Abstract
A system includes a first primary optics that receives light from a first light source and projects it onto a transparent shutter and a secondary optics. A second primary optics receives light from the second light source and projects it onto the transparent shutter. The transparent shutter receives light from the first light source via the first primary optics and prevents a lower part of it from entering the secondary optics. The transparent shutter further receives light from the second light source via the second primary optics and projects it onto the secondary optics. The secondary optics receives light from the first primary optics and the transparent shutter and projects it onto a road in front of the vehicle. The transparent shutter includes an air-exposed slit that redirects the light received by the transparent shutter from the second light source toward a middle axis of the transparent shutter.
Claims
1. A front-lighting system for a vehicle, the system comprising: a first light source; a second light source; a transparent shutter; a secondary optics; a first primary optics configured to receive light from the first light source and project the light onto the transparent shutter and the secondary optics; and a second primary optics configured to receive light from the second light source and project the light onto the transparent shutter; the transparent shutter being configured to receive light from the first light source via the first primary optics and prevent a lower part of the light, as seen when installed in the vehicle, from entering the secondary optics, the transparent shutter being further configured to receive light from the second light source via the second primary optics and project the light onto the secondary optics, and the secondary optics being configured to receive light from the first primary optics and the transparent shutter and project the light onto a road in front of the vehicle, and the transparent shutter comprising an air-exposed slit that extends perpendicularly to a direction in which the light received by the transparent shutter from the second light source propagates within the transparent shutter to redirect the light received by the transparent shutter from the second light source towards a middle axis of the transparent shutter.
2. The front-lighting system according to claim 1, wherein the air-exposed slit is further configured to redirect the light received by the transparent shutter from the second light source into a concentrated light spot on a light out-coupling surface of the transparent shutter.
3. The front-lighting system according to claim 1, wherein: the second light source comprises a plurality of sub-light sources arranged in an array of (2m+1) rows and (2n+3) columns, wherein m and n are both integers equal to or greater than 0, and the air-exposed slit comprises one or more sub-slits, wherein each sub-slit extends in parallel to a respective row of the sub-light sources and comprises two side parts, one on either side of a middle part of the transparent shutter being exempted from the sub-slits.
4. The front-lighting system according to claim 3, wherein: each sub-slit further comprises a first surface and a second surface opposite to the first surface, the first surface is closer than the second surface to a surface of the transparent shutter where light from the second light source is incident thereon, and at least portions of the first surface and the second surface located at the two side parts of each sub-slit are shaped to refract light incident thereon to be inclined towards the middle part of the transparent shutter relating to a middle-positioned sub-slit, which middle-positioned sub-slit has an equal number of sub-slits at either side thereof.
5. The front-lighting system according to claim 4, wherein: each sub-slit comprises a medial surface perpendicular to the direction in which the light received by the transparent shutter from the second light source propagates within the transparent shutter, and the first surface and the second surface of each sub-slit are mirror symmetrical to each other with respect to the medial surface of the respective sub-slit.
6. The front-lighting system according to claim 5, wherein the plurality of sub-light sources are arranged in an array of 1 row and (2n+3) columns, wherein n is an integer equal to or greater than 0, and the air-exposed slit comprises a single sub-slit.
7. The front-lighting system according to claim 6, wherein: the first surface comprises two side sections located on either side of the middle part of the transparent shutter relating to the single sub-slit, and each side section comprises a curved surface convex towards the second light source.
8. The front-lighting system according to claim 6, wherein: the first surface comprises two side sections located on either side of the middle part of the transparent shutter relating to the single sub-slit, and each side section comprises a sloped surface, a portion thereof adjoining the middle part being spaced farthest from the second light source as compared with remaining portions thereof.
9. The front-lighting system according to claim 6, wherein the first surface comprises two side sections located on either side of the middle part of the transparent shutter relating to the single sub-slit, wherein each side section comprises a stepped surface with one or more steps, wherein each step comprises a curved surface convex towards the second light source.
10. The front-lighting system according to claim 6, wherein the first surface comprises two side sections located on either side of the middle part of the transparent shutter relating to the single sub-slit, wherein each side section comprises a stepped surface with one or more step, where each step comprises a first facet and a second facet, wherein the first facet is perpendicular to the medial surface of the single sub-slit, and the second facet is sloped and has a portion thereof closest to the middle part of the transparent shutter relating to the single sub-slit, such closest portion of the second facet being spaced farthest from the second light source as compared with remaining portions thereof.
11. The front-lighting system according to claim 1, wherein the transparent shutter is made of polymethyl methacrylate (PMMA).
12. The front-lighting system according to claim 1, wherein: the first light source comprises a low-beam light source, and the second light source comprises a high-beam light source.
13. The front-lighting system according to claim 1, wherein the transparent shutter is further configured to project the light received from the second light source via the second primary optics onto the secondary optics through total internal reflection.
14. The front-lighting system according to claim 1, wherein each of the first primary optics and the second primary optics comprises a reflector.
15. The front-lighting system according to claim 1, wherein the second primary optics is integrated with the transparent shutter.
16. The front-lighting system according to claim 1, wherein each of the first primary optics and the second primary optics comprises a collimator.
17. The front-lighting system according to claim 1, wherein the transparent shutter is made of polycarbonate (PC).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) These and other aspects of the present invention will be described now 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 front-lighting system for a vehicle according to an embodiment of the present invention, where the front-lighting system comprises a reflector and a collimator;
(3) FIG. 2 schematically illustrates an enlarged view for a portion of a front-lighting system for a vehicle according to an embodiment of the present invention, which portion is indicated by a dashed box in FIG. 1;
(4) FIGS. 3(a) and 3(b) schematically illustrates simulated results for the light intensity distribution on a vertical screen positioned in front of a front-lighting system for a vehicle provided without and with an air-exposed slit within the transparent shutter respectively;
(5) FIG. 4 schematically illustrates an enlarged view for a portion of a front-lighting system for a vehicle according to another embodiment of the present invention, which portion is indicated by a dashed box in FIG. 1;
(6) FIG. 5 schematically illustrates an enlarged view for a portion of a front-lighting system for a vehicle according to a further embodiment of the present invention, which portion is indicated by a dashed box in FIG. 1;
(7) FIG. 6 schematically illustrates a front-lighting system for a vehicle according to another embodiment of the present invention, where the front-lighting system comprises a low-beam light source, a low-beam reflector, a high-beam light source and a high-beam collimator, and the high-beam collimator is integrated with the transparent shutter; and
(8) FIG. 7 schematically illustrates a front-lighting system for a vehicle according to a further embodiment of the present invention, where the front-lighting system comprises a low-beam light source, a low-beam collimator, a high-beam light source and a high-beam reflector.
DETAILED DESCRIPTION OF THE EMBODIMENTS
(9) While the present invention is susceptible of embodiments in many different forms, there is shown in the drawings and will be described in detail herein only one or more specific embodiments, with the understanding that the present description is to be considered as exemplary of the basic principle of the present invention and not intended to limit the present invention only to the specific embodiments shown and described herein.
(10) It should be noted that various components in different figures are not drawn to scale. Besides, relative positions between individual elements shown in the figures are only used to illustrate the basic principle of the present invention and should not be considered to limit the scope of the present invention.
(11) With reference to FIG. 1, a front-lighting system 10 is proposed for a vehicle according to an embodiment of the present invention. Specifically, the front-lighting system 10 mainly comprises a first light source BS1, a second light source BS2, a first primary optics 11, a second primary optics 12, a secondary optics 13, and a transparent shutter 14. Preferably, in the above proposed front-lighting system 10, the first light source BS1 is configured to provide a low-beam pattern, i.e., acting as a low-beam light source, and in the meanwhile, the second light source BS2 is configured to provide a high-beam pattern, i.e., acting as a high-beam source. Alternatively, with another configuration of the transparent shutter 14, it could also be the other way around. That is, the low-beam pattern is provided by the second light source BS2, and the first light source BS1 is used as the high-beam light source. In the specific embodiment as shown by FIG. 1, the first primary optics 11 is chosen as a reflector, the second primary optics 12 is a collimator, and the secondary optics 13 is selected as a projection lens. Furthermore, the first light source BS1 is positioned in a focal plane, especially in a focal point, of the reflector 11, and the transparent shutter 14 is located in another focal plane, especially in another focal point, of the same reflector 11. Obviously, this special arrangement of the first light source BS1 and the transparent shutter 14 with respect to focal points of the reflector 11 is just disclosed as specific examples, for the purpose of explaining the basic principle of the present invention. Those skilled in the art, having benefited from the teaching of the present invention, will find it easy to acquire some other alternatives. In a similar way, the second light source BS2 can also be positioned in a focal plane, especially in a focal point, of the second primary optics 12, and the transparent shutter 14 is positioned in another focal plane, especially in another focal point, of the second primary optics 12. Additionally, the transparent shutter 14 itself can also be located in a focal plane, especially a focal point, of the secondary optics 13. Again, this special positioning in a corresponding focal plane or focal point should not be interpreted to be limiting.
(12) In the specific embodiment as shown by FIG. 1, the first primary optics 11, i.e., the reflector 11 (also indicated as the first primary reflector), is configured to receive light from the first light source BS1, and then project part of it onto the transparent shutter 14 and part of it onto the secondary optics 13. With regard to the part of the light projected onto the transparent shutter 14 by the first primary reflector, a lower portion of it will be prevented from entering the projection lens. Especially, as shown in FIG. 1, a lower part of the light from the first primary optics 11 is refracted away from the secondary optics 13, and at the end possibly absorbed elsewhere within the system. In this case, the lower part of light from the first primary optics 11 will not form any image through the secondary optics 13. Specially, in case that the first light source BS1 is configured to be a low-beam light source, only the upper part of light emitted by the low-beam light source can pass through the projection lens, thus forming a low beam pattern with a clear cut-off line.
(13) Further, discussions with relevance to the other beam portion, i.e., the one emitted by the second light source BS2, are provided in the following. With continued reference to FIG. 1, the transparent shutter 14 is configured further to receive light from the second light source BS2 via the second primary optics 12 and project it onto the secondary optics 13. In particular, the second light rays can be projected from the transparent shutter 14 onto the secondary optics 13 horizontally. In this case, the projection of light from the second light source BS2 (received via the second primary optics 12) onto the secondary optics 13 is obtained by means of a total internal reflection within the transparent shutter 14. Optionally, the diversion of the light propagation direction, by 90° in FIG. 1, can occur only once within the transparent shutter 14, just as the case shown in FIG. 1. After the total internal reflection, a second beam pattern, such as a high beam pattern if the second light source BS2 is configured as a high-beam light source, will be projected onto a road in front of the vehicle by the secondary optics 13. Again, in an optional instance, a projection lens can be used as the secondary optics 13, but the present invention is not limited to it.
(14) With a transparent shutter 14 incorporated into a front-lighting system 1 for a vehicle, the traditional opaque shutter is replaced and no dark area will be observed in the final projected beam pattern, especially between the high beam pattern and the low beam pattern. This is definitely distinguished from the beam pattern obtained by an existing headlamp with an opaque shutter equipped. In other words, in the front-lighting system 1 for a vehicle as proposed by the present invention, a clear cut-off line is formed in the projected low beam pattern without any shading.
(15) Besides, as also shown in FIG. 1, the transparent shutter 14 in the above proposed front-lighting system 1 comprises further a light out-coupling surface 141, at which light is out-coupled towards the secondary optics 13. The light out-coupling surface 141 is preferably designed to be flat or in a free form, which helps to change the out-coupled light in angle and/or distribution.
(16) With continued reference to FIG. 1, in the above proposed front-lighting system 1 for a vehicle, the transparent shutter 14 also comprises an air-exposed slit 15, consisting of for example two curved parts at left and right sides respectively. As shown in FIG. 1, the air-exposed slit 15 is carved within the transparent shutter 14, and configured further to redirect the light received by the transparent shutter 14 from the second light source BS2 (especially, via the second primary optics 12) towards a middle axis X of the transparent shutter 14. For example, in the embodiment of FIG. 1, the transparent shutter 14 comprises a lower cylinder portion having a symmetry, middle axis X, wherein the air-exposed slit 15 is carved within the lower cylinder portion. To be specific, as shown in FIG. 1, the air-exposed slit 15 consists of two side parts located at respective sides of the middle axis X of the transparent shutter 14. In this case, the portion of light coming out from the second light source BS2 and entering the transparent shutter 14, especially its side parts at the left and right, will be incident onto the air-exposed slit 15 and refracted thereby towards the middle axis X of the transparent shutter 14. See for example the arrowed light rays shown schematically in FIG. 1. This helps to concentrate the incident light beam from the second light source BS2 towards the middle axis X of the transparent shutter 14, thus helping to reduce the second light beam in size, and also to avoid the loss of light that was otherwise caused for example by an outward refraction at outer edges of the transparent shutter 14.
(17) With further reference to FIG. 1, in the above proposed front-lighting system 10, the second light source BS2 and its second primary optics 12 are both disposed right beneath the transparent shutter 14, especially under its lower cylinder portion. In this case, the second light part coming out of the second light source BS2 via the second primary optics 12 is incident onto a lower surface of the lower cylinder portion of the transparent shutter 14, refracted into it, and then propagating from the bottom to up therethrough, i.e., propagating vertically in the figures. Furthermore, as shown in FIG. 1, in the transparent shutter 14, the air-exposed slit 15 has a horizontal extending direction Y which is perpendicular to the middle axis X of the transparent shutter 14 forming the propagation direction of light from the second light source BS2. This contributes to an effective redirection of the light towards the middle axis X of the transparent shutter 14. It should be understood that there might also be a possibility for the light coming out from the second light source BS2 to undergo some reflections and/or refractions when passing through the transparent shutter 14, but the propagation direction herein refers to a general direction in which the light from the second light source BS2 travels through the whole transparent shutter 14. Thus, in the embodiment as shown by FIG. 1, the propagation direction of light from the second light source BS2 is vertical in the lower part of the transparent shutter 14, but changes to horizontal in the upper part of the transparent shutter 14. Having benefited from the teaching of the present invention, a skilled person in the art shall easily understand the meaning of the term “propagation direction of light from second light source within transparent shutter” according to different structure forms of the transparent shutter.
(18) With reference to FIG. 2, an enlarged view for a portion of a front-lighting system for a vehicle is shown according to an embodiment of the present invention, which portion is indicated by a dashed box in FIG. 1, and apparently comprises at least the second light source, the second primary optics and the part of transparent shutter containing the air-exposed slit. As shown in FIG. 2, according to an embodiment of the present invention, the second light source comprises a plurality of sub-light sources arranged especially in an array, for example five sub-light sources BS20 arranged in 1 row and 5 columns. Accordingly, the second primary optics may comprise five sub-optics 220 as well, wherein each is configured to receive and redirect light from a respective sub-light source BS20 towards the transparent shutter 24. It should be noted that the total number of five sub-light sources and accordingly of five sub-optics as shown in FIG. 2 is only illustrated as an example for helping to grasp the technical essence of the present invention, rather than limiting the protection scope of the present invention. As a matter of fact, in practical implementations, a skilled person in the art, having benefited from the teaching of the present invention, shall easily conceive other suitable numbers and/or arrangements of the sub-light sources and the sub-optics, such as a plurality of sub-light sources in an array of (2m+1) rows and (2n+3) columns, where m and n are both integers equal to or greater than 0, and/or one or more sub-optics each corresponding to a single sub-light source, a row of sub-light sources, a column of sub-light sources, or an array of sub-light sources.
(19) With continued reference to FIG. 2, in case that multiple sub-light sources BS20 are comprised in the second light source, the air-exposed slit of the transparent shutter 24 consists only of a single sub-slit 25, which extends along a direction Y in parallel to the row of sub-light sources BS20 situated right below, and accordingly perpendicularly to the middle axis X of the transparent shutter 24. To be specific, as shown in FIG. 2, the only sub-slit 25 comprises two independent, side parts 251, 252 being located at either side of a middle part 240 (indicated by an dashed shadow area in the figures) of the transparent shutter 24, wherein the middle part 240 of the transparent shutter 24 refers to a cylinder part of the transparent shutter 24 centered for example around the middle axis X thereof. Especially, the sub-slit 25 is also shaped to have a first surface 25L and a second surface 25U being opposite to each other (i.e., the lower and upper surfaces in the figures), wherein as compared with the second, upper surface 25U, the first, lower one 25L is positioned closer to a light incident surface (i.e., a lower surface) of the transparent shutter 24. Preferably, the first surface 25L and the second surface 25U of the sub-slit 25 are mirror symmetric to each other with respect to a medial surface of the sub-slit 25, which medial surface is for example a horizontal plane cutting through the sub-slit 25 at the middle in the embodiment shown by FIG. 2. Further optionally, with reference to FIG. 2, the first, lower surface 25L of the sub-slit 25 comprises two side sections located respectively at the two side parts 251, 252 of the sub-slit 25, i.e., a left side section being the lower surface of the left side part 251 and a right side section being the lower surface of the right side part 252. The same applies to the second, upper surface 25U of the sub-slit 25 as well, i.e., comprising a left side section being the upper surface of the left side part 251 and a right side section being the upper surface of the right side part 252.
(20) According to an optional embodiment as for example shown by FIG. 2, the left side part 251 and the right side part 252 of the sub-slit 25 both have its respective lower surface being convex towards the array of sub-light sources BS20, i.e., towards the second light source, while have its respective upper surface being convex away from the array of sub-light sources BS20, i.e., away from the second light source, especially with the same curvature as the respective lower surface. This helps to refract light rays received from the sub-light sources BS20 (such as via the second primary optics) at the sub-slit 25, specifically at the upper and lower surfaces of the two side parts 251, 252 thereof, thus changing them to be more inclined towards the middle part 240 of the transparent shutter 24. The effect of inclination towards the middle part 240 of the transparent shutter 24 can be seen explicitly from the simulated results in FIGS. 3(a) and 3(b), where simulated light intensity distributions on a vertical screen positioned in front of a front-lighting system are shown respectively provided without and with an air-exposed slit within the transparent shutter. As shown, in case that no air-exposed slit is provided in the transparent shutter, the simulated light intensity distribution exhibits a multi-maxima pattern, see for example the three-maxima pattern in FIG. 3(a). By contrast, if an air-exposed slit is introduced into the transparent shutter, like the sub-slit 25 of FIG. 2, the simulated light intensity distribution will have only one maximum in a center spot, see for example the single-maximum pattern in FIG. 3(b). Obviously, this is attributed to the inclination of light caused by the air-exposed slit towards the middle part of the transparent shutter. Further preferably, according to an embodiment of the present invention, the single concentrated light spot on the light out-coupling surface of the transparent shutter also shows a distribution of light intensity such that the light intensity is largest at a center, but reduces gradually towards outer edges. This is beneficial for providing a desired distribution of light intensity for example to the high-beam pattern as projected onto the road in front of the vehicle, if the second light source is configured to be a high-beam light source.
(21) Apart from the single-maximum characteristic, as also evident from a comparison between FIGS. 3(a) and 3(b), the whole pattern on the light out-coupling surface of the transparent shutter is also reduced in size when the air-exposed slit is provided within the transparent shutter. This means that a large input light beam can be narrowed down when passing through the air-exposed slit of the transparent shutter, thus facilitating usage of a larger-sized, high-beam light source as compared with no air-exposed slit, or rendering it possible to use an array of sub-light sources for the second, high-beam light source rather than a single one of it. In this way, the high-beam pattern as projected finally onto the road in front of the vehicle can be provided with a higher, concentrated light intensity, making it more favorable for use in practical vehicle applications.
(22) With reference to FIGS. 4 and 5, alternative constructions for the air-exposed slit in the transparent shutter of the proposed front-lighting system are shown according to different embodiments of the present invention. As similar to FIG. 2, in both FIGS. 4 and 5, only enlarged views are provided for the portion indicated by a dashed box in the front-lighting system of FIG. 1. Thus, same or similar references are used in FIGS. 4 and 5 to indicate same or similar components, such as a row of sub-light sources BS20 for the second light source, a respective row of second primary optics with sub-optics 420, 520, transparent shutter 44, 54 and middle part 440, 540 thereof, as well as sub-slit 45, 55 of the air-exposed slit. Like those discussions about FIG. 2, in both FIGS. 4 and 5, light coming out of the sub-light sources BS20 is also projected upwards by the second primary sub-optics 420, 520, then incident into the transparent shutter 44, 54, and propagating therethrough from the bottom to up. Further, with the introduction of the air-exposed slit, specifically the sub-slits 45, 55, light propagating through the transparent shutter 44, 54 will encounter refractions at least at lower and upper surfaces of the sub-slits 45, 55, which is again similar to FIG. 2.
(23) However, the difference from FIG. 2 is that the sub-slits 45, 55 in FIGS. 4-5 are now provided with different constructions. To be specific, the lower surface 45L of the sub-slit 45 in FIG. 4 is shaped to comprise two sloped side sections, i.e., a left sloped section and a right sloped section, each of them rising up gradually from outer edges (left or right edges) towards middle part 440 of the transparent shutter 44. As for the upper surface 45U of the sub-slit 45 in FIG. 4, a left sloped section and a right sloped section are comprised as well, but each of them falling down gradually from outer edges (left or right edges) towards middle part 440 of the transparent shutter 44, preferably with the same slope as the respective left or right sloped section of the lower surface 45L. Due to a similar refraction towards the middle part 440 of the transparent shutter 44, the sub-slit 45 in FIG. 4 contributes as well to a smaller-sized and single-maximum high-beam pattern out-coupled from the transparent shutter 44, if high-beam light sources are used as the sub-light sources BS20.
(24) Turning to the enlarged view of FIG. 5, the lower surface 55L of the sub-slit 55 is shaped to comprise two stepped side sections, i.e., a left one and a right one, each containing one or more steps 5500. With reference to the further enlarged view (indicated by a dashed ellipse) of FIG. 5, each step 5500 of the sub-slit 55 comprises two facets 5501, 5502. For example, with respect to the lower surface 55L of the sub-slit 55, the first facet 5501 is configured to be vertical, i.e., being perpendicular to the horizontal, medial surface of the sub-slit 55, while the second facet 5502 is sloped, especially rising up gradually in a direction from outer edges (left or right edges) towards middle part 540 of the transparent shutter 54. Similarly, the upper surface 55U of the sub-slit 55 also comprises a first facet 5501 and a second facet 5502, wherein the first one 5501 is vertical as well, but the second one 5502 is sloped, especially falling down gradually in a direction from outer edges (left or right edges) towards middle part 540 of the transparent shutter 54, as similar to the sloped section shown in FIG. 4. Like those discussions with relevance to FIG. 4, each step 5500 of the sub-slit 55 helps to redirect light incident thereon to be more inclined towards the middle part 540 of the transparent shutter 54, thereby contributing together to form a smaller-sized and single-maximum high-beam pattern on the light out-coupled surface of the transparent shutter 54, if high-beam light sources are used as the sub-light sources BS20. It should be noted herein that although not shown in the above embodiment of FIG. 5, each step 5500 of the sub-slit 55 can be designed alternatively to comprise a single curved surface, rather than the first and second facets. In this case, the single curved surface can be shaped in a similar way as the sub-slit 25 of FIG. 2, i.e., being convex towards the second, sub-light sources BS20 for the lower surface 55L of the sub-slit 55, while convex in an opposite direction (that is, away from the second, sub-light sources BS20) for the upper surface 55U of the sub-slit 55. Again, this is beneficial for concentrating light incident onto the sub-slit 55 to be inclined more towards the middle part 540 of the transparent shutter 54.
(25) FIG. 6 schematically illustrates a front-lighting system 60 for a vehicle according to another embodiment of the present invention. The front-lighting system 60 in FIG. 6 basically stays the same as that in FIG. 1. Thus, similar reference numerals are used to indicate similar components, such as the first primary optics 61 (especially, a first primary reflector), the secondary optics 63 and the air-exposed slit 65. The difference between FIG. 6 and FIG. 1 lies in two aspects. In a first aspect, the first light source BS1 is now specified in FIG. 6 to be a low-beam light source LBS, and correspondingly, the second light source BS2 is a high-beam light source HBS. In a second aspect, the high-beam primary optics (such as the high-beam collimator) in FIG. 6 forms a collimating portion of the transparent shutter. That is to say, the transparent shutter and the second primary collimator are now integrated with each other, thus forming a one-piece component 600. The collimating portion of the integral component 600 here in FIG. 6 is arranged specifically for collimating the light emitted from the high-beam light source HBS towards the shutter portion thereof. Similarly to the second collimator in FIG. 1, a beam shaping of the high-beam light rays can be obtained in this way. But the difference from FIG. 1 is that in FIG. 6, the beam shaping of light emitted from the high-beam light source HBS occurs inside the one-piece component 600, which may be beneficial for quality improvements of the high-beam light rays.
(26) FIG. 7 schematically illustrates another alternative front-lighting system 70 for a vehicle according to a further embodiment of the present invention. The front-lighting system 70 here in FIG. 7 is almost the same as that in FIG. 1. Thus, similar reference numerals are used to indicate similar components, such as the transparent shutter 74, the secondary optics 73 and the air-exposed slit 75. The difference between FIG. 7 and FIG. 1 lies in two aspects. In a first aspect, the first light source BS1 is specified now in FIG. 7 to be a low-beam light source LBS, and correspondingly, the second light source BS2 is a high-beam light source HBS. In a second aspect, the first primary optics of FIG. 7 is designed to be a first collimator 71, not a first reflector; and the second primary optics is changed to be a second reflector 72, not a second collimator. In this case, the first collimator 71 helps to achieve not only a projection of light from the low-beam light source LBS onto the transparent shutter 74 and the secondary optics 73, but also a beam shaping of the same light. Also, the second reflector 72 will contribute to fold the propagation path for the light coming out from the high-beam light source HBS. It is important to indicate that only two specific embodiments are shown in FIGS. 1 and 7, where light coming from the first light source is reflected but light coming from the second light source is refracted (see FIG. 1), and light coming from the first light source is refracted but light coming from the second light source is reflected (see FIG. 7). This shall be never interpreted as limiting the present invention. In fact, having benefited from the teaching of the present invention, a skilled person in the art shall easily understand other similar embodiments, such as light from both the first and second light sources is reflected, or light from both the first and second light sources is refracted, and all these alternatives shall be encompassed within the protection scope of the present invention.
(27) It should be noted that although in the figures, the total internal reflection of light coming from the second light source is shown to occur only once, this should not be interpreted as limiting the present invention. As a matter of fact, a skilled person in the art, having benefited from the teaching of the present invention, will easily conceive other suitable constructions of the transparent shutter such that the total internal reflection of light coming from the second light source occurs more than once within the transparent shutter. By means of multiple times of total internal reflection, the second, such as high-beam, light source may be installed at the same side as the first, such as low-beam, light source. That is to say, a vertical distance between the two light sources can be greatly reduced, and the large spacing is mainly achieved through a horizontal distance between them. In this way, a vertical space of the front-lighting system will be shortened significantly, and thus the whole system becomes very compact at least in vertical direction. Besides, with multiple times of total internal reflection, the light path within the front-lighting system can be folded such that the first, such as low-beam, light source will keep away from the second, such as high-beam, light source in space based on practical implementations. This helps to offer design flexibility, outstanding heat dissipation feasibility and less color non-uniformity.
(28) It is also important to note that light rays shown in the figures, only represent part, but not all, of the light rays within the whole optical system. In fact, the light rays shown in all the figures are only used as representative examples for the purpose of illustrating the basic principle of the present invention, and clearly should not be read as exhaustive examples of all the light rays within the entire system.
(29) With regard to the materials and manufacturing or processing processes suitable for the transparent shutter, different options can be used. For example, in an embodiment, the transparent shutter can be fabricated by injection molding as a one-piece component, such as by polymethyl methacrylate (PMMA), polycarbonate (PC), or other plastic materials. Apparently, materials other than plastic, and processes other than injection molding can also be utilized based on specific situations, and the present invention should not be limited in this aspect.
(30) In should be noted as well that although the transparent shutter is shown in sectional views in all the figures of the present invention and seems to have a flat contour, the actual 3D shape of the transparent shutter, especially having the air-exposed slit introduced therein, might be rather complicated. In some embodiments, the transparent shutter can be designed to have a flat contour. Alternatively, in other embodiments, the transparent shutter can be designed as a curved body, maybe of a free-form contour. Specific illustrations about different contours of the shutter, both in the drawings and the specification, should not be interpreted to be limiting, but rather are to be considered as exemplary disclosures.
(31) It should also be noted 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 limited only by the accompanying claims. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention.
(32) Furthermore, although individual features may be included in different claims, these 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. In the claims, any reference signs placed between parentheses shall 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. Also, references to first, second etc. are merely to be considered as labels and do not imply or describe any ordering, sequence, relation or properties of the features prefixed by these terms. 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.
LIST OF REFERENCE NUMERALS
(33) 10 front-lighting system BS1 first light source BS2 second light source 11 first primary optics 12 second primary optics 13 secondary optics 14 transparent shutter 141 light out-coupling surface of transparent shutter 15 air-exposed slit X middle axis of transparent shutter Y extending direction of sub-slit BS20 sub-light source of second light source 220 sub-optics of second primary optics 24 transparent shutter 240 middle part or middle section of transparent shutter 25 sub-slit of air-exposed slit 251 252 side parts of sub-slit 25L first surface of sub-slit 25U second surface of sub-slit 420 sub-optics of second primary optics 44 transparent shutter 440 middle part or middle section of transparent shutter 45 sub-slit of air-exposed slit 45L first surface of sub-slit 45U second surface of sub-slit 520 sub-optics of second primary optics 54 transparent shutter 540 middle part or middle section of transparent shutter 55 sub-slit of air-exposed slit 55L first surface of sub-slit 55U second surface of sub-slit 5500 step of sub-slit 5501 first facet of step 5502 second facet of step 60 front-lighting system LBS low-beam light source HBS high-beam light source 61 low-beam reflector 600 one-piece or integral component 63 secondary optics 65 air-exposed slit 70 front-lighting system 71 low-beam collimator 72 high-beam reflector 73 secondary optics 74 transparent shutter 75 air-exposed slit
