Sources of information taken into account in the examination 1. Oscilloscope with digital memory mod 5480 A, the prospectus of the United States. 2. Domratsky A.N. and others. Multipurpose statistical analysis of random signals. Novosibirsk, Science, 1975, p. 146-149 (prototype). V7 " oj