Backlit advertising banner and method for adjusting the brightness of the advertising banner

Abstract

Advertising banner (1), in particular for the presentation of banner advertising at winter sports events, with a housing (10) in which at least one light source (21) is arranged for backlighting at least one at least partially translucent advertising surface (20, 51, 52, 53), wherein: - the advertising banner (1) has at least one control unit (30) for adjusting the radiant power emitted by the light source (21) in order to adjust the brightness of the backlit advertising area (51, 52, 53), and - the control unit (30) is connected to at least one sensor for determining the ambient brightness in the space surrounding the advertising banner, in order to determine the ambient brightness by means of the sensor and to adjust the brightness of the advertising area (20) to a value dependent on the ambient brightness by adjusting the radiant power of the light source (21), - the control unit (30) is connected to a brightness sensor (31) for measuring the actual value of the brightness of the partially translucent advertising surface (20) and regulates the actual value to a target value dependent on the ambient brightness by adjusting the radiant power of the light source (21), characterized in that - the control (30) captures at least one image showing the advertising banner, - the advertising banner (1) has at least one infrared light source marking the advertising area (20) and that - the control (30) determines an image section that at least partially depicts the advertising area based on the infrared marking and determines the brightness of the advertising area (20, 51, 52, 53) based on the brightness values ​​of the image section.

Description

Technical field

[0001] The invention relates to an advertising banner with a housing. At least one side or part of a side of the housing is formed by an at least partially translucent information surface (hereinafter referred to as the "advertising surface"), which carries optically perceptible information directed towards a viewer of the information surface. On the side of the cover facing away from the viewer, there is at least one light source to backlight the cover. State of the art

[0002] Sports advertising is a significant economic sector that leverages the interest of sports enthusiasts in sporting events to convey advertising messages from the sports organizers' clients. Stadium advertising, or advertising at sports venues in general, plays a major role in sports advertising. This refers specifically to the placement of advertisements within the sports venue itself. Often, the information is displayed on boards that define the boundaries of the actual sports area, such as a playing field. While watching the athletes, an observer will at least peripherally perceive the information displayed on the advertising boards. Advertisers hope to transfer the positive image associated with sports to their products or at least increase brand awareness.

[0003] In its simplest form, an advertising banner is a flat or curved panel erected at the edge of a sports venue and displaying an advertising message. Numerous patent and utility model applications exist that aim either to increase the viewer's attention to the advertising banner or to solve other technical problems such as stability, accident prevention, manufacturing issues, etc. Examples include DE 199 37 037 A1, EP 1 501 068 A1, DE 20 2008 006 975 U1, DE 203 17 063 U1, and DE 20 2004 003 651 U1.

[0004] To increase viewer attention to the information being conveyed, so-called rolling banners were proposed, which, as usual, each have a viewing surface facing the viewer. The viewing surface is formed by a printed, flexible advertising medium wound onto two rolls, so that different sections of the advertising medium can be made visible by rotating the rolls (see, e.g., DE 20 2004 006 875 U1).

[0005] Further flexibility in information display has been achieved with the APA-LED light bar (see www.APA-LED-Leuchtbande.de). This consists of a 2D array of multi-colored LEDs that can be individually controlled. The LEDs are located in recesses behind a black protective cover. Each LED corresponds to one pixel of the information to be displayed. A similar system is described, for example, in US 6,364,507 B1. These LED light bars are very well suited for some sports, such as soccer, but not for other sports that often take place in natural environments. A major reason for this is the high energy consumption of the LED light bars and their comparatively high weight. The purchase price also makes their use in less spectator-friendly sports currently uneconomical.Another problem with these LED light strips is their optical properties: As Lambertian radiators, the LEDs emit very poorly at large beam angles (relative to the surface normal at the emission point) and the individual LEDs are clearly visible up close, which makes the displayed information appear pixelated.

[0006] German patent DE 10 2009 056 806 A1 describes an illuminated sign in the form of a single illuminated letter. The illuminated letter has the usual construction consisting of a housing with a light channel integrated within it and a front panel that borders the light channel. A brightness sensor measures the ambient light level, and the light intensity emitted by the backlighting LEDs is adjusted based on this measurement. The LEDs are supplied with a pulsed DC voltage via a controller. The intensity of the light emitted by the LEDs can be adjusted by varying the number or width of the pulses. The brightness sensor is located on a circuit board next to the LEDs to determine the ambient light intensity during the pulse intervals. During the pulses, the brightness sensor measures the brightness inside the illuminated sign.

[0007] EP 2071 983 A1 concerns a lighted display case in which an object is illuminated with LEDs.

[0008] WO 2010 / 046065 A1 describes several variations of a buck converter for controlling LEDs. It starts with a classic buck converter circuit, which is supplemented by a capacitor connected in parallel to the LEDs. This capacitor smooths the current through the LEDs, so that the light appears flicker-free even at low intensities.

[0009] WO 2010 / 111 725 A1 discloses an advertising light source with a defined light emission area and a gas discharge lamp. The lamp illuminates a light chamber, with a specific light color and brightness emanating from a light emission area, and a light-emitting diode (LED) arranged in the light emission area changing the light color and / or brightness. The LED has several sub-areas that can be selectively controlled and activated.

[0010] US 2014 / 0253841A1 describes an LCD display and a control method for it. Conventional TN-LCDs, even with active-matrix control, still exhibit insufficient image quality and motion rendering compared to cathode ray tubes. Despite known methods such as overdrive or pulse control, problems arise due to environmental changes that affect the response time of the liquid crystals and the brightness of LED backlights. The invention solves this problem with a monitoring pixel and a light sensor that detect the luminance in real time. This allows the backlight to be automatically controlled with regard to brightness and on / off timing, enabling consistently high image quality and video performance under changing environmental conditions. Description of the invention

[0011] The invention is based on the observation that LED light boards are often not practical for outdoor sports due to the aforementioned problems, and their unique selling point—the display of moving images—is often not realized because the regulations of some sports prohibit it. Traditional advertising boards, as well as rolling boards, have the disadvantage that they are often not perceived to the desired extent by spectators under difficult or changing ambient light conditions, such as those regularly encountered in skiing.

[0012] Based on this, the invention aims to provide an advertising banner that is always clearly visible even under changing lighting conditions, both by the spectators of the event on site and, if applicable, by the spectators of a television broadcast.

[0013] This problem is solved by an advertising banner according to claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

[0014] The advertising banner can be used, in particular, for displaying advertising at winter sports events and has a housing in which at least one light source is arranged to backlight at least a translucent and / or at least partially transparent advertising surface. Translucent materials allow light to pass through, but scatter it, so that they are generally at least largely opaque. A backlit translucent material appears bright, without the light source(s) being clearly visible.

[0015] The advertising banner is, as usual, preferably placed at the edge of the sports area, for example next to a cross-country ski track. Consequently, during a television broadcast of the event on the sports field, the advertising space of the banner is also regularly shown.

[0016] However, particularly during television broadcasts of winter sports, difficult lighting conditions often prevail, causing standard advertising banners to recede into the background of the television image. This can be avoided with a backlit advertising surface featuring adjustable brightness, as the brightness of the advertising surface can be adjusted as a function of the brightness of the rest of the image.

[0017] The light source can, for example, consist of one or more LEDs. The advertising banner also has a control unit connected to the light source to adjust the emitted radiant power between a minimum value (e.g., light off) and a maximum value (maximum brightness). This allows the brightness of the advertising surface to be adjusted within the corresponding range. This adjustment allows the perception of the advertising banner, or more precisely, its backlit advertising surface, to be adapted to the respective ambient conditions. For example, if it is very bright around the advertising banner, but the advertising surface is in shadow, this shadow can be (over)compensated for by increasing the radiant power of the light source, so that the information displayed on the advertising surface is clearly visible. The system also adapts to changes in lighting conditions, such as those that frequently occur during winter sports, e.g.,Changes such as snowfall, early dusk, clearing skies, etc., can be effectively addressed by adjusting the brightness of the advertising space, ensuring that the advertising space is clearly visible even in difficult weather conditions, without unnecessarily dominating the image.

[0018] The advertising area can be, in particular, the side of a housing boundary facing away from the light source, e.g., a side panel. The boundary does not necessarily have to consist of a rigid (translucent) panel, but can also be made of a flexible material, such as a film or textile, that closes an opening in the housing.

[0019] A transparent cover, such as a sheet of glass or transparent plastic, can be positioned in front of and / or behind the translucent advertising surface to seal the housing against moisture. This cover can also serve as accident protection by absorbing the force exerted by athletes falling into the advertising banner and, at a suitable angle of impact, deflecting the athletes so that they slide along the banner, dissipating their kinetic energy relatively slowly.

[0020] On the at least partially translucent advertising surface, visually perceptible information can be displayed. This information could be, for example, an advertising graphic, a logo of a supplier of goods or services, or a trademark. To the viewer, the displayed information appears backlit and is thus highlighted from the surrounding image, whether in person or on a television screen. Therefore, instead of the terms "advertising surface" and "advertising banner," one could also use "information surface" and "information banner."

[0021] For the sake of simplicity, the at least partially translucent edge of the housing will subsequently be referred to as the advertising space. In traditional perimeter advertising, this advertising space would be the side facing the athletes, so that the advertising space appears in the background when viewing or recording the athletes.

[0022] The advertising banner has a control to adjust the brightness of the light source, i.e., the radiant power emitted by the light source. Adjustment here does not simply mean switching it on or off, but rather adapting the radiant power, and thus the brightness of the advertising surface, to the ambient conditions. Therefore, there are preferably at least two, and preferably a plurality, adjustable radiant power levels for the light source. In particular, the radiant power can be adjusted continuously. Depending on the selected radiant power of the light source, the visually perceptible information appears brighter or dimmer. By adjusting the radiant power emitted by the light source, the visibility of the advertising surface can be enhanced for the viewer and adapted to the frequently changing lighting conditions, especially during winter sports.

[0023] The brightness of the radiant power of the (electric) light source can be adjusted as usual by adjusting the voltage applied to the light source or the current flowing through the light source.

[0024] To adjust the brightness of the advertising banner, the ambient light level, e.g., the average ambient light, is detected, and the brightness emitted by the backlit information is adjusted accordingly. For this purpose, the control unit is connected to at least one sensor in the area surrounding the banner to determine the ambient light level. This sensor then uses the ambient light level to adjust the brightness of the advertising surface to a value dependent on the ambient light level. In the simplest case, the sensor for detecting the ambient light level can be a photodiode and / or a photoresistor. The ambient light level can also be determined from a camera image.

[0025] Brightness is generally understood, and also used in this application, to be the intensity of radiation acting on an observer or sensor. Brightness can be determined by measuring the spectrally averaged radiant power acting on the observer or sensor. This measurement can be weighted by the spectral brightness sensitivity of the eye and would then usually be expressed in candela (Cd).

[0026] A control element adjusts the radiant power of the light source based on the ambient brightness, ensuring that the brightness of the backlit side panel is greater than or equal to the average ambient brightness. For example, the set brightness of the backlit side panel can be between 1.05 and 10 times the average ambient brightness. A comparator compares the brightness emitted by the backlit advertising surface with the average ambient brightness. The radiant power emitted by the light source is increased if the brightness emitted by the backlit information is lower than the average ambient brightness. Conversely, the radiant power emitted by the light source can be decreased if the brightness emitted by the backlit advertising surface is significantly higher than the average ambient brightness.This prevents glare from the advertising space.

[0027] Accordingly, the control unit is connected to at least one sensor for determining the ambient brightness in the space surrounding the advertising banner, in order to determine the ambient brightness using the sensor and to adjust the brightness of the advertising surface to a value dependent on the ambient brightness by adjusting the radiant power of the light source.

[0028] The brightness of the advertising surface is not only adjusted, but regulated to a target value dependent on the ambient brightness and / or other environmental parameters. Other environmental parameters can include, for example, precipitation, the condition and state of surfaces located between the viewer and the advertising surface. For this purpose, the control unit is connected to a brightness sensor to measure the actual brightness of the translucent advertising surface. The control unit then adjusts the radiant power of the light source to regulate the actual value to a target value dependent on the ambient brightness. The (at least one) brightness sensor for measuring the actual value can, for example, be positioned at the edge of the advertising banner and directed at the advertising surface from an angle. The brightness sensor does not need to cover the entire advertising surface; it is sufficient if it only covers a portion of it. This also makes it less sensitive to external stray light.If you want to avoid having the brightness sensor mounted on the outside of the advertising banner, you can place it inside the housing, i.e., on the side of the advertising surface facing the light source. While this measures the brightness of the banner on the back side, it allows you to infer the brightness of the visible side of the advertising surface. Examples of suitable brightness sensors include photoresistors, semiconductor cameras, photodiodes, and similar devices.

[0029] The brightness of the backlit advertising space can be measured, in particular, using a digital camera image of the advertising space. This can be done using one (or more) separate camera(s) and / or the image, or more precisely, the images, from a camera used for reporting or documenting the sporting event. The first step involves identifying the advertising banner in the image and then determining the average brightness of the pixels or image section that represent at least a portion of the advertising space.The brightness thus determined is then compared with the average brightness of at least one other image section (that does not show the advertising space), and depending on this, the radiant power emitted by the light source is adjusted so that the average brightness of the image section representing the advertising space of the advertising banner is a multiple of the brightness of the other image section, e.g., 1.01 to 10 times the brightness of the other image section. The averaging is performed across the pixels of the respective image sections. Preferably, averaging is also performed over time, e.g., over the time interval of the preceding period, e.g., 0.5 seconds to 5 minutes, to reduce short-term brightness fluctuations, e.g., caused by shadows or athletes or other objects moving through one of the image sections. Longer-term changes in ambient brightness, e.g., due to...Snowfall, rain or clearing skies are then adequately taken into account when adjusting the radiant power emitted by the light source; short-term changes due to moving people or objects play only a minor role.

[0030] It follows from the above that the "other image section" is used to determine the ambient brightness. This other image section can be identical to the remaining image resulting from excluding the advertising space. However, the other image section can also be only a part of the remaining image, preferably a ring or segment surrounding the advertising space. This gives corresponding weight to the brightness of the part of the image that is particularly relevant for the perception of the advertising space.

[0031] If the brightness sensor is a static camera, the image area representing the advertising banner can be programmed into the control system by entering it into the control system, for example, by marking it in a playback of the image area. Programming therefore means transferring the information about which pixels represent the advertising space or a section of it.

[0032] Especially when the camera is panned or moved during the event, for example, to record the progress of the sporting event, the advertising banner must have at least one infrared light source in the area of ​​the backlit information, e.g., at the edge of the backlit area. Suitable infrared light sources are, for example, infrared LEDs (IR LEDs), which emit light (exclusively) in the non-visible IR range (e.g., with a wavelength λ between 1000 nm and 700 nm). For an advertising banner with a rectangular advertising area, at least one infrared light source (IR LED) can be positioned in each corner or along each edge of the advertising area. The radiation emitted by the IR LEDs can be easily detected in images from a digital camera by scanning the images for areas (pixels) of high intensity in the IR range. This allows for very simple identification of the image section showing the advertising banner.IR point light sources can be detected particularly reliably when they operate at a blinking frequency that is detectable by the camera and known to the control system, as this blinking frequency can then be used to identify the corresponding image areas. Any heating of the area around the advertising banner, for example due to sunlight, would not hinder the detection of the image section depicting the banner, since the blinking signal can be easily identified within the noise that reflects the increased temperature caused by the sunlight. The blinking frequency should be lower than the camera's frame rate, i.e., the frequency at which the camera records images. For example, the blinking frequency could be only 1 / 4 or less of the frame rate to ensure easy detection of the blinking signal.

[0033] Preferably, LEDs mounted on a substrate within the housing are used as the light source. A housing back panel, for example, can serve as the substrate. To adjust the brightness of the backlit advertising area, the LEDs can be pulsed. This allows for simple brightness adjustment by changing the pulse-to-pause ratio, preferably with a constant pulse frequency. However, the pulse frequency should be higher than a multiple of the frame rate at which the transmission cameras record the images, as otherwise, brightness fluctuations may occur when the camera images are displayed. This problem can also be avoided by smoothing the current through the LEDs, thus ideally operating them with a constant current source.

[0034] If LEDs or LED modules are used as the light source, they are preferably arranged on a substrate. The LEDs or LED modules preferably form a 2D grid with a preferably triangular unit cell, wherein the triangle is preferably an isosceles triangle (±20%, preferably ±10%, particularly preferably ±5%) with a right angle (±15°, preferably ±10°, particularly preferably ±5°). The basis vectors {a→, b→} such a grid (in Cartesian coordinates) can, for example, a→=(1,0), b→=(12, 12) Such a grid acts like a nested arrangement of two grids with square unit cells, where the grid points of a unit cell in the first grid lie in the center of adjacent unit cells in the other grid. A grid point here indicates the location of an LED or LED module. The described arrangement of the LEDs ensures particularly homogeneous backlighting of the advertising surface and can be further optimized by using appropriate LED lenses.

[0035] The advertising banner described allows advertising messages to be clearly visible on boards, especially for the demarcation of sports areas such as cross-country ski trails, even under difficult and changing lighting conditions, provided the advertising banner has a housing with at least one advertising surface backlit by an electric light source, the brightness of which is adjusted by a control system depending on the ambient brightness. Description of the drawings

[0036] The invention is described below by way of example, without limiting the general concept of the invention, with reference to the drawings. Fig. Figure 1 shows an advertising banner with a backlit advertising area; Fig. 2 shows the advertising banner after Fig. 1 with dismantled advertising space, Fig. Figure 3 shows a detail of the advertising banner. Fig. 1. Fig. Figure 4 shows an advertising banner with several backlit advertising areas, Fig. 5 shows the advertising banner after Fig. 3, with one advertising space removed.

[0037] The advertising banner 1 in Fig. 1 has a cuboid-shaped frame 10 with a back wall 11 (cf. Fig. 2) and surrounding side walls 12. In the example shown, the back wall 10 and the side walls 12 are made of non-transparent material. The front wall 13 of the advertising banner 1 is translucent and contains visually perceptible information. This is symbolized here by the word "Info" and could also be a graphic or the like. The surface of the front wall 13 facing outwards, i.e., towards the viewer, is also referred to as the advertising area 20. The surface of the front wall facing inwards, i.e., towards the light source, can be aptly, but somewhat imprecisely, described as the back of the advertising area. The front wall of the advertising banner is not necessarily a translucent panel. The front wall can also be curved, and if the front wall of the advertising banner does not have a static function, it can, as in this example, consist of a translucent fabric and / or a film stretched between the side walls.Polyester fabric is particularly suitable, for example. To improve its visual properties, it can be coated with acrylic and / or cotton. A suitable advertising area can then be printed, for example.

[0038] Fig. Figure 2 shows the advertising banner with the front panel 13 removed, exposing the inside of the back panel 13. On the inside of the back panel 13 are numerous LED modules 21 arranged in a 2D grid, serving as a light source for backlighting the front panel. These modules are connected via cables to a controller 30. Alternatively, the housing could contain a support frame or an intermediate wall to hold the light source (e.g., the LED modules 21). The controller 30 has a driver circuit to supply the LED modules 21 with an electrical power adjustable by the controller. This power is then converted into light output by the LED modules 21 with a given efficiency. The 2D grid has a triangular unit cell, where the triangle is at least approximately an isosceles (±10%) and right-angled triangle (±10°).The inner surfaces of the rear wall 11 and the side walls 12 are preferably made of a diffusing material or provided with a diffusing coating in order to achieve the most uniform possible backlighting of the advertising area.

[0039] To secure the flexible front panel, it can have a circumferential thickening 14 in the area of ​​the surrounding edge, e.g. a plastic strip (cf. Fig. 3) The plastic strip 14 preferably has a rectangular cross-section and can, for example, be glued, welded, and / or sewn onto the front wall. The thickened edge can be inserted into a forward-facing circumferential groove 121 of the side wall 12 for attachment (indicated by arrow 122). This allows the front wall 13 to be quickly and easily stretched in front of the opening "backlit" by the light source and replaced if necessary.

[0040] The advertising banner 1 after Fig. 4 has a shape that deviates from the usual banner shape and can be used, for example, to delineate and mark a finish line and thus increase the advertising area. The advertising banner 1 has a frame 40 that defines the edges 41 of the advertising banner and supports translucent panels 45. Instead of the translucent panels 45, other materials could also be used, as in the embodiment according to Fig. 1. Flexible coverings made of fabric and / or film are stretched into the frame. The advertising banner 1 according to Fig. 4 differs from advertising banner 1 according to Fig.1 because it has several backlit advertising surfaces 51, 52, 53. Therefore, the light source cannot be attached to the wall of the housing opposite the back of the advertising surfaces 51, 52, 53, because this would shade the corresponding advertising surface and thus result in uneven backlighting. Furthermore, the lighting conditions at the different advertising surfaces 51, 52, 53 are naturally different: If one advertising surface 51, 52, 53 is in the sun, the advertising surface facing away from it is in shadow. Therefore, the advertising banner 1 has a support 55 located centrally in the frame of the housing for attaching light sources.

[0041] Preferably, each advertising surface is assigned a light source, preferably supplied separately by the control unit 30. The support 55 is connected to the frame 40 via struts 46, which consequently run in the area of ​​the angle bisectors of the advertising surfaces 51, 52, 53 bounded by the frame and do not cast a shadow on the back of the respective advertising surfaces 51, 52, 53, provided that the light sources 21 assigned to the respective advertising surface 51, 52, 53 are arranged on the side of the support 55 facing the corresponding advertising surface 51, 52, 53; in other words, provided that the light source(s) 21 are arranged in the area bounded by the support 55 and the frame elements bounding the corresponding advertising surface 51, 52, 53.

[0042] Alternatively, the support 55 can be omitted, in which case the light sources can be attached to the struts. The struts can be attached to the frame as shown, but should preferably run along the diagonals of the frame. Preferably, the struts can be replaced or covered by panels, preferably opaque, so that a space is created behind each advertising surface to accommodate at least one light source. This allows the individual sides of the advertising banner to be backlit independently of one another; that is, the respective brightness levels of the advertising surfaces 51, 52, 53 can be adjusted independently of one another by a control unit 30, which controls the light source(s) arranged in the respective space. Reference symbol list 10 cases 11 Back panel 12 side wall 121 Nut 122 Insertion direction (symbolized by arrow) 13 Front wall 14 Thickening, e.g. plastic strips 20 advertising spaces 21 LED module / light source 30 control unit 40 frames 45 translucent plates 46 Strut 51, 52, 52 advertising space

Claims

Advertising banner (1), in particular for the presentation of banner advertising at winter sports events, with a housing (10) in which at least one light source (21) for backlighting at least one at least partially translucent advertising surface (20, 51, 52, 53) is arranged, wherein: - the advertising banner (1) has at least one control unit (30) for adjusting the radiant power emitted by the light source (21) in order to adjust the brightness of the backlit advertising surface (51, 52, 53), and - the control unit (30) is connected to at least one sensor for determining the ambient brightness in the space surrounding the advertising banner, in order to determine the ambient brightness by means of the sensor and to adjust the brightness of the advertising surface (20) to a value dependent on the ambient brightness by adjusting the radiant power of the light source (21).- the control unit (30) is connected to a brightness sensor (31) for measuring the actual brightness of the partially translucent advertising surface (20) and regulates the actual value to a target value dependent on the ambient brightness by adjusting the radiant power of the light source (21), characterized in that - the control unit (30) captures at least one image showing the advertising banner, - the advertising banner (1) has at least one infrared light source marking the advertising surface (20), and - the control unit (30) determines an image section depicting at least part of the advertising surface based on the infrared marking and determines the brightness of the advertising surface (20, 51, 52, 53) based on the brightness values ​​of the image section. Advertising banner (1), according to claim 1, characterized in that the infrared light source emits a flashing signal and the control (30) determines the position of the image of the infrared light source in the image on the basis of the flashing signal. Advertising banner (1) according to one of claims 1 to 2, characterized in that the control unit (30) averages the ambient brightness over several measurements, and the brightness of the advertising area is adjusted depending on the average brightness value. Advertising banner according to one of claims 1 to 3, characterized in that the light source (21) has at least one LED, the mean radiant power of which is set by the control by a pulse width modulation, wherein at least one coil is arranged between the output of the pulse width modulation and the LED. Method for adjusting the brightness of at least one translucent advertising surface (20, 51, 52, 53) of an advertising banner (1) backlit by at least one light source (21), in particular an advertising surface (20, 51, 52, 53) of an advertising banner (1) according to one of the preceding claims, comprising at least the steps of: (i) determining the brightness in the vicinity of the advertising surface (20, 51, 52, 53), (ii) backlit the advertising surface (20, 51, 52, 53) with at least one light source (21), wherein the radiant power of the light source (21) is adjusted as a function of the previously determined brightness of the surroundings, wherein the actual value of the brightness of the partially translucent advertising surface (20) is measured and regulated to a target value dependent on the ambient brightness by adjusting the radiant power of the light source (21), characterized in that the method further comprises the steps of: - capturing at least one image that the advertising banner (1) shows,by means of a controller (30),- marking the advertising area (20, 51, 52, 53) with an infrared marker by an infrared light source of the advertising banner (1),- determining an image section that at least partially depicts the advertising area (20, 51, 52, 53) based on the infrared marker, by the controller (30), and- determining the brightness of the advertising area (20, 51, 52, 53) based on the brightness values ​​of the image section, by the controller (30). Method according to claim 5, characterized in that the actual value of the brightness of at least a part of the advertising area (20, 51, 52, 53) is determined and compared with a lower target value, wherein the radiant power of the light source is increased if the actual value is less than the lower target value. Method according to claim 6, characterized in that the actual value of the brightness of at least a part of the advertising area (20, 51, 52, 53) is determined and compared with an upper target value, wherein the radiant power of the light source is reduced if the actual value is greater than the upper target value.

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