Apparatus for optical scanning of microfilms or the like

Optical scanning apparatus for microfilms or test films has a first carriage which is movable along the X-axis of a coordinate system, a second carriage which is mounted on the first carriage and is movable along the Y-axis of the coordinate system, a magnetic coupling device which connects a portion of the margin of a film to the second carriage so that each and every bit of information on the film can be moved into register with a reference point at the upper side of a horizontal base plate, and an optical scanning system having a light source below the base plate, an annular insert mounted in the base plate and serving to transmit light upwardly through the film at the reference point of the upper side of the base plate, and a magnifying lens system or a photoelectric cell above the film in register with the insert. A fan can direct a stream of air upwardly toward and through the insert to cool the light source and to impinge against the underside of the film so as to remove dust and reduce friction between the insert and the film.