PATENT DOCUMENT

Publication Number: US-9341878-B2
Application Number: US-201213607368-A
Country: US
Kind Code: B2

Title: Displays with low reflectance border regions

Abstract:
An electronic device may have a display such as a liquid crystal display. A color filter layer may be formed on a display layer such as a transparent substrate layer of the display. The color filter layer may include an array of color filter elements on an inner surface of the transparent substrate layer. The color filter layer may include opaque masking material. In an inactive portion of the display, the opaque masking material may be formed over the color filter elements and interposed between the color filter elements. In the inactive portion of the display, the opaque masking material and the color filter elements may form a ring that serves as a border region surrounding an active portion of the display. In the active portion of the display, the opaque masking layer may be patterned to from an opaque matrix that separates the color filter elements.

Claims:
What is claimed is: 
     
       1. A display, comprising:
 a first set of color filter elements in an active region of the display; 
 a second set of color filter elements in an inactive region of the display; 
 opaque masking material, wherein adjacent color filter elements in the first set of color filter elements are separated by the opaque masking material, and wherein adjacent color filter elements in the second set of color filter elements are separated by the opaque masking material; and 
 a planarization layer that covers the first and second sets of color filter elements, wherein the planarization layer is in direct contact with the first set of color filter elements, and wherein the planarization layer and the second set of color filter elements are not in direct contact. 
 
     
     
       2. The display defined in  claim 1 , wherein the opaque masking material covers the color filter elements in the second set of color filter elements. 
     
     
       3. The display defined in  claim 1 , wherein the first and second sets of color filter elements are formed on a display substrate, and wherein the display comprises a liquid crystal display. 
     
     
       4. The display defined in  claim 1 , wherein the inactive region forms a border around the active region of the display. 
     
     
       5. The display defined in  claim 1 , wherein the inactive region comprises a peripheral region of the display. 
     
     
       6. The display defined in  claim 1  further comprising a transparent substrate and a layer of liquid crystal material, wherein the first set of color filter elements and the second set of color filter elements are interposed between the transparent substrate and the layer of liquid crystal material. 
     
     
       7. The display defined in  claim 1  wherein the inactive region is devoid of active display pixels. 
     
     
       8. The display defined in  claim 1  wherein the opaque masking material comprises openings and wherein each of the openings overlaps a respective one of the color filter elements in the first set of color filter elements. 
     
     
       9. The display defined in  claim 3 , wherein a color filter element in the second set of color filter elements has first and second opposing sides that are each in direct contact with the opaque masking material. 
     
     
       10. The display defined in  claim 9 , wherein the color filter element has third and fourth opposing sides, wherein the third side is in direct contact with the display substrate, and wherein the entire fourth side is in direct contact with the opaque masking layer. 
     
     
       11. The display defined in  claim 1 , wherein at least some of the layer of opaque masking material forms a grid that separates adjacent color filter elements in the first set of color filter elements. 
     
     
       12. A display, comprising:
 a transparent substrate layer having a surface; 
 an array of display pixels configured to display images in an active portion of the display, wherein the active portion of the display is surrounded by an inactive portion of the display; 
 an array of color filter elements on the surface of the transparent substrate layer, wherein the array of color filter elements includes a first set of color filter elements aligned with the display pixels in the active portion of the display and includes a second set of color filter elements in the inactive portion of the display; 
 a layer of opaque masking material that covers the color filter elements in the inactive portion of the display, wherein each color filter element of the second set of color filter elements has a first portion that is in direct contact with the surface of the transparent substrate layer and a second portion that is in direct contact with the layer of opaque masking material, and wherein at least some of the layer of opaque masking material forms a grid that separates adjacent color filter elements in the first set of color filter elements; and 
 a planarization layer that covers the first and second sets of color filter elements, wherein the planarization layer is in direct contact with the first set of color filter elements, and wherein the planarization layer and the second set of color filter elements are not in direct contact. 
 
     
     
       13. The display defined in  claim 12  wherein the layer of opaque masking material separates adjacent color filter elements in the first and second sets of color filter elements. 
     
     
       14. The display defined in  claim 12 , wherein the opaque masking material comprises polymeric material. 
     
     
       15. The display defined in  claim 12 , further comprising a backlight unit that produces backlight, wherein the backlight passes through color filter elements in the first set of color filter elements. 
     
     
       16. The display defined in  claim 12  wherein the inactive portion is located at the periphery of the display and wherein the inactive portion is devoid of active display pixels. 
     
     
       17. The display defined in  claim 12  wherein the first and second sets of color filter elements are in direct contact with the surface of the transparent substrate layer. 
     
     
       18. The display defined in  claim 17  wherein the color filter elements in the inactive portion of the display are interposed between the transparent substrate layer and the opaque masking material. 
     
     
       19. A display, comprising:
 a transparent substrate layer having a surface; 
 an array of color filter elements on the surface of the transparent substrate layer, wherein the array of color filter elements includes a first set of color filter elements in an active portion of the display and includes a second set of color filter elements in an inactive portion of the display; 
 a layer of opaque masking material that completely covers the color filter elements in the inactive portion of the display, wherein the color filter elements in the inactive portion of the display are separated by the layer of opaque masking material, and wherein the color filter elements in the inactive portion are interposed between the layer of opaque masking material and the transparent substrate layer; and 
 a planarization layer that covers the first and second sets of color filter elements, wherein the planarization layer is in direct contact with the first set of color filter elements, and wherein the planarization layer and the second set of color filter elements are not in direct contact. 
 
     
     
       20. The display defined in  claim 19  wherein the first and second sets of color filter elements are in direct contact with the surface of the transparent substrate layer. 
     
     
       21. The display defined in  claim 19  wherein the second set of color filter elements comprises first, second, and third color filter elements that are positioned entirely in the inactive portion of the display, wherein the first and second color filter elements are separated by a first distance, and wherein the second and third color filter elements are separated by a second distance that is different than the first distance. 
     
     
       22. The display defined in  claim 19 , wherein the second set of color filter elements comprises first and second color filter elements that are positioned entirely in the inactive portion of the display, and wherein the first color filter element is in direct contact with the second color filter element.

Description:
This application claims the benefit of provisional patent application No. 61/620,933, filed Apr. 5, 2012, 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 such as computers and cellular telephones may have displays. In a typical display such as a liquid crystal display, an array of display pixels is used to display images for a user. The array of display pixels may be formed in an active display region of the display. The display may also include a peripheral border region that is inactive. 
     To provide a display such as a liquid crystal display with the ability to display color images, an array of color filter elements is often aligned with the array of display pixels. The color filter layer may be formed on an outer glass layer of the display. A typical color filter array often contains red, blue, and green color filter elements (e.g., elements that pass red, blue, and green light respectively) that are separated from each other by a patterned black masking layer. Portions of the black masking layer are also sometimes formed on the outer glass layer of the display in the inactive area around the periphery of the color filter array. 
     At the interface of an outer glass layer and other display components such as color filter elements and black masking layers, reflections of ambient light may arise. These reflections are caused by differences in the indices of refraction of the outer glass layer, the color filter elements and the black masking layer. Because the black masking layer and the color filter elements have different indices of refraction, these reflections at the inner surface of the outer glass layer can make the inactive peripheral region of the display stand out in contrast to the active portion of the display. With traditional display designs, it can be challenging to reduce reflections. 
     It would therefore be desirable to be able to provide electronic devices with improved displays such as electronic devices with minimized display reflections. 
     SUMMARY 
     An electronic device may have a display such as a liquid crystal display. The display may have multiple layers of material such as a display substrate, a color filter layer and a thin-film transistor layer. A layer of liquid crystal material may be interposed between the color filter layer and the thin-film transistor layer. 
     The color filter layer may be formed on an inner surface of the display substrate. The display substrate may be formed from a transparent rigid material such as glass or plastic. 
     An opaque masking layer may be formed on a display layer such as the color filter layer. The display may have a central active area such as a rectangular active area. Display pixels in the active area may present images to a user of the electronic device. The active area may be surrounded by an inactive area. For example, the active area may be surrounded by an inactive area that has the shape of a rectangular ring. 
     In the inactive portion of the display, the opaque masking layer may be formed over color filter elements to form a rectangular border that surrounds the active area. The color filter elements may be interposed between the opaque masking layer and the substrate layer in the inactive area. 
     Reflections may be reduced within the inactive border region of the display by forming the color filter elements interposed between the opaque masking layer and the substrate layer in the inactive border region. 
     During manufacturing of the display, display layers such as color filter layers, opaque masking layers, liquid crystal layers and other layers may be formed on a sheet of substrate layer material such as a sheet of glass. Alignment marks may be formed on the sheet of glass. Manufacturing equipment such as deposition equipment and patterning equipment may be used to deposit and pattern display materials such as color filter material, opaque masking material, planarization material, polarizing material, or other material on the sheet of glass. 
     The manufacturing equipment may use the alignment marks to determine where to deposit and pattern the display materials on the sheet of glass. The alignment marks may be formed from materials such as metal or color filter material. The alignment marks may be formed on the sheet of glass before forming color filter elements on the sheet of glass or may be patterned on the sheet of glass as a part of a color filter patterning process. 
     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 diagram of an illustrative electronic device with a display such as a portable computer in accordance with an embodiment of the present invention. 
         FIG. 2  is a diagram of an illustrative electronic device with a display such as a cellular telephone or other handheld device in accordance with an embodiment of the present invention. 
         FIG. 3  is a diagram of an illustrative electronic device with a display such as a tablet computer in accordance with an embodiment of the present invention. 
         FIG. 4  is a diagram of an illustrative electronic device with a display such as a computer monitor with a built-in computer in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of a portion of an illustrative liquid crystal display in accordance with an embodiment of the present invention. 
         FIG. 6  is cross-sectional side view of a portion of a display having an opaque masking layer over color filter elements in an inactive border region in accordance with an embodiment of the present invention. 
         FIG. 7  is a flow chart of illustrative steps involved in forming color filter elements, alignment marks and opaque masking layers on a sheet of cover layer material for forming device displays of the type shown in  FIG. 6  in accordance with an embodiment of the present invention. 
         FIG. 8  is a flow chart of illustrative steps involved in forming metal alignment marks, color filter elements, and opaque masking layers on a sheet of cover layer material for forming device displays of the type shown in  FIG. 6  in accordance with an embodiment of the present invention. 
         FIG. 9  is a diagram of illustrative deposition and patterning equipment for applying display materials to a sheet of cover layer material for forming device displays in accordance with an embodiment of the present invention. 
         FIG. 10  is a cross-sectional side view of a portion of an illustrative deposition device of the type shown in  FIG. 9  in accordance with an embodiment of the present invention. 
         FIG. 11  is a cross-sectional side view of a portion of an illustrative deposition device having an opposing alignment member in accordance with an embodiment of the present invention. 
         FIG. 12  is cross-sectional side view of a portion of a display having an opaque masking layer over color filter elements in an inactive border region in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device of the type that may be provided with a display is shown in  FIG. 1 . Electronic device  10  may be a computer such as a computer that is integrated into a display such as a computer monitor, a laptop computer, a tablet computer, a somewhat smaller portable device such as a wrist-watch device, pendant device, or other wearable or miniature device, a cellular telephone, a media player, a tablet computer, a gaming device, a navigation device, a computer monitor, a television, or other electronic equipment. 
     As shown in  FIG. 1 , device  10  may include a display such as display  14 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or other touch sensor components or may be a display that is not touch sensitive. Display  14  may include image pixels formed from liquid crystal display (LCD) components or other suitable display pixel structures. Arrangements in which display  14  is formed using liquid crystal display pixels are sometimes described herein as an example. This is, however, merely illustrative. Any suitable type of display technology may be used in forming display  14  if desired. 
     Device  10  may have a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. 
     Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     As shown in  FIG. 1 , housing  12  may have multiple parts. For example, housing  12  may have upper portion  12 A and lower portion  12 B. Upper portion  12 A may be coupled to lower portion  12 B using a hinge that allows portion  12 A to rotate about rotational axis  16  relative to portion  12 B. A keyboard such as keyboard  18  and a touch pad such as touch pad  20  may be mounted in housing portion  12 B. 
     Display  14  may have an active area such as active area AA and an inactive area such as area IA. Active area AA may be, for example, a rectangular region in the center of display  14  in which display pixels are actively used to display images for a user of device  10 . Inactive area IA may be devoid of active display pixels. In the example of  FIG. 1 , inactive area IA has the shape of a rectangular ring, surrounding the periphery of active area AA of display  14 . Circuitry and other components may sometimes be formed in inactive area IA. To hide the circuitry and other components from view by a user of device  10 , inactive area IA may sometimes be provided with an opaque mask. The opaque mask may be formed over transparent color filter elements in inactive area IA. The opaque mask can be formed from an opaque material such as a black material or may be formed from opaque masking materials of other colors. Configurations in which the opaque masking material in display  14  has a black appearance are sometimes described herein as an example. This is, however, merely illustrative. Opaque masking layers in device  10  may have any suitable colors. 
     In the example of  FIG. 2 , device  10  has been implemented using a housing that is sufficiently small to fit within a user&#39;s hand (i.e., device  10  of  FIG. 2  may be a handheld electronic device such as a cellular telephone). As show in  FIG. 2 , device  10  may include a display such as display  14  mounted on the front of housing  12 . Display  14  may be substantially filled with active display pixels or may have an inactive portion such as inactive portion IA that surrounds an active portion such as active portion AA. Display  14  may have openings (e.g., openings in inactive region IA or active region AA of display  14 ) such as an opening to accommodate button  22  and an opening to accommodate speaker port  24 . 
       FIG. 3  is a perspective view of electronic device  10  in a configuration in which electronic device  10  has been implemented in the form of a tablet computer. As shown in  FIG. 3 , display  14  may be mounted on the upper (front) surface of housing  12 . An opening may be formed in display  14  to accommodate button  22  (e.g., in inactive region IA surrounding active region AA). 
       FIG. 4  is a perspective view of electronic device  10  in a configuration in which electronic device  10  has been implemented in the form of a computer integrated into a computer monitor. As shown in  FIG. 4 , display  14  may be mounted on the front surface of housing  12 . Stand  26  may be used to support housing  12 . Display  14  may include an inactive region such as inactive region IA that surrounds active region AA. 
     If desired, display  14  may be configured so as to minimize or eliminate the size of inactive region IA along one or more edges of active region AA. Configurations in which inactive region IA extends along all four edges of a rectangular active region AA are described herein as an example. 
     Display  14  may be, for example, a liquid crystal display such as display  14  of  FIG. 5 . As shown in  FIG. 5 , backlight structures  64  may be used to produce backlight  66  that travels upwards (outwards) in dimension Z through display layers  81  of display  14 . Display layers  81  may include an upper polarizer layer such as layer  68  and a lower polarizer layer  74 . Upper polarizer layer  68  may be attached to one or more substrate layers such as display substrate  70 . Lower polarizer layer  74  may be attached to one or more substrate layers such as thin-film-transistor layer  72 . Layers  70  and/or  72  may be formed from transparent substrates such as glass, plastic, or other materials. During manufacturing of displays such as display  14 , layers such as layers  70  or  72  of an individual display may be cut from a sheet of transparent substrate such as a sheet of glass. Display substrate  70  may be known as a display layer or display color filter glass. 
     Display  14  may have additional display layers such as layer  71  formed on interior surface  73  of layer  70 . Layer  71  may include color filter layers, planarization layers, opaque masking patterns, layers that include color filter elements and opaque masking material, clear layers, or other suitable display layers. For example, color filter elements may be formed on interior surface  73  of substrate  70  and opaque masking material may be formed over and/or between the color filter elements on interior surface  73 . 
     Layer  72  of display  14  may include thin-film transistor layers, color filter layers, layers that include thin-film transistor structures and color filter elements, planarization layers, opaque masking patterns, clear layers, or other suitable display layers. 
     An array of electrodes may be controlled by the thin-film transistor circuitry in a thin-film transistor layer in display  14 . Thin-film transistor circuitry may include, as examples, amorphous silicon transistor circuitry or polysilicon transistor circuitry. Thin film transistor circuitry may also include interconnect lines to connect electrodes formed from conductive materials such as indium tin oxide and metal to thin-film structures such as thin-film transistors. Thin-file transistor circuitry may be used in adjusting voltages in display pixels  100  in active area AA, thereby selectively lightening and darkening pixels  100  and presenting an image to a user of device  10  such as viewer  76 , viewing display  14  in direction  78 . 
     As light  66  passes through lower polarizer  74 , lower polarizer  74  polarizes light  66 . As polarized light  66  passes through liquid crystal material  60 , liquid crystal material  60  may rotate the polarization of light  66  by an amount that is proportional to the electric field through liquid crystal material  60 . If the polarization of light  66  is aligned in parallel with the polarization of polarizer  68  in a given display pixel  100 , the transmission of light  66  through layer  68  in that pixel will be maximized. If the polarization of light  66  is aligned so as to run perpendicular to the polarization of polarizer  68  in a given pixel  100 , the transmission of light  66  through layer  68  will be minimized (i.e., light  66  will be blocked) in that pixel. 
     Backlight unit  28  may include a light source such as a light-emitting diode array for producing backlight  66 . Polarizers such as polarizer  68  and polarizer  74  may be formed from thin polymer films. For example, polarizer  68  may be formed from polymer film and an associated adhesive layer such as optically clear adhesive layer. 
     If desired, display  14  may be provided with layers for reducing fingerprints (e.g., a smudge-resistant coating in a touch-sensitive display), anti-scratch coatings, an antireflection coating, a layer for reducing the impact of static electricity such as an indium tin oxide electrostatic discharge protection layer, or other layers of material. The display layers that are used in the configuration of  FIG. 5  are merely illustrative. 
     As shown in  FIG. 6 , layer  71  on interior surface  73  of substrate  70  of display  14  may include a display layer such as color filter layer  38 . Color filter layer  38  may include an array of color filter elements  42  and opaque masking material  40 . Color filter layer  38  may be covered by a planarization layer such as planarization layer  44 . 
     Planarization layer  44  may be formed from a layer of silicon oxide, silicon nitride, silicon oxynitride, an organic material such as acrylic, other transparent planarizing materials, or a combination of two or more of these materials. If desired, layer  44  may be polished to help planarize layer  44 . If desired, planarization layer  44  may be covered by a relatively thin polymer layer such as polymer layer  46 . Polymer layer  46  may be formed from polymer material such as polyimide. Liquid crystal material (see, e.g.,  FIG. 5 ) of display  14  may be interposed between polymer layer  46  and a thin-film-transistor layer such as layer  72 . 
     Color filter layer  38  may include an array of color filter elements  42  formed on inner surface  73  of substrate  70 . Color filter elements  42  may include, for example, red elements R, green elements G, and blue elements B. The array of color filter elements in color filter layer  38  may be used to provide display  14  with the ability to display color images. 
     Adjacent color filter elements  42  may be separated by intervening portions of opaque masking material  40 . Opaque masking material may be formed from a dark substance such as a polymer that contains a black pigment and is therefore sometimes referred to as a black mask, black masking layer, black pigmented layer, or black masking material. Illustrative polymeric materials for forming black masking layer  40  include acrylic-based and polyimide-based photoresists. An illustrative black pigment that may be used for black masking layer  40  is amorphous carbon (e.g., carbon black). 
     In active region AA, portions of color filter elements  42  that are aligned with display pixels  100  may be free of black mask  40  so that light such as backlight  66  ( FIG. 5 ) may pass through color filter layer  38 . Black mask  40  may form a grid of relatively thin lines (sometimes referred to as a black matrix) in active region AA that visually separates individual display pixels  100 . 
     The black matrix may have a pattern of openings  48  aligned with pixels  100  in active area AA. Openings  48  may form an array of rectangular holes in which color filter elements  42  are formed. In inactive region IA, black masking material  40  and color filter elements  42  may be used in forming a peripheral opaque mask that serves as an opaque border for display  14 . The opaque mask in inactive area IA may have a rectangular ring shape that surrounds a central rectangular active area AA (as an example). If desired, active area AA may have other shapes such as a chevron shape. 
     Light such as ambient light  75  may reflect from the interfaces of the layers in display  14 , leading to the potential for undesired reflections. Light reflections in inactive region IA may be reduced by forming color filter elements  42  interposed between opaque masking material  40  and inner surface  73  of substrate  70  in inactive portion IA. 
     Because the index of refraction of the combination of black masking material  40  over color filter elements  42  on surface  73  may be configured to be similar to the index of refraction of black masking material  40  interposed between color filter elements  42 , display  14  may appear to a viewer  76  viewing display  14  in direction  78  as a seamless display without a visible border between active area AA and inactive area IA. Color filter layer  38  may, for example, be configured (e.g., by adjusting the aperture ratios of color filter elements  42 ) to have an index of refraction in inactive region IA and an index of refraction in active region AA that are near enough to equal to provide an inactive region IA that is visually indistinguishable from active region AA when display pixels  100  are turned off. 
     As shown in  FIG. 6 , display  14  may include layers such as layer  69  on an outer surface of substrate  70 . Layer  69  may include one or more layers such as polarization layer ( FIG. 5 ), layers for reducing fingerprints (e.g., a smudge-resistant coating in a touch-sensitive display), anti-scratch coatings, an antireflection coating, a layer for reducing the impact of static electricity such as an indium tin oxide electrostatic discharge protection layer, or other layers of material. 
     Layers of material such as color filter material (e.g., red color filter material, green color filter material, and blue color filter material) may be deposited on substrate  70  by screen printing, spin-on coating, spray coating, physical vapor deposition, chemical vapor deposition, or other suitable deposition techniques. 
     Color filter elements  42  of each color (e.g., red R, green G, and blue G) may be formed by depositing color filter material of that color on inner surface  73  (and over any previously deposited and/or patterned materials) and etching or otherwise patterning (e.g., using photolithographic equipment) the color filter material of that color to form the color filter elements. 
     During manufacturing of display  14 , opaque masking material  40  may be deposited over substantially all of color filter elements  42  in active region AA and inactive region IA. The opaque masking material that has been deposited may be patterned (e.g., etched or otherwise patterned) to remove the opaque masking material from the color filter elements in active region AA to form openings  48  over color filter elements  42  so that light may pass through color filter elements  42  and substrate  70 . 
     As shown in  FIG. 6 , in inactive area IA of display  14 , color filter elements  42  may be attached to inner surface  73  of substrate  70  and opaque masking material  40  may be formed over and interposed between color filter elements  42 . In active area AA of display  14 , color filter elements  42  may be attached to inner surface  73  of substrate  70  and opaque masking material may be interposed between color filter elements  42  and formed over portions of color filter elements  42  with openings  48  over other portions of color filter elements  42 . If desired, other types of material may be interposed between opaque masking material  40  and inner surface  73  of substrate  70  in inactive region IA. The arrangement of  FIG. 6  is merely illustrative. 
     Illustrative steps that may be used in forming a display having display layers of the type shown in  FIG. 6  are shown in  FIG. 7 . 
     At step  80 , color filter elements and alignment marks may be formed on a blank sheet of substrate material such as glass sheet  92  using color filter material having a first color (e.g., blue color filter material). 
     Color filter elements  42  and alignment marks  102  may be formed from the color filter material having the first color by depositing the color filter material having the first color on substantially all of a first surface of sheet  92  and etching or otherwise removing portions of the color filter material having the first color to form (e.g., blue) color filter elements and (e.g., blue) alignment marks on sheet  92 . 
     Alignment marks  102  may be used by equipment such as patterning and deposition equipment in forming additional display structures (e.g., additional color filter elements, opaque masking layers or other display structures) on sheet  92  and/or in cutting portions of sheet  92  to form multiple individual displays  14  for individual devices  10 . 
     At step  82 , additional color filter elements such as red color filter elements and green color filter elements may be formed on sheet  92 . Following formation of additional color filter elements  42  on sheet  92 , sheet  92  may have a multiplicity of color filter arrays for a corresponding multiplicity of displays  14  that are marked off by alignment marks  102 . 
     Color filter elements  42  of each color may be formed by coating substrate  92  with color filter material, soft baking the color filter material, applying a patterned guide to the soft baked color filter material, exposing the color filter material to light, and hard baking the patterned color filter material. However, this is merely illustrative, if desired, color filter elements may be formed using any suitable deposition and patterning methods. 
     At step  84 , opaque masking material  40  may be deposited over the color filter elements  42 . As shown in  FIG. 7 , opaque masking material  40  may be deposited (e.g., using slot coating equipment) in continuous strips  94  of opaque masking material that cover color filter elements to be used for multiple device displays. 
     At step  86 , continuous strips  94  of opaque masking material  40  may be patterned (e.g., using patterning equipment such as photolithography equipment) using alignment marks  102  to form separate black masks for separate displays and to remove opaque masking material  40  from color filter elements  42  in regions of sheet  92  to be used for active areas AA of each display (e.g., active areas of display  14 - 1 , active areas of display  14 - 2 , etc.). 
     As shown in  FIG. 7 , each portion of sheet  92  to be used for a display (e.g., display  14 - 1 ,  14 - 2 , etc.) may include uncovered color filter elements  42  and an interposed black matrix in a central portion (e.g., a portion to be used as an active area AA of a display) and opaque masking material over color filter elements in a rectangular ring around the uncovered color filter elements  42  (e.g., in a portion of sheet  92  to be used as an inactive border region IA for that display). 
     At step  88 , additional display layers (e.g., planarization layers, polymer layers such as polyimide layers, liquid crystal layers, thin-film transistor layers, additional substrate layers such as additional glass layers, adhesive layers and other additional display layers) may be formed over patterned opaque masking material  40  and color filter elements  42  using alignment marks  102 . Portions of sheet  92  and associated display layers may then be cut to form multiple individual displays  14  having display layers of the type shown in  FIG. 6  for corresponding individual devices  10 . 
     The deposition and patterning steps of  FIG. 7  are, however, merely illustrative. If desired, a display having an inactive border region with opaque masking material formed over color filter elements (e.g., a display having color filter elements interposed between an opaque masking layer and a transparent substrate in an inactive region) may be formed using other methods. 
     As another example, the illustrative steps shown in  FIG. 8  may be used in forming a display having display layers of the type shown in  FIG. 6 . 
     At step  110 , metal alignment marks such as alignment marks  120  may be formed on a blank sheet of substrate material such as glass sheet  92  using metallic material having a relatively high reflectance such as metallic material containing chrome or aluminum. 
     Alignment marks  120  may be used by equipment such as patterning and deposition equipment in forming additional display structures (e.g., color filter elements, opaque masking layers or other display structures) on sheet  92  and/or in cutting portions of sheet  92  to form multiple individual displays  14  for individual devices  10 . 
     At step  112 , color filter elements such as red color filter elements, blue color filter elements, and green color filter elements may be formed on sheet  92 . Color filter elements  42  may be formed on a common surface of sheet  92  with the metal alignment marks or on an opposing surface of sheet  92  (i.e., a surface that is opposite to the surface on which metal alignment marks  120  are formed). Following formation of color filter elements  42  on sheet  92 , sheet  92  may have a multiplicity of color filter arrays for a corresponding multiplicity of displays  14  that are marked off by metal alignment marks  120 . 
     At step  114 , opaque masking material  40  may be deposited over color filter elements  42 . As shown in FIG.  7 , opaque masking material  40  may be deposited (e.g., using slot coating equipment) in discontinuous rectangular deposits  95  of opaque masking material that cover color filter elements  42 . Each of discontinuous rectangular deposits  95  may be formed on a portion of sheet  92  to be used for an individual device display (e.g., for displays  14 - 1 ,  14 - 2 , etc.). However, this is merely illustrative. Opaque masking material  40  may be deposited in continuous strips or may be deposited over substantially all of the surface of sheet  92  having color filter elements  42 . 
     At step  116 , opaque masking material  40  may be patterned (e.g., using patterning equipment such as photolithography equipment) using alignment marks  120  to remove opaque masking material  40  from color filter elements  42  in regions of sheet  92  to be used for active areas AA of each display (e.g., active areas of display  14 - 1 , active areas of display  14 - 2 , etc.). 
     As shown in  FIG. 8 , each portion of sheet  92  to be used for a display (e.g., display  14 - 1 ,  14 - 2 , etc.) may include uncovered color filter elements  42  and an interposed black matrix in a central portion (e.g., a portion to be used as an active area AA of a display) and opaque masking material over color filter elements in a rectangular ring around the uncovered color filter elements  42  (e.g., in a portion of sheet  92  to be used as an inactive border region IA for that display). 
     At step  118 , additional display layers (e.g., planarization layers, polymer layers such as polyimide layers, liquid crystal layers, thin-film transistor layers, additional substrate layers such as additional glass layers, adhesive layers and other additional display layers) may be formed over patterned opaque masking material  40  and color filter elements  42  using alignment marks  120 . Portions of sheet  92  and associated display layers may then be cut to form multiple individual displays  14  having display layers of the type shown in  FIG. 6  for corresponding individual devices  10 . 
       FIG. 9  shows illustrative deposition and patterning equipment of the type that may be used in performing the deposition and patterning steps of  FIGS. 7 and 8 . As shown in  FIG. 9 , deposition and patterning equipment  130  may include deposition equipment such as deposition device  136  for depositing display materials (e.g., color filter material, opaque masking material, planarization material, polymer material, liquid crystal material, polarizing material, anti-reflection coating material, oleophobic material, etc.) onto a substrate such as sheet  92 . 
     Deposition device  136  may include screen printing equipment, spin-on coating equipment, spray coating equipment, physical vapor deposition equipment, chemical vapor deposition equipment, or other suitable deposition equipment. In one suitable example that is sometimes discussed herein as an example, deposition device  136  may be a slot coating device having, for example, a squeegee that applies a layer of material of a desired thickness to sheet  92 . Deposition device may, for example, be used to deposit opaque masking material on sheet  92  in direction  142  while moving in direction  144  to form continuous strips  94  or rectangular deposits  95  on sheet  92 . Continuous strips  94  may be formed by continuously releasing material  40  while moving device  136  in direction  144 . Rectangular deposits  95  may be formed by alternately releasing and stopping material  40  while moving device  136  in direction  144 . 
     Deposition device  136  may be provided with display materials (e.g., color filter materials and opaque masking materials) using pump  134  to deliver material from reservoir  132  through tubes  138 . However, this is merely illustrative. If desired, deposition device  136  may be provided with display materials using any suitable means. 
     Deposition and patterning equipment  130  may include patterning equipment such as patterning equipment  135 . Patterning equipment may include photolithographic patterning equipment (e.g., equipment for resist exposure and development), chemical etching equipment, or other suitable equipment for patterning photo-resistive materials such as color filter material and opaque masking material. During patterning operations, patterning equipment  135  may be moved over sheet  92 . Patterning equipment  135  and deposition device  136  may use alignment marks such as color alignment marks  102  or metal alignment marks  120  in patterning color filter material and opaque masking material on sheet  92 . 
     Patterning equipment  135  and deposition device  136  may include optical sensing components such as camera sensors  140  for locating and tracking alignment marks  102  and/or  120 . Patterning equipment  135  and deposition device  136  may include computing equipment such as microprocessors, memory or other computing equipment for controlling the position of patterning equipment  135  and deposition device  136 , for controlling the volume of material released by deposition device  136 , for determining a relative position with respect to alignment marks  102  or  120  using camera sensors  140 , or for performing other computing tasks associated with depositing and patterning display layers on sheet  92 . 
     As shown in  FIG. 10 , deposition device  136  may include a rigid shim such as shim  150  for guiding opaque masking material  40  onto sheet  92  in direction  142 . Shim  150  may be formed from a patterned plastic member having openings such as slots for guiding (for example) opaque masking material  40  from tubes  138  onto sheet  92 . 
     As shown in  FIG. 11 , deposition device  136  may include a portion such as portion  152  that moves above a first surface of sheet  92  and an additional extended portion such as portion  154  that moves below an opposing second surface of sheet  92  during deposition operations. Portion  152  may be used to deposit display materials onto sheet  92  in direction  142 . Portion  154  may include sensors such as camera sensors  140  for locating and tracking alignment marks on sheet  92 . Camera sensors  140  may be used for tracking alignment marks on the upper or lower surface of sheet  92  during deposition operations. 
     If desired, color filter material in inactive region IA may be formed in an arrangement other than a regularly spaced array of color filter elements. As shown in  FIG. 12 , in inactive region IA, display  14  may include color filters  42 ′ having at least two colors C 1  and C 2 . Display  14  may include color filters  42 ′ having a third color C 3 . Colors C 1 , C 2 , and C 3  may be, for example, red, blue, and green. Color filters  42 ′ may be formed adjacent to other color filters  42 ′ without any intervening opaque masking material or may be separated from other color filters  42 ′ by intervening opaque masking material. Color filters  42 ′ may include color filters of two colors, color filters of three colors, or color filters of more than three colors. 
     Color filters  42 ′ may have a common lateral width along surface  73  or some color filters  42 ′ may have a lateral width along surface  73  that is larger or smaller than the lateral width along surface  73  of other color filters  42 ′. Color filter elements  42 ′ may be configured (e.g., by adjusting the aperture ratios of color filter elements  42  and color filters  42 ′) to form a color filter layer  38  in inactive region IA having an index of refraction that matches the index of refraction of color filter layer  38  in active region AA. Color filter layer  38  may be configured to provide display  14  with a reflectance and color in inactive region IA that is visually indistinguishable from the reflectance and color of display  14  in active region AA (e.g., when display pixels  100  are turned off). 
     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: 20120907
Publication Date: 20160517
Grant Date: 20160517
Priority Date: 20120405
Inventors: CHEN CHENG
YANG YOUNG CHEOL
PARK YOUNG BAE
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133502", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133502", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133516", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133516", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2001/133388", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133516", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133502", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F2001/133565", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133565", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133388", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133388", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133565", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 49292037