SU1276905A1 - Photoelectric displacement transducer - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure a linear X displacement and rotation angle of an object. The sensor consists of n identical channels using one radiation source. Each of the channels consists of a source of reflective elements (for example, prisms) located along the radiation path, which direct the beams on collimators parallel to each other and spaced at regular intervals along the moving path of the movable raster. The moving raster has periodically arranged transparent windows with which the flows coming out of the collimators are modulated. Parallel to the movable raster, there is a fixed raster having n readout windows located on the axes of the beams of collimators. Photo detectors are installed opposite the fixed raster readout windows, the signals at the output of which determine the amount of movement. By using each channel of its collimator in S (L sensor reduces the divergence of beams in different channels, which contributes to increased accuracy. At the same time, by reducing the light diameters of the collimators, it is possible to use short-focus lenses, which will reduce the size of the sensor. 1 3.pf f-ly. 4 ill. O5 with &

Description

f 1

The invention relates to a measurement technique and can be used to measure a ruler of displacements and angles of rotation of objects.

The aim of the invention is to improve the accuracy and reduce the size of the sensor.

Figures 1 and 2 depict a diagram of an angular displacement sensor in two projections; FIG. 3 shows an optical channel with an additional plane-parallel plate; in fig. 4 - the location of the optical channels in the sensor linear displacements.

The sensor contains a source of 1 light, four reflective elements 2, 3 4 and 5, made in the form of prisms, the chip of the collimator 6, the CRANE raster 7, the fixed raster 8 with four reading windows 5 four photon receiver 9 and two plane-parallel us 1 and 11.

The sensor works as follows

The light from source 1, prisms 2-5, is directed to collimators 6, which form four identical beams. Kazh,. the beam passes through the movable raster 7 and the fixed raster 8, while the light is modulated. The modulated light fluxes are recorded by the photodetectors 9, from which electrical signals are taken that carry information about the magnitude of the displacement. The amount of movement is characterized by the number of periods and the level within the period of the variable component of the signal.

Two extreme channels formed by reflective elements: 3 and 5, are more distant from the source than channels formed by elements 2 and 4. To align the focus of the extreme channels with the place: source settings, when using all the same collimators in the extreme channels additional flat-plate plates 10 and 11 are installed.

The use of one source in combination with four identical optical channels ensures: an increase in accuracy due to a decrease in the difference in divergences of particles in different channels.

Reducing the overall dimensions of the sensor is achieved as a result of the point of view of one common call center:

76905I

large light diameter, determined by the length of the line for the location of all n readout windows, and with high requirements for divergence, a large focal distance.

In the sensor, each collimator forms a light beam to illuminate only one receiver, so its dimensions may be small. ten

Claims (1)

1. A photoelectric displacement sensor containing a 5 NIN source of radiation and a projection system arranged successively along its radiation, a raster installed in a plane perpendicular to the optical axis of the projection system, with a possible 20 movement in a raster plane and made of an opaque mask with : Pa / c windows arranged periodically in the direction of the trajectory of the intersection point of the optical axis of the projection of the 1st system with the raster plane, the second raster fixed fixedly parallel to the first The image is erased and e-filled as an opaque mask with n transparent 30 windows located along the path of movement of the projection of the windows of the first raster with a period T / n, where T is the location of the windows of the first raster, and n photodetectors located f opposite the windows of the second raster s characterized by the fact that and reduce the size of the sensor, the projection system contains n channels, each of the same collimators installed in such a way that their optical axes coincide with the sensitivity axes of photodetectors, reflective elements installed in 45, in which the images of the axes of the collimators formed by them are passed through the center of the source, and compensators, reducing the influence of the distance inequality from the source 50 TO the collimators on the divergence of the beams at the output of the collimators. 2, the sensor according to claim 1, about tl and h a and p and and with ret-ij that the compensators are made of 3 types of curds, it is parallel S3 plates 3 the thickness of which is selected depending on the removal of the col. Agglomerate from the source. / fl } f