Lightguide having a viscoelastic layer for managing light
Assignee3M Innovative Properties Company
InventorsAudrey A. Sherman, Michael A. Meis, Marie A. Boulos, Kevin R. Schaffer, Wendi J. Winkler
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Abstract
Disclosed herein is an optical device including a light source and an optical article. The optical article includes a lightguide and a viscoelastic layer disposed on the lightguide. Light emitted by the light source enters the lightguide and is transported within the lightguide by total internal reflection. The viscoelastic layer manages light, for example, at least about 50%, or less than about 10%, of light that enters the lightguide may be extracted. The optical device can be used in a variety of constructions for signs, markings, display devices, keypad assemblies, tail light assemblies and illumination devices.
Claims29
An optical device comprising a light source and an optical article, the optical article comprising a lightguide and a viscoelastic cladding layer, wherein the viscoelastic cladding layer comprises a pressure sensitive adhesive, wherein the viscoelastic cladding layer has an index of refraction lower by about 0.2 than an index of refraction of the lightguide and wherein the viscoelastic cladding layer is disposed on the lightguide, and wherein light emitted by the light source enters the lightguide and is reflected at at least a portion of an interface between the lightguide and the viscoelastic cladding layer;
- and wherein the interface between the lightguide and the viscoelastic cladding layer comprises a plurality of features oriented to extract light being transported within the lightguide.
Dependencies are inferred from the claim text.