Slow tool servo diamond turning of optical freeform surface for astigmatic contact lens

Chun Chieh Chen, Yuan Chieh Cheng, Wei Yao Hsu, Hsiao Yu Chou, Pei Jen Wang, Din Ping Tsai

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

15 Citations (Scopus)


Three ultra-precision machining processes namely fast tool servo, slow tool servo and diamond milling, are frequently used to produce optical freeform surface. Slow tool servo machining has the advantages of no extra attachment and fast setting-up, however the three dimensional tool shape compensation and tool-path generation must be conducted carefully for getting high form accuracy and fine surface finish. This research aimed to develop a model of three dimensional tool shape compensation for generating 3D tool path in slow tool servo diamond turning of asymmetrically toric surface for astigmatic contact lens. The form accuracy of freeform surface was measured by ultra-high accuracy 3D profilometer (UA3P) with user define function. After correction, the form error is less than 0.5μm both in X- and Y-direction and the surface roughness is less than 5nm.

Original languageEnglish
Title of host publicationOptical Manufacturing and Testing IX
Publication statusPublished - Aug 2011
Externally publishedYes
EventOptical Manufacturing and Testing IX - San Diego, CA, United States
Duration: 22 Aug 201124 Aug 2011

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceOptical Manufacturing and Testing IX
Country/TerritoryUnited States
CitySan Diego, CA


  • Astigmatic contact lens
  • Optical freeform surface
  • Slow tool servo diamond turning

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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