Freeform Spectacle Lens Detection Based On Hartmann Principle

With the rapid popularization and wide application of freeform spectacle,the eyewear market urgently needs to establish a reasonable evaluation standard to help consumers judge the quality of lens imaging.We propose to use Hartmann's principle to detect the imaging quality of freeform spectacle lens.We measure and research the refractive power,wavefront aberration and optical distortion of freeform spectacle lens,through theoretical analysis and experimental analysis,the three optical parameters are used to jointly evaluate the image quality of freeform spectacle lens.The main research contents of the curved lens are as follows:(1)Analyze the refractive power and its measurement principle,build a refractive power measurement system,and measure the same effective area of different freeform spectacle based on the Hartmann wavefront sensing principle,and then restore the refractive information through MATLAB.The refractive power curves were fitted and compared with the freeform spectacle optical analyzer(FFV).(2)Analyzed the measurement principle of the wavefront aberration of the freeform spectacle lens and a beam expander-contraction beam measurement system is proposed.The beam expander measurement is performed on the specific area of the freeform spectacle lens.The sub-aperture wavefront reconstruction principle and the sub-aperture stitching principle are used to complete the pair.The reconstruction and splicing of wavefront aberrations in the corresponding regions were combined with the refractive power values to analyze the imaging quality of the lenses.(3)Analyze the optical distortion and the measurement principle.The Hartmann wavefront sensor is used to measure the same effective area of different lenses,and the curve of the distortion value and the position information of the corresponding lens area is drawn and calculated.The root mean square error of the distortion value of the optical system,combined with the refractive power values of the freeform spectacle lens,further quantitatively evaluate its imaging quality.