Display system, light source, and method for operating the display system

Abstract

Display system comprising a multiplicity of movable light sources (2), each having a light-emitting means (3), a control unit (4), a data transfer unit (5) and an energy supply unit (6), wherein the light-emitting means (2), the control unit (4), the data transfer unit (5) and the energy supply unit (6) are operatively connected to one another in each light source (2), a central computing unit (7), at least one data transmission unit (8) operatively connected to the central computing unit (7) and to the data transfer unit (5) of the light sources (2), at least temporarily. The display system according to the invention is distinguished by the fact that the light sources (2) comprise at least one infrared transmitter (9, 9') which is operatively connected to the control unit (4) and is intended to generate infrared signals, that each light source (2) is assigned a unique identification code that can be transmitted with the infrared signal, that at least one image capture unit (10, 11) for capturing the infrared signals emitted by the infrared transmitters (9, 9') is provided, that the at least one image capture unit (10, 11) is operatively connected to the central computing unit (7) in which the positions of the individual light sources (2) can be determined, and that the central computing unit (7) has a data memory containing image data which are processed at least partially and on the basis of the position of the light sources (2) and are transmitted to the latter in order to adjust the brightness and / or colour of the corresponding light-emitting means (3).

Description

[0001] DISPLAY SYSTEM, LIGHT SOURCE AND METHOD OF OPERATING THE

[0002] DISPLAY SYSTEMS

[0003] TECHNICAL FIELD

[0004] The present invention relates to a display system according to the preamble of claim 1, a light source for use in the display system and a method for operating the display system.

[0005] STATE OF THE ART

[0006] It is well known that at large events such as concerts or sporting events, mobile devices are used by event attendees to create a giant screen. The mobile devices carried by the event attendees are used as pixels or image elements of the giant screen and controlled via a central server. This allows spectator areas, such as individual stands or an entire stadium, to be included in the game at sporting events. The same applies to artistic performances such as concerts or musicals.

[0007] To achieve high image quality on the resulting large screen, it is essential that the positions of the individual image elements are precisely known. The simplest solution, therefore, has been proposed: a fixed installation with a remotely controllable light source at each seat. A central control unit with a central server is used to adjust the brightness and / or color of the light source at a given time so that the overall image on the resulting large screen corresponds to the desired image.

[0008] This well-known solution, however, has the major disadvantage of requiring extremely complex installation work. In addition to the fixed installations for the lamps, which can also obstruct the field of vision of event attendees, the wiring for the lamps is also extremely laborious.

[0009] For this reason, solutions for locating mobile devices of event visitors have already been proposed.

[0010] A known teaching for determining the respective position of mobile telephone devices is disclosed in WO 2014 / 096861 A1. The transmitting and receiving units typically present in the devices are used to determine the position of the mobile devices. This can be a protocol based on the Bluetooth standard, on the one hand, or a protocol based on the WLAN (Wireless LAN) standard, on the other.

[0011] However, many event visitors refuse to access their mobile devices for data protection reasons, which makes it difficult or even impossible for the big screen to function properly.

[0012] Furthermore, EP 3 307 025 A1 describes a variety of light sources whose positions are determined using GPS (Global Positioning System). Alternatively, the position can also be determined by emitting high-frequency reference signals at defined locations in a stage, and a receiving unit at the light source determines the position based on the different signal propagation times of the reference signals.

[0013] Furthermore, it has already been proposed to provide event attendees with mobile lighting. For example, EP 3 307 025 A1 discloses providing event attendees with hats equipped with integrated lighting and the necessary electronics for communication with a central server. GPS (Global Positioning System) has been proposed for positioning. Accordingly, each unit carrying the lighting device is to be equipped with a GPS receiver and associated transmitter / receiver unit, which is operatively connected to the central server.

[0014] With the known method, a large screen can also be realized if the illuminants - i.e. the individual pixels - are not stationary, but move. Due to the known positions of the illuminants, the central server can

[0015] The intensity and / or color of the light source can be adjusted to the respective location so that the overall impression of the image displayed on the large screen remains within the desired projection range. However, this well-known system is also very complex to implement and therefore correspondingly costly. Furthermore, the position determined by GPS is relatively imprecise for this application, which can lead to distortions in the displayed image. The use of GPS signals is often not possible, especially indoors, as they are shielded by the building envelope.

[0016] DESCRIPTION OF THE INVENTION

[0017] An object of the present invention is therefore to be able to produce a large screen with mobile lighting units which is overall simpler and therefore more cost-effective and can be implemented indoors.

[0018] This object is achieved by the features specified in the characterizing part of claim 1. Further embodiments are defined by the features specified in the dependent claims.

[0019] A display system according to the invention is specified, comprising:

[0020] - a plurality of movable light sources, each comprising a lamp, a control unit, a data transmission unit and a power supply unit, wherein for each light source the lamp, the control unit, the data transmission unit and the power supply unit are operatively connected to one another,

[0021] - a central processing unit,

[0022] - at least one data transmission unit which is at least temporarily operatively connected to the central processing unit on the one hand and to the data transmission unit of the light sources on the other.

[0023] The display system according to the invention is characterized by

[0024] - that the light sources comprise at least one infrared transmitter operatively connected to the control unit for generating infrared signals,

[0025] - that each light source is assigned a unique identification code that is transmittable with the infrared signal,

[0026] - that at least one image acquisition unit is provided for capturing the infrared signals emitted by the infrared transmitters,

[0027] - that the at least one image acquisition unit is operatively connected to the central processing unit in which the positions of the individual light sources can be determined, and

[0028] - that the central processing unit has a data memory with image data which is processed at least partially and as a function of the position of the light sources and transmitted to them for adjusting the brightness and / or colour of the corresponding lighting devices.

[0029] The display system according to the invention proposes a cost-effective infrared transmitter in each light source, which emits a unique identification code and can be detected by an image capture unit in order to reliably locate all light sources within a given area.

[0030] One embodiment of the display system according to the invention consists in that the infrared signals have a wavelength in the range of 700nm to 1400nm.

[0031] This wavelength range corresponds to the near

[0032] Infrared spectrum, located just below the visible spectrum. It has the advantage of being invisible to the human eye and to cameras with an optical filter that blocks infrared signals. Another advantage of near-infrared is that this spectral range is very rarely used, thus minimizing interference from other communications devices.

[0033] Further embodiments of the display system according to the invention consist in that the infrared signals have a wavelength of 940nm.

[0034] Further embodiments of the display system according to the invention consist in that a bandpass filter is arranged in front of the image acquisition unit, wherein the

[0035] Bandpass filter mainly passes infrared signals with wavelengths in the range of 700nm to 1400nm.

[0036] This advantageously attenuates the ambient light outside the infrared range before it hits the sensor of the image acquisition unit. This allows the use of a high sensor gain, which allows weak infrared signals to be detected, since the sensor of the image acquisition unit cannot be saturated by ambient light - i.e. by light in the visible range. Preferably, the passband of the bandpass filter is reduced to such an extent that essentially only signals with the wavelength of the emitted

[0037] Infra-red signal are allowed to pass through, i.e. for example wavelengths in the range 940nm + / - 20nm.

[0038] Further embodiments of the display system according to the invention consist in that the light source is arranged on a cap.

[0039] Further embodiments of the display system according to the invention consist in the fact that the illuminant is of the LED type (light emitting diodes).

[0040] Further embodiments of the inventive display system include at least two infrared transmitters per light source, with the infrared transmitters arranged such that they are visible from different directions. This ensures the location of the light sources even when the light source's carrier is moving significantly, because detection occurs from different directions.

[0041] Further embodiments of the display system according to the invention consist in providing reference points with previously known positions in which at least one infrared transmitter is arranged.

[0042] With the reference points arranged at precisely defined positions, the display system can be easily calibrated, ensuring the exact location of the light sources at all times.

[0043] Furthermore, a light source for use in a display system is specified, wherein the light source comprises a lighting means, a control unit, a data transmission unit and a power supply unit, and wherein the lighting means, the control unit, the data transmission unit and the power supply unit are operatively connected to one another.

[0044] The light source according to the invention is characterized in that the control unit is provided with at least one

[0045] Infrared transmitter for generating infrared signals is operatively connected, - that with at least one infrared transmitter a unique identi fication code is assigned with the aid of the

[0046] Infra red signal is transmittable in order to be able to determine the position of the infra red transmitter after detection by an image acquisition unit,

[0047] - that a brightness value and / or a color value can be received with the data transmission unit in order to adjust the brightness value and / or the color value of the light source.

[0048] One embodiment of the light source according to the invention consists in that the infrared signals have a wavelength in the range of 700nm to 1400nm.

[0049] Further embodiments of the light source according to the invention consist in that the infrared signals have a wavelength of 940nm.

[0050] Finally, a method for operating a display system is specified, the method comprising the steps of:

[0051] - Emitting an infrared signal comprising a modulated identification code that is unique for a particular light source,

[0052] - Capturing the infrared signal with an image capture unit,

[0053] - Determine the current position of the light source,

[0054] - Determining a brightness value and / or a color value of a light source based on its position and stored image data, - Transferring the brightness values ​​and / or color values ​​to the respective light sources,

[0055] - Adjusting the brightness values ​​and / or the color values ​​in the light sources.

[0056] A further embodiment of the method according to the invention consists in that the infrared signals have a wavelength in the range of 700nm to 1400nm.

[0057] Further embodiments of the method according to the invention consist in that the infrared signals have a wavelength of 940nm.

[0058] Further embodiments of the method according to the invention comprise filtering signals with a bandpass filter before detection with the image processing unit, wherein the bandpass filter primarily passes infrared signals with wavelengths in the range from 700nm to 1400nm.

[0059] The mentioned embodiments of the display device, the light source, or the method can be combined in any way. Only those combinations are excluded that would obviously lead to a contradiction. BRIEF DESCRIPTION OF THE FIGURES

[0060] Examples of embodiments of the present invention are explained in more detail below with reference to the accompanying figures. These are for illustrative purposes only and are not to be interpreted in a restrictive manner. They show:

[0061] Fig. 1 shows a display system according to the present invention with several movable light sources,

[0062] Fig. 2 is a block diagram of a light source according to the invention and

[0063] Fig. 3 is a flow chart showing process steps for determining the position of a light source.

[0064] DETAILED DESCRIPTION OF THE INVENTION

[0065] Fig. 1 shows a schematic representation of a display system according to the invention, consisting of a projection surface 1 with a plurality of movable light sources as well as a central processing unit 7, a data transmission unit 8 and two image acquisition units 10 and 11.

[0066] The light sources located within the projection area 1 form a large screen, with the individual light sources representing image elements or pixels of the

[0067] Large screens are. The projection surface 1 can be part of a grandstand or other spectator area of ​​an event venue, such as a sports stadium, a theater, or a concert hall. It is intended that each event visitor wears a light source, although this is not mandatory.

[0068] The structure of the light sources will be explained in detail with reference to Fig. 2.

[0069] For correct image generation on the projection surface 1, the positions of the pixels, i.e. of the light sources, in the projection surface 1 must be known. For this purpose, in addition to an appropriate design of the light sources, the operatively connected central processing unit 7, the data transmission unit 8 and the two image acquisition units 10 and 11 are provided. It should be noted that it is not necessary for two image acquisition units 10, 11 to be present. Embodiments of the present invention with a single image acquisition unit or with several, in particular with more than two, image acquisition units are also conceivable. The use of several image acquisition units has the advantage that the positions of the light sources can be determined more robustly and reliably.

[0070] Fig. 2 shows a block diagram of an inventive

[0071] Light source 2 , which consists of a lamp 3 , a

[0072] Control unit 4 , a data transmission unit 5, a power supply unit 6 and at least one

[0073] Infrared transmitter 9, 9'. These components of the light source 2 are operatively connected to one another and, as far as possible, manufactured in a highly integrated manner in order to obtain a cost-effective light source 2 and to keep the overall weight of the light source 2 as low as possible.

[0074] To keep energy consumption as low as possible and to ensure the operation of the light source 2 for as long as possible, the light source 3 is implemented, for example, using LEDs (light-emitting diodes) or an LED matrix. The same applies to the infrared transmitters 9, 9', which are implemented with IR diodes.

[0075] The data transmission unit 5 can be designed as a pure data reception unit or as a bidirectional data transmission unit and serves as a communication unit with the data transmission unit 8 (Fig. 1). The information for controlling the lighting device 3 is determined or processed, for example, in the central processing unit 7 and transmitted by the data transmission unit 8 via a wireless connection to the data transmission unit 5. For this purpose, known transmission protocols such as those used in Bluetooth or WLAN (Wireless Local Area Networks) can be used.

[0076] The infrared transmitters 9 and 9' are essential components used to determine the position of the light source 2. The infrared transmitters 9, 9' emit an infrared signal invisible to the human eye, with an identification code unique to the respective light source 2. The infrared transmitter 9, 9' emits, for example, signals in the so-called near infrared range, in which the wavelengths are in the range from 700 nm to 1400 nm. In a particular embodiment of the present invention, the wavelength is essentially 940 nm.

[0077] The infrared signals emitted by the infrared transmitters 9, 9' are captured by the image capture units 10, 11 and processed in the central processing unit 7 to identify the respective light source 2. Accordingly, the image capture units 10, 11 are sensitive to the respective infrared spectrum of the infrared transmitters, i.e., the corresponding infrared signals of the infrared transmitters 9, 9' can be captured and detected in the image capture units 10, 11.

[0078] To further improve the sensitivity of the image capture units 10, 11, in a further embodiment of the present invention, an optical bandpass filter 16, 17 is arranged upstream of the respective image capture unit 10, 11—i.e., upstream of their sensors. This greatly attenuates signals that lie outside the near infrared range used by the infrared transmitters 9, 9'—such as ambient light in the visible range—so that these visible signal components cannot saturate the sensor of the respective image capture unit 10, 11. As a result, the weaker infrared signals can be amplified more and are thus easier to evaluate. Sensitivity is also improved by increasing the useful signal / interference signal ratio (also called the signal-to-interference ratio) through the use of the bandpass filter.

[0079] To distinguish the individual light sources 2, each light source 2 is assigned a unique identification code. The identification code is embedded in a signal sequence consisting of a synchronization sequence, an identification code, and a checksum. This allows the image acquisition unit 10, 11 to reliably determine the identification codes after receiving them from the infrared transmitter 9, 9', as will become clear in the following explanations.

[0080] Each message sequence begins with the synchronization sequence, which is identical for each light unit 2. The goal and purpose of the synchronization sequence is to define the beginning of the message sequence so that the beginning of the message sequence can be clearly detected. The synchronization sequence is followed by the identification code, which can also be detected after the synchronization sequence has been detected. Finally, the checksum (e.g., of type CRC-16 - "cyclic redundancy check"), which allows for the detection of transmission errors, follows.

[0081] The reporting sequence is used to modulate the intensity of the IR diodes of the infrared transmitter 9, 9'. For example, on-off keying (00K) is used as a modulation method, which represents digital data as the presence or absence of the carrier signal. The synchronization sequence is chosen to have excellent autocorrelation properties. This makes it easier for the image acquisition unit 10, 11 to detect the synchronization sequence within the received signal and to determine the exact position, since the highest correlation value is only found at zero time shift. The length of the synchronization sequence is a compromise between autocorrelation performance and message duration. On the one hand, the more chips used for the synchronization sequence, the better the autocorrelation property. On the other hand, a longer synchronization sequence increases the message duration.In addition, the speed with which the position of a light source 2 can be calculated decreases. For example, the synchronization sequence comprises 48 chips and is generated using a heuristic search-based algorithm, as described, for example, in the paper by M. Dimitrov, T. Baitcheva, and N. Nikolov entitled «Ef ficient Generation of Low Autocorrelation Binary Sequences» ( IEEE Signal Processing Letters , vol. 27, pp. 341-345 , 2020 ).

[0082] In addition, the number of on and off bits in the synchronization sequence was intentionally chosen to be the same to avoid correlation deviation caused by the brightness of the background. The same property is achieved for the remaining bits (i.e. the identification code and the checksum) by using a technique called BOC (Binary Offset Carrier) modulation. In BOC modulation, the data bits are multiplied by a binary carrier signal, which can have two, three or more half-periods per bit. All carriers with an even number of half-periods have the same number of on and off parts (also called chips). For example, BOC Sine-2 modulation (also called Manchester code) with two half-periods per bit is used.

[0083] For example, the identification code is specified as 24 bits, allowing a total of 16 million unique identification codes. Together with the 16 bits of the CRC-16 checksum, this results in a total of 24 + 16 = 40 bits, or 80 chips when using BOC Sine-2 modulation. Thus, the entire message consists of 48 + 80 = 128 chips.

[0084] In Fig. 1, the image acquisition units 10 and 11 are connected to the central processing unit 7 via a wired connection. An alternative embodiment of the present invention provides that the image acquisition units 10 and 11 are connected to the central processing unit 7 via a wireless connection.

[0085] The image acquisition units 10 and 11 are used

[0086] Film sequences, for example, are recorded with a single image size of 1640x1232 pixels and a frame rate of 30 frames per second.

[0087] The frame rate of the image capture units 10 and 11 also determines the maximum permissible chip rate that the infrared transmitter 9, 9' can use to transmit its message. If all infrared transmitters 9, 9' are theoretically perfectly synchronized with the image capture unit 10, 11, a single image per transmitted chip would theoretically suffice.

[0088] If the infrared transmitters 9, 9' are not synchronized with the image acquisition unit 10, 11, the exposure time of an image with two adjacent chips may overlap, which may lead to an incorrect amplitude if the two chips are unequal.

[0089] It has therefore been shown that the use of three individual images per chip can be tolerated, albeit with a slight loss of amplitude. With a frame rate of 30 frames per second, three images per chip, and a total of 128 chips for a message, the total duration of a message is 12.8 s.

[0090] The video file 18 recorded with the image acquisition unit 10, 11 described above is processed on the central computer unit 7 in order to generate a list of all valid messages of the video file 18.

[0091] Infrarotsender 9,9'. This is done in several steps I to III, which are explained below with reference to Fig. 3.

[0092] The first step I consists of extracting all images from the video file 18 and saving them as a multidimensional array 19 (an "array of frames" or "image sequence"). This facilitates the calculations applied to each individual image. To reduce storage requirements, each individual image can be reduced in size, for example, through reduction (so-called "pixel binning").

[0093] In a simplified embodiment of the present invention, the video sequences captured by the image capture units 10, 11 are processed directly into the multidimensional rows 19, i.e., the video sequences are not stored in the aforementioned video files.

[0094] The second step II consists of searching for a synchronization sequence at each pixel position. This is done by cross-correlating the synchronization sequence with the values ​​of a pixel across all frames. Here, calculating the cross-correlation using the Fast Fourier Transform (FFT) is proposed, as this significantly speeds up the calculations. The highest absolute correlation value of each pixel is then compared with a threshold corresponding to the correlation value of a pixel with the minimum permissible signal amplitude. In this way, only the pixels with a higher probability are considered.

[0095] This approach assumes that the light source 2 remains at approximately the same location (i.e., equally illuminated pixels) throughout the duration of a reporting sequence. The result of this processing step is a list of pixels that can be considered as possible candidates with a valid reporting sequence.

[0096] In the third step (III), the report sequences are extracted and decoded to verify the checksum for all report sequences. The result is a list containing the pixel coordinates, the report sequences, and the estimated signal amplitude for each pixel.

[0097] As soon as the pixel coordinates of the detected infrared transmitters 9, 9' are known, they can be transformed into position coordinates within the projection surface 1, whereby the underlying geometric problem in the considered projection surface 1 can often be simplified, since the possible positions of the light sources 2 are limited to positions in a stadium where spectators can be present.

[0098] For example, spectators can move freely on a grandstand, which means that the whole or at least part of the grandstand can be considered as a geometric plane.

[0099] Thus, the transformation problem consists of relating a point on the image plane (within the image acquisition unit 10, 11) to a point on the plane of the projection surface 1. In image processing, the relationship between any two planes in space is called a homography, which is explained, for example, in "Basic Concepts of Homography Explained with Code" (OpenCV, downloadable at: https: / / docs.opencv.org / 4.x / d9 / dab / tutorial_homograph.html).

[0100] The position (x, y) of one plane can be converted into the position (x' , y' ) of the other plane using the homography matrix M.

[0101] The homography matrix H can be calculated using at least four known reference points 13, 14, 15, 15a between the two planes. In practice, for example, the four corners of a projection surface 1 can be regarded as reference points 13-15, 15a and temporarily equipped with infrared transmitters 9, 9', for example. The known positions of the reference points 13-15, 15a and the pixel coordinates from the image can then be used to calculate the matrix H. As long as the respective image acquisition unit 10, 11 is aligned in the same way, the homography matrix remains valid and the reference points 13-15, 15a are no longer needed.

[0102] The display system according to the invention has been shown to be extremely robust and delivers precise results regarding the position of the movable light sources 2. Position inaccuracies of an average of 4 cm over larger distances were determined, which is extremely low considering an average distance between two light sources 2 of 60 cm. Accordingly, large screens can be easily implemented at large events using the display system according to the invention. It has proven particularly advantageous if the light source 2 and all its components are integrated into a cap, in particular a peaked cap, and thus given to the audience to wear during the event.

[0103] REFERENCE SYMBOL

[0104] 1 projection screen

[0105] 2 light source

[0106] 3 bulbs

[0107] 4 Control unit

[0108] 5 Data transmission unit

[0109] 6 Power supply unit

[0110] 7 central processing unit

[0111] 8 Data transmission unit

[0112] 9, 9' infrared transmitter

[0113] 10, 11 Image acquisition unit

[0114] 12 bandpass filters

[0115] 13-15, 15a Reference points

[0116] 16, 17 Bandpass filter

[0117] 18 Video file or video source

[0118] 19 array of frames

[0119] 20 pixels with high correlation values

[0120] 21 pixel list with valid messages

Claims

PATENT CLAIMS 1. Display system, comprehensive - a plurality of movable light sources (2), each comprising a lighting means (3), a control unit (4), a data transmission unit (5) and a power supply unit (6), wherein for each light source (2) the lighting means (2), the control unit (4), the data transmission unit (5) and the power supply unit (6) are operatively connected to one another, - a central processing unit (7) , - at least one data transmission unit (8) which is at least temporarily operatively connected to the central processing unit (7) on the one hand and to the data transmission unit (5) of the light sources (2) on the other hand, characterized in that - that the light sources (2) comprise at least one infrared transmitter (9, 9') operatively connected to the control unit (4) for generating infrared signals, - that each light source (2) is assigned a unique identification code which is transmittable with the infrared signal, - that at least one image capture unit (10, 11) is provided for capturing the infrared signals emitted by the infrared transmitters (9, 9'), - that the at least one image acquisition unit (10, 11) is operatively connected to the central processing unit (7), in which the positions of the individual light sources (2) can be determined, and - that the central processing unit (7) has a data memory with image data which is processed at least partially and as a function of the position of the light sources (2) and transmitted to them for adjusting the brightness and / or color of the corresponding lighting means (3).

2. Display system according to claim 1, characterized in that the infrared signals have a wavelength in the range of 700nm to 1400nm.

3. Display system according to claim 2, characterized in that the infrared signals have a wavelength of 940nm.

4. Display system according to one of claims 1 to 3, characterized in that a bandpass filter (16; 17) is arranged in front of the image capture unit (10; 11), wherein the bandpass filter (16; 17) primarily transmits infrared signals with wavelengths in the range from 700nm to 1400nm.

5. Display system according to one of claims 1 to 4, characterized in that the light source (2) is arranged on a cap.

6. Display system according to one of claims 1 to 5, characterized in that the illuminant is of the LED (light emitting diode) type.

7. Display system according to one of claims 1 to 6, characterized in that at least two infrared transmitters (9, 9') are provided per light source (2), wherein the Infrared transmitters (9, 9' ) are arranged such that they are visible from different directions.

8. Display system according to one of claims 1 to 7, characterized in that reference points (13, 14, 15, 15a) with previously known positions are provided, in which at least one infrared transmitter (9, 9') is arranged.

9. Light source (2) for use in a display system according to one of claims 1 to 8, wherein the light source (2) comprises a lighting means (3), a control unit (4), a data transmission unit (5) and a power supply unit (6), and wherein the lighting means (3), the control unit (4), the data transmission unit (5) and the power supply unit (6) are operatively connected to one another, characterized in that - that the control unit (4) is provided with at least one infrared transmitter (9, 9') for generating Inf rarotsignalen effectively connected, - that with the at least one infrared transmitter (9, 9' ) a unique identification code can be transmitted with the aid of the infrared signal in order to to be able to determine the position of the infrared transmitter (9, 9') by means of an image acquisition unit (10, 11), - that a brightness value and / or a color value can be received by the data transmission unit (5) for setting the brightness value and / or the color value of the illuminant (3).

10. Light source (2) according to claim 9, characterized in that the infrared signals have a wavelength in the range of 700nm to 1400nm.

11. Light source (2) according to claim 10, characterized in that the infrared signals have a wavelength of 940nm.

12. A method for operating a display system according to any one of claims 1 to 8, the method comprising the steps of: - Emitting an infrared signal comprising a modulated identification code which is unique for a respective light source (2), - detecting the infrared signal with an image acquisition unit (10, 11), - Determining a current position of the light source (2) , - Determining a brightness value and / or a color value of a light source (2) based on its position and on stored image data, - Transferring the brightness values ​​and / or the color values ​​to the respective light sources (2), - Adjusting the brightness values ​​and / or the color values ​​in the light sources (2) .

13. Method according to claim 12, characterized in that the infrared signals have a wavelength in the range of 700nm to 1400nm.

14. Method according to claim 13, characterized in that the infrared signals have a wavelength of 940nm.

15. Method according to one of claims 9 to 14, characterized by filtering signals with a bandpass filter (16; 17) before the detection with the image processing unit (10; 11), wherein the bandpass filter (16; 17) primarily filters infrared signals with wavelengths in Range from 700nm to 1400nm.

Images