Issued Patents 2002
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6493307 | OPTICAL HEAD HAVING TWO SEMICONDUCTOR LASERS OF DIFFERENT WAVELENGTH, AN OBJECTIVE LENS FOCUSING LASER BEAMS ON DIFFERENT THICKNESS SUBSTRATES, AND AN ANNULAR PHASE SHIFTER DECREASING FOCUSED LASER BEAM SPOT ABERRATION | Akira Arimoto | 2002-12-10 |
| 6477129 | Optical disc drive | Koichi Maruyama, Shigeru Nakamura, Akira Arimoto, Kazuo Shigematsu | 2002-11-05 |
| 6430140 | OPTICAL HEAD HAVING TWO SEMICONDUCTOR LASERS OF DIFFERENT WAVELENGTH, AN OBJECTIVE LENS FOCUSING LASER BEAMS ON DIFFERENT THICKNESS SUBSTRATES, AND AN ANNULAR PHASE SHIFTER DECREASING FOCUSED LASER BEAM SPOT ABERRATION | Akira Arimoto | 2002-08-06 |
| 6400664 | Optical head including electrical circuit which produces focus error signal and tracking error signal unaffected by variations in intensity distributions of reflected light beams | Shigeru Nakamura, Kunikazu Ohnishi, Masayuki Inoue, Yukio Fukui | 2002-06-04 |