SU1357987A1 - Graphic information read-out device - Google Patents

Abstract

The invention relates to automation and computer technology and may find application in systems encoding graphic information for preparing it for input into a computer. The aim of the invention is to improve the accuracy of the device. The goal is achieved by eliminating the phase error associated with a change in the amplitude of the signal of the coordinate remover and the time delays of the signals when reading the coordinates from the time formers. zp f-ly, 2 ill. (L with: oo ate with 00

Description

The invention relates to automation and computing, in particular, to devices for reading graphic information, and can be used in graphic information coding systems.

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

Figure 1 presents the block diagram of the device; Fig. 2 shows an example of a constructive implementation of a read signal detector.

The device comprises a tablet 1 with piezoelectric radiators 2, a 3-coordinate puller in the form of a sound-conducting rod, a strobe pulse shaper A, a first pulse generator 5, a shaper 6 of reference signals, a group of 7 And elements, a shaper of 8 coordinates, a second pulse generator 9, a detector 10 read signals, synchronization pulse generator 11.

In this case, the driver 6 of the reference signals contains a dial pad 12, a reference element 13, a D-flip-flop 14 and a counter 15.

The group of elements 7 has the first 16, second 17 and third 18 elements I.

The strobe pulse shaper 4 consists of a comparator 19 and an amplifier 20.

Shapers 8 coordinates contain a trigger 21, the first element And 22, the counter 23 and the second element And 24.

The synchronization pulse generator 11 has the first 25, second 26, third 27, fourth 28 and five 29 D-type triggers, pulse elements 30, 31 and 32 delays without preserving the waveform, the element NO 33 and the element EXCLUSIVE OR 34.

The detector 10 contains the first pulse counter 35 - an interpulse interval analyzer, the second pulse counter 36 - a pulse width analyzer, the first 37, the second 38. and the third 39 triggers, the HE element 40, the first 41 and the second 42 elements I.

The device works as follows.

The generator of 5 pulses with a shift in time, determined by the complete attenuation of the acoustic wave in the plate-duct 1, generates rectangular pulses. Under the influence of these pulses, piezoelectric radiation is alternately excited

five

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2. The elastic running acoustic wave, which is excited in this case in the flute plate 1, propagates at a constant velocity along the axis perpendicular to the corresponding side of the tablet.

When installing the puller 3, the coordinates on the surface of the tablet 1 at the measured point, after a time corresponding to the distance of the traveling wave front from the emitters 2 to the point of contact of the puller 3 with the surface of the tablet 1, an electrical signal begins to form in the puller fed to the input of the transducer 4.

The generated pulses from the output of shaper 4 are fed to the input of detector 10, where the signal sequence of pulses is extracted from a mixture of it with noise sequences in real time.

The pulse counter 35 of the detector 10 performs an analysis of the duration of the interpulse intervals of the incoming sequence, and the counter 36 of pulses is carried out | analysis of the duration of the pulses of the incoming sequence.

This analysis is performed by comparing with the code recorded in the corresponding counter when the generator pulses 9 arrive. At the time of the inter-pulse interval when the generator pulses K arrive, the pulse 35 is formed at the output of the counter 35, which triggers the trigger 37 to a single state. The trigger 39 remains in the initial zero-state. The potential of logic 1 from the output of the trigger 37 removes the blocking from the first zero setting input of the counter 36, and at the moment of action of the input pulse, the blocking is removed from the second zero setting input. Therefore, the pulses coming from the generator 9 begin to sum up in the counter 36, and a pulse is generated at the output of the counter, switching the 1Y trigger 38 to the one state, which prepares the trigger 39 for switching.

At the instant of the next interpulse interval of the input signal, the signal from the output of the counter 35 switches the trigger 39 to a single state. Another input im5

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the pulse passes through the element AND 42n the output of the detector 10 and through the element And 41 performs a reset of the triggers 37, 38 and 39.

The formed single pulse from the output of the detector 10 is fed to the input of the counter 15.

The code counted by the counter 15 number of pulses is compared with the code specified in dialing field 12. If these codes coincide, a short pulse is generated at the output of the comparison element 13, which triggers trigger 14. At the same time, the output potential of the And 16 elements enters from the output of the 16 17 and 18, allowing the passage of signals from the pulse generator 5 and the detector 10 to the inputs of the formers 8. co-dinat.

The generated time intervals at the outputs of the flip-flops 21 allow the passage of clock pulses from the generator 9 through the corresponding element AND 22 to the counting input of the corresponding counter of its 23. At the end of the time interval, the resizing of the measurement of the corresponding coordinate is fixed in the corresponding counter 23. The above impulse from detector 10 also enters the inputs of the generator 11, where, in addition, generator 9 pulses are applied. On the leading edge of the pulse entering the input of the generator 11, either trigger 29 or trigger 25 is counted, and then the unit state the raised trigger 25 is applied to the inputs of the flip-flops 26 and 27, preparing

their to switch. I

At the same time the installation is in the unit

The state of one of the indicated triggers 26 and 27 is made depending on the temporal position of the front of the incoming input pulse within the components of the clock frequency period, m, e, the time of the clock pulse action or its absence. In the event that the front of the input pulse arrives at the time of the clock pulse action, the trigger 27 is set to one, allowing the trigger 28 to be set to the single state at the time of the front also ending this interval at the moment of the pulse. The potential of logic 1 generated by the clock pulses of the digital clock of the trigger 28 is fed to the additional output of the driver 11 and to the input of the current characterizing it increases by half of the unit of the least significant bit.

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of the delay element 31. After the formation of the pulse, after a time determined by the pulse delay element 31, the pulse appears at the output of the pulse, the duration of which is sufficient to zero the trigger 28,

In the event that the front of the input pulse arrives at the moment the clock pulse pauses, the trigger 26 is set to one, and the signal generated at the output of this trigger is fed to the fourth control input of the driver 8,

In the case of a signal from the output of the detector 10 at the time of the action of the front or the fall of the clock pulse, when the output of the EXCLUSIVE OR 34 element has a zero reset signal of the trigger 25, to improve the accuracy of the device, logical 1 is triggered by the trigger 29 logical 1, 5 Potential logical 1 from the output of the trigger 29 is fed to the input of the third element 32 delay. After the pulse formation is completed, after a time determined by the pulse delay element 32, a pulse appears at the output of the latter, the duration of which is sufficient to zero the trigger 29 and write the potential of logic 1 to the trigger 25,

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The delay time depends on the pulse frequency following the pulse and the duration of the zero signal from the output of the EXCLUSIVE OR 34 element. The signal from the output of the former 11, which occurs at the time of the strobe pulse during the clock pulse pause and arrives at the fourth input of the 8 coordinate generator, is supplied through the element 24 to the counting input of the corresponding counter 23. The additional counting input is associated with the additional output discharge of the counter, the weight of which is equal to half of the low-order counter.

Thanks to the scheme described, the accuracy of coding coordinate intervals is doubled, since

the end of this interval at the time of the pause of the clock pulses of the digital

the code characterizing it is increased by half the unit of the lower order.

Claims (3)

1. A device for reading graphic information containing a tablet with piezoelectric radiators, the information inputs of which are connected to the output of the first pulse generator, an amplifier whose input is connected to the information output of the coordinate remover, and the output one connected to the information input of the comparator, a group of elements AND, some of the inputs are connected to the information output of the driver of the reference signals, and the outputs are connected to the first, second, and third control inputs coordinate drivers, the first synchronization inputs of which are connected to the output of the second generator : pulses, while the other inputs of the first and second elements of the AND group are connected to the outputs of the first pulse generator, characterized in that, in order to improve the accuracy of the device, it contains a detector of read signals, synchronizing 1, whose input is connected to the output the second pulse generator, the information input is connected to the information output of the comparator, and the output is connected to the counting input of the shredder of the reference pulses and the other input of the third element of the group I and the form, the synchronizer of synchronization pulses information input of which is connected to the output of the third element AND of the group, the synchronizing input is connected to the output of the second generator, pulses, the first control output of the synchronization pulse generator is connected to the fourth control inputs of the coordinate drivers, and the second control output is the control device output. 2. The device according to claim 1, wherein the read signal detector comprises a first counter, the counting input of which is the synchronization input of the detector, the setup input is the information input of the detector, and the information output is connected to the single input of the first trigger, the single output of which is connected with the first installation input of the second counter, the counting input of which is connected to the synchronization input of the detector. 0 five 0 five the information output of the second counter is connected to the single input of the second trigger, the element is NOT, the input of which is connected to the information input of the detector, and the output is connected to the second installation input of the second counter, the third trigger, the single input of which is connected to the information output of the counter nfipBoro, and the synchronizing input is connected to the single output of the second trigger, the first element And, one input of which is connected to the information input of the detector, the others are connected to the single outputs of the first and second triggers, and you od connected with adjusting inputs of said first, second and third flip-flops, and a second AND gate, one input of which GEOdklyuchen to the data input of the detector unit are connected to other outputs of the first, second and third flip-flops, and the output is a data output detector, 3. The device according to claim 1, characterized in that the synchronization pulse shaper comprises a first trigger, the single input of which is the information input of the driver, and the single output connected to the single inputs of the second and third triggers, the first delay element whose input is connected to a single the output of the second trigger, and the output is connected to the setup input of the second trigger, the synchronizing input of which is the synchronizing input of the driver, the fourth trigger, the single input of which is connected to one the third output trigger, the synchronization input is connected to the synchronization input of the imager, the setup input is connected to the output of the second delay element, the input of which is connected to the unit output of the fourth trigger, the fifth trigger, the unit input of which is connected to the information input of the imager, and the single output connected to the input the third delay element, the output of which is connected to the setup input of the fifth trigger and the synchronization input of the first trigger, the element NOT whose input is connected to synchronization input of the driver, and the output is connected to sync-. 0 five 0 five the drop input of the third trigger, the setup input of which is connected to the synchronization input of the former, and the EXCLUSIVE SHSh element, the inputs of which are connected 13579878 with the synchronizer input of the driver and the output of the element NOT, and the output is connected to the synchronization input of the fifth trigger and the installation input of the first trigger. Editor L. Langazo Figg Compiled by A. Romanov Tehred M. Khodanich Proofreader V. But ha Order 6001/51 Circulation 671 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow F-: 35, Raushsk nab., d, 4/5 Production and printing company, Uzhgorod, Projecto st., 4 srig.1