Side-light display illuminator

Abstract

A light guide for illuminating a display screen, including a vertical cone-shaped entrance surface including an aperture for admitting light beams emitted by an LED, a folding mirror for reflecting the admitted light beams at an angle of approximately 90°, and for horizontally collimating the admitted light beams, a horizontal guide for guiding the reflected light beams to an exit surface, and an exit surface positioned above a perimeter of a display screen for directing the guided light towards a portion of the display screen, the exit surface being tilted vertically from the horizontal at a slight angle to direct the guided light beams towards the display, and being shaped horizontally as a concave lens to spread the guided light beams horizontally over an angular expanse of the display screen.

1 - 7 . (canceled) 
     
     
         8 . A light transmission module for illuminating a display screen, comprising:
 a cone-shaped entrance surface comprising an aperture for admitting visible light beams emitted by a light source;   a light guide, coupled with said cone-shaped entrance, for guiding the admitted light beams to an exit surface; and   the exit surface, coupled with said light guide and positioned above a perimeter of a display screen, for directing the guided light beams towards a portion of the display screen, the exit surface being tilted downward from the light guide at a slight angle, to direct the guided light beams towards the display and to illuminate a displayed image, and being shaped horizontally as a concave lens to spread the guided light beams horizontally over an angular expanse of the display screen.   
     
     
         9 . The light transmission module of  claim 8  wherein said light guide comprises upper and lower walls that are painted black, to absorb light and prevent internal reflections off of said upper and lower walls. 
     
     
         10 . The light transmission module of  claim 8  wherein said exit surface is tilted so as to direct a central light beam emitted by the light source to a location that is between 25% and 50% along the extent of the display screen away from said exit surface. 
     
     
         11 . The light transmission module of  claim 8  wherein said exit surface is tilted at an angle of approximately 4°. 
     
     
         12 . The light transmission module of  claim 8  wherein said entrance surface, said light guide and said exit surface are comprised of a plastic material. 
     
     
         13 . A display for an electronic device in accordance with  claim 8 , comprising:
 a display screen;   a light source positioned near an edge of said display screen; and   a light transmission module in accordance with  claim 8  positioned near said light source, for admitting visible light beams emitted by said light source, and for transmitting the admitted light beams over said display screen so as to illuminate said display screen.   
     
     
         14 . The display of  claim 13  wherein a light emitting area of said light source is larger than the aperture for admitting visible light beams into said light transmission module. 
     
     
         15 . The display of  claim 13  further comprising:
 a plurality of infrared light emitters positioned near the perimeter of said display screen for emitting infrared light; 
 a plurality of infrared light receivers positioned near the perimeter of said display screen, for receiving infrared light emitted by said infrared light emitters; and 
 a projector mounted near the perimeter of said display screen for projecting the infrared light emitted by said infrared light emitters across said display screen in order to enable detection of a touch position when an object touches said display screen.