| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Japan | 8 | |
| #2 | United States | 3 | |
| #3 | Republic of Korea | 1 |
| # | Industry | |
|---|---|---|
| #1 | Measurement | |
| #2 | Semiconductors | |
| #3 | Electrical machinery and energy | |
| #4 | Optics | |
| #5 | Medical technology | |
| #6 | Chemical engineering | |
| #7 | Machines |
| # | Technology | |
|---|---|---|
| #1 | Analysing materials | |
| #2 | Geophysics | |
| #3 | Measuring light | |
| #4 | Semiconductor devices | |
| #5 | Diagnosis and surgery | |
| #6 | Chemical or physical laboratory devices | |
| #7 | Unspecified technologies | |
| #8 | Optical systems | |
| #9 | Magnets and transformers |
| # | Name | Total Patents |
|---|---|---|
| #1 | Yamakawa Masami | 12 |
| #2 | Yamakawa Miyuki | 1 |
| Publication | Filing date | Title |
|---|---|---|
| JPH0242381A | Photoelectric sensor | |
| KR940010588B1 | Photo electronic sensor | |
| US4792685A | Photoelectric sensor | |
| JPS63262529A | Photoelectric sensor | |
| JPS60186002A | Variable resistor | |
| JPS601817A | Annular transformer with terminal | |
| JPS5340873A | One shot output senddout device | |
| JPS52144136A | Automatic flushing device | |
| JPS52112215A | Power distribution carrierfrequency communication system | |
| JPS5298574A | Photoelectric detector for moving object |