Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4701663 | Lamp having interference film | Akira Kawakatsu, Yooji Yuge, Noriyuki Hayama, Umio Maeda | 1987-10-20 |
| 4634919 | Bulb | Yooji Yuge, Ariyoshi Ishizaki, Takeshi Ishii | 1987-01-06 |