Patent Application
20250224090
This application claims priority to German Application No. 10 2024 100173.9, filed Jan. 4, 2024, the entirety of which is hereby incorporated by reference.
The present invention relates to a projection module for a headlamp in a motor vehicle.
A projection module of this type is disclosed in DE 10 2019 118 968 A1. The projection module described therein contains numerous first light sources and numerous second light sources, as well as primary optics with first and second optical waveguides. The light from the first light sources generates a first light distribution and the light from the second light sources generates a second light distribution. The first can be a high beam light distribution, and the second can be a low beam light distribution. The first optical waveguide prefocuses the light from the first light sources, and the second optical waveguide prefocuses the light from the second light sources. The projection module also contains secondary optics for focusing the light exiting the primary optics in front of the motor vehicle.
Styling and design play an extremely important role for automobile headlamps, and manufacturers use these components to affect the appearance of the vehicle and its recognition value. The current trend is toward small, unobtrusive main lighting functions. At the same time, the importance of ratings, i.e. qualitative and quantitative evaluations, has increased. The appearance of clear light/dark boundaries, high intensities near the light/dark boundaries, and homogenous light distributions are essential. The projection module disclosed in DE 10 2019 118 968 A1 offers this. Because of the necessary size of the lens forming the secondary optics and the light distribution optics, these projection modules have increasingly smaller installation spaces in modern headlamps. Prior concepts for these projection modules require a comparatively thick aspherical lens as the secondary optics. Furthermore, the typical appearance of such a lens does not satisfy the styling requirements for a modern headlamp in which the main lighting functions are less important than the appearance of the signal lights. The headlamps contain more components, reducing the available space for the main lighting functions.
The fundamental problem addressed by the present invention is to create a projection module of the above type that is more compact, which can also generate high intensities near the light/dark boundary, and has an appearance that is aligned with current styling preferences.
One or more, or all, of the light-emitting diodes in the light sources are designed to emit light with a luminance of more than 400 cd/mm2. These light-emitting diodes can be designed to emit light with a luminance of more than 420 cd/mm2, in particular between 430 cd/mm2 and 450 cd/mm2, e.g. light with a luminance of approx. 440 cd/mm2. They emit light with a luminance that is significantly greater than those used in the projection module disclosed in DE 10 2019 118 968 A1. Because of the higher luminance, the primary optics do not have to be as large. This also results in higher intensities near the light/dark boundaries.
One or more, or all, of the light-emitting diodes in the light sources can be designed to emit light with a luminous flux of 200 lm to 300 lm, in particular with a luminous flux of 225 lm to 275 lm, e.g. approx. 250 lm. Furthermore, these light-emitting diodes can have an active light-emitting surface that is between 0.40 mm2 and 0.70 mm2, in particular between 0.50 mm2 and 0.60 mm2, e.g. approx. 0.56 mm2. These light-emitting diodes can be high-luminance light-emitting diodes (LEDs).
The length of the primary optics from the at least one light-entry surface on the first optical waveguide to the at least one light-emitting surface thereon can be between 17 mm and 30 mm, in particular between 20 mm and 27 mm, preferably approx. 23.5mm. Typical primary optics, such as those described in DE 10 2019 118 968 A1, are approx. 47 mm. Furthermore, the size of the primary optics can be between 3 cm3 and 7 cm3, in particular between 4 cm3 and 6 cm3, preferably 5 cm3. Typical primary optics such as those described in DE 10 2019 118 968 A1 are approx. 34 cm3. The primary optics in the projection module obtained with the invention are therefore substantially more compact that those in the prior art, thus requiring less installation space. In particular, the primary optics can comprise or be a monolithic optical component that contains both the first and second optical waveguides.
The secondary optics can comprise or be a projection lens with a light-entry surface for the light exiting the primary optics and a light-emitting surface for the light entering the light-entry surface. This projection lens can be a Fresnel lens with at least one Fresnel structure on the light-entry and/or light-emitting surface. Because of the Fresnel structure, the secondary optics can be substantially more compact than those in the projection module from the prior art. This Fresnel structure also gives the secondary optics a modern appearance.
The length of the optics for the projection module formed by the primary and secondary optics from light-entry surfaces of the primary optics to the light-emitting surface of the secondary optics is between 40 mm and 70 mm, in particular between 50 mm and 60 mm, preferably approx. 56 mm. Typical optics like those described in DE 10 2019 118 968 A1 are approx. 112 mm long. The compact size of the primary and secondary optics thus contributes to significantly reducing the necessary installation space in comparison with the prior art.
The first light distribution can be a high beam light distribution, or a part thereof, and/or the second light distribution can be a low beam light distribution, or a part thereof.
The projection module can contain more than one first light source and/or more than one second light source. The first optical waveguide can also have more than one light-entry surface and/or the second optical waveguide can contain more than one light-entry surface.
Each of the first light sources can have a dedicated light-entry surface on the first optical waveguide, such that the light from the first light sources enters the first optical waveguide through the dedicated light-entry surface thereon, and/or each of the second light sources can have a dedicated light-entry surface on the second optical waveguide, such that light from the second light sources enters the second optical waveguide through the dedicated light-entry surface thereon.
The first optical waveguide can have a single light-emitting surface for the light entering it through the numerous light-entry surfaces, and/or the second optical waveguide can have numerous separate light-emitting surfaces dedicated to separate light-entry surfaces, such that the light entering these light-entry surfaces exits the second optical waveguide through the dedicated light-emitting surfaces.
Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.
Identical and functionally identical parts have the same reference symbols in the drawings.
The embodiment of a projection module obtained with the invention shown in
The first and second light sources each contain at least one light-emitting diode (LED). One or more, preferably all, of the light-emitting diodes in the light sources are designed to emit light with a luminance of more than 400 cd/mm2, in particular with a luminance of between 430 cd/mm2 and 450 cd/mm2, e.g. approx. 440 cd/mm2. Furthermore, these light-emitting diodes can be designed to emit light with a luminous flux of 200 lm to 300 lm, in particular from 225 lm to 275 lm, e.g. approx. 250 lm. Moreover, one or more, preferably all, of the light-emitting diodes in the light sources can have an active light-emitting surface area of between 0.40 mm2 to 0.70 mm2, in particular 0.50 mm2 to 0.60 mm2, e.g. approx. 0.56 mm2. These light-emitting diodes can be high-luminance light-emitting diodes.
The first light sources are designed to emit light for generating a first light distribution, in particular a high beam light distribution or part thereof. The second light sources are designed to emit light for generating a second light distribution, in particular a low beam light distribution, or part thereof. The first and second light sources can be controlled separately to generate these light distributions.
The primary optics 1 contain a first optical waveguide 3 and second optical waveguide 4. The first optical waveguide 3 and second optical waveguide 4 each have numerous light-entry surfaces 5, 6. The light-entry surfaces 5 on the first optical waveguide 3 are adjacent to one another in a row, and the light-entry surfaces 6 on the second optical waveguide 4 are also adjacent to one another in a row that is parallel to and above the row of light-entry surfaces 5 on the first optical waveguide 3.
Each of the first light sources has a dedicated light-entry surface 5 on the first optical waveguide 3, such that the light from the first light source enters the first optical waveguide 3 through these light-entry surfaces 5. Furthermore, each of the second light sources has a dedicated light-entry surface 6 on the second optical waveguide 4, such that the light from the second light source enters the second optical waveguide 4 through these light-entry surfaces 6.
The first optical waveguide 3 has a single light-emitting surface 7 for the light entering through the numerous light-entry surfaces 5. The second optical waveguide has numerous separate light-emitting surfaces 8, each of which is dedicated to one of the light-entry surfaces 6, such that the light entering through the light-entry surfaces 6 exits the second optical waveguide 4 through these light-emitting surfaces 8.
As shown in particular in
The primary optics form a monolithic optical component that contains the first and second optical waveguides 3, 4 and the shutter 9.
The length LP of the primary optics from the light-entry surfaces 5 on the first optical waveguide 3 to the light-emitting surfaces 7 on the first optical waveguide 3 is between 17 mm and 30 mm, in particular 20 mm and 27 mm, preferably approx. 23.5 mm. The size of the primary optics is between 3 cm3 and 7 cm3, in particular 4 cm3 and 6 cm3, preferably approx. 5 cm3.
The secondary optics 2 is a projection lens with which the light for generating the desired light distribution is projected in front of the motor vehicle. This projection lens has a light-entry surface 11 for the light exiting the light-emitting surfaces 7, 8 in the primary optics 1, and a light-emitting surface 12 for the light entering through this light-entry surface 11. This projection lens can be a Fresnel lens that has at least one Fresnel structure 13 (see
The length LG of the optics of the projection module formed by the primary optics 1 and secondary optics 2 from the light-entry surfaces 5, 6 in the primary optics to the light-emitting surface 12 of the secondary optics is between 40 mm and 70 mm, in particular between 50 mm and 60 mm, preferably approx. 56 mm. Typical optics from the prior art, containing primary optics 1′ and secondary optics 2′, are shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 102024100173.9 | Jan 2024 | DE | national |
