13 May 2013 Optical resolution measurement system for small lens by using slanted-slit method
Author Affiliations +
For the optical resolution measurement, the Modulation Transfer Function (MTF) is widely applied. This paper presents the RD result of our developed optical resolution measurement system with the slanted slit method for small lenses. The MTF is built up by the Fourier's transformation of the Line-Spread Function (LSF) that is acquired by analyzing the projected dark-bright image of the measured lens. In order to obtain a smooth LSF, we propose a slanted slit method. And the slanted slit lets a part of the collimated light transmit through the measured lens, and a dark-bright slit-image is projected on the CCD-camera. Through a proper selection of the region of interest (ROI), a smooth LSF with dense sampled data can be formed by arranging pixels according to their distances to the slanted slit. And these sampled data of the LSF can effectively eliminate the aliasing effect and furthermore can accurately derive the MTF. The influences of the angle of the slanted slit and the ROI-selection on the performance of this optical resolution measurement system are thoroughly studied. The accuracy of its processing algorithm is experimentally verified by using the statistic factors GRR and STD-error. Based on a calibrated lens, the developed processing system and algorithm can achieve the industrial level with GRR of 27% and STDerror of 8%.
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kuang-Yuh Huang, Kuang-Yuh Huang, Chou-Min Chia, Chou-Min Chia, Elmer Chang, Elmer Chang, } "Optical resolution measurement system for small lens by using slanted-slit method", Proc. SPIE 8788, Optical Measurement Systems for Industrial Inspection VIII, 87882J (13 May 2013); doi: 10.1117/12.2016545; https://doi.org/10.1117/12.2016545

Back to Top