Patent ID: 8389957

Claim:
A system for providing metered dosage illumination for use in a bioanalysis or other system, comprising: a light engine that can provide a plurality of different colors of light as a light output; a light detector that can detect an indication of light flux at the light output; a light-to-frequency converter that can convert the indication of light flux as detected by the light detector to a pulse train, the frequency of which pulse train is proportional to the light flux; a counter that can compare an ongoing count as indicated by the pulse train, to a preset reference count for a particular color; and wherein, during operation, the illumination system determines a reference count for each color, for an exposure period, enables the light engine to turn on a particular color, monitors the indication of light flux at the light output, as detected by the light detector and converted to the pulse train counted by the counter, and when the counter reaches the reference count, disables the particular color currently provided by the light engine, to select a different color.