Illumination apparatus for ophthalmic refractors
US5281984A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1992 |
| Grant date | Jan 25, 1994 |
| Priority date | — |
| Expiry date | Jul 1, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/0285
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An illuminator assembly is provided for ophthalmic refractors which is formed as a singular light guide formed in unitary fashion of a transparent polymeric material. The light guide includes a light input portion located adjacent an incandescent light source mounted within the refractor housing. The light guide has transparent output portions which extend uniformly and continuously about the axis scale and further extend to the cylinder power window and the spherical power window. Through the use of a potentiometer/voltage regulator based circuit, the practitioner may alter the intensity of the light propagated to these readout functions by maneuvering a knob mounted upon the battery housing. To improve the characteristics of the illumination, the transparent outputs of the light guide are formed as Fresnel lenses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.