SU1383416A1 - Device for reading out graphic information - Google Patents

Abstract

The invention relates to the field of automation and computer technology, in particular to devices for reading graphic information, and can be used in automated design systems. The purpose of the invention is to increase the reliability of the device. The device contains a tablet with coordinate tires, current pulse drivers, keys. switchboard switching unit, switchboard, control unit, readout control unit, information exchange unit, coordinate determination unit, load element, threshold elements, AND elements, OR element, fault code register, display element, read element and inductive sensors located on tablet and the most distant from each other. When polling tires lying in the sensitivity zone of the sensors and the reading element, their location codes are recorded in the counters of the control unit and in the units for determining the coordinates. When polling the last bus in the control unit, a signal is generated by which the sensor codes are written to the readout control unit, where the sum of the two sensor codes with the number B is analyzed. If they are equal, the control unit generates a resolution pulse for the information exchange unit. 4 il. § (L

Description

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The invention relates to automation and computer technology and can be used to read graphical information for input into electronic computers.

The aim of the invention is to increase the reliability of the device.

FIG. 1 shows a block diagram of the device; in fig. 2 is a control block diagram; in fig. 3 is a diagram of the switching unit of the coordinate buses; in fig. 4 is a diagram of a read signal control unit.

The device contains a tablet 1 with systems of inter-orthogonal coordinate buses, a current pulse former 2, keys 3, inductive sensors 4, a read element 5, an inductive sensor 6, a coordinate bus switching unit 7, a control bus 8, a read signal control block 9, an exchange block 10 is "external unit.

The device also contains a switch 11 of read signals, a unit 12 for determining the coordinates, a load element 13, an amplifier 14, threshold elements 15-17 the first element AND 18, the element OR 19, the second element AND 20, the fault code register 21 and the display element 22.

Tablet 1 is made in the form of a supporting structure with a flat surface. On the tablet surface, two mutually orthogonal tire systems are laid, which sample the surface into equal parts.

The current pulse driver 2 and the keys 3 are designed to generate a pulse current through the bus at the time the control pulse arrives from the switching unit 7.

The inductive sensors 4 and 6 and the read element 5 comprise a series-connected inductor and an amplifier-limiter. Sensors 4 and 6 are permanently fixed in one place, the coordinates of which are known in advance. The read element 5 is connected to the switch 14 by a cable, which allows it to move freely along the surface of the tablet. When the readout element 5 is placed near the bus, through which a pulsed current flows, or a survey in the sensing range of the sensors is induced in the coil, the signal is amplified by the limiting amplifier L and fed to the input of the readout switch 11.

The control unit 8 (Fig. 2) is designed to generate control pulses for the switching unit 7, the switch 11, the control unit 9, the coordinate determining unit 12, and also to generate the coordinate codes of the two sensors 4 and 6 for the control unit 9 and the element code 5

readings for the coordinate determination units 12 and the fault code register 21.

The control unit 8 comprises a pulse generator 23, a multiplexer 24, the first element AND 25, the first counter 26, the second 27, the third 28 and the fourth 29 And elements, the second counter 30, triggers 31-33, the comparison circuit 34, the fifth 35 and the 36 elements And; trigger 37, delay element 38, block outputs - 39, the third 40 and fourth 41 counters.

Switching unit 7 (Fig. 3) contains a counter 42, a multiplexer 43 and decoders 44-47.

The read signal control unit 9 (Fig. 4) contains an adder 48 and a comparison circuit 49. The information exchange unit 10 is intended for communication with external devices.

The switch 11 of the read signals is intended for alternately connecting to the input of the control unit 8 signals from sensors 4 and 6 and from the read element 5.

The coordinate determining unit 12 is a register in which the code of the coordinates of the point is stored by the read element 5.

The entry in the register is made according to a permission signal from control unit 8.

Amplifier 14 contains an operational amplifier that pre-amplifies the voltage drop across the measuring resistor 13. The amplified signal is fed to the inputs of the threshold elements 15-17.

The threshold elements 15-17 convert the input signal from amplifier 14 to the level of a logical unit, provided that the signal is less than UH, greater than Ue or greater than UH, but less than Us. They are made on the comparator.

Register 21 is for storage

information about the malfunction of the tablet 1. In the lower bits of the register 21, the signal from the OR 19 element records the malfunctioning bus code, and the most significant bit is recorded as a malfunction: logical unit - the bus is closed with another bus; logical zero - the bus is broken.

The display element 22 is intended to alert the operator of the malfunction of the plate 1 and consists of a decoder and a single indicator.

The device works as follows.

In the initial state, all the memory elements are in the zero state, which corresponds to connecting the first bus along the X coordinate. When the read element 5 is located on the surface of the tablet 1 and the Start button (not shown) is pressed, the polling pulses from the counter output

32 of the control unit 8 initiates the switching unit 7, which sequentially connects the driver 2 current pulses and the keys 3. The buses are excited along the coordinate axes separately in time. At the first time cycle of the operating cycle, the switching unit 7 includes current drivers 2 and keys 3, providing a consistent excitation of the tires along the X axis, and the second connects the buses along the Y axis.

At the time of excitation of the coordinate tires, a pulse current flows through the load element 13. The voltage signal formed on element 13 and amplified by amplifier 14 is fed to the inputs of three threshold elements 15-17.

Three options are possible.

 , then at the output of the first threshold element 15 a pulse is formed, which will go to the first input of the element OR 19 and the inverse input of the element AND 20, the second inputs of which will receive a logic zero signal from the output of the third threshold element 17. At the output of the element OR 19, a pulse is generated will go to the input of the register entry 21, in which the polled bus code will be overwritten from the third output of control unit 8 and the malfunction code (logic level zero, which corresponds to the interrupted polling bus) from the output of the second element And 20 and the bus number and fault code are displayed on the display element.

, then a pulse is formed at the output of the second threshold element 16, which goes to the second input of the first element AND 18, the first input of which contains a logical zero signal from the output of the element OR 19. At the output of the first element And 18, a pulse is formed that will go to the resolution input control block 8. Register 21 does not record at this, since there is no permission from the OR element 19.

Uftx Ue, then at the output of the third threshold element 17 a pulse will be generated that will go to the second inputs of the element OR 19 and the second element AND 20. At the same time, at the first input of the element OR 19 there is a signal (logic level zero) from the output of the first threshold element, and the first input element And 20 the same signal, only inverse. At the output of the element And 19, a pulse is formed, which goes to the input of the recording permission of register 21, and the code of the polled bus from the third output of the control unit 8 will be overwritten into the register 21. At the same time, the malfunction code will be overwritten (the level of the logical unit formed by the second element 20 And that the tire is shorted with others). The bus number and fault code are displayed on the display element 22.

The signal from the coordinate tires is read by the read element 5 and the sensors.

4 and 6, if the inductance coil of these elements is in close proximity to the interrogated bus. The signals from the outputs of the element 5 readout and sensors 4 and 6 are fed to separate inputs

Q of switch II, which in turn connects them to the first input of control unit 8, at the control signal — from the second output of the same block.

The operation of the device in determining the location of the element 5 reading on

5, the X coordinate. When the start button is pressed, the pulse sequence from the first output of the control unit 8 arrives at the switching unit 7, which with the formers 2 to the keys 3 organize sequential polling of tires along the X coordinate.

When polling a tire located in the sensitivity zone of the first sensor 4, a pulse is generated at the output of the switch 11, which is sent to one input of control unit 8, to the other input of which

five

the resolution signal will come from the first element AND 18, since the voltage drop on element 13 is within the normal range, i.e. . The coordinate code of the location of the first sensor is recorded.

Q in the first register of the control block 8. When polling the bus, located in the sensitivity zone of the read element 5, the control signal from the second output of the control unit 8 generates a pulse at the output of the switch 11, which is fed to the input of the control unit 8, to the other input of which the resolution will come from the output of the first element 18. The coordinate code of the location of the read element 5 on the enable signal from the fourth output of the control block 8 will be overwritten in the register

0 of the block 18 for determining the coordinates.

When polling the bus, located in the sensitivity zone of the second sensor 6 by the resolution signal from the control unit 8, the output of the switch 11 is formed

With a pulse that goes to the second input of the control unit, the first input will receive a resolution signal from the output of the first element 18. The coordinate code of the location of the second sensor 6 will be written to the second register of the control block 8. Thus, the survey continues to the last tire. When polling the last bus by the X coordinate in the control block 8, the resolution is formed.

On the leading edge of this pulse, the coordinate codes of the first 4 and second 6 sensors from the fifth output of control unit 8 will be overwritten into control unit 9. On the falling edge from the first output of block 8 controls

The switching unit 7 will disconnect the drivers of current pulses 2 and the keys 3 from the buses along the X coordinate and connect the generator 1 and the keys to the buses along the Y coordinate. If the sum of the codes of the first 4 and second 6 sensors equals the number B code, then block 9 The control will generate an expansion pulse for the exchange, on the leading edge of which the code of the element 5 is read from the output of the coordinate determining unit 12, through the exchange unit 10 will be overwritten in the computer memory. The pulse generated by the control unit 8 when polling the last bus, the delayed delay element 38 of the control unit 8, the device returns to its original state. Similarly, the determination of the Y coordinate occurs.

The proposed device possesses, in comparison with the known high reliability of reading graphic information, by introducing two sensors, a switch 11 and a control unit. In block 9 of the control, at the end of the polling cycle, the sum of sensor codes 4 and 6 installed at fixed points of the tablet, with the code number B, is analyzed. If the codes are equal, block 9 fixes the resolution pulse for block 10 of the exchange. This means that the plate from the first 4 and second 6 sensors in the tablet is operational, and the obtained value of the coordinate of the read element is reliable.

Claims (1)

Invention Formula A device for reading graphic information containing a tablet with systems of mutually orthogonal coordinate buses connected respectively to the outputs of current pulse shapers and switches, the outputs of which are combined and connected to the amplifier input and the first output of the load element, the second output of which is connected to the zero potential bus, the control inputs of the current pulse drivers and switches are connected to the corresponding outputs of the switching bus, control five 0 5 0 0 The main input of which is connected to the first output of the control unit, the second output of which is connected to the control input of the coordinate determining unit, the output of which is the first information output of the device, the first and second threshold elements, the first information inputs of which are respectively the first and second information the inputs of the device, and the outputs are connected to the inputs of the OR element, and the reading element, which is inductively connected to the coordinate tires of the plate, is characterized in that, in order to increase the reliability of the device It contains two inductive sensors installed on the tablet and as far as possible apart from each other, a read signal switch, a third threshold element, the first information input of which is the third information input of the device, a read signal control unit, the first and second And elements, and connected in series the fault code register and the display element, with the amplifier output connected to the second analog inputs of the first, second and third threshold elements, the outputs of the first and second n The corneous elements are connected to the inputs of the second AND element, the output of which is connected to the first control input of the fault code register, the second control input of which is connected to the output of the OR element and the first input of the first AND element, the second input of which is connected to the output of the third threshold element, and the output connected to the first input of the control unit, the second input and the third output of which are connected respectively to the output and control input of the read signal switch, whose information inputs are connected to the outputs the readout element and the inductive sensors, the information inputs of the coordinate determination unit and the fault code register are connected to the fourth output of the control unit, the fifth output of which is connected to the information input of the read signal control unit, the output of which is the control output of the device. FIG. 3 Fy