Back-lightable diffusive display sign

A back-lightable sign which comprises in combination;

• a source of light,
• a display panel in the path of light from said source, said display panel for displaying alphanumeric characters and graphics comprising a plurality of mechanically movable display elements which move interchangeably from a first position in which a dark face is visible to a second position in which a bright face is visible;
• means for manipulating said mechanically movable display elements from said first position to said second position and vice versa;
• and diffusion means interposed between said source of light and said display panel for scattering the light falling on said display panel from said source whereby shadows cast by said means for manipulating said mechanically moving display elements are substantially invisible from the front of said display panel;
• in which said diffusion means comprises a plate of solid translucent material interposed between said source of light and said display panel, said plate constructed and arranged to diffuse light passing through said plate;
• wherein said mechanically-moveable elements are arranged in rows and columns corresponding to the width and length of said display panel, wherein each of said mechanically movable elements comprises a first rectangular plate having a dark surface, and a substantially identical second rectangular plate having a bright surface, said first plate and said second plate being fastened together along one of each of their edges to form a triangular configuration in which the dark plate faces outward on one side and the bright plate faces outward on the other side,
• a yoke connected between the undersides of said plates in each of said elements, said yoke having bearings at opposite ends.
• a pin interposed through said bearings in each row of said elements for rotating said mechanically movable element with said pin as an axis from a first position in which said dark face is in substantially parallel flush relation with the inner surface of said display panel to a second position in which said bright face is in substantially flush relation with the inner surface of said display panel, and vice versa;
• means for retracting each of said pins and each of said rows of mechanically movable elements under spring bias in a direction away from the inner surface of said display panel for conditioning a row of said movable elements for rotation from one said position to another said position;
• means comprising a comb having a plurality of teeth extended in the direction of said movable elements, which comb extends in a length direction of said display panel transverse to said pins, said comb constructed to be moved down under spring bias whereby said teeth contact said movable elements conditioned to rotate;
• driving means for conditioning said mechanically movable elements to rotate from one said position to another said position, and driving means for driving a selected comb to move downward, whereby the teeth of said comb contact a conditional mechanically movable element in response to a code of preselected signals to move said movable elements to form a sign in accordance with said signals.