Portable map display device

Claim 1

A portable display device comprising a rectangular box-like housing, a hinged lid on said housing in the form of a hinged frame supporting a rearview projection screen, a support rod member fixedly mounted in said housing, a hollow drum mounted rotatable around said support rod member and axially displaceable along said support rod member, said hollow drum having a peripheral cut-out portion with a microfilm fiche module insert removably and interchangeably disposed in said peripheral cut-out portion of the drum, said microfilm fiche module insert having a curvilinear frame supporting a microfilm transparency, said curvilinear frame of said microfilm fiche module insert and said peripheral cutout portion of said hollow drum being provided with interengageable attachment means, illuminating means fixedly mounted on said support rod within said drum for illuminating a portion of said microfilm transparency of said microfilm fiche module insert, lens means mounted in said housing proximate to said drum and optically aligned with said illuminating means for projecting on said rearview screen an image of said illuminated portion of said microfilm transparency, a pivotable sector knob edgewise projecting through a slot in said housing, a sleeve member rotatably disposed around said support rod member, said sleeve member having an end attached to said pivotable sector knob and another end attached to an end of said drum by sliding coupling means, a bifurcated member slidably engaging said drum at each end thereof, a manually actuated lever attached to said bifurcated member and having an end projecting through a second slot in said housing whereby said drum is longitudinally displaceable along its axis of rotation as a result of longitudinal displacement of said manually actuated lever, said drum is rotatable around said support rod member as a result of pivoting said second knob, and co-ordinate reference markings co-operate with said pivotable sector knob and said manually actuated lever for controllably indexing a predetermined portion of said microfilm transparency with said illuminating means and said lens means.