PATENT DOCUMENT

Publication Number: US-10061158-B2
Application Number: US-201213664892-A
Country: US
Kind Code: B2

Title: Light guide plate with integrated reflector for display backlight

Abstract:
An electronic device may be provided with a display. Backlight structures may be used to provide backlight for the display. The backlight structures may include a light guide plate. The light guide plate may include a planar extended portion that guides light along the back of the display and an integrated edge reflector along one or more edges of the planar extended portion. The planar extended portion and the integrated edge reflector may be formed from respective first and second shots of material. The integrated edge reflector may be formed from a polymer material with embedded reflective structures such as glass microbeads or other oxide particles. The backlight structures may include a reflective layer that is attached to the integrated edge reflector of the light guide plate using adhesive. The display may include active display pixels formed over a portion of the integrated edge reflector.

Claims:
What is claimed is: 
     
       1. A display, comprising:
 backlight structures that include a light guide plate having first and second pairs of opposing parallel peripheral edge surfaces that define a rectangular perimeter of the light guide plate, a light source that emits light into a first peripheral edge surface in the first pair, an integrated edge reflector attached directly to a second peripheral edge surface in the first pair, and optical films, wherein the first and second peripheral edge surfaces are interposed between the light source and the integrated edge reflector, wherein the first and second peripheral edge surfaces are perpendicular to the opposing parallel peripheral edge surfaces in the second pair, and wherein the light guide plate further comprises upper and lower surfaces that each extend from the first peripheral edge surface to the second peripheral edge surface and between the opposing parallel peripheral edge surfaces in the second pair; and 
 display structures formed over the backlight structures that receive backlight that exits the light guide plate through the upper surface, wherein the display structures comprise active display pixels in an active area of the display and an opaque masking layer in an inactive area of the display, wherein the opaque masking layer at least partially overlaps the integrated edge reflector of the light guide plate, wherein at least one of the active display pixels is located over a portion of the integrated edge reflector of the light guide plate, and wherein an axis perpendicular to the upper surface of the light guide plate passes through the upper surface, the lower surface, the optical films, and the active area of the display without passing through any of the first and second pairs of opposing parallel peripheral edge surfaces. 
 
     
     
       2. The display defined in  claim 1  wherein the backlight structures further comprise a reflective structure attached to the integrated edge reflector of the light guide plate. 
     
     
       3. The display defined in  claim 1  wherein the at least one of the active display pixels overlaps the portion of the integrated edge reflector of the light guide plate.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to displays for electronic devices. 
     Electronic devices such as cellular telephones, computers, and media players often contain displays. For example, electronic devices often include backlit displays such as backlit liquid crystal displays. 
     Backlit displays generally include a light distribution layer called a light guide plate. The light guide plate is typically formed from a rectangular sheet of clear plastic that has been injection molded, extruded, or die cut from a sheet of plastic. Light from an array of light-emitting diodes may be launched into the edge of the light guide plate. The light guide plate distributes light across the back of a display panel by total internal reflection. Light that exits the planar upper surface of the light guide plate serves as backlight for the display panel. 
     In relatively large electronic devices such as televisions, the light guide plate can have a thickness that allows reflective material such as reflective tape to be attached to edges of the light guide plate that prevents light from the light guide plate from leaking into undesired areas of the device. 
     However, it can be challenging to add reflective structures such as tape to relatively thinner light guide plates for compact devices such as laptop computers, tablet computers, and cell phones. For example, the housing of an electronic device can be adjusted to accommodate additional reflective structures or to accommodate a larger light guide plate in which edges of the light guide plate that are prone to light leakage are embedded within additional space within the housing. However, this can lead to undesirable enlargement of the size and weight of the housing and unappealing device aesthetics. 
     It would therefore be desirable to be able to provide improved display backlight structures such as improved light guide plates for display backlights. 
     SUMMARY 
     An electronic device may be provided with a display. Backlight structures may be used to provide backlight for the display. The backlight structures may include a light guide plate and a reflector. The backlight structures may be used in distributing backlight to display structures in the display such as a thin-film transistor layer, a color filter layer, polarizers, and other display layers. The display may include an opaque masking layer on one or more glass layers in the display that blocks internal components in the device from view. 
     The light guide plate may include a first portion that distributes light across the back of the display and an integral (integrated) second portion along one or more edges of the first portion that reflects some of the light from the first portion back into the first portion. The first portion and the second portion may be formed in a two-shot molding process in which the first portion is formed from a first shot of transparent plastic and the integral second portion is formed in a second shot of reflective material. 
     The light guide plate may have a thickness that is, for example, less than one millimeter. The reflective second portion of the light guide plate may be formed from plastic such as polycarbonate, polymethyl methacrylate, or other plastic materials. The reflective second portion may include additives such as glass beads (microbeads) or other oxide particles that scatter light that is incident on the reflective second portion so that the light is reflected away from the reflective second portion. 
     The reflector of the backlight structures may be attached to the reflective second portion of the light guide plate. The opaque masking layer may be formed on a portion of a glass layer for the display in a region of the glass layer that covers at least some of the reflective second portion. The opaque masking layer may have an edge that is aligned with the interface of the first and second portions of the light guide plate or the opaque masking layer may extend over the reflective second portion and some of the first portion. The display may include active display pixels formed over the reflective second portion of the light guide plate. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with display backlight structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of an illustrative electronic device such as a handheld electronic device with display backlight structures in accordance with an embodiment of the present invention. 
         FIG. 3  is a perspective view of an illustrative electronic device such as a tablet computer with display backlight structures in accordance with an embodiment of the present invention. 
         FIG. 4  is a top view of a portion of illustrative backlight structures including a light guide plate having an integral reflective edge portion in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative display showing how a light guide plate may include a first portion and an integral second portion that reflects light from the first portion back into the first portion in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of an illustrative display of the type shown in  FIG. 5  showing how an inactive area of the display may have an edge that is aligned with the interface between the first and second portions of the light guide plate in accordance with an embodiment of the present invention. 
         FIG. 7  is a cross-sectional side view of an illustrative display of the type shown in  FIG. 5  showing how a portion of an active area of the display may be formed over the integral second portion of the light guide plate in accordance with an embodiment of the present invention. 
         FIG. 8  is a diagram showing how injection molding techniques may be used in forming a light guide plate having a first portion and an integral reflective second portion in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may include displays. The displays may be used to display images to a user. A display may contain backlight structures (sometimes referred to as a backlight unit) to provide backlight illumination for the display. The backlight structures may include a reflective layer (sometimes referred to as a reflector) and a light guide plate. The light guide plate may include first and second portions formed from first and second shots of material. The first portion may be a planar light distribution layer and the second portion may be an integrated edge reflector formed along an edge of the first portion. The reflective layer may be a planar reflective layer formed behind the light guide plate that is attached to the light guide plate using adhesive that is interposed between the reflective layer and the integrated edge reflector. Illustrative electronic devices that may be provided with displays having backlight structures with light guide plates with integrated edge reflectors are shown in  FIGS. 1, 2, and 3 . 
       FIG. 1  shows how electronic device  10  may have the shape of a laptop computer having upper housing  12 A and lower housing  12 B with components such as keyboard  16  and touchpad  18 . Device  10  may have hinge structures  21  that allow upper housing  12 A to rotate in directions  122  about rotational axis  124  relative to lower housing  12 B. Display  14  may be mounted in upper housing  12 A. Upper housing  12 A, which may sometimes referred to as a display housing or lid, may be placed in a closed position by rotating upper housing  12 A towards lower housing  12 B about rotational axis  124 . 
       FIG. 2  shows how electronic device  10  may be a handheld device such as a cellular telephone, music player, gaming device, navigation unit, or other compact device. In this type of configuration for device  10 , housing  12  may have opposing front and rear surfaces. Display  14  may be mounted on a front face of housing  12 . Display  14  may, if desired, have a display cover layer or other exterior layer that includes openings for components such as button  126 . Openings may also be formed in a display cover layer or other display layer to accommodate a speaker port (see, e.g., speaker port  28  of  FIG. 2 ). 
       FIG. 3  shows how electronic device  10  may be a tablet computer. In electronic device  10  of  FIG. 3 , housing  12  may have opposing planar front and rear surfaces. Display  14  may be mounted on the front surface of housing  12 . As shown in  FIG. 3 , display  14  may have a cover layer or other external layer with an opening to accommodate button  126  (as an example). 
     Peripheral portions of display  14  may be provided with an opaque masking layer. As shown in  FIGS. 1, 2, and 3 , display  14  may be characterized by a central active region such as active area AA in which an array of active display pixels is used in displaying information for a user. Active region AA may be surrounded by an inactive region such as inactive border region IA. Active region AA may have a rectangular shape bordered by rectangular line  210 . Inactive region IA may have a rectangular ring shape that surrounds active region AA (as an example). 
     The underside of an outer layer of the display in inactive region IA may be covered with an opaque masking layer such as a layer of black ink (e.g., a polymer filled with carbon black). The outer layer of the display may be a transparent cover layer such as a cover layer formed from glass or transparent plastic or may be another layer of the display such as a color filter layer formed from a thin layer of glass having color filter elements formed on the glass. The opaque masking layer may help hide components in the interior of device  10  in inactive region IA from view by a user. 
     The illustrative configurations for device  10  that are shown in  FIGS. 1, 2, and 3  are merely illustrative. In general, electronic device  10  may be a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, or other wearable or miniature device, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. 
     Housing  12  of device  10 , which is sometimes referred to as a case, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined or cast aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device  10  may be formed using a unibody construction in which most or all of housing  12  is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal frame elements or other internal housing structures). 
     Display  14  may be a touch sensitive display that includes a touch-sensor or may be insensitive to touch. Touch-sensors for display  14  may be formed from an array of capacitive touch-sensor electrodes, a resistive touch array, touch-sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch-sensor components. 
     Displays for device  10  may, in general, include display pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable display pixel structures. In some situations, it may be desirable to use LCD components to form display  14 , so configurations for display  14  in which display  14  is a liquid crystal display are sometimes described herein as an example. It may also be desirable to provide displays such as display  14  with backlight structures, so configurations for display  14  that include a backlight unit may sometimes be described herein as an example. Other types of display technology may be used in device  10  if desired. 
     A display cover layer may cover the surface of display  14  or a display layer such as a color filter layer or other portion of a display may be used as the outermost (or nearly outermost) layer in display  14 . A display cover layer or other outer display layer may be formed from a transparent glass sheet, a clear plastic layer, or other transparent member. 
     Touch-sensor components such as an array of capacitive touch-sensor electrodes formed from transparent materials such as indium tin oxide may be formed on the underside of a display cover layer, may be formed on a separate display layer such as a glass or polymer touch-sensor substrate, or may be integrated into other display layers (e.g., substrate layers such as a thin-film transistor layer). 
     Backlight for display  14  may be provided using backlight structures of the type shown in  FIG. 4 . As shown in  FIG. 4 , backlight structures  20  may include a light guiding structure such as light guide plate  22 . Although display  14  may, in general, have any suitable shape, configurations for device  10  in which display  14  has a rectangular shape are sometimes described herein as an example. Light guide plate  22  may be used in providing backlight for display  14  and may have a shape that matches the shape of display  14 . 
     As shown in  FIG. 4 , backlight  26  may be launched into one or more of the edges of light guide plate  22  (e.g., one or more of the four edges of a rectangular light guide plate) from light sources such as light-emitting diodes  24 . In the example of  FIG. 4 , light-emitting diodes  24  are launching light  26  into the bottom edge of light guide plate  22 . Other configurations may be used if desired (e.g., configurations in which light is launched into multiple edges of the light guide plate, etc.). 
     Light guide plate  22  may include a first portion  23  and a second portion  32 . Portion  32  may be an insert-molded integral portion of light guide plate  22  (e.g., portion  23  and portion  32  may form a single continuous light guide plate structure formed form two shots of material). 
     Portion  23  of light guide plate  22  may be a planar light guiding portion of light guide plate  22  formed from a transparent material such as glass or a polymer such as acrylic or other clear plastic (as an example). Light  26  is guided within portion  23  of light guide plate  22  due to the principle of total internal reflection. Some of light  26  is extracted from light guide plate  22  via engineered features on the upper surface of the light guide plate, the lower surface of the light guide plate, or both the upper and lower light guide plate surfaces. 
     Downwardly directed light is reflected back into the light guide plate towards a viewer by a reflector layer under the light guide plate. Upwardly directed light travels through the active layers of display  14  that are formed above the backlight. For example, in a liquid crystal display, the upwardly directed light travels through a thin-film transistor layer, a color filter layer, and a layer of liquid crystal material that is interposed between the color filter layer and thin-film transistor layer. The color filter layer may be used to provide display pixels with different colors. The thin-film transistor layer may be used to control the transmission of individual display pixels of the liquid crystal material. Backlight may pass through upper and lower polarizers that are formed above and below the color filter layer and thin-film transistor layer, respectively. 
     Portion  32  of light guide plate  22  may be formed from a reflective material such as a polymer that is infused with light scattering or light reflecting particles such as particles  25 . Light scattering particles  25  may be formed from glass microbeads or other oxide particles that scatter light that is incident on portion  32  from portion  23  of light guide plate  22 . Light scattering particles  25  may be embedded in a polymer material such as polycarbonate (PC), polymethyl methacrylate (PMMA), or other plastic materials that are injection molded to form portion  32 . In this way, portion  32  may be formed as an integrated (integral) edge reflector for light guide plate  22 . Light  26  that travels through portion  23  of light guide plate  22  may be reflected off of integrated edge reflector  32  and back into portion  23 . 
     As shown in  FIG. 4 , light guide plate  22  may be provided with an integrated edge reflector  32  that is formed along top edge  27  of portion  23  of light guide plate  22  (i.e., an edge of portion  23  that is opposite to the edge of portion  23  into which light-emitting diodes  24  emit light into light guide plate  22 ). However, this is merely illustrative. If desired, additional integrated edge reflectors  32 ′ may be formed along sidewall edges  29  of portion  23 . In general, light guide plate  22  may be provided with integrated edge reflectors along some or all of one edge, two edges, three edges or four or more edges of light guide plate  22 . Integrated edge reflectors such as portions  32  and/or  32 ′ may conform to a straight edge of portion  23  (as in the example of  FIG. 4 ) or may conform to edges of portion  23  having other shapes (e.g., curved shapes). 
     Light guide plate  22  may be mounted in a display backlight chassis such as a chassis formed from plastic, metal, glass, ceramic, wood, carbon-fiber composites and other composites, other materials, and combinations of these materials. In some illustrative examples, one or more of the materials includes plastic. Plastic (polymer) materials for the chassis may be relatively stiff materials such as polycarbonate (PC), acrylonitrile butadiene styrene (ABS), or a PC/ABS blend or may be relatively soft polymers such as synthetic rubber, natural rubber, silicone, or other elastomeric materials. Rigid and elastomeric polymers are collectively referred to herein as “plastic.” 
     In some illustrative examples, light guide plate  22  may be formed in a chassis having opaque structures and/or reflective structures formed along the sidewall edges  29  of light guide plate  22  so that the chassis prevents light from leaking from sidewall edges of light guide plate  22  while integrated edge reflector  32  prevents light from leaking from the top edge of light guide plate  22 . Integrated edge reflector  32  may help reduce light leakage within (or from) display  14  without increasing the size of light guide plate  22 . 
     During operation of backlight structures  20 , light  26  is launched into the interior of portion  23  of light guide plate  22  from light-emitting diodes  24 . When light  26  reaches one of the edges of portion  23  such as top edge  27  in  FIG. 4 , light  26  may be incident on integrated edge reflector  32 . Due to the presence of integrated edge reflector  32 , light is reflected back into portion  23 . The reflected light may therefore be extracted by features on an upper surface of light guide plate  22  in portion  23  to serve as backlight for display  14 . Because light is reflected back into portion  23 , backlight is not wasted and overall backlight efficiency is enhanced. 
     A cross-sectional side view of backlight structures  20  of  FIG. 4  (and additional display structures) taken along line  60  and viewed in direction  30  is shown in  FIG. 5 . As shown in  FIG. 5 , backlight structures  20  may include a reflective layer such as reflector  46  formed along an inner surface of light guide plate  22  and may include diffuser films and other optical films such as optical films  70  formed along an opposing outer surface of light guide plate  22 . 
     Optical films  70  may include diffuser layers for helping to homogenize backlight  50  and thereby reduce hotspots, compensation films for enhancing off-axis viewing, and brightness enhancement films (also sometimes referred to as turning films) for collimating backlight  50 . Optical films  70  may overlap the other structures in backlight unit  20  such as light guide plate  22  and reflector  46 . For example, if light guide plate  22  has a rectangular footprint in the X-Y plane of  FIG. 5 , optical films  70  and reflector  46  may have a substantially similar rectangular footprint. 
     As shown in  FIG. 5 , light  26  may be emitted in direction Y and may be launched into the edge of portion  23  of light guide plate  22  (e.g., the left-hand edge of plate  22  in the orientation of  FIG. 5 ). Some of light  26  may be extracted in the downward direction towards the interior of device  10  and may reflect back in the upwards (Z) direction off of reflector  46 , as indicated by light ray  48 . Reflector  46  may be formed from a layer of white plastic, white paper, metal foil, or other suitable reflective surface. As indicated by light rays  50 , some of light  26  and reflected light from reflector  46  such as light that has been extracted from light guide plate  22  in the upward direction passes vertically through display structures  56 . 
     Display structures  56  may include display module structures such as polarizers, a thin-film transistor glass layer, a color filter glass layer, a liquid crystal layer, and other display layers. Display structures  56  may, if desired, include an outer cover layer formed from glass or clear plastic (as examples). Surface features may be incorporated into light guide plate  22  in portion  23  to enhance light extraction efficiency (e.g., to enhance extraction at particular locations on the light guide plate). 
     Some of light  26  will be guided to the edges of portion  23  of light guide plate  22  due to the principle of total internal reflection. This light, which is shown as light ray  52  in the diagram of  FIG. 5 , reflects off of integrated edge reflector  32  and returns into portion  23 , as indicated by light ray  54 . 
     Light guide plate  22  may have a thickness T. Thickness T may be between 0.5 mm and 0.7 mm, between 0.3 mm and 0.9 mm, less than 1 mm, less than 3 mm, less than 5 mm, or between 0.1 and 0.5 mm (as examples). Because of the relatively small thickness of light guide plate  22 , it may be difficult to add reflective structures such as reflective tape to an edge such as edge  27  of light guide plate  22 . For example, additional space within a housing such as housing  12  ( FIG. 1 ) of device  10  may be used to accommodate the additional reflective structures. As another example, the edge of light guide plate  22  may lack sufficient surface area for adhesive of an additional light reflecting structure. Because portion  32  is an integrated portion of light guide plate  22 , backlight structures  20  may be provided in device  10  without adding additional space within the housing for device  10  for additional reflective structure such as reflective tape. The presence of integrated light reflector  32  may therefore help to minimize the size of backlight structures  20  and device  10 . 
     Backlight structures  20  may include adhesive such as adhesive  62  that attaches reflector  46  to light guide plate  22 . Adhesive  62  may be a pressure sensitive adhesive (PSA), a light curable adhesive, or other suitable adhesive. Adhesive  62  may be formed between integrated reflective portion  32  of light guide plate  22  and reflector  46 . Because adhesive  62  is attached to integrated edge reflector  32 , light  26  may be prevented from reaching adhesive  62 . In this way, reflector  46  may be attached to light guide plate  22  without attaching any materials to portion  23  of light guide plate  22  that reduce the total internal reflection of light  26 , thereby increasing the efficiency of backlight structures  20  and reducing the risk of light leakage from light guide plate  22 . 
     As shown in  FIG. 5 , display structures  56  may include active display pixels  64  in active area AA that are used in controlling the emission of backlight  50  from display  14 . Active display pixels  64  may include portions of liquid crystal (LC) material in display structures  56  that are controlled by electrodes on a thin-film transistor (TFT) layer of display structures  56 . Each active display pixel  64  may include a color filter element on a color filter (CF) layer of display structures  56 . In this way, pixels  64  may be used to display color images to a user of device  10 . 
     Display structures  56  may include an opaque masking layer such as masking layer  66  in inactive area IA of display  14 . Opaque masking layer  66  may, for example, be a layer of black ink or reflective metal formed on a glass layer (e.g., a thin-film transistor glass layer, a color filter glass layer, or a cover glass layer) of display structures  56 . Opaque masking layer  66  may prevent a user of device  10  from viewing internal components of device  10 . 
     As shown in  FIG. 5 , opaque masking layer  66  may extend from an edge such as edge  67  of display structures  56  to a position (as indicated by dashed line  68 ) that is beyond the interface between portion  23  and portion  32  of light guide plate  22  (as indicated by dashed line  72 ). In this type of configuration, inactive area IA of display  14  may include substantially all of integrated edge reflector  32  and at least some of portion  23  of light guide plate  22 . However, this is merely illustrative. As shown in  FIGS. 6 and 7 , opaque masking layer  66  may be formed using other configurations with respect to integrated reflector  32 . 
     The presence of integrated edge reflector  32  having particles  25  along edge  27  of portion  23  of light guide plate  22  may prevent a sharp edge at which the intensity of backlight  26  changes (i.e., in comparison with sharp intensity changes at edges of light guide plates without integrated reflectors). Because the human eye is particularly sensitive to sharp changes, the more gradual edge of light guide plate  22  formed from integral reflector  32  with particles  25  may allow active area AA to be extended nearer to edge  67  of display structures  56  without generating undesirable intensity changes that are noticeable to a user, thereby reducing the size of inactive area IA. 
       FIG. 6  is a cross-sectional side view of backlight structures  20  of  FIG. 4  (and additional display structures) taken along line  60  and viewed in direction  30 , showing how an inner edge such as edge  69  of opaque masking layer  66  may be aligned with the interface of portions  23  and  32  of light guide plate  22  (as indicated by dashed line  78 ). In the configuration of  FIG. 6 , active display pixels  64  may be formed up to the line defined by the interface of portions  23  and  32  of light guide plate  22  (e.g., line  78 ). In this type of configuration, inactive area IA may include substantially all of portion  32  of light guide plate  22  without covering any of portion  23  of light guide plate  22 . 
       FIG. 7  is a is a cross-sectional side view of backlight structures  20  of  FIG. 4  (and additional display structures) taken along line  60  and viewed in direction  30  showing how inner edge  69  of opaque masking layer  66  may be formed over portion  32  of light guide plate  22  at a location (as indicated by dashed line  68 ) that does not reach the interface of portions  23  and  32  (as indicated by dashed line  78 ). In the configuration of  FIG. 7 , active display pixels  64  may be formed over integrated edge reflector  32  of light guide plate  22  (i.e., active display pixels  64  may be formed closer to edge  67  of display structures  56  than a line (e.g., line  78 ) defined by the interface of portions  23  and  32  of light guide plate  22 . In this type of configuration, inactive area IA may include less than all of portion  32  without covering any of portion  23  of light guide plate  22 . 
       FIG. 8  is a diagram showing how backlight structures  20  for device  10  may be formed. As shown in  FIG. 8 , portion  23  of light guide plate  22  may be formed using molding equipment such as a molding tools  58  (e.g., plastic injection molding equipment). For example, portion  23  of light guide plate  22  may be formed from a shot of plastic injected into a mold structure. If desired, molding tools  58  may also include one or more die cutting tools (e.g., to cut portion  23  of light guide plate  22  from a larger sheet of light guide material). 
     Molding tools  58  may then be used to mold a structure such as integrated edge reflector  32  (e.g., plastic or other polymer material with particles  25 ) onto the exterior edge of portion  23  of light guide plate  22 . In this way, integrated edge reflector  32  may be injection molded into a mold that contains a previously formed light guiding portion (e.g., portion  23 ) of a light guide plate. 
     Following formation of integrated edge reflector  32  onto edge  27  of portion  23  of light guide plate  22 , assembly equipment  59  (e.g., robotic equipment or manual tools) may be used to assemble light guide plate  22  and additional backlight members (e.g., optical films, a reflector, adhesive, and a plastic and/or metal chassis) to form backlight structures  20 . 
     Assembly equipment  59  may include die cutting tools, machining tools such as grinding and milling tools, laser cutting tools, welding tools, mechanical assembly tools such as tools for press fitting parts together, tools for exposing work pieces to light and/or heat, tools for applying coatings such as physical vapor deposition tools for depositing layers of dielectric and metal (e.g., to form a thin-film stack or metal coating), electrochemical deposition tools, photolithography tools, tools for patterning conductive materials such as metallic paint and other liquids (e.g., painting tools, pad printing tools, screen printing tool, ink jet tools, dipping tools, spraying tools, etc.), tools for injection molding plastic, tools for soldering, ovens and other tools for applying heat, equipment for bending structures, and other suitable manufacturing and assembly tools. 
     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: 20121031
Publication Date: 20180828
Grant Date: 20180828
Priority Date: 20121031
Inventors: QI, JUN
YIN, VICTOR H.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B6/0031", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133605", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0025", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133605", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0031", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0025", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/12", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0031", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/1335", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0025", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 50546804