@inproceedings{d21e78138aed44bd860dd3324942fff4,
title = "Development of an auto-focus system by the moir{\'e} method",
abstract = "An auto-focus system based on the moir{\'e} effect and the P control method is presented. First, a collimated laser beam passes through a focusing lens and falls incident on the surface of the sample. The deviation of the angle of the light reflected back is proportional to the defocus distance from the sample. The reflected light then passes through two spiral gratings, where three types of moir{\'e} patterns are observed and received by a linear CCD. A new formula is derived for finding the focus value (FV) in order to calculate the spiral angle of the moir{\'e} pattern and to determine the defocus distance from the sample. The results show that auto-focus should be achieved in a very short time by means of the defocus distance calculation and P control method.",
keywords = "Auto-focus, Moir{\'e}, Spiral grating",
author = "Lee, {Ju Yi} and Lin, {Yu Ju} and Wang, {Yung Hsing} and Liu, {Chien Sheng}",
year = "2010",
language = "???core.languages.en_GB???",
isbn = "9781617820199",
series = "10th International Symposium on Measurement and Quality Control 2010, ISMQC 2010",
pages = "485--488",
booktitle = "10th International Symposium on Measurement and Quality Control 2010, ISMQC 2010",
note = "10th International Symposium on Measurement and Quality Control 2010, ISMQC 2010 ; Conference date: 05-09-2010 Through 09-09-2010",
}