SU1531117A1 - Device for reading graphical information - Google Patents

Abstract

The invention relates to automation and computing and can be used to read graphic information. The purpose of the invention is to improve the accuracy of reading graphic information by automatically taking into account the influence of external conditions. To do this, a device containing a tablet with systems of mutually perpendicular coordinate buses divided into groups, first and second switches, a group of OR elements, a coordinate remover made in the form of an inductance coil inductively connected to coordinate buses and connected to a control unit, a block coordinate determination, a phase converter and a read signal duration analysis block are inserted, containing counters, frequency dividers, AND, OR elements, delay element, triggers, and comparison element, and a phase converter the recipient contains an emitter follower, the first and second comparators, an amplifier, separating capacitive elements and element I. 2 Cp. f-crystals, 7 ill.

Description

The invention relates to automation and computing, in particular, to devices for converting graphic information into digital code with subsequent input into a computer, and can be used in automated control and design systems.

The purpose of the invention is to improve accuracy.

FIG. 1 shows a block diagram of a device; FIG. 2 - electrical circuit diagram of the phase converter; in fig. 3 is a functional block diagram of the analysis of the duration of the read signal; in fig. k - scheme

control unit; in fig. S amplifier circuit} in FIG. 6 is a block diagram of the determination of coordinates; FIG. 7 is a diagram illustrating the principle of operation of the phase converter.

The device (Fig. 1) contains a tablet 1, coordinate buses 2, elements OR 3, first and second 5 switches, a read element 6, an amplifier 7, a control block 8, a coordinate determination block 9, a phase converter 10, a read signal duration analysis block 11 device output 12.

In addition, in FIG. 1 shows the first 13 and second 1A information

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the inputs of the first switch k, the outputs 16 and 16 of the second switch 5. inductively connect the coordinate buses 2 with the input 17 of the read element 6, the output 18 of the read element 6, the output 19 of the amplifier 7, the outputs 20-2 of the control unit, the output 25 of the phase converter 10 , outputs 2b and 27.

phase converter 10 (FIG. 2) contains an emitter follower 28 containing a resistor 29, a transistor 30, a capacitor 31, a resistor 32, a transistor 33, a resistor 3, the first 35 and second 36 separation (capacitor elements) capacitors, the first 37 and the second 38 comparators, amplifier 39, made on resistors kQ and k, field-effect transistor 2 and resistors 3 and 4, element I 45.

The unit 11 for analyzing the duration of the read signal (Fig. 3) contains the first counter 46, the first divider 47 the first 48, the second 49, the third 50, the fourth 51 and the fifth 52 elements And the second 53, the third 5 and the fourth 55 counters, the element 5b, the delay element 57, the second divider 58, the first trigger 59, the sixth 60 and the seventh 61 elements AND, the first element OR b2, the fifth counter 63, the second and third b5 triggers.

The control unit 8 (FIG. 4) contains the first generator 66, from the eighth to the tenth elements AND b7-B9, the indicator 70 connected to the thirteenth elements AND 71-73, the fourth Jk and the fifth 75 triggers, the second element OR 7b, sixth trigger 77, third divider 78, fourteenth to eighteenth elements AND 79-83, second generator, sixth 85 and seventh 86 counters.

Amplifier 7 (FIG. 5) comprises a linear amplifier 87 made on a resistor 88 and an amplifier 83, a diode 90, a comparator 91 made on a resistor 92 and a comparator 93. FIG. 5 also shows microswitch 9.

The coordinate determining unit 9 (Fig. 6 contains the first 95 and second 96 adders, the first 97 and second 98 registers.

The device works as follows.

When the power is turned on, the device is reset. In this case, all of its memory elements are reset (zeroed). In that

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The device is in a state before the start of the preparatory stage, which begins when the operator installs read element 6 at a fixed point of tablet 1. Fixed point is above the penultimate bus 2 in the first tire group 2 according to the x coordinate of tablet 1 .. When installing read element 6 on a tablet 1, a microswitch located in it (FIG. 5) is closed and the corresponding enable signal is fed through amplifier 7 to control unit 8. The control unit 8 sends to the switch 4 the code of the polled bus group on the X coordinate of tablet 1, the polling signal of bus 2, and the switch 5 sends the polled bus 2 code. According to the logic of the block 8, the first bus group 2 on the X coordinate is polled in the preparatory stage, t . the last bus is polled in the first group of tires 2. In this case, an EMF is induced in the coil of the readout element 6, the value of which depends on the distance from the polled tire 2 and on the external operating conditions of the device (temperature, humidity, etc.). The induced signal from the output 18 of element 6 enters the phase converter 10, where it is converted into square pulses, the duration of which is proportional to the amplitude of the signal. The frequency of the indicated pulses from the output 25 of the phase converter 10 and their number in one polling cycle of bus 2 is determined by the frequency of the harmonic signals received at this time from the fourth output 23 of the control unit 8 to the second input of the phase converter 40. Pulses of a certain duration from the output of the phase converter 10 is fed to the information input of the read signal duration analysis unit 11. In block 11, these pulses are filled with high frequency pulses and the number of high frequency pulses that are contained in one pulse from the output 25 of the phase converter 10 is counted.

Thus, the measurement of the pulse duration from the output of the phase converter 10 is carried out, and therefore, the amplitude of the signals from the output 18 of the readout element 6 is measured. Measuring amplitude51

the signal at the output of element 6, i.e. measuring the duration of the signal at the output 25 of the phase converter 10, you can determine the position of the element 6 relative to the interrogated bus 2 of the plate 1. The pulse duration at the output 25 of the phase converter 10 depends on the temperature and humidity of the surrounding atmosphere, on the thickness and

properties of used graphic media. In order to ensure high accuracy in measuring the coordinates under changing external conditions, it is necessary to provide the same number of filling pulses in the I1 pulses from the output 25 of the phase converter 10 with the fixed position of element 6 relative to the polled bus 2. In the preparatory stage of operation of the device element 6 is located at the indicated fixed point of the plate 1 and the device is adapted to the changing external conditions by changing the frequency of the filling pulses in block 11. The frequency of the filling pulses is changed by a corresponding change in the block 11 of the pulse frequency division factor, which continuously comes from the fifth 2k output of the block 8 to the synchronization input of the block 11 with the microswitch 96 of the element 6 closed. until their number in one pulse from the output 25 of the phase converter 10 becomes equal to the required number Y stored in block 11. At the same time, from the first output 26 of block 11, the synchronization input of block 8 receives a signal Indicator 52 lights up in it, which signals the operator that the device has been set up for external conditions. When the operator removes the readout element 6 from the specified fixed point of the tablet 1 (i.e., the microswitch 6 is opened in the element 6), the signal from the output of the microswitch 9, which came from the output 18 of the element 6 through the amplifier 7 to the information input of the control unit 8, is removed. This ensures the completion of the preparatory stage of the device and the installation of the unit

8 and the entire device to its original state. In this state, the corresponding memory elements are set

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The device is reset and the device is ready to read the coordinates of the points of graphic information.

The coordinate reading cycle starts when the reading element 6 is aligned with the selected image point within the working surface of the tablet 1. At the same time, the microswitch 9 in the read element 6 is closed and the corresponding resolution signal from the output 18 of the element 6 is fed through the amplifier 7 to the information input of the unit 8 management The reading of the coordinate begins with a search for a group by the coordinate X, in the region of which the read point is located. The control unit 8 starts the sequential polling of bus groups 2 by issuing to the switch C the code of the polled group and the clock pulse, and to switch 5 the code of the last bus 2 in the bus group. Thus, using switches + and 5, controlled by block 8, the serial connection of bus groups 2 along the X coordinate and supply of polling pulses to the last bus 2 alternately of each group begins, starting with the first, and then counting in block 8 the number of polled groups to until the signal from the first polled last tire in the group to the right of the read point (right pulse) induced in element 6 is detected. The specified signal from the output 18 of the element 6 is fed to the amplifier 7 and from its output 19 to the information input of the control unit I. Due to this, block 8 records the number of polled groups preceding the location area of the read point, and block 8 starts a consecutive search for tire 2 to the last of the polled tire groups along the X coordinate. At the same time, block 8 through the switch keeps the group open from the last bus which received the right pulse, and through the switch 5 performs the serial connection of buses 2 of this group, starting with the first one. Interrogation of connected tires 2 in the group fixed in block 8 and counting of interrogated tires 2 is carried out until the signal from the first interrogated bus 2 to the right of the read point appears in element 6. This signal with you 15

The stroke 18 of the element 6 through the amplifier 7 enters the information input of the block 8, so that in the block 8 the number of polled buses 2 is fixed in the fixed group. At the same time, the polling pulse of bus 2 (diagram a in Fig. 7) of control unit B outputs to the synchronization input of the phase converter 10 a sequence of harmonic signals (diagram b in Fig. 7). When a bus 2 arrives at the moment of polling from element 6 to the information input of the right pulse phase converter 10, the latter converts its amplitude to the pulse duration, which is fed from its output 25 to the information input of the read signal length analysis unit 11. The number of these pulses is determined by the number of harmonic signals received at the synchronization input of the phase converter 10 in the polling cycle of bus 2. The pulses from the phase converter 10 are fed to the information input of block 11. When the right pulse arrives in the search mode of bus 2 in group 8, in addition to fixing the number of tires in a group of tires 2 generates the specified pulse from its output 2k to the synchronization input of block 1 1 accompanied by high frequency pulses. If the right pulse arrives at the second synchronization input of the unit 11, the latter starts counting the filling pulses corresponding to the right signal of the pulses from the output 25 of the phase converter 10. The frequency of the filling pulses is determined by dividing the frequency of the pulses from the output 2k in block 11 block 8, by the coefficient stored in block 11 at the output of the counter 46, and determined at the preparatory stage of the device operation taking into account the existing external conditions. Simultaneously with counting the number of filling pulses in the pulses from the output 25 of the phase converter 10, the block 11 performs the counting of the last counter 55. After the right pulse from the output 2 of the block 11 has finished, the block 8 performs the determination and fixation in the counter 63 of the average number of filling pulses in one pulse output 7-5 phase conversion

eight

Summoner 10, i.e. fixation and determination of the exact reference. In this way, the position of the read point in the space between the tires 2 is refined by measuring the amplitude (counting the number of filling pulses) of the corresponding right pulse. The code of the exact reference comes from the output 27 of the block 11 to the second information input of the block 9 of the determination of the coordinates, accompanied by the recording clock pulse. In this case, the first information input of the block 9 from the output 22 of the block 8 receives the previously defined codes of the corresponding group and the bus. Thus, in block 9, the coordinate X of the read point is determined and fixed in register 97. After issuing in block 9 of the coordinate X of the read point, the device proceeds to determine its Y coordinate. The process of determining the Y coordinate is carried out similarly. The coordinates X and Y of the read point are stored in registers 97 and 98 of block 9 and are output to the device output 12 until the next point is read. After determining the coordinates of the points, the device returns to its original state. If the element 6 is on the tablet surface (microswitch 9 is closed), the next coordinate determination cycle begins. In the opposite case, the device remains in its original state. If the operator removes element 6 from plate 1 before the end of the corresponding coordinate determination cycle, the device will forcibly return to the initial state without completing the formation of the coordinates, while the codes previously recorded in registers 97 and 98 are retained.

Claims (3)

1. A device for reading graphic information containing a tablet with systems of mutually perpendicular coordinate buses divided into groups, the first switch. the first and second information inputs of which are connected through groups of elements OR to the coordinate buses, the second switch, the output of which is connected to the corresponding coordinate tires, the puller of coordinates, made in the form of an inductive coil. 51 inductively connected to coordinate buses and connected via an amplifier to the information input of the control unit, the first, second and third outputs of which are connected, respectively, to the control inputs of the first and second switches and the first information input of the coordinate determination unit, the output of which is the device output characterized in that, in order to increase the accuracy of the device, it contains a phase converter and a read signal duration analysis unit, an information input and a synchronization input the phase converter is connected respectively to the output of the coordinate remover and the fourth output of the control unit, the fifth output of which is connected to the synchronization input of the read signal duration analysis unit, the first and second outputs and whose information input is connected respectively to the synchronization input of the control unit, the second information input of the coordinate determining unit and the output of the phase converter. 2. A device according to claim 1, characterized in that the phase converter includes an emitter follower, a first and second comparators, an amplifier, capacitive coupling elements and an And element, the information input of the amplifier is an information input of the converter, a synchronization input through the first separating capacitive element connected to the first output of the emitter repeater, the second output of which is connected to the input of the second comparator via the second separating capacitor element, the output of the amplifier is connected to the input of the first the comparator, the outputs of the first and second comparators are connected to the inputs of the element AND, the output of which is the output converter 3. The device according to claim 1, about tl, which is that the block of analysis of the duration of the read signal contains counters, frequency dividers, AND, OR, delay elements, triggers and a comparison element, the output of the first counter is connected to the information input of the first divider five 5311  , 20 25 thirty t, q ds 50 55 1710 frequency, the output of which is connected to the second inputs of the first, third and fourth elements And, the output of which is connected to the subtractive input of the third counter and the counting input of the second frequency divider, the output of which is connected to the counting input of the fifth counter, the output of which is the second output of the block, the inputs resetting the third, fourth, and fifth counters, the second frequency divider, and the first trigger are connected to the output of the OR element, the first input of which is connected to the output of the delay element, which is the first output of the second one OR element connected to the second inputs of the second fifth AND elements, the third inputs of the third and fourth AND elements, to the installation input of the first trigger and the counting input of the first frequency divider, is the synchronization input of the block whose information input is the first inputs of the first, second , the third and fifth elements And, the output of the sixth element And connected to the reset input of the first de-i frequency, the counting input of the first counter, the reset input of the second counter and the setup input of the second trigger, you direct the stroke of the third trigger is the first output of the block and is connected to the first inputs of the sixth and seventh And elements, the installation input of the third trigger is connected to the output of the seventh And element, the second input of which is connected to the second output of the comparison element, the first output of which is the fourth input of which is connected to the inverse output of the second trigger, the reset input of which is connected to the output of the first element AND and the counting input of the second counter, the output of which is connected to the first information The input of the reference element, the second information input of which is the input of the constant, the output of the second element AND is connected to the third inputs of the sixth and seventh elements AND, the output of the third element AND is connected to the summing input of the third counter, the overflow output of which is connected to the input of the delay element and the first the output of the block, the output of the pth element And is connected to the counting input of the fourth counter, the output of which is connected J9 et ° l W F Fig 3 IS IZJ 94 JO 93 , 3t S 96 WITH 55 FIG. 6 of. - WITH t fZ -