SU1492379A1 - Crt line scanner - Google Patents

Abstract

The invention relates to automation and computing and can be used to create devices displaying sign and graphic information on a screen of a cathode ray tube (CRT) with magnetic beam deflection. The purpose of the invention is to expand the field of application of the device due to the possibility of forming a CRT scanner in the form of a continuous curve - achieved by introducing the first block 2 and the second block 4 of the elements AND, the pulse generator 3, the functional converter 5, the adder 6 and the corresponding functional connections. The invention allows organizing the output of information in a two-frame mode, with the device operating during one frame similar to the widespread television line scanner, and during the second frame the device operates in the linear amplifier mode of the beam deflection signal horizontally, which allows to organize high-quality graphical display information and expand the scope of the device. 2 Il.

Description

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The invention relates to automation and computing and can be used to create devices displaying sign and graphic information on a screen of a cathode ray tube (CRT) with magnetic beam deflection.

The purpose of the invention is to expand the field of application of the device due to the possibility of forming a CRT scanner in the form of a continuous curve.

FIG. 1 shows a functional diagram of the device; in fig. 2- amplifier output stage with a lowercase CRT coil; in fig. 3 - time diagram.

. The device contains a sawtooth voltage generator 1 (sweep), the first block 2 of the elements And, the generator of 3 pulses, the second block of 4 elements And, the functional converter 5, which is a differentiating chain, the adder 6, the amplifier 7, the output 8 of the device for connecting to the deviating CRT system (not shown).

The output stage of the amplifier 7 contains a powerful transistor 9, a diode 10 connected to a lowercase coil 11 CRT, and a capacitor 12.

The voltage control Vf is fed to the base of the transistor 9. The positions 13 and 14 denote the synchronous input and the information input of the device, respectively.

The device works as follows.

During the output of digital information during the formation of one frame, the device operates in the standard horizontal scanning generator, generator 1 generates voltage pulses U (Fig. 3) passing through the normally open block 4 of elements And, the adder 6 to the input of amplifier 7, and the opening transistor 9.

The collector current 1c (Fig. 3) of the transistor 9 changes in this case according to a linear law.

The current Iq (FIG. 3) of diode 10 also varies linearly. The sum of the currents Ij and 1c determines the linearly varying horizontal current

The time interval t coincides with the time interval of the reverse frame sweep, during which the electron beam is influenced by the frame deflection system linearly

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five

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in time it moves across the screen from top to bottom. Therefore, on the right side of the CRT screen, the oscillogram of the displayed Graphics is periodically (at a frame rate) displayed, with the x-axis being directed vertically from bottom to top.

When the to interval ends at time t, the next frame of image 1 of the digital information starts forming. When the frame of the image of digital information is formed, at the moment of beginning of the formation of graphic information, the sync pulse from input 13 enters the input of the first block 2 of the elements And as a result the generator of 3 pulses to starts at the time t (Fig. 3) (Fig .3) the duration of the half-frame of the image of graphic information. During this time interval, the second block of 4 elements is both locked and the differentiated analog signal of the output of the displayed graph is fed to the second input of the adder 6:

and pu,

where U) j, and - signals respectively at the output and input of the block

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p is the Laplace parameter. In this case, the amplifier 7 operates in the linear amplifier mode, the diode 10 is locked. Then the current Ij of the horizontal coil of the deflecting system is determined by the expression

ki,

ki, l

five

0

five

where K is the total gain of the amplifier 7 and the adder 6; L - inductance of small coils.

Thus, the current Ij is proportional to the signal and the sweep of the graph displayed on the screen.

The positive effect of the proposed image is the expansion of the area of application of the device due to the possibility of forming a CRT scanner in the form of a continuous curve, which improves the quality of the displayed graphic information by replacing the point representation of the graphs on the screen of common display devices by representing them in the form of continuous5

lines, as well as the possibility of the proposed device in information display devices that are interfaced with a low-cost computer without the use of expensive software and hardware, providing the ability to display alphanumeric and graphic information.

In particular, when using the proposed device in computer systems, the required amount of RAM for storing graphic information is determined by the number of dLR-ratios and is 128-256 bytes.

Claims (1)

Invention Formula A device for forming a horizontal scan of a cathode ray tube (CRT), comprising a sawtooth generator and an amplifier, the output of which is the output of the device for connection to a CRT deflection system, : iK Aiy if  4 j ten 2 923796 This is why, in order to expand the region 11rim (M1ria due to the possibility of forming a scrolling in the form of a continuous curve, it contains the first block of AND elements, the generator of pulses, the second block of elements AND, the functional converter and adder, the output of the general IQ the torus sawtooth voltage is connected to the first input of the first block of elements And, the second input of which is a synchronous input device, the output of the first block of elements And c is connected to the input of the pulse generator, the output of which is connected to the first input of the second block of elements And, the second input of which is connected to the output of the sawtooth generator, the output of the second block of elements And is connected to the first input of the adder, the second input of which is connected to the output of the functional converter, pass which was connected to the input of the device, and the output of the adder is connected to the input of the amplifier. 20