PATENT DOCUMENT

Publication Number: US-10386572-B1
Application Number: US-201816110893-A
Country: US
Kind Code: B1

Title: Electronic device display with a backlight

Abstract:
A backlight unit may be used to produce backlight illumination for a display. The backlight unit may have a row of light-emitting diodes that are mounted on a flexible printed circuit and that emit light into a light guide layer. The backlight unit may include a chassis that extends around the periphery of the light guide layer. The chassis may have a first portion that is mounted on the flexible printed circuit adjacent to the light-emitting diodes and a second portion that extends over the light-emitting diodes. A heat spreading layer may be attached to a reflector layer and the flexible printed circuit. The heat spreading layer may have a width that is less than the width of the reflector layer. Adhesive patches may attach the light guide layer to the flexible printed circuit. A patterned adhesive layer may be formed over the light-emitting diodes and the light guide layer.

Claims:
What is claimed is: 
     
       1. A display backlight comprising:
 a flexible printed circuit board; 
 a row of light-emitting diodes mounted on the flexible printed circuit board; 
 a light guide layer having first and second opposing surfaces connected by an edge, wherein the edge receives light from the row of light-emitting diodes; and 
 a chassis that extends around a periphery of the light guide layer, wherein the chassis has a first portion that is adjacent to the row of light-emitting diodes and that is attached to the flexible printed circuit board and wherein the chassis has a second portion that extends over the row of light-emitting diodes. 
 
     
     
       2. The display backlight defined in  claim 1 , wherein each light-emitting diode of the row of light-emitting diodes is soldered to the flexible printed circuit board. 
     
     
       3. The display backlight defined in  claim 2 , further comprising:
 a plurality of adhesive patches that attach the first surface of the light guide layer to the flexible printed circuit board; and 
 a patterned layer of adhesive that is formed over the row of light-emitting diodes and the second surface of the light guide layer. 
 
     
     
       4. The display backlight defined in  claim 3 , wherein the patterned layer of adhesive has a plurality of protruding portions and wherein each protruding portion of the plurality of protruding portions overlaps a respective adhesive patch of the plurality of adhesive patches. 
     
     
       5. The display backlight defined in  claim 3 , further comprising:
 a first optical film formed over the light guide layer, wherein a portion of the first optical film overlaps the patterned layer of adhesive; and 
 a second optical film formed over the first optical film. 
 
     
     
       6. The display backlight defined in  claim 5 , wherein the first optical film is a diffuser layer and the second optical film is a brightness enhancement film. 
     
     
       7. The display backlight defined in  claim 5 , further comprising:
 an additional adhesive layer that is attached to an upper surface of the second optical film and an upper surface of the chassis. 
 
     
     
       8. The display backlight defined in  claim 7 , wherein the additional adhesive layer comprises a polymer film interposed between first and second pressure sensitive adhesive layers and a cut-out in the first pressure sensitive adhesive layer. 
     
     
       9. The display backlight defined in  claim 8 , wherein the first pressure sensitive layer is attached to the upper surface of the second optical film and the upper surface of the chassis. 
     
     
       10. The display backlight defined in  claim 8 , wherein the second pressure sensitive layer is attached to the upper surface of the second optical film and the upper surface of the chassis. 
     
     
       11. The display backlight defined in  claim 8 , further comprising:
 an additional polymer film formed within the cut-out in the first pressure sensitive adhesive layer. 
 
     
     
       12. The display backlight defined in  claim 11 , wherein the cut-out in the first pressure sensitive adhesive layer extends only partially through the first pressure sensitive adhesive layer and wherein the additional polymer film is attached directly to the first pressure sensitive adhesive layer in the cut-out. 
     
     
       13. The display backlight defined in  claim 7 , wherein the additional adhesive layer comprises a first piece of tape and a second piece of tape, wherein the first piece of tape comprises a polymer film interposed between first and second pressure sensitive adhesive layers, wherein the first piece of tape comprises a cut-out through the first pressure sensitive adhesive layer, the polymer film, and the second pressure sensitive adhesive layer, and wherein the second piece of tape fills the cut-out in the first piece of tape. 
     
     
       14. The display backlight defined in  claim 7 , wherein the additional adhesive layer comprises a first piece of tape and a second piece of tape, wherein the first piece of tape comprises a polymer film interposed between first and second pressure sensitive adhesive layers, wherein the first piece of tape comprises a cut-out through the first pressure sensitive adhesive layer, the polymer film, and the second pressure sensitive adhesive layer, and wherein the second piece of tape is formed over the cut-out and attached to the first piece of tape on opposing sides of the cut-out. 
     
     
       15. The display backlight defined in  claim 7 , further comprising:
 a spacer interposed between the portion of the first optical film that overlaps the patterned layer of adhesive and the additional adhesive layer. 
 
     
     
       16. The display backlight defined in  claim 1 , further comprising:
 a reflector layer positioned below the first surface of the light guide layer; and 
 a heat spreading layer attached to the flexible printed circuit board and the reflector layer. 
 
     
     
       17. The display backlight defined in  claim 16 , further comprising:
 a strip of adhesive that attaches the heat spreading layer to the flexible printed circuit board; and 
 first and second patches of adhesive that attach the heat spreading layer to the reflector layer. 
 
     
     
       18. The display backlight defined in  claim 16 , further comprising:
 an opaque adhesive layer that is attached to a lower surface of the heat spreading layer and a side surface of the chassis. 
 
     
     
       19. The display backlight defined in  claim 1 , wherein each light-emitting diode has two light-emitting areas. 
     
     
       20. The display backlight defined in  claim 1 , further comprising:
 first, second, and third solder pads on the flexible printed circuit board, wherein a first light-emitting diode of the row of light-emitting diodes overlaps the first, second, and third solder pads; and 
 a first adhesive patch that is interposed between the first and second solder pads and that attaches the first light-emitting diode to the flexible printed circuit board; and 
 a second adhesive patch that is interposed between the second and third solder pads and that attaches the first light-emitting diode to the flexible printed circuit board. 
 
     
     
       21. A display backlight comprising:
 a flexible printed circuit board; 
 a row of light-emitting diodes mounted on the flexible printed circuit board; 
 at least first and second solder pads on the flexible printed circuit board, wherein a first light-emitting diode of the row of light-emitting diodes overlaps the first and second solder pads; 
 a first adhesive patch that attaches the first light-emitting diode to the flexible printed circuit board; and 
 a light guide layer having first and second opposing surfaces connected by an edge, wherein the edge receives light from the row of light-emitting diodes. 
 
     
     
       22. The display backlight defined in  claim 21 , wherein the first adhesive patch is interposed between the first and second solder pads on the flexible printed circuit board. 
     
     
       23. A display backlight comprising:
 a flexible printed circuit board; 
 a row of light-emitting diodes mounted on the flexible printed circuit board; 
 a light guide layer having first and second opposing surfaces connected by an edge, wherein the edge receives light from the row of light-emitting diodes; 
 a reflector layer that is positioned below the first surface of the light guide layer and that has a first width; 
 a heat spreading layer that is attached to the reflector layer and the flexible printed circuit board, wherein the heat spreading layer has a second width that is less than the first width; 
 a strip of adhesive that attaches the heat spreading layer to the flexible printed circuit board; and 
 first and second patches of adhesive that attach the heat spreading layer to the reflector layer. 
 
     
     
       24. The display backlight defined in  claim 23 , wherein the heat spreading layer comprises a layer of graphite interposed between first and second polymer films. 
     
     
       25. The display backlight defined in  claim 23 , wherein the heat spreading layer comprises first and second opposing edges connected by third and fourth opposing edges, wherein the strip of adhesive is formed along the first edge of the heat spreading layer, wherein the first patch of adhesive is formed in a first corner of the heat spreading layer where the second edge meets the third edge, and wherein the second patch of adhesive is formed in a second corner of the heat spreading layer where the second edge meets the fourth edge. 
     
     
       26. A display backlight comprising:
 a flexible printed circuit board; 
 a row of light-emitting diodes mounted on the flexible printed circuit board; 
 a light guide layer having first and second opposing surfaces connected by an edge, wherein the edge receives light from the row of light-emitting diodes; 
 a plurality of adhesive patches that attach the first surface of the light guide layer to the flexible printed circuit board; and 
 a patterned layer of adhesive that is formed over the row of light-emitting diodes and the second surface of the light guide layer, wherein the patterned layer of adhesive has a plurality of protruding portions and wherein each protruding portion of the plurality of protruding portions overlaps a respective adhesive patch of the plurality of adhesive patches. 
 
     
     
       27. The display backlight defined in  claim 26 , wherein the plurality of protruding portions include a first set of protruding portions that are interposed between adjacent light-emitting diodes in the row of light-emitting diodes and a second set of protruding portions that each extend from the middle of a respective light-emitting diode of the row of light-emitting diodes.

Description:
This application claims the benefit of provisional patent application No. 62/662,023, filed Apr. 24, 2018, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices with displays, and, more particularly, to displays with backlights. 
     Electronic devices such as computers and cellular telephones have displays. Some displays such organic light-emitting diode displays have arrays of pixels that generate light. In displays of this type, backlighting is not necessary because the pixels themselves produce light. Other displays contain passive pixels that can alter the amount of light that is transmitted through the display to display information for a user. Passive pixels do not produce light themselves, so it is often desirable to provide backlight for a display with passive pixels. Passive pixels may be formed from a layer of liquid crystal material formed between two electrode layers and two polarizer layers. 
     In a typical backlight assembly for a display, a light guide plate is used to distribute backlight generated by a light source such as a light-emitting diode light source. A reflector may be formed under the light guide plate to improve backlight efficiency. 
     Conventional backlight assemblies may cause visible artifacts, may not be robust, and may occupy an undesirably large amount of space within an electronic device. 
     It would therefore be desirable to be able to provide displays with improved backlights. 
     SUMMARY 
     A display may have an array of pixels for displaying images for a viewer. The array of pixels may be formed from display layers such as a color filter layer, a liquid crystal layer, a thin-film transistor layer, an upper polarizer layer, and a lower polarizer layer. 
     A backlight unit may be used to produce backlight illumination for the display. The backlight illumination may pass through the polarizers, the thin-film transistor layer, the liquid crystal layer, and the color filter layer. The backlight unit may have a row of light-emitting diodes that are mounted on a flexible printed circuit board and that emit light into a light guide layer. 
     The backlight unit may include a chassis that extends around the periphery of the light guide layer. The chassis may have a first portion that is mounted on the flexible printed circuit board adjacent to the row of light-emitting diodes and a second portion that extends over the row of light-emitting diodes. The chassis may have a different cross-sectional shape along the edge adjacent to the light-emitting diodes compared to the remaining edges of the chassis. 
     A reflector layer may be attached to a lower surface of the light guide layer. A heat spreading layer may be attached to a lower surface of the reflector layer and a lower surface of the flexible printed circuit board. The heat spreading layer may include a sheet of graphite interposed between first and second polymer carrier films. The heat spreading layer may have a width that is less than the width of the reflector layer to mitigate wrinkling of the reflector layer. A strip of adhesive may attach an edge of the heat spreading layer to the flexible printed circuit board. First and second patches of adhesive may attach respective first and second corners of the heat spreading layer to the reflector layer. 
     A plurality of adhesive patches may attach the lower surface of the light guide layer to the flexible printed circuit board. A patterned layer of adhesive may be formed over the row of light-emitting diodes and the upper surface of the light guide layer. The patterned layer of adhesive may have protruding portions that each extend over a respective one of the plurality of adhesive patches. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative electronic device having a display in accordance with an embodiment. 
         FIG. 2  is a cross-sectional side view of an illustrative display in an electronic device in accordance with an embodiment. 
         FIG. 3  is a top view of an illustrative display in accordance with an embodiment. 
         FIG. 4  is a perspective view of illustrative backlight structures with rounded corners and a notch in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of illustrative backlight structures on an edge of the backlight structures that does not include light sources in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of illustrative backlight structures on an edge of the backlight structures that includes light sources in accordance with an embodiment. 
         FIG. 7  is a rear view of an illustrative heat spreading layer showing how the heat spreading layer may have a reduced width relative to the reflector layer in accordance with an embodiment. 
         FIG. 8  is a top view of an illustrative heat spreading layer showing how adhesive may be patterned on the heat spreading layer in accordance with an embodiment. 
         FIG. 9  is a top view of illustrative backlight structures showing how adhesive may be patterned on an upper surface of the light-emitting diodes and light guide layer and a lower surface of the light guide layer in accordance with an embodiment. 
         FIG. 10  is a top view of an illustrative light-emitting diode with adhesive patches interposed between adjacent solder pads in accordance with an embodiment. 
         FIG. 11  is a top view of illustrative backlight structures showing an arrangement for a light-emitting diode array in accordance with an embodiment. 
         FIG. 12  is a top view of illustrative backlight structures showing how light from a light-emitting area of a light-emitting diode may be emitted an angle to fill rounded corners of the light guide layer in accordance with an embodiment. 
         FIG. 13  is a cross-sectional side view of illustrative ring tape having a cut-out through all of its layers in accordance with an embodiment. 
         FIG. 14  is a cross-sectional side view of illustrative ring tape having a cut-out through only one of its layers in accordance with an embodiment. 
         FIG. 15  is a cross-sectional side view of illustrative ring tape having a second piece of ring tape fill a cut-out in accordance with an embodiment. 
         FIG. 16  is a cross-sectional side view of illustrative ring tape having a second piece of ring tape overlap a cut-out in accordance with an embodiment. 
         FIG. 17  is a cross-sectional side view of illustrative ring tape having a cut-out through only one of its layers and an additional layer formed in the cut-out in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device of the type that may be provided with a display is shown in  FIG. 1 . As shown in  FIG. 1 , electronic device  10  may have control circuitry  16 . Control circuitry  16  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  16  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. 
     Input-output circuitry in device  10  such as input-output devices  12  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  12  may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  12  and may receive status information and other output from device  10  using the output resources of input-output devices  12 . 
     Input-output devices  12  may include one or more displays such as display  14 . Display  14  may be a touch screen display that includes a touch sensor for gathering touch input from a user or display  14  may be insensitive to touch. A touch sensor for display  14  may be based on an array of capacitive touch sensor electrodes, acoustic touch sensor structures, resistive touch components, force-based touch sensor structures, a light-based touch sensor, or other suitable touch sensor arrangements. 
     Control circuitry  16  may be used to run software on device  10  such as operating system code and applications. During operation of device  10 , the software running on control circuitry  16  may display images on display  14 . 
     Device  10  may be a tablet computer, laptop computer, a desktop computer, a television, a cellular telephone, a media player, a wristwatch device or other wearable electronic equipment, or other suitable electronic device. 
     Display  14  for device  10  includes an array of pixels. The array of pixels may be formed from liquid crystal display (LCD) components or other suitable display structures. Configurations based on liquid crystal display structures are sometimes described herein as an example. 
     A display cover layer may cover the surface of display  14  or a display layer such as a color filter layer, thin-film transistor 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 plastic layer, or other transparent member. 
     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 a backlight unit such as backlight unit  42  (sometimes referred to as a backlight or backlight structures) for producing backlight  44 . During operation, backlight  44  travels outwards (vertically upwards in dimension Z in the orientation of  FIG. 2 ) and passes through pixel structures in display layers  46 . This illuminates any images that are being produced by the pixels for viewing by a user. For example, backlight  44  may illuminate images on display layers  46  that are being viewed by viewer  48  in direction  50 . 
     Display layers  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 a housing in device  10  or display layers  46  may be mounted directly in an electronic device housing for device  10  (e.g., by stacking display layers  46  into a recessed portion in a metal or plastic housing). Display layers  46  may form a liquid crystal display or may be used in forming displays of other types. 
     In a configuration in which display layers  46  are used in forming a liquid crystal display, display layers  46  may include a liquid crystal layer such a liquid crystal layer  52 . Liquid crystal layer  52  may be sandwiched between display layers such as display layers  58  and  56 . Layers  56  and  58  may be interposed between lower polarizer layer  60  and upper polarizer layer  54 . 
     Layers  58  and  56  may be formed from transparent substrate layers such as clear layers of glass or plastic. Layers  56  and  58  may be layers such as a thin-film transistor layer and/or a color filter layer. Conductive traces, color filter elements, transistors, and other circuits and structures may be formed on the substrates of layers  58  and  56  (e.g., to form a thin-film transistor layer and/or a color filter layer). Touch sensor electrodes may also be incorporated into layers such as layers  58  and  56  and/or touch sensor electrodes may be formed on other substrates. 
     With one illustrative configuration, layer  58  may be a thin-film transistor layer that includes an array of pixel circuits based on thin-film transistors and associated electrodes (pixel electrodes) for applying electric fields to liquid crystal layer  52  and thereby displaying images on display  14 . Layer  56  may be a color filter layer that includes an array of color filter elements for providing display  14  with the ability to display color images. If desired, layer  58  may be a color filter layer and layer  56  may be a thin-film transistor layer. Configurations in which color filter elements are combined with thin-film transistor structures on a common substrate layer may also be used. 
     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 a display driver integrated circuit such as circuit  62 A or  62 B using a signal path such as a signal path formed from conductive metal traces in a rigid or flexible printed circuit such as printed circuit  64  (as an example). Integrated circuits such as integrated circuit  62 A and/or flexible printed circuits such as flexible printed circuit  64  may be attached to substrate  58  in ledge region  66  (as an example). 
     Backlight structures  42  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 plastic. 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 (e.g., a series of light-emitting diodes that are arranged in a row that extends into the page in the orientation of  FIG. 2 ). The array of light-emitting diodes may be mounted to a rigid or flexible printed circuit. The printed circuit may be adhered to adjacent layers in the electronic device. In certain embodiments, the printed circuit may be adhered to portions 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 principal of total internal reflection. Light guide layer  78  may include light-scattering features such as pits, bumps, grooves, or ridges that help light exit light guide layer  78  for use as backlight  44 . These features may be located on an upper surface and/or on an opposing lower surface of light guide layer  78 . With one illustrative configuration, a first surface such as the lower surface of light guide layer  78  has a pattern of bumps and an opposing second surface such as the upper surface of light guide layer  78  has a pattern of ridges (sometimes referred to as lenticules, lenticular structures, or lenticular ridges). Light source  72  may be located at any desired edge of light guide layer  78 . 
     Light  74  that scatters upwards in direction Z from light guide layer  78  may serve as backlight  44  for display  14 . Light  74  that scatters downwards may be reflected back in the upward direction by reflector  80 . Reflector  80  may be formed from a reflective structure such as a substrate layer of plastic coated with a dielectric mirror formed from alternating high-index-of-refraction and low-index-of-refraction inorganic or organic layers. Reflector  80  may be formed from a reflective material such as a layer of white plastic or other shiny materials. 
     To enhance backlight performance for backlight structures  42 , backlight structures  42  may include optical films  70 . Optical films  70  may include diffuser layers for helping to homogenize backlight  44  and thereby reduce hotspots. Optical films  70  may also include brightness enhancement films for collimating backlight  44 . Optical films  70  may overlap the other structures in backlight unit  42  such as light guide layer  78  and reflector  80 . For example, if light guide layer  78  has a rectangular footprint in the X-Y plane of  FIG. 2 , optical films  70  and reflector  80  may each have a matching rectangular footprint. Optical films  70  may include compensation films for enhancing off-axis viewing or compensation films may be formed within the polarizer layers of display  14  or elsewhere in display  14 . 
       FIG. 3  is a top view of a portion of display  14  showing how display  14  may have an array of pixels  90  formed within display layers  46 . Pixels  90  may have color filter elements of different colors such as red color filter elements R, green color filter elements G, and blue color filter elements B. Pixels  90  may be arranged in rows and columns and may form active area AA of display  14 . The borders of active area AA may be slightly inboard of the borders of light-guide layer  78  to ensure that there are no visible hotspots in display  14  (i.e., no areas in which the backlight illumination for display  14  is noticeably brighter than surrounding areas). For example, border  92  of active area AA may be offset by a distance  82  from lower edge  76  of light guide layer  78 . It is generally desirable to minimize the size of distance  82  so that display  14  is as compact as possible for a given active area size. Nevertheless, distance  82  should not be too small to ensure that there is adequate light mixing. In particular, distance  82  should be sufficiently large to allow light  74  that is emitted from light-emitting diodes  72  to homogenize enough to serve as backlight illumination. Distance  82  is often as long as necessary to ensure light from light-emitting diodes  72  is sufficiently mixed. Accordingly, distance  82  may sometimes be referred to as mixing distance  82 . When light  74  is initially emitted from individual light-emitting diodes  72 , light  74  is concentrated at the exits of light-emitting diodes  72  and is absent in the spaces between light-emitting diodes  72 . After light  74  has propagated sufficiently far within light-guide plate  78  (i.e., after light  74  has traversed a sufficiently large mixing distance  82 ), light  74  will be smoothly distributed along dimension X and will no longer be concentrated near the exits of respective individual light-emitting diodes  72 . 
     The rectangular shape of light guide layer  78  and active area AA in  FIG. 3  is merely illustrative. If desired, light guide layer  78  and/or the active area AA may have a non-rectangular shape (e.g., a shape with one or more curved portions). An example of this type is shown in  FIG. 4 . As shown in  FIG. 4 , backlight structures  42  (including light guide layer  78 ) may have rounded corners such as rounded corners  94 . Backlight structures  42  may also include a notch such as notch  96  (e.g., to accommodate other components within electronic device  10  such as sensor components). Detailed cross-sections of backlight structures  42  are shown in  FIGS. 5 and 6 . In particular,  FIG. 5  is a cross-sectional side view of backlight structures  42  taken along line  98  in  FIG. 4 .  FIG. 6  is a cross-sectional side view of backlight structures  42  taken along line  97  in  FIG. 4 . 
     As shown in  FIG. 5 , backlight structures  42  include light guide layer  78  and a reflector  80  attached to a lower surface of the light guide layer. Optical films  70 - 1  and  70 - 2  may be placed on an upper surface of the light guide layer. Optical film  70 - 1  may be a brightness enhancement film (BEF) or another desired type of optical film. Optical film  70 - 2  may be a diffuser layer (for helping to homogenize backlight) or another desired type of optical film. 
     Backlight structures  42  also include chassis  102 . Chassis  102  may be a plastic chassis (sometimes referred to as a p-chassis) that supports other layers (e.g., layers in backlight structures  42  and/or display layers  46 ) in the display. Chassis  102  may extend around the periphery of light guide layer  78  with a central opening in which the light guide layer  78  is positioned (e.g., chassis  102  may be ring-shaped). If desired, chassis  102  may be formed from two or more types of material. In the example of  FIG. 5 , chassis  102  is formed from a first shot of molded plastic  102 - 1  and a second shot of molded plastic  102 - 2 . The first shot of molded plastic may have a darker color than the second shot of molded plastic (e.g., plastic  102 - 1  may be black and plastic  102 - 2  may be white). The second shot of molded plastic  102 - 2  may be positioned adjacent the edge of light guide layer  78  such that the second shot of molded plastic reflects light back into the light guide layer. This example is merely illustrative and chassis  102  may be formed from a single dielectric material if desired. 
     Adhesive layer  104  may be attached to a top surface of chassis  102  and a top surface of optical film  70 - 1 . Adhesive layer  104  may extend around the periphery of light guide layer  78  and may have a central opening (e.g., adhesive layer  104  may be ring-shaped). Adhesive layer  104  may therefore sometimes be referred to as ring tape. Ring tape  104  may attach backlight structures  42  to display layers  46  if desired. Another adhesive layer  106  may attach a lower surface of chassis  102  to reflector layer  80 . Adhesive layers  104  and  106  may be pressure sensitive adhesive layers or any other desired type of adhesive layers. 
     The three edges of backlight structures  42  that do not include light-emitting diodes  72  may have cross-sections of the type shown in  FIG. 5 . For example, looking at  FIG. 3 , light-emitting diodes  72  are positioned along a lower edge of the light guide layer. The lower edge of the backlight structures has a different arrangement than the remaining three edges of the backlight structures. The remaining three edges of the backlight structures may have an arrangement of the type shown in  FIG. 5 . 
       FIG. 6  is a cross-sectional side view of the lower edge of the backlight structures where the light sources emit light into the light guide layer. As shown in  FIG. 6 , this portion of the backlight structures still includes light guide layer  78 , a reflector layer  80  attached to a lower surface of the light guide layer, an optical film such as diffuser layer  70 - 2  attached to an upper surface of the light guide layer, and an optical film such as brightness enhancement film  70 - 1  attached to an upper surface of optical film  70 - 2 . However, light sources  72  may be included to emit light  74  in the Y-direction through edge surface  76  of the light guide layer. 
     Light sources  72  may be light-emitting diodes that are arranged in a row along the edge surface  76  of the light guide layer. Each light-emitting diode  72  may be mounted on a printed circuit board such as flexible printed circuit board  108 . Flexible printed circuit board  108  may be a printed circuit formed from sheets of polyimide or other flexible polymer layers. Flexible printed circuit board  108  (sometimes referred to as flexible printed circuit  108  or printed circuit  108 ) may include patterned metal traces for carrying signals between components on the flexible printed circuit board. Flexible printed circuit board  108  may include contact pads  110  (sometimes referred to as solder pads  110 ). Solder pads  110  may be conductive (e.g., metal) pads formed on the upper surface of flexible printed circuit board  108 . Solder  112  may couple the light-emitting diodes  72  to solder pads  110 . Each light-emitting diode (sometimes referred to as a light-emitting diode package) may have one or more associated solder pads. The solder may electrically and mechanically connect the light-emitting diodes to flexible printed circuit board  108 . 
     In addition to being attached to flexible printed circuit board  108  by solder  112 , light-emitting diodes  72  may be attached to light guide layer  78  by adhesive layer  114 . As shown in  FIG. 6 , adhesive layer  114  is positioned on an upper surface of light-emitting diodes  72  and extends over the upper surface of light guide layer  78 . A portion of adhesive layer  114  is interposed between light guide layer  78  and optical film  70 - 2 . Adhesive layer  114  may be a pressure sensitive adhesive layer or any other desired type of adhesive layer. 
     Flexible printed circuit board  108  is coupled to light-emitting diodes by solder  112 . Flexible printed circuit board  108  may also be coupled to light guide layer  78  by an additional adhesive layer. As shown in  FIG. 6 , flexible printed circuit board  108  may include a coating layer  118  (sometimes referred to as a coverlay) and an adhesive layer  116  that is attached between light guide layer  78  and coating  118 . If desired, coating  118  may be omitted and adhesive layer  116  may attach light guide layer  78  directly to the flexible printed circuit board. Adhesive layer  116  may be a pressure sensitive adhesive layer or any other desired type of adhesive layer. Flexible printed circuit board  108  may also be attached to chassis  102  by an adhesive layer such as adhesive layer  120 . Adhesive layer  120  may be a pressure sensitive adhesive layer or any other desired type of adhesive layer. 
     Chassis  102  in  FIG. 6  is the same chassis as the chassis shown in  FIG. 5 . However, chassis  102  has a different cross-section on the lower edge of the backlight structures than the other three edges of the backlight structures. As shown in  FIG. 6 , chassis  102  has an overhang portion  122  that extends away from a main body portion  124  of the chassis. Main body portion  124  of the chassis is positioned adjacent to light-emitting diodes  72  and is attached to flexible printed circuit board  108 . Overhang portion  122  (sometimes referred to as an extension or a protrusion) extends over light-emitting diodes  72 . The overhang portion increases the surface area of the upper surface of chassis  102 , allowing a greater contact area with ring tape  104  (without increasing the width of the inactive area of the display). Chassis  102  may be said to have an L-shape along the lower edge of the backlight. 
     Ring tape  104  may be attached between an upper surface of optical film  70 - 1  and an upper surface of chassis  102 . A spacer such as spacer  126  (sometimes referred to as spacer structures  126 ) may be included between optical film  70 - 2  and ring tape  104  to help reduce bending in the ring tape. The spacer may also provide an additional surface for the ring tape to be attached, increasing the strength of the attachment of the ring tape. Spacer  126  may be formed from any desired material. 
     During operation of device  10 , light-emitting diodes and other components within the device produce heat. A heat spreading layer may be included in the device to spread the heat within device  10  to avoid creating thermal hotspots (which may cause visible artifacts).  FIG. 6  shows an example where backlight structures  42  include a heat spreading layer  128  to spread heat that is emitted from components such as light-emitting diodes  72 . In the example of  FIG. 6 , heat spreading layer  128  lies in the X-Y plane and spreads heat laterally in dimensions X and Y. Heat spreading layer  128  may optionally be coupled to an additional thermally conductive component within device  10  (e.g., a metal housing midplate) for additional heat dissipation. Heat spreading layer  128  may be formed from any suitable material that has a high thermal conductivity and can therefore serve to spread heat. Examples of materials that may be used for forming heat spreading layer  128  include metal (e.g., copper, other metals, or combinations of copper and other metals), carbon nanotubes, graphite, or other materials that exhibit high thermal conductivity. If desired, heat spreading layer  128  may be formed from two or more thermally conductive layers of different types (e.g., a layer of copper attached to a layer of graphite, etc.). Polymer carrier films may also be incorporated in layer  128  (e.g., to support a layer of graphite). In one illustrative example, heat spreading layer  128  includes a layer of graphite interposed between two polymer carrier films. 
     Heat spreading layer  128  may be attached to a lower surface of flexible printed circuit  108  by adhesive layer  130 . Adhesive layer  130  may be a pressure sensitive adhesive layer or any other desired type of adhesive layer. Backlight structures  42  may also include one or more additional adhesive layers such as adhesive layer  132  that attach heat spreading layer  128  directly to reflector layer  80 . Adhesive layer  132  may be a pressure sensitive adhesive layer or any other desired type of adhesive layer. 
     Backlight structures  42  may also include light shield tape  134  (sometimes referred to as opaque adhesive layer  134 ). Light shield tape  134  may be formed from an opaque material that allows the light shield tape to block stray light. Additionally, the light shield tape may help hold chassis  102  and flexible printed circuit board  108  together. As shown in  FIG. 6 , light shield tape  134  is coupled between a side surface of chassis  102  and a lower surface of heat spreading layer  128 . This may help secure printed circuit board  108  and chassis  102  in their desired positions (in addition to blocking stray light). 
     As discussed in connection with  FIG. 6 , a heat spreading layer ( 128 ) in backlight structures  42  may be attached directly to reflector layer  80 . However, differences in thermal conductivities of reflector layer  80  and heat spreading layer  128  may cause reflector layer  80  to wrinkle at certain temperatures. These wrinkles in reflector layer  80  may cause visible artifacts in the displayed light. 
       FIG. 7  shows a rear view of heat spreading layer  128  and reflector layer  80  in an arrangement that reduces wrinkling in reflector layer  80 . As shown in  FIG. 7 , reflector layer  80  may have a width  136 . Width  136  may be any desired distance (e.g., between 60 and 70 millimeters, between 50 and 100 millimeters, between 65 and 70 millimeters, less than 100 millimeters, greater than 40 millimeters, etc.). Heat spreading layer  128  may have a width  138  that is less than width  136 . Width  138  may be any desired distance (e.g., between 55 and 65 millimeters, between 50 and 100 millimeters, between 55 and 60 millimeters, less than 100 millimeters, greater than 40 millimeters, etc.). Each edge of the heat spreading layer may be separated from the edge of the reflector layer by a distance such as distance  140 . Distance  140  may be the same on each side of the heat spreading layer or may be different on each side of the heat spreading layer. Distance  140  may be any desired distance (e.g., between 2 and 10 millimeters, between 3 and 5 millimeters, less than 20 millimeters, greater than 1 millimeter, etc.). Having gaps  140  between the edges of the heat spreading layer and the edges of the reflector layer may prevent wrinkling of the reflector layer, thereby improving display performance. The length  142  of heat spreading layer  128  may be any desired length (e.g., between 50 and 100 millimeters, between 25 and 200 millimeters, less than 100 millimeters, less than 200 millimeters, greater than 40 millimeters, greater than 10 millimeters etc.). 
     The position of the adhesive that attaches heat spreading layer  128  to the other backlight structures (e.g., the reflector layer and flexible printed circuit board) may also influence wrinkling of the reflector layer. As previously shown in connection with  FIG. 6 , an adhesive layer  130  may attach an upper surface of the heat spreading layer to a lower surface of the flexible printed circuit board. Additional adhesive layers  132  may attach the upper surface of the heat spreading layer to a lower surface of the reflector layer.  FIG. 8  shows an arrangement for adhesive layers  130  and  132  to minimize wrinkling of the reflector layer. 
       FIG. 8  is a top view of heat spreading layer  128  and corresponding adhesive layers. As shown in  FIG. 8 , adhesive layer  130  between heat spreading layer  128  and the flexible printed circuit board ( 108 ) may be formed as a strip along the lower edge of heat spreading layer  128 . Two separate adhesive layers  132  may be formed between heat spreading layer  128  and the reflector layer ( 80 ). One of the adhesive layers  132  is attached to the upper-left corner of the heat spreading layer and one of the adhesive layers  132  is attached to the upper-right corner of the heat spreading layer. In other words, the heat spreading layer has first and second opposing edges connected by third and fourth opposing edges. A first strip of adhesive is formed along the first edge of the heat spreading layer and attaches the heat spreading layer to the flexible printed circuit board. A first patch of adhesive that attaches the heat spreading layer to the reflector layer is formed in the corner of the heat spreading layer where the second and third edges of the heat spreading layer meet. A second patch of adhesive that attaches the heat spreading layer to the reflector layer is formed in the corner of the heat spreading layer where the second and fourth edges of the heat spreading layer meet. 
     As previously shown in connection with  FIG. 6 , an adhesive layer  114  may attach an upper surface of light-emitting diodes  72  to an upper surface of light guide layer  78  and an adhesive layer  116  may attach a lower surface of light guide layer  78  to flexible printed circuit board  108 .  FIG. 9  is a top view showing how adhesive layers  114  and  116  may be patterned. The pattern of adhesive shown in  FIG. 9  may help optimize the mechanical and optical characteristics of the backlight. 
     As shown in  FIG. 9 , light-emitting diodes  72  may be mounted on flexible printed circuit  108 . Adhesive layer  114  may be formed over the upper surfaces of light-emitting diodes  72 . Each light-emitting diode may have two respective light-emitting portions. Adhesive layer may have protruding portions  144  that are interposed between each set of adjacent light-emitting portions in the light-emitting diodes. For example, a first set of protruding portions  144 - 1  are positioned in the middle of each light-emitting diode. A second set of protruding portions  144 - 2  are positioned between each adjacent pair of light-emitting diodes. Each protruding portion in the first set combines with a protruding portion in the second set to define an adhesive-free area that coincides with a light-emitting portion of one of the light-emitting diodes. The protruding portions of adhesive layer  114  may extend over and contact the upper surface of light guide layer  78 . 
     Adhesive layer  116  may include a number of patches of adhesive (sometimes referred to as islands of adhesive). Each adhesive patch  116  is coupled between the lower surface of light guide layer  78  and the flexible printed circuit board  108 . As shown in  FIG. 9 , each patch of adhesive  116  is also overlapped by a respective protruding portion  144  of adhesive layer  114 . In other words, for each adhesive patch  116 , a line parallel to the Z-axis can be drawn that runs through that adhesive patch and a respective protruding portion  144 . This example is merely illustrative, and other adhesive arrangements may be used if desired. 
     As discussed in connection with  FIG. 6 , light-emitting diodes  72  may be attached to flexible printed circuit board  108  using solder  112 .  FIG. 10  is a top view showing how the light-emitting diodes may be attached to the flexible printed circuit board. As shown in  FIG. 10 , a given light-emitting diode  72  may overlap three solder pads  110 . Each solder pad may have one or more notches to improve alignment of the light-emitting diode if desired. Each solder pad may have corresponding solder that is attached between the solder pad and the light-emitting diode. 
     In addition to using solder between the light-emitting diode and the contact pads, adhesive  146  may be used to attach light-emitting diodes to the flexible printed circuit board. Adhesive patches  146  (sometimes referred to as glue patches  146 ) may be interposed between each pair of adjacent solder pads. The adhesive patches may adhere the light-emitting diode directly to the flexible printed circuit board (e.g., without an intervening solder pad). The adhesive patches (e.g., underfill) may be added after the light-emitting diode is attached to the solder pads using solder. In this case, the adhesive patches  146  may improve the mechanical strength of the attachment between the light-emitting diode and the flexible printed circuit board. Alternatively, the adhesive patches may be deposited on the flexible printed circuit board before the light-emitting diode is placed on the flexible printed circuit board. In this case, the adhesive patches may improve alignment of the light-emitting diodes in addition to increasing the mechanical strength of the attachment. Adhesive patches  146  may be any desired type of adhesive (e.g., pressure sensitive adhesive, hot melt adhesive, etc.) and may be formed from any desired type of material (e.g., polymer). 
       FIG. 11  is a top view of an illustrative arrangement for light-emitting diodes  72  to allow the light-emitting diodes to emit light into light guide layer  78  having rounded corners. As shown in  FIG. 11 , there may be sixteen light-emitting diodes positioned in a row adjacent to the lower edge of light guide layer  78 . Each light-emitting diode may have two light-emitting areas. This example is merely illustrative. In general, backlight structures  42  may include any desired number of light-emitting diodes (e.g. more than eight, more than ten, more than fifteen, less than twenty, less than twelve, less than thirty, etc.) and each light-emitting diode may have any desired number of light-emitting areas (one, two, three, more than three, etc.). 
     Each light-emitting diode may have a width  150 . Width  150  may be any desired distance (e.g., between 3 and 4 millimeters, between 2 and 10 millimeters, greater than 1 millimeter, less than 10 millimeters, etc.). The centers of adjacent light-emitting diodes may be separated by pitch  148 . Pitch  148  may be any desired distance (e.g., between 3 and 4 millimeters, between 2 and 10 millimeters, greater than 1 millimeter, less than 10 millimeters, etc.). The light-emitting diode array may have a total overall length  152  (e.g., between 50 and 65 millimeters, between 40 and 100 millimeters, between 50 and 55 millimeters, less than 100 millimeters, greater than 30 millimeters, etc.). The light-emitting diodes may be positioned in an opening in chassis  102  (e.g., a portion of chassis  102  having overhang  122  shown in  FIG. 6 ) that has a width  154  (e.g., between 50 and 65 millimeters, between 40 and 100 millimeters, between 50 and 60 millimeters, less than 100 millimeters, greater than 30 millimeters, etc.). Chassis  102  may have a maximum width  156  (e.g., between 55 and 75 millimeters, between 40 and 100 millimeters, between 60 and 70 millimeters, less than 100 millimeters, greater than 30 millimeters, etc.). 
     The light-emitting diode arrangement of  FIG. 11  is merely illustrative. In an alternate embodiment, there may be fourteen light-emitting diodes that have two light-emitting areas and four light-emitting diodes that have single light-emitting areas. Two light-emitting diodes with single light-emitting areas may be positioned on both sides of the fourteen light-emitting diodes that have two light-emitting areas. 
       FIG. 12  is a top view of light-emitting diodes at the edge of the light-emitting diode array showing how light may be emitted to fill the corners of light guide layer  78 . As shown in  FIG. 12 , each light-emitting diode  72  may have two light-emitting areas (e.g., a first light-emitting area  158  and a second light-emitting area  160 ). To ensure that light reaches the rounded corners of light guide layer  78 , light from light-emitting area  158  may be emitted with an angle  162  relative to the Y-axis (e.g., the cone of light emitted by light-emitting area  158  has an outermost edge at angle  158  relative to the Y-axis). Angle  162  may be selected to ensure light reaches all portions of light guide layer  78 . Angle  162  may be 55°, between 50° and 60°, between 540 and 56°, between 40° and 70°, between 30° and 80°, less than 80°, less than 60°, less than 45°, greater than 30°, greater than 50°, greater than 65°, or any other desired angle. 
       FIGS. 5 and 6  showed ring tape  104  that has a lower surface attached to the upper surface of chassis  102  and the upper surface of optical film  70 - 1 . As previously mentioned, the upper surface of ring tape  104  may be attached to a layer of display layers  46  or another desired device component. Additionally, the ring tape may extend around the periphery of light guide layer  78  and have a central opening. If ring tape  104  extends entirely around the light guide layer, thus forming a seal around the entire light guide layer, the backlight structures and display structures may be susceptible to damage during a drop event (because air has nowhere to escape if compressed and instead deforms layers in the device). Accordingly, an opening may be formed in ring tape  104 , as shown in  FIG. 13 . 
       FIG. 13  is a cross-sectional side view of ring tape  104  that has a cut-out  164  through all of its layers. As shown, ring tape  104  is formed from a polymer film  168  that is interposed between an upper adhesive layer  166 - 1  (e.g., pressure sensitive adhesive or another desired type of adhesive) and a lower adhesive layer  166 - 2  (e.g., pressure sensitive adhesive or another desired type of adhesive). In  FIG. 13 , cut-out  164  passes through all of the layers of the ring tape. While preventing damage caused by a seal formed by the ring tape, the cut-out  164  in  FIG. 13  may cause visible artifacts during operation of the display. Alternate embodiments for cut-out  164  that provide an opening for air without causing visible artifacts are shown in  FIG. 14-16 . 
     In the cross-sectional side view of  FIG. 14 , ring tape  104  again has a polymer film  168  interposed between pressure sensitive adhesive layers  166 - 1  and  166 - 2 . However, the ring tape of  FIG. 14  has a cut-out  170  formed only in adhesive layer  166 - 2 . Polymer film  168  and adhesive layer  166 - 1  are left un-cut. This provides an air opening without causing visible artifacts. 
       FIG. 15  is a cross-sectional side view of an embodiment where first and second types of ring tape are used. Ring tape  104 - 1  having a polymer film  168  interposed between pressure sensitive adhesive layers  166 - 1  and  166 - 2  may be cut to form a cut-out  164 . In cut-out  164 , ring tape  104 - 2  that is different than ring tape  104 - 1  is formed. Ring tape  104 - 2  may, for example, have only a polymer film  174  and an adhesive layer  172 . An opening may be formed underneath polymer film  174 . Ring tape  104 - 1  and  104 - 2  may be formed from different materials if desired. 
       FIG. 16  is a cross-sectional side view of ring tape  104 - 1  that has a cut-out  164  through all of its layers. As shown, ring tape  104 - 1  is formed from a polymer film  168  that is interposed between an upper adhesive layer  166 - 1  and a lower adhesive layer  166 - 2 . In  FIG. 16 , cut-out  164  passes through all of the layers of ring tape  104 - 1 . A second piece of ring tape  104 - 2  is formed over cut-out  164  and bridges cut-out  164 . In  FIG. 16 , ring tape  104 - 2  is also formed from a polymer film  168  that is interposed between an upper adhesive layer  166 - 1  and a lower adhesive layer  166 - 2 . However, ring tape  104 - 1  and  104 - 2  may be formed from different materials if desired. 
     In the cross-sectional side view of  FIG. 17 , ring tape  104  again has a polymer film  168  interposed between pressure sensitive adhesive layers  166 - 1  and  166 - 2 . However, the ring tape of  FIG. 17  has a cut-out  170  formed only in adhesive layer  166 - 2 . Polymer film  168  and adhesive layer  166 - 1  are left un-cut. Cut-out  170  may extend only partially through adhesive layer  166 - 2  (as shown in  FIG. 17 ). In other words, a first portion of adhesive layer  166 - 2  is cut and a second portion of adhesive layer  166 - 2  is left un-cut. This example is merely illustrative and cut-out  170  may extend entirely through adhesive layer  166 - 2  (as shown in  FIG. 14 ) if desired. An additional layer  182  may be formed within cut-out  170  (e.g., on the exposed portions of adhesive layer  166 - 2 ). Additional layer  182  may be a non-adhesive layer. Layer  182  may be a polymer layer, as one example. Layer  182  may be formed from the same material as polymer film  168  or may be formed from a different material than polymer film  168 . 
     In  FIGS. 13-17 , the ring tape may be attached to a layer of backlight unit  42  on one side (e.g., chassis  102  in  FIG. 6 ). The layer of backlight unit  42  may be on either side of the ring tape in  FIGS. 13-17 . For example, in  FIG. 14  the layer of backlight unit  42  may be attached to upper adhesive layer  166 - 1  (e.g., to an upper surface of the ring tape) or to lower adhesive layer  166 - 2  (e.g., to a lower surface of the ring tape). For all of the embodiments of  FIGS. 13-17 , the layer of backlight unit  42  may be attached to either the upper surface of the ring tape or the lower surface of the ring tape. 
     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: 20180823
Publication Date: 20190820
Grant Date: 20190820
Priority Date: 20180424
Inventors: WAN, KA KUEN
LEE, AGNES
SCHLAUPITZ, ALEX D.
HUM, DAVID S.
XU, MING
HURLEY, SHAWN P.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B6/0091", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/009", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0083", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0068", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/005", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0055", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0053", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10106", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0068", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0085", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0203", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10522", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0083", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/009", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0051", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0055", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10106", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0083", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/009", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0053", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0203", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0085", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10522", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0051", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0068", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 67620586