SU1310861A1 - Scan correction unit of device for reading graphic information - Google Patents

Abstract

The invention relates to automation and computing technology and is intended for use in scanning drum-type input devices into computers for graphical information (graphical readers). The purpose of the invention is to improve the accuracy of reading social information in the forward and reverse sweep direction by compensating for the error introduced by the thickness of the carrier. graphic image. This goal is achieved by the fact that in the scanner correction unit of the counting reader, which contains the synchronous drum angle sensor, media thickness setting unit, pulse counter, trigger, first and second OR elements, a second pulse counter, code converter, third, fourth and n elements OR and two delay elements, - The indicated set of features, depending on the direction of the sweep, ensures the formation of incremental and decrementary correction pulses, which are added to the pulse mi feedback corresponding direction and are formed at the moments when the value of additional error reaches one quantization step movement. 1 il. 2 (L o: 00 05

Description

113

The invention relates to automation and computer technology and can be used in scanning devices for reading graphic information.

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

The drawing shows the functional diagram of the proposed correction unit for a graphic information reader (to which drum 1 belongs).

The correction unit contains a synchrodate tick 2 (drum angular position), a node 3 specifying the thickness of the information carrier, the first pulse counter 4, the trigger 5, the first b and the second 7 elements OR, the code converter 8, the second counter 9 pulses, the third 10, the fourth 11 and fifth 12 elements OR, first 13 and second 14 delay elements.

The correction unit works as follows.

In the initial state, the counters 4 and 9 of the pulses and the trigger 5 are in the zero state (the reset circuit of the indicated elements, the devices are not shown in the drawing). A carrier with a graphic image is placed on the surface of the drum 1 of the graph reading device. The manual controls of the aadani unit 3 of carrier thickness are set to a position corresponding to the thickness of the carrier. The counting reader is started up, and in order to provide a horizontal scan of the graphic image, the rotation of the drum 1 in the forward direction begins. The forward direction of rotation of the drum is considered to be the direction in which a positive increment of coordinates along the horizontal scanning axis is provided. The rotation of the drum can be carried out either electrically or manually. The synchro sensor 2 mechanically connected to it rotates along with the drum. At the moment drum 1 moves through the initial position corresponding to the origin of coordinates along the horizontal scanning axis, a reference pulse (BUT) is generated at the first output of synchro sensor 2, which passes to the control output of the device . During the revolution of the drum, one impulse BUT is formed. To form the coordinates of the points of the readable graphic

In the forward direction of the sweep image, feedback pulses + IOS generated at the second output of the sync sensor are used.

These pulses through the element 7 OR arrive at the first information output of the device. When reading the coordinates of individual points of the graphic image, there is a need

setting the drum to a certain position with a high degree of accuracy. When performing this operation, it may be necessary to reverse the rotation of the drum in the vicinity of the selected point. In this case, in the reverse direction of rotation of the drum, feedback pulses of IOS are generated at the third output of the sync sensor, passing through IZH element 12 to the second information output of the device.

Coordinates are generated along the unwinding axis in the graph reader by counting the inverse pulses.

communications formed on the first and second information outputs of the device. The elements of the counting reader, which calculate the indicated pulses, are not included in the proposed block.

One feedback pulse corresponds to a linear movement of the drum surface by a distance equal to the elementary quantization step of the movement.

The magnitude of the elementary step is determined by the formula

d - -15

l- n

(one)

where D is the diameter of the drum;

40 N - the number of pulses + IOS (-IOS) per one revolution of the drum.

When using an opaque carrier with a thickness h, the diameter of the cylindrical surface on which the graphic image is worn, increases by 2h, and the actual movement quantization step will be equal to

, "., -Sr1Lv.y ,," ("

where L --- is the error in the step of quantizing the movement introduced by the thickness of the carrier of the graphic image.

In order to compensate for the insertion thickness of the carrier, the errors 1 in the proposed block are used by adjusting

pulses + CI (-KI), which element 7 (12) OR are added to pulses + IOS (-IOS) and are formed at the moments when the value of the error accumulated in n steps reaches the value of one step I. The value of the number n is determined by the formula

     D. l N. 2h

(3)

Corrective impulses + KI are formed in the forward direction of rotation of the drum 1, and corrective impulses -KI are formed in the reverse direction of rotation of the drum.

The pulses + CI are formed from the delayed by element 13 delays of transfer impulses P1 and P2, formed by counters 4 and 9, respectively.

Pulses t are formed when the counter is divided by 4 feedback pulses + IOS by the number of n. To ensure this, counter P is entered into counter 4, which is a preset-setting counter, equal to:

Р 2 - п,. (4) where m is the number of bits of the counter.

It follows from formula (4) that the pulses + IOS arriving in the forward direction of the sweep to the summing input of the counter 4 increase its content and the nth pulse (after entering the number P in the counter) pulse + IOS ensures the formation of a transfer impulse Ш at its first output .

The pulses of < RTI ID = 0.0 > -CI < / RTI > are formed from the delay pulses 31 and 32 delayed by the delay element 14, which are generated by counters 4 and 9, respectively.

Pulses 31 are formed by dividing by the counter 4 feedback pulses - IOS by the number n. For this purpose, the number K, which corresponds to the return code of the number P, is preliminarily entered into the counter 4. The number K is determined by the formula

K 2 - 1 - P 2 - 1 - 2 + p-p - 1 (5)

From formula 5 it follows that the pulses arriving in the opposite direction of the sweep to the subtracting input of the counter 4-IOS reduce its content and the n-th impulse-IOS after 14

bakes the formation at its second output of a loan of 31.

For entering into the counter 4 numbers P or K its binary code is set

on the information inputs of the counter. The recording of the indicated code into counter 4 is effected by a pulse arriving at its preset input from the output of element 6 OR.

The code of the number P is formed by the node 3 specifying the thickness of the carrier, which is a combinational converter. It can be implemented using multiplexer chips. The control of the unit 3 for setting the carrier thickness is carried out with the help of manual controls.

The code of the number P is transmitted to the information inputs of the counter of 4 pulses through the converter 8 of the code.

Converter 8 codes in the presence of a signal at its second (control) input performs the appeal

code number P.

In the absence of a control signal, the code converter transmits the P number unchanged.

The code converter 8 is a combinational converter. Variants of its construction are well known, in particular, it can be performed according to a scheme that provides modulo two information

each of the input code bits with a signal on its control input. To ensure the cyclic mode of operation of the counter 4, the P or K numbers are entered into it by means of corrective pulses + QI and -KI, the summation of which is done by the element 6 OR. The first cycle of pulse formation + KI starts with the pulse of the BUT recording

P numbers in counter 4 through item 6 OR.

Pulse counter 9 ensures the formation of the first after the reverse

corrective impulse. In the forward direction of the sweep with the end of each cycle of pulse formation + IC. counter 9 is set to zero. Pulses following the impulse + KI + IOS increase the contents of counter 9 and, if the sweep direction is reversed before the end of the current cycle, then at the time of reversal

-five

in counter 9, some state k will be written. At the same time, k p. From this moment on the synchrometer 2 formed by the sync sensor, the IOS pulses arrive at the subtractive inputs of counters 4 and 9 and reduce their content. After the passage of k, the i-pulse pulses, the counter 4 returns to the state P, and the counter 9 returns to the zero state. It follows from the above that the Next k + 1-Y pulse - IOS ensures that a loan pulse 32 forms at the second output of the counter 9, which passes through element 11 OR and the delay element 14 forms a correction pulse -KI passing through element I2 OR to the second information block output From this, it follows that the first after the reverse, the impulse -KI is formed at the position of the carrier, in which the last impulse + CI was formed in the forward direction of the sweep. The impulse 32, in addition, also enters the second input (S input) of the trigger 5, which is then set to one state. The signal from the output of the trigger 5 is fed to the second (control) input of the converter of 8 codes, which at the same time provides the conversion of the forward code of the P number to the inverse code. Thus, the first pulse, KI after the reverse, provides the input of the K number to the counter 4, thereby preparing the counter 4 to form the loan pulses 31 by dividing the IOS pulses by the number n.

With the reverse sweep direction with the end of each cycle of pulse formation -KI counter 9 pulses -KI, arriving at its fourth input, is set to maximum filling state 2 Following the pulse -KI, IOS pulses reduce the contents of counters 4 and 9 and, if the end of the current cycle, the sweep direction changes from reverse to direct, then at the moment of reversal in the counter 9 some state 2 -I-k2 will be recorded. In this case, k2 p. The pulses + IOS generated by the synchro sensor 2 from this moment arrive at the summing inputs of counters 4 and 9 and increase their contents. After passing the kj pulses + IOS, the counter 4 returns to 616.

Stand K, and counter 9 - in the state of maximum filling 2 -. It follows from the above that the next k -I th pulse + IOS ensures the formation at the first output of the counter 9 of the transfer pulse P 2, which, having passed through the element 10 OR and the delay element 13, forms a correction impulse + CI passing

through element 7 OR to the first information output of the device. From this it follows that the first impulse + KI after the reverse is formed at the position of the carrier, in which

This, with the reverse sweep direction, was formed the last pulse -KI.

Pulse P2, in addition, arrives at the first input (R input) of the trigger 5, which is then set to the zero state. The signal from the control input of the converter 8 of the code is removed, the code of the P number is set at the information inputs of the pulse counter 4, and the counter 4 is prepared for generating the PG pulses.

Elements 13 and 14 of the delay provide the formation of corrective

impulses after termination of impulses ni, 31, П2 and 32, and therefore after the termination of coinciding with them in phase pulses + IOS and, which is necessary to avoid failures

in the work of the forming elements of the graph-reader. In addition, the delay of corrective pulses provides for the input of P or K numbers into counter 4 after setting the code corresponding to them on its information inputs.

Thus, in the proposed device, in any direction of the sweep, the magnitude of the additional error is reduced to a minimum and not. excels the magnitude of one move quantization step.

By compensating for the error introduced by the main carrier of the graphic

image, increases accuracy when reversing the direction of the sweep.

Claims (1)

Formula of gain A sweep correction unit for a graphic information reader comprising a sync sensor, the first output of which is control 7I block output and connected to the first input of the first OR element, the output of which is connected to the installation input of the first pulse counter, the summing input of which is connected to the second output of the sync sensor and the first input of the second OR element, the output of which is the first information output of the block, trigger and a node for setting the thickness of the information carrier, characterized in that, in order to increase the accuracy of the device, it contains a second pulse counter, a third, fourth and fifth elements OR the first and second delay elements and a code converter, whose information inputs are connected to the outputs of the node specifying the thickness of the information carrier, the control input to the output of the trigger, and the outputs to the information inputs of the first pulse counter, the subtracting input of which is connected to the subtracting input of the second counter and the first input of the fifth element OR, is connected to the third output of the synchro sensor, the second output of which is connected to the sum. Editor N. Gorvat Compiled by T. Nichiporovich Tehred M. Khodanych Proof-reader S. Cherni Order 1894/47 Circulation 673 Subscription VNIISH State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company, Uzhgorod, st. Project, 4 fO 108618 a second pulse input, the first output of which is connected to the first installation input of the trigger and the first input of the third OR element, the second input of which is connected to the first output of the first pulse counter, and the output is connected through the first delay element to the second inputs of the first and second OR elements and the first installation input of the second pulse counter, the second installation input of which is connected to the second input of the fifth OR element and the third input of the first OR element, is connected to the output of the second element that delay, the input of which is connected to the output of the fourth OR element, the first input of which is connected to the second setup input of the trigger, is connected to the second output of the second pulse counter, and the second input of the fourth OR element is connected to the second output of the first pulse counter, and the output n - 5 of that OR element is the second information output of the block. 15 20