SU890434A1 - Symbol generator - Google Patents

Description

one

The invention relates to automation and computer technology and can be used to generate symbols and other image elements in equipment displaying information on a screen of electron beam tubes (CRT).

Known sign generators, made on the basis of specialized CRT type monoscope and matrix. In a monoscope there is a target, which consists of a substrate, carrying in itself in the form of certain characters a material with a high secondary emission coefficient. The electron beam envelops the target area of the monoscope corresponding to the selected sign. Due to the difference in the secondary electron emission coefficients of the substrate, a signal is obtained from the sign material, which is sent to the backlight circuit of the reproducing CRT, the scan of which is synchronized with the monoscope scan. In the matrix there is one matrix — a target consisting of several conductive elements, isolated from each other and attached to a dielectric. By switching the required elements of the matrix, it is possible to obtain as a result of scanning the electron beam at the target a light signal corresponding to the selected l character.

The disadvantage of these devices lies in the low information capacity, since with a large number of isolated sections of the intersection of conductors, interference occurs during the reproduction of the sign and the impossibility of changing the set of reproduced signs.

The closest technical solution to the proposed one is a functional converter on a CRT, which uses a CRT with 15 insulated signal electrodes carried on the outside of the screen, made in the form of graphs of reproducible functions. Signal electrodes through keys controlled

20 of the outputs of the code converter, are connected to the input of the amplifier, the output of which is connected to the 6th input of the phase detector. The second input of the phase detector is connected to the output of a search oscillation generator, which is also connected to a CRT vertical deflection system. Search oscillation generator, phase detector and continuous integrator

30 extreme trace system

designed to keep the electron beam at the level of the desired signal electrode. The code of the electrode number is fed to the input of the code converter, the output of which opens the corresponding key, and the electrode is connected to the output of the device. The beam knocks out secondary electrons from the phosphor, and since the coefficient of secondary emission of the screen material is greater than unity, the region under the influence of the electron beam is charged to a positive potential. The charged spot under the action of the generator signals makes periodic search fluctuations. A signal is induced on the selected electrode, the phase of which changes to the opposite, depending on whether a charged spot is above or below the electrode. At the output of the phase detector, this changes the sign of the voltage, which, after integration, enters the CRT vertical deflection system 2}.

A disadvantage of the known device is the low repetition rate of the reproduced functions and the impossibility of reproducing functions having a slope to the horizontal axis that is close to the direct one. For stable operation of the device, it is necessary that the frequency of search fluctuations be approximately three orders of magnitude higher than the frequency of repetition of functions. The signal induced on the electrodes decreases with an increase in the frequency of search oscillations, due to the fact that the charged area of the screen does not have time to discharge by the time the beam re-passes through this area. The induced signal also falls as the angle of inclination of the electrode to the horizontal axis increases.

The purpose of the invention is to increase the speed and the expansion of the class of reproduced information.

The goal is achieved by the fact that a character generator containing a cathode-ray tube (CRT) with screened signal electrodes, which are connected to the information inputs of keys, the control inputs of which are connected to the outputs of the code converter, and the outputs to the inputs of the amplifier, the extremum selection unit and trigger, two sawtooth voltage generators are introduced, the outputs of which are connected to the horizontal and vertical deflection systems of the CRT, respectively, the start inputs of which are connected to the bus pulse A playback depression associated with a counting trigger input whose outputs are connected to one of the code converter inputs and to the control frequency inputs of oscillators.

the sawtooth voltage, another input of the code converter is connected to the character code bus, and the amplifier output is connected to the input of the extremum extraction unit, the output of which is the output of the character generator.

Fig, 1 shows a structural scheme of the character generator; in fig. 2 - timing charts of the signals at the outputs of the sawtooth voltage generators and the trigger.

The symbol generator contains CRTs with signaling electrodes 2, which are connected to the amplifier 4 through keys 3. Control 2. The inputs of the keys 3 are connected to the transducer outputs 5 codes, one of the inputs of which is connected to the output of trigger 6, the counting input of which is connected to the inputs start generators 7 and 8 sawtooth voltage, the outputs of which are connected respectively to the horizontal 9 and vertical 10 deflection systems. The output of amplifier 4 is connected to an extremum extraction unit 11, which is connected via a backlight pulse shaper 12 to a CRT modulator of an information display device.

The device works as follows.

The sign code (played) on the sign code bus 13 arrives at the input of the code converter 5, and the trigger b goes to the unit state n1 via the signal on the playback resolution bus 14 (Fig. 2, 15a). The same signal triggers the generators 7 and 8, and under the action of the control signals of the trigger, first the generator 8 produces a high-frequency signal (Fig. 2, 15 a), the period of which is an order of magnitude shorter than the order of oscillation of the generator 7 (Fig. 2, 15 V) . Under the action of signals from generators 7 and 8, the beam of a CRT 1 makes periodic oscillations along the vertical axis, and at the same time slowly shifts along the horizontal axis. Synchronously with it, the position of the CRT beam in the display device. The converter 5 converts a multi-bit word consisting of a sign code and a code the state of the trigger 6 to the output signals, opening the keys 3. At the same time, those keys 3 are opened, which are connected to electrodes 2, corresponding to the elements of the sign that have an angle of inclination to the horizontal axis not higher than 45. At the moment luminant a charged spot is at the level of the selected electrode, induced at the electrode signal has a maximum. This signal through the public key is fed to the input of the amplifier 4, from which it is then fed to the input of the extremum extraction unit 11, which can be made as a differentiator and a comparator,

at the output of which a potential jump is formed at the moment when the signal reaches an extreme value. Block 10 generates a pulse of illumination from this jump, which arrives at a CRT modulator of a display device, on the screen of which bright labels are formed at the points corresponding to the intersection of the beam with the selected electrodes Nos. After the reproduction of the parts of the mark that have an angle of inclination to the horizontal axis less than 45 °, the trigger 6 switches to the zero state according to the control signal from the display device. This changes the output code of the converter 5, and electrodes having a tilt angle to the horizontal axis greater than 45 are connected to the amplifier input. At the same time, under the control signals of the trigger 6, the frequencies of the generators are changed so that the generator 7 generates high-frequency oscillations and the generator 8 produces low-frequency . As a result, new sections of the mark are reproduced and the formation of the mark on the CRT screen of the display device is completed.

In the proposed device, due to the separate reproduction of the elements of the sign, having tilt angles greater than and less than 45 °, there is no restriction on the steepness of the reproduced functions due to the successive passage of various screen sections by the beam, the signal associated with the screen charge does not decrease, and by applying signal electrodes on a removable two-layer mask, which is reinforced on the screen, provides quick replacement of reproducible signs.

H systems eo /} azonta / and / oga and ver / ggi / ha / /nogo ominom

Claims (2)

1. Basics of building display equipment in automated systems. Ed. AND I. Breitbart 5 tbsp. I.N. Litvak, B.F. Lomov, N.E. Soloveychik. M., Soviet Radio, 1975, p. 161. 2. Authors certificate of the USSR 267195, cl. C, G 7/26 1969 (prototype). 0 ZLG