Patent 7804554 was granted and assigned to Sony on September, 2010 by the United States Patent and Trademark Office.
To provide source images is increased to enhance the uniformity of luminance distribution. A surface emitting device includes: a diffusing sheet constituting a light exiting surface; a reflector disposed opposite to the diffusing sheet; light sources disposed between the diffusing sheet and the reflector; and a prism sheet (light-source-image division sheet) disposed between the diffusing sheet and the light sources. The prism sheet has linear protrusions on the front surface thereof, and a flat portion parallel to the sheet surface between the adjacent linear protrusions. This generates light-source images through the flat portions in addition to the divided light-source images through the linear protrusions 16a to increase the number of light-source images, thereby improving luminance uniformity.