Flex Lighting Ii, LLC

Azumo, Inc.

Other

Massachusetts Institute of Technology

Anthony John Nichol

Zane Arthur Coleman

Shawn Pucylowski

Jose Romero

Eric Blair

Shawn Michael Pucylowski

George Barbastathis

Gil Palmon

William Jay Arora

Fernando J Castano

A light emitting device comprises a lightguide formed from a film with a core layer, a light emitting region, a light mixing region, at least one light source, and a light absorbing cladding region on at least one lateral edge of the core layer. In one embodiment, the cladding region is on the lateral edges of the core layer in the light mixing region. The light absorbing material in the cladding region may absorb light from the at least one light source propagating in the cladding region at an angle greater than 40 degrees to the optical axis. The difference in refractive index for the core material and cladding material may be between 0.001 to 0.01. The full angular width at half maximum intensity of light exiting the light emitting region may be less than 60 degrees in air in a first illumination plane.

Light emitting device including a light absorbing cladding region on edges of a core layer of a film-based lightguide

In some aspects, a display comprises a reflective spatial light modulator, a light source, and a film-based lightguide having an array of coupling lightguides in a form of strips of the film extending from and continuous with a lightguide region of the film. The coupling lightguides are folded and stacked behind the reflective spatial light modulator along fold lines oriented at different orientation angles. In some embodiments, the coupling lightguides comprise lateral edges with curved portions. In some embodiments, the coupling lightguides are tapered. In some embodiments, the reflective spatial light modulator comprises an active area in a shape of a polygon with more than four sides or an active area defined by a boundary with a circular, semi-circular, or arcuate portion.

Reflective display comprising coupling lightguides folded at different fold angles

A light emitting display has a light emitting area of a film-based lightguide frontlight positioned between a cover lens and a reflective spatial light modulator (SLM), the cover lens extends past a lateral edge of the reflective SLM and a housing positioned below the cover lens in a thickness direction of the film and along one or more lateral edges of the reflective SLM and positioned in an edge region. The edge region is defined as the region between the lower surface of the cover lens and a lower surface of the reflective SLM, and between the lateral edge of the reflective SLM and a distance from the lateral edge of the reflective SLM in a first direction in a plane orthogonal to the thickness direction equal to the distance the cover lens extends past the lateral edge in the first direction.

Light emitting display with a film-based lightguide frontlight, a reflective spatial light modulator, and a housing positioned in an edge region

A method of manufacturing a display includes coupling light from at least one light source into a front illumination film-based lightguide comprising a pressure sensitive adhesive layer between a core polymer film layer and a diffusely reflective release liner such that light from the at least one light source propagates by total internal reflection through the core polymer film layer, is extracted from the core polymer film layer, passes through the pressure sensitive adhesive layer, diffusely reflects from the diffusely reflective release liner and passes back through the pressure sensitive adhesive layer and core polymer film layer out of the front illumination film-based lightguide; analyzing the light exiting front illumination film-based lightguide from the at least one light source for defects; removing the diffusely reflective release liner from the front illumination film-based lightguide after analyzing; and laminating the front illumination film-based lightguide to a reflective spatial light modulator.

Method of manufacturing a display using a film-based lightguide and diffusely reflective release liner

In one embodiment, a film-based lightguide comprises a plurality interior light directing edges in a tapered light mixing region with curved sections which redirect light within the tapered light mixing region of the film. The interior light directing edges may be formed by cuts in the film that create an air gap between internal edges of the film. In one embodiment, the difference between radii of curvature of neighboring radii of arc sections of interior light directing edges is within 20% of an average distance between the arc sections. In one embodiment, the interior light directing edges totally internally reflect light propagating through the tapered light mixing region such that the light propagates at a smaller angle to a direction orthogonal to a width direction and orthogonal to the thickness direction of the film.

Film-based lightguide with interior light directing edges with curved sections in a tapered light mixing region

A display includes a reflective spatial light modulator, an angularly varying diffusion film that that transmits and scatters light incident within a first angular range and transmits light un-deviated incident within a second angular range outside of the first angular range, and a frontlight including a light source positioned to emit light into a film with a light emitting region positioned between the reflective spatial light modulator and the varying angle diffusion film. In one embodiment light extracted in the light emitting region is incident on a spatial light modulating layer at an angle of peak luminous intensity less than 30 degrees in a second layer from the surface normal of the spatial light modulating layer, reflects from the reflective spatial light modulator, passes through the film, is scattered by the angularly varying diffusion film, and exits the display.

Film-based frontlight with angularly varying diffusion film

In one embodiment, a display comprises a light source positioned to emit light into a 0.5 millimeter thick lightguide with light extraction features, a cladding layer optically coupled to a core layer of the lightguide on a first side, a light turning film optically coupled to the cladding layer on an opposite side, the light turning film comprising a light turning features that redirect frustrated totally internally reflected light from the core layer into a first portion of light with a first peak luminous intensity at a first angle and a second portion of light with a second peak luminous intensity at a second angle different from the first angle and on an opposite side of the thickness direction, and the light diffusely reflecting from a reflective spatial light modulator has a peak luminous intensity within degrees from a direction normal to a surface of the display.

Reflective display comprising a lightguide and light turning film creating multiple illumination peaks

A display comprises a film-based lightguide, a light source positioned to emit light into the lightguide, and a light turning film with light turning features comprising a first surface with a first coating of a first material with a first refractive index that redirects light extracted from lightguide toward a reflective spatial light modulator wherein the light turning features also comprise a second surface that does not comprise a coating of the first material or comprises a coating of a thickness of the first material less than 500 nanometers. The light turning film may comprise a base layer of a second material with a second refractive index, and the first refractive index is less than the second refractive index. The first surface may be an angled planar surface oriented at an angle the surface of the light turning film or comprise a curved surface.

Reflective display with film-based lightguide frontlight including light turning film with coated surfaces

A display includes a transmissive spatial light modulator with an active area; a plurality of lightguides stacked above the active area; and a light source positioned to emit light that propagates into the plurality of lightguides such that the light is totally internally reflected within each lightguide then extracted from each lightguide to illuminate the active area, wherein each lightguide is folded at a first fold. In a first embodiment, each of the plurality of lightguides include a core layer and an emitting region with a plurality of light extraction features arranged in a spatially varying pattern. In a second embodiment, each lightguide is a film-based light guide with a thickness between 0.005 millimeter and 0.175 millimeter. In a third embodiment, the light source is positioned behind the spatial light modulator.

Transmissive display including a backlight with multiple stacked lightguides with a fold

A light emitting device comprises a lightguide formed from a film having an array of coupling lightguides in the form of strips extending from a lightguide region of the film, the coupling lightguides are folded and stacked, and a light source is positioned to emit light into edges of the stacked coupling lightguides to propagate into a light mixing region and then into a light emitting region. The light mixing region comprises a plurality of reflecting surfaces that reflect a portion of the light from the coupling lightguides toward one or more of the lateral edges of the film prior to exiting the film in the light emitting region. The plurality of reflecting surfaces may a light transmitting material printed in the form of lines on the surface of the film and may improve the uniformity of light emitted from the light emitting region.

Light emitting device with film-based lightguide and added reflecting surfaces

An automobile comprises a light transmitting film with a thickness not greater than 0.5 millimeters with a core layer, a lightguide region of the film comprises a light emitting region with light extracting features positioned to receive and extract light from at least one light source propagating by total internal reflection within the core layer out of the core layer, and a light mixing region positioned between the at least one light source and the light emitting region, wherein a surface of the portion of the automobile is visible through the light emitting region of the film when the at least one light source is not emitting light and the light transmitting film is conformal with the surface of the portion of the automobile. The surface of the film may have arcuate cross-sectional shape conforming to a curved surface of the portion of the automobile.

Automobile with conformal film-based lightguide

A lightguide formed from a film comprises a light mixing region between a light emitting region and an array of coupling lightguides. The first coupling lightguide of the array of coupling lightguides comprises a first light input edge between an inner lateral edge of the first coupling lightguide and an outer lateral edge of the first coupling lightguide opposite the inner lateral edge, wherein a width of the first light input edge is less than a width of the first coupling lightguide at the light mixing region and the first coupling lightguide is folded toward the outer lateral edge such that the first light input edge is between the outer lateral edge and the inner lateral edge along the array direction. In one embodiment, the first light input edge is offset from the outer lateral edge and positioned above the first coupling lightguide.

Lightguide with a light input edge between lateral edges of a folded strip

In one aspect, a film-based lightguide includes a film with a light emitting region, a plurality of coupling lightguides in a form of an array of strips extended from the body of the film and folded along a fold line, a light mixing region of the film positioned along the film between the plurality of coupling lightguides and the light emitting region, and an extended coupling lightguide region of the coupling lightguides between the fold line and the light mixing region where the plurality of coupling lightguides are not folded. For one or more of the plurality of coupling lightguides, a length along a coupling lightguide between the fold line and a light input end of the coupling lightguide is less than a length of the coupling lightguide in the extended coupling lightguide region.

Film-based lightguide with extended coupling lightguide region

A display includes a reflective spatial light modulator with an active area; a plurality of lightguides stacked above the active area; and a light source positioned to emit light that propagates into the plurality of lightguides such that the light is totally internally reflected within each lightguide then extracted from each lightguide to illuminate the active area, wherein each lightguide is folded at a first fold. In a first embodiment, each of the plurality of lightguides include a core layer and an emitting region with a plurality of light extraction features arranged in a spatially varying pattern. In a second embodiment, each lightguide is a film-based light guide with a thickness between 0.005 millimeter and 0.175 millimeter. In a third embodiment, the light source is positioned behind the spatial light modulator.

Reflective display including a frontlight with multiple stacked lightguides with a fold

A device comprises a film with an adhesive layer on a first side of a core layer, a major sheet area of the film bounded by edges of the film with a light extracting region positioned to receive and extract light propagating by total internal reflection within the core layer out of the major sheet area, and a minor sheet between the major sheet area and an array of strips. The strips extend from the minor sheet area of the film, and each strip of the array of strips is folded within a fold region and stacked. The device further comprises a component extending a width of the array of strips where they extend from the minor sheet area, wherein the adhesive layer adheres the component to the film between fold region and the light extracting region. In some embodiments, the adhesive layer is a cladding layer.

Growing community of inventors

Chicago, IL, United States of America

Anthony John Nichol