Method and apparatus for selective filtering of an illumination device

For use with an illumination device of a type having a reflector having an exit opening, an illumination source mounted within the reflector, and a housing that encloses the illumination source and the reflector, the reflector being shaped to direct radiation emitted from the illumination source through the exit opening, a filter comprising:

• an inner support having a central lamp shield for engaging an electrode of the illumination source;
• an outer support having an inner peripheral ring and an outer peripheral support ring, the outer peripheral support ring fixed relative to the central lamp shield, and the outer support shaped to fit over a periphery of the exit opening;
• a composite filter having a plurality of filter elements, each of the filter elements configured to pivot about an associated, radially extending pivot axis extending from a common origin, and extending between and attached to the central lamp shield and the outer support;
• a plurality of pivots attaching the filter elements to the outer peripheral support ring and the inner peripheral support ring, the filter elements being shaped and positioned to lie in a composite filter plane and substantially cover the exit opening to filter the emitted radiation passing through the exit opening when pivoted to a closed position by rotation of the inner peripheral support ring relative to the outer peripheral support ring, and to rotate about the pivots from the composite filter plane to allow the emitted radiation to pass substantially unfiltered through the exit opening when pivoted to an open position by rotation of the inner peripheral support ring relative to the outer peripheral support ring;
• and
• an actuator connected to pivot the filter elements to the closed position and to the open position by rotating the inner peripheral support ring relative to the outer peripheral support ring.

A method for selectively filtering radiation from an illumination device of a type having a reflector with an exit opening, an illumination source mounted within the reflector, and a housing that encloses the illumination source and the reflector, the reflector shaped to direct the radiation emitted from the illumination source through the exit opening, the method comprising:

• attaching an outer support to a periphery of the exit opening, the outer support having an inner peripheral support ring and an outer peripheral support ring, the outer peripheral support ring fixed relative to the housing;
• providing an inner support concentric with the outer support, the inner support fixed relative to the outer peripheral support ring;
• placing a filter over the opening, the filter including a composite filter having a plurality of filter elements extending between and pivotally attached to the inner support and the inner peripheral support ring and outer peripheral support ring of the outer support, the filter elements being shaped and positioned to substantially cover the exit opening to filter the emitted radiation passing through the exit opening when pivoted to a closed position by rotation of the inner peripheral support ring relative to the outer peripheral support ring, wherein a first band or type of electromagnetic radiation from the illumination source is blocked, and to allow the emitted radiation to pass substantially unfiltered through the exit opening when pivoted to an open position by rotation of the inner peripheral support ring relative to the outer peripheral support ring;
• and
• selectively actuating the filter to pivot the filter elements to the closed position and to the open position by rotation of the inner peripheral support ring relative to the outer peripheral support ring.