SU1436115A1 - Device for reading coordinates off crt screen - Google Patents

Abstract

The invention relates to automation and computing and can be used in image processing systems displayed on the screen of a cathode ray tube (CRT) raster display. The purpose of the invention is to simplify the device. This target is achieved by the fact that the device for reading the coordinates contains a coordinate remover optically connected to the CRT screen, the counter's counter, the first register and the AND element, the CRT beam deflection input is the first control input of the device, and the second register and the OR element, the output of which is connected to the control input of the beam intensity of a CRT, the first input of the element RIO is connected to the output of the element AND, and the second input is the second control input of the device. 1 il. (AT

Description

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The invention relates to automation and computing technology that can be used in systems for processing images displayed on a screen of a cathode ray tube (CRT) of a raster display.

The aim of the invention is to simplify the device.

The drawing shows a diagram of the device.

The device contains the whale first 1 j second, | roy- 2 ,, third 3 and fourth 4 counters KHj first 5 and second 5 registers elements I 7 and ZhSh B ,,, CRT 9 to 10 coordinates.

I The first input of counter 1 is connected | to the second input of counter 2, connected with the third input of counter 3, I with the first input of counter 4 and with input j 11 horizontal sync pulses (axes). The second input is connected to the second input of counter 3 and c input 12 clock pulses (TI) 5; the third input is information input 13 for setting the correction code (KP); the output of counter 1 is connected to the second information input of register 5 whose output is connected to the first information input of counter 3 and to output 14 of the device (coordinate X) first control input register 5 and connected to the output of a stripper 10, the input of which is optically coupled c- CRT screen 9 and the first control. Yushch4 input of register b is the second input of which is connected with the stroke of counter 2, the first synchronization input of which is connected to the input of 15 frame clock pulses (XI) and the third input of counter 4, the second information: - the one input is connected to the output of regr; device (by Y coordinate), Vipsod counter 4 is connected to the first input element And 75 a second input of which is connected to the output of counter 3, The output of element I 7 is connected to the first input of an element ШШ 8 whose second input is connected to input 17 of the brightness control ., and the output of the VLI element 8 is connected to the CRT brightness control input, which has an electron beam deflection control input 18 in the X and Yo coordinates

The device works as follows.

In the initial state, for example, the puller of 10 coordinates is retracted from the screen of the CRT 9, therefore at its output sig0

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There is no signal, therefore, there is no signal at the control inputs of registers 3 and 6. At the outputs of the latter, some code is stored that corresponds to the previous state. At the information input 13 of the counter 1, a CP is set, which is defined as the difference between the code 111-111 and the binary code of the number N, equal to the ratio of the delay time of the signal at the puller output 10 coordinates to the TI period. For example, with (binary code 110) KP corresponds to the binary number 11-001. To install this control unit, it is sufficient to connect the code inputs of the second and third bits of counter 1, for example, with a jumper with a zero bus. The input 18 to the CRT receives a beam deflection signal (for example, the beam deflection coils along the X and Y coordinates) 5 which forms a rectangular raster on its screen. Synchronously with the deviation signal, the TIs enter the device 12, the frequency of which determines the number of coordinates read by X ,, to the input 1.1 - the FID, and to the input 15 - the XI. The luminance control signal from the input 17 through the element 8 to the control input of the tube forms on its screen an image to be processed.

When posting: {1, the OSI on the inputs of the entry -codes of counters 1 and 3 is recorded KP in the internal register of counter 1 and the code from the output of register 5 in the register-counter 3. When finished. action-ICSI counter 1 adds to the recorded TI code arriving at its summing input, whereby the output counter code increases to overflow and then starts counting pulses, starting at zero. As a result, at each time point, the code at the output of the counter corresponds to the number of TIs that have passed since the end of the AIM, minus the number 5 corresponding to the CP. Counter

3 subtracts from the THs code recorded from register 5, and at the moment of zero crossing, a pulse appears at the overflow output of the counter, and input element AND 7,

During the XSI, the counter 2 is set to zero, and in the counter register

4 A code is written from the output of register 6. At the end of the XSI, the counter 2 summarizes the FID received at its input,

and counter 4 subtracts the FID from the recorded 314

nogr code. At the output of counter 2, a code of current coordinates along Y is formed, and from the output of overflow of counter 4, a pulse with a duration corresponding to the length of the forward stroke of the rio line is removed. At the moment of coincidence of the pulses arriving at both inputs of the AND 7 element, a pulse passing through the OR8 element at the tube control input appears at its output, causing the raster element to appear on its screen corresponding to the X and Y codes recorded in registers 5 and 6.

When the puller 10 is installed against the required image element, a pulse appears at the puller output, which is fed to the recording inputs of registers 5 and 6 and writes the current X and Y coordinate codes taken from counters 1 and 2 to the registers. These codes are rewritten into registers counters 3 and 4, from the output of which the signals pass through elements 7 and 8 and cause illumination of the 10-point image element specified by the puller. With codes 14 and 16, the coordinate codes .X and Y of the element can be transferred to a computer.

Thus, the device implements the acquisition of the coordinates of the image element from the CRT screen taking into account the signal delay introduced by the puller of 10 coordinates, and the backlight of the corresponding element on the tube screen is monitored to ensure that the puller of the 10 coordinates is correctly guided.

The use of the proposed device for reading coordinates from the CRT screen of a raster display in comparison with the known one allows to simplify the scheme, since there is no need to use complex blocks and nodes and expand the functional capabilities due to the autonomous illumination of the element

ABOUT

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Which is a pointed remover of coordinates,

which makes it easier for the operator to control the reliability of the selected item.

Claims (1)

Invention Formula A device for reading coordinates from a cathode ray tube (CRT) 5 screen containing a coordinate remover optically coupled to a CRT screen, four counters, a first register and an And element, a CRT beam deflection input is the first control input of the device that differs in order to simplify the device, it contains a second register and an OR element, the output of which is connected to the CRT brightness control input, the first input of the OR element is connected to the output of the AND element, and the second input is the BTopHNi control input of the device, The second are the outputs of the first and second registers, the control inputs of which are connected to the output of the coordinate remover, and the information inputs are respectively to the outputs of the first and second counters, the output of the first register is connected to the information input of the third counter, the output of the second register is connected to the information input of the fourth counter , the output of which and the output of the third counter are connected to the inputs of the element I., the information input of the first counter is the information input of the device, the clock input of which is The clock inputs of the first and third counters, the first sync inputs of the second and fourth counters are the input frame sync pulses of the device, the input of the line-sync pulses of which IE are the second sync inputs of the first, second and fourth counters and the sync input of the third counter .