Fish finder capable of discriminating sizes of fish
US4081783A · kind A · utility
20Cited by
3References
3Claims
0Family size
Inventor
Key dates
| Filing date | Sep 22, 1976 |
| Grant date | Mar 28, 1978 |
| Priority date | — |
| Expiry date | Sep 22, 1996 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02B2075/025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention discloses a fish finder wherein one transducer is used to generate both high- and low-frequency ultrasonic waves which are simultaneously emitted and the electrical signal representative of the reflected high- or low-frequency ultrasonic waves is extracted by the signal representative of the reflected low- or high-frequency ultrasonic waves, thereby discriminating the sizes of fish detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.