SU543203A1 - Device for dynamic focusing of a beam of a cathode ray tube - Google Patents

Description

one

The invention relates to television technology.

A device containing a matrix circuit, the outputs of which are connected to transistor cascades, key circuits, is known.

A device containing a pulse transformer, a current generator, made by a bridge circuit of a radial-circular sweep, and a current driver, made on two logarithmic elements.

These devices are not characterized by a high quality of dynamic focusing.

In addition, a device is known for dynamically focusing a beam of a cathode ray tube containing a focusing system, a deflecting system along a line with a feedback resistor included in its circuit and a deflecting system over a frame with a feedback resistor included in its chain.

However, this device does not provide accurate focusing of the beam but the entire zero of the CRT image of the CRT.

In order to increase the beam focusing accuracy over the entire field of the CRT image, a sequentially switched on frame accumulator, a matching amplifier and a terminal adder connected to the focusing input are introduced into the proposed device.

2

systems, and two identical channels, each of which is connected between the feedback resistor and the corresponding input of the frame adder, with each channel

consists of an analog-code converter, connected by an input to a feedback resistor, and each of the two direct and reverse code outputs of this converter is connected through a series-connected matching stage, a code-analog converter, a step-exponential voltage driver, and a limiter amplifier to the first and second input of the adder of coordinates, the output of which is connected to one of the inputs of the frame adder.

Cherchelch shows the structural electrical circuit of the proposed device.

A device for dynamic focusing of a CRT beam contains a focusing system

1, to the input of which there are connected a series-connected adder 2, a frame, a matching amplifier 3 and an end adder 4, a deflecting system 5 along a line with a feedback resistor 6 connected in its circuit,

a deflecting system 7 and a frame with a feedback resistor 8 connected in its circuit, two identical channels, each of which is connected between a corresponding resistor 6, 8 and a corresponding adder input

frames, iri this each of the channels consists

from the converter 9 analog-code connected by the input to the corresponding resistor 6 (8), and each of the two outputs of the direct and reverse code converter 9 is connected through a series-connected matching stage 10, converter code-analog 11, driver 12 steps exponentially voltage and the amplifier-limiter 13, respectively, to the first and second inputs of the adder 14 coordinates, the output of which is connected to one of the inputs of the frame adder.

The device works as follows.

During operation, the device generates an additional parabolic step signal over the entire field of the frame, which is superimposed on the constant component of the focusing signal. Transducers 9 and 11 form the additional signal by decomposing the line into n elements, where each element of the expansion of the line corresponds to its frame, and each line to its own code.

The signals taken from the resistors 6, 8 are fed to the transducers 9, which issue both forward and reverse codes for the bits supplied through the matching stages 10 to the inputs of the transducers 11.

The number of bits of converters 9 and 1I depends on the number of elements of the expansion of the line and the number of lines in the frame.

The transducers 11 form a stepped sawtooth voltage supplied to the formers 12 and then to the limiters 13 that form the stepped signal corresponding to half an hour, to the number of the line corresponding to the number of lines of the frame.

The signals taken from the limiting amplifiers 13 are summed into parabolic stepped sigals on the adders 14. Formed an additional stepped parabolic sigil from the output of the adder 2 frames through the matching amplifier 3

enters the final adder 4, where it is summed with the constant component of the focusing signal.

Sigal from the terminal adder 4 directly enters the focusing system 1.

The use of transducers 9, 11 to form a stepped parabolic signal reduces the components of the errors of the focusing signal and reduces the number of consumed elements to achieve the same focusing accuracy in dynamics.

Claims (1)

Invention Formula A device for dynamically focusing the beam of an electron-beam tube containing a focusing system, a deflecting system along a line with a feedback resistor included in its circuit and a deflecting system along a frame with a reverse-acting resistor included in its circuit, the purpose of improving the accuracy of focusing the beam over the entire image field of the cathode ray tube, the sequentially included frame adder, the matching amplifier and the end adder connected to the input of the focusing amplifier are introduced into it threads and two identical channels, each of which is connected between the resistor and the addressed communication frames corresponding input of the adder, wherein each of said channels consists of transducer analogue code connected by the input to the feedback resistor, and each of the two inputs of the forward and reverse codes of this converter is connected through a series-connected matching stage, the converter the code analog, a step-exponential voltage driver and an amplifier-limiter, respectively, to the first and second inputs of the coordinate adder, the output of which is connected to one of the inputs of the said frame adder. .