Patent Application
20250020297
This application claims priority to German Application No. 10 2023 118666.3, filed Jul. 14, 2023, the entirety which is hereby incorporated by reference.
The invention relates to a method for constructing an optical functional unit containing an optical component, in particular for a lighting device for a vehicle, in which the optical component has a transparent surface, to at least part of which a opaque coating is applied, portions of which are then removed with a laser such that at least one window is created through which the light from at least one light source can pass, and in which the at least one light source is part of a light module.
Optical functional units with optical components in the form of optical collimators, for example, are used in lighting devices for vehicles. By way of example, there are optical collimators made entirely of glass placed in front of semiconductor lights such that an image is projected in front of the vehicle by semiconductor lamps. To generate a light/dark boundary for a low beam light, a blind must be placed between the light and the area in front of the vehicle, the edge of which forms the light/dark boundary in the low beam light in the area in front of the vehicle.
Because modern headlamps contain light modules that can be placed in the smallest installation spaces, tolerance deviations in the edges forming the light/dark boundaries in relation to the light sources have a much more significant effect on the light distribution in front of the vehicle, such that the demands on these tolerances increase as the light modules become smaller. It is therefore challenging to create an optical functional unit for vehicle lighting devices with which the light from the light sources entering the optical component can be projected into the area in front of the vehicle with the necessary tolerances. The light/dark boundary plays a special role in this, because the placement of an optical collimator and its dedicated blind with incorrect tolerances can blind oncoming traffic, even with low beams.
Newer designs use transparent coatings on the surface of the optical component through which light passes, which are then partially removed with lasers to create the necessary blind edge of the window in the coating created in this manner.
A method for constructing an optical functional unit with an optical component is disclosed in DE 10 2021 116 638 A1, which is intended in particular for a vehicle lighting device, in which the optical component has a surface through which light passes, to at least part of which an opaque coating is applied, portions of which are then removed with lasers such that at least one window is formed through which the light from a dedicated light source passes. The light source is part of a light module, which is then placed in relation to the optical component. In the method described herein, the window is aligned in relation to reference positions on the optical component, formed by subsections or edges in the grids formed in the optical components during production. This aligns the windows precisely with the actual collimator lenses, but not the light sources, i.e. the LEDs in the light module.
The object of the invention is to align the position of the window in relation to the light sources in the light module with a simple method, in particular such that the greatest possible portion of the light from the light sources passes through the window. This requires precision placement of the windows in relation to the light sources in the light module.
The invention proposes the following method steps: provision of a frame that has at least two reference points, placement of the optical component in the frame, detecting the reference points on the frame with an optical sensor, calculating the position of the window on the surface through which light passes in relation to the reference points using a control unit, removing portions of the opaque coating with lasers to obtain the at least one window, placement of the light module such that it is aligned with the reference points on the frame.
The method according to the invention results in the substantial advantage that the windows on the surface through which light passes are precisely aligned with the light sources in the light module, such that the greatest possible amount of light that can be generated by the light source can pass through the window. These steps do not place the windows in reference to the surface of the optical component, i.e. the optical collimator, but instead place them in relation to the reference points to which the light module, and therefore the light sources, are then aligned.
This does not result in an optimal position of the window in relation to the optical components, in particular the optical collimator, but this can be compensated for when adjusting the module during installation of the optical functional unit, e.g. a headlamp. This ultimately results in an optimal alignment of the windows in relation to the light sources, also resulting in a maximum luminous flux output from the optical functional unit, because less light is unintentionally blocked by the edges of the blind.
The frame has at least two alignment elements with which the optical component is aligned on the frame. The frame can be made of a single piece of molded plastic or metal, and the reference points and/or alignment elements can be calibrated or adjusted after the actual production of the frame. This ensures that the alignment elements are placed precisely in relation to the reference points on the frame. This then results in a very precise placement of the windows in relation to the collimator lenses.
The alignment elements can exhibit a bearing surface on which the optical component can be placed on or in the frame. The surface on the optical component through which light passes is flat, and the optical component can be placed with the alignment elements such that this surface is parallel thereto. In the same manner, the light module, which is also flat, formed in particular by a printed circuit board (PCB) populated with light sources, can also be aligned with the reference points.
The reference points on the frame are advantageously detected by an optical sensor based on an imaging and evaluation thereof. There are other means of detecting the reference points within the framework of the invention, e.g. with tactile methods or methods using a device that is aligned spatially with the reference points, in order to then remove portions the coating on the surface through which light passes with laser beams.
The optical component advantageously remains on the frame after the windows have been created, and is fastened thereto in particular, e.g. using spring clips or clasps. This has the advantage that when the optical component is first placed on the frame, the windows are aligned with the reference points on the frame by the laser processing, whereas if the optical component were removed and replaced, the alignment might become less precise.
After the optical functional unit has been produced, the position of the light sources in the light module can be adjusted in relation to the windows during installation in the optical functional unit, in particular by adjusting their position in a headlamp for a vehicle.
Lastly, execution of the method with a control unit is advantageous, in which the control unit calculates the location and/or position of the windows that are to be formed based on the positions of the reference points detected on the frame, such that the control unit controls the laser beam source for removing the opaque coating and forming the windows based on this calculation. The basis for this is the reference points, at least two of which are detected in a plane such that the windows can be formed in the coating on the surface of the optical component through which light passes in an identical, or at least parallel, plane.
The reference points on the frame can be formed by lugs, and the alignment elements for the optical component can be adjacent thereto, or part thereof. The lugs can be placed in holes or notches in the light module when it is placed on the frame, which then also results in an alignment with the windows.
The present invention also relates to an optical functional unit produced with the method described above. The optical functional unit is distinguished in particular in that when the at least one light source is in use, substantially all of the light, i.e. at least 70%, preferably 80%, ideally 90%, can pass through the dedicated window.
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.
The frame 16 has a receiving space 23 in which the optical component 10 is placed. The optical component 10 in this exemplary embodiment forms an optical collimator with numerous collimator lenses 22, which are adjacent to one another in a row.
An opaque coating 12 is placed on the surface 11 through which light passes, which lies opposite the collimator lenses 22, which is shown as separate from and therefore at a spacing to the surface 11 through which light passes merely for illustrative purposes.
Numerous windows 13 are formed in the opaque coating 12, the positions of which correspond to light sources 14 in a light module 15, which is also shown spaced apart from the coating. The opaque coating 12 and therefore the surface 11 through which light passes faces toward the light module 15 and therefore the light sources 14. When the light sources 14 emit light, it only passes through the surface 11 where the windows are located, because the opaque coating 12 otherwise prevents the passage of light.
The windows 13 are formed in the opaque coating 12 with laser beams, with which the coating 12 is removed from the surface 11 of the optical component 10 through which light passes in a targeted manner. The method for producing the optical functional unit 100 shown herein aligns the windows 13 with the light sources 14 in the light module 15. This should result in a precision placement of the windows 13 in relation to the light sources 14, such that the maximum luminous flux output can be obtained, in particular when the optical functional unit 100 is later adjusted in the production process. This shall be explained in reference to the subsequent drawings.
There are two reference points 17 formed on the frame 16, by way of example, which are formed by lugs protruding from the frame 16.
To place the windows 13 as precisely as possible in relation to the light sources 14, the optical component 10 is first placed in the receiving space 23 in the frame 16, as can be seen by viewing
Once the windows 13 are formed on the optical component 10, it remains in the frame 16, and the light module 15 containing the light sources 14 is subsequently placed thereon, which is then also aligned by the reference points 17 or the alignment elements 21. The light module 15 is preferably aligned by the reference points 17 in that it has holes or notches that the reference points 17 formed by lugs can engage in. This results in a precise alignment of the light module 15 in the flat plane such that the light sources 14 populating the surface of the light module 15, in particular a PCB, can be placed precisely in relation to the windows 13.
The invention is not limited to the preferred exemplary embodiment described above. A number of variations are conceivable with which the solution described herein is also obtained with fundamentally different embodiments. All of the features and/or advantages that can be derived from the claims, description or drawings, including structural details, spatial configurations, and steps of the method, may be regarded as substantial to the invention in and of themselves and in various combinations thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102023118666.3 | Jul 2023 | DE | national |
