Patent · US Expired

Light beam detection utilizing hologram

US5220409A · kind A · utility

56Cited by
11References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 18, 1991
Grant dateJun 15, 1993
Priority date
Expiry dateDec 18, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F3/0421
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Light beam detection is taught in method and apparatus where a light source of coherent light is directed toward a reflecting hologram made to simulate a parabolic mirror to generate light beams detected by photoreceptors along one side of an opto-frame, such receptors being scanned in a manner to preclude false detection of an object within the field of light. An an alternative, multiple light sources are used with a single receptor and an appropriate hologram.

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