SU1439633A1 - Optronic function converter - Google Patents

Abstract

Adapting to the field of instrumentation and improves the accuracy of the conversion. The converter contains a light-tight housing in which a directional light source is placed, a light probe formation unit and a coordinate-sensitive photopotentiometer of the arc structure. The light probe formation unit is made in the form of rotation symmetrically fixed on the input axis of an opaque body, the gap between the outer surface of which and the inner surface of the body has the shape of a light labyrinth in longitudinal section. An inclined cylindrical channel with a reflecting surface, optically connecting a directional light source with a photosensitive layer of a photopotentiometer, is made in the body of rotation. At the same time, the axis of symmetry of the radiation pattern of the light source coincides with the axis of the body of rotation and passes through the center of symmetry of the base of the near-directional channel closest to the directional light source. The distance h from the radiating surface of the directional light source to the point of intersection of the axis of the cylindrical channel with the axis of the body of rotation satisfies the relation. cosX2flt-f) a.h.- | ctg | -b. where a is the distance from the radiating surface of the directional light source to the outer surface of its body in the direction of the radiation, b the length of the light probe in the radial direction 2 is the width of the radiation pattern of the light source; A is the angle between the axis of the cylindrical channel and the photosensitive surface of the photopotentiometer. P is distinguished by increased reliability and resistance to mechanical overloads and can be used in the creation of industrial robots and automatic manipulators, in information-measuring and computing complexes as data-; Chuck angular position, functional converter, contactless. variable resistor. 3 il. i (L from 4:00 CD 9d DO

Description

The invention relates to the field of optoelectronic instrumentation and can be used in robotics, information-measuring and computing equipment as a functional transformation, an angular displacement sensor, a non-contact variable resistor.

The aim of the invention is to increase the accuracy of the converter by increasing the utilization rate of the luminous flux of the directional light source.

Figure 1 shows the constructive scheme of an optoelectronic functional converter (OEFP); FIG. 2 is a diagram of a coordinate-sensitive circular photopotential paj of FIG. 3 — a part of the optoelectronic converter circuit.

OEFP contains a coordinate-sensitive circular photopotentiometer 1, a directional source 2 of light, a light probe formation unit, made in the form of an opaque rotation body 3, a light maze, made in the form of two conjugate combs 4, -4j, a cylindrical channel 5, an input axis converter 6, the photopotentiometer 1 (figs2) contains a resistive layer 8 placed on a dielectric substrate 7, a photosensitive layer 9, an ohmic collector 10, and the edges of the resistive layer 8 are equipped with ohmic electrodes 11, while struction transducer placed in svetone- pronitsaempCh body 12; the light probe 13 and the load resistor 14, from which the output voltage is removed.

Fig. 3 shows schematically the limit stress, from which the maximum allowable value Bd, g of distance B is determined, and the geometric constructions necessary for this are presented. Directional light source 2 is taken as a point, because the distance h is at least five times larger than the geometrical dimensions of the radiating surface of directional light sources used in OEFP, which is enough to apply this approximation with satisfactory accuracy. The spatial position of the radiating surface of the directional source of light 2 is conventionally designated by the point A. Dal.e are marked: SC - large

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the axis of the upper base of the inclined cylindrical channel 5; B - the center of the upper base of the 5J AD channel - the light beam forming an angle with the AB segment; yi is the angle between the axis BR of the cylindrical channel 5 and the surface of the photosensitive layer 9 of the coordinate-sensitive photo receiver a, DP is the normal to the CE surface of the inclined cylindrical channel 5 at the point D of the incident light beam AD to the surface CE, KB is the normal to the surface CE, omitted from the point K. The magnitude. „.. you I X selected from the limiting case when the light beam AD after reflection at the point D hits the point K, i.e. there is still no return of the rays that are within the angle of the radiation 2, the directional source 2 of the light, from the cylindrical channel 5.

The device works as follows.

The light beam emitted by the directional source 2 of light enters the cylindrical channel 5, the output end of which is opposite the photosensitive layer 9 of the coordinate-sensitive photopotentiometer 1. After passing through the cylindrical channel 5 a part of the light flux on the photosensitive layer 9 forms a movable light probe 13, an angular whose position is transformed by it into an output voltage depending on the angle of rotation of the input axis 6 according to a given functional law. Photopotentiometer 1 (Fig. 2) with a non-profiled resistive layer 8 implements a linear conversion function. At the same time, the light probe 13, which together with the ohmic collector 10 performs the function of the electromechanical potentiometer engine, creates excessive over dark conductivity in a limited portion of the photosensitive layer 9, resulting in a local transfer of potential from the resistive layer 8 to the ohmic collector 10. Since non-profiled resistive layer 8 is distributed according to a linear law (provided that the surface resistivity of the photosensitive areas 9 of much higher surface resistivity of the resistive layer 8), in this case, the output voltage depends on the angle of rotation of the input axis 6 linearly. The implementation of non-linear conversion functions is usually accomplished by profiling the resistive layer 8.

An increase in the utilization factor of the light source of the light source is essential to ensure the required accuracy of the functional conversion, since the effect of the transient resistance of the photosensitive layer 9 on the functional conversion accuracy at significant current sampling levels cannot be corrected by additional profiling of the resistive layer 8. Therefore, the main optimization criterion of this device is to minimize the loss of luminous flux of directional source 2 over that For this purpose, the complex optimization of the device components, which is absent in other transducer designs, provides for a specific relationship between parameters: between the geometry of the coordinate-sensitive photopotentiometer, the diameter and inclination of the cylindrical channel 5, the height of the directional source 2 of light and the diagram of directivity from -. radiated light them. The mathematical expression of this relationship is the indicated ratio, which limits the minimum h .. ,,,, and

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the maximum h is the height of the radiating surface of the directional source 2 of the light above the entrance end of the cylindrical channel 5. Under the constraints given by this ratio, the light beam with an angular aperture 2 radiated by the directional source 2 of light, to which almost all radiated power falls, does not only fully enter the inclined cylindrical channel 5 ,. but at the same time, the condition of the absence of the return of a part of the light rays that were in this beam back after reflection from the lateral surface of the cylindrical channel 5 is also satisfied.

Prerequisite to ensure

The precision of the NEFP is the constant of the transition resistance of the illuminated portion of the photosensitive layer 9 when the angular position of the light probe 13 changes. Therefore, the axis of symmetry of the directional diagram 0

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These sources of light 2 must coincide with the axis of the body of rotation 3 and pass through the center of the base of the cylindrical channel 5 closest to the directional source 2 of light, which ensures a constant level of light flux at the exit of the cylindrical channel 5 when the body of rotation 3 rotates. In order to avoid radial movements of the light probe 13 relative to the photosensitive area 9, it is necessary to place the dielectric substrate 7 orthogonal to the input axis 6, and the annular photosensitive layer 9 should be centered on the input axis 6. The axis of the inclined cylindrical channel 5 should cross the surface of the photosensitive layer 9 along its average radius. The magnitude b of the length of the light probe in the radial direction is chosen in such a way that it is 1.2-1.5 times larger than the width of the photosensitive layer 9. In this case, the luminous flux is used most efficiently, since a decrease in b leads to an increase in the transition resistance due to an increase in the unevenness of the width of the light probe, and an excessive increase in the parameter b - to the unproductive loss of m of the light flux. .

In order to protect the dark areas of the photosensitive layer 9 from background illumination, multiple light reflections are used in the light labyrinth 4 with absorbing walls formed between the inner surface of the light-tight case 12 and the outer surface of the rotation body 3. This protection is most effective when performing this ratio, since reducing the loss of the light flux of the directional source 2 of the light provides simultaneously with a decrease in the transition resistance of the photopotentiometer 1 also a reduction in the power of one of the sources of background illumination.

Claims (1)

Invention Formula 0 five 0 five 0 An optoelectronic functional converter containing a directional light source and a coordinate-sensitive circular photo potentiometer, located between a co-, located on a common axis in an opaque housing. IB