COMPENSATION OF LIGHT SOURCE INTENSITY PULSE IN SCROLLING COLOUR TYPE PROJECTION SYSTEM

摘要

A scrolling colour projection system comprising a lamp ( 4 ) with a pulsed drive current ( 20 ) and a colour scanner ( 6, 8 a , 8 b , 8 c , 9 ) for generating a light beam ( 5 b) with a plurality of scrolling colour fields, which is arranged to illuminate a display device ( 3 ) to produce a projection of an image generated by the display device. The system further includes a filtering element ( 31 ) arranged in the light path between the lamp and the projected image, and the transmission of the filtering element ( 31 ) is synchronized with the lamp current so as to cancel an intensity peak in the lamp flux. The filtering element thus effectively removes the impact of the current pulse on the light intensity, resulting in a constant intensity in the projected image, and avoiding any interference patterns.