SU1748161A1 - Graphic data digitizer - Google Patents

Abstract

The invention relates to automation and computing and can be used as an external computer device for automated graphic information input. The purpose of the invention is to improve the accuracy and reliability of the device. The goal is achieved by introducing three analog switches. 2 Il.

Description

The invention relates to automation, in particular to devices for reading graphic information.

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

FIG. 1 shows a block diagram of the device; in fig. 2 shows an example of execution of the control unit.

The device (Fig. 1) contains a tablet 1 with main 2 and additional 3 coordinate buses, the first 4 and second 5 amplifiers, control unit 6, pulse generator 7. Counter 8, register 9, selective amplifier 10, coordinate remover 11, first 12 and second 13 comparators, the first 14, the second 15 and the third 16 analog switches.

The control unit (Fig. 2) contains a ROM 17, a processor 18, an address register 19, an input / output node 20.

The device works as follows.

At the moment of switching on, the generator 7 begins to generate clock pulses arriving at the counting input of the counter 8. The periodic signal of the rectangular form from the highest bit of the counter 8 enters the input of the selective amplifier 10, and from the output, the sinusoidal voltage enters the coil of the puller 11 coordinates. An alternating current passing through the coil excites in space an alternating magnetic field with an axis of symmetry passing perpendicular to the plane of the coil through the center of the coil. This field induces a voltage reading field in the windings, the absolute values of which depend on the location of the coil on the field. Analog switches 14 and 15 connect the main sine and cosine buses 2 to the inputs of the control unit 6 and connect the main sine and cosine buses 2 to the inputs of the amplifiers 4 and 5, respectively, of the X and Y coordinates. Amplifiers 4 and 5 produce a vector summation of the sinus and

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sinus windings and the gain of the resulting signal. The voltages from the output of the amplifiers 4 and 5 are fed to two information inputs of the analog switch 16, to the third input of which a signal is sent from the output of the selective amplifier 10. The signal from the output of the amplifier A goes directly to the output of the comparator 12. When the amplitude of the signal exceeds the threshold value at the output of the comparator 12 appears a low level signal that permits operation of the control unit 6, the latter exposes alternately to the address inputs of the analogue address switch 16, and the switch 16 connects to the input of the comparator 13 signals to the data inputs from the amplifiers 4 and 5 and the selective amplifier 10, comparator 13 converts the input signal into rectangular. The front of the rectangular signal entering the register entry 9 overwrites the current value of counter 8 into register 9. The signal from the output of the comparator 13 enters the control unit, which reads the codes from the front of the rectangular signal 9. Codes read from register 9 correspond to the phase shift of the corresponding analog signals relative to the decay of the high-angle senior-discharge signal of the counter 8. Block 6 sets the signal inputs and switches to the address inputs of the analog switches 14 and 15 Luciano to the input amplifiers 4 and 5 of tire 3 noniusnye floor reading with audio and similarly the measurement of the phase shift signals from the main busbar measurement phase shifts produced amplified signals from vernier tires. Since the stacking bus of the main and vernier tires is different, the control unit for the difference between the values of the corresponding signals determines the period numbers of the main tires by the benchmarks X and Y, in which the puller of the 11 coordinates is located, and then calculates the full values of the coordinates X and Y of the puller center 11 coordinates. Subsequently, the control unit 6 does not connect the vernier busses, and the period number of the main bus is determined by continuous analysis of transitions using the signal values. With detachment

the puller 11 coordinates from the readout field I and transferring it to an arbitrary point of the readout field, the signal sharply decreases, and at the output of the comparator 12 a high level signal appears that prohibits the readout of the coordinate control unit 6. Upon return to the readout field, the input signal increases and the measurement of the first pair of X and Y coordinates proceeds in the order similar to the order of operation of the device after switching on.

Claims (1)

Invention Formula A device for reading graphic information containing a tablet made in the form of two systems of mutually orthogonal main and additional coordinate buses, a counter, the counting input of which is connected to the output of the pulse generator, and the outputs are connected to the information input of the register, a selective amplifier whose input is connected to the output of the older the counter is discharged, and the output is connected to the input of the coil inductance coil, the first comparator, whose information input is connected to the output of the first amplifier, W The comparator, the output of which is connected to the synchronization input of the register, the output of which is connected to the information input of the control unit, and the second amplifier, characterized in that, in order to increase accuracy and reliability, it contains the first and second analog switches, whose information inputs are connected to the outputs the corresponding coordinate buses of the tablet, the address inputs are connected to the first output of the control unit, and the outputs are connected to the inputs of the first and second amplifiers, respectively, and the third analog switch p data inputs of which are connected to the outputs of the first and second amplifiers having an information input connected to the output of the selective amplifier are connected to the address inputs of the second and third output control unit .sinhroniziruyuschie whose inputs are connected to outputs of the first and second comparators, respectively. figi 1 $ 17 fie. 2