Patent · US Expired

Arrangement for measuring depth based on lens focusing

US4629324A · kind A · utility

54Cited by
4References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 29, 1983
Grant dateDec 16, 1986
Priority date—
Expiry dateDec 29, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01B11/24
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A pattern of light is projected upon a surface to be measured which may be devoid of surface detail. A sharply focused image of the surface provides distance discrimination. Although the projected pattern may be separate from the imaging optics, a common optics path removes distortion, provides maximum sensitivity and eliminates processing for misalignment between projector and imager. Sequential cross-correlation, synchronous detection or percent modulation processing methods may be readily implemented to develop three-dimensional co-ordinates relative to the sensor for all in-focus regions of the image. Refocusing the lens provides depth coverage.

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