Frontlit illuminated touch panel
Assignee3M Innovative Properties Company
InventorsGary T. Boyd, Stephan J. Pankratz
Life of this patent
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Abstract
A frontlit touch panel for use with a reflective light valve, comprising a front light guide having at least one light input face that supplies light to the guide, a viewing face, a light output face opposite the viewing face, and at least one component of a touch-sensitive transducer, the light output face having a light extraction layer thereon having a substantially flat light exit face and containing buried reflective facets that extract supplied light from the guide through the light exit face. The touch panel can be used with a light source, reflective light valve and suitable control electronics to form a compact, efficient illuminated touch panel display assembly.
Claims11
A flexible film having a substantially flat lower surface which provides a light exit face, a non-planar upper surface having finely-shaped projections with a generally trapezoidal cross-section comprising riser, plateau and facet portions flanked by land portions, and a layer of optically transparent adhesive on the plateau portions, such that if the plateaus are adhesively laminated to a light output face of a substantially planar light guide having at least one light input face that supplies light to the guide, a viewing face and the light output face opposite the viewing face, the resulting assembly encloses pockets containing a medium having a lower refractive index than a material from which the film is manufactured and buried facets which reflect and thereby extract supplied light from the guide through the light exit face.
Dependencies are inferred from the claim text.