Development of On-Machine Measurement Unit for Correction Processing of Aspheric Lens Mold with High Numerical Aperture
Tomohiro Hirose*,**, Yoshihiro Kami*, Tatsuhito Shimizu*,
Makoto Yabuya*, and Yoshitaka Morimoto**
*Nachi-Fujikoshi Corp., 1-1-1 Fujikoshi-Honmachi, Toyama 930-8511, Japan
**Kanazawa Institute of Technology, 7-1 Ohgigaoka Nonoichi, Ishikawa 921-8501, Japan
Most ultra-precision machine tools for fabricating optical lenses and lens molds have on-machine measurement units that can be used for form measurement with the workpiece held on the main spindle. However, for lenses with high numerical apertures, such as pick-up lenses for Blu-ray discs and their molds, the form measurement needs to be made even at a large angle of inclination, which is not feasible with a conventional on-machinemeasurement unit. In this study, an on-machine measurement unit with a measurement angle range±75 degrees is developed. Its performance assessment shows that it has high measurement reproducibility. Ultra-precision cutting are then made to verify the effectiveness of the on-machine measurement unit in the correction processing. It is also reported that, in grinding process, high-form-accuracy workpieces can be made through the correction processing by repeatedly using the on-machine measurement unit to make time-series measurements of the grinding wheel wear and by predicting the wear.
-  H. Ogawa and S. Tanaka, “Illustrated Blu-ray Disc Reader,” Ohmsha, Dec. 2006 (in Japanese).
-  M. Yabuya, “The future of Ultra precision machine tool and its element technology,” Journal of the JSPE, Vol.75, No.1, p.126, 2009 (in Japanese).
-  M. Usuki and M. Yabuya, “Ultra-Precision Aspheric Generator,” Journal of the JSPE, Vol.55, No.6, p.967, 1989 (in Japanese).
-  K. Echigo, M. Yabuya, and Y. Kami, “Processing of optical components and optical mold parts with ultra-precision machine tool,” JSPE Annual Conference Proceedings, 2001.
-  Y. Watanabe et al, “Development of On-machine Profile Measuring System with Contact-type Probe – Improvement of stylus for Contact-type Probe –,” JSPE Annual Conference Proceedings, 2005.
-  Y. Hong, “The Present Situation and Machining Example of Ultra Precision Machine,” Journal of the JSPE, Vol.78, No.9, p.744, 2012 (in Japanese).
-  H. Suzuki, “Multi-Axis Controlled Ultraprecision Machining and Measurement,” Int. J. of Automation Technology, Vol.3, No.3, 2009.
-  Y. Koike, D. Kono, A. Matsubara, and I. Yamaji, “In-situ Measurement by Using a Measurement-Fused Machining System,” Journal of the JSPE, Vol.76, No.8, pp. 945-949, 2010.
-  K. Yoshizumi et al, “Ultrahigh Accurate 3-D Profilometer Using Atomic Force Probe Measure Nanometer,” Journal of the JSPE, Vol.68, No.3, p.361, 2002 (in Japanese).
-  S. Kawai, “Lens dictionary & encyclopedia,” Optronics, 2009 (in Japanese).
-  T. Hirose, “Ultra Precision 5-axis High-Speed machine “Nano Aspher ASP01UPX,”” Nachi Technical Report, Vol.19, B2, 2009 (in Japanese).
-  T. Hirose et al, “Development of Ultra-Precision 5-Axis Machine Tool for Optical Mold – Evaluation of Basic Performance and Machined Workpiece –,” Journal of the JSPE (to be published, in Japanese)
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