Short-range scanning-based spectral confocal ranging method, device and equipment

Abstract

The invention discloses a short-range scanning-based spectral confocal ranging method, device and equipment. The method comprises the following steps: establishing a relation curve between the axial distance of a measuring head and the pixel serial number of a spectrometer; the measuring head scanning the current position in a short measuring range to obtain an actually measured reference light intensity signal; and obtaining a pixel sequence number value according to a noise spectrum signal, a reflection spectrum signal and the actually measured reference light intensity signal, and substituting the pixel sequence number value into the search relation curve to obtain the axial distance of the current position of the surface of the object to be measured. According to the invention, the current position is scanned by using the measuring head in a short measuring range, the maximum reference light intensity signal is obtained in real time, the maximum reference light intensity signal inthe calibration process is not required to be stored in advance, and the measurement precision is improved. In addition, full-range scanning is not needed, only short-range scanning covering the current position is needed, no positioning requirement is required for a scanning device, and the cost of the instrument is reduced.

Description

technical field [0001] The invention relates to the technical field of spectral confocal displacement measurement, in particular to a method, device and equipment for spectral confocal distance measurement based on short-range scanning. Background technique [0002] Spectral confocal displacement detection technology uses optical dispersion to focus light of different wavelengths on different optical axis positions, forming a one-to-one correspondence between wavelengths and axial distances. Through the design of the confocal optical path, the spectral peak wavelength reflected from the surface to be tested and passed through the conjugate hole is obtained, and the axial distance of the surface to be tested can be calculated. [0003] At present, all spectral confocal displacement sensors need to be calibrated with high precision before the instrument leaves the factory, and the search relationship curve between the axial distance and the focusing wavelength is stored in the...

AI Technical Summary

Problems solved by technology

However, since the surface to be tested used in the calibration process is not exactly the same as the surface to be tested in the real measurement, a certain error occurs in the customer's measurement, which is why some products require the customer to provide the sample to be tested for accurate calibration

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