Issued Patents 2002
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6490100 | Objective lens and optical head device | Yasuhiro Tanaka, Michihiro Yamagata | 2002-12-03 |
| 6349000 | Device for calculating diffraction efficiencies of a diffraction lens, lens with grating element, and optical system for reading | Michihiro Yamagata, Kazutake Boku, Yasuhiro Tanaka, Shusuke Ono | 2002-02-19 |