Patent ID: 9103956
Filing Date: 2015-08-11
Classification: G02B

Abstract:
1. An optically redundant light emitting device comprising: a. a light transmitting film comprising a lightguide region defining a light emitting area and an array of coupling lightguides extending from the light emitting area wherein each coupling lightguide of the array of coupling lightguides is bent to form a stacked array of coupling lightguides; b. a first group of light sources comprising at least two light sources positioned to emit light into end edges of the stacked array of coupling lightguides; and c. a second group of light sources comprising at least one light source positioned to emit light into the end edges of the stacked array of coupling lightguides, the first group of light sources and the second group of light sources positioned in a linear array parallel to the end edges of the stacked array of coupling lightguides, wherein: i) when the first group of light sources and the second group of light sources are emitting light, each coupling lightguide in the stacked array of coupling lightguides receives light emitted from the first group of light sources and light emitted from the second group of light sources, the light travels by total internal reflection through the light transmitting film to the light emitting area, the light emitted from the first group of light sources and the light emitted from the second group of light sources exit the light transmitting film in the light emitting area with a spatial luminance uniformity of the light emitting area along an edge of the lightguide region disposed to receive light from the array of coupling lightguides greater than 70%; and ii) when the first group of light sources is emitting light and the second group of light sources is not emitting light, the light emitted from the first group of light sources exits the light transmitting film in the light emitting area with a spatial luminance uniformity of the light emitting area along the edge of the lightguide region disposed to receive light from the array of coupling lightguides greater than 70%.