SU1551988A1 - Photoraster transducer of displacements - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure linear displacements. The purpose of the invention is to increase the accuracy by equalizing the amplitudes and phases of the output signals of the photodetectors. Radiation from sources 1 and 2 of radiation is modulated by moving the measuring raster 3 relative to the indicator raster 4. Diaphragms 5 and 6, installed in front of receivers 7 and 8, ensure that the amplitudes of the output signals from the photoreceivers 7 and 8 and the phase shift between they are 90 °. This leads to an increase in measurement accuracy. 1 hp f-ly, 2 ill.

Description

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The invention relates to a measurement technique and can be used to measure linear displacements.

The purpose of the invention is to increase the accuracy by equalizing the amplitudes and phases of the output signals of the photodetectors.

FIG. 1 given the scheme of the proposed converter; in fig. 2 is a view A of FIG. 1.

The photoraster displacement transducer contains sources 1 and 2 of radiation, the measuring raster 3, the indicating raster 4, and the diaphragms 5 and 6 located along the radiation path, located respectively in front of the photoreceivers 7 and 8 "

The device works as follows.

Radiation from sources 1 and 2 of radiation, such as LEDs, is modulated by moving the measuring raster 3 relative to the indicator raster 4, diaphragms 5 and 6, installed in front of the receivers 7 and 8, depending on their position relative to the radiation flux, ensure that the amplitudes of the output signals from the photodetectors 7 and 8, for example, photodiodes, and the phase shift between them is 90 °.

Diaphragms, made in the form of an isosceles wedge with the ability to move the strokes of the rasters, ensure the alignment of the amplitudes of the output signals. The amplitude of the signal depends on the power of the radiator, the position of the radiator relative to the other elements of the converter, the photoresponse of the photodetector. Moving the wedge diaphragm along

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strokes of rasters change the intensity of the light flux incident on the photodetector. By rotating the diaphragm around an axis perpendicular to the plane of the wedge, a portion of the light flux with a certain angle of incidence is diaphragmed. By excluding a certain part of it from the radiation flux, the phase of the photoreceiver output signal and, consequently, the phase difference of the photodetector signals is regulated. The degree of equality of the amplitudes of the output signals depends on the uniform distribution of the samples within the raster period, associated with the quantization levels, and, consequently, the accuracy of the measurement of the movement of

Claims (2)

1. A photo-transducer displacement transducer containing radiation sources and a measuring raster arranged successively along the radiation path for communication with an object, an indicator raster and photodetectors, characterized in that, in order to increase accuracy, it is equipped with diaphragms installed one before each photodetector with the possibility of adjustment. 2. The transducer of claim 1 J o T is characterized in that each diaphragm is made in the form of an isosceles wedge oriented in such a way that the apex of the wedge is directed along the strokes of the rasters and is mounted so that it can move along the strokes of the rasters and rotate around an axis perpendicular to the plane wedge. 3 Buff a fig.g