Synchronised lighting system for fixed image projection lamp - has screen illuminated during period between change of following images

摘要

The single objective lens fixed image projector is associated with a light box arranged so as to only illuminate a zone of the projection screen. The zone is equivalent to that covered by the projected images. The moment of illumination coincides with the occultation of an image before the appearance of the following image. The light box has on its front face an opening of dimensions proportional to those of the images to be projected. A clear electric lamp is placed inside the box near to the wall opposite to the opening. An adjustable lamp support permits variation of its position w.r.t. the opening. An electric contact is actuated mechanically by the image changer so that the lamp in the light box is illuminated at the start of image occultation and is extinguished when the following image appears.