Lighting system utilizing micro-LEDs and lenses, laminated in glass

Abstract

Lighting system (104), comprising: a layer of an optical medium (202), wherein the layer has a first interface (210) and a second interface (216); a light source (204) that emits a light beam (208) which enters the first interface (210) and travels through the optical medium (202) to exit the optical medium (202) at the second interface (216); and a lens arrangement configured to reduce the occurrence of total internal reflection of the light beam (208) at the second interface (216); characterized by the fact that the lens arrangement is incorporated into a surface (220) of one of the first interface (210) and the second interface (216); and / or the light source (204) generates a light beam (208) with a first light distribution profile and wherein the light beam (208) after passing through the lens and the layer of the optical medium (202) has a second light distribution profile, wherein the second light distribution profile has a reduced angular range compared with the first light distribution profile.

Description

introduction

[0001] The subject matter of the invention relates to a lighting system according to the preamble of claim 1 and to a window according to the preamble of claim 4, as is known essentially from US 2020 / 0384740A1.

[0002] A vehicle may have an embedded lighting system comprising a light source embedded in a window or pane of the vehicle. The light source emits a beam of light from a point within the pane, so that it passes through a layer of glass and into the outside environment. The light therefore passes through a first interface to enter the pane and a second interface to exit the pane. A beam of light incident at the first interface at a large angle of incidence may strike the second interface at an angle greater than a critical angle. Such light will undergo total internal reflection at the second interface. This internally reflected light is lost to an observer in the outside environment, thus reducing the brightness of the light source from the observer's perspective.Accordingly, it is desirable to provide a lighting system that can redirect the light to reduce internal total reflection. Summary

[0003] According to the invention, a lighting system is presented which is characterized by the features of claim 1.

[0004] The illumination system comprises a layer of an optical medium, wherein the layer has a first interface and a second interface, a light source emitting a light beam that enters at the first interface and passes through the optical medium to exit the optical medium at the second interface, and a lens arrangement configured to reduce the occurrence of total internal reflection of the light beam at the second interface.

[0005] The lens arrangement is formed or incorporated into a surface of one of the first interfaces and the second interface.

[0006] Additionally or alternatively, the light source may be designed to generate a light beam with a first light distribution profile, wherein the light beam, after passing through the lens and the layer of the optical medium, has a second light distribution profile, the second light distribution profile having a reduced angular range compared to the first light distribution profile.

[0007] In addition to one or more of the features described herein, the lens assembly is in contact with one of the first and second interfaces. A surface of a lens in the lens assembly forms a concave, prismatic, or triangular surface. The layer is part of a vehicle window, and the light source is embedded in the window. The lighting system also includes a diffuser plate between the light source and the optical medium.

[0008] Furthermore, according to the invention, a window of a vehicle is presented which is characterized by the features of claim 4.

[0009] The window comprises a layer of an optical medium, the layer having a first interface and a second interface, a light source emitting a light beam that enters the first interface and travels through the optical medium to exit the optical medium at the second interface, and a lens arrangement configured to reduce the occurrence of total internal reflection of the light beam at the second interface. The lens arrangement is embedded in a surface of the first interface and the second interface.

[0010] Additionally or alternatively, it can be provided that the light source generates a light beam with a first light distribution profile, the light beam has a second light distribution profile after passing through the lens arrangement and the layer of the optical medium, the second light distribution profile having a reduced angular range compared to the first light distribution profile.

[0011] In addition to one or more of the features described here, the lens assembly is in contact with one of the first and second interfaces. The light source is embedded in the window. The lens assembly is incorporated into a surface of the first or second interface. A surface of a lens in the lens assembly forms a concave, prismatic, or triangular surface. The light source is embedded in the window. The light source produces a light beam with a first light distribution profile, wherein the light beam, after passing through the lens and the layer of the optical medium, exhibits a second light distribution profile, the second light distribution profile having a reduced angular range compared to the first light distribution profile.

[0012] In a further exemplary embodiment, a vehicle is disclosed. The vehicle comprises a window with a layer of an optical medium, the layer having a first interface and a second interface, a light source emitting a light beam that enters the first interface and travels through the optical medium to exit the optical medium at the second interface, and a lens arrangement configured to reduce the occurrence of total internal reflection of the light beam at the second interface.

[0013] In addition to one or more of the features described herein, the lens assembly is in contact with one of the first and second interfaces. The lens assembly is located between micro-LEDs of the micro-LED array. One surface of a lens of the lens assembly is a concave surface, a prismatic surface, or a triangular surface.

[0014] The above features and advantages, as well as further features and advantages of the invention, are readily apparent from the following detailed description when viewed in conjunction with the accompanying drawings. Brief description of the drawings

[0015] Further features, advantages and details appear only as examples in the following detailed description, which refers to the drawings in which: Fig. 1 shows a vehicle in an exemplary embodiment; Fig. 2 a diagram showing the behavior of light passing through an optical medium; Fig. 3 shows a deflection of light that takes place using a lens surface at an interface of the optical medium; Fig. 4 shows a meta-lens that can be used to focus a beam of light; Fig. 5 a side sectional view of a window of the vehicle from Fig. 1 shows in one embodiment; Fig. Figure 6 shows a light distribution diagram illustrating different light distribution profiles for the lighting system; Fig. Figure 7 shows a side sectional view of the window of the vehicle in another embodiment; Fig. Figure 8 shows a side sectional view of the vehicle window in another embodiment; Fig. Figure 9 shows a side sectional view of the vehicle window in another embodiment; and Fig. Figure 10 shows a side sectional view of the window in another embodiment. Detailed description

[0016] The following description is merely exemplary. It should be understood that the corresponding reference numbers in the drawings denote identical or corresponding parts and features.

[0017] According to an exemplary embodiment, Fig. 1. A vehicle 100. The vehicle 100 comprises a window 102 with a lighting system 104 embedded therein. The window 102 can be any window of the vehicle 100, including a windshield, a side window, a rear window, etc. Furthermore, the window 102 can be a glass surface of an object such as a mirror, etc. For illustrative purposes, the window 102 described herein is a rear windshield that separates an exterior area 106 of the vehicle 100 from an interior area 108. As disclosed herein, a lighting system 104 is embedded in the windshield. The lighting system 104 is coupled to a processor 110 that controls the operation of the lighting system, for example, to illuminate an area or to display data. For ease of illustration, a coordinate system 112 is shown, which assigns a location orThis corresponds to the position of the lighting system 104 within the window 102. The z-axis of the coordinate system 112 is perpendicular to the outside of the window 102 and points towards the exterior 106. The x-axis and the y-axis lie within, or substantially within, the plane of the window 102. The lighting system 104 includes a deflecting optic, as discussed herein, for deflecting the light. A first arrow 120 indicates a direction in which the light from the lighting system 104 propagates naturally without any deflection. A second arrow 122 indicates a direction in which the light propagates when deflected by the optic of the lighting system 104.

[0018] Fig. Figure 2 shows a diagram 200 illustrating the behavior of light passing through an optical medium 202. The diagram 200 shows a light source 204 located on one side of the optical medium 202 and an observer 206 located on the opposite side of the optical medium 202. In various embodiments, the optical medium 202 is glass, and the light source 204 and the observer 206 are in air. The light source 204 emits light at a variety of angles. An initial light ray 208 is shown, propagating from the light source 204 at an angle to a first interface 210 of the optical medium 202. The refraction of light passing from one medium to another is determined by Snell's law, shown in Figure 1. ni sin θi=nr sin θr, where n ithe refractive index of the medium from which the light ray hits or is incident on the interface and n r The refractive index of the medium into which the light ray passes. The angles θ i and θ r are measured with respect to a line of normal passing through the interface at the point where the light ray is incident.

[0019] The original light ray 208 falls at an angle of incidence θ o at the first interface 210. According to Eq. (1), the original light ray 208 undergoes refraction at the first interface 210, resulting in a first ray 212 in the optical medium. The refraction causes the first ray 212 in the optical medium to be curved away from the normal (i.e., θ RO > θ o Since the second interface 216 is parallel to the first interface 210, the angle of incidence θ is i1For the first ray 212 in the optical medium at the second interface, the angle of refraction θ is the same. RO at the first interface (i.e., θ) i1 = θ RO Therefore, the first ray 212 in the optical medium strikes the second interface 216 at a large angle θ. i1 one. If this angle of incidence is greater than an angle known as the critical angle (i.e., when (θ) i1 > θ c ), a phenomenon known as internal total reflection occurs, in which the first ray 212 in the optical medium is reflected back into the optical medium, as shown by the internally reflected ray 218.

[0020] In the present invention, a lens surface 220 is placed at the first interface 210. The original light ray 208 incident on the lens surface 220 is refracted to form a ray 222 refracted at the lens. As a result of the refraction at the lens surface 220, the ray 222 refracted at the lens incident at the first interface 210 at an angle of incidence θ L , which is smaller than the angle of incidence θ O of the original light ray 208. The ray 222 refracted at the lens produces a second ray 224 in the optical medium 202. The angle of refraction θ RL for the second ray 224 in the optical medium is smaller than the angle of refraction θ OL for the first ray 212 in the optical medium. The second ray 224 in the optical medium therefore strikes the second interface 216 at an angle θ. i2 one that is smaller than the critical angle θ c, which enables an emerging light ray 226 to escape from the optical medium 202 and be seen by the observer 206.

[0021] Fig. Figure 3 is a diagram 300 showing a deflection of light that occurs at the first interface 210 of the optical medium 202 using a lens surface 220. It depicts an original light ray 208 propagating from the light source 204 in a direction perpendicular to the first interface 210. If it is not deflected (i.e., without passing through the lens surface 220), the original light ray 208 passes through the optical medium 202 without deflection and exits the optical medium along the same path as shown by the undeflected ray 302. However, if the original light ray 208 passes through the lens surface 220, the lens deflects the light to form a ray 304 within the optical medium that passes through the optical medium and strikes, or is incident on, the second interface 216 at a non-zero angle.As a result, the emerging light ray 306 is at an angle to the original direction of propagation. Both on . Fig. 3 as well Fig. Referring to 1, the presence of the lens surface 220 changes the propagation of a light ray along the first direction indicated by the first arrow 120 to a second direction indicated by the second arrow 122.

[0022] Fig. Figure 4 shows a meta-lens 400 that can be used to focus a light beam. The meta-lens 400 comprises an optical medium 402 and nanoparticles 404 located within the optical medium. Each of the nanoparticles 404 defines a light transmission axis 406. As shown in Fig. As shown in Figure 4, the nanoparticles 404 are spaced apart from one another along an x-axis that has its origin O at the center of the optical medium 402. The light transmission axis 406 of the nanoparticle 404 located at the origin O is aligned with the z-axis. The angle between a light transmission axis of a nanoparticle 404 and the z-axis increases with increasing distance between the nanoparticle 404 and the origin. In various embodiments, this angle is linearly related to the distance of the nanoparticle 404 from the origin O. Light incident at a first interface 408 perpendicular to the first interface is therefore deflected by each nanoparticle 404 based on its distance from the origin O, resulting in the focusing of the light exiting the optical medium onto a selected focal point 410. Although the meta-lens 400 in Fig. Although the meta-lens 400 is depicted as a two-dimensional object for illustrative purposes, it is generally a three-dimensional object. In such a three-dimensional meta-lens 400, the axis of light transmission of a nanoparticle 404 can be angled based on a radial distance of the nanoparticle 404 from the origin O and lie in a plane perpendicular to the second interface 410, which includes the origin O and the nanoparticle 404.

[0023] Fig. Figure 5 shows a side sectional view 500 of a window 102 of the vehicle 100 in one embodiment. The coordinate system 112 is provided for ease of illustration. The window 102 comprises an inner pane (first pane 502) and an outer pane (second pane 504), which are separated from each other by an intermediate optical bonding or connecting layer 506 that connects the first pane to the second pane. The first pane 502 and the second pane 504 are parallel to an xy-plane. A line normal to the first pane 502 or the second pane 504 is therefore aligned with the z-axis. Together with the first pane 502 and the second pane 504, the intermediate optical bonding layer 506 forms a hollow chamber 508 within which various optical elements are arranged.

[0024] The first disk 502 comprises a first glass layer 510, a backsheet film 512, and a rear adhesive or bonding layer 514 that connects the backsheet film to the first glass layer. The rear bonding layer 514 and the backsheet film 512 are transparent or semi-transparent in the optical range of the electromagnetic spectrum. One or more LEDs or micro-LEDs 516 are arranged within the hollow chamber 508 and attached to the backsheet film 512. The micro-LEDs 516 can be arranged to form a two-dimensional array in the xy-plane. The backsheet film 512 contains conductive wires through which electrical signals can be transmitted from the processor 110 to the micro-LEDs 516 to control their illumination, such as by switching them on and off. The backsheet film 512 can be a transparent substrate or a black printed substrate in various embodiments.The first glass layer 510 can be made from a polycarbonate material in various embodiments.

[0025] The second disk 504 comprises a second glass layer 518, a microlens film 520, and an upper connecting layer 522 that joins the microlens film to the second glass layer 518, thereby suspending the microlens film 520 above the micro-LEDs 516 at a separation distance d. The second glass layer 518 comprises a first interface 210 facing the cavity 508 and a second interface 216 facing the external environment. The microlens film 520 is attached to the first interface 210 of the second glass layer 518. The microlens film 520 comprises a plurality of refractive surfaces 524, which are used to reduce internal total internal reflection effects at the second interface 216 of the second glass layer 518. A refractive surface 524 can be a lens or a microlens. In one embodiment, a microlens comprises a concave surface that is exposed to the hollow chamber 508.In other embodiments, a microlens comprises a triangular surface or a prismatic surface exposed to the hollow chamber. In a further embodiment, the microlens film 520 can be augmented by the meta-lens 400. Fig. 4 can be replaced. The second glass layer 518 can be made of a polycarbonate material in various embodiments.

[0026] The microlens film 520 is arranged in the hollow chamber and is located between the array of micro-LEDs 516 and the second glass layer 518. Since the microlens film 520 extends over the area of ​​the array of micro-LEDs 516, at least one microlens receives light at a high angle of incidence. Light 526 incident at a high angle of incidence on a microlens is refracted by the microlens in such a way that the angle at which light incident on the second glass layer 518 is reduced, thereby reducing the occurrence of total internal reflection, as described in relation to Fig. 2 was discussed. In various embodiments, the microlens, which receives the light at a high angle of incidence, is located outside a central axis of a micro-LED and, viewed in the xy-plane, can be situated between two micro-LEDs.

[0027] Fig. Figure 6 shows a light distribution diagram 600 illustrating different light distribution profiles for the lighting system. A first light distribution profile 602 shows an initial angular light distribution for the array of micro-LEDs 516 before their light beam passes through the microlens film 520 and the second glass layer 518. The first angular light distribution has a relatively uniform brightness over an angular range of approximately seventy degrees to the direction of the normal (0°). The second light distribution profile 604 shows a second angular light distribution after the light beam has passed through the microlens film 320 and the second glass layer 318. The light beam is more focused, exhibiting high brightness over a range of approximately 35 degrees to the direction of the normal. Furthermore, the brightness in the direction of the normal is greater for the second light distribution profile 604 than for the first light distribution profile 602.It is understood that the second light distribution profile 604 is an illustrative distribution profile, which is defined by the in . Fig. Figure 5 shows a special triangular-shaped surface of the microlens film 520. A different light distribution profile will result from the use of microlenses with differently shaped surfaces. Furthermore, a designer can select a specific shape or type of surface for the microlens film 520 to achieve a desired light distribution profile.

[0028] Fig. Figure 7 shows a side sectional view 700 of the window 102 of the vehicle 100 in another embodiment. The window 102 comprises the first pane 502, the second pane 504, and the intervening optical interconnect layer 506, which forms a cavity 508 between the first pane 502 and the second pane 504. The first pane 502 comprises the backing film 512, a rear interconnect layer 514, and the first glass layer 510. The rear interconnect layer 514 connects the backing film 512 to the first glass layer 510 to form a light chamber 702, within which the one or more micro-LEDs 516 are arranged. The second pane 504 comprises the second glass layer 518, a microlens film 520, and an upper interconnect layer 522, which connects the microlens film to the second glass layer 518. The microlens film 520 can, in various embodiments, have lenses with light-refracting surfaces 524 or the meta-lens 400 made of Fig. 4. The light from the micro-LEDs 516 passes through the first glass layer 510 to enter the cavity 508. The first glass layer 510 can act as a diffuser plate to scatter the light from the array of micro-LEDs 516. This scattering improves the homogeneity of the light but also increases the angle of incidence at the microlens film 520. The microlens film 520 then deflects the light rays along a direction determined by its lens surfaces.

[0029] Fig. Figure 8 shows a side sectional view 800 of the window 102 of the vehicle 100 in another embodiment. The window 102 comprises the first pane 502, the second pane 504, and the intervening optical interconnect layer 506, which forms a cavity 508 between the first pane 502 and the second pane 504. The micro-LEDs 516 are arranged in the cavity 508.

[0030] The first disk 502 comprises the first glass layer 510, the backing film 512, and the back bonding layer 514 for connecting the backing film to the first glass layer. The second disk 504 comprises the second glass layer 518, the microlens film 520, and the top bonding layer 522, which connects the microlens film to the second glass layer 518. The microlens film 520 is located on the outer surface (i.e., the second interface 216) of the second glass layer 518. The presence of the microlens film 520 at the second interface 216 modifies the critical angle of the second interface (with respect to a glass-air interface) and therefore reduces the occurrence of total internal reflection at the second interface. Furthermore, uniformly parallel light is deflected uniformly at the second disk 504.The microlens film 520 can in various embodiments have lenses with light-refracting surfaces 524 or the meta-lens 400 made of . Fig. 4.

[0031] Fig. Figure 9 shows a side sectional view 900 of the window 102 of the vehicle 100 in a further embodiment. The second pane 504 comprises only the second glass layer 518. The second glass layer 518 has a first interface 210 facing the cavity 508 and a second interface 216 facing the external environment. The first interface 210 is a planar interface. The second interface 216 is a non-planar interface formed or etched into the shape of a plurality of lens surfaces 902. In various embodiments, the lens surfaces 902 can be triangular, concave, etc.

[0032] Fig. Figure 10 shows a side sectional view 1000 of window 102 in another embodiment. In contrast to Fig. 9 The intermediate optical bonding layer 506 fills the space between the first disk 502 and the second disk 504, so that no cavity is present. The second glass layer 518 also has a first interface 210 in contact with the intermediate optical bonding layer 506 and a second interface 216 facing the external environment. The first interface 210 is a planar interface. The second interface 216 is a non-planar interface that is formed or etched into the shape of a plurality of lens surfaces 902. In various embodiments, the lens surfaces 902 can be triangular, concave, etc.

[0033] Similar to Fig. 10 can Fig.8 be constructed in such a way that the intermediate optical connecting layer 506 fills the space between the first disk 502 and the second disk 504, so that no hollow chamber is present.

Claims

[1] Lighting system (104), comprising: a layer of an optical medium (202), wherein the layer has a first interface (210) and a second interface (216); a light source (204) that emits a light beam (208) which enters the first interface (210) and travels through the optical medium (202) to exit the optical medium (202) at the second interface (216); and a lens arrangement configured to reduce the occurrence of total internal reflection of the light beam (208) at the second interface (216); characterized by , that the lens arrangement is incorporated into a surface (220) of one of the first interface (210) and the second interface (216); and / or the light source (204) generates a light beam (208) with a first light distribution profile and wherein the light beam (208) after passing through the lens and the layer of the optical medium (202) has a second light distribution profile, wherein the second light distribution profile has a reduced angular range compared with the first light distribution profile. [2] Lighting system (104) according to claim 1, wherein the lens arrangement is in contact with: (i) the first interface (210); and (ii) the second interface (216). [3] Lighting system (104) according to claim 1, further comprising a diffuser plate between the light source (204) and the optical medium (202). [4] Window (102) of a vehicle (100), comprising: a layer of an optical medium (202), wherein the layer has a first interface (210) and a second interface (216); a light source (204) that emits a light beam (208) which enters the first interface (210) and travels through the optical medium (202) to exit the optical medium (202) at the second interface (216); and a lens arrangement configured to reduce the occurrence of total internal reflection of the light beam (208) at the second interface (216); characterized by , that the lens arrangement is incorporated into a surface of one of the first interface (210) and the second interface (216); and / or the light source (204) generates a light beam (208) with a first light distribution profile and wherein the light beam (208) after passing through the lens arrangement and the layer of the optical medium (202) has a second light distribution profile, wherein the second light distribution profile has a reduced angular range compared with the first light distribution profile. [5] Window (102) according to claim 4, wherein the lens arrangement is in contact with: (i) the first interface (210) and (ii) the second interface (216). [6] Window (102) according to claim 4, wherein the light source (204) is embedded in the window (102).

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