Self-calibrating vision test apparatus
US5078486A · kind A · utility
19Cited by
2References
25Claims
0Family size
Inventor
Key dates
| Filing date | Oct 13, 1989 |
| Grant date | Jan 7, 1992 |
| Priority date | — |
| Expiry date | Oct 13, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2360/144
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A vision test apparatus illuminated by internal light source generating a constant, predetermined light intensity in the vicinity of the eye chart. The unit employs at least one photocell to monitor the light intensity near the eye chart and thereby adjust the amount of light generated by the light source to provide a constant level of illumination near the eye chart.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.