SU1084841A1 - Device for reading graphic information - Google Patents

Abstract

1. DEVICE FOR READING GRAPHIC INFORMATION, containing a tablet with coordinate tires connected to the corresponding keys, a read amplifier, connected to the output of the coordinate remover, with an amplitude discriminator and a comparator, the first counter, whose inputs are connected to the pulse distributor, and the outputs are connected to a keypad, and the comparator, the inputs are connected to the pulse distributor, the outputs are connected to a keypad, and the comparator is connected to a pulse distributor, and the comparator is connected to a pulse distributor and the comparator. to the decoder connected to the keys and to the pulse distributor, the second counter connected to the pulse distributor and to the first digital-to-analogue converter, the output of which It is connected to a comparator, the first element is AND, whose inputs are connected to the amplitude discriminator and to the distributor of pulses, and the output is connected to the distributor of pulses, and the first element NOT that is connected to the distributor of pulses, in order to increase its speed, the second element And, the inputs of which are connected to the first element NOT and with the comparator, the third counter connected to the pulse distributor and to the output of the second element. And a fourth counter connected in series to a pulse distributor and to the output of the first element I, a register connected to a pulse distributor, a fifth counter connected to the pulse distributor, a second D / A converter and a DC amplifier whose output is connected to a coordinate tablet tires. 2. The device according to claim 1, distinguished by the fact that the pulse distributor contains the first trig (L ger, one input of which is the first input of the pulse distributor and the output is connected to the first one-oscillator connected to one input of the first IS-NOT element, the other input of which is connected to the second one-shot, and the third input is the second input of the pulse distributor, the second trigger, one input of which is the third input 42 ;. the house of the pulse distributor, the other is connected to the third one-vibration 4 torus connected to the gene The device is a single pulse, and the output is connected to the input of the second one-shot, the second element is NOT-NOT, the inputs of which are connected to the pulse generator, with the third one-shot and the second element NOT, the operation counter, the inputs of which are connected to the third one-shot trigger and with the output of the first element is NOT, and the outputs are connected to the second decryptor

Description

rum connected to the second element NOT and to the same inputs of the group of AND-NOT elements, the other inputs of which are connected to the output of the second AND-NOT element, the fourth one-shot that is connected to the code of the second elec- tion of the IS-NOT, and the third element NANDY, inputs which is connected to the fourth one-shot and the second element NOT, and the output is the output of the distributor. pulses.

The invention relates to automation and computing, in particular to devices for reading graphic information, and can be used in computer-aided processing systems for graphic information. A device for reading graphic information containing an inductive transducer (pen or viewfinder), a tablet with a system is known. orthogonal busbars, a read amplifier, a coordinate bus counter (coarse meter), a second counter (accurate meter), connected via a digital-to-analog converter eh with coordinate tires, polling keys, coordinate bus descrambler, amplitude discriminator, pulse generator ij. The closest to the invention is a device containing a tablet with coordinate tires, connected via keys to a decoder connected to a pulse distributor and to the first counter, successively connected by a coordinate remover, an amplifier, the output of which is connected to a comparator, an amplitude discriminator and element , the other input of which is connected to the pulse distributor connected to the element NOT, the second counter connected to the pulse distributor and to the digital-to-analog converter, the output of which connected to another input of the comparator, the output pulses of the distributor is connected to the input of the first counter 2 drawback of known devices is not sufficiently high speed. The purpose of the invention is to increase the speed of the device. The goal is achieved by the fact that in the device containing a tablet with coordinate tires connected to the corresponding keys, a read amplifier connected to the output of the coordinate remover with amplitude discriminator and a comparator, the first counter whose inputs are connected to the pulse distributor and the outputs are connected to the first decoder connected to the keys and to the pulse distributor, the second counter connected to the pulse distributor and to the first digital-to-analog converter, the output of which is It is connected with a comparator, the first element is And, the inputs of which are connected to the amplitude discriminator and to the distributor of pulses, and the output is connected to the distributor of imruls, and the first element is NOT connected to the distributor of pulses, the second element is AND, the inputs of which are connected to the first element NOT and the comparator, the third counter connected to the pulse distributor and to the output of the second element I, and the series-connected fourth counter connected to the pulse distributor and to the output of the first element And, reg A pp connected to the distributor, a fifth counter connected to the impulse distributor, a second digital-to-analog converter and a DC amplifier whose output is connected to the coordinate buses of the tablet. The pulse distributor contains the first trigger, one input of which is the first input of the pulse distributor, and the output is connected to the first one-oscillator connected to one input of the first NAND element, the other input of which is connected to the second one-oscillator, and the third input is the second input the pulse distributor, the second trigger, one input of which is the third input of the pulse distributor, the other connected to the third one-oscillator connected to the generator of single pulses, and the output connected to the second one-shot, the second element AND-NOT, the inputs of which are connected to the pulse generator, with the third one-shot and the second element NOT, the operation counter, the inputs of which are connected to the third one-shot, connected to another input of the first trigger and the output of the first element AND-NOT and the outputs are connected to the second decoder connected to the second element NOT and to the same inputs of the group of elements AND-NOT, the other inputs of which are connected to the output of the second element AND-NOT, the fourth one-shot, connected to the output of the second element It is the AND-NO, and third AND-NO element whose inputs are connected to the fourth monostable multivibrator and a second NOT member and the output is a pulse output distributor. The drawing shows a block diagram of the device. The circuit includes a tablet 1 with coordinate buses 2, a resistor 3, a DC amplifier 4, keys 5, first decoder 6, first 7, second 8, third 9, fourth 10 and fifth 11 counters, read amplifier 12, register 13, first 14 and 15 second digital-to-analog converters (DAC), the first element is NOT 1 the first element AND 17, the amplitude discriminator 18, the second element AND 19, the comparator 20, the distributor 21 pulses, the counter 22 operations, the second decoder 23, the first 24 and the second 25 triggers, the first 26, the second 27, the third 28 and the fourth 29 one-shot (waiting for the mule modifier), generator 30 single impulses, first 31, second 32 and third 33 elements AND-NOT, second element, NOT 34, group AND-NOT elements 35-37, generator 38 pulses, .copper 39 coordinates (pen). 4 G4 The device operates as follows. When the button 40 is pressed, the generator 30 is started. The output single pulse of this generator starts the waiting multivibrator 28. The output signal of the multivibrator sets all of the circuit triggers to their initial state. In this case, the maximum number for a particular case is recorded in the counter 11, as a result of which the maximum voltage appears at the output of the D / A converter 15, which is fed to the input of the amplifier 4. Due to the fact that this amplifier has approximately a unit gain factor for the voltage, then its output value the voltage will be with a slight deviation equal to the input voltage. After the initial installation at the end of the regenerative process of the multivibrator 28, the first stage of the work begins - a rough measurement; coordinate by counting the coordinate tires. This measurement starts from the moment the pulse 7 arrives at the output of the AND-NO element 35. The AND-NO element 35 is controlled by the first output of the decoder 23. Since the counter 22 connected by its outputs to the inputs of the decoder 23 is in the zero state, the element AND-NO 35 is opened to pass the first pulse through the AND-NE element 32 from the pulse generator 38. The same pulse from the output of the element AND-NOT 32, delayed by the standby multivibrator 29, is fed to the input of the element AND-NE 33, which is controlled by the output of the element HE 34, the input of which goes low from the decoder 23. As a result of the inversion element NO 34, the AND-NE element 33 is opened to pass the first delayed pulse from the output of the multivibrator 29 to the decoder 6. Thanks to the decryption of the 6 number decoder recorded in the counter 7, the first key 5 and its associated coordinate bus are polled first, then the second key ca 5 etc. The process of successive arrival of pulses to the input of the counter 7 and to the gated input of the decoder 6 occurs until the polled bus is in the sensing range of the readout path. This zone depends on the magnitude of the polling current and is regulated by variable resistors 3. Thus, as soon as the surveyed coordinate bus is in the sensing zone of the readout channel, the induced EMF at the input of the amplifiers of the readout body 12 is amplified to Taitoft magnitude, which amplifies the amplitude discriminator 18. The output signal of the discriminator 1 comes to the first input of the element AND 17. Since the trigger 25 is in the unit state, 1 then distribute 21 from the output to the second input of the element, And 17 receives a high (resolving) potential l. As a result of this, the first pulse from the discriminator 18, the AND 17 element is passed to the counting input of the counter 10. This same pulse sets the trigger 24 into the unit state. The voltage drop from the lower level to the high level of the single output of the trigger 2A is triggered by the waiting multivibrator 26, the output impulse of which is fed through the element AND-HE 31 to the input of the counter 22. Due to this, the first output potential of the decoder 23 appears The HE 35 is closed, and at the second output of the decoder 23 a resolving potential appears, which opens the AND-NOT element 37. The arrival of pulses from the IS-HE element 35 into the counter 7 is stopped, and the number fixed on it uniquely determines the number of the bus that has entered the sensing range of the pen reading channel. The second stage, the intermediate offsetting of the coordinate, is carried out by repeatedly requesting (opening) the key connected to the selected bus while simultaneously changing the output voltage of the amplifier A. During the intermediate measurement, the direct pulse arrives at the input of counter 11 from the output element AND-NOT 37, and the held pulses continue to be supplied from the output of element AND-NOT 33 through the counter code output of the decoder 6 to the input of that key, which is connected by its input to this output of the decoder 6. At With each pulse arriving at the input of counter 11, by subtracting this pulse from the number recorded at the initial setting, both the output voltage of the DAC 15 and the output voltage of amplifier A decrease. As a result, the magnitude of the magnetic field decreases linearly as the voltage decreases. the numbers in the counter 11. By virtue of the law of electromagnetic induction, the pulses of the induced emf at the input of the amplifier 12 are modulated according to a linear-step law. These pulses amplified in amplitude arrive at the input of the amplitude discriminator 18. The discriminator’s discrimination level is set based on the required accuracy of the intermediate measurement stage, i.e. from the required number of discrete sections of the distance between the tires. In the general case, the number of pulses transmitted from the discriminator to the input of counter 1C depends on which point between the selected polled bus and the next upward coordinate. If the pen 39 is in close proximity to the axis of the selected bus, the inductive coupling coefficient of the coil with the coordinate bus is greatest and, therefore, the weakest signals from the series of linearly modulated pulses coming from the coil are amplified to the discriminator level, and a greater number of pulses will pass to the discriminator output in comparison with the case if the pen coil was at a point farther from the bus where inductive coupling to carcass to the bus is less pronounced. Consequently, the nearer the coil of the pen is to the bus, which is fed by linearly varying current pulses, IfeM and a larger number of pulses will be detected by an intermediate meter. The pulse of the end of the intermediate measurement cycle goes from the output of the counter 11 to the setup input of the trigger 25 and sets it to the zero state. The voltage drop from a high level to a low starts the standby multivibrator 27, the impulse of which goes through the element I-HE 31 to the input of the counter 22.

Due to this, a transition from an intermediate measurement operation to an accurate measurement stage occurs. On the counter 10, a number will be recorded, specifying the location of the coil relative to the tire axis, the number of which was determined even at the rough measurement stage. At the stage of accurate measurement, the potential of logical zero arises at the second output of the decoder 23, whereby the NAND element 37 is closed, and the flow of pulses into the counter t1 stops j and the potential of the logical unit arises at the third output of the decoder 23, which opens the element IS-NOT 36. The pulses from the NAND 36 element begin to flow into the counter 8. In contrast to the intermediate measurement stage, at the stage of accurate measurement, the coordinate bus is interrogated by current pulses of the same amplitude, the value of which is determined by the number At the counter 10. To do this, the contents of the counter 10 are impulsed from the standby multivibrator 27 by means of the register 13 and transferred to the counter 11.

Since the interrogation pulses continue to flow into the selected coordinate bus, a pulsed magnetic field exists around it. The magnitude of the induced input signals of the amplifier 12 depends on where, within the intermediate discrimination step, determined by the price of the lower bit of the counter 10, is the center of the pen coil 39.

The amplified read pulses are received at the first input of the amplitude comparator 20. At the input of the comparator 20, the pulses from amplifier 12 are passed until the amplitude of the compensating voltage of the CDL 14 supplied to the second input of the comparator is equal to or greater than the amplitude of the output pulses from the reading amplifier . The output pulses of comparator 20 are fed to the input of element 19, which is controlled by the element NOT 16. Since the trigger 25 is in zero

state, the inhibitory potential of its single output prevents the passage of pulses through element 17 to counter 10, and due to the inversion element NOT 16, this same potential becomes permissive for the passage of pulses from element 19 to the input of counter 9. The number of transmitted pulses at the input of counter 9 depends on where the center of the induction pen coil is located within the intermediate sampling step. In the general case, the pulses in the counter 8 will come even after the offset signal is compensated for the sawtooth output voltage of the DAC 14. The accurate measurement cycle ends from the moment the overflow pulse arrives from the counter 8 to the second input of the distributor 21. This pulse goes to the third input of the AND-31 element , the output pulse of which will switch the counter 22 from the cycle of accurate measurement of the coordinate: X to the rough measurement cycle of the coordinate Y. In this case, the formation of the coordinate code along the axis X under consideration ends. At the fourth output of the decoder 23, a potential of the logical unit arises, which, when inverted by the element NOT 34, prohibits the passage of pulses through the element AND 33 to the input of the decoder 6, and also prohibits the flow of pulses through the element AND-HE 32 from the generator 38 of pulses. The number of pulses recorded on the counter 9, specifies the location of the center of the pen within the step, determined by the price of the younger bit of the counter 10 intermediate measurement. The code of the three counters: the coarse measurement counter 7, the intermediate measurement counter 10 and the accurate measurement counter 9 determine the coordinate of the center of the pen relative to the origin of the tablet. The total code of these counters can be transmitted to the microprocessor for the necessary processing.

The introduction of new units and blocks, as well as new constructive links, allows to significantly increase the speed of the device.

Claims (2)

1. DEVICE FOR READING GRAPHIC INFORMATION, containing a tablet with coordinate buses connected to the corresponding keys, a reading amplifier connected to the output of the coordinate picker, with an amplitude discriminator and a comparator, the first counter, the inputs of which are connected to the pulse distributor, and the outputs are connected to the first a decoder connected to the keys and to the pulse distributor, a second counter connected to the pulse distributor and to the first digital-to-analog converter, the output of which is connected is connected with a comparator, the first AND element, the inputs of which are connected to an amplitude discriminator and to a pulse distributor, and the output is connected to a pulse distributor, and the first element NOT to connect to a pulse distributor, characterized in that, in order to increase its speed, it contains the second element And, the inputs of which are connected to the first element NOT and to the comparator, the third counter connected to the pulse distributor and to the output of the second element. And, and in series, a fourth counter connected to the pulse distributor and to the output of the first AND element, a register connected to the pulse distributor, a fifth counter connected to the pulse distributor, a second digital-to-analog converter and a DC amplifier, the output of which is connected to the tablet’s coordinate buses. 2. The device pop. 1, characterized in that the pulse distributor g comprises a first trigger, one input of which is ^! the first input of the pulse distributor, and the output is connected to the first one-shot, connected to one input of the first AND-NOT element, the other input of which is connected to the second one-shot, and the third input is the second input of the pulse distributor, the second trigger, one input of which is the third input of the pulse distributor , the other is connected to the third one-shot connected to the single pulse generator, and the output is connected to the input of the second one-shot, the second AND-NOT element, the inputs of which are connected to the generator pulses, with a third one-shot and with a second element NOT, an operation counter whose inputs are connected to a third one-shot connected to another input of the first trigger and the output of the first AND-NOT element, and the outputs are connected to a second decoder connected to the second element ment AND-AND, and the third element AND NOT, that NOT and to one input of the group of elements AND NOT, the other inputs of which are connected to the output of the second element AND NOT, the fourth one-shot connected to the output of the second elem whose inputs are connected to the fourth one-shot and by sec th element of NO, and the output is an output of momentum distributor