SU1672519A1 - Unit to display data on projectorъs screen - Google Patents

Abstract

The invention relates to automation and computing and can be used in automated control systems and shared systems. The aim of the invention is to improve the quality of the display of information by aligning the brightness across the entire field of the projection screen without degrading the resolution. The goal is achieved by the fact that in a device for displaying information on a projection screen containing channels 1, 2 of information, focusing elements 3, 4, screen 5, each channel 1, 2 consists of a CRT 6, two coordinate amplifiers 7, 8, two displacement voltage formers 9, 10, sign amplifier 11, image luminance correction unit 12 with necessary connections. Additionally, the rectifier 13, the multiplier 14, the first and second drivers 15, 16 pulses with the necessary connections are introduced into each channel 1, 2. The introduced blocks allow a stable speed of moving the beam across the screen and changing the accelerating voltage on the accelerating electrode 21 of the CRT according to a predetermined law by means of the amplifier 11 and the multiplier 14. 8 Il.

Description

The invention relates to automation and computing and can be used in automated control systems and shared systems.

The aim of the invention is to improve the quality of the display of information by aligning the brightness across the entire field of the projection screen without degrading the resolution

FIG. 1 shows a structural diagram of the device, FIG. 2 shows the graphs of the brightness of the Bi 62 on the projection crane versus the beam deflection angle, respectively, for ELT1 and ELT2, FIG. 3 is a diagram of the coordinate amplifier, FIG. 4 is a diagram of the bias voltage driver, FIG. multiplier circuit, FIG. 6 - block diagram

Correction Correction, Fig. 7 is a schematic of a sign amplifier, Fig. 8 is a circuit of a pulse shaper.

The device contains information display channels 1 2, focusing elements 3, 4, screen 5 Each information display channel 1, 2 contains a cathode-ray tube 6, the first coordinate amplifier 7, the second coordinate amplifier 8, the first driver 9 of the bias voltage, the second driver 10 bias voltage, sign amplifier 11, image luminance correction unit 12, rectifier 13, multiplier 14, first pulse shaper 15 second pulse shaper 16 first information input 17 of the device

About vj

YU

the next

This information flow U ugtroisg pa the first information input 1v5 multiplier 14, the second information flow 20 multiplier 14, the accelerating electrode 21 EL1 the first and second inputs 22. 23 rectifier ((l, the first and second inputs 24, 25 amplifiers 11 , the second input 26 of the first coordinate amplifier 7. the second input 27 of the pgory coordinate amplifier 8, the coordinate coils 28 of the CRT,

Coordinate amplifiers 7 and 8 are designed to convert input coordinate voltages into deflection coil currents 28. In FIG. 3 shows an example of one of such amplifiers, for example X. It consists of a preliminary differential amplifier 29, at the expense of using resistors 30 and 31, the signals are compressed, r-in shikkmm 17 and 26, and the output amplifier 32 sec p , by the way of reverse communication 33. The current from the count LR, the mountain of fizizgor, enters the 01 slope of the y-i u i; cannon 28.

The PP interconnection and 10 (Fig. 4) are intended to convert the constant power supply EP into a higher baked voltage and can be performed, for example, according to a push-pull scheme that converts the input voltage Ep into a high voltage of high amplitude. The formers 9 and 10 consist of the same type of transistors 34 and 35, resistors 36 and 37, capacitor 38, which increases the transform mount 39, which has primary windings 39a and 396, windings 39h v. 39g reverse Cijucn and output winding 39e.

The YMI voltage energizer 14 is designed to rectify a high-voltage impedance voltage coming from the driver 9, and also to increase the nominal value of the high voltage received. The multiplier 14 can be performed according to the scheme depicted in flash. 5. It consists of a multiplication unit 40, a filter resistor 41 and a filter capacitor 42, a resistor 43. The input buses 19 and 20 of the multiplier 14 are connected to the corresponding output buses 19 and 20 of the voltage driver 9. The high voltage Ui is removed from the resistor 43 to the electrode 21, and this voltage is dissipated in DC voltage from the common bus and for it to stabilize, it is necessary that the current flowing through the resistor 43 be significantly greater than the load current flowing to the electrode 21. A load influx of the order of 1 μA, the current through the resistor 43 is set on the order of 20 μA.

The luminance correction unit 12 serves to generate a dynamic luminance signal Id. the control value of the high voltage applied to the / speeding electrode 21 of the CRT depending on the amount of deviation of the electron beam from the center of the screen

Such a signal can be a signal

five

0

the proportional values are (Ux ± С) 4- Uy, where Ux and Uy are deflection signals at X and Y coordinates, respectively, and C is the voltage equivalent to the lens offset relative to the center of the CRT screen. The ± sign indicates that the lens is shifted right or left along the X axis. For channel 1 CRTs, C is positive, and channel 2’s CRT is negative.

An example of the performance of the luminance correction unit 12 is shown in the ne figure. 6. It contains the first adder 14, the voltage divider 45, squares 46 and 47, the second adder 48 and the calculator 49 square root

It should be noted that depending on the typeЈ | The CRT luminance correction unit 12 can realize other, more complex, functional dependences of the dynamic luminance signal on the deflection signals Ux AND Uy.

Rectifier 13 serves to rectify high voltage voltage pulses from voltage generator 10 and may consist of a diode bridge and an RC filter. The rectified voltage Ua is fed to the input 24 and is intended to power the amplifier 11.

The amplifier 11 is designed to amplify the dynamic luminance signal and may consist, for example, (see FIG. 7) of the operational amplifier-inverter 50, the operational amplifier 51, the transistor 52, resistors 53-58. The input 24 is supplied with the power supply voltage of the amplifier U2, and the input 25 is supplied with a dynamic luminance signal which is inverted at the amplifier 50. To provide a positive voltage at the output of the operational amplifier 50, the ECM is fed to the non-inverted input. The output signal at input 19 is determined by the expression rb R54

- K (Uflqmax id),

where and the coefficient depending on the slider of the resistor 58 can be selected from 0 to 1; 5Rg3

K - a. - - gain coefficient usik54

letter;

Ud max - the maximum value Od determined by the screen dimensions:

0

five

0

five

U2 U2

a (bw max - id) - U2

id the current value of the dynamic luminance signal.

Thus, with a minimum id at the input 25 of the amplifier 11 at the output 19 will be the minimum Uz1. since the transistor 52 is open as much as possible, and for Od, max U2 is also as close as possible to 1/2.

Shapers 15 and 16 pulses serve to correct the accuracy of the coordinate amplifiers 7, 8, the need for which is caused by a change in the magnitude of the accelerating voltage. When the accelerating voltage is changed, the deviation (sensitivity) on the screen changes linearly, and with increasing accelerating voltage, the sensitivity decreases, i.e. it is necessary to increase the voltage at the input of the amplifier to maintain accuracy.

FIG. Figure 8 shows a diagram of one of the options for compensating for the sensitivity of a deviation, taking into account that the accelerating voltage varies. This role is played by the formers 15, 16, which consist of an opamp 59 and resistors 60-62. determining the mode of operation of the amplifiers 7, 8. Rotate the slider of the resistor 61 in one direction or the other, you can change the gain (slope) and phase at the output 26, 27 of the formers 15 and 16.

The device works as follows.

The coordinate voltage levels Ux and Uy are fed to inputs 17 and 18 from an external device (external device not shown) and then to the first inputs of amplifiers 7 and 8, as well as to the first and second inputs of the luminance correction unit 12, which generates a dynamic signal luminance supplied to the second input 25 of the amplifier 11, the first input 24 of which is supplied with the supply voltage U2. produced by the second driver 10 and the rectifier 13 voltage. From the output of amplifier 11, a voltage U2, proportional to the luminance correction signal, is added to the voltage Ui, which is obtained after the driver 9 and multiplier 14, and is applied to the accelerating electrode 21 of the CRT.

Simultaneously, from the second output of the brightness correction unit 12, the voltage Ux ± C, and from the input 18, the voltage Uy, through the corresponding drivers 15 and 16, arrive at the second inputs of the coordinate amplifiers 7, 8 in the form of correction signals, where they are added to the voltage Ux and Uy entering their first entrances. Amplifiers 7 and 8 convert analog voltages into currents that flow into the deflection coil 28 of the CRT. magnetic field which

sets the beam to a given point of ecl. where the writing of signographic information (character generator and other nodes) in the drawing (not shown) occurs.

5If the electron beam is in the center of the CRT screen, i.e. when Ux Uy is 0, the dynamic luminance signal will be equal to the voltage value C, which is equivalent to the magnitude of the lens offset along the X axis (along the axis

0 Y lens does not shift).

The voltage on the accelerating electrode is the sum of two voltages (see FIG.

one)

Uy ul + u2 ul + u2 k (idyatah-id),

5 where Ui is the high voltage taken from the output of the voltage multiplier 14, which is DC-coupled from the common bus of zero potential;

U2 is the supply voltage of the amplifier 11, 0 taken from the output of the rectifier 13;

U2 is the output voltage of amplifier 11:

id - dynamic luminance signal from luminance correction unit 12; 5K - coefficient of the amplifier 11;

id max is the maximum value of the dynamic luminance signal determined by the screen size.

Thus, if the electron beam is in the center of the screen, the expression K (id max - id) tends to U2, since id C, which is much less

id max.

Consequently, a voltage Ui will be applied to the accelerating electrode - 5th genus 21 of the CRT. When the beam is disconnected from the center of the screen, the luminance correction unit 12 generates a signal that corrects the accelerating voltage (its increase occurs, 0 proportional to the dynamic luminance signal id). By adjusting the gain of the amplifier 11, a uniform electron beam is achieved throughout the entire field of the screen.

5To maintain accuracy (sensitivity) of the deviation with an increase in the accelerating voltage, the drivers 15 and 16 produce increments that are proportional to the deflection signals, which are added to the main signals Ux and Uy at the input of amplifiers 7 and 8, respectively. The second channel 2 works in the same way. Images from CRT 6 screens of channel 1 and CRT 6 of channel 2 are projected through lenses onto a common screen 5, where the image of one CRT is superimposed on another CRT image.

Claims (1)

Apparatus of the Invention A device for displaying information on a projection screen, comprising x information displays on electron beam tubes (CRT), the screens of which are connected to a projection screen through the focusing elements, and each information display channel on a CRT contains the first and second coordinate amplifiers, the first and second bias voltage drivers, the sign amplifier and an image luminance correction unit, the first and second information inputs of which are the first and second information inputs of the device, respectively, connected to the first information inputs of the first and second coordinates Input amplifiers whose outputs are connected to the coordinate coils of a CRT, the first output of the luminance correction unit is connected to the first information input of a sign amplifier, characterized in that, in order to improve the quality of the displayed information by equalizing the brightness across the entire field of the projection screen without degrading the resolution, each channel display information on The CRT contains a rectifier, a multiplier i, the first and second pulse shapers; the information input of the first pulse shaper is connected to the second pulse generator. During the luminance correction block, the information input of the second pulse body is connected to the second information input of the device, the first and second pulse shaper output The coils are connected to the second information inputs of the first and second coordinate amplifiers, respectively, the output of the second bias driver for the keys to the rectifier input, the output of which is connected to the second information input of the sign amplifier, the output of which is connected to the first information input of the multiplier connected to the first output of the first the bias voltage driver, the second output of which is connected to the second information input of the multiplier, the output of which is connected to the accelerating electrode of the CRT. I FIG L nineteen FIG. five 24 59 FIG. 7 27 15