SU617777A1 - Graphic information readout arrangement - Google Patents

Description

one

The invention relates to automation and computing, in particular to devices for reading graphic information.

Apparatuses for reading graphic information are known.

One of the known devices contains a scanning unit with pulse sensors, an output connected via a video signal shaping unit to a coordinate measurement unit, the inputs of which are connected to a control unit and through the first element AND to a generator, a switching unit connected to the ordinate register and through a decoder to the second element And, a code conversion unit coupled to the control and coordinate measurement units 1.

The disadvantage of this device lies in its structural complexity.

Another device is known comprising a scanning unit connected to a video signal generating unit with the first and second pulse sensors and through a pulse generator with the first element I, a control unit whose inputs are connected to the second pulse sensor and the video signal generating unit, and the outputs are connected to the first and second And elements and through the delay element with the code conversion unit, the ordinate difference determination unit, the switching unit, the decoder and the third And 2 element.

Such a device is closest to the described technical solution.

The disadvantage of this device is its low accuracy.

The purpose of the invention is to improve the accuracy of the device.

The goal is achieved by the fact that in it the inputs of the unit for determining the difference of ordinates are connected to the code conversion and control units, to the first element AND, to the second element AND connected to the first pulse sensor, and through the third element And to the control unit and to the second pulse sensor and the outputs are connected via a serially connected switching unit, connected to the control unit and a delay element, and a decoder, connected to the code conversion unit.

The code conversion unit contains a series-connected pulse generator, a key and the first counter, the input of which is connected to the second counter, and the output is connected to the key input.

The drawing shows a block diagram of the device.

The device includes a scanning unit 1, the first 2 and second 3 pulse sensors, a video signal generating unit 4, a control unit 5 containing a line selection circuit 6, a key 7, a button 8 and a switch 9, an ordinate difference determining unit 10, a decoder 11, a switching unit 12 , delay element 13, first 14, second 15 and third 16 AND elements, code conversion block 17 consisting of first 18 and second 19 counters, key 20 and pulse generator 21, and pulse generator 22.

The device works as follows.

The start-up units of the control unit 5 establish the switching of the circuits for recording the first ordinate in block 10, for which the output of the element 16 is switched to the input of the block 10 by switch 16 and the key 7 is open. By pressing the button 8 from the power source once, the element 15 is prepared, and with the arrival of the start pulse of the sensor 2, it opens the element 14, while the pulses from the generator 22 are fed to the input of the block 10.

The same impulse prepares element 16 for actuation and arrives at another input of unit 10. With the input to element locking element 14 of the signal from block 4, the latter is blocked and the pulse at the input of unit 10 stops.

When the signal of the end of the scan from the sensor 3 pulses to the input element And 16, with its output passes the signal to the input unit 10 and the device is ready for operation. After that, the start-up units of block 5 are set to another position: with key 7, the sensor 3 of the end-of-pulse impulses is connected to the preparing input of element 15, and with switch 9 the output of element 16 and 16 to the input of block 12 and through element 13 of delay to the unlocking input of key 20 of block 17 A pulse from sensor 3 prepares element 15 and, when a signal from sensor 2 arrives at its input, the signal from output 15 of element 15 opens element 11, prepares element 16 and switches the output circuits of unit 10.

From the beginning of the supply of pulses to the input of the record of block 10 to the termination of their arrival, in block 10, subtraction of ordinates takes place.

When pulses are received from the sensor 3, the pulses of the end of the scan to the input of the element AND 16 from its output, the pulse passes to the input of block 12, which census the input of the decoder 11 of the ordinate difference code, and from the corresponding output of the decoder 11, the signal goes through the separation diodes bits of the counter 18 of the block 17. In addition, the same pulse from the output

element 16 through delay element 13 is applied to the unlocking input of key 20. Key 20 opens, and the filling pulses from generator 21 begin to hit the inputs of counters 18 and 19. When the counter 18 is filled with its last bit, a pulse is output to lock the key 20 and enter the pulses in counters 18 and 19 stop. The impulse from the last discharge of the counter 18 is also fed to the control input of the unit 10, thus preparing the device for the next cycle of operation.

With a quantization step on both axes of 0.2 mm and a maximum allowable line slope of 87 °, the difference in ordinates can take 21 values, from 0 to 4 mm. Therefore, the decoder must have 21 outputs.

For each particular value of the difference of ordinates, a signal appears at the corresponding output of the decoder, which is recorded in a combination of bits of counter 18 of block 17, corresponding to the inverse square root code of the sum of squares of the difference of ordinates and quantization step on the abscissa. Therefore, when the filling pulses are fed in parallel to the counters 18 and 19, the number of pulses received in counter 19 before locking the key 20 is proportional to the length of the segment of the curve between the corresponding ordinates. The sum of the lengths of the elementary segments is proportional to the length of the entire line.

The introduction of new constructive links has significantly improved the accuracy of the device.

Claims (2)

1. A device for reading graphic information containing a scanning unit connected to a video signal generating unit with the first and second pulse sensors and through a pulse generator to the first element I, a control unit whose inputs are connected to the second pulse sensor and to the video signal generating unit, and the outputs are connected to the first and second And elements and through a delay element with a code conversion unit, an ordinate difference determination unit, a switching unit, a decoder and a third AND element, characterized in that In order to improve the accuracy of the device, the inputs of the ordinate difference unit are connected to the code conversion and control units, to the first And element, to the second And element connected to the first pulse sensor, and through the third And element to the control unit and to the second pulse sensor, and the outputs are connected via a serially connected switching unit connected to the control unit and to the delay element, and the decoder is connected to the code conversion unit. 2. A device according to claim 1, characterized in that the code conversion unit comprises successively connected pulse generator, a key and a first counter, the input of which is connected to the second counter, and the output is connected to the input of the key. Sources of information taken by the attention in the examination 1. USSR author's certificate number 358710, cl. G 06K P / OO, 1973. 2.Japanese patent number 21906, cl. 97 (8) OT, publ. 1968.