VEHICLE HEADLIGHT WITH PCB-MOUNTED SHIELDING

Abstract

A lighting arrangement for a vehicle headlight comprises: a printed circuit board (PCB) defining a surface, a number of discrete LED devices arranged on the surface of the PCB, each defining an output area, the output areas together defining a layout arrangement with substantially continuous illumination, a shield attached directly to the PCB and positioned over the output area of ​​at least one discrete LED device of the number of discrete LED devices and defining at least one edge of a predetermined illumination pattern, and an imaging lens arrangement positioned over the number of discrete LED devices and configured to focus and direct light from the number of discrete LED devices to produce an illumination pattern in accordance with the predetermined illumination pattern.

Description

AREA

[0001] The present disclosure relates generally to automotive lighting. More specifically, the present disclosure relates to headlights for passenger vehicles, such as cars and trucks. BACKGROUND

[0002] Vehicle headlight assemblies are subject to cut-off regulations to illuminate the roadway ahead of the vehicle while minimizing disturbance to drivers of other vehicles, including oncoming traffic and vehicles traveling in front of and in the same direction. Different countries may have different regulations and standards for headlight illumination. Examples of such regulations and standards include the ECE standard prepared by the United Nations Economic Commission for Europe, the United States Department of Transportation (DOT) standard for use in the United States and Canada, the CCC certification for China, and the U.S. Society of Automotive Engineers (SAE) standards.

[0003] Adaptive high beam headlights and systems can provide improved automatic control of a vehicle's headlights by dimming the headlights when light (e.g., headlights from oncoming vehicles and / or taillights from vehicles ahead) is detected in the area ahead of the vehicle. SUMMARY

[0004] The present disclosure provides an illumination assembly for a vehicle headlight. The illumination assembly includes: a printed circuit board (PCB) defining a surface; a plurality of discrete LED devices disposed on the surface of the PCB, each defining an output surface, the output surfaces together defining a substantially continuous illumination layout; a shield directly attached to the PCB and overlying the output surface of at least one of the plurality of discrete LED devices and defining at least one edge of a predetermined illumination pattern; and an imaging lens assembly overlying the plurality of discrete LED devices and configured to focus and direct light from the plurality of discrete LED devices to produce an illumination pattern in accordance with the predetermined illumination pattern.

[0005] The present disclosure also provides an illumination assembly for a vehicle headlight. The illumination assembly comprises: a plurality of discrete LED devices, each defining an output surface having a polygonal shape, the output surfaces together defining a layout arrangement with substantially continuous illumination and having a shape corresponding to a predetermined illumination pattern; a shield overlying the output surface of at least one discrete LED device of the plurality of discrete LED devices and defining at least one edge of the predetermined illumination pattern having a contoured shape; and an imaging lens assembly overlying the plurality of discrete LED devices and the shield.The imaging lens assembly is configured to focus and direct light from the plurality of discrete LED devices to produce an illumination pattern in accordance with the predetermined illumination pattern.

[0006] These and other aspects of the present disclosure are disclosed in the following detailed description of the embodiments, the appended claims, and the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Further details, features and advantages of embodiments of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings. Fig. 1 shows a schematic block diagram of a vehicle with two headlight assemblies according to one aspect of the present disclosure, Fig. 2 shows a front view of an ADB light source according to one aspect of the present disclosure, Fig. 3 shows a side cross-sectional view of an imaging lens assembly of an ADB illumination assembly in accordance with one aspect of the present disclosure, Fig. 4 shows a perspective wire frame view of an ADB lens assembly in accordance with one aspect of the present disclosure, Fig. 5 shows a combined projection pattern according to one aspect of the present disclosure, including both an ADB illumination pattern and a foreground illumination pattern, and Fig. 6 shows an ADB lighting pattern with a dimmed region according to one aspect of the present disclosure. Fig. 7 shows an ADB illumination pattern having a top edge defining a clipping pattern with a gradually curved shape, in accordance with one aspect of the present disclosure. Fig. 8A-8B illustrate a second ADB light source in accordance with an aspect of the present disclosure. Fig. 9 shows a perspective cross-sectional view of the second ADB light source according to one aspect of the present disclosure. DETAILED DESCRIPTION

[0008] Referring to the drawings, the present invention will be described in detail with respect to the following embodiments.

[0009] Fig. 1 shows a schematic block diagram of a vehicle 10 with a lighting system 12 according to one aspect of the present disclosure. The vehicle 10 may be a motor vehicle, e.g., a car or a truck. However, the headlight assembly of the present disclosure may also be used for other types of vehicles, e.g., commercial vehicles, buses, trains, etc. The vehicle 10 with the lighting system 12 of the present disclosure may also be referred to as the ego vehicle or the subject vehicle. The lighting system 12 includes a left-side headlight assembly 20a and a right-side headlight assembly 20b. Each of the headlight assemblies 20a, 20b may be similar or identical to one another. In some embodiments, the headlight assemblies 20a, 20b may have similar or identical internal components and different external components, such as:a housing adapted to fit into the structure on the corresponding side of the vehicle 10.

[0010] As in Fig. 1, each of the headlamp assemblies 20a, 20b includes a low-beam illumination assembly 22 and an adaptive high-beam (ADB) illumination assembly 32. The low-beam illumination assembly 22 includes a low-beam (foreground) light source 24, which may also be referred to as a base light source or foreground base light source. The low-beam illumination assembly 22 also includes a low-beam lens 26 overlying the low-beam light source 24 to direct the light therefrom to create a foreground illumination pattern.

[0011] The low beam illumination assemblies 22 of the two headlight assemblies 20a, 20b cooperate to produce a low beam illumination according to a first predetermined illumination pattern 14. The first predetermined illumination pattern may be determined in accordance with legal regulations and / or in accordance with the requirements of an original equipment manufacturer (OEM). Fig. For example, in Figure 1, the first predetermined illumination pattern 14 is shown with an SAE pattern according to North American standards. The ADB illumination assemblies 32 of the two headlight assemblies 20a, 20b cooperate to produce high beam illumination according to a second predetermined illumination pattern 16. The second predetermined illumination pattern 16 may be determined in accordance with legal regulations and / or in accordance with the requirements specified by an original equipment manufacturer (OEM). Fig. For example, in Figure 1, the second predetermined illumination pattern 16 is depicted in the form of a stepped pyramid that becomes increasingly brighter toward the center. Both the first predetermined illumination pattern 14 and the second predetermined illumination pattern 16 may represent light patterns at a significant distance from the vehicle 10, which may be referred to as an infinite focusing distance.

[0012] The ADB illumination assembly 32 includes a first ADB light source 34 and an ADB lens assembly 36 disposed above the first ADB light source 34 and configured to focus and direct the light emanating therefrom to produce an ADB illumination pattern. The ADB lens assembly 36 may include an imaging lens assembly configured to produce the ADB illumination pattern in accordance with a predetermined illumination pattern generated by the ADB light source.

[0013] Each of the headlight assemblies 20a, 20b also includes a controller 40 that communicates with the low beam source 24 and the first ADB light source 34. The controller 40 may also be referred to as a headlight smart lighting driver or a headlight smart LED driver. The controller 40 may be configured to control a light pattern generated by the first ADB light source 34. In some embodiments, the controller 40 may control the operation of the low beam source 24. For example, the controller 40 may provide an on / off signal to a switching device to control the low beam source 24. Alternatively or additionally, the controller 40 may control a brightness level of the low beam source 24. In some embodiments, the controller 40 may control the light distribution of the first ADB light source 34, for example, a beam pattern generated by the first ADB light source 34.

[0014] The control unit 40 includes a processor 42 connected to a memory 44. The memory 44 contains an instruction memory 46 in which instructions, such as program code, are stored for execution by the processor 42. The memory 44 also includes a data memory 48 for storing data for use by the processor 42.

[0015] Fig. Figure 2 shows a front view of a first ADB light source 34. The first ADB light source 34 includes a printed circuit board (PCB) 50 defining a surface 52. The first ADB light source 34 also includes a number of discrete LED devices 54 arranged on the surface 52 of the PCB 50. Each of the discrete LED devices 54 defines an output surface 55 in the shape of a polygon. The output surfaces 55 of the Fig. The discrete LED devices 54 shown in Figure 2 each have a square shape. However, some or all of the discrete LED devices 54 may have an output surface 55 with a different polygonal shape, such as a triangle, rectangle, hexagon, octagon, etc.

[0016] The output surfaces 55 together form a layout arrangement 58 with substantially continuous illumination and with a shape corresponding to the predetermined illumination pattern. As shown in Fig. 2, the first ADB light source 34 includes, for example, forty-eight (48) of the discrete LED devices 54 arranged in four (4) rows, each of which has a different number of discrete LED devices 54. The number of discrete LED devices 54 substantially fills the layout array 58. However, the discrete LED devices 54 are spaced apart by a small distance, e.g., 25-70 micrometers, to form gaps between adjacent output surfaces 55.

[0017] To simplify the presentation, only one of the Fig. 2 are provided with reference numbers. The layout arrangement 58 defines a triangular pattern, with an upper row in which several of the discrete LED devices 54 are arranged symmetrically about a center line CL, and with three further rows, each arranged symmetrically about the center line and each having progressively fewer of the discrete LED devices 54. The layout arrangement 58 includes rows of twenty-one (21), fifteen (15), nine (9), and three (3) of the discrete LED devices 54, respectively.

[0018] Each of the discrete LED devices 54 can be individually controlled to produce a light intensity in accordance with the predetermined illumination pattern. For example, the ADB lighting assembly 32 can be operated such that each of the discrete LED devices 54 has a first predetermined brightness value, with different ones of the discrete LED devices 54 being operated to produce different light intensities to produce the second predetermined illumination pattern 16. Each of the discrete LED devices 54 can also be individually controlled to operate in a reduced intensity mode to produce a dimmed portion of the illumination pattern.For example, a group of one or more of the individual LED devices 54 may be operated in reduced intensity mode to create a dimmed area corresponding to a direction of oncoming traffic to reduce the intensity of the light directed toward oncoming traffic.

[0019] The layout arrangement 58 can be inverted with respect to the predetermined illumination pattern. For example, the layout arrangement 58 can include the triangular pattern with a flat top and a gradually tapered smallest width in a bottom row, which can be inverted by the ADB lens assembly 36 to produce the predetermined illumination pattern with a flat bottom that tapers to a smallest width at the top.

[0020] The first ADB light source 34 also includes three LED drivers 56 mounted on the surface 52 of the circuit board 50, each of the LED drivers 56 configured to power sixteen (16) of the discrete LED devices 54. Thus, the three (3) LED drivers 56 can be fully utilized to power the forty-eight (48) of the discrete LED devices 54.

[0021] Fig. 3 shows a side cross-sectional view of the ADB lens assembly 36. The ADB lens assembly 36 can modify a light pattern generated by the first ADB light source 34, e.g., by stretching the pattern and / or blending a certain amount of light between the adjacent discrete LED devices 54 to fill portions of the illumination pattern corresponding to the gaps, thereby causing the output pattern to appear smooth and unaffected by the gaps. However, the ADB lens assembly 36 can be configured to generate the second predetermined illumination pattern 16 having a shape substantially determined by the layout arrangement 58 of the discrete LED devices 54 on the surface 52 of the circuit board 50.

[0022] As in Fig. 3, the ADB lens assembly 36 includes a first lens element 60 adjacent to the circuit board 50. The first lens element 60 defines a first input surface 62 that receives light from the discrete LED devices 54. The first lens element 60 also defines a first output surface 64 for outputting light. The ADB lens assembly 36 also includes a second lens element 70 overlying the first lens element 60, with the first lens element 60 being disposed between the second lens element 70 and the circuit board 50. The second lens element 70 defines a second input surface 72 that receives light from the first output surface 64 of the first lens element 60. The second lens element 70 also defines a second output surface 74 for outputting light.As shown, the first input surface 62 and the second input surface 72 each have a concave shape, and the first output surface 64 and the second output surface 74 each have a convex shape. However, the first lens element 60 and / or the second lens element 70, or both, may have a different shape.

[0023] The ADB lens assembly 36 also includes a third lens element 80 overlying the second lens element 70, with the second lens element 70 being disposed between the third lens element 80 and the first lens element 60. The third lens element 80 defines a third input surface 82 that receives light from the second output surface 74 of the second lens element 70. The third lens element 80 also defines a third output surface 84 for outputting light. As illustrated, the third input surface 82 and the third output surface 84 each have a convex shape. However, one or both of the third input surface 82 and the third output surface 84 may have a different shape.

[0024] In some embodiments, each of the lens elements 60, 70, 80 has at least one aspherical lens surface. For example, some or all of the input surfaces 62, 72, 82 and / or some or all of the output surfaces 64, 74, 84 may be aspherical.

[0025] In some embodiments, at least two of the lens elements 60, 70, 80 are made of different materials, which can help reduce or prevent color separation of the light passing through them. In some embodiments, all three lens elements 60, 70, 80 are made of different materials. For example, the first lens element 60 may be made of glass, and the second lens element 70 and the third lens element 80 may each be made of different types of polymers such as polycarbonate (PC) and / or poly(methyl methacrylate) (PMMA), also called acrylic. The glass material allows the first lens element 60 to withstand relatively high temperatures generated by the operation of the discrete LED devices 54 and the LED drivers 56. In some embodiments, the second lens element 70 may be made of polycarbonate (PC) and the third lens element 80 may be made of PMMA.

[0026] Fig. 4 shows a perspective wire-frame view of the ADB lens assembly 36. As illustrated, each of the lens elements 60, 70, 80 is truncated to define a rectangular shape when viewed from the front, facing the surface 52 of the circuit board 50. The rectangular shape may be advantageous for packaging the ADB lens assembly 36 within the vehicle 10. Alternatively or additionally, the rectangular shape of the ADB lens assembly 36 may provide a particular desired aesthetic design.

[0027] Fig. 5 shows a combined projection pattern according to one aspect of the present disclosure, including both a first ADB illumination pattern 100 and a low beam pattern 102, which may also be referred to as a foreground pattern. The first ADB illumination pattern 100 extends below a horizon and overlaps the low beam pattern 102.

[0028] Fig. 6 shows a second ADB illumination pattern 100a with a dimmed region 104 created by operating two vertically adjacent ones of the plurality of discrete LED devices 54 in the reduced intensity mode, wherein the dimmed region 104 has a light intensity that meets an intensity threshold for low beam illumination. The dimmed region 104 is bounded on both sides by a transition region 106 that gradually brightens outside the dimmed region 104 until a light intensity is reached that meets a threshold for high beam illumination.The dimmed area 104 can be enlarged by increasing the number of individual LED devices 54 operating in the reduced intensity mode, for example, to create a larger dimmed area 104 when an oncoming vehicle approaches the lighting system 12 and fills a larger portion of the field of view. In some embodiments, the transition area 106 can have a width that does not exceed 1.0 degrees.

[0029] Fig. 7 shows a third ADB illumination pattern 200 having a top edge 220 defining a clipping pattern with a contoured shape, in accordance with one aspect of the present disclosure. The third ADB illumination pattern 200 may be similar or identical to the first ADB illumination pattern 100 and / or the second ADB illumination pattern 100a, except that the top edge 220 has a contoured shape with a gradual curve, rather than the stair-step pattern visible on the first ADB illumination pattern 100 and the second ADB illumination pattern 100a. The top edge 220 defines a bulbous center 222 with a hemispherical or parabolic shape. The upper edge 220 also defines a ramp portion 224 on each side of the bulbous center 222 and defines a continuous cut-off line extending upwardly toward the bulbous center 222. It should be appreciated that the Fig. 7 is merely an example, and the principles of the present disclosure may be used to create illumination clipping patterns having a different size and / or shape, and which may depend on a given implementation or design.

[0030] Fig. 8A-8B illustrate a second ADB light source 234 in accordance with one aspect of the present disclosure. The second ADB light source 234 may be similar or identical to the first ADB light source 34, except for the features described herein. The second ADB light source 234 includes a shield 240 that is attached directly to the surface 52 of the circuit board 50 and overlies the output surfaces 55 of some of the discrete LED devices 54. More specifically, the shield 240 includes a planar portion 242 that at least partially overlies one or more of the discrete LED devices 54 in a lower row corresponding to an upper portion of the predetermined illumination pattern. Thus, the shield 240 serves to define an upper edge of the predetermined illumination pattern having a contoured shape.The contoured shape may differ from a stair-step pattern that might otherwise be caused by the rows of different numbers of discrete LED devices 54 forming the upper edge of the predetermined illumination pattern. For example, the shield 240 may be configured to form the stair-step pattern shown in FIG. Fig. 7 shown third ADB illumination pattern 200 defined

[0031] The second ADB light source 234 includes the shield 240, which is configured to define the contoured top edge in combination with a relatively small number of individual LED devices 54. This combination can provide an illumination effect with one or more smooth contoured edges and without rough or jagged edges that might otherwise be created by a relatively small number of discrete LED devices 54. This combination can result in significant cost savings over alternative designs that require significantly more and / or smaller LED devices to achieve a similarly contoured edge.

[0032] The shield 240 may be made of metal, such as stainless steel or aluminum, although other materials may be used. In some embodiments, the shield 240 may be non-reflective on one or both of its back surfaces facing the individual LED devices 54 and / or on a front surface facing outward, away from the individual LED devices 54. In some embodiments, the shield 240 may reflect no more than 10% of the incident light. In some embodiments, the shield 240 may reflect no more than 5% of the incident light. In some embodiments, the shield 240 may include a non-reflective coating, such as paint, a powder coating, and / or an anodized layer. In some embodiments, the shield 240 may be made of aluminum that is anodized to be non-reflective.In some embodiments, a sheet of anodized aluminum may be used to form the shield 240. For example, pre-anodized aluminum may be stamped and bent to form the shield 240. However, other methods of fabricating the shield 240 may also be used, such as anodizing and / or another coating applied to a metal substrate before or after the metal is formed to form the shield 240.

[0033] The shield 240 is formed as a surface-mounted device (SMD) that is attached to the surface 52 of the circuit board 50 by soldering. However, the shield 240 may have a different configuration and be attached to the circuit board 50 in a different manner, such as by clips or pins that pass through the circuit board or rest against an edge thereof. In some embodiments, and as shown in Fig. 8A-8B, the shield 240 includes a number of feet 246 extending perpendicular to the planar portion 242 and configured for connection to the surface 52 of the circuit board 50. The feet 246 may serve to secure the shield 240 in position, with the planar portion 242 extending parallel to and spaced from the output surface 55 of the at least one discrete LED device 54 overlaid by the shield 240. The shield 240 is spaced from the output surface 55 of the at least one discrete LED device 54 by a distance of less than 1.0 millimeter. For example, the planar portion 242 may be spaced from the discrete LED devices 54 by approximately 0.5 millimeters. The flat portion 242 should maintain a distance from the individual LED devices 54 to prevent contact that could otherwise cause vibration and premature wear.However, the planar portions 242 are advantageously positioned relatively close to the output surfaces 55 of the discrete LED devices 54 to clearly define the top edge 220 of the third ADB illumination pattern 200.

[0034] Fig. 9 shows a perspective cross-sectional view of the second ADB light source 234 with the lens elements 60, 70, 80 overlying the plurality of discrete LED devices 54 on the circuit board 50. The lens elements 60, 70, 80 may together form an imaging lens arrangement defining a focal plane substantially coplanar with the output surfaces of the plurality of discrete LED devices 54.

[0035] The invention also relates to a computer program with program coding means suitable for carrying out a method according to the invention as described above when the computer program is executed on a computer. Both the computer program itself and the program stored on a computer-readable medium are claimed. Thus, in one aspect, each method described above and combinations thereof may be embodied in computer-executable code which, when executed on one or more computing devices, performs the corresponding steps. In another aspect, the methods may be embodied in systems that carry out the steps thereof and may be distributed across devices of various kinds, or the entire functionality may be integrated into a dedicated, stand-alone device or other hardware.In another aspect, the means for performing the steps associated with the processes described above may comprise any of the hardware and / or software described above. All such permutations and combinations are intended to be within the scope of the present disclosure.

Claims

[1] Lighting arrangement (20a, 20b) for a vehicle headlight, comprising: a number of discrete LED devices (54), each defining an output surface (55), the output surfaces (55) together defining a layout arrangement (58) with substantially continuous illumination and having a shape corresponding to a predetermined illumination pattern, a shield (240) overlying the output surface of at least one discrete LED device (54) of the plurality of discrete LED devices (54) and defining at least one edge of the predetermined illumination pattern, and an imaging lens arrangement (36) overlying the plurality of discrete LED devices (54) and the shield (240), the imaging lens arrangement (36) being configured that it focuses and directs light from the number of discrete LED devices (54) to produce an illumination pattern in accordance with the predetermined illumination pattern. [2] The lighting assembly of claim 1, wherein each of the discrete LED devices (54) defines an output surface (55) having a polygonal shape and / or wherein the at least one edge of the predetermined illumination pattern has a contoured shape. [3] The lighting assembly of claim 1 or 2, further comprising a printed circuit board (PCB) (50) defining a surface (52), and wherein the plurality of discrete LED devices (54) are disposed on the surface (52) of the PCB (50). [4] The lighting assembly of claim 3, wherein the shield (240) is formed as a surface mount device (SMD) that is attached to the surface (52) of the circuit board (50) by soldering. [5] The lighting assembly of claim 3 or 4, wherein the shield (240) includes a planar portion (242) having a flat shape overlying the plurality of discrete LED devices (54), and wherein the shield (240) includes a plurality of feet (246) extending perpendicular to the planar portion (242) and configured for connection to the surface (52) of the circuit board (50). [6] Lighting arrangement according to one of the preceding claims, wherein the shield (240) is made of metal and / or wherein the shield (240) has a non-reflective coating and / or wherein the shield (240) is spaced from the output surfaces (55) of the plurality of discrete LED devices (54) and / or wherein the shield (240) is spaced from the output surfaces (55) of the plurality of discrete LED devices (54) by a distance of less than 1.0 millimeter. [7] A lighting arrangement according to any one of the preceding claims, wherein each of the discrete LED devices (54) is individually controllable to produce a light intensity in accordance with the predetermined illumination pattern and to operate in a reduced intensity mode to produce a dimmed portion of the illumination pattern, and / or wherein the imaging lens arrangement (36) defines a focal plane that is substantially coplanar with the output surfaces (55) of the plurality of discrete LED devices (54). [8] The illumination assembly of any preceding claim, wherein the layout assembly (58) comprises the plurality of discrete LED devices (54) spaced apart to define gaps between adjacent output surfaces (55), and wherein the imaging lens assembly (36) is further configured to blend light between the adjacent discrete LED devices (54) to fill portions of the illumination pattern corresponding to the gaps, thereby causing the illumination pattern to appear smooth and unaffected by the gaps. [9] The lighting assembly of any preceding claim, wherein the layout assembly (58) comprises a plurality of rows of the plurality of discrete LED devices (54), each of the rows having a different number of the discrete LED devices (54). [10] The lighting assembly of any preceding claim, wherein the at least one edge includes an upper edge of the predetermined illumination pattern, and wherein the shield (240) at least partially covers some of the plurality of discrete LED devices (54) corresponding to the upper edge of the predetermined illumination pattern.