RU1830540C - Device for graphic data sensing - Google Patents

Abstract

The invention relates to the field of automation and computer engineering and can be used to input graphic information into computers. The purpose of the invention is to increase the accuracy of the device by enabling the use of a linear portion of discriminatory characteristics. The goal is achieved by introducing a memory block, a gating block, and a shift register with corresponding relationships. The device comprises a tablet with a mutually orthogonal bus system, X and Y polling units, a decoder, a counter, a register, a bus excitation generator, a memory unit, a gating unit, a coordinate picker, an amplifier, an analog-to-digital converter, four shift registers, a comparison unit, control unit. 1 ill.

Description

The invention relates to the field of automation and computer engineering and can be used to input graphic information into computers.

The purpose of the invention is to increase the accuracy of the device by enabling the use of a linear portion of discriminatory characteristics.

The drawing shows a block diagram of a device.

The device for reading graphic information includes a tablet 1 with a system of mutually orthogonal coordinate buses, a polling unit according to X 2, a polling unit no Y 3, a decoder 4, a counter 5, an output register 6, a bus excitation generator 7, a memory unit 8, a gating unit 9 , coordinate pick-up 10, amplifier 11, analog-to-digital converter 12, first 13, second 14, third 15, fourth 16 shift registers, comparison unit 17. control unit 18, output of device 19, control input of device 20.

The device operates as follows.

After turning on the power, the control unit 18 begins to produce rectangular pulses with a frequency f, for example, 100 kHz. These pulses are fed to the counter 5, to the bus excitation generator 7. The analog-to-digital converter 12, to the shift registers 13, 14. 15, 16 and to the comparison unit 17. The counter 5 summarizes the pulses arriving at its input, the summing results go to the decoder input 4, which generates control signals supplied to the inputs of the units for interrogating coordinate buses 2 and 3. To the other inputs of these units, from the output of the bus excitation generator 7, an excitation signal is generated, which is generated under the influence of synchronizing signals supplied to its input mpulsov output from the control unit 18. Blocks survey coordinate tires 2 and 3 are connected in series tablet tire 1 to the output of the generator field

cl

with

00

with

about sl

4. About

bus 7, creating a scanning electromagnetic pope above the tablet 1. When the coordinate pick-up 10 is placed in the scanning field of tablet t, EMF from the tablet 1 tires located in the sensitivity zone of the coordinate pick-up 10 will be induced in the pick-up 10. The read signal from the output of the pick-up 10 to the input of the amplifier 11, where it is amplified in amplitude and fed to the input of an analog-to-digital converter 12 to convert its value to a digital code and to the gating unit 9 to generate a signal defining the sensitivity zone c emnika coordinates 10. The output of analog-to-digital converter 12, the digital code converted signal is input to the first shift register 13, which is fixed under the influence of the clock pulse. From the output of the shift register 13, the digital code is fed to the input of the second shift register 14 and to the first input of the comparison unit 17. When the condition is met when the output of the fourth 16 and third 15 shift registers exceeds zero, and the output of the second 14 and the first 13 shift registers the code value is less than zero, then, under the influence of synchronizing pulses, a signal passes through zero at the output of the comparison unit 17. From the output of this block, the result is fed to the input of the gating unit 9, where it is gated by a signal defining the frost section of the discriminatory characteristic of the sensitivity zone of the coordinate pick-up 10. The output signal of the gating unit 9 is fed to the clock input of the output register b to fix the code of the read signal. In the output register in the initial state, the output will have a code value equal to zero in the absence of the coordinate pick-up 10 in the electromagnetic field of the tablet 1. To obtain the result, the coordinate pick-up is introduced into the electromagnetic field of the tablet 1 (or the communication link of the coordinate pick-up 10c with amplifier 11 is turned on). To stop the change of result, the coordinate remover is removed from the electromagnetic field of the tablet 1 (or the circuit is broken). To continue the process, the coordinate pick-up 10 is again inserted into the scanning electromagnetic floor of the tablet 1. In each reading cycle, the result in the output register is updated, therefore, when the coordinate pick-up 10 is removed from the electromagnetic field of the tablet 1, the code of the previous result remains at the output of the output register 6, and when placing the coordinate remover in the scanning electromagnetic field of the tablet 1 code on

register output 6 - new. This mode eliminates the input to the computer of a false coordinate — zero when reading coordinates from points. The code at the output of register 6 is determined by the result at the output of counter 5, i.e. the number of the bus closest to the stripper of the coordinates 10 on the scanning side, and the result from the output of the memory unit 8. The value of the code at the output of the memory unit 8 is determined by the input codes coming from the outputs of the second 14 and third 15 shift registers. The memory unit 8 is a reprogrammable memory element that is programmed so that the output at the output of the unit 8 is algebraically related to the input codes, with a fixed distance between the buses and the normalized amplitude of the drive signal. In this case, in any inter-tire gap in the coordinate pick-up 10, which is an inductor, the EMF will be induced from each of the tires, between which is the center of the coordinate pick-up coil 10. The magnitude of the EMF depends on the distance to these tires. When you move the center of the coil of the stripper coordinates 10 from one tire to another, the magnitude of the EMF from the first tire will decrease, and from the second - increase. When using the linear section of the discriminatory characteristics of the puller coil 10 to read precisely these responses, the result at the output of register 6 reflects the proportional linear dependence of the induced EMF values from the distance to these buses. In this way, the distance from the nearest bus from the scanning side to the center of the coordinate pickup 10 is determined. From the output of the output register 6, the read result is transmitted to the computer. As the signal from the buses located in the sensitivity zone of the coordinate pick-up 10 is read, the digital codes of these signals will be shifted from the first 13 shift registers to the fourth 16 shift registers, while being compared in the comparison block 17. The introduction of the fourth 16 shift registers into the device allows analyze a longer section of the discriminatory characteristic of the sensitivity zone of the coordinate pick-up 10 and, in addition, allows you to use a coordinate pick-up, the coil diameter of which, for example, is four times pain distance between coordinate buses. The use of four shift registers, a memory unit and a gating unit provides the ability to work in a linear section of the discriminatory characteristics of the sensitivity zone of the coordinate stripper, which,

ultimately, provides improved accuracy of reading coordinates by the device,

Claims (1)

The claims A graphic information reading device comprising a tablet made in the form of a system of two mutually orthogonal coordinate chic, the excitation inputs of which are connected to the decoder output via the corresponding bus interrogation units at the X and Y coordinates, and the clock inputs are connected to the output of the bus excitation generator. the decoder’s input is connected to the counter output, the coordinate stripper, the information output of which is connected through the amplifier to the information input of the analog-to-digital converter, the output of which is connected to the information input of the first shift register, and the clock input combined with the counter inputs of the same name and three shift registers, connected to the same output of the control unit, the first output of the first shift register is connected to the information input of the second shift register, the first output of which is connected to the information the third shift register, the second outputs of the first, second and third shift registers are connected to the corresponding inputs of the comparison unit, and an output register, characterized in that, in order to improve accuracy by making it possible to use the linear portion of the discriminating characteristic, a memory unit, a gating unit and a fourth shift register are introduced, the input of the bus excitation generator is connected to the clock output control unit, the second output of which is connected to the fifth input of the comparison unit, the fourth input of the second is connected to the output of the fourth shift register, the clock input of which is connected to the same name the output of the control unit, and the information input is to the first output of the third shift register, the output of the comparison unit is connected to the control input of the gating unit, the information input of which is connected to the output of the amplifier, and the output is connected to the clock input of the output register, the first information input of which is connected to the output of the counter, and the second to the output of the memory unit, the first information input of which is connected to the second output of the second shift register, and the second to the second output of the third shift register, the output of the output register is the output of the device, and the input of the control unit is the control input of the device.