SU811300A2 - Graphic information reading-out device - Google Patents

Description

dinene with outputs of adders 6-8, and outputs with corresponding inputs of block 4, additional information inputs associated with outputs of adder 6 and 7.

The analysis and control unit 4 (see Fig. 2) contains an amplitude comparator 10 connected to the outputs of adders 6 and 7, and connected to the input of control unit 11 of switches 2 and 3, the output of which is connected to the coordinate code register 12, An analog signal ratio determining node 13, consisting of series-connected analog-digital converter 14 and dividing node 15, represented by codes, is output (private) connected to another input of register 12. Digits 16 and 17 denote switch control signal outputs s 2 and 3, the numeral 18 - the output coordinate code.

The device works as follows.

In the initial state, the register 12 of the coordinate code of block 4 is set in the zero state, and the key circuits of the switches 2 and 3 are open. The device starts working from supplying 4th sequence of signals to switch 3. The pulses of the mentioned sequence of signals alternately switch coordinate buses X. The number of signals of this sequence is recorded by register 12 of block 4 as a code of the X coordinate of the switched bus in its highest bits. In this case, alternating current pulses are passed through each bar, and an electromagnetic field is created in the space surrounding it.

At the time of switching the bus, which is located in the established readout zone, an electromagnetic field is created sufficient to measure the inductance. Under the action of this zero, all the coils of the puller of coordinates 5 simultaneously induce electrical signals, the shape and amplitude of each of which, ceteris paribus, depends on the radius of the corresponding inductance coil and the number of its turns. Since the radii of all the coils are different, the induced signals are linearly independent. In the result of the weight summation with the help of adders 6, 7 and 8 are produced, the cumulative signals are formed.

The shape of the amplitude characteristics of the signals can be very diverse and depends on the parameters of the weight elements of the adders 6, 7 and 8. The weight elements of the adder 6 are chosen such that the amplitude of the measuring signal over the entire selected reading zone represents a linear function of the distance from the coordinate bus to the center puller coordinate. Similarly by weight

the elements of adders 7 and 8 are selected such that over the entire readout zone, the signals maintain a constant amplitude. The signal received in block 4 is compared by amplitude comparators 10 and in the case of a difference in signals, the counting of the coordinate tires is stopped, and in register 12 there appears a fixed code corresponding to the coordinate of the axis of the interrogated coordinate tire. At this point, the successive polling of the coordinate tires along the X coordinate is terminated. At the same time, the signals arrive at block 9 of forming differential signals, which, with

the outputs of block 9 go to block 4, in which their relationship is determined. The code equivalent of the pixel ratio, together with the code obtained by counting the number of coordinate lines, constitutes the value of the X coordinate of the readable point of the graphic image. The determination of the Y coordinate is done in the same way.

The determination of the ratio of analog signals can be made by analog dividing circuits. However, analog dividing schemes have low accuracy. According to the scheme (see fng. 2), this operation is performed by intermediate conversion of signals into digital form.

(analog-to-digital converter 14)

and then dividing them received

code equivalents with an angle of 14 divisions.

The role of the weight elements of the adder 6, 7

and 8 can, for example, perform resistors, or the coil 5 inductance coils themselves, connected in series. In the latter case, the number of inductors is tripled, the number of turns

each coil is proportional to the corresponding weight coefficient, and the order of switching on (consonant or counter) is determined by the sign of this coefficient. In the proposed device, signal shaping is performed using the same means (elements of an inductive coordinate remover system) and in the same neighborhood of the space centered at the reading point. therefore

all changes in the signals associated with the effect of destabilizing factors have the same effect on both measurement and reference signals, as well as on the value of the ratio of the difference

signals. As a result, the above relation maintains constancy, and the read accuracy is increased accordingly.

Claims (2)

1. A device for reading graphic information on the author. St. Ln 714435, characterized in that, in order to increase accuracy, it contains additional adders, the inputs of which are connected to inductors, and a unit for generating differential analog signals, the inputs of which are connected to the outputs of adders, and the outputs - to information inputs of the analysis and control unit. 2. The device according to claim 1, characterized in that, in it, the analysis and control unit comprises an analog-digital converter, a division node and a coordinate register, the output of which is connected to the information output of the analysis and control unit, whose information inputs are connected to analog inputs digital converter, the outputs of which are connected to the inputs of the division node, the output of which is connected to the input of the coordinate register. Sources of information taken into account in the examination I. USSR author's certificate № 714435, cl. G 06K P / 00, 15.09.77. IS W , g