Improved light module for a vehicle

Abstract

The invention relates to a light emitting module (100) for a vehicle, comprising a light source unit (120), a light reflecting device (140) and a lens (160). The light reflection device comprises a total internal reflection unit (142) and a transparent unit (144) which are used for reflecting light emitted by the light source unit. The lens comprises a lens light incident surface (162) and an optical axis. The transparent unit (144) has a minimum length of 6 mm in a direction of an optical axis of the lens (160). The lens incident surface comprises at least two lens areas with different focuses in the direction perpendicular to the optical axis of the lens (160). The light source unit (120) includes at least two light source regions in a direction perpendicular to an optical axis of the lens (160), and light emitted from each light source region faces a respective lens region.

Description

TECHNICAL FIELD

[0001] The present invention relates to the technical field of light modules for vehicles. BACKGROUND

[0002] Various light modules for vehicles are known in the art for producing a lighting beam, a signaling beam or a combination of both.

[0003] In a conventional design of a light module, in order to produce at least one lighting beam, a light source emits light rays, a light reflecting device (comprising a total internal reflection unit) is configured to reflect all light rays emitted by the light source towards a lens into a parallel and / or converging light beam. The lens emits a lighting beam forming a light distribution pattern. This light distribution pattern is usually measured in a standard test of light modules in the vehicle testing field, the measurement being performed on a surface at a distance of 25 meters from the light source. This pattern is represented as an iso-lux diagram, the isoclines representing points of equal luminance (in lux). This standard test and iso-lux diagram are well known to the person skilled in the art.

[0004] The light distribution pattern must comply with certain regulations for vehicle lighting beams, such as the United Nations Regulation No. 149 - Road Illumination Devices (RID). According to the requirements of this regulation, first, the light distribution should reach a prescribed luminance. Second, it should comply with certain dimensional requirements, such as width. Third, it should be uniform. A uniform light distribution is defined as an iso-lux diagram of the light distribution having a substantially regular distribution density of isoclines. Further details are not provided here. Similarly, in the following description, the terms "uniform light" and "uniformizing light" should be understood in the same way as "uniform light distribution".

[0005] In practice, the light rays emitted from the total internal reflection unit of the light reflecting device are far from being uniform. To solve this problem, existing modules let the light rays propagate through an empty space, i.e. in air, between the light reflecting device and the main focal point of the lens. Typically, in order to ensure a uniform light distribution according to the regulations, it is necessary to make the light rays propagate in air for a minimum distance of about 30 to 50 millimeters before reaching the main focal point of the lens. This distance also helps to reach the width of the light distribution required by the regulations. Therefore, the shortest distance from the light exit surface of the light reflecting device to the main focal point of the lens is typically between 30 and 50 millimeters, while the shortest distance from the light source to the main focal point of the lens is typically between 40 and 60 millimeters. Moreover, the back focal length of the lens is typically between 30 and 50 millimeters, for example 40 millimeters. The back focal length is defined as the distance between the focal point of the lens and the center of the surface of the lens where the light rays emitted by the light source enter the lens. This surface is also called the entrance surface of the lens.

[0006] If these distances are shorter than a prescribed range, the light distribution can result in insufficient brightness, insufficient size or insufficient uniformity, leading to poor lighting performance. Therefore, for a front fog lamp, a low beam headlamp, a high beam headlamp and a combination headlamp, the conventional design usually results in a total length of the light emitting module exceeding 100 mm.

[0007] Furthermore, for a low beam headlamp or a front fog lamp, a regulation requires a cut-off line in the light distribution. In the conventional design, this requires a shutter separate from other components of the light emitting module to be placed between the light exit surface of the light reflecting device and the main focal point of the lens. The placement of the shutter forms the required cut-off line in the light distribution. Therefore, the manufacturing process becomes more complicated due to the involvement of an additional component.

[0008] In recent years, with the development trend of vehicle styling, especially with the rapid development of electric vehicles, more requirements are placed on the shape and size of the light emitting module, as the light emitting module is an important element of the vehicle head and tail styling. For example, for an electric vehicle without a front grille, it is advantageous from the perspective of styling to arrange the light emitting module in the front of the vehicle in as compact a manner as possible, especially in the longitudinal direction of the vehicle, i.e. the X direction. Similarly, for a motorcycle, a compact design in the longitudinal direction is also highly desirable.

[0009] In order to shorten the overall length of the light emitting module in the X direction, some existing designs arrange at least two lenses in a row along the optical axis of the lens, which is usually parallel to the X direction. This arrangement shortens the focal length of the lens group while still meeting the regulatory requirements for the light distribution. However, this solution significantly increases the manufacturing cost and reduces the optical efficiency of the light emitting module.

[0010] In other words, the light emitting modules of the prior art are difficult to meet the new size requirements of vehicles in the X direction while still meeting functional requirements without increasing manufacturing costs. Therefore, the existing light emitting modules still need further improvement. SUMMARY

[0011] The present invention aims to overcome the disadvantages of the prior art by providing a light emitting module for a vehicle, which has a smaller total length while maintaining a light distribution that meets regulatory requirements and does not increase manufacturing costs. It should be noted that in this specification, the term "length" always refers to the length along the optical axis of the lens of the light emitting module, which, as mentioned above, in most cases coincides with the X direction of the vehicle.

[0012] The light emitting module in the present invention can be used for various types of vehicle lamps, including but not limited to, a front fog lamp, a low beam headlamp, a high beam headlamp and a combination headlamp.

[0013] To this end, the invention relates to a light module for a vehicle, comprising:

[0014] - a light source unit emitting light rays;

[0015] - a light reflection arrangement comprising a first component and a second component, wherein the first component is a total internal reflection unit configured to reflect all light rays emitted by the light source unit into a parallel and / or converging light beam, and the second component is a transparent unit directly connected to the total internal reflection unit and having a light exit face;

[0016] - a lens having an optical axis comprising a lens entrance face and a lens exit face, wherein:

[0017] - the transparent unit of the light reflection arrangement has a minimum length of 6 mm in the direction of the optical axis of the lens;

[0018] - the lens entrance face comprises at least two lens regions in a direction perpendicular to the optical axis of the lens, the at least two lens regions having different focal points,

[0019] - the light source unit comprises at least two light source regions in a direction perpendicular to the optical axis of the lens, each light source region comprising at least one light source, the light rays emitted from each light source region being directed towards a respective lens region.

[0020] Firstly, thanks to the transparent unit having a length of at least 6 mm, it is more effective than air in homogenizing the light rays. This ensures that the light rays are homogenized in the transparent unit over a short distance, as required by the regulations, and not, as in the prior art, through air. The light exit face of the transparent unit can thus be placed close to the main focal point of the lens, for example at a distance of between 0 and 2 mm from the main focal point.

[0021] Secondly, the design has at least two lens regions, each having its own focal point corresponding to a respective light source region. This arrangement maintains the width of the light distribution required by the regulations, while allowing the light sources to be placed closer to the lens than in the prior art. Furthermore, the combination of the two features has a synergistic effect, making it possible to significantly reduce the overall length of the light module, for example to approximately 55 mm, compared to more than 100 mm in the prior art.

[0022] According to a preferred embodiment, the light module for a vehicle according to the invention can also comprise the following features, which can be implemented individually or in technically feasible combinations.

[0023] Advantageously, the light module comprises a lens holder extending in the direction of the optical axis of the lens, the lens being fixed to the lens holder. The lens holder supports the lens and blocks stray light.

[0024] According to a preferred embodiment, the lens holder is integrally made with the light reflection device.

[0025] Preferably, the lens holder comprises at least one partition wall extending along the lens optical axis direction, the partition wall separating the at least two lens regions. The number of partition walls is equal to the number of lens regions minus one.

[0026] The partition wall is used to direct the light rays from the at least two light source regions into their respective lens regions without contamination from adjacent regions. At the same time, the partition wall is also used to block stray light reflected by the total internal reflection unit, thereby obtaining a more refined final light distribution.

[0027] Advantageously, the partition wall and / or the lens holder comprising the partition wall is made of light-absorbing material, such as black polycarbonate (PC).

[0028] According to a preferred embodiment, the light module comprises a light shield integrated on the bottom surface of the transparent unit of the light reflection device. The bottom surface refers to the surface facing downwards after the light module is installed on the vehicle. The light shield is used to form a cut-off line at the upper edge of the final light distribution to comply with regulatory requirements.

[0029] By contrast, in a conventional light module, a separate light shield, usually made of metal, is arranged between the lens focal point and the light reflection device along the lens optical axis direction. In the present invention, the light shield is integrated in the light reflection device, which reduces the number of optical components in the light module, lightens the light module, enhances compactness, and reduces manufacturing complexity and cost.

[0030] Advantageously, the light shield is integrally made with the transparent unit. Preferably, the light reflection device is also integrally made. Therefore, the number of mounting components and assembly steps is reduced, the assembly process of the light module is simplified, and the manufacturing cost is reduced.

[0031] Advantageously, each light source region comprises at least one light source, each light source comprising at least one light-emitting diode (LED). The total internal reflection unit comprises at least two total internal reflectors, each total internal reflector being connected to a corresponding light source and being configured to reflect all light rays emitted by the light source into a parallel and / or convergent light beam.

[0032] According to a preferred embodiment, the lens entrance surface comprises three lens regions, and the light source unit comprises three light source regions. Advantageously, the three lens regions consist of a central lens region having a main focal point and two side lens regions each having a side focal point aligned with a light source along the lens optical axis direction. For example, the three lens regions comprise a central lens region having a back focal length of 20 to 30 mm (preferably 27 mm) and two side lens regions each having a back focal length of 50 to 60 mm (preferably 51.5 mm).

[0033] Advantageously, according to the above described embodiment, the lens holder comprises two partition walls to separate the three lens areas.

[0034] Preferably, the three light source areas consist of a central light source area comprising one light source and two side light source areas each comprising two light sources. For example, the central light source area comprises one light source having at least one double-chip LED, while each side light source area comprises two light sources each having one single-chip LED.

[0035] The application also relates to a vehicle comprising at least one light module as described above. BRIEF DESCRIPTION OF DRAWINGS

[0036] The application will be more readily understood by reading the following description in conjunction with the attached drawings, which are provided by way of non-limiting example. The terms "top", "bottom", "front", "back" refer to the orientation of the light module after it is mounted on a vehicle. The following description refers to the attached drawings in which:

[0037] Figure 1 is a top view of a light module according to one embodiment of the application;

[0038] Figure 2 is a side view of the light module shown in Figure 1

[0039] Figure 3 is a perspective view of the light module shown in Figure 1

[0040] Figure 4 is a schematic view depicting a first part of the light path of the light module shown in Figure 1

[0041] Figure 5 is a schematic view depicting a second part of the light path of the light module shown in Figure 1

[0042] Figure 6 is a front view of the light reflection means of the light module shown in Figure 1 DETAILED DESCRIPTION

[0043] Figures 1 to 3 A light module 100 for a vehicle (not shown) is shown, which comprises a light source unit 120, light reflection means 140 and a lens 160. In the present example, the light module 100 is designed for a low beam headlight, the final light distribution of which complies with the low beam regulations. However, in other embodiments (not shown), the light module 100 can be designed to comply with regulations for other types of light, such as a front fog light, a high beam headlight and a combination of high and low beam headlight.​​​​​

[0044] The light source unit 120 comprises at least one light source 121 emitting light rays 200, as shown in Figure 4 and Figure 5

[0045] As shown in Figures 1 to 3 , the light reflecting device 140 comprises a total internal reflection unit 142 and a transparent unit 144 directly connected to the total internal reflection unit 142 in the direction of the optical axis D of the lens 160. The term "transparent" means transparent to at least any light radiation having a wavelength comprised in the visible spectrum, i.e. a wavelength of about 380 to 780 nm. In the present disclosure, "translucent" is not considered as "transparent".

[0046] The total internal reflection unit 142 is in contact with the light source unit 120. Typically, the total internal reflection unit 142 comprises total internal reflectors 1421, each corresponding to one light source 121. These total internal reflectors are typically constituted by a reflective coating mirror, the inner surface of the total internal reflectors 1421 can have the shape of an ellipsoid, a paraboloid, a hyperboloid or a free-form surface.

[0047] The transparent unit 144 comprises a light exit face 146. The light exit face 146 can be a continuous curved surface or not, and is intended to direct the light rays 200 out at a specific angle to achieve a final light distribution complying with regulations. The method to define the geometry of the light exit face 146 is well known to the person skilled in the art and is therefore not detailed here.

[0048] The lens 160 comprises a lens light exit face 164 and a lens light entry face 162.

[0049] In the present embodiment, the lens light entry face 162 is divided into three lens regions 1621, 1622 and 1623 in the direction perpendicular to the optical axis D of the lens 160. The optical axes of these different regions are typically parallel to each other, so that only one optical axis D represents the direction of all the optical axes.

[0050] Preferably, the lens regions 1621, 1622 and 1623 can have different or identical sizes and / or curvatures. For example, the lens light entry face 162 in each lens region 1621, 1622 and 1623 can be a single curved surface or a contoured curved surface. The design can be flexible according to the customization needs.

[0051] Dividing the lens light entry face 162 into multiple regions allows to reduce the thickness of the lens 160 (in the direction of the optical axis), to reduce the overall weight of the light emitting module 100, and thus to reduce the manufacturing costs.

[0052] ​The height and width of each lens region 1621, 1622, and 1623 are preferably between 10 and 30 mm. In this embodiment, the total width of lens 160 is 60 mm, and the height is 15 mm. (Width corresponds to...) Figure 1 The Y direction shown corresponds to the Z direction in height. For reference, after the light-emitting module 100 is installed on the vehicle, the X direction represents the longitudinal axis of the vehicle in its usage position, the Y direction represents the lateral axis of the vehicle, and the Z direction represents the vertical direction of the vehicle. In the embodiment shown in the figures, the X direction is aligned with the direction of the optical axis D of the lens.

[0053] In this embodiment, each lens region has a width of 20 mm and a height of 15 mm.

[0054] Each lens region 1621, 1622, and 1623 may have the same or different back focal lengths. Preferably, for the low beam lamp module, at least two regions have different back focal lengths. In this embodiment, the back focal length of the central lens region 1622 is 27 mm, while the back focal length of each of the two side lens regions 1621 and 1623 is 51.5 mm. Furthermore, in this embodiment, the thickness of the lens 160 (along the optical axis) measured at the center of the central lens region is 10 mm, while the thickness of the lens 160 measured at the center of each side lens region is approximately 3.5 mm.

[0055] The focal point can be located at different depths in the X direction. For example... Figure 1 As shown, the central focal point A of the central lens region 1622 is approximately located at the light-emitting surface 146 of the transparent unit 144 of the light reflecting device 140, while the focal points B and C of the side lens regions 1621 and 1623 are located at the location of the light source 121 of the light source unit 120.

[0056] The focal length selection for different lens regions 1621, 1622, and 1623 depends on regulatory requirements and specific customization preferences. This embodiment is designed to achieve a centrally focused beam in the final light distribution and optimize the overall beam width.

[0057] Preferably, the light-emitting module 100 includes a lens holder 170 to securely support the lens 160. The lens holder 170 extends along the optical axis of the lens 160. Advantageously, the lens holder 170 includes sidewalls to block stray light. In this embodiment, advantageously, the lens holder 170 is divided by two partition walls 172 into three regions corresponding to three lens regions 1621, 1622, and 1623. Preferably, the partition walls 172 and / or the lens holder 170 are made of a light-absorbing material, such as black polycarbonate (PC).

[0058] In this embodiment, the light source unit 120 includes five light sources distributed in three light source regions 1201, 1202, and 1203, which correspond to three lens regions 1621, 1622, and 1623. The central light source region 1202 includes one light source 121, while each of the two side light source regions 1201 and 1203 includes two light sources 121.

[0059] like Figure 4 As shown, light 200 emitted from the central light source region 1202 is reflected and focused by the total internal reflection unit 142, and propagates through the transparent unit 144 toward the central focal point A of the central lens region 1622. This arrangement allows for the formation of a concentrated parallel beam of light emanating from the center of the lens exit surface 164, thereby obtaining a strong, centrally focused light distribution.

[0060] like Figure 5 As shown, light 200 emitted from the two side light source regions 1201 and 1203 is reflected and focused by the total internal reflection unit 142 toward its respective side lens region. This arrangement achieves a wider light distribution.

[0061] In order to achieve uniform light distribution while shortening the overall length of the light-emitting module 100, the transparent unit 144 of the light-reflecting device 140 has a length greater than 6 mm in the optical axis direction of the lens 160. Preferably, the length of the transparent unit is between 6 and 30 mm, more preferably between 6 and 15 mm, and most preferably 8.5 mm. In this embodiment, the length of the transparent unit 144 is 8.5 mm.

[0062] Since light 200 propagates through a transparent unit 144 with a length exceeding 6 millimeters, it achieves a more efficient homogenization effect compared to light propagating through air. Therefore, the light emitted from the light-emitting surface 146 of the transparent unit 144 is well homogenized, eliminating the need for further propagation through air.

[0063] Therefore, in this embodiment, the light-emitting surface 146 of the transparent unit 144 can be arranged near the central focal point A of the lens, and in this example, the minimum distance from the central focal point A is 1.5 mm.

[0064] As shown in this embodiment, the length of the total internal reflection unit 142 is selected to be approximately 8 mm. Preferably, the lengths of the total internal reflection unit 142 and / or the transparent unit 144 can be varied within the above range according to the manufacturing process and / or customization requirements.

[0065] Therefore, the design of the light-emitting module 100 according to the present invention can achieve a total length of 55 mm, which is significantly shorter than that of conventional light-emitting modules.

[0066] Preferably, especially for low beam headlight designs, the light-shielding element 150 is disposed on the bottom surface 145 of the transparent unit 144 of the light-reflecting device 140, such as... Figure 2 and Figure 3 As shown.

[0067] Advantageously, the light-shielding element 150 is integrated with the transparent unit 144. Preferably, the light-reflecting device 140 and the light-shielding element 150 are integrally formed. For example, the light-reflecting device and the light-shielding element can be made of transparent polycarbonate (PC).

[0068] Preferably, the lens holder 170 and the light reflecting device 140 are also integrally formed.

[0069] Preferably, the selection of the light source 121 helps to achieve a uniformly concentrated beam at the center and a beam diffused to both sides in the final light distribution. Each light source 121 includes at least one single-chip LED 1211, such as... Figure 6 As shown. If the central focal length of the central lens region 1622 is less than 35 mm, the light source 121 of the central light source region 1202 preferably includes a single-chip LED 1211. If the central focal length of the central lens region 1622 is greater than 30 mm, the light source 121 of the central light source region 1202 preferably includes at least one dual-chip LED 1212. The brightness per watt of a dual-chip LED is twice that of a single-chip LED. In this embodiment, the light source of the central light source region 1202 consists of a dual-chip LED 1212, while each light source 121 in the two side light source regions consists of a single-chip LED 1211, as shown. Figure 6 As shown.

[0070] This invention is not limited to the embodiments shown, and other embodiments will be apparent to those skilled in the art. Any combination of the above embodiments or variations is readily apparent, for example.

[0071] List of reference numerals in the attached diagram:

[0072] 100: Light-emitting module

[0073] 120: Light source unit

[0074] 1201, 1202, 1203: Light source areas

[0075] 121: Light Source

[0076] 1211, 1212: LED

[0077] 140: Light reflecting device

[0078] 142: Total Internal Reflection Unit

[0079] 1421: Total Internal Reflector

[0080] 144: Transparent Unit

[0081] 145: Bottom

[0082] 146: Light-emitting surface

[0083] 150: Sunshade

[0084] 160: Lens

[0085] 162: Lens entrance surface

[0086] 1621, 1622, 1623: Lens area

[0087] 164: Lens exiting surface

[0088] 170: Lens bracket

[0089] 172: Partition wall

[0090] 200: Light

Claims

1. A light-emitting module (100) for a vehicle, comprising: - A light source unit (120) that emits light (200); - A light reflecting device (140) comprising a first part and a second part, wherein the first part is a total internal reflection unit (142) configured to reflect all light rays (200) emitted by the light source unit (120) into parallel and / or converging beams, and the second part is a transparent unit (144) directly connected to the total internal reflection unit (142), the transparent unit (144) having a light-emitting surface (146); and - A lens (160) having an optical axis (D), comprising a light-incident surface (162) and a light-exit surface (164); Its features are, - The transparent unit (144) of the light reflecting device (140) has a minimum length of 6 mm along the direction of the optical axis (D) of the lens (160); - The light-incident surface (162) of the lens includes at least two lens regions (1621, 1622, 1623) along the direction perpendicular to the optical axis (D) of the lens (160), and the at least two lens regions (1621, 1622, 1623) have different focal points; - The light source unit (120) includes at least two light source regions (1201, 1202, 1203) in a direction perpendicular to the optical axis (D) of the lens (160). Each light source region (1201, 1202, 1203) includes at least one light source (121), and the light emitted from each light source region (1201, 1202, 1203) is directed toward its respective lens region (1621, 1622, 1623).

2. The light-emitting module (100) for a vehicle according to claim 1, comprising a lens bracket (170) extending along the direction of the optical axis (D) of the lens (160), the lens (160) being fixed to the lens bracket (170).

3. The light-emitting module (100) for a vehicle according to claim 2, wherein the light-reflecting device (140) and the lens bracket (170) are integrally formed.

4. The light-emitting module (100) for a vehicle according to any one of claims 2 to 3, wherein the lens holder (170) includes at least one partition wall (172) extending along the direction of the optical axis (D) of the lens for separating the at least two lens regions.

5. The light-emitting module (100) for a vehicle according to claim 4, wherein the partition wall (172) and / or the lens holder (170) including the partition wall (172) are made of a light-absorbing material, such as black polycarbonate.

6. The light-emitting module (100) for a vehicle according to any one of the preceding claims, wherein, A light-shielding element (150) is integrated on the bottom surface (145) of the transparent unit (144) of the light-reflecting device (140).

7. The light-emitting module (100) for a vehicle according to claim 6, wherein the light-shielding member (150) and the transparent unit (144) are integrally formed.

8. The light-emitting module (100) for a vehicle according to any one of the preceding claims, wherein the light-reflecting device (140) is integrally formed.

9. The light-emitting module (100) for a vehicle according to any one of the preceding claims, wherein each light source region (1201, 1202, 1203) includes at least one light source (121), and each light source (121) includes at least one light-emitting diode (1211, 1212).

10. A light-emitting module (100) for a vehicle according to any one of the preceding claims, wherein the lens light-incident surface (162) includes three lens regions (1621, 1622, 1623) and the light source unit (120) includes three light source regions (1201, 1202, 1203).

11. The light-emitting module (100) for a vehicle according to claims 4 and 10, wherein the lens holder (170) includes two partition walls (172) for separating the three lens regions.

12. The light-emitting module (100) for a vehicle according to any one of claims 10 to 11, wherein the light-incident surface (162) of the lens includes a central lens region (1622) and two side lens regions (1621, 1623), the back focal length of the central lens region (1622) being between 20 and 30 mm, and the back focal length of each of the two side lens regions (1621, 1623) being between 50 and 60 mm.

13. The light-emitting module (100) for a vehicle according to any one of claims 10 to 12, wherein the three light source regions (1201, 1202, 1203) are composed of a central light source region (1202) and two side light source regions (1201, 1203), wherein the central light source region (1202) includes one light source (121), and each of the two side light source regions (1201, 1203) includes two light sources (121).

14. The light-emitting module (100) for a vehicle according to claim 13, wherein one light source (121) of the central light source region (1202) includes at least one dual-chip light-emitting diode (1212), and each of the two light sources (121) of each side light source region (1201, 1203) includes a single-chip light-emitting diode (1211).

15. A vehicle, characterized in that... It includes at least one light-emitting module (100) according to any one of claims 1 to 14.

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