SU896399A1 - Photoelectric device for checking non-linearity - Google Patents

Description

(54) PHOTOELECTRIC DEVICE FOR CONTROL OF INDIRECTNESS

one

The invention relates to a measurement technique and can be applied to control non linearity and non-flatness in instrumentation and mechanical engineering, construction, etc.

The known photoelectric linearity control device, comprising a collimator and a photodetector, mounted on opposite sides of the guides to be monitored, and a rectangular prism mounted by the hypotenuse edge on the carriage, moving along the guided guides ll.

The disadvantage of this device is the effect on its accuracy of interference caused by the turbulence of the air path.

The closest to the invention in technical essence and the achieved result is a photoelectric device for controlling linearity, containing sequentially installed along controlled guides a collimator, a carriage with optical

unit, a lens, coordinate-sensitive radiation receivers and an electronic information processing unit connected to the outputs of the coordinate-sensitive receivers f 2.

However, in this device, the failure due to turbulence is also not completely eliminated. In addition, the device contains a complex electronic path.

The purpose of the invention is to increase the measurement accuracy.

This goal is achieved by the fact that the device is equipped with a reflector freely placed on the carriage during radiation between the collimator and the optical unit under

Claims (2)

15 angle 45 ° to the optical axis of the collimator and the cedar entrance face of the optical unit, made with the possibility of splitting the radiation beam into two mirror-symmetric beams with different spectral composition, spectral beam-splitting unit, installed in front of the radiation receivers and made in the form of a beam-splitting plate with two selective lights4) each of which is consistent with the spectral composition of the corresponding beam of rays from the optical unit. With; This optical unit can be made in the form of a pentaprism, glued together from a truncated Schmidt prism and a rectangular prism, one of the catheter faces of which is the entrance face of the optical block, the other catheter face is the output face, the hypotenuse face adjacent to the Schmidt prism is semi-transparent and the spectral band of the reflection of the semitransparent coating of a right-angle prism does not coincide with the spectral bandwidth of the Schmidt prism material. On; The drawing shows a functional diagram of the device. The device contains successively located along the monitored direction of 1 collimator 2, the carriage 3, the reflector 4, such as a mirror, freely suspended on the racks of the carriage 3 on the path of the beam of rays from the collimator 2 above the optical unit 5, made in the form of a pentaprism, made of glued together a rectangular prism with a beam-splitting hypotenuse border and a truncated Schmidt prism, and mounted on a carriage 3, a receiving photoelectric device, -Containing b, a translucent plate 7, two voters light filter 8, one of which is installed in the path of the beam of rays reflected from the plate 7, and the other in the path of the beam passing through it, two coordinate-sensitive photosensors 9 of radiation with different spectral characteristics installed in the focal plane of the lens 6, the electronic processing unit information containing amplifiers H connected to the outputs of photodetectors 9, and the comparison circuit 11 connected to amplifiers 10 Mirror 4 is located at an angle of 45 to the axis of the beam of rays incident on it above the entrance face of the pentapri snakes. The translucent coating material of a rectangular prism is selected with a spectral reflection band that does not coincide with the spectral bandwidth of a Schmidt prism material. Instead of a translucent coating, you can use a mirror coating applied by rings or stripes on the hypotenuse face and occupying half of its area. The bandwidth of each of the selective light filters 8 is matched with the spectral composition of the corresponding mirror-symmetrical beam of rays from the pentaprism 5. The thickness of the light filters 8 are chosen from the condition of equality of signals from both radiation receivers 9. Instead of the pentaprism 5, it is possible to use other optical units for splitting the beam of rays into two mirror-symmetric beams with different spectral composition, for example, a mirror unit with mirrors arranged like a Schmidt prism. The device works as follows. When the slopes of the carriage 3 are mixed along the controlled rails 1, the mirror 4 always makes an angle of 45 °. with the axis of the beam incident on it, therefore the axis of the beam reflected by mirror 4 is normal to the optical axis of the lens. Pentaprism 5 with the slopes of the carriage splits a parallel ray of rays falling on it into two beams with different spectral composition. The image of the collimator diaphragm, the MnpoBajiHoe shape reflected by the rays reflected from the hypotenuse edge of a rectangular prism, is focused in the plane of one radiation receiver 9, and the image formed by the rays passing through the pentaprism 5 in the plane of the other receiver 9 forgiving through it, deviates from the optical axis of the lens 6 by an angle, due only to the action of the turbulence of the air path between the pentaprism 5 and lens 6, independent of the angle of a company of pentaprism 5, ejected by the inclination of the carriage 3. The image formed by the rays reflected from the hypotenuse face of the rectangular prism undergoes an angular deviation equal to the sum of two angles — twice the angle of inclination of the carriage 3, shifted along the guides, and angle due to the action of turbulence. Comparison circuit 11 generates a signal proportional to the difference of signals from both radiation receivers 9. As a result, the output signal is free from the air turbulence of the air path and is proportional only to the non linearity of the guides being monitored 1. With a significant movement of the carriage 3 relative to the collimator 2 in order to eliminate the air turbulence between the air path between them, it is possible to hang the collimator 2 on racks reinforced on the card 3, and placing the collimator -2 with the reflector 4 into a vacuum pipe. Claims I. A photoelectric device for monitoring the non-linearity of guide profiles containing a collimator, a carriage with an optical unit, a lens, coordinate-sensitive radiation receivers, and an electronic information processing unit connected to the outputs of coordinate-sensitive receivers, differently installed along controlled guides. the fact that, with the aim of increasing the accuracy of measurements, it is provided with a reflector freely suspended on the carriage during the radiation between the collimator m and an optical unit at an angle of 45 to the optical axis of the collimator and above the input face of the optical unit, the optical unit is designed to split the radiation beam into two mirror-symmetric beams with different spectral composition, a spectral beam-splitting unit installed in front of the radiation receivers and made in the form of a beam-splitting plates with two selective light filters, the bandwidth of each of which is matched with the spectral composition of the corresponding beam of rays from the landing block. 2. The device according to claim 1, characterized in that the optical unit is made in the form of a pentaprism, glued together from a truncated Schmidt prism and a rectangular prism, one of the catheter faces of which is the input face of the optical block, another catheter face the output face, the hypotenuse border, adjacent to the Schmidt prism, is translucent, and the spectral reflection band of the semi-transparent covering of the gm of the rectangular prism does not coincide with the spectral bandwidth of the Schmidt prism material. Sources of information taken into account in the examination 1. B. Levin, et al. Photoelectric devices for controlling the straightness of the surface profile. OMP, 1971, No. 8, p. 60 2. USSR author's certificate number 641274, cl. Q 01 B 11/30, 1979 (prototype).