Abstract: A contact printer, for exposing light sensitive sheets to relatively large size drawings and the like for making accurate duplications, is formed of an endless, movable, support belt having a flat support surface which is overlapped by a movable transparent belt. The drawing and sheet are overlapped and fed between and move in a longitudinal direction with the two belts. The overlapping portions of the transparent belt, the drawing and sheet are all flattened and tightly clamped together against the flat support surface by a vacuum system. Such system includes closely spaced, transversely extending, grooves formed in the surface of the support belt. The grooves open endwise into longitudinally extending border portions which are formed along the side edges of the support belt. A row of holes through at least one of the border portions passes over a vacuum chamber. Thus, air is evacuated through the grooves and out through the holes to the chamber.

Abstract: A photographic exposure unit for making a reproduction of non-dimensional engineering drawings to very close tolerances. The original drawing and the film are driven by a travelling vacuum system through a light exposure unit. In all cases, the exposure is made while the original drawing and film are held in close contact one against the other during their conjoint passage through a flat exposure area.

Abstract: A portable photographic exposure apparatus for making reproductions of loft drawings, body drafts or the like directly from the drawing table on which the drawing is made. A wheeled cabinet structure has a horizontal supporting surface, the height of which is adjustable to the height of a drawing table, with an exposure unit adapted to be mounted on the supporting surface and containing a light source, a set of electric motor driven wheels, and a source of static electricity. The exposure unit is driven over the drawing table to expose a sheet of film which is laid over the drawing on the drawing table to reproduce the drawing. Static electricity projected by the exposure unit presses the film firmly against the drawing to be reproduced. The electric motor is reversible to return the exposure unit to its supporting cabinet. The apparatus may also be used to expose a negative which is subsequently processed to provide positive reproductions of the loft drawing.