SU1401494A1 - Device for converting coordinates of images - Google Patents

Description

The invention relates to automation and computing, in particular to information display devices, and can be used to control the movement of a cursor on display screens.

The purpose of the invention is to improve the accuracy of the device by changing the optical communication of the tablet with photo receivers, as well as electrical. couplings of photodetectors with amplifiers, which leads to a reduction in conversion noise.

FIG. 1 shows the layout of the device; figure 2 - diagram of the tablet; in fig. 3 is a diagram of the electrical connections of the photo receiver with differential amplifiers and the layout of the photodetectors.

A device for converting into electrical signals (Fig. 1) contains a coordinate remover 1 mounted on the surface of the tablet 2, made in the form of a base with a rectangular mesh formed on it, formed by intersection of monochromatic optically contrasting strips to the background. The puller is made in the form of a body in which the light source 3, a light, a focusing element (lens) 4, and eight photo-receivers located close to each other in four rows and mounted in a common block 5 are fixedly fixed. Optical light source axes and the focusing element are intersected in the flatbed of the tablet, and the axis of the block 5 intersects with the axis of the focusing element, and the axis of the block 5 is perpendicular to the plane of the planchet. The axes of the light source are located in a plane perpendicular to the plane of the focusing element. Such an arrangement of elements of the optical assembly provides for displaying on the photodetectors a portion of the tablet surface with the same magnification both along the X axis and along the Y axis. A block 6 with four differential amplifiers is also installed in the case. The plate (Fig. 2) is made in the form of a rectangular grid formed by the intersection of monochrome stripes 7 parallel to the coordinates of displacement X, Y and having a width S equal to half the grid step. Contrast level

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The background also remains unchanged at the intersection of the lanes. Photodetectors (FIG. 3) are arranged in a checkerboard pattern in the same plane. The positions of photodetectors are marked with numbers 8. Photoreceivers through resistors 9 are connected to the corresponding differential amplifiers 1.0.

The device works in a dim way.

When the source 3 of the skeleton is turned on, the plate surface area EFGH is illuminated. With the help of the focusing element 4, an image of this surface is focused on each photo-terminal of block 5. By turning on the photodetectors, as shown in Fig. 3, the signals at the outputs of the differential amplifiers 10 are altered when the puller 1 of the device moves relative to the plate 2.

. The use of the invention allows to increase the reliability of the transformation, in particular due to the higher resistance to defects on the surface of the tablet and its contamination.

Claims (1)

Invention Formula A device for converting image coordinates, containing a coordinate remover, made in the form of a body mounted to move in orthogonal directions along the tablet surface; made as a base with a rectangular grid worn on it, formed by the intersection of monochrome optically contrasting { in relation to the background of the strips, the width of which is equal to half the grid step, installed in the housing and optically coupled light source, focusing element and eight photoreceivers, apertures They are located in the same plane, located in the rear) focal plane of the focusing element, the front focal plane of which coincides with the surface of the tablet, the optical axes of the light source and the focusing element being at right angles in the plane perpendicular to the surface of the tablet, four differential an amplifier whose inputs are connected to the outputs of photodetectors, characterized in that. In order to increase the accuracy of the device, the apertures of the photodetector are arranged in a matrix in a staggered order with a pitch multiple of half the strip width of the tablet and oriented along the stripes of the rectangular grid of the tablet, with the first and second inputs of the first differential amplifier connected to the outputs of the first, fifth and the second, sixth photodetectors, the first and second inputs of the second differential the amplifier is connected respectively to the outputs of the first, second and fifth, sixth photodetectors, the first and second inputs of the third differential amplifier are connected to the outputs of the third, seventh and fourth, eighth photodetectors, respectively, the first and second inputs of the fourth differential amplifier are connected to the outputs of the third, respectively, fourth and seventh, eighth photodetectors. figure 1 FIG. g w Bbixy te / CD 5wx K Exit Rig.Z