DE102022116998A1 - PROJECTION SYSTEM, VEHICLE LIGHT WITH A PROJECTION SYSTEM AND METHOD - Google Patents

Abstract

What is disclosed is a static projection system with projection optics and with a mask that is connected upstream of the projection optics. Using a light source, light can be emitted through the mask and then through the projection optics in order to project an image onto an imaging surface. In order to minimize color magnification errors in the image, a color layer is formed at least in sections in at least one translucent recess of the mask.

Description

The invention is based on a projection system with which images, in particular static ones, can be projected onto an imaging surface. The invention further relates to a vehicle light with such a projection system. A method for designing such a projection system is also provided.

Static projection systems are known from the prior art which have a GOBO (GOBO = Graphical Optical Blackout), via which, in particular based on a shadow projection, a logo, a pattern, a text or an image can be imaged on an image surface. The GOBO is preceded by a light source and followed by projection optics. This can, for example, have a single projection lens. Such a projection lens is not suitable for compensating for scale and color deviations in an image that can be projected onto an imaging surface via the projection system. This means that an undesirable colored border appears in the image, such as a logo. The colored edge or color fringe depends on the individual projection lens, the gobo-side numerical aperture (NA) - that is, the maximum open light cone that can be achieved with the projection lens -, the focal length and the maximum GOBO size can also be defined as a field angle, i.e. as an angle starting from the center of the projection lens to the maximum edge of the GOBO. The larger the NA and/or the shorter the focal length and/or the larger the GOBO, the larger the color fringes. The focal length determines the opening angle of the projection lens and thus the image size. It would be conceivable to compensate for the scale and color deviations using additional projection lenses made of different materials. For example, three projection lenses made of at least two different materials can be used for the projection optics instead of a single projection lens. Alternatively or additionally, it would be conceivable to apply a diffractive optical element to a lens surface of the individual projection lens or one of the projection lenses, which is known as a hybrid asphere. The disadvantage of these solutions is the comparatively high level of device technology and cost-intensive effort.

The object of the present invention is to create a projection system and a vehicle light in which an image with comparatively small or no scale and color deviations can be generated in a simple and cost-effective manner in terms of device technology. Furthermore, it is the object of the present invention to create a method with which a projection system can be designed in a simple manner, cost-effectively and with little effort, in such a way that images with comparatively small or no scale and/or color deviations can be projected via this system.

The task with regard to the projection system is solved according to the features of claim 1 or 8, with regard to the vehicle light according to the features of claim 9 and with regard to the method according to the features of claim 10.

Particularly advantageous refinements can be found in the dependent claims.

According to the invention, a projection system, in particular a static projection system, is provided. This has projection optics and a mask that is connected upstream of the projection optics. The mask is preferably designed in the form of a GOBO (GOBO = Graphical Optical Blackout). In particular, the mask is designed in such a way that it can be provided for shadow projection, for example in order to depict an image of a logo and/or a pattern and/or a text and/or an image on an imaging surface. The mask and the projection optics can be irradiated by a light source that can be connected upstream of the mask in order to carry out the shadow projection on the imaging surface. The mask is therefore provided in the beam path of the light source in front of the projection optics. The mask preferably has a non-transparent mask layer. At least one or more recesses are formed in this, which can be at least partially or completely irradiated by the light from the light source. The at least one recess can be designed, for example, in the form of at least one logo and/or in the form of at least one pattern and/or in the form of at least one text and/or in the form of at least one image. Shadow projection can be made possible with the non-transparent mask layer and the at least one irradiable recess made therein. According to the invention, at least part of the recess has a transmissible color layer and/or a color filter, it being conceivable to design the color filter as a color layer. The color filter is designed in such a way that a color magnification error and/or a color deviation and/or a scale deviation of the image on the imaging surface is at least reduced or avoided, in particular in comparison to a recess without a color filter.

The term color layer is used below, whereby the configurations described can be corresponding to a color filter or a color layer is provided as a color filter.

This solution has the advantage that color magnification errors are reduced or prevented in a simple manner in terms of device technology, in particular without adapting the projection optics. Since the color magnification errors are reduced or prevented due to the design of the mask with the irradiable color layer, projection optics with a simple device design can be used. It is therefore no longer necessary to elaborately design the projection optics in such a way that the color magnification errors are reduced or prevented. Of course, it is conceivable that the projection optics are also designed in such a way as to reduce the color magnification error, in which case, in combination with the mask, an image with an extremely high quality is then made possible. In other words, chromatic aberrations can be virtually completely corrected without requiring further investments, such as an injection mold for a hybrid asphere as projection optics.

According to the invention, a projection system with projection optics according to a further embodiment is provided. This has a mask, which is preferably designed for shadow projection and which is connected upstream of the projection optics. The mask and the projection optics can be irradiated by a light source that can be connected upstream of the mask, in particular to carry out the shadow projection on an imaging surface. The mask is advantageously designed as a liquid crystal display or LCD (LCD = Liquid Crystal Display). This has at least one switchable or several switchable liquid crystal region(s) and at least one non-switchable or several non-switchable liquid crystal region(s) or opaque region(s). A polarization filter is preferably arranged in the beam path between the light source and the areas in order to polarize the light from the light source before it enters the areas. This can be part of the liquid crystal display. In addition, an analyzer is preferably connected downstream of the areas, which is arranged, for example, in the beam path between the areas and the projection optics, so that only light with a specific polarization radiates from the projection system. The analyzer is preferably part of the liquid crystal display. The light entering this area can be controlled or polarized via the at least one switchable liquid crystal area in such a way that it is either blocked on the analyzer or radiates through the analyzer. In addition, it can be provided that liquid crystals in the at least one non-switchable liquid crystal region are oriented in such a way that light emerging from this region is blocked by the analyzer. Alternatively, it is conceivable to provide an opaque area instead of the non-switchable liquid crystal area. At least part of the at least one switchable liquid crystal region can have a color filter that can be transmitted through, which is designed to at least reduce a color magnification error on the imaging surface.

This solution has the advantage that the mask can be controlled due to the at least one switchable liquid crystal area and at the same time a high imaging quality is possible due to the color filter.

If a plurality of switchable liquid crystal areas are provided, a dynamic or changeable image can be formed in a simple manner in terms of device technology by appropriately controlling the liquid crystal area. Preferably, a control device is provided or at least connectable to the projection system - for example wirelessly or via cable - in order to control the controllable or switchable liquid crystal areas and/or to control the light source.

In a further embodiment of the invention, the at least one recess is delimited by one or more recess edges or a recess edge or recess edges of the mask layer. If the liquid crystal display is provided as a mask, the at least one switchable liquid crystal area is preferably delimited by an edge. The color layer is preferably formed at least adjacent to the recess edge or to the edge. This is advantageous because color magnification errors often occur in the image on the image surface in the edge or edge area. It is conceivable that the color layer extends from the recess edge or edge into the recess or area. Furthermore, it is conceivable that the color layer extends at least in sections along the recess edge or the edge or along the entire recess edge or the entire edge.

The entire or essentially the entire recess or the entire area is advantageously provided with a layer of color. This can be particularly advantageous in the case of comparatively small recesses or areas, since, for example, production of the color layer can be simplified.

The invention is explained using a switchable liquid crystal area. If several are provided, these or at least some of them can be designed accordingly. In a further embodiment of the invention, the color layer has sections with different colors. It has been shown that this allows color magnification errors to be specifically compensated for in a simple manner can do that. So that the color magnification error is evenly compensated for, it is conceivable that a width of the color layer - viewed in the direction of the mask layer and viewed starting from the at least one recess edge or the edge - is the same or essentially the same. It would therefore be conceivable that the color layer extends in a band-like manner along the recess edge or the edge, in particular with a constant width, the color layer preferably directly adjoining the recess edge or the edge or extending adjacent thereto. Alternatively or additionally, it can be provided that the color layer has at least a plurality of colors that have a predetermined/precalculated order starting from the recess edge or the edge. If the color layer is designed like a band, it would be conceivable, for example, for it to have several parallel extending band sections in different colors that extend in the band direction.

A plurality of recesses or switchable liquid crystal areas are advantageously provided, which differ in terms of their color layer(s), which enables flexible and precise adjustment of an emitted light image. For example, at least one band section can be provided in the same color in the plurality of recesses or areas, with a width of the band sections differing. Alternatively or additionally, it can be provided that the recesses or areas have different color layers and/or different tape sections. The recesses or areas can be designed the same or differently.

In a further embodiment of the invention, a single or single projection lens is provided as the projection optics, which is simple and cost-effective in terms of device technology. This is possible because, according to the invention, the color magnification error can at least be reduced over the mask and therefore no complex projection optics are necessary. In other words, only a single projection lens is advantageously arranged in the beam path between the light source and the imaging surface. If several projection lenses are provided in an alternative, these can also be designed to be simple in terms of device technology, since the color magnification error does not have to be compensated for. The projection lens, in particular the only one, is advantageously designed as an aspherical lens. This therefore has at least one refractive surface that deviates from the spherical or flat shape. In this way, an imaging error can be avoided or reduced, which is common with spherical lenses. In particular, chromatic or spherical-chromatic aberration can be corrected. In combination with the mask, an image with an extremely high quality can be achieved.

If a liquid crystal display is provided as a mask, two projection lenses are preferably arranged, in particular in series, in order to further improve image sharpness.

The projection lens/s is/are, for example, inexpensive and lightweight made of plastic. In a further embodiment of the invention, a pinhole or aperture diaphragm is connected downstream of the projection optics or integrated into the projection optics, in particular into the projection lens. This is therefore provided after the projection optics in the beam path of the light that can be emitted by the light source. In this way, for example, the sharpness of the image can be easily improved. In combination with the mask and, for example, a single projection lens, this leads to an extremely simple design of a projection system in terms of device technology that has a high imaging quality.

In a further embodiment of the invention, the mask is inexpensive and simply designed as a film. This is, for example, flat or even. Such a film can be formed extremely easily with the mask layer and/or color layer.

Preferably, the mask layer and/or the color layer is applied to the mask, in particular as a film, by a printing process. If the mask is designed as a film, it can be printed particularly easily and inexpensively. In other words, the mask, in particular as a film, can be printed on a printer with the mask layer and/or color layer or developed on a film, which is extremely cost-effective.

Alternatively, it is conceivable that the mask has a, in particular transparent, substrate, such as glass. The substrate in turn can have the opaque mask layer, into which the at least one transilluminable recess is then introduced. The color layer can, for example, be applied to the substrate as a varnish. Of course, it is conceivable to paint the mask as a film. It is also conceivable to apply the mask layer to the substrate as a lithographically produced layer or chrome layer.

It has been shown that a lithographic production process of the color layers - in particular the lithographically produced layer or chrome layer - on the mask in combination with a laser light source as the upstream light source in the projection system leads to images with an extremely low or no color magnification error.

Alternatively or additionally, it would be conceivable to simply produce the mask using a so-called color coupler reaction. Here, a transparent substrate or a transparent film is provided which has coloring substances as couplers in a colorless state. When exposed to energy, these substances react with a color change, whereby the mask and/or the color filter can be formed. Alternatively or additionally, it is conceivable to use a laser color film process. The mask in the form of the film can preferably have two or three layers of color, each with a different color (e.g. red, green and blue), which lie on top of each other. The color layers can be removed with a laser in order to form the desired design of the color filter. For example, if a section of the red paint layer is removed, the green and blue paint layers would still be present in this section, resulting in turquoise.

Further preferably, the projection system has the light source which is connected upstream of the mask. The light source is preferably designed such that it emits white light. It would also be conceivable that the light source emits light in the RGB color space.

The light source is preferably a light-emitting diode (LED) or an LED module, with several, in particular different colored LEDs. An LED can be in the form of at least one individually housed LED or in the form of a micro-LED or a nano-LED (Smart Dust). Several LED chips can be mounted on a common substrate (submount) and form an LED or can be attached individually or together, for example on a circuit board, using a chip on board process (CoB). Instead of or in addition to inorganic LEDs, for example based on AlInGaN or InGaN or AlInGaP, organic LEDs, for example OLEDs such as polymer OLEDs, can also generally be used. The LEDs can be directly emitting or have an upstream phosphor. Alternatively, the light-emitting component may be a laser diode or a laser diode array. It is also conceivable to provide an OLED luminous layer or several OLED luminous layers or an OLED luminous area. The emission wavelengths of the light-emitting components can be in the ultraviolet, visible or infrared spectral range. The light-emitting components can also be equipped with their own converter. The LEDs can emit white light in the standardized ECE white field of the automotive industry, for example realized by a blue emitter and a yellow/green converter. According to the invention, a vehicle light is provided with the projection system according to one or more of the preceding aspects. Such a vehicle light is designed to be simple and cost-effective in terms of device technology and can display images on an imaging surface in high quality. Since the projection system is simple and has a few components, it is also extremely robust and therefore extremely advantageous for a vehicle light that is exposed to external forces and weather conditions.

The projection system is preferably designed to be compact as a module.

The light source can be arranged and attached to a circuit board or a PCB (PCB = Printed Circuit Board). The circuit board can have a metallic core, which can therefore be a metal-core PCB.

The liquid crystal display is advantageously housed in a frame. The display can be attached to the circuit board via this. The frame is designed to be extremely robust as a metal frame in order to safely protect the liquid crystal display from external forces, especially when the projection system is used in a vehicle.

The liquid crystal display is, for example, electrically connected to the circuit board via a cable connection in order to power and control it.

Further preferably, a collimator is arranged between the light source and the mask, in particular in the form of the liquid crystal display, which guides light from the light source to the mask. The collimator preferably serves to generate light with an approximately parallel beam path. This collimation preferably serves to give the light a specific direction, which is particularly advantageous for the liquid crystal display.

The applicant reserves the right to make an independent claim to a vehicle with the vehicle lamp in accordance with one or more of the aforementioned aspects.

The vehicle may be an aircraft or a water-based vehicle or a land-based vehicle. The land-based vehicle may 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 furthermore be designed as a non-autonomous or semi-autonomous or autonomous vehicle.

• - Ermittlung einer vorgesehenen Zielabbildung, wie beispielsweise eines Logos, mit einer vorgesehenen Lichtverteilung auf einer vorgesehenen Abbildungsfläche. Die Zielabbildung soll hierbei vorzugsweise eine möglichst homogene Farbe, insbesondere weiß, und/oder eine möglichst homogene Farbverteilung aufweisen.
• - Ermittlung - basierend auf der ermittelten Zielabbildung der vorgesehenen Projektionsoptik des Projektionssystems - die Ausgestaltung der Farbschicht in der zumindest einen Aussparung der Maske oder in dem zumindest einen schaltbaren Flüssigkristall-Bereich und vorzugsweise die Ausgestaltung der Aussparung oder des zumindest einen schaltbaren Flüssigkristall-Bereich derart, dass das Projektionssystem mit dieser Maske die Zielabbildung auf der vorgesehenen Abbildungsfläche wunschgemäß ausbildet. Insbesondere wird basierend auf der Zielabbildung und basierend auf der vorgesehenen Projektionsoptik und bei Bedarf basierend auf weiteren Komponenten, wie beispielsweise die Lochblende, die Ausgestaltung, Anordnung und Verteilung der Farben, falls mehrere vorgesehen sind, ermittelt. In anderen Worten erfolgt eine Rückwärtsberechnung, um die farbige Maske zu erzeugen, wodurch Farbvergrößerungsfehler, insbesondere der einzelnen Projektionslinse, minimiert sind.
• - Vorzugsweise erfolgt die Ermittlung der Ausgestaltung der Farbschicht und möglicherweise auch die Ausgestaltung - insbesondere die Größe und Form - der Aussparung oder des zumindest einen schaltbaren Flüssigkristall-Bereichs, basierend auf den drei Basiswellenlängen für rot, grün und blau. Es hat sich gezeigt, dass dies ausreichend ist, um weitestgehend den Farbvergrößerungsfehler zu minimieren. Mit anderen Worten wird für das optische System in Form des Projektionssystems umgekehrt ausgehend von der Abbildung oder Zielabbildung, insbesondere für drei Hauptfarben (RGB) rückwärts eine Berechnung oder Auslegung durchgeführt. Somit gelangt man von der Zielabbildung zur Maske. Somit kann das Design oder die Auslegung des Projektionssystems derart erfolgen, dass das System kostengünstiger ist, da der Farbvergrößerungsfehler nicht mit Glaslinsen minimiert werden muss und somit eine Projektionslinse oder mehrere Projektionslinsen aus - vorzugsweise gleichem - Kunststoff für die Projektionsoptik eingesetzt werden können. Für bekannte optische Systeme und alle bekannten Bildfehler kann die Auslegung leicht durchgeführt werden.

According to the invention, a method for designing a projection system according to one or more of the aspects mentioned is provided with the following steps:

• - Determination of an intended target image, such as a logo, with an intended light distribution on an intended image area. The target image should preferably have a color that is as homogeneous as possible, in particular white, and/or a color distribution that is as homogeneous as possible.
• - Determination - based on the determined target image of the intended projection optics of the projection system - the design of the color layer in the at least one recess of the mask or in the at least one switchable liquid crystal area and preferably the design of the recess or the at least one switchable liquid crystal area in such a way, that the projection system uses this mask to form the target image on the intended imaging surface as desired. In particular, based on the target image and based on the intended projection optics and, if necessary, based on further components, such as the pinhole, the design, arrangement and distribution of the colors, if several are provided, are determined. In other words, a backward calculation is performed to generate the colored mask, thereby minimizing color magnification errors, particularly of the individual projection lens.
• - The design of the color layer and possibly also the design - in particular the size and shape - of the recess or the at least one switchable liquid crystal area are preferably determined based on the three basic wavelengths for red, green and blue. It has been shown that this is sufficient to minimize the color magnification error as much as possible. In other words, a calculation or design is carried out backwards for the optical system in the form of the projection system, starting from the image or target image, in particular for three main colors (RGB). This takes you from the target image to the mask. The design or interpretation of the projection system can therefore be carried out in such a way that the system is more cost-effective, since the color magnification error does not have to be minimized with glass lenses and thus one projection lens or several projection lenses made of - preferably the same - plastic can be used for the projection optics. The design can be easily carried out for known optical systems and all known image errors.

What is disclosed is a static projection system with projection optics and with a mask that is connected upstream of the projection optics. Using a light source, light can be emitted through the mask and then through the projection optics in order to project an image onto an imaging surface. In order to minimize color magnification errors in the image, a color layer is formed at least in sections in at least one irradiable recess of the mask.

• 1 in einer schematischen Darstellung ein Projektionssystem gemäß einem Ausführungsbeispiel,
• 2a eine aus dem Stand der Technik bekannte Maske,
• 2b eine über die Maske aus 2a ausgebildete Schattenprojektion,
• 2c einen vergrößerten Ausschnitt aus der Schattenprojektion der 2b,
• 3a eine Maske des erfindungsgemäßen Projektionssystems aus 1 zusammen mit einem vergrößerten Ausschnitt,
• 3b eine über die Maske aus der 3a ausgebildete Abbildung,
• 3c einen vergrößerten Ausschnitt der Abbildung aus 3b,
• 4 einen Vergleich eines Verfahrens zur Auslegung des Projektionssystems aus dem Stand der Technik mit der Erfindung,
• 5 in einer schematischen Darstellung ein Projektionssystem gemäß einem weiteren Ausführungsbeispiel,
• 6 in einer Draufsicht eine Maske des Projektionssystems aus 5,
• 7 einen vergrößerten Ausschnitt der Maske aus 6,
• 8a und 8b in einer schematischen Darstellung Lichtspektren,
• 9a und 9b in einer Draufsicht jeweils eine Maske in unterschiedlicher Größe für das Projektionssystem aus 1 oder 5,
• 10a und 10b jeweils einen vergrößerten Ausschnitt der jeweiligen Maske aus 9a und 9b,
• 11a und 11b in einer Explosionsdarstellung einen Teil eines Projektionssystems gemäß einem weiteren Ausführungsbeispiel,
• 12 in einer perspektivischen Darstellung das zusammengebaute Projektionssystem aus 11a und 11b,
• 13 in einer Seitenansicht schematisch das Projektionssystem aus den 11a und 11b,
• 14 in einer schematischen Darstellung das Projektionssystem aus 12 zusammen mit einer Abbildung,
• 15 in einer Draufsicht entgegen einer Strahlungsrichtung eine Maske in Form einer Flüssigkristallanzeige des Projektionssystem aus 11a und 11b,
• 16 einen vergrößerten Ausschnitt der Flüssigkristallanzeige aus 15 mit einem Farbfilter.

The invention will be explained in more detail below using exemplary embodiments. The figures show:

• 1 in a schematic representation a projection system according to an exemplary embodiment,
• 2a a mask known from the prior art,
• 2 B one over the mask 2a trained shadow projection,
• 2c an enlarged section of the shadow projection of the 2 B ,
• 3a a mask of the projection system according to the invention 1 together with an enlarged section,
• 3b one over the mask from the 3a trained figure,
• 3c an enlarged section of the illustration 3b ,
• 4 a comparison of a method for designing the projection system from the prior art with the invention,
• 5 in a schematic representation a projection system according to a further exemplary embodiment,
• 6 A mask of the projection system in a top view 5 ,
• 7 an enlarged section of the mask 6 ,
• 8a and 8b in a schematic representation of light spectra,
• 9a and 9b In a top view, a mask of different sizes is selected for the projection system 1 or 5 ,
• 10a and 10b an enlarged section of the respective mask 9a and 9b ,
• 11a and 11b in an exploded view a part of a projection system according to a further exemplary embodiment,
• 12 in a perspective view of the assembled projection system 11a and 11b ,
• 13 in a side view schematically the projection system from the 11a and 11b ,
• 14 in a schematic representation of the projection system 12 together with an illustration,
• 15 in a top view against a radiation direction, a mask in the form of a liquid crystal display of the projection system 11a and 11b ,
• 16 an enlarged section of the liquid crystal display 15 with a color filter.

According to 1 a static projection system 1 is shown. This has a light source 2, which is followed by a mask 4 in the form of a film. If necessary, it would be conceivable to provide one or more lighting optics between the light source 2, which is designed, for example, as an LED, and the mask 4. The mask 4 in turn is followed by projection optics 6 with a single projection lens 8. This has a convex light entry surface 10 and a convex light exit surface 12. The individual projection lens 8 is in turn followed by a pinhole 14. According to 1 Part of a light radiation 16 is shown schematically. The projection system 1 has an acceptance angle of, for example, +/- 10°. The acceptance angle can be determined with regard to the numerical aperture (gobo side), for example from the aperture or hole diaphragm, which is the maximum accepted angle. The numerical aperture can be measured from the center of the gobo or mask 4. This is advantageous because an angle far from the center can be asymmetrical (e.g. 0°-20°, with beam going below -20° to the optical axis). For a single lens with acceptable imaging quality (sharpness), the numerical aperture can preferably be up to a maximum of +/-20°. The more lenses used in a projection lens, the larger the angle that can be achieved. Further advantageously, a field angle between 10° and 30° is provided for the projection system 1. The field angle can be the opening angle of the projection system 1, which depends on the focal length. The field angle defines, for example, the image size with respect to a certain distance.

2a shows an example of a mask 18 known from the prior art in a plan view, into which an annular recess 20 is introduced. Is 18 light emitted via the mask, for example with a projection system similar to that in 1 is designed, a light ring 24 can be formed as an image on an imaging surface 22. The light ring 24 is also shown in a top view.

According to 2c an enlarged section of the light ring 24 is shown. It can therefore be seen that this has a color magnification error. For example, a first color ring 26 is formed in the area of its inner edge and a second color ring 28 adjoining it radially further out. The color ring 26 is a red color ring and the color ring 28 is a yellow color ring. A blue color ring 30 is formed radially on the outer edge.

The recess 20 of 2a has a width of 1 µm. Due to the resolution of the projection system, a width of at a distance of 1 m from the mask 18 8.5 mm. It is assumed that a single projection lens is provided that does not provide color correction for color magnification error. The color rings 26 and 28 together have a width of approximately 3.5 mm in the radial direction and the outer color ring 30 has a width of approximately 0.5 mm in the radial direction.

According to 3a the mask 4 of the projection system 1 is off 1 shown in a top view. This has an annular recess 32, the size of which is the recess 20 2a can correspond. A color layer 34 is introduced into the recess 32, which is shown in the enlarged section of the 3a is visible. The paint layer 34 has five annular sections, the sections 36 and 38 being provided with a reference number and the other sections not having a reference number due to their very small radial thickness for simplicity. The section 36, which extends in the direction of an outer recess edge of the recess 32, has a turquoise color because the green and blue of the RGB colors overlap. Radially outside of the section 36, three thin annular sections are formed - seen one behind the other in the radial direction - which include the section 36. An inner, a middle and an outer section are therefore provided. The annular (inner) section, which directly adjoins section 36 and surrounds it, is white. The next ring-shaped (middle) section, viewed radially, which surrounds the white section, is yellow because the green and red of the RGB colors overlap. The outermost ring-shaped section, which encompasses all other sections, is red. The three thin radially outermost sections extend - viewed together - in the radial direction from the outer recess edge of the recess 32 to the section 36. The three thin sections thus extend along the recess edge and the recess 32. The inner annular section 38 extends between an inner recess edge of the recess 32 and the annular section 36 and is blue. The section 38 adjoins both the section 36 and the inner recess edge. The recess 32 with the color layer 34 results in a according to 3b , which is an annular ring of light in plan view, has a small color magnification error compared to using a mask, such as that in the 2a until 2c is shown. 3c shows an enlarged section of the out of 3b , with a significantly improved light distribution and a greatly reduced magnification error compared to the prior art 2c is provided.

In other words, they show 2a until 2 B a classic GOBO with the corresponding illustration and the 3a until 3c a colored GOBO according to the invention with a classic lens.

According to 4 A method known from the prior art for the design and design of a projection system is shown in the top line. Here, based on a mask 18 known from the prior art, on a known projection optics 6 determined, see also 2a until 2c . Based on the The projection optics 6 are then designed and adjusted in such a way that color magnification errors are as small as possible. In contrast, in the projection system according to the invention in the bottom line 4 provided, from a desired target image in the form of and then determine the design of the colored mask 4 based on the projection optics 6. In contrast to the exemplary embodiment listed above, the projection optics 6 has: 1 three projection lenses. The method according to the invention described is for the individual projection lens 8, see 1 , as well as for several projection lenses, see 4 , applicable.

5 discloses a further embodiment of a projection system 44. This has a mask 46, which is preceded by an illumination system. The lighting system has a light source 48, which is preferably designed as a white LED, and a light guide 50 or taper that collects as much light as possible, reduces the angle of the emerging light and homogenizes the light both in space and in angle. This is thus arranged between the light source 48 and the mask 46. In addition, according to the embodiment 1 the mask 46 is followed by a projection lens 8 or individual lens and a pinhole 14. A distance between the mask 46 and the optics 8 is, for example, 500 mm.

According to 6 the mask 46 is shown in a top view. This has several circular ring sections as recesses 52, which are arranged concentrically. The recesses 52 extend all around a common center. Furthermore, some of the recesses 52 are the same and the other part of the recesses 52 are designed differently. The recesses 52 differ in their length as seen in the direction of rotation. It would also be conceivable that they differ in their width. A maximum diameter of the recesses 52 is preferably 3.978 mm (measured from the center to the outermost edge of the recess). A diameter of the next recess 52 seen from the radial outside is, for example, 3.580 mm. The mask 46 was calculated for three reference wavelengths, resulting in color contours in filter zones.

7 shows an enlarged section of the mask 46 6 . As an example, one of the recesses 52, which is the outermost recess, will be explained in more detail below. This has a central band-shaped section 54 which has no layer of paint or coating or color or tint and is therefore transparent. A width of the section 54 in the circumferential direction is constant. Starting from section 54, viewed in the radial direction outwards, there is a band-shaped yellow color layer 56. A band-shaped red color layer 60 extends between the yellow color layer 56 and a radial outer recess edge 58 or outer edge. Starting from the section 54 viewed in the radial direction inwards, a band-shaped turquoise or cyan color layer 62 follows. A band-shaped blue color layer 66 is formed between this and a radial inner recess edge 64. Outside the recesses 52, the mask 46 is formed with a non-transparent coating and/or color and/or tint.

According to 7 some of the recesses are shown schematically. The calculation of the color layers will be shown using the schematic recesses 68. Dashed polylines represent zones for a reference wavelength, such as red, green and blue. If all three zones overlap, the overlapping area is transparent. Two overlapping zones have additive colors in the overlapping area, such as cyan (cyan = green and blue) or yellow (yellow = red and green).

8a shows normalized LED spectra red, green and blue. 8b shows the combined “white” spectrum. Such spectra can result in minimal color effects at the edges of the image emitted via the projection system. The color effects can be caused by a wide spectrum of individual LEDs, particularly converted green that overlaps with blue and red.

9a and 9b each show a mask 70, 72, each of which is used for a different focal length. Chromatic aberration depends on the focal length: the longer the focal length, the greater the chromatic aberration. On the other hand, the focal length depends on the gobo or mask size: the larger the mask, the longer the focal length. The mask 70 in 9a is calculated for a focal length of 7.4 mm. The focal length of the mask is 72 in 9b is 4 mm.

10a shows an enlarged section of the mask 70 9a with actual recess and schematically shown recesses. In 10b is a section of the mask 72 9b shown with schematically illustrated recesses. It can be seen that the color filters or color layers in the mask 70 are larger compared to the mask 72. It has been shown that the larger the focal length, the larger the color zones or layers of color and the cheaper the manufacturing process. For example, using high-quality inkjet printers to produce the color layers, a resolution of up to 1440 dpi (25.4 mm/1440=17.6pm per pixel) can be achieved.

According to 11a and 11b a projection system 74 is shown according to a further embodiment. This has a mask in the form of a liquid crystal display 76. A light source 78 in the form of an LED is connected upstream of the display 76 and attached to a circuit board 79. A collimator 80 is arranged in the beam path between the light source 78 and the display 76. A first projection optics 82 and a second projection optics 84 are arranged in the beam path after the display 76. The display 76 is electrically contacted with the circuit board 79 via a flexible cable 86. The resolution of the liquid crystal display, for example, is 800PPI, i.e. 25.4mm/800=31pm per pixel.

12 shows an assembled state of the projection system 74 11a and 11b . Here, housing components 88 to 94 are additionally arranged in order to mechanically connect the display 76, the circuit board 79 and the optics 82, 84 to one another - in particular in a detachable manner.

13 illustrates a side view of some components of the projection system 74. The light source 78, the collimator 80, the liquid crystal display 76, the first projection optics 82 and the second projection optics 84 are shown, which are arranged in series. A disk 96 is arranged in the beam path after the second projection optics 84.

In 14 is the projection system 74 together with a shown, which is projected via a light radiation 100 emitted by the projection system 74. The light radiation 100 is shown schematically with a dash-dot line. The has a black or dark section 102 by forming a plurality of bright or illuminated sections 104. The light sections 104 have a parallelogram-like shape. The projection system 74 with the liquid crystal display 76 enables a static image to be made dynamic by appropriately controlling this liquid crystal display 76. With the liquid crystal display 76, liquid crystal areas or image segments can be switched on or off, in particular independently of one another. The projection system 74 is preferably set up in such a way that it either displays the entire or its image segments or bright sections 104 are projected in any order.

In the top view 15 On the liquid crystal display 76 it can be seen that it is surrounded by a frame 106 and is structured. Those from the light of the light source 78 - see 11a - Transmissible display 76 has a non-switchable liquid crystal area 108. This has liquid crystals that are preferably non-switchable, i.e. cannot change their orientation. The liquid crystals are oriented in such a way that polarized light passing through does not emerge from a downstream analyzer or polarization filter. The polarized light is formed by an upstream polarization filter. Furthermore, the liquid crystal display 76 has a large number of switchable liquid crystal areas 110, of which only one is provided with a reference number for the sake of simplicity. These are parallelogram-shaped. The liquid crystals in a respective region 110 can be oriented or switched to an off position such that polarized light cannot radiate through the analyzer. Additionally, the liquid crystals can be oriented or switched to an on position such that polarized light can shine through the analyzer. The areas 110 can be switched independently of one another. To switch the liquid crystals, appropriately designed electrodes are provided, which are connected via the cable 86, see 11a , can be powered.

According to 16 is an enlarged section of the liquid crystal display 76 15 shown. The switchable liquid crystal areas 110 each have a color filter 112. This is explained in more detail below using an area 110, which is designed accordingly in the other areas 110. The color filter 112 extends in a band shape along an edge of the area 110, the edge being formed by the non-switchable liquid crystal area 108. The color filter 112 has a plurality of filter sections 114 to 122, each having a different color. The filter section 114 is red and borders directly on the edge. It extends approximately L-shaped and affects about half of the edge. In other words, the filter section 114 extends along two edges. Seen towards the inside of the liquid crystal region 110, the filter section 114 is adjoined by the filter section 116, which is yellow and has a similar shape to the filter section 114 in terms of its shape. The filter section 116 is therefore also L-shaped. However, it is wider than the filter section 114. The filter section 120 is blue and is also formed directly on the edge. It extends essentially along the edge section that is free of the filter section 114 and is also L-shaped. In other words, the filter section 120 extends along two further edges. Seen towards the inside of the liquid crystal region 110, the filter section 118 adjoins the filter section 120, which is turquoise and is designed similarly to the filter section 118 in terms of its shape. Two smaller filter sections 122 adjacent to the edge section, which are provided between the L-shaped filter sections 114, 116 and 118, 120, are green. Legs of the L-shaped filter sections 114, 116, 118, 120 have different widths for a respective section. In other words, the color filter 112 has five different colors out of 14 to correct. The resolution of the liquid crystal display

REFERENCE SYMBOL LIST

1, 44, 74

Projection system

2, 48, 78

light source

4, 46, 70, 72

mask

6, 82, 84

Projection optics

8th

Projection lens

10

Light entry surface

12

Light exit surface

14

Pinhole

16

Light radiation

18

mask

20, 32, 52, 68

recess

22

Image area

24, 40

Light ring

26, 28, 30

Color ring

34, 56, 60, 62, 66

Color layer

36, 38, 54

Section

58, 64

recess edge

76

Liquid crystal display

79

Circuit board

80

Collimator

86

Cable

88 to 94

Housing components

96

disc

98

Illustration

100

Light radiation

102, 104

Section

106

Frame

108, 110

Liquid crystal area

112

Color filters

114 to 122

Filter sections

Claims (10)

Projection system with projection optics (6) and with a mask (4) which is designed for shadow projection and which is connected upstream of the projection optics (6), the mask (4) and the projection optics (6) being connected upstream of one of the mask (4). Light source (2) can be irradiated in order to carry out the shadow projection on an imaging surface, the mask (4) having a non-transparent mask layer into which at least one recess (32) which can be irradiated by light is introduced, at least part of the recess (32). has a transmissible color filter (34) which is designed to at least reduce a color magnification error on the imaging surface. projection system Claim 1 , wherein the at least one recess (32) is delimited by a recess edge of the mask layer, wherein the color filter (34) is formed at least adjacent or adjacent to the recess edge. projection system Claim 1 or 2 , where all or substantially the entire recess (32) has the color filter (34). Projection system according to one of the preceding claims, wherein the color filter (34) has sections (36, 38) with different colors, Projection system according to one of the preceding claims, wherein a single projection lens (8) is provided as the projection optics (6). Projection system according to one of the preceding claims, wherein the mask (4) is designed as a film. Projection system according to one of the preceding claims, wherein the mask layer and/or the color filter (34) are applied to the mask (4) designed as a film by a printing process. Projection system with projection optics (82, 84) and with a mask (76) which is designed for shadow projection and which is connected upstream of the projection optics (82, 84), the mask (76) and the projection optics (82, 84) being one The light source (78) connected upstream of the mask (76) can be irradiated in order to carry out the shadow projection on an imaging surface, the mask being designed as a liquid crystal display (76) which has at least one switchable liquid crystal region (110) and at least one opaque region (108). has, a polarization filter being arranged in the beam path between the light source (78) and the areas (108, 110) and an analyzer being connected downstream of the areas, with the passage of light into this area via the at least one switchable liquid crystal area (110). incoming light can be controlled in such a way that it is either blocked on the analyzer or radiates through the analyzer, at least part of the at least one switchable liquid crystal region (110) having a color filter (112) which can be transmitted through and which is designed in such a way as to prevent a color magnification error on the At least to reduce the imaging area. Vehicle light with a projection system according to one of the preceding claims. Method for designing a projection system according to one of Claims 1 until 8th with the steps: - Determination of an intended target image (40) with an intended light distribution on an intended imaging surface, - Determination based on the target image (40) and the intended projection optics (6) of the projection system (1), the design of the color layer (34) or the color filter in the at least one recess (32) of the mask (4) in such a way that the projection system (1) uses this mask (4) to form the target image (40) on the intended imaging surface.

Images