Lens meter with automated readout
US4180325A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 5, 1977 |
| Grant date | Dec 25, 1979 |
| Priority date | — |
| Expiry date | Jul 5, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/0235
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An automated readout for a lens meter is disclosed in combination with a light beam deflecting type of lens meter such as that of a Hartman test. In such a light beam deflecting type of lens meter, a light source having one or more beams is passed through a suspect optical system and deflected by the suspect optical system to a deviated path. Measurement of the deviated path within a preselected area of excursion is typically equated to various powers of the suspect optical system in sphere, cylinder, cylinder axis, and prism. The invention provides for a means of measurement of deviated paths and includes a moving boundary locus with edges of distinctly different shape placed to intercept and occult said deflected beam in a known plane within the area of excursion at a distance from the suspect optical system. The moving boundary locus is typically arranged for movement along a predetermined path at a velocity within the known plane. The boundary locus includes a first substantially transparent portion, a second substantially opaque portion, and at least two boundaries between the opaque and transparent portions. Each of the two boundaries defines a unique non-ambiguous intersecti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.