Compact low beam optics for vehicle headlamp

Abstract

The invention concerns a low beam vehicle headlamp optics made of at least one piece of solid transparent material (1), the surface of which comprises : - an entrance hole (2) extended by an entrance passage (3) delimited by an inner side wall (4), - at the end of the entrance passage (3), an inner primary optics surface (5) and an inner shutter surface (6) terminated by an edge (7) and located downstream of the primary optics surface (5), - an outer curved collimator surface (8) surrounding the entrance passage (3), - an outer imaging lens surface (9) opposite the entrance hole (2). The inner primary optics surface (5), the inner shutter surface (6) and the imaging lens surface (9) are arranged relative to each other so that light rays entering the entrance hole (2) and passing through the inner primary optics surface (5) can exit the optics through the imaging lens surface (9).

Description

Technical Field

[0001] The present invention relates generally to the field of vehicle lighting systems, and more particularly to techniques for producing a low beam using vehicle headlamp optics.Background

[0002] In the current state of the art, the production of a low beam in a vehicle is typically achieved by using either reflectors or projector systems. These systems have been the standard for a long time and are widely used across various vehicle models and types.

[0003] However, these systems often face challenges in fulfilling the technical, price, or styling requirements. The number of components and the complexity of these systems can lead to increased costs, both in terms of manufacturing and maintenance. In addition, the physical dimensions of these systems can limit on the styling options available for the vehicle headlamps.

[0004] It is therefore an objective of the present invention to provide a vehicle headlamp optical solution capable of producing a low beam, thereby overcoming, at least in part, the above-mentioned disadvantages of the prior art.Summary of the Invention

[0005] One object of the invention is a vehicle headlamp optics designed to produce a low beam.

[0006] The optics is made of at least one piece of solid transparent material. A piece of solid transparent material can be understood as a unitary structure made of a material that allows light to pass through it without significant scattering or absorption.

[0007] It may be provided that the optics consists of a single piece of solid transparent material. In such a case, the compactness and robustness of the optics is an advantage.

[0008] The surface of the piece of solid transparent material comprises the following portions: an entrance hole extended by an entrance passage delimited by an inner side wall, at the end of the entrance passage, an inner primary optics surface and an inner shutter surface terminated by an edge and located downstream of the primary optics surface, an outer curved collimator surface surrounding the entrance passage, an outer imaging lens surface opposite the entrance hole.

[0009] The inner primary optics surface, the inner shutter surface and the imaging lens surface are arranged relative to each other so that light rays entering the entrance hole and passing through the inner primary optics surface can exit the optics through the imaging lens surface.

[0010] In other words, the inner shutter surface deviates some of the light rays that would not directly hit the outer imaging lens, so that all the light rays coming from the inner primary optics exit the optics through the imaging lens surface.

[0011] One advantage of this arrangement is that it simplifies the design of the optics, making it easier and cheaper to manufacture. It also makes the optics more compact, which can be beneficial in situations where space within the headlamp is limited. In particular, no condenser secondary condenser lens is required, which brings a main advantage compared to prior art.

[0012] The configuration helps to ensure that the light entering the optics is directed towards the correct parts of the optics. This improves the efficiency of the optics and helps to produce an effective low beam.

[0013] It may be provided that the inner primary optics surface, the inner shutter surface and the imaging lens surface are arranged relative to each other so that light rays entering the entrance hole and passing through the inner primary optics surface can exit the optics only through the imaging lens surface. In such a case, no light ray coming from the inner primary optics surface feeds any other beam than the beam emitted by the imaging lens.

[0014] It may be provided that the surface of the optics also comprises, opposite the entrance hole, at least one outer faceted surface in addition to the outer imaging lens surface. An outer faceted surface can be understood as a surface with a series of flat faces, similar to the facets on a gemstone.

[0015] One advantage of this arrangement is that light reflected from the collimator is projected forward through the outer faceted surfaces around the imaging lens surface.

[0016] It may be provided that the surface also comprises an inner terminal surface at the end of the entrance passage. The inner terminal surface connects the edge of the inner shutter surface to the inner side wall. Said inner terminal surface is configured so that light rays entering the entrance hole and passing through the inner terminal surface cannot exit the optics through the imaging lens surface.

[0017] One advantage of the inner terminal surface is to avoid that too much light bypassing the shutter passes through the imaging lens surface. Preferably, no such light passes at all through the imaging lens surface.

[0018] It may be provided that the inner terminal surface is inclined and / or has pillows. An inclined surface can be understood as a surface that forms an angle with a plane perpendicular to a general direction of illumination of the optics, such as a longitudinal axis parallel to the entrance passage Pillows can be understood as cushions, undulations or waves on the surface.

[0019] It may be provided that the transparent material is a transparent plastics material. A plastic material can be understood as a material in which polymer is the main ingredient, such as polycarbonate (PC) or polymethylmethacrylate (PMMA) poly methyl methacrylate.

[0020] One advantage of this arrangement is that plastic materials are typically lighter and cheaper than other materials, such as glass. This can make the optics easier and cheaper to manufacture. Plastic materials are also more flexible than glass, which can make it easier to create complex shapes and structures within the optics.

[0021] Of course, glass can also be used as a transparent material if the application requires very high light transmission.

[0022] It may be provided that the surface of the optics also comprises a rib forming a mounting flange. A rib can be understood as a raised strip or ridge on the surface of the optics, while a mounting flange can be understood as a projection used to hold, secure, or attach the optics.

[0023] One advantage of this arrangement is that it can make it easier to install and secure the optics within a headlamp. This can help to ensure that the optics is properly aligned and positioned, improving the effectiveness of the low beam.

[0024] Another object of the invention is a vehicle headlamp module made of at least one piece of solid transparent material, the surface of which comprises at least two sets of surface portions, each set of surface portions comprising all the surface portions of one optics as described above.

[0025] One advantage of this arrangement is that it allows multiple low beams to be produced from a single module. Mounting such an arrangement in the vehicle is easier than when multiple optics are required, particularly considering the need for coinciding beams emitted by said multiple optics.

[0026] It may be provided that the surface portions of all the sets are configured to produce coincident beams. Coincident beams can be understood as beams that overlap to illuminate areas that coincide with each other.

[0027] One advantage of this arrangement is that it helps to produce a more intense low beam, thereby improving the visibility conditions for the driver, without the burden of arranging multiple optics and orienting each of them individually.

[0028] Another object of the invention is a vehicle headlamp comprising an optics or a module as a lighting device intended to be mounted on the front of a vehicle to illuminate the road ahead.

[0029] In order to facilitate understanding of the invention, several embodiments will now be described using the following figures. None of these embodiments should be construed as limiting the scope of protection. Where features of one embodiment can obviously be combined with features of another embodiment, the combination is also implicitly part of this description.Brief description of the Figures

[0030] Fig. 1 is a perspective three-quarter front view of an optics according to a first embodiment of the invention. Fig. 2 is a front view of the optics of Fig. 1. Fig. 3 is a side view of the optics of Fig. 1. Fig. 4 is a cross section along plane IV-IV of Fig. 6. Fig. 5 is a view from inside the material of one internal shape of the optics of Fig. 1. Fig. 6 is a top view of the optics of Fig. 1. Fig. 7 is a perspective three-quarter rear view of the optics according to a first embodiment of the invention. Fig. 8 is a side view of the optics of Fig. 1, showing two light rays of a first beam. Fig. 9 is a side view of the optics of Fig. 1, showing two light rays of a second beam. Fig. 10 is a side view of the optics of Fig. 1, showing a light ray of a third beam. Fig. 11 is a side view of the optics of Fig. 1, showing the light rays of the first, second, and third beams. Fig. 12 is a view from inside the material, similar to Fig. 5, of one internal shape of an optics according to a second embodiment of the invention. Fig. 13 is a perspective view of the optics of the second embodiment of the invention. Fig. 14 is a view, similar to Fig. 10, showing a light ray of a third beam in the optics of the second embodiment of the invention. Fig. 15 is a view, similar to Fig. 11, showing the light rays of the first, second, and third beams in the optics of the second embodiment of the invention. Fig. 16 is a graph showing the illumination produced by the optics of either the first and second embodiments of the invention. Fig. 17 is a view of a module according to a first embodiment of the invention. Fig. 18 is a view of a module according to a second embodiment of the invention. Detailed Description

[0031] In a first embodiment of the invention, the optics is made of a single piece 1 of transparent polymer, obtained by injection moulding.

[0032] Piece 1 is integral. An alternative embodiment (not shown) would be to have the optics made of several parts that are assembled together by gluing, melting or a holder.

[0033] Piece 1 has a surface comprising several portions that will be described individually. Each portion performs an optical function. Accordingly, each portion of the surface of the piece constitutes a functional optical element. In the present description, each portion of the surface considered is named after the corresponding functional optical element.

[0034] Piece 1 has a front face and a rear face, opposite the front face.

[0035] On the rear face, piece 1 comprises an entrance hole 2 extended by an entrance passage 3. Entrance passage 3 is delimited by a side wall 4. It will be understood can the term "entrance" here means that light enters the optics through entrance hole 2. A light source, not shown in Fig. 1, is to be placed at entrance hole 2.

[0036] In entrance passage 3, piece 1 is shaped so as to form three different surface portions: an inner primary optics surface 5, an inner shutter surface 6, and an inner terminal surface 10.

[0037] Inner primary optics surface 5 is best shown in Fig. 5. It should be understood that Fig. 5 shows the shapes from within the polymer. As illustrated by the cross section of Fig. 4, the air surrounding piece 1 enters entrance passage 3. Accordingly, as seen from inside the polymer in Fig. 5, surface portions are located at the interface between the polymer and the air.

[0038] Inner primary optics surface 5 performs a primary optics function for light rays coming from entrance hole 2 through entrance passage 3 and entering the polymer piece via surface 5.

[0039] Downstream of inner primary optics surface 5, inner shutter surface 6 extends parallel to the longitudinal axis of entrance passage 3. The optical function performed by inner shutter surface 6 is to prevent light rays exiting inner primary optics surface 5 from reaching a prohibited area above a height in front of the vehicle, as required by the regulation. In addition, in accordance with European Commission for Europe (ECE) standards relating to the visibility of vehicles on the road, the light rays are limited horizontally by an edge 7 which terminates inner shutter surface 6. Edge 7 creates a horizontal cut-off of the low beam.

[0040] Edge 7 consists of two parts 7a and 7c and a step 7b, which form a "kink". In the context of the ECE vehicle lighting standard, a "kink" refers to a change in the angle of the low beam pattern, which helps to improve visibility and safety during night-time driving, by creating a difference in height between the right and left parts of the low beam. In other words, inner shutter surface 6 and edge 7 are constituting an ECE shutter.

[0041] Surrounding the entrance passage 3, the surface of piece 3 comprises an outer curved collimator surface 8. The exact shape of surface 8, as well as the exact shape of surface 5, can be determined by the skilled person using general knowledge in the field of vehicle lighting, including official standards, taking into account the other parts of the optics.

[0042] On the front face of piece 3, an outer imaging lens surface 9 is located opposite the entrance hole 2. Said imaging lens surface 9 is intended to focus the light rays coming from inner primary optics surface 5 and inner shutter surface 6 as a first beam concentrated in front of the optics. This will be explained with reference to Fig. 16.

[0043] According to the invention, inner primary optics surface 5, inner shutter surface 6 and imaging lens surface 9 are arranged relative to each other so that light rays entering entrance hole 2 and passing through inner primary optics surface 5 can exit the optics through imaging lens surface 9. Preferably, these rays exit the optics only through imaging lens surface 9. However, some residual light may exit though other passages without the embodiment falling outside the scope of the invention, as long as the amount of such light is limited to an order of magnitude much smaller than the light exiting the optics through imaging lens surface 9.

[0044] An inner terminal surface 10, at the end of entrance passage 2, connects edge 7 of inner shutter surface 6 to inner side wall 4. Said inner terminal surface 10 is configured so that light rays entering entrance hole 2 and passing through inner terminal surface 10 cannot exit the optics through imaging lens surface 9. In this context, "cannot" means "as less as possible". This configuration may be a tilted surface which prevents that too much light from below inner shutter surface 6 passes through imaging lens surface 9.

[0045] On the front face of piece 3, opposite entrance hole 2, four outer faceted surfaces 11 surround imaging lens surface 9. These faceted surfaces 11 are intended to emit rays forming a second beam in front of the optics. This will be explained with reference to Fig. 16.

[0046] A rib 12 is formed on the surface of piece 3. This rib forms a flange which provides a means for mounting the optics in a headlamp housing.

[0047] Examples of light rays emitted by a light emitting diode (LED) 13 positioned at entrance hole 3, entering the optics and exiting from its front face, are shown in Figs. 8-11.

[0048] In Fig. 8, two light rays (represented by dotted lines) can be seen, coming directly from LED 13 to inner primary optics surface 5. One of them propagates in the transparent polymer directly to outer imaging lens surface 9. The other one hits inner shutter surface 6 and is reflected, preferably by total internal reflection, towards outer imaging lens surface 9.

[0049] Thanks to the cut-off provided by shutter edge 7, the light is prevented from illuminating beyond a boundary 18 in Fig. 16. The focussing provided by outer imaging lens surface 9 produces a focussed beam in the region bounded by a rectangle 16 in Fig. 16.

[0050] In Fig. 9, two further light rays (dashed lines) coming from LED 13 reach side wall 4 and enter the transparent polymer, in which they propagate to outer curved collimator surface 8. Surface 8 reflects the light rays, preferably by total internal reflection, towards faceted surfaces 11, thus creating a second beam in the area 17 in Fig. 16, around the first beam area 16.

[0051] The light from both light beams partially overlap to create a homogenous appearance.

[0052] A third type of light ray is shown in Fig. 10. The light comes from LED 13 and reaches inner terminal surface 10 at the end of entrance passage 2. This ray has not been subjected to the inner primary optics and is a parasitic light ray with respect to outer imaging lens 9. Inner terminal surface 10 is inclined and / or surface treated so as to prevent the light ray from reaching outer imaging lens 9. Instead, the light ray is directed onto faceted surfaces 11, thereby increasing the illumination of area 17, rather than being wasted in the optics.

[0053] In Fig. 11, all the beams described above are superimposed in the optics.

[0054] Fig. 12 shows an alternative embodiment of the inner terminal surface. Inner terminal surface 10' is tilted differently from inner terminal surface 10, as also shown in Fig. 13.

[0055] Although the geometry differs, the purpose remains the same, namely to prevent rays received directly from LED 13 from reaching outer imaging lens 9. Fig. 14 shows the tilting and / or a surface treatment of inner terminal surface 10', which directs the light ray towards outer faceted surfaces 11.

[0056] The resulting beam is the same as shown in Fig. 16.

[0057] In Fig. 17, a module 21 is shown, made from one piece of solid transparent material with a mounting rib 22 holding together three parts 21' stacked vertically with an air gap 23 between pairs of them.

[0058] Each part 21' is an equivalent of one piece 1' of Figs. 12-15. Each part 21' has a set of surface portions comprising all the surface portions 4, 5, 6, 8, 9, 10, 11 of the piece 1' described in reference to Figs. 1-15. The operation of the module gives rise to three beams (not shown), each emitted by a part 21. The total light beam is the sum of the beams from the three parts.

[0059] The main advantages of module 21 are: A width that is notably shorter, typically by 30%-60% narrower than the width of a standard low beam projector system. Here, the width is the dimension parallel to the general direction of illumination of the module. Lower costs. A "lens-like" appearance, which is often a styling requirement. No manufacturing tolerances between the parts. High optical efficiency, greater than 50%.

[0060] In the alternative embodiment of Fig. 18, the module 24 is even more compact, since no air gap isolates the three parts 24' corresponding to pieces 1'.

[0061] The embodiments used in this description to explain the invention are not limiting examples. Many adaptations or modifications could be made while still embodying the claimed invention.

Claims

1. Vehicle headlamp optics for producing a low beam, said optics being made of at least one piece of solid transparent material (1), the surface of which comprises the following portions: - an entrance hole (2) extended by an entrance passage (3) delimited by an inner side wall (4), - at the end of the entrance passage (3), an inner primary optics surface (5) and an inner shutter surface (6) terminated by an edge (7) and located downstream of the primary optics surface (5), - an outer curved collimator surface (8) surrounding the entrance passage (3), - an outer imaging lens surface (9) opposite the entrance hole (2), the inner primary optics surface (5), the inner shutter surface (6) and the imaging lens surface (9) being arranged relative to each other so that light rays entering the entrance hole (2) and passing through the inner primary optics surface (5) can exit the optics through the imaging lens surface (9).

2. Optics according to claim 1, wherein the shutter surface (6) and / or outer curved collimator surface (8) reflect rays through total internal reflection.

3. Optics according to claim 1 or 2, wherein the inner primary optics surface (5), the inner shutter surface (6) and the imaging lens surface (9) are arranged relative to each other so that light rays entering the entrance hole (2) and passing through the inner primary optics surface (5) can exit the optics only through the imaging lens surface (9).

4. Optics according to claim 1, the surface of which also comprises an inner terminal surface (10) at the end of the entrance passage (2), connecting the edge (7) of the inner shutter surface (6) to the inner side wall (4), said inner terminal surface (10) being configured so that light rays entering the entrance hole (2) and passing through the inner terminal surface (10) cannot exit the optics through the imaging lens surface (9).

5. Optics according to claim 4, wherein the inner terminal surface (10) is inclined and / or has pillows.

6. Optics according to any one of the preceding claims, the surface of which also comprises, opposite the entrance hole (2), at least one outer faceted surface (11) next to the outer imaging lens surface (9).

7. Optics according to any one of the preceding claims, wherein the transparent material is a plastic material, preferably polycarbonate or polymethylmethacrylate8. Optics according to any one of the preceding claims, the surface of which also comprises a rib (12) forming a mounting flange.

9. Optics according to any one of the preceding claims, consisting of one single piece of transparent material.

10. Vehicle headlamp module for producing a low beam, said module being made of at least one piece of solid transparent material (1), the surface of which comprises at least two sets of surface portions, each set of surface portions comprising all the surface portions of one optics according to any one of the preceding claims.

11. Module according claim 10, wherein the surface portions of all the sets are configured to produce coinciding beams.

12. Module according to claim 10 or 11, consisting of one single piece of transparent material.

13. Vehicle headlamp comprising optics according to any one of claims 1 to 10 or a headlamp module according to any one of claims 10 to 12.

14. Vehicle headlamp according to claim 13, wherein the light rays entering the entrance hole (2) are emitted by a light emitting diode.

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