TWI839870B - Hybrid backlight, hybrid display and method of operation of a hybrid backlight - Google Patents

Abstract

The application provides a hybrid backlight, a hybrid display, and an operation method of the hybrid backlight. The hybrid backlight includes: a first backlight having a plurality of dimming unit areas, one or more of the plurality of dimming unit areas being configured to be selectively driven to provide broad-angle emitted light independently of each other；and a second backlight configured to provide a plurality of directional light beams having directions corresponding to different view directions of a multi-view image, wherein the second backlight is arranged on a light-emitting surface of the first backlight and is transparent to the broad-angle emitted light, and the one or more dimming unit areas driven in the first backlight correspond to one or more areas where specific content is located in the multi-view image.

Description

Hybrid backlight, hybrid display, and method of operating a hybrid backlight

The present application relates to a hybrid backlight, a hybrid display and an operating method thereof.

Electronic displays are an almost ubiquitous medium for conveying information to users of a wide variety of devices and products. The most commonly used electronic displays include cathode ray tubes (CRTs), plasma display panels (PDPs), liquid crystal displays (LCDs), electroluminescent displays (EL), organic light emitting diode (OLED) and active matrix OLED (AMOLED) displays, electrophoretic displays (EPs), and various displays that employ electromechanical or electrofluidic light modulation (e.g., digital micromirror devices, electroeresis displays, etc.). Generally speaking, electronic displays can be classified as either active displays (i.e., displays that emit light) or passive displays (i.e., displays that modulate light provided by another source). The most obvious examples of active displays are CRTs, PDPs, and OLED/AMOLEDs. When considering the emitted light, displays that are generally classified as passive include LCD and EP displays.

Electronic displays can be divided into two-dimensional displays and three-dimensional displays based on the display mode. Two-dimensional displays are used to display two-dimensional image content, and three-dimensional displays are used to display three-dimensional image content. In some cases, for the same image, we need to display some of the content in two dimensions and other content in three dimensions at the same time. The current switchable two-dimensional/three-dimensional displays can only display the entire image content in one mode (i.e., two-dimensional or three-dimensional) at the same time, and cannot display two-dimensional content in two dimensions and three-dimensional content in three dimensions in the same image at the same time.

In order to achieve a mixed display of two-dimensional content and three-dimensional content in the same image, one aspect of the present application provides a hybrid backlight, including a first backlight having a plurality of dimming unit areas, one or more of the plurality of dimming unit areas being configured to be selectively driven to provide wide-angle emitted light independently of each other; and a second backlight configured to provide a plurality of directional light beams, the directions of the plurality of directional light beams corresponding to different video directions of a multi-video image, wherein the second backlight is disposed on a light emitting surface of the first backlight and is transparent to the wide-angle emitted light, and the one or more dimming unit areas driven in the first backlight correspond to one or more areas where specific content in the multi-video image is located.

In some embodiments, the remaining dimming unit areas in the first backlight that do not correspond to the one or more areas where the specific content in the multi-video image is located are not driven and do not provide the wide-angle emitted light.

In some embodiments, the plurality of directional light beams provided by the second backlight and the wide-angle emitted light provided by one or more dimming unit regions driven in the first backlight are jointly provided to one or more regions where the specific content in the multi-video image is located.

In some embodiments, the hybrid backlight further includes: a dimming controller, which is configured to determine one or more areas where the specific content is located based on the display content of the multi-video image, and determine one or more dimming unit areas to be driven in the first backlight according to the determined one or more areas.

In some embodiments, the multi-video image changes dynamically over time, and the dimming controller dynamically updates one or more regions where the specific content is located based on the displayed content of the changing multi-video image.

In some embodiments, the second backlight comprises: a light guide configured to guide light as guided light; and an array of multi-beam elements, each multi-beam element in the array of multi-beam elements being configured to scatter a portion of the guided light from the light guide as a beam in the plurality of directional light beams.

In some embodiments, the light guide is configured to guide the guided light with a predetermined collimation factor as collimated guided light.

In some embodiments, the multi-beam elements in the multi-beam element array include one or more of a diffraction grating, a micro-reflection element, and a micro-refraction element, wherein the diffraction grating is configured to diffractively scatter the portion of the guided light, the micro-reflection element is configured to reflectively scatter the portion of the guided light, and the micro-refraction element is configured to refractively scatter the portion of the guided light.

One aspect of the present application provides a hybrid display, comprising a first backlight having a plurality of dimming unit areas, wherein one or more of the dimming unit areas are configured to be selectively driven to provide wide-angle emitted light independently of each other; a second backlight configured to provide a plurality of directional light beams, wherein the directions of the plurality of directional light beams correspond to different video directions of a multi-video image, and a light valve array configured to modulate the wide-angle emitted light and the plurality of dimming unit areas. The plurality of directional light beams are used to provide the multi-video image including a two-dimensional display area and a three-dimensional display area, wherein the second backlight is arranged on the light-emitting surface of the first backlight and is transparent to the wide-angle emitted light, and one or more dimming unit areas driven in the first backlight correspond to one or more areas where specific contents in the multi-video image are located, and wherein the one or more areas where the specific contents are located correspond to the two-dimensional display area.

In some embodiments, areas in the multi-video image except for one or more areas where the specific content is located correspond to the three-dimensional display area, and the remaining dimming unit areas in the first backlight corresponding to the three-dimensional display area in the multi-video image are not driven and do not provide wide-angle emitted light.

In some embodiments, the plurality of directional light beams provided by the second backlight and the wide-angle emitted light provided by one or more dimming unit regions driven in the first backlight are jointly provided to the two-dimensional display area in the multi-video image.

In some embodiments, the hybrid display further includes: a dimming controller configured to determine the two-dimensional display area based on the display content of the multi-video image, and determine one or more dimming unit areas to be driven in the first backlight of the determined two-dimensional display area.

In some embodiments, the multi-video image changes dynamically over time, and the dimming controller dynamically updates the two-dimensional display area and the three-dimensional display area based on the display content of the changing multi-video image.

In some embodiments, the second backlight includes: a light guide configured to guide light as guided light; and an array of multi-beam elements, each multi-beam element in the array of multi-beam elements being configured to scatter a portion of the guided light from the light guide as a beam in the plurality of directional light beams.

In some embodiments, the multi-beam elements in the multi-beam element array include one or more of a diffraction grating, a micro-reflection element, and a micro-refraction element, wherein the diffraction grating is configured to diffractively scatter the portion of the guided light, the micro-reflection element is configured to reflectively scatter the portion of the guided light, and the micro-refraction element is configured to refractively scatter the portion of the guided light.

In some embodiments, the hybrid display further includes: a first light source, which includes a plurality of light-emitting units, the plurality of light-emitting units corresponding to a plurality of dimming unit areas in the first backlight, a dimming driver, which is configured to drive the one or more light-emitting units to be driven to illuminate the one or more dimming unit areas in the first backlight; and a second light source, which is configured to emit light to be guided by the light guide.

Another aspect of the present application provides a method for operating a hybrid backlight, including using a first backlight to provide wide-angle emitted light, the first backlight having a plurality of dimming unit areas, one or more of the plurality of dimming unit areas being selectively driven to provide wide-angle emitted light independently of each other, and using a second backlight to provide a plurality of directional light beams, the directions of the plurality of directional light beams corresponding to different video directions of a multi-video image, wherein the second backlight is arranged directly on a light emitting surface of the first backlight and is transparent to the wide-angle emitted light, and the one or more dimming unit areas driven in the first backlight correspond to one or more areas where specific content in the multi-video image is located.

In some embodiments, the remaining dimming unit areas in the first backlight that do not correspond to one or more areas where the specific content in the multi-video image is located are not driven and do not provide wide-angle emitted light.

In some embodiments, the plurality of directional light beams provided by the second backlight and the wide-angle emitted light provided by one or more dimming unit areas driven in the first backlight are jointly provided to one or more areas where the specific content in the multi-video image is located.

In some embodiments, the method further includes: based on the display content of the multi-video image, using a dimming controller to determine one or more areas where the specific content is located; and based on the determined one or more areas, using the dimming controller to determine one or more dimming unit areas to be driven in the first backlight.

In some embodiments, the method further includes guiding light in a light guide as guided light, by using each multi-beam element in an array of multi-beam elements to scatter a portion of the guided light from the light guide as a beam in the plurality of directional light beams.

In some embodiments, the method further includes: using a light valve array to modulate the wide-angle emitted light and the plurality of directional light beams to provide the multi-view image including a two-dimensional display area and a three-dimensional display area, wherein the one or more areas where the specific content is located correspond to the two-dimensional display area, and the area in the multi-view image other than the two-dimensional display area corresponds to the three-dimensional display area.

According to the examples and embodiments of the principles described herein, the present invention provides a hybrid backlight and an operating method thereof applied to a hybrid display. Specifically, according to the principles described herein, the hybrid backlight is configured to provide wide-angle emitted light to the area of the hybrid backlight corresponding to the two-dimensional display content, and to provide a directional light beam to the entire area of the hybrid backlight. In addition, the wide-angle emitted light can be selectively provided to the area corresponding to the specific display content on a regional basis. For example, the wide-angle emitted light can be used to display 2D content (e.g., 2D graphics or text), while the directional light beam can be used to display 3D information (e.g., multi-video images). For example, by using a hybrid display, two-dimensional content can be displayed in two dimensions, and three-dimensional content can be displayed in three dimensions for the same image.

FIG. 1A shows a perspective view of a multi-view display 10 according to an embodiment of the present application principles. As shown in FIG. 1A , the multi-view display 10 includes a screen 12 for displaying a multi-view image to be viewed. The multi-view display 10 provides different views 14 of the multi-view image in different view directions 16 relative to the screen 12. The view directions 16 extend from the screen 12 in various different primary angular directions as indicated by the arrows. The different views 14 are shown as darker multiple polygonal boxes at the termination of the arrows (i.e., arrows representing the view directions 16), and only four views 14 and four view directions 16 are shown, all by way of example and not limitation. It should be noted that although different videos 14 are shown as being above the screen 12 in FIG. 1A , when the multi-view image is displayed on the multi-view display 10, the video 14 actually appears on or near the screen 12. The video 14 is depicted above the screen 12 only for simplicity of explanation and is intended to represent viewing the multi-view display 10 from a corresponding one of the video directions 16 corresponding to the particular video 14.

According to the definition herein, a light beam having a view direction, or equivalently a direction corresponding to the view direction of a multi-view display, typically has a principal angular direction given by the angular components {θ, φ}. Here, the angular component θ is referred to as the "elevation component" or "elevation angle" of the light beam. The angular component θ is referred to as the "azimuth component" or "azimuth angle" of the light beam. By definition, the elevation angle θ is an angle in a vertical plane (e.g., a plane perpendicular to the multi-view display screen), and the azimuth angle φ is an angle in a horizontal plane (e.g., a plane parallel to the multi-view display screen).

FIG. 1B shows a graphical representation of the angular components {θ, φ} of a light beam 20 having a particular primary angular direction corresponding to a viewing direction of a multi-view display (e.g., viewing direction 16 in FIG. 1A ) in an example of an embodiment according to the principles of the present application. Additionally, the light beam 20 is emitted or emanates from a particular point as defined herein. That is, by definition, the light beam 20 has a central ray associated with a particular origin within the multi-view display. FIG. 1B also shows the origin O of the light beam (or viewing direction).

Furthermore, as used herein, the term "multi-view" as used in the terms "multi-view image" and "multi-view display" is defined as a plurality of images representing a plurality of different perspectives or including angle differences between images in a plurality of different images. In addition, as defined herein, the term "multi-view" here explicitly includes more than two different images (i.e., at least three images and typically more than three images). As such, a "multi-view display" as used herein is clearly distinguished from a stereoscopic display that includes only two different images to represent a scene or image. However, note that, as defined herein, although a multi-view image and a multi-view display include more than two images, the multi-view image can be viewed as a stereoscopic image pair (e.g., on a multi-view display) by selecting to view only two of the multi-view images at a time (e.g., one image per eye).

"Multi-video pixel" is defined herein as a group of pixels representing "video" pixels in each of a plurality of similar different videos of a multi-video display. Specifically, a multi-video pixel has a single pixel or a group of pixels corresponding to or representing a video pixel in each of the different videos of the multi-video image. Therefore, by definition herein, a "video pixel" is a pixel or a set of pixels corresponding to a video in the multi-video pixels of a multi-video display. In some embodiments, a video pixel may include one or more color sub-pixels. In addition, by definition herein, the video pixels of the multi-video pixels are so-called "directional pixels" because each of the video pixels is associated with a predetermined video direction of a corresponding one of the different videos. In addition, according to various examples and embodiments, different video pixels of the multi-video pixels may have identical or at least substantially similar positions or coordinates in each of the different videos. For example, a first multi-view pixel may have a separate video pixel located at {x, y} in each of a different video of a multi-view image, and a second multi-view pixel may have a separate video pixel located at {x, y} in each of the different videos.

A "light guide" is defined herein as a structure that uses total internal reflection to guide light within the structure. Specifically, a light guide may include a core that is substantially transparent at the operating wavelength of the light guide. The term "light guide" generally refers to a dielectric optical waveguide that employs total internal reflection to guide light at an interface between a dielectric material of the light guide and a material or medium surrounding the light guide. By definition, a condition for total internal reflection is that the refractive index of the light guide is greater than the refractive index of the surrounding medium adjacent to the surface of the light guide material. In some embodiments, in addition to or in lieu of the above-mentioned refractive index difference, the light guide may also include a coating to further promote total internal reflection. For example, the coating may be a reflective coating. The light guide may be any of a number of light guides, including but not limited to a flat plate light guide or one or both of a thick flat plate light guide and a strip light guide.

As used herein, the term "flat plate," when applied to a light guide, is defined as a piecewise or differentially flat layer or sheet, sometimes referred to as a "slab" light guide. Specifically, a flat plate light guide is defined as a light guide that guides light in two substantially orthogonal directions defined by a top surface and a bottom surface (i.e., opposing surfaces) of the light guide. Furthermore, according to the definition herein, the top surface and the bottom surface are both separate from each other and may be substantially parallel to each other, at least in a differential sense. That is, within any differentially small portion of the flat plate light guide, the top surface and the bottom surface are substantially parallel or coplanar.

In some embodiments, the flat panel light guide may be substantially flat (i.e., confined to a plane) and thus the flat panel light guide is a planar light guide. In other embodiments, the flat panel light guide may be curved in one or two orthogonal dimensions. For example, the flat panel light guide may be curved in a single dimension to form a cylindrical flat panel light guide. However, any curvature should have a sufficiently large radius of curvature to ensure that total internal reflection is maintained within the flat panel light guide to guide light.

As defined herein, a "non-zero propagation angle" of guided light is an angle relative to a guiding surface of a light guide. Furthermore, as defined herein, a non-zero propagation angle is both greater than zero and less than a critical angle for total internal reflection within the light guide. Furthermore, for a particular embodiment, a particular non-zero propagation angle may be selected so long as the particular non-zero propagation angle is less than a critical angle for total internal reflection within the light guide. In various embodiments, light may be introduced or coupled into a light guide at a non-zero propagation angle.

According to various embodiments, the guided light or equivalent guided "light beam" produced by coupling light into a light guide can be a collimated light beam. "Collimated light" or "collimated light beam" is generally defined herein as a plurality of light beams that are substantially parallel to each other within the light beam. In addition, according to the definition herein, light that diverges or scatters from a collimated light beam is not considered to be part of the collimated light beam.

A "diversion grating" is generally defined herein as a plurality of features (i.e., diffraction features) arranged to provide diffraction of light incident on the diversion grating. In some examples, the plurality of features may be arranged in a periodic or quasi-periodic manner. For example, the diffraction grating may include a plurality of features (e.g., a plurality of grooves or ridges in a material surface) arranged in a one-dimensional (1D) array. In other examples, the diffraction grating may be a two-dimensional (2D) array of features. For example, the diffraction grating may be a two-dimensional array of protrusions on a material surface or holes in a material surface.

Thus, a "diversion grating" according to the definition herein is a structure that provides diffraction of light incident on the diversion grating. If light is incident on the diversion grating from a light guide, the diffraction or diffractive scattering provided may result in and is therefore referred to as "divertive coupling", since the diffraction grating may couple the light out of the light guide by diffraction. The diffraction grating also redirects or changes the angle of the light by diffraction (i.e., at a diffraction angle). In particular, due to the diffraction, the light leaving the diffraction grating typically has a conduction direction that is different from the conduction direction of the light incident on the diffraction grating (i.e., the incident light). The change in the propagation direction of light by diffraction is referred to herein as "diffraction redirection". Therefore, a diffraction grating can be understood as a structure comprising diffraction features, which redirects light incident on the diffraction grating by diffraction, and, if the light is emitted by a light guide, the diffraction grating can also couple out light from the light guide by diffraction.

In addition, according to the definition in this article, the characteristics of the diffraction grating are referred to as "diffraction features" and can be one or more of at, in, and on the surface of a material (i.e., the boundary between two materials). For example, the surface can be the surface of a light guide. The diffraction feature can include any of a variety of structures that diffract light, including but not limited to one or more of grooves, ridges, holes, and protrusions at, in, or on the surface. For example, the diffraction grating can include a plurality of substantially parallel grooves in the surface of the material. In another example, the diffraction grating can include a plurality of parallel ridges protruding from the surface of the material. Diffraction features (e.g., grooves, ridges, holes, protrusions, etc.) can have any of a variety of cross-sectional shapes or profiles that provide diffraction, including but not limited to sinusoidal profiles, rectangular profiles (e.g., binary diffraction gratings), triangular profiles, and sawtooth profiles (e.g., flared gratings).

According to various examples described herein, a diffraction grating (e.g., a diffraction grating of a multi-beam element, as described below) can be used to diffractively scatter or couple light from a light guide (e.g., a flat light guide) into a light beam. Specifically, the diffraction angle θ _m of the local periodic diffraction grating or the diffraction angle provided by the local periodic diffraction grating can be given by equation (1) (1) Where λ is the wavelength of the light, m is the diffraction order, n is the refractive index of the light guide, d is the spacing or spacing between the features of the diffraction grating, and _θi is the angle of incidence of the light on the diffraction grating. For simplicity, equation (1) assumes that the diffraction grating is adjacent to the surface of the light guide and that the refractive index of the material outside the light guide is equal to l (i.e., _nout = 1). Typically, the diffraction order m is given as an integer. The diffraction angle _θm of a light beam generated by the diffraction grating can be given by equation (1) where the diffraction order is positive (e.g., m > 0). For example, first order diffraction is provided when the diffraction order m is equal to 1 (i.e., m = 1).

FIG2 shows a cross-sectional view of a diffraction grating 30 according to an embodiment of the present application principles. For example, the diffraction grating 30 can be located on the surface of the light guide 40. In addition, FIG2 shows an incident light beam 50 incident on the diffraction grating 30 at an incident angle _θi , and the incident light beam 50 can be a beam of guided light (i.e., a guided light beam) within the light guide 40. FIG2 also shows that due to the diffraction of the incident light beam, the diffraction grating 30 diffractively generates and couples out a directional light beam 60, and the directional light beam 60 has a diffraction angle _θm (or, in this article, a "main angular direction") as shown in equation (1). The diffraction angle _θm can correspond to a diffraction order "m" of the diffraction grating 30, for example, the diffraction order m = 1 (i.e., the first diffraction order).

According to the definition herein, a "multi-beam element" is a structure or element of a backlight panel or display that generates light including a plurality of light beams. In some embodiments, the multi-beam element can be optically coupled to a light guide of the backlight panel to provide a plurality of light beams by coupling out or scattering out a portion of the light guided in the light guide. Further, according to the definition herein, the light beams in the plurality of light beams generated by the multi-beam element have a plurality of main angular directions that are different from each other. Specifically, according to the definition, a light beam in the plurality of light beams has a predetermined main angular direction that is different from another light beam in the plurality of light beams. Therefore, according to the definition herein, the light beam is referred to as a "directional light beam", and the plurality of light beams can be referred to as a plurality of directional light beams.

In addition, the plurality of directional light beams may represent a light field. For example, the plurality of directional light beams may be confined to a substantially conical spatial region, or have a predetermined angular spread including different main angular directions of the light beams in the plurality of light beams. Thus, a combination of the predetermined angular spreads of the plurality of light beams (i.e., the plurality of light beams) may represent a light field.

According to various embodiments, the different main angular directions of various directional beams in the plurality of directional beams are determined according to characteristics, which may include but are not limited to the size of the multi-beam element (e.g., length, width, area, etc.). In some embodiments, the multi-beam element may be considered as an "extended point light source" according to the definition herein, that is, a plurality of point light sources are distributed within the range of the multi-beam element. In addition, the directional beams generated by the multi-beam element have a main angular direction given by the angular components {θ, φ}, as defined herein and as described above with respect to FIG. 1B.

"Collimator" is defined herein as substantially any optical device or apparatus for collimating light. For example, a collimator may include, but is not limited to, a collimator or reflector, a collimating lens, a diffraction grating, a conical light guide, and combinations of the above collimators. According to various embodiments, the amount of collimation provided by the collimator may vary from one embodiment to another by a predetermined angle or amount. Further, the collimator may be configured to provide collimation in one or both of two orthogonal directions (e.g., a vertical direction and a horizontal direction). In other words, according to some embodiments of the present invention, the collimator may include a shape or similar collimating feature for providing one or both of two orthogonal directions of light collimation.

"Collimation factor" is defined herein as the degree to which light is collimated. Specifically, the collimation factor defines the angular spread of light rays in a collimated light beam. For example, the collimation factor σ can specify that a majority of light rays in a beam of collimated light are within a particular angular spread (e.g., +/−σ degrees relative to the center or primary angular direction of the collimated light beam). According to some examples, the light rays of the collimated light beam can have a Gaussian distribution in angle, and the angular spread can be the angle determined by half the peak intensity of the collimated light beam.

"Light source" is defined herein as a source that emits light (e.g., an optical emitter configured to generate and emit light). For example, a light source may include an optical emitter, such as a light emitting diode (LED), which emits light when activated or turned on. Specifically, a light source herein may be essentially any source of light or an optical emitter, including but not limited to one or more LEDs, lasers, organic light emitting diodes (OLEDs), polymer light emitting diodes, plasma optical emitters, fluorescent lamps, incandescent lamps, and any other visually visible light beam source. The light generated by the light source may have a color (i.e., may include light of a specific wavelength), or may be a range of wavelengths (e.g., white light). In some embodiments, the light source may include a plurality of optical emitters. For example, a light source may include a set or group of optical emitters, at least one of which produces light having a color or equivalent wavelength that is different from the color or wavelength of light produced by at least one other optical emitter of the set or group. The different colors may include, for example, primary colors (e.g., red, green, blue). A "polarized" light source is defined herein as essentially any light source that produces or provides light having a predetermined polarization. For example, a polarized light source may include a polarizer at the output of the optical emitters of the light source.

A "multi-view image" is defined herein as a plurality of images (i.e., two or more images), wherein each image of the plurality of images represents a different view corresponding to a different view direction of the multi-view image. Thus, for example, a multi-view image is a collection of images (e.g., two-dimensional images) that, when displayed on a multi-view display, can facilitate the perception of depth, thereby appearing to be an image of a 3D scene to a viewer. For example, in some embodiments, where the multi-view image includes two images, binocular stereoscopic display can be achieved by viewing the two images as a stereoscopic image pair on the multi-view display (e.g., one image for each eye).

By definition, "wide-angle" emitted light is defined as having a certain cone angle that is greater than the cone angle of the video of a multi-vision image or a multi-vision display. Specifically, in some embodiments, the wide-angle emitted light can have a cone angle greater than about twenty degrees (e.g., >±20°). In other embodiments, the cone angle of the wide-angle emitted light can be greater than about thirty degrees (e.g., >±30°), or greater than about forty degrees (e.g., >±40°), or greater than about fifty degrees (e.g., >±50°). For example, the cone angle of the wide-angle emitted light can be greater than about sixty degrees (e.g., >±60°). It should be noted that when "wide-angle" emitted light is mentioned at the same time as "directional" emitted light, it means that the cone angle of the "wide-angle" emitted light is greater than the cone angle of each directional light beam in the "directional" emitted light. In other words, a directional light beam can be considered as a light beam with a very small cone angle (for example, < 10°, or < 5°, etc.) pointing in a certain direction.

In some embodiments, the cone angle of the wide-angle emitted light can be defined as being approximately the same as the viewing angle of an LCD computer screen, LCD flat panel computer, LCD television, or similar digital display device for wide-angle viewing (e.g., approximately ±40° to 65°). In other embodiments, the wide-angle emitted light can also be characterized or described as diffuse light, substantially diffuse light, non-directional light (e.g., lacking any particular or defined directionality), or light having a single or substantially uniform direction.

In addition, as used herein, the article "a" is intended to have its ordinary meaning in the patent art, that is, "one or more" such as "a multi-vision pixel" means one or more multi-vision pixels, and therefore, "multi-vision pixel" means "one or more multi-vision pixels" here. In addition, any reference to "top", "bottom", "upper", "lower", "up", "lower", "front", "back", "first", "second", "left" or "right" here is not intended to be limiting. Here, the term "about" when applied to a value generally means within the tolerance range of the equipment used to produce the value, or may mean plus or minus 10%, or plus or minus 5%, or plus or minus 1%, unless otherwise expressly stated. In addition, the term "substantially" as used herein refers to most, or almost all, or all, or an amount in the range of about 51% to about 100%. Additionally, the examples herein are intended to be illustrative only and are presented for purposes of discussion and not by way of limitation.

According to some embodiments of the principles described herein, the present invention provides a hybrid backlight. Fig. 3A shows a plan view of a hybrid backlight 100 according to an embodiment of the principles of the present application. Fig. 3B shows a plan view of a hybrid backlight 100 according to an embodiment of the principles of the present application. Fig. 3C shows a perspective view of a hybrid backlight 100 according to an embodiment of the principles of the present application. Specifically, the perspective view shown in Fig. 3C is a decomposed perspective view.

As shown in FIG. 3A , the hybrid backlight 100 has a plurality of different display regions, which are depicted as two-dimensional display regions 101 a - 1 , 101 a - 2 and a three-dimensional display region 101 b in FIG. 3A .

In this article, the term "two-dimensional display area" refers to a display area used to display two-dimensional image content or to display image content in a two-dimensional manner. In addition, it should be understood that although two fixed-position areas 101a-1 and 101a-2 are shown in FIG. 3A as the two-dimensional display area of the hybrid backlight 100, this is merely exemplary. It should be understood that the position of the two-dimensional display area is not fixed in the hybrid backlight 100, but changes dynamically based on the displayed image content, and the number of two-dimensional display areas is not fixed, but can change dynamically with the content of the image to be displayed. For example, the number of two-dimensional display areas can be one, two, or even more. In addition, in some cases where two-dimensional display is not required, the number of two-dimensional display areas can also be zero.

In some embodiments of the present application, the two-dimensional display area in the hybrid backlight 100 corresponds to one or more areas where specific content in the multi-visual image to be displayed is located. For example, if the multi-visual image to be displayed includes both image content and text content, we hope to be able to display the image content in a three-dimensional display manner so that it looks like it has a certain depth of field, thereby producing a three-dimensional effect. However, for text content (such as words, characteristic slogans in the image, text in the book in the image, etc.), compared with the three-dimensional display effect with depth of field, we prefer to display it more clearly in a flat, two-dimensional manner. As shown in FIG3B , assuming that the image 200-1 to be displayed includes both image content (e.g., the smiling face, clouds, and hills in FIG3B ) and text content (e.g., the text "Hello" in the dialog box), we want to display the image content such as the smiling face, clouds, and hills in a three-dimensional manner, and display the text content in the dialog box in a two-dimensional manner. In this case, the area where the dialog box is located can be limited to a two-dimensional display area 101a, and the other image content areas in the image 200-1 except the dialog box can be limited to a three-dimensional display area 101b.

Although FIG. 3B shows an example of identifying an area where text content is located as a two-dimensional display area, this is merely exemplary, and multiple types of two-dimensional display content can be predefined as needed. For example, special shapes (such as squares, triangles, circles, and other geometric figures) present in the display image can be pre-set as content to be displayed in two dimensions. In addition, specific objects such as traffic lights, traffic signs, and road signs can also be pre-set as content to be displayed in two dimensions. The examples of two-dimensional display content in this application are not limited to the above examples. In addition, it should be noted that the pre-setting of two-dimensional display content does not require only one of the above examples to be set. For example, one or more of text, geometric shapes, and road signs can be set as content to be displayed in two dimensions at the same time as needed. In this case, the hybrid backlight 100 described in this application will determine, based on the specific content of the displayed image, that an area including one or more contents such as text, geometric shapes, and road signs will be displayed in a two-dimensional form.

In this article, the term "three-dimensional display area" refers to a display area used to display three-dimensional image content or to display image content in a three-dimensional manner. It should be noted that the "three-dimensional display area" and the above-mentioned "two-dimensional display area" are complementary. For example, taking the image 200-1 in Figure 3B as an example, once the two-dimensional display area in the image 200-1 is determined to be the area 101a where the dialog box is located, it means that the other areas in the image 200-1 except the area 101a are used as the three-dimensional display area. In addition, since the two-dimensional display area changes dynamically with the image to be displayed, on the contrary, the three-dimensional display area also changes adaptively with the image to be displayed.

The above referenced FIG. 3A and FIG. 3B show a hybrid backlight 100 having a two-dimensional and three-dimensional display area. It should be understood that the two-dimensional and three-dimensional display areas of the hybrid backlight 100 described above are described for the hybrid backlight 100 in a working state, rather than for the hybrid backlight in a non-working state. In essence, when the hybrid backlight is in a non-working state, that is, when no image is displayed, the two-dimensional and three-dimensional display areas described above are obviously non-existent, because the two-dimensional and three-dimensional display areas are dynamically formed based on the content of the image to be displayed, and as the displayed image changes, the two-dimensional and three-dimensional display areas in the hybrid backlight 100 also change dynamically following the image content.

The working principle of the hybrid backlight 100 will be described below in conjunction with the perspective view of FIG3C . It should be noted that, for ease of description, the perspective view of FIG3C also shows other elements besides the hybrid backlight 100, such as the light valve array 106 for modulating the light emitted by the hybrid backlight 100, and the multi-visual image 200-2 displayed thereby.

According to various embodiments, the emitted light provided by the hybrid backlight 100 can be used to illuminate an electronic display using the hybrid backlight 100. For example, the emitted light can enter a light valve array 106 (as shown in FIG. 3C ) of the electronic display for modulation. In addition, as described below, an electronic display using or illuminated by the hybrid backlight 100 can be configured to selectively display a two-dimensional image in each of a plurality of different regions of the electronic display corresponding to a plurality of dimming unit regions 101 using the emitted light. It can be determined by selecting to emit a wide-angle emitted light in a specific region to display a two-dimensional image in the region, and display a three-dimensional image in the remaining regions.

As shown in FIG3C , the hybrid backlight 100 includes a wide-angle backlight 110 and a multi-view backlight 120. The multi-view backlight 120 is disposed on the light-emitting surface (the upper surface as shown in the figure) of the wide-angle backlight 110. The wide-angle backlight 110 has a plurality of dimming unit areas 101. When displaying an image, one or more dimming unit areas of the plurality of dimming unit areas 101 are configured to be selectively driven, thereby providing wide-angle emitted light 102' independently of each other.

In some embodiments, the hybrid backlight 100 may further include a dimming controller (not shown). The dimming controller is configured to determine one or more regions where specific content is located based on the display content of the multi-video image, and determine one or more dimming unit regions to be driven in the wide-angle backlight according to the determined one or more regions. For example, in the example shown in FIG. 3C , the dimming controller identifies the region 201 where the text "Hello" in the image 200-2 is located as a two-dimensional display region, and determines the dimming unit region 101 to be driven in the wide-angle backlight 110 according to the region 201 where the text "Hello" is located. It should be noted that the region 201 in the image 200-2 should be aligned with the dimming unit region 101 in the wide-angle backlight 110.

As described above, the two-dimensional display area in the hybrid backlight 100 corresponds to one or more areas where specific content in the multi-visual image to be displayed is located. For example, for image 200-2, if it is determined that the area that needs to be displayed in a two-dimensional manner is the square area 201 where the text "Hello" is located, then the dimming unit area 101 corresponding to the area 201 in the wide-angle backlight (the dimming unit area 101 highlighted in the wide-angle backlight 110) can be correspondingly determined as the activation area to be driven and emit wide-angle emission light 102', and the remaining dimming unit areas that do not correspond to the area 201 are determined as non-activation areas that do not need to be driven and do not emit wide-angle emission light 102'.

It should be noted that the multi-view backlight 120 is transparent or at least substantially transparent to the wide-angle emitted light 102' emitted by the dimming unit area 101. That is, the wide-angle emitted light 102' can penetrate the multi-view backlight 120 and enter the light valve array 106 for modulation, and the specific details will be discussed later.

While the dimming unit area 101 in the wide-angle backlight 110 emits wide-angle emitted light 102', the multi-view backlight provides a plurality of directional light beams 102", the directions of which correspond to different video directions of the multi-view image, which details have been described in detail in FIG. 1A and will not be repeated here. In contrast, the wide-angle emitted light 102' is generally non-directional, and its cone angle is typically larger than the cone angle of the multi-view image or the video of the multi-view display associated with the hybrid backlight 100.

When the wide-angle backlight 110 and the multi-view backlight 120 emit light at the same time, the multiple directional light beams 102" provided by the multi-view backlight 120 and the wide-angle emitted light 102' provided by one or more dimming unit areas driven in the wide-angle backlight 110 are jointly provided to the square area 201 where the text "Hello" is located in the multi-view image 200-2, thereby realizing a two-dimensional display of the text "Hello". It should be understood that, although the wide-angle emitted light 102' and the directional light beam 102" act on the square area 201 where the text "Hello" is located at the same time, the actual display effect is still dominated by the two-dimensional display, and the three-dimensional display effect produced by the directional light beam 102" can be ignored. Therefore, the "two-dimensional display" described in this article can also be called "quasi-two-dimensional display", which is essentially the superposition of the effects of three-dimensional display and two-dimensional display. Since the effect of three-dimensional display can be completely ignored from a visual point of view, we will refer to the "quasi-two-dimensional display" as "two-dimensional display".

In contrast, for the other areas of the multi-view image 200-2 except the square area 201 where the text "Hello" is located, since the corresponding multiple dimming unit areas in the wide-angle backlight 110 are in an inactive and non-luminous state, only the directional light beam 102" provided by the multi-view backlight 120 acts on the other areas, and these display areas (for example, the area where the smiling face is located in the image 200-2) are displayed in a true three-dimensional manner.

In various embodiments, the wide-angle backlight 110 may include a light source (not shown), and the multi-view backlight 120 may also include a light source (not shown). Specifically, the plurality of dimming unit areas of the wide-angle backlight 110 may include a corresponding plurality of light sources, and the multi-view backlight 120 may include a single light source. The plurality of light sources of the wide-angle backlight are configured to selectively turn on to provide light to the plurality of dimming unit areas. In these embodiments, the respective activation of the plurality of light sources may be configured to illuminate a corresponding one of the plurality of dimming unit areas.

Furthermore, it should be understood that although the plurality of directional light beams 102" are shown as arrows diverging in various directions in FIG. 3C, and the wide-angle emitted light 102' is shown as two parallel arrows, this is merely schematic and does not represent the actual direction of the light. For example, the plurality of diverging arrows representing the plurality of directional light beams 102" may be viewed as individual light beams pointing in different visual directions, and each arrow may be viewed as a cluster of light beams in each direction. Similarly, although the two arrows representing the wide-angle emitted light 102' are shown as parallel arrows perpendicular to the light valve array 106, they represent wide-angle emitted light or diffuse light having a certain conical angle range, rather than vertical light beams that are truly perpendicular to the light valve array 106, as defined above. For example, the wide-angle emitted light 102' is substantially non-directional and has a cone angle that is typically greater than the cone angle of a multi-view image or a multi-view display associated with the hybrid backlight 100.

4 to 6 show cross-sectional views of a hybrid backlight 100 according to an embodiment of the present application. For example, the cross-sectional views shown in FIGS. 4 to 6 may represent a cross-sectional view cut from the middle of the hybrid backlight 100. In addition, as an example and not a limitation, the emitted light 102 provided by the hybrid backlight 100 is shown using solid arrows, wherein the wide-angle emitted light 102' emitted by the wide-angle backlight 110 is shown using dashed arrows, and the directional light beam 102" emitted by the multi-view backlight 120 is shown as a plurality of arrows representing a plurality of directional light beams.

As shown in FIG4 , the hybrid backlight 100 is configured to provide wide-angle emitted light 102’ using a plurality of dimming unit areas. Specifically, FIG4 shows the wide-angle emitted light 102’ emitted from all dimming unit areas of the wide-angle backlight 110. In addition, the wide-angle emitted light 102’ is shown to pass through the multi-vision backlight 120 to be emitted from the hybrid backlight 100. Thus, in FIG4 , as shown by the cross-hatching, the lower surface of the wide-angle backlight 110 is arranged with a first light source 112, and the first light source 112 includes a plurality of light-emitting units corresponding one-to-one to all dimming unit areas of the wide-angle backlight 110. As shown in FIG4 , all the light-emitting units of the first light source 112 are activated, and all the dimming unit areas of the wide-angle backlight 110 are also activated.

In FIG4 , a second light source 122 is disposed on one side of the multi-view backlight 120. In the example shown in FIG4 , the second light source 122 is not filled with cross-hatching, which means that the second light source 122 is in an inactive state, so the second light source 122 does not emit light and the multi-view backlight 120 does not emit a directional light beam at this time. Note that the situation shown in FIG4 may correspond to a situation where all areas in the image need to be displayed in two dimensions, for example, all areas in the image are composed of text content.

On the other hand, as shown in FIG5 , the hybrid backlight 100 is configured to provide a directional light beam 102”. In FIG5 , as shown by the cross-hatching, the second light source 122 of the multi-vision backlight 120 is activated, and the entire area of the multi-vision backlight 120 provides the directional light beam 102”. In FIG5 , the plurality of light-emitting units of the first light source 112 of the wide-angle backlight 110 are not filled with the cross-hatching, meaning that the first light source 112 of the wide-angle backlight 110 is turned off, and therefore none of the dimming unit areas of the wide-angle backlight 110 emit light. Note that the situation shown in FIG5 may correspond to a situation where all areas in an image need to be displayed in three dimensions, for example, no area in the image contains text content or geometric graphic content, etc.

Figure 6 shows a diagram of an example in which the hybrid backlight 100 is configured to provide both a directional light beam 102" and a wide-angle emitted light 102', that is, an example in which a portion of the dimming unit area in the wide-angle backlight 110 emits light simultaneously with the multi-view backlight 120. For example, as shown by the cross-hatching, the second light source 122 of the multi-view backlight 120 is activated, and the entire area of the multi-view backlight 120 provides a directional light beam 102". In Figure 6, one light-emitting unit (for example, light-emitting unit 112-1) of the first light source 112 of the wide-angle backlight 110 is filled with hatching, meaning that the light-emitting unit 112-1 is activated, and the dimming unit area corresponding to the light-emitting unit 112-1 in the wide-angle backlight is illuminated and emits wide-angle emitted light 102'. At the same time, the remaining light-emitting units in the first light source 112 are not filled with shadow lines, which means that the remaining light-emitting units are not activated and do not emit light, so the dimming unit area corresponding to the remaining light-emitting units in the wide-angle backlight does not emit light. It should be understood that the dimming regional unit corresponding to the light-emitting unit 112-1 and the light valve in the light valve array corresponding to the dimming regional unit should correspond to the two-dimensional display area in the multi-visual image as described above. In FIG. 6 , for a clearer representation, the corresponding areas are highlighted differently from other areas.) Note that the situation shown in FIG. 6 may correspond to a situation in which the image includes both two-dimensional display content such as text and three-dimensional display content, for example, image 200-1 and image 200-2 shown in FIGS. 3B to 3C .

It should be understood that, although the light source 112 is shown as being separated from the wide-angle backlight 110 in FIGS. 4 to 6 , in practice, the light source 112 may also be integrated into the wide-angle backlight 110. For example, the wide-angle backlight 110 may be a planar backlight that directly emits light or directly illuminates, which will be described in detail later.

According to various embodiments, the wide-angle backlight 110 can be substantially any backlight having a plurality of separately activated regions. Fig. 7 shows a schematic diagram of a wide-angle backlight 110 according to an embodiment in accordance with principles of the present application.

For example, the wide-angle backlight 110 can be a planar backlight that directly emits light or directly illuminates, which is divided into separate areas that can be activated separately, referred to as dimming unit areas 101 in this application. Planar backlights that directly emit light or directly illuminate include, but are not limited to, backlight panels that use a planar array of cold cathode fluorescent lamps (CCFLs), neon lamps, or light-emitting diodes (LEDs), which are configured to directly illuminate a planar light-emitting surface 110' and provide wide-angle emitted light 102' (as shown in Figure 4). An electroluminescent panel is another non-limiting example of a planar backlight that directly emits light. In other examples, the wide-angle backlight 110 may include a backlight that is divided into a plurality of separate areas, each area using a separate indirect light source. Such indirectly lit backlights may include, but are not limited to, various forms of edge-coupled backlights or so-called "side-lit" backlights.

4 to 6, in some embodiments, for example, as shown, the multi-view backlight 120 can further include a light guide 124. According to various embodiments, the light guide 124 is configured to guide light as the guided light 104. In some embodiments, the light guide 124 can be a flat light guide.

According to various embodiments, the light guide 124 is configured to guide the guided light 104 within the light guide 124 along the length of the light guide 124 according to total internal reflection. The overall propagation direction 103 of the guided light 104 within the light guide 124 is shown by the thick arrows in Figures 5-6. In some embodiments, as shown in Figure 5, the guided light 104 can be guided in the propagation direction 103 at a non-zero propagation angle and can include collimated light collimated according to a predetermined collimation factor σ.

Referring again to Figures 4 to 6, for example, as shown in the figures, the multi-view backlight 120 can further include an array of multi-beam elements 126. According to various embodiments, the multi-beam elements 126 in the array of multi-beam elements 126 are spaced apart from each other on the light guide 124. For example, in some embodiments, the multi-beam elements 126 can be arranged in a one-dimensional (1D) array. In other embodiments, the multi-beam elements 126 can be arranged in a two-dimensional (2D) array. In addition, different types of multi-beam elements 126 can be used in the multi-view backlight 120, including but not limited to active emitters and various scattering elements. According to various embodiments, each multi-beam element 126 in the array of multi-beam elements 126 is configured to provide a beam in the directional beam 102", which has a direction corresponding to a different video direction of the multi-view image.

According to various embodiments, as shown in FIG. 5 , each multi-beam element 126 in the multi-beam element array is configured to scatter a portion of the guided light 104 from the light guide 124 and guide the scattered portion away from the first surface 124′ of the light guide 124 to provide a directional light beam 102″. For example, a portion of the guided light may be scattered out of the first surface 124′ by the multi-beam element 126. In addition, according to various embodiments, as shown in FIGS. 4 to 6 , a second surface 124″ of the multi-view backlight 120 opposite to the first surface may be adjacent to the light emitting surface 110′ of the wide-angle backlight 110.

It should be noted that, as described above, as shown in Figure 5, the multiple beams of the directional light beams 102" are multiple directional light beams with different main angular directions. In addition, the multi-view backlight 120 can be substantially transparent to allow the wide-angle emitted light 102' from the wide-angle backlight 110 to pass through or transmit through the thickness of the multi-view backlight 120, as shown by the dotted arrow in Figure 4, which starts from the wide-angle backlight 110 and then passes through the multi-view backlight 120. In other words, the wide-angle emitted light 102' provided by the wide-angle backlight 110 is configured to be transmitted through the multi-view backlight 120, for example, based on the transparency of the multi-view backlight 120.

For example, the light guide 124 and the plurality of spaced-apart multi-beam elements 126 may allow wide angle emitted light 102' to pass through both the second surface 124" and the first surface 124' and through the light guide 124. Due to the relatively small size of the multi-beam elements 126 and the relatively large inter-element spacing of the multi-beam elements 126, transparency may be enhanced. In addition, when the multi-beam elements 126 include a diffraction grating as described below, in some embodiments, the multi-beam elements 126 may also be substantially transparent to light that is guided orthogonally to the light guide surface 124' and the light guide surface 124". Thus, for example, according to various embodiments, light from a wide angle backlight 110 may pass through the light guide 124 of a multi-vision backlight 120 having an array of multi-beam elements in an orthogonal direction.

As described above, the multi-vision backlight 120 includes a second light source 122. For example, the multi-vision backlight 120 can be a side-lit backlight. According to various embodiments, the light source 122 is configured to provide light guided within the light guide 124 as the guided light 104. Specifically, the light source 122 can be located adjacent to an entrance surface or an entrance end (input end) of the light guide 124. In various embodiments, the light source 122 can include substantially any type of light source (e.g., an optical emitter) including one or more light emitting diodes (LEDs) or lasers (e.g., laser diodes), but is not limited thereto. In some embodiments, the light source 122 can include an optical emitter configured to generate substantially monochromatic light having a narrow spectrum representing a specific color. Specifically, the color of the monochromatic light can be a primary color of a specific color space or a specific color model (e.g., a red-green-blue (RGB) color model). In other examples, the light source 122 can be a basic broadband light source configured to provide basically broadband or polychromatic light. For example, the light source 122 can provide white light. In some embodiments, the light source 122 can include a plurality of different optical emitters configured to provide different colors of light. The different optical emitters can be configured to provide light having different, color-specific, non-zero propagation angles corresponding to each of the different colors of light. As shown in FIG. 5 using cross-hatching, activation of the multi-vision backlight 120 can include a post-activated light source 122.

In some embodiments, the light source 122 may further include a collimator (not shown). The collimator may be configured to receive substantially non-collimated light from one or more optical emitters of the light source 122. The collimator is further configured to convert the substantially non-collimated light into collimated light. Specifically, according to some embodiments, the collimator may provide collimated light having a non-zero propagation angle and collimated according to a predetermined collimation factor. In addition, when optical emitters of different colors are used, the collimator may be configured to provide collimated light having different, color-specific non-zero propagation angles. The collimator is further configured to emit the collimated light into the light guide 124 to guide it as guided light 104, as described above.

As described above, according to various embodiments, the multi-view backlight 120 includes an array of multi-beam elements 126. According to some embodiments (e.g., as shown in FIGS. 4 to 6 ), the multi-beam elements 126 in the array of multi-beam elements 126 may be located at the first surface 124 ′ of the light guide 124 (e.g., adjacent to the first surface 124 ′ of the multi-view backlight 120). In other embodiments (not shown in the figures), the multi-beam elements 126 may be located within the light guide 124. In other embodiments (not shown), the multi-beam element 126 can be located at or on the second surface 124″ of the light guide 124 (e.g., adjacent to the second surface of the multi-vision backlight 120). In addition, the size of the multi-beam element 126 is comparable to the size of a light valve of a multi-vision display configured to display multi-vision images. For example, the size of each multi-beam element in the multi-beam element array can be between one-quarter and twice the size of the light valve in the light valve array.

As an example and not a limitation, FIGS. 4 to 6 also illustrate an array of light valves 106 (e.g., an array of a multi-vision display). In various embodiments, any of different types of light valves may be used as the light valves 106 in the array of light valves 106, including but not limited to liquid crystal light valves, electrophoretic light valves, and electrorepellent light valves. In addition, as shown, for each multi-beam element 126 in the array of multi-beam elements 126, there may be a unique set of light valves 106. For example, the unique set of light valves 106 may correspond to the multi-vision pixels 106' of the multi-vision display.

In this document, "size" may include but is not limited to any of length, width, or area. For example, the size of the light valve may be its length, and the size of the multi-beam element 126 may also be the length of the multi-beam element 126. In another example, the size may be its area, so that the area of the multi-beam element 126 may be equivalent to the area of the light valve. In some embodiments, the size of the multi-beam element 126 may be equivalent to the size of the light valve, and the size of the multi-beam element is between twenty-five percent (25%) and two hundred percent (200%) of the size of the light valve. For example, if the multi-beam element size is labeled as "s" as shown in Figures 5-6 and the light valve size is labeled as "S", the size s of the multi-beam element can be given by equation (2), which is (2)

In other examples, the multi-beam element size is larger than approximately fifty percent (50%) of the size of the light valve, or larger than approximately sixty percent (60%) of the size of the light valve, or larger than approximately seventy percent (70%) of the size of the light valve, or larger than approximately eighty percent (80%) of the size of the light valve, or larger than approximately ninety percent (90%) of the size of the light valve, and the multi-beam element is smaller than approximately one hundred and eighty percent (180%) of the size of the light valve, or smaller than approximately one hundred and sixty percent (160%) of the size of the light valve, or smaller than approximately one hundred and forty percent (140%) of the size of the light valve, or smaller than approximately one hundred and twenty percent (120%) of the size of the light valve. According to some embodiments, the relative sizes of the multi-beam element 126 and the light valve can be selected with the goal of minimizing dark areas between videos of the multi-video display in some embodiments, while the overlap between multiple videos of the multi-video display or equivalent multi-video images can be reduced or minimized in some examples.

According to various embodiments, the multi-beam element 126 of the multi-vision backlight 120 may include any of a plurality of different structures configured to scatter out a portion of the guided light 104. For example, the different structures may include, but are not limited to, diffraction gratings, micro-reflection elements, micro-refractive elements, or various combinations thereof. In some embodiments, the multi-beam element 126 including the diffraction grating is configured to diffractively couple out or diffractively scatter out a portion of the guided light as directionally emitted light including a plurality of directional light beams having different primary angular directions. In some embodiments, the diffraction grating of the multi-beam element may include a plurality of separate sub-gratings. In other embodiments, the multi-beam element 126 includes a micro-reflection element that is configured to reflectively couple out or scatter out a portion of the guided light as a plurality of directional light beams. Alternatively, the multi-beam element 126 includes a micro-refractive element that is configured to couple out or scatter a portion of the guided light as a plurality of directional beams (ie, refractively scatter a portion of the guided light) by or using refraction.

FIG8 illustrates a cross-sectional view of a portion of a multi-vision backlight 120 including a multi-beam element 126 according to an embodiment of the present application principles. Specifically, FIG8 shows a multi-vision backlight 120 including a diffraction grating 126a. The diffraction grating 126a is configured to diffractively couple out or scatter out a portion of the guided light 104 as a plurality of directional light beams 102". The diffraction grating 126a includes a plurality of diffraction features separated from each other by diffraction feature spacings (or grating spacings), which are configured to diffractively couple out a portion of the guided light. According to various embodiments, the diffraction feature spacings or grating spacings of the diffraction grating 126a are 1/4" long. The diffraction grating 126a of the multi-beam element 126 may be a sub-wavelength (i.e., less than the wavelength of the guided light 104). In various embodiments, the diffraction grating 126a of the multi-beam element 126 may be located at or near a surface of the light guide 124, while in other embodiments, the diffraction grating 126a may be disposed between the guiding surfaces of the light guide 124. For example, as shown in FIG. 8 , the diffraction grating 126a may be at or near the second surface 124″ of the light guide 124.

In some embodiments, the diffraction grating 126a of the multi-beam element 126 is a uniform diffraction grating, wherein the diffraction feature spacing is substantially constant or invariant throughout the diffraction grating 126a. In other embodiments, the diffraction grating 126a can be a chirped diffraction grating. A "chirped" diffraction grating is defined as a diffraction grating having a diffraction spacing (i.e., grating spacing) of diffraction features that varies over the range or length of the chirped diffraction grating. In some embodiments (not shown), the diversion grating 126a may include a plurality of diversion gratings or an array of diversion gratings or equivalently a plurality of sub-gratings or an array of sub-gratings. In addition, according to some embodiments, the density difference of the sub-gratings within the diversion grating 126a can be configured to control the relative intensity of the directional light beam 102".

FIG9 shows a cross-sectional view of a portion of a multi-vision backlight 120 including a multi-beam element 126 according to an embodiment of the present application principles. Specifically, FIG9 shows an embodiment of a multi-beam element 126 including a micro-reflective element 126b. The plurality of micro-reflective elements in the beam element 126 may include, but are not limited to, a reflector using a reflective material (e.g., a reflective metal) or a film thereof, or a total internal reflection (TIR) reflector.

FIG10 illustrates a cross-sectional view of a portion of a multi-vision backlight 120 including a multi-beam element 126 according to an embodiment in accordance with the principles of the present application. Specifically, FIG10 shows a multi-beam element 126 including micro-refractive elements 126 c that are configured to refractively couple out or scatter a portion of the guided light 104 from the light guide 124 according to various embodiments. As shown in FIG. 10 , the micro-refractive element 126 c is configured to employ refraction to couple out or scatter a portion of the guided light from the light guide 124 as a directional light beam 102″ including a plurality of light beams. The micro-refractive element 126 c may have various shapes, including but not limited to a semicircular shape, a rectangular shape, or a prismatic shape. According to various embodiments, the micro-refractive element 126 c may extend or protrude from a surface (e.g., as shown, the first surface 124 ′) of the light guide 124, as shown, or may be a cavity in the surface (not shown). Further, in some embodiments, the micro-refractive element 126 c may include the material of the light guide 124. In other embodiments, the micro-refractive element 126 c may include another material adjacent to the surface of the light guide. And in some examples, the micro-refractive element 126 c may include another material in contact with the surface of the light guide.

According to some embodiments of the principles described herein, the present invention provides a hybrid display. The hybrid display has a plurality of different display areas, which are configured to emit modulated light on a region basis. The hybrid display in the present application divides the display area into a plurality of different areas for different contents in the same displayed image, for example, a two-dimensional display area for displaying an image in two dimensions, and a three-dimensional display area for displaying an image in three dimensions. For example, the three-dimensional display area can display the image content in a stereoscopic manner or in a multi-vision manner. The two-dimensional display area can display the image content in two dimensions in a manner showing a higher resolution, which is more suitable for displaying text and other 2D information, which may be blurred or cause blur when displayed in three dimensions. In addition, the hybrid display can be configured to selectively display the image content in two dimensions in each of the plurality of different areas. According to various embodiments, the display method in a specific area can be determined by selecting to emit wide-angle emitted light or directional light beams in the area.

FIG. 11 shows a block diagram of a hybrid display 2000 according to an embodiment of the present application. According to various embodiments, the hybrid display 2000 shown in FIG. 11 can be used to selectively present part of the content in the displayed image in two dimensions, and present the rest of the content in the displayed image in three dimensions. For example, the hybrid display 2000 can present the text, special geometric shapes and other contents in the displayed image in two dimensions, and present other image contents in three dimensions. For the convenience of description, FIG. 11 shows a 2D area that presents graphic content in two dimensions, and shows a 3D area that presents content in three dimensions. However, it should be understood that the position of the 2D area in the hybrid display 2000 is not fixed, but changes dynamically based on the content of the image to be displayed, and the number of 2D areas is not fixed, but can change dynamically with the content of the image to be displayed. For example, the number of 2D areas can be one, two, or even more. This feature has been described in detail in the previous text in conjunction with Figures 3A-3B, and will not be repeated here.

As shown in FIG11 , the hybrid display 2000 is configured to emit modulated emitted light 202, which includes modulated wide-angle emitted light 202' of 2D pixels representing 2D image content, and includes modulated directional light beams 202" of 3D pixels representing 3D image content. In addition, according to various embodiments, the hybrid display 2000 can selectively emit both the modulated wide-angle emitted light 202' and the modulated directional light beams 202" in the 2D area as shown in the figure on a region basis. At the same time, the hybrid display 2000 can emit only the modulated directional light beams 202" in the 3D area other than the 2D area.

As shown in FIG. 11 , the hybrid display 2000 includes a wide-angle backlight 210. A portion of the dimming unit region in the wide-angle backlight 210 (e.g., the region indicated by the dashed box in the wide-angle backlight) selectively illuminates the 2D display region of the hybrid display 2000 with wide-angle emitted light 204. In some embodiments, as described above, the wide-angle backlight 210 may be substantially similar to the wide-angle backlight 110 of the hybrid backlight 100 described above. For example, it may emit wide-angle emitted light 204 to illuminate one or more 2D regions of the hybrid display 2000 according to the content of the image to be displayed. Although FIG. 11 shows a 2D display area at a fixed position, it should be understood that the hybrid display 2000 may include more 2D display areas, and the position of the 2D display area changes dynamically with the content of the displayed image.

The hybrid display 2000 shown in FIG11 further includes a multi-view backlight 220. The multi-view backlight 220 is configured to illuminate the entire area of the hybrid display 2000 using a directional light beam 206 including a plurality of light beams. Therefore, the 3D area shown in FIG11 is illuminated only by the modulated directional light beam 202" emitted by the multi-view backlight 220. In contrast, the 2D area shown in FIG11 is illuminated jointly by the modulated directional light beam 202" and the modulated wide-angle emitted light 202'. It should be understood that the 3D area shown in FIG11 is the entire remaining area of the hybrid display 2000 except for the 2D area. In some embodiments, the multi-view backlight 220 may be substantially similar to the multi-view backlight 120 of the hybrid backlight 100 described above. For example, the multi-view backlight 220 may emit directional light beams 206 to illuminate the entire area of the hybrid display 2000.

In some embodiments, as shown in the example of FIG11 , the multi-view backlight 220 includes a light guide 222 and an array of spaced-apart multi-beam elements 224. The array of multi-beam elements 224 is configured to scatter the guided light from the light guide 222 into directional light beams 206. According to various embodiments, when a multi-view image is displayed, the directional light beams 206 provided by a single multi-beam element 224 in the array of multi-beam elements 224 include a plurality of directional light beams having different primary angular directions corresponding to the viewing direction of the multi-view image displayed by the hybrid display 2000. In some embodiments, the light guide 222 and the multi-beam element 224 can be substantially similar to the light guide 124 and the multi-beam element 126, respectively, described above.

Furthermore, according to various embodiments, the multi-beam elements 224 in the array of multi-beam elements 224 may include one or more of a diffraction grating, a micro-reflection element, and a micro-refractive element optically connected to the light guide 222 to scatter the guided light into the directional light beam 206.

As shown in FIG11 , the hybrid display 2000 further includes a light valve array 230. The light valve array 230 is configured to modulate the wide-angle emitted light 204 using the light valve set corresponding to the 2D area to achieve a two-dimensional display of the content. The light valve array 230 is also configured as a whole to modulate the directional light beam 206 to achieve a three-dimensional display of the content. Specifically, the light valve set corresponding to the 2D area in the light valve array 230 is configured to receive and modulate the wide-angle emitted light 204 to provide modulated wide-angle emitted light 202'. Similarly, the light valve array 230 is also generally configured to receive and modulate the directional light beam 206 to provide a modulated directional light beam 202". In some embodiments, the light valve array 230 can be substantially similar to the array of light valves 106 described above with respect to the hybrid backlight 100. For example, the light valves in the light valve array can include liquid crystal light valves. Furthermore, in some embodiments, the size of the multi-beam elements 224 in the array of multi-beam elements 224 can be comparable to the size of the light valves of the light valve array 230 (e.g., between one-quarter and twice the size of the light valves).

According to some embodiments (not shown), the hybrid display 2000 further includes a plurality of light sources. According to some embodiments, the plurality of light sources are configured to provide light to be guided within a light guide of the wide-angle backlight 210 or the multi-vision backlight 220 as guided light. For example, each of the plurality of light sources can be optically connected to provide light to the light guide 222 of the multi-vision backlight 220, or equivalently to the light guide of the wide-angle backlight 210. In some embodiments, the light sources in the plurality of light sources of the hybrid display can be substantially similar to the first light source 112 and the second light source 122 described above with respect to the hybrid backlight 100.

According to some embodiments (not shown), the hybrid display 2000 further includes a dimming driver (not shown), which is configured to drive one or more light-emitting units to be driven in the first light source to illuminate one or more dimming unit areas in the wide-angle backlight 210.

According to other embodiments of the principles described herein, the present invention provides a method for operating a hybrid backlight. FIG. 12 shows a flow chart of a method 3000 for operating a hybrid backlight according to an embodiment of the principles of the present application. As shown in FIG. 12 , the method for operating a hybrid backlight includes a step (S310) of providing wide-angle emitted light using one or more dimming unit regions in a wide-angle backlight. According to various embodiments, when activated, each dimming unit region provides wide-angle emitted light, respectively. In some embodiments, as described above, the wide-angle backlight can be substantially similar to the wide-angle backlight 110 of the hybrid backlight 100.

The operating method 3000 of the hybrid backlight also includes providing a plurality of directional light beams using a multi-view backlight (S320). The directional light beams have a main angular direction corresponding to different video directions of the multi-view image. According to some embodiments, the directional light beams include a plurality of directional light beams, which can be provided by each multi-beam element in the multi-beam element array. Specifically, according to various embodiments, the directions of the directional light beams in the plurality of directional light beams correspond to different video directions of the multi-view image. In some embodiments, the multi-view backlight can be substantially similar to the multi-view backlight 120 of the hybrid backlight 100 described above.

In some embodiments, the step of providing a plurality of directional light beams further includes: directing the light as guided light in a light guide, and scattering a portion of the guided light using a multi-beam element in an array of multi-beam elements (not shown). In addition, in some embodiments, each multi-beam element in the array of multi-beam elements may include one or more of a diffraction grating, a micro-refractive element, and a micro-reflective element. In some embodiments, the multi-beam elements in the array of multi-beam elements may be substantially similar to the multi-beam elements 126 described above with respect to the multi-vision backlight 120. In addition, the light guide may also be substantially similar to the light guide 124 described above. In some embodiments, the method 3000 of operating a hybrid backlight may further include the step of providing light to the light guide (not shown), as described above, and the guided light in the light guide is collimated according to a predetermined collimation factor.

According to some embodiments, the method 3000 of operating the hybrid backlight may further include a step of modulating the wide-angle emitted light and the plurality of directional light beams using a light valve array (S330). In some other embodiments, the size of the multi-beam elements in the multi-beam element array may be configured to be between one quarter and two times the size of the light valves in the light valve array. In some embodiments, the light valve array may be substantially similar to the array of light valves 106 described above with respect to the hybrid backlight 100.

So far, the present invention has described examples and embodiments of a hybrid backlight, a hybrid display, and an operating method of a hybrid backlight that mixes display image content in a two-dimensional plus three-dimensional manner according to the content of the displayed image. It should be understood that the above examples and embodiments only describe some of the many specific examples that represent the principles described herein. Obviously, a person skilled in the art can easily design many other arrangements without departing from the scope and spirit of the present application, and the arrangements also fall within the scope of protection of the present application.

This application claims priority to International Patent Application No. PCT/US2021/123026 filed on October 11, 2021, the entire text of each of which is incorporated herein by reference.

10: display 12: screen 14: video 16: video direction 20: light beam 30: diffraction grating 40: light guide 50: incident light beam 60: directional light beam 100: hybrid backlight 101a: area 101a-1: two-dimensional display area 101a-2: two-dimensional display area 101b: three-dimensional display area 101: dimming unit area 102: emitted light 102': wide-angle emitted light 102": directional light beam 103: propagation direction 104: guided light 106: light valve array 110: wide-angle backlight 110': luminous surface 112: first light source 112-1: light emitting unit 120: multi-view backlight 122: second light source 124: light guide 124': first surface 124": second surface 126: multi-beam element 126a: diffraction grating 126b: micro-reflection element 126c: micro-refractive element 200-1: image 200-2: image 201: region 202: emitted light 202': wide-angle emitted light 202": directional light beam 204: wide-angle emitted light 206: directional light beam 210: wide-angle backlight 220: multi-view backlight 222: light guide 224: multi-beam element 230: light valve array 2000: hybrid display 3000: Method O: Origin S: Dimension S310: Step S320: Step S330: Step s: Dimension θ: Angular component, elevation component, elevation angle θi: Incident angle θm: Diffraction angle σ: Collimation factor φ: Angular component, azimuth component, azimuth angle

Various features of examples and embodiments according to the principles described herein may be more readily understood with reference to the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals denote like structural elements, and wherein: FIG. 1A shows a perspective view of a multi-vision display according to an embodiment of the principles of the present application. FIG. 1B shows a schematic diagram of an angular component of a light beam having a particular primary angular direction according to an embodiment of the principles of the present application. FIG. 2 shows a cross-sectional view of a diffraction grating according to an embodiment of the principles of the present application. FIG. 3A shows a plan view of a hybrid backlight according to an embodiment of the principles of the present application. FIG. 3B shows a plan view of a hybrid backlight according to an embodiment of the principles of the present application. FIG. 3C shows a perspective view of a hybrid backlight according to an embodiment of the principles of the present application. FIG. 4 shows a cross-sectional view of a hybrid backlight according to an embodiment of the principles of the present application. FIG. 5 shows a cross-sectional view of a hybrid backlight according to an embodiment of the present application. FIG. 6 shows a cross-sectional view of a hybrid backlight according to an embodiment of the present application. FIG. 7 shows a schematic diagram of a wide-angle backlight according to an embodiment of the present application. FIG. 8 shows a cross-sectional view of a portion of a multi-vision backlight including a multi-beam element according to an embodiment of the present application. FIG. 9 shows a cross-sectional view of a portion of a multi-vision backlight including a multi-beam element according to an embodiment of the present application. FIG. 10 shows a cross-sectional view of a portion of a multi-vision backlight including a multi-beam element according to an embodiment of the present application. FIG. 11 shows a block diagram of a hybrid display according to an embodiment of the present application. FIG. 12 shows a flow chart of an operating method of a hybrid backlight according to an embodiment of the present application.

100: Hybrid backlight

101: Dimming unit area

102’: Wide-angle emission of light

102”: Directional beam

106: Light valve array

110: Wide-angle backlight

120: Multi-view backlight

200-2: Video

201: Area

Claims (19)

A hybrid backlight comprises: a first backlight having a plurality of dimming unit areas, one or more dimming unit areas of the plurality of dimming unit areas being configured to be selectively driven to provide wide-angle emitted light independently of each other; and a second backlight being configured to provide a plurality of directional light beams, the plurality of directional light beams having directions corresponding to different video directions of a multi-video image, wherein the second backlight is disposed on a light emitting surface of the first backlight and is transparent to the wide-angle emitted light, and the one or more dimming unit areas driven in the first backlight correspond to one or more areas where specific content in the multi-video image is located. As in claim 1, the hybrid backlight, wherein the remaining dimming unit areas in the first backlight that do not correspond to the one or more areas where the specific content in the multi-video image is located are not driven and do not provide the wide-angle emitted light. The hybrid backlight of claim 1 further comprises: a dimming controller configured to determine the one or more regions where the specific content is located based on the displayed content of the multi-video image, and to determine the one or more dimming unit regions driven in the first backlight according to the determined one or more regions. As in claim 3, the hybrid backlight, wherein the multi-video image changes dynamically over time, and the dimming controller dynamically updates the one or more regions where the specific content is located based on the changed display content of the multi-video image. A hybrid backlight as claimed in any one of claims 1 to 4, wherein the second backlight comprises: a light guide configured to guide light as guided light; and a multi-beam element array, each multi-beam element in the multi-beam element array being configured to scatter a portion of the guided light from the light guide as a light beam in the plurality of directional light beams. A hybrid backlight as claimed in claim 5, wherein the light guide is configured to guide the guided light with a predetermined collimation factor as collimated guided light. The hybrid backlight of claim 5, wherein the multi-beam elements in the multi-beam element array include one or more of a diffraction grating, a micro-reflection element, and a micro-refraction element, the diffraction grating is configured to diffractively scatter the portion of the guided light, the micro-reflection element is configured to reflectively scatter the portion of the guided light, and the micro-refraction element is configured to refractively scatter the portion of the guided light. A hybrid display comprises: a first backlight having a plurality of dimming unit areas, wherein one or more dimming unit areas of the plurality of dimming unit areas are configured to be selectively driven to provide wide-angle emitted light independently of each other; a second backlight configured to provide a plurality of directional light beams, wherein the plurality of directional light beams have directions corresponding to different video directions of a multi-video image; and a light valve array configured to modulate the wide-angle emitted light and the plurality of directional light beams. Directional light beams are used to provide the multi-video image including a two-dimensional display area and a three-dimensional display area, wherein the second backlight is disposed on a light-emitting surface of the first backlight and is transparent to the wide-angle emitted light, and the one or more dimming unit areas driven in the first backlight correspond to one or more areas where specific content in the video image is located, and wherein the one or more areas where the specific content is located correspond to the two-dimensional display area. A hybrid display as claimed in claim 8, wherein the area of the multi-video image other than the one or more areas where the specific content is located corresponds to the three-dimensional display area, and the remaining dimming unit areas in the first backlight corresponding to the three-dimensional display area in the multi-video image are not driven and do not provide the wide-angle emitted light. The hybrid display of claim 8 further includes: a dimming controller configured to determine the two-dimensional display area based on the display content of the multi-video image, and determine the one or more dimming unit areas driven in the first backlight of the determined two-dimensional display area. As in claim 10, the hybrid display, wherein the multiple video images dynamically change over time, and the dimming controller dynamically updates the two-dimensional display area and the three-dimensional display area based on the changing display content of the multiple video images. A hybrid display as claimed in any one of claims 8 to 11, wherein the second backlight comprises: a light guide configured to guide light as guided light; and a multi-beam element array, each multi-beam element in the multi-beam element array being configured to scatter a portion of the guided light from the light guide as a light beam in the plurality of directional light beams. A hybrid display as claimed in claim 12, wherein the multi-beam elements in the multi-beam element array include one or more of a diffraction grating, a micro-reflection element and a micro-refraction element, the diffraction grating is configured to diffractively scatter the portion of the guided light, the micro-reflection element is configured to reflectively scatter the portion of the guided light, and the micro-refraction element is configured to refractively scatter the portion of the guided light. The hybrid display of claim 8 further comprises: a first light source comprising a plurality of light-emitting units, the plurality of light-emitting units corresponding to the plurality of dimming unit regions in the first backlight; a dimming driver configured to drive the one or more light-emitting units to be driven to illuminate the one or more dimming unit regions in the first backlight; and a second light source configured to emit light to be guided by a light guide of the second backlight. A method for operating a hybrid backlight comprises: using a first backlight to provide wide-angle emitted light, the first backlight having a plurality of dimming unit areas, one or more dimming unit areas of the plurality of dimming unit areas being selectively driven to provide the wide-angle emitted light independently of each other; and using a second backlight to provide a plurality of directional light beams, the directions of the plurality of directional light beams corresponding to different video directions of a multi-video image, wherein the second backlight is disposed on a light emitting surface of the first backlight and is transparent to the wide-angle emitted light, and the one or more dimming unit areas driven in the first backlight correspond to one or more areas where specific content in the multi-video image is located. As in the method of claim 15, the remaining dimming unit areas in the first backlight that do not correspond to the one or more areas where the specific content in the multi-video image is located are not driven and do not provide the wide-angle emitted light. The method of claim 15 further includes: based on the display content of the multi-video image, using a dimming controller to determine the one or more areas where the specific content is located; and based on the determined one or more areas, using the dimming controller to determine the one or more dimming unit areas driven in the first backlight. The method of claim 15 or 16 further comprises: guiding light in a light guide as guided light; and scattering a portion of the guided light from the light guide as a light beam in the plurality of directional light beams by using each multi-beam element in a multi-beam element array. The method of claim 15 further comprises: using a light valve array to modulate the wide-angle emitted light and the plurality of directional light beams to provide the multi-visual image including a two-dimensional display area and a three-dimensional display area, wherein the one or more areas where the specific content is located correspond to the two-dimensional display area, and the area other than the two-dimensional display area in the multi-visual image corresponds to the three-dimensional display area.