Optical enlarging device

Claim 1

An optical enlarging device for a graphic copy, comprising a base member; a first plate horizontally supported on said base member and movable in one direction longitudinally thereof; a copy supporting second plate horizontally supported on said first plate and movable in another direction laterally of said base member and perpendicular to said one direction; a carriage assembly adapted to be positionally spaced above said graphic copy comprising a dome structure, a vertical translucent projection screen carried by said dome structure, an optical housing including a shelf assembly having a plurality of lamps which are arranged to illuminate said second plate in all positions of adjustment thereof, said optical housing having an open bottom and further including an electrically powered fan carried by said optical housing and arranged to withdraw air heated by said lamps, optical members in said housing disposed to define an optical path between said second plate and said screen for projecting an upright enlarged image of said copy on said screen; said optical members comprising a lens barrel for positioning over said copy and adapted to focus the image of said copy on said screen, a pair of small mirrors angularly inclined to one another and to the vertical axis of said lens barrel, a pair of larger mirrors supported in said housing and angularly inclined with respect to each other around a horizontal axis thereinbetween for projecting the image from said smaller mirrors to said screen and; means adjustably supporting said carriage assembly on said base member for vertical movement over said first and second plates, whereby said carriage assembly is positionally spaced above said graphic copy so that an upright enlarged image thereof is projected on said screen by said optical members and said fan can draw air between said graphic copy and said carriage assembly into said optical housing to keep said lamps cool.