Method and apparatus for the measurement of rapid light variation superimposed on a slowly changing background light intensity
US5180907A · kind A · utility
Inventors
Key dates
| Filing date | Jun 3, 1901 |
| Grant date | Jan 19, 1993 |
| Priority date | — |
| Expiry date | Jun 3, 1921 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/113
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention relates to measurements of light, where light variations superimposed on a background amount of light, which is changing relatively slowly, are measured. To give the light sensitive element (3,3') used a stable operational point a light emitting element (5,5') is used for injecting extra light into the light sensitive element (3,3'). Thus, the amount of light injected by this light emitting element (5,5') is chosen in such a way that the sum of the ambient light and the injected light is substantially constant. To this amount of light are added the light variations, e.g. caused by a second light emitting element (9,9'). This process and device can be used in a device for measuring the eye movements of a person.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.