SMALL, SIDE-EMISSIVING LED LIGHT STRIP

Abstract

Light-emitting diode device (100) with: a flexible printed circuit board (108) with at least one light-emitting diode (104) mounted thereon, wherein the at least one light-emitting diode includes an emitting section (118) configured to emit light; a flexible encapsulation structure (106) arranged above the flexible printed circuit board, having a reflective side and a light-emitting side (115) opposite the reflective side; and a reflective section (110) that is positioned above the reflective side of the encapsulation structure, wherein the emitting section of the light-emitting diode is oriented so that it emits light towards the reflecting side, wherein the reflective section comprises a reflective structure (102) integral with the encapsulation structure, wherein the integral reflective structure includes diffusion properties, wherein the reflective section comprises a reflective material applied to the encapsulation structure (106), wherein the reflective material comprises a white reflective film and a white reflective paint, wherein the reflective material has a thickness of one tenth (0.1) of a millimeter.

Description

INTRODUCTION

[0001] The information in this section is intended to provide a general context for the disclosure. The work of the presently identified inventors, to the extent described in this section, as well as aspects of the description not otherwise considered prior art at the time of filing, are not expressly or implicitly considered prior art to the present disclosure.

[0002] The present disclosure relates to a flexible light emitting diode (LED) light bar, more particularly to a flexible LED light bar with side light emitting diodes.

[0003] Light strips, such as flexible LED strips, are used in various applications, such as closet lighting, TV backlighting, stairwell lighting, architectural lighting, bar lighting, kitchen lighting, automotive accessory lighting, and the like. Flexible LED light strips typically include an elongated, flexible strip of circuit board with conductive traces arranged thereon that supply electrical power to the LEDs. The flexible LED light strips are arranged in a desired configuration and connected to a power source to create an illuminated environment.

[0004] CA 2 731 820 C describes, in some embodiments of the alternator, a heat sink, a reflector, and light-emitting diodes. Some embodiments of the heat sink include perforations. The reflector has a reflective surface that extends around at least a portion of the light-emitting diodes. In some embodiments, a portion of the reflector is arranged between the light-emitting diodes and the heat sink.

[0005] US 2015 / 0 023 054 A1 describes a reflective film having a first portion, with a layer including a resin A and a layer containing a resin B.

[0006] US 2012 / 0 113 644 A1 describes an elongated circuit board with a light-emitting diode circuit. Parts of the circuit board are flexible in at least one direction.

[0007] US Pat. No. 7,736,044 B2 describes a lighting device. One embodiment of the lighting device comprises a substrate and a lighting element. The lighting element is coupled to the substrate to emit light through a light exit surface.

[0008] US 2016 / 0 091 166 A1 describes a lighting device, such as a flexible LED module, comprising an elongated profiled body with a mouth portion, a first and a second lateral side arranged laterally of the mouth portion, and a web side opposite the mouth portion. The profiled body comprises a light-transmissive portion extending between the mouth portion and the first lateral side, and an opaque portion.

[0009] EP 2 454 520 B1 describes a flexible light strip comprising a flexible printed circuit board, a plurality of light sources arranged on the flexible printed circuit board for emitting light, first conductors for carrying current arranged on the flexible printed circuit board, which is connected to the light sources and arranged to supply them with energy, and a housing. In one aspect, the light sources are arranged such that they emit light substantially perpendicular to the flexible printed circuit board. The housing comprises at least a first section and a second section which extend along the flexible printed circuit board and have different optical properties. The first section is at least substantially transparent to light emitted by the light sources.

[0010] However, these disclosures have the disadvantage that they are designed for specific areas of application and cannot be adapted to changing requirements. SUMMARY

[0011] The invention is defined by the claims. The above-mentioned disadvantage of the prior art is overcome by a flexible encapsulation structure, as described below.

[0012] In one example, a light-emitting diode is disclosed. The light-emitting diode includes a flexible circuit board having at least one light-emitting diode mounted thereon. The at least one light-emitting diode includes an emitting portion configured to emit light. The light-emitting diode device also includes an encapsulation structure disposed over the flexible circuit board having a reflective side and a light-exit side opposite the reflective side. The light-emitting diode also includes a reflective portion disposed over the reflective side of the encapsulation structure, with the emitting portion of the light-emitting diode aligned with the reflective side.

[0013] In other features, the reflective portion comprises a reflective structure integrated with the encapsulation structure. In other features, the encapsulation structure and the reflective structure comprise a polymer material. In other features, the reflective structure comprises a maximum thickness of one-half (0.5) millimeter. In other features, the polymer material comprises a hardness of forty (40) Shore D to seventy-five (75) Shore D.

[0014] In other features, the reflective portion includes a reflective material applied to the encapsulation structure. In other features, the reflective material comprises at least one of a white reflective film and a white reflective paint. In other features, the reflective material has a thickness of one-tenth (0.1) of a millimeter to one-half (0.5) of a millimeter. In other features, the emitting portion is aligned along an axis parallel to a plane defined by a top surface of the flexible circuit, wherein the axis is perpendicular to a plane defined by a top surface of the reflective side.

[0015] In one example, a light-emitting diode is disclosed. The light-emitting diode includes a flexible circuit board having at least one light-emitting diode mounted thereon. The at least one light-emitting diode includes an emitting portion configured to emit light. The light-emitting diode device also includes an encapsulation structure disposed over the flexible circuit board having a reflective side and a light-exit side opposite the reflective side. The light-emitting diode also includes a reflective portion disposed over the reflective side of the encapsulation structure, with the emitting portion of the light-emitting diode aligned with the reflective side.

[0016] In other features, the reflective portion comprises a reflective structure integrated with the encapsulation structure. In other features, the encapsulation structure and the reflective structure comprise a polymer material. In other features, the reflective structure comprises a maximum thickness of one-half (0.5) millimeter. In other features, the polymer material comprises a hardness of forty (40) Shore D to seventy-five (75) Shore D.

[0017] In other features, the reflective portion includes a reflective material applied to the encapsulation structure. In other features, the reflective material comprises at least one of a white reflective film and a white reflective paint. In other features, the reflective material has a thickness of one-tenth (0.1) of a millimeter to one-half (0.5) of a millimeter. In other features, the emitting portion is aligned along an axis parallel to a plane defined by a top surface of the flexible circuit, the axis being perpendicular to a plane defined by a top surface of the reflective side.

[0018] In one example, a light-emitting diode is disclosed. The light-emitting diode includes a flexible substrate. The flexible substrate includes a flexible circuit board with at least one light-emitting diode mounted thereon. The at least one light-emitting diode includes an emitting portion configured to emit light. The light-emitting diode device also includes an encapsulation structure disposed over the flexible circuit board having a reflective side and a light-exit side opposite the reflective side. The light-emitting diode also includes a reflective portion disposed over the reflective side of the encapsulation structure.The emitting portion of the light-emitting diode is aligned along an axis parallel to a plane defined by a top surface of the flexible circuit board, the axis being perpendicular to a plane defined by a top surface of the reflective side.

[0019] In other features, the reflective portion comprises a reflective structure integrated with the encapsulation structure. In other features, the encapsulation structure and the reflective structure comprise a polymer material. In other features, the reflective structure comprises a maximum thickness of one-half (0.5) millimeter. In other features, the polymer material comprises a hardness of forty (40) Shore D to seventy-five (75) Shore D.

[0020] In other features, the reflective portion includes a reflective material applied to the encapsulation structure. In other features, the reflective material comprises at least one of a white reflective film and a white reflective paint. In other features, the reflective material has a thickness of one-tenth (0.1) of a millimeter to one-half (0.5) of a millimeter. In other features, the encapsulation structure is configured to diffuse between fifty percent (50%) and ninety percent (90%) of the light emitted by the light-emitting diode.

[0021] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are provided for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present disclosure will become more fully understood with reference to the detailed description and the accompanying drawings, in which: Fig. 1A is a cross-sectional view of a side-firing LED light bar according to an exemplary implementation of the present disclosure; Fig. 1B is a cross-sectional view of a side-firing LED light bar according to another exemplary implementation of the present disclosure; Fig. 2 is a flowchart illustrating an exemplary method for manufacturing the side-emitting LED light bar in Fig. 1A illustrates; The Fig. 3 to 6 illustrate the cross-section of the side-emitting LED light bar according to the Fig. 2 manufacturing processes; Fig. 7 is a flowchart illustrating an exemplary method for manufacturing the side-emitting LED light bar in Fig. 1B illustrates; and The Fig. 8 to 12 illustrate exemplary cross-sectional views of the side-emitting LED light bar according to the Fig. 7 shown manufacturing processes.

[0023] In the drawings, the same reference numerals are used for similar and / or identical elements. DETAILED DESCRIPTION

[0024] The present disclosure is directed to a side-emitting LED light bar. The side-emitting LED light bar includes a substrate employing side-emitting LEDs that include an emitting portion aligned with a transmission surface of the encapsulation structure. Thus, the viewer is not directly exposed to the light from the emitting portion of the LEDs. The substrate may also include an encapsulation structure with diffusion properties to scatter the light emitted by one or more LEDs. The diffused light may provide a uniform illumination level that may be aesthetically pleasing to the viewer. The diffusion properties may also disperse the heat generated by the light, unlike encapsulation structures with minimal diffusion properties.

[0025] The Fig. 1A and Fig. 1B illustrate an example of a side-emitting LED light bar 100 according to an exemplary implementation of the present disclosure. The side-emitting LED light bar 100 includes a flexible substrate 102 having one or more LEDs 104. The flexible substrate 102 includes an encapsulation structure 106 and a flexible circuit board 108. The flexible structure 102 includes, for example, an elongated encapsulation structure 106 mounted on an elongated flexible circuit board 108 to form an LED bar. The encapsulation structure 106 is disposed over the LEDs 104 and the flexible circuit board 108. The LEDs 104 are mounted on and interconnected to the flexible circuit board 108. The flexible circuit board 108 includes, for example, a plurality of conductive pads or terminations connected to the corresponding LEDs 104.

[0026] The LEDs 104 emit light that can be visible, ultraviolet, or infrared. The LEDs 104 can be formed from a combination of one or more Group III elements and one or more Group V elements (III-V semiconductors). Examples of suitable III-V semiconductor materials include nitrides, such as gallium nitride, and phosphides, such as indium gallium phosphide. Other types of III-V materials can also be used.

[0027] In some implementations, the encapsulation structure 106 includes an optically transmissive polymer material encapsulating the LEDs 104. The polymer material may include suitable polyurethane, polyurethane compositions, and the like. In various implementations, the polymer material includes a hardness of about forty (40) Shore Durometers (Shore D) to about seventy-five (75) Shore Durometers (Shore D). The flexible circuit board 108 may also have a hardness similar to the polymer material to allow the flexible circuit board 108 to flex with the polymer material. In some implementations, the flexible substrate 102 may have a width (W) of about five (5) millimeters and a length (L) of three (3) millimeters.

[0028] The encapsulation structure 106 includes translucent properties that scatter the light emitted by the LEDs 104. Thus, the encapsulation structure 106 diffuses between approximately fifty percent (50%) and approximately ninety percent (90%) of the light emitted by the LEDs 104. In one or more implementations, the diffusion properties assist in heat distribution within the encapsulation structure 106 based on the diffused light within the encapsulation structure 106.

[0029] The flexible substrate 102 also includes a reflective portion 110. The reflective portion 110 reflects the light from the LEDs 104. For example, the reflective portion 110 may have an average reflectivity for the visible light emitted by the LEDs 104 of greater than ninety percent (90%). The average reflectivity of the reflective portion 110 may be at least ninety percent (90%), ninety-five percent (95%), ninety-eight percent (98%), ninety-nine percent (99%), or more. In one implementation, as in Fig. 1A, the reflective portion 110 includes a reflective structure. In a further implementation, as shown in Fig. 1B, the reflective portion 110 includes a reflective layer. As described in more detail herein, the reflective portion 110 includes any suitable reflective material to reflect the light emitted by the LEDs 104. For example, the reflective portion 110 includes a reflective metal such as aluminum or the like, a reflective foil, a reflective paint, or the like. The reflective portion 110 may include a white reflective material to reflect light occurring in the visible light spectrum.

[0030] In some implementations, the reflective portion 110 extends completely over a reflective side 112 of the encapsulation structure 106 and partially over a top surface 114 of the encapsulation structure 106. The light reflected by the reflective portion 110 is scattered within the encapsulation structure 106 and exits the encapsulation structure 106 via a light exit side 115 of the encapsulation structure 106 and / or the uncovered portion 116 of the top surface 114. In various implementations, the reflective portion 110 covers at least fifty percent (50%) to at least ninety percent (90%) of the top surface 114. Thus, the uncovered portion 116 of the top surface 114 may occupy at most ten percent (10%) to at most fifty percent (50%) of the top surface 114.

[0031] The LEDs 104 are aligned to emit light toward the reflective portion 110. For example, the LED 104 includes an emitting portion 118 aligned along an axis parallel to a plane defined by a top surface 120 of the flexible circuit board 108. The plane defined by the top surface 120 is perpendicular to a plane defined by a top surface 122 of the reflective side 112. The emitting portion 118 is also aligned opposite the light exit side 115. The light emitted by the LEDs 104 is reflected by the reflective portion 110 before exiting the encapsulation structure 106.

[0032] With reference to Fig. 1A, the encapsulation structure 106 includes the reflective portion 110. In this implementation, the reflective portion 110 includes a reflective structure integrally formed with the encapsulation structure 106. In this example, the encapsulation structure 106 and the reflective portion 110 include the same polymer material to maintain a constant thermal expansion rate. In this implementation, the reflective portion 110 includes a maximum thickness (T) of half a millimeter (0.5 millimeters).

[0033] With reference to Fig. 1B, the encapsulation structure 106 and the reflective portion 110 form discrete portions of the device 102. For example, the encapsulation structure 106 includes the polyurethane material, and the reflective portion 110 includes a reflective material, such as a reflective film or reflective paint, applied to the encapsulation structure 106. In this implementation, the reflective portion 110 includes a thickness of one-tenth (0.1) of a millimeter to one-half (0.5) of a millimeter.

[0034] Fig. 2 illustrates an exemplary method 200 for forming the side-emitting LED light bar 100 according to the Fig. 1A. The method 200 begins at 202. At 204, the encapsulation structure 106 and the reflective structure are formed by a suitable extrusion process. For example, as shown in Fig. As shown in Figure 3, the encapsulation structure 106 and the reflective structure are manufactured by an extrusion process, such as an additive manufacturing process or the like. In one example, the extrusion process is a two-color extrusion process that integrally forms the encapsulation structure 106 and the reflective structure. The encapsulation structure 106 may be provided with a flexible circuit board receiving portion 302.

[0035] At 206, the flexible printed circuit board 108 is manufactured as in Fig. 4. In one example, the flexible circuit board 108 is manufactured by a substrate manufacturing process. In another example, the flexible circuit board is manufactured by an additive manufacturing process. At 208, the LEDs 104 are mounted on the flexible circuit board 108, as shown in Fig. 5. At 210, the flexible circuit board 108 is received by the flexible circuit board receiving portion 302 and attached to the encapsulation structure 106. The flexible circuit board 108 is secured to the encapsulation structure 106 by one or more suitable attachment methods, as shown in Fig. 6, to the encapsulation structure 106. For example, the flexible circuit board 108 may be attached to the encapsulation structure 106 with an adhesive, such as an optically transmissive adhesive. At 212, the method 200 ends.

[0036] Fig. 7 illustrates an exemplary method 700 for forming the side-emitting LED light bar 100 according to the Fig. 1B. The method 700 begins at 702. At 704, the encapsulation structure 106 is formed by a suitable extrusion process, as in Fig. 8. At 706, the reflection layer is applied to the encapsulation structure 106 (see Fig. 9). For example, a white reflective foil is applied to the encapsulation structure 106. In another example, a white reflective paint is applied to the encapsulation structure 106.

[0037] At 708, the flexible printed circuit board 108 is manufactured as in Fig. 10. At 710, the LEDs 104 are mounted on the flexible circuit board 108, as shown in Fig. 11. At 712, the flexible circuit board 108 is Fig.12. In one example, the flexible circuit board 108 is attached to the encapsulation structure 106 using the appropriate adhesive. In another example, the flexible circuit board 108 is attached to the encapsulation structure 106 using a suitable coextrusion process. In yet another example, the flexible circuit board 108 is attached to the encapsulation structure 106 using a suitable glue jetting process. At 714, the method 700 ends.

[0038] The foregoing description is merely illustrative and is in no way intended to limit the present disclosure, its embodiments, or uses. The broad teachings of the disclosure may be embodied in numerous forms. Thus, while the present disclosure includes specific examples, the true scope of the disclosure is in no way limited thereby, and further modifications will become apparent from a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of the present disclosure.Furthermore, although each of the embodiments is described above as having certain features, one or more of the features described with respect to each embodiment of the disclosure may be implemented and / or combined in any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments remain within the scope of this disclosure.

[0039] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "interlocked," "coupled," "adjacent," "beside," "on top of," "above," "below," and "disposed." Unless explicitly described as "direct," a relationship may be a direct relationship when a relationship is described between a first and second element in the above disclosure if no other intervening elements are present between the first and second elements, but may also be an indirect relationship if one or more intervening elements (either spatial or functional) are present between the first and second elements.As used herein, the phrase "at least one of A, B, and C" should be understood to mean a logic (A OR B OR C), using a non-exclusive logical OR, and should not be understood to mean "at least one of A, at least one of B, and at least one of C."

[0040] In the figures, the arrow directions, as indicated by the arrowhead, generally indicate the flow of information (such as data or commands) relevant to the context of the representation. For example, if element A and element B exchange a variety of information, but the information being passed from element A to element B is relevant to the representation, the arrow may point from element A to element B. These unidirectional arrows do not imply that no other information is being passed from element B to element A. Furthermore, in the context of information being sent from element A to element B, element B may send requests for or acknowledgments of that information to element A.

Claims

[1] Light-emitting diode device (100) comprising: a flexible circuit board (108) having at least one light-emitting diode (104) mounted thereon, wherein the at least one light-emitting diode includes an emitting portion (118) configured to emit light; a flexible encapsulation structure (106) arranged above the flexible printed circuit board, having a reflective side and a light exit side (115) opposite the reflective side; and a reflective portion (110) disposed above the reflective side of the encapsulation structure, wherein the emitting portion of the light-emitting diode is oriented to emit light toward the reflecting side, wherein the reflective portion comprises a reflective structure (102) integral with the encapsulation structure, wherein the integral reflective structure includes diffusion properties, wherein the reflective portion comprises a reflective material applied to the encapsulation structure (106), wherein the reflective material comprises a white reflective film and a white reflective paint, wherein the reflective material has a thickness of one-tenth (0.1) of a millimeter. [2] The light emitting diode device (100) of claim 1, wherein the encapsulation structure (106) and the reflective structure comprise a polymer material. [3] The light emitting diode device (100) of claim 1, wherein the reflective structure comprises a maximum thickness of one-half (0.5) millimeter.

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