Slat arrangement, method for producing a slat arrangement, cover arrangement with a slat arrangement

Description

[0001] The present invention relates to a slat arrangement, in particular for a cover arrangement for a head-up display, and to a method for producing such a slat arrangement. The invention also relates to a cover arrangement with such a slat arrangement and to a head-up display, in particular a head-up display for a means of transport having such a cover arrangement.

[0002] A head-up display, also known as a HUD, is a display system that allows the viewer to maintain their line of sight by projecting the content into their field of vision. While such systems were originally used primarily in aviation due to their complexity and cost, they are now also being installed in large-scale production in the automotive sector.

[0003] Head-up displays generally consist of an image generator, an optical unit, and a mirror unit. The image generator generates the image. The optical unit directs the image to the mirror unit. The image generator is often referred to as the imaging unit or PGU (Picture Generating Unit). The mirror unit is a partially reflective, translucent pane. The viewer therefore sees the content displayed by the image generator as a virtual image and, at the same time, the real world behind the pane. In the automotive sector, the windshield is often used as the mirror unit, and its curved shape must be taken into account when displaying the image. The interaction of the optical unit and the mirror unit results in the virtual image being an enlarged representation of the image generated by the image generator.

[0004] The viewer can only view the virtual image from the position of the so-called eyebox. The eyebox is an area whose height and width correspond to a theoretical viewing window. As long as one eye of the viewer is within the eyebox, all elements of the virtual image are visible to the viewer. If, however, the eye is outside the eyebox, the virtual image is only partially visible to the viewer or not visible at all. The larger the eyebox, the less restricted the viewer is in choosing their seating position.

[0005] The size of the virtual image in conventional head-up displays is limited by the size of the optical unit. One approach to enlarging the virtual image is to couple the light coming from the imaging unit into an optical fiber. The light coupled into the optical fiber, which carries the image information, is totally reflected at its interfaces and is thus guided within the optical fiber. In addition, a portion of the light is coupled out at numerous positions along the propagation direction, so that the image information is distributed across the surface of the optical fiber. In this way, the optical fiber dilates the exit pupil. The effective exit pupil is composed of images of the aperture of the imaging system.

[0006] Against this background, US 2016 / 0124223 A1 describes a display device for virtual images. The display device comprises an optical waveguide that causes light coming from an imaging unit, which is incident through a first light incidence surface, to undergo repeated internal reflection to move in a first direction away from the first light incidence surface. The optical waveguide also causes a portion of the light guided in the optical waveguide to exit to the outside through regions of a first light exit surface extending in the first direction. The display device further comprises a first light-incident-side diffraction grating that diffracts incident light to cause the diffracted light to enter the optical waveguide, and a first light-outgoing diffraction grating that diffracts light incident from the optical waveguide.

[0007] The currently known design of such a head-up display, in which the optical fiber consists of glass plates within which diffraction gratings or holograms are arranged, presents a problem when exposed to sunlight. The incoming sunlight is refracted multiple times in the optical fiber and broken down into its spectral colors. These reemerge from the optical fiber at numerous points and are refracted, among other things, towards the eye. This leads to rainbow-like or contrast-reducing quality losses. The actual image is therefore perceived even more faintly. Similar problems occur with other sources of interfering light, as well as with direct light reflections on the optical fiber or on the cover of an optical unit. Even with conventional head-up displays without optical fibers, light reflections due to sunlight or ambient light are disruptive.

[0008] In conventional devices, components where reflections may occur are tilted and combined with beam traps so that reflections do not reach the area where the driver's eye is expected. Alternatively, anti-reflective coatings and structural roughness are used to reduce reflection intensity.

[0009] Tilting components takes up considerable installation space, which is limited in automobiles. Furthermore, component performance is generally compromised when installed tilted. Layers and structures reduce the achievable intensity, but the reflections usually remain clearly visible and significantly reduce the contrast.

[0010] To reduce reflections, the head-up display can alternatively be equipped with a cover arrangement for reducing reflections, which has a louvre structure or a grid with numerous louvres. The louvres can largely block incoming stray light.

[0011] In this context, DE 10 2014 214 510 A1 describes an arrangement for reducing reflections for a windshield display device for a motor vehicle. The arrangement comprises a transparent cover plate for protecting a projection device and a shielding grid with flat grid elements of a grid structure arranged perpendicularly or inclined to a surface of the cover plate.

[0012] To further improve the suppression of stray light, adjustable slats can be used instead of a rigid slat arrangement, the angle of which is adjusted based on the viewer's head position.

[0013] For example, DE 10 2017 219 069 A1 describes a cover assembly for reducing reflections for a visual field display device for a motor vehicle. The cover assembly comprises a transparent cover plate for protecting a projection unit of the visual field display device and a dynamic shielding structure comprising a plurality of flat louvres distributed along a surface of the cover plate. The angles of inclination of the louvres relative to a surface normal of the cover plate are dynamically adjustable.

[0014] However, manufacturing such a lamella arrangement is a considerable effort, especially if the lamellae are to be very thin. A typical material thickness of the lamellae is in the range of 20 µm to 30 µm, depending on the material.

[0015] DE 10 2018 213 061 A1 discloses a device for generating a virtual image with stray light suppression. DE 10 2020 211 662 B3 discloses a device for generating a virtual image with an adjustment mechanism for anti-reflection louvers. DE 10 2015 224 939 A1 discloses an arrangement for reducing reflections for a windshield display device for a motor vehicle.

[0016] It is an object of the present invention to provide improved solutions for a slat arrangement for a cover arrangement for a head-up display.

[0017] This object is achieved by a lamella arrangement having the features of claim 1 and by a method according to claim 5 for producing such a lamella arrangement. Preferred embodiments of the invention are the subject of the dependent claims.

[0018] According to a first aspect of the invention, a slat arrangement comprises: a first rack having a plurality of teeth; a first cover rack having a plurality of teeth arranged on the first rack; a second rack having a plurality of teeth; a second cover rack having a plurality of teeth arranged on the second rack; and a plurality of blades fastened between the teeth of the racks and the cover racks.

[0019] In the slat arrangement according to the invention, the slats are attached at both ends between a rack and a corresponding cover toothed strip. The teeth of the rack or the cover toothed strip determine the precise arrangement of the slats. Preferably, the slats have a constant spacing and a constant angle of inclination along the entire length of the rack. Of course, both can also vary along the length of the rack if necessary.

[0020] According to one aspect of the invention, the racks, the cover toothed strips, and the slats are glued together. In this way, the rack and the associated cover toothed strip each form a glued unit into which the ends of the slats are embedded. This facilitates handling of the slat assembly during subsequent assembly in a frame of a cover assembly.

[0021] According to one aspect of the invention, the first rack and the second rack have fastening elements for support strips. The support strips, in turn, can be mounted in a frame of a cover assembly. The use of adapted support strips enables the installation of the slat arrangement in different cover arrangements.

[0022] According to one aspect of the invention, the slats are designed to be elastic. This makes it possible to adjust the angle of inclination of the slats after installation in a cover assembly using suitable adjusting elements. In particular, the slats can be formed from a plastic film. The slats are preferably made of a polyimide.

[0023] According to a further aspect of the invention, a method for producing a lamella arrangement according to the invention comprises the steps: Attaching a first rack and a second rack to an inner subframe; attaching a plurality of slats to a first subrack and a second subrack mounted on an outer subframe; inserting the plurality of slats into the first rack and the second rack using the outer subframe; attaching the plurality of slats to the first rack and the second rack using a first cover rack and a second cover rack; separating the plurality of slats from the first subrack and the second subrack; and detaching the first rack and the second rack from the inner subframe.

[0024] In the inventive method for producing a slat assembly, an auxiliary structure consisting of an outer subframe and auxiliary racks attached thereto is used to position the slats in a defined manner prior to assembly. The outer subframe is then positioned relative to the inner subframe so that the slats lie between the teeth of the racks. The slats can then be attached there using cover toothed strips and finally separated from the auxiliary racks. This has the advantage that the slats are transferred evenly to the racks. After the racks are detached from the inner subframe, the slat assembly can be further processed.

[0025] According to one aspect of the invention, the racks, the cover toothed strips, and the slats are glued together. In this way, the rack and the associated cover toothed strip each form a glued unit into which the ends of the slats are embedded. This facilitates handling of the slat assembly during subsequent assembly in a frame of a cover assembly.

[0026] According to one aspect of the invention, the slats are tensioned with defined weights before being attached to the auxiliary racks. This ensures that all slats have exactly the same preload when they are attached to the auxiliary racks and subsequently between the racks and the cover toothed strips. After mounting the slat arrangement in a frame of a cover assembly, this ensures that a defined force is required to adjust the inclination of the slats.

[0027] According to one aspect of the invention, the slats are bonded to the auxiliary racks. This ensures that the slats reliably retain their defined arrangement and preload when inserted into the racks.

[0028] A cover arrangement, in particular a cover arrangement for a head-up display, preferably has a slat arrangement according to the invention. Such a cover arrangement is preferably used in a head-up display for a means of transport, e.g. in a head-up display for a motor vehicle. However, a slat arrangement according to the invention can also be used in other areas of application in which reflection avoidance is desirable, for example in military applications, e.g. to prevent reflections for telescopic sights, or to prevent reflections for cameras and surveillance cameras. Furthermore, the solution according to the invention can also be used as a privacy screen for displays, e.g. as a privacy filter, or as a privacy screen for windows / skylights.

[0029] Further features of the present invention will become apparent from the following description and the appended claims taken in conjunction with the figures. Figure overview

[0030] Fig. 1 schematically shows a head-up display according to the prior art for a motor vehicle; Fig. 2 shows an optical fiber with two-dimensional magnification; Fig. 3 schematically shows a head-up display with an optical fiber; Fig. 4 schematically shows a head-up display with an optical fiber in a motor vehicle; Fig. 5 schematically shows the functioning of a cover arrangement with louvers; Fig. 6 shows an enlarged section of a cover arrangement; Fig. 7 shows an oblique view of a louver arrangement according to the invention; Fig. 8 shows a side view of the louver arrangement according to the invention; Fig. 9 schematically shows a method for producing a louver arrangement according to the invention; Fig. 10 shows the use of subframes in the production of a louver arrangement according to the invention; and Fig. 11 shows the finished louver arrangement before being detached from an inner subframe. Fig. 12 shows an integration of the louver arrangement from Fig. 7into a cover arrangement; Fig. 13 shows a section through the cover arrangement of Fig. 12 ; Fig. 14 illustrates the operation of an adjusting element for the slats of the slat arrangement; and Fig. 15 shows a plurality of actuators grouped by a common sprue. Character description

[0031] To better understand the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. Like reference numerals are used in the figures for like or equivalent elements and are not necessarily described again for each figure. It is understood that the invention is not limited to the illustrated embodiments and that the described features can also be combined or modified without departing from the scope of the invention as defined in the appended claims.

[0032] First, based on the Figures 1 to 4 the basic idea of ​​a head-up display with fiber optic cable is explained.

[0033] Fig. 1 shows a schematic diagram of a conventional head-up display for a motor vehicle. The head-up display comprises a display device 1 with an imaging unit 10 and an optical unit 14. A beam SB1 emanates from a display element 11, which is reflected by a folding mirror 21 onto a curved mirror 22, which reflects it toward a mirror unit 2. The mirror unit 2 is depicted here as the windshield 20 of the motor vehicle. From there, the beam SB2 travels toward the eye of a viewer 3.

[0034] The viewer 3 sees a virtual image VB, which is located outside the motor vehicle above the hood or even in front of the motor vehicle. Due to the interaction of the optical unit 14 and the mirror unit 2, the virtual image VB is an enlarged representation of the image displayed by the display element 11. A speed limit, the current vehicle speed and navigation instructions are symbolically shown here. As long as the eye of the viewer 3 is within an eyebox 4 indicated by a rectangle, all elements of the virtual image VB are visible to the viewer 3. If the eye of the viewer 3 is outside the eyebox 4, the virtual image VB is only partially visible or not visible at all to the viewer 3. The larger the eyebox 4, the less restricted the viewer is in choosing their seating position.

[0035] The curvature of the curved mirror 22 is adapted to the curvature of the windshield 20 and ensures that the image distortion is stable across the entire eyebox 4. The curved mirror 22 is rotatably mounted by means of a bearing 221. The resulting rotation of the curved mirror 22 enables the eyebox 4 to be moved and thus the position of the eyebox 4 to be adjusted to the position of the viewer 3. The folding mirror 21 ensures that the path traveled by the beam SB1 between the display element 11 and the curved mirror 22 is long, while at the same time the optical unit 14 remains compact. The imaging unit 10 and the optical unit 14 are separated from the surroundings by a housing 15 with a transparent cover plate 23. The optical elements of the optical unit 14 are thus protected, for example, against dust present in the interior of the vehicle. An optical film or coating may also be present on the cover plate 23.a polarizer 24. The display element 11 is typically polarized, and the mirror unit 2 acts like an analyzer. The purpose of the polarizer 24 is therefore to influence the polarization in order to achieve uniform visibility of the useful light. A cover arrangement 25 arranged on the cover plate 23 serves to reliably absorb the light reflected across the boundary surface of the cover plate 23, so that the viewer is not dazzled. In addition to sunlight SL, the light from another interfering light source 5 can also reach the display element 11. In combination with a polarization filter, the polarizer 24 can also be used to reduce incident sunlight SL.

[0036] Fig. 2shows a schematic spatial representation of an optical waveguide 6 with two-dimensional magnification. In the lower left area, a coupling hologram 63 can be seen, by means of which light L1 coming from an imaging unit (not shown) is coupled into the optical waveguide 6. In this area, it propagates to the top right in the drawing, according to arrow L2. In this area of ​​the optical waveguide 6 there is a folding hologram 61, which acts similarly to many partially transparent mirrors arranged one behind the other and generates a light beam that is broadened in the Y direction and propagates in the X direction. This is indicated by three arrows L3.In the part of the optical waveguide 6 extending to the right in the figure, there is an output hologram 62, which also acts similarly to many partially transparent mirrors arranged one behind the other and, indicated by arrows L4, outputs light upwards in the Z direction from the optical waveguide 6. This results in a broadening in the X direction, so that the original incident light beam L1 leaves the optical waveguide 6 in a light direction Lα as a light beam L4 enlarged in two dimensions.

[0037] Fig. 3shows a spatial representation of a head-up display with three optical waveguides 6R, 6G, 6B, which are arranged one above the other and each represent an elementary color: red, green, and blue. Together, they form the optical waveguide 6. The holograms 61, 62, 63 present in the optical waveguide 6 are wavelength-dependent, so that one optical waveguide 6R, 6G, 6B is used for each of the elementary colors. Above the optical waveguide 6, an imaging unit 10 and an optical unit 14 are schematically shown. The optical unit 14 has a mirror 16, which deflects the light generated by the imaging unit 10 and shaped by the optical unit 14 in the direction of the respective input hologram 63. The imaging unit 10 has three light sources 17R, 17G, 17B for the three elementary colors. It can be seen that the entire unit shown has a low overall height compared to its light-emitting surface.

[0038] Fig. 4 shows a head-up display in a motor vehicle similar to Fig. 1 , but here in a spatial representation and with an optical fiber 6. The schematically indicated imaging unit 10 can be seen, which generates a parallel beam SB1, which is coupled into the optical fiber 6 by means of the mirror plane 623. The optical unit is not shown for the sake of simplicity. Several mirror planes 622 each reflect a portion of the light incident on them towards the windshield 20, the mirror unit 2. From there, the light is reflected towards the viewer 3. The viewer 3 sees a virtual image VB above the hood or at an even greater distance in front of the motor vehicle. With this technology, too, the entire optics are installed in a housing that is separated from the surroundings by a transparent cover and has a cover arrangement to prevent stray light.

[0039] Fig. 5shows a schematic of the functioning of a cover arrangement 25 with adjustable slats 256. Shown is a cross-section through the cover arrangement 25, which in this example is integrated into the housing 15 together with the cover plate 23 and is arranged above an optical waveguide 6. An imaging unit 10 couples a light beam L1 into the optical waveguide 6. At its upper boundary surface 601, multiplied light beams L4 emerge at a main direction angle α. The light direction Lα defined by the main direction angle α deviates from the direction N of the normal of the optical waveguide 6 or the housing 15. The light beams L4 are reflected by the windshield 20 serving as the mirror unit 2 and reach the eye of the observer 3, who thus sees a virtual image VB. For reasons of space, this is indicated disproportionately close to the windshield 20.The cover assembly 25 comprises a slat assembly 250 with a plurality of inclined slats 256 that are aligned according to the light direction Lα, i.e., whose inclination angle β is adapted to the light direction Lα. The inclination angle β is adjustable by means of an adjustment element (not shown). An eye-tracking system 26 can be used to track the position of the viewer 3.

[0040] Fig. 6 shows an enlarged section of the cover arrangement 25 from Fig. 5 . Sunlight SL incident from outside can be seen as stray light. This can essentially only be incident at the same angle at which the slats 256 are inclined. It is therefore absorbed by the slats 256 after being reflected by the cover plate 23.

[0041] Fig. 7 and Fig. 8show an oblique view and a side view of a slat arrangement 250 according to the invention. The slat arrangement 250 has a first rack 251 with a plurality of teeth 252 and a first cover toothed strip 253 with a plurality of teeth 252 arranged on the first rack 251. The slat arrangement 250 also has a second rack 254 with a plurality of teeth 252 and a second cover toothed strip 255 with a plurality of teeth 252 arranged on the second rack 254. A plurality of slats 256 are fastened between the teeth 252 of the racks 251, 254 and the cover toothed strips 253, 255. In particular, the racks 251, 254, the cover toothed strips 253, 255, and the slats 256 can be glued together and form a first end piece 258 and a second end piece 259. Preferably, the slats 256 are formed by a plastic film, e.g., a polyimide film.For attaching support strips for installation in a cover assembly, the first rack 251 and the second rack 254 can have attachment sections 257. In the example shown, the slats 256 have a constant spacing d and a constant angle of inclination β over the entire length of the rack 251. Of course, both can also vary over the length of the rack 251 if necessary.

[0042] Fig. 9shows a schematic of a method for producing a slat arrangement according to the invention. First, a first rack and a second rack are fastened S1 to an inner auxiliary frame. Subsequently, a plurality of slats are fastened S2 to a first auxiliary rack and a second auxiliary rack. The two auxiliary racks are fastened to an outer auxiliary frame. Before being fastened to the auxiliary racks, the slats are preferably tensioned with defined weights and then glued to the auxiliary racks. The slats are then inserted S3 into the first rack and the second rack using the outer auxiliary frame. Using a first cover toothed strip and a second cover toothed strip, the slats are then fastened S4 in the racks. For this purpose, the racks, the cover toothed strips and the slats are preferably glued to one another.The slats are then separated from the auxiliary racks S5. Finally, the racks are detached from the inner subframe S6.

[0043] Fig. 10shows the use of auxiliary frames 30, 31 in the manufacture of a slat arrangement 250 according to the invention. Two auxiliary racks 310, 311 are attached to an outer auxiliary frame 31. The slats 256 are then glued under tension into the outer auxiliary frame 31 onto the auxiliary racks 310, 311. Two racks 251, 254 for receiving the slats 256 are attached to an inner auxiliary frame 30. The outer auxiliary frame 31 with the tensioned slats 256 is then placed over the inner auxiliary frame 30, and the tensioned slats 256 are transferred or glued to the racks 251, 254. Cover rack strips 253, 255 are then placed on the racks 251, 254 and glued to them. The slats are now sandwiched between rack 251, 254 and cover toothed strip 253, 255.

[0044] Fig. 11shows the finished slat arrangement 250 before being detached from the inner subframe 30. After the slats 256 are secured between the racks 251, 254 and the cover toothed strips 253, 255, the slats 256 are separated. The slats 256 are now evenly transferred to the racks 251, 254. Finally, the racks 251, 254 only need to be detached from the inner subframe 30.

[0045] Fig. 12 shows an integration of the lamella arrangement 250 from Fig. 7into a cover arrangement 25. The cover arrangement 25 has a frame 300 to which the two end pieces 258, 259 can be fastened. In the example shown, the first end piece 258 is fastened to the frame 300 with a first support strip 331, for example by gluing or screwing, and thus forms a fixed bearing for the slats 256. Alternatively, the first support strip 331 can be omitted and the first end piece 258 can be fastened directly to the frame 300. The second end piece 259, on the other hand, is fastened with spring tension and forms a loose bearing for the slats 256. For this purpose, the second end piece 259 is first screwed, pinned, or glued to a second support strip 32. The unit consisting of the second end piece 259 and the second support strip 32 is placed on the frame 300 and held down with springs 33. In the example shown, two springs 33 are used, but a different number of springs 33 can also be used.Instead of springs 33, other holding-down options can also be used, e.g., lateral guides for the second support bar 32 or a movable fastening using elongated holes in the second support bar 32. The slats 256 are then tensioned by tension springs 34, which are attached to fastening points 35 of the second support bar 32 and the frame 300. In the example shown, five tension springs 34 are used, but a different number of tension springs 34 can also be used. To adjust the inclination of the slats 256, the cover arrangement 25 has adjustment elements 36, which are actuated by stepper motors 37.

[0046] Fig. 13 shows a section through the cover arrangement 25 from Fig. 12along line AA. The second support strip 332 is screwed to the second rack 254 by means of a screw 320. As described, the second rack 254 and the second cover rack 255 form a unit due to the adhesive bond. In the embodiment shown, the second support strip 332 engages around the second cover rack 255. For this purpose, the second support strip 332 has an overlapping section 321. The tensile force of the tension springs 34 is transferred to the rigid second support strip 332. The force is transferred via the hooking to the second cover rack 255 and via the screw connection to the second rack 254. This places a central load on the adhesive bond of the slats 256 in the sandwich. The springs pull in the middle of the slats 256. The resulting tension in the slats 256 protects the slats 256 from vibration.In addition, the spring-loaded fastening ensures compensation for temperature-related changes in the linear expansion of the slats 256.

[0047] As in Fig. 13As can be clearly seen, the adjusting element 36 comprises a lower perforated strip 360, an upper perforated strip 361 and a plurality of actuators 362. Each slat 256 is assigned an actuator 362 of the adjusting element 36. The actuators 362 each have a base body 3620 as well as a lower extension 3621 and an upper extension 3622. The lower extension 3621 engages in an associated recess 3600 of the lower perforated strip 360, the upper extension 3622 engages in an associated recess 3610 of the upper perforated strip 361. The recesses 3600, 3610 of the perforated strips 360, 361 are preferably rectangular. The rectangular design, in conjunction with a substantially rectangular cross-section of the lower extension 3621 and the upper extension 3622, ensures that the actuators 362 have a defined orientation with respect to the perforated strips 360, 361 and that rotation of the actuators 362 relative to the perforated strips 360, 361 is not possible.

[0048] One of the first assembly steps of the cover assembly 25 consists of firmly connecting the lower perforated strip 360 to the frame 300. The slat assembly 250 is then placed on top, and the slats 256 are tensioned as described above. The actuators 362 are then positioned between the tensioned slats 256 such that their lower extension 3621 engages in the corresponding recess 3600 of the lower perforated strip 360. For this purpose, it is advantageous if groups of actuators 362, or even all actuators 362, are grouped by a common sprue. This can, for example, be arranged laterally at the upper end of the base body 3620. The upper perforated strip 361 is then placed on top such that the upper extension 3622 of the actuators 362 engages in the corresponding recess 3610 of the upper perforated strip 361. Finally, the actuators 362 are separated by breaking off the sprue.The lower perforated strip 360 is preferably arranged on the frame 300 such that, after assembly, the slats 256 each rest against one side of the base body 3620. By resting the slats 256 against the base body 3620, the shape of the slats 256 can be specifically influenced in the transverse direction. If the base body 3620 is flat in the area where the associated slat 256 rests, the slat 256 also has a flat surface.

[0049] Fig. 14 illustrates the operation of the adjustment element 36 for the slats of the slat arrangement. The lower perforated bar 360 is fixedly mounted on the frame 300. To adjust the inclination, the upper perforated bar 361 is moved horizontally in the longitudinal direction, parallel to the lower perforated bar 360, by the stepper motor. This displacement is shown in Fig. 14indicated by the double arrow. The displacement simultaneously tilts all actuators 362. Since the slats are elastic, they adjust according to the inclination of the actuators 362. The base bodies 3620 of the actuators 362 preferably have a convex shape. For this purpose, the side of the base body 3620 facing away from the respective slat can preferably be curved. Due to the curvature, the base body 3620 can roll on the surface of the lower perforated strip 360 during adjustment, thereby ensuring jerk-free adjustment. The actuators 362 or the base bodies 3620 of the actuators 362 are also designed so that the slats can slide on the actuators 362. In this way, the possibility of relative movement between the actuators 362 and the slats is ensured, thus preventing damage to the slats, even over a long period of time.

[0050] Fig. 15shows a plurality of actuators 362, which are grouped by a common sprue 3623 for easy assembly between the lower perforated bar 360 and the upper perforated bar 361. The sprue 3623 is arranged laterally at the upper end of the base body 3620, so that the remnants of the sprue 3623 do not touch the slats after breaking off. This ensures that the slats are not damaged. List of reference symbols

[0051] 1Display device 2Mirror unit 3Viewer 4Eyebox 5Strike source 6, 6R, 6G, 6BFiber optics 601Upper boundary surface 61Folding hologram 62Output hologram 622Mirror plane 623Mirror plane 63Input hologram 10Imaging unit 11Display element 14Optical unit 15Housing 16Mirror 17R, 17G, 17BLight source 20Windshield 21Folding mirror 22Curved mirror 221Bearing 23Cover plate 24Optical film / polarizer 25Cover assembly 250Slat assembly 251First rack 252Tooth 253First cover tooth strip 254Second rack 255Second cover tooth strip 256Slat 257Mounting section 258First end piece 259Second end piece 26Eye tracking system 30Inner subframe 300Frame 31Outer subframe 310First auxiliary rack 311Second auxiliary rack 320Screw 321Cross-section 33Spring 331First support bar 332Second support bar 34Tension spring 35Fastening point 36Adjustment element 360Lower perforated bar 3600Recess 361Upper perforated bar 3610Recess 362Actuator 3620Base body 3621Lower extension 3622Upper extension 3623Sprue 37Stepper motor αPrincipal direction angle βInclination angle dDistance L1...L4Light LαLight direction NNormal SB1, SB2Bench of rays SLSunlight VBVirtual image S1Attaching racks to an inner subframe S2Attaching slats to auxiliary racks on an outer subframe S3Inserting the slats into the racks S4Attaching the slats to the racks S5Detaching the slats from the auxiliary racks S6Detaching the racks from the inner subframe

Claims

1. Lamella arrangement (250), having: - a first rack (251) having a plurality of teeth (252); - a first cover rack strip (253) arranged on the first rack (251) and having a plurality of teeth (252); - a second rack (254) having a plurality of teeth (252); - a second cover rack strip (255) arranged on the second rack (254) and having a plurality of teeth (252); and - a plurality of lamellae (256) which are fastened between the teeth (252) of the racks (251, 254) and the cover rack strips (253, 255).

2. Lamella arrangement (250) according to Claim 1, wherein the racks (251, 254), the cover rack strips (253, 255) and the lamellae (256) are adhesively bonded to one another.

3. Lamella arrangement (250) according to Claim 1 or 2, wherein the first rack (251) and the second rack (254) have fastening portions (257) for support strips.

4. Lamella arrangement (250) according to one of the preceding claims, wherein the lamellae (256) are designed to be elastic.

5. Method for manufacturing a lamella arrangement (250) according to one of the preceding claims, comprising the steps: - fastening (S1) a first rack (251) and a second rack (254) on an inner subframe (30); - fastening (S2) a plurality of lamellae (256) to a first auxiliary rack (310) and a second auxiliary rack (311) which are fastened to an outer subframe (31); - incorporating (S3) the plurality of lamellae (256) into the first rack (251) and the second rack (254) using the outer subframe (31); - fastening (S4) the plurality of lamellae (256) in the first rack (251) and the second rack (254) using a first cover rack strip (253) and a second cover rack strip (255); - separating (S5) the plurality of lamellae (256) from the first auxiliary rack (310) and the second auxiliary rack (311); and - releasing (S6) the first rack (251) and the second rack (254) from the inner subframe (30).

6. Method according to Claim 5, wherein the racks (251, 254), the cover rack strips (253, 255) and the lamellae (256) are adhesively bonded to one another.

7. Method according to Claim 5 or 6, wherein the lamellae (256) are tensioned with defined weights before being fastened (S2) to the auxiliary racks (310, 311).

8. Method according to one of Claims 5 to 7, wherein the lamellae (256) are adhesively bonded to the auxiliary racks (310, 311).

9. Cover assembly (25), having a lamella arrangement (250) according to one of Claims 1 to 4.

10. Head-up display for a means of transport, having a cover assembly (25) according to Claim 9.