PATENT DOCUMENT

Publication Number: US-11003208-B2
Application Number: US-201916412285-A
Country: US
Kind Code: B2

Title: Display having optical films with bent alignment structures

Abstract:
An electronic device such as a laptop computer or other device may have a housing. A display may be coupled to the housing. The display may have a pixel array configured to display an image. Backlight illumination for the pixel array may be provide by a backlight unit. The backlight unit may have a light guide layer. A light source may provide light to an edge of the light guide layer. The light guide layer may scatter the light outwardly to serve as the backlight illumination for the pixel array. The backlight unit may have optical films interposed between the light guide layer and the pixel array. The optical films may include flexible polymer layers such as diffuser layers and prism films. The optical films may each have a bent alignment portion that bends back on itself while wrapping around an edge of the light guide layer.

Claims:
What is claimed is: 
     
       1. A display, comprising:
 a backlight having a light source, a light guide layer that receives light from the light source and that produces corresponding backlight illumination; 
 pixels that are illuminated with the backlight illumination and that are configured to display an image; and 
 optical films interposed between the backlight and the pixels, wherein the optical films include bent alignment portions that wrap around an edge of the light guide layer, each of the optical films doubles back on itself around the light guide layer, the optical films include a first optical film and a second optical film, and a first bent alignment portion of the first optical film is interposed between the light guide layer and a second bent alignment portion of the second optical film while the first and second optical films are bent around the edge of the light guide layer. 
 
     
     
       2. The display defined in  claim 1  wherein the edge of the light guide layer has a length and extends between opposing first and second sides of the light guide layer, wherein the first optical film has a bent edge portion that runs along the length of the edge of the light guide layer while wrapping around the edge of the light guide layer, and wherein the second optical film has bent protruding tabs that wrap around respective portions of the edge of the light guide layer. 
     
     
       3. The display defined in  claim 1  wherein the optical films include a prism film and a diffuser film. 
     
     
       4. The display defined in  claim 3  wherein the diffuser film has a bent edge portion wrapped around the edge of the light guide layer. 
     
     
       5. The display defined in  claim 4  wherein the prism film comprises first and second bent protruding tabs wrapped around the edge of the light guide layer, wherein a first portion of the bent edge portion is interposed between the first bent protruding tab and the light guide layer, and wherein a second portion of the bent edge portion is interposed between the second bent protruding tab and the light guide layer. 
     
     
       6. The display defined in  claim 1  wherein the pixels comprise liquid crystal display pixels, the display further comprising a reflector, wherein the light guide layer and the optical films are interposed between the reflector and the liquid crystal display pixels. 
     
     
       7. An electronic device, comprising:
 a support structure; 
 an array of pixels configured to display an image; and 
 a display backlight having a light guide layer that is configured to provide backlight illumination to the array of pixels and having flexible polymer films that are between the light guide layer and the pixels and that have bent alignment portions that wrap around an edge of the light guide layer and are coupled to the support structure, wherein the edge of the light guide layer has a length that extends between opposing first and second sides of the light guide layer, a given one of the bent alignment portions of a respective one of the flexible polymer films runs along the entire length of the edge of the light guide layer while wrapping around the edge, and the light guide layer is interposed between a first portion of the respective one of the flexible polymer films and a second portion of the respective one of the flexible polymer films. 
 
     
     
       8. The electronic device defined in  claim 7  wherein the support structure comprises an electronic device housing. 
     
     
       9. The electronic device defined in  claim 8  further comprising adhesive that attaches the flexible polymer films to the support structure. 
     
     
       10. The electronic device defined in  claim 9  wherein at least one of the bent alignment portions comprises a bent protruding tab. 
     
     
       11. The electronic device defined in  claim 10  wherein the bent protruding tab wraps around the edge and is bent back on itself and wherein the adhesive is configured to attach the bent protruding tab to the electronic device housing. 
     
     
       12. The electronic device defined in  claim 8  wherein the bent alignment portions comprise a bent protruding tab, wherein the electronic device comprises tape that is configured to couple the bent protruding tab to the electronic device housing. 
     
     
       13. The electronic device defined in  claim 12  wherein the tape has a non-sticky portion that overlaps the bent protruding tab to form a sliding joint that couples the bent protruding tab to the support structure while allowing the bent protruding tab to slide relative to the support structure. 
     
     
       14. The electronic device defined in  claim 7  wherein the light guide layer has a notch and wherein the bent alignment portions overlap a portion of the edge in the notch. 
     
     
       15. The electronic device defined in  claim 7  wherein the light guide layer has a notch and wherein the bent alignment portions overlap portions of the edge out of the notch. 
     
     
       16. An electronic device, comprising:
 a housing; and 
 a display in the housing having a backlight that produces backlight illumination and having a pixel array that is illuminated by the backlight illumination, wherein the backlight comprises a light-emitting diode, a light guide layer that receives light from the light-emitting diode and that provides the backlight illumination to the pixel array, and a flexible polymer layer interposed between the light guide layer and the pixel array, wherein the flexible polymer layer has a bent protruding tab that is bent around an edge of the light guide layer and that is secured to the housing with an adhesive portion of a tape, and wherein the tape has a non-sticky portion that overlaps the bent protruding tab to form a sliding joint that couples the bent protruding tab to the housing while allowing the bent protruding tab to slide relative to the housing. 
 
     
     
       17. The electronic device defined in  claim 16  wherein the flexible polymer layer comprises a prism film. 
     
     
       18. The electronic device defined in  claim 16  wherein the flexible polymer layer is secured to a housing wall using the tape. 
     
     
       19. The electronic device defined in  claim 16  wherein the flexible polymer layer comprises one of at least four optical films interposed between the light guide layer and the pixel array and wherein the optical films include at least two diffusers and at least two prism films each of which has a respective bent alignment portion coupled to the housing.

Description:
This application claims the benefit of provisional patent application No. 62/781,350, filed Dec. 18, 2018, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic devices, and, more particularly, to displays for electronic devices. 
     BACKGROUND 
     Electronic devices often include displays. For example, cellular telephones and computers may have displays for presenting information to a user. 
     Liquid crystal displays have arrays of pixels for presenting images. A backlight unit may be used to provide backlight illumination for the pixels. A backlight unit may contain a light guide layer. The light guide layer may have an edge that receives light from light-emitting diodes and that laterally distributes the light throughout the backlight unit. Optical films such as brightness enhancement films and diffuser layers may overlap the light guide layer. To ensure that the optical films are aligned satisfactorily and do not shift during use of the electronic device, the optical films may be provided with protruding alignment tabs. The alignment tabs may help secure the positions of the optical films, but can consume more lateral space within the electronic device than desired. This can cause the electronic device to have undesirably large inactive border areas. 
     SUMMARY 
     An electronic device such as a laptop computer or other device may have a housing. A display may be coupled to the housing. The display may have a pixel array configured to display an image. Backlight illumination for the pixel array may be provide by a backlight. 
     The backlight may have a light guide layer. A light source such as an array of light-emitting diodes may provide light to an edge of the light guide layer. The light that is received from the light-emitting diodes may be distributed throughout the light guide layer in accordance with the principle of total internal reflection. The light guide layer may having light scattering structures that scatter the light outwardly to serve as backlight illumination for the pixel array. 
     A stack of optical films such as diffusers and prism films may be interposed between the light guide layer and the pixel array. The optical films may be formed from flexible polymer layers. Edge portions of the flexible polymer layers may bent back on themselves to wrap around an edge of the light guide layer. The optical films may, for example, each have a bent alignment portion that bends back on itself while wrapping around an edge of the light guide layer. The bent alignment portions may include bent edge portions that extend along some or all of the length of the edge of the light guide layer and may include bent protruding tabs. 
     The bent alignment portions may be coupled to the housing of the electronic device to align the optical films with respect to the housing. This helps prevent misalignment and film wrinkling during use of the electronic device. Adhesive structures such as layers of adhesive and/or adhesive on strips of tape may be used to attach the bent alignment portions to the housing. 
     If desired, electronic device housings, electronic components, alignment members embedded in display trim members, and/or other structures may serve as alignment posts that are received within alignment openings in the optical films. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a laptop computer with a display in accordance with an embodiment. 
         FIG. 2  is a side view of illustrative layers in a display in accordance with an embodiment. 
         FIG. 3  is a side view of illustrative display layers in accordance with an embodiment. 
         FIG. 4  is a top view of an illustrative optical film with alignment tabs in accordance with an embodiment. 
         FIGS. 5 and 6  are cross-sectional side views of illustrative displays in which optical films have been bent to wrap around the edges of light guide layers in accordance with embodiments. 
         FIG. 7  is a top view of an illustrative light guide layer for a display in accordance with an embodiment. 
         FIG. 8  is a top view of an optical film with a bent alignment portion such as a strip-shaped bent edge portion for alignment of the optical film within a display in accordance with an embodiment. 
         FIGS. 9, 10, and 11  are top views of illustrative optical films with bent alignment portions such as bent protruding tabs in accordance with embodiments. 
         FIG. 12  is a perspective view of a portion of an illustrative display having optical films with bent alignment portions that are wrapped around the edge of a light guide layer in accordance with an embodiment. 
         FIGS. 13 and 14  are cross-sectional side views of edge portions of illustrative displays having optical films with bent portions such as bent edge portions wrapped around the edges of light guide layers in accordance with embodiments. 
         FIG. 15  is a cross-sectional side view of an illustrative optical film with a bent edge portion secured to a support structure such as a housing wall or other device structure in accordance with an embodiment. 
         FIGS. 16 and 17  are cross-sectional views of illustrative optical film structures attached to support structures in accordance with embodiments. 
         FIG. 18  is a top view of an illustrative display having an active area with a recess such as a notch running along the edge of the active area in accordance with an embodiment. 
         FIG. 19  is a top view of an edge of an illustrative display having a flexible optical film with a bent alignment portion and a notch in accordance with an embodiment. 
         FIG. 20  is a top view of an edge of an illustrative display having flexible optical films with bent protruding tabs and having a notch in accordance with an embodiment. 
         FIG. 21  is a cross-sectional side view of an illustrative display having an inactive area with a camera or other electrical component that is configured to serve as an alignment structure for optical films in the display in accordance with an embodiment. 
         FIG. 22  is a cross-sectional side view of an illustrative display having optical films aligned with an alignment pin that is formed from a bent sheet metal member embedded in an overmolded display trim member in accordance with an embodiment. 
         FIG. 23  is a top portion of an edge of an illustrative display showing how display layers such as optical films may have openings that receive alignment structures such as the illustrative alignment pin of  FIG. 22  in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may include displays. The displays may be used to display images to a user. An illustrative electronic device with a display is shown in  FIG. 1 . As shown in  FIG. 1 , device  10  may have a housing such as housing  12  and a display such as display  14  that is mounted in housing  12 . 
     Housing  12  may be a stand-alone housing (e.g., in scenarios in which device  10  is a cellular telephone or tablet computer), may form an upper portion of a two-part housing (e.g., housing  12  may be the upper portion of a laptop housing that also has a lower portion such as lower laptop housing  12 L that is coupled to the upper portion by a hinge that allows the upper and lower portions to rotate with respect to each other about hinge axis  24 ), may be supported on a stand (e.g., when housing  12  forms a desktop computer housing), may be coupled to straps (e.g., when housing  12  forms a wristwatch enclosure or a housing in a head-mounted device), and/or may have other suitable shapes. 
     In general, electronic device  10  may be a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device, a pendant device, a headphone or earpiece device, a head-mounted device, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. 
     Housing  12  of device  10 , which is sometimes referred to as a case, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device  10  may be formed using a unibody construction in which most or all of housing  12  is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal support structures or other internal housing structures). 
     Display  14  may be a touch sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display  14  may be formed from an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensor components. 
     Display  14  for device  10  may include pixels formed from liquid crystal display (LCD) components or other suitable pixel structures. The pixels may be formed in a pixel array having a rectangular shape, a circular shape, an oval shape, a shape with curved and/or straight edges, a shape with one or more recesses (e.g., a notch), a shape with rounded corners or straight corners, a shape with openings to accommodate speakers and/or other components, and/or other suitable shapes. Display  14  may include an active area such as active area AA (e.g., a rectangular region or a region of other suitable shape that includes rows and columns of pixels forming a pixel array). During operation, the pixels of active area AA display an image for a user of device  10 . Active area AA may be surrounded on one or more sides by inactive borders or other display regions that do not contain pixels and that do not emit light for forming images. These inactive display regions are shown as inactive area IA of  FIG. 1 . 
     A display cover layer may cover the surface of display  14  or a display layer such as a thin-film transistor layer, color filter layer, or other portion of a display may be used as the outermost (or nearly outermost) layer in display  14 . The outermost display layer may be formed from a transparent glass sheet, a clear polymer layer, a transparent structure formed from sapphire or other crystalline material, a transparent ceramic layer, or other transparent member. Coatings such as antismudge coatings, antireflection coatings, and/or antiscratch coatings may be formed on the outermost layer of display  14  and/or other layers of display  14 . 
     A cross-sectional side view of an illustrative configuration for display  14  of device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , display  14  may include backlight structures such as backlight unit  42  for producing backlight illumination such as backlight illumination (backlight)  44 . During operation, backlight illumination  44  travels outwards (vertically upwards in dimension Z in the orientation of  FIG. 2 ) and passes through pixels P in display layer  46 . Pixels P may, for example, be arranged in an array having rows and columns. The pixel array formed from pixels P is used to display images for a user. Backlight illumination  44  may illuminate the image in the pixels of display layer  46  for a user such as user  48  who is viewing display  14  in direction  50 . 
     Display layer  46  may be mounted in chassis structures such as a plastic chassis structure and/or a metal chassis structure to form a display module for mounting in housing  12  of  FIG. 1  or display layer  46  may be mounted directly in housing  12  (e.g., by stacking display layers such as layer  46  into a recessed portion in housing  12 ). Display layer  46 , which may sometimes be referred to as a pixel array layer, pixel array, pixel layer, display, or display module, may be a liquid crystal display formed or other suitable display. Border portion  46 B of layer  46  is free of pixels P and does not produce images. 
     In a configuration in which display layer  46  forms a liquid crystal display, display layer  46  may include a liquid crystal layer interposed between upper and lower layers formed from glass, transparent polymer, or other substrate materials. These upper and lower layers may include thin-film transistor circuitry for forming pixel circuits for pixels P and a color filter array that allows pixels P to display color images. The color filter array and pixel circuits may be formed on a common substrate and/or may be formed on separate substrates located on opposing sides of the liquid crystal layer. The liquid crystal layer and the upper and lower substrate layers may be interposed between opposing upper and lower polarizer layers (e.g., layer  46  may include upper and lower polarizers, upper and lower substrates such as a thin-film transistor layer and a color filter layer and/or other layers with thin-film transistor circuitry and color filter elements for pixels P, and a liquid crystal layer interposed between the upper and lower substrates). Touch sensor electrodes may also be incorporated into layer  46  and/or may be formed on a separate layer in display  14 . 
     During operation of display  14  in device  10 , control circuitry (e.g., one or more integrated circuits on a printed circuit) may be used to generate information to be displayed on display  14  (e.g., display data). The information to be displayed may be conveyed to one or more display driver integrated circuits and other display driver circuitry (e.g., thin-film gate drivers, etc.) using a signal path such as a signal path formed from conductive metal traces in a rigid or flexible printed circuit. 
     Backlight structures  42 , which may sometimes be referred to as a backlight unit or backlight, may include a light guide layer such as light guide layer  78 . Light guide layer  78  may be formed from a transparent material such as clear glass or polymer (e.g., a thin flexible polymer film or a plate formed from a sheet of transparent glass or polymer). During operation of backlight structures  42 , a light source such as light source  72  may generate light  74 . Light source  72  may be, for example, an array of light-emitting diodes. If desired, light sources such as light source  72  may be located along multiple edges of light guide layer  78 . 
     Light  74  from light source  72  may be coupled into edge surface  76  of light guide layer  78  and may be distributed in dimensions X and Y throughout light guide layer  78  due to the principle of total internal reflection. Light guide layer  78  may include light-scattering structures such as pits, grooves, or other recess and/or bumps, ridges, or other protrusions. Light scattering structures such as glass particles, microspheres, air bubbles, and/or other structures may also be incorporated within light guide layer  78  to help scatter light  74 . The light-scattering structures may be located on an upper surface and/or on an opposing lower surface of light guide layer  78  and/or may be embedded within light guide layer  78 . 
     Light  74  that scatters upwards in direction Z from light guide layer  78  may serve as backlight illumination  44  for display  14 . Light  74  that scatters downwards may be reflected back in the upward direction by a reflective film such as reflector  80 . Reflector  80  may be formed from a reflective material such as a reflective layer of white plastic, from a thin-film mirror (e.g., a thin-film mirror formed from a stack of dielectric materials), and/or other reflective structures. 
     To enhance backlight performance for backlight structures  42 , backlight structures  42  may include optical films  70 . Optical films  70  may include one or more layers of transparent material through which backlight illumination  44  passes between light guide layer  78  and display layer  46  (e.g., flexible polymer films). Optical films  70  may include diffuser layers for helping to homogenize backlight illumination  44  and thereby reduce hotspots and one or more prism films (sometimes referred to as brightness enhancement films) for collimating backlight illumination  44 . Compensation films for enhancing off-axis viewing may be included in optical films  70  or may be incorporated into other portions of display  14  (e.g., in polarizer layers in layer  46 ). In an illustrative configuration, optical films  70  include a first film adjacent to layer  78  such as a diffuser layer, second and third films such as brightness enhancement layers (prism films) that are located above the diffuser layer, and a fourth film above the brightness enhancement layers and adjacent to layer  46 . Other configurations for optical films  70  may be used, if desired. Each optical film  70  may be sufficiently thin to be bent back on itself. For example, each optical film  70  may have a thickness of 30-150 microns, at least 20 microns, at least 40 microns, at least 50 microns, less than 300 microns, less than 200 microns, less than 150 microns, or other suitable thickness. 
     Display  14  may have a protective display cover layer such as layer  52 . Layer  52  may be formed from glass, transparent polymer, transparent ceramic, crystalline material such as sapphire, and/or other transparent projective member that overlaps pixels P of display layer  46 . If desired, layer  52  may be omitted and one or more layers of display layer  46  may be provided with sufficient thickness to strengthen layer  52  and thereby allow layer  52  to serve as the outermost layer of device  10 . To hide internal structures in device  10  from view (e.g., display drive circuitry, interconnect lines, etc.), it may sometimes be desirable to form opaque masking layers on portions of the layers in display  14 . As shown in  FIG. 2 , for example, opaque masking layer  94  may be formed in inactive border area IA of display  14 . Masking layer  94  may be formed from a coating of black masking material (e.g., black ink), may be formed from ink or other material of other colors, or may be formed from other opaque material. In active area AA of display  14 , an opening is present in layer  94  so that user  48  may view an image presented using pixels P of layer  46 . In inactive area IA, the masking layer serves to block pixel-free portions  46 B of display layer  46  and other internal structures from view from the exterior of device  10 . 
     If desired, device  10  and the display structures in device  10  may have support structures (sometimes referred to as chassis structures, support structures, housing structures, frame structures, etc.). Consider, as an example, the arrangement of  FIG. 3 .  FIG. 3  is a cross-sectional side view of an edge portion of display  14  showing how backlight structures  42  can be supported within a support structure such as support structure  100  (e.g., a portion of housing  12  and/or other support structures). Foam  102  or other material may be interposed between backlight structures  42  and support structure  100  (e.g., to help hold light guide layer  78  and other display layers in place). Display layer  46  may overlap backlight structures  42  and may receive backlight illumination  44  from structures  42 . Light source  72  may be mounted in portion  100 E of support structure  100  (as an example). Support structure  100  may be a supporting chassis (metal and/or polymer structures such as polymer chassis structures that have been overmolded on metal chassis structures), may be an internal frame structure, may be an exterior housing wall in housing  12 , and/or may form other housing structures for housing  12  of device  10 . The illustrative support structures of  FIG. 3  are illustrative. Other supporting arrangements for backlight structures  42  may be used, if desired. 
     To prevent optical films  70  from shifting during use (e.g., moving excessively in the X-Y plane of  FIG. 2 ) and to help prevent undesired wrinkling of optical films  70 , optical films  70  may have alignment structures. These alignment structures may include, for example, protruding tabs or other portions that can be secured to support structures  100  (e.g., that can be coupled to housing  12  and/or other support structures). To help avoid undesirably enlarging the size of inactive borders in display  14  (e.g., to minimize the width of inactive area IA), these alignment portions may be bent so that these alignment portions fold back on themselves while wrapping around one or more layers in backlight structures  42  such as light guide layer  78  and/or reflector  80 . 
     The alignment portions, which may sometimes be referred to as bent alignment portions, may form bent protruding tabs or other alignment portions that are wrapped around the edge of light guide layer  78  so that the alignment portions of the light guide layer fold back on themselves after wrapping around light guide layer  78 . By configuring protruding tabs on optical films  70  to double back on themselves (e.g., when viewed from above along dimension Z), these tabs do not extend excessively in lateral dimensions X and Y, thereby helping to minimize inactive border regions in display  14 . At the same time, the presence of the alignment portions of optical films  70  may help align and secure films  70  at desired locations within display  14  and device  10 . 
       FIG. 4  is a top view of an illustrative optical film with portions that may be used to form bent alignment portions such as bent protruding tabs or bent edge portions that extend along some or all of the length of the edge of a light guide layer. As shown in  FIG. 4 , optical film  70  may have protrusions or other portions forming alignment structures such as alignment portions  70 P. Alignment portions such as alignment portions  70 P of  FIG. 4  may protrude from one of the four sides of optical film  70  and may be bent about bend axis  104  when installed in device  10  to form part of backlight structures  42 . For example, bent alignment portions such as portions  70 P of  FIG. 4  may be wrapped around an edge of light guide layer  78  that is aligned with bend axis  104  (and, if desired, an edge of reflector  80  that is aligned with bend axis  104 ). After being bent around and under a display layer such as light guide layer  78  (e.g., a light guide plate or a flexible light guide film), bent alignment portions  70 P of optical film  70  may be attached to support structure  100  (e.g., portions  70 P may be coupled to housing  12 , an internal display layer chassis, and/or other support structure). 
     Alignment portions  70 P may be formed from a single strip-shaped edge portion of optical film  70  that is bent about a bend axis such as bend axis  104  of  FIG. 4  along one of the edges of film  70 , may be an edge portion that runs along part of an edge of light guide layer  78 , may include one or more protrusions forming tabs (as shown in the example of  FIG. 4 ), may have openings that receive alignment pins or other alignment structures coupled to support structure  100  or other structures in device  10 , and/or may have other suitable configurations. As described in connection with  FIG. 2 , backlight structures  42  may include multiple optical films  70 . Backlight structures  42  may include, for example, at least two optical films  70 , at least three optical films  70 , at least four optical films  70 , fewer than 10 optical films  70 , and/or any other suitable number of optical films  70 . Each of these optical films  70  may have one or more alignment portions such as bent alignment portions  70 P that are bent back on themselves (while wrapping around the edge of light guide layer  78  and, if desired, the edge of reflector  80 ) so that these bent alignment portions  70 P may be secured in place relative to housing  12  and thereby align films  70  within device  10 . 
     Tape (e.g., pressure sensitive adhesive on a polymer film substrate), a layer of pressure sensitive adhesive, other adhesive, pins or other physical alignment structures, fasteners, and/or other attachment mechanisms may be used to attach each optical film  70  to support structure  100  (e.g., a display chassis or other internal housing structure, a housing wall in housing  12 , and/or other support structure). Consider, as an example, the cross-sectional side view of the portion of backlight structures  42  that is shown in  FIG. 5 . As shown in  FIG. 5 , backlight structures  42  may include light guide layer  78  and reflector  80 . One or more optical films such as illustrative optical film  70  may be included in backlight structures  42 . As shown in  FIG. 5 , optical film  70  may have a bent alignment portion such as bent alignment portion  70 P (e.g., a bent edge portion or bent protruding tab) that is wrapped around peripheral edge  78 E of light guide layer  78  and peripheral edge  80 E of reflector  80 . In this way, film  70  doubles back on itself in edge region  106 , rather than extending outwardly in lateral dimensions X and Y. Tape  110  and/or other attachment structures may be used to attach bent alignment portion  70 P to support structure  100  to secure each film  70  in backlight structures  42 . Edges  78 E and  80 E may run along the upper edge of display  14  and/or other peripheral edges of display  14 . As shown in  FIG. 6 , a layer of adhesive such as adhesive layer  112  (e.g., an adhesive layer that is not supported by a tape substrate) may be used to attach bent alignment portion  70 P to support structure  100 . Adhesive layer  112  may be a layer of pressure sensitive adhesive or other adhesive. 
     Illustrative layers for use in backlight structures  42  are shown in  FIGS. 7, 8, 9, 10, and 11 .  FIG. 7  is a top view of light guide layer  78 , showing how light guide layer  78  may have a rectangular outline (as an example).  FIGS. 8, 9, 10, and 11  are top views of four illustrative optical films  70 . Film F 1  of  FIG. 8 , which may be a diffuser, may be placed adjacent to the upper surface of layer  78 . Film F 2  of  FIG. 9 , which may be a brightness enhancement film, may be placed on top of and adjacent to film F 1 . Film F 3  of  FIG. 10 , which may be an additional brightness enhancement film, may be placed on top of an adjacent to film F 2 . Film F 4  of  FIG. 11 , which may be an additional diffuser, may be placed between film F 3  and display layer  46 . 
     As shown in  FIG. 8 , bent alignment portion (alignment portions)  70 P of film F 1  may form a strip-shaped bent edge portion that bends about line  114  to wrap around edge  78 E of layer  78  ( FIG. 7 ). As shown in  FIG. 9 , bent alignment portions (alignment portion)  70 P of film F 2  may form bent protruding tabs that wrap around edge  78 E.  FIGS. 10 and 11  show how films F 3  and F 4  may have bent alignment portions  70 P that form bent protruding tabs that are laterally offset from the tabs of layer F 1  (e.g., laterally offset along edge  78 E of layer  78 ). The lateral offsets of the protruding alignment portions  70 P in the different films of backlight structures  42  may help allow these portions  70 P to be securely taped or otherwise secured to support structure  100  without creating excessive thickness for the tape layers and/or other attachment structures in display  14 . 
     To prevent visible artifacts where light escapes between adjacent tabs of films  70 , the strip-shaped bent edge portion of lowermost film F 1  that forms bent alignment portion  70 P of  FIG. 8  may extend along the entire length of edge  78 E of light guide layer  78  (or at least a portion of the length of edge  78 E that is overlapped by tabs in subsequent films). Film F 1  may be a diffuser layer that diffuses any light exiting edge  78 E so that bright gaps between adjacent film tabs associated with films F 2 , F 3 , and F 4  may be minimized. This type of arrangement, in which the edge of film F 1  runs along the entire length of edge  78 E of layer  78  (and, if desired, along all of edge  80 E of reflector  80 ), is illustrated in  FIG. 12 . Reflector  80  may overlap the entire lower surface of layer  78  (e.g., reflector  80  may overlap central region  118  of layer  78  and border region  120  of layer  78 ) or reflector  80  may be omitted from some or all of these areas (e.g., reflector  80  may overlap region  118  while being omitted from region  120 ). 
     As described in connection with  FIGS. 4 and 5 , tape, adhesive, and/or other attachment mechanisms may be used in attaching films  70  to support structure  100 .  FIG. 13  is a cross-sectional side view of a portion of backlight structures  42  in an illustrative arrangement in which two tape layers such as first tape layer  110 A and second tape layer  110 B are being used to attach films  70  to support structure  100 .  FIG. 14  is a cross-sectional side view of a portion of backlight structures  42  in an illustrative arrangement in which tape layer  110  and adhesive layer  112  are being used to attach films  70  to support structure  100 . 
     To allow for potential expansion and contraction of films  70  during changes in temperature (due to the non-zero coefficient of thermal expansion that may be associated with films  70 ), it may be desirable to attach one or more bent alignment portions of films  70  to support structure  100  with a sliding joint such as sliding joint  134  of  FIG. 15 . Sliding joint  134  couples film  70  to support structure  100  while allowing for slight lateral movement of film  70  relative to support structure  100 . As shown in  FIG. 15 , portion  70 P of film  70  may be secured to housing  100  using tape layer  110  and an intervening layer of material with an underside that is not covered with adhesive such as polymer layer  122 . Polymer layer  122  has a surface facing portion  70 P that is free of adhesive and that therefore creates a non-sticky area of layer  122  that allows portion  70 P to slide relative to layer  122 . 
       FIG. 16  is a cross-sectional side view of an alignment tab attachment structure such as sliding joint  134  of  FIG. 15  viewed in direction  132  of  FIG. 15 . As shown in  FIG. 16 , polymer layer  122  is interposed between the lower surface of tape layer  110  and alignment portion  70 P. The presence of polymer layer  122  between tape layer  110  and alignment portion  70 P prevents the sticky adhesive-covered lower surface of tape  110  from fixing the position of portion  70 P. As a result, portion  70 P and nearby portions of film  70  can slide laterally (e.g., horizontally in the arrangement of  FIG. 16 ) to accommodate thermal expansion of film  70 . If desired, support structure  100  or other portion of device  10  may have a physical alignment structure such as pin  124  that mates with a corresponding feature in film  70  such as alignment opening  128  in film  70 . Opening  128  may have a circular shape, square shape, an elongated shape such as a rectangular slot shape or other slot configuration, the shape of a notch or other recess, and/or other opening shape. Opening  128  may receive pin  124  as shown in  FIG. 16 . 
     In the illustrative configuration used for sliding joint  134  of  FIG. 16 , opening  128  is a slot that allows portion  70 P to slid slightly to the left and right in the orientation of  FIG. 16  (e.g., parallel to edge  78 E of light guide layer  78  in backlight structures  42 ), but that is sufficiently narrow in the orthogonal direction (in and out of the page of  FIG. 16 ) to constrain excess motion in this orthogonal direction. A sliding joint such as sliding joint  134  of  FIG. 16  may, if desired, be used as one of a pair of first and second attachment structures for first and second corresponding alignment tabs in an optical film. A fixed joint may be used for the other of the pair of first and second attachment structures. 
       FIG. 17  is a cross-sectional side view of a fixed joint. Fixed joint  136  may not include adhesive-free polymer layer  122 , so tape  110  may attach to support structure  100  and the upper surface of portion  70 P, thereby fixing portion  70 P in place against structure  100 . The position of portion  70 P is also determined by pin  126  and mating opening  130  in portion  70 P. Opening  130  may be configured to have the same size as pin  126 , thereby further preventing lateral sliding of portion  70 P relative to support structure  100 . If desired, an optical film with first and second tabs may have a first tab formed using sliding joint  134  of  FIG. 16  and a second tab formed using fixed joint  136  of  FIG. 17 . Joints such as the tape and adhesive joints of  FIGS. 13 and 14  and/or other attachment structures may also be used for securing bent alignment portions  70 P of optical films  70 , if desired. 
     As shown in  FIG. 18 , active area AA of display  14  may have one or more straight sides and one or more sides that are not straight. Active area AA of display  14  of  FIG. 18  has a top edge that has a recessed portion such as recess  140 . The presence of recess  140 , which may sometimes be referred to as a notch, opening, or notch-shaped recess, may create additional inactive area (e.g., the strip of inactive area IA running along the upper edge of display  14  of  FIG. 18  may be locally widened). Electrical components  142  may be mounted in this inactive notch-shaped area. Components  142  may include optical components such as image sensors, light-emitting diodes, lasers, and other light sources, optical proximity sensors, color ambient light sensors, three-dimensional image sensors (e.g., structured light sensors that project light beams to create dots and that have image sensors for capturing images of the dots to determine the three-dimensional shape of an object), and/or other sensors that emit and/or detect visible light, infrared light, and/or ultraviolet light. 
     Illustrative layouts for optical films  70  that may be used in a notched display such as display  14  of  FIG. 18  are shown in  FIGS. 19 and 20 . 
     As shown in  FIG. 19 , optical film  70  may have portions  70 ′ that are located along left and right edge portions of a light guide layer on opposing ends of notch  140 . The tips of portions  70 ′ may form bent alignment tabs such as portion  70 P. Portions  70 P (e.g., bent edge portions that extend along the full edge of each of portions  70 ′ and/or bent protruding tabs formed in portions  70 P) may be wrapped around edge  78 E of light guide layer  78  in backlight structures  42  (e.g., around left and right portions of edge  78 E on opposing sides of notch  140 ). 
     In the example of  FIG. 20 , bent alignment portions for optical films  70  have been formed along the edge of layers  70  at the base of notch  140  (e.g., along a portion of edge  78  that lies in notch  140 ). Film F 1  may have a bent edge portion that is wrapped around the edge of layer  78  along the entire width of notch  140  and films F 2 , F 3 , and F 4  may have bent protruding tabs and/or other bent alignment portions may be formed in notch  140 . Configurations in which bent alignment portions are formed in both the out-of-notch locations of  FIG. 19  and the in-notch locations of  FIG. 20  may also be used, if desired. 
       FIG. 21  is a cross-sectional side view of a portion of display  14  showing how a camera or other electrical components may be used to help align optical films  70 . Display  14  of electronic device  10  may have a protective outer layer. The protective outer layer may protect pixels P of display layer  46 . The protective outer layer may be formed by the outermost substrate within layer  46  or, as shown in  FIG. 21 , may be formed by display cover layer  52 . Ink or other opaque masking material  94  may having an opening (window) such as opening  182  that is aligned with component  180 . For example, component  180  (e.g., one of components  142  of  FIG. 18 ) may have a portion such as portion  180 M that receives and/or transmits light through opening  182 . Component  180  may be an electrical component such as an optical component or other electrical component. As an example, component  180  may be an ambient light sensor, a camera (e.g., a digital image sensor with a lens), a three-dimensional sensor such as a structured light sensor, an optical proximity sensor, a camera flash, and/or other optical component. If desired, component  180  may be an audio component (e.g., a speaker or microphone) and/or other electrical component. 
     As shown in  FIG. 21 , portions of component  180  and/or associated supporting structures may be used as alignment structures (sometimes referred to as alignment pins or alignment posts). As examples, main portion  180 M of component  180  may serve as an alignment structure that protrudes into a corresponding alignment opening in optical films  70  or ancillary protruding portion  180 P of component  180  may serve as an alignment structure that is received within a corresponding alignment opening in optical films  70 . The portions of component  180  that serve as optical film alignment structures may be formed from polymer, metal and/or other materials and may serve as electrical component housing structures and/or electrical component mounting structures. For example, in an arrangement in which component  180  is a camera, portions of a polymer housing for the camera may be used to form alignment structures such as portions  180 M and/or  180 P. Mounting brackets and/or other component mounting structures may also be used to form alignment structures (e.g., alignment pins) that are received within corresponding alignment openings in films  70 . The openings in films  70  may have slot shapes (e.g., to allow lateral film movement from expansion and contraction due to temperature fluctuations) and/or other suitable shapes (e.g., circular or square shapes to receive alignment structures that help prevent lateral film movement). 
       FIG. 22  is a cross-sectional side view of device  10  in an illustrative configuration in which an alignment structure for optical films has been coupled to a trim member. As shown in  FIG. 22 , display  14  may include layers such as layers  200  and  202 . Layers  200  and  202  may form substrates in layer  46 , layer  200  may be formed by a display layer such as layer  46  and layer  202  may form display cover layer  52 , and/or layers  200  and  202  may form other structures in display  14  (e.g., structures for forming pixels P). Display  14  may be mounted in housing  12  using an elastomeric gasket, polymer support structures, and/or other supportive structures such as trim member  204 . Trim member  204  may, as an example, form a ring-shaped member that surrounds display  14  and prevents display  14  from damage due to direct contact with housing  12 . Trim member  204  may be formed from polymer or other material. With one illustrative arrangement, alignment members such as alignment member  208  may be embedded within trim member  204 . For example, polymer material for forming trim member  204  may be molded over member  208 . Member  208  may be formed from polymer, metal, and/or other material and may have a portion that forms an alignment structure. For example, member  208  may have a downwardly extending portion that forms an alignment post (pin) that is received within a corresponding alignment opening (hole) in optical films  70 , as shown in  FIG. 22 . 
       FIG. 23  is a top view of a portion of an illustrative display for device  10  that has a notch (notch  140 ). Notch  140  may, as an example, be formed along the upper side of display  14  and may be used to accommodate electrical components.  FIG. 23  shows how alignment structures such as alignment posts  210  may be received within corresponding alignment openings such as alignment holes  212  and  214  in optical films  70 . Illustrative hole  212  has a shape that receives an alignment post  210  without allowing for shifting movement of films  70  (e.g., to form a fixed joint). Illustrative hole  214  has an elongated shape forming a slot that receives an alignment post  210  while allowing for lateral movement of film  70  as films  70  expand and contract due to temperature changes (e.g., to form a sliding joint). 
     Device  10  may be operated in a system that uses personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     In accordance with an embodiment, a display is provided that includes a backlight having a light source, a light guide layer that receives light from the light source and that produces corresponding backlight illumination, pixels that are illuminated with the backlight illumination and that are configured to display an image, and optical films interposed between the backlight and the pixels, the optical films include bent alignment portions that wrap around an edge of the light guide layer. 
     In accordance with another embodiment, the optical films include a first optical film and a second optical film, the first optical film is interposed between the light guide layer and the second optical film, the edge of the light guide layer has a length and extends between opposing first and second sides of the light guide layer, the first optical film has a bent edge portion that runs along the length of the edge of the light guide layer while wrapping around the edge of the light guide layer, and the second optical film has bent protruding tabs that wrap around respective portions of the edge of the light guide layer. 
     In accordance with another embodiment, the optical films include a prism film and a diffuser film. 
     In accordance with another embodiment, the diffuser film has a bent edge portion wrapped around the edge of the light guide layer. 
     In accordance with another embodiment, the prism film includes first and second bent protruding tabs wrapped around the edge of the light guide layer, a first portion of the bent edge portion is interposed between the first bent protruding tab and the light guide layer, and a second portion of the bent edge portion is interposed between the second bent protruding tab and the light guide layer. 
     In accordance with another embodiment, the display includes a reflector, the light guide layer and the optical films are interposed between the reflector and the liquid crystal display pixels. 
     In accordance with an embodiment, an electronic device is provided that includes a support structure, an array of pixels configured to display an image, and a display backlight having a light guide layer that is configured to provide backlight illumination to the array of pixels and having flexible polymer films that are between the light guide layer and the pixels and that have bent alignment portions that wrap around an edge of the light guide layer and are coupled to the support structure. 
     In accordance with another embodiment, the support structure includes an electronic device housing. 
     In accordance with another embodiment, the electronic device includes adhesive that attaches the flexible polymer films to the support structure. 
     In accordance with another embodiment, at least one of the bent alignment portions include a bent protruding tab. 
     In accordance with another embodiment, the bent protruding tab wraps around the edge and is bent back on itself and the adhesive is configured to attach the bent protruding tab to the electronic device housing. 
     In accordance with another embodiment, the bent alignment portions include a bent protruding tab, the electronic device includes tape that is configured to couple the bent protruding tab to the electronic device housing. 
     In accordance with another embodiment, the tape has a non-sticky portion that overlaps the bent protruding tab to form a sliding joint that couples the bent protruding tab to the support structure while allowing the bent protruding tab to slide relative to the support structure. 
     In accordance with another embodiment, the light guide layer has a notch and the bent alignment portions overlap a portion of the edge in the notch. 
     In accordance with another embodiment, the light guide layer has a notch and the bent alignment portions overlap portions of the edge out of the notch. 
     In accordance with an embodiment, an electronic device is provided that includes a housing member, and a display in the housing having a backlight that produces backlight illumination and having a pixel array that is illuminated by the backlight illumination, the backlight includes a light-emitting diode, a light guide layer that receives light from the light-emitting diode and that provides the backlight illumination to the pixel array, and a flexible polymer layer interposed between the light guide layer and the pixel array, the flexible polymer layer has a bent protruding tab that is bent around an edge of the light guide layer and that is secured to the housing member. 
     In accordance with another embodiment, the electronic device includes adhesive that is configured to secure the bent protruding tab to the housing member. 
     In accordance with another embodiment, the flexible polymer layer includes a prism film. 
     In accordance with another embodiment, the electronic device includes tape, the housing member includes a housing wall, and the flexible polymer layer is secured to the housing wall using the tape. 
     In accordance with another embodiment, the flexible polymer layer includes one of at least four optical films interposed between the light guide layer and the pixel array and the optical films include at least two diffusers and at least two prism films each of which has a respective bent alignment portion coupled to the housing member. 
     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: 20190514
Publication Date: 20210511
Grant Date: 20210511
Priority Date: 20181218
Inventors: HENDREN, KEITH J.
GARELLI, ADAM T.
POSNER, BRYAN W.
MATHEW, DINESH C.
LIANG, MENGYANG
BENSON, ERIC
YIN, VICTOR
QI, JUN
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133314", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2201/46", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133615", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2202/28", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133603", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1601", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0055", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133314", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2201/46", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133322", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133317", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2201/54", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133608", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133606", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1601", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2202/28", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133615", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133322", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2201/54", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133608", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133606", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0055", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133603", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1601", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133603", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0055", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1601", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 71073707