PATENT DOCUMENT

Publication Number: US-8467177-B2
Application Number: US-91647410-A
Country: US
Kind Code: B2

Title: Displays with polarizer windows and opaque masking layers for electronic devices

Abstract:
An electronic device may have a display. Inactive portions of the display such as peripheral portions of the display may be masked using an opaque masking layer. An opening may be provided in the opaque masking layer to allow light to pass. For example, a logo may be viewed through an opening in the opaque masking layer and a camera may receive light through an opening in the opaque masking layer. The display may include upper and lower polarizers, a color filter layer, and a thin-film transistor layer. The opaque masking layer may be formed on the upper polarizer, may be interposed between the upper polarizer and the color filter layer, or may be interposed between the color filter layer and the thin-film transistor layer. The upper polarizer may have unpolarized windows for cameras, logos, or other internal structures.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a display having an active region and an inactive region; 
 a polarizer in the display, wherein the polarizer overlaps the active region and the inactive region; and 
 an unpolarized window in the polarizer within the inactive region, wherein the unpolarized window contains material from the polarizer. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the polarizer comprises a layer of polarizing material and wherein the unpolarized window comprises a bleached portion of the layer of polarizing material. 
     
     
       3. The electronic device defined in  claim 1  wherein the polarizer comprises a layer of polarizing material and wherein the unpolarized window comprises an ultraviolet-light-bleached portion of the layer of polarizing material. 
     
     
       4. The electronic device defined in  claim 3  wherein the polarizer comprises iodine and wherein the layer of polarizing material comprises a layer of polyvinyl alcohol. 
     
     
       5. The electronic device defined in  claim 1  wherein the polarizer comprises a layer of polarizing material and wherein the unpolarized window comprises a chemically bleached portion of the layer of polarizing material. 
     
     
       6. The electronic device defined in  claim 5  wherein the polarizer comprises iodine and wherein the layer of polarizing material comprises a layer of polyvinyl alcohol. 
     
     
       7. The electronic device defined in  claim 1  further comprising an electronic component mounted in alignment with the unpolarized window. 
     
     
       8. The electronic device defined in  claim 1  further comprising a camera that receives light through the unpolarized window. 
     
     
       9. The electronic device defined in  claim 8  further comprising a logo that receives light through the unpolarized window. 
     
     
       10. The electronic device defined in  claim 9  wherein the display comprises a color filter layer and wherein the logo comprises material on the color filter layer. 
     
     
       11. The electronic device defined in  claim 10  further comprising an opaque masking layer that covers the logo. 
     
     
       12. The electronic device defined in  claim 11  further comprising a thin-film transistor layer in the display, wherein the opaque masking layer and the logo are interposed between the color filter layer and the thin-film transistor layer. 
     
     
       13. Apparatus, comprising:
 a color filter layer; 
 a thin-film transistor layer; 
 an opaque ink layer that is interposed between the color filter layer and the thin-film transistor layer; and 
 first and second polarizers, wherein the first polarizer comprises an unpolarized window and wherein the opaque ink layer has an opening that is aligned with the unpolarized window. 
 
     
     
       14. The apparatus defined in  claim 13 
 wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer, wherein the color filter layer has an outer surface and an inner surface and wherein at least some of the ink layer is formed on the inner surface. 
 
     
     
       15. The apparatus defined in  claim 14  further comprising a camera that receives light through the unpolarized window and the opening. 
     
     
       16. Apparatus, comprising:
 a color filter layer; 
 a thin-film transistor layer; 
 an opaque ink layer that is interposed between the color filter layer and the thin-film transistor layer; and 
 first and second polarizers, wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer, wherein the color filter layer has an outer surface and an inner surface, wherein at least some of the ink layer is formed on the inner surface, wherein the first polarizer comprises an unpolarized window and wherein the apparatus further comprises a logo that is visible through the unpolarized window. 
 
     
     
       17. Apparatus, comprising:
 a color filter layer; 
 a thin-film transistor layer; 
 first and second polarizers, wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer and wherein the color filter layer is interposed between the first polarizer and the thin-film transistor layer; and 
 an opaque masking layer that is interposed between the first polarizer and the color filter layer. 
 
     
     
       18. The apparatus defined in  claim 17  wherein the color filter layer comprises portions defining a recess and wherein the opaque masking layer is formed on the color filter layer in the recess. 
     
     
       19. The apparatus defined in  claim 17  wherein the opaque masking layer comprises ink. 
     
     
       20. The apparatus defined in  claim 17  wherein the first polarizer comprises an unpolarized window and wherein the opaque masking layer has an opening that is aligned with the unpolarized window. 
     
     
       21. The apparatus defined in  claim 20  further comprising a camera that receives light through the unpolarized window and the opening. 
     
     
       22. The apparatus defined in  claim 17  wherein the first polarizer comprises an unpolarized window and wherein the apparatus further comprises a logo that is visible through the unpolarized window. 
     
     
       23. Apparatus, comprising:
 a color filter layer; 
 a thin-film transistor layer; 
 first and second polarizers, wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer and wherein the color filter layer is interposed between the first polarizer and the thin-film transistor layer; 
 an opaque masking layer on the first polarizer; and 
 a cover film, wherein the cover film comprises a coating selected from the group consisting of: an antireflection coating and an antiglare coating. 
 
     
     
       24. The apparatus defined in  claim 23  wherein the opaque masking layer is interposed between the cover film and the first polarizer. 
     
     
       25. The apparatus defined in  claim 23  wherein the first polarizer comprises first and second triacetate cellulose layers and a polyvinyl alcohol film interposed between the first and second triacetate cellulose layers and wherein the opaque masking layer is formed on the first triacetate cellulose layer. 
     
     
       26. The apparatus defined in  claim 25  wherein the coating is the antireflection coating. 
     
     
       27. The apparatus defined in  claim 25  wherein the coating is the antiglare coating. 
     
     
       28. The apparatus defined in  claim 23  wherein the opaque masking layer comprises ink. 
     
     
       29. Apparatus, comprising:
 a color filter layer; 
 a thin-film transistor layer; 
 first and second polarizers, wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer and wherein the color filter layer is interposed between the first polarizer and the thin-film transistor layer; and 
 an opaque masking layer on the first polarizer, wherein the first polarizer comprises an unpolarized window. 
 
     
     
       30. The apparatus defined in  claim 29  further comprising a camera that receives light through the unpolarized window. 
     
     
       31. The apparatus defined in  claim 29  wherein the apparatus further comprises a logo that is visible through the unpolarized window. 
     
     
       32. The apparatus defined in  claim 29  wherein the opaque masking layer has an opening that is aligned with the unpolarized window. 
     
     
       33. The apparatus defined in  claim 32  further comprising a camera, wherein the camera receives light through the unpolarized window and through the opening.

Description:
BACKGROUND 
     This invention relates to electronic devices and, more particularly, to display structures for electronic devices such as portable computers. 
     Electronic devices such as portable computers and cellular telephones typically have displays. To provide protection from damage, many displays are provided with cover glass layers. The cover glass layer helps protect underlying display structures from scratches and other damage during use of the electronic device. A patterned layer of black ink is sometimes formed on the underside of the cover glass layer to form an opaque border region. The opaque border region can hide internal device components from view. An opening in the black ink can be provided for a camera that is mounted behind the cover glass. 
     As device manufacturers strive to reduce device size and weight, it is becoming unacceptable to include potentially bulky and heavy display structures in a display. It may therefore be desirable to omit the cover glass layer from a display. Care must be taken, however, to ensure that unsightly internal components remain hidden from view and that internal components such as cameras are still able to function properly. 
     It would therefore be desirable to be able to provide improved display structures in electronic devices such as portable computers and cellular telephones. 
     SUMMARY 
     An electronic device such as a portable computer, cellular telephone, or other electronic equipment may have a display. The display may have an active portion such as a central rectangular region in which images are presented to a user of the device. Inactive portions of the display such as peripheral portions of the display may be masked using an opaque masking layer. The opaque masking layer may be formed from colored ink. 
     An opening may be provided in the opaque masking layer to allow light to pass. For example, a logo or other information may be viewed through an opening in the opaque masking layer. Cameras and other internal electronic components may receive light through an opening in the opaque masking layer. 
     The display may include upper and lower polarizers, a color filter layer, and a thin-film transistor layer. The opaque masking layer may be formed on the upper polarizer, may be interposed between the upper polarizer and the color filter layer, or may be interposed between the color filter layer and the thin-film transistor layer. 
     The upper polarizer may have unpolarized windows. The unpolarized windows may be formed by bleaching polarizer material within the polarizer. The polarizer material may be chemically bleached or may be bleached by exposure to ultraviolet light. The camera windows may be aligned with the openings in the opaque masking layer. A camera may be aligned with an unpolarized window in the polarizer and an opening in the opaque masking layer to receive image light. A logo may be aligned with an unpolarized window in a polarizer layer and an opening in the opaque masking layer so that the logo is visible from the exterior of the device. Other internal components of the electronic device such as sensors and status indicators may also be mounted beneath unpolarized windows in the polarizer and openings in the opaque masking layer. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative portable computer with display structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of a handheld device in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of an electronic device having a display in accordance with an embodiment of the present invention. 
         FIG. 4  is a cross-sectional side view of illustrative display structures in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of a polarizer for an electronic device display in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of a conventional liquid crystal display (LCD) module in a portable computer. 
         FIG. 7  is a cross-sectional side view of an illustrative display having a recessed polarizer layer that exposes internal device structures in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of a polarizer layer prior to treatment to form a transparent unpolarized window in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional side view of the polarizer of  FIG. 8  during exposure of a portion of the polarizer to ultraviolet light to bleach the polarizer and thereby form a window in the polarizer in accordance with an embodiment of the present invention. 
         FIG. 10  is a cross-sectional side view of a polarizer having a transparent unpolarized (bleached) window with which an internal device structure has been aligned in accordance with an embodiment of the present invention. 
         FIG. 11  is a graph showing how transmission for a film such as a triacetate cellulose (TAC) film within a laminated polarizer may vary as a function of wavelength. 
         FIG. 12  is a graph showing how absorption for a film such as a polyvinyl alcohol film in a laminated polarizer may vary as a function of wavelength. 
         FIG. 13  is a cross-sectional side view of a polarizer prior to formation of a patterned masking layer on the surface of the polarizer in accordance with an embodiment of the present invention. 
         FIG. 14  is a cross-sectional side view of the polarizer layer of  FIG. 14  following formation of a patterned masking layer in accordance with an embodiment of the present invention. 
         FIG. 15  is a cross-sectional side view of the masked polarizer layer of  FIG. 14  showing how a liquid depolarizing agent may be applied on top of the patterned masking layer to form an unpolarized region within the polarizer layer in accordance with an embodiment of the present invention. 
         FIG. 16  is a cross-sectional side view of the polarizer layer of  FIG. 15  following removal of the masking layer to complete formation of a chemically bleached unpolarized window in the polarizer layer in accordance with an embodiment of the present invention. 
         FIG. 17  is a flow chart of illustrative steps involved in forming display structures including a polarizer layer with an unpolarized window and an opaque masking layer with an opening in accordance with an embodiment of the present invention. 
         FIG. 18  is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed on the inner surface of a color filter layer in accordance with an embodiment of the present invention. 
         FIG. 19A  is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window that is aligned with a logo or other information printed on the inner surface of a color filter layer using physical vapor deposition (PVD) in accordance with an embodiment of the present invention. 
         FIG. 19B  is a cross-sectional side view of the display structures of  FIG. 19A  following formation of an opaque masking layer over the logo in accordance with an embodiment of the present invention. 
         FIG. 19C  is a cross-sectional side view of the display structures of  FIG. 19B  after the color filter and polarizer layers have been connected to other display structure layers such as a thin-film-transistor layer in accordance with an embodiment of the present invention. 
         FIG. 20  is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed on the outer surface of a color filter layer in accordance with an embodiment of the present invention. 
         FIG. 21  is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed within a recessed region on the outer surface of a color filter layer in accordance with an embodiment of the present invention. 
         FIG. 22  is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer that is formed on a layer of the polarizer such as a triacetate cellulose layer and that is interposed between the outer surface of the triacetate cellulose layer and an inner surface of a cover film in accordance with an embodiment of the present invention. 
         FIG. 23  is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed on the inner surface of a polarizer layer in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as notebook computers, tablet computers, cellular telephones, and other computing equipment may be provided with displays. 
     An illustrative electronic device such as a portable computer or other electronic equipment that has a display is shown in  FIG. 1 . As shown in  FIG. 1 , display  14  of device  10  may be mounted in upper housing portion  12 A of housing  12 . Housing  12  may be formed from a unibody construction in which some or all of housing  12  is formed form a unitary piece of material (e.g., metal, plastic, or fiber composite materials) or may be formed from multiple structures that have been mounted together using adhesive, fasteners, and other attachment mechanisms. For example, housing  12  may be formed from frame members and other internal supports to which external plates, housing sidewalls, bezel structures, and other structures are mounted. 
     Because housing portion  12 A may be used to house display  14 , housing portion  12 A may sometimes be referred to as a display housing. Display housing  12 A may be attached to housing portion  12 B (sometimes referred to as a main unit or base housing) using hinge structures  18 , so that display housing  12 A may rotate relative to main housing  12 B around hinge axis  16 . Device  10  may include ports for removable media, data ports, keys such as keyboard  20 , input devices such as track pad  24 , microphones, speakers, sensors, status indicators lights, etc. 
     Display  14  may have an active portion and an inactive portion. Active portion  28 A of display  14  may have a shape such as the rectangular shape that is bounded by dashed line  28 D in  FIG. 1 . Inactive portion  28 I of display  14  may have a rectangular ring shape or other suitable shape and may form a border around the periphery of display  14 . Image pixel array elements such as liquid crystal diode image pixels or other active image pixel structures may be used in portion  28 A to present images to a user of device  10 . Inactive portion  28 I is generally devoid of image pixel elements and does not participate in forming images for a user. To hide unsightly internal components from view, internal components in inactive portion  28 I may be blocked from view using an opaque masking layer such as a layer of ink. 
     Device  10  may have components that are formed in inactive device region  28 I. For example, device  10  may have a camera such as camera  22 . Camera  22  may be mounted within display housing  12 A and may operate through a window (sometimes referred to as a camera window) in display  14 . 
     Information structures  26  such as a logo may be mounted on device  10 . Information structures  26  may be a trademarked logo that represents a manufacturer of device  10 , may be printed text, may be trademarked text, may be a design, may be personalized information (e.g., information identifying an owner of device  10 ), may be formed from a combination of text and non-text information, or may include other suitable content. Information structures  26  may be formed from patterned ink, patterned paint, patterned polymer, patterned metal traces, or other suitable materials. 
     Information structures  26  may be mounted in upper housing  12 A. For example, information structures  26  or may be formed in inactive display region  28 I of upper housing  12 A under a transparent window in display  14 . 
       FIG. 2  is a perspective view of an illustrative configuration that may be used for a handheld electronic device. Electronic device  10  of  FIG. 2  may be, for example, a cellular telephone or other handheld electronic equipment. Device  10  of  FIG. 1  may have housing  12 . Display  14  may be mounted within housing  12  on the front of device  10 . Active portion  28 A of display  14  may lie within rectangular boundary  28 D. Inactive portion  28 I of display  14  may form a boundary around the periphery of display  14 . Housing  12  may have sidewalls that run around the periphery of device  10  (as an example). The sidewall structures of housing  12  may be formed from metal, plastic, glass, ceramic, carbon-fiber materials or other fiber-based composites, other materials, or combinations of these materials. The rear of housing  12  may be formed from metal, plastic, a planar member such as a glass or ceramic plate, fiber-based composites, other materials, or combinations of these materials. 
     Device  10  may have openings such as openings  34  in the sidewalls of housing  12 . Openings  34  may be used to form microphone and speaker ports, openings to accommodate button members, openings for data ports and audio jacks, etc. One or more openings may be formed in inactive region  28 I of display  14 . For example, one or more openings may be formed in inactive region  28 I for buttons such as button  32  (e.g., a menu button). Openings such as opening  30  may also be formed in inactive region  28 I (e.g., to form a speaker port for an ear speaker). 
     Window  22  may be formed over an internal structure in device  10  such as a camera (as an example). If desired, windows such as window  22  may also be formed over information such as logo information (see, e.g., information structures  26  of  FIG. 1 ) to allow the logo or other information to be viewed by a user of device  10 . 
     The illustrative electronic device structures of  FIGS. 1 and 2  are merely examples. Any suitable electronic devices  10  may be provided with displays  14 . Electronic devices  10  may, for example, include tablet computers, wristwatch devices, pendant devices, other miniature and wearable devices, televisions, computer displays, accessories, etc. 
     A cross-sectional end view of an electronic device with a display (e.g., a device such as device  10  of  FIG. 2 , a portion of device  10  of  FIG. 1 , etc.) is shown in  FIG. 3 . As shown in  FIG. 3 , display  14  may be mounted within housing  12  so that the exterior surface of display  14  is exposed. Device housing  12  may be used to enclose printed circuit boards such as printed circuit board  36 . Printed circuit board  36  may be a rigid printed circuit board such as a fiberglass-filled epoxy printed circuit board (e.g., FR4), a flexible printed circuit (“flex circuit”) formed from a flexible dielectric such as a sheet of polyimide with patterned conductive traces, a rigid flex substrate, or other substrate. 
     Electrical components such as components  37  may be mounted to boards such as board  36 . Electrical components  37  may include switches, resistors, inductors, capacitors, integrated circuits, connectors, cameras, sensors, speakers, or other device components. These components may be soldered or otherwise connected to board  36 . 
     Display  14  may be a touch screen display. Touch screen displays such as display  14  of  FIG. 3  may include an array of capacitive electrodes (e.g., transparent electrodes such as indium tin oxide electrodes), or may include a touch sensor array based on other touch technologies (e.g., resistive touch sensor structures, acoustic touch sensor structures, piezoelectric sensors and other force sensor structures, etc.) The touch structures for display  14  may be implemented on a dedicated touch sensor substrate such as a layer of glass or may be formed on the same layer of glass that is being used for other display functions. For example, touch sensor electrodes may be formed on a color filter array layer, a thin-film transistor layer, or other layers in a liquid crystal display (LCD). 
     Display  14  may, in general, be formed from any suitable type of display structures. Examples of display structures that may be used for display  14  include liquid crystal display (LCD) structures, organic light-emitting diode (OLED) structures, plasma cells, and electronic ink display structures. Arrangements in which display  14  is formed from liquid crystal display (LCD) structures are sometimes described herein as an example. This is merely illustrative. In general, display  14  may be formed using any suitable display technology. 
     A cross-sectional view of display  14  of  FIG. 2  is shown in  FIG. 4 . As shown in  FIG. 4 , display  14  may include a backlight unit (BLU) such as backlight unit  38 . Light  44  for backlight unit  38  may be launched into light-guide panel  51  from light source  32 . Light source  32  may be formed from an array of light-emitting diodes (as an example). Reflector  49  (e.g., white polyester) may be used to reflect light  44  upwards (outwards) in direction  46  through display module  40 . Optical films  48  may include a diffuser layer and light collimating layers (as an example). 
     Display  14  and display module  40  may have an active region  28 A that produces image pixel light  43  from an array of image pixels. Image pixel light  43  forms an image in active region  28 A that may be viewed by a user of device  10 . The image may include text, graphics, or other image information. A portion of display  14  and display module  40  such as region  28 I may be inactive. Region  28 I may have a shape that surrounds the periphery of display  14  and display module  40  as shown in  FIG. 1  (as an example). Inactive region  28 I generally does not contain active image pixels and may include an opaque masking layer to block interior structures from view. Backlight unit  38  may have a footprint that is aligned with active region  28 A or may have edges that extend under some or all of inactive region  28 I (as shown in  FIG. 4 ). 
     Display module  40  may include a lower polarizer such as lower polarizer  50  and an upper polarizer such as polarizer  62 . A thin layer (e.g., 3-5 microns) of liquid crystal material  58  may be interposed between color filter layer  60  and thin-film transistor layer  52 . 
     Thin-film transistor layer  52  may be formed on a transparent planar substrate such as a layer of glass or plastic. The upper surface of thin-film-transistor layer  52  may contain pixel electrode structures and thin-film transistors (shown as circuitry  54  above dashed line  56 ). The circuitry on thin-film-transistor layer  52  may be organized into an array of image pixels that can be controlled to display images on display  14  for a user of device  10 . 
     Color filter layer  60  may include colored filter pixel elements (e.g., red, green, and blue filter elements) that provide display  14  with the ability to display color images. Color filter layer  60  may be formed using a transparent planar substrate such as a glass or plastic substrate. 
     If desired, other layers of material may be included within display module  40  and backlight unit  38 . For example, display module  40  and backlight unit  38  may include one or more layers of material for forming a touch sensor, layers of optical films such as birefringent compensating films, antireflection coatings, scratch prevention coatings, oleophobic coatings, layers of adhesive, etc. 
     Polarizers such as upper (outer) polarizer  62  and lower (inner) polarizer  50  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. 5 . As shown in  FIG. 5 , polarizer  62  (i.e., an upper polarizer in this example) may have polarizer film  68 . Film  68  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  68  may be sandwiched between layers  66  and  70 . Layers  66  and  70  may be formed from a material such as tri-acetyl cellulose (TAC) and may sometimes be referred to as TAC films. The TAC films may help hold the PVA film in its stretched configuration and may protect the PVA film. Other films may be laminated to film  68  if desired. 
     Coating layer  72  may be formed from one or more films of material that provide polarizer  62  with desired surface properties. For example, layer  72  may be formed from materials that provide polarizer  62  with antiglare (light diffusing) properties, antireflection properties, scratch resistance, fingerprint resistance, and other desired properties. Layer  72  may be formed from one or more layers of material such as antireflection (AR) layers (e.g., films formed from a stack of alternating high-index-of-refraction and low-index-of-refraction layers), antiglare (AG) layers, antireflection-antiglare (AR/AG) layers, oleophobic layers, antiscratch coatings, or other coating layers. The functions of these layers need not be mutually exclusive. For example, an antiglare film in coating  72  may help provide polarizer  62  with scratch resistance. 
     Polarizer  62  may, if desired, be provided with a layer of adhesive such as adhesive  64  (e.g., optically clear adhesive) to help attach polarizer  62  to the upper surface of display module  40  (i.e., color filter  60  of  FIG. 4 ). The thickness of polarizer  62  may be about 50-200 microns (as an example). 
     It is often desirable to mount cameras within the interior of an electronic device. Conventionally, a camera may be mounted under a layer of cover glass in the inactive portion of a display. This type of arrangement is shown in  FIG. 6 . As shown in  FIG. 6 , conventional device structures  74  may include cover glass  76 . Cover glass  76  may be associated with a display that has active and inactive regions. For example, cover glass  76  of  FIG. 6  may be associated with inactive display region  98  and active display region  100 . 
     Black ink layer  78  is formed on the underside of cover glass  76  in inactive region  98  and blocks internal components such as camera  86  from view. Black ink layer  78  has opening  80  for camera  86 . During operation, light  82  from an image can pass through layer  76  and opening  80  into lens  84  of camera  86 . Display module  96  is mounted under active region  100 . Display module  96  includes color filter layer  92 , thin-film transistor layer  94 , upper polarizer  90 , and other LCD layers mounted within chassis structure  88 . Black ink  78  hides chassis structure  88  from view. 
     The illustrative structures of display  14  of  FIG. 4  do not include a cover glass layer. In this type of arrangement, it may be desirable to mount cameras and other internal structures under a portion of a housing that is separate from display  14  (e.g., under a camera opening in a bezel or other housing structure). If desired, a camera or other internal device structure may be mounted under a portion of the display module. As shown in  FIG. 7 , for example, internal structure  102  may be mounted below an edge portion of color filter layer  60  (as an example). Internal structure  102  may be a camera (e.g., a camera that receives image light through layer  60 , a sensor that receives light through layer  60 , patterned information structures in the shape of a logo or other information such as structures  26  of  FIG. 1 , a status indicator (e.g. a status indicator element that emits light through layer  60 ), or other suitable internal structures in device  10 . 
     Polarizer  62  may interfere with the operation of internal structure  102 . For example, if internal structure  102  is a camera, the presence of polarizer  62  above the camera&#39;s image sensor may reduce light intensity and may therefore adversely affect camera performance. As another example, if internal structure  102  includes patterned structures that form a logo or other information, the presence of polarizer  62  may make it difficult to view internal structures  102  from the exterior of device  10 . The operation of light sensors, status indicators, and other electronic components may also be adversely affected by the presence of polarizer layer  62 . 
     One way to minimize any possible adverse impact from polarizer layer  62  involves removing portions of polarizer layer  62 , so that color filter layer  60  is exposed. Portions of polarizer layer  62  may be removed following attachment of layer  62  to layer  60  or portions of polarizer layer  62  may be removed prior to attaching layer  62  to layer  60 . The portions of layer  62  that are removed may have circular shapes (e.g., for forming a circular opening that is aligned with a camera lens), rectangular shapes (e.g., for exposing a logo or other information that has a rectangular outline), or other suitable shapes. As shown in the example of  FIG. 7 , polarizer  62  may be removed in region  104  along the edge portion of color filter  60 , to avoid overlap between polarizer  62  and internal structures. 
     Arrangements of the type shown in  FIG. 7  may give rise to a step in height at the end of polarizer  62  (i.e., at the interface between polarizer  62  and region  104 ). In some circumstances, this step may be visible or may allow polarizer  62  to peel away from color filter  60 . 
     To avoid creating a step in height, the optical properties in polarizer may be modified to create step-less unpolarized windows that are integral parts of polarizer  62 . For example, a portion of polarizer  62  may be exposed to light with an intensity and wavelength suitable for bleaching (depolarizing) the polarizer material within polarizer layer  62 . Following light exposure, unexposed portions of polarizer  62  will function as polarizer layers. The exposed portions of polarizer  62  will not have significant polarizing properties and will serve as transparent windows. Unpolarized windows may also be formed in polarizer  62  using other localized treatments (e.g., exposure to a liquid that chemically bleaches polarizer  62 , etc.). Using this type of arrangement, polarizer  62  and its unpolarized window regions can smoothly overlap inactive display regions  28 I (see, e.g.,  FIG. 1 ) without introducing steps in height. 
     An illustrative process for bleaching polarizer  62  by applying light to a localized region of polarizer  62  is shown in  FIGS. 8 ,  9  and  10 . Initially, polarizer layer  62  is formed from a layer of polarizer material with no bleached regions ( FIG. 8 ). As shown in  FIG. 9 , light source  106  may emit light  108  (e.g., ultraviolet light) that strikes a localized region of the surface of polarizer  62 . Light  108  may be localized using a focusing arrangement (e.g., using a lens), using a mask (e.g., using a shadow mask or a patterned masking layer formed on the surface of polarizer  62 ), using other suitable masking techniques, or using a combination of these techniques. The localization of light  108  within polarizer  62  causes portion  110  of polarizer  62  to lose its polarizing properties and form a clear window such as window  112 . 
     As shown in  FIG. 10 , polarizer layer  62  may be mounted in a device so that internal structure  102  is aligned with window  112 . The material in window  110  (e.g., portion  110  of polarizer  62 ) is not polarized, so window  112  may allow light to pass freely between the exterior surface of polarizer layer  62  and internal structure  102 . 
     The intensity and wavelength of light  108  may be selected so as to effectively bleach polarizer  62  without inducing optical damage to polarizer  62  that could adversely affect the transparency and optical clarity of window  112 . If, for example, polarizer  62  is formed from a stretched PVA layer with a coating of aligned iodine molecules such as layer  68  of  FIG. 5 , light  108  is preferably able to break iodine bonds or otherwise disorder the PVA polarizer layer without damaging adjacent layers such as TAC layers  66  and  70 . As shown in  FIG. 11 , TAC layers  66  and  70  may exhibit satisfactory transmission at wavelengths above about 380 nm or 400 nm.  FIG. 12  shows how PVA absorption (i.e., the absorption in layer  68  of  FIG. 5 ) may decrease as a function of increasing wavelength. 
     Taking into consideration the properties of TAC films  66  and  70  (per  FIG. 11 ) and the properties of PVA film (per  FIG. 12 ), satisfactory disruption of the polarizer in layer  68  without excessive absorption and resulting damage in TAC layers  66  and  68  may be achieved by operating source  106  of  FIG. 9  with wavelengths in the range of 380-420 or other wavelengths. Longer wavelengths will be less efficient at bleaching polarizer  62 , as indicated by the graph of  FIG. 12 , but longer wavelengths will also be less likely to be absorbed in TAC layers  66  and  70  and will therefore tend to be less likely to adversely affect the transparency of TAC layers  66  and  70 . Ultraviolet light (light with a wavelength of less than 420 nm or less than 400 nm in wavelength) is typically satisfactory for light-bleaching polarizer layer  68 , but other types of light may be used if desired. 
     The intensity of light  108  may be adjusted based on its wavelength. For example, in a scenario in which light  108  has wavelengths in the range of 380-420 nm (as an example), a dose of about 10 J/cm 2  to 100 J/cm 2  (or more or less than 10 J/cm 2  or 100 J/cm 2 ) may be applied to layer  62  to create window  112 . 
     Unpolarized window  112  in polarizer layer  62  may also be formed by chemical treatment. Consider, as an example, the application of bleaching liquid to polarizer layer  62 , as illustrated in  FIGS. 13-16 . As shown in  FIG. 13 , polarizer layer  62  may initially contain no window regions. A masking layer such as masking layer  114  of  FIG. 14  may be applied to the surface of polarizer layer  62 . Masking layer  114  may contain one or more openings such as opening  116 . Masking layer  114  may be pattered using photolithographic techniques (e.g. when masking layer  114  is formed from a photosensitive material such as photoresist), may be patterned by pad printing, spraying, inkjet printing, etc. Opening  116  may have a size and shape suitable for forming an unpolarized window within polarizer  62 . As shown in  FIG. 15 , after layer  114  has been formed, a bleaching agent such as liquid  118  may be deposited on the surface of layer  62  in opening  116 . Liquid  118  may be, for example, a base such as NaOH, KOH, or other substance that removes the polarization from exposed portions of polarizer layer  62 . As shown in  FIG. 16 , following application and removal of masking layer  114  and liquid  118  (or other suitable bleaching agent), polarizer  62  may remain polarized in all areas except unpolarized window  112 . 
     During assembly of polarizer  62  into device  10 , window  112  may be aligned with a camera, information structures such as a logo, or other internal components in device  10 , as described in connection with window  112  of  FIG. 10 . To ensure that potentially unsightly internal portions of device  10  are blocked from view, device  10  may be provided with one more opaque masks. For example, one or more opaque masking layers may be incorporated onto one or more of the layers of material in display module  40  of  FIG. 4 . The opaque masking layer may be formed from black ink, ink with other (non-black) colors (e.g., white, silver, gray, red, blue), an opaque polymer, a layer of metal, or other suitable opaque substances. Examples of locations in which the opaque masking layer may be formed in module  40  include position P 1  on the top of polarizer  62 , position P 2  on the lower surface of polarizer  62 , position P 3  on the top surface of color filter layer  60 , and position P 4  on the lower surface of color filter layer  60 . Other masking layer locations and combinations of masking layer locations may be used if desired. 
     Illustrative steps involved in forming windows in polarizer layer  62  and in forming opaque masking layers and display module structures within an electronic device are shown in  FIG. 17 . 
     At step  120 , layers of material such as TAC films  66  and  70  and polarizer layer  68  may be laminated together to form polarizer  62 . For example, an extrusion tool may be used to stretch PVA layer  68  and laminating rollers may be used to laminating layers  66  and  70  to layer  68 . Iodine may be incorporated into the polarizer (e.g., on layer  68 ). 
     If desired, window  112  may be formed in the laminated polarizer layers during the operations of step  122  (i.e., prior to dividing the TAC and PVA sheets into device-sized panels with a die press or other cutting tool at step  124 ). Following cutting to form individual panels of polarizer, the polarizer may be laminated to color filter layer  60  (step  126 ). 
     Alternatively, the layers of polarizer that have been laminated together during the operations of step  120  may be divided into individual panels during the operations of step  130  (i.e., before forming window  112  in polarizer  62  during the operations of step  132 ). With this type of approach, the panel of polarizer in which window  112  is formed during step  132  may be laminated to color filter layer  60  at step  126 . 
     If desired, polarizer that has been cut into device-sized panels during the operations of step  130  may be laminated to color filter layer  60  (step  134 ) before forming window  112  (step  136 ). 
     Regardless of the order in which polarizer  62  is processed to form window  112  and attached to color filter layer  60 , polarizer  62  and other display structures may, during the operation of step  128  be assembled into device  10  so that a camera or other internal structures (see, e.g., structure  102  of  FIG. 10 ) are mounted in alignment with window  112 . Prior to the assembly operations of step  128  or during assembly, opaque masking layers may be formed on the layers of material that form display  14 . For example, a patterned layer of ink or other opaque masking material may be formed in locations such as locations P 1 , P 2 , P 3 , and P 4  in display module  40  (see, e.g.,  FIG. 4 ). Patterned masking layers may be formed using physical vapor deposition, pad printing, screen printing, spraying, dipping, inkjet printing, shadow mask deposition, photolithographic patterning, or other suitable deposition and patterning techniques. Examples of materials that may be used as opaque masking layers include metals, polymers, ink, paint, tinted adhesive, oxides (e.g., metal oxides), fiber-based composites, etc. 
       FIG. 18  is a cross-sectional side view of display structures in which an opaque masking layer has been formed in a position such as position P 4  of  FIG. 4  under color filter layer  60 . As shown in  FIG. 18 , display module  40  may have active region  28 A and inactive region  28 I. Opaque masking layer  138  may be formed on the inner surface of color filter layer  60 . Opaque masking layer  138  may be patterned to form an opening such as opening  140 . Opening  140  may have a size and shape that allows some or all of opening  140  to overlap window  112  in polarizer layer  62 . This allows light to pass between interior structure  102  and the exterior of module  40  adjacent to polarizer  62  via window  112 , color filter  60 , opening  140 , and thin-film transistor layer  52  (as an example). During deposition operations, some or all of masking layer  138  may overlap existing structures on color filter  60  (e.g., structures such as structure  142  of  FIG. 18  that are formed of chromium or other materials and that are used in forming light-blocking patterns for the color filter elements in filter  60 ). If desired, some of structures  142  may be used in forming layers such as layer  138 . 
     As shown in  FIG. 18 , internal structures  102  may be aligned along common vertical axis  114  with window  112  and mask opening  140 . Structures  102  may include a camera (image sensor), a status indicator, information structures such as a logo or other printed or patterned information, a sensor, etc. 
       FIGS. 19A ,  19 B, and  19 C show how internal structures  102  such as information structures that form a logo or other information may be formed on the lower surface of color filter layer  60  in a configuration in which masking layer  138  is being formed in a position such as position P 4  of  FIG. 4 . As shown in  FIG. 19A , structures  102  may be formed on the lower surface of color filter  60 . Structures  102  may, for example, be formed under window  112  in polarizer layer  62  (i.e., so that the outline of structures  102  is contained within the outline of window  112  and so that window  112  completely overlaps structures  102 ). Structures  102  may be formed from ink, metal, paint, polymer, or other materials and may be deposited using physical vapor deposition (PVD) or other suitable deposition and patterning techniques. 
     Following deposition of structures  102  on the inner surface of color filter layer  60 , opaque masking layer  138  may be formed over structures  102 , as shown in  FIG. 19B . In particular, a layer of black ink or other opaque masking substance may be formed over structures  102  (e.g., a PVD logo) using screen printing, inkjet printing, pad printing, or other suitable deposition techniques. Opaque masking layer  138  may cover the inactive portion of display  14  (see, e.g., inactive portion  28 I of  FIG. 1 ). 
     As shown in  FIG. 19C , following formation of structures  102  (e.g., a PVD logo or other information) and formation of patterned masking layer  138 , display module  40  may be completed by attaching lower polarizer  50  and thin-film-transistor layer  52  below liquid crystal material  58 , color filter layer  60 , and upper polarizer  62 . 
       FIG. 20  is a cross-sectional side view of display module  40  in a configuration in which opaque masking layer  138  has been formed in a position such as position P 3  of  FIG. 4  (i.e., on top of color filter layer  60 ). As shown in  FIG. 20 , polarizer  62  may be provided with unpolarized window  112  that is aligned with internal structures  102  (e.g., a logo or other information, a camera, a sensor or other electrical component, etc.). Opaque masking layer  138  may have an opening such as opening  140  that is aligned with window  112  and structures  102 . Polarizer layer  62  may be attached to display module  40  using adhesive  148  (e.g., a layer of adhesive that is about 0.5 to 6 microns thick). Opaque masking layer  138  may be about 40 to 120 microns thick (as an example). If desired, planarizing layer  146  may be interposed between polarizer  62  and the upper surface of color filter layer  60  to help accommodate the thickness of opaque masking layer  138 . Planarizing layer  146  may be formed from epoxy or other adhesive (e.g., some of adhesive  148 ), spin-on-glass, polymer, or other clear material. Opaque masking layer  138  may be formed from white ink, black ink, non-black colored ink, or other suitable opaque materials. 
     As shown in the cross-sectional side view of  FIG. 21 , color filter layer  60  may, if desired, be provided with a recess such as recess  150 . Recess  150  may have a depth (thickness) comparable to the thickness of opaque masking layer  138  (e.g., about 40-120 microns as an example). In this type of configuration, opaque masking layer (and, if desired, optional filler material  152 ) may be recessed within recess  150  so that the outermost surface of opaque masking layer  138  (and optional filler material  152 ) is flush or nearly flush with the outermost surface of color filter layer  160 . Filler material  152  may be formed from adhesive (e.g., some of adhesive  148 ), polymer, or other suitable transparent materials. 
     A cross-sectional side view of an illustrative configuration that may be used for display module  40  in which opaque masking layer  138  is formed on polarizer  62  (e.g., in position P 1  of  FIG. 4 ) is shown in  FIG. 22 . As shown in  FIG. 22 , polarizer  62  may include a polarizer layer such as PVA layer  68  and TAC layers such as TAC layers  66  and  70  or other optical films. Polarizer  62  may be attached to color filter layer  60  (e.g., using adhesive). Opaque masking layer  138  may be formed on the surface of TAC layer  70 . Opening  140  may be aligned with window  112  in polarizer  62 . Cover film  72  may be attached to the outer surface of TAC layer  70  (e.g., to form the outermost surface of display module  40 ). Cover film  72  may be a cover layer that includes one or more layers such as antireflection layers, antiglare layers, antiscratch layers, etc. Cover film  72  may be dispensed from one or more rolls of film and may be attached to TAC layer  70  using adhesive  154 . In this type of arrangement, opaque masking layer  138  may be aligned with the panel of material that forms polarizer  62  to a relatively high tolerance (e.g., to a 0.1-0.4 mm tolerance), because layer  138  can be aligned directly to the polarizer panel during printing operations or other opaque masking layer deposition operations (as an example). If desired, opaque masking layer  138  may be deposited onto the underside of cover film  72  before cover film  72  is attached to polarizer  62 . 
       FIG. 23  is a cross-sectional side view of illustrative structures for display module  40  showing how opaque masking layer  138  may be formed on the underside of polarizer  62  in alignment with window  112 . Adhesive  64  may be used to attach polarizer  62  to color filter layer  60  when polarizer  62  is moved in direction  156 . A recess may be provided in color filter layer  60  to help accommodate the thickness of opaque masking layer  138 , a layer of planarizing material may be interposed between polarizer  62  and color filter  60 , or other actions may be taken to help ensure that polarizer  62  is satisfactorily attached to color filter  60 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20101029
Publication Date: 20130618
Grant Date: 20130618
Priority Date: 20101029
Inventors: MATHEW DINESH C.
HENDREN KEITH J.
QI JUN
YIN VICTOR H.
WILSON, JR. THOMAS W.
GARELLI ADAM T.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04N23/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04N23/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0264", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1686", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N5/72", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0264", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1686", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0264", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N5/72", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N5/64", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N23/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133509", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N5/64", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1686", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133509", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133538", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/13312", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04N23/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133538", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/13312", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0264", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1686", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133538", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/13312", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/13312", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133538", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 45218212