Light module for motor vehicle, and method for producing the same

Abstract

To provide a light module that enables the power density to be increased.SOLUTION: The invention relates to a light module (1) for a motor vehicle, in particular a motor vehicle headlight. The light module (1) includes: a printed circuit board (2); at least one light unit (3) arranged flat on one side of the printed circuit board (2) and having a light exit surface (3a) for emitting light, the light unit (3) preferably comprising at least one LED light source (3b), in which a printed circuit board plane (yz) is formed by the one side of the printed circuit board (2), the printed circuit board (2) having at least one spacer element receiving opening (4) arranged in the vicinity of the at least one light unit (3), the at least one spacer element receiving opening (4) having the at least one light unit (3) configured to pass through the printed circuit board (2) and receive a spacer element (5); and at least one light guide (6).SELECTED DRAWING: Figure 2a

Description

Technical Field

[0001] The present invention relates to an optical module for a motor vehicle, in particular to a motor vehicle headlight, the optical module comprising a printed circuit board, at least one optical waveguide, and at least one optical unit flatly arranged on one side of the printed circuit board having a light exit surface for emitting light, the optical unit preferably comprising at least one LED light source, and the printed circuit board plane being formed by the said one side of the printed circuit board.

Background Art

[0002] An optical waveguide can be used to direct the light emitted by an optical unit from a printed circuit board towards a desired emission area and generate a desired light distribution within the emission area. For this purpose, the optical waveguide is usually supported directly above the optical unit on the printed circuit board such that the light incident surface of the optical waveguide is associated with the optical unit.

[0003] Such a design results in a gap between the light incident surface and the optical unit. In practice, the aim of developing an optical module with a higher output density and thus generally lower costs can sometimes be completely contrary to the technical problem of achieving a high degree of durability of the optical unit. For example, when the output density increases, the temperature of the components rises, often having an adverse effect on the durability of the electronic components. Therefore, a high-performance cooling system is actually used to achieve a higher power density while maintaining the same temperature load. Attempts are also constantly being made to increase the efficiency of the light sources used in the optical units.

Summary of the Invention

Problems to be Solved by the Invention

[0004] One object of the present invention is to develop an optical module that enables an increase in output density.

Means for Solving the Problems

[0005] This object is achieved by an optical module of the kind mentioned in the introduction part. According to the invention, the printed circuit board has at least one spacer element receiving opening arranged in the vicinity of at least one optical unit. The at least one spacer element receiving opening penetrates the printed circuit board and is configured to receive a spacer element. The optical module further has at least one spacer element arranged in the at least one spacer element receiving opening. The at least one spacer element has at least two parts, namely, a holding part passing through the spacer element receiving opening and at least one supporting part arranged at one end of the holding part. The supporting part is wider than the holding part to ensure that the spacer element is pushed through the spacer element receiving opening. The supporting part is arranged on the same side as at least one optical unit of the printed circuit board and has an end facing away from the printed circuit board by a flat supporting surface. The supporting surface is oriented substantially parallel to the printed circuit board plane. The optical waveguide has a light incident surface facing the optical unit for receiving light. The light incident surface of the optical waveguide is at least partially surrounded by at least one supporting region of the optical waveguide. The supporting region of the optical waveguide is supported on the supporting surface of the spacer element to fix a defined normal distance of the light incident surface of the optical waveguide with respect to the optical unit.

[0006] By using a spacer element, a defined minimum distance to the optical waveguide can be set, which is maintained regardless of the manufacturing and positioning accuracy of the optical waveguide. In this way, compared with a variant in which the optical waveguide is directly supported on the printed circuit board, the temperature on the optical waveguide can be reduced by about 3 to 4 °C in normal operation. Specifically, the size of the gap can be particularly affected by selecting the embodiment of the spacer element. In addition, the protrusions on the optical waveguide can be generally reduced or omitted.

[0007] In particular, the support portion of the spacer element may protrude further in the normal direction from the printed circuit board to the printed circuit board plane than the light-emitting surface of the optical unit, such that the support surface protrudes beyond the light-emitting surface in the normal direction. Therefore, even when no protrusion is arranged on the corresponding optical guide and the incident surface extends flatly over the entire cross-section of the optical guide, in this modification, the optical guide does not contact the optical unit.

[0008] At least one protrusion, preferably two protrusions, may be formed in the support region of the optical guide, protrude in the direction of the support surface of the spacer element from the optical guide, and may be supported on the support surface.

[0009] In particular, the holding portion of the spacer element may be designed to fill the spacer element receiving opening by form-fitting. Thereby, particularly good holding of the spacer element can be ensured.

[0010] Furthermore, at least one optical unit is surrounded by at least two, preferably exactly two, spacer element receiving openings, and these spacer element receiving openings are such that when there are exactly two spacer element openings in the vicinity of the optical unit, the center point of the conceptual connection line between the spacer element openings substantially coincides with the geometric center of the light-emitting surface of the optical unit, and / or when there are three or more spacer element openings in the vicinity of the optical unit, the center of the conceptual polygon substantially coincides with the geometric center of the light-emitting surface of the optical unit, and are spatially arranged around the optical unit. The conceptual polygon may be formed such that each spacer element opening existing in the vicinity of the optical unit forms a corner of the polygon and each corner is linearly connected to the two closest corners. This particularly imparts a mechanically stable mounting method. When there are three spacer element openings in the vicinity of the optical unit, a triangle is formed, and when there are four openings, a square is formed. It is advantageous that the geometric shape thus formed surrounds the light-emitting surface of the optical unit. Therefore, in the case of a circular or square light-emitting surface, it is advantageous that the openings are arranged at equal intervals.

[0011] "In the vicinity of the optical unit" can be understood to mean a distance of 3 mm or less measured between the optical unit (i.e., the edge point of the optical unit closest to the aperture) and the spacer element aperture (also the edge point of the spacer element aperture closest to the optical unit).

[0012] In particular, the optical module may have two or more optical units, and the two or more optical units may each be associated with at least one, two or more spacer element receiving apertures having a spacer element housed therein and an optical guide, respectively.

[0013] The support portion and the holding portion of the spacer element may each be substantially cylindrical having a common longitudinal axis.

[0014] In particular, the distance between the closest point (position) of the optical unit associated with the spacer element receiving aperture may be 3 mm or less, particularly between 1.5 mm and 3 mm. This distance can typically be, for example, 2 mm.

[0015] It should also be noted that any technical features described for individual elements may also apply to multiple or all elements of the same element type. This means that the aforementioned distances, geometric arrangements relative to each other, etc. may be applicable to one element, two or more, or even all elements.

[0016] The spacer element receiving aperture may be designed as a hole having a circular hole diameter of 1 mm to 2 mm. This diameter can typically be, for example, 1.2 mm.

[0017] In particular, the cross-sectional area of the support portion may be at least four times the cross-sectional area of the holding portion of the spacer element.

[0018] The holding portion of the spacer element may be firmly fixed to the spacer element receiving aperture.

[0019] In particular, the spacer element also has a fixing part, the fixing part being arranged at the end of the holding part opposite the support part, and the fixing part may be made wider (expanded) with respect to the holding part. This can be done, for example, by expansion or heat caulking.

[0020] Furthermore, the present invention relates to a method for manufacturing an optical module according to the present invention, the method comprising: a) providing a printed circuit board comprising at least one optical unit, the printed circuit board having at least one spacer element receiving opening configured to penetrate the printed circuit board and receive a spacer element; b) providing at least one spacer element, the at least one spacer element having at least two parts, namely a holding part passing through the spacer element receiving opening and at least one support part arranged at one end of the holding part, the support part being made wider (expanded) compared to the holding part; c) inserting at least one spacer element into at least one spacer element receiving opening; d) establishing a connection between the at least one spacer element and the at least one spacer element receiving opening, fixing the at least one spacer element against displacement in the normal direction of the printed circuit board; e) positioning on the printed circuit board an optical waveguide having a light incident surface such that the light incident surface faces the optical unit for receiving light, the light incident surface of the optical waveguide being surrounded by at least one support region of the optical waveguide, the support region of the optical waveguide being supported on the support surface of the spacer element to fix a defined normal distance of the light incident surface of the optical waveguide with respect to the optical unit.

[0021] The connection according to step d) can be made, for example, by adhesion, heat caulking, or mechanical expansion.

[0022] In particular, the optical waveguide may be spatially fixed in the positioning according to step e) with respect to the printed circuit board. This can be achieved, for example, by a fixed connection within a common housing, on the printed circuit board, and / or on other components fixedly connected to the printed circuit board.

[0023] At least one spacer element may be inserted in step c) in an automated manner using the optical detection of at least one spacer element receiving opening. For example, the predetermined geometric shape and size of the opening on the printed circuit board may be provided specifically for the spacer element receiving opening in the form of, for example, a circular hole having a specific diameter, which can then be automatically detected and assigned.

[0024] The support part of the spacer element may also be elliptical or have a cross-section corresponding to the shape of a slot (i.e., it can fill the slot by shape fitting). The oval or slotted embodiments have the advantage that more tolerances are given with respect to positioning in the longitudinal direction of the geometric shape of the support part, and less space is required by the spacer element in the narrow direction. This is particularly advantageous when there are different accuracies / tolerances in two different directions of the printed circuit board plane during assembly or manufacturing, and it is possible to respond to this by designing the shape and positioning the support part accordingly.

[0025] The present invention will be outlined in more detail below based on the exemplary and non-limiting embodiments shown in the drawings.

Brief Description of the Drawings

[0026]

Figure 1a

Figure 1b

Figure 1c

Figure 2a

Figure 2b

Figure 3

Figure 4

Figure 5a

Figure 5b

DETAILED DESCRIPTION OF THE INVENTION

[0027] In the following figures, unless otherwise specified, the same reference numerals denote the same features.

[0028] Fig. 1a shows a schematic view of an optical module 1 according to the invention without an optical waveguide 6 (shown in Fig. 2a). The optical module 1 is suitable for application in / on an automobile and can be used particularly in automobile headlights. The optical module 1 comprises a printed circuit board 2 and at least one optical unit 3 which is arranged flat on one side of the printed circuit board 2 and has a light-emitting surface 3a for emitting light. In this case, the optical unit 3 has, for example, an LED light source 3b. In the upper left region of Fig. 1a, two groups of four are shown, and on the right, two individual LEDs 3b are shown. The side of the printed circuit board 2 on which the light source 3b is arranged forms the printed circuit board plane yz. The axis x is oriented perpendicular thereto and thus projects perpendicularly from the printed circuit board plane yz.

[0029] In FIGS. 1a and 1b, for the purpose of showing that the printed circuit board 2 has spacer element receiving openings 4, which are openings 4 associated with each spacer element 5, one of the four spacer elements 5 provided in this example in principle is not intentionally shown. These openings 4 are arranged in the vicinity of the associated optical unit 3, and at least one spacer element receiving opening 4 penetrates the printed circuit board 2 and is configured to receive the spacer element 5.

[0030] As already described, the optical module 1 further has spacer elements 5 respectively arranged in the spacer element receiving openings 4. At least one spacer element 5 has at least two parts, namely, a holding part 5b passing through the spacer element receiving opening 4 (see FIG. 2b) and at least one supporting part 5a arranged at one end of the holding part 5b. The supporting part is widened wider compared to the holding part 5b to prevent the spacer element 5 from being pushed through the spacer element receiving opening 4. The supporting part 5a is arranged on the same side as at least one optical unit 3 of the printed circuit board 2. This is defined by its end facing away from the printed circuit board 2 by a flat supporting surface 5a'. This supporting surface 5a' is oriented substantially parallel to the printed circuit board plane yz. The optical module 1 has two or more optical units 3, and the two or more optical units 3 may each be associated with at least one, two or more spacer element receiving openings 4 having a spacer element 5 housed therein and an optical waveguide 6 respectively.

[0031] FIG. 1b shows that the spacer element 5 also has a fixing part 5c, and the fixing part 5c is arranged at the end of the holding part 5b opposite to the supporting part 5a, and the fixing part 5c is widened wider with respect to the holding part 5b. The widening can be achieved, for example, by expansion or heat caulking.

[0032] Figure 2a shows a perspective view of the optical module 1 according to FIGS. 1a to 1c including an optical waveguide. The optical module 1 has, by way of example, three optical waveguides 6. Each optical waveguide has a light incident surface 6a (see FIG. 2b) facing the target optical unit 3 for receiving light. The light incident surface 6a of the optical waveguide 6 is at least partially surrounded by at least one support region 6b of the optical waveguide 6. The support region 6b of the optical waveguide 6 is supported on the support surface 5a' of the spacer element 5 in order to fix a defined normal distance d of the light incident surface 6a of the optical waveguide 6 with respect to the optical unit 3.

[0033] Figure 2b shows a cross-sectional view of the optical module 1 according to FIG. 2a. FIGS. 2a and 2b show that the support portion 5a of the spacer element 5 projects further in the normal direction from the printed circuit board 2 to the printed circuit board plane yz than the light exit surface 3a of the optical unit 3 such that the support surface 5a' projects beyond the light exit surface 3a in the -x normal direction. In addition, it is shown that, for example, at least one projection 6b', preferably two projections 6b', may be arranged in the support region 6b of the optical waveguide 6, project in the direction from the optical waveguide 6 towards the support surface 5a' of the spacer element 5, and be supported on the support surface 5a'. The holding portion 5b of the spacer element 5 is preferably designed to fill the spacer element receiving opening 4 by form fit.

[0034] At least one optical unit 3 is surrounded by at least two, preferably exactly two, spacer element receiving openings 4. When there are exactly two spacer element openings 4 in the vicinity of the optical unit 3, the center point of the conceptual connection line between the spacer element openings 4 substantially coincides with the geometric center of the light emitting surface 3a of the optical unit 3, and / or when there are three or more spacer element openings 4 in the vicinity of the optical unit 3, the center of the conceptual polygon substantially coincides with the geometric center of the light emitting surface 3a of the optical unit 3. The conceptual polygon may be formed such that each spacer element opening 4 existing in the vicinity of the optical unit 3 forms a corner of the polygon, and each corner is linearly connected to the two closest corners. The holding part 5b of the spacer element 5 may be firmly fixed to the spacer element receiving opening 4.

[0035] FIG. 3 shows a perspective view of the optical module 1 according to FIG. 2a, including a heat sink 7 configured to dissipate heat loss generated by the printed circuit board 2 or electronic components disposed thereon.

[0036] FIG. 4 shows a perspective view of the optical module according to FIG. 3, including a part of the frame structure 8. This frame structure 8 is provided for guiding and at least partially attaching an optical guide and can also form a visible part of a vehicle headlight design.

[0037] Furthermore, the present invention relates to a method for manufacturing the optical module 1 according to the present invention. a) providing a printed circuit board 2 having at least one optical unit 3, the printed circuit board 2 having at least one spacer element receiving opening 4 configured to penetrate the printed circuit board 2 and receive a spacer element 5; b) providing at least one spacer element 5, the at least one spacer element 5 having at least two parts, namely, a holding part 5b passing through the spacer element receiving opening 4 and at least one support part (5a) disposed at one end of the holding part 5b, the support part being larger in dimension compared to the holding part 5b; c) inserting at least one spacer element (5) into at least one spacer element receiving opening (4); d) establishing a connection between at least one spacer element (5) and at least one spacer element receiving opening (4), the step of fixing at least one spacer element (5) against displacement in the normal direction (x) of the printed circuit board (2); e) positioning a light guide (6) having a light incident surface (6a) on the printed circuit board (2) such that the light incident surface (6a) faces the optical unit (3) for receiving light, the light incident surface (6a) of the light guide (6) being surrounded by at least one support region (6b) of the light guide (6), and the support region (6b) of the light guide (6) being supported on the support surface (5a') of the spacer element (5) for fixing a defined normal distance (d) of the light incident surface (6a) of the light guide (6) with respect to the optical unit (3).

[0038] The connection according to step d) is effected, for example, by thermal caulking in the embodiments shown in FIGS. 5b and 1b. Additionally, the light guide (6) may be spatially fixed with respect to the printed circuit board (2) in the positioning according to step e). This can be fixed by a firm connection to various components fixedly connected to the printed circuit board (2). For example, it can be directly connected to other components such as the printed circuit board and / or the frame element (8) via a common housing.

[0039] FIG. 5a shows a schematic view of an exemplary assembly process, namely the process in which the spacer element (5) is inserted into the printed circuit board (2). The support portion (5a) and the holding portion (5b) of the spacer element (5) may each be substantially cylindrical having a common longitudinal axis (x1). It is preferred that at least one spacer element (5) is inserted in step c) in an automated manner using optical detection of at least one spacer element receiving opening (4). FIG. 5a shows the spacer element (5) in two positions, one above the printed circuit board (2) and one already inserted but not yet fixed. FIG. 5b shows a cross-sectional view of an exemplary connection process that can be carried out by thermal caulking.

[0040] With respect to FIG. 5a, exemplary dimensions (in the non-stacked state) associated with the spacer element 5 should also be mentioned.

[0041] The spacer element receiving opening 4 is designed as a hole having a circular hole diameter between 1 mm and 2 mm, and the cross-sectional area of the support portion 5a may be at least four times the cross-sectional area of the holding portion 5b of the spacer element 5. The spacer element 5 has a diameter d1 between 2.5 mm and 6 mm in the region of the support portion 5a, and the diameter may typically be about 2.5 mm. The spacer element 5 has a diameter d2 between 0.8 mm and 1.5 mm in the region of the holding portion 5b, and the diameter may typically be about 1 mm. The length l1 of the support portion 5a can be, for example, between 1.4 mm and 2.5 mm, and is typically about 1.5 mm. The length l2 of the holding portion 5b can be, for example, between 3.5 mm and 5 mm, and is typically about 4.5 mm.

[0042] The distance between the spacer element receiving opening 4 and the nearest point (position) of the optical unit 3 associated therewith may be 3 mm or less, particularly between 1.5 mm and 3 mm.

[0043] The present invention is not limited to the embodiments shown, but is defined by the full scope of protection of the claims. Individual aspects of the present invention or embodiments can also be adopted and combined with each other. Any reference numbers in the claims are exemplary and are merely useful for making the claims easier to read without limiting the scope of the claims.

Claims

1. A light module (1) for a motor vehicle, in particular a motor vehicle headlight, said light module (1) comprising: - a printed circuit board (2), at least one light unit (3) having a light exit surface (3a) for emitting light and arranged flat on one side of said printed circuit board (2), said light unit (3) preferably comprising at least one LED light source (3b), said printed circuit board plane (yz) being formed by said one side of said printed circuit board (2); at least one light guide (6), the printed circuit board (2) has at least one spacer element receiving opening (4) arranged near the at least one optical unit (3), the at least one spacer element receiving opening (4) penetrating the printed circuit board (2) and configured to receive a spacer element (5); the optical module (1) further comprises at least one spacer element (5) arranged in at least one spacer element receiving opening (4), the at least one spacer element (5) having at least two parts, namely a holding part (5b) passing through the spacer element receiving opening (4) and at least one support part (5a) arranged at one end of the holding part (5b), the support part (5a) being wider than the holding part (5b) to ensure that the spacer element (5) is pushed through the spacer element receiving opening (4), the support part (5a) being arranged on the same side of the printed circuit board (2) as the at least one optical unit (3), the end of the support part (5a) facing away from the printed circuit board (2) being defined by a flat support surface (5a'), the support surface (5a') being oriented substantially parallel to the printed circuit board plane (yz); The light guide (6) has a light entrance surface (6a) facing the light unit (3) to receive light, the light entrance surface (6a) of the light guide (6) is at least partially surrounded by at least one support area (6b) of the light guide (6), and the support area (6b) of the light guide (6) is supported on the support surface (5a') of the spacer element (5) to fix a specified normal distance (d) of the light entrance surface (6a) of the light guide (6) relative to the light unit (3).

2. The optical module (1) of claim 1, wherein the support portion (5a) of the spacer element (5) protrudes further in the normal direction (-x) from the printed circuit board (2) to the printed circuit board plane (yz) than the light exit surface (3a) of the optical unit (3) so that the support surface (5a') protrudes beyond the light exit surface (3a) in the normal direction (-x).

3. 3. An optical module (1) according to claim 1, wherein at least one protrusion (6b'), preferably two protrusions (6b'), are formed in the support region (6b) of the light guide (6), protrude from the light guide (6) in the direction of the support surface (5a') of the spacer element (5) and are supported on the support surface (5a').

4. The optical module (1) according to any one of claims 1 to 3, wherein the holding portion (5b) of the spacer element (5) is designed to fill the spacer element receiving opening (4) by form-fitting.

5. The at least one optical unit (3) is surrounded by at least two, preferably exactly two, spacer element receiving openings (4), which are if there are exactly two spacer element openings (4) in the vicinity of the optical unit (3), the centre point of the notional connecting line between the spacer element openings (4) substantially coincides with the geometric centre of the light exit surface (3a) of the optical unit (3), and / or - An optical module (1) described in any one of claims 1 to 4, wherein when there are three or more spacer element openings (4) in the vicinity of the optical unit (3), they are spatially arranged around the optical unit (3) so that the center of a conceptual polygon substantially coincides with the geometric center of the light exit surface (3a) of the optical unit (3), and the conceptual polygon is formed so that each spacer element opening (4) in the vicinity of the optical unit (3) forms a corner of the polygon, and each corner is linearly connected to the two nearest corners.

6. The optical module (1) has two or more optical units (3), and the two or more optical units (3) at least one or more spacer element receiving openings (4) each having a spacer element (5) housed therein; An optical module (1) according to any one of claims 1 to 5, respectively associated with a light guide (6).

7. The optical module (1) according to any one of claims 1 to 6, wherein the support portion (5a) and the holding portion (5b) of the spacer element (5) are each substantially cylindrical with a common longitudinal axis (x1).

8. An optical module (1) according to any one of claims 1 to 7, wherein the distance between the spacer element receiving opening (4) and the closest point of the associated optical unit (3) is equal to or less than 3 mm, in particular between 1.5 mm and 3 mm.

9. The optical module (1) according to any one of claims 1 to 8, wherein the spacer element receiving opening (4) is designed as a hole with a circular hole diameter of 1 mm to 2 mm.

10. An optical module (1) according to any one of claims 1 to 9, wherein the cross-sectional area of the support portion (5a) is at least four times the cross-sectional area of the holding portion (5b) of the spacer element (5).

11. The optical module (1) according to any one of claims 1 to 10, wherein the holding portion (5b) of the spacer element (5) is firmly fixed to the spacer element receiving opening (4).

12. The optical module (1) according to any one of claims 1 to 11, wherein the spacer element (5) also has a fixing portion (5c), the fixing portion (5c) being arranged at an end of the holding portion (5b) opposite the support portion (5a), and the fixing portion (5c) being spread out relative to the holding portion (5b).

13. A method for manufacturing an optical module (1) according to any one of claims 1 to 12, comprising: a) providing a printed circuit board (2) having at least one optical unit (3), the printed circuit board (2) having at least one spacer element receiving opening (4) extending therethrough and configured to receive a spacer element (5); b) providing at least one spacer element (5), said at least one spacer element (5) having at least two parts, namely a retaining part (5b) passing through said spacer element receiving opening (4) and at least one support part (5a) arranged at one end of said retaining part (5b), said support part (5a) being enlarged compared to said retaining part (5b); c) inserting said at least one spacer element (5) into said at least one spacer element receiving opening (4); d) establishing a connection between said at least one spacer element (5) and said at least one spacer element receiving opening (4), fixing said at least one spacer element (5) against displacement in the normal direction (x) of said printed circuit board (2); e) positioning a light guide (6) having a light incident surface (6a) on the printed circuit board (2) so that the light incident surface (6a) faces the light unit (3) to receive light, wherein the light incident surface (6a) of the light guide (6) is surrounded by at least one support area (6b) of the light guide (6), and the support area (6b) of the light guide (6) is supported on the support surface (5a') of the spacer element (5) to fix a defined normal distance (d) of the light incident surface (6a) of the light guide (6) relative to the light unit (3).

14. 14. The method according to claim 13, wherein the light guide (6) is spatially fixed in position relative to the printed circuit board (2) according to step e).

15. 15. The method according to claim 13 or 14, wherein the at least one spacer element (5) is inserted in step c) in an automated manner using optical detection of the at least one spacer element receiving opening (4).

Images