Light module comprising a rectangular lens

Abstract

The invention relates to a light module (1) comprising: a light source extending in a first plane (X-Y) and capable of emitting a light beam along a third, orthogonal emission axis (Z) and a collector (100.2) comprising a reflective surface arranged so as to collect and reflect the emitted light beam; a rectangular lens (101) extending substantially in a second plane (Y-Z), the rectangular lens (101) being arranged so as to project the light beam, the lens (101) being arranged so as to form, on the road, an image of the reflective surface of the collector (100.2), the light source being rectangular, and a first angle formed between the direction of extension of the light source in the first plane relative to the first axis is substantially identical to a second angle formed between the direction of extension of the lens (101) in the second plane relative to the third axis.

Description

Light module with a rectangular lens

[0001] The invention relates to the technical field of light modules adapted for automobiles. State of the art

[0002] In the field of automotive lighting, it is generally known to use light modules comprising a light source, a collector with a reflective surface and a lens-type optical projection system imaging the reflective surface of the collector to project a beam of light onto the road.

[0003] In typical lighting modules, the light source is usually a roughly square LED, and the projection lens is a shallow rectangle. However, this type of light source can lead to luminous flux problems due to the lens shape. Because the light emitted from the edges of the light source is far from its center, it follows a very steep path relative to the lens's optical axis. This steeply angled light is not always captured by the lens, especially if it is rectangular. Less light will be captured along the shorter side of the rectangle than along the longer side. To compensate for the reduced luminous flux, it is common practice to place two square light sources side by side.However, this solution is not optimal because the edges of the light sources are then even further from the center of gravity of the two sources. This increases the angle of the light and further reduces the amount of light captured by the lens. Furthermore, the relative positioning of the two sources, their orientation, and their separation will significantly influence the angle of the light and the amount of light captured by the lens.

[0004] The invention is therefore situated within this context and seeks to resolve all of the aforementioned drawbacks. Thus, the invention aims to provide an efficient lighting module capable of producing a vertical or complex light signature using a rectangular lens. Presentation of the invention.

[0005] The invention relates to a light module for a motor vehicle comprising: a) a light source extending substantially in a first plane defined by a first axis and a second axis (XY) perpendicular and capable of emitting a light beam along a third emission axis (Z) orthogonal to the first plane; b) a collector comprising a reflective surface arranged to collect and reflect the light beam emitted by said light source; c) a rectangular lens extending substantially in a second plane (YZ) orthogonal to the first plane and defined by the second and third axes, the rectangular lens being arranged to project the light beam reflected by the collector, said lens being arranged to form on the road an image of the reflective surface of the collector.The light module is remarkable in that the light source is rectangular and in that a first angle formed between the direction of extension of the light source in the first plane with respect to the first axis is identical to a second angle formed between the direction of extension of the lens in the second plane with respect to the third axis, to plus or minus 10°.

[0006] The light module is described in relation to a classical orthonormal plane (X, Y, Z) formed by a first plane (XY), a second plane (YZ), and a third plane (XZ) perpendicular to each other. The first X-axis can be oriented towards the front of the module and in the direction of emission of the light beam. The second Y-axis can be a transverse axis to the light module.

[0007] The "direction of extension of the light source" corresponds to the direction in which the longest side of the rectangular light source extends. The "direction of extension of the lens" corresponds to the direction in which the longest side of the rectangular lens extends.

[0008] The light module includes a light source capable of emitting a beam of light in an emission direction along the third Z-axis. The light source is rectangular. By "rectangular light source," we mean that the light source has a rectangular emitting area. As will be seen later, the light source can, for example, consist of a single rectangular emitting chip or two square emitting chips, separated by a distance of 50 µm or less, so as to form a rectangular emitting area. The fact that the emitting area of ​​the light source is rectangular allows for maximizing the amount of emitted light transmitted by the rectangular lens.

[0009] The light module includes a collector with a reflective surface designed to collect and reflect the light beam emitted by the light source. The reflected light beam propagates along the first X-axis. The collector defines a cavity in which the light source is mounted. The light source is positioned directly above the collector, so that the collector's reflective surface collects and reflects the light beam emitted by the light source.

[0010] The light source extends in the foreground (XY) plane. Specifically, the light source has a support that extends in the foreground. When mounting the light source in the light module, its orientation can be selected by rotating it around the third Z-axis. Therefore, during the mounting process, the initial angle formed between the direction of the light source's extension in the foreground and the first X-axis can be adjusted. In particular, the orientation of the light source can be chosen based on the orientation of the lens. Once the orientation of the light source is selected, it is fixed in that orientation. It is then no longer possible to change the orientation of the light source.

[0011] The light source can, for example, be a light source marketed under the name "Nichia" with reference NC2W121G-SC or under the name "Seoul semiconductor" with reference WICOP UHL SWW0US10C.

[0012] The light module includes a lens extending in the second plane (YZ). During the design of the light module, the lens orientation can be selected. This orientation can be chosen, in particular, according to the desired style of the light module. During assembly, the lens orientation is set by rotating it around the first X-axis. Specifically, the second angle formed between the lens's extension direction in the second plane and the third axis can be selected. Once the desired lens orientation is achieved, it is fixed in that orientation. It is then no longer possible to change the lens orientation.

[0013] In a light module according to the invention, the orientation of the lens and the orientation of the light source are correlated; that is, the orientation of the lens influences the orientation of the light source and vice versa. Indeed, during the design of the light module, the chosen lens orientation, particularly for aesthetic reasons, will influence the orientation of the light source. In particular, the chosen lens orientation determines the second angle. The first angle is then chosen to be identical, within ±10°, to the second angle. The orientation of the light source is thus established based on the chosen lens orientation. Thanks to this correlation between the lens orientation and the light source orientation, the quantity of light rays emitted by the light source and transmitted by the lens is maximized. The efficiency of the light module is thereby improved.

[0014] Thus, thanks to the invention, it is possible to obtain an efficient light module, regardless of the lens orientation, because by adapting the orientation of the light source to that of the lens, the efficiency of the light module is ensured. A complex light signature, oblique or vertical, can therefore be achieved without compromising the optical performance of the light module. It should be noted that the invention also makes it possible to maximize the module's efficiency when the lens is horizontal.

[0015] The lens is arranged to form an image of the collector's reflective surface on the road. The lens projects the light rays received by the reflective surface to infinity onto the road when the light module is positioned on a motor vehicle.

[0016] Thanks to the invention, it is possible to obtain an efficient light module capable of providing a luminous signature, for example, vertical or complex, using a rectangular lens. Therefore, by using a light source and a lens with correlated orientations, it is possible to use a rectangular lens that provides a complex luminous signature.

[0017] Advantageously, the collector has an elliptical shape. In particular, the collector may have a first focal point at which the light source is positioned. Preferably, the collector may have a second focal point positioned close to the lens, that is, within the lens or at a distance of less than 50 mm, preferably 30 mm, and even more preferably 10 mm in front of or behind the lens. This positioning of the second focal point limits the height of the light rays at the lens, thus maximizing the amount of light transmitted through the lens. Alternatively, the second focal point of the collector could be located in front of the lens, at a distance greater than 10 mm.

[0018] Advantageously, the collector has a parabolic shape. In particular, the collector has a first focus at which the light source is positioned.

[0019] Advantageously, the lens has a focal point located on the reflective surface of the collector, or in the vicinity of the reflective surface of the collector. Preferably, the lens has a focal point located in the vicinity of a rear area of ​​the collector. By "in the vicinity" is meant, for example, at a distance less than or equal to 10 mm.

[0020] Advantageously, the light source comprises a single rectangular emitting chip or two square emitting chips, separated by a distance of less than 50µm. The light source could also comprise two rectangular emitting chips, separated by a distance of less than or equal to 50µm.

[0021] Advantageously, the first and second angles are similar to within ±5°, or even ±1°. The first and second angles are then practically identical. The orientation of the lens and the orientation of the light source are even more precisely matched, so that the amount of light ray emitted by the light source and transmitted by the lens is further increased. The light module is therefore even more efficient.

[0022] Advantageously, the first angle is between -89° and 0° and between 0° and +89°. The light source is then inclined with respect to the first X axis.

[0023] Advantageously, the second angle is between -89° and 0° and between 0° and +89°. The lens is then inclined with respect to the third Z-axis. In other words, the lens is not horizontal. The invention is particularly advantageous when the lens is not horizontal, as it is all the more beneficial to correlate its orientation with that of the light source in order to maximize the module's efficiency.

[0024] For example, the second angle could be 45°. The lens is then oblique. As another example, the second angle could be 0°. The lens is then vertical.

[0025] Advantageously, the height-to-length ratio of the light source is less than or equal to 2:3, preferably less than or equal to 1:2. A height-to-length ratio of 2:3 or less means that twice the length of the light source is greater than or equal to three times the height of the light source. A height-to-length ratio of 1:2 means that one length of the light source is greater than or equal to twice the height. The length of the light source is measured along the direction of extension of the light source, and the height of the light source is measured along a direction perpendicular to the direction of extension of the light source, in the foreground.

[0026] Advantageously, the lens is a thin lens. It has a limited height. For example, the height-to-length ratio of the lens is less than or equal to 2:3, preferably less than or equal to 1:2, or even less than or equal to 1:5. A height-to-length ratio less than 2:3 means that the dimension of twice the length of the lens is greater than or equal to the dimension of three times the height of the lens. A height-to-length ratio less than or equal to 1:2 means that the dimension of one times the length of the lens is greater than or equal to the dimension of twice the height. A height-to-length ratio less than or equal to 1:5 means that the dimension of one times the length of the lens is greater than or equal to the dimension of five times the height.The lens length is measured along the lens extension direction, and the lens height is measured along a direction perpendicular to the lens extension direction, in the second plane. In this case, despite the limited lens height, the correlation between the orientations of the lens and the light source allows for a maximum amount of light to be directed towards the lens.

[0027] In one embodiment, the height-to-length ratio of the lens may be substantially the same as, or less than, that of the light source. To maximize the efficiency of the light module, it is particularly advantageous to match the orientation of the source to that of the lens when the lens has a small height, i.e., a small height-to-length ratio, for example, less than 2:3, or even less than 1:2, or even less than 1:5. More specifically, when the lens has a height-to-length ratio smaller than that of the source, it becomes even more beneficial to have the lens orientation correlated with that of the light source to maximize the efficiency of the light module. Brief description of the figures.

[0028] Other advantages and features of the present invention are now described by means of purely illustrative and in no way limiting examples of the scope of the invention, and from the accompanying drawings, in which the various figures represent:

[0029] schematically represents a perspective view of a light module according to a first embodiment.

[0030] schematically represents a front view of the light module according to the first embodiment.

[0031] schematically represents a top view of the light module collector according to the first embodiment.

[0032] schematically represents a perspective view of a light module according to a second embodiment.

[0033] schematically represents a front view of the light module according to the second embodiment.

[0034] schematically represents a top view of the light module collector according to the second embodiment.

[0035] schematically represents a perspective view of a light module according to a third embodiment.

[0036] schematically represents a front view of the light module according to the third embodiment.

[0037] schematically represents a top view of the light module collector according to the third embodiment.

[0038] In the description that follows, identical elements, by structure or by function, appearing on different figures retain, unless otherwise specified, the same references. Description of a method of implementation.

[0039] Figures 1 and 2 represent a perspective view of a light module 1, respectively according to a first embodiment, a second embodiment, and a third embodiment. The light module 1 is also described in relation to figures 3 and 4, representing a front view of this light module 1, respectively according to the first embodiment, the second embodiment, and the third embodiment, and with figures 5 and 6, representing a top view of a portion of this light module 1, respectively according to the first embodiment, the second embodiment, and the third embodiment.

[0040] The light module 1 is described in a classical orthonormal plane X; Y; Z formed by a first plane XY, defined by a first axis X and a second axis Y, a second plane YZ, defined by the second axis Y and a third axis Z, and a third plane XZ, defined by the first axis X and the third axis Z. The first, second, and third planes, XY, YZ, XZ, are perpendicular to each other. The first axis X is oriented towards the front of module 1 and in the direction of emission of a light beam between a collector 100.2 and a lens 101. The second axis Y and the third axis Z are orthogonal to each other and orthogonal to the first axis X.

[0041] In all three embodiments, the light module 1 for motor vehicle comprises a light source 100.1, a collector 100.2 and a lens 101.

[0042] The light source 100.1 extends substantially in the first XY plane. The light source 100.1 is capable of emitting a light beam along the third axis Z orthogonal to the first XY plane. The light source 100.1 can, in particular, be positioned on a support extending in the first XY plane.

[0043] The light source 100.1 is rectangular. In particular, in the illustrated example, the light source 100.1 comprises a single rectangular emitting chip. Alternatively, the light source could be formed by several rectangular and / or square emitting chips, provided that these emitting chips are spaced at a distance of 50 µm or less. The support for the light source 100.1 can also be rectangular.

[0044] The light source 100.1 may have a height-to-length ratio less than or equal to 2:3, meaning that twice the length is greater than or equal to three times the height. Advantageously, the height-to-length ratio may even be less than or equal to 1:2, meaning that one length is greater than or equal to twice the height. The length of the light source 100.1 is measured along the direction of its extension, and the height of the light source 100.1 is measured along a direction perpendicular to its extension, in the first XY plane.

[0045] The collector 100.2 of the light module 1 has a reflective surface arranged to collect and reflect the light beam emitted by the light source 100.1. The light beam reflected by the collector 100.2 is then propagated along the first X axis towards the lens 101.

[0046] The collector 100.2 defines a cavity in which the light source 100.1 is mounted. The light source 100.1 is positioned opposite the collector 100.2, so that the reflective surface of the collector 100.2 collects and reflects the light beam emitted by the light source 100.1 towards the lens 101.

[0047] In the illustrated example, the collector 100.2 is elliptical. The first focus of collector 100.2 is located at the light source 100.1, and the second focus of collector 100.2 is located at lens 101. The second focus of collector 100.2 could also be located in front of or behind lens 101, at a distance of 50 mm or less, particularly less than 30 mm, and preferably less than 10 mm from lens 101. Thus, the height of the light beam at lens 101 is minimized, which maximizes the amount of light rays passing through lens 101. Alternatively, collector 100.2 could be parabolic.

[0048] The lens 101 of the light module extends substantially in the second YZ plane. The light beam reflected by the reflective surface of the collector 100.2 is shaped and projected onto the road by the lens 101.

[0049] The lens 101 is arranged to form on the road an image of the reflective surface of the collector 100.2 of the light module 100. The lens 101 has a focus located in the vicinity of the reflective surface of the collector 100.2, that is to say at a distance less than or equal to 10 mm from the reflective surface of the collector 100.2.

[0050] Lens 101 is rectangular. It extends along a direction of extension. The length of lens 101 is measured along the direction of extension, and the height of the lens is measured along a direction perpendicular to the direction of extension, in the second plane YZ. Lens 101 may, for example, have a height-to-length ratio less than or equal to 2:3, meaning that twice the length is greater than or equal to three times the height. Advantageously, lens 101 may have a height-to-length ratio less than or equal to 1:2, or even less than or equal to 1:5, meaning that one length is greater than or equal to two or even five times the height. Alternatively, or cumulatively, the height-to-length ratio of lens 101 may be substantially the same as that of the light source 100.1, or less than that of the light source 100.1.

[0051] In the light module according to the invention, the orientation of the lens 101 and the orientation of the light source 100.1 are correlated, that is to say that the choice of the orientation of the lens 101 influences the orientation of the light source 100.1 and vice versa during the design of the light module 1.

[0052] Indeed, when mounting the light source 100.1 in the light module 1, it is possible to orient the light source 100.1 by rotating it around the third axis Z. Similarly, when mounting the lens 101 in the light module 1, it is possible to orient the lens 101 by rotating it around the first axis X. It is therefore possible to choose a specific orientation for the lens 101 of the light module to obtain a given style, and to position the light source 100.1 according to the chosen orientation of the lens 101. Thanks to this correlation, it is possible to guarantee good optical efficiency of the light module, regardless of the orientation of the lens 101 chosen.

[0053] In particular, it is possible to define a first angle between the extension direction of the light source 100.1 and the first X axis in the first XY plane, and a second angle between the extension direction of the lens 101 and the third Z axis in the second YZ plane. According to the invention, the first angle is equal to the second angle to within ±10°, or even to within ±5°, or even to within ±1°.

[0054] The figures describe a first embodiment. In this embodiment, the extension direction of the lens is parallel to the second Y-axis, in the second YZ-plane. In other words, the extension direction of the lens is perpendicular to the third Z-axis in the second YZ-plane. The lens is thus oriented horizontally. Therefore, the second angle formed between the extension direction of lens 101 in the second plane and the third Z-axis is equal to 90°.

[0055] We can also observe that the extension direction of light source 100.1 is parallel to the second Y-axis, in the first XY plane. In other words, the extension direction of light source 100.1 is perpendicular to the first X-axis, in the first XY plane. Thus, the first angle formed between the extension direction of light source 100.1 in the first plane and the first X-axis is equal to 90°.

[0056] The orientation of the light source 100.1 is well correlated with the orientation of the lens 101.

[0057] The figures describe a second embodiment. In this second embodiment, the extension direction of lens 101 is inclined with respect to the third Z axis, in the second YZ plane. Lens 101 is thus oriented obliquely. In this example, the second angle formed between the extension direction of lens 101 in the second plane and the third Z axis is equal to 45°.

[0058] It can also be observed that the extension direction of the light source 100.1 is inclined with respect to the first X-axis, in the first XY plane. In this example, the first angle formed between the extension direction of the light source 100.1 in the first plane and the first X-axis is equal to 45°.

[0059] The orientation of the light source 100.1 is well correlated with the orientation of the lens 101.

[0060] The figures describe a third embodiment. In this embodiment, the extension direction of the lens is perpendicular to the second Y-axis in the second YZ-plane. In other words, the extension direction of the lens is parallel to the third Z-axis in the second YZ-plane. The lens is thus oriented vertically. Therefore, the second angle formed between the extension direction of lens 101 in the second YZ-plane and the third Z-axis is equal to 0°.

[0061] We can also observe that the extension direction of light source 100.1 is perpendicular to the second Y-axis in the first XY plane. In other words, the extension direction of light source 100.1 is parallel to the first X-axis in the first XY plane. Thus, the first angle formed between the extension direction of light source 100.1 in the first XY plane and the first X-axis is equal to 0°.

[0062] The orientation of the light source 100.1 is well correlated with the orientation of the lens 101.

[0063] The preceding description clearly explains how the invention achieves its stated objectives, namely to provide an efficient light module capable of providing a vertical or complex light signature using a rectangular lens.

[0064] In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically operative combination of these means.

Claims

Light module (1) for a motor vehicle comprising: a light source (100.1) extending substantially in a first plane defined by a first axis and a second axis (XY) perpendicular and capable of emitting a light beam along a third emission axis (Z) orthogonal to the first plane; a collector (100.2) comprising a reflective surface arranged to collect and reflect the light beam emitted by said light source (100.1); a rectangular lens (101) extending substantially in a second plane (YZ) orthogonal to the first plane and defined by the second and third axes, the rectangular lens (101) being arranged to project the light beam reflected by the collector (100.2), said lens (101) being arranged to form on the road an image of the reflective surface of the collector (100.2), characterized in that the light source (100.1) is rectangular and in that a first angle formed between the direction of extension of the light source (100.1) in the first plane with respect to the first axis is identical to a second angle formed between the direction of extension of the lens (101) in the second plane with respect to the third axis, to plus or minus 10°. Light module (1) according to claim 1 in which the collector (100.2) has an elliptical shape. Light module (1) according to claim 1 in which the collector (100.2) has a parabolic shape. Light module (1) according to any one of the preceding claims, wherein the lens has a focus located on the reflective surface of the collector, or in the vicinity of the reflective surface of the collector, preferably in the vicinity of a rear area of ​​the collector. Light module (1) according to any one of the preceding claims, wherein the light source (100.1) comprises a single rectangular emitting chip or two square emitting chips, separated by a distance less than or equal to 50µm. Light module (1) according to any one of claims 1 to 5 wherein the first angle and the second angle are identical to plus or minus 5°, or even to plus or minus 1°. Light module (1) according to any one of claims 1 to 5, wherein the first angle is between -89° and 0° and between 0° and +89° Light module (1) according to any one of claims 1 to 6, wherein the second angle is between -89° and 0° and between 0° and +89°. Light module (1) according to any one of the preceding claims, wherein a height-to-length ratio of the light source (100.1) is less than or equal to 2:3, preferably less than or equal to 1:

2. Light module (1) according to any one of the preceding claims, wherein a height-to-length ratio of the lens (101) is less than or equal to 2:3, preferably less than or equal to 1:2, or even less than or equal to 1:

5. Light module (1) according to any one of the preceding claims, wherein the height-to-length ratio of the lens (101) is substantially the same as or less than that of the light source (100.1).

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