Patent Description:
Aspects of the present disclosure generally relate to displays, and more specifically, to a partial light field display architecture.

With the advent of different video applications and services, there is a growing interest in the use of displays that can provide an image in three full dimensions (3D). There are different types of displays capable of doing so, including volumetric displays, holographic displays, integral imaging displays, and compressive light field displays, to name a few. Existing display technologies can have several limitations, including limitations on the views provided to the viewer, the complexity of the equipment needed to provide the various views, or the cost associated with making the display.

Light field or lightfield displays, however, present some of the better options as they can be flat displays configured to provide multiple views at different locations to enable the perception of depth or 3D to a viewer. Light field displays can require a large number of light emitting elements, at resolutions that can be two to three orders of magnitude greater than those of traditional displays. Therefore, there are challenges in both the number of light emitting elements and the manner in which they are organized that need consideration to enable the ultra-high-density required to provide the best possible experience to a viewer. <CIT> discloses a display apparatus for selectively displaying a two-dimensional image and a three-dimensional image. The display apparatus includes a flat panel display device which generates a two-dimensional image when two-dimensional image display is requested and generates viewpoint images having parallax when three-dimensional image display is requested and a switching panel which is disposed in front of the flat panel display device to be separated from the flat panel display device by a predetermined distance and is controlled according to a type of image generated by the flat panel display device so that two-dimensional images or three-dimensional images can be displayed. <CIT> discloses a spatio-temporal directional light modulator to create 3D displays, ultra-high resolution 2D displays or 2D/3D switchable displays with extended viewing angle. The spatio-temporal aspects of this novel light modulator allow it to modulate the intensity, color and direction of the light it emits within a wide viewing angle. <CIT> discloses a 2D/3D switching system including a 2D/3D switching device for selectively processing lights from 2D images and 3D images. The 2D/3D switching device includes a plurality of first electrodes, a plurality of second electrodes arranged corresponding to the plurality of first electrodes and separated with a distance, and a liquid crystal layer placed between the plurality of first electrodes and the plurality of second electrodes. The 2D/3D switching system also includes a driving unit coupled to the plurality of first electrodes and the plurality of second electrodes to provide driving voltages to the plurality of first electrodes and the plurality of second electrodes, and to provide at least one voltage adjustment signal to adjust corresponding driving voltages of at least one of plurality of first electrodes and the plurality of second electrodes.

Its purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

As used in this disclosure, the term sub-raxel may refer to a light emitting element, including light emitting element that produce a single color of light and light emitting elements that produce red, green, and blue light, the term raxel may refer to a group or allocation of sub-raxels (e.g., neighboring or nearby positioned sub-raxels), and the term super-raxel or picture element may refer to an array or arrangement of light emitting elements that are organized, grouped, or otherwise allocated into different raxels.

According to the invention, a light field display as set out in claim <NUM> includes multiple picture elements (e.g., super-raxels), where each picture element includes a first portion having a first set of light emitting elements, where the first portion is configured to produce light outputs that contribute to at least one two-dimensional (2D) view provided by the light field display. A picture element may also be referred to as a light field picture element. Each picture element also includes a second portion having a second set of light emitting elements (e.g., sub-raxels) that produce light outputs that contribute to at least one three-dimensional (3D) view provided by the light field display. The light field display also includes electronic means configured to drive the first set of light emitting elements and the second set of light emitting elements in each picture element. The light field display can also dynamically identify the first portion and the second portion and allocate light emitting elements accordingly. Separate groups (e.g., raxels) of light emitting elements can be configured to compose picture elements (e.g., super-raxels) and a directional resolution of the light field display can be based on the number of groups.

The appended drawings illustrate only some implementation and are therefore not to be considered limiting of scope.

<FIG> shows a diagram 100a describing an example of a picture element for light field displays, also referred to as multi-view displays, for example. A light field display (see e.g., light field displays <NUM> in <FIG>) can include multiple picture elements (see e.g., picture elements <NUM> in <FIG>), which can be organized in arrays, grids, or other types of ordered arrangements. In some implementations, the multiple picture elements can be monolithically integrated on a same semiconductor substrate. That is, multiple picture elements can be fabricated, constructed, and/or formed from one or more layers of the same or different materials disposed, formed, and/or grown on a single, continuous semiconductor substrate. Additional details regarding materials and other aspects related to the semiconductor substrate are provided below. In this disclosure, the term "picture element" and the term "super-raxel" can be used interchangeably to describe a similar structural unit in a light field display. In some instances, a "picture element" can be referred to as a pixel, but it is different from a pixel used in traditional displays.

A single picture element can include many light emitting elements <NUM>. As noted above, a picture element is different from a pixel in a traditional display in that a pixel generally identifies a discrete element that emits light (e.g., in a non-directional manner, Lambertian emission) while a picture element includes multiple light emitting elements <NUM>, which are themselves organized and configured to produce or generate light outputs that can be directional in nature, where these light outputs (e.g., ray elements) contribute to the formation of multiple, different light field views that are to be provided by the light field display to a viewer in different locations or positions away from the light field display. In an example, each particular location or position away from the light field display can be associated with a light field view provided by the light field display. Additional aspects regarding the arrangement and characteristics of the light emitting elements <NUM> in a picture element are described in more detail below, further identifying differences between a picture element in a light field display and a pixel in a traditional display.

A picture element can have a corresponding light steering optical element <NUM> as shown in <FIG>. The light steering optical element <NUM> can be configured to steer or direct different ray elements <NUM> produced (e.g., emitted) by the light emitting elements <NUM>. In an aspect, the different ray elements <NUM> may correspond to different directions of light outputs produced by one or more light emitting elements <NUM>. In this regard, the directional resolution of the picture element or the light field display may correspond to a number of light output directions supported. Moreover, the light field views provided by the light field display are produced by a contribution from various light outputs that are received by the viewer in a particular location or position away from the light field display. The light steering optical element <NUM> can be considered part of the picture element, that is, the light steering optical element <NUM> is an integral component of the picture element. The light steering optical element <NUM> can be aligned and physically coupled or bonded to the light emitting elements <NUM> of its respective picture element. In some implementations, there may be one or more layers or materials (e.g., optically transparent layers or materials) disposed between the light steering optical element <NUM> and the light emitting elements <NUM> of its respective picture element.

In one example, a light steering optical element <NUM> can be a microlens or a lenslet as shown in <FIG>, which can be configured to steer or direct the ray elements <NUM> (e.g., the different light field views) in the appropriate directions. A light steering optical element <NUM> can include a single optical structure (e.g., a single microlens or lenslet) or can be constructed or formed to include multiple optical structures. For example, a light steering optical element <NUM> can have at least one microlens, at least one grating, or a combination of both. In another example, a light steering optical element <NUM> can have multiple layers of optical components (e.g., microlenses and/or gratings) that combined produce the appropriate light steering effect. For example, a light steering optical element <NUM> can have a first microlens and a second microlens stacked over the first microlens, with the first microlens being associated with a first layer and the second microlens being associated with a second layer. A different example can use a grating or a grating and microlens combination in either or both layers. The construction of the light steering optical element <NUM>, and therefore the positioning and characteristics of any microlenses and/or gratings built or formed therein, is intended to produce the proper steering or directing of the ray elements <NUM>.

Different types of devices can be used for the light emitting elements <NUM>. In one example, a light emitting element <NUM> can be a light-emitting diode (LED) made from one or more semiconductor materials. The LED can be an inorganic LED. To achieve the high densities needed in light field displays, the LED can be, for example, a micro-LED, also referred to as a microLED, an mLED, or a µLED, which can provide better performance, including brightness and energy efficiency, than other display technologies such as liquid crystal display (LCD) technology or organic LED (OLED) technology. The terms "light emitting element," "light emitter," or "emitter," can be used interchangeably in this disclosure, and can also be used to refer to a microLED. Moreover, any of these terms can be used interchangeably with the term "sub-raxel" to describe a similar structural unit in a light field display.

The light emitting elements <NUM> of a picture element can be monolithically integrated on a same semiconductor substrate. That is, the light emitting elements <NUM> can be fabricated, constructed, and/or formed from one or more layers of the same or different materials disposed, formed, and/or grown on a single, continuous semiconductor substrate. The semiconductor substrate can include one or more of GaN, GaAs, Al<NUM>O<NUM>, Si, SiC, Ga<NUM>O<NUM>, alloys thereof, or derivatives thereof. For their part, the light emitting elements <NUM> monolithically integrated on the same semiconductor substrate can be made at least partially of one or more of AlN, GaN, InN, AlAs, GaAs, InAs, AlP, GaP, InP, alloys thereof, or derivatives thereof. In some implementations, each of the light emitting elements <NUM> can include a quantum well active region made from one or more of the materials described above.

The light emitting elements <NUM> can include different types of light emitting elements or devices to provide light of different colors, which in turn enable the light field display to make visually available to viewers a particular color gamut or range. In an example, the light emitting elements <NUM> can include a first type of light emitting element that produces green (G) light, a second type of light emitting element that produces red (R) light, and a third type of light emitting element that produces blue (B) light. In another example, the light emitting elements <NUM> can optionally include a fourth type of light emitting element that produces white (W) light. In another example, a single light emitting element <NUM> may be configured to produce different colors of light. Moreover, the lights produced by the light emitting elements <NUM> in a display enable the entire range of colors available on the display, that is, the display's color gamut. The display's color gamut is a function of the wavelength and linewidth of each of the constituent color sources (e.g., red, green, blue color sources).

In one implementation, the different types of colors of light can be achieved by having changing the composition of one or more materials (e.g., semiconductor materials) in the light emitting elements or by using different structures (e.g., quantum dots of different sizes) as part of or in connection with the light emitting elements. For example, when the light emitting elements <NUM> of a picture element are LEDs, a first set of the LEDs in the picture can be made at least in part of InGaN with a first composition of indium (In), a second set of the LEDs can be made at least in part of InGaN with a second composition of In different from the first composition of In, and a third set of the LEDs can be made at least in part of InGaN with a third composition of In different from the first and second compositions of In.

In another implementation, the different types of colors of light can be achieved by applying different color converters (e.g., color downconverters) to light emitting elements that produce a same or similar color of light. In one implementation, some or all of the light emitting elements <NUM> can include a respective color conversion media (e.g., color conversion material or combination of materials). For example, each of the light emitting elements <NUM> in a picture element is configured to produce blue light. A first set of the light emitting elements <NUM> simply provides the blue light, a second set of the light emitting elements <NUM> is further configured to downconvert (e.g., using one conversion media) the blue light to produce and provide green light, and a third set of the light emitting elements <NUM> is also further configured to downconvert (e.g., using another conversion media) the blue light this time to produce and provide red light.

The light emitting elements <NUM> of a picture element can themselves be organized in arrays, grids, or other types or ordered arrangements just like picture elements can be organized using different arrangements in a light field display.

Additionally, for each picture element there are one or more drivers <NUM> for driving or operating the light emitting elements <NUM>. The drivers <NUM> are electronic circuits or means that are part of a backplane <NUM> and electronically coupled to the light emitting elements <NUM>. The drivers <NUM> can be configured to provide the appropriate signals, voltages, and/or currents in order to drive or operate the light emitting elements <NUM> (e.g., to select a light emitting element, control settings, control brightness). In some implementations, there can be a one-to-one correspondence in which one driver <NUM> can be used to drive or operate a respective light emitting element <NUM>. In other implementations, there can be a one-to-many correspondence in which one driver <NUM> can be used to drive or operate multiple light emitting elements <NUM>. For example, the drivers <NUM> can be in the form of unit cells that are configured to drive a single light emitting element <NUM> or multiple light emitting elements <NUM>.

In addition to the backplane <NUM> that includes the drivers <NUM>, a light field display can also include a plane <NUM> having the light emitting elements <NUM>. Moreover, a light field display can also include a plane <NUM> having the light steering optical elements <NUM>. In an implementation, two of more of the plane <NUM>, the plane <NUM>, and the backplane <NUM> can be integrated or bonded together to form a stacked or three-dimensional (3D) structure. Additional layers, planes, or structures (not shown) can also be part of the stacked or 3D structure to facilitate or configure the connectivity, interoperability, adhesion, and/or distance between the planes. As used in this disclosure, the term "plane" and the term "layer" can be used interchangeably.

<FIG> shows a diagram 100b illustrating another example of a picture element for light field displays. In this example, the picture element can not only provide or emit ray elements <NUM> (as shown also in <FIG>), but can also be configured to receive ray elements <NUM> through the light steering optical element <NUM>. The ray elements <NUM> can correspond to directional light inputs that contribute to various views being received by the picture element or the light field display just like the ray elements <NUM> can correspond to directional light outputs that contribute to various views being provided by the picture element or the light field display to a viewer.

In the example in <FIG>, a plane 120a having the light emitting elements <NUM> can also include one or more light detecting elements <NUM> to receive or capture light associated with the ray elements <NUM>. The one or more light detecting elements <NUM> can be positioned in the plane 120a adjacently surrounded by the light emitting elements <NUM>, or alternatively, the one or more light detecting elements <NUM> can be positioned in the plane 120a separate from the light emitting elements <NUM>. The terms "light detecting element," "light detector," "light sensor," or "sensor," can be used interchangeably in this disclosure.

In some implementations, the light detecting elements <NUM> can be monolithically integrated on the same semiconductor substrate as the light emitting elements <NUM>. As such, the light detecting elements <NUM> can be made of the same types of materials as described above from which the light emitting elements <NUM> can be made. Alternatively, the light detecting elements <NUM> can be made of different materials and/or structures (e.g., silicon complimentary metal-oxide-semiconductor (CMOS) or variations thereof) from those used to make the light emitting elements <NUM>.

Moreover, a plane 130a having the drivers <NUM> can also include one or more detectors <NUM> electronically coupled to the light detecting elements <NUM> and configured to provide the appropriate signals, voltages, and/or currents to operate the light detecting elements <NUM> (e.g., to select a light detecting element, control settings) and to produce signals (e.g., analog or digital signal) representative of the light that is received or captured by the light detecting elements <NUM>.

The construction of the light steering optical element <NUM> in <FIG>, and therefore the positioning and characteristics of any microlenses and/or gratings built therein, is intended to produce the right steering or directing of the ray elements <NUM> away from the picture element to provide the various contributions that are needed for a viewer to perceive the light field views, and also to produce the right steering or directing of the ray elements <NUM> towards the appropriate light detecting elements <NUM>. In some implementations, the light detecting elements <NUM> may use separate or additional light steering optical elements than the light steering optical element <NUM> used in connection with the light emitting elements <NUM>. In such cases, the light steering optical element for the light detecting elements <NUM> can be included in the plane <NUM> having the light steering optical elements <NUM>.

The different picture element structures described in <FIG> and <FIG> enable control, placement, and directivity of the ray elements produced by the light emitting elements <NUM> of the picture element. In addition, the picture element structures in <FIG> enable control, placement, and directivity of the ray elements received by the picture element.

In <FIG>, a diagram <NUM> shows an example of a pattern or mosaic of light emitting elements <NUM> in a picture element. In this example, a portion of an array or grid of light emitting elements <NUM> that are part of a picture element is enlarged to show one of different patterns or mosaics that can be used for the various types of light emitting elements <NUM>. This example shows three (<NUM>) different types of light emitting elements <NUM>, a first type of light emitting element 125a that produces light of one color, a second type of light emitting element 125b that produces light of another color, and a third type of light emitting element 125c that produces light of yet another color. These light colors can be red light, green light, and blue light, for example. In some implementations, the pattern can include twice as many light emitting elements that produce red light than those that produce green light or blue light. In other implementations, the pattern can include a light emitting element that produces red light that is twice a size of those that produce green light or blue light. In other implementations, the pattern can include a fourth type of light emitting element <NUM> that produces light of fourth color, such as white light, for example. Generally, the area of light emitting elements of one color can be varied relative to the area of light emitting elements of other color(s) to meet particular color gamut and/or power efficiency needs. The patterns and colors described in connection with <FIG> are provided by way of illustration and not of limitation. A wide range of patterns and/or colors (e.g., to enable a specified color gamut in the display) may be available for the light emitting elements <NUM> of a picture element. In another aspect, additional light emitting elements (of any color) can be used in a particular pattern to provide redundancy.

The diagram <NUM> in <FIG> also illustrates having the various types of light emitting elements <NUM> (e.g., light emitting elements 125a, 125b, and 125c) monolithically integrated on a same semiconductor substrate. For example, when the different types of light emitting elements <NUM> are based on different materials (or different variations or compositions of the same material), each of these different materials needs to be compatible with the semiconductor substrate such that the different types of light emitting elements <NUM> can be monolithically integrated with the semiconductor substrate. This allows for the ultra-high-density arrays of light emitting elements <NUM> (e.g., arrays of RGB light emitting elements) that are needed for light field displays.

A diagram <NUM> in <FIG> shows a light field display <NUM> having multiple picture elements or super-raxels <NUM>. A light field display <NUM> can be used for different types of applications and its size may vary accordingly. For example, a light field display <NUM> can have different sizes when used as displays for watches, near-eye applications, phones, tablets, laptops, monitors, televisions, and billboards, to name a few. Accordingly, and depending on the application, the picture elements <NUM> in the light field display <NUM> can be organized into arrays, grids, or other types of ordered arrangements of different sizes. In the example shown in <FIG>, the picture elements <NUM> can be organized or positioned into an N × M array, with N being the number of rows of picture elements in the array and M being the number of columns of picture elements in the array. An enlarged portion of such an array is shown to the right of the light field display <NUM>. For small displays, examples of array sizes can include N ≥ <NUM> and M ≥ <NUM> and N ≥ <NUM> and M ≥ <NUM>, with each picture element <NUM> in the array having itself an array or grid of light emitting elements <NUM>. For larger displays, examples of array sizes can include N ≥ <NUM> and M ≥ <NUM>, N ≥ <NUM>,<NUM> and M ≥ <NUM>,<NUM>, N ≥ <NUM>,<NUM> and M ≥ <NUM>,<NUM>, and N ≥ <NUM>,<NUM> and M ≥ <NUM>,<NUM>, with each picture element <NUM> in the array having itself an array or grid of light emitting elements <NUM>.

In a more specific example, for a <NUM> light field display in which the pixels in a traditional display are replaced by the picture elements <NUM>, the N × M array of picture elements <NUM> can be a <NUM>,<NUM> × <NUM>,<NUM> array including approximately <NUM> million picture elements <NUM>. Depending on the number of light emitting elements <NUM> in each of the picture elements <NUM>, the <NUM> light field display can have a resolution that is one or two orders of magnitude greater than that of a corresponding traditional display. When the picture elements or super-raxels <NUM> include as light emitting elements <NUM> different LEDs that produce red (R) light, green (G) light, and blue (B) light, the <NUM> light field display can be said to be made from monolithically integrated RGB LED super-raxels.

Each of the picture elements <NUM> in the light field display <NUM>, including its corresponding light steering optical element <NUM> (e.g., an integral imaging lens), can represent a minimum picture element size limited by display resolution. In this regard, an array or grid of light emitting elements <NUM> of a picture element <NUM> can be smaller than the corresponding light steering optical element <NUM> for that picture element. In practice, however, it is possible for the size of the array or grid of light emitting elements <NUM> of a picture element <NUM> to be similar to the size of the corresponding light steering optical element <NUM> (e.g., the diameter of a microlens or lenslet), which in turn is similar or the same as a pitch <NUM> between picture elements <NUM>.

An enlarged view of an array of light emitting elements <NUM> for a picture element <NUM> is shown to the right of the diagram <NUM>. The array of light emitting elements <NUM> can be a P × Q array, with P being the number of rows of light emitting elements <NUM> in the array and Q being the number of columns of light emitting elements <NUM> in the array. Examples of array sizes can include P ≥ <NUM> and Q ≥ <NUM>, P ≥ <NUM> and Q ≥ <NUM>, P ≥ <NUM> and Q ≥ <NUM>, P ≥ <NUM> and Q ≥ <NUM>, P ≥ <NUM> and Q ≥ <NUM>, P ≥ <NUM> and Q ≥ <NUM>, and P ≥ <NUM> and Q ≥ <NUM>. In an example, a P × Q array is a <NUM> × <NUM> array including <NUM> light emitting elements or sub-raxels <NUM>. The array of light emitting elements <NUM> for the picture element <NUM> need not be limited to square or rectangular shapes and can be based on a hexagonal shape or other shapes as well.

For each picture element <NUM>, the light emitting elements <NUM> in the array can include separate and distinct groups of light emitting elements <NUM> (see e.g., group of light emitting elements <NUM> in <FIG>, <FIG> and <FIG>) that are allocated or grouped (e.g., logically grouped) based on spatial and angular proximity and that are configured to produce the different light outputs (e.g., directional light outputs) that contribute to produce light field views provided by the light field display <NUM> to a viewer. The grouping of sub-raxels or light emitting elements into raxels need not be unique. For example, during assembly or manufacturing, there can be a mapping of sub-raxels into particular raxels that best optimize the display experience. A similar re-mapping can be performed by the display once deployed to account for, for example, aging of various parts or elements of the display, including variations in the aging of light emitting elements of different colors and/or in the aging of light steering optical elements. In this disclosure, the term "groups of light emitting elements" and the term "raxel" can be used interchangeably to describe a similar structural unit in a light field display. The light field views produced by the contribution of the various groups of light emitting elements or raxels can be perceived by a viewer as continuous or non-continuous views.

Each of the groups of light emitting elements <NUM> in the array of light emitting elements <NUM> includes light emitting elements that produce at least three different colors of light (e.g., red light, green light, blue light, and perhaps also white light). In one example, each of these groups or raxels includes at least one light emitting element <NUM> that produces red light, one light emitting element <NUM> that produces green light, and one light emitting element <NUM> that produce blue light. In another example, each of these groups or raxels includes two light emitting elements <NUM> that produce red light, one light emitting element <NUM> that produces green light, and one light emitting element <NUM> that produces blue light. In yet another example, each of these groups or raxels includes one light emitting element <NUM> that produces red light, one light emitting element <NUM> that produces green light, one light emitting element <NUM> that produces blue light, and one light emitting element <NUM> that produces white light.

Because of the various applications (e.g., different sized light field displays) descried above, the sizes or dimensions of some of the structural units described in connection with the light field display <NUM> can vary significantly. For example, a size of an array or grid of light emitting elements <NUM> (e.g., a diameter, width, or span of the array or grid) in a picture element <NUM> can range between about <NUM> microns and about <NUM>,<NUM> microns. That is, a size associated with a picture element or super-raxel <NUM> can be in this range. The term "about" as used in this disclosure indicates a nominal value or a variation within <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% from the nominal value.

In another example, a size of each group of light emitting elements <NUM> (e.g., a diameter, width, or span of the group) in a picture element <NUM> can range between about <NUM> micron and about <NUM> microns. That is, a size associated with a group of light emitting elements <NUM> (e.g., raxel <NUM>) can be in this range.

In another example, a size of a group of light emitting elements <NUM> in a picture element <NUM> can be greater than <NUM> microns because a size of the light emitting elements <NUM> in such a group could be as large as <NUM> microns.

In yet another example, a size of each light emitting element <NUM> (e.g., a diameter, width, or span of the light emitting element or sub-raxel) can range between about <NUM> microns and about <NUM> microns. Similarly, a size of each light emitting element <NUM> (e.g., a diameter, width, or span of the light emitting element or sub-raxel) can be less than about <NUM> micron. Moreover, a size of each light emitting element <NUM> in some implementations can be as large as <NUM> microns. That is, a size associated with a light emitting element or sub-raxel <NUM> can be in the ranges described above.

In yet another example, a size of a light steering optical element <NUM> (e.g., a diameter, width, or span of a microlens or lenslet) can range between about <NUM> microns and about <NUM>,<NUM> microns, which is similar to the range of sizes for a picture element or super-raxel.

In <FIG>, a diagram <NUM> shows another example of the light field display <NUM> illustrating an enlarged view of a portion of an array of picture elements <NUM> with corresponding light steering optical elements <NUM>. The pitch <NUM> can represent a spacing or distance between picture elements <NUM> and can be about a size of the light steering optical element <NUM> (e.g., size of a microlens or lenslet).

In this example, the light field display <NUM> in <FIG> can be a <NUM> light field display with a <NUM>,<NUM> × <NUM>,<NUM> array of picture elements or super-raxels <NUM>. In such a case, for a viewer distance of about <NUM> meters or about <NUM> feet, a size of the light steering optical element <NUM> can be about <NUM> millimeters. Such a size can be consistent with human acuity of about <NUM> arc-minute/picture element. The viewer's field of view (FOV) in this example can be about <NUM> degrees, which can be less than a viewing angle provided by the picture element (e.g., viewing angle > FOV). Moreover, the multiple views provided by the <NUM> light field display in this example can have a <NUM> millimeter width, consistent with a diameter of the human pupil. This can translate to the light steering optical element <NUM> steering the output light produced by a picture element <NUM> having, for example, <NUM><NUM> light emitting elements <NUM>. Accordingly, the <NUM> light field display in this example can provide continuous parallax with light field phase or horizontal parallax with light field phase.

The light field display <NUM> includes a picture element configuration controller <NUM> that can select, identify, or otherwise choose a configuration that is to be used for the picture elements <NUM> in the light field display <NUM>. There are different types of configurations associated with whether a picture element is to support the generation of light outputs that contribute to produce 2D views, 3D views, or a combination of 2D views and 3D views. The picture element configuration controller <NUM> can identify a particular configuration and can use hardware, software, or a combination of hardware and software to take the light emitting elements of the picture element <NUM> and organize them into different portions or regions that support the particular configuration of interest. <FIG>, which are described in more detail below, provide some illustrative examples of different configurations that can be programmed or configured into the picture elements <NUM>.

Accordingly, the picture element configuration controller <NUM> can dynamically identify a first portion (e.g., to produce 2D views) and a second portion (e.g., to produce 3D views) of each picture element <NUM> as in the various configurations described below in connection with <FIG>. The picture element configuration controller <NUM> can then, based on the identified first portion and second portion, configure a first set of light emitting elements <NUM> in the picture element <NUM> and associated with the first portion, and a second set of light emitting elements <NUM> in the picture element <NUM> and associated with the second portion.

Each of the configurations supported includes a corresponding first portion and second portion. As such, when identifying the first portion and the second portion as described above, the first portion is identified from a set of several possible first portions based on several possible configurations, and the second portion is similarly identified from a set of several possible second portions based on several possible configurations.

The picture element configuration controller <NUM> can include a memory <NUM> with instructions and a processor <NUM> configured to execute the instructions to perform the dynamic identification and configuration described above. The picture element configuration controller <NUM>, via the processor <NUM> and/or the memory <NUM>, can configure one or both of hardware means or software means to perform the dynamic identification and configuration. For example, the picture element configuration controller <NUM> can configure and/or control the drivers <NUM> (or unit cells used for driving) in the backplane <NUM>, any software/firmware that controls the drivers <NUM>, and/or hardware/software (not shown) that provides information to the drivers <NUM> in order to perform the dynamic identification and configuration described above. By doing so, it is possible for the picture element configuration controller <NUM> to identify, select, and configure a first set of light emitting elements <NUM> in a picture element <NUM> to be part of the first portion of the picture element <NUM> and a second set of light emitting elements <NUM> in a picture element <NUM> to be part of the second portion of the picture element <NUM>.

A diagram <NUM> in <FIG> illustrates an alternative configuration of a light field display that is also capable of operating as a camera by performing light field capture using neighboring light detecting elements or sensors <NUM>. In this example, a light field display and camera 310a includes an N × M array of picture elements <NUM>, a portion of the array is shown enlarged to the right of the diagram <NUM>. The light detecting elements <NUM> can be, for example, silicon-based image sensors assembled with similar integral optical elements as those used by the picture elements <NUM> (e.g., the light steering optical elements <NUM>). In one implementation, as shown in <FIG>, the light detecting elements <NUM> can be positioned nearby or adjacent to the picture elements <NUM> in a one-to-one correspondence (e.g., one capture element for each display element). In other implementations, the number of light detecting elements <NUM> can be less than the number of picture elements <NUM>.

In an example, each light detecting element <NUM> can include multiple sub-sensors for capturing light in the same fashion as each picture element <NUM> (e.g., a super-raxel) can include multiple light emitting elements <NUM> (e.g., multiple sub-raxels) or multiple groups of light emitting elements <NUM> (e.g., multiple raxels).

As described above in connection with <FIG>, the light detecting elements <NUM> can be integrated in the same plane 120a as the light emitting elements <NUM>. Some or all of the features of the light detecting elements <NUM>, however, could be implemented in the backplane 130a since the backplane 130a is also likely to be silicon-based (e.g., a silicon-based substrate). In such a case, at least some of the features of the light detecting elements <NUM> can be integrated with the detectors <NUM> in the backplane 130a to more efficiently have the circuitry or electronic means in the detectors <NUM> operate the light detecting elements <NUM>.

A diagram 600a in <FIG> shows a cross-sectional view of a portion of a light field display (e.g., the light field display <NUM>) to illustrate some of the structural units described in this disclosure. For example, the diagram 600a shows three adjacent picture elements or super-raxels 320a, each having a corresponding light steering optical element <NUM>. In this example, the light steering optical element <NUM> can be considered separate from the picture element 320a but in other instances the light steering optical element <NUM> can be considered to be part of the picture element.

As shown in <FIG>, each picture element 320a includes multiple light emitting elements <NUM> (e.g., multiple sub-raxels), where several light emitting elements <NUM> (e.g., several sub-raxels) of different types can be grouped together into the group <NUM> (e.g., into a raxel) associated with a particular light view to be provided by the light field display. A group or raxel can produce various components (see <FIG>) that contribute to a particular ray element <NUM> as shown by the right-most group or raxel in the middle picture element 320a. Is it to be understood that the ray elements <NUM> produced by different groups or raxels in different picture elements can contribute to a view perceived by viewer away from the light field display.

An additional structural unit described in <FIG> is the concept of a sub-picture element <NUM>, which represents a grouping of the light emitting elements <NUM> of the same type (e.g., produce the same color of light) of the picture element 320a. Additional details related to sub-picture elements <NUM> are described below in connection with <FIG>, <FIG>, and <FIG>.

A diagram 600b in <FIG> shows another cross-sectional view of a portion of a light field display (e.g., the light field display <NUM>) to illustrate the varying spatial directionality of the ray elements produced by three adjacent picture elements or super-raxels 320a, each having a corresponding light steering optical element <NUM>. In this example, a group of light emitting elements <NUM> in the left-most picture element 320a produces a ray element 105a (e.g., light output), where the ray element 105a is a combination of ray element components <NUM> (e.g., light output sub-components) produced or generated by the group of light emitting elements <NUM>. For example, when the group of light emitting elements <NUM> includes three light emitting elements <NUM>, each of these can produce or generate a component (e.g., a light component of a different color) of the ray element 105a. The ray element 105a has a certain, specified spatial directionality, which can be defined based on multiple angles (e.g., based on two or three angles).

Similarly, a group of light emitting elements <NUM> in the middle picture element 320a produces a ray element 105b (e.g., light output), where the ray element 105b is a combination of ray element components <NUM> produced or generated by the group of light emitting elements <NUM>. The ray element 105b has a certain, specified spatial directionality, different from the one of the ray element 105a, which can also be defined based on multiple angles. The same applies for the ray element 105c produced by a group of light emitting elements <NUM> in the right-most picture element 320a.

The following figures describe different configurations for a light field display (e.g., the light field display <NUM>). In <FIG>, a diagram 700a shows a first configuration or approach for a light field display. In this configuration, which can be referred to as a picture element array of raxel arrays different light field views (e.g., View A, View B) can be provided by combining the ray elements <NUM> emitted by the various picture elements 320b in the light field display <NUM>. In this example, the light steering optical element <NUM> can be considered to be part of the picture elements 320b. For each picture element 320b, there is an array or grid <NUM> of groups of light emitting elements <NUM> (e.g., an array or grid of raxels), where each of these groups produces a light output having at least one component (see <FIG>) that is provided by the light field display <NUM> as a contribution to construct or form a view perceived by a viewer at a certain location or position from the light field display <NUM>. For example, in each of the picture elements 320b, there is at least one group or raxel in the array <NUM> that contributes to View A and there is at least another group or raxel in the array <NUM> that contributes to View B. In some instances, depending on the location or position of the viewer relative to the light field display <NUM>, the same group or raxel can contribute to both View A and View B.

In an aspect of the light field display <NUM> in <FIG>, for each picture element 320b, there can be a spatial (e.g., lateral) offset between a position of the light steering optical element <NUM> and a position of the array <NUM> based on where the picture element 320b is positioned in the light field display <NUM>.

In <FIG>, a diagram 700b shows a second configuration or approach for a light field display that supports light capture as well. The light field display and camera 310a in this configuration is substantially similar to the light field display <NUM> shown in <FIG>, however, in the light field display and camera 310a there is a camera lens <NUM> to steer or direct the ray elements <NUM> to the appropriate light detecting elements (e.g., sensors <NUM>) in an array 710a having groups of light emitting elements <NUM> along with the light detecting elements.

<FIG> shows a diagram 800a describing various details of one implementation of a picture element <NUM>. For example, the picture element <NUM> (e.g., a super-raxel) has a respective light steering optical element <NUM> (shown with a dashed line) and includes an array or grid <NUM> of light emitting elements <NUM> (e.g., sub-raxels) monolithically integrated on a same semiconductor substrate. The light steering optical element <NUM> can be of the same or similar size as the array <NUM>, or could be slightly larger than the array <NUM> as illustrated. It is to be understood that some of the sizes illustrated in the figures of this disclosure have been exaggerated for purposes of illustration and need not be considered to be an exact representation of actual or relative sizes.

The light emitting elements <NUM> in the array <NUM> include different types of light emitting elements to produce light of different colors and are arranged or configured (e.g., via hardware and/or software) into separate groups <NUM> (e.g., separate raxels), each of which produces a different light output (e.g., directional light output) that contributes to one or more light field views perceived by a viewer. That is, each group <NUM> is configured to contribute to one or more of the views that are to be provided to a viewer (or viewers) by the light field display that includes the picture element <NUM>.

As shown in <FIG>, the array <NUM> has a geometric arrangement to allow adjacent or close placement of two or more picture elements. The geometric arrangement can be one of a hexagonal shape (as shown in <FIG>), a square shape, or a rectangular shape.

Although not shown, the picture element <NUM> in <FIG> can have corresponding electronic means (e.g., in the backplane <NUM> in <FIG>) that includes multiple driver circuits configured to drive the light emitting elements <NUM> in the picture element <NUM>. In the example in <FIG>, the electronic means can include multiple unit cells configured to control the operation of individual groups and/or light emitting elements that are part of a group.

<FIG> shows a diagram 800b describing various details of another implementation of a picture element <NUM>. For example, the picture element <NUM> (e.g., a super-raxel) in <FIG> includes multiple sub-picture elements <NUM> monolithically integrated on a same semiconductor substrate. Each sub-picture element <NUM> has a respective light steering optical element <NUM> (shown with a dashed line) and includes an array or grid 810a of light emitting elements <NUM> (e.g., sub-raxels) that produce the same color of light. The light steering optical element <NUM> can be of the same or similar size as the array 810a, or could be slightly larger than the array 810a as illustrated. For the picture element <NUM>, the light steering optical element <NUM> of one of the sub-picture elements <NUM> is configured to minimize the chromatic aberration for a color of light produced by the light emitting elements <NUM> in that sub-picture element <NUM> by optimizing the structure of the light steering optical element for the specified color wavelength. By minimizing the chromatic aberration it may be possible to improve the sharpness of the light field views and compensate for how the magnification is different away from the center of the picture element. Moreover, the light steering optical element <NUM> is aligned and bonded to the array 810a of the respective sub-picture element <NUM>.

The light emitting elements <NUM> of the sub-picture elements <NUM> are arranged into separate groups <NUM> (e.g., raxels). Each group <NUM> can provide a contribution (e.g., a ray element) to a view perceived by a viewer at a certain position or location from the light field display. In one example, each group <NUM> can include collocated light emitting elements <NUM> from each of the sub-picture elements <NUM> (e.g., same position in each sub-picture element). In another example, each group <NUM> can include non-collocated light emitting elements <NUM> from each of the sub-picture elements <NUM> (e.g., different positions in each sub-picture element). In yet another example, each group <NUM> can include a combination of collocated and non-collocated light emitting elements <NUM> from each of the sub-picture elements <NUM>.

As shown in <FIG>, the array 810a has a geometric arrangement to allow adjacent placement of two or more sub-picture elements. The geometric arrangement can be one of a hexagonal shape (as shown in <FIG>), a square shape, or a rectangular shape.

Although not shown, the picture element <NUM> in <FIG> can have corresponding electronic means (e.g., in the backplane <NUM> in <FIG>) that includes multiple driver circuits configured to drive the light emitting elements <NUM> in the picture element <NUM>. In some examples, one or more common driver circuits can be used for each of the sub-picture elements <NUM>. In the example in <FIG>, the electronic means can include multiple unit cells configured to control the operation of individual sub-picture elements and/or light emitting elements that are part of a sub-picture element.

What follows below are descriptions of various examples of architectures for picture elements (e.g., the picture element <NUM>) that can provide a full set of light field views or a partial set of light field views from a display such as a light field display. A light field display that provides a partial set of light field views can be referred to as a partial light field display, for example. In this regard, the features described above in connection with different light field displays can apply as appropriate to a partial light field display, including having similar physical characteristics and structural units (e.g., picture elements or super-raxels, light emitting elements or sub-raxels, light detecting elements, groups of light emitting elements or raxels, light steering optical elements). In this disclosure, the terms "light field views" and "views" can be used interchangeably.

A diagram 900a in <FIG> shows an example of a picture element <NUM> configured to provide or contribute to a full set of light field views. In this example, the entire area of the picture element <NUM> is covered with an array or grid of groups of light emitting elements <NUM> (or raxels <NUM>), where each of these groups provides or contributes to a different light field view. When multiple picture elements <NUM> in <FIG> are used to construct a light field display, the light field display can provide a full set of light field views based on the contributions from the raxels <NUM> in the picture elements <NUM>.

In <FIG>, a diagram 900b shows an example of a picture element <NUM> configured to provide or contribute to light field views in the middle. In this example, a first or outer portion or region <NUM> of the picture element <NUM> provides a single two dimensional (2D) view around the perimeter of the picture element <NUM>. A second or inner portion or region <NUM> of the picture element <NUM>, which is surrounded by the first portion <NUM> and is placed or positioned about the middle of the picture element <NUM>, is configured to provide light field views in this portion of the picture element <NUM>. In one implementation, being placed or positioned about the middle can refer to the second portion <NUM> being offset (e.g., laterally offset, vertically offset, or a combination) from a center or middle of the picture element <NUM>. The second portion <NUM> includes an array or grid of groups of light emitting elements <NUM> (or raxels <NUM>), where each of these groups provides or contributes to a different light field view. When multiple picture elements <NUM> in <FIG> are used to construct a light field display, the light field display can provide a 2D view in the perimeter and light field views in the middle based on the contributions from the raxels <NUM> in the picture elements <NUM>. In some implementations, however, the first portion <NUM> can be used to provide more than one (at least one) 2D view. That is, there could be different 2D views (or light outputs that contribute to different 2D views) provided throughout the first portion <NUM>. For example, a different 2D view can be provided on a right side of the first portion <NUM> than one a left side of the first portion <NUM>. In another example, a different 2D view can be provided in a center or middle of the first portion <NUM> than on either or both of the right side or the left side of the first portion <NUM>. Similarly for the various other configurations described below.

In <FIG>, a diagram 900c shows an example of a picture element <NUM> configured to provide or contribute to horizontal light field views in the middle. In this example, a first or outer portion or region <NUM> of the picture element <NUM> provides a single 2D view around the perimeter of the picture element <NUM>. A second or inner portion or region <NUM> of the picture element <NUM>, which is surrounded by the first portion <NUM> and is placed or positioned about the middle of the picture element <NUM>, is configured to provide horizontal light field views in this portion of the picture element <NUM>. In one implementation, being placed or positioned about the middle can refer to the second portion <NUM> being offset (e.g., laterally offset, vertically offset, or a combination) from a center or middle of the picture element <NUM>. The second portion <NUM> includes an array or grid of groups of light emitting elements <NUM> (or raxels <NUM>), where each of these groups provides or contributes to a different horizontal light field view. As illustrated, the groups or raxels <NUM> in <FIG> are different from those in <FIG> because the configuration of the raxels <NUM> in <FIG> supports horizontal views only as opposed to support for both horizontal and vertical views as done by the configuration of the raxels <NUM> in <FIG>. When multiple picture elements <NUM> in <FIG> are used to construct a light field display, the light field display can provide at least a 2D view in the perimeter and horizontal light field views in the middle based on the contributions from the raxels <NUM> in the picture elements <NUM>. Moreover, similar to <FIG>, more than one 2D view can be produced, with contributions to different 2D views being produced by different areas or regions of the first portion <NUM>.

In <FIG>, a diagram 900d shows an example of a picture element <NUM> configured to provide or contribute to light field views in designated locations or positions. In this example, a first or outer portion or region <NUM> of the picture element <NUM> provides a single 2D view generally around the perimeter of the picture element <NUM>. A second or inner portion or region <NUM> of the picture element <NUM>, which is surrounded by the first portion <NUM>, is configured to provide light field views in designated or predetermined locations or positions of the picture element <NUM>. For example, the second portion <NUM> can include multiple, separate sub-portions <NUM>, each of which is in a different location or position of the picture element <NUM>. Although the example shown in <FIG> has three sub-portions <NUM> horizontally aligned, this disclosure need not be so limited. That is, the number of sub-portions <NUM> can be less or greater than the number shown in <FIG>. Moreover, the sub-portions <NUM> can be aligned in different ways (e.g., horizontally aligned, vertically aligned, or a combination), or need not be aligned at all.

Each of the sub-portions <NUM> of the second portion <NUM> includes an array or grid of groups of light emitting elements <NUM> (or raxels <NUM>), where each of these groups provides or contributes to a different light field view. When multiple picture elements <NUM> in <FIG> are used to construct a light field display, the light field display can provide a 2D view in the perimeter and light field views in the designated positions based on the contributions from the raxels <NUM> that are located in the various sub-portions <NUM> in the picture elements <NUM>.

In <FIG>, a diagram 900e shows another example of the picture element <NUM> in <FIG>, where the picture element <NUM> is configured to provide or contribute to light field views in designated locations or positions that enable support for two left-right eye orientations. In this example, there are four (<NUM>) sub-portion <NUM>, two of which are vertically aligned about the center or middle of the picture element <NUM> to provide a left-right eye vertical or portrait orientation, and another two are horizontally aligned about the center or middle of the picture element <NUM> to provide a left-right eye horizontal or landscape orientation. When multiple picture elements <NUM> in <FIG> are used to construct a light field display, the light field display can provide a 2D view in the perimeter and light field views in the designated positions based on the contributions from the raxels <NUM> that are located in the various sub-portions <NUM> in the picture elements <NUM>, where the light field views provided support vertical and horizontal left-right eye orientations.

In <FIG>, a diagram 900f shows an example of a picture element <NUM> configured to provide or contribute light field views to support any left-right eye orientation. In this example, a first or outer portion <NUM> of the picture element <NUM> provides a single 2D view around the perimeter of the picture element <NUM>. A second or inner portion <NUM> of the picture element <NUM>, which has a disk-shape and is surrounded by the first portion <NUM>, is placed or positioned about the middle of the picture element <NUM>, and is configured to provide light field views that support any left-right eye orientation. In one implementation, being placed or positioned about the middle can refer to the second portion <NUM> being offset (e.g., laterally offset, vertically offset, or a combination) from a center or middle of the picture element <NUM>. The inside of the disk-shaped second potion <NUM> can be considered to be part of the first portion <NUM> and can therefore provide a 2D view in the middle of the picture element <NUM>. The second portion <NUM> includes an arrangement of groups of light emitting elements <NUM> (or raxels <NUM>), where each of these groups provides or contributes to a different horizontal light field view. When multiple picture elements <NUM> in <FIG> are used to construct a light field display, the light field display can provide a 2D view in the perimeter and in the middle/center, and light field views in a disk-shaped portion about the middle/center based on the contributions from the raxels <NUM> in the picture elements <NUM>.

Each of the configurations described above in connection with <FIG> can be implemented using the array of light emitting elements in a picture element as shown in the diagram 800a in <FIG>, or using a picture element with sub-picture elements as shown in the diagram 800b in <FIG>. That is, the light emitting elements <NUM> and/or the groups or raxels <NUM> of light emitting elements <NUM> can be arranged, organized, and controlled (e.g., addressed) as described in <FIG> or as described in <FIG>.

In one example associated with the arrangement shown in <FIG>, for the portion of the picture element <NUM> that is used to provide at least one 2D view, there are light emitting elements that produce red light, light emitting elements that produce green light, and light emitting elements that produce blue light, where each of the light emitting elements and/or each group of light emitting elements in this portion can be individually controlled by respective circuits in the electronic means. For the portion of the picture element <NUM> that is used to provide at least one 3D view, there are also light emitting elements that produce red light, light emitting elements that produce green light, and light emitting elements that produce blue light, where each of the light emitting elements and/or each group of light emitting elements in this portion can be individually controlled by respective circuits in the electronic means.

In another example associated with the arrangement shown in <FIG>, for the portion of the picture element <NUM> that issued to provide at least one 2D view, there are light emitting elements that produce red light, light emitting elements that produce green light, and light emitting elements that produce blue light, where the light emitting elements that produce light of the same color (or a subset thereof) can be controlled by respective circuits in the electronic means. In one implementation, the light emitting elements of a particular color (or a subset thereof) in this portion can effectively operate as a single light emitting element. For the portion of the picture element <NUM> that is used to provide at least one 3D view, there are also light emitting elements that produce red light, light emitting elements that produce green light, and light emitting elements that produce blue light, where the light emitting elements that produce light of the same color (or a subset thereof) can be controlled by respective circuits in the electronic means.

In yet another aspect, the picture elements <NUM> described in connection with various configurations as described in <FIG> can be configured to have certain portions or regions produce light outputs that contribute to providing one or more 2D views to a viewer away from the light field display. In this regard, the picture elements <NUM> can be further configured to control the light output properties (e.g., illumination levels) of the appropriate light emitting elements <NUM> and/or groups of light emitting elements (e.g., raxels <NUM>) for dimming or turning off the 2D views to, for example, de-emphasize the 2D views relative to 3D views and/or to save power.

Claim 1:
A light field display (<NUM>), comprising:
multiple picture elements (<NUM>), each picture element including a plurality of light emitting elements (<NUM>) and having:
a first portion (<NUM>) including a first set of light emitting elements (<NUM>), the first portion being configured to produce light outputs that contribute to at least one two-dimensional, 2D, view, and
a second portion (<NUM>) including a second set of light emitting elements (<NUM>) configured to produce light outputs that contribute to at least one three-dimensional, 3D, view;
a picture element configuration controller (<NUM>) configured for dynamically identifying said first portion (<NUM>) and said second portion (<NUM>) of each picture element and for dynamically configuring said first set and said second set of light emitting elements according to the identified first portion and second portion, such that the light emitting elements (<NUM>) of each picture element (<NUM>) support the generation of light outputs that contribute to produce a combination of two-dimensional, 2D, and three-dimensional, 3D, views, and
a backplane (<NUM>) comprising electronic circuits (<NUM>) configured to drive the first set of light emitting elements (<NUM>) and the second set of light emitting elements (<NUM>) in each one of the multiple picture elements (<NUM>) that are dynamically configured by the picture element configuration controller (<NUM>).