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Title:
LIGHT EMITTING MODULE FOR VEHICLE, VEHICLE HEADLAMP AND VEHICLE
Document Type and Number:
WIPO Patent Application WO/2022/171693
Kind Code:
A1
Abstract:
The present invention relates to a light emitting module for a vehicle, a vehicle headlamp and a vehicle, wherein the light emitting module comprises: a primary optical unit (2), having a light entry section (3), a light exit section (5) having a light exit face (6), and a light interception surface (10) between the light entry section (3) and the light exit section (5); a secondary optical unit (7) arranged downstream of the primary optical unit; and light sources allocated to the light entry section, wherein the light entry section (3) has a first light entry region (3A) and a second light entry region (3B), which are configured such that light rays received from the light sources are focussed at an edge (30) of the light interception surface (10) remote from the light entry section (3) by the first light entry region and second light entry region, so as to form a primary image, and the light exit face (6) forms a virtual image of the primary image at a virtual focus region (30'), wherein a focus region of the secondary optical unit is situated at the virtual focus region.

Inventors:
BAI LU (FR)
CHEN LIN (FR)
CHEN FEI (FR)
Application Number:
PCT/EP2022/053159
Publication Date:
August 18, 2022
Filing Date:
February 09, 2022
Export Citation:
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Assignee:
VALEO VISION (FR)
International Classes:
F21S41/143; F21S41/151; F21S41/153; F21S41/265; F21S41/27; F21S41/32; F21S41/43; F21S41/663; G02B19/00
Domestic Patent References:
WO2020064978A12020-04-02
Foreign References:
US10151437B22018-12-11
US10082272B22018-09-25
US20180058651A12018-03-01
CN210740266U2020-06-12
US10663134B22020-05-26
DE102018209303A12019-12-12
Attorney, Agent or Firm:
VALEO VISIBILITY (FR)
Download PDF:
Claims:
Claims

1. Light emitting module (1) for a vehicle, comprising: a primary optical unit (2), having

- a light entry section (3), the light entry section (3) having a first light entry region (3A) for a first light function and a second light entry region (3B) for a second light function,

- a light exit section (5) having a light exit face (6),

- a light interception surface (10) being arranged between the light entry section (3) and the light exit section (5), and configured to form a cutoff profile; a secondary optical unit (7), arranged downstream of the primary optical unit (2); a first light source (LI), allocated to the first light entry region (3A) of the light entry section (3); a second light source (L2), allocated to the second light entry region (3B) of the light entry section (3), characterized in that the light emitting module (1) is configured such that light rays of the light sources received via the first light entry region (3A) and the second light entry region (3B) are focussed at an edge (30) of the light interception surface (10) remote from the light entry section (3), so as to form a primary image, and the light exit face (6) forms a virtual image of the primary image at a virtual focus region (30’), wherein a focus region of the secondary optical unit (7) is situated at the virtual focus region (30’).

2. Light emitting module (1) according to Claim 1, characterized in that the primary optical unit (2) is in the form of a block, and the first light entry region (3A) and second light entry region (3B) of the light entry section (3) are stacked at one end side of the primary optical unit (2).

3. Light emitting module (1) according to Claim 2, characterized in that the primary optical unit (2) is constructed as a single piece.

4. Light emitting module (1) according to Claim 3, characterized in that the light interception surface (10) is flat, or has a step (10B) or a depression (10D).

5. Light emitting module (1) according to Claim 3, characterized in that the first light entry region (3A) has at least one first light entry unit, and the second light entry region (3B) has at least one second light entry unit.

6. Light emitting module (1) according to Claim 5, characterized in that in the case that the corresponding light entry region has multiple light entry units, the light entry units of the corresponding light entry region are arranged side by side.

7. Light emitting module (1) according to Claim 6, characterized in that the first light entry unit of the first light entry region (3A) takes the form of a collimator, and a light- emitting surface of the first light entry unit is configured to guide and gather light rays of the light source to the edge (30).

8. Light emitting module (1) according to Claim 6, characterized in that corresponding light-emitting surfaces of the first light entry units guide and gather light rays of the light source to the edge (30), wherein the light rays can be gathered at one or more regions of the edge (30).

9. Light emitting module (1) according to Claim 6, characterized in that light-emitting surfaces of the corresponding first light entry units are discontinuous, with adjacent said light-emitting surfaces being connected via an intermediate face (1 ID).

10. Light emitting module (1) according to any one of Claims 1 - 9, characterized in that the primary optical unit (2) and the secondary optical unit (7) are lenses, and at least one of them is preferably an achromatic lens.

11. Light emitting module (1) according to any one of Claims 1 - 9, characterized in that the primary optical unit (2) and the secondary optical unit (7) are constructed as a single piece.

12. Light emitting module (1) according to any one of Claims 1 - 9, characterized in that the light source is a semiconductor light source.

13. Vehicle headlamp, having the light emitting module (1) according to any one of Claims 1 - 12.

14. Vehicle, having the light- emitting module (1) according to any one of Claims 1 - 12 or the vehicle headlamp according to Claim 13.

Description:
Description

Light emitting module for vehicle, vehicle headlamp and vehicle TECHNICAL FIELD

The present invention relates to a light emitting module for a vehicle, a vehicle headlamp and a vehicle.

BACKGROUND

It is known that light emitting modules for vehicle headlamps can be implemented via different technical solutions, for example a pure reflector system based on a curved surface, or a hybrid system based on a reflector, a light blocker and a lens. The systems mentioned above require a large structural space: the former requires a large structural space in a direction transverse to the optical axis direction of the light emitting module, while the latter requires a large structural space in the direction of the optical axis of the light emitting module.

SUMMARY

Thus, an objective of the present invention is to provide a light emitting module for a vehicle that has a compact size while achieving a desired light distribution.

According to the present invention, this objective is achieved as follows: the proposed light emitting module for a vehicle comprises: a primary optical unit, having a light entry section having a first light entry region for a first light function and a second light entry region for a second light function, a light exit section, having a light exit face, a light interception surface being arranged between the light entry section and the light exit section, and configured to form a cutoff profile; a secondary optical unit, arranged downstream of the primary optical unit; a first light source, allocated to the first light entry region of the light entry section; a second light source, allocated to the second light entry region of the light entry section, wherein the light emitting module is configured such that light rays of the light sources received via the first light entry region and the second light entry region are focussed at an edge of the light interception surface remote from the light entry section, so as to form a primary image, and the light exit face forms a virtual image of the primary image at a virtual focus region, wherein a focus region of the secondary optical unit is situated at the virtual focus region.

In the proposed light emitting module, light emitted by the light sources is focussed at the edge of the light interception surface via the primary optical unit of the light emitting module, and forms a virtual image via the light exit section of the primary optical unit, before being projected by means of the secondary optical unit. This is very helpful for reducing the size of the whole light emitting module in a main light propagation direction.

According to an embodiment of the present invention, the primary optical unit is in the form of a block, and the first light entry region and second light entry region of the light entry section are stacked at one end side of the primary optical unit. Such a design may for example be suitable for situations where the light emitting module is used to realize a low beam function and a high beam function. For this purpose, for example, the first light entry region is located above the second light entry region overall, and the first light entry region is used for the low beam function, while the second light entry region is used for the high beam function.

According to an embodiment of the present invention, the primary optical unit is constructed as a single piece. This enables simple installation. According to an embodiment of the present invention, the light interception surface is flat, or has a step or a depression, in order to satisfy a corresponding light distribution requirement. In one example, the cutoff profile of the light interception surface may have two flat cutoff parts, which may be offset one above the other, thereby forming a step connecting the two flat cutoff parts, wherein the step profile may for example be inclined to the left or right by an angle of 15°. Alternatively, a depression may also be formed between the two flat cutoff parts.

According to an embodiment of the present invention, the first light entry region has at least one first light entry unit, and the second light entry region has at least one second light entry unit. In particular, in the case where the corresponding light entry region has multiple light entry units, the light entry units of the corresponding light entry region are arranged side by side. The light entry units may be arranged side by side so as to be adjacent to each other, or a gap may be present therebetween. The number and arrangement of the light entry units may be set according to the desired light distribution.

According to an embodiment of the present invention, the first light entry unit of the first light entry region takes the form of a collimator, and a light- emitting surface thereof is configured to guide and gather light rays of the light source to the edge. This is conducive to better guiding of light.

According to an embodiment of the present invention, corresponding light-emitting surfaces of the first light entry units guide and gather light rays of the light source to the edge, wherein the light rays can be gathered at one or more regions of the edge. Especially in the case where a wide outgoing light angle is needed, the light rays can be gathered at multiple regions of the edge, i.e. there are multiple gathering points at the edge.

According to an embodiment of the present invention, light-emitting surfaces of the corresponding first light entry units are discontinuous, with adjacent light- emitting surfaces being connected via an intermediate face. This may for example help to reduce the overall longitudinal size of the first light entry units.

According to an embodiment of the present invention, the primary optical unit and the secondary optical unit are lenses, and at least one of them is preferably an achromatic lens. Compared with a combination of a reflector and a lens, a smaller aperture can be achieved through the solution of the present invention in which both the primary optical unit and the secondary optical unit are lenses. In the case that the lens has an achromatic function, chromatic aberration can be corrected.

According to an embodiment of the present invention, the primary optical unit and the secondary optical unit are constructed as a single piece, thereby facilitating assembly.

According to an embodiment of the present invention, the light source is a semiconductor light source, e.g. a light emitting diode. Such a light source may be obtained very easily on the market.

According to another aspect of the present invention, a vehicle headlamp is proposed, having the light emitting module described above.

According to another aspect of the present invention, a vehicle is proposed, having the light emitting module or vehicle headlamp described above.

BRIEF DESCRIPTION OF THE FIGURES

The present invention is expounded in details below with the aid of the drawings. In the drawings:

Fig. 1 shows schematically a light emitting module for a vehicle according to an embodiment of the present invention;

Fig. 2 shows a top view of the light emitting module in Fig. 1;

Fig. 3 shows a side view of the light emitting module in Fig. 1; and Fig. 4 shows a profile of one embodiment of the light interception surface of the light emitting module in Fig. 1; and

Fig. 5 shows a profile of another embodiment of the light interception surface of the light emitting module in Fig. 1.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described demonstratively below. As those skilled in the art should realise, the embodiments described may be amended in various ways without departing from the concept of the present invention. Thus, the accompanying drawings and the specification are in essence demonstrative and non-limiting. In the following text, identical drawing reference labels generally indicate functionally identical or similar elements.

To enable better explanation, a vehicle coordinate system is introduced, referring to the mounting position of the light emitting module according to the present application in a vehicle, wherein the X direction represents a longitudinal direction of the vehicle, i.e. a length direction of the light emitting module of the present application, corresponding to a main light exit direction of the light emitting module; the Y direction represents a transverse direction of the vehicle, i.e. a width direction of the light emitting module of the present application; and the Z direction represents a height direction of the vehicle, i.e. a height direction of the light emitting module of the present application.

Fig. 1 shows schematically a light emitting module 1 for a vehicle according to the present invention, comprising a light source, a primary optical unit 2 and a secondary optical unit 7. The primary optical unit 2 has: a light entry section 3, having a first light entry region 3 A for a first light function and a second light entry region 3B for a second light function; a light exit section 5, having a light exit face 6; and a light interception surface 10, arranged between the light entry section 3 and the light exit section 5, and configured to form a cutoff profile. The secondary optical unit 7 is arranged downstream of the primary optical unit 2. The light source comprises a first light source LI allocated to the first light entry region 3 A of the light entry section 3, and a second light source L2 allocated to the second light entry region 3B of the light entry section 3. The light emitting module 1 is configured such that light rays of the light sources received via the first light entry region 3 A and second light entry region 3B are focussed at an edge 30 of the light interception surface 10 remote from the light entry section 3 by the light emitting module, so as to form a primary image, and the light exit face 6 forms a virtual image of the primary image at a virtual focus region 30’, wherein a focus region of the secondary optical unit 7 is situated at the virtual focus region 30’.

Thus, the light emitting module 1 according to the present invention may be regarded as a projection system; the secondary optical unit 7 forms a desired light image of light rays of the light sources received by the primary optical unit 2, and projects this light image into a region in front of the light emitting module or vehicle. Since the primary optical unit 2 first forms a virtual image of light rays received from the light sources, and the virtual image is then projected outwards through the secondary optical unit 7, in the case where two light source units are both lenses, in particular when the virtual image is remote from an edge of the light interception surface 10 in the direction opposite to the main light exit direction, this is especially favourable for making the structure of the light emitting module 1 compact overall, because the primary optical unit 2 can be designed to have a small length, while the secondary optical unit 7 itself can also have a small size in the main light exit direction. Two optical units having a small size in the main light exit direction is also advantageous for the injection moulding thereof. In addition, the cooperation of the primary optical unit 2 and the secondary optical unit 7 also enables better gathering of light rays of the light sources, in order to realize a light emitting module with a smaller aperture.

As can be seen from Fig. 1, the primary optical unit 2 is in the form of a block, i.e. has predetermined dimensions in the X, Y and Z directions.

The primary optical unit 2 may be made of any material suitable for allowing light rays to be guided in the manufactured primary optical unit from a light entry face to the light exit face, and light rays can be totally reflected at a sidewall of the primary optical unit made from the material. Exemplary materials may be polycarbonate (PC), polymethyl methacrylate (PMMA), silicone, silicone rubber of glass, etc.

The primary optical unit 2 shown is constructed as a single piece, e.g. is injection moulded from the material mentioned above. The first light entry region 3A and second light entry region 3B of the light entry section 3 may be arranged at one end side of the primary optical unit 2 in a stacked fashion.

An opening 4 may be formed in the primary optical unit 2, in order to form the light interception surface 10. In the example shown, the light interception surface 10 is flat. As can also be seen from Figs. 4 and 5, the cutoff profile of the light interception surface 10 may have two flat parts 10A, IOC offset from one another in the Z direction, with a step 10B (see Fig. 4) or a depression 10D (see Fig. 5) provided therebetween. In other words, the course of the cutoff profile may be configured according to the stipulations of the corresponding regulations relating to the cutoff line for low beam of the vehicle. For this purpose, as can be seen in the side view in Fig. 3, the opening 4 may have a level bottom, the light entry section is arranged at one side of the bottom, and an edge at the opposite side forms the edge 30 mentioned above.

The first light entry region 3A and second light entry region 3B may each have at least one first entry unit. In the example shown, the first light entry region 3A has six first light entry units 11 - 16, and the second light entry region 3B has three second light entry units 21 - 23. Other numbers of light entry units are also feasible. Each light entry unit has a light entry face. For the sake of clarity, reference labels are only provided for a light entry face 11 A of one light entry unit 11 of the first light entry region 3 A and for a light entry face 21 A of one light entry unit 21 of the second light entry region 3B in the figure.

The light entry faces 11 A, 21 A are used to receive light rays from the light sources; the light rays are coupled into the light entry regions 3 A, 3B through the light entry faces. The light entry faces 11 A, 21 A have the form of cavities; each cavity has a protrusion in the middle and a sunken part surrounding the protrusion, both the protrusion and the sunken part being rotationally symmetric about the optical axis of the light source allocated to the light entry face, wherein the light source is positioned at a focus of the protrusion. Preferably, the sunken part is a section of a spherical surface, having a centre that coincides with the focus of the protrusion. A portion of the light coupled into the light entry units is reflected by reflecting walls 11B, 21B of the light entry units and then continues to propagate, i.e. is reflected in the first light entry unit towards an light- emitting surface 11C configured to guide light rays of the light source to the edge 30 in a gathered manner, and is reflected in the second light entry unit towards the edge 30 of the light interception surface 10. Thus, the edge 30 forms a light ray focus region shared by the first light entry unit and the second light entry unit.

Preferably, the first light entry unit of the first light entry region 3A takes the form of a collimator, i.e. collimates light of the light source so that it is guided from the light entry face to the light-emitting surface in a parallel fashion. In the case where the first light entry region and second light entry region have multiple light entry units, the light entry units of the corresponding light entry region are arranged side by side. In this case, one light source, for example a light emitting diode, may be allocated to each light entry unit. All of the light emitting diodes may advantageously be arranged in the same plane.

The first light entry region guides light received from the light sources to the edge 30 in a gathered manner, according to requirements. For this purpose, the corresponding light entry units of the first light entry region may have the same gathering region, or have respective gathering regions, or have the same gathering region in a partially joint fashion. In simple terms, the light- emitting surfaces of the first light entry units may specifically enable light rays of the light sources to have one or more gathering regions at the edge 30. This also applies to the second light entry region, i.e. the corresponding light entry units of the second light entry region may have the same gathering region, or have respective gathering regions, or have the same gathering region in a partially joint fashion. In simple terms, the second light entry units may enable light rays of the light sources to have one or more gathering regions at the edge 30.

A light path diagram in the X-Y plane is shown in Fig. 2, wherein light rays leaving the light- emitting surface 11C of the first light entry unit 11 are gathered at FI, and light rays leaving light- emitting surfaces 13C, 14C of the first light entry units 13, 14 are gathered at F2 in a joint fashion. The light exit section 5 forms virtual images, at FI’, F2’ of the virtual focus region 30’, of the images formed at FI, F2 by the light rays. The images of the light emitted by the corresponding light sources, which are formed at the virtual focus region 30’ by the primary optical unit 2, are projected outward into the distance by the secondary optical unit 7.

A light path diagram in the X-Z plane is shown in Fig. 3, wherein light rays leaving the light- emitting surface 14C of the first light entry unit 14 are gathered at F2 on the edge 30, and the second light entry unit 22 guides in-coupled light rays towards F2 in a gathered fashion. The light exit section 5 forms virtual images, at F2’ of the virtual focus region 30’, of the images formed at F2 by the light rays. The images of the corresponding light sources, which are formed at the virtual focus region 30’ by the primary optical unit 2, are projected outward into the distance by the secondary optical unit 7.

Thus, the light emitting module 1 according to the present invention may be regarded as comprising the primary optical unit 2 used to form a light beam having a cutoff profile, and the secondary optical unit 7 used to project the light beam outward into the distance.

As can be seen from the light path diagram in Fig. 2, the light beams from the first light entry units which are projected through the secondary optical unit 7 may not be parallel to each other. This helps to achieve a broad illumination width in the Y direction.

The light- emitting surfaces of the corresponding first light entry units may be discontinuous, i.e. may be discrete, with adjacent light- emitting surfaces being connected via an intermediate face 11D.

The secondary optical unit 7 has a light input surface 8 and a light output surface 9. For a given profile of the light output surface 9, the light input surface 8 may be designed as a convex surface, a concave surface or a freely curved surface.

For example, the first light entry region 3A may be used for a low beam function, and the second light entry region 3B may be used for a high beam function.

The primary optical unit 2 and secondary optical unit 7 are lenses, and preferably, at least one of them is an achromatic lens, in order to correct chromatic aberration. The primary optical unit 2 and secondary optical unit 7 may be constructed as a single piece, for example injection moulded; this facilitates assembly. For this purpose, the light emitting module may have a holding frame, not shown in the drawings, for holding the primary optical unit 2 and secondary optical unit 7.

The light source may be a semiconductor light source, e.g. a light emitting diode, such as a white light emitting diode.

It must be explained that although the light entry units of the light entry regions are shown in the drawings as being arranged adjacent to each other, they may also be spaced apart.

The present invention, instead of being limited to the above-described structure, may also have other variants. Although the present invention has already been described by means of a limited number of embodiments, those skilled in the art could, drawing benefit from this disclosure, design other embodiments which do not depart from the scope of protection of the present invention disclosed herein. Thus, the scope of protection of the present invention should be defined by the attached claims alone.