PATENT DOCUMENT

Publication Number: US-9025112-B2
Application Number: US-201213364885-A
Country: US
Kind Code: B2

Title: Display with color mixing prevention structures

Abstract:
An electronic device may have a liquid crystal display having a backlight and color mixing prevention structures. The color mixing prevention structures may, in part, be formed from one or more arrays of color filter elements. The liquid crystal display may include first and second transparent substrate layers on opposing sides of a liquid crystal layer. The display may include a first array of color filter elements on the first transparent substrate layer and a second array of color filter elements on the second transparent substrate layer. One or more of the arrays of color filter elements may include a black matrix formed over portions of the color filter elements. The color filter elements may fill or partially fill openings in the black matrix. The display may include a collimating layer on the second transparent substrate layer. The color filter elements may include cholesteric color filter elements.

Claims:
What is claimed is: 
     
       1. A display, comprising:
 a first transparent substrate layer; 
 a second transparent substrate layer; 
 a layer of liquid crystal material formed between the first and second transparent substrate layers; 
 a first color filter layer formed on the first transparent substrate layer; 
 a second color filter layer formed on the second transparent substrate layer, wherein the first color filter layer comprises a first array of color filter elements and a first black matrix having openings for the first color filter elements and wherein the second color filter layer comprises a second array of color filter elements and a second black matrix having openings for the second color filter elements, and wherein the second black matrix openings are completely filled with the color filter elements of the second array and wherein the first black matrix openings are partially filled with the color filter elements of the first array. 
 
     
     
       2. The display defined in  claim 1  wherein the second color filter layer comprises thin-film transistors and electrodes that are configured to produce electric fields to adjust the liquid crystal material. 
     
     
       3. The display defined in  claim 2  wherein the first transparent substrate comprises a layer of cover glass. 
     
     
       4. The display defined in  claim 1  wherein each of the color filter elements of the first array has a central opening. 
     
     
       5. The display defined in  claim 1  wherein the second transparent substrate layer comprises thin-film transistors, interconnect lines, and electrodes that are configured to produce electric fields to adjust the liquid crystal material, and wherein at least some of the interconnect lines are embedded within the second black matrix. 
     
     
       6. The display defined in  claim 1  wherein at least some of the second color filter elements comprise a multilayer dielectric stack that includes materials with different indices of refraction configured to form an optical filter. 
     
     
       7. A display, comprising:
 a first transparent substrate layer; 
 a second transparent substrate layer; 
 a layer of liquid crystal material formed between the first and second transparent substrate layers; 
 a color filter layer formed on an inner surface of the first transparent substrate layer, wherein the color filter layer comprises an array of colored filter elements and a black matrix having openings for the color filter elements and wherein at least a portion of the array of color filter elements is interposed between the black matrix and the inner surface, wherein the black matrix contacts the inner surface of the first transparent substrate layer, and wherein the black matrix comprises protrusions that extend past the color filter layer and are selected from the group consisting of: rounded protrusions, triangular protrusions, and protrusions with faceted edges. 
 
     
     
       8. The display defined in  claim 7  wherein the black matrix has first regions in which the portion of the color filter elements is interposed between the black matrix and the inner surface and has second regions in which the black matrix is formed on the inner surface without any interposed color filter elements. 
     
     
       9. The display defined in  claim 7  wherein the first transparent substrate comprises a layer of cover glass that forms an outermost layer of the display.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to displays for electronic devices. 
     Electronic devices such as computers and cellular telephones are generally provided with displays. Displays such as liquid crystal displays contain a thin layer of liquid crystal material. Color liquid crystal displays include color filter layers. The layer of liquid crystal material in this type of display is interposed between the color filter layer and a thin-film transistor. Polarizer layers may be placed above and below the color filter layer, liquid crystal material, and thin-film transistor layer. 
     When it is desired to display an image for a user, display driver circuitry applies signals to a grid of data lines and gate lines within the thin-film transistor layer. These signals adjust electric fields associated with an array of pixels on the thin-film transistor layer. The electric field pattern that is produced controls the liquid crystal material and creates a visible image on the display. 
     Image quality in conventional displays can be degraded during off-axis viewing, because off-axis viewing angles can allow light from display pixels of one color to bleed into adjacent display pixels of another color. Although off-axis quality can be improved somewhat by incorporating wide black matrix structures into the display, the use of excessively wide black matrix masking lines can adversely affect display brightness and may be impractical for use in a high-resolution display in which increasingly narrow black matrix masking lines are desired. 
     It would therefore be desirable to be able to provide improved electronic device displays. 
     SUMMARY 
     Electronic devices may be provided with displays such as liquid crystal displays. A display may have an array of display pixels. A liquid crystal display may be provided with backlight structures. The backlight structures may produce backlight that passes through the array of display pixels. The display pixels may include electrode structures and thin-film transistor structures for controlling electric fields in a layer of liquid crystal material. The liquid crystal material may be formed between an outer display layer formed in part by a first transparent substrate and an inner display layer formed, in part, by a second transparent substrate. 
     The inner display layer may be interposed between the backlight structures and the liquid crystal material. Thin-film transistor structures, electrodes, and conductive interconnection lines may be deposited in a layer on the inner surface of the inner display layer. In one suitable configuration, the first transparent substrate may form a layer of cover glass for the display. 
     A layer of color filter elements may be used to provide the display with color pixels. Color filter elements may be formed on the thin-film transistor layer. Color filter elements may be formed on the outer display layer. In some configurations, color filter elements may be formed on both the thin-film transistor layer and the outer display layer. 
     A patterned layer of opaque masking material may be formed in a peripheral border region of the outer display layer. A portion of the opaque masking material may form black matrix mask that visually separates adjacent color filter elements. A planarization layer may be used to cover some, or all, of the opaque masking layer. If desired, the planarization layer may be interposed between the black matrix and the color filter elements. 
     A first black matrix on the outer display layer may include openings for color filter elements on the outer display layer and a second black matrix on the inner display layer may include openings for the color filter elements one the thin-film transistor layer. The black matrix openings may be completely or partially filled with the color filter elements. 
     If desired, some or all of the interconnect lines of the thin-film transistor layer may be embedded within a black matrix that is formed on the thin-film transistor layer. 
     If desired, some or all of the color filter elements may be formed using cholesteric filter material such as a multilayer dielectric stack that includes materials with different indices of refraction configured to form an optical filter. 
     If desired, a light collimating layer may be provided on the second transparent substrate layer. The light collimating layer may be formed from collimating structures such as Fresnel lens structures, microlens structures, or structures containing an array of microprisms. 
     If desired, a portion of the array of color filter elements may be interposed between the black matrix and an inner surface of a transparent substrate layer. The portion of the color filter elements may be interposed between first regions of the black matrix and the inner surface while second regions of the black matrix are formed on the inner surface without any interposed color filter elements. 
     If desired, the array of color filter elements may form a contiguous array of color filter elements of different colors having adjoining edges. The black matrix may cover the adjoining edges without touching the inner surface of the transparent substrate 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 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 circuit diagram showing circuitry that may be used in operating an electronic device with a display in accordance with an embodiment of the present invention. 
         FIG. 6  is a circuit diagram of an illustrative display pixel in accordance with an embodiment of the present invention. 
         FIG. 7  is a cross-sectional side view of a portion of an illustrative liquid crystal display with backlight structures in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional view of an illustrative electronic device having a display that overlaps housing sidewall structures in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional view of an illustrative electronic device having a display that overlaps housing sidewall structures and having a display cover layer in accordance with an embodiment of the present invention. 
         FIG. 10  is a cross-sectional view of an illustrative electronic device having a display with edges that are mounted between opposing housing sidewalls in accordance with an embodiment of the present invention. 
         FIG. 11  is a cross-sectional view of an illustrative electronic device having a display with edges that are mounted between opposing housing sidewalls and having a display cover layer in accordance with an embodiment of the present invention. 
         FIG. 12  is a cross-sectional side view of a display showing how backlight structures may be used to provide the display with backlight in accordance with an embodiment of the present invention. 
         FIG. 13  is a cross-sectional view of an illustrative display having a substrate layer on which thin-film transistor structures have been formed in accordance with an embodiment of the present invention. 
         FIG. 14  is a top view of a portion of a display showing how a black matrix may be used to visually separate color filter elements in accordance with an embodiment of the present invention. 
         FIG. 15  is a cross-sectional side view of a conventional color filter array showing how color mixing may be present at off-axis viewing angles. 
         FIG. 16  is a cross-sectional side view of a portion of an illustrative display showing how formation of a black matrix layer over an array of color filter elements on an outer display layer may help improve off-axis display performance in accordance with an embodiment of the present invention. 
         FIG. 17  is a cross-sectional side view of a portion of a color filter array showing how a portion of an array of color filter elements may be interposed between a region of a black matrix and an inner surface of a transparent substrate in accordance with an embodiment of the present invention. 
         FIG. 18  is a cross-sectional side view of a portion of a color filter array showing how a portion of an array of color filter elements may be interposed between substantially all of a black matrix and an inner surface of a transparent substrate in accordance with an embodiment of the present invention. 
         FIG. 19  is a cross-sectional side view of a portion of a color filter array showing how color filter elements may have adjoining edges and a black matrix may cover the adjoining edges in accordance with an embodiment of the present invention. 
         FIG. 20  is a cross-sectional side view of a portion of a color filter array showing how a planarization layer may be interposed between a portion of an array of spatially-separated color filter elements and a black matrix formed from a thin metal matrix in accordance with an embodiment of the present invention. 
         FIG. 21  is a cross-sectional side view of a portion of a color filter array showing how a planarization layer may be interposed between a portion of an array of partially overlapping color filter elements and a black matrix formed from a thin metal matrix in accordance with an embodiment of the present invention. 
         FIG. 22  is a cross-sectional side view of a portion of a color filter array showing how color filter elements may have adjoining edges and a black matrix formed from a thin metal matrix may cover the adjoining edges in accordance with an embodiment of the present invention. 
         FIG. 23  is a cross-sectional side view of a portion of an illustrative display showing how a first color filter array and black matrix may be formed on a first transparent display substrate and a second color filter array and black matrix may be formed on a second transparent display substrate in accordance with an embodiment of the present invention. 
         FIG. 24  is a cross-sectional side view of a portion of an illustrative display showing how color filter elements may partially fill openings in a black matrix formed on an inner display layer in accordance with an embodiment of the present invention. 
         FIG. 25  is a cross-sectional side view of an illustrative display showing how color filter elements may partially fill openings in a black matrix formed on an outer display layer in accordance with an embodiment of the present invention. 
         FIG. 26  is a cross-sectional side view of a portion of an illustrative display showing how a collimating layer may be provided on an inner display layer that redirects light through color filter elements formed on an outer display layer in accordance with an embodiment of the present invention. 
         FIG. 27  is a cross-sectional side view of an illustrative display showing how a collimating layer may be provided on an inner display layer that redirects light through color filter elements formed on an opposing surface of the inner display layer in accordance with an embodiment of the present invention. 
         FIG. 28  is a cross-sectional side view of an illustrative display showing how some color filter elements may be configured to reflect selected colors of light in accordance with an embodiment of the present invention. 
         FIG. 29  is a cross-sectional side view of an illustrative display showing how a first color filter array may be formed on a first transparent display substrate and a second color filter array and black matrix may be formed on a thin-film transistor layer having control lines that are immersed in the black matrix 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. 
     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 active portion and an inactive portion. Display  14  may have openings (e.g., openings in the inactive or active portions 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 . 
       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 . 
     Other configurations may be used for electronic device  10  if desired. The examples of  FIGS. 1 ,  2 ,  3 , and  4  are merely illustrative. 
     A diagram showing circuitry of the type that may be used in device  10  is shown in  FIG. 5 . As shown in  FIG. 5 , display  14  may be coupled to device components  28  such as input-output circuitry  30  and control circuitry  32 . Input-output circuitry  30  may include components for receiving device input. For example, input-output circuitry  30  may include a microphone for receiving audio input, a keyboard, keypad, or other buttons or switches for receiving input (e.g., key press input or button press input from a user), sensors for gathering input such as an accelerometer, a compass, a light sensor, a proximity sensor, touch sensor (e.g., touch sensors associated with display  14  or separate touch sensors), or other input devices. Input-output circuitry  30  may also include components for supplying output. 
     Output circuitry may include components such as speakers, light-emitting diodes or other light-emitting devices for producing light output, vibrators, and other components for supplying output. Input-output ports in circuitry  30  may be used for receiving analog and/or digital input signal and may be used for outputting analog and/or digital output signals. Examples of input-output ports that may be used in circuitry  30  include audio ports, digital data ports, ports associated with 30-pin connectors, and ports associated with Universal Serial Bus connectors and other digital data connectors. 
     Control circuitry  32  may be used in controlling the operation of device  10 . Control circuitry  32  may include storage circuits such as volatile and non-volatile memory circuits, solid state drives, hard drives, and other memory and storage circuitry. Control circuitry  32  may also include processing circuitry such as processing circuitry in a microprocessor or other processor. One or more integrated circuits may be used in implementing control circuitry  32 . Examples of integrated circuits that may be included in control circuitry  32  include microprocessors, digital signal processors, power management units, baseband processors, microcontrollers, application-specific integrated circuits, circuits for handling audio and/or visual information, and other control circuitry. 
     Control circuitry  32  may be used in running software for device  10 . For example, control circuitry  32  may be configured to execute code in connection with the displaying of images on display  14  (e.g., text, pictures, video, etc.). 
     Display  14  may include a pixel array such as pixel array  34 . Pixel array  34  may be controlled using control signals produced by display driver circuitry such as display driver circuitry  36 . Display driver circuitry  36  may be implemented using one or more integrated circuits (ICs) and may sometimes be referred to as a driver IC, display driver integrated circuit, or display driver. Display driver integrated circuit  36  may be mounted on an edge of a thin-film transistor substrate layer in display  14  (as an example). The thin-film transistor substrate layer may sometimes be referred to as a thin-film transistor (TFT) layer. 
     During operation of device  10 , control circuitry  32  may provide data to display driver  36 . For example, control circuitry  32  may use a path such as path  38  to supply display driver  36  with digital data corresponding to text, graphics, video, or other images to be displayed on display  14 . Display driver  36  may convert the data that is received on path  38  into signals for controlling the pixels of pixel array  34 . 
     Pixel array  34  may contain rows and columns of display pixels  40 . The circuitry of pixel array  34  may be controlled using signals such as data line signals on data lines  42  and gate line signals on gate lines  44 . 
     Pixels  40  in pixel array  34  may contain thin-film transistor circuitry (e.g., polysilicon transistor circuitry or amorphous silicon transistor circuitry) and associated structures for producing electric fields across liquid crystal material in display  14 . The thin-film transistor structures that are used in forming pixels  40  may be located on a substrate (sometimes referred to as a thin-film transistor layer or thin-film transistor substrate). The thin-film transistor (TFT) layer may be formed from a planar glass substrate, a plastic substrate, or a sheet of other suitable substrate materials. 
     Gate driver circuitry  46  may be used to generate gate signals on gate lines  44 . Circuits such as gate driver circuitry  46  may be formed from thin-film transistors on the thin-film transistor layer. Gate driver circuitry  46  may be located on both the left and right sides of pixel array  34  (as shown in  FIG. 5 ) or may be located on only one side of pixel array  34 . 
     The data line signals in pixel array  34  carry analog image data (e.g., voltages with magnitudes representing pixel brightness levels). During the process of displaying images on display  14 , display driver integrated circuit  36  may receive digital data from control circuitry  32  via path  38  and may produce corresponding analog data on path  48 . The analog data signals on path  48  may be demultiplexed by demultiplexer circuitry  50  in accordance with control signals provided by driver circuitry  36 . This demultiplexing process produces corresponding color-coded analog data line signals on data lines  42  (e.g., data signals for a red channel, data signals for a green channel, and data signals for a blue channel). 
     The data line signals on data lines  42  may be provided to the columns of display pixels  40  in pixel array  34 . Gate line signals may be provided to the rows of pixels  40  in pixel array  34  by gate driver circuitry  46 . 
     The circuitry of display  14  such as demultiplexer circuitry  50  and gate driver circuitry  46  and the circuitry of pixels  40  may be formed from conductive structures (e.g., metal lines and/or structures formed from transparent conductive materials such as indium tin oxide) and may include transistors that are fabricated on the thin-film transistor substrate layer of display  14 . The thin-film transistors may be, for example, polysilicon thin-film transistors or amorphous silicon transistors. 
       FIG. 6  is a circuit diagram of an illustrative display pixel in pixel array  34 . Pixels such as pixel  40  of  FIG. 6  may be located at the intersection of each gate line  44  and data line  42  in array  34 . 
     A data signal D may be supplied to terminal  500  from one of data lines  42  ( FIG. 5 ). Thin-film transistor  52  (e.g., a thin-film polysilicon transistor or an amorphous silicon transistor) may have a gate terminal such as gate  54  that receives gate line signal G from gate driver circuitry  46  ( FIG. 5 ). When signal G is asserted, transistor  52  will be turned on and signal D will be passed to node  56  as voltage Vp. Data for display  14  may be displayed in frames. Following assertion of signal G in one frame, signal G may be deasserted. Signal G may then be asserted to turn on transistor  52  and capture a new value of Vp in a subsequent display frame. 
     Pixel  40  may have a signal storage element such as capacitor Cst or other charge storage element. Storage capacitor Cst may be used to store signal Vp between frames (i.e., in the period of time between the assertion of successive signals G). 
     Display  14  may have a common electrode coupled to node  58 . The common electrode (which is sometimes referred to as the Vcom electrode) may be used to distribute a common electrode voltage such as common electrode voltage Vcom to nodes such as node  58  in each pixel  40  of array  24 . Capacitor Cst may be coupled between nodes  56  and  58 . A parallel capacitance Clc arises across nodes  56  and  58  due to electrode structures in pixel  40  that are used in controlling the electric field through the liquid crystal material of the pixel (liquid crystal material  60 ). As shown in  FIG. 6 , electrode structures  62  may be coupled to node  56 . Capacitance Clc is associated with the capacitance between electrode structures  62  and common electrode Vcom at node  58 . During operation, electrode structures  62  may be used to apply a controlled electric field (i.e., a field having a magnitude proportional to Vp-Vcom) across a pixel-sized portion of liquid crystal material  60  in pixel  40 . Due to the presence of storage capacitor Cst, the value of Vp (and therefore the associated electric field across liquid crystal material  60 ) may be maintained across nodes  56  and  58  for the duration of the frame. 
     The electric field that is produced across liquid crystal material  60  causes a change in the orientations of the liquid crystals in liquid crystal material  60 . This changes the polarization of light passing through liquid crystal material  60 . The change in polarization may be used in controlling the amount of light that is transmitted through each pixel  40  in array  34 . 
     A portion of display  14  illustrating how changes in the light polarization produced by liquid crystal material  60  can be used to affect the amount of light that is transmitted through display  14  is shown in  FIG. 7 . As shown in  FIG. 7 , 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 layer  70 . Lower polarizer layer  74  may be attached to one or more substrate layers such as layer  72 . Layers  70  and/or  72  may be formed from transparent layers such as layers of glass, plastic, or other sheets of material. Layers  70  and/or  72  and other layers of display  81  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. 
     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 , the transmission of light  66  through layer  68  will be maximized. If the polarization of light  66  is aligned so as to run perpendicular to the polarization of polarizer  68 , the transmission of light  66  through layer  68  will be minimized (i.e., light  66  will be blocked). The display circuitry of  FIG. 5  may be used in adjusting the voltages Vp across the electrodes  62  of display pixels  40  in display pixel array  34 , thereby selectively lightening and darkening pixels  40  in pixel array  34  and presenting an image to a user of device  10  such as viewer  76 , viewing display  14  in direction  78 . 
     Displays such as display  14  may be mounted on one or more surfaces of device  10 . For example, displays such as display  14  may be mounted on a front face of housing  12 , on a rear face of housing  12 , or on other portions of device  10 . 
     As shown in  FIG. 8 , display  14  may be mounted in housing  12  so that some or all of the edges of display  14  overlap housing sidewalls  12 ′. Internal electrical components  82  (e.g., input-output components  30 , control circuitry  32 , etc.) may be mounted on one or more substrates such as substrate  80  within housing  12 . Substrate  80  may be formed from one or more printed circuits. For example, substrate  80  may include a rigid printed circuit board (e.g., a printed circuit board formed from a material such as fiberglass-filled epoxy) and/or a flexible printed circuit (“flex circuit”) such as a printed circuit formed from patterned conductive traces on a sheet of polyimide or other flexible polymer. 
     If desired, some or all of the outermost surface of display  14  may be covered with a display cover layer such as display cover layer  84  of  FIG. 9 . Display cover layer  84  may be formed from a layer of glass, a layer of plastic, a layer of ceramic, or other suitable transparent materials. One or more additional display layers may also be included in display  14  if desired (e.g., antireflection films, scratch-resistance coating layers, fingerprint-reducing layers, layers that perform multiple functions such as reducing reflection, reducing scratches, and reducing fingerprints, etc.). 
       FIG. 10  is a cross-sectional view of device  10  in a configuration in which display  14  has been mounted between respective housing sidewalls  12 ′ (i.e., without overlapping upper edges  12 ″ of sidewalls  12 ′).  FIG. 11  shows how display cover layer  84  may be used to cover display  14  in a configuration in which display  14  is mounted between housing sidewalls  12 ′. 
     The illustrative mounting arrangements of  FIGS. 8 ,  9 ,  10 , and  11  are merely illustrative examples of ways in which display  14  may be mounted in housing  12  of device  10 . Other mounting configurations may be used if desired. 
       FIG. 12  is a cross-sectional view of display  14  showing how backlight structures  86  may be used in producing backlight  66  for display  14 . As shown in  FIG. 12 , a light source such as light source  92  may produce light  94 . Light source  92  may include, for example, one or more light-emitting diodes. Backlight structures  86  may include a light guide plate and other layers  88  (e.g., a diffuser and other optical films). A reflective layer such as reflector  90  may be placed on the rear surface of the light guide plate. As light  94  travels through the light guide plate, some of light  94  scatters upwards in direction Z towards viewer  76  and serves as backlight  66  for display  14 . Light that scatters downwards may be reflected upwards by reflector  90  to serve as additional backlight  66 . 
     Display layers  81  may include thin-film transistors such as transistor  52  of  FIG. 6  and conductive structures (e.g., electrodes such as electrode  62 , gate lines, data lines, and other lines and conductive structures formed from metal and/or indium tin oxide or other transparent conductive materials). Display layers  81  may also include color filter structures for imparting colors such as red, blue, and green colors to pixels  40  in pixel array  34 . The color filter structures may be formed in an array (e.g., an array of alternating red, green, and blue color filter elements) and are therefore sometimes referred to as a color filter array or color filter array structures. 
     Color filter array structures may be formed using colored substances such as dye or pigment (e.g., colored red, blue, and green ink or materials of other suitable colors). Color filter structures may be formed by ink-jet printing, screen printing, pad printing, photolithographic patterning, or other suitable deposition and patterning techniques. Color filter structures may be formed on the same substrate as the thin-film transistors and conductive structures of display pixels  40  or may be formed separately (e.g., on a transparent substrate that is separated from a thin-film transistor substrate layer). 
     As shown in  FIG. 13 , thin-film transistor layer  108  may be formed on substrate  96 . Each electrode  62  (i.e., each set of three common electrode finger structures in the example of  FIG. 13 ) may be configured generate electric fields in liquid crystal material associated with a given pixel  40 . If desired, color filter elements  116 ′ of color filter layer  116  may be used to impart colors to backlight  66  generated by backlight structures  86  ( FIG. 12 ). Color filter layer  116  may include lines of black matrix material  124 . 
     Black matrix material  124  may be formed on one or more surfaces of color filter array  116  and may be configured to overlap structures in thin-film transistor layer  108  such as structures  126  (e.g., gate lines  44 , data lines  42 , etc.) and thereby block structures  126  from view. The thickness T of thin-film transistor layer  108  may be relatively small (e.g., less than 25 microns, less than 5 microns, less than 2 microns, etc.). One or more color filter layers  116  may be provided. If desired, a color filter array such as color filter array  116  may be formed on thin-film transistor layer  108 . If desired, a layer of liquid crystal material such as liquid crystal layer  60  may be formed between color filter array  116  and thin-film transistor layer  108 . 
     As shown in  FIG. 14 , color filter elements  116 ′ in color filter array  116  may be separated by lines of opaque material (sometimes referred to as black matrix material or opaque masking material). The black matrix may be used to block metal lines and other structures from view by the user of device  10  and may help reduce light leakage between adjacent pixels. The black matrix may be formed from opaque organic or inorganic materials such as chrome and black ink (as examples). 
     The top view of color filter array  116  in  FIG. 14  shows how black matrix  124  may form a grid of opaque masking lines on color filter layer  116  that visually separate respective color filter elements  116 ′. The width of the masking lines (shown as width W in  FIG. 15 ) may be less than 50 microns, less than 30 microns, less than 20 microns, less than 15 microns, less than 10 microns, less than 7 microns, less than 3 microns, or any other suitable width. The lateral dimensions of color filter elements  116 ′ may be 500 microns or less, 100 microns or less, 50 microns or less, or microns or less (as examples). For example, rectangular color filter elements  116 ′ in array  116  may be provided with pixel dimensions of 25 microns by 75 microns (as an example). 
     It may be desirable to reduce the magnitude of black matrix line width W relative to the lateral dimensions D of color filter elements  116 ′ to improve display brightness (i.e., brightness efficiency). However, as shown in  FIG. 15 , a conventional display  100  having separators  101  between color filters  115  may provide a line of sight to an operating light source through a color filter associated with a non-operating light source. Conventional display  100  includes an array  103  of light sources associated with pixels  41  that are aligned with color filters  115 . 
     While the light source associated with the green filter (g) is operating (ON), the light sources associated with the red filter (r) and the blue filter (b) are not operating (OFF). A viewer  113  viewing conventional display  100  along on-axis viewing angle  117  views the operating light source through the desired filter g. However, a viewer  111  viewing conventional display  100  along an off-axis viewing angle  121  will see the operating light source through the incorrect (r) filter, thereby reducing the quality of the content displayed using conventional display  100 . 
     In order to prevent this type of color mixing display content degradation, device  10  may be provided with color mixing prevention structures. Consider, as an example, display  14  of  FIG. 16 . As shown in  FIG. 16 , color filter layer  116  may be provided color mixing prevention structures such as black matrix material  124  that is formed at least partially on an interior surface of color filter elements  116 ′ of color filter array  116  on outer display layer  118 . 
     Color filter array (color filter layer)  116  may be formed on an inner surface (e.g., a surface that faces liquid crystal layer  60 ) of transparent substrate layer  118 . Color filter layer  116  may include an array of color filter elements  116 ′ and a black matrix  124  having openings  142  for color filter elements  116 ′. As shown in  FIG. 16 , a portion of array  116  of color filter elements  116 ′ may be interposed between black matrix  124  and the inner surface of layer  118 . If desired, a transparent planarization layer such as planarization layer  130  may be interposed between black matrix material  124  and color filter elements  116 ′. 
     Viewer  76  may view display  14  through substrate  118  and color filter layer  116  by viewing in a direction such as direction  78 . (Polarizer layers, cover glass, backlight structures and other layers have been omitted from  FIG. 16  for clarity). Backlight  66  passes through liquid crystal material  60 . Electrodes  62  are located in thin-film transistor layer  108  on substrate  96 , so the electric field that is produced in liquid crystal material  60  is strongest near layer  108  and is weakest near layer  118 . Color filter array  116  may be deposited on substrate  118 . Layer  118  may be formed from clear glass, clear plastic, or other transparent material. 
     In the  FIG. 16  example, the red pixel “R” and the blue pixel “B” are not receiving signals on their respective electrodes  62 , so the liquid crystals  60 ′ in the portions of liquid crystal layer  60  that are associated with the R and B pixels have not been rotated. The electrode  62  that is associated with the green pixel “G” is, however, receiving a signal (in this example) and is therefore producing an electric field in an adjacent portion of layer  60 . As a result, liquid crystals  60 ′ above electrode  62  in the green pixel “G” are rotated. 
     When viewing the pixels of display  14  “on-axis” (i.e., along a direction that is parallel to the surface normal n for substrate  118 ), backlight  66  will generally not leak appreciably into adjacent pixels and the pixel colors will tend not to bleed into each other. When, however, viewer  76  views display  14  along an off-axis angle such as the angle associated with direction  78  of  FIG. 16 , there is a risk that the viewer will view part of the liquid crystal material associated with one pixel through the color filter of another pixel. If not well controlled, this effect can reduce display performance by reducing color accuracy. 
     With a display of the type show in  FIG. 16 , off-axis performance may be enhanced, because off-axis light rays that have the potential to cause interference are blocked by black matrix material  124  that is formed on the inner surface of color filter array  116 . When viewer  76  views display  14  along viewing axis  78 , viewer  76  will observe black matrix structures  124  blocking rotated liquid crystals  60 ′ associated with green pixel “G”. In other words, light  66  that has travelled through rotated (i.e., “on”) liquid crystals  60 ′ toward red (“R”) color filter element  116 ′ is blocked by black matrix material  124 . 
     A viewer observing the center of the green pixel “on-axis” will therefore correctly observe that the green pixel is emitting green filtered backlight  66  and has a green color. When viewer  76  views display  14  along viewing axis  78 , however, viewer  76  will only observe black matrix  124 . The red pixel “R” in  FIG. 16  will therefore correctly appear “off” (e.g., the red pixel&#39;s liquid crystals  60 ′ have not been rotated, so the viewer should not be observing any red light through the red color filter element  116 ′). 
     The enhanced blocking for display  14  of color bleeding between adjacent pixels may be exploited to enhance color accuracy and/or to reduce the width of black matrix  124  and thereby improve display brightness efficiency. 
     The example of  FIG. 16  is merely illustrative. If desired, color filter array  116  may be formed on thin-film transistor layer  108 . If desired, a color filter array  116  that is formed on thin-film transistor layer  108  may include a black matrix  124  over an interior surface of at least a portion of color filter layer. If desired, a color filter layer  116  and/or a black matrix  124  may be formed on both layer  108  and layer  118 . In configurations in which a color filter layer  116  is formed on both layer  108  and layer  118 , the thickness of each color filter layer may be equal, the thickness of the color filter layer on layer  118  may be larger than the thickness of the color filter layer on layer  108 , or the thickness of the color filter layer on layer  118  may be smaller than the thickness of the color filter layer on layer  108 . 
     As shown in  FIGS. 17 ,  18 , and  19 , black matrix material  124  may be an organic opaque polymer that is formed over at least a portion of color filter elements  116 ′. In the examples of  FIGS. 17 ,  18 , and  19 , color filter elements  116 ′ are formed on a transparent substrate layer  119 . Transparent substrate layer  119  may be formed from clear glass, plastic, or any other suitable transparent substrate. Transparent substrate layer  119  may be, as examples, an outer display layer such as layer  118  or an inner display layer such as combined layers  96  and  108  of  FIG. 16 . 
     As shown in the example of  FIG. 17 , individual color filter elements  116 ′ that have a lateral separation from each other may be formed on layer  119 . Layer  119  may have an inner surface  138  and an outer surface  140 . Inner surface  138  may, for example, be a surface of layer  119  that is closer to a liquid crystal layer such as liquid crystal layer  60  (see, e.g.,  FIG. 16 ) than outer surface  140 . Black matrix material  124  may be partially formed on color filter elements  116 ′ and partially formed on inner surface  138 . 
     Regions such as regions  148  of black matrix material  124  may be formed directly on inner surface  138  of layer  119  without any interposed color filter elements. Regions  150  of black matrix material  124  may be formed on portions  144  of array  116  of color filter elements  116 ′ that are interposed between black matrix  124  and inner surface  138  of layer  119 . 
     Black matrix  124  may include openings such as openings  142 . Color filter elements  116 ′ may be formed in openings  142  so that portions  146  of color filter elements  116 ′ may pass light of a corresponding color. Color filter elements  116 ′ may be characterized by a first thickness  152  on inner surface  138 . Black matrix layer  124  may be characterized by a second thickness  154  on inner surface  138  that is greater than thickness  152 . However, this is merely illustrative. If desired, thickness  154  may be substantially the same as thickness  152  or may be smaller than thickness  152 . 
     A planarization layer such as layer  130  may be formed over some or all of opaque masking layer  124  and color filter elements  116 ′. Planarization layer  130  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. Layer  130  may be deposited by screen printing, spin-on coating, spray coating, physical vapor deposition, chemical vapor deposition, or other suitable deposition techniques. If desired, layer  130  may be polished to help planarize layer  130 . 
     If desired, black matrix  124  may include protruding portions (indicated by dashed lines  136 ) that extend beyond color filter elements  116 ′ to form extended barriers to light an off-axis viewing angles. Protruding portions  136  may be rounded, may be triangular, may be rectangular, may have faceted edges, or may have any other suitable shape for blocking off-axis light. 
     During manufacturing of device  10 , a first set of color filter elements  116 ′ (e.g., green color filter elements  116 ′) may be formed on layer  119  by, for example, providing a coating of a first color photoresist (e.g., a photoresist material that is configured to pass green light) on inner surface  138 , providing a patterned ultraviolet (UV) light mask on the color photoresist material, etching the color photoresist material using UV light, and removing the UV mask. 
     A subsequent set of color filter elements  116 ′ (e.g., red color filter elements  116 ′) may then be formed on layer  119  by, for example, providing a second coating of a color photoresist (e.g., a photoresist material that is configured to pass red light) on inner surface  138  and remaining portions of the first color photoresist material, providing a second patterned UV mask on the second color photoresist material, etching the second color photoresist material using UV light, and removing the UV mask. Additional sets of color filter elements  116 ′ (e.g., blue color filter elements, or other color filter elements) may then be formed on substrate layer  119  by repeating the steps of providing a color photoresist, providing a UV mask, etching the color photoresist, and removing the UV mask. 
     Black matrix  124  may then be formed over portions  144  of color filter layer  116  and on portions of inner surface  138  by providing a coating of black matrix material over color filter elements  116 ′ and on exposed portions of inner surface  138  of layer  119 , providing a patterned UV mask on the coating of black matrix material  124 , etching openings  142  into black matrix material  124  and removing the UV mask. 
     Other steps may be involved in forming color filter elements  116 ′ and black matrix  124  such as baking steps (e.g., soft baking and hard baking), deposition steps (e.g., screen printing, spin-on coating, spray coating, physical vapor deposition, and chemical vapor deposition) or other suitable steps. The steps described in connection with  FIG. 17  are merely illustrative. 
     The example of  FIG. 17  in which color filter elements  116 ′ of color filter array  116  are spatially separated and black matrix material  124  is formed in contact with inner surface  138  is merely illustrative. As shown in the example of  FIG. 18 , individual color filter elements  116 ′ may be formed on layer  119  so that each individual color filter element  116 ′ partially overlaps a portion of an adjacent color filter element  116 ′ of a different color. Black matrix material  124  may be formed over color filter elements  116 ′ so that a portion of black matrix material  124  is formed over overlapping portions of color filter elements  116 ′. 
     In the example of  FIG. 18 , portion  144  of color filter array  116  that is covered by black matrix  124  may include overlapping portions of color filter elements  116 ′ while portion  150  of black matrix  124  that is formed on color filter elements  116 ′ may include substantially all of black matrix  124  (i.e., black matrix  124  may be formed on color filter elements  116 ′ without touching inner surface  138  of layer  119 ). 
     As with the example of  FIG. 17 , in the example of  FIG. 18 , planarization layer  130  is formed over opaque masking layer  124  and color filter elements  116 ′. 
     During manufacturing of device  10 , a first set of color filter elements  116 ′ (e.g., red color filter elements  116 ′) may be formed on layer  119  by, for example, providing a coating of a first color photoresist (e.g., a photoresist material that is configured to pass red light) on inner surface  138 , providing a patterned ultraviolet (UV) light mask on the color photoresist material, etching the color photoresist material using UV light, and removing the UV mask. 
     A subsequent set of color filter elements  116 ′ (e.g., green color filter elements  116 ′) may then be formed on layer  119  by, for example, providing a second coating of a color photoresist (e.g., a photoresist material that is configured to pass green light) on inner surface  138  and remaining portions of the first color photoresist material, providing a second patterned UV mask on the second color photoresist material, etching the second color photoresist material using UV light so that a portion of the second color photoresist material remains on a portion of the first color photoresist material, and removing the UV mask. 
     Additional sets of color filter elements  116 ′ (e.g., blue color filter elements, or other color filter elements) may then be formed on substrate layer  119  by repeating the steps of providing a color photoresist, providing a UV mask, etching the color photoresist, and removing the UV mask. 
     Black matrix  124  may then be formed over portions  144  of color filter layer  116  by providing a coating of black matrix material  124  over color filter elements  116 ′, providing a patterned UV mask on the coating of black matrix material  124 , etching openings  142  into black matrix material  124 , and removing the UV mask. 
     Other steps may be involved in forming color filter elements  116 ′ and black matrix  124  such as baking steps (e.g., soft baking and hard baking), deposition steps (e.g., screen printing, spin-on coating, spray coating, physical vapor deposition, and chemical vapor deposition) or other suitable deposition steps. The steps described in connection with  FIG. 18  are merely illustrative. 
     The example of  FIG. 18  in which color filter elements  116 ′ of color filter array  116  are partially overlapping is merely illustrative. As shown in  FIG. 19 , array  116  of color filter elements  116 ′ may form a contiguous array of color filter elements  116 ′ of different colors having adjoining edges  156 . Black matrix  124  may be configured to cover adjoining edges  156 . Color filter elements  116 ′ having adjoining edges  156  may be interposed between substantially all of black matrix  124  and inner surface  138  of layer  119  (i.e., region  150  of black matrix  124  may include substantially all of black matrix  124  so that black matrix  124  is formed on color filter array  116  and without touching inner surface  138  of layer  119 ). 
     The examples of  FIGS. 17 ,  18 , and  19  in which black matrix material  124  is formed from an organic opaque polymer that is formed over at least a portion of color filter elements  116 ′ and covered by planarization layer  130  are merely illustrative. If desired, planarization layer  130  may be interposed between black matrix  124  and color filter elements  116 ′ as shown in  FIGS. 20 and 21 . 
     In configurations in which planarization layer  130  is interposed between black matrix  124  and color filter elements  116 ′, black matrix  124  may be formed from thin patterned inorganic material such as a layer of patterned metal (e.g., chrome) or other inorganic material. A black matrix  124  that is formed from a thin patterned metal layer may have a thickness T. Thickness T may be (as examples) between 1-25 microns, 1-10 microns, less than 10 microns, less than 5 microns, less than 3 microns, less than 2 microns, or less than 1 micron. 
     As shown in  FIG. 20 , individual color filter elements  116 ′ that are formed on layer  119  may have a lateral separation from each other. Planarization layer  130  may be formed on color filter elements  116 ′ and on portions of inner surface  138  in gaps between color filter elements  116 ′ (i.e., some of planarization layer  130  may be interposed between color filter elements  116 ′ in array  116  of color filter elements). Black matrix material  124  may be formed on planarization layer  130  over gaps between color filter elements  116 ′. Openings  142  in black matrix  124  may be aligned with color filter elements  116 ′ so that color filter elements  116 ′ that are formed in openings  142  may pass light of a corresponding color. 
     If desired, some of color filter elements  116 ′ formed on layer  119  may have a portion that partially overlaps a portion of an adjacent color filter element  116 ′ of a different color. Planarization layer  130  may be formed over color filter elements  116 ′ so that raised overlapping portions of color filter array  116  may be covered by a planar layer. Black matrix material  124  may be formed on planarization layer over color filter elements  116 ′ so that a portion of black matrix material  124  is formed on planarization layer  130  over overlapping portions of color filter elements  116 ′. 
     During manufacturing of display  14 , color filter elements  116 ′ of  FIGS. 20 and 21  may be formed using some or all of the illustrative steps described above in connection with  FIGS. 17 and 18 , respectively. Planarization layer  130  may then be deposited over color filter elements  116 ′. Black matrix  124  may then be formed on planarization layer  130  by providing a coating of black matrix material  124  on planarization layer  130 , providing a patterned UV mask on the coating of black matrix material  124 , etching openings  142  into black matrix material  124  and removing the UV mask. 
     The examples of  FIGS. 20 and 21  in which planarization layer  130  is interposed between color filter array  116  and a patterned metal black matrix  124  is merely illustrative. As shown in  FIG. 21 , a patterned metal black matrix  124  may be formed directly on color filter elements  116 ′ so that patterned metal black matrix  124  covers adjoining edges  156  of adjacent color filter elements  116 ′ and color filter elements  116 ′ are interposed between substantially all of black matrix  124  and inner surface  138  of layer  119 . 
     During manufacturing of display  14 , color filter elements  116 ′ of  FIG. 22  may be formed using some or all of the illustrative steps described above in connection with  FIGS. 17  and/or  18 . Black matrix  124  may then be formed on color filter elements  116 ′ by providing a coating of black matrix material  124  over color filter elements  116 ′, providing a patterned UV mask on the coating of black matrix material  124 , etching openings  142  into black matrix material  124  and removing the UV mask. 
     Black matrix  124  and color filter layer  116  may be formed on outer display layer  118  (see, e.g.,  FIG. 16 ) in any of the configurations described above in connection with  FIG. 17 ,  18 ,  19 ,  20 ,  21 , or  22 , or in any combination of those configurations. 
     As shown in  FIG. 23 , display  14  may be provided with multiple color filter layers. Color filter layers such as color filter layers  116 - 1  and  116 - 2  may be formed on opposing sides of liquid crystal layer  60 . Color filter layers  116 - 1  and  116 - 2  may, if desired, each be provided with black matrix material  124 . 
     Black matrices  124 - 1  and  124 - 2  may be formed on color filter layers  116 - 1  and  116 - 2  respectively in any of the configurations described above in connection with  FIG. 17 ,  18 ,  19 ,  20 ,  21 , or  22 , or in any combination of those configurations. 
     In the example of  FIG. 23 , color filter layer  116 - 1  is formed on transparent substrate layer  118  and color filter layer  116 - 2  is formed over layer  108  on transparent substrate layer  96 . In this way, backlight  66  may pass through both layers  116 - 1  and  116 - 2  as backlight  66  passes through display  14 . 
     Viewer  76  may view display  14  through substrate  118  and color filter layers  116 - 1  and  116 - 2  by viewing in a direction such as direction  78 . (Polarizer layers, cover glass, backlight structures and other layers have been omitted from  FIG. 23  for clarity). In configurations in which color filter elements  116 ′ are formed on both the inner display layer (e.g., thin-film transistor layer  108  and transparent substrate layer  96 ) and the outer display layer (e.g., transparent substrate layer  118 ), black matrix  124 - 1  may include openings  142  for color filter elements  116 ′ of array  116 - 1  and black matrix  124 - 2  may have openings  142  for color filter elements  116 ′ of array  116 - 2 . 
     In the example of  FIG. 23 , openings  142  in both black matrix  124 - 1  and black matrix  124 - 2  are completely filled with color filter elements  116 ′ of array  116 - 1  and  116 - 2  respectively. However, this is merely illustrative. As shown in  FIG. 24 , if desired, openings  142  of black matrix  124 - 1  on array  116 - 1  may be completely filled with color filter elements  116 ′ of array  116 - 1  and black matrix openings  142  of black matrix  124 - 2  may be partially filled with color filter elements  116 ′ of array  116 - 2 . Each color filter element  116 ′ of array  116 - 2  may have a central opening within one of openings  142 . As shown in  FIG. 25 , if desired, openings  142  of black matrix  124 - 1  on array  116 - 1  may be partially filled with color filter elements  116 ′ of array  116 - 1  and black matrix openings  142  of black matrix  124 - 2  may be completely filled with color filter elements  116 ′ of array  116 - 2 . Each color filter element  116 ′ of array  116 - 1  may have a central opening within one of openings  142 . 
     As shown in  FIG. 26 , display  14  may be provided with a single color filter array  116  on substrate  118  and a light collimating layer such as collimator  160  on transparent substrate  96 . Substrate  96  may have opposing first and second surfaces  97  and  95 . Thin-film transistor layer  108  may be formed on first surface  97  of substrate  96 . Light collimating layer  160  may be formed on opposing second surface  95  of substrate  96 . In this way, display  14  may be configured to redirect backlight  66  that is emitted in an off-axis direction such as one of directions  162  onto an on-axis path so that light that passes through liquid crystal layer  60  forms a collimated beam of light with minimal off-axis components. 
     Collimating layer  160  may be formed from, as examples, collimating structures such as Fresnel lens structures, microlens structures, or structures containing an array of microprisms that generates multiple internal reflections of light that is received from off-axis directions and re-transmits that light after an internal reflection into an on-axis direction. 
     The arrangement of  FIG. 26  is merely illustrative. In configurations in which display  14  is provided with a collimating layer such as collimating layer  160  on substrate  96 , color filter array  116  may, if desired, be formed on thin-film transistor layer  108  as shown in  FIG. 27 . 
     If desired, color filter elements  116 ′ of color filter arrays  116  (including arrays  116 - 1  and  116 - 2  of  FIGS. 23 ,  24 , and  25 ) may each be formed from a common color filter material or, if desired, some of color filter elements  116 ′ may be formed from one or more different color filter materials. As an example, color filter array  116 - 2  on thin-film transistor layer  108  may include one or more color filter elements  116 C that are formed from a different material than the material used to form color filter elements  116 ′ as shown in  FIG. 28 . 
     In the example of  FIG. 28 , color filter elements  116 C may be formed from a multilayer dielectric stack that includes materials with different indices of refraction configured to form an optical filter that selectively reflects some colors of light while reflecting other colors of light. Color filter elements  116 C may, for example, be cholesteric color filter elements formed from chiral nematic materials or other wavelength-dependent reflective materials that are configured to reflect selected colors of light. As shown in  FIG. 28  as an illustrative example, green “G′” color filter element  116 C may reflect red light  66 R and blue light  66 G and to pass green light  66 G. Similarly, red “R′” color filter element  116 C may be configured to reflect green light and blue light while passing red light and blue “B′” color filter element  116 C may be configured to reflect green light and red light while passing blue light. 
     As shown in  FIG. 29 , a color filter layer such as color filter array  116 - 1  on substrate  118  may be formed free of black matrix material. In configurations in which color filter array  116 - 1  on substrate  118  is formed free from black matrix material, at least some of interconnect lines  126  may be embedded within black matrix  124 - 3  that is part of a color filter layer such as color filter array  116 - 2  on thin-film transistor layer  108 . Black matrix  124 - 3  may include openings  142  for the color filter elements  116 ′ of array  116 - 2 . If desired, black matrix  124 - 3  may have an inner surface that is coplanar with color filter elements  116 ′ of array  116 - 2  (as indicated by dashed lines  170 ) or black matrix  124 - 2  may have an inner surface that is formed in a different plane from color filter elements  116 ′ of array  116 - 2 . 
     Black matrices  124  and color filter layers  116  of  FIGS. 24 ,  25 ,  26 ,  27 ,  28  and  29  may be formed having any of the configurations described above in connection with  FIG. 17 ,  18 ,  19 ,  20 ,  21 , or  22 , or in any combination of those configurations. 
     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: 20120202
Publication Date: 20150505
Grant Date: 20150505
Priority Date: 20120202
Inventors: XU MING
GETTEMY SHAWN R.
YANG YOUNG CHEOL
GE ZHIBING
CHEN CHENG
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F2001/136222", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/136209", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2001/133521", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133526", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/136222", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133521", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133521", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133357", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/136222", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/136209", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133509", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/1368", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133512", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/1362", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/136209", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133526", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B5/201", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133526", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 47561862