Optical projector for transparencies - has objective and variable diaphragm and magnifier on single frame at front of normal projector

摘要

The projector shows all or part of a document such as a transparency. At the front is a holder (10) to carry the document. An objective (12) produces an image (11') of the document at the position of a variable opening diaphragm (14) and a continuously variable magnifying objective (15). The diaphragm is in the image plane of the transfer objective (12). This diaphragm and the magnifying objective are individually controlled by motors (23,35) with coupled controls. The diaphragm and magnifying objective are on the same frame (20), which forms a sub-assembly at the front of a normal projector.