Measurement Research of Free-form Lens Optical Parameters Based on Transmission Fringe Deflectometry

This paper presents a measurement system based on the transmission fringe deflectometry, which is designed to facilitate the rapid attainment of the free-form lens optical parameters, including spherical power, cylindrical power, and prismatic power. In this paper, we analyze the principle of transmission fringe deflectometry. The key technology, camera calibration, and phase unwrapping techniques are introduced in detail. A single-focus lens is given to demonstrate the validity of the proposed fringe deflection algorithm. Then the optical parameters calculation models of free-form lens, such as progressive lens, is presented and the detection results are given. Moreover, the results of the proposed fringe deflection algorithm are in close agreement with those obtained from simulations and the FFV interferometer. The error of free-form lens measured in this paper is less than 0.02D. The experimental outcomes validate the efficacy of the method, suggesting the potential for its application in the mass measurement of optical parameters for free-form lenses.