SU736135A1 - Graphic information readout device - Google Patents

Description

(54) DEVICE FOR READING GRAPHIC INFORMATION

The invention relates to automation and computing and can be used to enter graphic and textual information into computers or specialized devices for computer processing of information. A device for reading graphic information, containing a tablet with systems of mutually perpendicular coordinates, buses connected to switches, a reading element connected through an amplifier to an information processing unit and other blocks and nodes 1, is known. A disadvantage of this device is a large amount of equipment. The closest technical solution to the present invention is a device for reading gras (the first information containing a ferromagnetic plate and a readout element, made, for example, in the form of perpendicular conductive frames 2. The plate of such a device is made in the form of systems of perpendicular coordinate buses connected to switches, and the device contains counting nodes and other blocks, which complicates the circuit design of the device. The purpose of the invention is to simplify the device. Operators connected mutually perpendicular to the conductor frame, and the ferromagnetic plate is made in the form of a plate permanent magnet, in the field of which are perpendicular to the conductive frame. At the same time, the working surface of the plate permanent magnet can be made in the form of a curved surface. Figure 1 shows the proposed device, its general view, in Fig. 2 is a section A-A in Fig. 1, and Fig. 3 is a projection of the magnetic field lines of a ferromagnetic plate made in the form of a flat permanent magnet and with parallel surfaces, and the position of one of the frames registering the movement along the X axis; on (}) 4 shows the voltage plot at the integrator output as the frame moves from the center of the tablet along semi-axes X; in fig. 5 is a graphical depiction of a rectangular lattice and its display by reading devices containing a permanent magnet with a flat and curved upper surface. The proposed device comprises a plate 1 consisting of a non-magnetic body 2 with a plate-like permanent magnet 3 placed in it, a readout element 4 with conductive frames 5 placed inside it, arranged mutually perpendicularly and along the axis of the readout element 4, integrators 6, whose inputs connected to the conductive frames 5. In FIG. Figure 3 shows two projections of a flat permanent magnet 3 of a rectangular shape, a projection of a frame -5 and conditional projections of magnetic field lines 7 emerging from a flat magnet. The device works as follows. A flat permanent magnet 3 (see Fig. 3), having poles with flat edges, creates around itself a constant magnetic field. By virtue of the magnitude of the magnet, the magnetic field lines 7 are directed radially from the center O and, with varying degrees of inclination, increasing with distance from the center 0. At the same time, part of the magnetic field lines 7 penetrate the conductive frame 5, if the side cd of the frame 5 had an infinite length, then all magnetic field lines 7, emerging from the surface of the magnet bounded by the plane of the triangle Ova, would penetrate the contour of the frame. The area S of the triangle OSa is equal to the product of the half of the segment a8 (frame width) and the length of the segment OX (the distance of the frame from the center of the magnet 3). Thus, moving the frame 5, which is parallel to itself in the plane of the plate constant magnet 3 (see Fig. 3), can be changed in proportion to the distance of the frame from the center of the magnet and piercing its magnetic flux f. However, if the frame moves parallel to the Y axis , the area of the triangle O8a remains constant, and the change in the magnetic flux of the Fnet occurs. According to the Farad-Maxwell law, an induction signal arises in the conductive frame, proportional to the rate of change of the magnetic flux coupled to this frame. The voltage appearing in the frame is fed to integrator 6, which calculates the instantaneous value of the integral of the input voltage. Thus, at the output of the integrator 6, a voltage occurs that is proportional to the distance OX of the frame 5 from the center of the magnet 3. As the frame moves to the left of the Y axis, the direction of the magnetic flux changes and the signal in frame 5 changes its sign. Accordingly, it changes its sign and direction at the output of integrator 6. The change in voltage U at the output of integrator 6 as the frame moves along the x axis of the plane magnet 3 is illustrated in graph 8 shown in FIG. 4. The second frame is mechanically connected to the frame and is located perpendicular to it and parallel to the X axis. This frame records the change in the magnetic flux when the frame system moves along the Y axis, the voltage from it is fed to the input of the second integrator 6, the output of which occurs in a similar way voltage proportional to the movement of the frame system along the Y axis. In the proposed device, the length of the frames 5 (cd) is limited by the size of the read element 4 in which they are placed. When the dimensions of the magnetic core 3, defining the working field of the plate 1 exceeding the length of the frames 5 and, accordingly, the length of the reading element 4 are more than 2 times, the voltage at the output of the integrator 6 begins to nonlinearly depend on the movement of the reading element 4 as shown by graph 9 in fig. 4 .. In the case of inputting handwritten characters, the indicated nonlinearity leads to a change in the scale of the characters depending on their location in the working area of the tablet 1. If this change in the scale lies within the variation of the handwriting, then the resulting nonlinearity can not be compensated. In cases where this non-linearity is undesirable, its adjustment is carried out by reducing the size of the magnetic core 3 and, accordingly, the working field of the plate 1 with respect to the length of the frames 5 and the reading element 4, or this correction is performed by a computing device into which the graphic information is entered. by recoding, performing the function of inverse nonlinear transformation of the incoming data. The rectangular shape of magnet 3 makes it possible to maximize its surface as a working surface for entering textual information. However, such a shape of magnet 3 creates an inhomogeneous density of magnetic field lines 7 in a plane parallel to the surface of the magnet. This discontinuity is most pronounced at the edges of the magnet 3. As a result, the image of the grid lattice shown in FIG. 5a, when drawing its element on the tablet 1 and then displaying it in terms of voltages at the inputs of the integrator 6, gives the image shown in FIG. 56. As can be seen from FIG. 56, the elementary lattice rectangle, which has retained its dimensions in the center of the magnetic core 3, has a maximum distortion at the corners of this core. When depicting handwritten symbols on the tablet, those that are located at the corners of the magnetic core 3,

will be depicted with an additional slope and distortion of their proportions. These distortions will not be if the magnet 3 is made in the form of a circular disc. Since it is technically not feasible to use the magnet 3 in the form of a disk, the proposed device for expressing the magnetic flux plane along the edges uses a curvilinear working surface of the magnet 3, which forms the antinodes of the magnetic flux in those places where it is weakened by the shape of the magnet edges. The shape of the surface is determined experimentally or by calculation. One of the forms of the magnet surface used in the proposed device and the display of a rectangular lattice with the help of such a core is shown in FIG. 5c. As can be seen from FIG. 5c, the resulting lattice mapping has significantly less distortion.

In order to increase the level of the signal taken from frames 5, the latter are performed multi-turn.

The use of the invention as input devices for drawings, drawings, handwriting text and other graphic information in computing and specialized electronic machines due to the simplicity of the design, high resolution and low power consumption will significantly expand the sphere .1

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use and cost effectiveness of graphic input devices.

Claims (2)

1. A device for reading graphic information containing a ferromagnetic plate and a reading element, made, for example, in the form of perpendicular conductive frames, characterized in that, in order to simplify the device, it comprises integrators connected to mutually perpendicular conductive frames, and the ferromagnetic plate is made in the form of a plate-shaped permanent magnet, in which field perpendicular conductive frames are located. 2. A device for reading graphic information according to claim 1, characterized in that the working surface of the plate-shaped permanent magnet is made in the form of a curved surface. Sources of information taken into account in the examination 1. USSR Author's Certificate No. 413504, cl. G 06 K 11/00, 1972. 2. USSR author's certificate No. 313211, cl. G 06 K 11/00, 1970 (prototype) L - Have / / f, / / U | . 1g n I h / .fti ..-     736135 JT FIG. five