Estimation Method of the Best-Approximated Form Factor Using the Profile Measurement of the Aspherical Ophthalmic Lens

단면 형상 측정을 이용한 비구면 안경 렌즈의 최적 근사화된 설계 계수의 추정 방법

  • 이호철 (한밭대학교 기계공학부)
  • Published : 2005.05.01

Abstract

This paper presents mainly a procedure to get the mathematical form of the manufactured aspherical lens. Generally Schulz formula describes the aspherical lens profile. Therefore, the base curvature, conic constant. and high-order polynomial coefficient should be set to get the approximated design equation. To find the best-approximated aspherical form, lens profile is measured by a commercial stylus profiler, which has a sub-micrometer measurement resolution. The optimization tool is based on the minimization of the root mean square of error sum to get the estimated aspherical surface equation from the scanned aspherical profile. Error minimization step uses the Nelder-Mead simplex (direct search) method. The result of the lens refractive power measurement shows the experimental consistency with the curvature distribution of the best-approximated aspherical surface equation

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References

  1. Zimmerman, J., 'Continuous process improvement: manufacturing optics in twenty-first century,' Proc. SPIE Vol. 1994, pp. 176-182, 1994 https://doi.org/10.1117/12.167966
  2. Yoo, J., Lee, C., Jeong, S., 'An optical head with special annular lens for laser disc compatible digital versatile disc pickup,' Jpn J. Appl. Phys., Vol. 37, pp. 2184-2188, 1998 https://doi.org/10.1143/JJAP.37.2184
  3. Venkatesh, V. C., Zhong, Z., Wihardjo, E., 'Studies on polishing of glass moulds after lapping with hard and soft pellets,' J. Material processing technology vol. 62, pp. 415-420, 1996 https://doi.org/10.1016/S0924-0136(96)02445-4
  4. Lee, H., Yang, M, 'Dwell time algorithm for computer-controlled polishing of small axissymmetrical aspherical lens mold,' Optical Engineering, Vol. 40, No. 9, pp. 1936-1943, 2001 https://doi.org/10.1117/1.1396323
  5. Yang, M., Lee, H., 'PC-NC based aspherical lens polishing system with minimum translation mechanism,' J. of Korean Society of Precision Engineering, Vol. 18, No.5, pp. 65-71, 2001
  6. Malacara, D., 'An optical surface and its characteristics,' Appendix 1 in Optical Shop Testing 2nd Ed., John Wiley & Sons, New York, pp. 743-753, 1992
  7. 'Operating manual of the Formtalysurf,' Rank Talyor Hopson Co., 2001
  8. Borse, G. J., 'Numerical Methods with MATLAB,' PWS Publishing Company, Boston, 1997
  9. Seong, P., 'Optometry,' Daehakseorim, pp. 69, 2004