Light-emitting device and automotive headlamp

Abstract

The light-emitting device comprises an LED light source, a light guiding device and a first lens, on a section A, after light emitted by the LED light source passes through the light guiding device, at least part of the light is converged to form a focus A, and the focus A is located between the light guiding device and the first lens; the light guiding device is an optical element made of a transparent material and comprises a light-in recess and a light-out surface. Wherein the light-emitting surface of the light guide device is recessed towards the LED light source. A focus A is formed on the section A by using the light guide device, and light rays are divergently emitted into the first lens after passing through the focus A, so that the illumination brightness can be effectively improved; and meanwhile, by utilizing the characteristic that the light-emitting surface of the light guide device is sunken towards the direction of the LED light source, the incident angle of light rays entering the second region of the light-entering sunken part is reduced, so that the formation of chromatic aberration is reduced.

Description

Technical Field

[0001] The utility model relates to the field of automobile lighting, in particular to a light emitting device and an automobile headlamp using the light emitting device. Background Art

[0002] In the field of automotive lighting, the requirements for automotive headlights are the most stringent, and the lighting range and illumination of headlights have strict legal requirements. The structural diagram of automotive headlights currently on the market is as follows: Figure 1 As shown. The light 121 emitted by the light source 101 is incident on the reflective surface 102 and is reflected and converged by it, forming a light band at the convergence point. The cross-sectional position of the light band is shown in Figure 1 As shown in 121a in FIG. Figure 1 The cut-off aperture 104 is located at the convergence focus 121a and blocks a portion of the light to form a cut-off line. The light after the convergence focus 121a is incident on the lens 103, and the lens 103 can image the light distribution of the plane where the cut-off aperture 104 is located (that is, the plane where the convergence focus is located) to the far field. In this way, the light band at the convergence focus 121a forms a light band in the far field, and due to the effect of the cut-off aperture 104, the edge of the far-field light band has a clear cut-off line to meet the requirements of regulations.

[0003] The problem with the current solution is that the light source generally uses an LED light source, which emits light at all angles. This will inevitably result in light rays such as light 123 directly emitted outside the reflective surface, thereby reducing the efficiency of the system. In particular, nowadays, there is a requirement for the outlet shape of the car light module to be flat, that is, the lens 103 is required to be in a long strip shape. In this case, the efficiency of the existing car headlight structure will be even lower. Summary of the invention

[0004] In order to solve the problem of low efficiency of current vehicle lamp solutions, the utility model proposes a light emitting device, including an LED light source, a light guiding device and a first lens, the light guiding device including a relative light inlet and a light outlet surface, and a reflective surface surrounding the light inlet and the light outlet surface, the light emitted by the LED light source is incident from the light inlet and at least partially reflected by the reflective surface, then emitted from the light outlet surface, and then incident on the first lens, and after being acted on by the first lens, an emitted light is formed; a plane perpendicular to the optical axis of the system is defined as a main surface of the system, and the main surface of the system includes mutually orthogonal directions A and B; a plane passing through the optical axis of the system is defined as a system cross section, wherein the system cross section parallel to the A direction is called the A cross section, and the system cross section parallel to the B direction is called the B cross section; on the A cross section, after the light emitted by the LED light source passes through the light guiding device, at least part of the light is generated The light rays converge to form a focus A, which is located between the light guiding device and the first lens; the light guiding device is an optical element made of transparent material, including a light entrance recess, the light entrance port being the opening of the light entrance recess, and the LED light source emits light toward the light entrance recess; wherein the surface of the light entrance recess includes a first area facing the direction of the light axis of the LED light source and a second area surrounding the first area; a first portion of light emitted by the LED light source is incident on the first area of ​​the light entrance recess and is transmitted through the first area to enter the interior of the light guiding device, and then is emitted from the light exit surface of the light guiding device; a second portion of light emitted by the LED light source is incident on the second area of ​​the light entrance recess and is transmitted through the second area to enter the interior of the light guiding device, and then is incident on the reflective surface and is at least partially fully reflected before being emitted from the light exit surface; wherein the light exit surface of the light guiding device is recessed toward the direction of the LED light source.

[0005] In the above-mentioned light emitting device, the first lens comprises a first focal plane, and the A focus is located on the first focal plane.

[0006] The above-mentioned light-emitting device further includes an aperture, which is located on the first focal plane and blocks part of the incident light; a light-shielding edge exists in the light-shielding area of ​​the aperture, and the light-shielding edge is at least partially parallel to the B direction.

[0007] In the above-mentioned light emitting device, a light scattering device is also included, which is located between the reflective surface of the light guiding device and the light path of the first focal plane.

[0008] In the above-mentioned light emitting device, the width H of the first lens in the A section is A Greater than its width H in section B B The reflective surface of the light guiding device forms two sectional lines on the A section, and the distance between the two sectional lines on the light emitting surface is L A , the distance on the light entrance side is S A The reflecting surface of the light guiding device forms two sections on the B section, and the distance between the two sections on the light emitting surface is L. B , the distance on the light entrance side is S B, then L A -S A <L B -S B .

[0009] In the above-mentioned light emitting device, there is at least one point M on the section Y of the A section on the light emitting surface of the light guiding device, and the line connecting the point M and the focus of A is perpendicular to the tangent of the section Y at the point M.

[0010] In the above-mentioned light-emitting device, the surface of the first area of ​​the light-incident recess is a curved surface, and the center of the curved surface protrudes toward the LED light source.

[0011] In the above-mentioned light-emitting device, the height difference D of the section line of the surface of the first area of ​​the light-entering recess on the section A is A , greater than or equal to the height difference D of the section line of the surface of the first area of ​​the light entrance recess on the B section B , that is, D A ≥D B .

[0012] The utility model also provides an automobile headlamp, comprising a lamp body and the above-mentioned light emitting device, wherein the light emitting device is located inside the lamp body, and the lamp body comprises a light emitting window, through which light emitted from the light emitting device is emitted.

[0013] The utility model also proposes an automobile headlamp, comprising the above-mentioned light-emitting device, wherein the light-emitting device forms a first light spot in the far field, wherein the first light spot has a first edge, and the first edge is a light-dark dividing line parallel to the B direction; and further comprises a second light-emitting group, wherein the second light-emitting group forms a second light spot in the far field, wherein the second light spot has a second edge, and the second edge is a light-dark dividing line parallel to the B direction; in the far field, the first edge coincides with the second edge.

[0014] In the light-emitting device and automobile headlamp of the utility model, a light guiding device is used to form a focus A on the A section, and the light is divergently incident on the first lens after passing through the focus A, which can effectively improve the lighting brightness; at the same time, the light guiding device is used to reduce the incident angle of the light incident on the light emitting surface due to the concave surface toward the LED light source, thereby reducing the formation of chromatic aberration and improving the lighting uniformity and consistency of the far-field light spot. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It shows the structural schematic diagram of the vehicle lamp in the prior art;

[0016] Figure 2a , 2b Schematic diagrams showing the structure of the light emitting device in two directions according to the first embodiment of the utility model;

[0017] Figure 2c ,2d Schematic diagrams showing two situations of the reflecting surface and its light path;

[0018] Figure 2e express Figure 2b Another possible alternative embodiment of;

[0019] Figure 2f express Figure 2a , 2b A front view of the light exit surface of the light guide device in the illustrated embodiment;

[0020] Figure 3a , 3b Schematic diagrams showing the structure of a light emitting device in two directions according to another embodiment of the utility model;

[0021] Figure 3c express Figure 3a , 3b A front view of the light exit surface of the light guide device in the illustrated embodiment;

[0022] Figure 3d express Figure 3a , 3b A front view of the diaphragm in the illustrated embodiment;

[0023] Figure 3e , 3f Respectively Figure 3a , 3b Schematic diagram of far-field light spot with and without using an aperture in the illustrated embodiment;

[0024] Figure 4a , 4b Schematic diagrams showing the structure of a light emitting device in two directions according to another embodiment of the utility model;

[0025] Figure 5a A schematic diagram showing the structure of a light emitting device according to another embodiment of the utility model;

[0026] Figure 5b , 5c Respectively Figure 5a Schematic diagram of far-field light spot with and without using an aperture in the illustrated embodiment;

[0027] Figure 6a A schematic diagram showing the structure of a light guiding device in another embodiment of the utility model;

[0028] Figure 6b , 6c Schematic diagrams showing the refraction of light in the second regions of two types of light entrance recesses;

[0029] Figure 7 A schematic diagram showing the structure of a light guiding device in another embodiment of the utility model;

[0030] Figure 8a , 8b Schematic diagrams showing the structure of the light guiding device in another embodiment of the utility model in two directions;

[0031] Figure 9a , 9b Schematic diagrams showing the structure of a light emitting device in two directions according to another embodiment of the utility model;

[0032] Fig.10a A schematic structural diagram showing an embodiment of a vehicle lamp of the utility model;

[0033] Fig.10b express Fig.10a Schematic diagram of a far-field light spot according to an embodiment. DETAILED DESCRIPTION

[0034] The utility model provides a light emitting device, and the structural schematic diagram of the first embodiment is as follows Figure 2a and 2b The light emitting device comprises an LED light source 201, a light guiding device 202 and a first lens 203. The light guiding device 202 comprises a light inlet 2021 and a light outlet surface 2022 opposite to each other, and a reflective surface surrounding the light inlet 2021 and the light outlet surface 2022. The light emitted by the LED light source 201 enters the light inlet 2021 and is at least partially reflected by the reflective surface before exiting from the light outlet surface 2022. The light is then incident on the first lens 203 and forms an exit light 220 after being acted upon by the first lens 203.

[0035] The plane perpendicular to the system optical axis AX is defined as the system main plane, and the system main plane includes the mutually orthogonal A direction and B direction, which have been marked in the figure. The plane passing through the system optical axis AX is defined as the system section, where the system section parallel to the A direction is called the A section, and the system section parallel to the B direction is called the B section. Figure 2a FIG. 1 is a schematic diagram of a cross section of the light emitting device A of this embodiment. Figure 2b The diagram shown is a schematic diagram of the B section of the light emitting device of this embodiment. The section line of the reflective surface at the A section is Figure 2a It is represented as 2023A in the figure, and the section line of the reflecting surface at section B is Figure 2b It is represented as 2023B.

[0036] In this embodiment, the width H of the first lens 203 in the A section is A Greater than its width H in section B B That is, the first lens in this embodiment has an elongated shape, which makes the appearance of the headlight more technological and fashionable.

[0037] like Figure 2aAs shown, in the A section, after the light emitted by the LED light source 201 passes through the light guiding device 202, at least part of the light converges to form the A focus 242, and the A focus 242 is located between the light guiding device 202 and the first lens 203. For example, the light 221 and the light 222 are focused on the A focus 242 after being reflected by the reflection surface 2023A, and then diverge from the A focus 242 and enter the first lens 203. Since the width H of the first lens 203 in the A section A The optical element 221 is relatively large, so the mutually divergent light beams 221 and 222 can be received simultaneously and efficiently.

[0038] In order to compare the situation of section A and section B, we Figure 2a and 2b The virtual surface 241 is used as a reference in Figure 2a In the figure, the focus A is located on the virtual surface 241. Let's look at the situation of the B section. In this embodiment, on the B section, after the light emitted by the LED light source 201 is reflected by the reflective surface 2023B of the light guiding device 202, part of the light is also converged, such as the light 231 in the figure, but it does not form a focus on the virtual surface 241, but forms a focus on the B focus 244. The B focus 244 is behind the light path of the virtual surface 241 and is closer to the first lens 203. Therefore, although the width H of the first lens in the B section is B H A However, since the B focal point 244 is closer to the first lens 203, the first lens can still efficiently collect and process the light 231 in the B section. Figure 2b As shown in FIG. 1 , the light emitted by the LED is converged by the light guiding device to the vicinity of the first lens, so the width of the light beam is compressed to the maximum extent in the B direction near the first lens, so the width H of the first lens in the B section is B It can be minimized, so that a long lens shape that better meets market demand can be achieved.

[0039] The reflective surface of the light guiding device forms two section lines on the A section, such as Figure 2a As shown, the distance between the two sections on the light-emitting surface is L A , the distance on the light entrance side is S A , the reflecting surface of the light guiding device forms two sections on the B section, such as Figure 2b As shown, the distance between the two sections on the light-emitting surface is L B , the distance on the light entrance side is S B In order to achieve the convergence of the light at the B focus in the B section, and the position of the B focus is closer to the first lens 203 than the A focus, the following conditions need to be met: A -S A <LB -S B The following combination Figure 2c and Figure 2d Explain this.

[0040] In order to compare the shape and optical path differences of the cross-sections of the reflecting surface in section A and section B, Figure 2c and 2d In the figure, we draw the two light paths together, with the solid line representing the section 2023A of the reflecting surface at section A and its reflected light path, and the dotted line representing the section 2023B of the reflecting surface at section B and its reflected light path. Figure 2c The situation shown in FIG. The section line 2023A of the reflecting surface at section A and the section line 2023B of the reflecting surface at section B have the same width S at one end of the light entrance. A =S B , as the reflecting surface extends toward the light-emitting surface (extending to the left in the figure), the width of the reflecting surface will gradually widen, and the faster the widening, the greater the incident angle of the incident light, and the smaller the ability to twist the light. The conclusion that the greater the incident angle, the smaller the ability to twist the light can be understood as follows: when the incident angle is the smallest 0 degrees, the light is reflected back along the original path, that is, the direction of light propagation is twisted 180 degrees; and when the incident angle is the largest 90 degrees, the light propagates along the original direction, that is, the direction of light propagation is twisted 0 degrees. Therefore, when the incident angle is any value between 0 and 90 degrees, the angle of light twisting is between 180 degrees and 0 degrees, and the greater the incident angle, the smaller the twisting angle of the reflecting surface to the propagation direction of the light.

[0041] from Figure 2c It can be seen intuitively that in order to achieve that the B focus 244 is closer to the first lens (i.e., farther away from the light guide device) than the A focus 242, the light needs to be twisted less on the B section than on the A section. Therefore, in the process of extending from the light entrance side to the light exit surface, the section line 2023B of the reflective surface on the B section needs to be wider faster than the section line 2023A of the reflective surface on the A section. Therefore, when the section line 2023A of the reflective surface on the A section and the section line 2023B of the reflective surface on the B section have the same width S at the light entrance end, A =S B When the width of the section line of the reflecting surface at section A on the light-emitting surface side is L A , must be smaller than the width L of the section of the reflecting surface at section B on the light-emitting surface side. B . Similarly, from Figure 2d It can be seen intuitively that when the section line 2023A of the reflective surface in section A and the section line 2023B of the reflective surface in section B have the same width L at one end of the light emitting surface A =L BWhen the width of the section line of the reflecting surface at section A on the light entrance side is S A , must be greater than the width S of the section of the reflecting surface at the B section on the light entrance side B In short, as long as L A -S A <L B -S B , it can be ensured that in the process of the reflection surface extending from the light entrance side to the light exit side, the section line 2023B of the reflection surface in the B section becomes wider faster than the section line 2023A of the reflection surface in the A section, so that the light is less twisted in the B section than in the A section. Since the light converges at the A focus in the A section, the light must converge at the rear end of the optical path of the A focus in the B section, so that even if the width H of the first lens in the B section is B Smaller yet more efficient light collection and processing.

[0042] From the above principle description, it can be seen that on the B section, the light does not have to be completely focused and form the B focus, as long as L A -S A <L B -S B , it is possible to achieve that the width of the light is narrower at a position closer to the first lens relative to the A section, thereby improving the collection efficiency of the first lens on the B section. For example, Figure 2e FIG. 4 shows a schematic diagram of the structure and optical path of the B section of another embodiment. Figure 2b The difference between the structure and the optical path shown in the embodiment is that the light emitted from the LED light source 201 does not converge but is emitted in parallel after being reflected by the light guiding device 2023B on the upper and lower sides, such as light beams 231 and light beam 232, which are parallel light beams themselves, but there is an angle between these parallel light beams, that is, these parallel light beams converge as a whole and converge at the rear end of the optical path of the first focal plane 241, that is, near the first lens 203. The advantage of this is that on the first focal plane 241, the light distribution in the B direction is more uniform and has a larger range, which corresponds to the far-field light spot being more uniform in the lateral direction and covering a larger illumination range. Therefore, whether the light forms a focus in the B section is not a limitation of the utility model. As long as the light beam (light) reflected by the reflecting surface is farther away from the light guiding device relative to the first focal plane, the beneficial effects of the utility model can be achieved.

[0043] In the above description, Figure 2c It means that when the section line 2023A of the reflecting surface in section A and the section line 2023B of the reflecting surface in section B have the same width S at one end of the light entrance A =S B situation, and Figure 2dIt means that when the section line 2023A of the reflecting surface in section A and the section line 2023B of the reflecting surface in section B have the same width L at one end of the light emitting surface A =L B These two situations are also commonly used in actual design, because a certain parameter being equal will simplify the design. Figure 2c The cross section 2023A of the reflecting surface in section A and the cross section 2023B of the reflecting surface in section B have the same width S at one end of the light entrance. A =S B The situation is more preferred, that is, the design is simpler. A -S A <L B -S B It can be simplified to L A <L B , that is, the section length of the light emitting surface 2022 of the light guiding device 202 at the section A is less than the section length at the section B. At this time, the front view of the light emitting surface of the light guiding device 202 is as follows: Figure 2f As shown, it can be seen that the light outlet 2022 of the light guiding device 202 is elliptical or approximately elliptical.

[0044] In this embodiment, preferably, the first lens 203 includes a first focal plane, and the A focus 242 is located on the first focal plane. Figure 2a In the figure, the virtual surface 241 is used to simultaneously represent the first focal plane 241. According to optical principles, the first lens 203 will project the light distribution on its first focal plane to the far field for imaging. Since part of the light emitted from the light guiding device 202 is focused on the A focus on the A cross section, and the A focus is located on the first focal plane, there is a highlight point in the A direction on the first focal plane. Thus, after being projected by the first lens 203, a light distribution with a highlight point in the A direction is formed in the far field. If the A direction is a vertical direction, then the far-field light distribution, that is, a highlight point in the center in the vertical direction, can increase the lighting distance of the vehicle headlights. On the other hand, referring to Figure 2b , in the B section, the light does not converge on the first focal plane 241, but has a certain illumination range on the first focal plane. Therefore, in the light distribution formed in the far field, the light along the horizontal direction has a larger illumination range, which also meets the lighting requirements of the car headlights. Therefore, in this embodiment, when the long strip shape of the first lens 203 is realized, the far-field light spot not only realizes the center highlight and increases the illumination distance, but also realizes a larger illumination range in the horizontal direction, and improves the system efficiency at the same time. Of course, the A focus may not be on the first focal plane of the first lens 203, and even the first lens 203 may not have a first focal plane. In this way, other practical light distributions can be realized by designing the first lens, and the beneficial effect of high system efficiency can still be achieved.

[0045] In this embodiment, more preferably, a stop 204 is further included, and the stop 204 is located on the first focal plane 241 and blocks part of the incident light. Figure 2a As shown, the light 223 is blocked by the aperture 204. Since the first lens 203 can project the light distribution image on the first focal plane 241 to the far field, the shape of the far-field light spot can be changed by setting and designing the aperture to block a part of the light, for example, to form a cutoff line to prevent glare. This will be described in detail in the following embodiments.

[0046] In the above embodiment, there is a problem that the efficiency of the light guiding device is relatively low. Figure 2a In the figure, the light 225 is not reflected by the reflective surface 2023A but is directly emitted from the light emitting surface 2022 of the light guiding device. The light 225 is not reflected by the reflective surface but is directly emitted outside the aperture of the first lens 203, thus causing waste. In addition, the light 224 is not reflected by the reflective surface either. Although it is incident within the aperture of the first lens 203, it is not controlled to be focused on the A focal point. Therefore, the light 224 does not contribute to the central highlight point of the far-field light spot, which of course reduces the brightness of the central highlight point. In order to solve the problem of uncontrolled light, the utility model proposes another embodiment, the structure and optical path schematic diagram of the A section and the B section are shown as follows. Figure 3a and 3b As shown. Figure 2a and 2b What is different from the illustrated embodiment is that, in this embodiment, the light guiding device 302 is an optical element made of transparent material, including a light entrance recess 3021, the light entrance port is the opening of the light entrance recess 3021, and the LED light source 301 emits light facing the light entrance recess 3021; ​​wherein, the surface of the light entrance recess 3021 includes a first area 3026 facing the light axis direction of the LED light source 301 and a second area 3027 surrounding the first area 3026. The first part of the light emitted by the LED light source 301 (such as the light 321) is incident on the first area 3026 of the light entrance recess and transmits through the first area 3026 to enter the interior of the light guiding device 302, and then is emitted from the light emitting surface 3022 of the light guiding device 302; the second part of the light emitted by the LED light source 301 (such as the light 322 and the light 324) is incident on the second area 3027 of the light entrance recess and transmits through the second area 3027 to enter the interior of the light guiding device 302, and then is incident on the reflecting surface (the section line of the reflecting surface in the A section is 3023A, and the section line of the reflecting surface in the B section is 3023B) and after at least partial full reflection occurs, it is emitted from the light emitting surface.

[0047] In this embodiment, a solid optical element of a transparent material is used to realize the light guiding device. The transparent material generally uses a polycarbonate (PC) material that can withstand high temperatures. Of course, other transparent materials such as PMMA can also be used. The second part of the light is refracted by the second area 3027 of the light entrance recess and then incident on the reflecting surface. In this embodiment, the reflecting surface is a smooth surface. When the light is incident on the reflecting surface from the inside of the light guiding device, it is incident on the interface from the optically dense medium to the optically sparse medium. Therefore, as long as the incident angle is large enough, total reflection will occur. The efficiency of total reflection is close to 100%, so one of the advantages of this embodiment is that the reflection efficiency of the reflecting surface is high. At the same time, the light at the center angle emitted by the LED light source 301 will be refracted and controlled by the first area 3026 of the light entrance recess 302. By designing the curved surface shape of the first area 3026 of the light entrance recess, the propagation direction of this part of the light can be effectively controlled. This part of the light (for example, light 321) is Figure 2a In the embodiment shown, light loss or inefficient light will be caused because the light cannot be incident on the reflective surface, but in the present embodiment, the light will be efficiently utilized and controlled.

[0048] In this embodiment, in section A, reference Figure 3a , the first part of the light (such as light 321) emitted by the LED light source 301 is incident on the first area 3026 of the light entrance recess and transmits through the first area 3026 to enter the interior of the light guiding device 302, and then is emitted from the light exit surface 3022 of the light guiding device 302 and converges at the A focus 342; at the same time, the second part of the light (such as light 322) emitted by the LED light source 301 is incident on the second area 3027 of the light entrance recess and transmits through the second area 3027 to enter the interior of the light guiding device 302, and then is incident on the reflective surface 3023A and at least partially fully reflected, then is emitted from the light exit surface and converges at the A focus 342. In this way, in addition to the second part of the light reflected by the reflective surface, the first part of the light is also converged at the A focus 342 after being controlled by the first area 3026 of the light entrance recess, which can effectively improve the maximum brightness of the central highlight area of ​​the far-field light spot. In this embodiment, Figure 2a The same as the embodiment shown is that the first lens 303 also has a first focal plane 341, and the A focus 342 is located on the first focal plane 341, which ensures that the first lens can project the light distribution image on the first focal plane 341 to the far field. Figure 3b , the light emitted by the LED light source 301 is focused on the B focus 344 after passing through the light guiding device 302. The B focus 344 is at the rear end of the optical path of the first focal plane 341 and is closer to the first lens 303. The beneficial effect of setting the optical path is Figure 2a and 2b This has been explained in the embodiments and will not be described again here.

[0049] Although this embodiment uses the total reflection principle of the transparent medium surface to realize the reflection surface, the direction of the reflection surface has the same influence on the light. Figure 2c and Figure 2d The situation described is the same as Figure 2a , 2b Similar to the embodiment described in 2f, the light emitting surface 3022 of the light guiding device in this embodiment is also elliptical. Figure 3c As shown, the length of the section line at section A is L A Less than its section length L at section B B .

[0050] Since the first part of the light (such as light 321) emitted by the LED light source needs to be refracted and converged, it is preferred that the surface of the first area 3026 of the light-entering recess 3021 is a curved surface, and the center of the curved surface protrudes toward the LED light source, that is, the surface of the first area 3026 plays the effect of a convex lens for the incident light, so through reasonable design, the incident light 321 can be converged at the A focus on the A section. Of course, this is only a preferred case, and the direction of the first part of the light (such as light 321) can be controlled by designing and controlling the surface shape of the first area 3026 surface, which can be determined according to actual needs.

[0051] Similarly, on section B, refer to Figure 3b By designing the shape of the section line of the first area 3026 in the B section, the direction of the incident first part of the light can be controlled, for example, to converge at the B focus 344. Preferably, since the convergence point B focus 344 on the B section is located farther than the A focus 342, preferably, the height difference D of the section line of the first area 3026 of the light incident recess 3021 on the A section is A , greater than or equal to the height difference D of the section line of the surface of the first area of ​​the light entrance recess on the B section B , that is, D A ≥D B In this way, the curvature of the first area 3026 in the B section is less than or equal to the curvature in the A section, so the first area has a weaker ability to bend light in the B section, thereby achieving the purpose of the B focus being closer to the first lens 303 than the A focus. B Possibly with D A The reason is that the first part of the light in the B section can also be focused on the A focus, because this part of the light is along the optical axis. Even if it is focused on the A focus, it can be incident on the first lens aperture when it propagates to the first lens 303. A ≥D BThis is only a preferred case, because the cross-sectional shape of the first area 3026 in the A section and the B section can be freely controlled to control the light distribution of the first part of the light in the A section and the B section. This can be designed according to actual conditions and does not affect the beneficial effects of this embodiment.

[0052] In this embodiment, a stop 304 is also included. The shape of the stop 304 is as follows: Figure 3d The aperture 304 is located on the first focal plane 341 and blocks part of the incident light (such as the light 324). Figure 2a and 2b The embodiment shown is different in that the light shielding area of ​​the aperture 304 has a light shielding edge 304a, and the light shielding edge is at least partially parallel to the B direction. That is, the aperture 304 extends into the light path to block a portion of the light, wherein the light shielding edge 304a is the outer edge of the portion extending into the light path. Since the first lens 303 projects the light distribution image on its first focal plane 341 into the far field, the dark area formed by the light shielding of the aperture 304 on the first focal plane 341 is also imaged into the far field. The following describes the light spot effect achieved after using the aperture.

[0053] First combine Figure 3e The light spot effect formed in the far field of this embodiment when the aperture 304 is not added is described. Since the first lens 303 projects the light distribution image on its first focal plane 341 to the far field, it is only necessary to examine the light distribution on the first focal plane 341, and it can be equivalently considered that this is the light distribution in the far field (rotated 180 degrees in the A direction). The light incident on the first focal plane 341 includes two distributed parts. One part is the converged light after refraction through the first area 3026 of the light entrance recess. The other part of the light approximately forms an image of the LED light source on the first focal plane 341, that is, an approximately square (or rectangular) light spot located in the center, which forms a rectangular light spot 351 located in the center in the far field. The other part is the incident light formed after passing through the second area of ​​the light entrance recess and then being reflected by the reflective surface. As mentioned above, this part of the light forms a focus (central highlight area) in the vertical direction and is stretched in the horizontal direction to form an illumination width, which forms an approximately elliptical light spot that is long in the horizontal direction and short in the vertical direction on the first focal plane 341, thereby forming an approximately elliptical light spot 352 that is longer in the horizontal direction in the far field. The light spot in the far field is like Figure 3e What is shown is the superposition of two parts of the light spot.

[0054] When using Figure 3d After the aperture 304 shown in FIG. 1 , it blocks a part of the light spot, and the edge of the remaining light spot must form a complementary relationship with the light-shielding edge 304a of the aperture, so the remaining light spot must include an edge parallel to the light-dark dividing line in the B direction, as shown in FIG. Figure 3f As shown, in Figure 3fThe edge of the light-dark dividing line parallel to the B direction is represented as the boundary 353. If the light shielding edge 304a of the aperture 304 has an inflection point, then the residual light spot in the far field must also have an edge inflection point with a shape complementary to it, thus forming a low beam cutoff line that complies with regulations. Of course, whether the light shielding edge has an inflection point does not affect the formation of the cutoff line extending in the horizontal direction.

[0055] exist Figure 3a and Figure 3b In the embodiment shown, almost all the light emitted from the light guiding device on the A section is converged at the A focus, and almost all the light emitted from the light guiding device on the B section is converged at the B focus, and the B focus is located at the front end of the optical path of the first lens. In fact, this does not mean that all designs in reality are like this. In another embodiment of the utility model, on the A section, part of the light emitted from the light guiding device is converged at the A focus, and the rest is not converged at the A focus; at the same time, on the B section, the B focus is located at the rear end of the optical path of the first lens.

[0056] Specifically, the structural diagram of this embodiment is as follows Figure 4a and 4b First, let’s look at the situation of section A. Figure 4a As shown. Figure 3a The same as the embodiment shown is that the second part of the light (such as light 421 and light 422) emitted by the LED light source 401 is reflected by the reflective surface 4023A and converges at the A focus 442, which is located on the first focal plane 441 of the first lens 403; Figure 3a The difference from the embodiment shown is that in this embodiment, after the first part of the light (such as light 423) emitted by the LED light source is refracted by the first area 4026 of the light entrance recess 4021, it does not converge at the focus A, but is emitted in parallel to enter the first lens. In this way, on the first focal plane 441, although the brightness of the central highlight point is weakened, the brightness around the central highlight point is enhanced, so that the central highlight area is closer to a continuous piece, which is conducive to improving the visual uniformity of the light spot in the vertical direction. It can be seen that in the design, we can completely control the far-field light distribution according to actual needs by designing the surface shapes of each area of ​​the light guiding device, so as to achieve a more ideal visual effect. Therefore, as long as part of the light emitted from the light guiding device 402 is converged and a highlight area can be formed in the center, the beneficial effects of the utility model are achieved.

[0057] Looking at the B section, Figure 4b As shown. Figure 3bThe difference between the embodiment shown is that, in this embodiment, the second part of the light (such as light 431 and 432) emitted from the LED light source 401 is reflected by the reflection surface 4023B to form a B focus 444 located at the rear end of the optical path of the first lens 403, which can obviously also achieve the effect of reducing the width of the first lens in the B section. Figure 3b Another difference of the embodiment shown is that in this embodiment, after the first part of the light (such as light 433) emitted by the LED light source is refracted by the first area 4026 of the light entrance recess 4021, it does not converge at the B focal point, but is emitted in parallel and enters the first lens. This is also conducive to improving the visual uniformity of the far-field light spot in the horizontal direction. Figure 2e We have mentioned in the description of the embodiment that the light emitted from the light guiding device does not necessarily form a single focus on the B section, and in combination with this embodiment, it can be seen that the convergence position of the light emitted from the light guiding device can be before the light path of the first lens, or after the light path of the first lens, and part of the light can also be converged. In short, at the position of the first lens, as long as the light beam is more concentrated in the B section than in the A section, the beneficial effects of the utility model can be achieved.

[0058] observe Figure 3e and Figure 3f As shown in the far-field light spot, it can be seen that in direction A, the light spot 351 formed by the first part of the light from the LED light source is larger than the light spot 352 formed by the second part of the light from the LED light source. This is mainly because the aperture of the first area of ​​the light-entering recess is smaller than the exit aperture of the reflecting surface. According to the principle of conservation of optical etendue, the light-emitting angle of an optical device with a small aperture for the same light source is large. Therefore, the first part of the light emitted from the first area of ​​the light-entering recess forms a larger light spot in the far-field direction A. This causes the discontinuity of the edge shape of the light spot, especially the discontinuity of the lower edge (the middle part of the lower edge protrudes downward). When this type of light illuminates the road surface, the protruding part of the light will illuminate the nearby area, while there is no transition light on its left and right sides. Therefore, a central bright spot will be formed in the nearby area, affecting the visual uniformity of the illumination.

[0059] In order to solve this problem, the present invention proposes another embodiment, in which the structural schematic diagram and the optical path diagram of the A section are as follows: Figure 5a In this embodiment, Figure 3aThe difference between the illustrated embodiments is that the light-emitting center of the LED light source 501 is offset in the A direction relative to the axis AX of the light-guiding device 502, and the offset Delta is greater than 1 / 10 of the diameter of the inscribed circle of the light-emitting surface of the LED light source 501. Let us first consider the case where there is no aperture 504. The first part of the light emitted from the LED light source 501 is refracted by the first area 5026 of the light-entering recess, and the first area 5026 is equivalent to a convex lens. According to optical principles, we know that the light-emitting center of the LED light source 501 is offset by Delta in the A direction relative to the axis AX of the light-guiding device 502, so the propagation direction of the light after passing through the first area 5026 of the light-entering recess (here understood as a convex lens) will be offset in the opposite direction. Specifically in this embodiment, the light emitting center of the LED light source 501 is offset by Delta in the +A direction relative to the axis AX of the light guiding device 502. Therefore, the first part of the light emitted from the light guiding device 502 (such as light rays 522 and 523) will be deflected in the -A direction, and then the light spot 551 in the far field will be offset in the +A direction again after being projected by the first lens 503. Figure 5b As shown in Figure 5b The far-field light spot 551 of the first part of the light is offset upward. At the same time, the second part of the light 521 emitted from the LED light source 501 converges at the A focus after passing through the reflective surface 5023A. When the light emitting center of the LED light source 501 is offset by Delta in the +A direction relative to the axis AX of the light guiding device 502, since the reflective surface is a full circle around the LED, the reflected convergent light spot on the first focal plane will not be offset in the -A direction, but will become larger as a whole, which is equivalent to the LED light source becoming larger. Therefore, the position of the light spot 552 formed in the far field remains basically unchanged. In this way, for the lower edge of the overall light spot, the light spot 551 formed by the first part of the light moves upward into the range of the light spot 552 formed by the second part of the light, and the lower edge of the overall light spot becomes continuous and smooth, which greatly improves the uniformity of road lighting.

[0060] Considering that the present embodiment also includes the aperture 504, the aperture 504 blocks a portion of the light and forms a clear light-dark dividing line (cutoff line) 553 at the upper edge of the far-field light spot. In this way, the light spot bulge formed by the first portion of the light emitted by the LED light source moving upward in the far field is completely blocked by the aperture, and the illumination visual uniformity of such a light spot is better. In order to enable the aperture to block this portion of the light spot bulge, in the direction A, the light emission center of the LED light source 501 is offset in the direction away from the aperture 504 relative to the axis AX of the light guiding device 502; in this embodiment, combined with Figure 5a , the LED light source is offset in the +A direction, and the aperture 504 blocks part of the light from the -A direction, so that the aperture can block the central protrusion on the upper edge of the light spot formed by the first part of the light in the far-field light spot.

[0061] Of course, even if you don't use an aperture, Figure 5b The light spot also performs well in terms of lighting, because the lighting visual effect is brighter or darker for the lower edge of the light spot (because the lower edge will illuminate the road surface nearby), while the upper edge of the light spot illuminates the distant and high place, so it has little effect on the visual effect. In addition, the upper edge of the overall light spot protrudes upward, and the lighting height on the upper side is increased. If it is used for high beam lighting, it is helpful to increase the lighting range. In the CNCAP headlight scoring system, the No. 3 point for high beam evaluation refers to the position 5.2 degrees above the horizontal direction. Obviously, if Figure 5b The overall light spot shown can cover this point because of the upward shift of the far-field light spot 551 of the first portion of light, thereby improving the CNCAP high-beam score.

[0062] and Figure 3a Another difference of the embodiment shown is that, in the light emitting device of the embodiment, a light scattering device 509 is also included, which is located between the reflective surface 5023A of the light guiding device and the light path of the first focal plane 541. After the light passes through the light scattering device 509, a certain amount of scattering will occur, which is conducive to improving the uniformity of the light distribution on the first focal plane, thereby improving the uniformity of the far-field light distribution. In the embodiment, the light scattering device 509 is a scattering sheet. By controlling the roughness of the surface of the scattering sheet, the degree of light scattering can be controlled, thereby meeting the requirements of improving the uniformity of light distribution while not reducing the brightness too much. In practical applications, the light scattering device may not be an independent scattering device, but a rough surface of the light emitting surface of the light guiding device. The light emitting surface of the light guiding device is located between the reflective surface of the light guiding device and the light path of the first focal plane. If the entire surface or part of the surface of the light emitting surface of the light guiding device is processed into a rough surface, the effect of scattering the emitted light can also be mentioned. The advantage of this is that the assembly is more convenient. Obviously, the light scattering device can also be applied to other embodiments.

[0063] According to the aforementioned embodiment, the inventor made samples and conducted actual measurements. The lighting effect was very good, but there was also a problem, that is, the edge of the far-field light spot was yellowish or bluish. Although this phenomenon does not affect the actual lighting effect and can be eliminated by scattering, the inventor hopes to solve this problem in principle. The inventor analyzed that the phenomenon of the edge of the light spot being blue or yellowish is the color difference caused by the refraction of light on the surface of a light-guiding device made of a transparent material. Therefore, the utility model proposes another embodiment, in which the schematic diagram of the light-guiding device in section A is shown as follows: Figure 6a As shown in the figure, the optical principle of the entire optical system has been clearly explained in the previous embodiment, so this embodiment will not be repeated, but only the improvement of the light guiding device will be explained.

[0064] In this embodiment, the light guiding device 602 is an optical element made of transparent material, including a light entrance recess 6021, the light entrance port is the opening of the light entrance recess, and the LED light source 601 emits light facing the light entrance recess 6021. The surface of the light entrance recess 6021 includes a first area 6026 facing the light axis direction of the LED light source 601 and a second area 6027 surrounding the first area. The first part of the light emitted by the LED light source 601 is incident on the first area of ​​the light entrance recess and passes through the first area to enter the interior of the light guiding device, and then exits from the light exit surface 6022 of the light guiding device; the second part of the light emitted by the LED light source is incident on the second area 6027 of the light entrance recess and passes through the second area 6027 to enter the interior of the light guiding device 602, and then is incident on the reflective surface 6023 and at least partially fully reflected, and then exits from the light exit surface 6022. The curved surface of the second area 6027 of the light entrance recess 6021 is arched in the direction away from the LED light source.

[0065] Before explaining the improvement principle of this embodiment, we need to first explain the principle of chromatic aberration caused by the refraction of light in the second area of ​​the light-entering recess. Figure 6b As shown, if the section line 6023x of the second area of ​​the light-entering recess in the A section is a straight line, then the incident light rays 621x, 622x and 623x emitted from the LED light source 601 at different angles cannot be incident perpendicularly on the surface of the second area of ​​the light-entering recess at the same time. Figure 6b In the example, the large-angle light 623x is incident on the reflecting surface 6023x perpendicularly, so the other two light rays 621x and 622x cannot be incident on the reflecting surface 6023x perpendicularly, but must be incident on the reflecting surface 6023x at an incident angle greater than 0 degrees, then angle deflection will inevitably occur, and this angle deflection will form chromatic aberration, that is, color splitting will be formed at the edge of the far-field light spot.

[0066] To solve this problem, the ideal Figure 6c As shown, the section line 6027 of the second area of ​​the light-entering recess is an arc with the light-emitting center of the LED light source 601 as a circle, so each light emitted from the center of the LED light source 601 can be vertically incident on the second area 6027, such as Figure 6c As shown by the middle light rays 621, 622, and 623. Therefore, preferably, there is a first system cross section, and at least part of the section line of the second area 6027 of the light-entering recess on the first system cross section is an arc with the light-emitting center of the LED light source as the center. In fact, even if the section line of the second area of ​​the light-entering recess is not an arc with the LED light source as the center, as long as the curved surface of the second area 6027 of the light-entering recess 6021 is arched away from the LED light source, the refraction of light at this interface can be effectively reduced, thereby reducing the occurrence of chromatic aberration.

[0067] In order to further reduce the chromatic aberration, the present invention further proposes another embodiment, the schematic diagram of the light guiding device is as follows: Figure 7 As shown. Figure 6a The difference of the light guide device shown is that the light emitting surface 7022 of the light guide device 702 is concave toward the LED light source 701. When the light is emitted from the light emitting surface 7022 of the light guide device 702, chromatic aberration will also occur due to refraction. If this part of chromatic aberration is to be avoided or reduced, the emitted light needs to be incident on the light emitting surface 7022 vertically or nearly vertically.

[0068] Since the light emitted from the light guiding device 702 is convergent and converges at the A focus 742 in the A section, the light emitting surface 7022 of the light guiding device 702 is concave toward the LED light source 701, which makes the light more nearly vertically incident on the light emitting surface and emitted, thereby reducing chromatic aberration. More preferably, as Figure 7 As shown, there is at least one point M on the section Y of the A section on the light emitting surface 7022 of the light guiding device 702, and the line connecting the point M and the A focal point 742 is perpendicular to the tangent Yx of the section Y at the point M. This ensures that the light rays converged on the A focal point 742 are vertically incident at the point M and transmitted through the light emitting surface 7022, so that the light rays emitted at the point M can completely eliminate chromatic aberration.

[0069] Figure 8a and 8b Schematic diagrams of the A section and the B section of the light guide device in another embodiment of the utility model, and Figure 7The difference of the light guiding device of the illustrated embodiment is that, in the present embodiment, the light emitting surface 8022 of the light guiding device 802 includes an inner area 8022a and an outer area 8022b, and the light (e.g., light 821) passing through the first area 8026 of the light entrance recess is at least partially incident on the inner area 8022a of the light emitting surface, and the light reflected by the reflective surface 8023 is at least partially incident on the outer area 8022b of the light emitting surface. The section line of the inner area 8022a of the light emitting surface in the A section is an arc line with a central convexity. Thus, in the A section, the inner area 8022a of the light emitting surface and the first area 8026 of the light entrance recess together form a thick convex lens, which together completes the collection of the first part of the light 821 and converges it at the A focus 842. The advantage of this is that the light outlet of the convex lens formed by the inner area 8022a of the light outlet surface and the first area 8026 of the light entrance recess is closer to the A focal point 842, so the incident angle becomes larger. Therefore, according to the conservation of optical extension, the focused spot at the focusing point becomes smaller, thereby increasing the maximum light intensity of this part of the light at the A focal point. In this embodiment, the first part of the light emitted from the LED light source 801 enters the light guiding device 802 after being refracted by the first area 8026 of the light entrance recess, and then exits after being refracted by the inner area 8022a of the light exit surface. There is a certain distance between the first area 8026 of the light entrance recess and the inner area 8022a of the light exit surface. In order to make as much light as possible enter the inner area 8022a of the light exit surface, preferably, the first part of the light emitted from the LED light source enters the first area 8026 of the light entrance recess and enters the light guiding device 802 in a collimated manner after being refracted by the first area 8026, and then at least partially enters the inner area 8022a of the light exit surface. In this way, the first area 8026 of the light entrance recess is used to control the first part of the light 821 not to diverge and to enter as much as possible into the inner area 8022a of the light exit surface, and the inner area 8022a of the light exit surface converges the incident light at the A focus 842.

[0070] Next reference Figure 8b Let's look at the situation of section B. In section B, if the first part of the light emitted by the LED light source passes through the first area 8026 of the light entrance recess and enters the light guide device 802 in a collimated manner, since the position of the B focus is farther away from the light guide device than the A focus, the section line of the inner area 8022a of the light emitting surface in section B has a weaker ability to bend light than the section line of the inner area 8022a in section A, that is, the section line of the inner area 8022a of the light emitting surface in section B has a smaller curvature than the section line of the inner area 8022a in section A. Therefore, the difference P between the center height and the edge height of the section line of the inner area 8022a of the light emitting surface in section A is A , which is greater than the difference P between the center height of the inner area 8022a of the light-emitting surface and the edge height at the section B B , that is, P A >P B . Satisfy P A >PB This condition can ensure that the section line of the inner area of ​​the light emitting surface in the B section has a smaller curvature than that in the A section, thereby achieving the design goal that the distance from the B focus in the B section to the light guiding device is longer than the distance from the A focus to the light guiding device.

[0071] Satisfy P A >P B There is also a special case P B = 0, that is, the section line of the inner area 8022a of the light-emitting surface in the B section is a straight line without any curvature. At this time, if the light incident on the inner area 8022a of the light-emitting surface is collimated, then these lights are also collimated rather than converged in the B section when they are emitted from the inner area 8022a of the light-emitting surface, which is conducive to improving the uniformity of the lateral light distribution. In fact, P B It can also be less than 0, that is, the inner area 8022a of the light emitting surface is concave in the center of the section line of the B section. At this time, the light is divergent in the B section after passing through the inner area 8022a of the light emitting surface, which is used to form a wider spot range on the first focal plane.

[0072] In this embodiment, the outer area 8022b of the light emitting surface of the light guiding device is recessed toward the LED light source. Figure 7 The concave light-emitting surface 7022 is the same and will not be described here. In this embodiment, a light scattering device can also be used to homogenize the light. For example, the surface of the inner area 8022a of the light-emitting surface of the light-guiding device is processed into a rough surface, so that the first part of the light 821 emitted by the LED light source can be homogenized, while the surface of the outer area 8022b of the light-emitting surface of the light-guiding device is still kept smooth, that is, the light reflected by the reflection surface is not homogenized, so that the maximum light intensity of this part of the light can be maintained and should not be reduced due to homogenization. Therefore, the surfaces of the inner area 8022a and the outer area 8022b of the light-emitting surface of the light-guiding device are processed into different roughnesses, so that the two parts of the light can be homogenized separately according to the actual situation, in order to optimize the compromise between the central light intensity and uniformity.

[0073] In the above embodiments, the light emitting device forms a focus A in the A section through the light guiding device, so as to make full use of the characteristic that the first lens has a relatively large length in the A direction. In fact, the light emitting device may not form a focus in the A section, which will be explained in another embodiment of the utility model. The structural schematic diagram and optical path schematic diagram of the embodiment in the A section and the B section are shown in FIG. Figure 9a and 9b shown.

[0074] In this embodiment, Figure 3a and Figure 3bThe difference of the embodiment shown in FIG. 1 is that, in the embodiment, in the A section, the light emitted by the LED light source 901 passes through the light guiding device 902 and is incident on the first lens in a divergent state. Figure 9a The light beam 921 in the light guide device 902 is collimated and emitted after passing through the first lens 903. If it is not necessary to form a focus A, and there is no need for an aperture to form a cutoff line, such as when applied to the high beam part of a car light, then the light path can be designed with reference to this embodiment. Since the light 921 emitted from the light emitting surface 9022 of the light guiding device 902 is in a divergent state, the length of the first lens 903 in the A direction can be fully utilized, thereby maximizing the center brightness. At the same time, the reflective surface of the light guiding device 902 forms two sections 9023A on the A section, and the distance between the two sections on one side of the light emitting surface is L A , the distance on the light entrance side is S A The reflecting surface of the light guiding device forms two sections 9023B on the B section, and the distance between the two sections on the light emitting surface is L B , the distance on the light entrance side is S B , then L A -S A >L B -S B .according to Figure 3a and 3b From the principle description of the embodiment shown, it can be seen that the reflective surface has a stronger beam twisting ability in the B section than in the A section, so the outgoing light 931 can be more concentrated in the B section, so the width of the first lens 903 in the B section is smaller. In this way, the purpose of the long strip-shaped exit lens can also be achieved.

[0075] Preferably, in the B section, the light emitted by the LED light source 901 is incident on the first lens 903 after passing through the light guiding device 902, and is collimated after passing through the first lens 903. This is conducive to forming a light beam with high central brightness, which is well used in the high beam of a vehicle lamp. Figure 9b As shown, in the B section, after the light emitted by the LED light source 901 passes through the light guiding device 902, at least part of the light converges to form a B focus 944, and the B focus 944 is located at the rear end of the optical path of the first lens 903, and the first lens 903 is a negative lens in the B section. The virtual focus of the first lens 903 in the B section coincides with the B focus, so that collimated light can be emitted. Of course, the B focus can also be located before the optical path of the first lens 903, but in this case, the curvature of the first lens 903 in the B section will be very large, and the processing difficulty is relatively high.

[0076] In summary, in the present embodiment, the first lens 903 is a convex lens (positive lens) in the A section and a concave lens (negative lens) in the B section. If these two functions are realized by the same surface, this surface is not a traditional lens surface, but a design similar to a saddle surface, and both functions are not realized very well. Therefore, preferably, the first lens 903 includes a first light-transmitting surface and a second light-transmitting surface, wherein the first light-transmitting surface extends congruently in the A direction, and the second light-transmitting surface extends congruently in the B direction, that is, the function of the first lens in the A section is realized by the second light-transmitting surface, and the second light-transmitting surface is extended congruently along the B direction, so no matter how it is designed, it will not affect the light in the B section. At the same time, the function of the first lens in the B section is realized by the first light-transmitting surface, and the first light-transmitting surface is extended congruently along the A direction, so no matter how it is designed, it will not affect the light in the A section. In this way, the different functions of the first lens 903 in the A section and the B section are realized independently by two light-transmitting surfaces, and such a design is simple and has low processing cost.

[0077] In this embodiment, the height difference D of the section line of the surface of the first region 9026 of the light incident recess on the A section is A , which is less than or equal to the height difference D of the section line of the surface of the first area 9026 of the light-entering recess on the B section B , that is, D A ≤D B Thus, for the first part of light emitted by the LED light source 901, the divergence angle after incident on the first light incident concave area 9026 in the A section is relatively large, and the light incident on the first light incident concave area 9026 in the B section is relatively more convergent, which is conducive to reducing the width of the first lens 903 in the B section.

[0078] It is worth noting that the distinguishing features of the aforementioned multiple embodiments can be used in combination with each other. Due to the limitation of words, this specification cannot list all the combinations of various features. It can only describe the characteristics of each typical solution by describing each distinguishing feature. The combination of each distinguishing feature is also within the protection scope of the present utility model. Figures 6a to 8b The multiple improved features of the light guide device described can be used in a superimposed manner and can also be applied Figure 9a and 9b In the embodiment shown in FIG. Figures 6a to 8b The various embodiments of the light guide device described above can of course also be applied to Figure 3a and Figure 3b in optical systems other than

[0079] The light-emitting device described above can be applied to automobile headlights, so the utility model also proposes an automobile headlight, including a lamp body and the above-mentioned light-emitting device, the light-emitting device is located inside the lamp body, the lamp body includes a light exit window, and the light emitted from the light-emitting device is emitted through the light exit window.

[0080] More specifically, the utility model also provides a vehicle headlamp, such as Fig.10a As shown, the schematic diagram of the far-field light distribution of the car headlight is as follows Fig.10b The vehicle headlamp includes Figure 3a-3d The light emitting device 1091 shown forms a first light spot 1058 in the far field. The first light spot 1058 has a first edge 1053, which is a light-dark dividing line parallel to the B direction. The formation principle has been explained above. It also includes a second light emitting group 1092, which forms a second light spot 1059 in the far field. The second light spot 1059 has a second edge 1054, which is a light-dark dividing line parallel to the B direction. In the far field, the first edge 1053 coincides with the second edge 1054. In other words, the first edge 1053 and the second edge 1054 together constitute the cutoff line of the far field light spot. In the light field distribution below the far field light spot cutoff line, the second light spot 1059 emitted by the second light emitting group 1092 has the characteristic of a large illumination range, while the first light spot 1058 formed by the light emitting device 1091 in the far field has the characteristic of high central brightness. The combination of the two takes into account both the illumination range and the illumination distance.

[0081] In this embodiment, the second light-emitting group 1092 includes a second LED light source 1011 and a second reflective surface 1012 extending congruently along the B direction, and also includes a second lens 1014. At least part of the light emitted by the second LED light source 1011 is reflected by the second reflective surface 1012 and then incident on the second lens 1014 and emitted. The second lens 1014 has a second focal plane 1048, and an end 1049 of the second reflective surface 1012 away from the LED light source is located on the second focal plane 1048. The second reflective surface 1012 extends congruently along the B direction, so the end 1049 away from the LED light source is a straight line extending along the B direction, and one side of the end line (at Fig.10a The middle is the upper side) has light, one side (in Fig.10aThe end line is the boundary line between light and dark, and the end line is located on the second focal plane 1048. Therefore, the boundary line between light and dark is projected to the far field by the second lens 1014 to form the second edge 1054. In this embodiment, a reflector 1013 extending congruently along the B direction is also included. The reflector 1013 and the second reflecting surface 1012 together play the role of projecting the light emitted by the second LED light source 1011 to the second lens 1014, as shown in the light beam 1031. In this embodiment, the reflector 1013 is a plane, but it can also be a curved surface. The end of the reflector 1013 away from the second LED light source is not on the second focal plane 1048, so a clear boundary line between light and dark will not be formed at the lower edge of the far-field light spot 1059. In this embodiment, the second reflecting surface 1012 can also be a plane reflector, and the utility model does not limit the surface shape of the second reflecting surface.

[0082] It is worth noting that the "headlights" mentioned in the present invention refer to headlights in a broad sense. Headlights in a broad sense refer to the lighting lamps of vehicles traveling on roads. They do not necessarily have to be car lights, but also include electric car lights, bicycle lights, etc.

[0083] It should be noted that the distinguishing technical features between the various embodiments of the utility model are not limited to being applied to their respective embodiments, but can be applied to various embodiments. It is impossible to list all possible combinations in the description of the utility model. Therefore, the implementation principles and beneficial effects of various technical features are explained by way of examples. When applied to other embodiments, personnel in this technical field will use their implementation principles to achieve the beneficial effects.

[0084] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A light emitting device, characterized in that: The light guide device comprises an LED light source, a light guiding device and a first lens. The light guiding device comprises a light inlet and a light outlet surface opposite to each other, and a reflective surface surrounding the light inlet and the light outlet surface. Light emitted by the LED light source is incident from the light inlet and at least partially reflected by the reflective surface before being emitted from the light outlet surface. The light is then incident on the first lens and is formed into an outlet light after being acted upon by the first lens. The plane perpendicular to the optical axis of the system is defined as the main surface of the system, and the main surface of the system includes the mutually orthogonal directions A and B; The plane passing through the optical axis of the system is defined as the system section, where the system section parallel to the A direction is called the A section, and the system section parallel to the B direction is called the B section; On the A section, after the light emitted by the LED light source passes through the light guiding device, at least part of the light converges to form a focus A, and the focus A is located between the light guiding device and the first lens; The light guiding device is an optical element made of transparent material, including a light entrance recess, the light entrance port is the opening of the light entrance recess, and the LED light source emits light toward the light entrance recess; wherein the surface of the light entrance recess includes a first area facing the light axis direction of the LED light source and a second area surrounding the first area; a first portion of light emitted by the LED light source is incident on the first area of ​​the light entrance recess and is transmitted through the first area to enter the interior of the light guiding device, and then is emitted from the light exit surface of the light guiding device; a second portion of light emitted by the LED light source is incident on the second area of ​​the light entrance recess and is transmitted through the second area to enter the interior of the light guiding device, and then is incident on the reflective surface and is at least partially fully reflected before being emitted from the light exit surface; Wherein, the light emitting surface of the light guiding device is recessed toward the LED light source.

2. The light emitting device according to claim 1, characterized in that: The first lens comprises a first focal plane, and the A focus is located on the first focal plane.

3. The light emitting device according to claim 2, characterized in that: It also includes an aperture, which is located on the first focal plane and blocks part of the incident light; a light-shielding edge exists in the light-shielding area of ​​the aperture, and the light-shielding edge is at least partially parallel to the B direction.

4. The light emitting device according to claim 2, characterized in that: Also included is a light scattering device located between the reflective surface of the light guiding device and the first focal plane light path.

5. The light emitting device according to claim 1, characterized in that: The width H of the first lens in the A section A Greater than its width H in section B B The reflective surface of the light guiding device forms two sectional lines on the A section, and the distance between the two sectional lines on the light emitting surface side is L A , the distance on the light entrance side is S A The reflecting surface of the light guiding device forms two sections on the B section, and the distance between the two sections on the light emitting surface is L. B , the distance on the light entrance side is S B , then L A -S A <L B -S B .

6. The light emitting device according to claim 1, characterized in that: There is at least one point M on the section Y of the A section of the light emitting surface of the light guiding device, and the line connecting the point M and the focus of A is perpendicular to the tangent of the section Y at the M point.

7. The light emitting device according to claim 1, characterized in that: The surface of the first area of ​​the light incident recess is a curved surface, and the center of the curved surface protrudes toward the LED light source.

8. The light emitting device according to claim 7, characterized in that: The height difference D of the section line of the surface of the first area of ​​the light entrance recess on the A section A , greater than or equal to the height difference D of the section line of the surface of the first area of ​​the light entrance recess on the B section B , that is, D A ≥D B .

9. An automobile headlamp, characterized in that: The invention comprises a lamp body and a light emitting device according to any one of claims 1 to 8, wherein the light emitting device is located inside the lamp body, and the lamp body comprises a light exit window, through which light emitted from the light emitting device is emitted.

10. An automobile headlamp, characterized in that: The method comprises the light-emitting device according to claim 3, wherein the light-emitting device forms a first light spot in the far field, wherein the first light spot has a first edge, and the first edge is a light-dark dividing line parallel to the B direction; and further comprises a second light-emitting group, wherein the second light-emitting group forms a second light spot in the far field, wherein the second light spot has a second edge, and the second edge is a light-dark dividing line parallel to the B direction; in the far field, the first edge coincides with the second edge.

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