Novel optical lens measuring method

Abstract

The invention relates to a novel optical lens measuring method which comprises the following steps: (1) establishing a lens measuring system consisting of a display and a CCD camera; (2) displaying phase shifting strips through the display, and enabling the camera to acquire strips of a display screen without a lens to be measured and with the lens to be measured in a position 1 and a position 2;(3) calculating primary phase distribution of the strips by using a four-step phase shifting method and a rhombus seed algorithm, performing system calibration through a phase without the lens to be measured, fitting a planar equation of the display screen in the two positions, calculating a rotational matrix R and a translation vector T from a screen physical coordinate system to a camera coordinate system, and further calculating the wave front slopes of the position of the lens and each point on the lens; (4) performing integration on the wave front slopes by using a Poisson reconstructionmethod so as to obtain wave front distribution of the lens to be measured; (5) calculating a spherical lens degree and astigmatic power distribution of the whole surface of the lens by using a dioptercalculation model according to the wave front distribution of the lens. By adopting the method, free-form surface lenses with relatively large curvature variations can be measured, and high resolution ratios and rapid measurement speeds can be achieved.

Description

technical field [0001] The invention belongs to the field of optical measurement, and relates to the measurement of lens wavefronts, in particular to an optical lens measurement method. Background technique [0002] The entire manufacturing process of optical free-form surfaces includes design, precision machining, and precision measurement. The entire manufacturing process has extremely high requirements for machining accuracy. The surface roughness generally needs to reach the nanometer or even sub-nanometer level, and the shape accuracy needs to reach the micron to sub-micron level. Therefore, it is a key issue in this field to inspect the processed free-form surface lens to judge whether it meets the requirements of use. [0003] To measure the optical performance of a lens, it is necessary to measure its wavefront. Lens wavefront measurement methods can be roughly divided into two categories. The first type of measurement method directly measures the lens wavefront, s...

AI Technical Summary

Problems solved by technology

The use of mechanical motors complicates the entire measurement system

As the density of sampling points increases, the period of measurement will increase

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