Integrated optically functional multi-layer structure and related manufacturing method - Patents.com

Abstract

An integrated functional multi-layer structure (100, 200, 300, 350, 500, 600, 700, 800, 900, 1000) comprising a flexible, preferably 3D formable and thermoplastic substrate film (102) and a circuit (104, 105, 106) provided on the substrate film, the circuit (104, 105, 106) comprising a first light source (104) comprising at least one light emitting unit (optionally an LED), the circuit (104, 105, 106), and a monolithic light guide layer (108) molded on the substrate film to cover and optically couple to the first light source (104), the light guide layer (108) comprising an optically attenuating semi-transparent material, the light guide layer (108) including a first surface (108A) and an opposite second surface (108B), the second surface (108B) facing the first light source (104), and the first surface (108A) a portion of the first light source (104) including a predefined out-coupling region (112) for light emitted by the first light source (104) and transmitted through the light guiding layer (108) within a first distance (H) from the first light source (104), the light guiding layer (108) further including a no-leak region (114) that does not overlap the out-coupling region (112) and is separated from the first light source (104) by at least a second, preferably larger, distance (D). a functional multilayer structure, wherein the attenuation of the emitted light occurring on a direct optical path between the first light source (104) and the out-coupling region (112) is less than the attenuation occurring on a shortest, optionally also direct, optical path between the first light source (104) and the light-restriction region (114), and further wherein the optical transmittance of the semitransparent material of the light guide layer is from about 25% to about 80% at the selected wavelength for an approximately 2 mm thick sample of the semitransparent material, while the associated half-power angle is from about 5 to about 70 degrees. Related manufacturing methods are presented.

Description

[Technical field]

[0001] The present invention relates generally to a monolithic structure incorporating various functional features such as electronic, mechanical or optical elements. In particular, but not exclusively, the present invention relates to the provision of a structure including several light sources adapted to emit light also outside the structure. [Background technology]

[0002] In the context of various functional ensembles, for example in the field of electronics and electronic products, there are various different stacked assemblies and multi-layer structures. For example, the motivation behind integrating functionality including electronics, mechanical features, or optical features can be as diverse as the relevant use scenarios. Relatively often, when the resulting solution ultimately exhibits multi-layering, size reduction, weight reduction, cost reduction, or just efficient integration of components is required. And the relevant use scenarios may concern product packaging or casing, visual design of device housing, wearable electronics, personal electronic devices, displays, detectors or sensors, vehicle interiors, antennas, labels, vehicle electronics, etc.

[0003] Electronic devices, such as electronic components, ICs (integrated circuits), and conductors, may generally be provided on substrate elements by a number of different techniques. For example, prefabricated electronic devices, such as various surface mounted devices (SMDs), may be attached onto substrate surfaces that ultimately form inner or outer interface layers of a multi-layer structure. Furthermore, techniques falling under the term "printed electronics" may be applied to actually manufacture electronic devices directly and additively on the substrates involved. The term "printed" in this context refers to various printing techniques (e.g., without limitation, screen printing, flexographic printing, and inkjet printing) that can manufacture electronic devices / electrical elements from printed matter through a substantially additive printing process. The substrates used may be, but are not necessarily, flexible and organic printed materials.

[0004] Furthermore, the concept of injection molded structural electronics (IMSE) involves building functional devices and parts therefor in the form of multi-layered structures that encapsulate the electronic functions as seamlessly as possible. A feature for IMSE is also that electronics are generally manufactured in real or more real 3D (non-planar) shapes according to an overall 3D model of the target product, part, or general design. To achieve the desired 3D layout of electronics on the 3D substrate and in the associated final product, the electronics may also be provided using two-dimensional (2D) methods of electronics assembly on an initially planar substrate (e.g., a film), whereupon the substrate already housing the electronics may be formed into the desired three-dimensional (i.e., 3D) shape and subjected to overmolding. This may be done, for example, with a suitable plastic material that covers and embeds the underlying elements (e.g., electronics), thus protecting and potentially hiding the elements from the environment. Of course, further layers and elements may be added to the configuration.

[0005] In connection with a monolithic structure packed with various optically functional features (eg, light sources), various problems are readily presented and advantageously addressed.

[0006] For example, unwanted light leakage from a structure and between its different internal volumes and regions can easily cause both functional and aesthetic problems, for example in the field of illumination and sensing, as those skilled in the art will readily appreciate. Therefore, in the past, various additional light blocking components, material layers, light guide arrangements, cavity structures, machining, etc. have been introduced to address this problem. However, these conventional solutions typically increase the cost, weight, thickness, general size, complexity, and therefore manufacturing time of the structure, and often even the resulting yield, while at the same time requiring the preparation and use of various additional tools. However, the final result may not be perfect in terms of the optical objectives originally set for the structure being taken into account.

[0007] Furthermore, achieving high resolution control of the internal and out-coupled light, e.g., in terms of the shape, size, and location of the illuminated surface area, can be difficult, at least at times, in highly integrated structures: to achieve the desired end result, one may need to place the light source sub-optimally close to the desired exit or "out-coupling" surface of the light, while being forced to stick to a fairly limited number of orientations or types of light sources that are typically made available, e.g., for conventional top- or side-shooting LEDs.

[0008] In various applications, controlling or especially improving the uniformity, for example, on the light outcoupling surface, has previously proven to be a burden. This can be a significant issue when the surface includes an icon or symbol that should be uniformly illuminated, for example, to indicate to an observer outside the structure that a device function or status associated with the icon or symbol is active. Simply utilizing multiple light sources to more effectively illuminate a common target area or feature (e.g., an icon) can still result in illumination hotspots and leakage, while also requiring more (often valuable) power and space. Adding light guides or processing elements into the structure then has its own drawbacks, as already discussed above.

[0009] In some cases, a light source included in an integral structure, for example to illuminate certain internal features or the environment of the structure, must remain hidden from external perception. Placing additional masking elements or layers (e.g., printed layers) on the light path of the light source to simply better hide the light source from the environment may work in a limited way, but usually is also detrimental to the optical efficiency of the structure and may result in poor yields, since the masking effect may be difficult to reliably control during manufacturing. In any case, the structure becomes bulkier, heavier, and more complex, while placing further limitations on the usability of, for example, additional optical features along the light path.

[0010] However, in the field of these optically integrated structures (e.g. LED matrix or segmented displays), the optical dividing grid may be embedded within the structure, usually in combination with some overlay material in the form of a sheet of material, which creates various problems, such as a significant increase in the overall thickness of the structure, a significant amount of assembly work, especially when preparing true 3D structures (e.g. curved or doubly curved structures), color-related limitations, and design constraints regarding the overall appearance and configuration.

[0011] Yet reworking included (e.g., optical) features has been extremely difficult, if not completely impossible, in today's highly integrated structures. Replacement or updating of parts has typically required extensive dismantling and destruction of the existing structure. Summary of the Invention

[0012] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to at least alleviate one or more of the drawbacks associated with known solutions in the context of an integrated construction of an optical function, an associated receiving device and an associated manufacturing method.

[0013] This objective is achieved by various embodiments of an integrated functional multi-layer structure and related methods for providing the multi-layer structure.

[0014] According to one embodiment, the integrated functional multi-layer structure includes a flexible, preferably 3D formable and thermoplastic substrate film, a circuit provided on the substrate film, the circuit including a first light source including at least one light emitting unit (optionally an LED), and a monolithic light guide layer molded on the substrate film to cover and optically couple to the first light source, the light guide layer including an optically attenuating translucent material, the light guide layer including a first surface and a second surface opposite the first surface, the second surface facing the first light source, a portion of the first surface being transparent to light emitted by the first light source and transmitted through the light guide layer within a first distance (H) from the first light source. and the lightguide layer further comprises a no-leak area that does not overlap the out-coupling area and is separated from the first light source by at least a second, preferably greater distance (D), wherein the attenuation of the emitted light occurring on a direct optical path between the first light source and the out-coupling area is less than the attenuation occurring on a shortest, optionally also direct, optical path between the first light source and the no-leak area, and preferably further wherein the light transmittance of the translucent material of the lightguide layer is between about 25% and about 80% at a selected wavelength (e.g., visible, infrared, and / or other target wavelength) for an about 2 mm thick sample of the translucent material, and / or an associated half-power angle is between about 5 and about 70 degrees.

[0015] The light guide material may, in some embodiments, include sub-volumes or sections of different properties (e.g., may optionally include one or more substantially transparent portions or sections having about 90%, 95% or more transmittance and / or half-power angles of about a few degrees or substantially 0%), and suitable optical properties may be considered specifically for the sub-volumes or sections. In some embodiments, the preferred half-power angle for the aforementioned samples may be higher than 70 degrees at least at the selected wavelength(s). However, the angle may depend on the wavelength of light. In some embodiments, the angle may vary, for example, from about 10 to 50 degrees within the range of the target wavelength. In some embodiments, the half-power angle should be at least about 10 or 20 degrees within the selected wavelength(s). In these or other embodiments, the half-power angle should preferably not exceed about 50 or 60 degrees, respectively.

[0016] The semi-transparent material used may exhibit a desired color (e.g., red, blue, green, yellow, etc.), i.e., the material may, for example, better reflect or transmit certain wavelengths and filter out other wavelengths by absorption. The semi-transparent material may, in some preferred embodiments, exhibit, for example, a substantially white or whitish appearance. The material may emit corresponding, substantially all or most visible wavelengths, 400-700 nm. Alternatively, the material may appear very opaque (e.g., dark if not substantially black), meaning that most wavelengths are significantly absorbed or otherwise attenuated by the material. The material properties (e.g., presented color(s) / filtered wavelengths) may result from color pigments or masterbatches originally applied in the transparent resin, as described in more detail below. In some preferred embodiments, the desired transmittance may be about 50% to about 60% (2 cm thick sample). The preferred half-power angle may, for example, be about 40 to about 50 degrees for samples of similar thickness.

[0017] A so-called light depletion distance (DD) from the first light source, which indicates a selected predominant or significant, e.g. 90% or significantly more as described below, amount of intensity loss of the light emitted by the first light source at a selected wavelength, preferably at least at visible wavelengths, during propagation through the translucent material, advantageously lies between the first distance (H) and the second distance (D) or corresponds substantially to the first distance (H) or the second distance (D).

[0018] The relevant depletion characteristic or indicator may first be determined, for example, through measuring on the surface of the material by comparing the surface area and / or specifically the area of ​​e.g. an icon provided thereon (printed, coated, mask aperture based, etc.) with respect to their optical emission characteristics (e.g. brightness due to light emitted by the first light source). For example, the ratio of the maximum brightness (L_max_leaked) of the area outside the out-coupling area to the average brightness (L_average_illuminated) of the intentionally illuminated area (e.g. the out-coupling area or a sub-area thereof, preferably even larger than the area outside the out-coupling area) may be determined (i.e. L_max_leaked / L_average_illuminated).

[0019] The diameter or size of the area outside the out-coupling area used as a numerator in the comparison may be selected as the case may be, but may for example consider half the line width of the icon, or may for example consider a selected percentage of the diameter or size of the intentionally illuminated area which in turn is used as a reference type of divider in the ratio. A desired threshold may be selected for the ratio, for example 10% (corresponding to a ratio of 0.1), or preferably less, for example about 1%, about 0.1%, or less. The distance from the first light source to the area outside the particular out-coupling area on the light guide layer that provides the selected threshold may then be considered as the light depletion distance. In many practical applications, the depletion distance may be on the order of magnitude, for example about a few millimeters, centimeters, or centimeters, or more, as will be understood by those skilled in the art based on the teachings and discussion provided herein. In some alternative embodiments, the luminance measured to determine the ratio may be either the maximum luminance or the average luminance. Additionally or alternatively, the areas considered in the ratio may be of the same diameter or size.

[0020] Correspondingly, the light-proof area may define a portion or portions of the first surface of the light guide layer, and the intensity of the light of the first light source that is coupled out through the light-proof area through said portion of the first surface of the light guide layer is then preferably less than about 5%, more preferably less than about 2% or 1%, and most preferably less than about 0.1% of the light emitted by the first light source at the selected wavelength, preferably at least visible wavelengths, that is coupled out through the out-coupling area. Obviously, the intensity of the light that is coupled out through said portion or any such portion should preferably be at most less than or equal to that provided at the depletion distance. In general, similar luminance determinations (typically measured as Cd / m^2) and ratios (and e.g. areas) as described above may again be considered for each of the light intensity measurements and subsequent ratio determinations.

[0021] Furthermore, the selected surface area(s), e.g., the out-coupling area, a portion thereof (e.g., an illuminated icon thereon, or a portion of an icon), or a surface area included in, defined by, or consisting of a no-light-leak area on the first surface of the light guide layer, may preferably exhibit a desired value of luminance uniformity, e.g., at least about 50%, or more preferably at least about 70%, in response to the light of the first light source out-coupled therethrough. The desired method of measuring uniformity may be flexibly selected or determined by the skilled person, but one applicable definition is the minimum luminance / maximum luminance ratio (e.g., 0.7 ratio, thus naturally corresponding to 70% uniformity). In case of an icon, the diameter of the measurement area may correspond, for example, to the line width of the icon. In general, a larger target surface area under scrutiny may be divided into several typically non-overlapping measurement (sub)areas (e.g., 4, 6, 8, or 10 areas, or more), preferably of equal size, from which the areas providing the maximum and minimum luminance are first identified and the ratio is then determined. For this measurement, and other measurements focusing specifically on properties related to light or light intensity, or for example luminance, a suitable device may be applied, for example a luminance meter.

[0022] The discussion provided above and below with respect to the first light source is, of course, generally applicable, mutatis mutandis, to other light sources and their respective output coupling areas, no-light-leak areas, and associated distances as they relate to them.

[0023] The structure may optionally include a second light source disposed on the substrate film and covered by the light guide layer, the second light source configured to emit light into and out-couple from the light guide layer through at least a portion of the no-leak light area of ​​the first light source, the distance between the second light source and the no-leak light area being less than a second distance (D). Thus, the no-leak light area of ​​the first light source may include at least a portion of the light out-coupling area of ​​the second light source.

[0024] The second light source may be positioned, and optionally aligned, such that the intensity of light emitted by the second light source and reaching the out-coupling region of the first light source is less than the intensity of light reaching the no-leak light region of the first light source. Thus, the no-leak light region of the second light source may include at least a portion of the out-coupling region of the first light source.

[0025] Additional light sources may be included in the multi-layer structure, each of which may be configured generally according to the above principles to reach its own out-coupling region on the first surface with a desired intensity and / or other properties, while out-coupled light therefrom does not substantially reach the light-prohibited regions of the other light sources. Additionally or alternatively, some of the included light sources may have out-coupling regions and / or light-prohibited regions that are at least partially bonded to one another.

[0026] In accordance with the principles generally defined in this specification, preferably at least a first light source is oriented with respect to at least its light emission direction(s) so as to provide or direct more light towards the associated out-coupling region than the no-light-leak region and / or to make the resulting out-coupling region larger(larger) and / or farther away, or vice versa.

[0027] In a further aspect, a method for producing an integrated functional multi-layer structure includes: Obtaining a flexible substrate film, preferably comprising a formable, optionally thermoformable material; providing a circuit on the substrate film t, preferably using printed electronics technology and / or selected packaging technology, said circuit including a first light source including at least one light emitting unit (optionally an LED); fabricating, optionally by molding or casting, a monolithic light guide layer, which is optically attenuating, translucent and preferably also thermoplastic, on the substrate film to cover, optically couple and preferably at least partially embed the first light source; the light guide layer and the first light source are configured with respect to each other such that the light guide layer includes a first surface and an opposing second surface, the second surface facing the first light source, a portion of the first surface including a predefined out-coupling area for light emitted by the first light source and transmitted through the light guide layer within a first distance (H) from the first light source, the light guide layer further including a no-leak light area, the no-leak light area not overlapping the out-coupling area and spaced apart from the first light source by at least a second, preferably larger, distance (D), such that an attenuation of the emitted light occurring on a direct light path between the first light source and the out-coupling area is less than an attenuation occurring on a shortest, optionally also direct, light path between the first light source and the no-leak light area, and The light transmittance of the translucent material of the light guide layer is from about 25% to about 80% at the selected wavelength for an approximately 2 mm thick sample of the translucent material, while the associated half-power angle is from about 5 to about 70 degrees.

[0028] The present invention offers different advantages over a wide variety of previously implemented solutions, depending of course on each particular embodiment thereof.

[0029] In various embodiments, optically attenuating (scattering and / or absorbing), semi-transparent, potentially colored, or more strongly colored materials (e.g., typically thermoplastics) (which can generally be selected or configured with great flexibility) may be utilized as light guide materials in the structures to effectively control light propagation and confine it to desired areas and distances while avoiding substantial leakage to non-desired areas, referred to as no-light areas. Thus, different surfaces, icons, symbols, shapes, other features and structures may be effectively and controllably illuminated while non-target areas, even close or adjacent areas, are not exposed to similar illumination. This facilitates providing highly integrated smaller sized structures, where different features can be placed close to each other without causing interaction problems due to their rather short distances.

[0030] The light source used may for example be provided with a carrier element that allows the light source to be oriented as desired, thus offering the possibility for example to flexibly adjust its emission direction and the resulting out-coupling area with respect to its position and size. For example, a top-shooting light source may be tilted such that its beam is shifted laterally from directly above the light source towards the side(s). Various embodiments of the invention can be manufactured or implemented substantially mould-independently, and therefore for example different printing layouts can be easily accommodated. However, the invention proposes a low-cost and relatively simple approach to implementing a solution for many purposes. A great many realizable light guide materials have rather low injection moulding temperatures, which may make for example the use of IMSE techniques even more reliable and increase the associated yields. This is in contrast to materials that require high moulding temperatures, which easily adversely affect the function and condition of already existing features on the substrate film(s) or other elements exposed to such temperatures.

[0031] The aforementioned light guide material is advantageously scattering or diffusive (large scale scattering or multiple scattering can be considered as diffusion) so that the lighting effect obtained by, for example, a light source embedded on a selected target surface (e.g., outer surface) of a structure (which may include, for example, icons or other graphical elements to be illuminated) is uniform without obvious hot spots or dark areas, while still avoiding significant or at least excessive light leakage into adjacent areas that may optionally be associated with different light source(s) and target features (e.g., icons) to be illuminated separately.

[0032] The color, translucency or diffusion properties of the material(s) used (e.g. lightguide material) may be configured, for example, by mixing therein additives (e.g. selected masterbatches or pigment-based color additives). However, the materials of the lightguide layer or other layer(s) may locally differ in terms of their properties (e.g. attenuation or especially diffusion) even within one and the same integrated layer or part, obtained by varying the material properties (e.g. mixing ratios) during manufacture or its application.

[0033] Various embodiments of the invention furthermore make it possible to provide so-called "hide until lit" effects, for example in IMSE structures, by a clever combination of the materials used, the light sources, e.g. their mutual positioning, orientation, and dimensions. For example, structures or various components as well as elements such as graphical symbols provided in conductive traces can be hidden from external visual perception until the light source targeted to illuminate them is activated. In these types of embodiments of the invention, it is possible to have decorative surface printing on the output coupling areas, e.g. on the relevant films (not only the openings), and by embedding features that should be masked from simple external visual perception, e.g. at a depth of several mm in the light guide material, the relevant optical aspects are much easier to control than when using very shallow layers. The proposed solution also saves time and costs process-wise.

[0034] For example, for implementing (LED) matrix or segmented displays, various embodiments of the present invention provide distinct advantages by reducing or overcoming typical problems with light spill (leakage) and uniformity, and further enabling 3D shaped displays (e.g. curved displays or 3D dome displays), while requiring fewer wiring (traces).

[0035] Additionally, to improve light uniformity in a target area and further reduce the number of light sources required, the multi-layer structures described herein may include one or more diffusers, which may even be monolithic with the light guide material.

[0036] In various embodiments, some elements of the multi-layer structure (e.g., at least one light source) may be contained within a module whose interior remains accessible after fabrication of the structure via a removable cover. Thus, the contained elements may be conveniently accessed, for example, for purposes of inspection, repair, rework, reprogramming, or replacement. The module may include a wall structure and an internal hollow section that houses one or more elements and, optionally, a joint carrier (e.g., a circuit board therefor).

[0037] In some embodiments, a reflector may be provided around one or more light sources to, for example, reduce light leakage and improve the intensity and uniformity of the light on the target out-coupling surface. Reflectors may be conveniently implemented, for example, in conjunction with aspects of the modules and circuit boards described above.

[0038] Various other advantages provided by different embodiments of the present invention will become apparent to those skilled in the art based on the following detailed description.

[0039] The expression "several," as used herein, may refer to any positive integer starting with one (1) and up to, for example, one (1), two (2), or three (3).

[0040] The expression "plurality" may each refer to any positive integer beginning with two (2).

[0041] The terms "first" and "second" are used herein, unless otherwise specified, to distinguish one element from another element(s) and are not used to particularly prioritize or order them.

[0042] The exemplary embodiments of the invention presented herein should not be construed as creating limitations on the applicability of the appended claims. The verb "comprise" is used herein as an open limitation that does not exclude the presence of unrecited features. Features recited in various embodiments (e.g., dependent claims) are freely combinable with one another unless expressly stated otherwise.

[0043] The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims, but the invention itself, both as to its organization and its method of operation, together with further objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

[0044] Some embodiments of the present invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. [Brief description of the drawings]

[0045] [Figure 1] 1 illustrates various aspects of the invention through an embodiment of a multi-layer structure according to the invention; [Diagram 2] FIG. 13 illustrates another embodiment in which different features, including, for example, 3D shaping of the substrate film portion that receives the light source, can be utilized, at least selectively, in addition to or instead of those of other embodiments contemplated herein to implement the present invention. [Figure 3A] FIG. 1 illustrates another embodiment, the different features of which, for example, the use of one or more side-shooting light sources, optical masking or light control features, may be utilized, at least selectively, in addition to or instead of any of the other embodiments contemplated herein for carrying out the invention. [Figure 3B]FIG. 1 illustrates another embodiment, different features of which, e.g., the use of multiple light-emitting units in a light source, may be utilized, at least selectively, in addition to or instead of any of the other embodiments contemplated herein for carrying out the present invention. [Figure 4] FIG. 2 is a flow diagram of an embodiment of a method according to the present invention. [Diagram 5] FIG. 1 shows another embodiment of a multilayer structure, the different features of which, for example the provision of an inclined carrier element for a light source, can be utilized, at least selectively, in addition to or instead of any of the other embodiments contemplated herein for implementing the present invention. [Figure 6] FIG. 1 illustrates another embodiment of a multi-layer structure, different features of which, e.g., a diffuser, may be utilized, at least selectively, in addition to or instead of any of the other embodiments contemplated herein for carrying out the present invention. [Figure 7] FIG. 1 illustrates an embodiment of an at least partially replaceable and / or post-installation accessible module that includes one or more of the light sources and / or other circuits that can be utilized in connection with various embodiments of the present invention. [Figure 8] FIG. 1 illustrates another embodiment of a multi-layer structure, the different features of which, such as a reflector or a preferably rigid circuit board for a circuit that preferably includes at least one light source, may be utilized, at least selectively, in addition to or instead of any of the other embodiments contemplated herein for implementing the present invention. [Figure 9] FIG. 1 illustrates another embodiment of a multi-layer structure, the different features of which, e.g., voids, may be utilized, at least selectively, in addition to or instead of any of the other embodiments contemplated herein for carrying out the invention. [Figure 10]FIG. 1 illustrates another embodiment of a multilayer structure, the different features of which, for example, a 3D-shaped film having optical functionality or other 3D-shaped (i.e., not merely substantially planar) material layer, may be utilized, at least selectively, in addition to or instead of any of the other embodiments contemplated herein for carrying out the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] FIG. 1 shows an embodiment of a multi-layer structure according to the present invention at 100.

[0047] The multi-layer structure includes at least one substrate film 102, which is preferably made of a flexible, 3D formable (moldable) material, such as a thermoformable (plastic) material. As will be readily understood by those skilled in the art, instead of a single, optionally monolithic film 102, the substrate film 102 can be of a multi-layer and / or multi-section construction, for example having layers that are different from one another, at least in places.

[0048] Item 108 refers to at least one light guide layer, preferably provided by molding on the substrate film 102, optionally between the substrate film 102 and element 120. This may be, for example, another (substrate) film, either different or similar to film 102.

[0049] The light guide layer 108 includes a first side and associated first surface 108A. The first surface 108A is advantageously directed to the environment of use of the structure, e.g., a user of the structure, or a device that includes the structure therein. Additionally, the substrate film 102 includes an opposing second side and associated second surface 108B. The second surface 108B, for example, substantially faces the interior of the structure or a receiving device.

[0050] As previously mentioned, item 120 may refer to at least one additional film, coating, or other functional element. In many embodiments, multiple such may be deposited, at least locally, on surface 108A.

[0051] The substrate film 102 and / or the further film(s) 120 or generally the material layer(s) included in the multi-layer structure may comprise at least one material selected from the group consisting of polymers, thermoplastic materials, electrically insulating materials, PMMA (polymethyl methacrylate), polycarbonate (PC), flame retardant PC film, copolyesters, copolyester resins, polyimides, copolymers of methyl methacrylate and styrene (MS resins), glass, polyethylene terephthalate (PET), carbon fibers, organic materials, biomaterials, leather, wood, textiles, fabrics, metals, organic natural materials, solid wood, veneers, plywood, bark, tree bark, birch bark, cork, natural leather, natural fiber or fabric materials, naturally grown materials, cotton, wool, linen, silk, and any combination.

[0052] The thickness of the film 102 and optionally further film(s) or layer(s) 120 may vary depending on the embodiment: it may be, for example, only a few tens or hundreds of millimeters, or it may be much thicker, on the order of one or several millimeters.

[0053] The thickness of the light guide layer 108 may also be selected on an as-needed basis, but may be as little as a few millimeters (e.g., about 2-5 millimeters). The thickness may be significantly greater as well, e.g., about 1 cm or more, at least in places. The thickness may in fact vary locally. In addition to housing various elements (e.g., electronic or optical elements), the light guide layer 108 may optionally include recesses or internal cavities, e.g., for light guiding, processing, and / or thermal management purposes.

[0054] Item 104 refers to circuitry provided on the substrate film 102, in particular circuitry including light source type circuits or components. If the structure includes a further film 120, the film 120 may also be provided with circuitry including, for example, the light source(s) and may optionally be electrically or electromagnetically connected to the circuitry on the film 102, for example via intermediate wiring or wirelessly (e.g. capacitively or inductively).

[0055] As shown, a (first) light source 104 emits light as indicated by the dotted line extending from the light source 104 to a target out-coupling region 112 on the light guide layer 108, which may be, for example, a top shooting LED. The out-coupling region 112 is within a first distance H from the light source 104, such that the shortest distance between the first light source 104 and the out-coupling region 112 is equal to or less than the first distance H.

[0056] Preferably, but not necessarily, in various embodiments, the minimum distance is less than about 20 millimeters, more preferably less than about 10 millimeters, even more preferably less than about 8 millimeters, and most preferably less than about 5 millimeters, e.g., about 2-5 millimeters. Similarly, the order of magnitude of the first distance H that defines an outer limit for the distance between the first light source 104 and the associated out-coupling region 112 may be about the same or greater, as will be appreciated by those skilled in the art.

[0057] Item 105 refers to a possible further, or second, light source, which may be similar or different to the first light source 104, for example in terms of radiation characteristics (emission technology, wavelength, power, beam type and direction, etc.), configuration or dimensions. The second light source 105 is located at a distance from the first light source 104. The distance may be selected accordingly. For completeness, it is of course mentioned that in various embodiments of the invention, more light sources 104, 105 may be embedded. These may be jointly or independently controllable by included or at least functionally connected control circuit(s).

[0058] In a supplementary or alternative embodiment, the light source 104, 105 may be, for example, any of top-emitting, side-emitting, double-sided-emitting, and bottom-emitting LEDs, or other types of light sources. In general, for example, packaged semiconductor type or chip-on-board semiconductor type light sources (preferably LEDs) may be used. Furthermore, in terms of packaging, the light source 104, 105 may optionally be of flip-chip type. In some embodiments, the light source 104 may include multiple (two, three, four, or more) light-emitting units (e.g., LEDs) packaged or at least grouped together. For example, a multicolor or specifically RGB (red-green-blue) LED consisting of multiple LED emitters may be provided in a single package.

[0059] Item 114 preferably refers to a light forbidden region that receives less light from and / or transmits less light of the first light source 104. The optional second light source 105 mentioned above may still be located, for example, within the light forbidden region 104 or at least closer to the light forbidden region than the first light source 104. The first light source 104, in this embodiment, has a direct line of sight (LOS) to both the out-coupling region 112 and the light forbidden region 114 that is substantially free of blocking elements.

[0060] In some embodiments, the light forbidden region 114 may consist substantially of a surface region or area of ​​the light guide layer 108 above the first surface 108 A. In some other embodiments, the light forbidden region 114 may additionally or alternatively include or consist of at least a volume or area of ​​the light guide layer 108 below the surface 108 A (e.g., at least a plane intersecting the substrate film 102 at distance D), as illustrated in FIG.

[0061] Indeed, in some embodiments, the no-light-leak area 114 may define a selected, optionally substantially cubic, cubic or cylindrical sub-volume of the light guide layer 108, for example, optionally extending through the light guide layer 108 in a direction spanning the first surface 108A and the second surface 108B.

[0062] However, light forbidden region 114 may include multiple surface regions in some embodiments, for example at least one region on surfaces 108A and 108B of light guide layer 108.

[0063] Preferably, the structure 100 is configured, for example, in terms of dimensions, features, such as location and arrangement of components, elements or material layers, and materials used, such that light of the first light source 104 reaching the light forbidden region 114 is less than a threshold value (threshold value considered as the depletion distance DD), which may be determined in terms of selected criteria, such as luminous intensity, illuminance or brightness, as described in more detail elsewhere herein.

[0064] Thus, the depletion of light on its way from the light source 104 to the forbidden region 114 can generally be controlled, for example, by (the selection and / or preparation of) the semi-transparent material of the light guiding layer 108, substantially through its attenuation properties, including scattering (diffusion) and absorption. However, the depletion can also be controlled, for example, by the position of the light source 114 and its distance D (preferably greater than distance H) to the region 114.

[0065] In a preferred embodiment, the light transmittance of the translucent material selected for the light guide layer 108 may be about 25% to about 80% at a selected wavelength (e.g., at least a portion of the visible wavelengths), considering, for example, a translucent material sample about 2 mm or 3 mm thick. The associated half-power angle may be about 5 to about 70 degrees, or 75 degrees (on an intensity basis). In different usage scenarios, the desired transmission and scattering may of course vary further. As previously mentioned, in some embodiments, the light guide layer 108 may include, at least in certain locations, a material that is substantially transparent (e.g., 95% or more transmission and a half-power angle that is substantially low, if not zero degrees).

[0066] Suitable translucency and attenuation of the light guide layer 108 can be achieved, for example, by using scattering elements in the light guide material. As the amount of scattering elements increases, the light transmission through the layer generally decreases, although the scattering / diffusion and half-value angle also increase as one possible measurable indicator. Correspondingly, as the layer thickness increases, the scattering / diffusion properties (e.g., half-value angle) generally increase and the transmission decreases.

[0067] For example, considering the scattering (diffusion) properties as mentioned above, the light guide layer 108 may generally include at least one material selected from the group consisting of, for example, polymer, organic material, biomaterial, composite material, thermoplastic material, thermoset material, elastomeric resin, PC, PMMA, ABS, PET, copolyester, copolyester resin, nylon (PA, polyamide), PP (polypropylene), TPU (thermoplastic polyurethane), polystyrene (GPPS), TPSiV (thermoplastic silicone vulcanizate), and MS resin.

[0068] One example of a polycarbonate-based applicable material is Makrolon®, available in various colors / shades (e.g., white / whitish and black / blackish or dark), transparency, and scattering properties. For example, color code 021182 ("cool white") may be considered.

[0069] As mentioned above, a pigmented or more strongly pigmented resin may provide a viable option for the light guide layer 108 to restrict unwanted light leakage in and out of the structure 100 to nearby elements and hide the interior (e.g., light sources 104, 105 or other circuitry) from external perception. Originally, for example, a transparent base material, for example, a plastic resin (e.g., polycarbonate), may be doped with a pigmented master batch. In many use scenarios, the structure 100 must be perhaps only a few millimeters or centimeters thick in total, on which the light guide layer 108 must be even thinner, and a 2-4 millimeter (e.g., 3 mm) plastic resin with a selected master batch (e.g., white or desired selected wavelength resin) at a desired concentration (e.g., about 1% let-down ratio) as the light guide layer 108 may provide very satisfactory results. Overall, in many embodiments in the context of the present invention, the feasible let-down (dosing or doping) ratio is actually about 5%, 4%, 3%, 2%, 1%, or even less. For example, masterbatches suitable for the purpose are offered by Lifocolor®.

[0070] Furthermore, provided that the light sources 104, 105 provided on the film 102 for illuminating the different dedicated target output coupling regions 112 are separated from each other by an appropriate distance (e.g., about 4 millimeters), good illumination uniformity is obtained on the output coupling region(s) 112 without significant light leakage into adjacent regions, including the prohibited region(s) 114.

[0071] It has been found that for a 12 mA LED type light source, the light intensity measured on the surface of the light guide layer 108 only about 15 millimeters laterally away from the actual LED's location underneath is only a small fraction of the original intensity, e.g., about 5%, 1%, or even 0.1%, or less, which is beyond the possible attenuation for many real-world usage scenarios in terms of undesirable light leakage.

[0072] When the light guide layer 108 exhibits a substantially white or whitish color, the color perceived in the environment can be tuned by the light source and its emission wavelength, as will be understood by those skilled in the art. Such tuning can be flexibly achieved by multi-color light sources, for example RGB-LEDs (Red-Green-Blue LEDs), or multiple grouped light sources emitting different wavelength(s).

[0073] The aforementioned "hidden until lit" effect may be achieved, for example, by adding a translucent (e.g., showing a selected color) masterbatch into the injection molding-based resin that constitutes the light guide layer 108. However, the substrate film 102 used may be substantially opaque, black, and / or otherwise dark. Thus, for example, a "hidden until lit icon" may be provided on the surface 108A with reference to the printed elements 122, the transparent or translucent film 120 with the printed icon, and / or the opaque / dark / color film arranged with one or more openings among other options. Using, for example, about 3% translucent black masterbatch may be sufficient to visually hide the underlying components, e.g., the circuit or light source 104, and e.g., the traces 106, from outside perception. The embedded underlying elements (e.g., components and traces) may further be prepared from a material that provides a dark color (preferably highly optically attenuating or absorbing). Alternatively, a transparent material may be utilized. Different lighting effects may be achieved with different colors. The translucent material of light guide layer 108 may be generally or selectively matched to the color(s) used on surface 108A, for example the color(s) exhibited by an ink or film thereon.

[0074] As mentioned above, by using a white-colored resin as the light guide layer 108 and using a suitable configuration with embedded multicolored light sources (e.g. RGB-LEDs), essentially any color can be illuminated on the (white) surface 108A according to the configuration required.

[0075] To measure and characterize the scattering (diffusion) properties of a considered or selected material, a portion of the material (e.g., one corresponding to the dimensions of the light guide layer 108, or a representative sample of other size) may be covered with a mask containing small orifices and illuminated from the backside. A goniometer may be used to measure the intensity of light passing through the holes at different angles to determine, for example, the half-power angle.

[0076] Scattering or diffusion (multiple scattering occurring in a material can be considered as diffusion) may be characterized and determined based on the so-called haze level of a translucent material. Haze may be defined as the percentage of diffuse transmittance from the total transmittance of a specimen or sample of a material. Haze may be measured or determined based on a selected standard (e.g., ASTM D1003). Haze, in the context of various embodiments of the present invention, may be, for example, about or at least about 20%, 30%, 40%, 50%, 60%, or more (percentage of diffuse transmittance from the total transmitted light beyond 2.5 degrees from the incident beam). A haze meter or photometer may be utilized for the measurement, for example, according to a selected test method or standard (e.g., those mentioned above). Thus, in view of the present invention, there are different methods and approaches that may be selectively used by a person skilled in the art to select, verify, and compare several different materials and their configurations (dimensions, doping / mixing with additives, etc.).

[0077] The aforementioned second light source 105, if included, may in some embodiments be configured to emit light into the light guiding layer 108 from which it is outcoupled through at least a portion of the no-leak region 114 of the first light source 104. The second light source 105 may be positioned, and optionally aligned, such that the intensity of light emitted by the second light source 105 and reaching the out-coupling region 112 of the first light source 104 is less than the intensity of light reaching the no-leak region 114. As such, the distance between the second light source 105 and the no-leak region 114 may be less than the second distance D.

[0078] Thus, in some embodiments, the first light source 104 and the second light source 105 may have at least a partially mirror-like functional configuration, and optionally also a dimensional or positional configuration, within the structure 100, and each of them 104, 105 may have their own out-coupling area that also defines at least a portion of the light forbidden area of ​​the other light source. The light sources 104, 105 may optionally be dynamically (e.g., alternately or generally over time and / or independently) controlled to illuminate their own out-coupling area and / or elements thereon, while at least not causing significant problems (e.g., light leakage) and thus not causing undesired illumination of the other light out-coupling area.

[0079] Item 121 refers to an optional encapsulant, globe top, or other conformal coating (e.g., Illumabond® or Triggerbond®), for example, for light shaping or other processing, protective and / or fixturing purposes. The substance used may be dispensed onto a selected circuit (e.g., first light source 104). For example, it may be substantially clear (transparent). Alternatively, it may be tinted and / or translucent. In some embodiments, a particular optical function or feature (e.g., a lens) may be provided by the encapsulant. The lens may be, for example, diffusive, Fresnel, or, for example, collimating. Additionally or alternatively, prefabricated lenses or optical components in general may also be included in the structure.

[0080] As briefly mentioned above, item 122 may refer to at least one functional element, which may be attached and / or additionally manufactured in situ, for example printed (e.g., screen printed, inkjet or 3D printed) on the first surface 108A of the lightguide layer 108, optionally located adjacent to and / or on the out-coupling region 112 or the light-tight region 114. If there is also, for example, a film 120 on the surface 108A, the functional element 122 may be provided on any side thereof, i.e., on the side facing the lightguide layer 108 or on the opposite side, and therefore on the side facing the environment. On the side facing the lightguide layer 108, the element 122 will be better protected from the environment.

[0081] The functional element(s) 122 may be selected from the group consisting of: light-blocking (masking) elements, graphical elements (e.g., icons, symbols, patterns, alphanumeric elements, images, etc., which may have indicative properties, e.g., status indicators of the receiving device or the connected device), light diffusers, reflectors, dispersive elements, and collimators. Optically, the functional element(s) 122, as well as, for example, the film(s) 102, 120, may be transparent, semi-transparent, or opaque, e.g., color prints or layers. However, the items 122 may also refer to, for example, conductive traces, electrodes, electrical insulators, electronic components, circuit elements, or connectors.

[0082] In some embodiments, the functional element may be monolithic with the light guiding layer 108, as described in more detail below with reference to FIG.

[0083] Thus, the functional element(s) 122 may have, for example, a display function, an optical function, a connecting function, or an electrical (conductive, insulating, sensing, or other) nature, among other options.

[0084] As mentioned above, the element(s) 122 may be located, for example, adjacent to or partially or completely overlapping the out-coupling area 112. The first light source 104 may be configured to illuminate the element(s) 122 (e.g., graphical elements) so as to be visually noticeable to a user in the structure's environment 100. Further light sources (e.g., second light source 105) potentially included within the structure 100 may have similar functionality, as already mentioned above, with respect to their associated out-coupling area / functional element (which may be different or the same as for the first light source 104).

[0085] Item 122a shows an example of a graphical, in this example specifically icon-type, element 122, essentially a snowflake and a seat belt, arranged at a distance from each other. This can then be selectively illuminated by the underlying light source(s) contained within the structure 100. For example, at least one of the elements 122 can be located within a first distance H (and therefore also within a second distance D) from the first light source 104 on the out-coupling area 112 so as to be illuminated by it when the light source 104 is on (emitting). The remaining elements 122 can then be located on the out-coupling area of ​​the second light source 105, which may be included within the light forbidden area 114 of the first light source 104, and can be correspondingly illuminated by the second light source 105 or further light sources. A surface area exhibiting the aforementioned light exhaustion distance for the light of the first light source 104 can be present between the two elements 122. In any case, preferably the light sources 104, 105 are independently controllable in order to make the elements 122 perceptible also independently from the environment 100 of the structure.

[0086] The circuitry 106 included within the structure 100 may include several light source(s) 104, 105 as well as electrically conductive traces or contact pads that are optionally printed, for example, using printed electronics techniques onto the film 102 and / or other material layers of the structure 100. Such traces may be configured for the transfer of power and / or data (e.g., signaling data or other data) between elements (e.g., light sources and associated controllers and / or power sources, etc.).

[0087] Additionally, circuitry 106 may generally include one or more electrodes, electrical connectors, electronic components, and integrated circuits (ICs) (e.g., control or data transfer circuitry). Circuitry 106 may be fabricated directly in or for structure 100 by a selected method(s), such as printed electronics techniques, optionally screen printing or other additive printing, or generally coating techniques.

[0088] Additionally or alternatively, the circuit 106 may include several mounted components (e.g., surface mounted devices (SMD)). Accordingly, non-conductive and / or conductive adhesives may be utilized to secure the mounted components onto the carrier. In some embodiments, the mechanical fixation is implemented or at least enhanced by an electrically non-conductive adhesive material, while solder or other electrically highly conductive (but less adhesive type) material is used to obtain electrical connectivity.

[0089] For example, if capacitive sensing of gestures (e.g., touch or touchless gestures) on structure 100 is to be implemented, the sensing electrodes of circuitry 106 may be configured (dimensioned, positioned, etc.) such that their sensing areas or volumes, e.g., defined by an associated electric field, are positioned as needed to cover, for example, selected sidewall and / or top areas of the structure, and / or other areas that are to be detectably sensitive to touch and / or touchless gestures. This type of configuration may be achieved or performed, for example, by utilizing appropriate simulations or measurements.

[0090] Additionally, the circuit 106 may include, and / or the remaining multi-layer structure may include, at least one component selected from the group consisting of: electronic components, electromechanical components, electro-optical components, radiation emitting components, light emitting components, LEDs (light emitting diodes), OLEDs (organic LEDs), side shooting LEDs or other light sources, top shooting LEDs or other light sources, bottom shooting LEDs or other light sources, radiation detecting components, light detecting or photosensitive components, photodiodes, phototransistors, photovoltaic devices, sensors, micromechanical components, switches, touch switches, touch panels, proximity switches, touch sensors, air sensors, temperature sensors, pressure sensors, moisture sensors, gas sensors, proximity sensors, capacitive switches, capacitance sensors, projected capacitive sensors or switches, single electrode capacitive switches or sensors, capacitive buttons, multi-electrode capacitive switches or sensors, self-capacitance sensors, mutual capacitance sensors, inductive sensors, sensor electrodes, micromechanical components, UI elements, user input elements, vibration elements, sound generating elements, communication elements, transmitters, receivers, transceivers, antennas, infrared (IR) receivers or transmitters, wireless communication elements, wireless tags, radio tags, tag readers, data processing elements, microprocessors, microcontrollers, digital signal processors, signal processors, programmable logic chips, ASICs (application specific integrated circuits), data storage elements, and electronic subassemblies.

[0091] The structure 100 may be, and in many use scenarios may be connected to, an external system or device (e.g., a receiving device or arrangement of the structure). This may be accomplished by connectors, e.g., electrical connectors, or connector cables, that may be attached to the structure 100 and its elements (e.g., circuitry 106) in a selected manner (e.g., for communication and / or power). Attachment points may be, for example, on the side or bottom of the structure. Through holes may be placed in the film 102 for connectivity purposes.

[0092] In various embodiments, at least the first light source 104 may be generally oriented with respect to at least its light emission direction(s) to generally provide more light, for example, toward its target out-coupling area 112 than toward the no-light-leak area (114) and / or to adjust the resulting out-coupling area 112 to be larger and farther away, or vice versa (smaller and closer).

[0093] With regard to the available options for positioning and orienting the light source(s) of the structure 100 as required, for example with respect to its illumination properties, the following embodiment is shown in FIG. 2 at 200: the first light source 104 is tilted with respect to a reference (for example, the top surface of the arrangement 200 or the original plane of the substrate film 102) by 3D shaping (preferably thermoforming) the receiving substrate film 102 to establish at least a local 3D shape (for example, a protrusion or recess at the location of the first light source 104) and thus tilt the light source 104. Thus, the emission direction(s) of the light source 104 is adjusted in a desired manner. For example, a top-shooting light source may be adjusted to hit or shoot further on the surface 108A (for example, an icon or other graphical / functional element 122 may be conveniently illuminated from the side, while the volume directly below the illuminated feature may optionally be utilized for other purposes (for example, sensing and sensing electronics)). A side-shooting light source may additionally or instead be adjusted to illuminate an area 112 (as shown) thereon. Thus, depending on the embodiment, tilting may facilitate illuminating a larger or smaller area than would otherwise be possible and / or obtaining better uniformity for the surface illumination.

[0094] 3A illustrates one particular aspect already briefly discussed above at 300. In one embodiment, a light source (e.g., the first light source 104) may be configured to illuminate multiple out-coupling regions 112 rather than a single unified region. However, the light source 104 may be configured to illuminate an out-coupling region 112 that is not directly above the light source 104 but is laterally shifted therefrom.

[0095] The multiple regions 112 and the lateral shift may be achieved, for example, by the emission characteristics of the light source 104 itself and / or by using functional elements 122 (e.g., shading or masking features on the relevant light path). The light source 104 may be able to emit light in multiple (e.g., two) directions or substantially via two beams, for example considering suitable side-emitting LEDs. Additionally or alternatively, masking features (e.g., opaque printing) may be used to split the illumination pattern into multiple cut parts when visually inspecting from the outside. However, a carrier element, which will be described in more detail with reference to FIG. 5, or 3D shaping of the substrate film 102 (back to FIG. 2) may also be utilized.

[0096] Similarly, FIG. 3B illustrates the use of multiple light-emitting units 104a in at least a functionally single light source 104 at 350. The units 104a may have similar and / or different characteristics (emission direction, emission wavelength / color, beam width, intensity, etc.) from each other. Collectively, they 104a may span a larger out-coupling area 112 than would otherwise be possible. Nevertheless, for example, the light uniformity over the area 112 may be advantageously adjusted or "fine-tuned", for example, by varying the proportional intensity of the units. Various lighting effects (e.g., fades, temporally and spatially complex lighting patterns, animations, etc.) may be obtained over the area 112 and the elements 122 (e.g., icons or other graphical elements thereon).

[0097] By applying multiple light sources 104, 105, or at least multiple light emitting units 104a within a single light source 104, 105, more complex features (e.g., matrix or segment displays) may be implemented as already described above. As with other applications and embodiments, a diffusive semi-transparent resin as the light guide layer 108 may be used to properly block the light. The light emitted from each light source or emitting unit can be transmitted to the surface and the associated out-coupling area, but due to the limited extent within the semi-transparent material, the light does not at least substantially intermix with the adjacent out-coupling areas of the other light source(s) or unit(s) to any noticeable extent. Furthermore, the surface features (e.g., embossment, film, or print 120, 122) may be configured to provide a desired visual effect (e.g., a pixel map appearance or a 3D effect) if required by the application in question.

[0098] At 360, it is shown how different externally visible dynamically illuminated elements (e.g. symbols or matrix / segment displays) can be constructed by a combination of embedded light source(s) 104, 105, intermediate semi-transparent light guide layer 108, and e.g. top film(s) 120 and / or other functional element(s) 122. The lighting effect can be restricted to the desired out-coupling area 112 by surrounding (preferably substantially opaque) light blocks or masks 120, 122, e.g. printed or laminated film type. A more transparent (e.g. semi-transparent) and optionally color-exhibiting print or film can then be used on the actual out-coupling area 112. Segment division lines can be implemented by e.g. local substantially opaque print or film.

[0099] FIG. 4 shows, at 400, a flow diagram of an embodiment of a method in accordance with the present invention.

[0100] At the beginning of the method for manufacturing a multi-layer structure, a start-up phase 402 may be performed. During start-up, the necessary tasks may be performed (e.g., material, component and tool selection, acquisition, calibration and other configuration tasks). Special care must be taken to ensure that the individual elements and material selection work together to withstand the selected manufacturing and installation process. This is of course preferably checked in advance, e.g., based on the manufacturing process specifications and component data sheets, or by inspecting and testing manufactured prototypes. The equipment used (e.g., molding, IMD (in-mold decoration), lamination, bonding, (thermo)forming, electronic assembly, cutting, punching, printing and / or equipment providing measurements such as desired optical measurements, among others) may therefore be brought up to an operational state at this phase.

[0101] At 404, at least one, optionally flexible, substrate film of plastic or other material, for example for housing electronic devices, is obtained. The substrate film may be initially substantially planar or may be, for example, curved. The substrate film may be at least primarily of electrically substantially insulating material(s). Prefabricated elements (e.g. rolls or sheets of plastic film) may be obtained for use as substrate material. In some embodiments, the substrate film itself may be initially manufactured in-house by shaping the selected starting material(s) using a mold or forming device or other method. Optionally, the substrate film may be further processed at this stage. For example, holes, notches, recesses, cuts, etc. may be provided.

[0102] At 406, several electrically conductive elements, for example defining conductor lines (traces), sensing elements (e.g. electrodes), and / or contact areas (e.g. pads) to build the circuit design, are provided on one or both sides of the substrate film(s), preferably by one or more additive techniques of printed electronics technology. For example, screen, inkjet, flexographic, gravure, or offset lithographic printing may be applied by a suitable printing device or devices. In some cases, subtractive or semi-additive processes may also be utilized. For example, further actions of developing the film(s) may be performed here, including printing or generally providing graphics, visual indicators, thermal conductors, optical elements, etc.

[0103] In various embodiments, the electrically conductive element may include at least one material selected from the group consisting of conductive ink, conductive nanoparticle ink, copper, steel, iron, tin, aluminum, silver, gold, platinum, conductive adhesive, carbon fiber, alloys, silver alloys, zinc, brass, titanium, solder, and any components thereof. The conductive material used may be optically opaque, translucent, and / or transparent at a desired wavelength (e.g., at least a portion of visible light), for example, to mask or reflect radiation (e.g., visible light) therefrom, absorb it therein, or pass it. This aspect is discussed elsewhere herein.

[0104] In 408, further circuitry (e.g., one or more typically prefabricated components including electronic components (e.g., various SMDs)) may be attached to the contact areas on the film(s), e.g., by solder and / or adhesive. For example, light source(s) (e.g., LEDs) of the selected technology and packaging may now be provided, as well as various elements of control electronics, communication, sensing, connection (e.g., connectors), reception (circuit board(s), carrier(s), etc.), and / or power supply (e.g., battery), e.g., depending on the embodiment. For example, a suitable pick-and-place or other attachment device may be utilized for this purpose. Alternatively or additionally, printed electronics techniques may be applied to actually fabricate at least some of the components (e.g., OLEDs (organic LEDs)) directly on the film(s). Thus, as one skilled in the art will appreciate, the execution of items 406, 408 for providing the desired circuitry in the multilayer structure may overlap in time. Additionally, the installed components may include various optical elements (e.g., lenses, reflectors, diffusers, masks, filters, etc.) or carrier elements, optionally having angled surfaces, for example, to accommodate circuits and / or circuit boards for the circuits.

[0105] Selected and provided elements may be subjected to further processing (eg, encapsulation).

[0106] For the sake of completeness, and in view of the provision of circuits and components to the structure, item 409 refers to the possible mounting of one or more modules or other subsystems or "subassemblies" that may incorporate an initially separate secondary board, e.g., a circuit board, with electronics, e.g., light source(s), IC(s), and / or various components as also contemplated elsewhere herein. At least a portion of the multi-layered electronics and / or other elements may be provided to the substrate film(s) via such modules or subassemblies. Optionally, the modules or subassemblies may be at least partially overmolded with a protective plastic layer before attachment to the main board. For example, adhesives, pressure, and / or heat may be used for mechanical bonding of the module subassembly to the primary (receiving) board. Solder, traces, and conductive inks are examples of applicable options for providing electrical connections between the elements of the modules or subassemblies and with the remaining electrical elements on the main board. Item 409 may also be performed, for example, during item 408. Its illustrated positions are primarily representative.

[0107] In some embodiments, before or during the forming step 412, the substrate film(s), preferably already including, for example, at least a part of the circuit design, for example (printed) conductive elements, and further elements, for example electronic components, optical elements, and / or modules or subassemblies, may be (3D) shaped or "formed" 410, for example using thermoforming or cold forming, to exhibit a desired shape, for example at least locally a three-dimensional (substantially non-planar) shape. Any suitable forming device (for example a thermoforming machine) may of course be utilized for this purpose. The double-headed curved arrow is shown in the figure to highlight the fact that forming 410 can alternatively or additionally take place, for example at item 408, between items 406 and 408, or even at or before item 406. Additionally or alternatively, at least some forming can take place after forming, if the already established multi-layer stack is designed to withstand such processing.

[0108] Advantageously, the circuitry is at least partially, if not completely, provided on film 102 and optionally film 120 prior to the aforementioned 3D shaping of the film(s) or when the film(s) were still substantially planar or at least more planar, to avoid subsequent redundant and less reliable 3D assembly of the electronics on the already 3D shaped carrier.

[0109] In 412, at least one plastic layer, preferably a thermoplastic or thermosetting layer, which for example serves as a light guide, is fabricated and preferably molded (e.g. injection molded) on the substrate(s) to preferably at least partially embed the circuitry of the multi-layer structure and further components, elements or even modules / subassemblies. Desired parts may remain transparent or may be made transparent later by mechanical or chemical treatments, as described elsewhere herein, for example considering cover parts of a module for receiving replaceable elements. The molding material(s) may be provided using multiple molding steps or shots or via a single step. The molding material may optionally even flow, for example, through the film from one side of it to the opposite side, through holes provided therein, or by penetrating the substrate material itself (e.g. thinned / thinner parts). The molding material(s) may for example be substantially electrically insulating. As contemplated herein, the material is also advantageously translucent to suitably function as a lossy or attenuating light guide.

[0110] In practice, at least one substrate film already equipped with some further features (e.g., at least part of the circuitry and potentially some various optical elements or modules, etc.) may be used as an insert in the injection molding process applying at least one molding machine. If two films are used, both may be inserted in their own mold halves so that the plastic layer is injected at least between them. Alternatively, the second film may be attached later to the already established assembly of the first film and the plastic layer by a suitable lamination technique, for example utilizing an adhesive between them.

[0111] With regard to the resulting total thickness of the resulting laminated multi-layer structure, it depends, for example, on the materials used and the associated minimum material thickness that provides the necessary strength in view of manufacturing and subsequent use. These aspects must be considered on a case-by-case basis. For example, the total thickness of the structure can be on the order of magnitude of about a few millimeters, as noted elsewhere herein, although significantly thicker or thinner embodiments are also feasible.

[0112] Item 414 refers to possible further tasks (e.g. post-processing and installation operations). Further layers or general features may be added in the multi-layer structure by molding, lamination, or suitable coating (e.g. deposition) procedures, not forgetting other possible positioning or fastening techniques. The layers may have protective, displaying, and / or aesthetic value (graphics, colors, figures, text, numerical data, etc.) and may include, for example, textile, leather, or rubber materials instead of or in addition to (further) plastics. Further elements (e.g. electronics, modules, module internals or parts, and / or optical components) may be attached and fastened, for example, to the outer surface(s) of the structure (e.g., the outer surface of an included film or molded layer, depending on the embodiment). The necessary material may be shaped / cut. For example, a diffuser may be manufactured by locally laser machining the light guide material, as contemplated elsewhere in this specification. If connectors are provided, the connectors of the multi-layer structure may be connected to the desired external connection elements (e.g., to an external device, system, or structure, e.g., an external connector of a receiving device). For example, the two connectors may together form a plug and socket type connection and interface. As used herein, the multi-layer structure may also be generally disposed and attached to a larger assembly, such as an electronic receiving device, optionally a personal communication device, a computer, a home device, an industrial device, or a vehicle, for example in embodiments where the multi-layer structure forms part of the exterior or interior (e.g., dashboard) of the vehicle.

[0113] At 416, execution of the method ends.

[0114] Fig. 5 shows at 500 an inclined carrier element 513 for the light source, which can be utilized, at least selectively, in addition to or instead of any of the features of the embodiments of the preceding figures in carrying out the invention. Indeed, instead of or in addition to 3D shaping the underlying substrate film as done in Fig. 2, an optionally beveled surface 513A inclined with respect to the plane of the underlying substrate film and / or surface 108A for receiving at least the first light source 104 can be provided, for example by an element 513 arranged on the substrate film 102, to skillfully orient the light source 104 and, for example, its emission direction(s) or, in the case of a sensor-type circuit, the sensing direction(s) arranged on the element 513, if necessary and as described above.

[0115] The element 513 may comprise a plastic material (e.g. thermoplastics, metals, ceramics, etc.). It may for example be (injection) molded or 3D printed. However, it may be manufactured for different tilt angles depending on the use case. The material may be at least locally thermally conductive to improve heat dissipation. Electrical conductivity may be provided at least in certain locations to enable electrical connectivity on and / or through it.

[0116] When accommodating light sources, the angled surface 513A may improve the size and uniformity of the resulting more remote illumination area, but may also be used to accommodate sensors or various actuators, thereby improving the effective area of ​​these sensors or actuators. The illumination area / output coupling area 112 on the surface 108A may be shifted horizontally or laterally, e.g., from the area directly above the light source 104 associated with a top-emitting light source, or moved closer, e.g., associated with a side-shooting light source. Similar beneficial effects may be obtained with the 3D shaped substrate film 102 described in connection with FIG. 2.

[0117] Element 513 may include flat surface(s) and / or a top for convenient assembly (e.g., a pick-and-place surface mounting process) and / or to receive further elements, such as printed or attached electrodes (e.g., for capacitive sensing or other touch / gesture sensing) or other electronic elements or components. For example, it may be useful to utilize the top surface of element 513 for sensing purposes, since the top surface of element 513 is closer to the environment of structures on surface 108A.

[0118] In some embodiments, a circuit board 502 for housing at least a portion of the circuitry (e.g., first light source 114, and e.g., traces or other circuitry 106) can be provided integral, optionally even monolithically, or separate from the angled element 513 that defines surface 513A. The circuit board 502 may in some embodiments be employed separately, without element 513 and associated angled surface 513A as well.

[0119] The circuit board 502 may include at least one element selected from the group consisting of: a flexible film or sheet, a rigid sheet, a rectangular sheet or film, a rounded or substantially circular sheet or film, an FR4 based circuit board, a flame retardant circuit board, a metal core circuit board, a plastic board, a molded article such as an injection molded plastic board, a metal board such as a sheet metal board optionally at least selectively provided with an electrically insulating layer, or a ceramic circuit board.

[0120] The circuits 106, 114 on the circuit board 502 may be configured to electrically and preferably thermally connect at some location to the remaining multi-layer structure beside or below the circuit board. The connection may be made by utilizing at least one connecting material 516 disposed between them, and preferably disposed at least around the periphery of the circuit board 502 (if present). For example, electrically and / or thermally conductive solder, ink, or adhesive may be used for this purpose.

[0121] The use of the circuit board 502 may, for example, facilitate thermal management associated with high-power light sources (e.g., high-power LEDs). Damage to the substrate film 102 due to excessive heat build-up by the electronics may then be avoided, among other benefits. The circuit board 502 may function as a heat sink. However, the use of the circuit board 502 may, for example, facilitate the assembly and provision of electronics on the surface 513A, for which purpose mechanical attachment features (e.g., matching fastening features, e.g., protrusions and matching recesses or holes on the surface 513A and the substrate 502, respectively) and / or adhesives may be utilized.

[0122] 6 shows at 600 an embodiment of a diffuser included in any multi-layer structure described herein. Item 122 generally indicating a functional element may refer here in particular to a printing (e.g. an icon) to be illuminated, potentially covering all or most of the out-coupling area 112, while item 122A may refer for example to a surrounding or at least adjacent opaque printing, coating or film that blocks light. A further film 120 may additionally or instead be provided on top for protection and / or other uses (e.g. performing further optical functions). Film 120 may be transparent / substantially transparent or may be colored, for example with specular or diffuse transmission properties for transmitted wavelengths.

[0123] Thus, a diffuser 109, preferably of varying thickness, is provided and placed on the light path extending from the light source 104, 105 through the out-coupling region 112 of said light source 104, 105 to the environment of the structure. The diffuser 109 may optionally be monolithic with the light guide layer 108 and the semi-transparent material of the light guide layer 108. Moreover, it 109 may be additively manufactured on the light guide layer and / or subtractively manufactured from, for example, layers 120, 120b, 122 on the light guide layer 108. The inclusion of a prefabricated diffuser 109 component in the structure is a further option, optionally provided in connection with or integral with a larger module including, for example, light sources, carrier elements, circuit boards, and / or associated wall structures. These different options may also be selectively combined by a person skilled in the art to come up with a desired diffuser 109. Optionally, the diffuser 109 may include or be adjacent to an air cap or cavity filled with some other material (eg, a diffusing material).

[0124] The diffuser 109 may improve the illumination performance of the structure (e.g., illumination uniformity over the out-coupling region 112). Thus, the diffuser 109 may, for example, prevent the occurrence of hot spots or dark spots.

[0125] The diffuser 109 may be manufactured, for example, from a diffusing plastic, for example by (injection) molding, 3D printing, or other additive methods, or by CNC milling or laser processing. For example, a laser may be used to locally modify the transparency and translucency of the light guide layer 108 and implement the diffuser 109 therefrom. On the other hand, the diffuser 109 may be constructed from multiple printed laminations. The filtering properties of the diffusing layer(s) of the diffuser 109 may optionally differ from each other and may be utilized, for example, to block selected colors. A diffuser 109 exhibiting a white, whitish, or single color, although not a substantially transparent or at least colorless diffuser 109, may be used as a default solution for general applications, while a multicolor option may prove useful, for example, in an area diffuser 109 having various regions associated with a certain color. Light blocking or black regions may further be integrated with and implemented in the diffuser 109. Thus, the diffuser 109 may be used to block light from entering undesired areas (e.g., surface 108A). This may reduce the need for additional blocking (opaque) printing.

[0126] FIG. 7 illustrates at 700 an embodiment of an at least partially replaceable or post-installation accessible module that includes, for example, one or more of the light sources 104, 105 and / or other circuitry generally included within the multi-layer structures described herein.

[0127] Adjacent to the translucent material of the light guide layer 108, advantageously a module is provided having a wall structure 724 that at least laterally substantially surrounds and preferably also contacts an optionally spring-loaded (see spring element 722) circuit board 502, optionally having the characteristics already described above in relation to Figure 5, to accommodate the light sources 104, 105 and optionally further circuitry 106 (e.g. traces, control electronics, etc.). However, a replaceable power source (e.g. a rechargeable or disposable battery) can be provided within the module to make it easily accessible.

[0128] Advantageously, the substrate 502, the light source(s) 104, 105 thereon and / or further elements contained therein (e.g. radiation / photodetectors, batteries, processing units, memories, data interface devices, contact or especially programming pads, pins, traces, etc.) are accessible, one or both of which are even more preferably replaceable externally from the environment of the structure, for example via a movable, optionally for example hinged or fully removable cover 718 of the module provided on the first surface 108A and / or the second surface 108B. The surface layer(s) 108A, 108B may in fact include openings to provide easy access to the embedded modules. Item 702 refers for example to a base layer of the module that provides support to the wall structure 724 and / or the substrate 502. In some embodiments, the base 702 may be omitted.

[0129] The cover 718 may, for example, include mechanical, externally operable fastening features (such as wedge-shaped resilient protrusions) with compatible counterparts (such as recesses or holes in the wall 724) or vice versa. Alternatively or additionally, for example screws may be utilized to keep the module intact and protected by the cover 718 during use, while still allowing convenient maintenance whenever required.

[0130] In some embodiments, the cover 718 may be configured as an optical element (e.g., a lens, such as a collimating lens, a diffusive lens, or a Fresnel lens or other specialized lens) for an element included in the module (e.g., a light source or a light / radiation detector).

[0131] In some embodiments, some elements provided within the module (e.g., any of the options previously contemplated) may be placed within a socket, e.g., to facilitate assembly or replacement after manufacture. The socket(s) may be provided on the substrate 502.

[0132] 8 illustrates, via an exploded view at 800, selected details of an embodiment in which at least one light source 104, 105 is at least partially surrounded by an optionally cylindrical optical reflector structure 802 that preferably extends through the thickness of the light guide layer 108. The interior of the reflector structure 802 may optionally include a diffusive translucent resin 822 that is different from the translucent material of the light guide layer 108.

[0133] As can be seen based on the figure, the circuitry (eg, light source 104) may be provided on a circuit board 502, which has been described in more detail above in connection with FIG. 5 and the associated text.

[0134] However, in some embodiments, the reflector 802 may be integrated with, connected to, or at least implemented together with the wall structure 724 of the solution of Figure 7. Other features of the module and the overall general solution may also be adopted in the context of the reflector from Figure 7.

[0135] 9 and 10 show, at 900 and 1000, respectively, additional features (e.g., shapes of voids and / or optical features) that can be at least selectively utilized in the constructed multi-layer structures in addition to or in place of any of the other embodiments contemplated herein for practicing the invention.

[0136] In FIG. 9, the multi-layer structure embodiment described above includes a front material stack or layer 9006, preferably of a plastic top film 912, optionally a plastic or glass light guide layer 914, for example substantially of polycarbonate or TPU resin, and / or an optional display or decorative film / layer 916, optionally having limited light transmission (e.g., less than about 30%, 20%, or 10%).

[0137] The shape(s) of the optical features 918 (graphical and / or 3D shapes, e.g., some icons, symbols, patterns, alphanumeric characters, etc.) may be established, for example, in the light guide layer 914 and / or the film / layer 916 to form the desired lighting effect from the light emitted by the light source(s) 104, 105 (e.g., top shooting LEDs) below in the multi-layer structure (see the two dashed lines with their end at the light source 104). 3D shaping methods, optionally including thermoforming or surface treatments (e.g., embossing, milling, etc.), may be used for this purpose in addition to or instead of molding. The film 120 is optional, but may be used, for example, for optical balancing or other optical features.

[0138] In Fig. 10, the film 120 is configured to hold the 3D shape 1004 of the printed (preferably screen printed or otherwise additively manufactured) optical features, for example, and / or to directly define the shape 1002 by local 3D shaping / shaping of the film itself 120 (or at least its surface), obtained by thermoforming or other applicable 3D shaping methods. The 3D shape may additionally or instead be achieved during injection molding of the film 120 or the material provided thereon. Item 9006 refers to some front layer or associated material stack, preferably including at least in places a transparent or semi-transparent layer, to allow the light emitted by the light source(s) 104, 105 arranged below to propagate towards the environment. Item 1008 refers to a light-blocking layer (e.g. a film or printed layer).

[0139] The optical functions considered above in relation to Figures 9 and 10 may vary and be selected on a case-by-case basis, but may include, for example, light transmission, masking, filtering, scattering, collimation, etc., depending on the requirements set by the usage scenario.

[0140] In addition to being combined with each other, the solutions of figures 9 and 10 may be selectively combined with any of the embodiments previously described herein.

[0141] The scope of the present invention is determined by the appended claims together with their equivalents. Those skilled in the art will appreciate the fact that the disclosed embodiments are constructed for illustrative purposes only, and that other arrangements applying many of the principles described above can be readily prepared as best suited to each potential usage scenario.

Claims

1. An integrated functional multi-layer structure (100, 200, 300, 350, 500, 600, 700, 800, 900, 1000), a flexible, preferably 3D formable, thermoplastic substrate film (102); A circuit (104, 105, 106) provided on the substrate film, the circuit (104, 105, 106) including a first light source (104) including at least one light emitting unit (optionally an LED); a monolithic light guide layer (108) molded on the substrate film to cover and optically couple to the first light source (104), the light guide layer (108) comprising an optically attenuating semi-transparent material; the light guide layer (108) comprises a first surface (108A) and an opposite second surface (108B), the second surface (108B) facing the first light source (104), a portion of the first surface (108A) comprising a predefined out-coupling region (112) for light emitted by the first light source (104) and transmitted through the light guide layer (108) within a first distance (H) from the first light source (104), the light guide layer (108) further comprising a light leakage prevention region (114) that does not overlap with the out-coupling region (112) and is separated from the first light source (104) by at least a second, preferably larger, distance (D); the attenuation of emitted light occurring on a direct optical path between the first light source (104) and the out-coupling area (112) is less than the attenuation occurring on a shortest, optionally also direct, optical path between the first light source (104) and the no-light-leak area (114); Further, the light transmittance of the translucent material of the light guide layer is from about 25% to about 80% at a selected wavelength for an approximately 2 mm thick sample of the translucent material, while the associated half-power angle is from about 5 to about 70 degrees.

2. 2. The structure of claim 1, wherein the first light source (104) has a direct line of sight (LOS) to both the out-coupling area (112) and the no-light-leak area (114) without any shading elements.

3. 3. The structure of claim 1 or claim 2, wherein a light depletion distance (DD) from the first light source that exhibits significant intensity loss of the emitted light at selected wavelengths, preferably at least visible wavelengths, during propagation through the translucent material is between the first distance (H) and the second (D) distance.

4. The structure of any one of claims 1 to 3, wherein the light-blocking region (114) comprises or consists of a portion of the first surface (108A) of the light guide layer (108), said portion being optionally visually perceptible from the outside.

5. The structure of any one of claims 1 to 4, wherein the light-blocking region (114) defines a selected, optionally substantially cubic, cubic or cylindrical, sub-volume of the light guiding layer (108), optionally extending through the light guiding layer (108) in a direction spanning the first surface (108A) and the second surface (108B).

6. the no light leak area (114) defining a portion of the first surface of the light guide layer exhibits a luminance uniformity of at least 50% in response to the light of the first light source outcoupled therethrough; and / or The structure of any one of claims 1 to 5, wherein the out-coupling region (112) exhibits a luminance uniformity of at least about 70% in response to light of the first light source out-coupled therethrough.

7. 7. The structure of claim 1, wherein the light-leak-proof region defines a portion of the first surface of the light guiding layer, and the intensity of light of the first light source coupled out through the light-leak-proof region through the portion of the first surface of the light guiding layer is significantly less than the intensity of light emitted by the first light source at a selected wavelength, preferably at least visible wavelengths, and coupled out through the out-coupling region.

8. The structure of any one of claims 1 to 7, wherein the second distance (D) is about 1.2, 1.5, 2, 3, 4, or 5 times greater than the first distance (H).

9. The at least a first light source (104) Top-emitting, side-emitting, double-sided, or bottom-emitting, and optionally flip-chip type light-emitting units, such as LEDs; A plurality of light emitting units (104a) packaged or at least grouped together; and / or A structure according to any one of the preceding claims, comprising multiple LED emitters of multicolour or in particular RGB LEDs provided in a single package.

10. (300) A structure according to any one of claims 1 to 9, wherein at least the first light source is associated with at least one further out-coupling region, the first and further out-coupling regions optionally having at least partially a shading element (122) between them.

11. 11. The structure of any one of claims 1 to 10, wherein a shortest distance between the first light source (104) and the out-coupling area (112) is equal to or less than the first distance (H) and is less than about 20 mm, more preferably less than about 10 mm, even more preferably less than about 8 mm, and most preferably less than about 5 mm.

12. A structure according to any one of the preceding claims, wherein the light guide layer (108) of translucent material has a thickness of about 10 mm or less, more preferably about 5 mm or less.

13. A structure according to any one of the preceding claims, wherein the translucent material comprises a plastic resin, preferably a thermoplastic resin.

14. The structure of any one of claims 1 to 13, wherein the translucent material is pigmented and optionally includes a masterbatch or pigment-based color additive therein.

15. 15. The structure of claim 14, having a let down ratio of about 5%, 4%, 3%, 2%, 1% or less.

16. 16. A structure as claimed in any one of claims 1 to 15, comprising an optionally bevelled surface (513A) inclined with respect to the plane of the underlying substrate film to receive at least the first light source (104), said inclined surface optionally further receiving a circuit board for said at least one light source.

17. 17. The structure of any one of claims 1 to 16, comprising a diffuser (109), preferably of varying thickness, on the light path extending from the first light source through the out-coupling region (112) to the environment of the structure, the diffuser being optionally monolithic with the light guiding layer and the semi-transparent material of the light guiding layer, additively manufactured on the light guiding layer and / or subtractively manufactured from a layer (120, 120b, 122) on the light guiding layer.

18. 18. A structure as claimed in any one of claims 1 to 17, comprising a module having a wall structure (724) adjacent to the translucent material of the light guide layer, substantially enclosing at least laterally an optionally spring-loaded circuit board (502) and receiving at least the first light source (104), wherein the circuit board and the first light source are accessible, one or both of which are preferably replaceable externally from the environment of the structure, and more preferably replaceable via a movable, optionally hinged or removable cover (718) on the first surface (108A) or second surface (108B).

19. 19. The structure of any one of claims 1 to 18, comprising an optionally cylindrical light reflector wall structure extending in the thickness direction of the light guide layer laterally surrounding at least the first light source and at least partially embedding the reflector wall structure, an interior of the reflector wall structure optionally comprising a diffusive resin different from the translucent material of the light guide layer.

20. A structure according to any one of claims 1 to 19, comprising on said light guide layer preferably a stack of voids or air cavities (906) and / or an assembly (9006) of one or more layers optionally further comprising plastic and / or glass, at least a film (120, 916) advantageously comprising a 3D shape of an optical function (900, 1000) additively manufactured from an opaque or translucent material, optionally screen printed or locally shaped from said film, optionally thermoformed.

21. The structure of any one of claims 1 to 20, comprising at least one deposited and / or additionally in-situ manufactured, e.g. printed, functional element (120, 122) on the first surface (108A) of the light guide layer (108), optionally disposed adjacent to and / or on the output coupling region (112) or the no-light-leakage region (114), the functional element (120, 122) being selected from the group consisting of conductive traces, electrodes, electrical insulators, electronic components, circuit elements, connectors, light blocking elements, graphical elements, light diffusers, reflectors, dispersive elements, and collimators.

22. 22. The structure of any one of claims 1 to 21, comprising at least one applied and / or additionally in situ manufactured, e.g. printed, film (120) or coating on the first side of the light guide layer, optionally arranged adjacent to and / or on the out-coupling area (112) or the light-tight area (114) and defining at least a part of an opaque or semi-transparent light masking or filtering element and / or a graphical element to be illuminated by the first light source or any further light sources included.

23. (200) The structure of any one of claims 1 to 22, wherein the substrate film (102) includes a 3D formed, optionally thermoformed, portion (111) that receives the first light source (104) thereon in an oblique orientation relative to a first surface (108A).

24. The structure of any one of claims 1 to 23, wherein the circuit further comprises at least one element (106) selected from the group consisting of a number of electrically conductive traces, optionally printed using printed electronics techniques, that connect to at least the first light source, an electronic component, an integrated circuit, an electrode, a contact pad, and / or an electrical connector.

25. 25. The structure of any one of claims 1 to 24, wherein the substrate film and / or further film or material layers comprise at least one material selected from the group consisting of polymers, thermoplastic materials, electrically insulating materials, PMMA (polymethyl methacrylate), polycarbonate (PC), copolyesters, copolyester resins, polyimides, copolymers of methyl methacrylate and styrene (MS resins), glass, polyethylene terephthalate (PET), carbon fibres, organic materials, biomaterials, leather, wood, textiles, fabrics, metals, organic natural materials, solid wood, veneers, plywood, bark, tree bark, birch bark, cork, natural leather, natural fibre or fabric materials, naturally grown materials, cotton, wool, linen, silk, and any combination of the above.

26. 26. The structure according to any one of claims 1 to 25, wherein the light guide layer, in particular the translucent material thereof, and / or further filler layers (110) contained within the structure, comprise at least one material selected from the group consisting of polymers, organic materials, biomaterials, composite materials, thermoplastic materials, thermosetting materials, elastomeric resins, PC, PMMA, ABS, PET, copolyesters, copolyester resins, nylon (PA, polyamide), PP (polypropylene), TPU (thermoplastic polyurethane), polystyrene (GPPS), TPSiV (thermoplastic silicone vulcanizates), and MS resins.

27. A method (400) for producing an integrated functional multi-layer structure, comprising: Obtaining 404 a flexible substrate film, preferably comprising a formable, optionally thermoformable, material; providing (406, 408) a circuit on said substrate film, preferably using printed electronics technology and / or selected packaging technology, said circuit including a first light source (104) including at least one light emitting unit (optionally an LED); fabricating (412), optionally by molding or casting, a monolithic light guide layer, which is optically attenuating, translucent, and preferably also thermoplastic, on said substrate film to cover, optically couple to, and preferably at least partially embed, said first light source; The light guide layer (108) and the first light source are configured such that the light guide layer includes a first surface (108A) and an opposite second surface (108B), the second surface (108B) facing the first light source (104), a portion of the first surface (108A) including a predefined output coupling area (112) for light emitted by the first light source (104) and transmitted through the light guide layer (108) within a first distance (H) from the first light source (104), the light guide layer (108) further comprising: the optical fiber includes a no-leak region (114) that does not overlap with the out-coupling region (112) and is separated from the first light source (104) by at least a second, preferably larger, distance (D), and is mutually configured such that an attenuation of emitted light occurring on a direct optical path between the first light source (104) and the out-coupling region (112) is less than said attenuation occurring on a shortest, optionally also direct, optical path between the first light source (104) and the no-leak region (114); and The method (400), wherein the light transmittance of the translucent material of the light guide layer is from about 25% to about 80% at a selected wavelength for an approximately 2 mm thick sample of the translucent material, while the associated half-power angle is from about 5 to about 50 degrees.

28. 28. The method of claim 27, wherein the substrate film is 3D formed, preferably by thermoforming, and at least locally exhibits a resulting 3D shape in which the first light source is optionally positioned.

29. 29. The method of claim 27 or claim 28, wherein the translucent material is produced by blending at least a pigment or masterbatch color additive with a stock resin at a selected let down ratio.

30. 30. The method of any one of claims 27 to 29, wherein the light guide layer is manufactured on the substrate film by injection molding, optionally low pressure injection molding, and / or using molding temperatures below about 250, 200, or 150°C.

Images