SU805369A1 - Graphic information readout device - Google Patents

Description

(54) DEVICE FOR READING GRAPHIC INFORMATION

one

The invention relates to automation and computing and can be used to determine the coordinates of lines in a drawing.

A device for reading graphic information is known. It contains a tablet with electroacoustic transducers, connected with amplifiers and logic elements AND with a pulse generator, a counter, registers, a control unit / connected with a coordinate counter, two ultrasonic generators, logical elements AND, OR, and elements delays 1.

The disadvantage of such a device is the low accuracy of reading graphic information.

It is also known a device containing a movable electroacoustic transducer associated with a control circuit, acoustic oscillation receivers located at a right angle to each other and connected through time pulse transducers to the inputs of the corresponding coordinate counters, a clock pulse generator connected to one of the time pulse inputs converters, other inputs

which are connected to electroacoustic converters, an additional electroacoustic converter, connected to the auxiliary input of one of the time pulse converters, a block of permanent memory, a decoder, serially connected code reading unit, an adder and a converter code - voltage, the output of which is connected to the control clock pulse generator, and the bit outputs of one of the coordinate meters and the outputs of the fixed memory unit are connected to the inputs of the code reading unit, Which odes are connected to the inputs of the adder. And through the decoder - to the control circuit.

This device also has insufficient accuracy.

The closest in technical essence to the present invention is a device for reading a graphic

information containing a tablet

electroacoustic transducers; generators of measurement cycles and correction cycles, conversion channels, each of which consists of a series-connected amplifier, amplitude discriminator, logical element And and counter,., a sound receiver, made in the form of a correction microphone, acoustically. connected to one of the electroacoustic transducers, a memory unit connected to one of the comparison inputs, the output of which is connected to the input of a reversible counter connected via a digital-to-analog converter to the control input of the clock generator connected to one of the inputs of logic elements And the conversion channels, the input of the amplifier of one of the conversion channels is connected to the correction microphone, the output of the counter and one of the inputs of the trigger of the said conversion channel are connected tween the other input of the comparison and correction cycle generator unit connected to one of elektroakusti iCal converters, and:. emnik information drawback of the known apparatus is low accuracy of the read image information. The purpose of the invention is to increase the visibility. This goal is achieved by the fact that the device contains additional logic elements AND, prohibition elements and an additional trigger, the output of the generator of measurement cycles is connected to the counting input of the additional trigger and one of the input of the prohibition element, the other inputs of which are connected to the outputs of the additional trigger, and outputs to one of the inputs of additional logical elements And, the other inputs of which are combined and connected with a puller of information made in the form of a circular micro Background with a viewfinder, and the outputs of additional ogicheskih AND elements are connected to the inputs of the amplifiers of the other two channels converting one of the inputs of AND logical elements ENTOV which are connected to the outputs of the respective elements barring and other electroacoustic transducers, are constructed as sound emitters and a point located at the plate corners. The drawing shows the block diagram of the proposed device. The device for reading graphic information contains a tablet 1, a circular microphone 2 with a sight, a first electroacoustic transducer 3, a second electro-acoustic transducer 4, a generator of 5 measurement cycles, a trigger with a counting input, a first prohibition element, a second prohibition element 8, the first logical element And 9, the second logical element And 10, three identical conversion channels, in which amplifiers 11–13 are included, amplitude discriminators 14–16 of a trigger 17–19, logic elements I 20–22, counters 23–25, a microprocessor 26 , block 17 memory, comparator unit 28, reversible counter 29, digital-to-analog converter 30, clock generator 31, correction cycle generator 32, third electro-acoustic converter 33, correction microphone 34, button K 35. A drawing is placed in tablet 1, the coordinates of which lines are to be measured and convert to a form suitable for digital processing. The circular microphone 2 is integrated with the viewfinder, which at the time of reading is combined with the point measured in the drawing. A device for reading graphic information operates as follows. When the button 35 is pressed, the generator of 5 measurement cycles produces the first measuring pulse, the duration of which is taken longer than the propagation time of ultrasound at the largest possible distance. A flip-flop of trigger b with a counting input occurs in such a way that the signal 1 from its output goes to one of the inputs of the first prohibition element 7, which opens and transmits a pulse from the generator output of 5 measurement cycles to the first electroacoustic converter 3. At the same time one of the inputs of the trigger 17 of the first conversion channel overturns it so that the logic element 20 connected to the output of the trigger 17 starts to pass pulses from the generator output 31 clock pulses to the input of the counter 23. Therefore, at the moment of emission of the acoustic signal by the electro-acoustic converter 3, the counter 23 of the first conversion channel is filled. One of the inputs of the second prohibition element 8 at this time enters O from the output of flip-flop 6 with a counting input, therefore the first impulse of the generator 5 measurement cycles is not fed to the inputs to: the high-frequency electroacoustic converter 4. and flip-flop 18 of the second conversion channel. The sound emitted by the electro-acoustic transducer 3 propagates in the direction of the circular microphone 3 with the Hue and is converted by this microphone into an electrical signal. So to & to one of the inputs of the first logical element AND 9 continues

to receive a signal from the exhaust of the first prohibition element 7, the electric signal of the circular microphone 2 connected to one of the inputs of the first logic element AND 9 passes through it to the input of the amplifier AND of the first conversion channel, converted by the discriminator 14 and leads to the reverse tipping of the trigger 17. By this the passage of pulses from the output of the geigator to 31 clock pulses is terminated.

i conversion, and in the counter 23 the number of pulses is recorded,. proportional to the time of sound propagation at a distance p,,

By the end of the counting by the counter 23, there is a short pause between pulses, after which a second pulse is generated by generator 5, leading to a flip-flop of the trigger with a counting input 6, i j. from its output it is fed to one of the inputs of the second prohibition element 8, it permits the arrival of a pulse from the output of the generator 5 measuring signals to the second electroacoustic transducer 4 and the trigger 18 of the second conversion channel.

Subsequently, all the processes occur in the same way as for the first conversion channel.

The second pulse of the generator of measurement cycles 5 ends with a record in the counter 24 of the second channel of converting the numbers of pulses proportional to the propagation time of the sound at a distance of p. Thus, the measured are both the PJ and P2 distances expressed as the number of pulses in the counters 23 and 24 of the conversion channels K and Kg. At known distances, R Pj and L microprocessor 26 calculates the desired coordinates X and Y. The calculation procedures can be completely different, one of them is recommended as a microprocessor function algorithm;

y / r / - x

2

The coordinates X and Y are the output data of the entire device.

The upper conversion channel together with a generator of 32 correction cycles, an additional electroacoustic converter 33, a correction microphone 34, a memory unit 27 and series-connected comparison unit 28, a reversible counter 29, a D / A converter 31 and a clock pulse generator 31 acts as a system with negative

feedback, the assignment of which is V to keep the number of pulses filling counter 25 unchanged. This immutability is maintained by comparing the number of pulses: counter 25 and the reference number recorded in memory block 27. If, as a result of the comparison, you see the difference registered as a code by the reversible counter 29, then. it is converted to digital-to-analog

the converter 30 is in voltage and acts on the controlled oscillator 31 clock pulses in such a way that the difference in the number of pulses of the memory block 27 and the counter 25 tends to zero. This establishes the correspondence of the constant number of pulses of the counter 25 to the reference jpac.

Thanks to such immutability in

the undesirable effect of ambient factors — temperature, pressure, humidity, etc. — is largely eliminated. - on the accuracy of measurements, and the use of point emitters 3 and 4 and circular microphone 2 makes it possible to further increase the device's depth.

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Claims (3)

1. US Patent 3692936, kl.178-18, published. 1972. 2. USSR author's certificate number 488231, cl. G 06 K 11/00, 1974. 3. USSR author's certificate №525976, cl. G 06 KI / 00, 1974 (prototype).