Extra compact edge light for back side or front side illumination

Abstract

This invention discloses aspects of development and integration of extra compact edge light for front or back side illumination using a light guide structure. In particular, it discloses a method of creating a compact edge-lighting using a microLED light strip. In addition, it discloses a microLED edge-lighting assembly comprising a light guide having an edge surface and a top surface, a microLED light strip. In addition, there are aspects of MicroLED structure to enable two color or RGB configuration within the integration. Moreover, the application includes applications for the automotive and transportation industry.

Description

Extra Compact Edge Light for Back Side or Front Side IlluminationBackground and Field of the invention

[0001] This invention deals with the development and integration of extra compact edge light for front or back side illumination using a light guide structure.Summary

[0002] The present invention relates to a method of creating a compact edge-lighting using a microLED light strip, the method comprising, having the microLED light strip comprising of components a base polymer, microLED, conductive layers, reflectors, and encapsulation layers, applying a bonding layer to either a top surface of the microLED light strip or an edge of a light guide, to facilitate attachment, bonding the microLED light strip to an edge surface or an edge of the top surface, wherein the light is extracted from either the top or bottom surface, wherein edge surfaces are covered with reflectors or additional light strips to optimize light extraction and after bonding the light strip to the light guide, the base polymer layer is delaminated from a rigid substrate.

[0003] The present invention relates to a microLED edge-lighting assembly comprising, a light guide having an edge surface and a top surface, a microLED light strip comprising a base polymer layer, conductive traces formed on the base polymer layer, at least one microLED mounted to the conductive traces, and an encapsulation layer, a bonding layer positioned between the microLED light strip and the light guide, the bonding layer attaching the microLED light strip to either the edge surface or a top-edge region of the light guide and a reflective structure positioned below, beside, or around the microLED, wherein the microLED light strip is delaminated from a rigid substrate after attachment to the light guide,and wherein light emitted by the microLED is injected into the light guide and extracted from either a top surface or a bottom surface of the light guide.Brief Description of the Drawings

[0004] The foregoing and other advantages of the disclosure will become apparent upon reading the following detailed description and upon reference to the drawings.

[0005] Figure 1(a) depicts an exemplary embodiment of a compact edge-lighting solution using a microLED light strip.

[0006] Figure 1(b) illustrates that the light strip includes several key components, such as the base polymer, microLEDs, conductive layers, reflectors, and encapsulation layers.

[0007] Figure 2(a) illustrates the structure consisting of conductive traces and at least one microLED integrated.

[0008] Figure 2(b) shows another related embodiment with a reflective layer under the microLEDs.

[0009] Figure 2(c) shows another related embodiment where reflective layers are formed around the base polymer.

[0010] Figure 3 illustrates two-tones microLED light strips.

[0011] Figure 4 illustrates a two-tones microLED structure.

[0012] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments or implementations have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of an invention as defined by the appended claims.Detailed Description

[0013] The present invention details various aspects of methods and devices of compact microLED- based illumination.

[0014] The present invention relates to compact microLED-based illumination systems, methods and devices, configured for efficient edge-light coupling into a light guide. The invention enables front-side or back-side illumination using an ultra-thin, high-efficiency microLED light strip fabricated on a polymer carrier and subsequently bonded to a planar, curved, or structured lightguide edge. The system provides substantial improvements in compactness, color control, manufacturability, and optical performance relative to traditional LED edge-lighting modules.

[0015] The described microLED light strip is initially fabricated on a rigid substrate and includes conductive traces, microLED devices, reflective structures, and encapsulation layers formed on a base polymer. The polymer may include polyimide, polyamide, or other thin flexible substrates compatible with microfabrication processes. Conductive traces formed on the polymer layer supply electrical signals to microLEDs that are bonded directly to the traces. The microLEDs may be individual devices or grouped in multi-LED arrangements, and may include blue, green, red, ultraviolet, or multi-contact monolithic structures.

[0016] In various embodiments, at least one subset of the microLEDs includes a color conversion material such as phosphors or quantum dots to produce a second emission wavelength. This allows a single type of microLED to produce a mixed spectrum. In other embodiments, a dual color microLED structure is used, incorporating two identical contacts and one shared contact, enabling two different emission regions to be independently driven. Color-converted regions associated with one of the identical contacts provide a second output color, enabling a single microLED chip to achieve tunable correlated color temperature (CCT) or multi-color operation.

[0017] The microLED strip further includes encapsulation layers that protect the microLED devices from moisture, dust, and mechanical stress. These layers may also serve optical functions such as diffusing, focusing, or shaping emitted light. The encapsulation may be constructed using silicones, acrylics, thin inorganic layers, or combinations thereof. Reflective layers may be placed beneath or around the microLEDs to redirect stray light toward the light-guide edge and enhance couplingefficiency. These reflectors can be metal films, dielectric mirrors, molded reflective housings, or reflective coatings integrated with the encapsulation structure.

[0018] In one manufacturing approach, a bonding layer is applied either to the top of the microLED strip or to the edge of the light guide. The light strip is then positioned and bonded to either the side edge or the top-edge surface of the light guide. Depending on the configuration, light may be extracted from the top surface or the bottom surface of the light guide, enabling multiple application modes including front-side display backlighting, back-side architectural illumination, and embedded optical surfaces.

[0019] After bonding the microLED strip to the light guide, the base polymer layer is separated from the rigid substrate using delamination methods such as laser lift-off, thermal release, or dissolvable adhesive layers. This process yields a compact, flexible, and lightweight microLED edge-lighting module bonded directly to the light guide. The resulting construction enables extremely thin and high-efficiency illumination systems.

[0020] Alternative embodiments include microLED light strips with dual-sided emission, in which microLEDs are mounted on both surfaces of the polymer carrier to provide bi-directional illumination. Additional embodiments incorporate thermal management layers such as thin metal or ceramic sheets embedded within the polymer carrier to dissipate heat and enhance reliability. The invention also encompasses modular configurations in which multiple microLED strips can be connected through standardized connectors, enabling long illumination systems or increased brightness through parallel operation.

[0021] Further variations include waterproof strips using robust encapsulation materials, integrated optical features such as microlenses or microprisms formed directly in the encapsulation, edgelighting structures configured for curved light-guide surfaces, and smart illumination modules incorporating photodiode or temperature sensors for real-time feedback and automatic adjustment of brightness or color temperature.

[0022] The embodiments described are applicable to a wide range of fields including display backlighting, architectural lighting, automotive lighting, optical communication surfaces, wearable displays, augmented reality optics, and signage. The invention provides a compact, efficient, andmanufacturable illumination module with improved optical coupling, greater design flexibility, and advanced color control capabilities.

[0023] In one related embodiment, the design includes conductive traces formed on base polymer layers that are supported by a rigid substrate. Dielectric layers may be incorporated to separate specific conductive layers, ensuring proper insulation and functionality. MicroLEDs are bonded directly to these conductive traces, and encapsulation layers are applied to protect the microLEDs from environmental factors. Interestingly, the encapsulation layers can be formed from the same material as the base polymer layers, offering material efficiency and design simplicity.

[0024] To enhance adaptability, the base polymer layers can be etched to create individual islands for each light strip, allowing precise customization. Alternatively, the base polymer may remain continuous, depending on the application. At least one microLED light strip is bonded to the edge of a light guide, which can be positioned either on the surface or directly along the side edge. A bonding layer ensures secure attachment between the light strip and the light guide. In some configurations, the bonding layer can also serve as the encapsulation layer, streamlining the overall structure. Once the bonding process is complete, the base polymer is delaminated from the rigid substrate, using a method such as laser separation, with polyamide being a suitable material for the base polymer.

[0025] Figure 1(a) illustrates an embodiment of an ultra-compact microLED edge-lighting module configured for direct coupling into a light guide. In this embodiment, a microLED light strip (104) is fabricated on a rigid substrate (102) that provides mechanical stability during microfabrication, alignment, and device transfer steps. The light strip includes a base polymer layer on which conductive traces, microLED devices, reflective structures, and encapsulation layers are formed. The base polymer may comprise polyimide, polyamide, or other flexible materials compatible with subsequent delamination. Conductive traces are patterned onto the polymer to receive microLEDs transferred onto the substrate using pick-and-place, wafer transfer, or stamp-transfer techniques. The microLEDs may be arranged as single devices or grouped arrays, such as in automotive and aero and space transportation applications, and may include devices that are color-converted, dual-contact, or multi-mode emitters as described elsewhere in this application.

[0026] In the configuration depicted in Figure 1(a), the microLED light strip (104) is positioned adjacent to an edge of a light guide (100), which may be planar or curved depending on the application. A bonding layer (106) is applied either to the upper surface of the microLED strip or directly onto the edge of the light guide to facilitate optical and mechanical attachment. The bonding layer may include silicone, epoxy, UV-curable adhesive, index-matched gel, or physical coupling films. Upon bonding, the microLED strip may be aligned to either the vertical edge surface (110) of the light guide or a stepped or chamfered region at the edge of its top surface (108). This configuration allows the injected light to be extracted from either the upper or lower surface of the light guide, depending on scattering structures or surface treatments within the light-guide body.

[0027] Figure 1(b) provides additional details of the structures forming the microLED light strip. The microLED light strip comprises a base polymer layer that acts as a carrier for the conductive layer and microLEDs. A reflector may be included beneath the microLEDs to redirect downward or lateral light toward the light-guide coupling interface. Side reflectors or reflective housings may also be applied to further confine and direct emitted light, increasing coupling efficiency. An encapsulation layer covers the microLEDs to protect them from moisture, oxidation, and mechanical damage. The encapsulation may simultaneously serve as an optical element by diffusing, focusing, or shaping light emitted from the microLEDs. In certain embodiments, the bonding layer used to attach the light strip to the light guide also serves as the encapsulation layer, streamlining the structure.

[0028] After the microLED light strip is bonded to the light guide as depicted in Figures 1(a) and 1(b), the base polymer layer is separated from the rigid substrate (102). Delamination may be performed using laser lift-off, thermal release, mechanical peeling, or dissolution of a sacrificial release layer. This removal transforms the bonded microLED strip into a thin, flexible structure suitable for conforming to curved or irregular edges of the light guide, enabling compact form factors not achievable with conventional edge-lit LED packages.

[0029] The configuration shown in Figure 1 enables light injections at extremely close proximity to the light-guide edge, minimizing optical losses typically associated with packaged LED spacing, encapsulant thickness, or bulky PCB structures. The use of integrated reflectors ensures that light emitted toward the substrate or laterally outside the coupling region is redirected into the entranceaperture of the light guide. Additional microLED strips may be placed along multiple edges of the light guide, including the edge surface (110) or the stepped top edge (108), enabling increased brightness, symmetric illumination, or directional lighting patterns as required in automotive, architectural, or display applications.

[0030] The embodiment shown in Figure 1 is suited for front-lit or back- lit illumination systems, ultra-thin display modules, AR / VR optical elements, decorative lighting, and embedded lighting panels. By eliminating the bulk associated with traditional LED edge-lighting assemblies and by enabling homogeneous, high-efficiency light injection through direct microLED edge bonding, this embodiment forms a key foundation for the advanced edge-lighting systems described throughout this specification.

[0031] Figure 1(a) depicts an exemplary embodiment of a compact edge-lighting solution using a microLED light strip. In this configuration, at least one light strip (104) is fabricated on a rigid substrate (102). The light strip includes several key components, such as the base polymer, microLEDs, conductive layers, reflectors, and encapsulation layers, as detailed in Figure 1(b). A bonding layer (106) may be applied to either the top surface of the light strip or the edge of the light guide (100), facilitating attachment. The light strip can be bonded to the edge surface (110) or the edge of the top surface (108), with the light being extracted from either the top or bottom surface. For enhanced performance, edge surfaces can be covered with reflectors or additional light strips to optimize light extraction and minimize losses. After bonding the light strip to the light guide, the base polymer layer is delaminated from the rigid substrate, completing the manufacturing process. This approach enables the creation of ultra-compact and efficient edge-lighting solutions suitable for a variety of applications.Base Polymer Layer and MicroLED Integration

[0032] The base polymer layer serves as a foundational platform for conductive traces and microLEDs. This layer is typically made from materials like PDMS or polyamide due to their excellent flexibility, thermal stability, and compatibility with microfabrication processes. Conductive traces are patterned on the surface of the polymer layer to provide electrical connections for the microLEDs. MicroLEDs are bonded directly to these traces using techniques such as pick-and-place transfer or wafer bonding, ensuring precise alignment and robust electrical contact.

[0033] Once the microLEDs are attached, the encapsulation layer is applied to protect the devices from mechanical stress. In certain configurations, the encapsulation layer and the base polymer layer can be fabricated from the same material, simplifying the manufacturing process and enhancing compatibility between the layers.Light Strip Bonding to Light Guides

[0034] At least one microLED light strip (104) is bonded to the edge of a light guide (100), which serves as a medium to distribute and extract light. The light guide 100 can be glasses (e.g. in automotive, architecture, packaging, etc.) or light distribution layer for front or backlight structure. The light guide may be positioned on the surface or directly along the side edge of the strip, depending on the desired light extraction direction. A bonding layer (106) is introduced between the light strip and the light guide to ensure a secure and durable attachment. This bonding layer may also function as the encapsulation layer, reducing the number of layers and simplifying fabrication.

[0035] Here, the positioning of the bonding layer is flexible. It can be on the top surface of the light strip or directly on the edge of the light guide. This allows light to be extracted either from the top surface, for applications like backlit displays, or the bottom surface, for specialized lighting setups. Additionally, the edge surfaces of the light guide can be covered with reflectors or additional light strips to enhance light intensity and ensure uniform distribution.Delamination from Rigid Substrate

[0036] Once the bonding process is complete, the base polymer layer is delaminated from the rigid substrate (102). This step involves separating the polymer layer using techniques such as laser ablation or thermal release. For example, a laser can be used to precisely target the interface between the base polymer and the rigid substrate, allowing for clean separation without damaging the functional layers of the light strip. This delamination process is critical for applications requiring flexibility, as it transforms the light strip from a rigid form to a pliable and adaptable structure.Compact Design and Light Extraction Optimization:

[0037] The microLED light strip design is optimized for compact edge-lighting applications, making it suitable for devices where space is limited, such as ultra-thin displays or compact optical systems. The inclusion of reflectors within the light strip ensures that any light emitted toward the substrate is redirected toward the light guide, maximizing efficiency. Reflective coatings or structures can be tailored to the specific application, providing either focused or diffused illumination as needed.

[0038] Furthermore, additional microLED light strips can be bonded to the edge surfaces (110) or the edge of the top surface (108) of the light guide, enabling multi-directional lighting. This flexibility in configuration allows for highly customizable lighting solutions, catering to a wide range of industrial, automotive, and consumer applications.

[0039] Figure 2 illustrates exemplary embodiments of microLED light strips, showcasing various configurations and design possibilities.

[0040] In Figure 2(a), the structure (202) comprises of conductive traces (220) and at least one microLED integrated with these traces. In one related embodiment, multiple microLEDs are utilized to enable different color points, providing versatile lighting options. For instance, in one configuration, a single type of microLED (224, 222) is transferred onto the strip (204), with a subset of these microLEDs (222) being coated with a color conversion material. This design ensures that at least one conductive trace is distinct for the microLED sets covered by the color conversion material, enabling independent brightness adjustments for each set. Such independent control facilitates the creation of varied color points.

[0041] In another embodiment, the color conversion material is designed to produce a mix of red and green, while the uncoated microLEDs emit blue light. By finely tuning the brightness ratio between the blue microLEDs and those influenced by the color conversion material, it becomes possible to adjust the correlated color temperature (CCT) of the light, effectively enabling dynamic control over white light output. This innovative approach supports applications requiring tunable white light, such as adaptive lighting solutions or displays with customizable hues.

[0042] Figure 2(b) shows another related embodiment with reflective layer 230 under themicroLEDs 224 and 222. The reflective layer can be the same as the electrode. In one related case, the dielectric layer can separate the reflective layer from the electrodes. A side reflector 232 formed on the side of an encapsulation layer 234. This structure is formed on a substrate 240.

[0043] Figure 2(c) shows another related embodiment where reflective layers are formed around the base polymer. The reflector can be a housing structure and added to the structure after bonding to the waveguide.

[0044] Figure 2 illustrates several embodiments of microEED light strip structures optimized for coupling into a light guide and enabling multi-color output, reflective enhancement, and structural variation for different optical requirements. As shown in Figure 2(a), a microLED light strip (204) is formed on a base polymer layer that carries conductive traces (220) deposited or patterned on its surface. These conductive traces provide electrical routing to at least one microLED device (224, 222) integrated onto the strip. The microLED devices may include multiple units arranged along the strip length or individual microLED emitters positioned at specific intervals depending on illumination requirements.

[0045] In the embodiment of Figure 2(a), the microLEDs comprise at least two categories: uncoated microLEDs (224) and microLEDs (222) that are coated with a color conversion material. The color conversion material is applied selectively to a subset of microLEDs to modify their emission spectrum. For example, blue-emitting microLEDs (224) may remain unaltered, while a separate subset (222) is coated with phosphor, quantum dot, or hybrid conversion layers producing green, red, amber, or mixed spectral outputs. This selective application of color conversion enables the light strip to generate multiple color points or tunable white light by adjusting the relative drive currents delivered through distinct conductive traces (220). At least one conductive trace is isolated for the color-converted microLEDs to allow independent brightness control and facilitate dynamic spectral mixing.

[0046] In another case, different color conversion layers are applied to different subset of microLEDs. These structures enable the light strip to generate multiple color points or tunable colors.

[0047] Figure 2(b) illustrates another related embodiment in which the microLED devices (224, 222) are positioned above a reflective layer (230). The reflective layer may be formed of metal,dielectric stacks, and may be patterned to coincide with or extend beyond the footprint of the microLEDs. In some implementations, the reflective layer also functions as an electrical electrode, while in others it is isolated by a dielectric layer for optical purposes. A side reflector (232) is shown adjacent to an encapsulation layer (234), forming a partially enclosed reflective cavity. This configuration increases the proportion of emitted light directed toward the edge of the light guide, improves overall brightness, and reduces light leakage into surrounding components. The side reflector (232) may be metallic, dielectric, molded white polymer, or multilayer optical film optimized to redirect lateral emission.

[0048] Figure 2(c) depicts a further related embodiment in which reflective structures (e.g., metalized surfaces, polymer housings, dielectric mirrors) are formed around the base polymer layer to create a more completely enclosed optical housing. In this configuration, the microLEDs reside within a reflective cavity, directing the majority of emitted light toward the bonding interface with the light guide. This embodiment may be fabricated either before bonding the light strip to the waveguide or formed as an additional housing structure after attachment. The reflective enclosure reduces optical losses, enhances uniformity, and enables tailored emission profiles by controlling the extent and geometry of reflective surfaces.

[0049] Across these embodiments, the design of Figure 2 enables dynamic color control. By independently adjusting the drive currents of the uncoated microLEDs (224) and the color-converted microLEDs (222), a wide range of correlated color temperatures (CCT) or multi-color outputs can be achieved. For example, when the color conversion material produces a mixture of red and green and the unconverted microLED emits blue light, the strip can generate tunable white light by adjusting the blue-to-converted intensity ratio. This dynamic tunability is advantageous for circadian lighting, adaptive ambiance control, display illumination requiring precise color temperatures, and signaling applications demanding high color accuracy.

[0050] The structure of Figure 2 also supports high-precision fabrication techniques. The base polymer can be etched to form isolated islands corresponding to each microLED group, preventing electrical crosstalk and optimizing thermal dissipation. Alternatively, the base polymer may remain continuous for mechanical rigidity and simplicity of handling during manufacturing. The encapsulation layer (234) covering the microLEDs may incorporate engineered optical features suchas scattering particles, micro-lenses, diffusers, or beam-shaping elements, enhance uniformity and directing emitted light more effectively toward the light-guide interface.

[0051] The embodiments shown in Figure 2 are compatible with various light-guide edge-bonding configurations described in connection with Figure 1. The microLED strips of Figure 2 may be attached to the side edge, top edge, or stepped surfaces of the light guide depending on desired extraction characteristics. Reflective structures shown in Figures 2(b) and 2(c) further improve coupling efficiency by minimizing absorption and redirecting laterally emitted light toward the edge aperture. When bonded to a waveguide with engineered extraction features, these microLED strips create high-brightness, energy-efficient illumination suitable for ultra-thin displays, architectural panels, automotive lighting assemblies, e-ink or reflective display modules, and other surface- illuminated applications.

[0052] Figure 2 therefore illustrates key structural variants of the microLED strip — selective color conversion, reflective enhancement, optical housing formation, and adjustable color mixing — each contributing to improved performance, manufacturability, and optical flexibility of the edge-lighting module.Dynamic Color Control Through Brightness Adjustment

[0053] One of the key features of this embodiment is the ability to dynamically adjust the brightness of each microLED set. For example, by varying the brightness ratio between the blue-emitting microLEDs (224) and those coated with color conversion material (222), a wide range of color temperatures can be achieved. This capability is particularly beneficial for applications requiring adaptive white light, such as circadian lighting, where the color temperature can shift from cool white during the day to warm white in the evening. In one related embodiment, the controller is running an Al engine making decisions based on environmental parameters, applications, user habits, and other factors. The brightness, color and location are adjusted locally or globally based on this Al engine output.

[0054] In another related configuration, the color conversion material generates a combination of red and green light, while the uncoated microLEDs emit blue light. By carefully controlling the intensity of these light sources, it is possible to achieve precise white balance and adjust thecorrelated color temperature (CCT). Such tunable white lighting solutions are ideal for environments like offices, retail spaces, and smart home systems.High-Precision Structuring for Light Strips

[0055] To optimize performance, the base polymer layer can be etched to form isolated islands for each microLED set. These islands prevent crosstalk between adjacent sets and enable greater precision in controlling light output. In cases where the polymer base remains connected, the structure retains mechanical integrity, making it easier to handle and integrate during assembly.Encapsulation and Protection Layers

[0056] In some embodiments, an encapsulation layer may be applied over the microLEDs to protect them from external factors, such as moisture, dust, and physical damage. This layer can also serve as an optical element, diffusing or focusing light to achieve specific illumination patterns. For instance, in applications requiring uniform light distribution, the encapsulation layer can be engineered with scattering particles or textured surfaces.Edge Bonding and Light Extraction

[0057] In some configurations, the microLED light strip is bonded to the edge of a light guide, as seen in Figure 2(b). This allows the emitted light to be efficiently coupled into the light guide, which then distributes the light across its surface. The bonding process is facilitated by a bonding layer, which may be the same as the encapsulation layer for simplicity. The position of the light guide can vary, being either on the surface or along the side edge, depending on the desired light extraction direction.Enhanced Lighting Efficiency with Reflectors

[0058] In some embodiment's to maximize efficiency, reflectors may be integrated into the light strip structure. These reflectors redirect any stray light toward the desired output direction, reducing losses and enhancing brightness. This is particularly useful for edge-lighting applications, such as backlit displays or illuminated panels, where uniform light distribution is critical.Applications and Advanced Configurations

[0059] The versatility of the embodiments in Figure 2 makes them suitable for a wide range of applications. These may include:1. Display Backlighting: The ability to achieve high brightness and tunable color points makes these light strips ideal for advanced display systems, such as LCDs.2. Architectural Lighting: Dynamic color control and adaptive white light capabilities enable the creation of customizable lighting environments for homes, offices, and public spaces. The lighting strips can be coupled to the glass used in the architecture.3. Automotive Applications: Compact and efficient designs allow integration into vehicle interiors and exteriors, such as dashboard lighting, ambient lighting, or decorative and functional lighting.4. Surface lighting: the lights can be used to light up a surface through a light guide. The application can be traditional lighting structure, e-inks, etc.Dual-Color MicroLED Structure

[0060] Figure 3 shows an embodiment where one microLED structure 300 can provide two different colors, 302 and 304. The structure has two of the same type of contacts 306 and 308 and one different contact 310. At least one area associated with one of the same contacts is augmented by the color conversion layer.

[0061] Figure 3 illustrates an embodiment where a single microLED structure (300) is designed to emit two distinct colors (302 and 304), enabling versatile lighting or display applications. This configuration leverages an innovative contact and color conversion strategy to produce multiple color outputs from a single device.MicroLED Structure Design

[0062] The microLED structure (300) includes three or more electrical contacts: at least two contacts of the same type (306 and 308) and one distinct shared contact (310). These contacts 306 308 enableindependent control of different emission areas within the same microLED structure. The arrangement allows the device to emit light in two separate regions or modes.Color Conversion for Dual-Color Output

[0063] At least one area of the microLED structure, associated with one of the identical contacts (306 or 308), is augmented with a color conversion layer. This layer could be made of materials such as phosphors or quantum dots, which absorb the original emission from the microLED and re-emit light at a different wavelength. The color conversion layer can be patterned using photo definable resist, printing, etching.

[0064] In one example, the unconverted area emits the native light color of the microLED, such as blue. The area with the color conversion layer emits a different color, such as red or green, depending on the properties of the conversion material. This configuration enables the structure to produce two distinct colors, one from the native emission (302) and another from the converted emission (304).

[0065] This configuration enables the structure to produce two distinct colors, one from the native emission (302) and another from the converted emission (304).Independent Control of Emission Areas

[0066] The two identical contacts (306 and 308) and the different contacts (310) allow for independent electrical control of the microLED regions. This means that the brightness and intensity of each color (302 and 304) can be individually adjusted. Such control is critical for applications that require dynamic color mixing, precise lighting effects, or tunable white light.Applications and Benefits

[0067] This dual color microLED structure offers several advantages and is suitable for a wide range of applications, including:1. Dynamic Lighting Solutions: The ability to produce two distinct colors from a single structure simplifies the design of RGB or tunable white lighting systems, reducing the number of individual components required.2. Compact Displays: This structure is ideal for high-resolution displays, as it minimizes the footprint while enabling full-color functionality through precise control of the emission areas.3. Energy Efficiency: By utilizing a single microLED with a color conversion layer, the structure reduces the need for additional light sources, optimizing power consumption.4. Automotive and Wearable Devices: The compact and versatile design makes it suitable for integration into automotive lighting systems, HUDs, or smart wearables where space and power efficiency are crucial.5. Signage and Decorative Applications: Dual-color output enables creative lighting effects for digital signage or architectural decorations.

[0068] The described embodiment in Figure 3 can be scaled or customized by varying the size, shape, or configuration of the microLED structure. For instance, additional contacts and emission areas can be incorporated to enable tricolor or full-spectrum outputs. Similarly, the color conversion layer can be tailored to achieve specific wavelengths, expanding the range of potential applications.

[0069] Flexible MicroLED Light Strip for Curved Applications: In one embodiment, the microLED light strip includes a flexible base polymer layer, such as polyimide, which allows the light strip to conform to curved or irregular surfaces. Conductive traces are patterned on the flexible layer, and microLEDs are bonded to these traces. An encapsulation layer, which can also be flexible, protects the microLEDs. This design is suitable for applications like automotive lighting or wearable devices, where curved or dynamic surfaces are common. The light strip can be directly bonded to curved light guides or reflective surfaces to enhance illumination.

[0070] Integrated Optical Elements for Beam Shaping: In another embodiment, integrated optical elements, such as microlenses or microprisms, are formed directly on the encapsulation layer of the light strip. These optical elements shape the emitted light beam to achieve specific illumination patterns, such as focused beams or diffused light. This configuration is ideal for applications like projectors or displaying backlighting, where precise light control is critical. The optical elements can be created through molding or photolithography during the encapsulation process.

[0071] Thermally Optimized Light Strips: A related embodiment focuses on thermal management by integrating a thin metallic or ceramic layer within the base polymer. This layer acts as a heat spreader, efficiently dissipating heat generated by the microLEDs. The design ensures stable performance and longevity, particularly in high-power applications such as industrial or outdoor lighting. The heat- spreading layer can also serve as a ground plane for the conductive traces, improving the electrical performance of the strip.

[0072] Dual-Sided Light Strips for Increased Illumination: In one embodiment, the microLED light strip is designed with microLEDs on both sides of the base polymer layer. This configuration allows light to be emitted from both the top and bottom surfaces, doubling the illumination capacity. The strip is bonded to a transparent light guide, allowing light extraction from both sides. This dual-sided design is ideal for edge lighting in large-format displays or architectural lighting.

[0073] Color-Tunable Light Strips with Embedded Sensors: In a related embodiment, the microLED light strip includes embedded sensors, such as photodiodes or temperature sensors, integrated within the conductive traces. These sensors provide real-time feedback on light output or thermal conditions, enabling dynamic adjustments to the brightness and color temperature of the microLEDs. For instance, the system can automatically modify the ratio of blue and color-converted microLEDs to achieve the desired color temperature based on ambient conditions. In one related embodiment, the controller is running an Al engine making decisions based on environmental parameters, applications, user habits, sensors outputs and other factors. The brightness, colour and location are adjusted locally or globally based on this Al engine output.

[0074] Seamless Modular Light Strip Systems: Another embodiment enables modularity by designing light strips with interconnects at each end. These interconnects allow multiple light strips to be joined seamlessly, creating continuous lighting systems of any length. The modular strips include standardized connectors for power and data transfer, simplifying installation, and enabling dynamic control of the entire system. This design is particularly beneficial for architectural lighting and large-scale display backlighting.

[0075] Embedded Reflective Layers for Improved Efficiency: In this embodiment, a reflective layer is embedded beneath the base polymer layer to redirect light emitted downward back through the light guide. This improves overall light output and reduces losses. The reflective layer can be made from materials like aluminum or silver and may include textured surfaces to enhance reflectivity and light distribution. This configuration is especially useful for applications where maximizing brightness is essential, such as automotive headlights or high-intensity task lighting.

[0076] Waterproof and Robust MicroLED Light Strips: In another embodiment, the microLED light strip includes a specialized encapsulation layer made from a waterproof and UV-resistant material, such as silicone or polyurethane. This makes the light strip suitable for outdoor or underwater applications, including signage, pool lighting, or marine displays. Additional protective coatings can be applied to the conductive traces to prevent corrosion, ensuring long-term durability in harsh environments.

[0077] Eigure 3 illustrates an embodiment of a dual color microLED structure (300) designed to emit at least two distinct colors from a single microLED device footprint. This embodiment enables multi- wavelength emission, tunable color output, and high-efficiency illumination without requiring separate RGB chips or complex multi-pixel layouts. The structure of Figure 3 may be used in standalone microLED systems or implemented within the microLED light strips described in connection with Figures 1 and 2.

[0078] The microLED structure (300) includes at least three electrical contacts, namely two contacts of a first type (306 and 308) and a third contact (310) of a second type that is shared between the two main emission regions. The two same-type contacts (306, 308) each address a distinct emission zone or segment within the microLED. These two segments may share an epitaxial stack but are electrically isolated via internal trenching, mesa isolation, dielectric deposition, or patterned metallization. The shared contact (310) may be a common anode, a common cathode, or a shared ground, depending on the selected drive configuration.

[0079] A key feature of the embodiment in Figure 3 is the selective application of a color conversion layer to only one portion of the microLED device. In this configuration, the emission regionassociated with one of the identical contacts (for example, contact 306) is coated with a color conversion material such as phosphors, quantum dots, perovskite materials, or hybrid emissive particles. The uncoated emission region associated with the other identical contact (308) remains unchanged and emits at the native wavelength of the underlying microLED (e.g., blue light in the case of GaN-based devices). As a result, activating the region corresponding to contact 308 produces native emission (302), while activating the region associated with contact 306 results in converted emission (304) at a different color such as green, red, amber, cyan, or white.

[0080] This dual-emission architecture enables a single microLED footprint to generate two independently controllable output colors. In one example, the uncoated region emits blue light, while the color-converted region emits either green or red light depending on the conversion material. When both regions are driven simultaneously at properly selected intensities, the device can produce tunable color output or adjustable correlated color temperature (CCT). The relative brightness of each region may be varied continuously through modulation of the drive current delivered to the corresponding contact. This configuration provides precise dynamic control over output spectral characteristics using minimal surface area, significantly simplifying system design compared to conventional multi-LED mixing approaches.

[0081] The dual-color structure of Figure 3 may be fabricated using several methods, including lithographic masking for selective deposition of color conversion layers, inkjet printing of quantum dot materials, micro-transfer printing of phosphor films, or deposition of hybrid emissive materials within micro-patterned wells formed over the designated contact region. The structure may be further optimized by including reflective layers beneath or beside the emission regions to ensure efficient extraction of both native and converted emission. Additionally, the color conversion layer may be encapsulated within the overlying microLED encapsulation layer to maintain stability and prevent oxygen or moisture degradation.

[0082] The three-contact microLED design shown in Figure 3 offers multiple advantages including a reduction in component count, improved optical uniformity, simplified electrical routing, and increased luminous efficacy. Because both emission regions originate from a single microLED, the footprint is smaller than any arrangement using separate discrete emitters. This enables compact, high-resolution pixel layouts and is particularly useful for micro-display, AR / VR, and high-densityillumination applications. In lighting scenarios, the device may be used to produce warm-to-cool tunable white light, multi-color glow patterns, adaptive automotive signals, or decorative lighting with adjustable hues.

[0083] Furthermore, the microLED structure (300) can be scaled in size and configuration. Additional contacts and emission regions may be incorporated to create three-color (RGB) or multi- spectral versions. Similarly, the number and placement of color conversion regions can be adjusted to tailor spectral output for specific wavelengths or color performance targets. This design may also be integrated into the microLED strip architectures described in Figures 1 and 2, enabling edgelighting modules with embedded color tunability.

[0084] Thus, Figure 3 demonstrates a compact and versatile dual color microLED architecture enabling independent electrical control of two emission regions with different spectral properties, allowing dynamic color control within a single microLED footprint and supporting advanced illumination, display, and signaling applications.

Claims

Claims1. A method of creating a compact edge-lighting using a microLED light strip, the method comprising: having the microLED light strip comprising of components a base polymer, microLED, conductive layers, reflectors, and encapsulation layers; applying a bonding layer to either a top surface of the microLED light strip or an edge of a light guide, to facilitate attachment; bonding the microLED light strip to an edge surface or an edge of the top surface, wherein the light is extracted from either the top or bottom surface, wherein edge surfaces are covered with reflectors or additional light strips to optimize light extraction; and after bonding the light strip to the light guide, the base polymer layer is delaminated from a rigid substrate.

2. The method of claim 1, wherein there is a microLED with structure providing two different colors having two same type of contacts and one different contact wherein further where one area associated with one of the same contacts is augmented by a color conversion layer.

3. The method of claim 1, wherein the light guide can be glasses.

4. The method of claim 1, wherein a subset of microLEDs is coated with a color conversion material.

5. The method of claim 1, wherein the base polymer comprises polyimide, polyamide, or other flexible materials compatible with the subsequent delamination.

6. The method of claim 1, wherein conductive traces are patterned onto the polymer to receive microLEDs transferred onto the substrate using pick-and-place, wafer transfer, or stamptransfer techniques.

7. The method of claim 1, wherein microLEDs are arranged as single devices or grouped arrays, such as in automotive and aero and space transportation applications, and comprise devices that are color-converted, dual-contact, or multi-mode emitters8. The method of claim 1, wherein the microLED light strip is positioned adjacent to an edge of the light guide, which is planar or curved.

9. The method of claim 1, wherein the bonding layer comprises silicone, epoxy, a UV-curable adhesive, an index-matched gel, or a physical coupling film.

10. The method of claim 1, wherein upon bonding, the microLED strip is aligned to either the vertical edge surface of the light guide or a stepped or a chamfered region at the edge of its top surface to enable an injected light to be extracted from either the upper or lower surface of the light guide, depending on scattering structures or surface treatments within a lightguide body.

11. The method of claim 1, wherein the base polymer layer acts as a carrier for the conductive layer and microLEDs. A reflector may be included beneath the microLEDs to redirect downward or lateral light toward the light-guide coupling interface. Side reflectors or reflective housings may also be applied to further confine and direct emitted light, increasing coupling efficiency12. The method of claim 11, wherein a reflector is included beneath the micro LEDs to redirect downward or lateral light toward a light-guide coupling interface and wherein further side reflectors or reflective housings are applied to further confine and direct emitted light, increasing coupling efficiency13. The method of claim 1, wherein an encapsulation layer covers the microLEDs to protect them from moisture, oxidation, and mechanical damage and simultaneously serve as an optical element by diffusing, focusing, or shaping light emitted from the microLEDs.

14. The method of claim 1, the bonding layer used to attach the light strip to the light guide also serves as the encapsulation layer, streamlining the structure.

15. The method of claim 1, wherein the delamination is performed using laser lift-off, thermal release, mechanical peeling, or dissolution of a sacrificial release layer wherein this removal transforms the bonded microLED strip into a thin, flexible structure suitable for conforming to curved or irregular edges of the light guide, enabling compact form factors enables light injection at extremely close proximity to the light-guide edge, minimizing optical lossestypically associated with packaged LED spacing, encapsulant thickness, or bulky PCB structures. The use of integrated reflectors ensures that light emitted toward the substrate or laterally outside the coupling region is redirected into the entrance aperture of the light guide. Additional microLED strips may be placed along multiple edges of the light guide, including the edge surface (110) or the stepped top edge (108), enabling increased brightness, symmetric illumination, or directional lighting patterns as required in automotive, architectural, or display application not achievable with conventional edge-lit LED package.

16. The method of claim 1, wherein a configuration enables light injection at extremely close proximity to the light-guide edge, minimizing optical losses typically associated with packaged LED spacing, encapsulant thickness, or bulky PCB structures wherein the use of integrated reflectors ensures that light emitted toward the substrate or laterally outside the coupling region is redirected into the entrance aperture of the light guide.

17. The method of claim 1, wherein additional micro LED strips are placed along multiple edges of the light guide, including the edge surface or the stepped top edge, enabling increased brightness, symmetric illumination, or directional lighting patterns as required in automotive, architectural, or display applications.

18. A microLED edge-lighting assembly comprising: a light guide having an edge surface and a top surface; a microLED light strip comprising a base polymer layer, conductive traces formed on the base polymer layer, at least one microLED mounted to the conductive traces, and an encapsulation layer; a bonding layer positioned between the microLED light strip and the light guide, the bonding layer attaching the microLED light strip to either the edge surface or a top-edge region of the light guide; and a reflective structure positioned below, beside, or around the microLED, wherein the microLED light strip is delaminated from a rigid substrate after attachment to the light guide, and wherein light emitted by the microLED is injected into the light guide and extracted from either a top surface or a bottom surface of the light guide.

19. The assembly of claim 18, wherein the bonding layer comprises an index-matched optical adhesive, gel, or thermosetting polymer.

20. The assembly of claim 18, wherein the microLED light strip is conformable to a curved lightguide surface following delamination from the rigid substrate.

21. The assembly of claim 18, wherein the microLED light strip is modular and includes electrical or optical connectors at its ends.

22. The assembly of claim 18, wherein the light guide comprises extraction features to direct injected light uniformly across a surface.

23. The assembly of claim 18, wherein the light guide comprises extraction features to direct injected light uniformly across a surface.

24. The assembly of claim 18, wherein the microLED light strip comprises integrated sensors selected from photodiodes, thermal sensors, strain gauges, or ambient-light sensors.

25. The assembly of claim 18, wherein the bonding layer also functions as the encapsulation layer.

26. The assembly of claim 18, wherein the microLED light strip includes a thermal- spreading layer comprising metal, ceramic, or composite material.

27. The assembly of claim 18, wherein the microLEDs on the strip are arranged on both sides of the base polymer layer to create bi-directional illumination.

28. The method of claim 1, wherein the microLED structure is scaled in size and configuration, and additional contacts and emission regions are incorporated to create three-color (RGB) or multi- spectral versions.

29. The method of claim 28, wherein the number and placement of color conversion regions are adjusted to tailor spectral output for specific wavelengths or color performance targets

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