Characterization of surface defects in fast tool servo machining of microlens array using a pattern recognition and analysis method

Chi Fai Cheung, K. Hu, X. Q. Jiang, L. B. Kong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

24 Citations (Scopus)


Microlens array (MLA) is a type of structured freeform surfaces which are widely used in advanced optical products. Fast tool servo (FTS) machining provides an indispensible solution for machining MLA with superior surface quality than traditional fabrication process for MLA. However, there are a lot of challenges in the characterization of the surface defects in FTS machining of MLA. This paper presents a pattern recognition and analysis method (PRAM) for the characterization of surface defects in FTS machining of MLA. The PRAM makes use of the Gabor filters to extract the features from the MLA. These features are used to train a Support Vector Machine (SVM) classifier for defects detection and analysis. To verify the method, a series of experiments have been conducted and the results show that the PRAM produces good accuracy of defects detection using different features and different classifiers. The successful development of PRAM throws some light on further study of surface characterization of other types of structure freeform surfaces.
Original languageEnglish
Pages (from-to)1240-1249
Number of pages10
JournalMeasurement: Journal of the International Measurement Confederation
Issue number9
Publication statusPublished - 1 Nov 2010


  • Fast tool servo
  • Freeform optics
  • Microlens array
  • Pattern recognition
  • Structured freeform surfaces
  • Surface characterization
  • Surface measurement
  • Ultra-precision machining

ASJC Scopus subject areas

  • Instrumentation
  • Electrical and Electronic Engineering

Cite this