Privacy mode-switchable display system

Abstract

A privacy mode-switchable display system can include an array of controllable lenses. Each controllable lens can receive, as received light, light emitted from a light-emitting diode (LED) of an array of LEDs. Each controllable lens can control an angular width of the received light to form width-controlled light that can propagate away from the lenses in an angular distribution having a controllable angular width. In some examples, each controllable lens can direct the respective received light through a curved interface between a first interface material, having a controllable refractive index, and a second interface material, having a fixed refractive index. In some examples, a controllable lens, positioned to receive light from a specified LED, may also receive off-axis light from an LED adjacent to the specified LED, to form spurious light. An optional cover layer can use total internal reflection to block the spurious light.

Description

LI-247 / 5552.211W01PRIVACY MODE-SWITCHABLE DISPLAY SYSTEMFIELD OF THE DISCLOSURE

[0001] This document relates generally to display systems, and more specifically relates to privacy displays.BACKGROUND OF THE DISCLOSURE

[0002] A multiview display can provide different views of a multiview image to a viewer. A stereoscopic display can provide two different views of a three-dimensional image to the two eyes of a viewer. An autostereoscopic display can provide the two different views to the two eyes of the viewer without requiring the viewer to wear special glasses or eyewear. There is ongoing effort to improve autostereoscopic displays.SUMMARY

[0003] In an example, a privacy mode-switchable display system can include an array of light-emitting diodes (LEDs) that can emit light. The privacy mode-switchable display system can include an array of controllable lenses. Each controllable lens of the array of controllable lenses can receive, as received light, the light emitted from an LED of the array of LEDs. Each controllable lens of the array of controllable lenses can control an angular width of the received light to form width-controlled light. The width-controlled light can propagate away from the array of controllable lenses in an angular distribution having a controllable angular width.

[0004] In an example, a method for operating a privacy mode-switchable display system can include emitting light from an array of light-emitting diodes (LEDs) toward an array of controllable lenses. The method can include receiving, with each controllable lens of the array of controllable lenses, as received light, the light emitted from an LED of the array of LEDs. The method can include controlling, with each controllable lens of the array of controllable lenses, an angular width of the received light to form width-controlled light. The method can include propagating the width-controlled light away from the array of controllable lenses in an angular distribution having a controllable angular width.LI-247 / 5552.211W01

[0005] In an example, a privacy mode-switchable display system can include a display panel. The display panel can include an array of light-emitting diodes (LEDs) configured to emit light. The display panel can include an array of controllable lenses having a one-to-one correspondence to the array of LEDs. Each controllable lens of the array of controllable lenses can receive, as received light, the light emitted from a respective LED of the array of LEDs. Each controllable lens of the array of controllable lenses can direct the respective received light through a curved interface between a first interface material and a second interface material to form width-controlled light. The first interface material can have a controllable refractive index. The first interface material can be included in a single layer that extends over the full array of controllable lenses. The display panel can include transparent electrodes disposed on opposite sides of the first interface material and extending over the full array of controllable lenses. The display panel can include a voltage supply that can apply a controllable voltage to the transparent electrodes to control the controllable refractive index of the first interface material to simultaneously control the controllable lenses of the array of controllable lenses. The privacy mode-switchable display system can include processing circuitry. The processing circuitry can, at a first time, cause the voltage supply to apply a non-zero voltage to the transparent electrodes to cause the width-controlled light to propagate away from the array of controllable lenses in an angular distribution having a first angular width such that an image displayed on the display panel is viewable only from a first angular range. The processing circuitry can, at a second time different from the first time, cause the voltage supply to apply a ground or reference voltage to the transparent electrodes to cause the width-controlled light to propagate away from the array of controllable lenses in an angular distribution having a second angular width different from the first angular width such that an image displayed on the display panel is viewable only from a second angular range different from the first angular range.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 shows an exploded, perspective-view schematic drawing of an example of an autostereoscopic display system.

[0007] FIG. 2 shows a front-view drawing of an example of a display panel that includes an array of light-emitting diodes.LI-247 / 5552.211W01

[0008] FIG. 3 shows a front-view drawing of an example of a display panel that includes a backlight and a light valve array.

[0009] FIG. 4 shows a front-view drawing of an example of a parallaxgenerating optic that includes a lenticular lens.

[0010] FIG. 5 shows a cross-sectional view of the lenticular lens of FIG. 4.

[0011] FIG. 6 shows a front-view drawing of an example of a parallaxgenerating optic that includes a parallax barrier.

[0012] FIG. 7 shows a cross-sectional view of the parallax barrier of FIG. 6 having transmissive slits.

[0013] FIG. 8 shows a side-view cross-sectional drawing of an example of a single subpixel of a privacy mode-switchable display system, when the privacy mode-switchable display system is in a non-privacy mode.

[0014] FIG. 9 shows a side-view cross-sectional drawing of the single subpixel of FIG. 8, when the privacy mode-switchable display system is in a privacy mode.

[0015] FIG. 10 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system, when the privacy mode-switchable display system is in the non-privacy mode.

[0016] FIG. 11 shows a side-view cross-sectional drawing of the portion of the privacy mode-switchable display system of FIG. 10 when the privacy mode-switchable display system is in the privacy mode.

[0017] FIG. 12 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array, when the privacy mode-switchable display system is in the non-privacy mode.

[0018] FIG. 13 shows a side-view cross-sectional drawing of the portion of the privacy mode-switchable display system array of FIG. 12 when the privacy mode-switchable display system is in the privacy mode.

[0019] FIG. 14 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array.

[0020] FIG. 15 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array.

[0021] FIG. 16 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array.LI-247 / 5552.211W01

[0022] FIG. 17 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system.

[0023] FIG. 18 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system.

[0024] FIG. 19 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system.

[0025] FIG. 20 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system.

[0026] FIG. 21 shows a flowchart of an example of a method for operating a privacy mode-switchable display system.DETAILED DESCRIPTION

[0027] A privacy-mode switchable display can be switchable between privacy modes. In a first mode, such as a non-privacy mode, an image on the display is viewable from a relatively broad range of viewing angles. In a second mode, such as a privacy mode, the image is viewable from only a relatively narrow range of viewing angles, such as for a single viewer.

[0028] The privacy-mode switchable display can use controllable lenses to modify the angular pattern of light emitted from light-emitting diodes (LEDs) to determine the privacy mode. The image can be viewable in angular regions that receive the LED light that is output from the display. The image may not be viewable in angular regions that do not receive the LED light that is output from the display. For example, the controllable lenses can optionally broaden the angular output of the LEDs for the first mode, such as the non-privacy mode, and / or can optionally narrow the angular output of the LEDs for the second mode, such as the privacy mode. Other configurations can be used.

[0029] In an example, a privacy mode-switchable display system can include an array of controllable lenses. Each controllable lens can receive, as received light, light emitted from an LED of an array of LEDs. The array of LEDs can include mini -LEDs and / or micro-LEDs. Each controllable lens can control an angular width of the received light to form width-controlled light that can propagate away from the lenses in an angular distribution having a controllable angular width. In some examples, each controllable lens can direct the respective received light through a curved interfaceLI-247 / 5552.211W01between a first interface material, having a controllable refractive index, and a second interface material, having a fixed refractive index. In some examples, a controllable lens, positioned to receive light from a specified LED, may also receive off-axis light from an LED adjacent to the specified LED, to form spurious light. An optional cover layer can use total internal reflection to block the spurious light.

[0030] The preceding paragraphs are merely a summary of some technical details regarding the privacy mode-switchable display system. The array of LEDs and the array of controllable lenses can form a portion of a display panel for a two-dimensional display system, a three-dimensional display system, a display system that includes one or more two-dimensional display regions and one or more three-dimensional display regions, and / or a display system that can include one or more display regions that can switch between two-dimensional and three-dimensional modes.

[0031] In the description that follows of an example of a display, the array of LEDs and the array of controllable lenses can be incorporated into the display panel, and more specifically, into the array of subpixels that can display an image. For example, each subpixel can include an LED of an array of LEDs, and a controllable lens of an array of controllable lenses.

[0032] For the specific case of three-dimensional or autostereoscopic displays, the display may additionally include a parallax-generating optic such as a lenticular lens or a parallax barrier. The display may additionally include a viewer tracker or eye tracker that can dynamically track a position of the viewer in real-time or nearly in realtime. The display may additionally include processing circuitry that can determine whether a specific subpixel can direct light to a viewer’s left eye or the viewer’s right eye, and, in response, can display a subpixel of a left image (of a stereoscopic image pair) or a corresponding subpixel of a right image (of the stereoscopic image pair).

[0033] FIGS. 1-7 provide a more complete description of the hardware of an autostereoscopic display. It will be understood that a conventional (e.g., 2-D) display may include some elements found in an autostereoscopic display (such as the display panel) and may omit other elements found in an autostereoscopic display (such as the parallax-generating optic and the viewer tracker). FIGS. 8-21 provide a more complete description of various aspects of the array of LEDs and the array of controllable lenses of the privacy mode-switchable display system.LI-247 / 5552.211W01

[0034] FIG. 1 shows an exploded, perspective-view schematic drawing of an example of an autostereoscopic display system 100 that includes an autostereoscopic display 110. The configuration of FIG. 1 is but one example of an autostereoscopic display system 100; other configurations can be used.

[0035] The sign conventions shown in FIG. 1 and used below assume that the autostereoscopic display 110 extends in an (x, y) plane, and that az-axis extends away from the autostereoscopic display 110 and generally toward a viewer 42, along a direction that is orthogonal to a plane of the autostereoscopic display 110. Other sign conventions can be used.

[0036] The autostereoscopic display system 100 can include an autostereoscopic display 110. The autostereoscopic display 110 can provide different views of a stereoscopic image pair to the viewer 42. For example, as the viewer 42 moves in space, the autostereoscopic display 110 can direct different views of the stereoscopic image pair to the left and right eyes of the viewer 42, so that the viewer 42 can observe the different views of the stereoscopic image pair from different locations or orientations. In some configurations, the autostereoscopic display 110 can provide the multiple views at respective fixed location regions in space, so that the autostereoscopic display 110 can operate without using eye tracking. In other configurations, such as the autostereoscopic configurations described in detail below, the autostereoscopic display system 100 can use eye tracking to dynamically and continuously (or at relatively frequent discrete times) determine a location of the viewer 42, and in response, can dynamically and continuously control how the autostereoscopic display 110 displays the stereoscopic image pair so that the multiple views follow the viewer 42 or follow the tracked eye location(s) of the viewer 42 as the viewer 42 moves in space relative to a position of the autostereoscopic display 110.

[0037] The autostereoscopic display can provide a left image to a left eye of the viewer 42 and a right image to a right eye of the viewer 42. The left image and the right image can correspond to different views of an object or a scene, and can allow the viewer 42 to perceive the object or scene in 3D with just the viewer’s naked eyes, without the use of additional glasses or headgear.

[0038] The autostereoscopic display system 100 can include a viewer tracker 120 that can dynamically determine the location of the viewer 42. The autostereoscopic display system 100 can use the determined location of the viewer 42 to direct the leftLI-247 / 5552.211W01image to the left eye of the viewer 42 and the right image to the right eye of the viewer 42. Because the viewer’s location can vary as the viewer 42 moves in space, using eye tracking can allow the autostereoscopic display system 100 to follow the viewer 42, so that the autostereoscopic display can automatically direct the left image to the left eye at the viewer’s (dynamically varying) location and automatically direct the right image to the right eye at the viewer’s (dynamically varying) location. The viewer tracker 120 can provide a tracked position of the viewer 42, such as a tracked position of a head of the viewer 42, of one or both eyes of the viewer 42, or of another anatomical feature of the viewer 42. The viewer tracker 120 can be coupled to the processing circuitry 130 (described below) or controller, such as by providing viewer location data (shown in FIG. 1 as coordinates x, y, and z) that represents a measured position or location of the viewer 42. The viewer tracker 120 can provide the viewer location data at regular or irregular intervals to the processing circuitry 130. In a specific example of a viewer tracker 120, a camera can capture an image of the viewer 42. The viewer tracker 120 can further include an image processor (or general-purpose computer programmed as an image processor) that can determine a position of the viewer 42 within the captured image to provide the tracked position. In some examples, the processing circuitry 130 can include the image processor of the viewer tracker 120. In other examples, the processing circuitry 130 can be separate from the image processor of the viewer 42 tracker. Other suitable viewer trackers can be used, including viewer trackers based on lidar (e.g., using time-of-flight of reflected light over a scene to determine distances to one or more objects in the scene, such as a viewer’s head or a viewer’s eyes) or other technologies. The processing circuitry 130 can use an output of the viewer tracker 120, among other data, to perform one or more downstream calculations involved with providing the left view or left image to the left eye of the viewer 42 and the right view or right image to the right eye of the viewer 42.

[0039] The autostereoscopic display can be a lenticular autostereoscopic display. In a lenticular autostereoscopic display, a display panel 112 can display the stereoscopic image pair, and a parallax-generating optic 118 can direct light from the display panel 112 to the viewer 42 such that a left image can be visible from the left eye of the viewer 42 and a right image can be visible from the right eye of the viewer 42. During use of the lenticular autostereoscopic display, the processing circuitry 130 can track the location of the viewer 42, and can use the tracked location to dynamically determine how toLI-247 / 5552.211W01distribute content of the stereoscopic image pair over a surface area of the display panel 112 (e.g., using pixels distributed over the display panel 112) such that a left image remains visible from the left eye of the viewer 42 and a right image remains visible from the right eye of the viewer 42, even as the viewer 42 changes location. In this manner, the location tracking and the image content distribution can be performed in software, such that following the location of the viewer 42 may not involve physically moving any components of the lenticular autostereoscopic display with respect to one another.Examples of suitable display panels and examples of suitable parallax-generating optics are described below.

[0040] In an example, a display panel 112 can display the stereoscopic image pair. The display panel 112 can have an array of subpixels 114 that can display an image according to stereo mapping coordinates associated with the viewer 42. The subpixels 114 can be located at subpixel locations in a grid having grid axes (for example, the x-axis and -axis). Each subpixel 114 can generate light having a specified color. For example, the subpixels 114 can include red subpixels, green subpixels, and blue subpixels, which generate red light, green light, and blue light, respectively. Other color / wavelength schemes can be used. The subpixels 114 can be grouped into pixels, with each pixel including at least two subpixels 114 that produce light of different colors. The display panel 112 can receive, from the processing circuitry 130 (described below), a display panel driving electrical signal 136 that can specify how the content of the stereoscopic image pair is distributed over the pixels and / or subpixels 114 of the display panel 112. Two possible configurations for the display panel 112 are described below and shown in FIGS. 2 and 3. Other configurations can be used.

[0041] FIG. 2 shows a front-view drawing of an example of a display panel 112A that includes an array 202 of light-emitting diodes 204, such as an array 202 of organic light-emitting diodes. Each light-emitting diode 204 can correspond to a subpixel. The array 202 of light-emitting diodes 204 can include red light-emitting diodes 204R, green light-emitting diodes 204G, and blue light-emitting diodes 204B, which correspond to the red subpixels, green subpixels, and blue subpixels, respectively. Each light-emitting diode 204 can controllably generate light in response to an electrical signal provided by the processing circuitry 130, such as display panel-driving electrical signal 136, or by suitable light-emitting diode-driving circuitry in communication with the processing circuitry 130. The processing circuitry 130 can cause a specified light-LI-247 / 5552.211W01emitting diode 204 to be directly powered with a power that varies as a function of an intensity in a corresponding location in the image. The power delivered to a lightemitting diode 204 can optionally be pulse-width modulated at a modulation frequency that is greater than can be perceived by a human eye. Using pulse-width modulation can simplify a design of a light-emitting diode array controller, because it can generate an arbitrary average power level from a relatively small number of instantaneous power levels by varying a duty cycle of the power. In some examples, the array 202 of lightemitting diodes 204 can be arranged in a rectangular or square repeating pattern over a surface area 206 of the array 202. For example, the array 202 can have grid axes 208 that are orthogonal to each other. In some examples, the grid axes 208 can be parallel to edges 210 of the array 202 of light-emitting diodes 204.

[0042] FIG. 3 shows a front-view drawing of an example of a display panel 112B that includes a backlight 302 and a light valve array 304. Although FIG. 3 shows the backlight 302 and the light valve array 304 as being separated, in practice, the backlight 302 and the light valve array 304 may be in contact or may be located as close together as is practical. The backlight 302 can provide illumination having a uniform or substantially uniform intensity over a surface area of the backlight 302. The backlight 302 can provide illumination having a relatively broad spectrum, such as including most or all of the visible portion of the electromagnetic spectrum. The backlight 302 can provide the illumination into a continuum of propagation angles toward the light valve array 304. The backlight 302 can provide unmodulated illumination to the light valve array 304. The light valve array 304 can include light valves 306 that are individually controllable or controllable in one or more groups by the processing circuitry 130 (described below). Each light valve 306 can controllably attenuate the illumination from the backlight 302, such as in response to an electrical signal provided by the processing circuitry 130, such as display panel-driving electrical signal 136, or by suitable light valve driving circuitry in communication with the processing circuitry 130. Each light valve 306 can have a corresponding color filter that allows only a portion of the electromagnetic spectrum to pass through the light valve. For example, the light valves 306 can include red light valves 306R that have a red filter that allows only red light to pass through the red light valves 306R, green light valves 306G that have a green filter that allows only green light to pass through the green light valves 306G, and blue light valves 306B that have a blue filter that allows only blue light to pass through the blueLI-247 / 5552.211W01light valves 306B. Other color schemes and numbers of colors can be used. Suitable light valves can include liquid crystal light valves, electrophoretic light valves, light valves based on electrowetting, and others. In some examples, the light valves 306 of the light valve array 304 can be arranged in a rectangular or square repeating pattern over a surface area 308 of the light valve array 304. For example, the light valve array 304 can have grid axes 208 that are orthogonal to each other. In some examples, the grid axes 208 can be parallel to edges 312 of the light valve array 304.

[0043] Referring again to FIG. 1, the autostereoscopic display can include a parallax-generating optic 118 that can direct light from the display panel 112 to the viewer 42, such that a left view or a left image can be visible from a left eye of the viewer 42 and a right view or a right image can be visible from a right eye of the viewer 42. Two possible configurations for the parallax-generating optic 118 are described below and shown in FIGS. 4 and 5 and in FIGS. 6 and 7. Other configurations can be used. Each of the configurations of FIGS. 4 and 5 and in FIGS. 6 and 7 can be used in combination with any of the configurations of the display panel 112 shown in FIGS. 2 and 3 (e.g., the array of light-emitting diodes 204 in FIG. 2 or the backlight 302 and light valve array 304 in FIG. 3).

[0044] FIG. 4 shows a front-view drawing of an example of a parallaxgenerating optic 118A that includes a lenticular lens 402. FIG. 5 shows a cross-sectional view of the lenticular lens 402 of FIG. 4. The lenticular lens 402 can include a plurality of cylindrical lenses 504 that are equally spaced apart. The lenticular lens 402 can have a focal plane coincident with the display panel 112. The lenticular lens 402 can be positioned to receive light from the display panel 112 and at least partially focus the received light to direct the light to specified regions proximate the viewer’s eyes. For simplicity, the lenticular lens 402 is shown in FIG. 4 as having no gaps between adjacent cylindrical lenses 504. As an alternative, there may be one or more gaps between adjacent cylindrical lenses 504. As a further alternative, two or more of the cylindrical lenses 504 may have properties that differ, such as having different radii of curvature.

[0045] FIG. 6 shows a front-view drawing of an example of a parallaxgenerating optic 118B that includes a parallax barrier 602. The parallax barrier can include a plurality of transmissive slits 704 that are equally spaced apart. FIG. 7 shows a cross-sectional view of the parallax barrier 602 (FIG. 6) having transmissive slits 704. The parallax barrier 602 can include an array of opaque strips 706 and thin transmissiveLI-247 / 5552.211W01slits 704 arranged to occlude portions of a displayed image in left and right viewing regions. The transmissive slits 704 can be spatially arranged to ensure that the left / right image portions are only visible in the corresponding left / right viewing regions for which they are intended. The parallax barrier 602 can be provided by a static physical layer in which the slits are precisely positioned, or electronically generated on an adaptive intermediate liquid crystal display layer.

[0046] The parallax-generating optic 118 can be invariant along an optical axis (OA) that is angled with respect to the grid axes (e.g., the x-axis and the -axis), such as at a rotational orientation (a) of 45 degrees or about 45 degrees with respect to the grid axes 208 or the x-axis. For example, the parallax-generating optic 118 can have transmissive features, such as the cylindrical lenses or the transmissive slits, that are invariant along the optical axis (OA) and are periodic along an axis that is orthogonal to the optical axis (OA).

[0047] Referring again to FIG. 1, the autostereoscopic display can include a material 116 disposed between the display panel 112 and the parallax-generating optic 118. In some examples, the material 116 may extend fully between the display panel 112 and the parallax-generating optic 118, such that a light ray originating at the display panel 112 passes only through the material 116 (and does not pass through any air or unfilled volume) before arriving at the parallax-generating optic 118. In other examples, the material 116 may occupy only a portion of the volume between the display panel 112 and the parallax-generating optic 118, such that a light ray originating at the display panel 112 passes through at least some of the material 116 and passes through a volume of air before arriving at the parallax-generating optic 118. The material 116 may have a refractive index denoted by quantity n. The value of the refractive index n may be between about 1.3 and about 2, although other suitable values may be used. Suitable materials 116 can include glass, plastic, a transparent optical adhesive, and others. In some examples, the material 116 can be dispensed in a liquid form, then cured in place, such as by exposure to ultraviolet light or heat. In other examples, the material 116 can be manufactured as a solid unit and placed in its location in the autostereoscopic display. For example, the material 116 can function as a cover glass for the display panel 112. In some examples, the material 116 can function as a relatively precise spacing element. For example, the material 116 can be manufactured to have a specified thickness to within a specified thickness tolerance, and can set the spacing between the display panelLI-247 / 5552.211W01112 and parallax-generating optic 118 to have a value equal to the specified thickness when the autostereoscopic display is assembled.

[0048] As an alternative configuration, the autostereoscopic display can include, in order along the Z-axis, a backlight, the parallax-generating optic, and a display panel that can selectively modulate light that passes through the pixels or subpixels of the display panel. In other words, the parallax-generating optic may be disposed in an optical path between the backlight and the display panel. The material of refractive index n may be disposed between the parallax-generating optic and the display panel.

[0049] As illustrated in FIG. 1, the autostereoscopic display system 100 can include processing circuitry 130. The processing circuitry 130 can include a processor 132 and memory 134 storing instructions executable by the processor 132. The instructions can be executable by the processor 132 to perform data processing activities. The data processing activities can include, among other activities: at a first time, causing the voltage supply to apply a first voltage to transparent electrodes to cause the width-controlled light to propagate in an angular distribution having a first angular width; and at a second time different from the first time, causing the voltage supply to apply a second voltage different from the first voltage to the transparent electrodes to cause the width-controlled light to propagate in an angular distribution having a second angular width different from the first angular width. By executing these data processing activities, the processing circuitry can cause the autostereoscopic display system 100 to operate with a specified privacy mode, or toggle between two specified privacy modes. These data processing activities are described in detail below.

[0050] During use of the autostereoscopic display system 100, the processing circuitry 130 can determine, in real time, whether a particular pixel or subpixel displays a corresponding pixel from the left image or a corresponding pixel from the right image. There are many ways to make this determination; one specific example is described presently.

[0051] One technique for determining whether the left image is used or the right image is used involves calculating a phase function for each pixel or subpixel. The phase function can be a closed-form algebraic expression based on raytracing from the viewer, through the parallax-generating optic, to the display panel. The phase function can be a function of the pixel or subpixel location (e.g., within an operational area of the display panel), a location of the viewer (e.g., dynamically measured in real-time forLI-247 / 5552.211W01systems that use a viewer tracker), and the stored physical parameter values. The phase function can generate a scalar value as output. If the value of the phase function is within a specified range (such as between 0 and 0.5 after taking a modulus of 1), then the light from the pixel or subpixel is directed to the left eye, and the processing circuitry uses the intensity value of the left image on the pixel or subpixel or the display panel. If the value of the phase function is within another specified range (such as between 0.5 and 1 after taking a modulus of 1), then the light from the pixel or subpixel is directed to the right eye, and the processing circuitry uses the intensity value of the right image on the pixel or subpixel or the display panel. The term “stereo mapping coordinates” can include the data that represents whether a particular pixel or subpixel displays the intensity of the corresponding pixel or subpixel from the left image or the right image. The stereo mapping coordinates can be a function of a viewer location and a pixel or subpixel location.

[0052] FIG. 8 shows a side-view cross-sectional drawing of an example of a single subpixel of a privacy mode-switchable display system when the privacy mode-switchable display system is in a non-privacy mode. FIG. 9 shows a side-view cross-sectional drawing of the single subpixel of FIG. 8, when the privacy mode-switchable display system is in a privacy mode. The subpixel can be one subpixel of an array of pixels or subpixels on the display panel, such as the array of subpixels 114 of the display panel 112 of FIG. 1.

[0053] Each subpixel can include an LED 802, of an array of LEDs, such as array 202 of light-emitting diodes 204. The array of LEDs can emit light. Each LED 802 can emit light of a respective color, such as red, green, or blue. Processing circuitry, such as processing circuitry 130 of FIG. 1, can receive or generate an image, and in response, can cause each LED 802 to emit light with an intensity or brightness that corresponds to a corresponding subpixel of the image. The image can be a frame of a video image. The image can be a two-dimensional image, a multiview image, or a stereoscopic image.

[0054] Each subpixel can further include a controllable lens 804 of an array of controllable lenses. Each controllable lens 804 of the array of controllable lenses can receive, as received light, the light emitted from an LED 802 of the array of LEDs. Each controllable lens 804 can control an angular width of the received light to form width-controlled light. The width-controlled light can propagate away from the array ofLI-247 / 5552.211W01controllable lenses in an angular distribution having a controllable angular width. In other words, each subpixel can include an LED to generate light and a controllable lens to affect the width of the light emitted by the LED.

[0055] In some examples, such as the configurations of FIGS. 10-16, the array of controllable lenses can have a one-to-one correspondence to the array of LEDs. Each controllable lens can receive, as the received light, the light emitted from a respective LED of the array of LEDs.

[0056] There may be configurations in which it may be difficult to design or manufacture controllable lenses that are small enough to use one lens per LED. For example, LEDs with a relatively small spacing may require designing lenses with a curvature that is too steep to manufacture reliably. For these examples, such as the configurations of FIGS. 17-20, a controllable lens can receive light from multiple LEDs of the array of LEDs.

[0057] Each controllable lens 804 of the array of controllable lenses can direct the respective received light through a curved interface 806 between a first interface material 808 and a second interface material 810. Note that the lens 804 may be a separate and distinct element, and / or may be a result of two materials that are disposed on either side of the curved interface 806. The first interface material 808 can have a controllable refractive index. The second interface material 810 can have a fixed refractive index or a controllable refractive index. For example, the second interface material 810 can be shaped as a plano-convex body. The planar side of the convex body can face the LED 802, as in FIGS. 8 and 9, or can alternatively face away from the LED 802. The convex side of the convex body can face away from the LED 802, as in FIGS.8 and 9, or can alternatively face the LED 802. The first interface material 808 can be formed as a layer, with a concave indentation corresponding to the convex surface of the plano-convex body. In practice, the plano-convex bodies can first be disposed on the LEDs 802, then the first interface material 808 can be flowed onto the plano-convex bodies and cured in place to form a layer. The curved interface 806 between the first interface material 808 and the second interface material 810 can provide optical power (e.g., an inverse of focal length, in diopters or other suitable unit) to the controllable lens 804, with an amount of optical power corresponding to a difference in refractive indices between the first interface material 808 and the second interface material 810. In the specific example of FIGS. 8 and 9, the second interface material 810 can have a fixedLI-247 / 5552.211W01refractive index, the second interface material 810 can be shaped to be convex at the curved interface 806 and have a planar surface opposite the curved interface 806, and the planar surface can be disposed directly on the LEDs 802 of the array of LEDs. In the configurations shown in FIGS. 8 and 9, the first interface material 808 can have a refractive index that increases when a voltage is applied. As an alternative, the first interface material 808 can have a refractive index that decreases when a voltage is applied.

[0058] Each subpixel can include transparent electrodes 812 disposed on opposite sides of the first interface material 808. A voltage supply can include a voltage source 814 and can optionally include a switch 816 that can be used to apply a controllable voltage to the transparent electrodes 812 to control the controllable refractive index of the first interface material 808 at or near the LED 802. In some examples, each subpixel (or group of subpixels) can correspond to a respective set of transparent electrodes and a respective voltage supply, so that the privacy mode of each subpixel (or group of subpixels) can be controlled independently of the other subpixels (or groups of subpixels). In other examples, such as the configurations shown in FIGS.10-20, the first interface material 808 can be included in a single layer that extends over the full array of controllable lenses 804, and the transparent electrodes 812 can extend over the full array of controllable lenses 804 to simultaneously control the controllable lenses 804 of the array of controllable lenses.

[0059] Processing circuitry, such as processing circuitry 130 of FIG. 1, can switch the privacy mode between a non-privacy mode (as shown in FIGS. 8, 10, and 12) and a privacy mode (as shown in FIGS. 9, 11, and 13). For example, the processing circuitry can, at a first time, cause the voltage supply 814 to apply a first voltage to the transparent electrodes 812 to cause the width-controlled light to propagate in an angular distribution having a first angular width. The processing circuitry can, at a second time different from the first time, cause the voltage supply 814 to apply a second voltage, different from the first voltage, to the transparent electrodes 812 to cause the width-controlled light to propagate in an angular distribution having a second angular width different from the first angular width. In some examples, the first voltage can be a nonzero voltage. In some examples, the second voltage can be a ground or reference voltage.LI-247 / 5552.211W01

[0060] In the example of FIG. 8, the processing circuitry has opened a switch 816 to disconnect the voltage supply 814 across the transparent electrodes 812. As a result, the refractive index of the first interface material 808 is relatively close to the refractive index of the second interface material 810, and the controllable lens 804 has a relatively small (or zero) optical power. In this example, the curved interface 806 has little or no effect on light rays 818 from the LED 802, such that the light rays 818 pass through the curved interface 806 with little or no change in direction. The light distribution exiting the subpixel has a relatively large angular width 820. The light from the subpixel is viewable over a relatively large angular range, so that the configuration of FIG. 8 is for a non-privacy mode.

[0061] In the example FIG. 9, the processing circuitry has closed the switch 816 to connect the voltage supply 814 across the transparent electrodes 812. The voltage supply 814 provides a specified voltage across the transparent electrodes 812. As a result, the refractive index of the first interface material 808 becomes significantly different from (e.g., less than) the refractive index of the second interface material 810.As a result, the controllable lens 804 has a relatively large optical power. In this example, the curved interface 806 at least partially focuses light from the LED 802. Light rays 818 passing through the curved interface 806 change direction toward a surface normal with respect to a plane of the subpixel (e.g., the light rays 818 become more vertical in FIG. 9, compared to FIG. 8), due to refraction at the curved interface 806. In some examples, the controllable lens 804 can collimate, or at least partially focus, the light from the LED 802. The light distribution exiting the subpixel has a relatively small angular width 920. The light from the subpixel is viewable over a relatively small angular range, so that the configuration of FIG. 9 is for a privacy mode.

[0062] It will be understood that the refractive indices of the materials can be selected such that opening the switch 816 can switch into the non-privacy mode (as in FIG. 8), or can alternatively be selected such that opening the switch 816 can switch into the privacy mode. Similarly, the refractive indices of the materials can be selected such that closing the switch 816 can switch into the privacy mode (as in FIG. 9), or can alternatively be selected such that closing the switch can switch 816 into the non-privacy mode.LI-247 / 5552.211W01

[0063] The subpixels can include a cover layer 822, which can help reduce or eliminate spurious light arising from one or more adjacent LEDs 802 in the LED array. The effect of the cover layer 822 is described below with respect to FIGS. 14-20.

[0064] FIG. 10 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system when the privacy mode-switchable display system is in the non-privacy mode. FIG. 11 shows a side-view cross-sectional drawing of the portion of the privacy mode-switchable display system of FIG.10, when the privacy mode-switchable display system is in the privacy mode.Specifically, a difference between the configurations of FIGS. 10 and 11 is that the switch 816 is open in FIG. 10 but closed in FIG. 11. The change in switch position produces a difference in refractive index of a material on one side of the curved interfaces 806, and, as a result, produces a difference in the effect of the controllable lenses 804 on a width of the light emergent from the controllable lenses 804. In the example of FIGS. 10 and 11, at least some controllable lenses 804 have a planar surface disposed directly on respective LEDs 802 of the array of LEDs.

[0065] In the example of FIGS. 10 and 11, the array of controllable lenses 804 can have a one-to-one correspondence to the array of LEDs 802. Because the controllable lenses 804 are disposed directly on the LEDs 802, each controllable lens 804 can receive the light from a single respective LED 802. Because the controllable lenses 804 are disposed directly on the LEDs 802, each LED 802 can emit light into a single respective controllable lens 804. Because the controllable lenses 804 are disposed directly on the LEDs 802, a particular controllable lens 804 may receive little or no light from an adjacent LED 802 in the array of LEDs 802.

[0066] There may be instances when it may be preferable to space the controllable lenses 804 apart from the LEDs 802. For example, the LEDs 802 may be formed with a protective layer of transparent material disposed on the LEDs 802, such as for protection or sealing from the environment. As another example, the controllable lenses 804 may be formed on a substrate, rather than directly on the LEDs 802, such as for easier handling. For these cases, the second interface material 810 can be spaced apart from the array of LEDs 802 by a solid material having a refractive index greater than a refractive index of air. Using such a solid material (specifically, having a refractive index greater than a refractive index of air) can reduce or eliminate the amount of light lost due to reflection upon entering the controllable lenses 804.LI-247 / 5552.211W01

[0067] FIG. 12 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array when the privacy mode-switchable display system is in the non-privacy mode. FIG. 13 shows a side-view cross-sectional drawing of the portion of the privacy mode-switchable display system array of FIG. 12 when the privacy mode-switchable display system is in the privacy mode.Specifically, a difference between the configurations of FIGS. 12 and 13 is that the switch 816 is open in FIG. 12 but closed in FIG. 13. The change in switch position produces a difference in refractive index of a material on one side of the curved interfaces 806, and, as a result, produces a difference in the effect of the controllable lenses 804 on a width of the light emergent from the controllable lenses 804. In the example of FIGS. 12 and 13, the array of controllable lenses 804 is spaced apart from the array of LEDs 802 by a solid material 1224 having a refractive index greater than a refractive index of air (e.g., 1.0 or about 1.0).

[0068] In the example of FIGS. 12 and 13, the array of controllable lenses 804 can have a one-to-one correspondence to the array of LEDs 802. Because the controllable lenses 804 are spaced apart from the LEDs 802, each controllable lens 804 can receive the light from more than one LED 802 in the array of LEDs 802.Specifically, if a controllable lens 804 is designed to receive light from a first LED in the array of LEDs 802, the controllable lens 804 may also receive spurious light from an LED adjacent to the first LED in the array of LEDs 802.

[0069] FIGS. 14-20 show examples of a cover layer 822 that can fully or partially prevent spurious light 1426 from exiting the privacy mode-switchable display system array toward a viewer.

[0070] FIG. 14 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array. In the example of FIG. 14, the array of controllable lenses 804 is spaced apart from the array of LEDs 802 by a solid material 1224, and an exiting surface 1428 of the cover layer 822 reflects spurious light 1426 via total internal reflection.

[0071] The cover layer 822 can receive the width-controlled light 1430 and direct the width-controlled light 1430 to exit the cover layer through the exiting surface 1428 of the cover layer 822. The exiting surface 1428 can be parallel to the planar surface of the second interface material. At least some controllable lenses 804 of the array of controllable lenses 804 can receive light emitted from one or more LEDs adjacent to theLI-247 / 5552.211W01respective LED 802 of the array of LEDs 802 to form the spurious light 1426. At least some of the spurious light 1426 can propagate from the array of controllable lenses 804 into the cover layer 822. The exiting surface 1428 of the cover layer 822 can reflect, via total internal reflection, at least some of the spurious light 1426 and, as a result, prevent at least some of the spurious light 1426 from exiting the cover layer 822 through the exiting surface 1428 of the cover layer 822. Although FIG. 14 shows the light rays for just one controllable lens 804, it will be understood that the cover layer 822 can help control the spurious light 1426 simultaneously for some or all of the controllable lenses 804 of the array of controllable lenses 804.

[0072] FIG. 15 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array. In the example of FIG. 15, at least some of the controllable lenses 804 are multi-element lenses. Specifically, each multi-element lens 804 can include a first curved surface spaced apart from a second curved surface, where each curved surface can include a curved interface between materials having different refractive indices in the privacy mode and (approximately) the same refractive indices in the non-privacy mode. Bending the light rays sequentially through two curved interfaces that are spaced apart can reduce aberrations and can relax manufacturing and placement tolerances, compared to bending the light rays at a comparable single curved interface. In the example of FIG. 15, the controllable lenses 804 can have a planar surface disposed directly on respective LEDs 802 of the array of LEDs 802.

[0073] FIG. 16 shows a side-view cross-sectional drawing of a portion of an example of a privacy mode-switchable display system array. In the example of FIG. 16, the array of controllable lenses 804 is spaced apart from the array of LEDs 802 by a solid material 1224 having a refractive index greater than a refractive index of air.

[0074] In the examples of FIGS. 10-16, the array of LEDs 802 and the array of controllable lenses 804 are in a one-to-one correspondence, so that an LED 802 receives (non-spurious) light from a single respective controllable lens 804. There may be instances when such a one-to-one correspondence may be difficult or impossible to achieve. For example, the curvature at the edge of the controllable lenses 804 may be too steep to achieve in practice. As another example, the corners at adjacent controllable lenses 804 may be too sharp to achieve in practice. For instances when the one-to-one correspondence may be difficult or impossible to achieve, the privacy mode-switchableLI-247 / 5552.211W01display system can use controllable lenses that span across multiple LEDs 802. Using controllable lenses that span across multiple LEDs 802 can reduce the number of pixels available for a three-dimensional image (or a two-dimensional image in privacy mode) because one or more LEDs 802 per lens may produce spurious light directed into an errant direction. The cover layer 822 (described above) can help reduce or eliminate the spurious light.

[0075] FIG. 17 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system. In the example of FIG. 17, at least some controllable lenses 1730 span across and receive light from multiple LEDs 802 of the array of LEDs 802. At least some controllable lenses 1730 can have a planar surface disposed directly on LEDs 802 of the array of LEDs 802.

[0076] FIG. 18 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system. In the example of FIG. 18, at least some controllable lenses 1730 span across multiple LEDs 802 of the array of LEDs 802.At least some controllable lenses 1730 can be multi-element lenses that have a planar surface disposed directly on LEDs 802 of the array of LEDs 802.

[0077] FIG. 19 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system. In the example of FIG. 19, at least some controllable lenses 1730 span across multiple LEDs 802 of the array of LEDs 802.The array of controllable lenses 1730 can be spaced apart from the array of LEDs 802 by a solid material 1224.

[0078] FIG. 20 shows a side-view cross-sectional drawing of an example of a portion of a privacy mode-switchable display system. In the example of FIG. 20, at least some controllable lenses 1730 span across multiple LEDs 802 of the array of LEDs 802.At least some of the controllable lenses 1730 can be multi-element lenses, and the array of controllable lenses 1730 can be spaced apart from the array of LEDs 802 by a solid material 1224.

[0079] In the examples of FIGS. 8-20, the array of LEDs 802, the array of controllable lenses 1730, the transparent electrodes 812, and the voltage supply 814 may be included in a display panel, such as the display panel 112 of FIG. 1. When the transparent electrodes 812 receive a first voltage, an image displayed on the display panel can be viewable only from a first angular range. When the transparent electrodes 812 receive a second voltage, an image displayed on the display panel can be viewableLI-247 / 5552.211W01only from a second angular range different from the first angular range. The privacy mode-switchable display system can include a parallax-generating optic, such as parallax-generating optic 118, that can direct the width-controlled light 1430 from the display panel to a viewer, such that the privacy mode-switchable display system is an autostereoscopic privacy mode-switchable display system.

[0080] FIG. 21 shows a flowchart of an example of a method 2100 for operating a privacy mode-switchable display system. The method 2100 can be executed on the autostereoscopic display system 100 of FIG. 1, or on another suitable privacy mode-switchable display system. The method 2100 of FIG. 21 is but one method for operating a privacy mode-switchable display system. Other suitable methods can be used.

[0081] At operation 2102, an array of LEDs, such as the array of LEDs 802, can emit light toward an array of controllable lenses, such as the array of controllable lenses 804 or the array of controllable lenses 1730.

[0082] At operation 2104, each controllable lens of the array of controllable lenses can receive, as received light, the light emitted from an LED of the array of LEDs. In an example, one or more of the lenses can receive light from one or multiple LEDs of the array of LEDs.

[0083] At operation 2106, each controllable lens of the array of controllable lenses can provide width-controlled light using the received light.

[0084] At operation 2108, the width-controlled light can propagate away from the array of controllable lenses in an angular distribution having a controllable angular width.

[0085] In some examples, controlling the angular width of the received light can include directing the received light through a curved interface, such as the curved interface 806, between a first interface material, such as the first interface material 808, and a second interface material, such as the second interface material 810. The first interface material can have a controllable refractive index.

[0086] In some examples, the second interface material can have a fixed refractive index. The second interface material can be shaped to be convex at the curved interface and have a planar surface opposite the curved interface. The planar surface can be disposed directly on the LEDs of the array of LEDs, such as in the configurations of FIGS. 10, 11, 15, 17, and 18LI-247 / 5552.211W01

[0087] In some examples, the second interface material can have a fixed refractive index. The second interface material can be shaped to be convex at the curved interface and have a planar surface opposite the curved interface. The second interface material can be spaced apart from the array of LEDs by a solid material having a refractive index greater than a refractive index of air, such as in the configurations of FIGS. 12-14, 16, 19, and 20

[0088] The method 2100 can optionally further include propagating the width-controlled light into a cover layer. The method 2100 can optionally further include directing the width-controlled light to exit the cover layer through an exiting surface of the cover layer. The exiting surface can be parallel to the planar surface of the second interface material. The method 2100 can optionally further include receiving, with at least some controllable lenses of the array of controllable lenses, light emitted from one or more LEDs adjacent to the respective LED of the array of LEDs to form spurious light. The method 2100 can optionally further include propagating at least some of the spurious light from the array of controllable lenses into the cover layer. The method 2100 can optionally further include reflecting, with the exiting surface of the cover layer, via total internal reflection, at least some of the spurious light and, as a result, preventing at least some of the spurious light from exiting the cover layer through the exiting surface of the cover layer.

[0089] Discussion thus far has involved techniques that may be compatible with autostereoscopic displays, in which the autostereoscopic display directs a left image of a stereoscopic image to a left eye of a viewer and directs a right image of the stereoscopic image to a right eye of the viewer. The autostereoscopic display can use viewer tracking or eye tracking to monitor a position of the viewer. For some systems, the viewer may be in a fixed location, and the viewer tracking or eye tracking may be omitted. It will be understood that the privacy mode techniques described above can be generalized to multiview display systems, in which the multiview display generates more than two views of a multiview image (the autostereoscopic case being a special case in which just two views are generated), and to two-dimensional display, in which the two-dimensional display presents a single view of a single image.

[0090] To further illustrate the system and method disclosed herein, a nonlimiting list of examples is provided below. Each of the following non-limitingLI-247 / 5552.211W01examples can stand on its own or can be combined in any permutation or combination with any one or more of the other examples.

[0091] In Example 1, a privacy mode-switchable display system can comprise: an array of light-emitting diodes (LEDs) configured to emit light; and an array of controllable lenses, each controllable lens of the array of controllable lenses being configured to: receive, as received light, the light emitted from an LED of the array of LEDs; and control an angular width of the received light to form width-controlled light, the width-controlled light configured to propagate away from the array of controllable lenses in an angular distribution having a controllable angular width.

[0092] In Example 2, the privacy mode-switchable display system of Example 1 can optionally be configured such that: the array of controllable lenses has a one-to-one correspondence to the array of LEDs; and each controllable lens of the array of controllable lenses is configured to receive, as the received light, the light emitted from a respective LED of the array of LEDs.

[0093] In Example 3, the privacy mode-switchable display system of any one of Examples 1-2 can optionally be configured such that each controllable lens of the array of controllable lenses is configured to direct the respective received light through a curved interface between a first interface material and a second interface material, the first interface material having a controllable refractive index.

[0094] In Example 4, the privacy mode-switchable display system of any one of Examples 1-3 can optionally be configured such that: the second interface material has a fixed refractive index; the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; and the planar surface is disposed directly on the LEDs of the array of LEDs.

[0095] In Example 5, the privacy mode-switchable display system of any one of Examples 1-4 can optionally be configured such that: the second interface material has a fixed refractive index; the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; the second interface material is spaced apart from the array of LEDs by a solid material having a refractive index greater than a refractive index of air; and the privacy mode-switchable display system further comprises: a cover layer configured to receive the width-controlled light and direct the width-controlled light to exit the cover layer through an exiting surface of the cover layer, the exiting surface being parallel to the planar surface of the secondLI-247 / 5552.211W01interface material, at least some controllable lenses of the array of controllable lenses being configured to receive light emitted from one or more LEDs adjacent to the respective LED of the array of LEDs to form spurious light, at least some of the spurious light configured to propagate from the array of controllable lenses into the cover layer, the exiting surface of the cover layer configured to reflect, via total internal reflection, at least some of the spurious light and, as a result, prevent at least some of the spurious light from exiting the cover layer through the exiting surface of the cover layer.

[0096] In Example 6, the privacy mode-switchable display system of any one of Examples 1-5 can optionally further comprise: transparent electrodes disposed on opposite sides of the first interface material; a voltage supply configured to apply a controllable voltage to the transparent electrodes to control the controllable refractive index of the first interface material; and processing circuitry configured to: at a first time, cause the voltage supply to apply a first voltage to the transparent electrodes to cause the width-controlled light to propagate in an angular distribution having a first angular width; and at a second time different from the first time, cause the voltage supply to apply a second voltage different from the first voltage, to the transparent electrodes to cause the width-controlled light to propagate in an angular distribution having a second angular width different from the first angular width.

[0097] In Example 7, the privacy mode-switchable display system of any one of Examples 1-6 can optionally be configured such that: the first voltage is a non-zero voltage; and the second voltage is a ground or reference voltage.

[0098] In Example 8, the privacy mode-switchable display system of any one of Examples 1-7 can optionally be configured such that the array of LEDs, the array of controllable lenses, the transparent electrodes, and the voltage supply are included in a display panel.

[0099] In Example 9, the privacy mode-switchable display system of any one of Examples 1-8 can optionally be configured such that: the first interface material is included in a single layer that extends over each lens of the full array of controllable lenses; the transparent electrodes extend over the full array of controllable lenses to simultaneously control the controllable lenses of the array of controllable lenses; when the voltage supply is applying the first voltage, an image displayed on the display panel is viewable only from a first angular range; and when the voltage supply is applying theLI-247 / 5552.211W01second voltage, an image displayed on the display panel is viewable only from a second angular range different from the first angular range.

[0100] In Example 10, the privacy mode-switchable display system of any one of Examples 1-9 can optionally further comprise a parallax-generating optic configured to direct the width-controlled light from the display panel to a viewer, such that the privacy mode-switchable display system is an autostereoscopic privacy mode-switchable display system.

[0101] In Example 11, a method for operating a privacy mode-switchable display system can comprise: emitting light from an array of light-emitting diodes (LEDs) toward an array of controllable lenses; receiving, with each controllable lens of the array of controllable lenses, as received light, the light emitted from an LED of the array of LEDs; controlling, with each controllable lens of the array of controllable lenses, an angular width of the received light to form width-controlled light; and propagating the width-controlled light away from the array of controllable lenses in an angular distribution having a controllable angular width.

[0102] In Example 12, the method of Example 11 can optionally be configured such that controlling the angular width of the received light comprises directing the received light through a curved interface between a first interface material and a second interface material, the first interface material having a controllable refractive index.

[0103] In Example 13, the method of any one of Examples 11-12 can optionally be configured such that: the second interface material has a fixed refractive index; the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; and the planar surface is disposed directly on the LEDs of the array of LEDs.

[0104] In Example 14, the method of any one of Examples 11-13 can optionally be configured such that: the second interface material has a fixed refractive index; the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; and the second interface material is spaced apart from the array of LEDs by a solid material having a refractive index greater than a refractive index of air.

[0105] In Example 15, the method of any one of Examples 11-14 can optionally further comprise: propagating the width-controlled light into a cover layer; directing the width-controlled light to exit the cover layer through an exiting surface of the coverLI-247 / 5552.211W01layer, the exiting surface being parallel to the planar surface of the second interface material; receiving, with at least some controllable lenses of the array of controllable lenses, light emitted from one or more LEDs adjacent to the respective LED of the array of LEDs to form spurious light; propagating at least some of the spurious light from the array of controllable lenses into the cover layer; reflecting, with the exiting surface of the cover layer, via total internal reflection, at least some of the spurious light and, as a result, preventing at least some of the spurious light from exiting the cover layer through the exiting surface of the cover layer.

[0106] In Example 16, a privacy mode-switchable display system can comprise: a display panel comprising: an array of light-emitting diodes (LEDs) configured to emit light; an array of controllable lenses having a one-to-one correspondence to the array of LEDs, each controllable lens of the array of controllable lenses being configured to: receive, as received light, the light emitted from a respective LED of the array of LEDs; and direct the respective received light through a curved interface between a first interface material and a second interface material to form width-controlled light, the first interface material having a controllable refractive index, the first interface material being included in a single layer that extends over the array of controllable lenses; transparent electrodes disposed on opposite sides of the first interface material and extending over the full array of controllable lenses; and a voltage supply configured to apply a controllable voltage to the transparent electrodes to control the controllable refractive index of the first interface material to simultaneously control the controllable lenses of the array of controllable lenses; and processing circuitry configured to: at a first time, cause the voltage supply to apply a non-zero voltage to the transparent electrodes to cause the width-controlled light to propagate away from the array of controllable lenses in an angular distribution having a first angular width such that an image displayed on the display panel is viewable only from a first angular range; and at a second time different from the first time, cause the voltage supply to apply a ground or reference voltage to the transparent electrodes to cause the width-controlled light to propagate away from the array of controllable lenses in an angular distribution having a second angular width different from the first angular width such that an image displayed on the display panel is viewable only from a second angular range different from the first angular range.LI-247 / 5552.211W01

[0107] In Example 17, the privacy mode-switchable display system of Example 16 can optionally be configured such that: the second interface material has a fixed refractive index; the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; and the planar surface is disposed directly on the LEDs of the array of LEDs.

[0108] In Example 18, the privacy mode-switchable display system of any one of Examples 16-17 can optionally be configured such that: the second interface material has a fixed refractive index; the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; and the second interface material is spaced apart from the array of LEDs by a solid material having a refractive index greater than a refractive index of air.

[0109] In Example 19, the privacy mode-switchable display system of any one of Examples 16-18 can optionally further comprise: a cover layer configured to receive the width-controlled light and direct the width-controlled light to exit the cover layer through an exiting surface of the cover layer, the exiting surface being parallel to the planar surface of the second interface material, at least some controllable lenses of the array of controllable lenses being configured to receive light emitted from one or more LEDs adjacent to the respective LED of the array of LEDs to form spurious light, at least some of the spurious light configured to propagate from the array of controllable lenses into the cover layer, the exiting surface of the cover layer configured to reflect, via total internal reflection, at least some of the spurious light and, as a result, prevent at least some of the spurious light from exiting the cover layer through the exiting surface of the cover layer.

[0110] In Example 20, the privacy mode-switchable display system of any one of Examples 16-19 can optionally further comprise a parallax-generating optic configured to direct the width-controlled light from the display panel to a viewer, such that the privacy mode-switchable display system is an autostereoscopic privacy mode-switchable display system.

[0111] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as "examples." Such examples can include elements in addition to those shown or described. However, examples are contemplatedLI-247 / 5552.211W01in which only those elements shown or described are provided. Moreover, other examples can any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0112] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" can include "A but not B," "B but not A," and "A and B," unless otherwise indicated. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein". Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0113] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

LI-247 / 5552.211W01CLAIMS WHAT IS CLAIMED IS:

1. A privacy mode-switchable display system, comprising:an array of light-emitting diodes (LEDs) configured to emit light; and an array of controllable lenses, each controllable lens of the array of controllable lenses being configured to:receive, as received light, the light emitted from an LED of the array of LEDs; andcontrol an angular width of the received light to form width-controlled light, the width-controlled light configured to propagate away from the array of controllable lenses in an angular distribution having a controllable angular width.

2. The privacy mode-switchable display system of claim 1, wherein:the array of controllable lenses has a one-to-one correspondence to the array of LEDs; andeach controllable lens of the array of controllable lenses is configured to receive, as the received light, the light emitted from a respective LED of the array of LEDs.

3. The privacy mode-switchable display system of claim 1, wherein each controllable lens of the array of controllable lenses is configured to direct the respective received light through a curved interface between a first interface material and a second interface material, the first interface material having a controllable refractive index.

4. The privacy mode-switchable display system of claim 3, wherein:the second interface material has a fixed refractive index;the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; andthe planar surface is disposed directly on the LEDs of the array of LEDs.

5. The privacy mode-switchable display system of claim 3, wherein:the second interface material has a fixed refractive index;LI-247 / 5552.211W01the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface;the second interface material is spaced apart from the array of LEDs by a solid material having a refractive index greater than a refractive index of air; andthe privacy mode-switchable display system further comprises:a cover layer configured to receive the width-controlled light and direct the width-controlled light to exit the cover layer through an exiting surface of the cover layer, the exiting surface being parallel to the planar surface of the second interface material,at least some controllable lenses of the array of controllable lenses being configured to receive light emitted from one or more LEDs adjacent to the respective LED of the array of LEDs to form spurious light,at least some of the spurious light configured to propagate from the array of controllable lenses into the cover layer,the exiting surface of the cover layer configured to reflect, via total internal reflection, at least some of the spurious light and, as a result, prevent at least some of the spurious light from exiting the cover layer through the exiting surface of the cover layer.

6. The privacy mode-switchable display system of claim 3, further comprising:transparent electrodes disposed on opposite sides of the first interface material; a voltage supply configured to apply a controllable voltage to the transparent electrodes to control the controllable refractive index of the first interface material; and processing circuitry configured to:at a first time, cause the voltage supply to apply a first voltage to the transparent electrodes to cause the width-controlled light to propagate in an angular distribution having a first angular width; andat a second time different from the first time, cause the voltage supply to apply a second voltage different from the first voltage, to the transparent electrodes to cause the width-controlled light toLI-247 / 5552.211W01propagate in an angular distribution having a second angular width different from the first angular width.

7. The privacy mode-switchable display system of claim 6, wherein:the first voltage is a non-zero voltage; andthe second voltage is a ground or reference voltage.

8. The privacy mode-switchable display system of claim 6, wherein the array of LEDs, the array of controllable lenses, the transparent electrodes, and the voltage supply are included in a display panel.

9. The privacy mode-switchable display system of claim 8, wherein:the first interface material is included in a single layer that extends over each lens of the full array of controllable lenses;the transparent electrodes extend over the full array of controllable lenses to simultaneously control the controllable lenses of the array of controllable lenses;when the voltage supply is applying the first voltage, an image displayed on the display panel is viewable only from a first angular range; andwhen the voltage supply is applying the second voltage, an image displayed on the display panel is viewable only from a second angular range different from the first angular range.

10. The privacy mode-switchable display system of claim 8, further comprising a parallax-generating optic configured to direct the width-controlled light from the display panel to a viewer, such that the privacy mode-switchable display system is an autostereoscopic privacy mode-switchable display system.

11. A method for operating a privacy mode-switchable display system, the method comprising:emitting light from an array of light-emitting diodes (LEDs) toward an array of controllable lenses;receiving, with each controllable lens of the array of controllable lenses, as received light, the light emitted from an LED of the array of LEDs;LI-247 / 5552.211W01controlling, with each controllable lens of the array of controllable lenses, an angular width of the received light to form width-controlled light; andpropagating the width-controlled light away from the array of controllable lenses in an angular distribution having a controllable angular width.

12. The method of claim 11, wherein controlling the angular width of the received light comprises directing the received light through a curved interface between a first interface material and a second interface material, the first interface material having a controllable refractive index.

13. The method of claim 12, wherein:the second interface material has a fixed refractive index;the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; andthe planar surface is disposed directly on the LEDs of the array of LEDs.

14. The method of claim 12, wherein:the second interface material has a fixed refractive index;the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; andthe second interface material is spaced apart from the array of LEDs by a solid material having a refractive index greater than a refractive index of air.

15. The method of claim 14, further comprising:propagating the width-controlled light into a cover layer;directing the width-controlled light to exit the cover layer through an exiting surface of the cover layer, the exiting surface being parallel to the planar surface of the second interface material;receiving, with at least some controllable lenses of the array of controllable lenses, light emitted from one or more LEDs adjacent to the respective LED of the array of LEDs to form spurious light;propagating at least some of the spurious light from the array of controllable lenses into the cover layer;LI-247 / 5552.211W01reflecting, with the exiting surface of the cover layer, via total internal reflection, at least some of the spurious light and, as a result, preventing at least some of the spurious light from exiting the cover layer through the exiting surface of the cover layer.

16. A privacy mode-switchable display system, comprising:a display panel comprising:an array of light-emitting diodes (LEDs) configured to emit light; an array of controllable lenses having a one-to-one correspondence to the array of LEDs, each controllable lens of the array of controllable lenses being configured to:receive, as received light, the light emitted from a respective LED of the array of LEDs; and direct the respective received light through a curved interface between a first interface material and a second interface material to form width-controlled light, the first interface material having a controllable refractive index, the first interface material being included in a single layer that extends over the array of controllable lenses; transparent electrodes disposed on opposite sides of the first interface material and extending over the full array of controllable lenses; anda voltage supply configured to apply a controllable voltage to the transparent electrodes to control the controllable refractive index of the first interface material to simultaneously control the controllable lenses of the array of controllable lenses; and processing circuitry configured to:at a first time, cause the voltage supply to apply a non-zero voltage to the transparent electrodes to cause the width-controlled light to propagate away from the array of controllable lenses in an angular distribution having a first angular width such that an image displayed on the display panel is viewable only from a first angular range; andLI-247 / 5552.211W01at a second time different from the first time, cause the voltage supply to apply a ground or reference voltage to the transparent electrodes to cause the width-controlled light to propagate away from the array of controllable lenses in an angular distribution having a second angular width different from the first angular width such that an image displayed on the display panel is viewable only from a second angular range different from the first angular range.

17. The privacy mode-switchable display system of claim 16, wherein:the second interface material has a fixed refractive index;the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; andthe planar surface is disposed directly on the LEDs of the array of LEDs.

18. The privacy mode-switchable display system of claim 16, wherein:the second interface material has a fixed refractive index;the second interface material is shaped to be convex at the curved interface and have a planar surface opposite the curved interface; andthe second interface material is spaced apart from the array of LEDs by a solid material having a refractive index greater than a refractive index of air.

19. The privacy mode-switchable display system of claim 18, further comprising: a cover layer configured to receive the width-controlled light and direct the width-controlled light to exit the cover layer through an exiting surface of the cover layer, the exiting surface being parallel to the planar surface of the second interface material,at least some controllable lenses of the array of controllable lenses being configured to receive light emitted from one or more LEDs adjacent to the respective LED of the array of LEDs to form spurious light,at least some of the spurious light configured to propagate from the array of controllable lenses into the cover layer,the exiting surface of the cover layer configured to reflect, via total internal reflection, at least some of the spurious light and, as a result, prevent at least some of the spurious light from exiting the cover layer through the exiting surface of the cover layer.

20. The privacy mode-switchable display system of claim 16, further comprising a parallax-generating optic configured to direct the width-controlled light from the display panel to a viewer, such that the privacy mode-switchable display system is an autostereoscopic privacy mode-switchable display system.

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