LIGHTING ELEMENT FOR A TEST TUNNEL, LIGHT STRIP AND TEST TUNNEL

Description

State of the art

[0001] The invention relates to a test tunnel with an arrangement of several light strips.

[0002] Such test tunnels are used in vehicle manufacturing to inspect painted surfaces of motor vehicles in particular. To illuminate the workstations, particularly the inspection stations, lighting elements on a frame substructure are usually used. These lighting elements are equipped with fluorescent tubes and arranged at different angles around the substrate, in this case the vehicle body or body parts. These lighting elements emit diffuse light and, thanks to a corresponding reflector geometry, create a reflected image on the substrate. The orientation of these reflected images and thus also of the lighting elements is based on the specific task of troubleshooting and is subordinate to ergonomic aspects, among other things. With this arrangement of lighting elements, only a portion of the energy used is utilized due to the occurrence of diffuse light. This can also result in increased glare for inspectors.

[0003] Another, more recent configuration is based on indirect lighting through single or multiple reflections from aluminum slats illuminated by LEDs. Here, horizontal slats are installed along the entire length of the control station, creating a more or less pronounced reflected image on the substrate.

[0004] With this arrangement of lighting elements, horizontally running reflective strips require the inspector to actively search for reflective lines on the sides of the car bodies. Large differences in luminance reflections can lead to locally varying reflective line patterns and an unstable overall perception. Such lighting arrangements can also be very expensive.

[0005] US 20190113464 A1 discloses a system for surface inspection. Modular light panels are connected to each other at their ends and, when connected, form a fixed light tunnel geometry. The light panels have rows of LEDs, e.g., LED light strips. The LED strips are positioned behind a diffuser. The diffuser is supported, for example, between the frame elements, which are secured at their ends by corner fasteners. The LED strips can be semi-rigid, rigid, or flexible. The LED strips are configurable to achieve a desired light coverage and intensity. The LED strips can be wired together within a panel or across multiple panels, e.g., with electrical connectors arranged between panels. The panels can be rectangular or curved.A control may be provided to change the intensity, color, or other characteristics of the light emitted by the light panels.

[0006] DE 10 2014 215481 A1 describes a test tunnel for testing coated surfaces of motor vehicle bodies. The lights are designed as light strips arranged transversely to the longitudinal axis of the test tunnel. Each light has a housing in which strip-shaped circuit boards with light-emitting diodes are arranged along both lateral edge regions. The lights each have at least two light-emitting surfaces separated by at least one black field, allowing one light to create four or more sharp contrasting edges when illuminating the body surface. The light-emitting diodes are directed toward a cavity within the light.

[0007] US 2015 / 360271 A1 describes a curved LED array for inspecting painted vehicle surfaces during repairs. The curved LED array comprises a housing in which LED strips are arranged along the side edges. The LED array can be held by a tripod or can be placed directly on the painted surface.

[0008] EP 0 792 452 A1 and GB 2 295 224 A describe a lighting unit with a housing in which two parallel fluorescent tubes are mounted longitudinally of the housing, producing a light intensity distribution with two maxima transverse to the housing. GB 2 295 224 A mentions the use of several such lighting units to construct a test tunnel. Disclosure of the invention

[0009] An object of the invention is to provide a test tunnel with an arrangement of several light strips which have an improved luminance distribution.

[0010] The problem is solved by the features of the independent claim. Advantageous embodiments and advantages of the invention emerge from the further claims, the description, and the drawings.

[0011] A test tunnel with a longitudinal tunnel axis is proposed, in particular for testing shiny, especially painted, vehicle bodies, with an arrangement of several light strips.

[0012] The lighting strips comprise an arrangement of lighting elements, wherein the lighting elements are connected to one another at their end-face connection areas. In particular, the lighting elements can be arranged at least partially along an arcuately curved line, with the light-emitting surfaces of the lighting elements oriented toward a concave inner side of the arcuate curve.

[0013] The luminaire strips are arranged next to one another transversely to the longitudinal axis of the tunnel, with the light exit surfaces of the luminaire elements being aligned on a concave inner side of the arched curvature of a tunnel wall towards a central area of ​​the longitudinal axis of the tunnel.

[0014] The lighting elements for the test tunnel comprise at least two strip-shaped arrangements of light sources in a luminaire housing with at least two edge regions located opposite one another along a longitudinal extension of the luminaire housing. The strip-shaped arrangements of light sources are formed along the longitudinal extension at the edge regions, and a light exit surface of the luminaire housing has a higher radiant intensity along the edge regions than in a central region.

[0015] The described luminaire structure can advantageously lead to an improved luminance distribution with the help of a new arrangement of the light sources in the luminaire housing.

[0016] Instead of positioning the light sources in the center of the light emitting surfaces, as was previously the case, thus achieving a luminance that gradually decreases from the center to the edge areas with a low gradient, the light sources are now mounted at the two edge areas of the luminaire housing, where the transition from the luminaire housing directly to maximum luminance enables a high luminance gradient. This increases the probability of detecting defects on or in the substrate being inspected, e.g. a painted surface. In addition, this arrangement of the light sources also creates large zones of low and relatively homogeneous luminance. These zones can facilitate an undisturbed inspection of the surface for flat defects such as clouds, veils, holograms, etc., i.e. one free of high contrasts, and significantly improves the inspector's attention span.This can reduce errors during inspection.

[0017] An advantageous luminance distribution can be achieved by high contrasts at the transition from the luminaire housing to the light emitting surface and by undisturbed, visually calm areas.

[0018] With the low-loss radiation principle, a high system efficiency can be achieved.

[0019] According to an advantageous embodiment of the test tunnel, the light exit surface of the luminaire housing of the respective luminaire element can have at least one diffuser and a cover plate. According to a further advantageous embodiment of the luminaire element, a multi-prism plate can also be arranged between the diffuser and the cover plate.

[0020] The luminaire structure is based on the principle of backlighting, whereby the light rays pass through a pane package before leaving the luminaire element, which preferably consists of a diffuse pane, a multi-prism pane and a protective cover pane.

[0021] The multi-prism lens can be used in particular to further reduce any possible glare for the inspector.

[0022] According to an advantageous embodiment of the test tunnel, the light sources of the respective lighting element can comprise one or more light-emitting diodes and / or one or more fluorescent tubes and / or one or more light guides.

[0023] Light-emitting diodes (LEDs), such as mid-power LEDs with a luminous flux of 20 to 100 lumens and a luminous efficacy of approximately 180 lumens / watt, are preferred. Alternatively, fluorescent tube designs can also be used. LEDs and fluorescent tubes are highly energy-efficient and long-lasting light sources and can therefore keep operating costs low. Using fiber optic cables, the light sources can be arranged centrally and, for example, be supplied with energy and cooled inexpensively.

[0024] According to an advantageous embodiment of the test tunnel, the light sources of the respective lighting element can be designed to be color-variable, in particular as light-emitting diodes (LEDs) with adjustable color temperature.

[0025] Light sources with LEDs with variable color temperatures can optionally be used. This allows the light color to be adapted to the color of the substrate or the inspector's requirements, for example. The LEDs can be mounted and wired on a luminaire insert made of, for example, white painted sheet steel or aluminum to increase reflection, or a plastic panel. The corresponding drivers for the LEDs can be mounted on the back of the luminaire insert, for example. If the drivers or LEDs are defective, the luminaire housing can be opened at the back to replace the luminaire insert, including the LEDs and drivers. The back of the housing can be opened, for example, by removing a cover which is attached to the housing body with screws. Alternatively, the cover can be attached using a sash lock or similar. The luminaire inserts can be screwed, clamped, or attached in some other way into the luminaire housing.

[0026] The light color of the light sources in a lighting element can either be fixed, ranging, for example, between 2700 K (warm white) and 6500 K (cool white). For example, a "zebra arrangement" is also possible, in which cool white and warm white lighting elements are used alternately, or in other sequences.

[0027] The lighting elements can be dimmable. The degree of dimming can be based on the color of the substrate, for example. The color of the lighting element can be adapted to the color of the substrate.

[0028] According to an advantageous embodiment of the test tunnel, the luminaire housing can have end-face connection areas perpendicular to the edge areas, which are designed to connect adjacent luminaire elements. In this way, several luminaire elements can be conveniently combined to form a longer luminaire strip for examining larger substrates.

[0029] According to an advantageous design of the test tunnel, the frontal connection areas of the respective luminaire element can be designed as standardized connection elements for the mechanical and / or electrical connection of adjacent luminaire elements. This allows multiple luminaire elements to be efficiently combined into a longer luminaire strip for the inspection of larger substrates.

[0030] According to an advantageous embodiment of the test tunnel, the luminaire housing of the respective luminaire element can be curved in an arc, with the light exit surface oriented toward a concave inner side of the arc. Curved luminaire elements can be conveniently combined to form a curved luminaire strip, for example, to inspect large objects in a test tunnel.

[0031] According to an advantageous embodiment of the test tunnel, the central region of the light-emitting surface of the respective luminaire element can have a lower transparency than the edge region; in particular, the central region can be opaque.

[0032] This allows high-contrast zones to be created at the edge of the luminaire element, especially for detecting point defects. Differently bright zones on the light-emitting surface can improve the detection of surface defects such as clouding, haze, etc. in a paint surface.

[0033] In order to create multiple light strips in the reflected image with one lighting element, one or more opaque strips can be applied to the inside, e.g. in the middle, of the light emitting surface. This can then advantageously be designed to be highly reflective towards the light source space. In some circumstances it can also be advantageous to separate the space between the LEDs and the pane package with the aim of creating areas with different light colors. For this purpose a partition wall can be used, for example, to divide this space down the middle. This partition wall can also be designed to be highly reflective. The two LED strips to the right and left of the partition wall can then be designed with different color temperatures. Without a partition wall, different colors can also be achieved using color filters that can be placed in the area of ​​the pane package.

[0034] According to an advantageous embodiment of the test tunnel, the luminaire housing can be designed to be openable at the rear; in particular, the luminaire housing can be designed with a maintenance opening at the rear. This allows for the easy replacement of defective light sources and / or driver stages without having to completely dismantle the luminaire element.

[0035] According to an advantageous embodiment of the test tunnel, the light sources of the respective lighting element can be arranged on a support element. In particular, the support element can be designed to reflect the light exit surface. This advantageously increases the contrast of the emerging light beam to increase reflection on the substrate under investigation. Different color temperatures of the light sources in the lighting element can also be advantageously implemented.

[0036] According to an advantageous design of the test tunnel, the luminaire housing of the respective luminaire element can be designed as a closed structure. Advantageously, the light sources can be glued to a support element. Another variant is to design the luminaire housing as a closed structure and as a "disposable luminaire." The luminaire insert with light sources and drivers can then be glued into the luminaire housing, for example.

[0037] According to an advantageous embodiment of the test tunnel, end pieces of the respective lighting strip can be formed by flat lighting elements between which curved lighting elements are arranged.

[0038] The individual luminaire elements, assembled into a luminaire strip, which may, for example, have an arched structure, can be screwed together at the ends. For this purpose, six curved luminaire elements, each 1420 mm long, and two flat luminaire elements, each 750 mm long, can be used. Because the light-emitting surface is approximately the length of the luminaire housing, only minimal sections of interrupted light-emitting surface occur in the circumferential direction. This nearly continuous light-emitting surface creates a favorable, almost uninterrupted, reflected image on the substrate.

[0039] In order to combine individual lighting elements with a single length of, for example, 1400 mm into a continuous lighting strip, these can be screwed or plugged together at the head sides to avoid areas without light.

[0040] Here, for example, the power supply and the control signals could be passed on from one lighting element to the next via the particularly standardized plug connection.

[0041] The concentric arrangement of the lighting elements ensures that the light beams are primarily directed onto the substrate, such as a painted vehicle body. This increases the light output and reduces direct glare for inspectors.

[0042] The width of the individual light strips can be 200 mm, for example, and the clearance between the light arcs can be 500 mm. This provides both a sufficiently high number of contrast transitions and sufficient visually "unobstructed" space, which is also required for inspecting the entire substrate.

[0043] By using the described light strips with the light elements according to the invention in such a test tunnel, a vehicle body can advantageously be optically modulated by the type of lighting.

[0044] The inspection station can be given a positive experience for the inspector thanks to the innovative lighting, which leads to better efficiency in the inspection of the substrate.

[0045] This allows for highly targeted work focused on the bodywork with minimal fatigue. A carefully engineered luminance ratio between the inspection room and the surrounding area minimizes glare, thus providing a psychologically supportive viewing experience for the inspector.

[0046] This allows for improved ergonomics through significantly reduced glare and reflex orientation, so that no unpleasant (head) movements are required when troubleshooting.

[0047] More reliable inspection is made possible by a nearly continuous reflective image on the body.

[0048] The test tunnel according to the invention opens up application possibilities in the field of defect inspection, e.g., of large substrates such as car bodies or even finished vehicles. Furthermore, these inspection stations can also be used for other substrates, such as bumpers, mirror housings, etc. Furthermore, the uniform illumination of other workstations also offers advantageous applications beyond paint inspection.

[0049] According to an advantageous design of the inspection tunnel, the light strips can be arranged at a predetermined grid spacing. This allows for the creation of favorable reflection patterns for targeted inspections of specific defect patterns on substrates. This also allows for defect control over a wide range, from locally limited defect patterns to large-area defect patterns.

[0050] According to an advantageous embodiment of the test tunnel, luminaire elements of different luminaire strips can have light sources with different color temperatures, in particular in the range between 2700 K and 6500 K.

[0051] The color temperature can be constant within a luminaire strip, while a neighboring luminaire strip can have a different color temperature. In particular, neighboring luminaire strips can have alternating sequences of high and low color temperatures.

[0052] The light color of the light sources in a strip light can either be fixed, ranging, for example, between 2700 K (warm white) and 6500 K (cool white). For example, a "zebra arrangement" is also possible, in which cool white and warm white strip light sources are used alternately, or in other sequences.

[0053] The lighting elements can be dimmable. The degree of dimming can be based on the color of the substrate, for example, and the color of the lighting element can also be adjusted to match the color of the substrate.

[0054] According to an advantageous embodiment of the test tunnel, areas between the light strips can have surfaces with predetermined, in particular different, reflectances. In particular, the surface material can have reflectances between 20% and 70%, preferably between 27% and 55%, based on a wavelength range of visible light and with perpendicular incidence.

[0055] Each luminous strip creates the above-described light-dark contrast areas on the substrate by entering and exiting the luminous strip, in whose transition the defects such as lacquer inclusions, which appear as punctual deviations of a flat surface, can be recognized as line deformation.

[0056] To ensure sufficient contrast even on bright surfaces, such as white, a minimum contrast ratio of 1:1.7 was determined for an exemplary ambient luminance. This can be used as a basis for the design of a lighting element. To create a psychologically supportive environment (“stable viewing”) at the interface between very bright and very dark substrates under these contrast conditions, the necessary reflectances of the materials that can be installed between the lighting strips can be determined.

[0057] These reflection levels can, for example, be between 27% and 55%, each based on a wavelength range of visible light and with perpendicular incidence of light.

[0058] It can also be advantageous to line the space between the strip lights with matte panels, e.g., in Le Corbusier's architectural colors or other natural earth tones that create a pleasant spatial feeling. The panels can be made of fabric, plastic, wood, or sheet metal, for example. A film with a tinted coating can be used.

[0059] According to an advantageous embodiment of the test tunnel, at least one lighting strip can be arranged running parallel to the longitudinal axis of the tunnel, wherein the light exit surfaces of the lighting elements are aligned towards the longitudinal axis of the tunnel.

[0060] When using a test tunnel for large substrates, such as car bodies, it may be advantageous to use longitudinal light strips of the same design in addition to the light strips running transversely to the tunnel's longitudinal axis. This allows for additional advantageous reflection patterns or contrast changes to be created on the substrate.

[0061] Especially when inspecting the hood and trunk lid of a car body, for example, it can be advantageous to install longitudinally mounted light strips, as the inspector often moves across the body. This natural movement of the inspector across the body then creates a light / dark contrast change without any additional head movement.

[0062] According to an advantageous embodiment of the test tunnel, light strips can be arranged in the floor along the tunnel's longitudinal axis and / or transversely to the tunnel's longitudinal axis.

[0063] If light strips are used in the floor of the test tunnel, they can be advantageously constructed in terms of luminance characteristics analogous to those installed in the tunnel wall, thus resulting in a uniform reflection pattern on almost all areas of the substrate, e.g. a car body. drawing

[0064] Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations. Examples include:

[0065] Fig. 1 a plan view of a lighting element according to an embodiment of the invention with section lines BB and DD drawn in; Fig. 2 a longitudinal section through the lighting element in the section plane DD according to Figure 1 ; Fig. 3 an isometric view of the lighting element according to Figure 1 ; Fig. 4 a schematic cross-section through the luminaire element in the section plane BB according to Figure 1 ; Fig. 5 shows a schematic cross section through a lighting element according to a further embodiment of the invention; Fig. 6 shows a plan view of a curved lighting element according to a further embodiment of the invention with a section line AA drawn in; Fig. 7 shows a longitudinal section through the lighting element according to Figure 6 in the section plane AA; Fig. 8 a cross section through a test tunnel according to an embodiment of the invention; Fig. 9 a longitudinal section through the test tunnel according to Figure 8; Fig. 10 shows a luminance curve across two luminaire elements according to the invention; and Fig. 11 shows color temperature arrangements of luminaire strips of a test tunnel according to an embodiment of the invention. Embodiments of the invention

[0066] In the figures, components of the same type or function similarly are designated by the same reference numerals. The figures are merely examples and are not to be construed as limiting.

[0067] The directional terminology used below, including terms such as "left," "right," "top," "bottom," "before," "behind," "after," and the like, is intended solely to enhance understanding of the figures and is in no way intended to limit the scope of the invention. The components and elements depicted, as well as their design and use, may vary according to the considerations of a person skilled in the art and may be adapted to specific applications.

[0068] Figure 1shows a plan view of a lighting element 10 according to an embodiment of the invention with section lines BB and DD drawn in, while the lighting element 10 in Figure 2 in the longitudinal section in the section plane DD and in Figure 3 can be seen in an isometric representation. In Figure 4 The schematic cross-section in the section plane BB through the luminaire element 10 is shown.

[0069] The lighting element 10 for a test tunnel 100 comprises two strip-shaped arrangements 12 of light sources 13 in a lighting housing 14. The lighting housing 14 has two edge regions 16 which are opposite one another along a longitudinal extension L of the lighting housing 14. The strip-shaped arrangements 12 of the light sources 13 are formed along the longitudinal extension L at the edge regions 16, as shown in particular in Figure 2 and Figure 4can be seen. As a result, a light exit surface 20 of the luminaire housing 14 has a higher radiant intensity along the edge regions 16 than in a central region 30.

[0070] The light sources 13 can comprise one or more light-emitting diodes and / or fluorescent tubes and / or light guides. The light sources 13 can be color-variable, in particular as light-emitting diodes with adjustable color temperature.

[0071] Light-emitting diodes (LEDs), such as mid-power LEDs with a luminous flux of 20 to 100 lumens and a luminous efficacy of approximately 180 lumens / watt, are preferred as light sources. Alternatively, fluorescent tube designs can also be used.

[0072] The light sources 13 are arranged on a support element 32 for mechanical fixation. The support element 32 can be designed to be reflective toward the light exit surface 20, in particular to increase the reflection contrast.

[0073] The light exit surface 20 of the luminaire housing 14 is formed by a pane package 22, which has at least one diffuser 24 and a cover pane 28. Preferably, a multi-prism pane 26 can be arranged between the diffuser 24 and the cover pane 28, as in the embodiment in Figure 4 can be seen.

[0074] The luminaire design is based on the principle of backlighting, with the light rays passing through a pane assembly 22 before leaving the luminaire element 10. This assembly preferably consists of a diffuse pane 24, a multi-prism pane 26, and a protective cover pane 28. The multi-prism pane can, in particular, serve to further reduce any potential glare for the inspector.

[0075] The central region 30 of the light exit surface 20 can advantageously have a lower transparency than the edge region 16. In particular, the central region can be designed to be opaque, for example by applying an opaque strip to the diffuser, which can also be designed to be reflective towards the light source 13.

[0076] The luminaire housing 14 has end-face connection areas 18 transverse to the edge areas 16, which are designed to connect adjacent luminaire elements 10, 11. The end-face connection areas 18 can advantageously be designed as standardized connection elements for the mechanical and / or electrical connection of adjacent luminaire elements 10, 11.

[0077] The luminaire housing 14 can be designed to be openable at the rear, in particular provided with a maintenance opening 34, as shown in Figure 2 This allows for the replacement of light sources 13 and / or driver stages to be carried out advantageously from the rear of the luminaire housing 14.

[0078] Alternatively, the luminaire housing 14 can also be designed as a closed unit. If replacement of the light sources 13 is not intended, they can also be glued to the support element 32.

[0079] Figure 5shows a schematic cross-section from the light exit side 20 through a lighting element 10 according to a further exemplary embodiment of the invention. Arrangements 12 of light sources 13 are arranged along the two edge regions 16. The central region 30 of the light exit surface 20 can advantageously have a lower transparency than the edge region 16. In particular, the central region can be designed to be opaque, for example by applying an opaque strip to the diffuser 24, i.e., on the inside of the pane stack 22, which can also be designed to be reflective toward the light sources 13.

[0080] In Figure 6 a plan view of a curved lighting element 11 according to a further embodiment of the invention is shown with a section line AA drawn in. Figure 7 shows the longitudinal section in the section plane AA through the luminaire element 11.

[0081] The structure of the curved luminaire element 11 is similar to the structure of the Figures 1 to 5 The difference is that in the curved luminaire element 11, the luminaire housing 14 is curved in an arcuate manner. The light exit surface 20 is oriented toward a concave inner side of the arcuate curve. The light sources 13 are arranged on the likewise curved luminaire insert 32. The curved luminaire element 11 also has connection areas 18 at its ends, with which the luminaire element 11 can be mechanically and / or electrically connected to adjoining flat and / or curved luminaire elements 10, 11.

[0082] Figure 8 shows a cross section through a test tunnel 100 according to an embodiment of the invention, while in Figure 9 a corresponding longitudinal section through the test tunnel 100 is shown.

[0083] The test tunnel 100 is used in particular for testing painted vehicle bodies 120, which pass through the test tunnel 100 along a longitudinal tunnel axis 102. The test tunnel 100 has an arrangement of several light strips 50 arranged side by side transversely to the longitudinal tunnel axis 102. The light exit surfaces 20 of the light elements 10, 11 are aligned on a concave inner side of the arcuate curvature of the tunnel wall 108 toward a central region of the longitudinal tunnel axis 102.

[0084] A lighting strip 50 comprises a plurality of lighting elements 10, 11, which are connected to one another at their end-face connection areas 18. In particular, the lighting elements 10, 11 are arranged at least partially on an arcuately curved line, with the light exit surfaces 20 of the lighting elements 10, 11 oriented toward the concave inner side of the arcuate curve. End pieces 52 of a lighting strip 50 are formed by flat lighting elements 10, between which a plurality of curved lighting elements 11 are arranged.

[0085] The individual lighting elements 10, 11, joined to form a lighting strip 50, which may, for example, have an arch-like structure, can be screwed together at the end faces. For this purpose, for example, six curved lighting elements 11, each 1420 mm long, and two flat lighting elements 10, each 750 mm long, can be used. Because the light exit surface 20 is approximately the length of the luminaire housing 14, only minimal sections arise in the circumferential direction where the light exit surface is interrupted. With this almost continuous light exit surface 20, an advantageous, almost uninterrupted, reflected image can be created on the substrate.

[0086] To combine individual lighting elements 10, 11 with a length of, for example, 1400 mm into a continuous lighting strip, they can be screwed or plugged together at the ends to avoid unlit areas. In this case, the power supply and control signals could also be transmitted from one lighting element 10, 11 to the next via the plug connection.

[0087] Due to the concentric arrangement of the lighting elements 10, 11, the light beams are directed primarily onto the substrate, for example, a painted vehicle body 120. This increases the light output and reduces direct glare for the inspectors.

[0088] The width of the individual 50-inch light strips can be 200 mm, for example, and the clearance between the light arcs can be 500 mm. This provides both a sufficiently high number of contrast transitions and sufficient visually "undisturbed" space, which is also required for inspecting the entire substrate.

[0089] Figure 9 shows a cross-section of a test tunnel 100 with a plurality of light strips 50 arranged in two so-called cycles 110. The two cycles 110 are spaced apart from each other so that a vehicle body 120 can be inspected simultaneously in both cycles 110. The individual light strips 50 are separated from each other by areas 106. One cycle 110 can, for example, have a length of 6.3 m.

[0090] The lighting strips 50 of a cycle are arranged at a predetermined pitch 104, which may be, for example, 0.70 m, while the distance between the two cycles may be, for example, 0.8 m.

[0091] The regions 106 between the light strips 50 can have materials or surfaces with predetermined, in particular different, reflectances. In particular, reflectances between 20% and 70%, preferably between 27% and 55%, based on a wavelength range of visible light and with perpendicular light incidence, can be provided in order to achieve the best possible contrast situation for the examination of substrates.

[0092] In addition, at least one lighting strip 50 can be arranged in a test tunnel 100 running parallel to the tunnel longitudinal axis 102, wherein the light exit surfaces 20 of the lighting elements 10, 11 are aligned towards the tunnel longitudinal axis 102.

[0093] Furthermore, it is also possible for light strips 50 to be arranged in the floor 124 in the tunnel longitudinal axis 102 and / or transversely to the tunnel longitudinal axis 102.

[0094] Especially when inspecting, for example, the hood and trunk lid of a body 120, it can be advantageous to install longitudinally mounted light strips 50, since the inspector often moves transversely to the body 120. This natural movement of the inspector transversely to the body 120 then results in a light / dark contrast change without additional head movement.

[0095] Figure 10shows a luminance profile across two luminaire elements 10 according to the invention, which are arranged spaced apart by a region 106. Luminance regions 60 with a very high luminance can be seen at the edge regions 16 of the luminaire elements 10. The rise and fall of the luminance in these regions 60 is very steep, so that a high contrast occurs there, which favors the perception of point defects on a substrate. Between the luminance regions 60 with high luminance, a region 62 of low luminance can be seen in the central region 30 of the luminaire elements 10. The region 106 between the two luminaire elements 10 has a dark region 64.

[0096] Optionally, light sources 13 with LEDs with variable color temperatures can be used. This allows, for example, the light color to be adjusted to the color of the substrate or to the inspector's preferences.

[0097] In Figure 11 possible color temperature arrangements of light strips 50 of a test tunnel 100 according to an embodiment of the invention are shown.

[0098] Lighting elements 10, 11 of different lighting strips 50 of a test tunnel can have light sources 13 with different color temperatures. In particular, the color temperatures can vary in the range between 2700 K and 6500 K. Adjacent lighting strips 50 can have alternating sequences of high and low color temperatures.

[0099] The light color of the light sources 13 in a 50-series light strip can either be fixed and range, for example, between 2700 K (warm white) and 6500 K (cool white). For example, alternating cool white and warm white 50-series light strips or other sequences can be used.

[0100] The lighting elements 10 can be dimmable. The degree of dimming can be based, for example, on the color of the substrate. The color of the lighting element 10 can be adapted to the color of the substrate.

[0101] In Figure 11 Various possible color temperature arrangements S1 to S9 are shown. However, this representation is not intended to be limiting; other color temperature combinations are certainly conceivable.

[0102] Luminaire elements 50 with a high color temperature 70 are shown in white, while luminaire elements 50 with a medium color temperature 72 are shown in dotted lines, and luminaire elements 50 with a low color temperature 74 are shown in dense dotted lines. However, further gradations are shown in between. The arrows are intended to illustrate the color temperature progression from high color temperatures 70 to low color temperatures 74. For clarity, only individual luminaire elements 50 are provided with reference symbols. 10Luminaire element 11Curved luminaire element strip-shaped arrangement of 12light sources 13Light source 14Luminaire housing 16Edge area 18Connection area 20Light emission surface 22Disc package 24Diffuser 26Multi-prism disc 28Cover disc 30Central area 32Luminaire insert 34Maintenance opening 50Light strip 52End piece 60High contrast 62Low luminosity 64Dark area 70high color temperature 72medium color temperature 74low color temperature 100Test tunnel 102Tunnel longitudinal axis 104Grid dimension 106Area 108Tunnel wall 110Cycle 120Vehicle body 124Floor LLongitudinal extension

Claims

1. Test tunnel (100) having a longitudinal tunnel axis (102), in particular for testing shiny, in particular painted, vehicle bodies (120), having an arrangement of a plurality of luminaire bands (50), wherein the luminaire bands (50) have an arrangement of luminaire elements (10, 11), wherein the luminaire elements (10, 11) are connected to one another at their end-side connection regions (18), in particular wherein the luminaire elements (10, 11) are arranged at least in regions on an arc-shaped line, wherein the light exit surfaces (20) of the luminaire elements (10, 11) are oriented towards a concave inner side of an arc-shaped curvature, wherein the luminaire elements (10, 11) comprise at least two strip-shaped arrangements (12) of light sources (13) in a luminaire housing (14) with at least two edge regions (16) located opposite one another along a longitudinal extent (L) of the luminaire housing (14), wherein the strip-shaped arrangements (12) of the light sources (13) are formed along the longitudinal extent (L) at the edge regions (16), wherein a light exit surface (20) of the luminaire housing (14) has a higher radiation intensity along the edge regions (16) than in a centre region (30), and wherein the luminaire bands (50) are arranged side by side transversely to the tunnel longitudinal axis (102), characterized in that the light exit surfaces (20) of the luminaire elements (10, 11) on a concave inner side of the arc-shaped curvature of a tunnel wall (108) are oriented towards a central region of the tunnel longitudinal axis (102).

2. Test tunnel according to Claim 1, wherein the luminaire bands (50) are spaced at a predetermined grid dimension (104).

3. Test tunnel according to Claim 1 or 2, wherein end pieces (52) are formed by planar luminaire elements (10), between which curved luminaire elements (11) are arranged.

4. Test tunnel according to any of the preceding claims, wherein luminaire elements (10, 11) of different luminaire bands (50) have light sources (13) having different colour temperatures, in particular in the range between 2700 K and 6500 K, in particular wherein adjacent luminaire bands (50) have alternating sequences of high and low colour temperatures.

5. Test tunnel according to any of the preceding claims, wherein regions (106) between the luminaire bands (50) have surfaces of predetermined, in particular different, reflectances, in particular reflectances of between 20% and 70%, preferably between 27% and 55%, based on a wavelength range of visible light and with perpendicular light incidence.

6. Test tunnel according to any of the preceding claims, wherein at least one luminaire band (50) is arranged parallel to the tunnel longitudinal axis (102), wherein the light exit surfaces (20) of the luminaire elements (10, 11) are oriented towards the tunnel longitudinal axis (102).

7. Test tunnel according to any of the preceding claims, wherein luminaire bands (50) are arranged in the ground (124) in the longitudinal tunnel axis (102) and / or transversely to the longitudinal tunnel axis (102).

8. Test tunnel according to any of the preceding claims, wherein the light exit surface (20) of the luminaire housing (14) has at least one diffuser (24) and a cover plate (28), in particular wherein a multi-prism plate (26) is arranged between the diffuser (24) and the cover plate (28).

9. Test tunnel according to any of the preceding claims, wherein the light sources (13) comprise one or more light-emitting diodes and / or one or more fluorescent tubes and / or one or more light guides.

10. Test tunnel according to any of the preceding claims, wherein the light sources (13) are colour-variable, in particular are designed as light-emitting diodes with adjustable colour temperature.

11. Test tunnel according to any of the preceding claims, wherein the luminaire housing (14) has end-side connection regions (18) transversely to the edge regions (16), which are designed for connecting adjacent luminaire elements (10, 11), in particular wherein the end-side connection regions (18) are formed as standardized connection elements for the mechanical and / or electrical connection of adjacent luminaire elements (10, 11).

12. Test tunnel according to any of the preceding claims, wherein the luminaire housing (14) is arc-shaped, wherein the light exit surface (20) is oriented towards the concave inner side of the arc-shaped curvature.

13. Test tunnel according to any of the preceding claims, wherein the centre region (30) of the light exit surface (20) has a lower transparency than the edge region (16), in particular wherein the centre region (30) is designed to be opaque.

14. Test tunnel according to any of the preceding claims, wherein the luminaire housing (14) is designed to be openable at the rear, in particular wherein the luminaire housing (14) is designed with a maintenance opening (34) at the rear.

15. Test tunnel according to any of the preceding claims, wherein the light sources (13) are arranged on a carrier element (32), in particular wherein the carrier element (32) is designed to be reflective towards the light exit surface (20).

16. Test tunnel according to any of Claims 1 to 15, wherein the luminaire housing (14) is designed to be closed and / or the light sources (13) are adhesively bonded on a carrier element (32).