Patent · US Expired

Display system for fish sonar

US4644511A · kind A · utility

6Cited by
3References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 14, 1985
Grant dateFeb 17, 1987
Priority date
Expiry dateJun 14, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S15/96
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A display system for fish sonar displays two ultrasonic echo signals of different frequencies from the left side to the central portion and from the central portion to the right side on the screen of a cathode ray tube. After the two ultrasonic echo signals are displayed on the entire screen of the cathode ray tube, the old echo signals are eliminated and the display is refreshed with new echo signals so that a picture of a school of small fish which is displayed by ultrasonic echo signals of high frequency can be compared with a horizontally adjacent picture of a large fish simultaneously displayed by ultrasonic echo signals of low frequency on a single cathode ray tube screen.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.