PATENT DOCUMENT

Publication Number: US-10222529-B1
Application Number: US-201715703568-A
Country: US
Kind Code: B1

Title: Lighting systems

Abstract:
A lighting system may include one or more light sources and one or more light guides. A lighting system may be integrated into a window, a skylight, an exterior light such as a headlight, a tail light, or a high center-mounted stop light, or other exterior or interior portions of a system such as a vehicle. The light guide may be embedded in an adhesive layer in a vehicle structure. The light guide may be index-matched to the adhesive layer so that unilluminated portions of the light guide are indistinguishable from the vehicle structure. The light guide may be formed from optical fibers. The optical fibers may include a light-scattering optical fiber that scatters light out of the vehicle structure. The light-scattering optical fiber may be fused to a non-scattering optical fiber that guides light from a light source to the light-scattering optical fiber.

Claims:
What is claimed is: 
     
       1. An illumination system, comprising:
 first and second layers, wherein at least the first layer is transparent; 
 a polymer layer interposed between the first and second layers, wherein the polymer layer attaches the first layer to the second layer; 
 an optical fiber embedded in the polymer layer; and 
 a light source that emits light into the optical fiber, wherein the optical fiber has light extraction features that cause the light to scatter outwards through the first layer. 
 
     
     
       2. The illumination system defined in  claim 1  wherein the first and second layers each comprise glass. 
     
     
       3. The illumination system defined in  claim 1  further comprising an additional optical fiber that is free of light extraction features, wherein the additional optical fiber guides the light from the light source to the optical fiber. 
     
     
       4. The illumination system defined in  claim 3  wherein the optical fiber and the additional optical fiber are fused together. 
     
     
       5. The illumination system defined in  claim 3  wherein the additional optical fiber and the second layer are transparent and wherein objects on one side of the illumination system are viewable from an opposing side of the illumination system through the first layer, the polymer layer, the additional optical fiber, and the second layer. 
     
     
       6. The illumination system defined in  claim 3  wherein the optical fiber forms an illuminated loop. 
     
     
       7. The illumination system defined in  claim 3  wherein the optical fiber has a first tapered region and the additional optical fiber has a second tapered region, wherein the first and second tapered regions are fused together to form an optical coupler that couples the light from the additional optical fiber into the optical fiber. 
     
     
       8. The illumination system defined in  claim 3  wherein the optical fiber has a reflective end that reflects the light back through the optical fiber. 
     
     
       9. The illumination system defined in  claim 1  wherein the polymer layer comprises polyvinyl butyral. 
     
     
       10. The illumination system defined in  claim 1  wherein the polymer layer has a first index of refraction, wherein the optical fiber has a second index of refraction, and wherein the second index of refraction is within five percent of the first index of refraction. 
     
     
       11. A vehicle, comprising:
 a body; 
 a window mounted in the body; and 
 an illumination system having a light guide embedded in the window, wherein the light guide is indistinguishable from the window when the illumination system is unilluminated. 
 
     
     
       12. The vehicle defined in  claim 11  wherein the light guide comprises first and second optical fibers, wherein the illumination system comprises a light source that emits light into the first optical fiber, wherein the first optical fiber guides the light to the second optical fiber, and wherein the second optical fiber provides the light to an interior of the vehicle when the illumination system is illuminated. 
     
     
       13. The vehicle defined in  claim 12  wherein the second optical fiber has light extraction features that cause the light to escape the second optical fiber towards the interior of the vehicle, and wherein the first optical fiber is free of light extraction features. 
     
     
       14. The vehicle defined in  claim 13  wherein objects outside of the vehicle are viewable through the window and the first optical fiber when the illumination system is illuminated. 
     
     
       15. A vehicle, comprising:
 a body; 
 a vehicle structure mounted to the body, wherein the vehicle structure comprises a layer of adhesive and a transparent layer; and 
 an exterior lighting system mounted to the body, wherein the exterior lighting system comprises an optical fiber in the layer of adhesive and wherein the optical fiber scatters light through the transparent layer to illuminate an exterior area of the vehicle. 
 
     
     
       16. The vehicle defined in  claim 15  wherein the exterior lighting system forms part of a light selected from the group consisting of: a headlight, a tail light, and a center high-mounted stop light. 
     
     
       17. The vehicle defined in  claim 15  wherein the layer of adhesive has a first index of refraction, wherein the optical fiber has a second index of refraction, and wherein the second index of refraction is within five percent of the first index of refraction. 
     
     
       18. The vehicle defined in  claim 15  wherein the exterior lighting system comprises a light source and an additional optical fiber, wherein the additional optical fiber is fused to the optical fiber, and wherein the additional optical fiber guides light from the light source to the optical fiber.

Description:
This application claims priority to provisional patent application No. 62/397,076, filed Sep. 20, 2016, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to lighting systems and, more particularly, to lighting systems that can blend in with surrounding structures. 
     BACKGROUND 
     Systems such as vehicles generally have lighting systems. Lighting systems in vehicles include interior lighting for providing aesthetic lighting and informative visual output and exterior lighting such as head lights and tail lights. 
     Existing lighting systems are generally visible to a user even when the lighting system is unilluminated. The visible presence of a lighting system in a vehicle may be aesthetically appealing or may prevent other objects from being visible through the lighting system. 
     SUMMARY 
     A lighting system may include one or more light sources and one or more light guides. A lighting system may be integrated into a window, a skylight, an exterior light such as a headlight, a tail light, or a high center-mounted stop light, a door panel, a dashboard, or other interior or exterior portions of a system such as a vehicle. 
     The light guide may be embedded in a polymer layer in a vehicle structure. The light guide may be index-matched to the polymer layer so that unilluminated portions of the light guide are transparent and indistinguishable from the vehicle structure. 
     The light guide may be formed from one or more optical fibers. The optical fibers may include a light-scattering optical fiber that scatters light out of the vehicle structure towards the interior or exterior of the vehicle. The light-scattering optical fiber may be fused to a non-scattering optical fiber that guides light from a light source to the light-scattering optical fiber. 
     Further features will be more apparent from the accompanying drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a portion of an illustrative vehicle in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative system with lighting in accordance with an embodiment. 
         FIG. 3  is a front view of an illustrative illumination system having a light guide embedded in a vehicle structure in accordance with an embodiment. 
         FIG. 4  is a front view of the illumination system of  FIG. 3  in an unilluminated state in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative illumination system having a light guide embedded in a polymer layer in a vehicle structure in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative light guide having a fiber core surrounded by cladding in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative light guide having a fiber core in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative light guide formed from a bundle of optical fibers in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of an illustrative light guide having an optical fiber surrounded by a buffer layer with straight sides in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of an illustrative light guide having an optical fiber surrounded by a buffer layer with curved sides in accordance with an embodiment. 
         FIG. 11  is a perspective view of illustrative light guides grouped together in a common buffer layer in accordance with an embodiment. 
         FIG. 12  is a front view of an illustrative illumination system having a non-scattering optical fiber that guides light to a light-scattering optical fiber with a reflective end in accordance with an embodiment. 
         FIG. 13  is a front view of an illustrative illumination system in which a tapered portion of a first optical fiber is fused to a tapered portion of a second optical fiber to form an optical coupler in accordance with an embodiment. 
         FIG. 14  is a front view of an illustrative illumination system in which an optical coupler is used to couple light from a non-scattering optical fiber into a light-scattering optical fiber in accordance with an embodiment. 
         FIG. 15  is a front view of an illustrative vehicle structure having multiple illumination systems in accordance with an embodiment. 
         FIG. 16  is a front view of an illustrative vehicle structure having an illumination system with a light guide having multiple light-scattering portions and multiple non-scattering portions in accordance with an embodiment. 
         FIG. 17  is a cross-sectional side view of an illustrative illumination system having a light guide with a cleaved end to form a spotlight in accordance with an embodiment. 
         FIG. 18  is a cross-sectional side view of an illustrative illumination system having a light guide with a bulged end to form a spot light in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative system of the type that may be provided with illumination is shown in  FIG. 1 . System  10  may be a vehicle, a kiosk, a room in an office or other building, or other environment that includes lighting. Illustrative configurations in which system  10  is a vehicle may sometimes be described herein as an example. 
     As shown in  FIG. 1 , system  10  may include windows such as front window  12 , rear window  14 , side windows  16 , and one or more top windows  18  (e.g., a skylight) that are mounted in body  20 . Body  20  may have doors  30 . The surfaces of doors  30  may sometimes be referred to as door panels and face the interior of body  20 . Dashboard  76  may be located in front of seats  22 . Buttons, dials, and other components may be provided on dashboard  76  and elsewhere in system  10  and may be provided with illumination from a lighting system. Footwells  80  may be covered with carpeting or other suitable material. 
     Illumination may be provided in system  10  to illuminate the interior of system  10  and/or to illuminate the exterior of system  10 . As examples, interior lighting may be provided on windows of system  10  (e.g., front window  12 , rear window  14 , skylight window  18 , side windows  16 , or other suitable windows), the interior surface of doors  30  (e.g., on door panels), in footwells  80  (e.g., in the carpet or other material in footwells  80 ), on dashboard  76  (e.g., locations associated with input-output components and/or other portions of dashboard  76 ), on horizontal areas (seating surfaces) of seats  22 , on the front of rear of seatbacks in seats  22 , on the front or rear of headrests on seats  22 , on a headliner (e.g., on the interior of a vehicle roof), on interior surfaces of A pillars, B pillars, C pillars, or other structural components), on seatbelts, on a steering wheel, on an arm rest or console between seats  22 , on an arm rest on doors  30 , on mirrors, on rear seat footwells or other portions of the floor of system  10 , or any other interior surfaces of system  10 . 
     Lighting may also be provided on the exterior of vehicle  10 . For example, side mirrors may be formed on the left and right sides of vehicle  10  and may include light-based output devices such as light-emitting diodes. Vehicle  10  may also be provided with lights on the rear of vehicle  10  such as rear lights  26  (e.g., turn signal lights, brake lights, tail lights, etc.). Rear lighting may also be provided on rear window  14  and/or other portions of the rear of vehicle  10 . The rearward facing lighting of vehicle  10  may include center high mounted stop lamps (CHMSL) such as light  28 . Light  28  may emit light through rear window  14  or may be mounted on other rear portions of vehicle  10 . Additional lights in vehicle  10  such as lights  24  may include headlights, turn signal lines, and fog lights. In general, lighting may be provided on any interior and/or exterior surface of vehicle  10  such as the roof of vehicle  10 , the rear window or other rear surfaces of vehicle  10 , the front window or other front surface of vehicle  10 , the doors or other side surface of vehicle  10 , protruding portions of vehicle  10  such as mirrors or bumpers, or any other vehicle surface. The lighting for vehicle  10  may be provided using light-based devices (light sources) that have been mounted on the surface of vehicle  10  (e.g., on body  20 , inside a portion of body  20 , in body  20  in an arrangement where the exterior of the light-based devices is flush with the surface of body  20 , etc.) and/or using lighting that emits light through windows  12 ,  14 ,  16 , and/or  18 . 
       FIG. 2  is a schematic diagram of an illustrative system with lighting. As shown in  FIG. 2 , system  10  may include control circuitry  34 . Control circuitry  34  may include one or more microprocessors, application-specific integrated circuits, digital signal processors, microcontrollers, or other processing circuitry. Control circuitry  34  may also include storage such as volatile and non-volatile memory, solid state drives, hard disk drives, and removable storage media. During operation of device  10 , control circuitry  34  may process data and take suitable actions in response. Data may be gathered from circuitry  34  (e.g., clock information, status information on the current operating state of system  10 , etc.) and may be gathered from input devices  36 . Based on the data that is processed by control circuitry  34 , control circuitry  34  may use electrical components such as output devices  38  to take actions such as displaying visual output for a user of system  10  with a lighting system in devices  38 , presenting audio output to the user, adjusting an electromechanical actuator (e.g., to adjust steering, braking, etc.), controlling a motor (e.g., to position a seat), etc. 
     Input devices  36  may include force sensors. For example, devices  36  may include force sensors based on strain gauges, force sensors based on piezoelectric materials, force sensors based on compressible resistive foam, capacitive force sensors (e.g., force sensors based on collapsible foam, fabric with conductive strands that serve as capacitive electrodes, or other capacitive force sensor structures), or other force sensor structures that detect applied force such as applied force from the fingers (or other body part) of a user. Devices  36  may include one or more proximity sensors that detect when a user&#39;s fingers (or other body part) or other external object is in the vicinity of the proximity sensor. The proximity sensors may include light-based proximity sensors formed using light emitters (e.g., infrared light-emitting diodes) and corresponding light detectors (e.g., infrared light detectors that detect infrared light from the infrared light-emitting diodes that have been reflected off of nearby objects), may include capacitive proximity sensors (e.g., sensors with capacitive proximity sensor electrodes that make capacitance measurements to detect when objects are nearby), may be acoustic proximity sensors, and/or may be other types of proximity sensors. Input devices  36  may also include touch sensors. The touch sensors may be based on acoustic touch technology, light-based touch technology, resistive touch, force-based touch, or other touch technologies. As an example, the touch sensor(s) may be capacitive touch sensors having capacitive touch sensor electrodes such as electrodes formed from strands of conductive material in a fabric, electrodes formed from strips of metal or other conductive material on dielectric substrates, or electrodes formed from conductive pads with other configurations. Input devices  36  may also include environmental sensors (e.g., gas sensors, humidity sensors, temperature sensors, particulate sensors, etc.), keyboards and other devices with one or more keys or other buttons, accelerometers, magnetic sensors, compasses, pressure sensors (e.g., air pressure sensors and/or force sensors), touch sensors in displays, microphones to gather voice commands and other audio input, and other input components. 
     Output devices  38  may include devices for presenting audio output (e.g., speakers, tone generators, etc.), may include vibrators and other haptic devices, and other components for presenting information to a user. Output devices  38  may also include light-based devices  32  for generating visible output. Light-based devices  32  may include displays (e.g., light sources with arrays of individually controlled pixels such as liquid crystal displays, organic light-emitting diode displays, projector displays, etc.), status indicator lights, and gauges to display navigation system information, media system information, vehicle status information, and other information in the interior of vehicle  10 . Light-based devices  32  may include external lighting for providing light-based output outside of vehicle  10  (e.g., displays that emit light externally and/or other light sources that emit light in exterior areas of vehicle  10 ). In general, light-based devices  32  may include any suitable light sources that produce light in response to applied electrical signals such as lamps, light-emitting diodes, plasma display panel pixels, illuminated status indicators, displays, lasers, arrays of light sources, individual light sources, backlight units for displays, backlit or edge-lit light guides, light sources that emit one or more beams of light (e.g., a laser beam, light-emitting diode beam, or a beam associated with another collimated light source), light sources that emit light in a fixed pattern of one or more beams, light sources that emit light using raster scanning techniques, light sources that emit steerable beams (e.g., light sources with mirror arrays to steer light in a light projector system, light sources with one or more steerable mirrors, steerable lasers and light-emitting diodes, etc.), image projecting systems and other light projectors, light guide panels that contain light extraction features that cause the light guide panels to emit light in various patterns, and other electrically controlled light sources. 
     Light-based devices  32  may contain individually controlled areas. These areas may be relatively small areas that serve as pixels in an array of pixels for a display-type output device (e.g., a display integrated into a dash-mounted navigation and media system or an external portion of vehicle  10 ). Light-based devices  32  may also include components that include one or only a few larger individually controlled areas (e.g., one or more areas of about 1-100 cm 2 , 10-1000 cm 2 , 100-1,000,000 cm 2 , more than 1000 cm 2 , less than 500 cm 2 , etc.). For example, light-based devices  32  may contain light-producing devices that produce a single block of light over entire windows in vehicle  10  or other large areas of vehicle  10 . Individually controlled areas may be used to display fixed icons or other shapes, adjustable (e.g., customizable) icons or other shapes, fixed text (e.g., “stopping” to indicate the vehicle  10  is stopping, “road hazard ahead” to indicate that dangerous road conditions are in the road ahead, “fog ahead” to indicate that there is fog in the road ahead, “22 mph” to indicate that vehicle  10  is travelling at 22 mph, “closing speed is 22 mph” to indicate that a vehicle following vehicle  10  is closing in on vehicle  10  at a relative speed of 22 mph, etc.), customizable text, time-varying text, scrolling text, blinking text, and/or output of other shapes. The light output produced by light-based devices  32  may have multiple adjustable attributes (e.g., color, shape, intensity, duration, location, etc.) and any set of one or more of these attributes may be used in conveying information to a viewer. 
     During operation, control circuitry  34  may generate control signals that direct a lighting system to generate output light (e.g., images, ambient lighting, lighting to adjust the aesthetic appearance of a structure in system  10  by illuminating an interior surface of system  10  with a decorative pattern, virtual speedometers and other vehicle gauges, media playback information panels and other information regions, exterior illumination, etc.). 
     Light-based devices  32  may be based on light-emitting diodes, lasers, or other sources of light. In some configurations, light-based devices  32  may be formed from light-emitting diodes or other light sources mounted adjacent to curved mirrors within clear plastic housings or other mounting structures (e.g., when forming headlights, etc.). If desired, light-based devices  32  may also have thin planar shapes (e.g., when light-based devices  32  are being mounted to windows  12 ,  14 ,  16 , and/or  18 , or over relatively large surface areas on body  20  of vehicle  10 ). For example, light-based devices  32  may include flexible or rigid light-emitting panels formed from edge-lit light guide films, organic light-emitting diode substrates, backlit liquid crystal displays, or other planar light sources. Light-based devices  32  (e.g., light-emitting panels or other light sources) may be opaque or transparent. Opaque structures associated with light-based devices  32  may be used on portions of vehicle  10  such as opaque portions of body  20  or on portions of windows  12 ,  14 ,  16 , and/or  18  that can be obscured without interfering with the fields of view of the occupants of vehicle  10 . Transparent light-based devices  32  may be placed on transparent portions of vehicle  10  such as portions of windows  12 ,  14 ,  16 , and/or  18 . When not emitting light, transparent devices will not block the views of the occupants of vehicle  10 . 
     Light-based devices  32  may, if desired, include light guiding structures such as optical fibers and/or other light guiding elements. Light guides in devices  32  may be used to guide light from a light source to a location in vehicle  10  where illumination is desired. Light guides in devices  32  may, in some arrangements, be transparent and may blend in with a surrounding portion of vehicle  10  (e.g., to generate a uniform appearance). For example, light guides in devices  32  may be embedded in or attached to a transparent surface in vehicle  10  (e.g., a window, a skylight, a transparent cover for an exterior light such as a headlight, a brake light, a tail light, etc., or other suitable transparent or semi-transparent surface). The light guide may be index-matched to the surrounding transparent structure and may therefore be invisible to the human eye when the light source is off (e.g., a user may be able to look through the transparent structure without detecting the light guide or light source) and/or when the light is propagating through a non-scattering portion of the light guide. 
       FIGS. 3 and 4  show an illustrative illumination system that blends in with a surrounding structure in vehicle  10 . In  FIG. 3 , illumination system  32  is in an illuminated state (an “on” state), and in  FIG. 4 , illumination system  32  is in an unilluminated state (an “off” state). 
     Illumination system  32  may be incorporated into a portion of vehicle  10  such as vehicle structure  40 . Structure  40  may be a transparent structure or an opaque structure. As an example, structure  40  may be a transparent structure such as a portion of a window (e.g., front window  12 , rear window  14 , side window  16 , skylight  18 , or other suitable window), a transparent cover for an exterior light (e.g., headlight  24 , tail light  26 , a center high-mount stop light such as light  28 , or other suitable exterior light), a transparent cover for an interior surface of vehicle  10 , or other suitable transparent structure in vehicle  10 . Arrangements where structure  40  is an opaque structure in vehicle  10  (e.g., an opaque portion of body  20 , dashboard  76 , or other structure in vehicle  10 ) may also be used. Structure  40  may be mounted to a surrounding support structure such as body  82  (e.g., a portion of vehicle body  20  or other suitable support structure). Arrangements in which vehicle structure  40  is transparent are sometimes described herein as an example. Illumination system  32  may be mounted on the inside or outside of structure  40 , may be embedded within structure  40 , may be mounted on or embedded in an opaque body surface of vehicle  10 , or may be mounted elsewhere in vehicle  10 . 
     As shown in  FIG. 3 , illumination system  32  may include a light source such as light source  56  and one or more light guides such as light guide  42 . In the example of  FIG. 3 , light source  56  is mounted to body  82  and light guide  42  is mounted to vehicle structure  40 . Illumination system  32  may be used to supply ambient lighting, decorative lighting (e.g., illuminated trim, surfaces with aesthetically pleasing decorative patterns), exterior lighting (headlights, etc.), or other types of illumination. Control circuitry  34  ( FIG. 2 ) may issue control signals on path  84  that determine the amount of light  44  that is emitted by light source  56 . Light source  56  may be any suitable light source that produces light in response to applied electrical signals (e.g., one or more light-emitting diodes, lasers, or other light sources). 
     As shown in  FIG. 3 , light-emitting diode  56  may emit light  44  into light guide  42 . Light guide  42  may be a fiber, a molded plastic structure, or other light guiding structure that guides light internally in accordance with the principle of total internal reflection. Light guide  42  may be formed from clear plastic, glass, sapphire or other transparent crystalline materials, or other transparent materials. In some configurations, light guides  42  may have inner structures (sometimes referred to as cores) that are coated with one or more outer layers (sometimes referred to as claddings or coating layers). In this type of arrangement, the core may have a higher index of refraction than the cladding to promote total internal reflection of the light that has been coupled into light guide  42 . High/low index of refraction arrangements may also be created by embedding a light guide structure of a first index of refraction into a transparent material of a second index of refraction that is higher than the first index of refraction. The transparent material into which the light guide structure is embedded may be a polymer or other clear binder. 
     In general, light guides  42  may be formed by injection molding, by machining plastic light guide structures, by dipping or spraying polymer coatings onto machined or molded plastic core parts or glass core parts, by extruding polymers, by elongating glass or plastic rods using heat and tension, or by otherwise forming structures that can internally guide light within vehicle structure  40  or other part of vehicle  10 . With one suitable arrangement, which may sometimes be described herein as an example, light guides  42  are formed from optical fibers. The fibers may have circular cross-sectional shapes with central cores surrounded by cladding layers of lower index of refraction material. The fibers may be formed form glass, plastic, or other transparent material. Arrangements in which light guides  42  have non-circular cross-sectional shapes may also be used. In the example of  FIGS. 3 and 4 , fibers  42  are configured to emit light  44  at discrete locations across vehicle structure  40 . 
     Light guides such as light guide  42  may have one or more light-scattering portions such as portion  42 A and one or more non-scattering portions such as portion  42 B. In light-scattering portions  42 A, light guide  42  may have light extraction features such as particles, changes in refractive index, roughened surfaces, protrusions such as bumps or ridges, recesses such as pits or grooves, or other light extraction features. In the presence of light extraction features in portion  42 A of light guide  42 , light  44  from the interior of light guide  42  may be scattered out of light guide  42 . For this reason, light-scattering portions  42 A of light guide  42  may sometimes be referred to as illuminable portions  42 A (which may be illuminated or unilluminated depending on whether light source  56  is on or off). In non-scattering portions of light guide  42  such as portion  42 B, light guide  42  may be free of light extraction features so that light  44  propagates through and is contained within light guide  42  via total internal reflection. Because light does not escape from non-scattering portions  42 B, portions  42 B may sometimes be referred to as unilluminated portions  42 B. If desired, light-scattering portions  42 A and non-scattering portions  42 B may be joined via a fusion splice. 
     Light guides in illumination system  32  such as light guide  42  may, if desired, be transparent such that users are able to see through light guide  42  when light guide  42  is unilluminated and/or when portions of light guide  42  are unilluminated. Unilluminated portions of light guide  42  (e.g., portions of light guide  42  where no light is present and portions in which light is present but not escaping from light guide  42 ) may therefore blend in with vehicle structure  40 . As shown in the illuminated state  FIG. 3 , for example, non-scattering portion  42 B contains light  44  within light guide  42  and blends in with the surrounding portion of vehicle structure  40 . Illuminated portion  42 A, on the other hand, scatters light  44  outwards (e.g., towards a passenger or other individual) and therefore stands out visibly from vehicle structure  40 . 
     In arrangements where vehicle structure  40  is opaque, unilluminated portions of light guide  42  may blend in with the surrounding opaque material of structure  40 . In arrangements where vehicle structure  40  is transparent, unilluminated portions of light guide  42  may blend in with the surrounding transparent material of structure  40 . With this type of arrangement, light may pass through structure  40  and light guide  42 . This may allow a driver or other occupant of vehicle  10  to look out of vehicle  10  through structure  40  (e.g., through a window on which illumination system  32  is mounted and through illumination system  32 ) to see objects on the other side of vehicle structure  40 . 
     If desired, light guide  42  may be index-matched with the surrounding material of vehicle structure  40 . With this type of arrangement, a user will be unable to detect unilluminated portions of light guide  42  in vehicle structure  40 . For example, unilluminated portion  42 B in  FIG. 3  may be undetectable to the human eye (e.g., may be indistinguishable from vehicle structure  40 ), even when portion  42 A is illuminated. Illuminated portion  42 A may therefore appear to be “floating” in the middle of vehicle structure  40 . In the off state of  FIG. 4 , the entirety of light guide  42  may be unilluminated and may be invisible to a user (e.g., indistinguishable from vehicle structure  40 ), making vehicle structure  40  appear completely clear and uniform. 
     In the example of  FIGS. 3 and 4 , light-scattering portion  42 A of light guide  42  forms a rectangle with rounded corners. Thus, when illuminated with light  44 , an illuminated rectangle with rounded corners may appear to be “floating” in the middle of vehicle structure  40  since non-scattering portion  42 B remains transparent and unilluminated even when illumination system  32  is turned on. The shape of  FIGS. 3 and 4  is merely illustrative, however. If desired, illuminated portion  42 A of light guide  42  may form other illuminated shapes such as circles, ovals, parallel lines, triangles, text, symbols, and/or any other suitable shape or pattern. Arrangements in which multiple illuminated shapes are formed (e.g., separated from one another by non-illuminated regions  42 B) may also be used. 
       FIG. 5  shows a cross-sectional side view of an illustrative illumination system having a light guide of the type shown in  FIGS. 3 and 4 . In the example of  FIG. 5 , vehicle structure  40  is a laminated structure including first and second layers  46  and  48  that are laminated together with a polymer layer such as polymer layer  50 . Layers  46  and  48  may be formed from glass, sapphire, diamond-like materials, plastics such as polycarbonate, or other clear materials. Polymer layer  50  may be an optically clear adhesive such as polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), polyurethane, other suitable resin or adhesive. In one illustrative arrangement, which is sometimes described herein as an example, vehicle structure  40  may be laminated safety glass. This is, however, merely illustrative. If desired, one or more of layers  46  and  48  may be opaque or only partially transparent. In some arrangements, layer  46  (e.g., the layer that forms a “background” for illumination  44  because light  44  is emitted away from layer  46 ) may be a matte material, an ultra-black material, a light-absorbing material, a light-reflective material (e.g., a mirror), a light-scattering material, or other material. Layers  46  and  48  need not be planar, as shown in the example of  FIG. 5 . If desired, one or more of layers  46  and  48  may be curved or may have curved portions. 
     As shown in  FIG. 5 , light guide  42  may be embedded in polymer layer  50 . In the example of  FIG. 5 , light guide  42  includes light-scattering portion  42 A that receives light  44  (e.g., directly from a light source or from a non-scattering portion of light guide  42 ) and guides light  44  so that it propagates in direction  86  (e.g., parallel to the y-axis of  FIG. 5 ). In light-scattering portion  42 A, light guide  42  may have light extraction features  90  (e.g., a change in refractive index, roughened surfaces, protrusions such as bumps or ridges, recesses such as pits or grooves, embedded particles, or other light extraction features) that allow some of light  44  to escape in direction  88  (e.g., parallel to the z-axis of  FIG. 5 ) towards viewer  54 . In non-scattering portion  42 B, light guide  42  may be free of light extraction features  90  so that light  44  propagates in direction  86  without escaping light guide  42 . Light guide  42  may have a diameter D between 140 microns and 170 microns, between 150 microns and 200 microns, between 100 microns and 130 microns, between 150 microns and 180 microns, less than 140 microns, or greater than 140 microns. 
     In arrangements where illumination system  32  is an exterior lighting system, layer  46  may face the interior of vehicle  10  and layer  48  may face the exterior of vehicle  10  so that light  44  is emitted away from vehicle  10  towards viewer  54  (e.g., a viewer that is outside of vehicle  10 ). In arrangements where illumination system  32  is an interior lighting system, layer  46  may face the exterior of vehicle  10  and layer  48  may face the interior of vehicle  10  so that light  44  is emitted towards the interior of vehicle  10  towards viewer  54  (e.g., a viewer that is inside of vehicle  10 ). 
     If desired, light guide  42  and polymer layer  50  may have matching or nearly matching indices of refraction. For example, the index of refraction of light guide  42  may be within 3% 5%, 10%, 15%, 20%, 30%, or 40% of the index of refraction of polymer layer  50 . In one illustrative example, polymer layer  50  may have an index of refraction of about 1.478 and light guide  42  may have an index of refraction of about 1.43. This is merely illustrative, however. Polymer layer  50  and light guide  42  may have other indices of refraction, if desired. By matching or almost matching the refractive index of light guide  42  to that of polymer layer  50 , unilluminated portions of light guide  42  may be invisible. For example, non-scattering portion  42 B may be invisible to users (e.g., indistinguishable from vehicle structure  40 ), and light-scattering portion  42 A may only be visible when illuminated. 
       FIGS. 6-11  show cross-sectional side views of illustrative light guides that may be used in illumination system  32 . In the example of  FIG. 6 , light guide  42  is formed from an optical fiber having a core such as core  70  that is surrounded by a protective layer such as cladding 72. Optical fiber  42  may have light-scattering features  90  along its length. Light-scattering features  90  may be formed at uniform discrete locations along the length of fiber  42 , may be formed at pseudorandom discrete locations along the length of fiber  42 , or may be formed continuously along the length of fiber  42 . Light-scattering features  90  may be formed from any suitable structures that locally defeat the total internal reflection within fiber  42  (e.g., pits, bumps, scratches or other grooves, ridges, particles with a different refractive index, local changes in fiber shape and/or diameter, changes in cladding material and/or index of refraction, abrupt bends, etc.). In the presence of light scattering features  90 , light from light source  56  ( FIG. 3 ) may be scattered outwards towards a user. 
     If desired, cladding 72 may be formed from the same material as polymer layer  50  ( FIG. 5 ). For example, cladding 72 and polymer layer  50  may both be formed from polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), polyurethane, other suitable resin or adhesive. By forming polymer layer  50  and cladding 72 from the same material, the difference in refractive index between cladding 72 and polymer layer  50  will be minimized and unilluminated portions of fiber  42  will be undetectable in vehicle structure  40 . This is, however, merely illustrative. If desired, cladding 72 and polymer layer  50  may be formed from different materials. 
     If desired, fibers  42  may not include a cladding, as shown in the example of  FIG. 7 . With this type of arrangement, light-scattering features  90  may be formed from a difference in refractive index between core  70  and polymer layer  50 , or may be formed from pits, bumps, scratches or other grooves, ridges, particles with a different refractive index, local changes in fiber shape and/or diameter, abrupt bends, etc. 
       FIG. 8  shows how light guide  42  may be formed from a bundle of optical fiber cores  70 . 
     Optical fiber cores  70  may be free of cladding, as shown in the example of  FIG. 8 , or some or all of fiber cores  70  may have cladding (e.g., individual cladding the surrounds individual fiber cores  70  or a collective cladding that surrounds multiple fiber cores  70 ). 
       FIG. 9  shows how light guide  42  may include a buffer layer such as buffer layer  74 . Buffer layer  74  may be formed from fluoropolymer such as, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, or other polymer material. If desired, buffer layer  74  may be formed from the same material as polymer layer  50 . For example, buffer  74  and polymer layer  50  may both be formed from polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), polyurethane, other suitable resin or adhesive. By forming polymer layer  50  and buffer  74  from the same material, the difference in refractive index between buffer  74  and polymer layer  50  will be minimized and unilluminated portions of fiber  42  will be undetectable in vehicle structure  40 . This is, however, merely illustrative. If desired, buffer  74  and polymer layer  50  may be formed from different materials. Optical fiber cores  70  may include cladding 72, as shown in the example of  FIG. 9 , or fiber cores  70  may be free of cladding. 
     In the example of  FIG. 9 , buffer  74  has a rectangular cross-section. With this type of arrangement, the outer surfaces of buffer  74  may be used to help align fiber core  70  within polymer layer  50 . For example, the light-emitting surface of optical fiber  70  may face surface  74 A of buffer  74 . When placing light guide  42  in polymer layer  50 , the light-emitting surface of core  70  may face a particular direction by orienting surface  74 A of buffer  74  towards that direction in polymer layer  50 . 
     In the example of  FIG. 10 , buffer  74  has a curved outer surface such as curved outer surface  74 B. The shapes of  FIGS. 9 and 10  are merely illustrative, however. If desired, buffer  74  may have an oval cross-section, a circular cross-section, a triangular cross-section, or any other suitable cross-sectional shape. 
     If desired, buffer  74  may surround multiple fibers  70 . This type of arrangement is shown in  FIG. 11 . As shown in  FIG. 11 , multiple fibers  70  may be embedded in buffer  74 . Fibers  70  may be parallel to one another or may have non-parallel orientations. With this type of arrangement, the outer surfaces of buffer  74  may be used to help align multiple fiber cores  70  within polymer layer  50 . For example, the light-emitting surfaces of optical fibers  70  may face surface  74 C of buffer  74 . When placing light guides  42  in polymer layer  50 , the light-emitting surfaces of cores  70  may face a particular direction by orienting surface  74 C of buffer  74  towards that direction in polymer layer  50 . 
     The examples of  FIGS. 6-11  in which light guides  42  have fiber cores with cross-sectional shapes are merely illustrative. If desired, light guides  42  may include fibers with non-circular cross-sectional shapes (e.g., rectangular, triangular, polygonal, oval, trilobal, or any other suitable cross-sectional shape). 
       FIG. 12  shows an illustrative arrangement for illumination system  32  in which one end of light guide  42  has a reflective surface to increase the homogeneity and light extraction efficiency of light guide  42 . As shown in  FIG. 12 , light guide  42  includes light-scattering portion  42 A that allows some of light  44  to escape from light guide  42  and non-scattering portion  42 B that propagates light  44  while containing light  44  in light guide  42 . Non-scattering portion  42 B may be coupled to scattering portion  42 A (e.g., via fusion splicing, mechanical splicing, or other coupling methods). 
     One end of light guide  42  such as end  92  may receive light  44  from light source  56 . The opposing end of light guide  42  such as end  94  may have a reflective coating such as reflective coating  58 . Reflective coating  58  may be formed from metal such as gold, silver, chrome, aluminum, or other metal, or may be formed from any other reflective material. Any light  44  that does not escape from scattering portion  42 A of light guide  42  on its first pass through scattering portion  42 A may be reflected at coating  58  so that it passes back through light-scattering portion  42 A a second time. Additional light  44  may escape from light guide  42  after it is reflected back from coating  58 , thereby increasing the uniformity of light from light guide  42  and improving light extraction efficiency. 
       FIG. 13  shows an example in which first and second fibers  42 A and  42 B are optically coupled to produce a continuous illuminated loop. As shown in  FIG. 13 , fiber  42 B may have opposing ends  102  and  104 . End  102  of light guide  42  may receive light  44  from light source  56 A, and end  104  of light guide  42  may receive light  44  from light source  56 B. Fiber  42 A may a light-scattering fiber that form a continuous loop. Fiber  42 B may be a non-scattering fiber that couples light  44  into fiber  42 A. In particular, fibers  42 A and  42 B may have portions that form an optical coupler such as optical coupler  62 . 
     In the example of  FIG. 13 , optical coupler  62  is a fused biconical tapered coupler that is formed from a tapered region of fiber  42 A and a tapered region of fiber  42 B that are fused (e.g., melted) together along length L. This is merely illustrative, however. If desired, optical coupler  62  may be formed by twisting fiber  42 A and  42 B along length L, by tapering fiber  42 A and  42 B along length L without fusing the fibers together, etc. 
     In the tapered regions that form optical coupler  62 , the respective diameters of fibers  42 A and  42 B may be reduced relative to the rest of fibers  42 A and  42 B. The reduced diameters of fibers  42 A and  42 B and their proximity to one another brings the centers of the two fiber cores closer together, causing light  44  from non-scattering fiber  42 B to escape into light-scattering Fiber  42 A. This light is then cycled through light-scattering fiber  42 A. Because fiber  42 A is a continuous loop, the extraction features in fiber  42 A and the absence of breaks in fiber  42 A cause light  44  to escape from fiber  42 A to form a continuous illuminated loop. Meanwhile, fiber  42 B is free of light-scattering features, so that fiber  42 B is unilluminated (and thus undetectable to users) and the continuous illuminated loop formed by fiber  42 A appears to be “floating” in the middle of vehicle structure  40 . 
     The example of  FIG. 13  in which fiber  42 A forms a rectangular loop with rounded corners is merely illustrative. If desired, fiber  42 A may form other loop shapes (e.g., circles, ovals, triangles, other polygons, etc.) or may form non-loop shapes with end portions (e.g., a symbol, letter, word, a set of parallel lines, etc.). Also, the use of two light sources to inject light into fiber  42 B is merely illustrative. If desired, fiber  42 B may only receive light from one light source. Arrangements in which multiple fibers are used to form multiple optical couplers with light-scattering fiber  42 A may also be used. 
       FIG. 14  shows an example in which a separate optical coupler such as optical coupler  64  is used to couple light from non-scattering fiber  42 B into light-scattering fiber  42 A. Optical coupler  64  may be a micro optics coupler (e.g., having one or more prisms, mirrors, and/or other optical elements to redirect light  44  from fiber  42 B to fiber  42 A), a fused-fiber coupler (e.g., having two or more fiber cores that are melted together to transmit light from one fiber core to another fiber core), a planar waveguide coupler, or other suitable type of optical coupler. In the example of  FIG. 14 , optical coupler  64  has two inputs receiving light from fiber  42 B and two outputs providing light to fiber  42 A. This is, however, merely illustrative. If desired, optical coupler  64  may have more than two inputs, less than two inputs, more than two outputs, less than two outputs, etc. 
     If desired, multiple light guides may form multiple illuminated shapes on one vehicle structure in vehicle  10 , as shown in  FIG. 15 . In the example of  FIG. 15 , four illumination systems  32  are provided on vehicle structure  40 . Each illumination system  32  includes a light source  56  that emits light  44  into a non-scattering fiber  42 B of light guide  42 , which in turn guides light  44  to light-scattering fiber  42 A of light guide  42 , where it escapes to form an illuminated shape on vehicle structure  40 . Because light  44  is guided to light-scattering fiber  42 A with a non-scattering fiber  42 B, the illuminated shape formed by fiber  42 A may appear to be floating in vehicle structure  40 . This is merely illustrative, however. If desired, the entirety of light guide  42  may be illuminated (e.g., may be formed entirely from light-scattering fiber  42 A). 
     In configurations where fibers  42 A and  42 B are index-matched (or nearly index-matched) to polymer layer  50  in vehicle structure  40 , a user may be unable to see fibers  42 A and  42 B in vehicle structure  40 . This allows users to see objects such as object  98  through vehicle structure  40  and through unilluminated portions of light guide  42 . In other words, vehicle structure  40  may appear to be completely transparent when illumination systems  32  are turned off. 
     If desired, each illumination system  32  in  FIG. 15  may be independently controlled (e.g., each illumination system may receive separate, independent control signals from control circuitry  34  of  FIG. 2 ), or illumination systems  32  may be controlled as a single illumination system that responds to one set of control signals. There may be fewer or more than four illumination systems in vehicle structure  40 . The example of  FIG. 15  is merely illustrative. 
     Illuminable portions of light guide  42  may have any suitable shape (e.g., loop, spiral, text, symbols, parallel lines, zigzag lines, checker pattern, an array of one or more of these shapes, etc.). As shown in  FIG. 16 , for example, light guide  42  may have a curvy shape that starts at one edge of vehicle structure  40  and ends on an opposing edge of vehicle structure  40 . Light guide  42  may have one, two, three, or more than three light-scattering fibers  42 A and one, two, three, or more than three non-scattering fibers  42 B. In general, any suitable number and shape of light-scattering portions  42 A and non-scattering portions  42 B may be used to form the desired illuminated shape or shapes on vehicle structure  40 . 
       FIGS. 17 and 18  show examples in which light guide  42  provides more focused illumination (e.g., to form a spotlight). In the example of  FIG. 17 , light guide  42  has an angled end such as cleaved end  60  that helps focus light  44  towards area  66  (e.g., an area inside of vehicle  10  or an area outside of vehicle  10 ). Cleaved end  60  may be reflective or may have a different index of refraction that causes light  44  to exit light guide  42  towards area  66 . The shape of cleaved end  60  may help collimate light  44  to form a bright spot in area  66 . 
     In the example of  FIG. 18 , light guide  42  has an enlarged end such as enlarged end  68 . Enlarged end  68  may serve as a lens that helps focus light  44  onto area  66 . Enlarged end  68 , may, if desired, be formed by melting the end of fiber  42  so that the melted portion of fiber  42  begins to fall into the curved shape of  FIG. 18 . The bulged shape of end  68  helps to collimate light  44  to form a bright spot in area  66 . 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20170913
Publication Date: 20190305
Grant Date: 20190305
Priority Date: 20160920
Inventors: COHOON, GREGORY A.
MAZUIR, Clarisse
LAST, MATTHEW E.
Assignee: APPLE INC
CPC Classifications: [{"code": "F21S41/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/237", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/245", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/245", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q3/64", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q3/62", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/268", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "F21S43/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/001", "inventive": true, "first": true, "tree": "[]"}, {"code": "F21S43/247", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q3/208", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/27", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/001", "inventive": true, "first": true, "tree": "[]"}, {"code": "B60Q3/54", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q3/208", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/237", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/241", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/3608", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q1/44", "inventive": false, "first": false, "tree": "[]"}, {"code": "F21S43/251", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q1/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60Q3/64", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/001", "inventive": true, "first": true, "tree": "[]"}, {"code": "B60Q1/44", "inventive": false, "first": false, "tree": "[]"}, {"code": "F21S43/237", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S41/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/245", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q3/208", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/27", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q3/62", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/3608", "inventive": false, "first": false, "tree": "[]"}, {"code": "F21S43/247", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/241", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21S43/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q1/268", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60Q3/54", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 65495692