PATENT DOCUMENT

Publication Number: US-9348169-B2
Application Number: US-201414444765-A
Country: US
Kind Code: B2

Title: Border structures for displays

Abstract:
A display may have an active area surrounded by an inactive border area. The inactive border area may be provided with an opaque masking material. The display may be a liquid crystal display having a liquid crystal layer sandwiched between a color filter layer and a thin-film transistor layer. Upper and lower polarizers may be provided above and below the color filter and thin-film transistor layers. The upper polarizer may have a polarized central region that overlaps the active area of the display. The upper polarizer may also have an unpolarized portion in the inactive border area overlapping the opaque masking material. The opaque masking material may alternatively be formed on the underside of a clear polymer substrate that is attached to the display above the upper polarizer or may be incorporated within the layers that make up the upper polarizer.

Claims:
What is claimed is: 
     
       1. A display having an active area completely surrounded by an inactive border area, comprising:
 a plurality of layers; 
 an opaque masking material on one of the plurality of layers in the inactive border area; and 
 a polarizer on the plurality of layers, wherein the polarizer has a polarized portion in the active area and has an unpolarized portion in the inactive border area that overlaps the opaque masking material, wherein the unpolarized portion includes every portion of the polarizer that is in the inactive border area. 
 
     
     
       2. The display defined in  claim 1  wherein the plurality of layers comprises a color filter layer and wherein the opaque masking material comprises opaque masking material on the color filter layer. 
     
     
       3. The display defined in  claim 2  wherein the color filter layer has opposing upper and lower surfaces, the display further comprising:
 a thin-film transistor layer; and 
 a liquid crystal layer between the lower surface of the color filter layer and the thin-film transistor layer, wherein the opaque masking material is formed on the upper surface of the color filter layer. 
 
     
     
       4. The display defined in  claim 3  wherein the opaque masking material comprises white material. 
     
     
       5. The display defined in  claim 2  wherein the color filter layer has opposing upper and lower surfaces, the display further comprising:
 a thin-film transistor layer; and 
 a liquid crystal layer between the color filter layer and the thin-film transistor layer in the active area, wherein the opaque masking material is formed in the inactive border area between the lower surface of the color filter layer and the thin-film transistor layer. 
 
     
     
       6. The display defined in  claim 5  wherein the opaque masking material comprises white material. 
     
     
       7. A display having an active area surrounded at least partly by an inactive border area, comprising:
 a polarizer layer having an upper surface; 
 a clear substrate layer; 
 an opaque masking material on the clear substrate layer, wherein the opaque masking material comprises a plurality of white ink layers on a non-white opaque layer; and 
 adhesive that attaches the clear substrate layer to the polarizer layer so that the opaque masking layer is in the inactive border area. 
 
     
     
       8. The display defined in  claim 7  further comprising:
 a color filter layer; 
 a thin-film transistor layer; and 
 a liquid crystal layer between the color filter layer and the thin-film transistor layer, wherein the polarizer has a lower surface that is attached to the color filter layer and has an upper surface to which the clear substrate is attached with the adhesive. 
 
     
     
       9. The display defined in  claim 8  wherein the clear substrate layer comprises a transparent polymer layer. 
     
     
       10. The display defined in  claim 9  wherein the adhesive comprises liquid adhesive. 
     
     
       11. The display defined in  claim 7  wherein the non-white opaque layer comprises gray ink. 
     
     
       12. The display defined in  claim 7  wherein the non-white opaque layer comprises metal. 
     
     
       13. A display having an active area surrounded at least partly by an inactive border area, the display comprising:
 display layers including a color filter layer, a thin-film transistor layer, and a liquid crystal layer between the color filter layer and the thin-film transistor layer; 
 a polarizer on the display layers, wherein the polarizer comprises a polyvinyl alcohol layer and a tri-acetyl cellulose layer; and 
 an opaque masking material in the inactive border area, wherein the opaque masking material is between the polyvinyl alcohol layer and the tri-acetyl cellulose layer. 
 
     
     
       14. The display defined in  claim 13  wherein the opaque masking layer comprises a white material. 
     
     
       15. The display defined in  claim 14  wherein the white material comprises white ink.

Description:
This application claims the benefit of provisional patent application No. 61/897,730, filed Oct. 30, 2013, 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, computers, and televisions have displays. 
     The center of a display such as a liquid crystal display contains an array of display pixels. This portion of the display, which is sometimes referred to as the active area of the display, is used to display images to a user. Peripheral circuits and other portions of the display that do not display images form a border that surrounds the inactive area. This border is sometimes referred to as the inactive area of the display. 
     To ensure that a display has an appealing appearance, it is generally desirable to hide internal components such as signal traces and other structures in the inactive area from view by the user. Accordingly, displays are often provided with plastic bezel structures that overlap the internal components in the inactive region. Bezel structures can be bulky and unsightly, so some displays are provided with a black ink border. The black ink border can be printed on the underside of a protective cover glass layer within the inactive area. The black ink border is thinner than a plastic bezel and helps hide internal display components in the inactive area of the display from view by the user. 
     Use of a display cover layer can introduce undesirable thickness and weight into a display. Some displays therefore dispense of the display cover layer and instead ensure that other display layers such as a color filter layer are sufficiently thick to provide the display with desired structural integrity. Black ink in this type of display may be incorporated under an upper polarizer layer in the inactive area of the display. 
     This type of arrangement poses challenges due to the presence of the polarizer. The polarizer reduces light transmission by half, resulting in reduced light reflection from the ink in the inactive area. If care is not taken, the border to have an unsightly appearance. For example, a white ink border would have an unsightly gray appearance rather than a desired white appearance. 
     It would therefore be desirable to be able to provide electronic devices with improved display structures such as improved border masking structures. 
     SUMMARY 
     An electronic device may be provided with a display. The display may have an active area surrounded by an inactive border area. The inactive border area may be provided with an opaque masking material such as white ink or other material to hide internal display components from view by a user of the electronic device. 
     The display may be a liquid crystal display having a liquid crystal layer sandwiched between a color filter layer and a thin-film transistor layer. Upper and lower polarizers may be provided above and below the color filter and thin-film transistor layers. The upper polarizer may have a polarized portion that overlaps the active area of the display. The upper polarizer may also have an unpolarized portion in the inactive border area overlapping the opaque masking material. 
     If desired, the opaque masking material may be formed on the underside of a clear polymer substrate that is attached to the display above the upper polarizer or may be incorporated within the layers that make up the upper polarizer instead of providing the polarizer with an unpolarized region. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a laptop computer with display structures in accordance with an embodiment. 
         FIG. 2  is a perspective view of an illustrative electronic device such as a handheld electronic device with display structures in accordance with an embodiment. 
         FIG. 3  is a perspective view of an illustrative electronic device such as a tablet computer with display structures in accordance with an embodiment. 
         FIG. 4  is a perspective view of an illustrative electronic device such as a display for a computer or television with display structures in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of a liquid crystal display in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of a polarizer in accordance with an embodiment. 
         FIG. 7  is a top view of a display having a polarizer with a circular unpolarized region in accordance with an embodiment. 
         FIG. 8  is a top view of a display having a polarizer with a rectangular ring-shaped unpolarized region that runs along the rectangular periphery of the display and that serves as part of the border of the display in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of an illustrative display showing how an opaque masking layer may be provided between display layers such as a color filter layer and thin-film transistor layer in a liquid crystal display and may be overlapped by an unpolarized border region in a polarizer layer in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of an illustrative display showing how an opaque masking layer in an inactive border region may be provided on top of display layers such as a color filter layer and thin-film transistor layer in a liquid crystal display and may be overlapped by an unpolarized border region in a polarizer layer in accordance with an embodiment. 
         FIG. 11  is a cross-sectional side view of an illustrative display showing how an opaque masking layer may be provided on the underside of a clear substrate layer that is incorporated into a liquid crystal display on top of a polarizer and other display layers in accordance with an embodiment. 
         FIG. 12  is a cross-sectional side view of an illustrative display showing how an opaque masking layer may be provided on a layer within a polarizer in a liquid crystal display in accordance with an embodiment. 
         FIG. 13  is a cross-sectional side view of an illustrative display showing how an opaque masking layer may be provided on the underside of a clear substrate layer that is incorporated into a liquid crystal display on top of a polarizer with single sided support in accordance with an embodiment. 
         FIGS. 14 and 15  are cross-sectional side views of illustrative opaque masking layers that may be provided in inactive areas of a display in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device may be provided with a display. The display may have an active area and an inactive area. The active area may have a rectangular array of display pixels that produce images for viewing by a user. The inactive area may have the shape of a rectangular ring that surrounds the active area and that serves as a border for the display. An opaque masking structure may be used to provide the border with a desired appearance. The opaque masking structure may include a layer of material such as plastic with light scattering bubbles, dye, pigment, ink, paint, metal, or other materials that are sufficiently opaque to prevent a user from viewing internal display structures in the inactive area. The opaque masking structure may include dye, pigment, or other structures that impart a desired color or other visible characteristics to the border when viewed from the exterior of the display. 
     The inactive area of the display may, as an example, be provided with opaque masking structures that are formed from white ink (i.e., a liquid polymer containing light scattering particles such as titanium oxide particles or other material that cause the polymer to have a white appearance) Inks of other colors and other opaque masking materials may also be used if desired (e.g., black ink, gray ink, silver ink, gold ink, red ink, blue ink, green ink, ink of different colors, polymers with light scattering features such as bubbles, metal, etc.). The use of white opaque masking structures such as white ink in forming opaque masking structures for the inactive area of a display is sometimes described herein as an example. 
     Illustrative electronic devices that have housings that accommodate displays are shown in  FIGS. 1, 2, 3, and 4 . 
     Electronic device  10  of  FIG. 1  has the shape of a laptop computer and has upper housing  12 A and lower housing  12 B with components such as keyboard  16  and touchpad  18 . Device  10  has hinge structures  20  (sometimes referred to as a clutch barrel) to allow upper housing  12 A to rotate in directions  22  about rotational axis  24  relative to lower housing  12 B. Display  14  is mounted in housing  12 A. Upper housing  12 A, which may sometimes referred to as a display housing or lid, is placed in a closed position by rotating upper housing  12 A towards lower housing  12 B about rotational axis  24 . 
       FIG. 2  shows an illustrative configuration for electronic device  10  based on 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  has opposing front and rear surfaces. Display  14  is mounted on a front face of housing  12 . Display  14  may have an exterior layer that includes openings for components such as button  26  and speaker port  28 . 
     In the example of  FIG. 3 , electronic device  10  is a tablet computer. In electronic device  10  of  FIG. 3 , housing  12  has opposing planar front and rear surfaces. Display  14  is mounted on the front surface of housing  12 . As shown in  FIG. 3 , display  14  has an external layer with an opening to accommodate button  26 . 
       FIG. 4  shows an illustrative configuration for electronic device  10  in which device  10  is a computer display, a computer that has an integrated computer display, or a television. Display  14  is mounted on a front face of housing  12 . With this type of arrangement, housing  12  for device  10  may be mounted on a wall or may have an optional structure such as support stand  30  to support device  10  on a flat surface such as a table top or desk. 
     Display  14  may be a liquid crystal display or a display formed using other display technologies (e.g., a plasma display, an organic light-emitting diode display, an electrophoretic display, an electrowetting display, a hybrid display that incorporates multiple display types into a single display structure, etc.). Liquid crystal display structures for forming display  14  are sometimes described herein as an example. 
     A cross-sectional side view of an illustrative configuration that may be used 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 display pixel structures in display layers  46 . This illuminates any images that are being produced by the display 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 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 by forming transistor circuits on a glass layer and to form a color filter layer may patterning color filter elements on a glass 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 thin-film transistors and associated electrodes (display 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, the positions of color filter layer  56  and thin-film-transistor layer  58  may be inverted so that the thin-film-transistor layer is located above the color filter layer. 
     During operation of display  14  in device  10 , control circuitry (e.g., one or more integrated circuits such as components  68  on printed circuit  66  of  FIG. 5 ) may be used to generate information to be displayed on display  14  (e.g., display data). The information to be displayed may be conveyed from circuitry  68  to display driver integrated circuit  62  using a signal path such as a signal path formed from conductive metal traces in flexible printed circuit  64  (as an example). 
     Display driver integrated circuit  62  may be mounted on thin-film-transistor layer driver ledge  82  or elsewhere in device  10 . A flexible printed circuit cable such as flexible printed circuit  64  may be used in routing signals between printed circuit  66  and thin-film-transistor layer  60 . If desired, display driver integrated circuit  62  may be mounted on printed circuit  66  or flexible printed circuit  64 . Printed circuit  66  may be formed from a rigid printed circuit board (e.g., a layer of fiberglass-filled epoxy) or a flexible printed circuit (e.g., a flexible sheet of polyimide or other flexible polymer layer). 
     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  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 upwards 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) 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 have a matching rectangular footprint. If desired, optical films may be incorporated into other layers of display  14 . For example, compensation films may be incorporated into polarizer  54  (as an example). 
     Polarizers such as upper (outer) polarizer  54  and lower (inner) polarizer  60  may be formed from multiple layers of material that are laminated together. An illustrative laminated polarizer is shown in the cross-sectional side view of  FIG. 6 . As shown in  FIG. 6 , polarizer  54  (i.e., an upper polarizer in this example) may have polarizer film (layer)  92 . Film  92  may be formed from a stretched polymer such as stretched polyvinyl alcohol (PVA) and may therefore sometimes be referred to as a PVA layer. Iodine may be placed on to the stretched PVA film so that iodine molecules align with the stretched film and form the polarizer. Other polarizer films may be used if desired. Polarizer film  92  may be sandwiched between layers  90  and  94 . Layers  90  and  94  may be formed from clear polymers. For example, layer  90  may be formed from a material such as tri-acetyl cellulose (TAC) and may sometimes be referred to as a TAC film. The TAC film or other supporting substrate may help support and protect the PVA film. Other films may be laminated to film  92  if desired. For example, lower film(s)  94  may be formed from one or more compensation films  94 A and  94 B (i.e., birefringent films that help enhance off-axis viewing performance for display  14 ). Adhesive layers may be used to hold laminated films together. 
     The presence of polarizer material over the entire surface of display  14  may create challenges in forming desired border regions and in mounting components behind display  14 . For example, it may be desirable to mount components such as a camera, ambient light sensor, light-based proximity sensor, or other light-based components under a portion of the upper polarizer in display  14 . This allows the components to be hidden from view while receiving light through the surface of display  14 . In the presence of polarizer material, light transmittance is cut in half. The reduced amount of light that would reach a camera, light sensor, or other light-based component in this type of arrangement would tend to decrease component performance (e.g., low-light camera and sensor performance would be degraded). This challenge can be addressed by forming an unpolarized area in polarizer  54  such as illustrative circular unpolarized area  96  of  FIG. 7 . The unpolarized area may be used in forming a light window such as a camera window or light sensor window in display  14  that is not subject to transmission losses due to polarizer material. 
     The presence of polarizer material around the edge of display  14  may affect the appearance of the border of display  14 , because reduced light transmittance can affect the appearance of underlying opaque masking material. As an example, when an opaque masking material such as white ink is used to form the border for display  14 , the presence of overlapping polarizer material may case the white ink to have an undesirable gray appearance. To ensure that the border of display  14  has a desired appearance, polarizer  54  can be provided with a central rectangular polarized portion  98  surrounded by an unpolarized border such as border  96  that overlaps the opaque masking material, as shown in  FIG. 8 . Other unpolarized areas may be provided within polarizer  54  if desired. The examples in which polarizer  54  has been provided with a circular unpolarized region (unpolarized region  96  of  FIG. 7 ) and rectangular ring-shaped unpolarized region (unpolarized region  96  of  FIG. 8 ) are merely illustrative. 
     With one suitable technique, polarizer  54  may be laser-bleached to change the chemical properties of the polarizer (i.e., to disrupt the iodine on the PVA layer) and thereby create an unpolarized layer. Chemical treatment of polarizer  54  (e.g., with a strong base such as KOH) or other techniques may also be used to form patterned unpolarized regions within polarizer  54 . 
     In a typical display configuration, display  14  may be provided with a rectangular array of display pixels that provide images for a user (see, e.g., display pixels  100  in  FIG. 8 ). This rectangular portion of display  14  is sometimes referred to as the active area AA of display  14 . An inactive border region, sometimes referred to as inactive area IA, may run along some or all of the peripheral edges of the active area AA. For example, display  14  may have an inactive area IA that has the shape of a rectangular ring and that forms a border running along all four sides of a central rectangular active area AA, as shown by inactive border area IA in  FIG. 8 . 
     To hide signal traces and other internal device structures from view by a user, inactive area IA may be provided with an opaque masking layer such as a layer of white ink or other opaque material. Particularly in scenarios in which the opaque masking material has a color that would be degraded by the presence of overlapping polarizer, it may be desirable to form unpolarized regions such as unpolarized border  96  in inactive area IA of  FIG. 8  or to otherwise provide display  14  with a configuration that avoids placement of polarizer material on top of the opaque masking material. 
     Consider, as an example, the configuration of  FIG. 9 . In this type of arrangement, polarizer  54  has been provided with a polarized region  98  that overlaps active area AA of display  14  and an unpolarized border region  96  that lies within the inactive area IA along the border of display  14  (e.g., a rectangular border of the type shown in  FIG. 8 ). Opaque masking material  104  may be located at an internal position within the layers of display  14 . As an example, layer  104  may be formed on the underside of layer  56  or on the upper surface of layer  58  in inactive area IA. (Liquid crystal material  52  may be located between layers  56  and  58  in active area AA.) Adhesive  102  may be used to attach polarizer  54  to layer  56 . Opaque masking material  104  may be a layer of white ink or other white opaque masking material (as an example). Because the portion of polarizer  54  that overlaps opaque masking material  104  in inactive area IA is unpolarized, the transmittance of polarizer  54  in inactive area IA is high. The appearance of opaque masking material  104  to a user of display  14  will therefore be satisfactory (e.g., white border material will appear as an attractive shade of white rather than gray). 
       FIG. 10  is a cross-sectional side view of a portion of display  14  in an illustrative configuration in which opaque masking material  104  (e.g., a layer of white ink or other white opaque masking material) has been formed on the upper surface of layer  56 . Adhesive  102  may be a liquid adhesive such as optically clear adhesive or a pressure sensitive adhesive that is able to accommodate surface-height variations. This may help avoid creating undesirable surface features on polarizer  54  due to the thickness of underlying opaque masking material  104 . As with the illustrative arrangement of  FIG. 9 , unpolarized portion  96  of polarizer  54  in display  14  of  FIG. 10  may be laterally aligned with opaque masking material  104  to enhance the visibility of opaque masking material  104 . 
     If desired, a clear polymer layer or other substrate material may be used as a carrier for opaque masking material  104 . As shown in  FIG. 11 , for example, transparent substrate material  106  may be attached to display  14  above upper polarizer  54 . Transparent substrate material  106  may be, for example, a sheet of a flexible polymer such as triacetate cellulose, acrylic, polyethyleneterephthalate (PET), etc. Opaque masking material  104  (e.g., white ink or other white opaque masking material) may be formed in inactive area IA. Opaque masking material  104  may be located on the lower surface of substrate  106 . Liquid adhesive such as optically clear adhesive  102  or other adhesive may be used to attach substrate  106  to the upper surface of upper polarizer  54 . The opposing lower surface of upper polarizer  54  may be attached to layer  56 . The use of adhesive  102  to attach substrate  106  may help avoid creating undesirable surface features on the exposed surface of substrate  106  due to the thickness of underlying opaque masking material  104 . Unlike polarized material, portion  106 ′ of transparent substrate layer  106  has a high (near 100%) transmittance, so that opaque masking material  104  may have a desired appearance (e.g., a white appearance rather than a gray appearance in situations in which material  104  is formed form a white ink or other white opaque masking material). 
     If desired, the outermost layer of display  14  (e.g., layer  106  in the example of  FIG. 11 ) may be provided with materials and/or sublayers that integrate desired functionality into the outermost layer. As an example, layer  106  may be provided with coatings and/or integral materials so that layer  106  exhibits antireflection properties, antiglare properties, anti-smudge properties, scratch resistance, etc. 
     As indicated by illustrative opaque masking material  104 ′, the opaque masking material (e.g., white ink or other white opaque masking material) may, if desired, be formed on the upper surface of polarizer  54 , rather than on the underside of substrate  106 . 
       FIG. 12  shows how opaque masking material  104  may be incorporated into display  14  as one of the internal layers of polarizer  54 . In the illustrative configuration of  FIG. 12 , opaque masking material  104  has been formed on the underside of polarizer layer  90  (e.g., a TAC layer or other clear polymer layer). Adhesive  102  (e.g., pressure sensitive adhesive, liquid adhesive, etc.) may be used in attaching layer  90  to polarizer layer  92  (e.g., a polyvinyl alcohol layer). Compensation layer(s)  94  or other clear polymer layer(s) may be attached to the underside of layer  92 . Polarizer  54  may be attached to display layers  56  and  58  and lower polarizer  60  to form display  14 . If desired, opaque masking layer  104  may be formed on the upper surface of layer  92 , as indicated by illustrative opaque masking layer  104 ′. The opaque masking layer may also be formed on other sublayers in polarizer  54  (e.g., layer  104  may be formed on other surfaces of layer  92  and/or layers  94  under an unpolarized portion of polarizer  54 ). 
       FIG. 13  shows how polarizer  54  may be implemented using a single-sided support structure (i.e., using only a single support layer such as support layer  94  to support polyvinyl alcohol layer  92 ). This type of polarizer  54  may be used in displays of the type shown in  FIGS. 9, 10, 11, and 12 , if desired. 
       FIGS. 14 and 15  are cross-sectional side views of illustrative opaque masking layers that may be provided in inactive areas of display  14 . 
     In the illustrative configuration of  FIG. 14 , opaque masking material  104  has been formed from multiple white layers W (e.g., two or more white layers, three or more white layers, or four or more white layers) on top of a non-white layer such as gray layer G. Inks or other opaque masking materials may be used in forming the layers of  FIG. 14 . 
     In the illustrative configuration of  FIG. 15 , opaque masking material  102  has been formed from multiple white layers W (e.g., two or more white layers, three or more white layers, or four or more white layers) on top of a non-white layer such as metal layer S. Inks or other opaque masking materials may be used in forming the white layers of  FIG. 14 . A metal such as silver or aluminum or other metals may be used in forming metal layer S. 
     Layer  102  may have a thickness in the range of 2 to 60 microns, a thickness in the range of 4 to 20 microns, a thickness of 5 to 30 microns, or other suitable thickness. As an example, a four layer structure of the type shown in  FIG. 14  may have a thickness of about 20-25 microns, whereas a three layer structure of the type shown in  FIG. 15  may have a thickness of about 6-10 microns (as examples). The use of thinner layers helps to avoid visible bumps on display  14  at the interface between active area AA and inactive area IA. Conformal layers such as liquid adhesive layers, pressure sensitive adhesive layers, and layers of other material that can flow to accommodate the locally enhanced thickness from layer  102  may be incorporated into display  14  to help reduce visible thickness discontinuities. 
     Ink, metal, and other opaque masking materials may be deposited and patterned using roll-to-roll screen printing techniques, gravure printing using a patterned drum feed by an inked roller, or photolithographic techniques such as lift-off masking techniques may be used in patterning opaque masking material  102 . 
     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: 20140728
Publication Date: 20160524
Grant Date: 20160524
Priority Date: 20131030
Inventors: CHEN CHENG
POSNER BRYAN W.
MATHEW DINESH C.
QI JUN
YIN VICTOR H.
CHANG SHIH CHANG
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F2001/133388", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133388", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133388", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 52995028