Patent · US Expired

Optical calibration apparatus and procedure

US4199816A · kind A · utility

34Cited by
11References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 28, 1978
Grant dateApr 22, 1980
Priority date
Expiry dateJun 28, 1998

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01M11/0221
  • WIPO fieldMedical technology
  • WIPO sectorInstruments

Abstract

A process and apparatus for the calibration of an optical instrument. An optical instrument--such as a lens meter or ophthalmometer--is provided with a light source, a light detector, and an optical train of assembled optical elements therebetween. A suspect optical element to be measured is placed within the optical train at a measuring interval to deflect light passing along the optical train. An occulting moving boundary locus having at least two boundaries of differing shape, and a dedicated computer may be used to measure beam deflection. The dedicated computer also makes use of stored computer constants to transform raw measurements into the desired optical properties of the suspect optical element. The optical train of the instrument has its assembled optical elements randomly placed to production tolerances; precision registration of the optical elements to traditional close optical tolerances is omitted. Calibration occurs by manipulating the instrument's beam deflection apparatus under the control of a calibration program, by providing the optical instrument being calibrated with an umbilical cord which bypasses the central processing unit of the dedicated computer, but o…

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