MICRO-PROJECTION LIGHT MODULE FOR A MOTOR VEHICLE HEADLIGHT, FOR ACHIEVING APLANATIC LIGHT DISTRIBUTION

Abstract

The invention relates to a microprojection light module (1) for a motor vehicle headlight, comprising at least one light source (2) and at least one projection device (3), which images the light exiting the at least one light source (2) into a region in front of the motor vehicle in the form of at least one light distribution, wherein the projection device (3) comprises an entrance lens system (30) including one, two or more micro entrance lenses (31), which are preferably arranged in an array, and an exit lens system (40) including one, two or more micro exit lenses (41), which are preferably arranged in an array, wherein each micro entrance lens (31) is associated with exactly one micro exit lens (41), wherein the micro entrance lenses (31) are designed in such a way and/or the micro entrance lenses (31) and the micro exit lenses (41) are arranged with respect to one another in such a way that substantially all the light exiting the micro entrance lens (31) enters exactly only the associated micro exit lens (41), and wherein the light preshaped by the micro entrance lenses (31) is imaged by the micro exit lenses (41) into a region in front of the motor vehicle as at least one light distribution (LV1to LV5; GLV), wherein a first diaphragm device (50) is arranged between the entrance lens system (30) and the exit lens system (40), wherein at least one second diaphragm device (60, 70) is arranged between the entrance lens system (30) and the exit lens system (40).

Claims

1. A microprojection light module (1) for a motor vehicle headlight, comprising: at least one light source (2); and at least one projection device (3), which images the light exiting the at least one light source (2) into a region in front of the motor vehicle in the form of at least one light distribution, the projection device (3) comprising: an entrance lens system (30) including one, two or more micro entrance lenses (31), which are preferably arranged in an array; and an exit lens system (40) including one, two or more micro exit lenses (41), which are preferably arranged in an array, wherein each micro entrance lens (31) is associated with exactly one micro exit lens (41), wherein the micro entrance lenses (31) are designed in such a way and/or the micro entrance lenses (31) and the micro exit lenses (41) are arranged with respect to one another in such a way that substantially all the light exiting the micro entrance lens (31) enters exactly only the associated micro exit lens (41), and wherein the light preshaped by the micro entrance lenses (31) is imaged by the micro exit lenses (41) into a region in front of the motor vehicle as at least one light distribution (LV1 to LV5; GLV), and wherein a first diaphragm device (50) is arranged between the entrance lens system (30) and the exit lens system (40), and wherein at least one second diaphragm device (60, 70) is arranged between the entrance lens system (30) and the exit lens system (40), the second diaphragm device (60, 70, 80) comprising a diaphragm (61 to 65, 71 to 75, 81 to 89), having at least one respective optically effective diaphragm edge (61 to 65, 71 to 75, 81 to 89), for at least one pair of mutually associated micro entrance and micro exit lenses (31, 41).

2. The microprojection light module according to claim 1, wherein the second diaphragm device (60, 70) is arranged between the first diaphragm device (50) and the exit lens system (40).

3. The microprojection light module according to claim 1, wherein a micro entrance lens (31) and a micro exit lens (41) associated with the micro entrance lens (31) form a micro lens system, the micro lens system having at least one micro lens focal point (F1).

4. The microprojection light module according to claim 3, wherein each micro entrance lens (31) focuses the light passing through it into the at least one micro lens focal point (F1).

5. The microprojection light module according to claim 3, wherein a micro lens focal point (F1) of each micro entrance lens (31) is located in front of the associated micro exit lens (41), in the light exit direction, the micro entrance lenses (31) focusing the light passing through them in the vertical direction onto the respective micro lens focal point (F1) located in front of the micro exit lens (40), and the micro exit lenses (41) having a focal point that coincides with the respective micro lens focal point (F1) of the associated micro entrance lens (31).

6. The microprojection light module according to claim 3, wherein each micro lens system widens the light passing through it in the horizontal direction (H).

7. The microprojection light module according to claim 1, wherein each micro entrance lens (31) is designed as a converging lens, the converging lens causing light to come together in at least one direction.

8. The microprojection light module according to claim 1, wherein each micro exit lens (41) is designed as a projection lens, or as a spherical lens or as an aspherical lens, or as a free-form lens.

9. The microprojection light module according to claim 1, wherein mutually facing interfaces (31, 41) of the mutually associated micro entrance lenses (31) and micro exit lenses (41) are designed so as to be congruent so as to be planar.

10. The microprojection light module according to claim 1, wherein the optical axes (310, 410) of mutually associated micro entrance lenses (31) and micro exit lenses (41) extend parallel to one another and coincide.

11. The microprojection light module according to claim 1, wherein the first diaphragm device (50) is located in a plane spanned by the micro lens focal points (F1), the first diaphragm device (50) comprising a diaphragm (51 to 55) having at least one respective optically effective diaphragm edge (51, 52, 53, 54, 55) for at least one pair of mutually associated micro entrance and micro exit lenses (31, 41).

12. The microprojection light module according to claim 1, wherein the second diaphragm device (60, 70, 80) comprises a diaphragm (61 to 65, 71 to 75, 81 to 89), having at least one respective optically effective diaphragm edge (61 to 65, 71 to 75, 81 to 89), for multiple pairs, and in particular for all pairs, for at least one pair of mutually associated micro entrance and micro exit lenses (31, 41), preferably for multiple pairs and in particular for all pairs, the at least one optically effective diaphragm edge (61 to 65, 71 to 75, 81 to 89) preferably having a gable-like progression, and preferably either all diaphragms of the second diaphragm device (60, 70, 80) having identical diaphragm edges or at least two diaphragms of the second diaphragm device (60, 70, 80) having differently configured diaphragm edges.

13. The microprojection light module according to claim 12, wherein, with respect to the vertical direction (V), a lower optically effective diaphragm edge (61 to 65, 71 to 75) of the diaphragm (61 to 65, 71 to 75) and/or an upper optically effective diaphragm edge (81 to 89) of the diaphragm (81 to 89) comprise two or more curved and/or rectilinear segments.

14. The microprojection light module according to claim 12, wherein the second diaphragm device (60) is arranged in relation to the first diaphragm device (50) in such a way that the diaphragms (61 to 65, 71 to 75, 81 to 89) of the second diaphragm device (60, 70, 80) are offset parallel to the vertical direction (V), in relation to the diaphragms (51 to 55) of the first diaphragm device (50).

15. The microprojection light module according to claim 1, wherein the first diaphragm device (50) and the second diaphragm device (60) are spaced apart in the horizontal direction (H) and/or designed identically and/or in one piece, the second diaphragm device (60) being arranged in a mirrored fashion in relation to the first diaphragm device (50) with respect to a horizontal plane (B-B).

16. The microprojection light module according to claim 1, wherein the first diaphragm device (50) is arranged on the interface (31) of the entrance lens system (30) which faces the exit lens system (40), and the second diaphragm device (60, 70) is arranged on the interface (41) of the exit lens system (40) which faces the entrance lens system (30).

17. The microprojection light module according to claim 1, wherein the entrance lens system (30) and the exit lens system (40) are designed as two separate components.

18. The microprojection light module according to claim 1, wherein the first diaphragm device (50) is designed as a component that is separate from the entrance lens system (30), the exit lens system (40), and the second diaphragm device (60, 70), and the second diaphragm device (60, 70) is designed as a component separate from the entrance lens system (30) and the exit lens system (40).

19. The microprojection light module according to claim 1, wherein the projection device (3) comprising the entrance lens system (30), the exit lens system (40), the first diaphragm device (50) and the second diaphragm device (60, 70) is designed in one piece.

20. The microprojection light module according to claim 1, wherein the at least one light source (2) comprises at least one semiconductor-based light source.

21. The microprojection light module according to claim 1, wherein at least one supplementary lens unit (4) is arranged between the at least one light source (2) and the at least one projection device (3), the at least one light source (2) radiating the light emitted by it into this at least one supplementary lens unit (4), and the supplementary lens unit (4) being designed in such a way that the light exiting therefrom is directed substantially parallel.

22. The microprojection light module according to claim 1, wherein exactly one light source, which comprises exactly one light-emitting diode or exactly one laser diode, is associated with each micro lens system comprising a micro entrance lens (31) and a micro exit lens (41).

23. An illumination device for a vehicle headlight, comprising one, two or more microprojection light modules (1) according to claim 1.

24. The illumination device according to claim 23, wherein two or more groups of microprojection light modules (AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2) are provided, each group comprising one, two or more microprojection light modules (1), microprojection light modules (AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2) of one group generating the same light distribution (LV.sub.AA, LV.sub.AA1, LV.sub.AA2, LV.sub.ss1, LV.sub.BF1 to LV.sub.BF8, LV.sub.FL, LV.sub.ABL, LV.sub.SA1, LV.sub.SA2), and microprojection light modules (AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2) from different groups generating different light distributions (LV.sub.AA, LV.sub.AA1, LV.sub.AA2, LV.sub.ss1, LV.sub.BF1 to LV.sub.BF8, LV.sub.FL, LV.sub.ABL, LV.sub.SA1, LV.sub.SA2), the light sources of each group of microprojection light modules being actuatable independently of the light sources of the other groups, the projection devices (3) of microprojection light modules (AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2) of one group, and in particular of all microprojection light modules, preferably forming a joint component (300).

25. The illumination device according to claim 24, wherein two or more groups for generating different light distributions (LV.sub.AA, LV.sub.AA1, LV.sub.AA2, LV.sub.ss1, LV.sub.BF1 to LV.sub.BF8, LV.sub.FL, LV.sub.ABL, LV.sub.SA1, LV.sub.SA2) are provided, each group forming a different light distribution (LV.sub.AA, LV.sub.AA1, LV.sub.AA2, LV.sub.ss1, LV.sub.BF1 to LV.sub.BF8, LV.sub.FL, LV.sub.ABL, LV.sub.SA1, LV.sub.SA2), which is selected from one of the following light distributions (LV.sub.AA, LV.sub.AA1, LV.sub.AA2, LV.sub.ss1, LV.sub.BF1 to LV.sub.BF8, LV.sub.FL, LV.sub.ABL, LV.sub.SA1, LV.sub.SA2): turning light light distribution; city light light distribution; rural road light light distribution; highway light light distribution; light distribution for auxiliary light for highway light; cornering light light distribution; low-beam light light distribution; low-beam light apron light distribution; light distribution for asymmetrical low-beam light in the far field; light distribution for asymmetrical low-beam light in the far field in cornering light mode; high-beam light light distribution; and no-dazzle high-beam light light distribution.

26. A vehicle headlight, comprising one or more illumination devices according to claim 23.

27. The microprojection light module according to claim 11, wherein the diaphragm has exactly one optically effective diaphragm edge (51, 52, 53, 54, 55) for multiple or all pairs of mutually associated micro entrance and micro exit lenses (31, 41).

28. The microprojection light module according to claim 13, wherein the lower optically effective diaphragm edge (61 to 65, 71 to 75) of the diaphragm (61 to 65, 71 to 75) and/or the upper optically effective diaphragm edge (81 to 89) of the diaphragm (81 to 89) have a triangular or trapezoidal or curved or circular design.

29. The microprojection light module according to claim 20, wherein the at least one semiconductor-based light source comprises one, two or more LEDs and/or laser diodes.

30. The microprojection light module according to claim 20, comprising two or more of the semiconductor-based light sources which are actuatable independently of one another.

31. The microprojection light module according to claim 21, wherein the at least one supplementary lens unit (4) comprises a collimator.

Description

[0087] The invention will be described in more detail hereafter based on the drawings. In the drawings:

[0088] FIG. 1 shows a schematic representation of a microprojection light module according to the invention in an exploded view;

[0089] FIG. 2a shows a schematic representation of a micro lens system of a microprojection light module according to the invention in a perspective view and a vertical cutting plane;

[0090] FIG. 2b shows a sectional view through the micro lens system from FIG. 2a along plane A-A;

[0091] FIG. 2c shows a micro lens system from FIG. 2a, with a horizontal cutting plane;

[0092] FIG. 2d shows a sectional view through the micro lens system from FIG. 2c along plane B-B;

[0093] FIG. 3 shows a schematic representation of a first diaphragm device according to the prior art comprising one, two or more diaphragms;

[0094] FIG. 3a shows a schematic representation of an overall light distribution having aberrations, generated by way of a light module comprising the first diaphragm device according to the prior art from FIG. 3;

[0095] FIG. 3b shows the partial light distributions having aberrations, generated by way of the individual diaphragms of the first diaphragm device according to the prior art from FIG. 3, which together form the overall light distribution from FIG. 3a;

[0096] FIG. 4 shows a first variant of a second diaphragm device according to the invention;

[0097] FIG. 4a shows the partial light distributions having no aberrations, generated by way of the individual diaphragms of the second diaphragm device according to the invention from FIG. 4;

[0098] FIG. 5 shows a second variant of a second diaphragm device according to the invention;

[0099] FIG. 5a shows the partial light distributions having no aberrations, generated by way of the individual diaphragms of the second diaphragm device according to the invention from FIG. 5;

[0100] FIG. 6a shows a schematic detail of a projection device of a light module according to the invention in a single-piece design;

[0101] FIG. 6b shows a schematic detail of a projection device of a light module according to the invention in a two-piece design;

[0102] FIG. 6c shows a schematic detail of a projection device of a light module according to the invention in a four-piece design;

[0103] FIG. 7 shows a schematic representation of an illumination device, composed of a plurality of microprojection light modules according to the invention;

[0104] FIGS. 8a to 8c show different variants of micro lens systems;

[0105] FIG. 9a and FIG. 9b show a schematic arrangement for generating a white overall light distribution, using light sources of different colors; and

[0106] FIG. 10 to FIG. 15 shows different embodiments of the diaphragms of the second diaphragm device.

[0107] FIG. 1 schematically shows a microprojection light module 1 according to the invention for a motor vehicle headlight. The microprojection light module 1 comprises a light source 2 and a projection device 3, which images the light exiting the light source 2 into a region in front of the motor vehicle in the form of at least one light distribution. The shown coordinates denote the light exit direction Z and the horizontal direction H, which is normal to Z and normal to the vertical direction V.

[0108] The terms horizontal and vertical refer to the state in which the microprojection light module is installed in a vehicle headlight mounted in the vehicle.

[0109] The light source 2 is preferably at least one semiconductor-based light source, which comprises one, two or more LEDs and/or laser diodes, for example.

[0110] The light source 2 radiates the light thereof into a supplementary lens 4, such as a collimator, which orients the light of the light source 2 substantially parallel before the light impinges on the projection device 3.

[0111] As shown in FIG. 1, this projection device 3 comprises an entrance lens system 30, which is composed of an array of micro entrance lenses 31, and an exit lens system 40, which is composed of an array of micro exit lenses 41, wherein exactly one micro exit lens 41 is associated with each micro entrance lens 31. Moreover, the projection device comprises a first diaphragm device 50 and a second diaphragm device 60.

[0112] In a light module according to the invention in accordance with FIG. 1, the micro entrance lenses 31 are designed in such a way and/or the micro entrance lenses 31 and the micro exit lenses 41 are arranged relative to each other in such a way that the light exiting a micro entrance lens 31 enters exactly only the associated micro exit lens 41, and wherein the light preshaped by the micro entrance lenses 31 is imaged by the micro exit lenses 41 into a region in front of the motor vehicle as at least one light distribution LV1 to LV5; GLV.

[0113] Furthermore, as is generally apparent from the figures, a first diaphragm device 50 and a second diaphragm device 60 are arranged between the entrance lens system 30 and the exit lens system 40. As will be described in greater detail hereafter, the first diaphragm device 50 can be used to cut the luminous flux passing through the projection device so as to be able to generate one or more light distributions having defined shapes, for example having one or more light-dark boundaries. By using the second diaphragm device 60, the light distribution generated by way of the diaphragm device 50 can be substantially corrected. For example, in the case of a first diaphragm device 50 (see, for example, FIG. 3) provided for generating a low-beam light distribution, the second diaphragm device 60, 70, 80 (FIGS. 4, 5, 13 to 15) is used, among other things, to reduce the chromatic aberrations (longitudinal and/or lateral chromatic aberrations) in the light pattern, these aberrations possibly resulting in a discoloration of the light-dark boundary and being perceived as unpleasant and bothersome by the human eye.

[0114] For the sake of completeness, it shall be noted here that the illustration in FIG. 1 comprising a substantially light first diaphragm device 50 and a substantially dark second diaphragm device 60 provides no information as to the configuration of the diaphragm devices 50, 60. The illustration shall be understood to be purely schematic and is merely intended to demonstrate the presence of a first diaphragm device 50 and of a second diaphragm device 60, and the approximate positions thereof.

[0115] The entrance lens system 30 is a single component, which is formed of the micro entrance lenses 31. The micro entrance lenses 31 directly abut one another, preferably without distance, and form an array, as mentioned above and shown in FIG. 1.

[0116] Additionally, the exit lens system 40 is a single component, which is formed of the micro exit lenses 41. The micro exit lenses 41 directly abut one another, preferably without distance, and form an array, as mentioned above and shown in FIG. 1.

[0117] Moreover, as will be described in greater detail hereafter, the entrance lens system and the exit lens system, optionally together with a respective diaphragm device, can be designed in one piece. For example, the entrance lens system together with the first diaphragm device and the exit lens system together with the second diaphragm device can be designed in one piece.

[0118] FIGS. 2a and 2c show a micro lens system comprising a micro entrance lens 31 and an associated micro exit lens 41, which, as described above, are designed and/or arranged in such a way that light from the shown micro entrance lens 31 exclusively enters the associated micro exit lens 41. The optical axis 310 of the micro entrance lens 31 coincides with the optical axis 410 of the micro exit lens 41. Furthermore, FIG. 2a shows a portion of the first diaphragm device 50 and of the second diaphragm device 60 in the region between the two micro lenses 31, 41.

[0119] From a look at the micro lens systems from FIGS. 2b and 2d, it is apparent, in FIG. 2b, that the micro entrance lens 31 focuses the light passing through it in the vertical direction into a micro lens focal point F1, wherein the micro lens focal point F1 preferably coincides with the focal point of the micro lens system comprising the micro entrance lens 31 and the micro exit lens 41. FIG. 2b thus shows rays located in a vertical plane (namely plane A-A from FIG. 2a), or the projection of rays into this plane A-A.

[0120] The rays exiting the supplementary lens (not shown here) in a parallel manner are thus focused by the micro entrance lens 31 into the micro lens focal point F1, which is located in front of the associated micro exit lens 41, as viewed in the light exit direction.

[0121] As was already mentioned at the outset, it shall be mentioned again here for the sake of completeness that focusing into a focal point is mentioned here, and in general within the scope of the present entire disclosure in other passages, for easier wording. In fact, which is to say in reality, the rays are not focused into a single focal point, but are imaged into a focal surface which includes the aforementioned focal point. This focal surface may be a focal plane; however, in general, this focal surface is not planar, due to aberrations and corrections of a higher order, and these corrections, in addition to the paraxial approximation, must be taken into account in the consideration of the light propagation of rays that form a large angle with respect to the optical axis, but instead this focal surface may also have a curved shape, which is to say the rays are imaged into a curved surface which includes the focal point. The curvature of the focal surface results in defects in the generated light distribution (see FIG. 3a and FIG. 3b).

[0122] Each micro lens system thus has a focal point F1, which is located between the entrance lens system and the exit lens system, and into which light of the associated micro entrance lens is preferably focused.

[0123] Moreover, the micro exit lens 41 has a focal point, this focal point coinciding with the micro lens focal point F1 and with the focal point of the micro entrance lens 31 of the associated micro exit lens 41. Light is thus focused into the focal point F1 and subsequently, upon passing through the associated micro exit lens 41, is collimated accordingly in the vertical direction and projected into a region in front of the vehicle, as is schematically illustrated in FIG. 2b.

[0124] FIG. 2d furthermore shows the behavior in the horizontal direction, which is to say rays are considered which are located in a horizontal plane, such as in plane B-B from FIG. 2c, or the projection of rays into this plane. As is apparent from FIG. 2d, each micro lens system, comprising the micro entrance lens 31 and the micro exit lens 41, widens the light passing through it in the horizontal direction. For this purpose, each micro lens system focuses the light passing through this micro lens system in the horizontal direction onto a focal point F2, which is located behind the micro exit lens 41 (in the main radiation direction). The light is thus scattered in the horizontal direction, so as to achieve the desired width of the partial light distributions of the individual micro lens systems.

[0125] It shall be noted again here that idealized optical systems are described here; in practice, both the first lens system (micro entrance lens) and the second lens system (micro exit lens) of a micro lens system are often implemented in a free-form design, resulting in imaging, as described above, into a focal surface. Furthermore, at least a portion SL of the light will exit from a micro lens system between the micro entrance lens 31 and the associated micro exit lens and scattered into a micro lens system adjoining the micro lens system (FIG. 2b). This results in what is known as crosstalk between the micro lens systems, whereby a defective light distribution (see 3a, 3b) is generated. An essential feature of the above-described micro lens systems is that these widen the light passing through them in the horizontal.

[0126] The micro entrance lenses 31 are preferably designed as converging lenses, which cause the light to come together in the vertical and/or horizontal directions. The micro entrance lenses 31 can be designed as free-form lenses, for example.

[0127] The use of micro entrance lenses that converge light in the vertical direction V and/or in the horizontal direction H depends on the particular application of the microprojection light module. For example, micro entrance lenses 31 that converge the light in the vertical direction V (FIG. 2b) and leave it substantially defocused in the horizontal direction H (FIG. 2d), or even widen it, can be used to generate a wide light distribution (for example, of a low-beam light distribution). The micro exit lenses 41 can be arranged in such a way that the focal points thereof coincide, in the vertical direction V, with the focal point F1 of the corresponding micro entrance lenses. This may cause the light exiting the micro lens systems to be focused in the horizontal direction H into the focal point F2, wherein these focal points F2 are substantially located in a horizontal plane. As a result of the focal points F2 substantially located in a horizontal plane being arranged a small distance behind the micro exit lenses, each micro lens system widens the light beam passing through this micro lens system, as is apparent from FIG. 2d, for example. A small distance here shall be understood to mean a size in the millimeter to centimeter range, for example in a range of 1 mm to 10 cm, which is small compared to the distance at which lighting-related measurement in motor vehicle construction is carried out (a light distribution radiated by a motor vehicle headlight is usually measured on a measuring screen positioned at a distance of 25 meters transversely to the main radiation direction). Micro entrance lenses converging light both in the horizontal direction and in the vertical direction can be used to generate a less wide light distribution, for example a high-beam light partial distribution. Each micro entrance lens would thus focus the light both in the vertical and in the horizontal direction onto a focal point, the focal point being located in front of the micro exit lens. In this way, widening of the light beam passing through the micro lens system in the horizontal direction can be avoided, and a substantially oval (with a projection onto the aforementioned screen) light distribution can be generated, which can be used, for example, to generate a high-beam light distribution.

[0128] The micro exit lenses 41 are usually designed as projection lenses, which is to say as spherical or aspherical lenses. It may also be provided that the micro exit lenses 41 are free-form lenses.

[0129] At this point, FIGS. 8a to 8c shall be briefly referenced: above and in the description hereafter, it is assumed that each micro entrance lens 31 and each micro exit lens 41 is formed of a respective single lens. However, it may also be provided that either the micro entrance lenses 31 and/or the micro exit lenses 41 themselves each again comprise one, two or more lenses or optical elements. Each of these micro micro optical elements of a micro lens must have the same focal plane for this purpose. For example, one or both micro lenses can be Fresnel lenses, which have different optically effective regions. Each of the optical regions (micro micro lens) of a micro entrance lens can, but does not have to, radiate light into each micro micro exit lens.

[0130] FIG. 8a shows an example in which the micro entrance lens 31 in a micro lens system is designed as a Fresnel lens, and the micro exit lens 41 is designed as a conventional lens.

[0131] FIG. 8b shows an example in which the micro entrance lens 31 is designed as a conventional lens, and the micro exit lens 41 is designed as a Fresnel lens.

[0132] FIG. 8c shows an example in which the micro entrance lens is designed as a conventional lens, and the micro exit lens is designed as an array of micro lenses.

[0133] FIGS. 8a to 8c show only a few conceivable variants, combinations or other subdivisions of the micro lenses and the diaphragm devices. What is important is that the second diaphragm device 60, 70 is arranged in the light propagation direction between the first diaphragm device 50 and the micro exit lens 41 and acts as an aperture stop. The position of the second diaphragm device 60, 70 can thus not be freely selected in the beam path. The first diaphragm device 50 is a field diaphragm/field stop. With respect to the quality of the light pattern, it is advantageous to dispose the first diaphragm device in the focal surface or in the intermediate image plane of the micro lens system.

[0134] Furthermore, as is apparent from FIGS. 2a and 2c, the mutually facing interfaces 31, 41 of mutually associated micro entrance lenses 31 and micro exit lenses 41 are designed so as to be congruent, and preferably are also arranged congruently with respect to one another.

[0135] It is also expedient when the interfaces 31, 41 are planar.

[0136] In the example shown, the interfaces 31, 41 are square; other possible shapes are rectangular or hexagonal.

[0137] The optical axes 310, 410 (FIGS. 2b, 2d) of mutually associated micro entrance lenses 31 and micro exit lenses 41 advantageously extend parallel to one another, wherein it is in particular advantageous when the optical axes 310, 410 coincide.

[0138] The first diaphragm device 50 is located in a plane spanned by the micro lens focal points F1.

[0139] The diaphragm device 50 preferably comprises a respective diaphragm for each micro lens system (see FIGS. 2a, 2c), the diaphragm having one or more optically effective diaphragm edges.

[0140] The second diaphragm device 60 is located between the first diaphragm device 50 and the exit lens system 40. The second diaphragm device 60 preferably comprises a respective diaphragm for each micro lens system (see FIGS. 2a, 2c), the diaphragm having one or more optically effective diaphragm edges and being used to prevent scattered light SL (FIG. 2b) from passing through.

[0141] FIGS. 2a, 2c show a micro lens system, which is associated with a first diaphragm 52 having an optically effective diaphragm edge 52, and a second diaphragm 62 having a further optically effective edge 62. The light passing through this system is initially cut in keeping with the first diaphragm edge 52, and the diaphragm edge 52 is imaged as a light-dark boundary in the light pattern. Furthermore, the light is cut in keeping with the second diaphragm edge 62 in such a way that no crosstalk takes place between the individual micro lens systems, and the aberrations of the light distribution GLV caused by the curvature of the focal surface (see FIGS. 3a, 3b) are eliminated.

[0142] The first diaphragm device 50 and the second diaphragm device 60 comprise a diaphragm for at least one pair of mutually associated micro entrance and micro exit lenses 31, 41. The first diaphragm device 50 and the second diaphragm device 60, however, preferably comprise a diaphragm 51, 52, 53, 54, 55 or 61, 62, 63, 64, 65, having at least one respective, and for example exactly one, optically effective diaphragm edge 51, 52, 53, 54, 55 or 61, 62, 63, 64, 65, for multiple pairs, and in particular for all pairs.

[0143] The first diaphragm device 50 known from the prior art is schematically illustrated in FIG. 3. FIG. 3 shows the first diaphragm device 50 in a view from the front, wherein the first diaphragm device 50 comprises five different types of diaphragms 51 to 55. Each of these diaphragms 51 to 55 is made of an opaque material 51 to 55, which includes exactly one (as shown) or more (not shown) translucent through-passages 51 to 55 through which light is able to pass. The diaphragm edges 51, 52, 53, 54, 55 of the diaphragms are imaged in the respective partial light pattern as top light-dark boundaries, which delimit the light pattern toward the top.

[0144] Each of these diaphragms is associated with exactly one micro lens system, and when all micro lens systems are irradiated with light, an overall light distribution GLV, as shown schematically in FIG. 3a, is obtained as the superimposition of all partial light distributions. In the shown example, the overall light distribution GLV is a low-beam light distribution having an asymmetrical light-dark boundary.

[0145] FIG. 3b shows one each of the diaphragms 51 to 55 and, to the left of the diaphragms, it schematically shows the respective partial light distribution LV1 to LV5 generated therewith.

[0146] It is clearly discernible that aberration sub-regions X1, X2, X3, X4, X5, X6 are created in the partial light distributions LV2, LV4, LV5 as a result of aberrations and crosstalk between adjoining micro lens systems, the superimposition of these aberration sub-regions resulting in the creation of major aberration regions Y1, Y2, Y3 in the overall light distribution GLV.

[0147] FIG. 4 shows a second diaphragm device 60 according to the invention, with the aid of which aberrations are eliminated. The second diaphragm device 60 is shown in a front view. Five different types of diaphragms 61 to 65 are apparent, which the second diaphragm device 60 comprises. Each of these diaphragms 61 to 65 is made of an opaque material 61, 62, 63, 64, 65, which includes exactly one (as shown) or more (not shown) translucent through-passages 61, 62, 63, 64, 65 through which light is able to pass. As a result of the through-passages, the light pattern, which was already cut with the aid of the first diaphragm device, is cut further in such a way that aberration sub-regions X1 to X6, and consequently also major aberration regions Y1, Y2, are no longer present in the generated partial light distributions and light distributions. This is achieved by the shaping of the diaphragm edges. It has proven to be particularly advantageous to have a gable-like design of the lower diaphragm edge 62, 63, 64, 65 of the diaphragms, but generally a shape that ascends obliquely from the center outward. These are imaged in the respective partial light pattern as top light-dark boundaries, which delimit the light pattern toward the top. The opaque regions 61 to 65 are designed and configured in such a way that no crosstalk takes place between the micro lens systems, which is to say no scattered light SL (portion SL of the light in FIG. 2d) from one micro lens systems finds its way into the adjoining micro lens system. In this way, the aberration Y2 is reduced or eliminated.

[0148] FIG. 4a shows one of the diaphragms 61 to 65 and, to the left of the diaphragms, it schematically shows the respective partial light distribution LV1 to LV5 generated therewith, without aberrations X1 to X6, Y1, Y2.

[0149] FIG. 5 shows a further exemplary embodiment of the second diaphragm device 70 according to the invention. Compared to the second diaphragm device 60 from FIGS. 4 and 4a, at least a portion of the diaphragms 73a to 73d and 75a to 75f of the second diaphragm device 70 from FIG. 5 has a respective translucent through-passage 73a to 73d and 75a to 75f. The diaphragms 73a to 73d and 75a to 75f are arranged in such a way that the light passing through the through-passages 73a to 73d and 75a to 75f thereof forms partial light distributions LV3 and LV5 (FIG. 5a), wherein the partial light distributions LV3 and LV5 contribute to a region in the center of the overall light distribution, which is to say around the desired maximum of the illumination intensity of the radiated light distribution, in which a higher illumination intensity is required, for example.

[0150] The embodiment of the second diaphragm device 70 shown in FIG. 5 is particularly advantageous since, for example, the use of the second diaphragm device 60 from FIG. 4 would cause the majority of the luminous flux to be shadowed and therefore, for example, statutory luminous flux values would not be achieved at the HV point. The reason for this is that the light necessary for generating the partial light distributions LV3 to LV5 is strongly focused in the focal surface or intermediate image plane of the projection device. The further propagation of the ray takes place in such a way that some of the rays are able to form a large angle with respect to the optical axis, so that the through-passages 73a to 73d and 75a to 75f of the second diaphragm device 70 have to be very large to allow a sufficient amount of light to pass through.

[0151] In this way shown in FIGS. 4, 4a, 5, 5a, for example, an aberration-free low-beam light distribution can be generated by way of a light module according to the invention, wherein individual micro lens systems each generate a defined contribution to the aberration-free low-beam light distribution in the form of an aberration-free partial light distribution.

[0152] These light modules can additionally be used to generate arbitrary aberration-free overall light distributions. As a result of the group-wise illumination of micro lens systems comprising the first and second diaphragms by way of at least one respective dedicated light source, it is possible to specifically activate (or suppress) predefined aberration-free partial light distributions (determined by the shape of the diaphragm edge), whereby a dynamic light distribution can be generated, for example.

[0153] The design of the entrance lens(es) and exit lens(es), in some circumstances, may only allow limited shaping of the light distribution. By using preferably standardized diaphragms, as described above, it is possible to generate one, two or more partial light distributions, which result in the desired overall light distribution when appropriately selected.

[0154] The diaphragms can also be designed as individual diaphragms, for example, which form the diaphragm device; preferably, however, as is shown, these are diaphragm device components, such as flat foils and the like, in which corresponding openings/through-passages for light to pass through are provided.

[0155] With respect to the arrangement of the second diaphragm device 60, 70, care must be taken to ensure that this is correctly positioned with respect to the first diaphragm device 50. This means that, when both diaphragm devices are installed, the types of diaphragms of the second diaphragm device 60, 70 should correspond to the particular types of the first diaphragm device 50, as is apparent from FIGS. 2a and 2c, for example. With reference to FIG. 3, FIG. 4 and FIG. 5, the diaphragms of the first diaphragm row 51 of the first diaphragm device 50 should correspond to the diaphragms of the first diaphragm row 61, 71 of the second diaphragm device 60, 70, the diaphragms of the second diaphragm row 52 of the first diaphragm device 50 should correspond to the diaphragms of the second diaphragm row 62, 72 of the second diaphragm device 60, 70, and so forth.

[0156] As was already briefly addressed above, it may be provided in a first embodiment of the invention, as shown in FIG. 6a, that the projection device 3 comprising an entrance lens system 30 and an exit lens system 40 of a first diaphragm device 50 and a second diaphragm device 60, 70 is designed in one piece. The lens body is a plastic lens, for example, which was deliberately carbonized to implement diaphragm devices. Such carbonization can take place, for example, by way of laser beams or electron beams and the like.

[0157] In a second variant, which is shown in FIG. 6b, it is provided that the projection device 3 is formed of two separate components, these being an entrance lens system 30 and an exit lens system 40, which typically are also arranged at a distance from one another. It is advantageous when the first diaphragm device 50 is arranged on the interface 31 of the entrance lens system 30 which faces the exit lens system 40, and the second diaphragm device 60, 70 is arranged on the interface 41 of the exit lens system 40 which faces the entrance lens system 30.

[0158] A diaphragm device can be generated by vapor coating one of the interfaces 31 or 41, or by applying an absorbing layer, which thereafter is deliberately removed again, such as way by way of laser beams. It is also conceivable to apply an exit lens system onto an entrance lens system thus provided with a diaphragm device, for example, by way of two-component injection molding, so that ultimately one component is obtained again.

[0159] However, in this case it may also be provided that both diaphragm devices 50, 60, 70 are designed as components configured separately from the entrance lens system 30 and the exit lens system 40, as is shown in FIG. 6c. In this case, the diaphragm devices 50, 60, 70 can be inserted in the form of a precise mask, for example made of metal (shadow mask, slot mask, screen and the like).

[0160] The variants shown in FIGS. 6a to 6c can, of course, be combined. So as to be able to set the projection device 3 (distances of the focal planes, orientation of the optical axis and the like), for example, it may be advantageous to design the second diaphragm device 60, 70 separately from the exit lens system 40, the first diaphragm device, however, in one piece with the entrance lens system 30, or the first diaphragm device 50 in one piece with the second diaphragm device 60, 70, but separately from the entrance lens system 30 and the exit lens system. With respect to the quality of the light pattern, it is advantageous when the first diaphragm device 50 is located in the surface area spanned by the focal points of the micro lens systems, which forms the focal surface of the projection device 3. The light pattern is then defined by the shape of the first diaphragm device 50, and is corrected by the second diaphragm device 60, 70 and brought into an aberration-free state.

[0161] It shall be noted at this point that the inner surfaces of the lens systems 30, 40 are planar in the existing figures, while the outer surfaces are curved. In principle, it is also possible for one inner surface or both inner surfaces of the lens systems 30, 40 to be curved; however, this is only possible with a two-piece or multi-piece configuration.

[0162] A one-piece configuration has the advantage that, after production, which must be carried out with precision, a single, stable component is available, which can be installed without difficulty.

[0163] In a conventional projection system comprising a projection lens, the lens typically has a diameter between 60 mm and 90 mm. In a module according to the invention, the individual micro lens systems have typical dimensions of approximately 2 mm2 mm (in V and H), and a depth (in Z) of approximately 6 mm to 10 mm, resulting in a considerably smaller depth of a module according to the invention in the Z direction compared to conventional modules.

[0164] The light modules according to the invention have a lower depth and, in general, can be shaped freely, which is to say it is possible, for example, for a first light module for generating a first partial light distribution to be configured separately from a second light module for a second partial light distribution, and to dispose these offset from one another relatively freely, which is to say vertically and/or horizontally and/or in terms of depth, so that design specifications are also easier to implement.

[0165] It is a further advantage of a light module according to the invention that, while the projection device must be produced with very high precision, which is easily possible with current manufacturing methods, the exact positioning of the light source(s) in relation to the projection lens is eliminated. Exact positioning is of lesser importance in so far as the at least one light source illuminates an entire array of micro entrance lenses, which all essentially generate the same light pattern. In other words, this means nothing other than that the actual light source is formed by the real light source(s) and the array of the micro entrance lenses.

[0166] This actual light source then illuminates the micro exit lenses and, if necessary, the associated diaphragms. However, since the micro entrance and micro exit lenses are already optimally matched to one another, these forming essentially a system, less than exact positioning of the real light source(s) carries less weight.

[0167] FIG. 7 shows an illumination device for a vehicle headlight, which comprises one, two or more microprojection light modules as described above. Multiple groups of different light modules are provided, for example FIG. 7 shows light modules of groups AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2, which together form the illumination device. Each group AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2 comprises one, two or more light modules.

[0168] In the example shown, each group comprises exactly one light module, which are listed hereafter: They are denoted as follows:

[0169] AA a light module for generating an asymmetrical aberration-free low-beam light LV.sub.AA in the far field;

[0170] AA1, AA2 aberration-free asymmetrical low-beam light LV.sub.AA1, LV.sub.AA2 in the far field in the cornering light module;

[0171] SS1 light module for generating a symmetrical aberration-free light distribution LV.sub.ss1 (apron of a low-beam light, city light);

[0172] BF1 to BF8 light modules for generating an aberration-free and no-dazzle high-beam light LV.sub.BF1 to LV.sub.BF8; the individual aberration-free light distributions LV.sub.BF1 to LV.sub.BF8 together generate an aberration-free high-beam light distribution, or a portion thereof, and the individual aberration-free light distributions can be suppressed independently of one another, if needed;

[0173] FL a light module for generating an aberration-free high-beam light LV.sub.FL;

[0174] ABL a light module for generating an aberration-free turning light LV.sub.FL;

[0175] SA1, SA2 additional light components for aberration-free highway light LV.sub.sA1, LV.sub.SA2.

[0176] It is advantageous with such an illumination device when the light sources of each group of light modules AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2 can be actuated independently of the light sources of the other groups, so that the individual aberration-free light distributions, or partial light distributions, can be switched on and off and/or dimmed independently of one another.

[0177] FIG. 7 is a purely schematic representation, and reference is made to light modules in connection with FIG. 7. In fact, FIG. 7 shows only and purely schematically the projection devices AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2 of the individual micro projection light modules and, as is apparent from FIG. 12, the projection devices AA, AA1, AA2, SS1, BF1 to BF8, FL, ABL, SA1, SA2 of the individual light modules form a joint component, for example in the form of a curved ribbon. These projection device can be arranged on a foil, for example.

[0178] It is thus possible, by way of the present invention, to freely form the lens arrays from micro entrance and micro exit lenses, and it is also possible to combine two or more light modules according to the invention via a joint projection device component to form an illumination device, wherein then preferably the micro lens systems are designed to be identical in the regions of the projection device component which are associated with a particular light module (and thus with an independently actuatable light source).

[0179] FIG. 9a and FIG. 9b show two further embodiments. It is provided that different regions, for example exactly three different regions, of micro lens systems 3 are illuminated with light sources 2 of different colors R, G, B, for example one region with red light R, another region with green light G, and a third region with blue light B.

[0180] The different regions can belong to one projection device 3 (FIG. 9a), but also to different (two or more, such as three, as shown in FIG. 9b) projection devices, or to one projection device or to two or more, and in particular three, projection devices. It is only important that each region of micro lens systems generates the same light distribution as the other regions. So as to take the above-described chromatic aberrations into account, it is provided in the projection device from FIG. 9a that the first diaphragm device comprises three partial diaphragm devices 50R, 50G, 50B, wherein each partial diaphragm device is arranged in the focal surface corresponding to the respective color. The focal points of the micro lens systems for the red light L are thus, as seen in the light propagation direction, located further forward than the focal points of the micro lens systems for the green light G, which, in turn, are located in front of the focal points of the micro lens systems for the blue light B, as is apparent from FIG. 9a.

[0181] The embodiment shown in FIG. 9a has the advantage that all light sources, which emit light of different colors, are associated with a single, preferably one-piece, entrance lens system. It may also be provided that the first diaphragm device and/or the second diaphragm device comprise three partial diaphragm devices, which can be used to correct the chromatic aberrations.

[0182] In the embodiment shown in FIG. 9b, there are three projection devices 3R, 3G, 3B, which can be designed in one piece or separately from one another. The first diaphragm device 50 and the second diaphragm device 60, 70 are provided. In the example, the projection devices differ in the shape of the entrance lens systems 30R, 30G, 30B, which are designed in such a way that the focal surfaces of the three projection devices 3R, 3G, 3B, each corresponding to one color, coincide. This effect can be achieved, for example, by adapting the thicknesses and/or the curvatures of the micro entrance lenses forming the entrance lens systems. By varying the thicknesses and/or the curvatures of the micro entrance lenses, the focal distances of the micro lens systems are changed, whereby the distance between the interface 31 of the entrance lens system 30 which faces the exit lens system 40 and the focal surface can be established independently of the color of the light R, G, B, as is shown in FIG. 9b. The first diaphragm device 50 from FIG. 9b, which preferably has a one-piece design, is arranged in the coinciding focal surfaces of the projection devices 3R, 3G, 3B. The embodiment shown in FIG. 9b has the advantage of offering great design freedom, which can be ensured, for example, by three projection devices 3R, 3G, 3B designed separately from one another.

[0183] Superimposing the aberration-free light patterns from the different regions then, in the overall, yields a white aberration-free light pattern.

[0184] If laser light sources are used as light sources in this connectionsee, in particular, also the explanations provided above - only few microprojection arrays (regions) are required to generate a white light distribution due to the high light intensities of lasers, so that a smaller light module can be created in the lateral direction.

[0185] Finally, it shall be noted that the diaphragms of the second diaphragm device can have differently configured lower (for correcting the aberrations Y1, Y2 from FIG. 3a) and/or upper (for correcting the aberration Y3 from FIG. 3a) optically effective diaphragm edges. This is addressed in FIGS. 10 to 15. FIG. 10 shows examples of diaphragms of the second diaphragm device 60, the lower diaphragm edges of which are designed as a triangular gable, which extends downwardly from the optical axis. FIG. 11 shows diaphragms, the lower diaphragm edges of which are designed as a segment of an ellipse (an elliptical arc), in particular of a circle (a circular arc). The diaphragms of FIG. 12 have lower diaphragm edges that comprise three diaphragm edge segments (for each of the shown diaphragms). Two diaphragm edge segments are designed as elliptical arcs or circular arcs curved inwardly toward the diaphragm stop, and are arranged mirror-symmetrically with respect to the vertical center line M extending through the optical axis. The third diaphragm edge segment is designed as a straight line. The embodiments of the lower diaphragm edges just described can help correct the above-described aberrations Y1, Y2 from FIG. 3a. The exact shape of the lower diaphragm edges of the second diaphragm device 60 can be adapted to the beam path between the micro entrance lens and the micro exit lens. However, it is advantageous when the lower diaphragm edges comprise at least two sections that steadily transition into one another, wherein the first (considered from left to right) section (in relation to the vertical direction V) is descending and the last section is ascending. FIG. 13 shows examples of diaphragms of the second diaphragm device 80, the upper diaphragm edges 81 to 83 of which are trapezoidal. The lower diaphragm edges are designed identically to the lower diaphragm edges of FIG. 10. FIG. 14 shows diaphragms, the upper diaphragm edges 84, 86 of which are designed as a segment of an ellipse (an elliptical arc), in particular of a circle (a circular arc). Moreover, FIG. 14 shows an upper diaphragm edge 85, which essentially has a curved gable-like progression. This gable-shaped progression (directed to the outside of the diaphragm stop) can have a steep, flat or normal shape. The progression of the lower diaphragm edges of FIG. 14 is substantially identical to the progression of the lower diaphragm edges of FIG. 11. The diaphragms of FIG. 15 have lower diaphragm edges that have a shape substantially identical to that of the lower diaphragm edges of FIG. 12. The upper diaphragm edges 87 to 89 are trapezoidal, as is the case in FIG. 13. The embodiments of the upper diaphragm edges just described can help correct the above-described aberrations Y3 from FIG. 3a. The exact shape of the upper diaphragm edges of the second diaphragm device 60, 70, 80 can be adapted to the beam path between the micro entrance lens and the micro exit lens. However, it is advantageous when the upper diaphragm edges comprise at least two sections that steadily transition into one another, wherein the first (considered from left to right) section (in relation to the vertical direction V) is ascending and the last section is descending.