Projection screen frame on rails fixed to wall - is adjustable to different levels using support arms joining bearings on panel and upright frame for horizontal positioning

摘要

The frame is mounted upright for sliding on rollers in the groove of a horizontal rail secured to a wall. A vertical guide rod extends downward from the frame, and carries, at its free end, a distance piece with a roller which touches the wall. The projection panel is hinged at its base to a retaining plate whose rearward and upward sloping arm slides up and down the rod to set the level at which the plate is clamped, with its two carrying arms deployed at a downward angle from the top of the frame. ADVANTAGE - Legibility esp. of text display is not marred by foreshortening due to slope of projection panel which is also easy to handle.