ILLUMINATION SYSTEM, METHOD AND PROJECTION DEVICE FOR CONTROLLING LIGHT EMITTED DURING SPOKE TIME PERIOD Russian patent published in 2012 - IPC H04N9/31 

FIELD: physics.

SUBSTANCE: illumination system has a light source, having a first light-emitting unit and a second light-emitting unit, each emitting light towards a light output window. The illumination system has a colour wheel comprising a plurality of colour segments (R, G, B), the boundary between two neighbouring colour segments being a spoke. The first light-emitting unit, the second light-emitting unit and the spoke are configured to prevent the spoke, when transiting the optical path between the light source and the light output window, to simultaneously transit a first optical path between the first light-emitting unit and the light output window and a second optical path between the second light-emitting unit and the light output window. The illumination system further comprises a drive unit which is configured to switch off the first light-emitting unit during a time interval (pl) when the spoke transits the first optical path.

EFFECT: colour of the light emitted during the spoke time does not change gradually but changes relatively abruptly enabling the projection device to use the light emitted during the spoke time without the need for complex compensation techniques.

13 cl, 20 dwg