Patent Application
20240019773
This application claims the priority to DE application Serial No. 102022117917.6, filed Jul. 18, 2022, the disclosure of which is hereby incorporated in its entirety by reference herein.
The invention is based on a projector assembly, in particular for a vehicle, with which a light image is displayed in a far field. In addition, the invention relates to a projection system with this type of projector assembly.
Using projector assemblies in a vehicle, for example a passenger car, is known from the prior art. These serve, for example, to display a vehicle logo on an imaging surface, for example a road surface, next to the vehicle. Such a projector assembly has, for example, a light source in the form of an LED (light emitting diode), which is connected downstream of a gobo screen with a logo. The gobo screen in turn is connected downstream of one or more lenses to display the logo on the gobo screen in the far field.
The object of the present invention is to provide a projector assembly and a projection system for displaying information, in particular a logo, which displays in high quality and/or to provide a comparatively large focal length in a cost-effective and/or simple manner in terms of apparatus and/or with little installation space.
The object with regard to the projector assembly is solved according to the features of claim 1 and with respect to the projection system according to the features of claim 10.
Particularly advantageous embodiments are found in the dependent claims.
According to the invention, a projector assembly with at least one light source is provided, via which light can be emitted. In addition, the projector assembly has at least one gobo that is connected downstream of the light source, i.e. is arranged in the beam path of the emitted light. The gobo screen preferably contains information, in particular a logo, which can be displayed via the projector assembly. Further preferably, a gobo aperture diaphragm is arranged upstream or downstream or is assigned to the gobo screen. Alternatively, it is conceivable that the gobo screen has a gobo aperture diaphragm. In addition, a gobo lens is provided, which is connected upstream or downstream of the gobo screen. If the gobo lens is connected upstream of the gobo screen, the gobo lens is preferably arranged between the light source and the gobo screen. A projection lens is provided as a further lens, which is in turn arranged downstream of the gobo screen, that is to say is arranged downstream of the gobo screen in the beam path. In addition, an aperture diaphragm is arranged, which is likewise connected downstream of the gobo screen. As seen in the beam path, the aperture diaphragm for the projection lens can be, for example, arranged upstream or downstream of the projection lens. Preferably, the gobo lens is configured and arranged in such a way that the light emitted by the light source, in particular via the gobo, is focused into the image plane of the aperture diaphragm. Furthermore, the projection lens is preferably designed and arranged in such a way that it displays the image plane from the gobo screen in the far field.
The projector assembly according to the invention is based on so-called “Köhler Illumination”. Köhler improved the lighting system of microscopes with his system. Köhler developed an optical system in order to enable a homogeneous illumination of a microscope stage. This system has a tungsten lamp, a collector lens and a condenser lens. The collector lens bundles the light from the tungsten lamp and projects an image of a coil from the tungsten lamp onto an aperture diaphragm upstream of the condenser lens. The condenser lens, in turn, projects the image plane of a further aperture diaphragm downstream of and assigned to the collector lens onto the microscope stage. In the projector assembly according to the invention, based on the Köhler principle, the image plane of the gobo, which contains a logo, for example, is imaged in the far field, with it being shown that this results in a high image quality with little outlay in terms of apparatus due to the embodiment according to the invention. Moreover, it has been shown that opto-mechanical tolerances for the components of the projector assembly can be comparatively large and nevertheless a comparatively high imaging quality is made possible, which overall leads to a robust product design. Furthermore, it has been shown that, with the projector assembly, a comparatively large gobo screen or a comparatively large logo is made possible in a simple manner in the case of a comparatively high imaging quality. Due to the comparatively large gobo screen, an energy density resulting from the light that acts on the gobo screen is lower compared to the prior art. As a result of the possibility of making the gobo screen larger, a higher flexibility also results for different gobo or logo sizes. Furthermore, the projector assembly advantageously leads to a reduction of a chromatic aberration without a diffractive optical element, such as a hybrid asphere, having to be used. In addition, the projector assembly according to the invention allows a focal length for the same image or gobo size to be increased compared to the prior art, whereby tolerances for positioning the projection lens are increased. In addition, a large selection of projection lenses for different image sizes can be used. Image sizes can be provided, for example, between 350 to 1,400 mm in the far field at a projection distance of 1 m, wherein the projection lenses have low or moderate chromatic aberrations.
In a further embodiment of the invention, the gobo lens has a convex light entry surface and a planar light exit surface. For example, the gobo lens is designed as a plano-convex lens. With the gobo lens, the light can thus be focused in a simple manner.
In a further embodiment of the invention, a collimation lens can additionally be provided, which is connected upstream of the gobo lens and the gobo screen and the gobo aperture diaphragm and downstream of the light source. With the collimation lens, the radiation of the light source can be collimated in a simple manner in terms of device technology, which leads to an improvement in the imaging quality and supports the focusing of the gobo lens. Preferably, the collimation lens collimates the light in a light cone or light cone frustum, which tapers in the direction of radiation and whose lateral surface is inclined with respect to the main emission axis by 10° or by approximately 10°. The projector assembly according to the invention advantageously allows a distance between the collimation lens and the light source to be comparatively large. As a result, a cost-effective material, such as plastic, can be used for the collimation lens and/or for one or more of the further lenses instead of, for example, comparatively cost-intensive silicone.
Preferably, the collimation lens and/or the gobo lens and/or the projection lens are arranged one behind the other in the beam path of the light emitted by the light source. These are further preferably located on a main emission axis and can be arranged coaxially to one another. It is also conceivable that one or more or all lenses is/are rotationally symmetrical. In addition, the aperture diaphragm and gobo aperture diaphragm can have a circular opening cross section and/or lie on the main emission axis and/or be arranged coaxially to one or more lenses.
The gobo screen is preferably a simple gobo (gobo=graphic optical blackout). The gobo screen can have, for example, a, in particular transparent, carrier with a light entry and a light exit surface. Further preferably, the gobo device is easily formed or arranged on the light exit surface. The gobo can be designed particularly easily as a film. This is, for example, simply printed and can thereby have light-permeable film sections and light-impermeable and/or light-partially permeable film sections in order to form information, such as a logo. The gobo in the form of the film can be easily applied to the light entry surface and/or to the light exit surface of the carrier in terms of device technology. It is also conceivable, for example, to apply a film onto the light entry surface and a film onto the light exit surface of the carrier. The carrier can be designed, for example, as a carrier disk or the gobo lens is simply provided as a carrier. Alternatively or additionally, provision can be made for the gobo to be colored or for the film to be printed in color in order to form the gobo. The light entry surface and the light exit surface of the carrier can be arranged, for example, at a parallel distance from one another. Preferably, the gobo is in a plane, whereby it can be easily displayed. In other words, the projection lens can display the gobo, which is flat or applied to a flat surface of the gobo lens or the carrier, in the far field. By using the gobo as a film, it is conceivable, as already mentioned, to print and/or scale this, wherein one or more colors or different colors can be used. In this way, a colored image can be formed. By using the film, a cost-intensive glass gobo disk, as is frequently used in the prior art, is no longer necessary. As already mentioned above, due to the projector assembly the gobo screen can be comparatively large and thus the gobo can also be comparatively large. This further leads to the advantage that, for example, color printers with a lower resolution, which are more cost-effective and nevertheless lead to a gobo that has a high image quality in the far field, can be used. The gobo has, for example, a size or a maximum diameter between 2 and 5 mm, wherein the size in the gobo plane is measured.
The gobo screen preferably contains information to be displayed via the projector assembly, such as a logo or a symbol or a character or an image.
In a further embodiment of the invention, the gobo aperture diaphragm is connected upstream of the carrier and/or the gobo, in particular, directly connected. It is also conceivable to connect the gobo aperture diaphragm directly to the carrier and/or the gobo. Furthermore, it is conceivable that the gobo aperture diaphragm surrounds the projection lens, in particular, completely surrounds. The gobo aperture diaphragm can, for example, extend in a plane in which an edge of the light entry surface of the projection lens can lie. The gobo aperture diaphragm is arranged, for example, at a parallel distance or parallel to the gobo.
The arrangement of the gobo lens at or adjacent to the gobo position is extremely advantageous for high imaging quality. Due to the convex-planar configuration of the gobo lens, the gobo can be arranged as close as possible to or onto the planar or planar surface or light exit surface of the gobo lens.
Preferably, at least one or more light-emitting diodes (LEDs) are provided as the light source, which are preferably designed as surface emitters with homogeneous spatial light distribution.
In a further embodiment of the invention, the aperture diaphragm downstream of the gobo screen is arranged downstream of the projection lens. In contrast, the aperture diaphragm in front of the projection lens is usually provided in the case of the classic Köhler illumination. The position of the aperture diaphragm defines the length of the projector assembly. By positioning this behind the projection lens, a greater length of the projector assembly and/or of the projection lens is made possible. It would also be conceivable to form or arrange the aperture diaphragm arranged downstream of the gobo screen on the light exit surface of the projection lens or at the end of the projection lens. Alternatively, the aperture diaphragm can be spaced apart from the projection lens. It is conceivable here to form the aperture diaphragm on or in a window that is connected downstream of the projection lens and forms, for example, a light exit window or end window of the projector assembly. The aperture diaphragm has a light passage that is comprised of a light-impermeable and/or light-absorbing material, for example metal. The aperture diaphragm is preferably a mechanical diaphragm that reduces a diameter of the beam path for the light or of the beam of rays from the light. It can thus serve as a correction parameter for the objective diameter of the projection lens and for the image quality. In other words, the aperture diaphragm is arranged on the rear side of the projection line.
The projection lens is, for example, cylindrical or circular cylindrical and/or can have a convex light entry surface and/or a convex light exit surface. The projection lens and the projector assembly can be designed in such a way that light entering via the or a light entry surface of the projection lens is spaced apart from a circumference of the light entry surface. In other words, light only enters in the inner region of the light entry surface or the projection lens. By using the projector assembly or Köhler illumination, the image quality is improved as a result, since only the inner part of the projection lens is inserted and illuminated. This allows better imaging quality in combination with a smaller lens size and a robust optically mechanical design.
The collimation lens is, for example, cylindrical or circular cylindrical and has a convex light entry surface and/or a convex light exit surface.
Advantageously, the projection lens has a frustoconical lateral surface starting from its light exit surface or is configured in the shape of a truncated cone. The frustoconical lateral surface is distributed in the direction towards the light source or counter to the radiation direction. As a result of the frustoconical lateral surface, the light exit surface forms the aperture diaphragm. In a further embodiment, the lateral surface can extend up to the light entry surface of the projection lens or the lateral surface extends up to a radial mounting collar for the projection lens. This can be formed between the light entry surface and the lateral surface of the projection lens. The mounting collar, in turn, can extend from the light entry surface, viewed in the direction of the main emission axis. The aperture diaphragm is formed on or in the light exit surface of the rear side of the projection lens or through the light exit surface. A physical aperture diaphragm, which consists, for example, of metal or light-absorbing material, can be conserved by the truncated cone-shaped lateral surface or by the frustoconical section of the projection lens formed thereby, which is delimited at the end by the light exit surface. In other words, due to the special beam pattern in the interior of the projection lens, the aperture diaphragm is realized as a conical surface, which tapers from the clear optical diaphragm from the front surface of the projection lens to the rear surface of the projection lens.
In a further embodiment of the invention, a housing is provided in which the collimation lens and/or the projection lens and/or the carrier and/or the gobo lens are arranged and attached or fixed. With the components arranged therein, the housing preferably forms a module. Preferably, all the lenses and/or the carriers are provided and fixed in the housing. In turn, the housing can, for example, be arranged or integrated into a further housing or lamp housing or projector housing, in particular inside. Preferably, the housing has a housing inlet and a housing outlet opening for the light. It is thus possible that the light source can also be arranged outside the housing or can be coupled directly into the housing inlet opening and light via the housing inlet opening. Of course, it is conceivable that the light source is also provided within the housing. It would also be conceivable for no housing inlet opening to be formed.
The housing advantageously has a gobo contact surface for the gobo. This can surround the beam path of the beams at least in sections or completely. The housing and the carrier and/or the gobo lens are designed in such a way that the carrier and/or the gobo lens can be fastened at different positions onto the gobo contact surface. As a result, the carrier and/or the gobo lens can be displaced and positioned within a certain region before the final fixing in the housing, in order to position and orient them relative to the collimation lens and/or to the projection lens. In other words, a clearance suitable for the carrier and/or for the gobo lens in the transverse direction to the beam path or in the transverse direction to the main emission axis is formed in the housing. In other words, the gobo contact surface, the carrier and/or the gobo lens and the housing are designed in such a way that the carrier and/or the gobo lens can be displaced relative, in particular transversely, to the main emission axis on the gobo contact surface before fastening.
Preferably, one or more adhesive region(s) or adhesive point(s) is/are provided between the gobo contact surface and the carrier or the gobo lens in order to bond them to one another. The adhesive for the adhesive region (s) is preferably UV-curable. It is conceivable that, after arranging the carrier or the gobo lens on the gobo contact surface, adhesive regions with adhesive are provided and the carrier or gobo lens is then initially positioned, wherein this/these is/are displaceable on the gobo contact surface. After positioning, the adhesive is UV-cured, whereby the relative position of the carrier or of the gobo lens is fixed onto the gobo contact surface.
The gobo aperture diaphragm is preferably formed by the housing, which is simple and cost-effective in terms of device technology. For example, the gobo aperture diaphragm is formed by an inner radial collar on the housing, which has an inner, in particular circular cylindrical or cylindrical or frustoconical lateral surface, which surrounds the beam path. An end face of the radial collar pointing in the radiation direction can form the gobo contact surface in a simple way in terms of device technology. The gobo contact surface can point in the radiation direction and/or lie in a plane that extends transversely to the main emission direction.
The housing is preferably designed to be space-saving and simple in terms of device technology in an approximately tubular manner.
In a further embodiment of the invention, the housing has an inner step. This can have a stepped surface pointing counter to the direction of radiation, on which the collimation lens is supported axially, in particular via a radial collar formed on the collimation lens. As seen in the direction of radiation, the stepped surface is formed in front of the gobo contact surface and/or in front of the inner radial collar. The inner step can have a first inner, in particular circular cylindrical or cylindrical or frustoconical, stepped lateral surface. This can form a housing inlet opening or can be open towards the housing inlet opening and extend up to the stepped surface. In addition, the inner step can have a second inner, in particular circular cylindrical or cylindrical or frustoconical, stepped lateral surface. This can extend from the stepped surface as seen in the direction of radiation and have a smaller diameter compared to the first stepped surface. The stepped lateral surfaces are preferably arranged coaxially to one another. The collimation lens can be radially supported on the inner first stepped lateral surface, in particular via its radial collar. The stepped lateral surface(s) is/are truncated cone-shaped and taper(s) preferably in the radiation direction.
Furthermore, provision can be made that at least one housing spring, in particular in one piece with the housing, is formed in the region of the first inner stepped lateral surface of the step. In the mounted state of the collimation lens, in particular via the radial collar of the collimation lens, this can apply a spring force to the collimation lens on its side facing the housing opening. As a result, the collimation lens between the stepped surface and the housing spring can be held or tensioned in a simple manner. Preferably, a plurality of housing springs, in particular on a pitch circle, are designed to apply a spring force uniformly to the collimation lens.
The gobo lens is advantageously arranged in the region of the second inner stepped lateral surface of the inner step. The gobo lens can be supported on one or the radial collar of the housing, which is preferably adjacent to the second inner stepped lateral surface in the radiation direction.
At least one housing spring can be formed in the region of the second inner stepped lateral surface, in particular in one piece in the housing. In the mounted state of the gobo lens, this can apply a spring force to the gobo lens on its side facing the housing opening. The gobo lens can thus be easily tensioned between the radial collar of the housing and the housing spring. It would be conceivable to provide a plurality of housing springs, which are preferably arranged on a pitch circle in order to apply force to the gobo lens uniformly.
In a further embodiment of the invention, the housing has an inner step which has a stepped surface pointing in the direction of radiation, on which the projection lens can be axially supported, in particular via a radial collar formed on the projection lens. As seen in the direction of radiation, the stepped surface can be formed after the gobo contact surface and/or after the inner radial collar of the housing with the gobo contact surface. The projection lens can be easily arranged and mounted in the housing via the inner step. The inner step can have a first inner, in particular circular cylindrical or cylindrical or frustoconical, stepped lateral surface, which forms a housing outlet opening or is open towards the housing outlet opening. If the inner stepped lateral surface has a truncated cone shape, it preferably widens in the radiation direction. The projection lens can easily be inserted into the housing via the first inner stepped lateral surface. The first inner stepped lateral surface preferably extends up to the stepped surface. In the step, a second inner, in particular cylindrical or circular cylindrical or frustoconical, stepped lateral surface can be provided, which extends from the stepped surface counter to the radiation direction and has a smaller diameter compared to the first stepped lateral surface. The stepped lateral surfaces are preferably arranged coaxially to one another. If the second inner stepped lateral surface has a truncated cone shape, it preferably widens in the radiation direction. The carrier and/or the gobo lens can be radially supported on the second inner stepped lateral surface. Preferably, the carrier and/or the gobo lens is mounted into the housing via the inner step. The projection lens can be radially supported on the inner first stepped lateral surface, in particular via its radial collar.
In the region of the first inner stepped lateral surface, at least one housing spring is formed, in particular integrally, with the housing. In the mounted state of the projection lens, this can apply a spring force to the projection lens, in particular to the radial collar of the projection lens, on its side facing the housing outlet opening. As a result, the projection lens can easily be tensioned between the stepped surface and the housing spring.
If two inner steps are provided, the lenses can be mounted in a simple manner from different sides, which enables rapid assembly. This can be made possible in particular without tools due to the housing springs.
Advantageously, the housing spring or a respective housing spring projects in a ramp-like manner from a spring space formed in the housing and opened to the respective stepped lateral surface in the lens space tensioned by the respective stepped lateral surface and has a ramp surface. This can extend inward and in the mounting direction when viewed in the mounting direction of the corresponding lens. When the corresponding lens is mounted, when it is inserted axially or along the optical main axis into the housing, it can press the housing spring elastically into the spring space over the ramp surface. After a predetermined mounting path, the corresponding lens leaves the ramp surface, as a result of which the housing spring is relaxed back into the lens space and projects therein and, in this case, overlaps the lens, in particular with a spring contact surface. The housing spring can be configured in such a way that, when the corresponding lens is overlapped, the latter is acted upon with a spring force, in particular via the spring contact surface.
According to the invention, a projection system comprising the projector assembly is provided according to one or more of the aspects set forth above and below. The projection system has a system housing into which the projector assembly, which preferably has a housing, is inserted and/or integrated. The projection system can have further functional components. The projector assembly can thus be easily mounted as a “component” or module in the system housing.
The applicant reserves the right to make an independent claim in respect of a vehicle that has the projection system and/or the projector assembly according to one or more of the aforementioned aspects. The vehicle may be a utility vehicle or a water-bound vehicle or a land-bound vehicle. The land-bound vehicle can be a motor vehicle or a rail vehicle or a bicycle. The vehicle is particularly preferably a truck or a passenger car or a motorcycle. The vehicle can also be designed as a non-autonomous or partially autonomous or autonomous vehicle.
The invention will be explained in more detail below with reference to exemplary embodiments. In the figures:
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
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The collimation lens 4 collimates the light emitted by the light source 2 in a light cone, which tapers in the beam direction. According to
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A projector assembly with at least one light source, which is connected downstream of a gobo screen, is disclosed. The gobo screen has a gobo aperture diaphragm and a gobo lens. A projection lens is connected downstream of the gobo screen. In addition, an aperture diaphragm is connected downstream of the gobo screen. The light emitted by the light source is focused in the aperture diaphragm via the gobo lens. The image from the gobo screen is displayed in the far field via the projection lens.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102022117917.6 | Jul 2022 | DE | national |
