SU966711A1 - Device for reading-out graphic information - Google Patents

Description

(5) DEVICE FOR READING GRAPHIC INFORMATION

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The invention relates to automation, computer technology and can be used to create semi-automatic graphic information input devices into electronic computers.

A device for reading graphic information containing a tablet made in the form of a system of two mutually orthogonal coordinate buses, the inputs of which are connected through the bus polling units connected in series by the decoder, the counter and the first coordinate register, the coordinate remover connected to the gain unit, the control unit connected to the counter, the first and second coordinate registers and And elements, the comparison unit and shift registers, an interpolator connected to the And elements and with the second coordinate register , analog-to-digital converter, connected

To the control, gain, and serially connected shift registers, the outputs of which are connected to the comparison unit and to the elements.

The disadvantage of this device is the limited accuracy due to the additional error in the measurement of coordinates when the thickness of the information carrier is changed.

10 absolute measurement of the amplitude of the measuring signal, given in the coordinate remover when current flows through the coordinate buses, limiting the reading area.

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The closest in technical essence to the proposed device is a device for reading graphic information containing a tablet with systems of mutually perpendicular coordinate TIRS connected through the first and second valve blocks to the switches, the generator 39 of the pulses, the output of which is connected to the control inputs of the first and the second valve block, and the control; input - with one of the outputs of the control unit, the other outputs of which are connected respectively to the control input of the third valve block, to the inputs of the counter of the exact coordinates and to the inputs of the coarse coordinates counter, the outputs of which are connected to the inputs of switches, coordinate remover connected to the amplifier reading, first and second memory blocks, dividing blocks and comparison block, the output of which is connected to the input of the control unit, the corresponding outputs of which are connected to the control inputs of the first and second block of the memory and dividing units, the outputs of which are connected to the comparison unit, and the other inputs through the first and second memory blocks to the direct and inverse outputs of the read amplifier C 2 J. There is no error in this device due to the change in the carrier thickness providing a relative measurement of the amplitude of the measuring signal induced in the puller when current flows along a coordinate bus located inside the reading section. However, it is characterized by limited accuracy due to the presence of measuring, comparing, dividing, and converting analog signals, which have limitations on the accuracy of operations. Thus, the presence of tunable analog voltage dividers in the divider blocks, the outputs of which are connected to the inputs of the comparison unit, introduces additional errors resulting from the errors of their manufacture and adjustment. The purpose of the invention is to increase the device's hardware. The goal is achieved by the fact that in a known device containing a tablet made in the form of a system of two mutually orthogonal coordinate buses connected to the corresponding group keys, one inputs of which are connected to the first and second switches, respectively, the first counter whose input is connected to a pulse distributor and the output is connected to one input of elements AND of a group, the other inputs of which are connected to the pulse distributor and 14. Modulators connected to the pulse distributor, a third switch, the inputs of which are connected to the unit, are connected to the second counter connected to the pulse distributor and to the inputs of the first and second switches, and the serially connected coordinate remover, the first amplifier and the comparison unit connected to the pulse distributor. comparison, with a pulse distributor and with modulators, and the output is connected to other inputs of the group keys, and a filter connected in series, the input of which is connected to the output of the first amplifier l, the second amplifier, a key, another input of which is connected to the output of the comparison unit, a trigger, another input: of which is connected to the corresponding inputs of the first and second modulators, and the output is connected to the pulse distributor, and the And element whose other input is connected to the pulse distributor and the output is connected to the input of the first counter. The drawing shows the block diagram of the device. The device contains a tablet 1 with coordinate tires, keys of the first 2 and second 3 groups, first k and second 5 switches, distributor 6 pulses, a group of elements M 7 first 8 and second 9 counters, coordinate remover 10, first amplifier 11, filter 12, unit 13 comparisons, the converter, the third switch 15 and the modulator 16 and 17. At the same time, the pulse distributor 6 includes a synchronizer 18, a frequency divider 19, a pulse generator 20, a signal conditioner 21, and the converter 1 contains a second amplifier 22, a key 23, a trigger 2 and element and 25. The device is working t as follows. According to the signal of the synchronizer 18 of the distributor 6, a divider 19, a block 13 and counters 8 and 9 are set to the initial state, after which the frequency divider 19 begins to generate pulses for interrogating coordinate buses, which simultaneously arrive at the third switch 15 and through the for-. The worldlord 21 on. The input of the counter 9 is a rough reference. Through the third switch 15, the polling pulses arrive in keys 2 or Z, depending on whether. which coordinate is being measured, signals are sent to horizontal or vertical tires of tablet 1, respectively. The number of the excited bus is determined by switches i or 5, the counter 9 whose contents change by one 1-bit discharge each time after the next pulse from the output of the divider frequency 19 in the shaper 21. Thus, the excitation of the coordinate tires is carried out sequentially in increasing numbers. Upon successive excitation of the coordinate tires in the coordinate remover 10, an electrical measurement signal is induced, which is amplified by amplifier 11 and fed to the input of unit 13, in which the polarity of the induced signal is analyzed. If the signal induced in the coordinate remover 10 is missing or has a negative polarity, block 13 by a signal at one of its outputs allows the next polling pulse through the driver 21 at the input of the counter 9- When the polarity of the signal induced in the puller 10 changes to the opposite At one of the outputs of block 13, a signal appears prohibiting the further arrival of interrogation pulses through the driver 21 to the input of counter 9 and the device switches to the mode of precise determination of the location of the coordinate remover 10. In this case, the third switch 15 is switched by the same signal from the output of the block 13 and allows the receipt of periodic pulse modulated signals with the output of the first and second modulators 16 and 17 through the thirds of the switch 15 to the input of the keys 2 or 3 To the first and second inputs of the module The tori 16 and 17 receive pulsed periodic signals of different frequencies with the output of frequency divider 19. In this case, the type and nature of modulation (PWM, AMMi FIM) is determined by modulators. Coordinate bus numbers to which these signals are applied are determined by the switches or 5, respectively, depending on the counter state at the moment the device enters the precise coordinate-read point mode. At the same time, the signal from the other output of block 13 is allowed to work. converter T, the signal induced in the coordinate puller 10 is amplified by 1.4 amp amplifier 11, filtered by filter 12 tuned to the frequency of the first harmonic component of the envelope of the peirrod modulated pulse signals interrogating the co-ordinate buses in the read section, and fed to the input of amplifier 22, then from the output of amplifier 22, the received signal through the switch 23, controlled by the signal from block 13, is fed to the input of trigger 2, to the other input of which the reference signal from frequency divider 19 is applied. At the same time, at the output of trigger 2, a signal appears, the duration of which corresponds to the magnitude of the phase mismatch by the signal induced in the coordinate remover and the reference signal. This difference signal from the output of the trigger 2k is fed to the input of the element 25 And the other input of this element is pulsed with a clock frequency from the output of the generator of 20 pulses. At the output of the AND 25 element, a pulse sequence is formed, the number of pulses in which corresponds to the duration of the phase error pulse. These pulses arrive at the input of the counter 8. At the end of the phase mismatch pulse, i.e., after the generation of the exact coordinate value of the read point on the falling edge of the phase mismatch pulse from the trigger 2 output, the synchronizer 18 generates pulses that will overwrite the contents of the coarse counters 9 and an exact 8 reference of the coordinates through the elements AND 7 in the computer and the installation of the counters 8 and 9 of the block 13 into the initial state, and then another coordinate of the read point is measured in the same way. The greatest effect from the use of the device is obtained by processing the sources of information depicted in metric form, for example, in the field of cartography. In addition, the implementation of the device allows a significant increase in the distance between the coordinate tires of the tablet compared to the prototype, since when accurately determining the position of the coordinate remover on the read area, the upstream part of the amplitude characteristic of the measuring signal is fully used, in contrast to the prototype where

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only its linear part, which is approximately the total length of the upstream segment. This makes it possible to reduce the amount of equipment necessary for controlling the switching of the coordinate buses, which, in turn, makes it possible to increase the reliability of the device and the manufacturability of its manufacture. With the current wholesale price for PKGMO and. elemental base used saves when manufactured from one device 3,5 +, 0 thousand rubles.

Claims (2)

1. USSR author's certificate №, cl. G About K 11/06, 1976. 2. USSR author's certificate №661578, cl. G About K 11/06, 1976 (prototype).