PATENT DOCUMENT

Publication Number: US-9625948-B2
Application Number: US-201514833999-A
Country: US
Kind Code: B2

Title: Electronic devices with retractable displays

Abstract:
An electronic device may have a pair of elongated housings. A flexible display may be placed in a first position in which the display is retracted within one of the housings and a second position in which the flexible display is deployed and extends between the housings in a planar shape for viewing by a user. Support structures such as rigid slats that run parallel to the housings and bistable slats that run perpendicular to the rigid slats may be used to support the flexible display. Speakers, microphones, cameras, and other components can be mounted in the housings. The housings may be held together using magnets and may contain electrical components such as integrated circuits, batteries, and other devices. The components may be mounted on printed circuit boards that rotate within a rotating roller around which the display is wrapped when retracted.

Claims:
What is claimed is: 
     
       1. An electronic device comprising: a housing having first and second housing portions; a rotating roller within the first housing portion; a flexible display that is attached to the second housing portion and that is attached to the rotating roller so that the flexible display is retracted within the first housing portion by rotation of the rotating roller, wherein the flexible display comprises a substrate having first and second opposing surfaces with a pixel array on the first surface and flexibility-enhancing grooves in the second surface, and wherein the flexibility-enhancing grooves are located behind the pixel array such that light from the pixel array is directed away from the flexibility-enhancing grooves; support members that are perpendicular to the first and second housing portions and that extend entirely behind the flexible display, wherein the support members are bistable members that exhibit a rigid state and a flexible state, and wherein the support members wrap around the rotating roller with the flexible display when the flexible display is retracted within the first housing portion; and additional support structures that are parallel to the first and second housing portions. 
     
     
       2. The electronic device defined in  claim 1  further comprising:
 printed circuits in the rotating roller that rotate with the rotating roller. 
 
     
     
       3. The electronic device defined in  claim 2  wherein the rotating roller has an opening through which an edge of the flexible display passes to couple the edge of the flexible display to at least one of the printed circuits. 
     
     
       4. The electronic device defined in  claim 3  further comprising a battery in the second housing portion. 
     
     
       5. The electronic device defined in  claim 3  further comprising a first camera in the first housing portion and a second camera in the second housing portion. 
     
     
       6. The electronic device defined in  claim 3  further comprising a spring in the first housing portion that is coupled between the first housing portion and the rotating roller to rotate the rotating roller and retract the flexible display into the first housing portion. 
     
     
       7. The electronic device defined in  claim 6  further comprising a brush in the first housing portion that removes dust from the flexible display. 
     
     
       8. The electronic device defined in  claim 7  wherein the brush comprises a rotating brush. 
     
     
       9. The electronic device defined in  claim 3  further comprising a first speaker in the first housing portion and a second speaker in the second housing portion. 
     
     
       10. The electronic device defined in  claim 1  wherein the flexible display comprises an organic light-emitting diode display layer. 
     
     
       11. The electronic device defined in  claim 10  wherein the flexible display comprises a touch sensor. 
     
     
       12. The electronic device defined in  claim 11  further comprising a light-blocking and thermal spreading layer to which the organic light-emitting diode display layer is attached. 
     
     
       13. The electronic device defined in  claim 12  wherein the light-blocking and thermal spreading layer comprises a polymer layer that contains graphite. 
     
     
       14. The electronic device defined in  claim 13  further comprising a metal foil layer to which the organic light-emitting diode display is attached. 
     
     
       15. The electronic device defined in  claim 14  wherein the metal foil layer has an edge portion that covers and protects an edge of organic light-emitting diode display layer. 
     
     
       16. The electronic device defined in  claim 1  wherein the additional support structures are separated by gaps and the flexible display bends at the gaps when the flexible display is retracted within the first housing portion. 
     
     
       17. The electronic device defined in  claim 1  further comprising an additional rotating roller within the second housing portion. 
     
     
       18. A flexible display, comprising:
 a flexible organic light-emitting diode layer that has an array of organic light-emitting diodes and that is operable in a retracted position in which the flexible organic light-emitting diode layer is wrapped around an axis and a deployed position in which the flexible organic light-emitting diode layer is planar; 
 first elongated support members that run parallel to the axis; and 
 second elongated support members that run perpendicular to the first elongated support members and that are located entirely behind the flexible organic light-emitting diode layer when the flexible organic light-emitting diode layer is in the deployed position, wherein the second elongated support members are bistable members that exhibit a rigid state and a flexible state, wherein the first and second elongated support members maintain the flexible organic light-emitting diode layer in a rigid planar configuration when the flexible organic light-emitting diode layer is in the deployed position and when the second elongated support members are in the rigid state and wherein the second elongated support members wrap around the axis with the flexible organic light-emitting diode layer when the organic light-emitting diode layer is in the retracted position. 
 
     
     
       19. The flexible display defined in  claim 18  wherein the second elongated support members comprise metal slats that have a curved profile in the rigid state and a flat profile in the flexible state. 
     
     
       20. An electronic device, comprising: a first elongated housing that extends along a first longitudinal axis; a second elongated housing that extends along a second longitudinal axis parallel to the first longitudinal axis; a flexible display having a first state in which the flexible display is retracted within the first elongated housing and a second state in which the flexible display is deployed and extends between the first and second elongated housings for viewing by a user; bistable metal slats that extend between the first and second elongated housing and that are located entirely behind the flexible display, and that hold the flexible display in a rigid state when the flexible display is deployed in the second state, wherein the flexible display completely overlaps the bistable metal slats when the flexible display is in the second state, and wherein the bistable metal slats are retracted within the first elongated housing when the flexible display is in the first state; and additional support structures that are parallel to the first and second elongated housings. 
     
     
       21. The electronic device defined in  claim 20  further comprising a hollow drum in the first elongated housing, wherein the flexible display wraps around the hollow drum when the flexible display is retracted within the first elongated housing. 
     
     
       22. The electronic device defined in  claim 21  further comprising:
 printed circuits in an interior portion of the hollow drum; and 
 integrated circuits mounted on the printed circuits. 
 
     
     
       23. An electronic device, comprising:
 a first elongated housing that extends along a first longitudinal axis; 
 a second elongated housing that extends along a second longitudinal axis parallel to the first longitudinal axis; 
 a flexible display having a first state in which the flexible display is retracted within the first elongated housing and a second state in which the flexible display is deployed and extends between the first and second elongated housings for viewing by a user; 
 first support members that extend parallel to the first and second elongated housings, wherein the first support members support the flexible display when the flexible display is in the second state, wherein the first support members are separated from one another by gaps, and wherein the flexible display flexes at the gaps when the flexible display is in the first state; 
 second support members that extend perpendicular to the first and second elongated housings, wherein the second support members support the flexible display when the flexible display is in the second state; and 
 speakers in the first and second elongated housings. 
 
     
     
       24. The electronic device defined in  claim 23 , wherein the flexible display comprises an organic light-emitting diode display mounted to a metal sheet. 
     
     
       25. The electronic device defined in  claim 24  wherein the organic light-emitting diode display comprises a polymer substrate having grooves that extend parallel to the first longitudinal axis. 
     
     
       26. The electronic device defined in  claim 23  wherein the first and second elongated housings comprise metal housings and wherein the electronic device further comprises at least one dust brush in the first elongated housing. 
     
     
       27. The electronic device defined in  claim 23  further comprising magnets that hold the first and second housings together when the flexible display is in the first state. 
     
     
       28. The electronic device defined in  claim 23  wherein the first support members comprise slats with magnets.

Description:
BACKGROUND 
     This relates generally to electronic devices, and, more particularly, to electronic devices with displays. 
     Electronic devices often include displays for presenting image to a user. Displays are typically formed from rigid planar substrates. The use of rigid display substrates can cause displays and electronic devices to be more bulky than desired. Although devices can be reduced in size by using smaller displays, this may result in viewing areas that are not as large as desired. 
     It would therefore be desirable to be able to provide improved electronic devices with displays. 
     SUMMARY 
     An electronic device may have a pair of elongated housings. A flexible display may be coupled between the housings. The flexible display may be placed in a first state in which the display is retracted within one of the housings and second state in which the flexible display is deployed and extends between the housings for viewing by a user. 
     The flexible housing may wrap around a rotatable roller in one of the elongated housings. A spring may rotate the roller when it is desired to retract the display. The device may contain electrical components such as integrated circuits, and other devices. The components may be mounted on printed circuit boards that rotate within the rotating roller. 
     Support structures such as horizontal and vertical slats may be attached to the rear of the display. The slats may include rigid slats that run parallel to the elongated housings and may include bistable slats that run perpendicular to the rigid slats. The bistable slats may have a rigid bowed state that helps maintain the display in a rigid state when deployed and may have a flexible flat state that allows the display to flex and wrap around the roller when retracted. 
     The flexible display may be provided with a light blocking and heat spreading layer, a grooved flexible substrate, a touch sensor, and other structures. Speakers, microphones, cameras, and other components can be mounted in the housings. The housings and support slats may be held together using magnets when the display is retracted. Dust brushes may be provided to remove dust from the flexible display. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device having a display in a deployed configuration in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of the illustrative electronic device of  FIG. 1  in which the display has been retracted into the housing of the electronic device in accordance with an embodiment. 
         FIG. 3  is a schematic diagram of an illustrative electronic device in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative electronic device of the type shown in  FIG. 1  in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative electronic device having a left housing portion into which a flexible display may be retracted in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative electronic device showing how the flexible display may be coupled to circuitry within the device in accordance with an embodiment. 
         FIG. 7  is a perspective view of an illustrative dust brush for an electronic device with a retractable flexible display in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of a housing portion with a rotating dust brush for cleaning a retractable flexible display in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of a flexible display in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of a flexible display showing how the display may be mounted on a support substrate and may be covered with functional and protective layers in accordance with an embodiment. 
         FIGS. 11, 12, and 13  are cross-sectional side views of a display during illustrative operations to provide the display with a grooved flexible support structure in accordance with an embodiment. 
         FIG. 14  is a perspective view of a portion of an illustrative display showing how the display may be provided with a protective edge trim in accordance with an embodiment. 
         FIG. 15  is a top view of an illustrative electronic device with a flexible retractable display that has been provided with a web of support structures in accordance with an embodiment. 
         FIG. 16  is a perspective view of an illustrative flexible display with parallel rigid support slats in accordance with an embodiment. 
         FIG. 17  is a cross-sectional side view of a portion of the flexible display of  FIG. 16  showing how flexible portions of the display between the slats allow the display to be rolled into a cylindrical shape in accordance with an embodiment. 
         FIG. 18  is a cross-sectional side view of an illustrative flexible display with support slats that have magnets in accordance with an embodiment. 
         FIG. 19  is a cross-sectional side view of an illustrative flexible display in which support slat members have been mounted to a flexible substrate that can be separated from a flexible organic light-emitting diode substrate by an air gap in accordance with an embodiment. 
         FIG. 20  is a perspective view of an illustrative elongated support member formed from a bistable metal strip in accordance with an embodiment. 
         FIG. 21  is a cross-sectional side view of the support member of  FIG. 20  in its flat flexible state in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device of the type that may be provided with a retractable flexible display is shown in  FIG. 1 . Electronic device  10  may be used as a portable monitor (e.g., for displaying content from an associated computer or other electronic equipment), may be a stand-alone computing device (e.g., an electronic device that can display media, handle wireless communications, receive input from a user, etc.), or may be any other electronic device. Device  10  may contain an embedded computer or may have reduced functionality to reduce device cost and complexity. 
     Device  10  may have a flexible display such as display  14 . In the deployed position of  FIG. 1 , display  14  may have a planar shape (i.e., display  14  may lie in the X-Y plane of  FIG. 1 ). The outline of display  14  may be rectangular or display  14  may have other suitable deployed shapes. Because display  14  is flexible, display  14  may be retracted into housing  12  of device  10  when it is desired to store display  14 . 
     Housing  12 , which may sometimes be referred to as an enclosure or 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 have elongated left and right portions such as barrel-shaped left-housing  12 A and barrel-shaped right housing  12 B in the example of  FIG. 1 . Housings  12 A and  12 B may be formed using a unibody configuration in which some or all of each of these housing structures 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.). Housings  12 A and  12 B may be formed from a stainless steel layer (e.g., a stainless steel shell structure) or may be formed from aluminum, other metals, or other materials. 
     Electrical components for device  10  may be mounted in housings  12 A and  12 B. For example, one or more speakers and/or microphones may be mounted in alignment with openings  16  in housings  12 A and/or  12 B. Openings  16  may be microperforations having diameters of less than 1 mm, less than 0.5 mm, less than 0.1 mm, 0.05 to 4 mm, more than 0.01 mm, or other suitable size. Openings  16  may or other openings in housing  12  may form audio ports to accommodate speakers and microphones. 
     Optical components in electronic device  10  such as sensors, cameras, light-emitting diodes and other light-based components can be accommodated using optical windows  18 . Optical windows  18  may be associated with left and right cameras in left housing  12 A and right housing  12 B, respectively (e.g., to provide device  10  with the ability to capture stereoscopic images of a user of device  10 ). Device  10  may also be provided with buttons and other user input devices mounted on housing  12 . 
     Housing portions  12 A and  12 B may have elongated cylindrical (barrel) shapes. As shown in  FIG. 1 , housing  12 A may have an elongated shape that extends along longitudinal axis  60 A and housing  12 B may have an elongated shape that extends along longitudinal axis  60 B. Rollers may be provided in housing portions  12 A and/or  12 B to receive flexible display  14  when flexible display  14  is retracted. The rollers may rotate about axes  60 A and/or  60 B when retracing and deploying flexible display  14 , so axes  60 A and  60 B may sometimes be referred to as roller axes or rotational axes. To ensure that display  14  remains in its deployed state, the rollers in housing  12  may be provided with a latching mechanism. When the latching mechanism is released, springs within housing  12  can pull display  14  into housing  12 A and/or housing  12 B.  FIG. 2  shows how device  10  may appear when display  14  has been fully retracted. In the configuration of  FIG. 2 , housings  12 A and  12 B may mate along surface  20 . Magnets or other structures (e.g., mating engagement structures such as clips and springs, hook and loop fasteners, etc.) may be used to hold housings  12 A and  12 B together when device  10  has been placed in the retracted display configuration of  FIG. 2 . 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads, a metal mesh of wires that are sufficiently thin to appear transparent, or other transparent conductive structures. A touch sensor may be formed using electrodes or other structures on a display layer that contains a pixel array or on a separate touch panel layer that is attached to the pixel array (e.g., using adhesive). 
     Display  14  may include pixels formed from liquid crystal display (LCD) components, electrophoretic pixels, microelectromechanical (MEMs) shutter pixels, electrowetting pixels, micro-light-emitting diodes (small crystalline semiconductor die), organic light-emitting diodes (e.g., a thin-film organic light-emitting diode display), or pixels based on other display technologies. Configurations in which display  14  is an organic light-emitting diode display are sometimes described herein as an example. 
     A schematic diagram of an illustrative electronic device such as device  10  of  FIG. 1  is shown in  FIG. 3 . As shown in  FIG. 3 , electronic device  10  may have control circuitry  30 . Control circuitry  30  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  30  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. 
     Input-output circuitry in device  10  such as input-output devices  32  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  32  may include display  14 , buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones  36 , speakers  34 , tone generators, vibrators, cameras  38 , sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  32  and may receive status information and other output from device  10  using the output resources of input-output devices  32 . 
     Control circuitry  30  may be used to run software on device  10  such as operating system code and applications. During operation of device  10 , the software running on control circuitry  30  may display images on display  14  (e.g., video, still images such as text, alphanumeric labels, photographs, icons, other graphics, etc.) using an array of pixels in display  14 , may gather still and/or moving images using cameras  38 , may play audio through speakers  34 , may gather audio input using microphones  36 , and may control other device operations. 
       FIG. 4  is a cross-sectional side view of device  10  showing how electrical components  52 A may be mounted in housing  12 A and showing how electrical components  52 B may be mounted in housing  12 B. Components  52 A and  52 B may include batteries, integrated circuits, sensors, and other components (see, e.g., control circuitry  30  and input-output devices  32  of  FIG. 3 ). Metal traces or other signal lines may be used to form signal paths  50  in display  14 . Signal paths  50  may be used to allow electrical components  52 A to communicate with electrical components  52 B. Signal paths  50  may also be used to route data signals and control signals to an array of organic light-emitting diodes  40  on the upper surface of display  14 . Each light-emitting diode  40  may form part of a pixel in an array of pixels in display  14  that is used to display images for a user (see, e.g., viewer  44  of  FIG. 4 ). Light-emitting diodes  40  may emit light  42  of different colors (e.g., red, blue, and green, etc.). 
     When not in use, display  14  may be stored in housing  12 A, in housing  12 B, or may be stored using cavities inside both housing  12 A and housing  12 B. 
       FIG. 5  is a cross-sectional side view of display  10  in an illustrative configuration in which display  14  is retracted into housing  12 A when not in use. As shown in  FIG. 5 , housing  12 A may contain a cylindrical display storage member such as roller  58  (e.g., a cylindrical drum, a hollow elongated member with non-circular profiles, etc.). Roller  58  may be a hollow cylinder that is filled with electrical components  52 A. Roller  58  may rotate about axis  60 A in direction  56  when it is desired to retract display  14  into housing  12 A. With each successive rotation of roller  58 , another layer of display  14  may be wrapped around roller  58 . A mechanically or electrically actuated latch may retain roller  58  in place until it is desired to deploy display  14 . 
     In the example of  FIG. 5 , housing  12 B does not contain rotating internal structures such as roller  58 , but rather contains components  52 B that remain stationary with respect to display  14  and housing  12 B. Other configurations for device  10  may be used if desired (e.g., configurations in which display  14  is retracted into housing  12 B using a rotating drum in housing  12 B, etc.). 
     As shown in the illustrative side view of  FIG. 6 , roller  58  may have an opening such as opening  60  into which the left edge of display  14  may be inserted and held in place using adhesive  66 . A clamp may also be used to help secure display  14  within roller  58 . The arrangement of  FIG. 6  allows signal paths in display  14  to be coupled to signal paths in printed circuits  52 A′ and thereby be electrically coupled to electrical components  52 A on printed circuits  52 A′. In the example of  FIG. 6 , printed circuits  52 A′ have been mounted to form a four-sided tube in the interior of roller  58 . Other arrangements for mounting electrical components  52 A and printed circuits  52 A′ within roller  58  may be used, if desired. 
     Right housing  12 B may contain an elongated hollow structure such as structure  70  with an opening  72  through which the right edge of display  14  may be inserted and attached to electrical components  52 B. Structure  70  may be fixed to housing  12 B or may be a hollow drum or other structure that rotates about axis  60 B with respect to housing  12 B. Components  52 B may include a battery and other electrical devices. 
     Housing  12 A and  12 B may be provided with structures such as magnets  62  on housing  12 A and corresponding magnets  64  on housing  12 B. Magnets  62  and  64  may be configured to attract each other and thereby pull mating housing surfaces  20  of housings  12 A and  12 B together when display  14  is retracted. If desired, mechanical engagement structures (e.g., springs and clips, locking mechanisms, and other structures) may be used to supplement magnets  62  and magnets  64  or may be used to hold housings  12 A and  12 B together in configurations for device  10  without magnets. Configurations in which a set of magnets mates with a corresponding ferromagnetic structure such as an iron bar may also be used. 
     During normal use of display  14 , contaminants such as dust particles may be deposited on the surface of display  14 . To remove these dust particles and thereby prevent damage to display  14  when display  14  is wrapped on top of itself within housing  12 , device  10  may be provided with brushes or other dust removal structures. In the example of  FIG. 7 , device housing  12 A has been provided with a portion  12 A′ that is separated from upper surface  14 - 1  of display  14  by gap  80  and has a portion  12 A″ that is separated from lower surface  14 - 2  of display  14  by gap  82 . Gaps  80  and  82  form an opening into which display  14  may pass when moved in and out of housing  12 A. 
     Brushes may be formed from foam, bristles, or other brush structures in gaps  80  and  82 , respectively. As shown in  FIG. 7 , brush bristles  84  may form a brush that spans gap  80  and brush bristles  86  may form a brush that spans gap  82 . Bristles  84  and  86  may be formed from plastic or other suitable materials. 
       FIG. 8  shows how bristles  84  may be mounted on a rotating support structure such as structure  90  (e.g., a cylindrical member). When structure  90  is rotated about brush rotational axis  92 , dust is swept off of upper display surface  14 - 1  and out of gap  80 . If desired, a rotating brush may be formed in housing  12 A that cleans the lower surface of display  14 . The configuration of  FIG. 8  is merely illustrative. 
     As shown in  FIG. 8 , device  10  may be provided with springs such as coil spring  94 . In the example of  FIG. 8 , spring  94  has one end attached to roller  58  and another end coupled to housing  12 A (e.g., at an attachment point near axis  60 A or other suitable mounting point). Spring  94  may be tensioned when display  14  is pulled out of housing  12 A to deploy display  14  for viewing by viewer  44  of  FIG. 4 . When roller  58  is released and allowed to rotate about axis  60 A to retract display  14 , the tension exerted by spring  94  may help rotate roller  58  in direction  56  and thereby retract display  14  into housing  12 A in direction  100 . In housing  12 A, display  14  wraps around roller  58  and axis  60 A. Housing  12 B may also have a spring or other biasing member to exert a biasing force on a display storage structure such as a hollow cylindrical roller, if desired. 
     As shown in  FIG. 9 , display  14  may have an organic light-emitting diode display layer such as layer  102 . Layer  102  may contain a polymer substrate, thin-film transistor circuitry on the substrate, an array of diode terminals and areas of emissive material to form diodes  40 , and an encapsulation layer. Display  14  may also have additional layers above and/or below organic light-emitting diode layer  102  such as layers  104 . Layers  104  may include functional layers (e.g., a circular polarizer above layer  102  to suppress reflections, a touch sensor layer on the polarizer, a protective layer above the polarizer layer and touch sensor to prevent damage from scratches, support layers below layer  102 , etc.). Layers  104  may include metal (e.g., stainless steel, aluminum, copper, and other metals), may include polymers, may include carbon-fiber composites and other composite materials, may include ceramics, may include glasses, may include crystalline materials such as sapphire, may include fabric formed from plastic, metal, glass, and/or other materials, or may include other materials. The metal in layers  104  may include flexible metal foil (e.g., a thin sheet of stainless steel or other metal). 
     A cross-sectional side view of display  14  in an illustrative configuration in which organic light-emitting diode layer  102  is attached to additional layers of material is shown in  FIG. 10 . In the example of  FIG. 10 , organic light-emitting diode layer  102  includes a polymer substrate, thin-film transistor circuitry on the substrate, emissive material, conductive structures, and encapsulation for forming encapsulated array of light-emitting diodes  40 . Organic light-emitting diode layer  102  may be attached to layer  106 . Layer  106  may be a polymer layer containing nanoparticles to enhance thermal conductivity. For example, layer  106  may be formed from a polymer such as polyethylene terephthalate (PET). Layer  106  may be filled with graphite particles to enhance thermal conductivity. In addition to enhancing the thermal conductivity of display  14  and helping to dissipate heat from diodes  40 , layer  106  may serve as an opaque layer that blocks stray light (e.g., a black masking layer). Because layer  106  may serve both light block functions and thermal spreading functions, layer  106  may sometimes be referred to as a light blocking and thermal spreading layer. 
     Layer  106  may be attached to support layers such support layer  108 . Support layer  108  may be formed from a thin metal foil such as a foil of stainless steel or copper. Layer  108  may also be a metallic glass or other material that provides mechanical strength and helps the lower surface of display  14  resist scratches when device  10  is placed on a table or other support surface. 
     Layer  112  may cover organic light-emitting diode layer  102 . Layer  112  may include a polarizer layer (e.g., a circular polarizer having a thickness of about 50 microns). 
     Layer  114  may cover layer  112 . Layer  114  may be a touch sensor layer. Touch sensor layer  114  may be formed from a silver mesh, other metal mesh structures, an array of indium tin oxide capacitive electrodes, or other touch sensor structures. 
     Protective layer  114  may be formed from a layer of polymer or other flexible structures that help display  14  resist damage (e.g., a thin flexible glass layer, etc.). 
     If desired, additional support structure such as structures for providing display  14  with a rigid rear support when display  14  is deployed may be added to structures to the type shown in  FIG. 10 . The example of  FIG. 10  is merely illustrative. 
     One or more of the layers in display  14  may be provided with corrugations or other grooves to enhance flexibility.  FIGS. 11, 12, and 13  show illustrative process steps involved in forming a flexible display of this type. In the example of  FIGS. 11, 12, and 13 , a flexible polymer substrate for organic light-emitting diode layer  102  is being provided with a series of parallel grooves (grooves that extend parallel to axis  60 A and dimension Y in the example of  FIG. 1 ). As shown in  FIG. 11 , a carrier such as glass carrier  120  may be provided with protrusions  122  (e.g., ridges formed from glass portions of carrier  120 , ridges formed from polymer, or ridges formed from other material on the surface of carrier  120 ). 
     As shown in  FIG. 12 , carrier  120  and ridges  122  may be coated with substrate layer material for forming substrate  124 . As an example, substrate  124  may be formed from a liquid polymer such as a liquid polyimide precursor that is cured to form a polyimide substrate for organic light-emitting diode layer  102 . Thin-film layers  126  may be deposited and patterned on substrate  124 . Substrate  124  may then be removed from carrier  120  to form organic light-emitting diode layer  102  of  FIG. 13 . As shown in  FIG. 13 , because substrate layer  124  was formed on a carrier with ridges, substrate  124  has a series of parallel flexibility-enhancing grooves  128 . Other structures may be used to enhance the flexibility of display  14  if desired. The corrugated shape of  FIG. 13  is merely illustrative. 
     Layers  126  may include a thin-film transistor layer and associated light-emitting diode structures. Layers  126  may also include moisture barrier structures. Layers  126  may include inorganic and organic dielectric layers, semiconductor layers, and metal layers. These layers may form buffer layers, gate insulator layers, semiconductor channel regions in transistors, capacitor plates, metal interconnects, component terminals, interlayer dielectric layers, planarization layers, moisture barrier layers, etc. 
     One or more edges of display  14  (e.g., the top and bottom edges of display  14  of  FIG. 1  that run parallel to lateral dimension X in the example of  FIG. 1 ) may be provided with edge protection structures. Consider, as an example, the arrangement of  FIG. 14 . As shown in  FIG. 14 , display  14  has layers  130 . Layers  130  may be mounted on support layer  108 . Layers  130  may include, for example, a series of layers such as a protection layer, a touch sensor layer, a polarizer layer, an organic light-emitting diode layer, and a light-blocking and thermal spreading layer. Layers  130  may be mounted on layer  108  (e.g., a flexible stainless steel layer or other supporting structure). Edge portion  108 E of rear support layer  108  may be bent around the edge of layers  130  and crimped into place as shown in  FIG. 14 . This allows bent edge portion  108 E of layer  108  to provide edge protection to layers  130 . If desired, edge portion  108 E may be separated from the rest of layer  108 , edge portion  108 E may be attached to the edge and top surfaces of layers  130  using adhesive, and/or other edge protection structures may be used to protect the exposed edges of display  14 . The example of  FIG. 14  is merely illustrative. 
     It may be desirable to provide display  14  with a support structure that is rigid when display  14  is deployed and that may be made sufficiently flexible to allow display  14  to be wrapped around rollers in housing  12  when display  14  is stored. This type of structure is shown in the top view of display  14  of  FIG. 15 . In the example of  FIG. 14 , display  14  has been provided with two different types of support structures on the rear surface of display  14 : supports  140  and supports  142 . Supports  140  and  142  may be separate sets of elongated support members (sometimes referred to as slats or strips) or supports  140  and  142  may be formed as parts of an integral web structure. Supports  140  run parallel to the Y dimension of  FIG. 15  (i.e., parallel to longitudinal housing axes  60 A and  60 B). Supports  140  may be rigid along their lengths to help support display  14 . Supports  142  run parallel to the X dimension of  FIG. 15  (perpendicular to supports  140 ). Supports  142  may be bistable members that exhibit both rigid and flexible states. 
     Supports  140  and  142  may be formed from plastic, metal, fiber-composites, and/or other materials. There may be any suitable number of supports  140  in display  14  and any suitable number of supports  142  in display  14  (e.g., 1-100, 5-20, 3-50, etc.). Supports  142  may include a pair of edge supports that run along the exposed edges of display  14  and one or more additional optional central supports that lie between the edge supports. Supports  140  may, as an example, cover all of display  14 . Gaps may be formed between respective supports  140  to provide display  14  with flexing regions. 
     As shown in the illustrative perspective view of display  14  of  FIG. 16 , support structures  140  may be configured to form a series of parallel supports on the lower surface of display layer  144  that are separated by respective gaps  146 . In gaps  146 , flexible portions of display layer  144  such as flexible portions  144 ′ may allow display  14  to bend about axis  60 A (i.e., the Y axis), as shown in  FIG. 17 . Layer  144  may include organic light-emitting diode layer  102  and one or more other layers (see, e.g., the layers of  FIG. 10 ). 
       FIG. 18  is a cross-sectional side view of a flexible display with support slats  140  in a planar configuration (i.e., when display  14  is deployed). Magnets  148  may be provided in slats  140  or on slats  140  to hold slats  140  against each other and thereby maintain display  14  in a rigid planar configuration when in a deployed position (e.g., so that a user can supply touch input to the touch sensor of layer  14 ). 
       FIG. 19  is a cross-sectional side view of display  14  showing how the support structures on the rear of display  14  may be implemented by mounting support slats  140  on a flexible layer such as layer  150  (e.g., a flexible polymer layer) that is separate from layer  144 . As shown in  FIG. 19 , layer  144  and flexible layer  150  may be separated by an air gap such as gap  152 . The presence of gap  152  allows layers  150  and  144  to slide laterally with respect to each other as display  14  is deployed and retracted, thereby helping to avoid an undesirable build up of stress in display  14 . 
       FIG. 20  is a perspective view of an illustrative bistable structure that may be used in implementing elongated support members such as support slats  142 . As shown in  FIG. 20 , support slats  142  may have elongated rectangular strip shapes or other shapes. Each slat  142  may extend along a longitudinal axis  154  parallel to axis X in the example of  FIG. 15 . Slats  142  may have a curved shape (i.e., a curved profile) that provides slats  142  with bistability. Slats  142  may be formed from plastic, metal (e.g., spring metal, etc.), or other suitable materials. When allowed to relax, slats  142  assume their bowed (curved) shape and assume a rigid state to form rigid supports on the rear surface of display  14 . Because slats  142  run perpendicular to slats  140 , slats  142  (in their relaxed bowed state) will resist bending about axes  60 A and  60 B (i.e., the Y axis of  FIG. 20 ) and will therefore help to maintain display  14  in a planar rigid state. When forced into their flat state by applying sufficient bending force ( FIG. 21 ), slats  142  will snap into their flat (flexible) state and will no longer significantly resist bending about axis Y. When in their flexible flat state, slats  142  can be wrapped around drum  58  as display  14  is retracted into housing  12 . If desired, other bistable support structures may be used to provide display  14  with the ability to transition between rigid and flexible states. The illustrative bistable metal strip configuration of slat  142  of  FIGS. 20 and 21  is merely illustrative. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20150824
Publication Date: 20170418
Grant Date: 20170418
Priority Date: 20150824
Inventors: ZHANG ZHEN
DRZAIC PAUL S.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/1605", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04102", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1652", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1628", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1652", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1615", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1652", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1628", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1615", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L51/0097", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04102", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K2102/311", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K77/111", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K77/111", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02E10/549", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/87", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K77/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/8794", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 58098140