LIGHT EMISSION SYSTEM WITH HOMOGENEOUS AND DIFFUSE LIGHT; VEHICLE EQUIPPED WITH THIS SYSTEM AND ITS MANUFACTURING PROCESS

Abstract

This disclosure relates to a light-emitting system (1) for an automotive application, comprising: at least one light source; at least one mask (5); at least one lens (3); and at least one adhesive (7) for diffusing the light to provide substantially homogeneous illumination. It also relates to a vehicle comprising at least one such light-emitting system and a method for manufacturing at least one such light-emitting system. Figure for the abstract: Fig. 1

Description

Title of the invention: LIGHT EMISSION SYSTEM WITH HOMOGENEOUS AND DIFFUSED LIGHT; VEHICLE EQUIPPED WITH THIS SYSTEM AND METHOD FOR MANUFACTURING THE SAME

[0001] The present disclosure relates to a light emitting system for an automotive application, comprising at least one light source; at least one mask; and at least one lens. It also relates to a vehicle provided with at least one such light emitting system and a method of manufacturing such a light emitting system.

[0002] Vehicles, such as passenger cars, vans, and trucks, include various interior and exterior lighting components capable of emitting light for various purposes. Aesthetic features, which have become desirable in automotive applications, include providing exterior and / or interior badges and / or emblems or the like on vehicles or on specific parts of a vehicle. These aesthetic features are backlit by key elements of the particular badge or emblem or are illuminated for optical or safety reasons. In particular, manufacturers seek to make their vehicles more appealing to customers by creating a premium atmosphere. For example, the dashboard, certain parts, or all of the door trim may be illuminated in this manner.It is desirable that these elements be backlit with equal (uniform or homogeneous) luminance using, for example, light-emitting diodes (LEDs). An LED is a directional light source whose relative luminous intensity decreases as the viewing angle increases. This may result in the appearance of bright or hot spots for an external observer of the badge.

[0003] Light emitting systems are known which provide uniform light intensity, such as systems generally using complex arrangements of lenses and reflectors. High diffusion lenses have the disadvantage of giving a milky or hazy appearance and of having poor optical efficiency and / or of being expensive. Optical elements can also be used on transparent materials to diffuse light, but these have the disadvantage of being visible in the unilluminated state, which is undesirable. A desirable feature of a light emitting system is that the input of the illumination means, for example an LED, is not directly visible to the external observer.

[0004] It is therefore practical to hide any illumination means from the light emitting systems, i.e. to ensure that the illumination means is not visible from the outside except once the illumination means has been switched on. Such a system is known as a Hidden Till Lit (HTL) system. Reflective metal coatings, which provide such features, are known, for example, from WO 2011 / 075796 and WO 2013 / 110122. Several problems arise from such an HTL system known in the art, such as light bleeding along the lens walls, light pipe and / or double imaging. Furthermore, such systems may be less flexible. Furthermore, known HTL systems require a plurality of separate elements resulting in design and assembly complexity and increased costs.

[0005] Document US 10,969,080 B2 discloses a multi-function lamp unit for a vehicle comprising a housing, at least one light pipe with at least one light source disposed at least partially within the housing, and a transparent lens substantially surrounding the housing, T at least one light pipe and T at least one light source, the lens having an inner surface, an outer surface disposed opposite the inner surface and at least one of a continuous transparent and translucent coating on the outer surface.

[0006] Document EP 4 105 678 A1 relates to an illuminated cover for an electromagnetic sensor, such as a radar sensor, wherein the cover comprises a multi-layer plate which is substantially transparent to electromagnetic radiation emitted and / or received by the electromagnetic sensor, and the plate comprises a first layer of optically transparent material and a second layer on at least one surface of the first layer and having a lower refractive index than the first layer. Furthermore, a graphic layer is provided on the second layer and at least one light source is arranged to couple light into the first layer, which acts as a light guide, wherein at least one surface of the first layer is further provided with at least one optical element for decoupling light from the first layer.

[0007] Considering the disadvantages of the current state of the art, it is desirable to have an effective solution for providing homogeneous light emission along parts of a vehicle, in particular with complex geometries and / or narrow cross-sections such as logos and / or fine stripes. Thus, the object of the present disclosure is to further develop the known light emission system to overcome the disadvantages of the prior art.

[0008] This objective is achieved by means of a light emitting system for an automotive application, comprising: at least one light source; at least one mask; and at least one lens; remarkable in that it further comprises at least one adhesive for diffusing light in order to provide substantially homogeneous illumination.

[0009] Thus, the light emitting system comprises at least one adhesive for diffusing light to provide substantially homogeneous illumination of the light emitting system.

[0010] In one aspect, the light source may be adapted to emit light into a light pipe, preferably included in the light emitting system, and disposed at least partially within the light emitting system; the lens may have at least one inner surface substantially facing the light pipe and at least one outer surface substantially opposite the inner surface, the outer surface preferably emitting light directly or indirectly from the light emitting system, and the lens and the mask form a lens-mask system, some portions of the lens-mask system being translucent and others not; and / or the lens-mask-adhesive system may be a three-layer system, the inner surface of the lens preferably being substantially covered by the mask and the adhesive.

[0011] In one aspect, the adhesive may diffuse light from the light pipe; light from the light pipe may pass through the adhesive and then through the lens; the lens may substantially surround the light pipe and the light source; and / or the lens, mask, and adhesive may form a lens-mask-adhesive system, wherein the mask, adhesive, and lens are permanently affixed together and are not interchangeable.

[0012] According to another aspect, the mask may be opaque and / or the lens has at least one continuous transparent or translucent coating on the outer surface, preferably the continuous transparent or translucent coating is at least partially permeable to at least a portion of the light emitted by the light source and passing through the lens.

[0013] Embodiments of the present disclosure may be provided with the adhesive comprising insoluble particles substantially providing the light scattering effect of the adhesive.

[0014] Embodiments of the present disclosure may require that the insoluble particles comprise PMSQ beads, PMMA beads, and / or glass beads.

[0015] According to another aspect, the adhesive may be applied to the lens with a variable thickness, the adhesive may have at least a drop shape or substantially angular or substantially round or substantially triangular, and / or the adhesive may be substantially in the shape of a fine stripe, bead or ball along at least a portion of the length of the lens.

[0016] It may also be a one-part or multi-part adhesive; and / or a pressure-sensitive, temperature-sensitive, anaerobic adhesive and / or a combination thereof; and / or the adhesive comprises fillers such as ethylene glycol dimethacrylate and / or multifunctional monomers.

[0017] In other embodiments of the present disclosure, the adhesive may be a one-part adhesive and may cure under UV light, heat, an anaerobic environment, moisture, and / or upon contact with oxygen.

[0018] In another embodiment, the adhesive may comprise acrylic, polyester, silicone, styrene copolymer and / or vinyl, preferably methacrylate and more preferably thixotropic methacrylate.

[0019] In another aspect, the adhesive may affect a color shift of the transmitted light, preferably the color shift is corrected by pigmenting the lens and / or selecting a colored lens and / or tuning and / or calibrating the light source for the shifted color.

[0020] It is also possible that the light source comprises at least one LED and, preferably, the color shift is corrected by the selection of the LED levels, where, preferably, in the case of predominantly white light, the distribution of the LEDs is chosen up to several color levels cooler or warmer than the desired emitted light color.

[0021] In other embodiments of the present disclosure, the light source may be arranged adjacent to the at least one light pipe and directed toward the at least one light pipe.

[0022] In another embodiment, the lens-mask system may be formed in one piece by 2K molding.

[0023] In another embodiment, the lens-mask-adhesive system is formed in one piece by 3K molding.

[0024] There is further provided a vehicle equipped with at least one light emitting system as described above.

[0025] Still further, a method of manufacturing the light emitting system, as described above, is provided, comprising the steps of: providing at least one adhesive, preferably by mixing light diffusing particles such as PMSQ and methacrylate, more preferably thixotropic modified methacrylate, using at least one mixer, preferably in the form of a centrifugal planetary mixer to remove and prevent the addition of air bubbles; providing the mask and the lens, preferably by 2K molding; dispensing the adhesive on the mask and the lens using a robot equipped with a dispensing gun, the adhesive being introduced directly into the dispensing gun at a high pressure, preferably between 2 and 10 bar, more preferably between 4 and 6 bar, even more preferably between 2 and 3 bar; and adjusting the speed of the robot and the dispensing speed in order to control the thickness of the adhesive, the thickness of the adhesive preferably being between 1 and 2 mm, the speed of the robot preferably being between 38 mm / s and 85 mm / s and the supply voltage of the dispensing gun preferably being between 4 V and 10 V.

[0026] In another embodiment of the method, the feed to the dispensing gun may be provided by a recirculating feed system to maintain the light scattering particles in the adhesive, and / or the robot speed and the dispensing speed may be varied at different points along the length of the lens, the thickness of the adhesive preferably being adjustable by varying the robot speed and / or the gun supply voltage.

[0027] Further, another method of manufacturing the light emitting system, as described above, is provided, comprising the step of providing the lens, the mask and the adhesive by 3K molding.

[0028] Adhesives are generally used to bond two separate surfaces. However, in some applications, it is not possible to mold the diffusing layer with the transparent lens and the opaque mask due to limitations of the molding process, such as filling narrow cross-sections. In this case, the present disclosure provides the use and production of an adhesive for light diffusion in an automotive application. This includes dispersing insoluble particles to produce a light-diffusing, sand-cured adhesive.

[0029] To initiate the bonding of an adhesive, an internal chemical reaction is required, this reaction varying depending on the type of adhesive. The most common types used in industry are multi-part adhesives, one-part adhesives, pressure-sensitive adhesives, temperature-sensitive adhesives, and anaerobic adhesives. Those skilled in the art are able to select the adhesive based on the application and manufacturing requirements.

[0030] The present disclosure overcomes limitations related to the molding process, such as filling narrow sections for lighting applications. One-part adhesives, particularly UV-curable adhesives, have the advantage of requiring only a single dispensing nozzle and curing quickly, making them preferable for processing applications.

[0031] These adhesives may also contain fillers, for example multifunctional monomers, to provide various characteristics such as strength chemical, viscosity change, cure speed, and bond strength. For example, copolymerization of ethylene glycol dimethacrylate results in optical and viscosity change in methyl methacrylate-based adhesives. Various additives can be used to adjust the chemistry to the application. It is best to use methyl methacrylate with additives to achieve a refractive index similar to that of the lens substrate and a viscosity of 30,000 to 60,000 cP at 2.5 rpm.

[0032] However, for applications with complex geometry, a methacrylate-based adhesive may be preferred due to its controllable viscosity with additives and its chemical compatibility with polycarbonate, which is often used as a substrate for a lens.

[0033] Different materials have unique optical properties that can affect light transmission, transmitted color, and light scattering. Using transmission and thickness proportionality, brightness can be varied by adjusting the applied thickness of the adhesive. To achieve a decreasing light pipe, the adhesive can be applied in a thickness gradient (e.g., from thick to thin) to vary the brightness across the lens, preferably with the lens shaped like a fine stripe. This provides a consistent output for a light pipe containing hot spots and decreasing brightness along its length; furthermore, it can also be used to minimize / suppress hot spots from direct light sources such as LEDs.

[0034] The present disclosure also provides a vehicle comprising at least one such light emitting system and a method of manufacturing at least one such light emitting system.

[0035] It is to be understood that each of the features of the disclosure may be used separately or in combination with other features. The present disclosure itself, as well as other features and advantages, will become apparent from the following detailed description, taken in conjunction with the accompanying drawings. One or more embodiments of the present disclosure are described below, by way of example only, in which like reference numerals represent like elements and in which:

[0036] [Fig.l] illustrates a schematic representation of a light emitting system according to an exemplary embodiment of the present disclosure; and

[0037] [Fig.2] illustrates a schematic representation of a partial sectional view of a light emitting system according to an exemplary embodiment of the present disclosure.

[0038] The drawings referred to in this description are not to be understood as being to scale, unless otherwise indicated, and these drawings are for illustrative purposes only.

[0039] Before explaining in detail the embodiments of the present disclosure, it should be understood that the disclosure is not limited in its application to the construction details and arrangement of the components set forth in the following description or illustrated in the drawings. The disclosure may be embodied in other ways and may be practiced and performed in a variety of ways. Those skilled in the art will appreciate that not all features of a commercial embodiment are shown for the sake of clarity and understanding. Those skilled in the art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present disclosures will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment.Although these efforts can be complex and time-consuming, they are nonetheless a routine undertaking for skilled persons who have benefited from this disclosure.

[0040] Furthermore, it is understood that the phraseology and terminology employed herein are for the purpose of description and should not be construed as limiting. For example, the use of relational terms, such as, but not limited to, "top", "bottom", "left", "right", "upper", "lower", "bottom", "top", "side", is used in the description for clarity with specific reference to the figures and is not intended to limit the scope of the disclosure or the appended claims. Furthermore, it is to be understood that each of the features of the disclosure may be used separately or in combination with other features. Other systems, methods, features and advantages of the disclosure will be or become apparent to a person skilled in the art upon examination of the figures and the detailed description.It is intended that all such additional systems, methods, features, materials, chemicals, and advantages be included in this description, fall within the scope of this disclosure, and be protected by the accompanying claims.

[0041] Those skilled in the art will appreciate that modifications may be made to the embodiments described above without departing from the general concept of the present disclosure. It is therefore understood that the disclosure presented herein is not limited to the particular embodiments disclosed, but is intended to cover modifications within the spirit and scope of the present disclosure.

[0042] According to the embodiment of [Fig.l], the light-emitting system 1 is composed of a three-layer system, in which one layer is a lens transparent 3 to allow light transmission, one layer is an opaque mask 5 to create the desired Hidden Till Lit patterns (with the lens 3 and an optional coating of the lens 3), and one layer is the diffusive layer in the form of an adhesive 7 to achieve homogeneous light emission along the lens 3, eliminate hot spots near the light entry into one or more light pipes, and to locally control the brightness of complex patterns such as logos or pinstripes. Thus, the adhesive 7 diffuses light from a light pipe to ensure substantially homogeneous illumination of the light emitting system 1. Furthermore, the lens 3, the mask 5 and the adhesive 7 form a lens-mask-adhesive system, in which the mask 3, the adhesive 7 and the lens 3 are permanently fixed together and are not interchangeable.The light from the light pipe passes through the adhesive 7 and then through the lens 3. .

[0043] A lens 3 according to the present disclosure may be provided in various shapes. Thus, round, lenticular or fine stripe shapes are covered by the subject matter of the present disclosure. Furthermore, the lens 3 has at least one inner surface 2 substantially oriented towards the light pipe and at least one outer surface 4 substantially arranged opposite the inner surface 2. The outer surface 4 emits light directly or indirectly from the light emitting system 1.

[0044] The lens of this disclosure may be formed from any suitable plastic material. For example, the lens may be formed from a material selected from the group including, but not limited to, acrylonitrile ethylene styrene (AES), acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), polyamide (PA), polybutylene terephthalate (PBT), polycarbonate (PC), polyethylene (PE), polyethylene terephthalate (PET), poly(methyl methacrylate) (PMMA), polyoxymethylene (POM), polypropylene (PP), polyurethane (PU), polyvinyl chloride (PVC), high flow AES, acrylonitrile-(ethylene-propylene-diene)-styrene (AEPDS), blends of thermoplastics, or a PC-ABS blended thermoplastic. In a preferred embodiment, the lens is made of polycarbonate.

[0045] In preferred forms, the lens may have a maximum physical thickness of between 0.1 mm and 20 mm, more preferably between 1 mm and 5 mm, and most preferably between 2 mm and 3 mm, but not limited thereto.

[0046] According to the embodiment of [Fig. 1], the lens 3 is made of polycarbonate and may be covered with a decorative and / or functional coating, preferably on the outer surface 4, so as to color at least one surface of the lens 3 and / or to support the HTL function and / or to modify the light emission of the lens 3. preferably there is at least one continuous transparent or translucent coating on the outer surface 4, wherein preferably the continuous transparent or translucent coating is at least partially permeable to at least part of the light, which is emitted by the light source and passes through the lens 3.

[0047] In the embodiment of [Fig.l], the mask 5 is an opaque mask that creates an aperture to produce the designed light pattern (e.g., a fine stripe or a logo). Furthermore, the adhesive 7 may be a dispersion comprising insoluble particles that substantially provide the light scattering effect of the adhesive 7.

[0048] According to the embodiment of [Fig.l], the lens 3 and the mask 5 are formed as a single component, with the adhesive 7 being dispensed in a separate manufacturing step. In this embodiment, a one-part adhesive 7 is used, which has been cured by UV light. One-part adhesives 7, particularly UV-curable adhesives, have the advantage of requiring only a single dispensing nozzle and a rapid curing time, making them preferable for processing applications.

[0049] UV curable adhesives are generally composed of various monomers and photoinitiator molecules that are activated and decompose when they absorb the energy emitted by UV light. The activated molecules produce free radicals that initiate and accelerate crosslinking producing a cured polymer. These monomers or chemicals are generally acrylic, polyester, silicone, styrene copolymer, or vinyl based. Each chemical base has different use cases, but acrylic-based adhesives are generally used due to their chemical compatibility and adhesive strength. All suitable chemicals known to a person skilled in the art are included in this disclosure.

[0050] According to other embodiments, the one-component adhesives cure under the influence of heat (known as hot melts), humidity and upon contact with oxygen.

[0051] The adhesives 7 may also contain fillers, for example in the form of multifunctional monomers, in order to provide various characteristics such as chemical resistance, viscosity adjustment, curing speed and adhesive strength. According to the embodiment of [Fig.l], methacrylate was chosen as the adhesive 7 because of its controllable viscosity with additives, for example ethylene glycol dimethacrylate, (may be necessary for complex geometry) and its chemical compatibility with polycarbonate, which is the substrate of the lens 3. The adhesive 7 chosen is strongly influenced, for example, by the intended manufacturing process and the geometry of the part. Therefore, in other cases, other chemistries may be used and are therefore also included in this disclosure.

[0052] Materials have unique optical properties that can affect light transmission, transmitted color, and light scattering. Light scattering can be achieved by scattering light rays at different angles; in general, the amount of transmitted light decreases as it increases. This proportionality between scattering and transmission can be used to determine the required size, e.g., bead thickness, and / or the amount of light-scattering particles of the adhesive 7. Due to the liquid state of the adhesives 7 during manufacture, the amount of scattering can be controlled by introducing light-scattering particles.

[0053] In the embodiment of [Fig.l], the adhesive 7 exhibits high transmission and minimal color shift, while ensuring homogeneous illumination.

[0054] By introducing light-diffusing particles into an adhesive 7, the optical properties of the material are modified. The additive particles use their material type and shape to manipulate transmitted light and color. In general, any material that does not dissolve in the adhesive but is present in solid or liquid droplet form can be used. Advantageously, polymeric materials such as PMSQ beads, PMMA beads, or glass beads can be used. PMSQ, PMMA, and glass beads have been found to be chemically stable in various epoxies, for example, methyl methacrylate (MMA), urethane acrylate, and other two-part epoxies such as 650 series two-part epoxy.

[0055] By adjusting the amount of additive(s), preferably between 0.1 wt% and 10 wt%, more preferably between 0.5 wt% and 2 wt%, even more preferably 1 wt%, mixed with a material, the overall optical properties can be adjusted. For example, by mixing 1 wt% of PMSQ beads with methyl methacrylate, optical transmission is reduced by 11.5% and haze is increased by 23.4% at a thickness of 2 mm. According to the embodiment of [Fig.l], the PMSQ beads were selected due to their UV stability and resistance to yellowing at temperature.

[0056] Adjusting the volume of the diffusive particles in the adhesive 7 can control the homogeneity and brightness of the hot spots created by the light pipe and the hot spots caused by the ambient light pipes at the ends of the light pipe produced directly by the proximity light source.

[0057] Using the proportionality of transmission and thickness, the brightness can be changed by adjusting the thickness of the adhesive 7. By increasing the thickness of the adhesive from 1 mm to 2 mm, a decrease in transmission can be observed. of approximately 8.35% and an increase in haze of approximately 9.3%. Due to this relationship, different geometries of the adhesive layer will result in an increase or decrease in brightness.

[0058] For example, a square profile of the adhesive in a fine scratch will produce homogeneous light because the optical face of the adhesive is constant. For wider and / or thicker profiles of the adhesive, a triangular profile may be used to account for intensity at greater angles to the light source.

[0059] According to the embodiment of Figures 1 and 2, aiming to reduce the light conduit, the adhesive 7 is applied according to a thickness gradient (for example from thick to thin) to modify the brightness by a fine scratch. The arrangement of the lens substrate 3 according to a complex geometry and arranged with a degraded thickness of the adhesive 7 is visible respectively in Figures 1 and 2. This thickness of the adhesive can be determined according to the optical properties of the adhesives with / without optical additives such as PMMA, PMSQ or glass beads.

[0060] This property of adjusting the thickness of the adhesive 7 can also be used for more complex geometries such as logos with varying slit cross-sections. For example, a logo with thin and wide slits will allow different amounts of light to pass through at different locations due to the design of the mask 5.

[0061] The adhesive 7 may be applied with a drop or triangle shaped cross section, preferably the adhesive 7 may be drop or stripe or ball shaped over at least a portion of the length of the lens. Applying a thicker cross section of the diffusive adhesive 7 or, in the case of molding, a gradient adhesive will control the amount of light produced through the slit. In summary, varying the thickness of the diffusive adhesive layer 7 at different locations can produce homogeneous and diffuse light.

[0062] The adhesive 7 acts as a filter and therefore changes the color of the transmitted light. For lighting design and to meet different application requirements, it may be necessary to correct the color shift of the adhesive 7. In the case of a light source in the form of an LED, this may be achieved by the selection of LED levels. In the case of white, the LED distribution may be chosen up to several color levels cooler or warmer than the desired emitted light color, due to the color temperature shift across the diffuse adhesive, for colors other than white, similar compensation may also be necessary. For example, a yellow / warmer white LED will account for a cooler / blue shifted material. Furthermore, pigmentation and / or selection of a colored substrate of a lens 3 and / or tuning and / or calibrating an LED for the shifted color may be appropriate.. In embodiments with a light source in the form of an RGB LED, calibration and / or adjustment of the RGB LED may be a suitable method.

[0063] According to various embodiments, the lens 3, the mask 5, and the adhesive 7 are formed as a single component. This can be achieved by 3K molding. In this embodiment, the three layers are permanently attached to each other. This solution can eliminate the need for additional processing steps and their control, in particular mixing the diffusive additive into an adhesive, applying the adhesive, and curing the adhesive. The resulting 3K molding operation allows for high process control and throughput that is well suited for high-volume manufacturing.

[0064] In some applications, it is not possible to mold the diffusive layer of the adhesive 7 at the same time as the transparent lens 3 and the opaque mask 5 due to limitations of the molding process, such as the filling of narrow sections. In this case, the adhesive 7 is applied separately to the mask 5 and / or the lens 3.

[0065] In a preferred embodiment, the adhesive 7 is provided by mixing the adhesive. Preferably, the PMSQ particles may be mixed with the methacrylate. For mixing an adhesive, a mixer in the form of a centrifugal planetary mixer may be used. In addition, it is preferable to use a thixotropic modified methacrylate. The lower viscosity of the mixture allows for a homogeneous, air-free mixture of the adhesive 7 to be produced. After mixing, the material returns to a high "non-sag" viscosity that keeps the adhesive 7, particularly the PMSQ beads, in suspension.

[0066] In order to obtain a controlled thickness of the adhesive 7 over the entire length of the lens 3 and / or the mask 5, it is possible to use a robot equipped with a dispensing gun. The adhesive can be introduced directly into the dispensing gun at a high pressure, preferably between 2 and 10 bars, more preferably between 4 and 6 bars, the pressure preferably depending on the pressure supply, the chemical composition of the adhesive and / or the temperature of the adhesive. These values ​​are important to avoid any degassing or deformation of the adhesive. For the adhesive, a temperature of between 5 and 25° may be suitable. Depending on the adhesive in question, this temperature can vary and is generally between -5° and 30°.

[0067] Preferably, with a pressure of 3 bars, a thickness of 2 mm can be obtained using a supply voltage of 9 V at 38 mm / s and a thickness of 1 mm can be obtained with a supply voltage of 5.4 V at 45 mm / s. Along the entire length of the lens, the robot speed and the voltage can be adjusted between these two ranges to obtain a gradual decrease in thickness and maintain uniform brightness along the entire length of the optic. The progressive thickness can be achieved by setting different supply voltages and robot speeds at several points along the lens length. For example, on the side closest to the LED, the supply voltage will be 9 V and the robot speed 38 mm / s, at half the part the parameters are set to 8 V at 45 mm / s and at 2 / 3 of the length the parameters are set to 5.4 V at 45 mm / s.

[0068] The robot parameters may not be linear, so it may be necessary to dispense and measure each part. A relationship between the supply voltage of the dispensing gun and the robot speed can be used to adjust the adhesive thickness. Both of these values ​​can be decreased to reduce the adhesive thickness and increased to increase the adhesive thickness. By setting reduction values, i.e., a 30% reduction from the starting point (at 1 / 3 of the lens length) and a 60% reduction from the starting point (at 2 / 3 of the lens length), it is possible to achieve a gradual thickness. It is also possible to achieve this by reducing the starting parameters as a function of time. By setting a starting point and an ending point, the robot's internal system can change both values ​​to achieve a gradual change in the adhesive thickness.

[0069] The adhesive 7 may be introduced directly into one or more dispensing guns at an elevated pressure to increase viscosity and reduce any cavitation that may be produced by the feed inlet. A target pressure of 4 to 8 bar significantly improves bead quality, but due to air supply limitations, a pressure of 2 to 3 bar may also be used. In production, a recirculating feed system may be used to ensure that the particles remain in the adhesive 7 suspension and minimize any cavitation.

[0070] In a preferred embodiment, the lens 3 substantially surrounds the light pipe and the light source in order to receive all the light to be emitted. Thus, the light pipe does not protrude or extend beyond and / or outside the lens 3.

[0071] According to another embodiment, the lens 3, the mask 5 and the adhesive 7 form a lens-mask-adhesive system, in which the mask 5, the adhesive 7 and the lens 3 are permanently fixed together after manufacture and are preferably not interchangeable.

[0072] Although the subject matter has been described in language specific to structural features and / or acts, it is understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to fall within the scope of the claims.

[0073] List of reference signs 1 light emission system 2 inner surface of the lens 3 lens 4 outer surface of the lens 5 mask 7 adhesive

Claims

Claims

1. A light emitting system (1) for an automotive application, comprising: at least one light source; at least one mask (5); and at least one lens (3); characterized by at least one adhesive (7) for diffusing the light to provide substantially homogeneous illumination.

2. Light emitting system (1) according to claim 1, the light source being adapted to emit light in at least one light pipe, included in the light emitting system (1) and arranged at least partially inside the light emitting system (1).

3. A light emitting system (1) according to claim 2, the lens (3) having at least one inner surface (2) substantially oriented towards the light pipe and at least one outer surface (4) substantially arranged opposite the inner surface (2), the outer surface (4) emitting light directly or indirectly from the light emitting system (1).

4. Light emitting system (1) according to one of the preceding claims, the lens (3) and the mask (5) forming a lens-mask system, - parts of the lens-mask system being translucent and parts of the lens-mask system being non-translucent, and / or - the lens-mask system being formed in one piece by 2K molding.

5. Light emitting system (1) according to one of the preceding claims 1 to 3, the lens (3), the mask (5) and the adhesive (7) forming a lens-mask-adhesive system in the form of a three-layer system.

6. A light emitting system (1) according to claim 5, the inner surface (2) of the lens (3) being substantially covered by the mask (5) and the adhesive (7), and / or the lens (3), the mask (5) and the adhesive (7) forming a lens-mask-adhesive system, wherein the mask (5), the adhesive (7) and the lens (3) are permanently fixed together and are not interchangeable, or the lens-mask-adhesive system being formed in one piece by 3K molding.

7. A light emitting system (1) according to any one of claims 2 to 6, the adhesive (7) diffusing light from the light pipe; the light from the light pipe passing through the adhesive (7) and then through the lens (3); and / or the lens (3) substantially surrounding the light pipe and the light source.

8. A light emitting system (1) according to any preceding claim, wherein the mask (5) is opaque; and / or the lens (3) has at least one continuous transparent or translucent coating on its outer surface (4), which is at least partially permeable to at least a portion of the light which is emitted by the light source and has passed through the lens (3).

9. A light emitting system (1) according to any preceding claim, the adhesive (7) comprising insoluble particles substantially providing the light scattering effect of the adhesive (7).

10. A light emitting system (1) according to claim 9, the insoluble particles comprising PMSQ beads, PMMA beads and / or glass beads.

11. A light emitting system (1) according to any preceding claim, wherein the adhesive (7) is applied to the lens (3) with a thickness gradient, and / or the adhesive (7) has at least one drop or substantially angular or substantially round or substantially triangular shape, or the adhesive (7) has substantially the shape of fine stripes or a bulge or a ball over at least part of the length of the lens (3).

12. A light emitting system (1) according to any preceding claim, - the adhesive (7) being a one-part or multi-part adhesive, the adhesive (7) preferably being a one-part, curing adhesive under the effect of UV light, heat, an anaerobic environment, humidity and / or in contact with oxygen; and / or - the adhesive (7) being a pressure-sensitive, temperature-sensitive, anaerobic adhesive and / or a combination thereof; and / or - the adhesive (7) comprising fillers such as ethylene glycol dimethacrylate and / or multifunctional monomers; and / or - the adhesive (7) comprising acrylic, polyester, silicone, styrene copolymer and / or vinyl, preferably methacrylate and more preferably thixotropic methacrylate.

13. A light emitting system (1) according to any preceding claim, wherein the adhesive (7) affects a color shift of the transmitted light.

14. A light emitting system (1) according to claim 13, wherein the color shift is corrected by pigmenting the lens (3) and / or selecting a colored lens (3) and / or tuning and / or calibrating the light source for the shifted color.

15. A light emitting system (1) according to any preceding claim, the light source comprising at least one LED, the color shift being corrected by selecting the LED levels.

16. A light emitting system (1) according to claim 15, in the case of essentially white light, the distribution of the LEDs being chosen up to several color levels cooler or warmer than the desired emitted light color.

17. A light emitting system (1) according to any one of claims 2 to 15, the light source being arranged adjacent to and directed towards the at least one light pipe.

18. Vehicle comprising at least one light emitting system (1) according to any one of the preceding claims.

19. A method of manufacturing the light emitting system (1) according to any one of claims 1 to 17, comprising the steps of: - providing at least one adhesive (7), by mixing light diffusing particles such as PMSQ and methacrylate, more preferably modified methacrylate thixotropic, using at least one mixer or centrifugal planetary mixer to eliminate and prevent the addition of air bubbles; - providing the mask (5) and the lens (3); - dispensing the adhesive (7) onto the mask (5) and the lens (3) using a robot equipped with a dispensing gun, the adhesive (7) being introduced directly into the dispensing gun at high pressure; and - adjusting the robot speed and the dispensing flow rate to control the thickness of the adhesive (7).

20. A method according to claim 19, comprising dispensing the adhesive (7) onto the mask (5) and the lens (3) at a pressure between 2 and 10 bar, or between 4 and 6 bar, or between 2 and 3 bar, and / or the thickness of the adhesive being controlled to be between 1 mm and 2 mm and / or the speed of the robot being between 38 mm / s and 85 mm / s and / or the supply voltage of the dispensing gun being between 4 V and 10 V.

21. A method according to claim 19 or 20, wherein the feed to the dispensing gun is provided by a recirculating feed system, in particular to maintain the light-scattering particles in the adhesive, and / or the robot speed and the dispensing flow rate are varied at different points along the length of the lens (3).

22. A method according to any one of claims 19 to 21, comprising the step of providing the lens (3), the mask (5) and the adhesive (7) by 3K molding.

Images