| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United Kingdom | 7 | |
| #2 | Hong Kong | 5 | |
| #3 | Canada | 4 | |
| #4 | Germany | 4 | |
| #5 | France | 4 | |
| #6 | Italy | 4 | |
| #7 | United States | 3 | |
| #8 | Taiwan | 1 |
| # | Industry | |
|---|---|---|
| #1 | Optics |
| # | Technology | |
|---|---|---|
| #1 | Cameras |
| # | Name | Total Patents |
|---|---|---|
| #1 | Yan Chan Kwok | 6 |
| #2 | Yan Chan K | 4 |
| #3 | Ko Norman Wah Man | 3 |
| #4 | Chan Kwok Yan | 3 |
| #5 | Kwok Yan Chan | 2 |
| #6 | Norman Wah Man Ko | 2 |
| #7 | Ko Norman W M | 1 |
| Publication | Filing date | Title |
|---|---|---|
| HK30578A | Camera for underwater and above water use | |
| HK30678A | Camera for underwater and above water use | |
| CA1063411A | Plastic-housed pocket-sized underwater camera system | |
| IT1051028B | Camera for underwater and normal use - has watertight apertures for lens and support frame and has controls which can be operated underwater | |
| DE2535551A1 | PHOTOGRAPHIC CAMERA | |
| US4041507A | Camera for underwater and above water use | |
| US4032940A | Retractable camera | |
| GB1495412A | Cameras | |
| US4014033A | Percussive flash unit operating mechanism |