0

Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

First aspheric form and texture results from a production machine embodying the precession process

[+] Author Affiliations
David D. Walker

Univ. College London and Zeeko Ltd. (United Kingdom)

David Brooks, Andrew King

Univ. College London (United Kingdom)

Richard Freeman, Gerry McCavana, Roger Morton, David Riley, John Simms

Zeeko Ltd. (United Kingdom)

Proc. SPIE 4451, Optical Manufacturing and Testing IV, 267 (December 27, 2001); doi:10.1117/12.453652
Text Size: A A A
From Conference Volume 4451

  • Optical Manufacturing and Testing IV
  • H. Philip Stahl
  • San Diego, CA, USA | July 29, 2001

abstract

We report on progress developing the Precession Process, that has recently been embodied for the first time in a fully-productionised aspheric polishing machine. We describe how the process uses inflated polishing tools of continuously-variable size and hardness. Despite the rapid tool rotation needed to give high removal rates, the method produce well-behaved and near-Gaussian tool influence functions, by virtue of the precession of the spin axis. We then describe how form errors are controlled. The method takes influence-function data and an error map as input, together with, uniquely, weighting factors for height and slope residuals and process time. A numerical optimisation of the cost function with variable dwell time, tool path and tool size is then performed. The advantages of this new technique are contrasted with conventional deconvolution methods. Results of form control on aspheric surfaces are presented, with an interpretation in terms of spatial frequencies. We draw particular attention to control of form at the centre and periphery of a workpiece. Finally, we describe how Precession processing gives multi- directional rubbing of surfaces, and we present the superb texture achieved on samples.

© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Citation

David D. Walker ; David Brooks ; Richard Freeman ; Andrew King ; Gerry McCavana, et al.
"First aspheric form and texture results from a production machine embodying the precession process", Proc. SPIE 4451, Optical Manufacturing and Testing IV, 267 (December 27, 2001); doi:10.1117/12.453652; http://dx.doi.org/10.1117/12.453652


Access This Article
Sign In to Access Full Content
Please Wait... Processing your request... Please Wait.
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
 

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement

Buy this article ($18 for members, $25 for non-members).
Sign In