Flicker photometer
US6017122A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1998 |
| Grant date | Jan 25, 2000 |
| Priority date | — |
| Expiry date | Mar 11, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/02
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A flicker photometer comprises generating means (1, 8, 4) for generating two beams of light of different colors. Both beams are directed to a viewing means (190), and a subject can vary the intensity of light from one beam relative to the other. The color of the light seen by the subject is caused to alternate by a shutter (18) which is rotated about an axis by a motor, the shutter having a portion which extends non-perpendicularly relative to the axis to facilitate a compact construction of photometer. The performance of the photometer is improved by screens which scatter light before it reaches the subject. A first of the screens reflects light from one beam, whilst a second screen transmits light from the other. If light of wavelengths to which the eye is less sensitive is passed through the second screen, whilst light of a wavelength to which the eye is more sensitive passes through the first screen, the screens help to make it practicable for the generating means to use a single lamp (1) to produce the light for both beams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.