Confocal non-contact position sensor

Abstract

The invention discloses a confocal non-contact position sensor. According to the sensor, a point light source is formed by using a light source through a pin hole. Parallel light beams are formed from the point light source by a collimator; linearly polarized light is obtained by a polarizer; the obtained linearly polarized light is processed by a quarter-wave plate to form circularly polarized light and the circularly polarized light is focused at the surface of an object by an objective lens; the light is reflected from the surface of the object and the reflected light passes through the objective lens the quarter-wave plate, the polarizer, and a small hole to arrive at a photoelectric detector; and the detector generates a maximum output current signal. When the object is not at a focal plane, the output signal of the detector is weakened because of restriction of the small hole. The detection signal of the detector is amplified by a post processing circuit; the amplified signal is processed by a comparison circuit and is converted into a voltage signal for outputting; and the position information of the object is obtained by observing the outputted voltage signal. The sensor has the following advantages: contact with any object during measurement is not required; the measuring precision is high; the working distance is long; and the application range is wide and the like.

Description

technical field [0001] The invention belongs to the field of non-contact measurement, in particular to a confocal non-contact position sensor. Background technique [0002] Position measurement can be divided into contact measurement and non-contact measurement. Contact measurement uses the probe to directly touch the surface of the object, and the photoelectric signal returned by the probe head is converted into the spatial coordinate position information of the measured object, thereby realizing the position detection of the object. At present, the Renishaw touch probe is more commonly used, which is mainly used in the three-coordinate probe system and the machine tool probe system. [0003] In the three-coordinate measurement system, the Renishaw touch probe head determines an initial position (origin of coordinates) through the computer and the control system, and then controls the probe head to move along the three directions of x, y, and z. When the probe head touches...

AI Technical Summary

Problems solved by technology

This measurement method has a large amount of data, complex control process, cumbersome equipment, large amount of manual programming, low measurement efficiency, and contact measurement itself will introduce measurement errors due to slight deformation of the contact object. At the same time, contact measurement is widely used in applications There are also certain limitations. For some high-precision parts, contact measurement is easy to damage the parts, and some measurement environments use contact measurement to damage the probe head and make it impossible to measure

Images