Automotive lighting system for vehicles

Abstract

The present invention relates to the field of automotive lighting, and in particular to an automotive lighting system for a vehicle. The automotive lighting system for a vehicle comprises: a plurality of light sources; a plurality of primary optics, each being a reflector, arranged in a matrix and configured to receive and redirect light from the plurality of light sources; and a secondary optics configured to receive the redirected light from the plurality of primary optics and project the received light in front of the vehicle. Further, each light source is disposed in a focal plane of a corresponding one of the plurality of primary optics, and at least one of the plurality of primary optics is disposed in a focal plane of the secondary optics.

Claims

1. An automotive lighting system for a vehicle, comprising: a plurality of light sources on a first optical axis; a plurality of primary reflective optics in a matrix and configured to receive and redirect light from the plurality of light sources, each of the plurality of light sources being at a focal point of a corresponding one of the plurality of primary optics with each of the plurality of light sources in a focal plane of the corresponding one of the plurality of primary optics, the plurality of primary optics being configured to fold a direction of the propagation of the light from the plurality of light sources; and a secondary optic on a second optical axis and oriented in a different plane than the first optical axis, the secondary optic configured to receive the folded light from the plurality of primary optics and project the received light in front of the vehicle, with at least one of the plurality of primary optics in a focal plane of the secondary optic.

2. The automotive lighting system according to claim 1, wherein the secondary optic comprises a projection lens.

3. The automotive lighting system according to claim 1, wherein one of the plurality of primary optics is disposed at a focal point of the secondary optic.

4. The automotive lighting system according to claim 3, wherein the other ones of the plurality of primary optics are all disposed in the focal plane of the secondary optic.

5. The automotive lighting system according to claim 1, wherein the reflector of at least one of the plurality of primary optics has a shape of a paraboloid with a rectangle contour.

6. The automotive lighting system according to claim 5, wherein the rectangle contour has a side length in a range of 3-15 mm.

7. The automotive lighting system according to claim 1, wherein at least one of the plurality of light sources is rotatable for maximizing light emitted therefrom and impinging onto the plurality of primary optics.

8. The automotive lighting system according to claim 7, wherein the at least one rotatable one of the plurality of light sources is rotatable around an axis parallel to a row or column of the matrix of primary optics.

9. The automotive lighting system according to claim 1, further comprising: a switching circuit configured to turn off one or more of the plurality of light sources such that no light is emitted therefrom.

10. The automotive lighting system according to claim 1, wherein at least one of the plurality of primary optics has a focal length in a range of 5-10 mm.

11. The automotive lighting system according to claim 1, wherein the secondary optic has a focal length in a range of 30-50 mm.

12. The automotive lighting system according to claim 1, wherein at least one of the plurality of light sources comprises one or more sub-light sources.

13. The automotive lighting system according to claim 1, wherein the folding of the light enables the lighting system size to be reduced.

14. The automotive lighting system according to claim 1, wherein the folding of the light enables the lighting system size to be comp act.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the present invention will be described in the following in more detail, with reference to the appended drawings showing embodiments and forming a part of the present invention. Specifically, in the drawings:

(2) FIG. 1 schematically illustrates a cross section view for one of the conventional primary optics as currently used in some Mercedes Benz vehicles;

(3) FIG. 2 schematically illustrates a perspective view for an automotive lighting system according to an embodiment of the present invention, where a row of reflectors but only one light source are included so as to not obscure the drawing;

(4) FIG. 3 schematically illustrates a cross section view for an automotive lighting system according to an embodiment of the present invention, where only one reflector and one LED light source are included; and

(5) FIGS. 4(a) and 4(b) schematically show a simulated light intensity distribution (or beam pattern) as projected into the far field respectively when all the light sources keep emitting light and when only two of them are turned-on.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) While the present invention is susceptible of embodiments in different forms, there is shown in the drawings and will be described in detail hereinafter one or more specific embodiments, with understanding that the present description is to be considered as only exemplary of the basic principle of the present invention and not intended to limit the present invention to any specific embodiments as shown and described herein.

(7) In the following, by referring to FIGS. 2 and 3, a detailed description will be given with regard to the automotive lighting system for a vehicle as proposed in an embodiment of the present invention, where a perspective view and a cross section view are shown respectively in FIGS. 2 and 3 for the automotive lighting system which is suitable for use in vehicles.

(8) As shown in FIG. 2, the automotive lighting system 20 can comprise specifically a plurality of light sources 21 (where only one of them is depicted for clarity), a plurality of primary optics 21, and a secondary optics 23. As can be seen, the plurality of primary optics 21 are disposed in an array. To be specific, the total number of primary optics 21 as illustrated schematically in FIG. 2 is seven. That is to say, the primary optics 21 is disposed in a 1×7 array. However, as explained above, this specific number of 7 as shown in FIG. 2 should never be deemed in a limited sense for the present invention. As a matter of fact, the plurality of primary optics 21 can be also arranged broadly in a matrix form, where more than one row and more than one column are included. Further, as can be seen in FIG. 2, each of the primary optics 21 is designed to be in a paraboloid form with a rectangle contour. Also, among all these paraboloid primary optics 21 as shown in FIG. 2, all of them are chosen as a reflector. As for positions of the primary optics 21, they are all located in a focal plane of the secondary optics 23. As a preferred instance, only one of the primary optics 21, such as the center one, can be located at a focal point of the secondary optics 23, and the rest are all located around in the corresponding focal plane. Apparently, putting the center primary optics at a focal point of the secondary optics 23 is provided merely as one of numerous implementations for the specific positioning of the primary optics 21. The present invention is susceptible to various alternatives, such as putting a peripheral primary optics at the focal point of the secondary optics 23.

(9) In order to elaborate in more detail about the working process and, specifically, the light propagation within the automotive lighting system 20 as proposed by the present invention, a cross section view of the lighting system 20 is schematically shown in FIG. 3. It should be noted that in FIG. 3, only the primary optics, i.e., reflector 32, located at a center position of the matrix, is illustrated. Moreover, the center reflector 32 is disposed further at a focal point F2 of the secondary optics, and in this case, a projection lens 33 is used as the secondary optics. As for the light source used for providing light input to the reflector 32, a light emitting diode (LED) 31 may be selected and positioned at a focal point F1 of the reflector 32.

(10) In FIG. 3, lines with arrows are also included so as to show schematically how the light emitted from the LED 31 propagates within the automotive lighting system 30. As can be seen, light as emitted from the LED 31 is firstly incident on the reflector 32. After being reflected by the reflector 32, the reflected light is then going to impinge onto the secondary projection lens 33, where the projection lens 33 is configured to project the light as received from the reflector onto a road in front of the vehicle. It should be pointed out that all the lines with arrows as depicted in FIG. 3 are only used to represent schematically, but not necessarily accurately, the propagation path of light. In practical implementations, the actual light path is dependent not only on the positions of various components such as LED 31, reflector 32, and projection lens 33, but also on the structural and/or optical parameters thereof, such as the curvature and/or reflectivity at different portions of the reflector 32. In other words, the portion of beam pattern as reflected by the center reflector 32 and projected then by the projection lens 33 are determined by any of the above mentioned factors, either individually or in any combination. This should be easily understood by a skilled person in the art. Therefore, the portion of beam pattern, corresponding to such as the center reflector 32, as desired in shape and/or light distribution, can be obtained, for example, by selecting suitable curvatures and/or reflectivity for different parts of the reflector 32. In a preferred embodiment of the present invention, the reflector 32 can be designed to be a freeform, and possibly curved, reflector 32, whose structural and optical parameters help to project more light onto the road near the vehicle than in the far field. In this way, a desirable low beam pattern is facilitated, while still avoiding glare for the drivers of oncoming cars.

(11) According to an optional embodiment of the present invention, the LED 31 as shown in FIG. 3 can be further configured to be rotatable, for example around a rotation axis thereof perpendicular to an optical axis of the projection lens 33. Alternatively, the LED 31 is rotatable around an axis being parallel to an extension direction of the array of reflectors 32, i.e., an axis passing through the LED 31 itself and being perpendicular to the paper as shown in FIG. 3. Rotating the LED 31 in this way helps to find an optimal orientation of the LED 31 relative to the reflector 32 such that light emitted from the LED 31 is maximally incident onto the reflector 32. In this case, an improved and further maximized utilization of light is allowed. Although only one LED 31 is shown in FIG. 3 in connection with its corresponding reflector 32, the above described rotation of LED 31 can be applied to any other light sources in the entire lighting system 30. After rotation, light emitted from each and every light source in the whole system 30 will be used efficiently, contributing to a high efficiency of the automotive lighting system 30.

(12) As mentioned above in the previous section and referring back to FIG. 2, one or more of the light sources 21 may not emit light due to receipt of a turn-off signal from a switching circuit (not shown in the figures). In this case, one or more of the primary optics 22 as arranged in a matrix, such as in an array of FIG. 2, corresponding to those turned-off light sources 21, will not receive sufficient light input, and thus reflect little or none light towards the secondary optics 23. If this is the case, the part of beam pattern, which would otherwise originate from the turned-off light sources 21, now becomes missing in the final projected beam pattern, leading to a crack or gap with no or little light distribution therein. This is illustrated schematically in FIGS. 4(a) and 4(b), wherein FIG. 4(a) schematically shows a simulated light intensity distribution as projected into the far field when all the light sources keep turned-on, and FIG. 4(b) schematically shows a simulated light intensity distribution as projected into the far field when only two light sources in the array are emitting light. Please note that isolines for the light intensity are used in FIGS. 4(a) and 4(b) to show how the intensity is distributed across the far field, where the highest light intensity is located at the lower left corner, and the light intensity decreases gradually with an increasing distance from the left lower edge. Further, a skilled person will easily understand as well that in both FIGS. 4(a) and 4(b), only a right part of the final beam pattern is depicted for the purpose of clarity. In practical applications, the full beam pattern as projected finally into the far field shall also contain a left part, being formed in an analogous way to the right part. In the present description, for the sake of simplicity, discussions are only given with regard to the right part of the beam pattern. By comparing the light intensity distributions or beam patterns as shown in FIGS. 4(a) and 4(b), the original rectangle and intact beam pattern with all the light sources turned-on will be transformed into only two bright strips which are spaced up and contain contributions from each of the two turned-on light sources. Therefore, freedom or flexibility will be given in terms of the shape or intensity distribution of the final beam pattern, for example by introducing a switching circuit such that one or more light sources can be turned off as desired. It should be easily understood by those skilled in the art having benefited from the present disclosure, various positions and/or constructions can be used for the above mentioned switching circuit, and the present invention is never going to be limited in this regard.

(13) To sum up, the present invention is focused on providing an automotive lighting system for a vehicle, which automotive lighting system has fewer components, a simper structure, and higher performance or efficiency as compared with the traditional approach where not only a complex optical structure but also a significant loss of light is involved. The objective is accomplished by incorporating a simple, light redirecting element instead of a complex, bulk transmissive portion such that not only the difficulty and great efforts as required for preparing the transmissive portion is avoided, but also an improved and high efficiency and performance are guaranteed.

(14) It should be noted that various components or elements as shown in the figures are not drawn to scale. Besides, relative positions between various components or elements as shown in the figures are only used to illustrate the basic principle of the present invention, and should not be considered to limit the spirit or protection scope of the present invention.

(15) Further, it should be noticed that the above-mentioned embodiments illustrate rather than limit the present invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope and spirit of the present invention. Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific forms as set forth herein. Rather, the scope of the present invention is defined only by the accompanying claims. Additionally, although features may appear to be described in connection with particular embodiments, those skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the disclosure of the present invention.

(16) Furthermore, although individual features may be included in different claims, they may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Also, the inclusion of a feature in one category of claims does not imply a limitation to this category, but rather indicates that the feature is equally applicable to other claim categories as appropriate.

(17) In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. Use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.