Projection of microfilm and other documents - is by use of variable focal length lenses and reflecting light beams in plane parallel to document using mirrors

摘要

The system is for projecting reduced images of documents (24) and enlarged images of micro-documents comprises permutations of objective lenses (28, 65) of fixed and/or variable focal lengths, so that the object screen distance is constant. The beam of rays transmitted between the document plane and the projection plane (10) is reflected at least twice by mirrors (15, 18, 20, 29) and is orientated in a direction parallel to the document, between the first and last mirrors. A microfilm camera (4) could also be incorporated in the system. The documents may be macro- or micro- scale units with macro-format insertions arranged laterally.