Micro-lens and filter layer for emission control of a curved display

Abstract

A light emitting structure comprising: a pixel layer having at least one sub-pixel; a microlens layer having at least one microlens aligned with the at least one sub-pixel to provide a narrowly confined on-axis emission profile along an on-axis direction; a first and a second filler material layer between the pixel layer and the microlens layer, an interface between the first and the second filler material layer configured to reflect a portion of off-axis emission from the at least one sub-pixel by total internal reflection (TIR).

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to microlens and filter layers for emissive devices, particularly for curved automotive displays. In particular, the present disclosure aims to improve the narrow defined emission profile of curved displays. BACKGROUND

[0002] Screens are becoming more and more prevalent in vehicles, such as cars, and provide functionality such as information, entertainment and navigation. The potential market is huge and display technology offers a way for car manufacturers to differentiate their products. This is a challenging environment as displays are subject to space constraints, environmental heat, electrical interference and ambient lighting from direct sunlight to near complete darkness.

[0003] Displays in vehicles, for example curved displays in the vehicle dashboard area, are becoming more and more prevalent. However, unlike displays used within a fixed enclosure, for example in the home, office etc, curved displays in vehicles can emit light that can distract the vehicle operator. For example, light emitted from a vehicle display can reflect from the side window of the vehicle or the display screen can be too wide to distract the operator, especially at night. It is therefore preferable to prevent light from being emitted towards the driver. Additionally, a passenger next to the vehicle operator can see the screen directly in front of them, some areas of which are prohibited from being seen by the operator. These are some of the reasons why display devices are able to provide a limited emission profile to allow control of the aforementioned challenges.

[0004] One method of applying a narrow emission profile in a display device is a micro-louvre film which uses vertically aligned slats of absorbing material in a transparent medium. Micro-louvre films are effective, but are inefficient and work only in one optical axis, such as the axis normal to the display surface of a flat panel. Furthermore, micro-louvre films restrict light to a symmetrical distribution around the vertical axis. If a micro-louvre film is applied to a curved display, the micro-louvre film will present a varying appearance of brightness to the viewer when viewed from different angles, which is undesirable and only acceptable when the display has low curvature.

[0005] Another method of applying a narrow emission profile is a tri-band filter. Dolby (JP6648065B2) describes a system that uses a curved tri-notch filter to create a stereoscopic image, while Holophane Optical (US5103323A) shows how a tri-notch reflective holographic filter allows laser reflection to a user.

[0006] Micro-lenses that can effectively convert small light sources with a wide divergence into large light sources with a narrower divergence can be another alternative to micro-blinds and tri-films to apply a narrow emission profile. For a display where the pixel emission area is one quarter of the total area, the angular divergence will be halved. However, micro-lenses suffer from secondary emission (secondary windows) where part of the light emission from one pixel enters the micro-lens adjacent to the nearest micro-lens of that pixel. The adjacent micro-lens tends to refract part of the light emission that will exit the adjacent micro-lens at a small angle relative to the display surface of the display and this part of the light emission will reflect off the window and distract the vehicle operator. In addition to secondary emission, tertiary emission (tertiary windows) and above are also possible.

[0007] Another method of controlling the emission profile is to adjust the viewing angle with micro-lenses. For example, Fuji (JP2005070639A) describes how to arrange micro-lenses in an irregular manner to shrink the viewing angle and Am Onar (WO2002059657A1) describes how to provide an autostereoscopic system with micro-lenses that sufficiently shrink the viewing angle.

[0008] In yet another method, secondary color filters are used with a display to control the emission profile. For example, 4D Vision (JP2003521181A) describes how a striped color filter selects light exiting a display and produces an autostereoscopic device.

[0009] Prior art documents

[0010] Patent documents

[0011] Japanese patent number JP6648065B2 (Dolby Laboratories Licensing Corporation, patented February 14, 2020).

[0012] US patent number US5103323A (Holographic Optics Inc, patented April 7, 1992).

[0013] Japanese publication number JP2005070639A (Fuji Photo Film Co Ltd, published March 17, 2005).

[0014] International publication number WO2002 / 059657A1 (AM, Onar, published August 1, 2002).

[0015] Japanese Publication No. JP 2003521181 A (4D-Vision GmbH, published July 8, 2003). SUMMARY

[0016] The present disclosure relates to a curved display having a microlens and filter layer for emission control.

[0017] In a first aspect of the present disclosure, a light emission structure comprises: a pixel layer having at least one sub-pixel; a microlens layer having at least one microlens aligned with the at least one sub-pixel to provide a narrowly confined on-axis emission profile along an on-axis direction; a first filler material layer and a second filler material layer located between the pixel layer and the microlens layer, an interface between the first filler material layer and the second filler material layer being configured for reflecting a portion of off-axis emission from the plurality of sub-pixels by total internal reflection (TIR).

[0018] In an implementation form of the first aspect, the light emission structure further comprises one or more filter layers located between the pixel layer and the microlens layer, the one or more filter layers being configured for preventing another portion of the off-axis emission from interfering with on-axis emission of at least one adjacent sub-pixel.

[0019] In another implementation form of the first aspect, the first filler material layer is formed on the second filler material layer, a first refractive index of the first filler material layer being lower than a second refractive index of the second filler material layer.

[0020] In yet another implementation form of the first aspect, the portion of the off-axis emission comprises light emitted towards at least one adjacent microlens of the at least one adjacent sub-pixel along an off-axis direction at an angle to the on-axis direction, wherein the light emitted along the off-axis direction is reflected by the interface in TIR, otherwise it would pass through the at least one adjacent microlens.

[0021] In yet another implementation form of the first aspect, the another portion of the off-axis emission comprises light emitted towards at least one adjacent microlens of the at least one adjacent sub-pixel along an off-axis direction at an angle to the on-axis direction, wherein the light emitted along the off-axis direction is filtered by the one or more filter layers, otherwise it would pass through the at least one adjacent microlens.

[0022] In yet another implementation form of the first aspect, the one or more filter layers include at least one of a color filter layer and a tri-tap filter layer; the light emitted along the off-axis direction is absorbed by the color filter layer; and the light emitted along the off-axis direction is reflected by the tri-tap filter layer in TIR.

[0023] In yet another implementation form of the first aspect, the narrowly limited on-axis emission profile includes light emitted along the on-axis direction only through the at least one microlens.

[0024] In yet another implementation form of the first aspect, the one or more filter layers include a color filter layer, the color filter layer including at least one color filter aligned with the at least one sub-pixel for passing at least one on-axis emission from the at least one sub-pixel and filtering at least one off-axis emission from the at least one adjacent sub-pixel.

[0025] In yet another implementation form of the first aspect, the light emission structure further includes one or more shear adhesive layers positioned between the pixel layer and the microlens layer, wherein the one or more shear adhesive layers are configured to maintain optical alignment of the at least one microlens with the at least one sub-pixel when the light emission structure is subjected to elastic deformation for providing the narrowly limited on-axis emission profile.

[0026] In yet another implementation form of the first aspect, the light emission structure further includes one or more shear adhesive layers positioned between the pixel layer and the microlens layer, wherein at least one of the one or more shear adhesive layers includes a low viscosity adhesive material or a vertical support adhesive material.

[0027] In yet another implementation form of the first aspect, the light emission structure further includes: one or more filter layers positioned between the pixel layer and the microlens layer, the one or more filter layers including one of a color filter layer and a tri-tap filter layer, the light emitted along an off-axis direction being absorbed by the color filter layer, the light emitted along the off-axis direction being reflected by the tri-tap filter layer in TIR; and one or more shear adhesive layers positioned between the pixel layer and the microlens layer and configured to maintain optical alignment of the at least one microlens with the at least one sub-pixel when the light emission structure is subjected to elastic deformation for providing the narrowly limited on-axis emission profile, wherein the first fill material layer is formed on the second fill material layer, a first refractive index of the first fill material layer being lower than a second refractive index of the second fill material layer such that the interface reflects a portion of the off-axis emission from the at least one sub-pixel in TIR.

[0028] In a second aspect of the disclosure, a display device includes: a pixel layer having a plurality of sub-pixels; a microlens layer having a plurality of microlenses, each of the plurality of microlenses aligned with a corresponding one of the plurality of sub-pixels; a first filler material layer and a second filler material layer between the pixel layer and the microlens layer, an interface between the first filler material layer and the second filler material layer configured for reflecting a portion of off-axis emission from the plurality of sub-pixels by total internal reflection (TIR).

[0029] In implementations of the second aspect, the display device further includes at least one of a color filter layer and a tri-tap filter layer between the pixel layer and the microlens layer, the at least one of the color filter layer and the tri-tap filter layer configured for preventing another portion of the off-axis emission from interfering with on-axis emission from the plurality of sub-pixels.

[0030] In another implementation of the second aspect, the tri-tap filter layer includes a plurality of tri-tap filters for passing the on-axis emission and filtering the off-axis emission, and the color filter layer includes at least one color filter aligned with at least one of the plurality of sub-pixels for passing at least one on-axis emission from the at least one of the sub-pixels and filtering at least one off-axis emission from at least one adjacent sub-pixel.

[0031] In yet another implementation of the second aspect, the first filler material layer is formed on the second filler material layer, a first refractive index of the first filler material layer being lower than a second refractive index of the second filler material layer.

[0032] In yet another implementation of the second aspect, the portion of the off-axis emission includes light emitted along an off-axis direction at an angle from an on-axis direction toward at least one adjacent microlens of at least one adjacent sub-pixel, wherein the light emitted along the off-axis direction is reflected by the interface in TIR, otherwise would pass through the at least one adjacent microlens.

[0033] In yet another implementation of the second aspect, the another portion of the off-axis emission includes light emitted along an off-axis direction at an angle from an on-axis direction toward at least one adjacent microlens of at least one adjacent sub-pixel, wherein the light emitted along the off-axis direction is absorbed by the color filter layer or reflected by the tri-tap filter layer in TIR, otherwise would pass through the at least one adjacent microlens.

[0034] In a further implementation form of the second aspect, the display device further includes one or more shear adhesive layers positioned between the pixel layer and the microlens layer, wherein the one or more shear adhesive layers are configured to maintain the alignment of at least one of the plurality of microlenses with the corresponding one of the plurality of sub-pixels when the display device is subjected to elastic deformation.

[0035] In a further implementation form of the second aspect, the display device further includes one or more shear adhesive layers positioned between the pixel layer and the microlens layer, wherein the one or more shear adhesive layers are configured to maintain the alignment of at least one of the plurality of microlenses with the corresponding one of the plurality of sub-pixels when the display device is subjected to elastic deformation.

[0036] In a further implementation form of the second aspect, the display device further includes: one or more filter layers positioned between the pixel layer and the microlens layer, the one or more filter layers including one of a color filter layer and a tri-tap filter layer, the light emitted along the off-axis direction being absorbed by the color filter layer, the light emitted along the off-axis direction being reflected by the tri-tap filter layer in a TIR manner; and one or more shear adhesive layers positioned between the pixel layer and the microlens layer and configured to maintain optical alignment of at least one microlens of the plurality of microlenses with at least one sub-pixel of the plurality of sub-pixels when the display device is subjected to elastic deformation, for providing a narrowly confined on-axis emission profile, wherein the first filler material layer is formed on the second filler material layer, a first refractive index of the first filler material layer being lower than a second refractive index of the second filler material layer, such that the interface reflects a portion of the off-axis emission from the at least one sub-pixel in a TIR manner. BRIEF DESCRIPTION OF DRAWINGS

[0037] Aspects of the disclosure can best be understood with reference to the following detailed description when read in conjunction with the accompanying drawings. The various features are not drawn to scale. Individual components can be exaggerated or reduced in size for clarity.

[0038] Figure 1 is a schematic cross-sectional view of a light emission structure having a micro-louver layer.

[0039] Figure 2 is a schematic cross-sectional view of a light emission structure having a micro-lens layer.

[0040] Figure 3 is a schematic cross-sectional view of an example light emission structure according to an example implementation of the present disclosure.

[0041] Figure 4is a schematic cross-sectional view of an example light emitting structure according to an example implementation of the present disclosure.

[0042] Figure 5 is a schematic cross-sectional view of an example light emitting structure according to an example implementation of the present disclosure.

[0043] Figure 6A is a schematic cross-sectional view of an example light emitting structure according to an example implementation of the present disclosure.

[0044] Figure 6B is a schematic cross-sectional view of an example light emitting structure under elastic deformation according to an example implementation of the present disclosure. Figure 6A in FIG. 1 1. DETAILED DESCRIPTION

[0045] The following disclosure contains specific information related to example implementations in the present disclosure. The figures and accompanying detailed implementations in the present disclosure are directed to example implementations only. However, the present disclosure is not limited to only these example implementations. Other variations and implementations of the present disclosure will occur to those skilled in the art.

[0046] Unless otherwise stated, like or corresponding elements in the figures can be denoted by like or corresponding reference numerals. Furthermore, the figures and illustrations in the present disclosure are generally not drawn to scale, and are not intended to correspond to actual relative dimensions.

[0047] For purposes of consistency and ease of understanding, like numerals or reference characters can designate like ultimate components or steps throughout the drawings and the description, unless otherwise specified. However, different implementations can utilize different nomenclature, and thus, the use of like numerals or reference characters is not intended to limit the scope of the disclosure.

[0048] This description uses the phrases “in one implementation” or “in some implementations,” each of which can refer to one or more of the same or different implementations. The term “comprising” means “including, but not necessarily limited to,” and specifically indicates open-ended including or membership in the group or series and the like. The expression “at least one of A, B, and C” or “at least one of the following: A, B, and C” means “only A, or only B, or only C, or any combination of A, B, and C.”

[0049] In addition, for purposes of explanation and non-limitation, specific details are set forth such as functional entities, techniques, protocols, standards, etc. in order to provide an understanding of the described technology. In other instances, detailed descriptions of well-known methods, techniques, systems, architectures, etc. are omitted so as not to obscure the description with unnecessary detail.

[0050] The present disclosure relates to a design for a curved display with a narrowly limited emission profile. The curvature of the display can subtend more than 50° of arc, and the emission profile can be limited to within 40°. Typically, the curvature will be limited in one axis, giving the device a cylindrical curvature. Some limited twist is common for device applications, and bending along multiple axes is possible. The limitation of panel emission can be limited in one or two axes.

[0051] The present disclosure aims to maintain the benefits of lenticulars, but avoid the undesirable secondary and tertiary emission off the pixel that can distract the vehicle operator. The display device of the present disclosure includes at least a lenticular layer and a pixel layer. In the present disclosure, the lenticulars can have other shapes than hemispherical, but are single refractive lenses with at least one curved surface. To provide a narrowly limited emission profile without the undesirable secondary or tertiary emission, at least two of the three layers described below are included between the lenticular layer and the pixel layer.

[0052] In one or more implementations of the present disclosure, the display device can include a light emission structure that can have a low refractive index layer and a high refractive index layer between a pixel layer having a plurality of sub-pixels and a lenticular layer having a plurality of lenticulars. The high refractive index layer can be located near the pixel layer, and the low refractive index layer can be located near the lenticular layer. The low refractive index layer can be air, a nitrogen or vacuum filled layer, a liquid layer, an adhesive layer, or a flexible adhesive. In the present disclosure, the low refractive index layer is preferably a polymer with a refractive index of about 1.1 to 1.5, while preferably 1.15 or 1.2 to 1.3. If this layer is filled with air, it can include a longitudinal support between the high refractive index layer and the lenticular layer to ensure correct alignment and spacing. The low refractive index layer and the high refractive index layer create a high refractive index to low refractive index interface between them to limit light rays emitted at wide angles (e.g., tertiary emission) by total internal reflection (TIR). In a conventional system, TIR would occur at the interface of the cover glass and air (e.g., in the environment), but when the last surface is a lenticular array instead of a flat cover glass, light that would otherwise be trapped can escape through the curved surface of the lenticular.

[0053] In one or more implementations of the disclosure, the light emission structure can further include a color filter layer between the microlens layer and the pixel layer. The color filter layer can include an array of red, green, and blue color filters, with each color filter aligned with one of the pixels in the pixel layer, respectively. This arrangement prevents secondary emission of a pixel from entering the color filter corresponding to an adjacent pixel. For example, since a red pixel is not directly adjacent to any other red pixel, light emitted at a slightly shallow angle will pass through the red color filter and enter the desired microlens directly above the pixel, or will be absorbed by the green and blue color filters around that lens. However, a limited amount of light can be tertiary emission.

[0054] In one or more implementations of the disclosure, the light emission structure can further include a dichroic interference filter or an interference filter layer, such as a tri-pass filter, between the microlens layer and the pixel layer. The interference filter layer can be designed to transmit light emitted from a pixel of three color bands, e.g., red, green, and blue color bands (e.g., containing wavelength ranges of red, green, and blue), only when the emission of the color band is on-axis with respect to the pixel, but can reflect off-axis incident light emission. This filter layer can prevent secondary and tertiary emission and does not require patterning. Care must be taken to ensure that the interference filter layer is flexible and to ensure that the acceptance angle is within the curvature range of the display panel.

[0055] In one or more implementations of the disclosure, the light emission structure can further include one or more shear adhesive layers for maintaining optical alignment of at least one microlens in the microlens layer with at least one sub-pixel in the pixel layer while providing a narrowly restricted on-axis emission profile when the light emission structure is under elastic deformation. In one or more implementations of the disclosure, the “on-axis” direction of on-axis emission is not necessarily emission normal to the display plane, but is substantially normal to the display plane, as long as the emission does not emit to an adjacent microlens. The one or more shear adhesive layers allow some shear motion between any two layers above while continuing to restrict separation between the microlens layer and the pixel layer. It should be noted that interference layers are more easily applied with shear adhesive layers than micro-louvers. The shear adhesive layers can be low viscosity adhesives or vertical support structures. The light emission structure with shear adhesive layers allows the microlenses to move in lateral directions with respect to the sub-pixels while maintaining optical alignment with respect to the microlenses, sub-pixels, and viewer’s eyes when the light emission structure is bent. In other words, when the light emission structure including at least two of the aforementioned three layers is bent, the optical axis passing through the center of the sub-pixel and the optical axis passing through the center of the microlens are aligned with the optical axis passing through the viewer’s eye, such that the viewer will perceive similar display brightness from the curved display device.

[0056] In one or more implementations of the disclosure, the light emission structure can include one or more filter layers between the pixel layer and the microlens layer, and one or more shear adhesive layers between the pixel layer and the microlens layer. The one or more filter layers can include one of a color filter layer and a tri-pass filter layer, light emitted along the off-axis direction being absorbed by the color filter layer, light emitted along the off-axis direction being reflected by the tri-pass filter layer in a TIR manner. The one or more shear adhesive layers can be configured to maintain alignment of at least one microlens with at least one sub-pixel when the light emission structure is subjected to elastic deformation for providing the narrow restricted on-axis emission profile. A first filler material layer can be formed on a second filler material layer, and a first refractive index of the first filler material layer is lower than a second refractive index of the second filler material layer, such that the interface reflects a portion of the off-axis emission from the at least one sub-pixel in a TIR manner.

[0057] Figure 1 is a schematic cross-sectional view of a light emission structure 100 with a micro-louver layer. In Figure 1 , the light emission structure 100 can include a substrate 102, a pixel layer 104 including a plurality of sub-pixels (e.g., 104a), a filler material 106, and a micro-louver layer 105 including a plurality of vertically oriented slats 105a.

[0058] In Figure 1 , the structure 100 illustrates example components of a micro-louver based emission control structure in a display device. Light can be emitted from the sub-pixels 104a near the bottom of the structure 100 in a wide angular range. Some on-axis light emission 107a and 107b travels perpendicularly, with some of the emission 107a incident on the slats 105a being lost due to absorption by the slats 105a, while other emission 107b travels unimpeded to the front of the display device and exits the display device with a narrow angular distribution or emission profile. Off-axis emission 109 travels at a much wider angle relative to the on-axis emission 107a and 107b, which can be distracting to a vehicle operator.

[0059] Figure 2 is a schematic cross-sectional view of a light emission structure 200 with a micro-lens layer. The light emission structure 200 can include a substrate 202, a pixel layer 204 including a plurality of sub-pixels (e.g., 204a), a filler material 206, and a micro-lens layer 210 including a plurality of micro-lenses. The substrate 202, the pixel layer 204 including a plurality of sub-pixels, and the filler material 206 can correspond to the substrate 102, the pixel layer 104 including a plurality of sub-pixels, and the filler material 106, respectively, of the structure 100 in Figure 1 .

[0060] In Figure 2In particular, light emission structure 200 illustrates example components of a micro-lens based emission control structure in a display device. Light can be emitted from a sub-pixel 204a near the bottom of structure 200. With an array of micro-lenses 210, the on-axis emission of the display device can be greatly improved, each micro-lens can narrow the on-axis emission profile (e.g., a narrowly limited on-axis emission profile) 207 of light from the nearest pixel (e.g., 204a). However, there are other light emissions (e.g., 209a and 209b) that are off-axis with respect to the on-axis emission 207. For example, secondary emission (e.g., a window or light path) 209a and tertiary emission (e.g., a window or light path) 209b, where the micro-lenses 210 do not narrow the emission profile, and can even widen it. For example, these secondary and tertiary light paths can be detrimental to automotive displays. In this example, the secondary or tertiary light paths can be incident on a windshield or other window, and cause a distraction to the driver. Figure 2

[0061] Figure 3 is a schematic cross-sectional view of an example light emission structure 300 according to example implementations of the present disclosure. Light emission structure 300 can include a substrate 302, a pixel layer 304 including a plurality of sub-pixels (e.g., 304a, 304b), a second fill material 306, a first fill material 312, a glass substrate 314, and a micro-lens layer 310 including a plurality of micro-lenses. In one or more implementations of the present disclosure, substrate 302, pixel layer 304 including a plurality of sub-pixels, and second fill material 306 can correspond to substrate 202, pixel layer 204 including a plurality of sub-pixels 204a, and fill material 206, respectively, of structure 200 in Figure 2

[0062] In one or more implementations of the present disclosure, on-axis light emission 307 can be transmitted through second fill material 306, first fill material 312, glass cover 314, and micro-lens layer 310 with a narrowly limited emission profile.

[0063] In one or more implementations of the present disclosure, second fill material 306 (e.g., a high index layer) can have a higher refractive index than first fill material 312 (e.g., a low index layer). First fill material 312 having a lower refractive index can remove a portion of light off-axis emission (e.g., tertiary emission) 309b that produces light at a shallower angle relative to light emission structure 300. In Figure 3 ​​In particular, the first filler material 312 having a lower refractive index and the second filler material 306 having a higher refractive index create an interface 308 between the first filler material 312 and the second filler material 306 such that a portion of off-axis emission from the sub-pixel 304a, such as the third off-axis emission 309b, is reflected within the light emission structure 300 in TIR without reaching the first filler material 312, and thus the third emission 309b is removed.

[0064] In another example implementation, the first filler material 312 can be a low refractive index layer to prevent scattering. For example, the first filler material 312 can be a highly porous aerogel layer. The first filler material 312 can form a layer having a thickness equal to or greater than 4 um.

[0065] In one or more implementations, the angle of emission of off-axis emission, in particular, a second angle θ2 at which the second emission 309a can be emitted or a third angle θ3 at which the third emission 309b can be emitted relative to an emission surface of the sub-pixel 304a, is related to a pitch P and a thickness T, where P is a distance from a center of the sub-pixel 304a to a center of an adjacent sub-pixel 304b, and T is a distance between an emission surface of the sub-pixel 304a in the pixel layer 304 (e.g., Figure 3 and a bottom surface of the microlens layer 310 in the microlens layer 310 (e.g., Figure 3 If the maximum second angle θ2 and the maximum third angle θ3 at which the second off-axis emission 309a and the third off-axis emission 309b can be emitted are determined, the thickness T and the pitch P can also be determined to satisfy the maximum angles. The above-described relationships between the second angle θ2, the third angle θ3, the pitch P, and the thickness T can be represented by the following equations:

[0066] tan θ2 = T / (P / 2) Equation (1), and

[0067] tan θ3 = T / (3*P / 2) Equation (2).

[0068] It should be noted that the equations (1) and (2) assume that if the refractive indices of the layers are different, the thickness of the layers that make up T is weighted by their refractive indices, and if the refractive indices are the same, the thickness of the layers that make up T is simply the actual thickness.

[0069] Further, a refractive index N 低 of the first filler material 312 (e.g., the low refractive index layer) and a refractive index N 高 of the second filler material 306 (e.g., the high refractive index layer) can be determined by the angle of emission of the emission that is totally internally reflected by the interface 308. In particular, the refractive indices N低 and N 高 Related to the angle of emission that is totally internally reflected by the interface 308, the following equation (Snell’s law) applies:

[0070] N 高 *sin(90-8) = N 低 Equation (3),

[0071] where N 高 and N 低 are the refractive indices of the high and low layers, respectively.

[0072] In one implementation, the angle of emission that is totally internally reflected by the interface 308 can be the same as the tertiary angle 83. Due to the interface 308, only the tertiary off-axis emission 309b is removed, thus narrowing the overall emission profile of the light emission structure 300. The secondary angle 02may be arranged such that there is no secondary emission. Thus, the angle 0 in equation 3 will correspond to the angle 02calculated in equation 1 to determine the refractive indices of the two layers.

[0073] Figure 4 is a schematic cross-sectional view of an example light emission structure 400 according to an example implementation of the present disclosure.

[0074] Figure 4 The example light emission structure 400 in can include a substrate 402, a pixel layer 404 including a plurality of sub-pixels (e.g., 404a), a second fill material 406, a first fill material 412, a color filter layer 416, and a microlens layer 410 including a plurality of microlenses. In one or more implementations of the present disclosure, the substrate 402, the pixel layer 404 including a plurality of sub-pixels, the second fill material 406, the first fill material 412, and the microlens layer 410 can correspond to the substrate 302, the pixel layer 304 including a plurality of sub-pixels (e.g., 304a), the second fill material 306, the first fill material 312, and the microlens layer 306 of the structure 300 in Figure 3 For brevity, details of the example structure 400 are omitted. It should be noted that the sub-pixels are typically colored (e.g., red, green, or blue) and the corresponding colors of the pixels should be positioned so as to define a viewing axis (e.g., perpendicular to the display). For a red pixel under a red filter, the adjacent color filters are green and blue, thus there are three pixel spacings (microlenses) to the next red filter and microlens to form a secondary window.

[0075] In one or more implementations of the present disclosure, the on-axis light emission 407 can be transmitted through the second fill material 406, the first fill material 412, the color filter layer 416, and the microlens 410 with a narrowly defined emission profile.

[0076] In one or more implementations, the first fill material 412 having a lower index of refraction and the second fill material 406 having a higher index of refraction create an interface 408 between the first fill material 412 and the second fill material 406 such that a portion of off-axis emission (such as third off-axis emission 409b) from the sub-pixel 404a is reflected within the light emission structure 400 in a TIR manner without reaching the first fill material 412, thus the third emission 409b is removed.

[0077] In one or more implementations, the example structure 400 differs from the example structure 300 in that, Figure 3 the glass cover 314 in the example structure 300 is replaced by a color filter layer 416 in order to remove the second emission 409a. In the example structure 400, Figure 4 In the example structure 400, the color filter layer 416 can include an array of color filters arranged (e.g., red filters, green filters, blue filters arranged horizontally in an alternating fashion) such that a particular color of light emission 407 (e.g., a red emission or a narrowly confined on-axis emission profile) can be emitted from the sub-pixel 404a and pass through a corresponding color filter (e.g., a red filter) 416a located directly above the sub-pixel 404a. In addition, the color filters adjacent to (e.g., to the left and right of a red filter) the corresponding color filter 416a located directly above the sub-pixel 404a are designed to only transmit other color emissions (e.g., green and blue light emissions). Due to the interface 408 and the color filter layer 416, the second off-axis emission 409a and the third off-axis emission 409b are removed, thus further narrowing the overall emission profile of the light emission structure 400 compared to the light emission structure 300.

[0078] In one or more implementations, the color filter layer 416 can be above the microlens layer 410, or the microlens layer 410 can be made in whole with various colors. In other implementations, the color filter layer 416 and the first fill material (lower index of refraction layer) 412 can not need to be arranged as shown in the example structure 400 in the example structure 300 as long as the first fill material 412 is below the microlens layer 410. Figure 4 As long as the light emission from a sub-pixel (e.g., 404a) travels through a layer with a higher index of refraction (e.g., the second fill material 406) and then through a layer with a lower index of refraction (e.g., the first fill material 412), the multiple layers of the example structure 400 can be rearranged as described above.

[0079] Figure 5 is a schematic cross-sectional view of an example light emission structure 500 according to an example implementation of the present disclosure. In the example structure 500, Figure 5In particular implementations, the example light emission structure 500 can include a substrate 502, a pixel layer 504 including a plurality of sub-pixels (e.g., 504a), a second fill material 506, a first fill material 512, an interference filter layer 518, a glass substrate 514, and a microlens layer 510 including a plurality of microlenses (e.g., 510a, 510b). In one or more implementations of the disclosure, the substrate 502, the pixel layer 504 including a plurality of sub-pixels, the second fill material 506, the first fill material 512, and the microlens layer 510 can correspond to the substrate 402, the pixel layer 404 including a plurality of sub-pixels, the second fill material 406, the first fill material 412, and the microlens layer 410 of the structure 400 in FIG. 4, respectively. Thus, details of the example structure 500 are omitted for brevity. Figure 4 In particular implementations, the example light emission structure 500 can include a substrate 502, a pixel layer 504 including a plurality of sub-pixels (e.g., 504a), a second fill material 506, a first fill material 512, an interference filter layer 518, a glass substrate 514, and a microlens layer 510 including a plurality of microlenses (e.g., 510a, 510b). In one or more implementations of the disclosure, the substrate 502, the pixel layer 504 including a plurality of sub-pixels, the second fill material 506, the first fill material 512, and the microlens layer 510 can correspond to the substrate 402, the pixel layer 404 including a plurality of sub-pixels, the second fill material 406, the first fill material 412, and the microlens layer 410 of the structure 400 in FIG. 4, respectively. Thus, details of the example structure 500 are omitted for brevity.

[0080] In one or more implementations, the on-axis light emission or narrow-limited on-axis emission 507 profile can be transmitted through the second fill material 506, the first fill material 512, the interference filter layer 518, the glass substrate 514, and the microlens 510 with a narrow emission profile.

[0081] In one or more implementations, the first fill material 512 having a lower refractive index and the second fill material 506 having a higher refractive index create an interface 508 between the first fill material 512 and the second fill material 506 such that a portion of off-axis emission from the sub-pixel 504a, such as the third off-axis emission 509b, is reflected within the light emission structure 500 in a TIR manner without reaching the first fill material 512, thus the tertiary emission 509b is removed. Furthermore, any light that would leak through the boundary between the first fill material 512 and the second fill material 506 (e.g., due to scattering, poor adhesion, etc., or even a bend in the panel) will be further reduced by the additional interference layer 518 or color filter layer.

[0082] In one or more implementations, the example structure 500 in FIG. 5 differs from the example structure 400 in FIG. 4 in that, Figure 5 In one or more implementations, the example structure 500 in FIG. 5 differs from the example structure 400 in FIG. 4 in that, Figure 4The color filter layer 416 in the color light emitting structure 400 is replaced by an interference filter layer 518 and a glass substrate 514. The replacement or supplement of the color filter layer can be the interference filter layer 518. The interference filter layer 518 is designed to transmit three bands of wavelengths, where each band is centered on the red, green, and blue emissions of the on-axis emission 507. However, the transmission of the interference filter layer 518 changes for off-axis emissions. For example, if the red, green, and blue emissions from the sub-pixel 504a are emitted on-axis (e.g., 507) relative to the interference filter layer 518, the on-axis color emissions can be transmitted through the interference filter layer 518, the glass cover 514, and the microlens layer 510. However, if the color emissions from the sub-pixel 504a are off-axis, for example, the secondary emission 509a on a path into a microlens (e.g., 510b) adjacent (e.g., 510a) to the microlens directly above the sub-pixel 504a, the secondary emission 509 can be reflected by the interference filter layer 518. The secondary and tertiary off-axis emissions are removed due to the interfaces 508 and the interference filter layer 518, thus narrowing the overall emission profile of the light emitting structure 500.

[0083] Figure 6A is a schematic cross-sectional view of an example light emitting structure 600A according to an example implementation of the present disclosure.

[0084] In Figure 6A , the example light emitting structure 600A can include a substrate 602, a pixel layer 604 including a plurality of sub-pixels (e.g., 604a, 604b), a second fill material 606, a first fill material 612, a color filter layer 616 or an interference filter layer 618, and a microlens layer 610 including a plurality of microlenses (e.g., 610a, 610b). In one or more implementations of the present disclosure, the substrate 602, the pixel layer 604 including a plurality of sub-pixels, the second fill material 606, the first fill material 612, and the microlens layer 610 can correspond to the substrate 402, the pixel layer 404 including a plurality of sub-pixels, the second fill material 406, the first fill material 412, and the microlens layer 410, respectively, of the structure 400 in Figure 4 , or can correspond to the substrate 502, the pixel layer 504 including a plurality of sub-pixels, the second fill material 506, the first fill material 512, and the microlens layer 510, respectively, of the structure 500 in Figure 5 . Thus, details of the example structure 600A are omitted for brevity.

[0085] In one or more implementations of the present disclosure, the example structure 600A can be different from the example structure 400 in Figure 4 and the example structure 500 in Figure 5example structure 600A can include a color filter layer 616, an interference filter layer 618, or a combination of both the color filter layer 616 and the interference filter layer 618, such that the secondary off-axis emission can be removed and only a narrowly limited on-axis emission profile 607 can be emitted through the second fill material 606, the first fill material 612, the color filter layer 616 or the interference filter layer 618, and the microlens layer 610.

[0086] In one or more implementations, the example structure 600A can also be different from the example structure 400 in Figure 4 and the example structure 500 in Figure 5 because the example structure 600A can also include one or more shear adhesive layers (e.g., at least one shear adhesive layer 620). The at least one shear adhesive layer 620 can be included between the substrate 602 and the pixel layer 604, between the pixel layer 604 and the second fill material 606, between the second fill material 606 and the first fill material 612, between the first fill material 612 and the color filter layer 616 or the interference filter layer 618, and between the color filter layer 616 or the interference filter layer 618 and the microlens layer 610 to maintain optical alignment of at least one microlens (e.g., 610b) in the microlens layer 610 with at least one sub-pixel (e.g., 604b) in the pixel layer 604 (see Figure 6A and Figure 6B while providing the narrowly limited on-axis emission profile 607. The one or more shear layers allow the layers to move freely along each other but not away from each other. However, the layers must be fixed along a line that determines the primary collimation direction (e.g., the center of the panel) and perpendicular to the bending direction. In one implementation, for example, the optical axis (e.g., OA 604b ) through the center of the sub-pixel 604b can be aligned with the optical axis (e.g., OA 610b ) through the center of the microlens 610b. In one or more implementations, the shear adhesive layer 620 can be a low viscosity adhesive or a vertical support structure. Figure 6A An example light emission structure 600A under minimal elastic deformation is illustrated.

[0087] Figure 6B An example light emission structure 600A under elastic deformation according to an example implementation of the present disclosure is illustrated. Figure 6A A schematic cross-sectional view of the example light emission structure 600A under elastic deformation according to an example implementation of the present disclosure is illustrated.

[0088] In Figure 6BIn the example, the light-emitting structure 600B may include a substrate 602, a pixel layer 604 including multiple sub-pixels (e.g., 604a, 604b), a second filling material 606, a first filling material 612, a color filter layer 616 or an interference filter layer 618, and a microlens layer 610 including multiple microlenses (e.g., 610a, 610b). In one or more implementations of this disclosure, the substrate 602, the pixel layer 604 including multiple sub-pixels, the second filling material 606, the first filling material 612, and the microlens layer 610 are substantially integrated with the substrate 602. Figure 6A The example structure of 600A in the example is the same, and can be respectively corresponding to Figure 4 The structure 400 in the figure includes a substrate 402, a pixel layer 404 comprising multiple sub-pixels, a second filling material 406, a first filling material 412, and a microlens layer 410, or may correspond to the structure 500 in the figure, which includes a substrate 502, a pixel layer 504 comprising multiple sub-pixels, a second filling material 506, a first filling material 512, and a microlens layer 510. Therefore, for the sake of simplicity, the details of the example structure 600B are omitted.

[0089] In one or more implementations, example structure 600B can be compared with... Figure 6A The example structure 600A is essentially the same. However, the example structure 600B differs from the example structure 600A in that the example light-emitting structure 600B is subjected to significant or obvious elastic deformation (e.g., in...). Figure 6Bthe example structure 600B in a flexed state), and the example structure 600B has at least one shear adhesive layer 620 between any two of the substrate 602, the pixel layer, the second fill material 606, the first fill material 612, the color filter layer 616 or the interference filter layer 618, and the microlens layer 610 that are also in a flexed state. When the example structure 600B is in a flexed state, the at least one shear adhesive layer 620 can continue to maintain optical alignment of at least one microlens (e.g., 610b) in the microlens layer 610 with at least one sub-pixel (e.g., 604b) in the pixel layer 604, such that a narrowly confined on-axis emission profile 607 is provided. The at least one shear adhesive layer 620 allows some shear motion between any two of the layers above while continuing to limit separation between the microlens layer 610 and the pixel layer 604. The light emission structure 600B with the at least one shear adhesive layer 620 allows microlenses (e.g., 610a, 610b) in the microlens layer 610 to move in lateral directions relative to sub-pixels (e.g., 604a, 604b) in the sub-pixel layer 604 while maintaining optical alignment relative to the microlenses, the sub-pixels, and a viewer's eye when the light emission structure 600B is flexed. In one implementation, when the light emission structure 600B comprising multiple layers is flexed, for example, an optical axis (e.g., OA 604b ) through the center of a sub-pixel 604b can align with an optical axis (e.g., OA 610b ) through the center of a microlens 610b, such that a flexed or bent light emission structure 600B that can be accommodated in a display device can be perceived at different angles with similar display luminance.

[0090] In some implementations, if each of the layers (substrate 602, pixel layer 604, second fill material 606, first fill material 612, color filter layer 616 or interference filter layer 618, and microlens layer 610) are firmly joined together by the at least one shear adhesive layer 620 to allow for some degree of shear, and when the light emission structure 600B applied to a curved display device is flexed, the stresses and strains within most of the layers can be minimized while the microlens layer 610 and the sub-pixels (e.g., 604a) can remain in optical alignment. In some implementations, the layers are only joined to not move, but are only firmly joined in a line perpendicular to the intended flex.

[0091] As can be seen from the present disclosure, the concepts described in the present disclosure can be implemented using a variety of technologies without departing from the scope of the concepts described in the present disclosure. Although the concepts have been described with reference to certain implementations, persons of ordinary skill in the art will recognize that changes can be made in the form and details of the concepts described herein without departing from the scope of the concepts described in the present disclosure.

[0092] As such, the described implementations should be considered in all respects as illustrative and not restrictive. It should also be understood that the present disclosure is not limited to the particular implementations described herein but can vary from these without departing from the scope of the present disclosure.

Claims

1. A light emitting structure, characterized by, comprises: a pixel layer having at least one sub-pixel; a microlens layer having at least one microlens aligned with the at least one sub-pixel for providing a narrowly confined on-axis emission profile along an on-axis direction; and a first and a second filler material layer between the pixel layer and the microlens layer, an interface between the first and the second filler material layer being configured for reflecting a portion of off-axis emitted light from the at least one sub-pixel by total internal reflection, TIR, further comprising one or more filter layers between the pixel layer and the microlens layer, the one or more filter layers being configured for preventing another portion of the off-axis emitted light from interfering with on-axis emission of at least one neighboring sub-pixel, the another portion of the off-axis emitted light comprising light emitted towards at least one adjacent microlens of the at least one neighboring sub-pixel along an off-axis direction at an angle to the on-axis direction, wherein the light emitted along the off-axis direction is filtered by the one or more filter layers, which would otherwise pass through the at least one adjacent microlens, the one or more filter layers comprising at least one of a color filter layer and a tri-tap filter layer, wherein, the light emitted along the off-axis direction is absorbed by the color filter layer; the light emitted along the off-axis direction is reflected by the tri-tap filter layer in TIR.

2. A light emitting structure, characterized by comprises: a pixel layer having at least one sub-pixel; a microlens layer having at least one microlens aligned with the at least one sub-pixel for providing a narrowly confined on-axis emission profile along an on-axis direction; and a first and a second filler material layer between the pixel layer and the microlens layer, an interface between the first and the second filler material layer being configured for reflecting a portion of off-axis emitted light from the at least one sub-pixel by total internal reflection, TIR, further comprising: one or more filter layers between the pixel layer and the microlens layer, the one or more filter layers comprising one of a color filter layer and a tri-tap filter layer, the light emitted along an off-axis direction being absorbed by the color filter layer, the light emitted along the off-axis direction being reflected by the tri-tap filter layer in TIR; and one or more shear adhesive layers between the pixel layer and the microlens layer and configured to maintain optical alignment of the at least one microlens with the at least one sub-pixel for providing the narrowly confined on-axis emission profile when the light emission structure is subjected to elastic deformation, wherein the first layer of filler material is formed on the second layer of filler material, the first layer of filler material having a first refractive index lower than a second refractive index of the second layer of filler material, such that the interface reflects a portion of the light from the at least one sub-pixel that is off-axis emitted in TIR.

3. A display device, characterized by comprising: comprising: a pixel layer having a plurality of sub-pixels; a microlens layer having a plurality of microlenses, each of the plurality of microlenses aligned with a corresponding one of the plurality of sub-pixels; and a first layer of filler material and a second layer of filler material between the pixel layer and the microlens layer, an interface between the first layer of filler material and the second layer of filler material configured to reflect a portion of light from the plurality of sub-pixels that is off-axis emitted by total internal reflection (TIR), further comprising at least one of a color filter layer and a tri-tap filter layer between the pixel layer and the microlens layer, the at least one of the color filter layer and the tri-tap filter layer configured to prevent another portion of the off-axis emitted light from interfering with on-axis emission from the plurality of sub-pixels.

4. The display device of claim 3, wherein: the tri-tap filter layer includes a plurality of tri-tap filters for passing the on-axis emission and filtering the off-axis emission, the color filter layer includes at least one color filter aligned with at least one of the plurality of sub-pixels for passing at least one on-axis emission from the at least one of the sub-pixels and filtering at least one off-axis emission from at least one adjacent sub-pixel. the other portion of the off-axis emitted light includes light emitted along an off-axis direction at an angle from an on-axis direction toward at least one adjacent microlens of at least one adjacent sub-pixel, wherein the light emitted along the off-axis direction is absorbed by the color filter layer or reflected by the tri-tap filter layer in TIR, otherwise the light would pass through the at least one adjacent microlens.

5. The display device according to claim 3, wherein comprising:

6. A display device, characterized by comprising: a pixel layer having a plurality of sub-pixels; a microlens layer having a plurality of microlenses, each of the plurality of microlenses aligned with a corresponding one of the plurality of sub-pixels; and a first layer of filler material and a second layer of filler material between the pixel layer and the microlens layer, an interface between the first layer of filler material and the second layer of filler material configured to reflect a portion of light from the plurality of sub-pixels that is off-axis emitted by total internal reflection (TIR), further comprising: one or more filter layers between the pixel layer and the microlens layer, the one or more filter layers including one of a color filter layer and a tri-tap filter layer, the light emitted along an off-axis direction being absorbed by the color filter layer, the light emitted along the off-axis direction being reflected by the tri-tap filter layer in TIR; and ​ ​ one or more shear adhesive layers located between the pixel layer and the microlens layer and configured to maintain optical alignment of at least one of the plurality of microlenses with at least one of the plurality of sub-pixels when the display device is subjected to elastic deformation to provide a narrowly confined on-axis emission profile, wherein the first layer of filler material is formed on the second layer of filler material, the first refractive index of the first layer of filler material being lower than the second refractive index of the second layer of filler material, such that the interface reflects a portion of the off-axis emission of the light from the at least one sub-pixel in a TIR manner.

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