PATENT DOCUMENT

Publication Number: US-9201452-B2
Application Number: US-201213407492-A
Country: US
Kind Code: B2

Title: Electronic device with illuminated logo structures

Abstract:
An electronic device may have a liquid crystal display with backlight structures. The backlight structures may produce backlight that passes through the liquid crystal display. A reflector may be used to enhance backlight efficiency. The electronic device may have a housing in which the display is mounted. The housing may be formed from an opaque material such as metal. An opening may be formed in the housing. Transparent housing structures such as a transparent logo structure may be mounted in the opening of the housing. During operation, a light source may produce light that passes through the transparent logo structure. A light guide structure may be used to guide light from the light source to the transparent logo structure. The reflector may be formed from a coating of metal on the light guide structure. Light from the light source may be used to form the backlight for the backlight structures.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; 
 a transparent housing structure mounted in an opening in the housing, wherein the transparent housing structure has a first width; 
 a display in the housing that has a second width; 
 a display backlight reflector that reflects backlight through the display; 
 a light source; 
 a first light guide structure through which light is conveyed from the light source to the display; and 
 a second light guide structure that conveys light from the light source to the transparent housing structure, wherein the display backlight reflector is interposed between the first light guide structure and the second light guide structure, wherein the light conveyed by the second light guide structure passes through the transparent housing structure, wherein the second light guide structure has a first portion that is adjacent to the light source and has a third width, wherein the second light guide structure has a second portion that is adjacent to the transparent housing structure and has a fourth width, wherein the first width is substantially equivalent to the fourth width, wherein the second width is substantially equivalent to the third width, and wherein the fourth width is smaller than the third width. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the display backlight reflector comprises a layer of metal that transmits less than 1% of the backlight. 
     
     
       3. The electronic device defined in  claim 2  further comprising a light guide plate that receives the backlight from the light source. 
     
     
       4. The electronic device defined in  claim 3  wherein the light guide plate comprises a planar sheet of clear plastic having an edge that receives light from the light source. 
     
     
       5. The electronic device defined in  claim 2  wherein the second light guide structure comprises a planar sheet of clear plastic. 
     
     
       6. The electronic device defined in  claim 5  wherein the transparent housing structure comprises a logo structure. 
     
     
       7. The electronic device defined in  claim 6  wherein the second light guide structure comprises light-leakage promotion structures that overlap the logo structure and that locally cause the light from the light source to exit the second light guide structure and pass through the logo structures. 
     
     
       8. The electronic device defined in  claim 7  wherein the light-leakage promotion structures comprise protrusions on a surface of the second light guide structure. 
     
     
       9. The electronic device defined in  claim 8  wherein the housing comprises an opaque material. 
     
     
       10. The electronic device defined in  claim 9  wherein the housing comprises a portable computer upper housing. 
     
     
       11. The electronic device defined in  claim 9  wherein the housing comprises a housing selected from the group consisting of: a portable computer housing, a housing for a computer monitor with an integrated computer, a computer monitor housing, a cellular telephone housing, and a tablet computer housing. 
     
     
       12. An electronic device, comprising:
 an opaque housing having an opening; 
 a housing structure in the opening; 
 a light source; 
 a light guide structure having first and second opposing surfaces; 
 a liquid crystal display module; 
 a light guide plate; and 
 a reflector that covers the first surface, wherein the light guide structure conveys light from the light source through the housing structure in the opening, wherein the light guide structure comprises light-leakage promotion structures within a region at the second surface of the light guide structure that is defined by the opening in the housing structure, wherein the second surface of the light guide structure has a planar portion, wherein the second surface of the light guide structure has a plurality of protrusions that extend towards the housing structure, wherein the plurality of protrusions extend past the planar portion of the second surface of the light guide structure, wherein the plurality of protrusions form the light-leakage promotion structures, wherein the light guide plate is interposed between the reflector and the liquid crystal display module and provides backlight to the display module, wherein the reflector comprises a metal coating on the first surface of the light guide structure, wherein the light guide plate receives the backlight from the light source, wherein the light guide structure comprises a clear plastic sheet, wherein the housing structure comprises a logo structure, wherein the light-leakage promotion structures overlap the logo structure and cause light received from the light source to pass through the housing structure, wherein the logo structure comprises translucent plastic, wherein the housing structure comprise metal, wherein the light guide structure has a width and a length, wherein the width is at least five times smaller than the length, and wherein the light guide structure routes light from a single light-emitting diode to the opening. 
 
     
     
       13. The electronic device defined in  claim 1 , wherein the second light guide structure continuously narrows from the third width to the fourth width to guide light from the light source to the transparent housing structure. 
     
     
       14. The electronic device defined in  claim 12 , wherein the opening is positioned in a center of the display, wherein the display has a first surface area, wherein the opening has a second surface area, and wherein the second surface area is less than twenty percent of the first surface area. 
     
     
       15. The electronic device defined in  claim 12 , wherein the liquid crystal display module has a first surface area, wherein the region of the light guide structure has a second surface area, and wherein the second surface area is less than twenty percent of the first surface area.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with illuminated housing structures such as illuminated logos. 
     Electronic devices such as computers have housings. Components such as logic boards, keyboards, and displays may be mounted within a housing. Some computers are provided with logo structures. For example, some portable computers have metal housings with plastic logos that are illuminated using a portion of the backlight associated with a liquid crystal display in the computer. 
     With this type of logo illumination scheme, a fraction of the backlight for a display is purposefully allowed to leak through the rear of a backlight structure. Ensuring that there is sufficient leaked backlight available to illuminate a logo may, however, reduce backlight efficiency. 
     It would therefore be desirable to be able to provide improved arrangements for illuminating housing structures such as logos in electronic devices. 
     SUMMARY 
     An electronic device may have a housing. The housing may be formed from metal or other materials. A display such as a liquid crystal display may be mounted in the housing. Backlight structures may be used to produce backlight for the display. The backlight structures may include a light source such as an array of light-emitting diodes that produces light. The backlight structures may also include a light guide plate that distributes backlight from the light source over the rear surface of the display. A reflector may be used to reflect light that escapes the light guide plate in an inwards direction back in an outwards direction towards the display. The reflector may be formed from a highly reflective material such as metal. 
     The electronic device housing may have an opening. Transparent housing structures such as transparent logo structures may be mounted in the opening of the housing. The transparent logo structures may be formed from a material such as translucent plastic. During operation, the logo structures may be illuminated from within the electronic device. 
     A light guide structure may be used to guide light from a light source such as the light source for the backlight structures to the transparent logo structures. The reflector may be formed from a coating of metal that covers an inner surface of the light guide structure. An outer surface of the light guide structure may be provided with localized light leakage promotion features to cause light to exit the light guide structure and serve as illumination for the logo structures. 
     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 front perspective view of an illustrative electronic device such as a portable computer of the type that may be provided with housing structures such as logo structures that are illuminated in accordance with an embodiment of the present invention. 
         FIG. 2  is a rear perspective view of an illustrative electronic device such as a portable computer of the type that may be provided with housing structures such as logo structures that are illuminated in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of a conventional computer housing that includes an illuminated logo structure. 
         FIG. 4  is a cross-sectional side view of an illustrative electronic device with illuminated housing structures such as illuminated logo structures in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative display and illustrative structures for illuminating a logo or other housing structures in which separate light sources are used to provide display backlight and housing structure illumination in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of an illustrative display and illustrative structures for illuminating a logo or other housing structures in which a reflective backlight layer for the display has been formed as a coating on an upper surface of a housing structure illumination light guide layer in accordance with an embodiment of the present invention. 
         FIG. 7  is a cross-sectional side view of an illustrative display and illustrative structures for illuminating a logo or other housing structures in which a light guide structure that extends partway under a backlight reflector layer has been used to provide illumination in accordance with an embodiment of the present invention. 
         FIG. 8  is a bottom view of a light source that is being used to launch light into logo illumination structures formed from a light guide layer with a modified portion for locally enhancing light leakage for use in logo illumination in accordance with an embodiment of the present invention. 
         FIG. 9  is a bottom view of a light source that is being used to launch light into logo illumination structures formed from a light guide layer with a portion that narrows towards a modified region that locally promotes light leakage for logo illumination in accordance with an embodiment of the present invention. 
         FIG. 10  is a bottom view of logo illumination structures that have a modified region that locally promotes light leakage for logo illumination and a light guide that carries light from a dedicated light source to the modified light leakage promotion region in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device of the type that may be provided with an illuminated logo or other illuminated housing structures is shown in  FIG. 1 . Electronic device  10  may be a computer such as a computer that is integrated into a display (i.e., a computer integrated into 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  18  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. Display  14  may be mounted in upper portion  12 A (sometimes referred to as a display housing or upper housing). A keyboard such as keyboard  18  and a touch pad such as touch pad  20  may be mounted in housing portion  12 B (sometimes referred to as a lower housing or base). Upper housing portion  12 A may be coupled to lower housing portion  12 B using a hinge that allows portion  12 A to rotate about rotational axis  16  relative to portion  12 B. 
       FIG. 2  is a rear perspective view of electronic device  10  of  FIG. 1  showing how device  10  may be provided with illuminated housing structures such as illuminated logo structures  22 . In the example of  FIG. 2 , illuminated logo structures  22  have been formed in the center of the rear (outer) surface of upper housing portion  12 A in housing  12 . Housing  12  may, for example, be formed from an opaque material such as opaque plastic or metal (e.g., aluminum). Logo structures  22  may be formed from a material that is at least partly transparent to light, so that logo structures  22  can be illuminated using light from within device  10 . Logo structures  22  may have the shape of a logo (e.g., a trademark or other logo that is associated with the manufacturer of device  10  or other organization). If desired, device  10  may be provided with other types of illuminated structures (e.g., illuminated housing structures of other shapes and types). The use of illuminated logo structures is sometimes described herein as an example. 
     Logo structures  22  are shown as being formed on the outer surface of upper housing portion  12 A in device (portable computer)  10  of  FIG. 2 , but may, if desired, be provided in other suitable locations. For example, in a computer that is integrated into a computer monitor, logo structures  22  may be provided on the rear surface of the housing for the computer monitor. In a tablet computer or cellular telephone, logo structures  22  may be formed on the rear surface of the device housing. Illuminated logo structures or other illuminated structures (e.g., other transparent housing window structures) may also be formed on front housing surfaces, on housing sidewalls, on more than one of these surfaces, or on any other suitable portion of an electronic device housing. 
     Illuminated logo structures  22  may be formed from a transparent material (e.g., a translucent material) that can be illuminated by illumination structures within housing  12  of device  10 . Examples of materials that may be used in forming illuminated logo structures  22  include plastic (e.g., clear plastic, colored plastic, translucent white plastic, or translucent plastic of other colors), colored glass, ceramic, other materials that are transparent to light, or combinations of two or more of these materials. Illuminated logo structures  22  may be mounted in an opaque housing, so that the illumination of logo structures  22  causes logo structures  22  to be brighter than surrounding portions of the housing. Configurations in which some or all of housing  12  is transparent may also be used. 
     Although a single logo is shown in  FIG. 2 , device  10  may be provided with any suitable number of logos (or other illuminated housing structures). For example, device  10  may be provided with two or more illuminated logos, three or more illuminated logos, or four or more illuminated logos. 
     A cross-sectional view of a conventional upper housing in a portable computer that includes an illuminated logo is shown in  FIG. 3 . As shown in  FIG. 3 , components such as liquid crystal display module  240  are mounted within portable computer upper housing  254 . Backlight is provided for liquid crystal display module  240  using backlight unit  260 . Backlight unit  260  include light-emitting diodes  244 , reflector  256 , and light guide plate  242 . Light-emitting diodes  244  produce light  246  for backlight unit  260 . Reflector  256  is formed from a partly transparent sheet of white plastic. Light guide plate  242  is a clear layer of plastic. Light  246  travels within light guide plate  242  due to the principle of total internal reflection. Some of light  242  escapes upwards in direction  262  towards viewer  264  and serves as backlight  248  for display  240 . Light  242  that escapes downwards is reflected upwards by reflector  256  and serves as additional backlight  250  for display  240 . Logo  252  is formed from translucent white plastic mounted in an opening in housing  258 . Reflector  256  allows a fraction of light  246  that has escaped light guide plate  260  and is traveling downwards to pass through reflector  256  to serve as illumination light  266  for logo  252 . Light  246  that has passed through reflector  256  in portions of device  10  away from logo  252  (e.g., light rays  268 ) will be blocked by housing  254  and will not participate in forming illumination for logo  252 . The blocking of light rays  268  serves as a source of inefficiency in the logo illumination arrangement of  FIG. 3 . 
       FIG. 4  is a cross-sectional view of an illustrative arrangement that may be used for device  10  in which illumination for logo structures or other housing structures has been provided using light guide structures other than the light guide plate in a backlight unit. As shown in  FIG. 4 , device  10  may include a display such as display  14 . Display  14  may include a display module such as display module  34 . Display module  34  may be, for example, a liquid crystal display module. Liquid crystal display module  34  (sometimes referred to as a liquid crystal display, liquid crystal display layers, or liquid crystal display structures) may have any suitable number of display module layers (display layers) such as layers  44 ,  42 ,  40 ,  38 , and  36 . With one suitable arrangement, layer  44  is an upper polarizer, layer  36  is a lower polarizer, layer  42  is a color filter array layer, layer  38  is a thin-film transistor layer, and layer  40  is a layer of liquid crystal material. Other types of layers may be included if desired (e.g., smudge-resistant layers, scratch resistant layers, antireflection coatings, layers that perform multiple functions such as these, or other suitable layers). An optional cover layer of glass or plastic may be used to cover display  14 . If desired, one or more of these display layers may be omitted and/or the layers of display module  34  may be organized in different orders. The arrangement of  FIG. 4  is merely illustrative. 
     Device  10  may include backlight structures for providing backlight illumination for display structures  34 . The backlight structures may include a light source such as light source  24 , a light guide structure such as light guide plate  46 , and a reflector such as reflector  48 . 
     Light source  24  may be formed from light-emitting diode structures or other suitable source of light. For example, light source  24  may be formed from an array of light-emitting diodes mounted on a flexible printed circuit (“flex circuit”), a rigid printed circuit board, or other suitable substrate. There may be light-emitting diodes on one edge of light guide plate  46  or on two or more edges of light guide plate  46 . In the example of  FIG. 4 , light source  24  has been formed from an array of light-emitting diodes along the left-hand edge of light guide plate  46 . 
     Light guide plate  46  may be formed from a clear material such as clear plastic (e.g., clear acrylic). When light such as light  28  is launched into light guide plate  46 , the light disperses and travels within light guide plate  46  due to the principle of total internal reflection. This helps distribute light  28  across the entire inner surface of display module  34  and ensures that display  14  will be evenly backlight. With one suitable arrangement, display module  34  may have a rectangular shape (i.e., display  14  may have a rectangular periphery), light guide plate  46  may be rectangular, and light  28  may be distributed over substantially all of the rectangular area of light guide plate  46  and display module  34 . If desired, optical films (e.g., a diffuser, a brightness enhancing film, an optical compensator layer, etc.) may be mounted on the upper surface of light guide plate  46 . 
     To improve backlight efficiency, the lower surface of light guide plate  46  may be provided with a reflective layer such as reflector  48 . Reflector  48  may be formed from plastic, metal, or other suitable reflective materials. As light  28  exits light source  24  and enters the edge of light guide plate  46 , some of light  28  leaks vertically upwards (outwards) and serves as backlight  32 . Light  28  that leaks vertically downwards (inwards) towards reflector  48  is reflected back in the upwards direction by reflector  48  and serves as additional backlight  32 . Reflector  48  may be configured to reflect 80% or more or 90% or more of light  28  (as an example). Reflector  48  may transmit less than 10%, less than 5%, less than 1%, or less than 0.1% of the light incident on reflector  48 . As shown in  FIG. 4 , backlight  30  and  32  passes through display module  34  and is viewed by a user of device  10  such as viewer  58  who is observing display  14  in direction  60 . The backlight that is passing through display module  34  helps the viewer observe images that are displayed on display module  34  by control circuitry within device  10 . 
     In addition to producing light  28  (i.e., backlight that is distributed to display module  34  via light guide plate  46 ), light source  24  may produce light  26  to illuminate housing structures such as logo structures. 
     As shown in  FIG. 4 , housing  12  (e.g., housing  12 A of  FIG. 1 , the housing of a computer monitor with an integrated computer, or other electronic device housing) may be provided with one or more openings such as opening  56 . Housing  12  may be formed from aluminum or other metals, plastic, carbon-fiber materials, fiberglass materials, or other fiber-based composites, wood or other organic materials, ceramic, glass, other materials, or combinations of these materials. Openings in housing  12  such as opening  56  may be round, square, may have curved edges, may have straight edges, may have combinations of curved and straight edges, may be formed from a single hole in housing  12  or may be formed from a set of multiple associated holes (e.g., when implementing a logo shape that has separate parts), or may have any other suitable shape. Housing structures (e.g., transparent housing windows) such as logo structures  22  may be mounted in opening  56  (e.g., logo structures  22  may cover opening  56 ). Logo structures  22  may be formed from a transparent material (e.g., plastic, glass, ceramic, composites, etc.). For example, logo structures  22  may be formed from white translucent plastic. 
     Light  26  from light source  24  may be emitted into the interior of light guide structure  50 . For example, light  26  may be launched into light guide structure  50  through an edge of light guide structure  50 . Light guide structure  50  may be formed from a transparent material that can guide light though the principle of total internal reflection. As an example, light guide structure  50  may be formed from a clear structure formed from glass, ceramic, plastic, other materials, or combinations of these materials. Light guide structure  50  may have the shape of a planar rectangular sheet of material (e.g., a light guide plate) or other suitable shape. For example, light guide structure  50  may have a rectangular shape of the same size as display  14  or may cover only a subset of the area of display  14 . 
     To encourage light  26  to exit light guide structure  50  in the vicinity of logo structures  22 , light guide structure  50  may be provided with localized optical properties in the vicinity of opening  56  that cause an elevated fraction of the internally guided light in light guide structure  50  to exit light guide structure  50 . As shown in  FIG. 4 , for example, a portion of light guide structure  50  may be provided with structures (features)  52  that enhance light leakage from light guide structure  50  in the portion of light guide structure  50  that is covered by logo structure  22 . Structures  52  may cause light  26  to leak outwards from light guide structures  50  (e.g., in the downwards direction in  FIG. 4 ) to serve as illumination  54  (i.e., backlight) for logo structures  22  or other transparent housing structures that form windows between the interior and exterior of housing  12 . 
     Structures  52  may be formed using surface textures on the surface of light guide structure  50 . For example, the lower surface of light guide structure  50  may be provided with ribs, circular protrusions (e.g., bumps), pyramidal protrusions, protrusions or other shapes, randomly shaped localized surface roughness, or other textures that promote light leakage by locally discouraging total internal reflection within light guide structure  50 . Localized light leakage promotion structures may also be formed in light guide structure  50  using internal features such as bubbles filled with air or particles of other material with an index of refraction that differs from that of the index of refraction for light guide structure  50 , metal particles for promoting scattering, or internal structural features (e.g., features formed from metal, plastic, ceramic, or other materials that deflect light  26  outwardly through logo structures  22  as backlight illumination  54 ). The amount of surface area on light guide structure  50  that is encompassed by localized light leakage promotion structures  52  is preferably less than the total surface area of display  14 . For example, if the surface area of display  14  is 600 cm 2 , the surface area of localized light leakage promotion structures  52  may be about 40 cm 2  (as an example). In other configurations, other fractions of the total display area may be consumed by structures  52 . For example, structures  52  may have an area that is less than 50% of the total surface area of display  14 , less than 20% of the total surface area of display  14 , less than 10% of the total surface area of display  14 , or less than 5% of the total surface area of display  14 . With this type of arrangement, light  26  that has been injected into the interior of light guide structures  50  is encouraged to leak out of light guide structures  50  only where such leakage will allow the leaked light to serve as backlight  54  for logo structure  22 , thereby maximizing logo illumination efficiency and reducing power consumption by light source  24 . 
     As shown in  FIG. 5 , light source  24  may, if desired, have one portion such as portion  24 - 1  that is used for providing light  28  for light guide plate  46  and another portion such as portion  24 - 2  that is used for providing light  26  for light guide structure  50 . In light guide plate  46 , light  28  may be used to produce display backlight  30  and  32  for display module  34 . In light guide structure  50 , light  26  may be used to produce logo backlight for logo structures  22  in housing  12 . 
     Light source  24 - 1  may be formed from one or more light-emitting diodes mounted on a printed circuit or other suitable substrate. Light source  24 - 2  may be formed from one or more separate light-emitting diodes. The light-emitting diodes of light source  24 - 2  may be mounted to a printed circuit or other substrate. The substrate on which light source  24 - 1  is mounted may be different than the substrate on which light source  24 - 2  is mounted or light sources  24 - 1  and  24 - 2  may be mounted on a common printed circuit. 
     Another illustrative configuration that may be used for providing logo illumination in device  10  is shown in  FIG. 6 . In the arrangement of  FIG. 6 , light reflector  48  has been implemented using a material layer that is attached to the upper surface of light guide structure  50 . Light reflector  48  of  FIG. 6  may be, for example, a layer of material that is attached to light guide structure  50  using adhesive. Light reflector  48  of  FIG. 6  may be formed from white plastic, metal (e.g., metal foil), or other reflective substances. With one suitable arrangement, light reflector  48  may be formed by depositing a coating of metal on light guide structure  50  (e.g., using physical vapor deposition or other suitable coating techniques). The coating of metal may be highly reflective (e.g., the metal coating layer may reflect 70% or more of incident visible light, 80% or more of incident visible light, or 90% or more of incident visible light (as examples) and may transmit less than 10% or less than 1% of the incident visible light (as examples). In this type of configuration, it may be desirable to implement light guide structure  50  using a piece of material that is sufficiently large to cover substantially all of the area of display  14  (i.e., so that reflector  48  is used to reflect light  32  upwards over substantially all of display  14 ). The logo illumination structures of  FIG. 6  use a common light source  24  to produce light  28  and light  26 . If desired, separate light sources such as light sources  24 - 1  and  24 - 2  may be used, as described in connection with  FIG. 5 . 
       FIG. 7  shows how light guide structure  50  may be formed over only part of the area of display  14 . In the example of  FIG. 7 , light guide structure  50  is being used to distribute light  26  to structures  52  that are located in the center of display  14 . Light leakage promotion structures  52  in light guide structure  50  may cause light  26  to exit light guide structure  50  and pass through logo structure  20  as logo illumination (backlight)  54 . Light guide structure  50  of  FIG. 7  is only formed on the left-hand side of display  14  (in the orientation of  FIG. 7 ), so there is room for additional internal device components such as electrical components  62  within housing  12 . To ensure that there is satisfactory upwards light reflection from reflector  48 , reflector  48  may be configured to cover the entirety of display  14  (i.e., reflector  48  may have the same area as display module  34  and may overlap the entire rear surface of display module  34 ). 
       FIG. 8  is a bottom view of light guide structure  50  showing how light leakage promotion structures  52  may be formed in the shape of a rectangle or other shape in the center of light guide structure  50  (as an example). Light  26  may be emitted from light source  24  into the edge of light guide structure  50 . When light  26  reaches light leakage promotion structures  52 , light  26  may exit light guide structure  50  (out of the page in the orientation of  FIG. 8 ) and may serve as backlight illumination for logo structures  22  that overlap structures  52 . Light source  24  may include light-emitting diodes such as light-emitting diodes  24 A,  24 B,  24 C,  24 D,  24 E, and  24 F. The light-emitting diodes of light source  24  may be mounted on printed circuit substrate  70 . As shown in  FIG. 8 , the light-emitting diodes of light source  24  may be arranged to form a one-dimensional array along the left-hand edge of light guide structure  50  (as an example). As with the other illustrative configurations for display  14 , some of the light produced by light source  24  may serve as display backlight and some of the light produced by light source  24  may serve as logo structure illumination. 
       FIG. 9  is a bottom view of light guide structure  50  in an illustrative arrangement in which light guide structure  50  has been configured to cover only part of the surface area of display  14 . In particular, light guide structure  50  has been configured to taper inwardly as structure  50  extends towards light-leakage promotion features  54 . At the left edge of display  14 , light guide structure  50  of  FIG. 9  has a lateral dimension D 1  that spans display  14 . This allows the left edge of light guide structure  50  to receive light from all of the light-emitting diodes in light source  24  (as an example). Near the center of display  14 , light guide structure  50  of  FIG. 9  narrows to a lateral dimension D 2 . The narrowing of light guide structure  50  may help guide and concentrate light  26  towards light leakage promotion structures  54 . As with reflector  48  of  FIG. 7 , reflector  48  in the arrangement of  FIG. 9  may be configured to cover the entirety of display  14  to ensure that there is satisfactory upwards light reflection from reflector  48  over the entire area of display  14 . 
       FIG. 10  is a bottom view of light guide structure  50  in an illustrative arrangement in which light guide structure  50  has been used to route light  26  from the right-hand side of display  14  to light leakage promotion structures  54  in the center of display  14 . Light guide structure  50  of  FIG. 10  has a relatively narrow width W that is significantly smaller than its length L (e.g., five times or more, ten times or more, etc.). Light guide structure  50  of  FIG. 10  may be provided with light  26  using light source  24 F. Light source  24 F may be, for example, a light-emitting diode. With this type of arrangement, light source  24  and its light-emitting diodes  24 A,  24 B,  24 C,  24 D, and  24 E may be used exclusively to produce light  28  to serve as backlight for display  14 , whereas light-source  24 F may be used exclusively to produce light  26  to serve as illumination for logo structures  22 . The mounting locations for light sources  24  and  24 F of  FIG. 10  are merely illustrative. Other mounting locations may be used if desired. For example, light-emitting diode  24 F may be located along the left-hand edge of display  14  with the light-emitting diodes of light source  24 . Moreover, light structure  50  may have other suitable shapes (e.g., a shape that covers all of display  14 , a shape that covers only the right-hand side or only the left-hand side of display  14 , etc.). Reflector  48  may extend over the entire surface of display  14 , to ensure that backlight for display  14  is distributed uniformly. 
     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: 20120228
Publication Date: 20151201
Grant Date: 20151201
Priority Date: 20120228
Inventors: QI JUN
YIN VICTOR H.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B6/002", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0016", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1601", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0045", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F2001/133342", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1601", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/002", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0045", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0045", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0016", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133342", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/002", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1601", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0016", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133342", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 47846128