Patent · US Expired

Device for measuring small distances

US4744661A · kind A · utility

16Cited by
4References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 10, 1986
Grant dateMay 17, 1988
Priority date
Expiry dateDec 10, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01B11/303
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A device for measuring small distances, provided with a sensing tip mounted to be movable in the direction of the length to be measured, a transducer for converting the movements of the sensing tip into corresponding electric signals, and indicating means to indicate such signals. The transducer comprises an optical interferometer provided with a measuring waveguide. One end of the waveguide is connected to a laser and the other end to optical means for directing the light onto a measuring mirror disposed at a distance. The light is reflected by the mirror back to the optical means. The measuring mirror is connected to the sensing tip. The interferometer further includes a reference waveguide linked to the measuring waveguide. The reference waveguide has a mirror disposed at one end and a photoelectric transduer at the other end. The transducer is connected to the indicating means for indicating the output signals of the transducer. The device permits a cost-effective and uncomplicated construction as an integrated unit. The device affords precision measurements at accuracies in the range of one half of the wavelength of the lasr beam, or even far below such a value. The device als…

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