PATENT DOCUMENT

Publication Number: US-10302844-B2
Application Number: US-201514918405-A
Country: US
Kind Code: B2

Title: Display with backlight recycling structures

Abstract:
A display may have an array of pixels. The pixels may have color filter elements such as red, green, and blue color filter elements. A layer of opaque material may be used to form a black matrix. The black matrix may have openings that receive the color filter elements. A backlight unit may produce backlight illumination for the display. A reflector layer may be interposed between the black matrix and the backlight unit. The reflector layer may have openings aligned with the openings in the black matrix and the color filter elements and may overlap the black matrix. Some of the backlight from the backlight unit may pass through the color filter elements. Other backlight may by be recycled by being reflected off of the reflector layer, thereby enhancing backlight efficiency.

Claims:
What is claimed is: 
     
       1. A display, comprising:
 backlight structures that emit backlight; 
 liquid crystal display layers that form pixels through which the backlight passes, wherein the liquid crystal display layers include a thin-film transistor layer having gate lines and data lines, a color filter layer having a plurality of color filter elements for the pixels, and a liquid crystal layer interposed between the thin-film transistor layer and the color filter layer; and 
 a reflector layer with openings aligned with the pixels, wherein the reflector layer is interposed between the backlight structure and at least some of the liquid crystal display layers, wherein the reflector layer reflects some of the backlight towards the backlight structures, wherein the reflector layer includes the gate lines and the data lines, wherein the gate lines and the data lines occupy more than 80% of an area of the display that is not occupied by the plurality of color filter elements, wherein a data line of the data lines has locally widened portions and at least partially surrounds a color filter element of the plurality of color filter elements on at least three sides, wherein the data line has a first portion that extends between first and second adjacent color filter elements, wherein the first portion has a first length along a first axis and a first width along a second axis that is perpendicular to the first axis, wherein the first width is smaller than the first length, wherein the data line has a second portion that has a second width along a third axis that is parallel to the second axis, wherein the second width is longer than the first width, and wherein the second width is longer than a width of the first color filter element. 
 
     
     
       2. The display defined in  claim 1 , wherein the gate lines and the data lines occupy more than 90% of the area of the display that is not occupied by the plurality of color filter elements. 
     
     
       3. The display defined in  claim 1 , wherein the gate lines and the data lines occupy more than 95% of the area of the display that is not occupied by the plurality of color filter elements. 
     
     
       4. A display having pixels, comprising:
 a color filter layer having a color filter layer substrate on which a plurality of color filter elements are formed for the pixels; 
 a layer of thin-film transistor circuitry that includes a plurality of data lines; 
 a backlight unit that emits backlight; and 
 a reflector layer having openings aligned with the color filter elements, so that wherein some of the backlight passes through the color filter elements and so that some of the backlight is reflected from the reflector layer towards the backlight unit, wherein the reflector layer includes the plurality of data lines, wherein a data line of the plurality of data lines has locally widened portions and at least partially surrounds a color filter element of the plurality of color filter elements on at least three sides, wherein the color filter element has a first length and a first width, wherein the data line has a second length that is greater than the first length, and wherein one of the locally widened portions of the data line has a second width that is greater than the first width. 
 
     
     
       5. The display defined in  claim 4 , wherein the reflector layer occupies more than 80% of an area of the display that is not occupied by the plurality of color filter elements.

Description:
This application claims the benefit of provisional patent application No. 62/092,680 filed on Dec. 16, 2014, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices, and more particularly, to electronic devices with displays. 
     Electronic devices often include displays. For example, cellular telephones and portable computers often include displays for presenting information to a user. 
     Liquid crystal displays contain a layer of liquid crystal material. Pixels in a liquid crystal display contain thin-film transistors and electrodes for applying electric fields to the liquid crystal material. A liquid crystal display includes substrate layers such as color filter layers and thin-film transistor layers. The liquid crystal layer of a liquid crystal layer is sandwiched between the substrate layers. Upper and lower polarizers are formed above and below the substrate layers. The strength of the electric field in each pixel controls the polarization state of the liquid crystal material associated with the pixel and thereby adjusts the brightness of the pixel. 
     The color filter layer in a liquid crystal display contains an array of color filter elements such as red, blue, and green elements and is used to provide the display with the ability to display color images. The thin-film transistor layer contains thin-film transistor circuitry that forms thin-film transistors and electrodes for the pixels. 
     A display may have a backlight unit that provides backlight illumination for the pixels. Backlight from the backlight unit travels outwardly through the layers of the display. White backlight that has been modulated in intensity using the liquid crystal layer, thin-film transistor circuitry, polarizers, and other display layers is converted to colored light as the white light passes through the color filter elements. 
     The color filter elements are typically formed within openings in a black matrix. The black matrix is a grid of opaque material that blocks stray light between adjacent pixels and hides underlying signal lines from view. The black matrix can help reduce color mixing between adjacent pixels and can reduce signal line visibility, but also absorbs a fraction of the backlight in the display, thereby reducing backlight efficiency. Low backlight efficiency can lead to excessive power consumption and reduced battery life in battery-powered devices. 
     It would therefore be desirable to be able to provide a display with improved backlight efficiency. 
     SUMMARY 
     A display may have an array of pixels. The pixels may be formed from liquid crystal display structures such as a color filter layer, liquid crystal layer, thin-film transistor layer, and polarizer layers. 
     The color filter layer may have color filter elements such as red, green, and blue color filter elements that are associated with respective pixels. A layer of opaque material may be used to form a black matrix. The black matrix may have openings that receive the color filter elements. 
     A backlight unit may produce backlight for the display. The backlight may pass outwards through the liquid crystal display structures. 
     A reflector layer may be interposed between the black matrix and the backlight unit. The reflector layer may have openings aligned with the openings in the black matrix and the color filter elements and may overlap the black matrix. Some of the backlight from the backlight unit may pass through the color filter elements. Other backlight may by be recycled by being reflected off of the reflector layer towards the backlight unit, thereby enhancing backlight efficiency. 
    
    
     
       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 perspective view of an illustrative electronic device such as a handheld electronic device with a display in accordance with an embodiment. 
         FIG. 3  is a perspective view of an illustrative electronic device such as a tablet computer with a display in accordance with an embodiment. 
         FIG. 4  is a perspective view of an illustrative electronic device such as a computer display with display structures in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative display in accordance with an embodiment. 
         FIG. 6  is a top view of a portion of an illustrative display in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative display with reflector structures on a lower substrate layer such as a thin-film transistor substrate layer to enhance backlight efficiency in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative display with reflective metal structures formed within a layer of thin-film transistor circuitry to enhance backlight efficiency in accordance with an embodiment. 
         FIG. 9  is a bottom view of an illustrative display of the type shown in  FIG. 8  in which metal lines within thin-film transistor circuitry such as data lines and gate lines have been patterned to form a reflector structure in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of an illustrative display in which a reflector layer has been deposited on the surface of a color filter layer and provided with openings to receive color filter elements in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may include displays. The displays may be used to display images to a user. Illustrative electronic devices that may be provided with displays are shown in  FIGS. 1, 2, 3, and 4 . 
       FIG. 1  shows how electronic device  10  may have the shape of a laptop computer having upper housing  12 A and lower housing  12 B with components such as keyboard  16  and touchpad  18 . Device  10  may have hinge structures  20  that allow upper housing  12 A to rotate in directions  22  about rotational axis  24  relative to lower housing  12 B. Display  14  may be mounted in upper housing  12 A. Upper housing  12 A, which may sometimes referred to as a display housing or lid, may be placed in a closed position by rotating upper housing  12 A towards lower housing  12 B about rotational axis  24 . 
       FIG. 2  shows how electronic device  10  may be a handheld device such as a cellular telephone, music player, gaming device, navigation unit, or other compact device. In this type of configuration for device  10 , housing  12  may have opposing front and rear surfaces. Display  14  may be mounted on a front face of housing  12 . Display  14  may, if desired, have openings for components such as button  26 . Openings may also be formed in display  14  to accommodate a speaker port (see, e.g., speaker port  28  of  FIG. 2 ). 
       FIG. 3  shows how electronic device  10  may be a tablet computer. In electronic device  10  of  FIG. 3 , housing  12  may have opposing planar front and rear surfaces. Display  14  may be mounted on the front surface of housing  12 . As shown in  FIG. 3 , display  14  may have an opening to accommodate button  26  (as an example). 
       FIG. 4  shows how electronic device  10  may be a computer display or a computer that has been integrated into a computer display. With this type of arrangement, housing  12  for device  10  may be mounted on a support structure such as stand  27  or stand  27  may be omitted (e.g., to mount device  10  on a wall). Display  14  may be mounted on a front face of housing  12 . 
     The illustrative configurations for device  10  that are shown in  FIGS. 1, 2, 3, and 4  are merely illustrative. 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 wrist-watch device, a pendant device, a headphone or earpiece device, or other wearable or miniature device, 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 frame elements 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  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  (e.g., for display  14  of the devices of  FIG. 1 ,  FIG. 2 ,  FIG. 3 ,  FIG. 4  or other suitable electronic devices) is shown in  FIG. 5 . As shown in  FIG. 5 , display  14  may include backlight structures such as backlight unit  42  for producing backlight  44 . During operation, backlight  44  travels outwards (vertically upwards in dimension Z in the orientation of  FIG. 5 ) 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 housing  12  or display layers  46  may be mounted directly in housing  12  (e.g., by stacking display layers  46  into a recessed portion in housing  12 ). 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). 
     Backlight structures  42  may include a light guide plate such as light guide plate  78 . Light guide plate  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. 
     Light  74  from light source  72  may be coupled into edge surface  76  of light guide plate  78  and may be distributed in dimensions X and Y throughout light guide plate  78  due to the principal of total internal reflection. Light guide plate  78  may include light-scattering features such as pits or bumps. The light-scattering features may be located on an upper surface and/or on an opposing lower surface of light guide plate  78 . Light source  72  may be located at the left of light guide plate  78  as shown in  FIG. 5  or may be located along the right edge of plate  78  and/or other edges of plate  78 . 
     Light  74  that scatters upwards in direction Z from light guide plate  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 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, compensation films for enhancing off-axis viewing, and brightness enhancement films (also sometimes referred to as turning films or prism films) for collimating backlight  44 . Optical films  70  may overlap the other structures in backlight unit  42  such as light guide plate  78  and reflector  80 . For example, if light guide plate  78  has a rectangular footprint in the X-Y plane of  FIG. 5 , optical films  70  and reflector  80  may each have a matching rectangular footprint. If desired, compensation films and other optical films may be formed within the polarizer layers of display  14  or may be incorporated elsewhere in display  14 . 
       FIG. 6  is a top view of a portion of display  14  showing how display  14  may have an array of pixels  90 . 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. Black matrix  92  may have a grid shape with openings to accommodate the red, green, and blue color filter elements. The color filter elements may be rectangular (as shown in  FIG. 6 ), may have chevron shapes, or may have other shapes. Black matrix  92  may be formed from black polymer or other opaque masking material. 
     The presence of black matrix  92  helps prevent stray backlight that is associated with a pixel of one color from passing through the color filter element of an adjacent pixel of another color and helps prevent metal signal lines in thin-film transistor layer  58  from being visible from the front of display  14 . Because black matrix  92  is opaque, the presence of black matrix  92  blocks a portion of backlight  44  and thereby reduces backlight efficiency. 
     To enhance backlight efficiency, reflective structures may be incorporated into display  14  that recycle the backlight that would otherwise be blocked by black matrix  92 . Consider, as an example, the cross-sectional side view of  FIG. 7 . As shown in  FIG. 7 , display  14  may have an upper polarizer layer such as upper polarizer  54  and a lower polarizer layer such as lower polarizer  60 . Layer  56  (e.g., a color filter layer or other upper substrate layer) may be interposed between polarizer  54  and liquid crystal layer  52 . Layer  58  (e.g., a thin-film transistor layer or other lower substrate layer) may be interposed between polarizer  60  and liquid crystal layer  52 . 
     Layer  56  may be a color filter layer having layers such as transparent substrate layer  56 - 2  and a layer of color filter elements such as color filter element layer  56 - 1 . Transparent substrate layer  56 - 2  may be a layer of clear glass, plastic, or other transparent material. Color filter element layer  56 - 1  may have an array of color filter elements such as red color filter elements R, green color filter elements G, and blue color filter elements B. Color filter element layer  56 - 1  may also include black matrix  92 . Black matrix  92  may have a grid shape or other shape with openings that receive the color filter elements (i.e., the red elements R, green elements G, and blue elements B) of pixels  90 . 
     Layer  58  may be a thin-film transistor layer having layers such as transparent substrate layer  58 - 1 , planarization layer  58 - 2 , and thin-film transistor circuitry layer  58 - 3 . Substrate layer  58 - 1  may be a layer of clear glass, plastic, or other transparent material. Thin-film transistor circuitry layer  58 - 3  may include thin-film transistors (e.g., transistors with polysilicon channel regions, semiconducting-oxide channel regions, or other thin-film semiconductor channel regions). As shown in  FIG. 7 , the circuitry of layer  58 - 3  may include pixel electrodes  94  associated with each pixel  90  for applying electric fields to the portion of liquid crystal layer  52  that is above electrodes  94 . Light that passes through these portions of display  14  may be modulated in intensity by controlling the strength of the applied electric field. 
     Reflector structures such as reflector layer  96  may be provided under black matrix  92 . Reflector layer  96  may have the same layout as black matrix  92  (or a similar layout). For example, if black matrix  92  has a grid shape with chevron-shaped openings to accommodate chevron-shaped color filter elements, reflector layer  96  may have the same grid shape and matching chevron-shaped openings  98 . With arrangements such as these, black matrix  92  and reflector layer  96  overlap each other and openings  98  in reflector layer  96  are aligned with the openings in black matrix  92 . 
     Reflector layer  96  may be formed from reflective materials such as a layer of reflective metal or a dielectric stack with alternating high-index-of-refraction and low-index-of-refraction layers. The layers in the dielectric stack may be organic layers such as polymer films and/or may be inorganic layers (e.g., silicon oxide, magnesium fluoride, silicon nitride, metal oxides such as aluminum oxide, etc.). Reflector layer  96  may be deposited through a shadow mask, may be patterned using photolithography, or may be formed using other suitable deposition and patterning techniques. The reflectivity of reflector layer  96  is preferably 80% or greater or is 90% or greater. 
     Reflector layer  96  reflects the portion of backlight  44  that would otherwise be absorbed by black matrix layer  92  back into backlight  42 , so that this backlight is not wasted. As shown in  FIG. 7 , for example, a ray of backlight  44  such as backlight ray  44 - 1  may be emitted upwards from backlight unit  42  in direction Z. In the absence of reflector layer  96 , backlight rays such as ray  44 - 1  that are emitted underneath black matrix  92  would strike black matrix  92  and be absorbed and/or scattered by black matrix  92 . These backlight rays would therefore be lost and not used in producing illumination for display  14 . In the presence of reflector layer  96 , however, rays such as backlight ray  44 - 1  are reflected off of the underside of reflector layer  96  in downwards direction −Z, as shown by illustrative reflected backlight ray  44 - 2 . Rays such as ray  44 - 2  that are directed back into light guide plate  42  are effectively recycled and are not lost by absorption in matrix  92 . As shown by light ray  44 - 3 , recycled light such as reflected backlight ray  44 - 2  may be reflected back upwards in direction Z by the structures of backlight unit  42  (e.g., reflector layer  80 ). In the example of  FIG. 7 , backlight ray  44 - 3  is not blocked by black matrix  92  or reflector layer  96  and therefore passes through opening  98  in reflector layer  96  and the red color filter layer R in color filter element layer  56 - 1  to viewer  48 . 
     As this example demonstrates, the presence of reflector layer  96  does not block the outgoing backlight rays that are aligned with the color filter elements (R, G, B) of pixels  90  and effectively recycles outgoing backlight rays that are aligned with black matrix  92 . Backlight that would otherwise be unused in providing illumination for display  14  is reflected back into backlight unit  42  and is subsequently emitted from backlight unit  42  in direction Z for use in providing illumination. This ability to recycle backlight that would otherwise be blocked by opaque masking layer structures surrounding the color filter elements such as black matrix  92  improves the backlight efficiency of display  14  and thereby reduces the power consumption associated with powering light source  72 . 
     In the illustrative configuration of  FIG. 7 , reflector layer  96  is formed on the upper surface of substrate layer  58 - 1 . Planarization layer  58 - 2  may be used to planarize layer  58 . Planarization layer  58 - 2  may smooth out any surface irregularities produced by reflector layer  96 , so that subsequent layers such as thin-film circuitry layer  58 - 3  can be formed for layer  58 . Planarization layer  58 - 2  may be a layer of spin-on-glass or other planarization layer that is compatible with elevated processing temperatures (e.g., the processing temperatures associated with forming thin-film transistor circuitry layer  58 - 1  on planarization layer  58 - 2 ). 
     If desired, reflector layer  96  may be formed within other layers in display  14 . As shown in  FIG. 8 , for example, reflector layer  96  may be formed as part of thin-film transistor circuitry layer  58 - 3  by forming metal structures or other reflective structures within layer  58 - 3  that lie in the area of display outside of pixels  90  and color filter elements R, G, and B. With an arrangement of the type shown in  FIG. 8 , color filter element layer  56 - 1  is formed on the lower (inner) surface of transparent substrate layer  56 - 2 . Color filter element layer  56 - 1  may include black matrix  92  and color filter elements such as red, green, and blue color filter elements (R, G, B). Reflector layer  96  may be formed from one or more metal layers in thin-film transistor circuitry layer  58 - 3 . Openings  98  in reflector layer  96  may be aligned with corresponding openings in black matrix  92  in which the color filter elements are formed (i.e., reflector layer  96  and black matrix  92  may overlap each other and may have matching shapes). 
     Liquid crystal layer  52  may be interposed between layer  56  and layer  58 . Layer  58  may have substrate layer  58 - 1  on which thin-film transistor circuitry layer  58 - 3  is formed. Layers  56  and  58  and liquid crystal layer  52  may be sandwiched between lower polarizer layer  60  and upper polarizer layer  54 . 
     Backlight structures such as backlight unit  42  may generate backlight for display  14  of  FIG. 8 . Backlight rays such a ray  44 - 1  that would be blocked by black matrix  92  in a display without reflective layer  96  may instead be reflected downwards by layer  96  in direction −Z towards backlight unit  42  (see, e.g., ray  44 - 2 ). Backlight unit  42  contains structures such as reflector  80  that reflect rays such a ray  44 - 2  back in upwards direction Z through opening  98  in reflector layer  96  and black matrix  92 , as illustrated by ray  44 - 3 . The use of reflector layer  96  therefore helps enhance backlight efficiency. 
     The reflective material that forms reflector layer  96  in a configuration of the type shown in  FIG. 8  may be formed from metal signal traces in thin-film transistor circuitry layer  58 - 3  that have been enlarged to serve as a reflector for recycling backlight  44 . In general, any suitable signal lines or other metal layers in circuitry  58 - 3  may be used as reflective structures. For example, reflector layer  96  of  FIG. 8  may be formed from a light shielding layer that is also used to prevent backlight from reaching thin-film transistor gates in layer  58 - 3 , a gate metal layer, a data line layer, a gate line layer, an extra metal layer (e.g., a third metal layer) that is used to cover a common voltage (Vcom) electrode formed from indium tin oxide, etc. Overlap between signal lines may, if desired, be minimized to avoid creating excessive parasitic capacitances. Metals such as aluminum, tungsten, molybdenum, titanium, and/or other metals may be used in forming reflector layer  96 . The reflective metal that forms reflector layer  96  of  FIG. 8  preferably occupies 80% or more, 90% or more, or 95% or more of the area of display that is not occupied by color filter elements R, G, and B to enhance reflectivity for backlight  44  (i.e., to ensure that the reflectivity of layer  96  is more than 80%, more than 90%, or is more than 95%, or other suitable value that enhances backlight recycling).  FIG. 9  is a bottom view of an illustrative display in which metal lines such as a data line D and gate lines G have been patterned to form a reflective structure in accordance with an embodiment (i.e., an arrangement in which data lines D have been enlarged to surround the color filter elements and thereby enhance reflectivity). Other metal layers may be used in forming reflector layer  96  within thin-film circuitry layer  58 - 3  if desired. 
     As shown in the cross-sectional side view of display  14  of  FIG. 10 , the thin-film transistor layer in display  14  may be located on top of the color filter layer (i.e., the thin-film transistor layer may be interposed between the color filter layer and viewer  48 ). As shown  FIG. 10 , color filter layer substrate CF is interposed between liquid crystal layer  52  and backlight unit  42 . Light  44  may pass through the color filter layer before passing through liquid crystal layer  52  and thin-film transistor layer TFT to reach viewer  48 . In this type of arrangement, reflector layer  96  may be formed directly on the outermost surface of the glass or other material of color filter substrate CF. Reflector layer  96  may have openings  98  that receive respective color filter elements R, G, and B. Polarizer layers may be formed on the top and bottom of layers  46 . 
     If desired, additional layers of material may be incorporated into display  14 . For example, display  14  may include one or more planarization layers, buffer layers, antireflection layers, antiscratch layers, antismudge layers, and other functional layers. Moreover, reflector layer  96  may be formed in other locations of display  14 . Reflector layer  96  may, as an example, be formed under black matrix, on other substrate surfaces, on a separate reflector layer substrate, on a substrate layer or other layer that forms part of a display in which color filter elements and thin-film transistor circuitry are supported on the same substrate, or any other suitable location. The configurations of  FIGS. 7, 8, 9, and 10  are merely illustrative. 
     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: 20151020
Publication Date: 20190528
Grant Date: 20190528
Priority Date: 20141216
Inventors: XU, MING
CHEN, CHENG
OSAWA, HIROSHI
CHEN, YU CHENG
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/136209", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0055", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/136286", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133553", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2001/133565", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133615", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133553", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/136286", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133615", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133553", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133565", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/136209", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/136209", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133565", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0055", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133615", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 56110992