SU842875A1 - Graphic information reading-out device - Google Patents

Description

(54) DEVICE FOR READING. GRAPHIC INFORMATION

I

The invention relates to computing technology and advantageously can be used to enter graphic information into electronic computers.

A device for reading graphic information is known, comprising a tablet and a reading element connected to a signal processing circuit. The signal is generated as a result of the movement of the readout element over the system of orthogonal flat tires of tablet 1.

However, the manufacture of such a tablet is associated with technical difficulties. In addition, to increase the resolution of the device, it is necessary to increase the number of tires, which entails a proportional increase in the volume of signal processing equipment. .

The closest in technical essence to the proposed technical solution is a known device for reading graphic information containing a tablet with a rectangular working surface, a plate-shaped permanent magnet, whose field is normal to the working surface of the tablet, and a reading element 2

nor, the winding of which is connected via amplifiers to the integrators. The magnet material is uniformly magnetized in a direction perpendicular to the working surface. The principle of operation of this device is based on the guidance of signals in the windings of noise

when it moves in the field of a permanent magnet of the tablet, which can be determined by the law of electromagnetic induction. The signals induced in the windings of the read element are proportional

J corresponding to the velocity vector projections. This allows using the signal processing circuit to determine the current coordinates of the read element, and hence its trajectory 2.

The main disadvantage of the known device is the non-identical conditions of reading information from the working surface of the plate, which is associated with the presence of edge effects of the distribution of its magnetic field. This leads to the fact that only in the central part of the working surface

Claims (2)

0 plate signals induced in the windings are proportional to the corresponding component of the speed of movement of the noise. When approaching the periphery of the tablet (magnet), distortions appear as the signals of each of the windings become dependent on both velocity projections. Therefore, to obtain a working surface of the required dimensions, it is necessary to increase the actual dimensions of the magnet. However, with this, the field in the central part of the magnet becomes increasingly homogeneous, which leads to a decrease in the level of the signals being picked. The purpose of the invention is to reduce distortions and increase the level of the read signal. The target is achieved in that the device for reading graphic information containing a tablet with a rectangular working surface, a plate-shaped permanent magnet, whose field is normal to the working surface of the tablet, and a reading element whose windings are connected through amplifiers to integrators, in that the lamellar permanent lamellar permanent magnet in it is made in the form of a symmetric cross, the central rectangular part of It is combined with the working surface of the tablet and has a double magnetization with respect to the rest of the cross. Such an embodiment of the magnet eliminates edge effects of the field in the areas of the working surface. To unify the magnetic materials used, the central part of the cross can be made of two identical magnets superimposed on each other, having the same magnetization as the rest of the cross. FIG. 1 is a block diagram of the device; in fig. 2 shows a magnetic tablet in the form of a symmetric cross; in fig. 3 given the possible implementation of the tablet. The device contains (Fig. 1) a tablet with a rectangular working surface 1, a readout element 2 with mutually perpendicular windings 3 (windings W and W,), amplifiers 4 and integrators 5. The working surface of the tablet is geometrically formed by the intersection of two rectangles 6 7 ( Fig. 2). When element 2 moves above the working surface 1 of the plate in the windings 3, according to the law of electromagnetic induction, signals are induced. The field of the magnet in the form of a symmetric cross (Fig. 2) can be represented as the result of the fields of the rectangular magnets shown in FIG. 2 and 3. Signals occurring in the windings 3 are proportional to the respective vectors Vy and iTy of the velocity vector Y, with which the readout element 2 moves. Constructively, a magnet in the form of a symmetric cross can be made monolithic with a doubled magnetization of the central part (Fig. 3a); of the five individual rectangular magnets, of which one, the central one, has double the magnetization (Fig. 3b); monolithic with uniform magnetization and an additional rectangular magnet of the same magnetization located under the working surface (Fig. Sv); out of six separate rectangular magnets of the same magnetization, the central part being formed by two superimposed magnets (Fig. 3g). From a technical point of view, the variants corresponding to FIG. 3 b and g. Making a magnet in the form of a symmetric cross provides for obtaining a proportional dependence of the signals of the windings of the read element on the respective components of its speed on the entire working surface of the tablet, while simultaneously increasing the level of the picked signals. Claims of the invention A device for reading graphic information containing a plate with a rectangular working surface, a plate-shaped permanent magnet, after which it is normal to the working surface of the tablet. a read element, the windings of which are connected via amplifiers to integrators, characterized in that, in order to reduce distortion and increase the level of the read signals, the plate-like permanent magnet is made in the form of a symmetrical cross, the central rectangular part of which is aligned double magnetization with respect to the rest of the cross. Sources of information taken into account during the examination 1. USSR author's certificate No. 441576, cl. G 06 K P / OO, 1972. 2. USSR author's certificate for application number 2543125 / 18-24, cl. G 06 K P / OO, 1977 (prototype). (Reg. 2 k-h .l /  at zs s gp 2S I I S 1 i f I I I I 1 - /