WO2014052468A2

WO2014052468A2 - Display with structures for minimizing display borders

Info

Publication number: WO2014052468A2
Application number: PCT/US2013/061709
Authority: WO
Inventors: Tseng-mau YANG; Dale N. MEMERING; Christopher D. Prest
Original assignee: Apple Inc.
Priority date: 2012-09-28
Filing date: 2013-09-25
Publication date: 2014-04-03
Also published as: WO2014052468A3

Abstract

An electronic device may be provided with a display mounted in a housing. The display may have an array of display pixels that provide light to a user. The array of display pixels may form active display structures with a rectangular shape. The rectangular active display structures may be surrounded by an inactive border region. In one suitable embodiment, reflector structures may be used to reflect light emitted from peripheral portions of the active display structures to a portion of the display overlapping the inactive border region, thereby providing the display with an effective active area that is larger than the area of the active display structures. In another suitable embodiment, liquid crystal light distribution structures may be used to distribute light emitted from peripheral portions of the active display structures to a portion of the display overlapping the inactive border region, thereby increasing the apparent area of the display.

Description

DISPLAY WITH STRUCTURES

FOR MINIMIZING DISPLAY BORDERS

This application claims priority to United

States patent application 13/631,125 filed September 28, 2012, and United States patent application No. 13/631,153 filed September 28, 2012, which are hereby incorporated by reference herein in their entireties.

Background

This relates generally to electronic devices, and more particularly, to electronic devices with

displays .

Electronic devices often include displays. For example, cellular telephones and portable computers often include displays for presenting information to a user. An electronic device may have a housing such as a housing formed from plastic or metal. Components for the

electronic device such as display components may be mounted in the housing. It can be challenging to incorporate a display into the housing of an electronic device. Size and weight are often important considerations in designing electronic devices. If care is not taken, displays may be bulky or may be surrounded by overly large borders. The housing of an electronic device can be adjusted to accommodate a bulky display with large borders, but 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 displays for electronic devices.

Summary

An electronic device may be provided with a display mounted in a housing. The display may have an array of display pixels that provide light to a user. The array of display pixels may form an active display

structure with a rectangular shape. The rectangular active display structure may be surrounded by an inactive border region. Reflector structures may be provided around the periphery of the display structure. The reflector structures may be used to reflect light that is emitted from peripheral portions of the active display structure to a portion of the display overlapping the inactive border region, thereby providing the display with an effective area that is larger than the area of the active display structures.

The active display structures may have portions such as bent edge portions that emit light that is

reflected by a fixed reflector or other reflector

structures. The reflector structures may, for example, include a rotatable reflector. Control circuitry may use a rotatable positioner to rotate the rotatable reflector while simultaneously with controlling which pixel data is displayed by the display pixels in the peripheral portions of the active display structure. This allows pixel data to be distributed across the portion of the display that overlaps the inactive border region.

Display pixels may, if desired, be provided with enhanced brightness in the peripheral portion of active display structures to compensate for the use of the rotatable reflector to distribute display pixel light across multiple display locations. Curved or other non- planar surfaces may be used in the reflector structures.

An imaging system may use rotatable reflector structures to enhance the area of an image sensor used to capture digital image data.

Liquid crystal light distribution structures may be used to distribute light that is emitted from

peripheral portions of the active display structures to a portion of the display overlapping the inactive border region, thereby providing the display with an apparent active area that is larger than the area of the active display structures.

The liquid crystal light distribution structures may include a liquid crystal cell that receives light from display pixels in the peripheral portions of the active display structures. The liquid crystal cell may be controlled by control circuitry to adjust the orientation of linearly polarized light received from the display pixels. Light that has passed through the liquid crystal call may be received by a reflecting polarizer, which reflects or transmits the light based on the polarization state of the light. A reflector may be used to reflect light from the peripheral portions of the active display structures vertically upwards towards a viewer after the light has passed through the liquid crystal cell and has reflected off of the reflecting polarizer.

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 such as a laptop computer with a display 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 a display 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 a display in accordance with an embodiment of the present invention.

FIG. 4 is a schematic diagram of an illustrative electronic device with a display in accordance with an embodiment of the present invention.

FIG. 5 is a cross-sectional side view of an illustrative display in accordance with an embodiment of the present invention.

FIG. 6 is a top view of illustrative display layers in a display having an active region with an array of display pixels and an inactive border region in accordance with an embodiment of the present invention.

FIG. 7 is a cross-sectional side view of an illustrative electronic device with an electromechanical mirror to distribute light from pixels in the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 8 is a set of graphs showing how pixel content may be modulated and mirror position synchronously adjusted to distribute light from pixels in the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 9 is a cross-sectional side view of an illustrative electronic device with an electromechanical mirror to distribute light from multiple pixels in the edge of a display in parallel to minimize display borders in accordance with an embodiment of the present invention.

FIG. 10 is a cross-sectional side view of an illustrative display with a bent edge portion and an electromechanical mirror to distribute light from multiple pixels in the bent edge portion along the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 11 is a cross-sectional side view of an illustrative display with a bent edge portion and a stationary mirror to distribute light from multiple pixels in the bent edge portion along the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 12 is a cross-sectional side view of an illustrative display with an electromechanical mirror in a first of three positions during the process of distributing light along the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 13 is a cross-sectional side view of the illustrative display of FIG. 12 in which the

electromechanical mirror is in a second of three positions during the process of distributing light along the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 14 is a cross-sectional side view of the illustrative display of FIG. 12 in which the

electromechanical mirror is in a third of three positions during the process of distributing light along the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 15 is a cross-sectional side view of an illustrative display with an electromechanical mirror and a stationary mirror of the type that may be provided with optional non-planar surfaces for use in distributing light from pixels along the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 16 is a cross-sectional side view of an illustrative image sensor system having an

electromechanical mirror for enlarging the effective lateral dimensions of a digital image sensor in accordance with an embodiment of the present invention.

FIG. 17 is a perspective view of an illustrative electronic device such as a laptop computer with a display in accordance with an embodiment of the present invention.

FIG. 18 is a perspective view of an illustrative electronic device such as a handheld electronic device with a display in accordance with an embodiment of the present invention.

FIG. 19 is a perspective view of an illustrative electronic device such as a tablet computer with a display in accordance with an embodiment of the present invention.

FIG. 20 is a schematic diagram of an

illustrative electronic device with a display in

accordance with an embodiment of the present invention.

FIG. 21 is a cross-sectional side view of an illustrative display in accordance with an embodiment of the present invention.

FIG. 22 is a top view of illustrative display layers in a display having an active region with an array of display pixels and an inactive border region in

accordance with an embodiment of the present invention.

FIG. 23 is a perspective view of a liquid crystal cell in a state that does not rotate the

polarization of incoming light in accordance with an embodiment of the present invention.

FIG. 24 is a perspective view of the liquid crystal cell of FIG. 23 in a state that rotates the polarization of incoming light by 90° in accordance with an embodiment of the present invention.

FIG. 25 is a cross-sectional side view of an illustrative electronic device with liquid crystal light distribution structures to distribute light from a pixel on the edge of a display to minimize display borders in accordance with an embodiment of the present invention.

FIG. 26 is a cross-sectional side view of an illustrative electronic device with liquid crystal light distribution structures to distribute light from multiple pixels on the edge of a display to minimize display borders in accordance with an embodiment of the present invention .

FIG. 27 is a cross-sectional side view of an illustrative liquid crystal shutter structure with an associated reflector having non-planar surfaces in

accordance with an embodiment of the present invention.

FIG. 28 is a cross-sectional side view of a display having a light guide plate with a locally

increased scattering feature density to enhance light intensity for a peripheral display pixel producing light that is distributed using liquid crystal light

distribution structures 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.

In some configurations, reflector structures may be used to reflect light emitted from peripheral portions of the active display structures to a portion of the display overlapping the inactive border region, thereby providing the display with an effective active area that is larger than the area of the active display structures. FIGS. 1-16 show examples of display configurations in which reflector structures are used to enlarge the

effective active area of a display.

In some configurations, liquid crystal light distribution structures may be used to distribute light emitted from peripheral portions of the active display structures to a portion of the display overlapping the inactive border region, thereby increasing the apparent area of the display. FIGS. 17-28 show examples of display configurations in which light distribution structures are used to enlarge the apparent area of a display.

Illustrative electronic devices that may be provided with displays having reflector structures 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 12A and lower housing 12B with components such as keyboard 16 and touchpad 18. Device 10 may have hinge structures 20 that allow upper housing 12A to rotate in directions 22 about rotational axis 24 relative to lower housing 12B. Display 14 may be mounted in upper housing 12A. Upper housing 12A, which may sometimes referred to as a display housing or lid, may be placed in a closed position by rotating upper housing 12A towards lower housing 12B about rotational axis 24.

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 26. 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 26 (as an example) .

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 television, a computer display that does not contain an embedded computer, 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 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 image pixels formed from light-emitting diodes (LEDs) , organic LEDs (OLEDs) , plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image 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. The use of liquid crystal display structures and backlight structures in device 10 is merely illustrative .

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 structures.

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) .

A schematic diagram of an illustrative configuration that may be used for electronic device 10 is shown in FIG. 4. As shown in FIG. 4, electronic device 10 may include control circuitry 29. Control circuitry 29 may include storage and processing circuitry for

controlling the operation of device 10. Control circuitry 29 may, for example, 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.

Control circuitry 29 may include processing circuitry based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc.

Control circuitry 29 may be used to run software on device 10, such as operating system software and application software. Using this software, control circuitry 29 may present information to a user of

electronic device 10 on display 14. Display 14 may contain an array of display pixels (e.g., liquid crystal display pixels) that are organized in rows and columns. Control circuitry 29 may be used to display content for a user of device 10 on the array of display pixels in display 14.

Control circuitry 29 may include display driver circuitry and other circuitry for controlling the rate at which display pixels are refreshed and for controlling which pixel data is displayed by each display pixel.

Display driver circuitry may be formed using thin-film- transistor circuitry on display 14 and/or integrated circuits mounted on a layer in display 14 or on a printed circuit. In addition to controlling the display of pixel data using the display pixels of display 14, control circuitry 29 may perform control operations within device 10 such as controlling the positions of movable mirrors such as electromechanical mirrors and other controllable electronic components. Control circuitry 29 may, for example, issue control commands that direct a movable mirror to move to a desired position. Mirror adjustments such as these may be synchronized with display control operations (e.g., to ensure that electromechanical mirrors are positioned as desired in synchronization with the operation of display pixels in display 14) .

Input-output circuitry 30 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 circuitry 30 may include communications circuitry 32.

Communications circuitry 32 may include wired

communications circuitry for supporting communications using data ports in device 10. Communications circuitry 32 may also include wireless communications circuits

(e.g., circuitry for transmitting and receiving wireless radio-frequency signals using antennas) .

Input-output circuitry 30 may also include input-output devices 34. A user can control the operation of device 10 by supplying commands through input-output devices 34 and may receive status information and other output from device 10 using the output resources of input- output devices 34.

Input-output devices 34 may include sensors and status indicators 36 such as an ambient light sensor, a proximity sensor, a temperature sensor, a pressure sensor, a magnetic sensor, an accelerometer, and light-emitting diodes and other components for gathering information about the environment in which device 10 is operating and providing information to a user of device 10 about the status of device 10.

Audio components 38 may include speakers and tone generators for presenting sound to a user of device 10 and microphones for gathering user audio input.

Display 14 (e.g., the array of display pixels in display 14) may be used to present images for a user such as text, video, and still images. Sensors 36 may include a touch sensor array that is formed as one of the layers in display 14.

User input may be gathered using buttons and other input-output components 40 such as touch pad

sensors, buttons, joysticks, click wheels, scrolling wheels, touch sensors such as sensors 36 in display 14, key pads, keyboards, vibrators, cameras, and other input- output components. A cross-sectional side view of an illustrative configuration that may be used for display 14 of device 10 (e.g., for display 14 of the devices of FIG. 1, FIG. 2, or FIG. 3 or other suitable electronic devices) is shown in FIG. 5. As shown in FIG. 5, display 14 may include backlight structures such as backlight unit 42 for

producing backlight 44. During operation, backlight 44 travels outwards (vertically upwards in dimension Z in the orientation of FIG. 5) and passes through display pixel structures in display layers 46. This illuminates any images that are being produced by the display pixels for viewing by a user. For example, backlight 44 may

illuminate images on display layers 46 that are being viewed by viewer 48 in direction 50.

Display 14 may, if desired, have one or more optical structures that are located above display layers 46. For example, display 14 may have a display cover layer such as display cover layer 84. Display cover layer 84 may be formed from a layer of clear glass, a

transparent sheet of plastic, or other transparent

structure. Display cover layer 84 may be mounted in housing 12 (e.g., using housing sidewalls) . During operation, light 44 may pass through the array of display pixels formed from display layers 46 and display cover layer 84 for viewing by user 48.

Display layers 46 may be mounted in chassis structures such as a plastic chassis structure and/or a metal chassis structure to form a display module for mounting in housing 12 or display layers 46 may be mounted directly in housing 12 (e.g., by stacking display layers

46 into a recessed portion in housing 12) . Display layers 46 may form a liquid crystal display or may be used in forming displays of other types. Display layers 46 may sometimes be referred to as a display module, a display, or an array of display pixels. The light (light 44) that passes through the array of display pixels is used in displaying content on display 14 for user 48.

In a configuration in which display layers 46 are used in forming a liquid crystal display, display layers 46 may include a liquid crystal layer such a liquid crystal layer 52. Liquid crystal layer 52 may be

sandwiched between display layers such as display layers 58 and 56. Layers 56 and 58 may be interposed between lower polarizer layer 60 and upper polarizer layer 54.

Layers 58 and 56 may be formed from transparent substrate layers such as clear layers of glass or plastic. Layers 56 and 58 may be layers such as a thin-film

transistor layer and/or a color filter layer. Conductive traces, color filter elements, transistors, and other circuits and structures may be formed on the substrates of layers 58 and 56 (e.g., to form a thin-film transistor layer and/or a color filter layer) . Touch sensor

electrodes may also be incorporated into layers such as layers 58 and 56 and/or touch sensor electrodes may be formed on other substrates.

With one illustrative configuration, layer 58 may be a thin-film transistor layer that includes an array of thin-film transistors and associated electrodes

(display pixel electrodes) for applying electric fields to liquid crystal layer 52 and thereby displaying images on display 14. Layer 56 may be a color filter layer that includes an array of color filter elements for providing display 14 with the ability to display color images. If desired, layer 58 may be a color filter layer and layer 56 may be a thin-film transistor layer.

During operation of display 14 in device 10, control circuitry 29 (e.g., one or more integrated

circuits such as components 68 on printed circuit 66 of FIG. 5) may be used to generate information to be

displayed on display 14 (e.g., display data). The

information to be displayed may be conveyed from circuitry 68 to display control circuitry such as display driver integrated circuit 62 using a signal path such as a signal path formed from conductive metal traces in flexible printed circuit 64 (as an example) .

Display driver integrated circuit 62 may be mounted on thin-film-transistor layer driver ledge 82 or elsewhere in device 10. During operation of display 14, display driver circuitry 62 and/or other display control circuitry such as gate driver circuitry formed on

substrate 58 or coupled to substrate 58 may be used in controlling the array of display pixels in layers 46

(e.g., using a grid of vertical data lines and horizontal gate lines) .

A flexible printed circuit cable such as

flexible printed circuit 64 may be used in routing signals between printed circuit 66 and thin-film-transistor layer 58. If desired, display driver integrated circuit 62 may be mounted on printed circuit 66 or flexible printed circuit 64. Printed circuit 66 may be formed from a rigid printed circuit board (e.g., a layer of fiberglass-filled epoxy) or a flexible printed circuit (e.g., a flexible sheet of polyimide or other flexible polymer layer) . Backlight structures 42 may include a light guide plate such as light guide plate 78. Light guide plate 78 may be formed from a transparent material such as clear glass or plastic. During operation of backlight structures 42, a light source such as light source 72 may generate light 74. Light source 72 may be, for example, an array of light-emitting diodes.

Light 74 from light source 72 may be coupled into edge surface 76 of light guide plate 78 and may be distributed in dimensions X and Y throughout light guide plate 78 due to the principal of total internal

reflection. Light guide plate 78 may include light- scattering features such as pits or bumps. The light- scattering features may be located on an upper surface and/or on an opposing lower surface of light guide plate 78.

Light 74 that scatters upwards in direction Z from light guide plate 78 may serve as backlight 44 for display 14. Light 74 that scatters downwards may be reflected back in the upwards direction by reflector 80.

Reflector 80 may be formed from a reflective material such as a layer of white plastic or other shiny materials.

To enhance backlight performance for backlight structures 42, backlight structures 42 may include optical films 70. Optical films 70 may include diffuser layers for helping to homogenize backlight 44 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 44. Optical films 70 may overlap the other structures in backlight unit 42 such as light guide plate 78 and reflector 80. For example, if light guide plate 78 has a rectangular footprint in the X-Y plane of FIG. 5, optical films 70 and reflector 80 may have a matching rectangular footprint. Display layers 46 and the other display structures of FIG. 5 typically have rectangular shapes with four peripheral edges, but display configurations with other shapes may be used in forming display 14 if desired .

As shown in FIG. 6, display structures 46 of display 14 may include a plurality of display pixels 86. Display pixels 86 may be organized in rows and columns. Display control circuitry may be used in controlling the operation of display pixels 86 using signal lines such as data lines 88 and gate lines 90. In liquid crystal displays, display pixels 86 may each contain an electrode for applying an electric field to an associated portion of liquid crystal layer 52 (FIG. 5) and a thin-film

(amorphous silicon or polysilicon) transistor for

controlling the magnitude of the signal applied to the electrode and therefore the magnitude of the electric field. In other types of displays, display pixels 86 may be formed from other types of structures (e.g., organic light-emitting diodes, etc.).

Lines 90 may be coupled to the gates of the thin-film transistors and may sometimes be referred to as gate lines. Lines 88 may be coupled to the sources of the thin-film transistors and may sometimes be referred to as source lines or data lines. Gate driver circuitry (e.g., thin-film transistor gate driver circuitry) may be coupled to gate lines 90. Display driver circuitry that produces data signals for lines 88 (e.g., a display driver integrated circuit) may be coupled to data lines 88.

Gate driver circuitry, one or more display driver integrated circuits, traces for distributing gate and data signals and other display control signals, and other display control circuitry may be formed in inactive region 461 of display 14 and display structures 46. As an example, a display driver integrated circuit may be mounted along the upper segment of inactive region 461, whereas gate driver thin-film circuitry may be formed along the left and right segments of inactive region 461. During operation of display 14, display pixels 86 may display images for a user, so the portion of display structures 46 containing display pixels 86 may sometimes be referred to as active display structures or the active area of display 14. The metal traces and other display control circuit structures in inactive region 461 do not display any images, so this portion of structures 46 may sometimes be referred to as inactive display structures.

Inactive region 461 may form a border that surrounds some or all of active area 46A. For example, inactive region 461 may have a rectangular ring shape of the type shown in FIG. 6 having opposing upper and lower border segments and left and right border segments.

To provide display 14 with a borderless appearance, display 14 may be provided with reflective structures that distribute light from peripheral display pixels 86 near the edge of active area 46A into a portion of the display overlapping inactive area 461. In this way, image content can be displayed over inactive area 461, effectively increasing the lateral dimensions of display 14 sufficiently to eliminate inactive area 461 from view by a user.

The reflective structures that are used for distributing edge light in display 14 may be formed from stationary (fixed) mirrors, stationary reflecting prisms, movable reflective structures such as movable mirrors or prisms, or other reflective structures. As an example, a movable mirror may be implemented using

microelectromechanical systems (MEMs) mirror structures (sometimes referred to as electromechanical mirrors) . If desired, other types of adjustable reflective structures may be used in distributing light near the edge of display 14 to minimize visible borders. Configurations for display 14 in which reflective structures based on

electromechanical mirrors are used in distributing light near the edge of display 14 may sometimes be described herein as an example.

FIG. 7 is a cross-sectional side view of device 10 in a configuration in which adjustable reflective structures such as electromechanical mirror structures are being used to redistribute light from display pixels near the edge of display 14. As shown in FIG. 7, display 14 may include a display cover layer such as display cover layer 84. Display cover layer 84 may be mounted in housing 12 of device 10 so as to cover and protect display structures 46.

Control circuitry 29 can control which content is displayed on display pixels 86 of display structures 46 at a given time. Control circuitry 29 may, for example, supply display pixel data and control signals to display pixels 86 using signal paths such as signal path 110.

Synchronously, control circuitry 29 may supply control signals on path 108 to adjust electromechanical mirror structures 100. Mirror structures 100 may include one or more mirrors arranged around the periphery of display 14. Mirrors such as illustrative electromechanical mirror 100 of FIG. 7 may, for example, be formed in linear arrays along the left and right borders of display 14 (and, if desired, along the upper and lower borders of display 14 in addition to along the left and right borders of display 14) .

Electromechanical mirror structures 100 may include reflective structures such as mirror structures or prism structures. Mirror structures 100 may, for example, include a rotatable mirror such as mirror 104. Mirror 104 may be mounted on an adjustable support such as rotatable actuator 102. Rotatable actuator 102 may be a yolk that is adjusted by application of a voltage control signal, part of a microelectromechanical systems structure such as a diving board structure on a semiconductor substrate, a solenoid-based structure, a stepper motor structure, a piezoelectric actuator structure, or other controllable positioner. By applying control signals to positioner 102 over path 108 from control circuitry 29, control circuitry 29 can be used to control the rotation of positioner 102 to control the direction in which mirror 104 reflects light from display structures 46 in real time.

Display structures 46 may include active area structures 46A such as display pixels 86 and inactive area structures 461. Structures 461 do not produce light for displaying content and therefore are associated with an inactive border region around display 14. Using

electromechanical mirror structures 100, pixel light from some of the display pixels near the edge of display structures 46 (e.g., peripheral display pixels in a rectangular ring shaped peripheral portion of display structures 46) can be distributed over inactive region 461, thereby providing display 14 with a borderless appearance to a viewer such as viewer 48 who is viewing device 10 in direction 50.

As shown in FIG. 7, display pixels 86 may display pixel content such as pixel data PI, P2, and P3. The light from some of the display pixels in display structures 46 such as the light associated with pixel data P2 and P3 of display pixels 86 in the example of FIG. 7 travels vertically to viewer 48 unimpeded, as indicated by light ray lines 112. Display pixels at the edge of active area 46A such as the display pixels associated with pixel data Pl/Pl' of FIG. 7 produce light that is distributed across pixel locations overlapping inactive border region 461.

Control circuitry 29 can alter the pixel data that is being presented by the Pl/Pl' display pixel while synchronously adjusting the position of mirror 104 in adjustable electromechanical mirror structures 100. Light from display pixel Pl/Pl' may be reflected onto mirror 104 using reflective structures 106 such as a mirror, prism, or other reflector (e.g., a stationary reflector that is coupled to the display pixel array or other support) . By alternating the state of mirror 100 while controlling the pixel data that is displayed by display pixel Pl/Pl', control circuitry 29 can distribute display light over inactive border region 461, so that display 14 appears borderless . In the configuration of FIG. 7, for example, when control circuitry 29 is directing display pixel

Pl/Pl' to display pixel data PI', mirror 100 may be placed in a state in which light from reflector 106 is reflected along path L, whereas when control circuitry 29 is

directing display pixel Pl/Pl' to display pixel data PI, mirror 100 may be placed in a state in which light from reflector 106 is reflected along path R. In this way, viewer 49 may observe pixel data PI, P2, P3, ... in region 114 and may observe pixel data PI in region 116. Region 116 overlaps inactive display structure structures 461 of display structures 46, so the presence of pixel data PI' in region 116 causes viewer 48 to observe a display that is entirely filled with active pixel data and has no inactive border.

The graphs of FIG. 8 illustrate how control circuitry 29 may synchronize the display of pixel content on display pixels 86 with the control of mirror position for electromechanical mirror 100 to produce a borderless display of the type shown in FIG. 7. As shown in the upper trace of FIG. 8, control circuitry 29 use path 110 to provide display pixels 86 such as peripheral display pixel Pl/Pl' of FIG. 7 with pixel data PI and PI' in alternation (e.g., so that pixel data is displayed at twice the data rate of the pixel data in the center of display 14) . In synchronization with the alternation of pixel data PI and PI', control circuitry 29 adjusts electromechanical mirror structures 100 so that mirror 104 is alternately placed in position L (see ray L of FIG. 7) or position R (see ray R in FIG. 7) . Mirror structures 100 will therefore distribute pixel data across an area that is sufficiently large that inactive area 461 is covered with active pixel data (pixel data PI' in this example) .

To ensure that the pixel data that is displayed over inactive region 461 is sufficiently bright, display structures 46 can be configured so that peripheral display pixels produce more light than center pixels. For

example, in the configuration of FIG. 7, central display pixels 86 may display pixel data P2, P3, ... at an intensity of I/pixel, whereas edge pixel structures 86 may display pixel data Pl/Pl' at an intensity of 2I/pixel. Because each pixel along the edge is illuminated for half of the time that each pixel in the center is illuminated, the resulting image on display 14 will have uniform pixel intensities. Pixel brightness can be adjusted by locally adjusting the type and density of surface pits and/or bumps used on light guide plate 78 (e.g., so that more backlight is produced under peripheral pixels than central display pixels 86) .

If desired, reflector 106 and electromechanical mirror structures 100 may be configured to reflect pixel data from multiple edge pixels at the same time. As shown in FIG. 9, electromechanical mirror structures 100 may, for example, use positioner 102 to adjust the position of mirror 104 so as to distribute light from a strip of display pixels that is N pixels wide. In adjusting mirror structures 100, positioner 102 controls the rotational orientation of mirror 104 about rotational axis 130 (i.e., mirror 102 is rotated back and forth to distribute pixel light so as to overlap the pixel content with inactive area 461, as described in connection with FIG. 7) . The value of N may be 2-10, 2-50, 2-100, less than 50, less than 30, less than 20, 1 or more, more than 5, 10 or more, or other suitable value.

FIG. 10 shows how display structures 46 may have a bend such as bend 132. One or more pixels such as pixels 86' in side region 136 may be controlled to produce pixel data in synchronization with the movement of

electromechanical mirror structures 100. This allows electromechanical mirror structures 100 to distribute edge light such as light 134 over the border portion of display 14, so that viewer 48 perceives display 14 to be

borderless. Examples of display structures 46 that may be configured to form a bend include flexible display

structures such as organic light-emitting diode display structures formed on a flexible substrate such as a flexible polymer sheet, flexible liquid crystal display structures, flexible electrowetting pixels, an array of flexible electrophoretic display pixels, etc.

FIG. 11 is a cross-sectional side view of display 14 in device 10 showing how device 10 may be provided with a fixed reflector to minimize inactive display border width. In the FIG. 11 example, display structures 46 include a bent peripheral portion such as portion 136 and a planar central region 140. Bent portion 136 may contain active display pixels 86' that produce display light 134. Reflector 138 may be a mirror or prism that is configured to reflect light 134 from pixels 86' upwards into active peripheral edge region 116. Pixels 86 in central portion 140 lie in a plane parallel to display cover layer 84 and produce light 112 that is visible in active central display region 114. When using reflector 138 to reflect pixel light 134 upwards into edge region 116, edge region 116 will be filled with active image content in addition to central region 114, thereby increasing the apparent size of display 14 and eliminating or at least reducing visible inactive border portions of display 14 that would otherwise be visible to a viewer such as viewer 48 viewing display 14 in direction 50.

In the illustrative configuration of FIG. 7, display pixel light from edge pixels such as edge pixel Pl/Pl' was distributed using a 1:2 distribution ratio

(i.e., light from each active edge pixel in structures 46 was fanned out to cover two corresponding pixels in region 116) . If desired, other distribution ratios may be used in distributing edge light in display 14. As an example, a fan-out ratio of 1:3 or 1:4 may be used.

Consider, as an example, the display

configuration of FIGS. 12, 13, and 14, which uses a 1:3 edge light distribution ratio. As shown in FIG. 12, peripheral pixel 86'' may produce light 134 that reflects off of electromechanical mirror structures 100. Mirror structures 100 may be adjusted by control circuitry 29 to reflect light 134 into edge pixel location 116-1 (as shown in FIG. 12), edge pixel location 116-2 (as shown in FIG. 13), or edge pixel location 116-3 (as shown in FIG. 14).

When reflecting light 134 into location 116-1, display pixel 86'' may be controlled by control circuitry 29 to display pixel data PI'', as shown in FIG. 12. When reflecting light 134 into location 116-2, display pixel 86'' may be controlled by control circuitry 29 to display pixel data PI', as shown in FIG. 13. FIG. 14 shows how control circuitry 29 may direct display pixel 86'' to display pixel data PI when electromechanical mirror structures 100 are adjusted to reflect light 134 into location 116-3.

To compensate for the light intensity reduction that is experienced by pixels 116-1, 116-2, and 116-3

(each of which receives only one third of light 134 from pixel 86'' when averaged over time), pixel 86'' can be configured to emit light 134 with an intensity that is proportionally greater than the intensity with which light 112 is emitted by pixels 86. In particular, pixels such as pixel 86'' from which light is distributed across edge portion 116 in display 14 may be configured to be three times brighter than pixels such as pixels 86. In displays with different fan-out ratios, the brightness of edge pixels such as pixel 86'' can be adjusted accordingly. Light from multiple edge pixels such as pixel may be redistributed in parallel using a mirror configuration of the type shown in FIG. 9.

Reflective structures such as reflector 106 and/or reflector 104 in electromechanical mirror 100 may be provided with non-planar surfaces. As shown in FIG. 15, for example, reflector 106 may have non-planar surface shapes such as curved surface shapes 140 and/or reflector 104 may have non-planar surface shapes such as curved surface shapes 142. Lenses and other optical structures may also be interposed in the path of light 134 to help direct light 134 along the edge of display 14.

If desired, electromechanical mirror structures 100 may be used to direct light into an image sensor.

This type of arrangement is shown in FIG. 16. As shown in FIG. 16, imaging system 150 may have optical structures 151 such as one or more lenses for gathering and focusing image light and a digital image sensor such as digital image sensor 154 that detects the focused image light. Image sensor 154 may be formed from a semiconductor substrate such as a silicon substrate (i.e., image sensor 154 may be a silicon digital imaging integrated circuit) . Image sensor 154 may have central image sensor pixels such as pixels 158 that directly receive image light from an external object such as light 164. Image sensor 154 may also include peripheral image sensor pixels such as pixel 156 of FIG. 16 that receive incoming light from an external object that has reflected off of reflectors such as mirror 104 and mirror 106.

Image sensor 154 may have an inactive border region such as border region 160. Border region 160 may have a shape of a rectangular ring that runs around the peripheral edge of image sensor 154. Electromechanical mirror structures 100 may be adjusted in real time by control circuitry 29 via control path 166 while control circuitry 29 is provided with digital image data from image sensor 154 via digital data path 168. Mirror structures 100 may run along one or more, two or more, three or more, or four edges of image sensor 154.

During the acquisition of digital data using sensor 154, control circuitry 166 can adjust the position of mirror 104 in electromechanical mirror structures 100. Edge pixels such as edge pixel 156 may gather light such as light 152 when mirror 104 is in a first position and may gather light such as light 162 from another direction when mirror 104 is in a second position that is different from the first position. Because mirror structures 100 overlap inactive image sensor structures 160, the use of mirror structures 100 to deflect light into pixel 156 helps to expand the effective size of digital image sensor 154 (e.g., to effectively produce a digital image sensor that has a minimal inactive border region or has no inactive border region) . If desired, mirror 100 may be used to deflect light for multiple image pixels in

parallel. The configuration of FIG. 16 in which mirror 100 is being used to reflect light onto edge pixel

structures with a one-pixel width is merely illustrative.

In accordance with an embodiment, a display for displaying content with an apparent size to a user is provided that includes active display structures having a central region of display pixels and a peripheral edge region of display pixels, and adjustable reflecting structures that reflect light from the display pixels in the peripheral edge region to make the apparent size of the display larger than the area of the active display structures .

In accordance with another embodiment, the active display structures include an array of display pixels with a rectangular periphery and the adjustable reflecting structures are located along at least part of the rectangular periphery.

In accordance with another embodiment, the adjustable reflecting structures include electromechanical mirror structures.

In accordance with another embodiment, the electromechanical mirror structures include a reflector and a positioner that rotates the reflector.

In accordance with another embodiment, the display includes a stationary reflector configured to reflect the light to the adjustable reflecting structures from the display pixels in the peripheral edge region.

In accordance with another embodiment, the stationary reflector includes a mirror.

In accordance with another embodiment, the mirror has a non-planar surface.

In accordance with another embodiment, the stationary reflector includes a prism.

In accordance with another embodiment, the reflector includes a mirror with a non-planar surface.

In accordance with another embodiment, the peripheral edge region of display pixels has a display pixel width of at least two display pixels.

In accordance with an embodiment, a display is provided that includes display structures having a first set of active display pixels and a second set of active pixels, and reflector structures that reflect light from the second set of active display pixels without reflecting light from the first set of display pixels to reduce visible inactive display borders.

In accordance with another embodiment, the reflector structures include a stationary reflector.

In accordance with another embodiment, the reflector structures include a reflector and a positioner that rotates the reflector.

In accordance with another embodiment, the second set of active display pixels displays pixels in synchronization with movement of the reflector by the positioner.

In accordance with another embodiment, the first set of active display pixels includes an array of display pixels lying in a plane and the second set of active display pixels includes at least some pixels on a bent edge portion of the display pixels that lies out of the plane.

In accordance with another embodiment, the display structures include organic-light-emitting diode display structures with a bent edge on which the second set of active display pixels is formed.

In accordance with another embodiment, the display structures include a display pixel array, the first set of display pixels forms a central portion of the display pixels in the display pixel array, the second set of display pixels forms peripheral display pixels that surround the central portion of the display, and the reflector structures include rotatable electromechanical mirror structures.

In accordance with an embodiment, an imaging system is provided that includes an image sensor having an array of image sensor pixels including a central region of image sensor pixels surrounded by peripheral image sensor pixels, optical structures that focus light for the array of image sensor pixels, and an adjustable mirror that directs image light from the optical structures onto the peripheral image sensor pixels.

In accordance with another embodiment, the adjustable mirror includes a reflector and a rotatable positioner configured to rotate the reflector while the reflector directs the image light onto the peripheral image sensor pixels.

In accordance with another embodiment, the imaging system includes a stationary reflector that reflects light from the adjustable mirror onto the

peripheral image sensor pixels.

Illustrative electronic devices that may be provided with displays having light distribution

structures are shown in FIGS. 17, 18, and 19.

FIG. 17 shows how electronic device 10 may have the shape of a laptop computer having upper housing 412A and lower housing 412B with components such as keyboard 416 and touchpad 418. Device 10 may have hinge structures 420 that allow upper housing 412A to rotate in directions 422 about rotational axis 424 relative to lower housing 412B. Display 414 may be mounted in upper housing 412A. Upper housing 412A, which may sometimes referred to as a display housing or lid, may be placed in a closed position by rotating upper housing 412A towards lower housing 412B about rotational axis 424.

FIG. 18 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 412 may have opposing front and rear surfaces. Display 414 may be mounted on a front face of housing 412. Display 414 may, if desired, have a display cover layer or other exterior layer that includes openings for components such as button 426. Openings may also be formed in a display cover layer or other display layer to accommodate a speaker port (see, e.g., speaker port 428 of FIG. 18) .

FIG. 19 shows how electronic device 10 may be a tablet computer. In electronic device 10 of FIG. 19, housing 412 may have opposing planar front and rear surfaces. Display 414 may be mounted on the front surface of housing 412. As shown in FIG. 19, display 414 may have a cover layer or other external layer with an opening to accommodate button 426 (as an example) .

The illustrative configurations for device 10 that are shown in FIGS. 17, 18, and 19 are merely

functionality of two or more of these devices, or other electronic equipment.

Housing 412 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 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 412 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 414 may be a touch sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display 414 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 image pixels formed from light-emitting diodes (LEDs) , organic LEDs (OLEDs) , plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image pixel structures. In some situations, it may be desirable to use LCD components to form display 414, so configurations for display 414 in which display 414 is a liquid crystal display are

sometimes described herein as an example. It may also be desirable to provide displays such as display 414 with backlight structures, so configurations for display 414 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. The use of liquid crystal display structures and backlight structures in device 10 is merely illustrative.

A display cover layer may cover the surface of display 414 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 414. A display cover layer or other outer display layer may be formed from a transparent glass sheet, a clear plastic layer, or other transparent structures. 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) .

A schematic diagram of an illustrative configuration that may be used for electronic device 10 is shown in FIG. 20. As shown in FIG. 20, electronic device 10 may include control circuitry 429. Control circuitry 429 may include storage and processing circuitry for controlling the operation of device 10. Control circuitry 429 may, for example, include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory

Control circuitry 429 may include processing circuitry based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc.

Control circuitry 429 may be used to run

software on device 10, such as operating system software and application software. Using this software, control circuitry 429 may present information to a user of

electronic device 10 on display 414. Display 414 may contain an array of display pixels (e.g., liquid crystal display pixels) that are organized in rows and columns. Control circuitry 429 may be used to display content for a user of device 10 on the array of display pixels in display 414.

Control circuitry 429 may include display driver circuitry and other circuitry for controlling the rate at which display pixels are refreshed and for controlling which pixel data is displayed by each display pixel.

Display driver circuitry may be formed using thin-film- transistor circuitry on display 414 and/or integrated circuits mounted on a layer in display 414 or on a printed circuit. In addition to controlling the display of pixel data using the display pixels of display 414, control circuitry 429 may perform control operations within device 10 such as controlling the states of liquid crystal light distribution structures (sometimes referred to as liquid crystal shutter structures) and other controllable

electronic components. Control circuitry 429 may, for example, issue control commands that place liquid crystal light distribution structures in a desired state.

Adjustments to liquid crystal light distribution

structures such as these may be synchronized with display control operations. For example, control circuitry 429 can ensure that light passing through the liquid crystal light distribution structures is distributed as desired while simultaneously controlling the operation of

peripheral display pixels in display 414 so that those pixels display desired pixel data for distribution by the liquid crystal light distribution structures.

Input-output circuitry 430 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 circuitry 430 may include communications circuitry 432. Communications circuitry 432 may include wired

communications circuitry for supporting communications using data ports in device 10. Communications circuitry 432 may also include wireless communications circuits

Input-output circuitry 430 may also include input-output devices 434. A user can control the

operation of device 10 by supplying commands through input-output devices 434 and may receive status

information and other output from device 10 using the output resources of input-output devices 434.

Input-output devices 434 may include sensors and status indicators 436 such as an ambient light sensor, a proximity sensor, a temperature sensor, a pressure sensor, a magnetic sensor, an accelerometer, and light-emitting diodes and other components for gathering information about the environment in which device 10 is operating and providing information to a user of device 10 about the status of device 10.

Audio components 438 may include speakers and tone generators for presenting sound to a user of device 10 and microphones for gathering user audio input.

Display 414 (e.g., the array of display pixels in display 414) may be used to present images for a user such as text, video, and still images. Sensors 436 may include a touch sensor array that is formed as one of the layers in display 414.

User input may be gathered using buttons and other input-output components 440 such as touch pad sensors, buttons, joysticks, click wheels, scrolling wheels, touch sensors such as sensors 436 in display 414, key pads, keyboards, vibrators, cameras, and other input- output components.

A cross-sectional side view of an illustrative configuration that may be used for display 414 of device 10 (e.g., for display 414 of the devices of FIG. 17, FIG. 18, or FIG. 19 or other suitable electronic devices) is shown in FIG. 21. As shown in FIG. 21, display 414 may include backlight structures such as backlight unit 442 for producing backlight 444. During operation, backlight 444 travels outwards (vertically upwards in dimension Z in the orientation of FIG. 21) and passes through display pixel structures in display layers 446. This illuminates any images that are being produced by the display pixels for viewing by a user. For example, backlight 444 may illuminate images on display layers 446 that are being viewed by viewer 448 in direction 450.

Display 414 may, if desired, have one or more optical structures that are located above display layers 446. For example, display 414 may have a display cover layer such as display cover layer 484. Display cover layer 484 may be formed from a layer of clear glass, a transparent sheet of plastic, or other transparent

structure. Display cover layer 484 may be mounted in housing 412 (e.g., using housing sidewalls) . During operation, light 444 may pass through the array of display pixels formed from display layers 446 and display cover layer 484 for viewing by user 448.

Display layers 446 may be mounted in chassis structures such as a plastic chassis structure and/or a metal chassis structure to form a display module for mounting in housing 412 or display layers 446 may be mounted directly in housing 412 (e.g., by stacking display layers 446 into a recessed portion in housing 412) .

Display layers 446 may form a liquid crystal display or may be used in forming displays of other types. Display layers 446 may sometimes be referred to as a display module, a display, or an array of display pixels. The image light (light 444) that passes through the array of display pixels is used in displaying content on display 414 for user 448.

In a configuration in which display layers 446 are used in forming a liquid crystal display, display layers 446 may include a liquid crystal layer such a liquid crystal layer 452. Liquid crystal layer 452 may be sandwiched between display layers such as display layers 458 and 456. Layers 456 and 458 may be interposed between lower polarizer layer 460 and upper polarizer layer 454.

Layers 458 and 456 may be formed from transparent substrate layers such as clear layers of glass or plastic. Layers 456 and 458 may be layers such as a thin-film transistor layer and/or a color filter layer. Conductive traces, color filter elements, transistors, and other circuits and structures may be formed on the

substrates of layers 458 and 456 (e.g., to form a thin- film transistor layer and/or a color filter layer) . Touch sensor electrodes may also be incorporated into layers such as layers 458 and 456 and/or touch sensor electrodes may be formed on other substrates.

With one illustrative configuration, layer 458 may be a thin-film transistor layer that includes an array of thin-film transistors and associated electrodes

(display pixel electrodes) for applying electric fields to liquid crystal layer 452 and thereby displaying images on display 414. Layer 456 may be a color filter layer that includes an array of color filter elements for providing display 414 with the ability to display color images. If desired, layer 458 may be a color filter layer and layer 456 may be a thin-film transistor layer.

During operation of display 414 in device 10, control circuitry 429 (e.g., one or more integrated circuits such as components 468 on printed circuit 466 of FIG. 21) may be used to generate information to be

displayed on display 414 (e.g., display data). The information to be displayed may be conveyed from circuitry 468 to display control circuitry such as display driver integrated circuit 462 using a signal path such as a signal path formed from conductive metal traces in

flexible printed circuit 464 (as an example) .

Display driver integrated circuit 462 may be mounted on thin-film-transistor layer driver ledge 482 or elsewhere in device 10. During operation of display 414, display driver circuitry 462 and/or other display control circuitry such as gate driver circuitry formed on

substrate 458 or coupled to substrate 458 may be used in controlling the array of display pixels in layers 446

(e.g., using a grid of vertical data lines and horizontal gate lines) .

A flexible printed circuit cable such as flexible printed circuit 464 may be used in routing signals between printed circuit 466 and thin-film- transistor layer 458. If desired, display driver integrated circuit 462 may be mounted on printed circuit 466 or flexible printed circuit 464. Printed circuit 466 may be formed from a rigid printed circuit board (e.g., a layer of fiberglass-filled epoxy) or a flexible printed circuit (e.g., a flexible sheet of polyimide or other flexible polymer layer) .

Backlight structures 442 may include a light guide plate such as light guide plate 478. Light guide plate 478 may be formed from a transparent material such as clear glass or plastic. During operation of backlight structures 42, a light source such as light source 472 may generate light 474. Light source 472 may be, for example, an array of light-emitting diodes.

Light 474 from light source 472 may be coupled into edge surface 476 of light guide plate 478 and may be distributed in dimensions X and Y throughout light guide plate 478 due to the principal of total internal

reflection. Light guide plate 478 may include light- scattering features such as pits or bumps. The light- scattering features may be located on an upper surface and/or on an opposing lower surface of light guide plate 478.

Light 474 that scatters upwards in direction Z from light guide plate 478 may serve as backlight 444 for display 414. Light 474 that scatters downwards may be reflected back in the upwards direction by reflector 480. Reflector 480 may be formed from a reflective material such as a layer of white plastic or other shiny materials.

To enhance backlight performance for backlight structures 42, backlight structures 442 may include optical films 470. Optical films 470 may include diffuser layers for helping to homogenize backlight 444 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 444. Optical films 470 may overlap the other structures in backlight unit 442 such as light guide plate 478 and reflector 480. For example, if light guide plate 478 has a rectangular footprint in the X-Y plane of FIG. 21, optical films 470 and reflector 480 may have a matching rectangular footprint. Display layers 446 and the other display structures of FIG. 21 typically have rectangular shapes with four peripheral edges, but display

configurations with other shapes may be used in forming display 414 if desired.

As shown in FIG. 22, display structures 446 of display 414 may include a plurality of display pixels 486. Display pixels 486 may be organized in rows and columns. Display control circuitry may be used in controlling the operation of display pixels 486 using signal lines such as data lines 488 and gate lines 490. In liquid crystal displays, display pixels 486 may each contain an electrode for applying an electric field to an associated portion of liquid crystal layer 452 (FIG. 21) and a thin-film

(amorphous silicon or polysilicon) transistor for

controlling the magnitude of the signal applied to the electrode and therefore the magnitude of the electric field. In other types of displays, display pixels 486 may be formed from other types of structures (e.g., organic light-emitting diodes, etc.).

Lines 490 may be coupled to the gates of the thin-film transistors and may sometimes be referred to as gate lines. Lines 488 may be coupled to the sources of the thin-film transistors and may sometimes be referred to as source lines or data lines. Gate driver circuitry (e.g., thin-film transistor gate driver circuitry) may be coupled to gate lines 490. Display driver circuitry that produces data signals for lines 488 (e.g., a display driver integrated circuit) may be coupled to data lines 488.

Gate driver circuitry, one or more display driver integrated circuits, traces for distributing gate and data signals and other display control signals, and other display control circuitry may be formed in inactive region 4461 of display 414 and display structures 446. As an example, a display driver integrated circuit may be mounted along the upper segment of inactive region 4461, whereas gate driver thin-film circuitry may be formed along the left and right segments of inactive region 4461. During operation of display 414, display pixels 486 may display images for a user, so the portion of display structures 446 containing display pixels 486 may sometimes be referred to as active display structures or the active area of display 414. The metal traces and other display control circuit structures in inactive region 4461 do not display any images, so this portion of structures 446 may sometimes be referred to as inactive display structures.

Inactive region 4461 may form a border that surrounds some or all of active area 446A. For example, inactive region 4461 may have a rectangular ring shape of the type shown in FIG. 22 having opposing upper and lower border segments and left and right border segments.

To provide display 414 with a borderless appearance, display 414 may be provided with light

distribution structures that distribute light from

peripheral display pixels near the edge of active area 446A into a portion of the display overlapping inactive area 4461. In this way, image content can be displayed over inactive area 4461, effectively increasing the lateral dimensions of display 414 and the apparent size of the display sufficiently to eliminate inactive area 4461 from view by a user (i.e., making the apparent size of the display to the viewer larger than the area of structures 446 and active area 446A) .

The light distribution structures that are used for distributing edge light in display 414 may be based on liquid crystal light distribution structures. As an example, a liquid crystal cell may be mounted over a peripheral display pixel. The liquid crystal cell can be controlled by control circuitry 429 to adjust the

polarization of the light from the peripheral display pixel. A reflective polarizer may receive light exiting the liquid crystal cell. When the liquid crystal cell is placed in a first of two states, the light will pass vertically upwards. When the liquid crystal cell is placed in a second of the two states, the light will be deflected to the side. A secondary mirror or other reflector may then reflect the deflected light vertically upwards. If desired, other types of light distribution components may be used in distributing light near the edge of display 414 to minimize visible borders.

Configurations for display 414 in which light distribution structures based on liquid crystal structures are used in distributing light near the edge of display 414 may sometimes be described herein as an example.

FIG. 23 is a perspective view of a liquid crystal cell of the type that may be used in forming liquid crystal light distribution structures for display 414. As shown in FIG. 23, liquid crystal cell 300 may, during operation of the light distribution structures, receive polarized light such as linearly polarized light 308. Light 308 may, for example, be vertically polarized light having an electric field that runs vertically (in the orientation of FIG. 23) . Light 308 may propagate through liquid crystal cell 300 along axis 310.

Liquid crystal cell 300 may include a layer of liquid crystal material such as liquid crystal material 304. Liquid crystal material 304 may be sandwiched between a pair of transparent electrodes such as

electrodes 302 and 306. Electrodes 302 and 306 may be formed from transparent conductive material such as indium tin oxide. If desired, other electrode configuration may be used for liquid crystal cell 300. The configuration of FIG. 23 is merely illustrative.

Using electrodes 302 and 306, control circuitry 429 may provide control signals (e.g., a control voltage) across liquid crystal material 304. The control signals may be adjusted in real time to adjust the orientation of liquid crystals within liquid crystal material 304. The orientation of the liquid crystals determines the amount of polarization rotation that will be imposed on incoming polarized light 308. When placed in a first state, such as the state of FIG. 23, liquid crystal cell 300 will not rotate vertically polarized light, so light 308 at the exit of liquid crystal cell 300 will not be rotated with respect to incoming light 308 and will have the same vertically polarized state as incoming light 308. When placed in a second state, such as the state of FIG. 24, however, liquid crystal cell 300 will rotate incoming vertically polarized light 308 by 90° to produce

horizontally polarized light 308 at the exit of cell 300.

Liquid crystal polarization rotating structures such as cell 300 of FIGS. 23 and 24 may be combined with polarizer structures such as a reflecting polarizer (i.e., a linear reflecting polarizer) to form a liquid crystal shutter that can be used as a light distribution structure along the peripheral edge of display 414.

FIG. 25 is a cross-sectional side view of display 414 in device 10 showing how light distribution structures based on liquid crystal shutter structures may be used to enhance the apparent size of display 414 and thereby reduce or eliminate the size of visible inactive border regions in display 414. As shown in FIG. 25, display 414 may include a display cover layer such as display cover layer 484. Display cover layer 484 may be mounted in housing 412 of device 10 so as to cover and protect display structures 446. Display structures 446 may include active structures 446A containing display pixels and inactive structures 4461 that are devoid of display pixels. Display structures 446 may include central pixels such as display pixels 486. Display pixels 486 may produce light 512 that travels vertically upwards to viewer 448 in region 514 of display 414. Display structures 446 may also include a rectangular ring of peripheral display pixels such as peripheral display pixel 486' that surround central display pixels 486. During operation of display 414, light distribution structures 216 may be used to distribute light from peripheral pixels such as display pixel 486' alternately into portions 516-1 and 516-2 of region 516 of display 414. Because region 516 overlaps inactive portion 4461 of display structures 446 (when viewed from the position of viewer 448), the use of light distribution structures 216 to distribute pixel data from peripheral display pixel 486' into region 516 increases the apparent size of display 414 and minimizes or eliminates visible inactive border regions in display 414.

Control circuitry 429 can control which content is displayed on display pixels 486 of display structures 446 at a given time. Control circuitry 429 may, for example, supply display pixel data and control signals to display pixels 486 using signal paths such as signal path 510. Synchronously, control circuitry 429 may supply control signals on path 108 to adjust liquid crystal cell 300. By adjusting liquid crystal cell 300, control circuitry 429 can adjust the polarization of light from display pixel 486'.

Light exiting display pixel 486' is linearly polarized, because this light has passed through upper linear polarizer 454 (FIG. 21) . In response to control signals from control circuitry 429, cell 300 may be used to maintain the initial linear polarization orientation of the light exiting display pixel 486' or may be used to rotate the polarization of this light by 90°, as described in connection with FIGS. 23 and 24.

Upon exiting cell 300, light from display pixel

486' will either be linearly polarized with an electric field that is oriented within the page of FIG. 25 (as illustrated by light ray 210) or will be linearly

polarized with an electric field that is oriented

perpendicular to the page of FIG. 25 (as illustrate by light ray 212).

Reflective polarizer 208 may be mounted on a support structure such as support structure 206 at a 45° angle relative to display structures 446. Light rays such as light rays 210 will be produced when display pixel 486' is producing light and cell 300 has been placed in a first of its two polarization rotating states. Light rays such as light rays 212 will be produced by display pixel 486' when display pixel 486' is producing light and cell 300 has been placed in a second of its two polarization rotating states. Reflective polarizer 208 is oriented to allow light 210 to pass vertically through reflective polarizer 208 to portion 516-2 of region 516 while

reflecting light 212 horizontally onto reflector 214.

Reflector 214 is configured to reflect light 212 from reflective polarizer 208 vertically upward into portion 516-1 of region 516.

Control circuitry 429 may direct pixels 486 to display pixel data such as pixel data P2, P3, ... in the central portion of display structures 446. Control circuitry 429 may change the state of display pixel 486' at twice the rate of display pixels 486. For example, while displaying pixel data P2 in the leftmost display pixel 486, control circuitry 429 may direct pixel 486' to display pixel data PI (while placing cell 300 is its first state) and then to display pixel data PI' (while placing cell 300 in its second state) . Control circuitry 429 can therefore alter the pixel data that is being presented by display pixel 486' while synchronously adjusting the state of cell 300 in liquid crystal light distribution structures 216 so as to ensure that the light from display pixel 486' is

distributed across portion 516 of display 414. Taken together, display portion 516, which receives light from light distribution structures 216, and display portion 514, which is associated with light 512 from central display pixels 486, have a size that is larger than display structures 446 (and that is larger than active structures 446A) . By alternating the state of cell 300 while simultaneously controlling the pixel data that is displayed by display pixel 486', control circuitry 429 can distribute display light over inactive border region 4461, increasing the apparent size of the active region in display 414 and ensuring that display 414 appears

borderless .

Light distribution structures such as light distribution structures 216 of FIG. 25 that are formed from liquid crystal cell 300, reflective polarizer 208 and reflector 214 may be formed in linear arrays along the left and right borders of display 414 (and, if desired, along the upper and lower borders of display 414 in addition to along the left and right borders of display 414) . This allows one or more, two or more, three or more, or four or more of the edges of display 414 to be provided with distributed pixel data in regions such as region 516 of FIG. 25.

If desired, the components of light distribution structures 216 such as reflective polarizer 208 may be used to distribute light from multiple peripheral display pixels in parallel. This type of configuration is shown in FIG. 26. As shown in FIG. 26, a set of peripheral display pixels 486' such as a strip of display pixels 486' of width N may run along the peripheral edge of display structures 446 (into the page in the orientation of FIG. 26) . Liquid-crystal cell 300 may distribute light 210 from display pixels 486' into portion 516-2 of peripheral display region 516 and may, after control circuitry 429 has changed the data being displayed by display pixels

486', distribute light 210 from display pixels 486' into portion 516-1 of display region 516.

FIG. 27 shows how reflector 214 may, if desired, have a non-planar surface. In the example of FIG. 27, reflector 214 has three curved surface regions each of which has a radius of curvature R. The use of curved surfaces in reflector 214 may help distribute reflected light 210.

Because light distribution structures 216 spread out the light from display pixels 486' over multiple regions such as regions 516-1 and 516-2, whereas light 212 from display pixels 486 passes directly through display cover layer 486 to viewer 448 in region 514, the intensity of light in region 516 has the potential for being lower than the intensity of light in region 514. For example, when spreading light from a peripheral display pixel over two regions such as regions 516-1 and 516-2, the intensity of light in each pixel location in region 516 will be half of the intensity of light in each pixel location in region 514, because pixel regions 516-1 and 516-2 are each illuminated for half of the time as the pixel regions in region 516.

To compensate for the decreased light intensity in region 516 relative to region 514, backlight unit 442 may be configured to provide backlight 444 with a greater intensity under peripheral pixels such as pixel 486' than under central pixels such as pixels 486. The backlight for pixel 486' of FIG. 25 may be, for example, twice as bright as the backlight for each of pixels 486.

As shown in FIG. 28, locally increased backlight intensity may be produced by configuring light scattering features 220 (e.g., bumps, pits, and/or the type of bumps or pits used) in light guide plate 478 to ensure that the amount of backlight 444 that is scattered upwards through pixel 486' is twice as much (or other suitable ratio) as the amount of backlight 444 that is scattered upwards through pixels 486' . For example, in a light guide plate configuration that uses pits to scatter backlight, the pits that are formed on the portion of light guide plate 478 that lies under pixels 486' may be twice the density of pits that are formed on the portion of light guide plate 478 that lies under pixels 486 (or other suitable ratio) .

In accordance with an embodiment, a display for displaying content with an apparent size to a user is provided that includes active display structures having an area, having a central region of display pixels, and having a peripheral edge region of display pixels, and adjustable liquid crystal light distribution structures that distribute light from the display pixels in the peripheral edge region to make the apparent size of the display larger than the area of the active display structures .

In accordance with another embodiment, the adjustable liquid crystal light distribution structures include a reflecting polarizer.

In accordance with another embodiment, the adjustable liquid crystal light distribution structures include a liquid crystal cell having a layer of liquid crystal material interposed between a pair of transparent electrodes .

In accordance with another embodiment, the active display structures include an array of display pixels with a rectangular periphery and the adjustable liquid crystal light distribution structures are located along at least part of the rectangular periphery.

In accordance with another embodiment, the adjustable liquid crystal light distribution structures include a reflector that receives reflected light from the reflecting polarizer.

In accordance with another embodiment, the reflector includes non-planar surfaces.

In accordance with another embodiment, the reflector is configured to reflect the light from the display pixels in the peripheral edge region that has passed through the liquid crystal cell and that has reflected from the reflecting polarizer.

In accordance with an embodiment, a display for viewing by a viewer is provided that includes display structures having a first set of active display pixels and a second set of active pixels, and liquid crystal light distribution structures that are operable in a first state in which light from the second set of active display pixels has a linear polarization with a first orientation and is passed vertically upwards towards the viewer and a second state in which the light from the second set of active display pixels has a linear polarization with a second orientation that is different than the first orientation and is reflected horizontally.

In accordance with another embodiment, the display includes a reflector that reflects the light that is reflected horizontally in a vertical direction towards the viewer.

In accordance with another embodiment, the display structures include a color filter layer, a thin- film-transistor layer, a liquid crystal layer interposed between the color filter layer and the thin-film

transistor layer, an upper polarizer on the color filter layer, and a lower polarizer on a lower surface of the thin-film transistor layer.

In accordance with another embodiment, the display structures include a display pixel array, the first set of display pixels forms a central portion of the display pixels in the display pixel array, the second set of display pixels forms peripheral display pixels that surround the central portion of the display, and the liquid crystal light distribution structures are

configured to distribute light from the peripheral display pixels .

In accordance with another embodiment, the liquid crystal light distribution structures include a liquid crystal cell having a layer of liquid crystal material.

In accordance with another embodiment, the liquid crystal light distribution structures include a reflecting polarizer that receives light from the

peripheral display pixels that has passed through the layer of liquid crystal material in the liquid crystal cell.

In accordance with another embodiment, the liquid crystal light distribution structures include a reflector that reflects light that has reflected from the reflecting polarizer.

In accordance with another embodiment, the display structures include a color filter layer, a thin- film-transistor layer, and a liquid crystal layer

interposed between the color filter layer and the thin- film transistor layer.

In accordance with another embodiment, the display includes a polarizer on the color filter layer through which the light from the peripheral display pixels passes .

In accordance with another embodiment, the display includes a backlight unit having a light guide plate, the light guide plate has light scattering

structures that are configured to scatter brighter

backlight through the peripheral display pixels than through the central portion of the display pixels.

In accordance with an embodiment, an electronic device is provided that includes liquid crystal display structures including central display pixels and peripheral display pixels that surround the central display pixels, liquid crystal light distribution structures that

distribute light from the peripheral display pixels, and control circuitry that synchronously controls the peripheral display pixels and the liquid crystal light distribution structures.

In accordance with another embodiment, the liquid crystal light distribution structures include a reflecting polarizer.

In accordance with another embodiment, the light crystal display structures include an upper polarizer and the liquid crystal light distribution structures include a liquid crystal cell having a layer of liquid crystal material that receives light from the peripheral display pixels that has passed through the upper polarizer.

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.

Claims

What is Claimed is:

1. A display for displaying content with an apparent size to a user, the display comprising:

active display structures having a central region of display pixels and a peripheral edge region of display pixels; and

adjustable reflecting structures that reflect light from the display pixels in the peripheral edge region to make the apparent size of the display larger than the area of the active display structures.

2. The display defined in claim 1 wherein the active display structures include an array of display pixels with a rectangular periphery and wherein the adjustable reflecting structures are located along at least part of the rectangular periphery.

3. The display defined in claim 2 wherein the adjustable reflecting structures comprise

electromechanical mirror structures.

4. The display defined in claim 3 wherein the electromechanical mirror structures include a reflector and a positioner that rotates the reflector.

5. The display defined in claim 4 further comprising a stationary reflector configured to reflect the light to the adjustable reflecting structures from the display pixels in the peripheral edge region.

6. The display defined in claim 5 wherein the stationary reflector comprises a mirror.

7. The display defined in claim 6 wherein the mirror has a non-planar surface.

8. The display defined in claim 5 wherein the stationary reflector comprises a prism.

9. The display defined in claim 4 wherein the reflector comprises a mirror with a non-planar surface.

10. The display defined in claim 1 wherein the peripheral edge region of display pixels has a display pixel width of at least two display pixels.

11. A display, comprising:

display structures having a first set of active display pixels and a second set of active pixels; and

reflector structures that reflect light from the second set of active display pixels without reflecting light from the first set of display pixels to reduce visible inactive display borders.

12. The display defined in claim 11 wherein the reflector structures comprise a stationary reflector.

13. The display defined in claim 11 wherein the reflector structures comprise a reflector and a positioner that rotates the reflector.

14. The display defined in claim 13 wherein the second set of active display pixels displays pixels in synchronization with movement of the reflector by the positioner .

15. The display defined in claim 11 wherein the first set of active display pixels comprises an array of display pixels lying in a plane and wherein the second set of active display pixels includes at least some pixels on a bent edge portion of the display pixels that lies out of the plane.

16. The display defined in claim 11 wherein the display structures comprise organic-light-emitting diode display structures with a bent edge on which the second set of active display pixels is formed.

17. The display defined in claim 11 wherein the display structures include a display pixel array, wherein the first set of display pixels forms a central portion of the display pixels in the display pixel array, wherein the second set of display pixels forms peripheral display pixels that surround the central portion of the display, and wherein the reflector structures comprise rotatable electromechanical mirror structures.

18. An imaging system, comprising:

an image sensor having an array of image sensor pixels including a central region of image sensor pixels surrounded by peripheral image sensor pixels;

optical structures that focus light for the array of image sensor pixels; and

an adjustable mirror that directs image light from the optical structures onto the peripheral image sensor pixels.

19. The imaging system defined in claim 18 wherein the adjustable mirror comprises a reflector and a rotatable positioner configured to rotate the reflector while the reflector directs the image light onto the peripheral image sensor pixels.

20. The imaging system defined in claim 19 further comprising a stationary reflector that reflects light from the adjustable mirror onto the peripheral image sensor pixels.

21. A display for displaying content with an apparent size to a user, the display comprising:

active display structures having an area, having a central region of display pixels, and having a peripheral edge region of display pixels; and

adjustable liquid crystal light

distribution structures that distribute light from the display pixels in the peripheral edge region to make the apparent size of the display larger than the area of the active display structures.

22. The display defined in claim 21 wherein the adjustable liquid crystal light distribution structures include a reflecting polarizer.

23. The display defined in claim 22 wherein the adjustable liquid crystal light distribution structures include a liquid crystal cell having a layer of liquid crystal material interposed between a pair of transparent electrodes .

24. The display defined in claim 23 wherein the active display structures include an array of display pixels with a rectangular periphery and wherein the adjustable liquid crystal light distribution structures are located along at least part of the rectangular periphery .

25. The display defined in claim 24 wherein the adjustable liquid crystal light distribution structures include a reflector that receives reflected light from the reflecting polarizer.

26. The display defined in claim 25 wherein the reflector includes non-planar surfaces.

27. The display defined in claim 25 wherein the reflector is configured to reflect the light from the display pixels in the peripheral edge region that has passed through the liquid crystal cell and that has reflected from the reflecting polarizer.

28. A display for viewing by a viewer, comprising :

liquid crystal light distribution

structures that are operable in a first state in which light from the second set of active display pixels has a linear polarization with a first orientation and is passed vertically upwards towards the viewer and a second state in which the light from the second set of active display pixels has a linear polarization with a second orientation that is different than the first orientation and is reflected horizontally.

29. The display defined in claim 28 further comprising a reflector that reflects the light that is reflected horizontally in a vertical direction towards the viewer .

30. The display defined in claim 29 wherein the display structures include a color filter layer, a thin- film-transistor layer, a liquid crystal layer interposed between the color filter layer and the thin-film

31. The display defined in claim 28 wherein the display structures include a display pixel array, wherein the first set of display pixels forms a central portion of the display pixels in the display pixel array, wherein the second set of display pixels forms peripheral display pixels that surround the central portion of the display, and wherein the liquid crystal light distribution structures are configured to distribute light from the peripheral display pixels.

32. The display defined in claim 31 wherein the liquid crystal light distribution structures include a liquid crystal cell having a layer of liquid crystal material .

33. The display defined in claim 32 wherein the liquid crystal light distribution structures include a reflecting polarizer that receives light from the

peripheral display pixels that has passed through the layer of liquid crystal material in the liquid crystal cell .

34. The display defined in claim 33 wherein the liquid crystal light distribution structures include a reflector that reflects light that has reflected from the reflecting polarizer.

35. The display defined in claim 14 wherein the display structures include a color filter layer, a thin- film-transistor layer, and a liquid crystal layer

interposed between the color filter layer and the thin- film transistor layer.

36. The display defined in claim 35 further comprising a polarizer on the color filter layer through which the light from the peripheral display pixels passes.

The display defined in claim 36 further comprising a backlight unit having a light guide plate, wherein the light guide plate has light scattering

structures that are configured to scatter brighter backlight through the peripheral display pixels than through the central portion of the display pixels.

38. An electronic device, comprising:

liquid crystal display structures including central display pixels and peripheral display pixels that surround the central display pixels;

liquid crystal light distribution

structures that distribute light from the peripheral display pixels; and

control circuitry that synchronously controls the peripheral display pixels and the liquid crystal light distribution structures.

39. The electronic device defined in claim 38 wherein the liquid crystal light distribution structures include a reflecting polarizer.

40. The electronic device defined in claim 38 wherein the light crystal display structures include an upper polarizer and wherein the liquid crystal light distribution structures include a liquid crystal cell having a layer of liquid crystal material that receives light from the peripheral display pixels that has passed through the upper polarizer.