Display system

Abstract

A display system includes: a display area configured to form an image throughout the display area for viewing by a viewer, and including a light emitting area configured to emit light and a non-light emitting area not configured to emit light; and a light diffraction layer configured to be interposed between the viewer and the display area, and disposed substantially parallel to the display area and spaced apart from the display area in a thickness direction of the display system. The light diffracting layer includes a light diffracting region configured to diffract light and a light non-diffracting region not configured to diffract light. The light diffracting region and the light non-diffracting region of the light diffracting layer are aligned with the respective light non-emitting region and light emitting region of the display region, and substantially coextend in length and width.

Description

Technical Field

[0001] This specification generally relates to display systems. Background Art

[0002] The display system may include an organic light emitting diode (OLED) display panel. Summary of the invention

[0003] In some aspects, the present specification provides a display system, which includes: a display area, which is configured to form an image on the entire display area for viewing by a viewer, and includes a light-emitting area configured to emit light and a non-light-emitting area that is not configured to emit light; and a light diffraction layer, which is configured to be between the viewer and the display area, and is arranged substantially parallel to the display area and spaced apart from the display area along the thickness direction of the display system. The light diffraction layer includes a light diffraction area configured to diffract light and a light non-diffraction area that is not configured to diffract light. The light diffraction area and the light non-diffraction area of ​​the light diffraction layer can be aligned with the corresponding light non-emitting area and light emitting area of ​​the display area, and substantially extend together in length and width.

[0004] In some aspects, the specification provides a display system, the display system including a plurality of luminescent pixels, the plurality of luminescent pixels defining a plurality of first inter-pixel regions therebetween, each of the first inter-pixel regions being free of any luminescent pixels; and a light diffraction layer disposed on the luminescent pixels and spaced apart from the luminescent pixels along a thickness direction of the display system, and the light diffraction layer including a plurality of light diffraction regions substantially aligned and coextensive with the plurality of first inter-pixel regions in a one-to-one correspondence. The light diffraction regions may include a plurality of substantially parallel linear diffraction elements extending along a first direction in the same plane and arranged along an orthogonal second direction in the same plane. Light emitted by the pixels is diffractively transmitted by the light diffraction layer and leaves the display system in air toward a viewer. The output light and the comparison output light of the comparison display system have corresponding intensity distributions and comparison intensity distributions as functions of the light propagation angle. The comparison display system has the same construction as the display system except that it does not include the light diffraction layer, so that in a first plane parallel to the thickness direction and orthogonal to the first direction and for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm: the peak intensity of the intensity distribution is at least 10% greater than the peak intensity of the comparison intensity distribution; and the half-width at half maximum (HWHM) of the intensity distribution is at least 10 degrees smaller than the HWHM of the comparison intensity distribution.

[0005] In some aspects, the specification provides a display system, the display system including a plurality of light-emitting pixels, the plurality of light-emitting pixels defining a plurality of first inter-pixel regions therebetween, wherein each of the first inter-pixel regions is free of any light-emitting pixels; and a light diffraction layer disposed on the light-emitting pixels and spaced apart from the light-emitting pixels along a thickness direction of the display system, and the light diffraction layer including a plurality of light diffraction regions substantially aligned and coextensive with the plurality of first inter-pixel regions in a one-to-one correspondence. The light diffraction regions may include a plurality of substantially parallel linear diffraction elements extending along a first direction in the same plane and arranged along an orthogonal second direction in the same plane. Light emitted by the pixels is diffractively transmitted by the light diffraction layer and leaves the display system in air toward a viewer. The output light and the comparison output light of the comparison display system have corresponding intensity distributions and comparison intensity distributions as functions of the light propagation angle, and the comparison display system has the same construction as the display system except that it does not include the light diffraction layer, so that in a first plane parallel to the thickness direction and the first direction, for at least one wavelength in the visible wavelength range extending from about 420nm to about 680nm, and for each propagation angle in the angular range from at most 10 degrees to at least 50 degrees, the intensity distribution has a larger amplitude than the comparison intensity distribution.

[0006] In some aspects, the present specification provides a display system, the display system including one or more light-emitting regions, the one or more light-emitting regions being configured to emit light, being substantially coplanar with one or more non-light-emitting regions that are not configured to emit light, and one or more light-diffraction regions, the one or more light-diffraction regions being disposed on the one or more non-light-emitting regions and spaced apart from the one or more non-light-emitting regions along a thickness direction of the display system, such that in a top plan view, the one or more light-diffraction regions cover more than 60% of the one or more non-light-emitting regions and less than 40% of the one or more light-emitting regions. At least some of the light obliquely emitted by the one or more light-emitting regions leaves the display system after being diffractively transmitted by the one or more light-diffraction regions, such that in each of a first orthogonal plane and a second plane both parallel to the thickness direction, and for at least one wavelength in a visible wavelength range extending from about 420 nm to about 680 nm, the half-width at half maximum (HWHM) of the intensity distribution of the exiting light is less than the HWHM of a comparative intensity distribution of a comparative display system, the comparative display system having the same construction as the display system except that the one or more light-diffraction regions are not included.

[0007] In some aspects, the present specification provides a display system comprising one or more light-emitting regions configured to emit light and one or more non-light-emitting regions that are not configured to emit light and are substantially coplanar with the one or more light-emitting regions; and one or more light diffraction regions, the one or more light diffraction regions being disposed on the one or more non-light-emitting regions and spaced apart from the one or more non-light-emitting regions along a thickness direction of the display system such that, in a top plan view, the one or more light diffraction regions cover more than 60% of the one or more non-light-emitting regions and less than 40% of the one or more light-emitting regions. At least some of the light obliquely emitted by the one or more light emitting regions leaves the display system after being diffracted and transmitted by the one or more light diffraction regions, so that in each of at least one plane parallel to the thickness direction and for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, the normalized intensity distribution of the display system is normalized relative to the comparative intensity distribution of a comparative display system, which has the same construction as the display system except that the one or more light diffraction regions are not included, and the normalized intensity distribution includes a peak at a propagation angle of less than about 10 degrees and a global minimum set between the peak and the propagation angle of less than about 60 degrees.

[0008] In some aspects, the present specification provides a display system comprising one or more light-emitting regions configured to emit light and one or more non-light-emitting regions that are not configured to emit light and are substantially coplanar with the one or more light-emitting regions; and one or more light diffraction regions, the one or more light diffraction regions being disposed on the one or more non-light-emitting regions and spaced apart from the one or more non-light-emitting regions along a thickness direction of the display system such that, in a top plan view, the one or more light diffraction regions cover more than 60% of the one or more non-light-emitting regions and less than 40% of the one or more light-emitting regions. At least some of the light obliquely emitted by the one or more light emitting regions leaves the display system after being diffracted and transmitted by the one or more light diffraction regions, so that for a first plane and a second plane substantially orthogonal to each other and parallel to the thickness direction, and for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, the normalized intensity distribution of the display system is normalized relative to the comparative intensity distribution of a comparative display system, which has the same construction as the display system except that the one or more light diffraction regions are not included, and the normalized intensity distribution includes: in the first plane, a global minimum at a propagation angle less than about 60 degrees; and in the second plane, for all propagation angles from about zero degrees to at least about 40 degrees, an amplitude greater than about 1.

[0009] These and other aspects will become apparent from the following detailed description.This brief summary, however, should not be construed in any way as limiting the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic cross-sectional view of a display system according to some embodiments.

[0011] Figure 2 is a schematic cross-sectional view of at least a portion of a display system according to some embodiments.

[0012] Figure 3 is a schematic top plan view of a display system according to some embodiments.

[0013] Figure 4 is according to some embodiments may correspond to Figure 3 A schematic cross-sectional view of at least a portion of a display system of a display system.

[0014] Figure 5 to Figure 6 is a schematic cross-sectional view of a plurality of substantially parallel linear diffraction elements according to some embodiments.

[0015] Figure 7 is a schematic cross-sectional view of a display system including a light diffraction layer including a backfill structured layer according to some embodiments.

[0016] Figure 8 is a schematic top plan view of a display system including pixels arranged on a square lattice according to some embodiments.

[0017] FIG. 9A to FIG. 9B Schematic cross-sectional views of a display system according to some embodiments and a corresponding comparative display system, respectively.

[0018] Figure 10 to Figure 11 is a graph of intensity as a function of light propagation angle for various display systems and corresponding comparative display systems, according to some embodiments.

[0019] Fig.12 is a schematic diagram of a light diffraction layer according to some embodiments, and a first plane and a second plane, both of which are parallel to the thickness direction and form an angle α1 with each other.

[0020] Figures 13 to 15 is a graph of normalized intensity of a display system as a function of light propagation angle in different planes according to some embodiments DETAILED DESCRIPTION

[0021] In the following description, reference is made to the accompanying drawings, which form a part of the present disclosure and in which various embodiments are shown by way of example. The drawings are not necessarily drawn to scale. It should be understood that other embodiments may be envisioned and carried out without departing from the scope or essence of the present specification. Therefore, the following specific embodiments should not be considered to have a limiting meaning.

[0022] The display system may emit light in an axial direction toward the viewer and in an off-axis direction. In some cases, it is desirable to redirect at least some of the off-axis light substantially in the axial direction to increase the axial intensity and brightness experienced by the user. According to some embodiments, it has been found that a suitably patterned light diffraction layer as described herein can be used to achieve this effect.

[0023] Diffraction gratings have been used with organic light emitting diode (OLED) displays for other purposes. A diffraction grating may be placed over an organic light emitting diode (OLED) display panel to correct for off-axis color shift, as described, for example, in U.S. Pat. No. 10,991,765 (Freier et al.). A diffraction structure may be disposed over an emitting region of an OLED device, within an evanescent region of the emitting region, to improve extraction of light that would otherwise be trapped in the OLED device, as described, for example, in U.S. Patent Application Publication No. 2010 / 0110551 (Lamansky et al.). In each of these cases, a diffraction layer is placed over the entire emitting layer of the OLED device. It has been found that when a diffraction grating is placed over the entire emitting layer, and the diffraction grating is selected to provide first order diffraction of at least some of the off-axis light into an axial direction, some of the light emitted by the pixel in the axial direction will be diffracted into the off-axis direction, thereby substantially increasing the axial brightness by redirecting the off-axis light.

[0024] According to some embodiments of the present specification, it has been found that the light diffraction layer can be patterned to include light diffraction regions on non-light-emitting regions but not on light-emitting regions (e.g., pixels), and this allows at least some of the off-axis light to be diffracted into the axial direction without substantially diffracting the axially emitted light into the non-axial direction. According to some embodiments, it has been found that this can result in a significant increase in axial intensity (e.g., an increase of at least 10%, 20%, 30%, 40%, or even 50%) compared to a comparative display system that does not include a diffraction layer and / or compared to a display system that includes a diffraction layer having a diffraction structure covering the entire display panel.

[0025] Figure 1is a schematic cross-sectional view of a display system 300 according to some embodiments. In some embodiments, the display system 300 includes a display area 10, which is configured to form an image 11 on the entire display area for viewing by a viewer 301, and includes a light-emitting area 12 configured to emit light (e.g., 14b, 14g, 14r) and a non-light-emitting area 13 that is not configured to emit light; and a light diffraction layer 20, which is configured to be between the viewer 301 and the display area 10, and is substantially parallel to the display area 10 (e.g., parallel within 30 degrees, 20 degrees, 10 degrees, or 5 degrees) and is spaced apart from the display area along the thickness direction (z direction) of the display system 300. The light diffraction layer 20 may include a light diffraction area 21 configured to diffract light and a light non-diffraction area 22 that is not configured to diffract light. In some embodiments, the light diffraction region 21 and the light non-diffraction region 22 of the light diffraction layer 20 are aligned with the corresponding light non-emitting region 13 and the emitting region 12 of the display area 10, and are substantially coextensive in length (x-axis) and width (y-axis). The emitted light 14b, 14g, 14r may include a wavelength in the visible wavelength range extending from about 420nm to about 680nm. For example, the emitted light 14b may be blue light in the wavelength range of about 420nm to about 490nm, the emitted light 14g may be green light in the wavelength range of about 490nm to about 590nm, and the emitted light 14r may be red light in the wavelength range of about 590nm to about 680nm.

[0026] If more than 50% of the length and width of each layer or element are coextensive with more than 50% of the length and width of each other layer or element, the layer or element can be described as being substantially coextensive with each other in length and width. In some embodiments, for layers or elements described as being substantially coextensive with each other in length and width, at least about 60%, or at least about 70%, or at least about 80%, or at least about 90%, or at least about 95% of each layer or element are coextensive with at least about 60%, or at least about 70%, or at least about 80%, or at least about 90%, or at least about 95% of the length and width of each other layer or element.

[0027] In some embodiments, at least 30%, or 35%, or 40%, or 45%, or 50%, or 55%, or 60%, or 65%, or 70%, or 75%, or 80%, or 85%, or 90%, or 95% of the total area of ​​the light diffraction region of the light diffraction layer overlaps with at least 30%, or 35%, or 40%, or 45%, or 50%, or 55%, or 60%, or 65%, or 70%, or 75%, or 80%, or 85%, or 90% or 95% of the total area of ​​the non-luminescent region of the display region. For example, in some embodiments, at least 50% of the total area of ​​the light diffraction region of the light diffraction layer overlaps with at least 50% of the total area of ​​the non-luminescent region of the display region, or at least 75% of the total area of ​​the light diffraction region of the light diffraction layer overlaps with at least 75% of the total area of ​​the non-luminescent region of the display region, or at least 90% of the total area of ​​the light diffraction region of the light diffraction layer overlaps with at least 80% of the total area of ​​the non-luminescent region of the display region. In some embodiments, at least 30%, or 35%, or 40%, or 45%, or 50%, or 55%, or 60%, or 65%, or 70%, or 75%, or 80%, or 85%, or 90%, or 95% of the total area of ​​the light non-diffraction region of the light diffraction layer overlaps with at least 30%, or 35%, or 40%, or 45%, or 50%, or 55%, or 60%, or 65%, or 70%, or 75%, or 80%, or 85%, or 90%, or 95% of the total area of ​​the light emitting region of the display region. For example, in some embodiments, at least 50% of the total area of ​​the light non-diffraction region of the light diffraction layer overlaps with at least 50% of the total area of ​​the light emitting region of the display region, or at least 75% of the total area of ​​the light non-diffraction region of the light diffraction layer overlaps with at least 75% of the total area of ​​the light emitting region of the display region, or at least 90% of the total area of ​​the light non-diffraction region of the light diffraction layer overlaps with at least 80% of the total area of ​​the light emitting region of the display region.

[0028] In some embodiments, the average spacing S1 between the light diffraction layer 20 and the display area 10 is greater than about 10 microns, or 15 microns, or 20 microns, or 30 microns, or 40 microns, or 50 microns, or 100 microns, or 150 microns, or 200 microns, or 250 microns, or 300 microns, or 350 microns, or 400 microns, or 400 microns, or 500 microns, and less than about 5000 microns, or 4500 microns, or 4000 microns, or 3500 microns, or 3000 microns, or 2500 microns, or 2000 microns, or 1500 microns, or 1000 microns. In some embodiments, the average spacing S1 is, for example, in the range of about 10 microns to about 5000 microns, or about 20 microns to about 4000 microns, or about 30 microns to about 2000 microns.

[0029] Figure 230 is a schematic cross-sectional view of at least a portion of a display system (e.g., display system 300, or display systems 305 or 310 described elsewhere herein) according to some embodiments. In some embodiments, light emitting region 12 is configured to emit a first emission light cone 30 and a second emission light cone 33. The first emission light cone 30 and the second emission light cone 33 are incident on the light diffraction layer at a certain angle range, which may depend on the spacing S1 (see, e.g., Figure 1 ) and the origin of the light cone. The light diffraction region 21 can diffract at least a portion of the light in the second cone 33 incident on the light diffraction region 21 into a diffraction direction range within a certain direction range (for example, given by the diffraction grating equation). The first emission light cone 30 includes a first emission central light ray 31 propagating along a first emission direction 32. The first emission light cone 30 is incident on the non-diffraction (22) region of the light diffraction layer instead of the diffraction (21) region, and at least a portion of the first emission light cone 30 is transmitted by the non-diffraction region 22 of the light diffraction layer as a first transmission light cone 30', which has a first transmission central light ray 31' propagating along the first transmission direction 32' within about 10 degrees, or 8 degrees, or 6 degrees, or 4 degrees, or 2 degrees, or 1 degree of the first emission direction 32. The second emission light cone 33 includes a second emission central ray 34 propagating along a second emission direction 35, which forms an angle α greater than about 10 degrees, or 15 degrees, or 20 degrees, or 25 degrees, or 30 degrees with the first emission direction 32. The second emission light cone 33 is incident on the diffraction (21) area of ​​the light diffraction layer rather than the non-diffraction (22) area, and at least a portion of the second emission light cone 33 is diffracted by the diffraction area 21 of the light diffraction layer to transmit a second diffraction light cone 33', which has a second diffraction central ray 34' propagating along a second diffraction direction 35', which forms an angle θ less than about 10 degrees, or 8 degrees, or 6 degrees, or 4 degrees, or 2 degrees, or 1 degree with the first emission direction 32. In some embodiments, at least 50%, or 60%, or 70%, or 80%, or 90% of the first emission light cone 30 is transmitted by the non-diffraction area 22 of the light diffraction layer. In some embodiments, at least 5%, or 10%, or 15%, or 20%, or 25%, or 30%, or 35%, or 40%, or 45%, or 50% of the second emission light cone 33 is diffractively transmitted by the diffraction region 21 of the light diffraction layer.

[0030] Figure 3 is a schematic top view of a display system 310 according to some embodiments. Figure 4 is a schematic cross-sectional view of at least a portion of a display system 310 according to some embodiments. Display system 310 may correspond to display system 300, except that at least Figure 3In the embodiment shown, in addition to the light-emitting pixels 12b, 12g, and 12r (e.g., blue pixels, green pixels, and red pixels), the display system 310 also includes an optional light-emitting pixel 12w (e.g., white pixel), and the pixels in different embodiments may have different arrangements. In some embodiments, the light-emitting region 12 includes a plurality of spaced-apart light-emitting pixels (e.g., 12b, 12g, 12r, and optional 12w), and the areas between the light-emitting pixels (e.g., Figure 1 13b or 13rg, 13gb, 13br) schematically shown in the figure include non-luminescent regions 13. In some embodiments, the regions between the emitting pixels (e.g., 13a, 13b) are interconnected to form a continuous non-luminescent region 113. For example, the luminescent pixels may be as shown in FIG. Figure 3 The arrangement may be as schematically shown in FIG. 1 , or may have any other suitable arrangement as would be appreciated by a person of ordinary skill in the art.

[0031] In some embodiments, the display system 300, 310 includes a plurality of luminescent pixels (e.g., 12 or 12b, 12g, 12r, 12w) defining a plurality of first inter-pixel regions 13a therebetween, wherein each of the first inter-pixel regions 13a does not have any luminescent pixels. In some embodiments, a plurality of luminescent pixels define a plurality of second inter-pixel regions 13b therebetween, wherein each of the second inter-pixel regions does not have any luminescent pixels and has an area that is at most 1 / 2, or 1 / 5, or 1 / 10, or 1 / 20, or 1 / 30, or 1 / 40, or 1 / 50, or 1 / 100 of the area of ​​each of the first inter-pixel regions 13a. For example, the pixels may be arranged in rows, wherein the inter-pixel regions (e.g., 13a) between the rows have a much larger total area than the inter-pixel regions (e.g., 13b) between the pixels within the row. The light diffraction region 21 may be substantially coextensive with the inter-pixel regions between the rows in length and width.

[0032] In some embodiments, the light diffraction region 21 includes a plurality of substantially parallel linear diffraction elements 23, which extend along a first direction (y direction) within the same plane and are arranged along an orthogonal second direction (x direction) within the same plane. Figure 5 to Figure 6 is a schematic cross-sectional view of a plurality of substantially parallel linear diffraction elements 23 according to some embodiments. In some embodiments, the plurality of substantially parallel linear diffraction elements 23 form an irregular pattern along the second direction (e.g., Figure 5 In some embodiments, a plurality of substantially parallel linear diffraction elements 23 form a periodic pattern along the second direction (e.g., as Figure 6Schematically shown). As is known in the art, the geometry of the grating and the refractive index difference across the grating can be selected to provide a desired first order diffraction peak in a desired direction. In some embodiments, the periodic pattern has a period P1 in the range of about 0.2 microns to about 5 microns, or about 0.3 microns to about 3.5 microns, or about 0.4 microns to about 3 microns, or about 0.5 microns to about 2.5 microns, or about 0.6 microns to about 2 microns. In some embodiments, the linear diffraction elements 23 form an irregular pattern having an average spacing or pitch in any range described for P1. In some embodiments, the plurality of substantially parallel linear diffraction elements 23 have an average height h1 in the range of about 0.05 microns to about 3.5 microns, or about 0.1 microns to about 3.25 microns, or about 0.2 microns to about 3 microns, or about 0.3 microns to about 2.75 microns, or about 0.4 microns to about 2.5 microns, or about 0.5 microns to about 2.25 microns, or about 0.6 microns to about 2 microns, or about 0.7 microns to about 1.75 microns, or about 0.8 microns to about 1.5 microns, or about 0.8 microns to about 1.25 microns, or about 0.8 microns to about 1 micron.

[0033] As is known in the art, when light is transmitted through the light diffraction layer, the light diffraction structure of the light diffraction layer can be selected to deflect the light into the desired direction. The light diffraction region 21 may include any suitable diffraction structure that causes the light to be diffracted into a suitable direction. For example, the light diffraction region 21 may include a phase grating, an amplitude grating, a one-dimensional grating (e.g., including substantially parallel linear diffraction elements 23), a two-dimensional grating (e.g., on a square lattice, a rectangular lattice, or a hexagonal lattice), a sub-wavelength structure, a metasurface structure, and / or other diffraction structures known in the art. In some embodiments, the light diffraction structure forms a grating, and the geometry and refractive index of the light diffraction structure can be related to the desired direction by, for example, a diffraction grating equation. Exemplary diffractive structures described by diffraction grating equations can be found, for example, in Miller et al., "Design and fabrication of binary slanted surface-relief gratings for a planar optical interconnection," Applied Optics, Vol. 36, No. 23, 1997, and Moharam et al., "Formulation for stable and efficient implementation of the rigorous coupled-wave analysis of binary gratings," J. Opt. Soc. Am. A, Vol. 12, No. 5, 1995. In some embodiments, the light diffractive structure forms a metasurface (which can be considered a diffractive surface) that provides appropriate steering into a desired direction. Exemplary metasurfaces for beam steering are described, for example, in U.S. Patent Application Publication No. 2021 / 0109364 (Aieta et al.) and Jiang et al., “Free-Form Diffractive Metagrating Design Based on Generative Adversarial Networks,” ACS Nano, 13, 8872-8878, 2019. The geometry of the diffractive element may be selected based in part on the geometry of the pixel layout. For example, when the pixels are arranged in rows (see, e.g., Figure 2 ), substantially parallel linear diffraction elements 23 extending along the areas between the rows may be preferred, while a two-dimensional grating may be preferred when the pixels are arranged in a pentagonal or rectangular lattice arrangement.

[0034] Figure 7 305 is a schematic cross-sectional view of a display system 305 according to some embodiments. The display system 305, which may correspond to the display system 300 or 310, includes, for example, a pixelated layer 112, a light diffraction layer 20, and a layer 116 disposed between the light diffraction layer 20 and the pixelated layer 112 and on the pixelated layer 112. Layer 116 may be a (e.g., thin film) sealant layer and / or an (e.g., optically transparent) adhesive layer, or a glass layer or another display layer, such as, for example, a polarizer or a touch sensor layer. The pixelated layer 112 includes a light emitting region 12 and a non-light emitting region 13. The pixelated layer 112 may be any suitable pixelated layer. In some embodiments, the pixelated layer 112 includes, for example, an organic emissive material of an organic light emitting diode (OLED) display panel. In some embodiments, for example, the pixelated layer 112 is a layer of a micro OLED display. In other embodiments, for example, the pixelated layer 112 is a layer of an inorganic μLED (micro light emitting diode) display. It should be understood that the light diffraction structure of the light diffraction layer 20 may have a substantially smaller Figure 7 The length ratios of the length ratios schematically shown in FIG.

[0035] The light diffraction layer may include a first layer 20a and a second layer 20b. In some embodiments, the first layer 20a is formed on layer 116 (or formed on another layer and then laminated to layer 116) using a casting and curing process, wherein the diffraction structure is manufactured by the tool by casting a polymerizable resin composition onto layer 116 (or another layer) and curing the resin in contact with the structured surface of the tool. Such casting and curing methods are described in, for example, U.S. Patent Nos. 5,175,030 (Lu et al.) and 5,183,597 (Lu) and in U.S. Patent Application Publication No. 2012 / 0064296 (Walker, JR. et al.). The structured surface of the tool may be selected to define the light diffraction area and the light non-diffraction area, or the tool may define the light diffraction structure on the entire structured surface of the first layer 20a, and then in a subsequent coating step, the portion of the light diffraction structure may be filled with the same material as used to form the first layer 20a in the casting and curing process or a different material with a similar refractive index (e.g., substantially closer in refractive index to the casting and curing material than the material of the second layer 20b) to define the light non-diffraction area. The second layer 20b may be a (e.g., planarized) backfill layer coated over the structured surface defined in the first layer 20a. For example, for at least the same first wavelength (e.g., about 550nm) in the wavelength range of 420nm to 680nm, the first layer 20a and the second layer 20b typically have different refractive indices na and nb, respectively. In some embodiments, for at least the first wavelength, the difference nb-na may be, for example, at least about 0.03, 0.05, 0.07, 0.09, or 0.1. In some such embodiments, or in other embodiments, for at least the first wavelength, the difference nb-na may be, for example, at most about 2, 1.5, 1, 0.8, 0.6, 0.5, or 0.4. In some embodiments, the non-diffractive region includes a structured interface, and for at least the first wavelength, the difference in refractive index across the structured interface may be less than, for example, about 0.08, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01. In some embodiments, the diffractive layer 20 includes more than 2 materials or layers. For example, the diffractive layer 20 may include a thin (e.g., substantially thinner than the grating height) outer coating at the grating interface, which may have a high refractive index (e.g., the refractive index may be at least about 2, such as, for example, a refractive index of about 2.5) for at least the first wavelength. In some embodiments, at the first wavelength, layer 20a has a refractive index of about 1.4 to about 1.55, and layer 20b has a refractive index of about 1.75 to about 1.85. For example, layer 116 may have a thickness of about 20 microns to 1000 microns, layer 20a may have a thickness of about 10 microns to 20 microns, and layer 20b may have a thickness of about 5 microns to about 15 microns.For example, in cell phone applications, the thickness of layer 116 may be in the range of about 20 microns to about 30 microns, and in television applications, for example, may be in the range of about 500 microns to about 1000 microns. In some embodiments, the light diffraction layer 20 is formed separately and then disposed on the emissive layer with an optional air gap therebetween, or the light diffraction layer 20 may be laminated to the emissive layer.

[0036] Light diffraction region and light non-diffraction region can be patterned by any other suitable manner. In some embodiments, light diffraction region and light non-diffraction region can be patterned by inkjet printing, photolithography, mask or other suitable patterning techniques. In some embodiments, patterning technique determines the placement of refractive index matching (for example, the refractive index difference is less than about 0.08, 0.06, 0.05, 0.04, 0.03, 0.02 or 0.01) material to limit the position of light non-diffraction region. In some embodiments, patterning technique determines the placement of refractive index mismatch (for example, the refractive index difference is at least about 0.03, 0.05, 0.07, 0.09 or 0.1) material to limit the light diffraction region. In some embodiments, patterning technique defines exposure region, and grating is preferentially manufactured or removed above the exposure region by, for example, etching or scribing. In some embodiments, the light diffraction layer can be formed on the surface of another layer already present in the display system by etching or scribing, wherein the etching or scribing process is patterned to define light diffraction areas and light non-diffraction areas. Other patterning methods known in the art can be alternatively utilized.

[0037] At least a portion 131' of the light 131 is transmitted through the light non-diffraction region of the light diffraction layer 20 in a direction (e.g., z direction) substantially perpendicular to (e.g., within a normal of 30 degrees, 20 degrees, 10 degrees, or 5 degrees) the plane (xy plane) of the emission layer 112, while at least a portion 134a' and 134b' of the corresponding lights 134a and 134b is transmitted through the light diffraction region of the light diffraction layer and is diffracted to a direction (z direction) closer to the direction substantially perpendicular to the plane (xy plane) of the emission layer 112. For example, the light 131' may correspond to light in the transmission light cone 30', while the lights 134a', 134b' may correspond to light in the diffraction light cone 33'.

[0038] The display system 305 may further include a circular polarizer 125 disposed on the light diffraction layer 20. For example, the circular polarizer 125 may be included to reduce reflections from an OLED display panel including the emission layer 112. For example, the circular polarizer 125 may be a combination of a linear absorption polarizer and a quarter-wave retarder. The circular polarizer 125 may be disposed between a first layer 126 and a second layer 127, wherein the first layer 126 may be or include an adhesive layer that bonds the circular polarizer 125 to the light diffraction layer 20. The second layer 127 may be a protective layer disposed on the circular polarizer 125 opposite to the first layer 126.

[0039] Figure 8 3 is a schematic top plan view of a display system 305 according to some embodiments, schematically illustrating a diffractive layer including diffractive elements 23 disposed above a two-dimensional array of pixels 12. In other embodiments, the pixels 12 have different arrangements (see, e.g., Figure 3 ).

[0040] Fig. 9A is a schematic cross-sectional view of a display system 310 including a light diffraction layer 20 according to some embodiments. Fig. 9B is a schematic cross-sectional view of a comparative display system 310', which has the same construction as the display system 310 except that the light diffraction layer 20 is not included. Generally speaking, the comparative display system refers to a display system that does not include the light diffraction layer 20 and / or does not include the light diffraction region 21, but has the same construction as the display system in other aspects. The display systems 310, 310' may include an outer layer 225, which may include one or more of a circular polarizer, a touch panel, or a protective cover layer. Other layers commonly used in displays (e.g., color filters and / or down-conversion layers) may optionally be present above or below the light diffraction layer 20 in the display system 310 and are located at corresponding positions in the comparative display system 310'.

[0041] Figure 10 to Figure 11 is a graph of intensity as a function of the light propagation angle in air (the angle between the light propagation direction and the display normal) for various display systems and corresponding comparative display systems according to some embodiments. The angle can be defined in various planes, such as the xz plane, the yz plane, and / or a plane that is at an angle of about 45 degrees to the xz plane and the yz plane, for example. Figure 10 to Figure 11 The implementation scheme corresponds to Figure 3 An embodiment is schematically shown in FIG. Figure 10 to Figure 11 The curves in are for light coming from blue pixels and green pixels, respectively. Fig.12is a schematic diagram of a light diffraction layer 20 according to some embodiments, and a first (xz plane) plane and a second (x'z plane) plane, both of which are parallel to the thickness direction (z direction) and are at an angle α1 to each other. Angle α1 may be at least about 30 degrees, 35 degrees, 40 degrees, or 45 degrees. Angle α1 should be understood as the minimum angle between the first plane and the second plane, so that the angle is no greater than 90 degrees. Angle α1 may not exceed about 70 degrees, 60 degrees, 50 degrees, 40 degrees, or 45 degrees. For example, angle α1 may be about 45 degrees. The output light 60 of the display system 310 (see, for example, Fig. 9A ) and the comparison output light 60' of the comparison display system 310' have corresponding intensity distributions as a function of the light propagation angle (e.g., Fig.10 61, 63, 25 or Fig.11 66, 69, 67) and comparative intensity distributions (e.g., Fig.10 61', 63', 25' or Fig.11 66', 69', 67'), the comparison system does not include the light diffraction layer 20 (see example, Fig. 9B ) has the same configuration as the display system except for the above. For each of the curves in these figures, the angle is in a plane parallel to the thickness direction (z direction) at an angle indicated in the legend (0 degrees, 45 degrees, or 90 degrees) relative to a first in-plane direction, which may be a direction along which the diffractive elements 23 are arranged (e.g., x direction).

[0042] In some embodiments, the display system 300, 305, 310 includes a plurality of luminous pixels (e.g., 12 or 12b, 12g, 12r, 12w), defining a plurality of first inter-pixel regions 13a therebetween, wherein each of the first inter-pixel regions 13a does not have any luminous pixels; and a light diffraction layer 20, which is disposed on the luminous pixels and spaced apart from the luminous pixels along the thickness direction (z direction) of the display system, and the light diffraction layer includes a plurality of light diffraction regions 21 that are substantially aligned and extend together in a one-to-one correspondence with the plurality of first inter-pixel regions 13a. In some embodiments, the light diffraction region 21 includes a plurality of substantially parallel linear diffraction elements 23, which extend along a first direction (y direction) within the same plane and are arranged along an orthogonal second direction (x direction) within the same plane. In some embodiments (see, for example, FIG. 9A to FIG. 9B), light emitted by the pixel (e.g., emitted light 40) is diffracted transmitted by the light diffraction layer (e.g., diffracted transmitted light 50) and leaves the display system in air toward the viewer 301 (e.g., exit light 60), wherein the exit light 60 and the comparative exit light 60' of the comparative display system 310' have respective intensity (61, 63) distributions and comparative intensity (61', 63') distributions as a function of the light propagation angle, the comparative display system having the same configuration as the display system except that the light diffraction layer 20 is not included The system is constructed in the same manner, so that in a first plane (e.g., xz plane) parallel to the thickness direction and orthogonal to the first direction and for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm (e.g., blue, red and / or green wavelengths), the peak intensity 62 of the intensity distribution 61 is at least 10% greater than the peak intensity 62' of the comparative intensity distribution 61'; and the half-width at half maximum (HWHM) Wb0 of the intensity distribution 61 is at least 10 degrees less than the HWHM Wb0' of the comparative intensity distribution 61'. In some such embodiments, or in other embodiments, the peak intensity 62 of the intensity distribution 61 is at least 15%, or 20%, or 30%, or 35%, or 40%, or 45% greater than the peak intensity 62' of the comparative intensity distribution 61'. In some such embodiments, or in other embodiments, the half width at half maximum (HWHM) Wb0 of the intensity distribution 61 is at least 15 degrees, 20 degrees, 25 degrees, 30 degrees, or 35 degrees less than the HWHM Wb0' of the comparative intensity distribution 61'. In some such embodiments, or in other embodiments, Wb0 is in the range of 10 degrees to 25 degrees, and Wb0' is in the range of 30 degrees to 60 degrees, or Wb0 is in the range of 12 degrees to 20 degrees, and Wb0' is in the range of 40 degrees to 50 degrees. For example, the at least one wavelength may be or include a wavelength of about 550 nm.

[0043] In some embodiments, in a second plane (e.g., yz plane) parallel to the thickness and the first direction, and for at least one wavelength (e.g., blue, red, and / or green wavelength), the HWHM Wb90 of the intensity distribution 63 is less than the HWHM Wb90' of the comparative intensity distribution 63'. In some embodiments, the HWHM Wb90 is at least 1 degree, 2 degrees, or 3 degrees less than the HWHM Wb90'. In some such embodiments, or in other embodiments, the HWHM Wb90 is in the range of 40 to 50 degrees, and the HWHM Wb90' is in the range of 40 to 60 degrees or 43 to 55 degrees. In some embodiments, it may be desirable for Wb0 and Wb90 to be less than Wb0' and Wb90', respectively, as this may correspond to collimation in the vertical and horizontal directions that may be desired, for example, in a handheld display. In some embodiments, Wb0 is less than Wb0', and Wb90 and Wb90' are approximately equal (e.g., within 20, 15, 10, or 5 percent of being equal). This may be desirable in some cases because it may correspond to collimation in the vertical direction, but little or no collimation in the horizontal direction, which may be desirable in, for example, television applications. In some embodiments, substantially parallel linear diffractive elements 23 are used to provide approximately equal Wb90 and Wb90', and a two-dimensional pattern of diffractive elements is used to provide Wb90 that is substantially less than Wb90'.

[0044] In some embodiments, the display systems 300, 305, 310 include a plurality of luminous pixels (e.g., 12 or 12b, 12g, 12r, 12w), defining a plurality of first inter-pixel regions (e.g., 13 or 13a) therebetween, wherein each of the first inter-pixel regions does not have any luminous pixels; and a light diffraction layer 20, which is disposed on the luminous pixels and spaced apart from the luminous pixels along the thickness direction (z-axis) of the display system, and the light diffraction layer includes a plurality of light diffraction regions 21 that are substantially aligned and extend together with the plurality of first inter-pixel regions in a one-to-one correspondence. The light diffraction regions 21 include a plurality of substantially parallel linear diffraction elements 23 that extend along a first direction (e.g., y-direction) within the same plane and are arranged along an orthogonal second direction (e.g., x-direction) within the same plane. The diffraction elements 23 may have any geometric shape described elsewhere herein and / or may be arranged in any pattern described elsewhere herein. In some embodiments (see, for example, FIG. 9A to FIG. 9B), light emitted by the pixel (e.g., emitted light 40) is diffractively transmitted (e.g., diffractively transmitted light 50) by the light diffraction layer 20, and leaves (e.g., exit light 60) the display system in the air toward the viewer 301. The exit light 60 and the comparative exit light 60' of the comparative display system 310' have corresponding intensity (e.g., 63, 69) distributions and comparative intensity (e.g., 63', 69') distributions as a function of the light propagation angle, the comparative display system having the same construction as the display system except that the light diffraction layer 20 is not included, so that in a first plane (e.g., yz plane) parallel to the thickness direction and the first direction, for at least one wavelength (e.g., blue, red, and / or green wavelength) in the visible wavelength range extending from about 420 nm to about 680 nm, and for each propagation angle in the angular range from at most 10 degrees to at least 50 degrees, the intensity distribution has a larger magnitude than the comparative intensity distribution. In some embodiments, the angular range is at most 10 degrees, 8 degrees, 6 degrees, 4 degrees, 2 degrees, 1 degree, or 0.5 degrees. In some such embodiments, or in other embodiments, the angular range is at least 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, or 80 degrees. For example, the angular range can be 10 degrees to 50 degrees, or 8 degrees to 55 degrees, or 6 degrees to 60 degrees, or 4 degrees to 70 degrees. In some embodiments, for each identical propagation angle in the angular range, the intensity distribution has an amplitude that is at least 5, 10, 15, 20, or 25 percent greater than the comparative intensity distribution.

[0045] In some embodiments, the display system 310, 305, 310 includes one or more light emitting regions 12 configured to emit light (e.g., 14b, 14g, 14r), wherein one or more non-luminous regions 13 are not configured to emit light; and one or more light diffraction regions 21, which are disposed on one or more non-luminous regions 13 and spaced apart from the one or more non-luminous regions along the thickness direction (z direction) of the display system. In some embodiments, the one or more light diffraction regions 21 are substantially aligned with and extend together with the one or more non-luminous regions 13 (which may be or include a plurality of first inter-pixel regions). For example, in some embodiments, in a top plan view (e.g., along the z-axis), the one or more light diffraction regions 21 cover more than 60% of the one or more non-luminous regions 13 and less than 40% of the one or more light emitting regions 12. In some embodiments, in a top plan view, the one or more light diffraction regions 21 cover more than 65%, or 70%, or 75%, or 80%, or 85%, or 90%, or 95% of the one or more non-luminous regions 13. In some embodiments, in a top plan view, one or more light diffraction regions 21 cover less than 40%, or 35%, or 30%, or 25%, or 20%, or 15%, or 10%, or 5% of one or more light emitting regions 12. One or more non-luminous regions 13 and one or more light emitting regions 12 may be substantially coplanar (e.g., xy plane). For example, one or more non-luminous regions 13 and one or more light emitting regions 12 may be in the same plane, or nominally in the same plane, or in the same plane with very little deviation from the total length and width of the display (e.g., along the x-direction and the y-direction). In some embodiments, at least some of the light emitted obliquely by one or more light emitting regions (e.g., 33, 34, 134a, 134b; see, e.g., Figure 2 and Figure 7 ) is diffractively transmitted by one or more light diffraction regions 21 (e.g., diffractively transmitted light 50; see, e.g., Fig. 9A ) then exits (eg, as output light 33', 34', 134a', 134b') the display system 300, 305, 310.

[0046] In some embodiments, the display system 300, 305, 310 is such that in each of the orthogonal first (e.g., xz plane) plane and the second (e.g., yz plane) plane, both parallel to the thickness direction (z direction), and for at least one wavelength (e.g., blue, red, and / or green wavelength) in the visible wavelength range extending from about 420 nm to about 680 nm, the half-width at half maximum (HWHM) (Wb0, Wb90) of the intensity distribution (61, 63) of the exit light is less than the HWHM (Wb0', Wb90') of the comparative intensity distribution (61', 63') of the comparative display system 310', which has the same configuration as the display system except that it does not include one or more light diffraction regions. In some embodiments, Wb0'-Wb0 is at least 10 degrees, 20 degrees, or 25 degrees. Wb0'-Wb0 can be, for example, at most about 60 degrees, 55 degrees, or 50 degrees. In some embodiments, Wb90'-Wb90 is at least 1 degree, 2 degrees, 2.5 degrees or 3 degrees. Wb90'-Wb90 may be, for example, at most about 15 degrees, 10 degrees or 5 degrees. In some embodiments, Wb0 is less than Wb0', and Wb90 and Wb90' are approximately equal. In some embodiments, |Wb90'-Wb90| is less than about 15 degrees, 10 degrees or 5 degrees. In some embodiments, one or more light diffraction regions 21 include a plurality of substantially parallel linear diffraction elements 23, which extend in a first direction (e.g., y direction) in the same plane and are arranged in an orthogonal second direction (e.g., x direction) in the same plane, wherein the first plane and the second plane are substantially orthogonal to the corresponding first direction and the second direction (e.g., orthogonal within 30 degrees, 20 degrees, 10 degrees or 5 degrees).

[0047] Figures 13 to 15 is according to some embodiments as different planes (e.g., Fig.12 Graphs of normalized intensity of a display system as a function of light propagation angle in air in planes (those planes schematically shown in ), where the normalized intensity is normalized relative to the comparative intensity of a corresponding comparative display system. For example, the normalized intensity at each given angle may be determined by dividing the intensity of the display system at that angle by the comparative intensity of the comparative display system at the same angle. Normalized intensities 64, 65, and 68 (and similarly, 74, 75, 78 and 84, 85, 88) are in planes that are angled at 0, 45, and 90 degrees, respectively, relative to a first in-plane direction, which may be the direction along which the diffractive elements 23 are arranged (e.g., the x-direction). Normalized intensities 64, 74, and 84 (and corresponding intensities in different planes) are used in different embodiments. Normalized intensities 64, 65, 68 correspond to Fig.11Normalized intensities 74, 75, 78 correspond to an embodiment in which pixels are arranged on a square lattice with a 40 micron pitch and a 20 square micron pixel size (see, e.g., Figure 8 ), and the grating pattern covers the area between pixels. The grating pattern has a pitch P1 of 1200 nm (see, for example, Figure 6 ). The normalized intensities 84, 85, 88 correspond to a single 20 square micron pixel, where the grating pattern forms a 10 micron frame around the pixel.

[0048] In some embodiments, the display system 300, 305, 310 is such that in each of at least one plane parallel to the thickness direction (z direction), and for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm (e.g., blue, red, and / or green wavelengths), the normalized intensity distribution (64, 65) of the display system is normalized relative to the comparative intensity distribution (66', 67') of a comparative display system 310', the comparative display system having the same configuration as the display system except that the one or more light diffraction regions are not included, the normalized intensity distribution includes a peak (64a, 65a) at a propagation angle (64b, 65b) less than about 10 degrees and a global minimum (64c, 65c) disposed between the peak and a propagation angle (64d, 65d) less than about 60 degrees. In some embodiments, the peak (64a, 65a) is at a propagation angle (64b, 65b) less than about 8 degrees, or 6 degrees, or 4 degrees, or 2 degrees, or 1 degree. In some such embodiments, or in other embodiments, the global minimum (64c, 65c) is disposed between the peak and a propagation angle (64d, 65d) of less than about 60 degrees, or 55 degrees, or 50 degrees, or 45 degrees, or 40 degrees, or 35 degrees. In some such embodiments, or in other embodiments, the global minimum (64c, 65c) is disposed at an angle greater than about 5 degrees, or 10 degrees, or 15 degrees, or 20 degrees. In some embodiments, at least one plane includes a first (e.g., xz plane) and a second (e.g., x'z plane; see, e.g., Fig.12) planes, which are parallel to the thickness direction and at an angle α1 of at least about 30 degrees, 35 degrees, 40 degrees or 45 degrees between each other. In some embodiments, one or more light diffraction regions 21 include a plurality of substantially parallel linear diffraction elements 23, which extend in the same plane in a first direction (e.g., y direction) and are arranged in an orthogonal second direction (e.g., x direction) in the same plane. In some embodiments, the first plane is substantially parallel to the second direction. In some embodiments, the peak value (e.g., 64a and / or 65a) at a propagation angle less than about 10 degrees has a normalized intensity of at least 1.1, 1.2, 1.2, 1.4 or 1.5. For example, the normalized intensity at the peak value may be at most about 2, 1.8, 1.7 or 1.6.

[0049] In some embodiments, the display systems 300, 305, 310 are such that for first (e.g., xz plane) and second (e.g., yz plane) planes that are substantially orthogonal to each other and parallel to the thickness direction, and for at least one wavelength (e.g., blue, red, and / or green wavelengths) in the visible wavelength range extending from about 420 nm to about 680 nm, the normalized intensity distribution (64, 68) of the display system is relative to the comparative intensity distribution (66', 69') of the comparative display system (e.g., 310'). ') is normalized, the comparative display system having the same configuration as the display system except that it does not include one or more light diffraction regions 21, the normalized intensity distribution including: in the first plane, a global minimum 64c at a propagation angle 64d less than about 60 degrees; and in the second plane, for all propagation angles from about zero degrees (e.g., less than about 10 degrees, or 8 degrees, or 6 degrees, or 4 degrees, or 2 degrees or 1 degree) to at least about 40 degrees, an amplitude greater than about 1, or 1.05, or 1.1, or 1.15 or 1.2. In some embodiments, for all propagation angles from about zero degrees to at least about 45 degrees, or 50 degrees, or 55 degrees, or 60 degrees, or 65 degrees, or 70 degrees, or 75 degrees or 80 degrees, the amplitude is in at least one of these ranges. For example, in some embodiments, the magnitude is greater than about 1.1 for all propagation angles from about zero to at least about 50 degrees, or greater than about 1.2 for all propagation angles from about zero to at least about 55 or to at least about 60 degrees in the second plane. For example, the second plane may correspond to the horizontal direction in a television or other display application, and in such applications, a normalized intensity greater than 1 may be desired in the second plane for a wide range of propagation angles. In some embodiments, the global minimum 64c is at a propagation angle 64d less than about 55, or 50, or 45, or 40, or 35, or 30, or 25 degrees. For example, the global minimum 64c may be at a propagation angle 64d greater than about 5, 10, 15, or 20 degrees. In some embodiments, one or more light diffraction regions 21 include a plurality of substantially parallel linear diffraction elements 23 extending in a first direction (e.g., y direction) in the same plane and arranged in an orthogonal second direction (e.g., x direction) in the same plane, wherein the first plane and the second plane are substantially orthogonal to the respective first and second directions. The diffraction elements 23 may have any geometric shape described elsewhere herein and / or may be arranged in any pattern described elsewhere herein.

[0050] Example

[0051] Usually Figure 3 and Figure 8The OLED display system shown is simulated using conventional ray tracing techniques. The diffraction grating is simulated via rigorous coupled wave analysis (RCWA) and then the scattering information is compiled for use during ray tracing. The source is modeled as a weak cavity, bottom-emitting white OLED pixel using microcavity simulation software. In ray tracing, the white OLED source is filtered by blue, green, red and white filter materials to produce blue, green, red and white emissions, respectively.

[0052] FIG. 9 shows a graph of light intensity recorded in air, which is typically Figure 3 6 is a function of the polar angle emitted by a blue OLED pixel (peak wavelength of about 460 nm) of the display system schematically shown in FIG. Curves 61, 25 and 63 are for the case where a light diffraction layer is provided thereon and is separated by 500 microns in the thickness direction from the OLED pixel space made of a material with a refractive index of about 1.5. All light diffraction areas of the light diffraction layer (100% area in the top view) overlap 100% with the inter-pixel display area 13a. There is no overlap between the diffraction areas of the diffraction layer and the pixel area 12 or the inter-pixel area 13b. The diffraction layer includes a one-dimensional (1D) linear grating such that the grating ridges are along Figure 3 The binary rectangular grating includes a bottom material and a top material having refractive indices of approximately 1.5 and 1.85, respectively (see, e.g., Figure 7 ), and has a pitch of 1200nm, a 900nm high rectangular ridge and a duty cycle of 60% (material with a refractive index of ~1.5). Curves 61', 25' and 63' are used for a comparative display system, which has the same construction as the above-mentioned display system except that it does not include a light diffraction layer. Curves 61, 64 and 25 correspond to light emitted in the xz plane, the yz plane and a plane parallel to the thickness direction (z direction), respectively, which is rotated 45 degrees from the xz plane. In the xz plane, the peak intensity 62 of the intensity distribution is about 0.195W / sr, the corresponding peak intensity 62' of the comparative intensity distribution is about 0.135W / sr, the HWHM Wb0 of the intensity distribution is about 16 degrees, and the HWHM Wb0' of the comparative intensity distribution Wb0' is about 51.5 degrees. In the yz plane, the HWHM Wb90' of the intensity distribution is about 45 degrees, and the HWHM Wb90' of the comparative intensity distribution Wb0' is about 48.5 degrees.

[0053] Fig.11 Used with Fig.10 The same display structure and layout, except that the intensity recorded as a function of polar angle in air is for the emission from the green OLED pixel (peak wavelength of about 550 nm) instead of Fig.11Here, in the xz plane, the peak intensity 82 with the diffractive layer is 0.196 W / sr, and the peak intensity 82' of the comparative intensity distribution is 0.128 W / sr.

[0054] Fig.13 The normalized intensity recorded in air as a function of the polar angle of emission from a green OLED pixel is shown for three different display structure cases. In each case, the intensity recorded for a given display structure and layout with a diffractive layer (DL) present is normalized relative to the comparative intensity of a corresponding comparative display system with the diffractive layer removed. All data in this graph are intensities recorded along the xz plane (the only lateral component is perpendicular to the grating). (The curves are labeled DL(angle)(i), where the angle is 0 degrees relative to the xz plane ( Fig.13 ), 45 degrees ( Fig.14 ) or 90 degrees ( Fig.15 ), and i(1, 2, or 3) represents three sample layouts, as described further below). Curve 64 shows Figure 3 The normalized intensity of the display layout schematically shown in FIG. Fig.10 The modeling parameters and Fig.11 The emission of the green OLED pixel. Curve 74 shows Figure 8 Normalized intensity for a display layout schematically shown in FIG, wherein pixels are arranged on a square lattice with a pitch of 40 microns and with a pixel size of 20 square microns, and the grating pattern covers the area between the pixels. Here, the diffractive layer is spaced 25 microns apart from the OLED pixels in the thickness direction. The diffractive layer comprises a binary rectangular grating whose bottom and top materials have refractive indices of approximately 1.45 and 1.8, respectively (see, e.g., Figure 7 ). The grating ridges are oriented so that they are parallel to the y-direction and the grating has a pitch of 1200 nm, a ridge height of 1000 nm and a duty cycle of 70% (material with a refractive index of ~1.45). Curve 84 is for a single 20 square micron pixel where the grating pattern forms a 10 micron frame around the pixel. The spacing of the diffractive layer to the OLED pixel is 25 microns and the grating structure is the same as described by curve 74. Curve 64 has a global minimum 64c at a propagation angle 64d of about 23 degrees.

[0055] Fig.14 shows the normalized intensity of the display system, which is equivalent to the Fig.13The case described, where all data recorded here is for intensity in a plane parallel to the thickness direction, which plane is rotated 45 degrees from the xz plane. Here, curve 65 is for the same display system as described as curve 64, curve 75 is for the same display system as described as curve 74, and curve 85 is for the same display system as described as curve 84. Curve 65 has a global minimum 65c at a propagation angle 65d of about 32 degrees.

[0056] Fig.15 shows the normalized intensity of the display system, which is equivalent to the Fig.13 The case described, wherein all data recorded here are for the intensity in the yz plane. Here, curve 68 is for the same display system as described as curve 64, curve 78 is for the same display system as described as curve 74, and curve 88 is for the same display system as described as curve 84. Curve 68 shows a normalized intensity greater than 1 for all polar angles between 0 and 80 degrees, which means that for all polar angles up to 80 degrees, the intensity is greater when the diffractive layer is present than in the contrast case in the yz plane.

[0057] Terms such as "about" will be understood by one of ordinary skill in the art in the context of use and description in this specification. If it is not clear to one of ordinary skill in the art in the context of use and description in this specification that "about" should be used to express the amount of feature size, quantity, and physical properties, then "about" will be understood to mean within 10% of the specified value. A quantity given as about a specified value may be exactly the specified value. For example, if it is not clear to one of ordinary skill in the art in the context of use and description in this specification, a quantity having a value of about 1 means that the quantity has a value between 0.9 and 1.1, and the value may be 1.

[0058] Those of ordinary skill in the art will understand terms such as "substantially" in the contexts used and described in this specification. If the use of "substantially" with respect to a property or characteristic is not clear to those of ordinary skill in the art in the contexts used and described in this specification, and when the opposite meaning of the property or characteristic is clear to those of ordinary skill in the art, the term "substantially" will be understood to mean that the property or characteristic is exhibited to a greater extent than the opposite meaning of the property or characteristic.

[0059] All references, patents, and patent applications cited above are hereby incorporated by reference in their entirety in a consistent manner. In the event of inconsistencies or conflicts between an incorporated reference portion and the present application, the information in the foregoing description shall prevail.

[0060] Unless otherwise indicated, the description of the elements in the drawings should be understood to be equally applicable to the corresponding elements in the other drawings. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that the specific embodiments shown and described may be replaced with a variety of alternative and / or equivalent implementations without departing from the scope of the present disclosure. The present application is intended to cover any modification or variation or combination of the specific embodiments discussed herein. Therefore, the present disclosure is intended to be limited only by the claims and their equivalents.

Claims

1. A display system, comprising: a display area configured to form an image on the entire display area for viewing by a viewer and including a light-emitting area configured to emit light and a non-light-emitting area not configured to emit light; and A light diffraction layer, the light diffraction layer is configured to be between the viewer and the display area, and is arranged substantially parallel to the display area and spaced apart from the display area along the thickness direction of the display system, the light diffraction layer includes a light diffraction area configured to diffract light and a light non-diffraction area not configured to diffract light, the light diffraction area and the light non-diffraction area of ​​the light diffraction layer are aligned with the corresponding light non-emitting area and light emitting area of ​​the display area, and substantially extend together in length and width.

2. The display system of claim 1, wherein an average spacing between the light diffraction layer and the display area is greater than about 10 microns and less than about 5000 microns.

3. The display system of claim 1 , wherein the light emitting region is configured to emit: a first emission light cone, the first emission light cone including a first emission central ray propagating along a first emission direction, the first emission light cone being incident on the non-diffraction region of the light diffraction layer instead of the diffraction region, and at least a portion of the first emission light cone being transmitted by the non-diffraction region of the light diffraction layer as a first transmission light cone, the first transmission light cone having a first transmission central ray propagating along the first transmission direction within about 10 degrees of the first emission direction; and A second emission light cone, the second emission light cone includes a second emission central ray propagating along a second emission direction, the second emission direction forms an angle greater than about 10 degrees with the first emission direction, the second emission light cone is incident on the diffraction area of ​​the light diffraction layer instead of the non-diffraction area, and at least a portion of the second emission light cone is diffracted and transmitted by the diffraction area of ​​the light diffraction layer as a second diffraction light cone, the second diffraction light cone has a second diffraction central ray propagating along a second diffraction direction that forms an angle less than about 10 degrees with the first emission direction.

4. The display system of claim 3, wherein at least 50% of the first emitted light cone is transmitted by the non-diffractive region of the light diffraction layer.

5. The display system of claim 3, wherein at least 5% of the second emitted light cone is diffractively transmitted by the diffraction region of the light diffraction layer.

6. A display system according to any one of claims 1 to 5, wherein the light diffraction region comprises a plurality of substantially parallel linear diffraction elements, the plurality of substantially parallel linear diffraction elements extending along a first direction within the same plane and arranged along an orthogonal second direction within the same plane.

7. A display system comprising: a plurality of light-emitting pixels, wherein the plurality of light-emitting pixels define a plurality of first inter-pixel regions therebetween, wherein each of the first inter-pixel regions does not have any light-emitting pixel; and a light diffraction layer, the light diffraction layer being disposed on the light-emitting pixel and spaced apart from the light-emitting pixel along the thickness direction of the display system, and the light diffraction layer comprising a plurality of light diffraction regions substantially aligned and extending together in one-to-one correspondence with the plurality of first inter-pixel regions, the light diffraction regions comprising a plurality of substantially parallel linear diffraction elements extending along a first direction in the same plane and arranged along a second direction orthogonal to the same plane, light emitted by the pixel being diffractively transmitted by the light diffraction layer and leaving the display system toward a viewer in the air, the exit light and the comparative exit light of the comparison display system having corresponding intensity distributions and comparative intensity distributions as functions of light propagation angles, the comparison display system having the same construction as the display system except that the light diffraction layer is not included, so that in a first plane parallel to the thickness direction and orthogonal to the first direction and for at least one wavelength in a visible wavelength range extending from about 420 nm to about 680 nm: The peak intensity of the intensity distribution is at least 10% greater than the peak intensity of the comparative intensity distribution; and The half width at half maximum (HWHM) of the intensity distribution is at least 10 degrees smaller than the HWHM of the comparative intensity distribution. 8 . The display system of claim 7 , wherein in a second plane parallel to the thickness direction and the first direction and for the at least one wavelength, a HWHM of the intensity distribution is smaller than a HWHM of the comparative intensity distribution.

9. A display system comprising: a plurality of light-emitting pixels, wherein the plurality of light-emitting pixels define a plurality of first inter-pixel regions therebetween, wherein each of the first inter-pixel regions does not have any light-emitting pixel; and A light diffraction layer, the light diffraction layer is arranged on the light-emitting pixel and is spaced from the light-emitting pixel along the thickness direction of the display system, and the light diffraction layer includes a plurality of light diffraction regions that are substantially aligned and extend together in a one-to-one correspondence with the plurality of first inter-pixel regions, the light diffraction regions include a plurality of substantially parallel linear diffraction elements extending along a first direction in the same plane and arranged along an orthogonal second direction in the same plane, light emitted by the pixel is diffracted and transmitted by the light diffraction layer and leaves the display system toward a viewer in the air, the exit light and the comparative exit light of the comparison display system have corresponding intensity distributions and comparative intensity distributions as functions of the light propagation angle, the comparative display system has the same structure as the display system except that it does not include the light diffraction layer, so that in a first plane parallel to the thickness direction and the first direction, for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, and for each propagation angle in the angular range from at most 10 degrees to at least 50 degrees, the intensity distribution has a larger amplitude than the comparative intensity distribution.

10. A display system comprising: one or more light emitting regions configured to emit light, the one or more light emitting regions being substantially coplanar with one or more non-light emitting regions not configured to emit light; and One or more light diffraction regions, wherein the one or more light diffraction regions are arranged on the one or more non-luminous regions and are spaced apart from the one or more non-luminous regions along the thickness direction of the display system, so that in a top plan view, the one or more light diffraction regions cover more than 60% of the one or more non-luminous regions and less than 40% of the one or more luminous regions, and at least some of the light obliquely emitted by the one or more luminous regions leaves the display system after being diffracted and transmitted by the one or more light diffraction regions, so that in each of a first plane and a second plane both orthogonal to the thickness direction, and for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, a half-width at half maximum (HWHM) of an intensity distribution of the exiting light is less than the HWHM of a comparative intensity distribution of a comparative display system, wherein the comparative display system has the same construction as the display system except that the one or more light diffraction regions are not included.

11. A display system according to claim 10, wherein the one or more light diffraction regions include a plurality of substantially parallel linear diffraction elements, the plurality of substantially parallel linear diffraction elements extending along a first direction within the same plane and arranged along an orthogonal second direction within the same plane, the first plane and the second plane being substantially orthogonal to the corresponding first direction and second direction.

12. A display system comprising: one or more light emitting regions configured to emit light and one or more non-light emitting regions not configured to emit light and substantially coplanar with the one or more light emitting regions; and one or more light diffraction regions, the one or more light diffraction regions being disposed on the one or more non-luminescent regions and spaced apart from the one or more non-luminescent regions in a thickness direction of the display system, such that in a top plan view, the one or more light diffraction regions cover more than 60% of the one or more non-luminescent regions and less than 40% of the one or more luminescent regions, at least some of the light obliquely emitted by the one or more luminescent regions leaves the display system after being diffractively transmitted by the one or more light diffraction regions, Such that in each of at least one plane parallel to the thickness direction and for at least one wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, the normalized intensity distribution of the display system is normalized relative to the comparative intensity distribution of a comparative display system, the comparative display system having the same construction as the display system except that the one or more light diffraction regions are not included, the normalized intensity distribution including a peak at a propagation angle of less than about 10 degrees and a global minimum set between the peak and the propagation angle of less than about 60 degrees.

13. The display system of claim 12, wherein the at least one plane comprises a first plane and a second plane, the first plane and the second plane are both parallel to the thickness direction and form an angle of at least about 30 degrees with each other.

14. A display system according to claim 13, wherein the one or more light diffraction regions include a plurality of substantially parallel linear diffraction elements, the plurality of substantially parallel linear diffraction elements extending along a first direction within the same plane and arranged along an orthogonal second direction within the same plane, the first plane being substantially parallel to the second direction.

15. A display system comprising: one or more light emitting regions configured to emit light and one or more non-light emitting regions not configured to emit light and substantially coplanar with the one or more light emitting regions; and one or more light diffraction regions, the one or more light diffraction regions being disposed on the one or more non-luminescent regions and spaced apart from the one or more non-luminescent regions in a thickness direction of the display system, such that in a top plan view, the one or more light diffraction regions cover more than 60% of the one or more non-luminescent regions and less than 40% of the one or more luminescent regions, at least some of the light obliquely emitted by the one or more luminescent regions leaves the display system after being diffractively transmitted by the one or more light diffraction regions, such that, for first and second substantially mutually orthogonal planes parallel to the thickness direction and for at least one wavelength in a visible wavelength range extending from about 420 nm to about 680 nm, a normalized intensity distribution of the display system is normalized relative to a comparative intensity distribution of a comparative display system, the comparative display system having the same configuration as the display system except that the one or more light diffraction regions are not included, the normalized intensity distribution comprising: a global minimum at a propagation angle of less than about 60 degrees in said first plane; and In the second plane, the magnitude is greater than about 1 for all propagation angles from about zero degrees to at least about 40 degrees.

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