Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4873429 | Optical pick-up head without pick-up of stray light | Hidehiro Kume, Yoshiyuki Matsumoto | 1989-10-10 |
| 4823331 | Focusing detection apparatus | Yoshiyuki Matsumoto, Hidehiro Kume | 1989-04-18 |