SU798912A1 - Graphic information reading out device - Google Patents

Description

No amplitude simultaneously delivers current pulses. As a result, a differential EMF signal of the electromagnetic field is induced in the coordinate remover, current pulses are fed to conductors that restrict a selected section of the tablet, until the EMF signal in the puller (intermittently) changes its phase (polarity). The number of pairs of pulses emitted by a block of amplitude changes corresponds to the number of quantization samples into which a coarsely selected section of the tablet is divided. By the secondary polarity reversal, the EMF of the puller determines exactly in which discrete the center of the puller G3J is located.

The disadvantages of the known device are that the switching elements have different response times, as a result of which the differential electromagnetic field is distorted, and the accuracy of determining the coordinates is reduced.

A disadvantage is also that around each conductor (frame) there is a dead zone, which is formed due to the limited gain of the amplifier, taking into account the cutoff level from interference and the final size (cross section) of these conductors.

In addition, the unit for changing the amplitudes of current pulses operates in large. the dynamic range of their change. At low excitation currents, the signal induced in the puller becomes comparable with the level of interference. It also reduces the accuracy of determining the coordinates.

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

The goal is achieved by the fact that it contains a dividing unit, the inputs of which are connected respectively to the outputs of the amplifier and logic unit, a comparison unit and a unit for setting standards, the output of which is connected, to one of the inputs of the comparison unit, the other input of which is connected to the output of the division unit, output - with another input of the unit for determining the coordinates.

FIG. 1 shows a block diagram of the device, FIG. 2, is a roughly distinguished area of the tablet, at which point C is located, the coordinates of which must be determined precisely. This area is bounded by two conductors (frames) C and .6 + 1, and also (it shows the -1 and C + 2

The device contains a tablet 1 with orthogonal conducting wires (frames) located on its surface, a puller 2 coordinates, an amplifier 3, a gate node 4 / pulse generator 5, a control block b, a logic block 7, a block

KI 8 of the survey, block 9 of determining the coordinates, block 10 of the division, block 11 of the comparison and block 12 of the task of standards. The device works as follows.

Combine the center of the puller 2 with the point of the graph line, the coordinates of which yado to measure. In this case, the control unit 6 generates signals that ensure the operation of the entire device. The coordinates of the readable point of the graph are measured in each cycle of the operation of the device and are fed to block 9 for determining the coordinates.

Using a button located in the case of the 2-coordinate puller, a signal is sent to the coordinate determination unit 9, according to which the coordinates of the graph line point are output to an external device, for example, a computer. The coordinates of the point are determined in two stages. At the first stage, a rough determination of the coordinates is carried out, and at the second a precise determination is made. Consideration of the operation of the device for simplification is carried out only when determining the X coordinate.

Claims (2)

At the command of the control block b, the pulses of the generator 5 are detected in the polling block 8 along the X coordinate and from its outputs into the conductors (frames) of the tablet 1. The signal induced in puller 2 is fed to the amplifier 3 and from its output through the gate node 4 to the logical block 7 The signal from the output. Amplifier 3 is also fed to the input of block 10 division. If there is a change in the phase (polarity) of the signal, then the logic unit 7 captures this moment and enters a signal preparing the division unit 10 for operation. The same signal enters the control unit 6, according to KOTppoiviy it stops the flow of pulses to the coordinate determination unit 9. The interrogation unit 8 of the X coordinate, at the command of the control unit 6, gives alternately current pulses of the same amplitude to the conductors. and .C + 2, after which it ceases its work on the command of the same block. The signals of the puller 2 coordinates induced in it upon excitation and the f + 2 conductors of plate 1, from the output of amplifier 3, go to dividing unit 10, which determines the magnitude of the ratio of these signals, and the ratio of the larger signal to the smaller signal is always taken. The result obtained by dividing unit 10 is compared with the specified tolerance by unit 11 cf & 8i with the set of reference values stored in block 12 to specify standards. As a result of this comparison, with the output of block 11, the comparison of relations to the second input of block 9 will receive an additional number of pulses corresponding to the exact position of the center of the puller. In block 9, the determination of the coordinates after scaling, making the appropriate corrections and adding in the pulse counter of the coarse and accurate readings fixes the value of the X coordinate of the point of the line .. graph. The scaling, adding and adjusting operation is performed while pulses are received at the X coordinate counter. The exact coordinates of the line point are explained graphically (Fig. 2, which shows the selected area of the plate bounded by two conductors t and i + 1. -point ,, the coordinates of which need to be determined exactly The selected area is divided into n increments in accordance with a given TQ4HOCTbro determination of the coordinates of point C. The boundaries of the increments from the 1st to the nth are shown (figure 2) by dashed lines. and -1 poocher the bottom receives two current pulse excitations of the same amplitude.At the same time, in the catwalker of the puller 2, when the conductor -C + 2 is built, an emf of A is induced, and when it is excited} the output of the conductor A-1 is an EMF of value B. for point C, it will be -) denoted by M. The number M corresponds to the exact value of the X coordinate of point C, which is in the fourth sample. The numbers designated N4 and N5 correspond to the boundaries of this discrete. Since the dependences of the EMF values on the distance of the center of the puller to the excited conductors have a quasilinear character (in Fig. 2 this is shown by the straight lines of the EMF), for each boundary of the discrete area the ratio of the larger emf to the lower emf is calculated, i.e . numbers- N4 and N. . . Thus, the number M is in the interval between the numbers N4 and Nj and corresponds to the X coordinate of point C located in the fourth sample, whose position is known in advance. The position of the center of the stripper (points C of the graph line) is determined by comparing the number M with the numbers N and H with a certain tolerance. So, as theoretically calculated values of the relations are identical for the left and right parts of the roughly selected area of the tablet, counting from the middle (where the ratio is equal to one), they are calculated only for one half, and the location of point C in the left or right half is determined by using the comparison more, less EDSl and EDSV values The value of the EMF / EMF value does not change with simultaneous and proportional measurement of the EMF values themselves. Simultaneous change of the values of EDS and EMF; equivalent to changing the thickness of the information carrier. The determination of the Y coordinate is similar. The proposed device provides an increase in the accuracy of determining the coordinates while simplifying it in comparison with the known ones. The introduction of a dividing unit, a unit for comparison of relations and a unit for setting standards to the device made it possible to completely eliminate the instrumental error introduced by the dashboard elements. At the same time, the number of high-current elements (keys) with the same design parameters of the tablet is reduced several times. . Claims An apparatus for reading graphic information comprising a tablet with systems of orthogonal conducting conductors connected to respective interrogation units, a coordinate remover connected through an amplifier connected in series and a gating node to one of the inputs of a logic unit, a control unit whose first input is connected to . a pulse generator, the second with a logic block, and outputs with corresponding 1 and inputs of polling blocks, a coordinate determination unit and another input of the logic block, which, in order to improve the accuracy of the device, contains a division block, inputs which connected respectively to the outputs of the amplifier and logic unit, the comparison unit and the standard setting unit, the output of which is connected to one of the inputs of the comparison unit, the other input of which is connected to the output of the division unit, and the output to the other input of the coordinate determining unit. Sources of information taken into account in the examination. 1. USSR author's certificate number 467377, cl. G H 11/00, 1973. 2. USSR author's certificate number 520603, cl. G About 11/00, 1974. 3-. USSR Author's Certificate in Application No. 2546709 / 18-24, cl. G 06 K 11/00, 1977 (prototype).