SU1383418A1 - Device for reading out graphic information - Google Patents

Abstract

The invention relates to automation, in particular to devices for reading graphic information, and can be used to enter information into a computer. The purpose of the invention is to improve the accuracy and noise immunity of the device. The goal is achieved by introducing a ring counter, level formers, threshold elements, adders, voltage dividers and keys. 1 il.

Description

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The invention relates to automation, in particular to devices for reading graphic information, and can be used to enter data into a computer.

The purpose of the invention is to improve the accuracy and noise immunity of the device.

The drawing shows the block diagram of the device.

The device contains lines 1 and 2 mutually orthogonally located on the coordinate field of light sources optically connected with photo detectors 3 and 4, also forming lines, ring counter 5, generator 6 of pulses and blocks 7 and 8 of measurement and output of coordinates, each of which contains triggers 9 with one steady state, for example, Schmitt triggers, register 10, voltage level generators 11, AND elements 12, counter 13, voltage divider 14, adder 15, OR element 16, threshold element 17 and key 18, device group inputs 19 and information tional outputs of the first 20, second 21 and third 22 unit groups and 23 output synchronizing ring counter.

The device works as follows.

In the initial state, all elements and nodes of the device are reset.

The polling of the triggers of register 10 is performed using an annular counter 5. For this, generator b pulses, arriving at the input of the circular counter 5, cause its next discharge to be turned on and, thus, alternately opening the elements 12, which causes the output signals to pass register bits 10 through the element OR 16 to the input of the counter 13.

However, as soon as the SRI's light beams using the pointer, the output of photodetectors 3 and 4 receives signals leading to the Schmitt trigger 9, the output signals of which translate the trigger 10 of the register 10 from the zero state into one, and at the output of the corresponding driver 11 voltage levels form voltages corresponding to the X and Y coordinates of the pointer position. Practically, the pointer overlaps several (or more) coordinate lines and then a voltage equal to the total value of the voltages corresponding to the levels of the overlaid coordinate lines is obtained at the output of the adder 15, and a voltage equal to the number of interrupted coordinate lines is formed at the output of the counter 13. The voltage divider 14, having carried out the operation of dividing the total signal from different coordinate lines by their number, gives the average position of the pointer on the coordinate field at the output.

interrupted occurs (coordinate data). After each polling cycle, the output signal from the clock output of the ring counter 5 is set to the “On Triggers of the Register 10 and the Counter 13, and blocks 7 and 8 are ready for operation again.

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If the object appears in the coordinate field with dimensions different from the pointer dimensions (up), this leads to the overlapping of a greater number of coordinate lines and the appearance of the number of pulses at the output of the counter 13 exceeding the preset level of the threshold element 17, which causes it to trigger and closing the key 18, and the output signal of the coordinate does not pass.

The introduction of new nodes and elements improves the accuracy and noise immunity of the device.

Claims (1)

Invention Formula A device for reading graphic information containing two lines of mutually orthogonally located light sources, the outputs of which are optically connected to the inputs of the corresponding photo receivers arranged parallel to the corresponding light sources, counters whose counting inputs are connected to the outputs of the corresponding OR elements, whose inputs are connected to the outputs corresponding And elements, registers, information outputs of which are connected to the same inputs of the corresponding And elements, and information inputs Dineny with the outputs of the corresponding triggers with one steady state, the signal inputs of which are connected to the outputs of the respective photodetectors, and a pulse generator, characterized in that, in order to improve the accuracy and noise immunity of the device, it contains a ring counter, the counting input of which is connected to the output of the pulse generator , information outputs are connected to other inputs of the corresponding AND elements, and the synchronization output is connected to the installation inputs of registers and counters, level drivers voltages whose inputs are connected to the information outputs of the respective registers, threshold elements, some of the inputs of which are inputs to the device group, others connected to the information outputs of the corresponding counters, and outputs are information outputs of the first group of device, adders, information inputs of which are connected to the outputs appropriate voltage level drivers, voltage divider, whose inputs are connected to the information outputs of the corresponding adders and counters, and you The moves are the information outputs of the second device group, and the keys whose inputs are connected f I I 20 21 22 with the outputs of the respective threshold elements and voltage dividers, and the outputs are the information outputs of the third group of devices. 20 27 y 22