Portable microfilm viewer

Claim 1

A control for a microfilm viewer comprising a housing including a microfilm viewing port, said housing being shaped to operatively support a cassette containing microfilm bearing a plurality of image frames, and means for driving the microfilm in the cassette past the film viewing port, a film gate located alongside the film viewing port and pivotally mounted to the housing for movement against the film and away from the viewing port, a film claw shaped to positively engage the microfilm, said film claw being movably mounted to the housing and coupled to the driving means for a repeatable motion selected to advance the microfilm a distance corresponding to a dimension of an image frame, a single frame control wheel driven into rotation by the driving means and having a stop, a stop shaft disposed to normally engage the single frame control wheel stop and mounted to the housing for movement towards and away from the single frame control wheel, a control switch mounted adjacent the stop shaft for actuation thereby upon release movement of the stop shaft away from the single frame control wheel stop, a single frame control lever projecting from the housing and coupled to the stop shaft to initiate release movement and enable said driving means to actuate the film claw for single frame advancement thereof, a continuous film advance control lever projecting from the housing and disposed for movement towards and away from the film claw and tHe film gate to separate the film claw from the microfilm, said continuous film advance control lever further being coupled to the stop shaft to initiate a release movement thereof and actuation of the control switch for a continuous advance of the microfilm commensurate with the duration of the actuation of the continuous film advance control lever.