WO2014090258A1

WO2014090258A1 - Configurable led pixel device with automatic pixel detection

Info

Publication number: WO2014090258A1
Application number: PCT/DK2013/050425
Authority: WO
Inventors: Wouter Verlinden
Original assignee: Martin Professional Aps
Priority date: 2012-12-10
Filing date: 2013-12-10
Publication date: 2014-06-19
Also published as: CN104871235A; CN104871235B; EP2929526A4; EP2929526A1

Abstract

The present invention relates to a LED pixel device comprising a number of LED pixels arranged at a plurality of interconnected pixel segments, where controlling means is connected to the pixel segments and is to control the number of LED pixels. At least one of the pixel segments is disconnectable from the LED pixel device and the LED pixel device comprises pixel segment detection. The pixel detection means is adapted to detect which of the pixel segments that are connected to LED pixel device and the controlling means is adapted to control the number of LED pixels based on said pixel segment detection means. The present invention relates also to a display system comprising a central controller connected to a LED pixel device as described above. Also the present invention relates to e method of controlling a LED pixel device as described above.

Description

CONFIGURABLE LED PIXEL DEVICE WITH AUTOMATIC PIXEL DETECTION

Field of the Invention

The present invention relates to a configurable LED pixel device comprising a number of LED pixels and controlling means adapted to control the LED pixels. The present invention relates further to a pixel display system comprising a central controller and a number of LED pixel devices.

Background of the Invention

LED pixel devices where a number of LED pixels are used to create dynamic graphical elements is widely known and used in the field of visual solutions. For instance the LED pixel devices can be used to generate dynamic graphics elements in connection with architectural installations or as a part of a stage in connection with an entertainment event. Typically each LED pixel comprises a number of red LEDs, a number of blue LEDs and a number of green LED which can be dimmed in relation to each other whereby a large number of colors can be created by each LED pixel as known in the art of additive color mixing and LED video display systems.

Presently there exists a number of different types of products which can be used to create dynamic graphical elements ranging from simple LED pixel devices with few LED pixels (typical 5-10 pixels) to high resolution LED pixel screens with a large number of LED pixels (+1000 pixels) arranged in flat rectangular array. Flexible LED pixel devices, where the LED pixels are provide as a flexible structure for instance a flexible LED pixel string do also exist. The use of the different of LED pixel device depends on the desired look and the structure wherein in the LED pixel devices are used. Typically, when creating such dynamic graphical elements the type of LED pixel devices that is use in an installation is planned and ordered as a part of the planning before building the structure. Therefore the LED pixel devices are often ordered and supplied before constructing the actual installation. Common for all kind of LED pixel devices is the fact that they are provided in predefined sizes and with a predefined number of pixels. As a consequence during the construction phase it often turns out that that, even though careful planning have been performed, some of the LED pixel devices do not fit into the planed spaces or that in some spaces further pixels are needed in order to create a descent look. As a consequence new LED pixel devices need to be ordered which results in delay of the installation.

W09941785 discloses a LED light panel substantially comprises an assembly of mutually insulated electroconducting structures which allow supplying electric voltage in parallel to a plurality of non-housed light-emitting diodes (LED chips) selectively interconnected in series, forming various groups. A dimensionally stable, optically transparent protective layer which ensures the desired spatial distribution of the light irradiated by the LED chips and protects the chips from outer influences can be provided on top of this assembly. The whole assembly of electroconducting structures electric insulation, LED chips and dimensionally stable, optically transparent protective layer is designed in such a way that the LED light panel can be manufactured as a surface of theoretically any size, with a very dense or loose arrangement of LED chips, and which can subsequently be cut into pieces of any shape capable of operating independently, provided they are not smaller than a particular smallest operative sub-unit.

Description of the Invention

The object of the present invention is to solve the above described limitations related to prior art. This is achieved by configurable LED pixel device, a display system and method as described in the independent claims. The dependent claims describe possible embodiments of the present invention. The advantages and benefits of the present invention are described in the detailed description of the invention.

Description of the Drawing

Fig. 1 illustrates a block diagram of LED pixel device according to the present invention; fig. 2 illustrates a block diagram of another embodiment LED pixel device according to the present invention; fig. 3 illustrates a block diagram of another embodiment LED pixel device according to the present invention; fig. 4 illustrates a block diagram of another embodiment LED pixel device according to the present invention; fig. 5a and 5b illustrate a simplified structural diagram of another embodiment LED pixel device according to the present invention; fig. 6 illustrates a simplified structural diagram of another embodiment LED pixel device according to the present invention; fig. 7 illustrates a block diagram of a display system according to the present invention; fig. 8 illustrates a block diagram of another embodiment of a display system according to the present invention. Detailed Description of the Invention

The figures serve to illustrate the principles and different aspects of the present invention and the skilled person realizes that the present invention can be carried in many embodiments varying from those shown in the figures.

Fig. 1 illustrates a simplified block diagram of a LED pixel device 101 according to the present invention. The LED pixel device 101 comprises controlling means 103 adapted to control a number of LED pixels 105a and 105b as known in the art of LED pixel devices. The LED pixel comprises a number of LEDs, which can be turned on and off and/or dimmed in order to adjust the visual appearance of the pixel. In some embodiments the LED pixel comprises a number of red LEDs, a number of blue LEDs and a number of green LED which can be dimmed in relation to each other, whereby a large number of colors can be created by each LED pixel. The LEDs can be any kind of LEDs such a solid state emitters and/or organic LEDs. In the illustrated embodiment the controlling means 103 is embodied as a micro controller which typically comprises processing means, memory means and a number of input and output ports for instance for communication and /or sensing proposes. However it noticed that the controlling means also can be embodied as separate components and thus not need to be integrated in to a micro controller.

The LED pixels are arranged on a number of interconnected pixel segments. In the illustrated embodiment LED pixel 105a is arranged on pixel segment 107a and LED pixel 105b is arranged on pixel segment 107b. The controlling means is connected to the pixel segments 1 07a and 107b through communication line 1 09 (illustrated as a solid line) and is adapted to control the LED pixels 105a and 1 05b. In the illustrated embodiment the LED pixel device comprise two LED pixels and two pixel segment, however it is to be understood that any number of LED pixels and pixel segments can be provided. Further in the illustrated embodiment each pixel segment comprises one LED pixel, however it is to be understood that the individual pixel segment can comprise any number of LED pixels. In the illustrated embodiment the controlling means is arranged on a controller segment 1 1 1 . At least one of the pixel segments is disconnectable from the other of pixel segments and can as a consequence be separate and removed from the pixel device. The pixel device will thus not comprise the removed pixel segment when is has been disconnected. For instance, in the illustrated embodiment pixel segment 107b can be disconnected from pixel segment 107a along separation/disconnection line 1 13b (dash-dotted-dotted line). Further the pixel segment 107a can be removed from the controller segment 1 1 1 along separation/disconnection line 1 13a.

The LED pixel device comprises pixel segment detection means 1 15 adapted to detect which of the plurality of pixel segments 107a and 107b that are connected to the LED pixel device and the controlling means. The controlling means is further adapted to control the number of LED pixels based on the pixel segment detection means 1 15. The pixel segment detection means makes it possible to determine which pixel segments that are connected to controlling means and the controlling means can thus control the LED pixels based on this detection. This make is possible to provide at configurable LED pixel device where a number of LED pixels can be separated and removed from the LED pixel device and where the controlling means automatically can account for the fact that some of the pixel segments have been removed. The result is, when installing dynamic graphical imaging systems, that it is easy for the person installing the equipment to configure the LED pixel device so that it fits in the installations. This adjustment is performed by disconnecting and separating excess pixel segments so that the pixel device fits into the installation. Such adjustment is easy to perform and predefined separation means (will be describe below) can be provided at different positions at the LED pixel device. The pixel segment detection means detects which pixel segments that still are forming a part of the pixel device and communicates this to the controlling means. The controlling means 103 can then control the LED pixel device based on knowledge about which pixel segments that still are connected to the LED pixel device. The pixel detection means can be embodied based on a number of different techniques for identifying which pixel segments that are still connected to the pixel device. One possibility is to provide identification means 1 1 7a and 1 1 7b at each pixel segment and make the detection means capable of sensing which identification means that are present. For instance the identification means can be embodied as memory means comprise data indicating the pixel segment and the detection means 1 15 can then be adapted through a number of communication lined to identify which memory means the detection means has contact with and thereafter communicate this to the controlling means. The identification and detection means can also be based on RFID tags where each segment comprises a RFID tag for identifying the pixel segment and the detection means can be a RFID tag reader. Once a pixel segment has been removed the detection means formed as a RFID reader cannot find the corresponding RFID tags and the removed pixel segment will not be detected. Magnet based identification and detection means can also be provided where for instance the detection means is based on a hall sensor which is adapted to sense the presence of an identification magnet at the pixel segments. Additionally and according to another aspect of the present invention the detection means can be based on a voltage divider circuit, where the identification means are embodied as a number of electric loads arranged in parallel and at the different pixel segments. This system is described in further detail in connection with figures 3-7.

Fig. 2 illustrates a simplified block diagram of another LED pixel device 201 according to the present invention. This LED pixel device is similar the LED pixel device 101 shown in fig. 1 and substantial identical features are labeled with the same reference numbers as in fig. 1 and will not be described in further detail.

In the figure an internal power supply 221 is indicated. The internal power supply 221 receives electrical power from an external power supply 223 (not shown) for instance the power grid or a battery source. The electrical power is received by the internal power supply 221 which adapts and distributes electrical power through internal power lines 225 (dotted lines) to the subsystems of the LED pixel device. The internal power system can be constructed in many different ways and the illustrated power lines is for simplicity illustrated as one system where all components are connected to the same power line. However the skilled person realizes that some of the components in the LED pixel device need different kind of power, which can be distributed through a number of sub-systems.

In this embodiment the LED pixel device comprises input means 227 receiving an input signal 229 and the input signal is indicative of pixel data related to the LED pixels. The pixel data can for instance be indicative of color and/or brightness that the LED pixel must create. The controlling means is adapted to control the number of LED pixels based on the pixel data and can for instance adjust the color and/or brightness of the individual LED pixels according the pixel data. The input signal can be generated and send by a central controller (e.g. media server, PC, and/or light controller) that are adapted to control a number of LED pixels devices as known in the art of entertainment system such as light systems and/or display systems. The input signal can also be indicative of other commands and instructions intended for the LED Pixel device.

The pixel device comprises also output means 231 adapted to generate an output signal 233. The output signal can be sent to the central controller and be indicative of a number of status settings related to the LED pixel device. The central controller can use the status settings related to the LED pixel device when controlling the LED pixel device.

According to one aspect of the present invention the output signal 233 may be generated based on the pixel segment detection means 1 1 5 and be indicative of which pixel segments 107a and/or 107b that are connected to the LED pixel device and controlling means. This makes it possible for the LED pixel device to send its' pixel configuration the central controller, which then can control the LED pixel data based on this information. The pixel configuration can for instance define the type and/or number of LED pixel of the LED pixel device further the pixel configuration can also be indicative of the pattern that the LED pixels are arrange in. The controlling means and output means can generate the pixel configuration based the pixel detection means and information stored in a memory of the LED pixel device. For instance the controlling means can be adapted to generate a certain pixel configuration when a certain combination of pixel segments are connected to the LED pixel device and another pixel configuration if another combination of pixel segments are connected to the LED pixel device. This setup makes it possible for the person programming the dynamic graphical display system to easily map and locate the pixels in the programming software, since the central controller automatic can import the pixel configuration of the different LED pixel devices in the display system. This is useful when installing the large dynamic graphical systems as some of the LED pixel devices may be adjusted by removing some of the pixel segments from the LED pixel devices. The pixel devices were a number of pixel segments have been removed can then send its' pixel setting to the central controller, where the programmer can account for these changes when programming the system. This simplifies and speeds up the installation process of such system as the LED pixel devices easy can be configured in order to fit them into certain places in the installation that an eventual configuration change of the LED pixels can be automatic recorded by the central controller.

Fig. 3 illustrates a simplified structural diagram of a LED pixel device 301 according to another aspect of the present invention. This LED pixel device is similar the LED pixel devices shown in fig. 1 and 2 and substantial identical features are labeled with the same reference numbers as in fig. 1 and fig. 2 and will not be described in further detail. In this embodiment the pixel segment detection means comprises a detection circuit, where the detection circuit comprises a power supply, a first electric load 335, a second electric load 337 and voltage detection means 339. The first electric load 335 and the second electric load 337 are coupled in series and a voltage VCC is applied across the first and second electric load by the power supply. The voltage detection means 339 is adapted to detect the voltage across the second electric load 337.

The second electric load 337 comprises a number of segment electric loads coupled in parallel, where each of the segment electric loads is arranged at one of the pixel segments. In the illustrated embodiment segment electric load 341 a is arranged at pixel segment 107a and segment electric load 341 b is arranged at pixel segment 107b. The electric loads can be any component known in the art of electronics and capable of creating an electric load, for instance resistor, capacitors, inductors, transformers, diodes, transistors etc.

The pixel segment detection means is adapted to determine which pixel segments that are connected to the controlling means based the voltage across the second electric load and detected by the voltage detection means 339. In the illustrated embodiment the voltage detecting means is integrated as a part of the controlling means 103, where the voltage across the second load is converted into digital signals by an analog to digital converter ADC. The controlling means is adapted to determine which pixel segments that are connected to the controlling means based on the obtained voltage across the second electric load. This is possible as the voltage across the second electric load depends on which pixel segments that are connected to the LED pixel device. The voltage across the second electric load changes in the case that one of the pixel segments have been disconnected and removed. The reason for this is that the size of the second electric load changes if some of the pixel segments have been removed, as some of the parallel coupled segment electric loads (341 a, 341 b) will be disconnected causing the second electric load to change whereby the voltage cross the second electric load also will be changed.

By embodying the pixel segment detection means as a detection circuit comprising a first and a second electric load, where the second electric load comprises a number of segment electric loads arranged at the pixel segments makes it possible to provide a cheap and reliable pixel segment detection mechanism, as the detection circuit can be made of cheap electric components which reduces the manufacturing costs of the LED pixel device. As a consequence the end user will experience such low price that he/she would not mind throwing excess pixel segments away after they have been removed from the LED pixel device. The pixel segment detection mechanism detecting which pixels segments that are connected to the controlling means of the LED pixel device 301 will be described in further details here below. In the illustrated embodiment the electric loads are embodied as a number of resistors the first electric load 335 is embodies as a resistor with resistance Ri_, he segment electric load 341 a is embodied as a resistor with resistance R_a and segment electric load 341 b is as a resistor with resistance Rt When all pixel segments are connected to the LED pixel device the resistance of the second electric load 337 R₂ can be expressed as:

Ra+Rb where R_a is the resistance of the second electric load at the first pixel segment 1 07a and Rb is the resistance of the second electric load at the second pixel segment 1 07b.

The voltage across V₂ the second electric load can be given as:

(2) V₂ = _^Ra+ _R ^RX VCC

Ra+Rb where R_a is the resistance of the second electric load at the first pixel segment 1 07a, R_b is the resistance of the second electric load at the second pixel segment 1 07b, Ri is the resistance of the first electric load and VVC the voltage applied across the first and second electric load.

In the case that the second pixel segment 1 07b has be disconnected and separated from the LED pixel device the resistance of the second electric load 337 changes due the fact that the segmental electric load 341 b is removed. Now the second electric load can be expressed as:

(3) R₂ = R_a and the voltage across the second electric load is now given as: (4) V₂ = -^—VCC

' Rl +Ra

In the case that the first pixel segment 1 07a has been separated and disconnected from the LED pixel device it can be seen that the second electric load has been removed and the voltage detection means will the detect the voltage VCC applied to the detection circuit.

The voltage detection means will thus detect three different voltage levels depending on the configuration of LED pixel device and which of the pixel segments that are connected to the LED pixel device. The controlling means can be adapted to control the LED pixels based on the detected voltage and thereby control the LED based on which of the pixel segments that are connected to the LED pixel device. The controlling means can for instance be adapted to look up the configuration of the LED pixels segments in a memory of the microcontroller where a database or look up table indicate the configuration of the pixel segment based on the detected voltage.

As a non limiting numeric example the following values can be chosen for the electric loads and the applied voltage:

VCC=5V

R_a =5000 ohm

R_b = 2500 ohm

As a result the voltage detection means will detect. 1 ,25 V when both the first 107a and second 107b pixel segments are connected to the LED pixel device; 2,5 V when only the first pixel segments is connected to the LED pixel device; and 5V when none of the first and second pixel segments are connected to the LED pixel device.

The skilled person realize that many different configurations as sizes of the electric loads can be used depending on the requirements and wanted current flow through the detection circuit. Further it is noticed that one of the segmental electric loads can be zero meaning that that is connected directly to ground such situation is illustrated in fig.4. Fig. 4 illustrates another embodiment of the LED Pixel device 401 according to the present invention. In this embodiment the LED pixel device 401 comprises controlling means 403 adapted to control a number of LED pixels 405a-405p. In the illustrated embodiment the controlling means 403 is embodied as a micro controller which typically comprises processing means, memory means and a number of input and output ports for instance for communication and /or sensing proposes. The controlling means is connected to a number of driving means 408a -408d through communication line 409 (illustrated as a solid line). The driving means 408a-408d is adapted to control the LED pixels 405a-405p as instructed by the controlling means. In this embodiment each of the LED pixels comprises a red LED, a green LED and a blue LED and the driving means 408a-408d are adapted to control the LED pixels by adjusting the current flowing through each of the LEDs as known in the art of LED control. For instance the driving means may control the LEDs base on PWM control or any other controlling technique known in the art of LED control. Dotted lines 41 0 indicate which of the LED pixels the different drivers controls and it can be seen that driving means 408a controls LED pixels 405a-405d; driving means 408b controls LED pixels 405e-405h, driving means 408c controls LED pixels 405Ϊ-405Ι and driving means 408d controls LED pixels 405m-405p.

In the illustrated embodiment the controlling means 403, driving means 408a and 408b, and LED pixels 405a-405h are arranged on a controller segment 41 1 . The LED device 401 comprises further a number of interconnected pixel segments 407a, 407b, 407c or 407b, where driving means 408c and LED pixels 405i and 405j are arranged on pixel segment 407a; LED Pixels 405k and 405I are arranged on pixel segment 407b; driving means 408d and LED pixels 405m and 405n are arranged on pixel segment 407c and LED pixels 405o and 405p are arranged on pixel segment 407d. The pixel segments are disconnectable from the LED pixel device and can as a consequence be separate and removed. The LED pixel device will thus not comprise the removed pixel segment when it has been disconnected. For instance, pixels segments 407a-d can be disconnected from the LED pixel device (and the other pixels segments) along separation/disconnection lines 413a-d (dash-dotted-dotted lines).

The LED pixel device comprises pixel segment detection means adapted to detect which of the pixel segments 407a-407db that are connected to the controlling means and the controlling means is adapted to control the number of LED pixels based 405a-405p based on the pixel segment detection means.

The pixel detection means comprises a detection circuit comprises a power supply, a first electric load 435, a second electric load 437 and voltage detection means 439. The first electric load 435 and the second electric load 437 are coupled in series and a voltage VCC is applied across the first and second electric load by the power supply. The voltage detection means 439 is adapted to detect the voltage across the second electric load 437.

The second electric load 437 comprises a number of segment electric loads 441 a-441 d coupled in parallel, where each of the segment electric loads is arranged at one of the pixel segments 407a-407d. The electric loads can be any component known in the art of electronics capable of creating an electric load, for instance resistor, capacitors, inductors, transformers, diodes, transistors etc.

The pixel segment detection mechanism functions similar to the pixel segment detection mechanism described in connection with fig. 3, as the size of the second electric load changes when the pixel segments 407a-407d are separated and disconnected from the LED device. This causes the voltage across the second electric load to change and as a non-limiting example the electric loads can be embodied as a number of resistors where:

• the first electric load 435 has a resistance of 3300 ohm,

• the segment electric load 441 a has a resistance of 10000 ohm

· the segment electric load 441 b has a resistance of 4700 ohm

• the segment electric load 441 c has a resistance of 1500 ohm

• the segment electric load 441 d has a resistance of 0 ohm

as consequence the following values will be measured by the voltage detection device 439:

· 0^* VCC, if all segments are connected to the LED pixel device,

• 0,25^* VCC, if segments 407a-407c are connected to the LED pixel device and pixel segment 407d have be disconnected,

• 0,5^* VCC, if segments 407a-407b are connected to the LED pixel device and pixel segments 407c-407d have be disconnected,

· 0,75^* VCC, if segments 407a is connected to the LED pixel device and pixel segments 407b-407d have be disconnected,

• 1 ^*VCC, when none of the segments are connected to the LED pixel device. In this embodiment input and output means have been integrated into the same unit 428 receiving and sending an input/output signal and the input signal is indicative of pixel data related to the LED pixels. The pixel data can for instance be indicative of color and/or brightness that the LED pixel must create. The controlling means is adapted to control the number of LED pixels based on the pixel data and can for instance adjust the color and/or brightness of the individual LED pixels according the pixel data. The input signal can be generated and send by a central controller (e.g. media server, PC, and/or light controller) that are adapted to control a number of LED pixels devices as known in the art of entertainment and display systems such as light systems and/or video display systems. The input signal can also be indicative of other commands and instructions intended for the LED Pixel devices. Like the LED pixel devices shown in fig. 2 and 3, this LED pixel device 401 comprise an internal power supply 421 receiving electrical power from an external power supply 423 (not shown) for instance the power grid or a battery source. The internal power supply 421 adapts and distributes electrical power through a number of internal power lines (not shown for simplicity).

The input/output means 428 is adapted to receive and generate an input/output signal 430. The input/output signal may be any signal capable of carrying information and where the LED pixel device also is allowed to send information back to the central controller e.g. a DMX/RDM signal, an Ethernet signal etc., The LED pixel device comprise also an additional input/output means 432 for sending and receiving the input/output signal 434 which make it possible to daisy chain further LED pixel device. It is noticed that the power supply 421 and input/output means can be integrated in the same interface at the connecting caple can carry both power and communication signals.

In one embodiment, the LED pixel device according to the present invention is embodied as a circuit board whereon the LED pixels, the controlling means and the pixel segment detection means have been arrange. The printed circuit board can comprise a number of scored lines, where the scored lines define the boundaries of the pixel segments where the pixels segments can be separated from the LED pixel device. The scored lines can be clearly marked at the circuit board, whereby the user easily can identify, where the LED Pixel device can be reduced in size. The scored line may be designed such that a tool is required in order to disconnect and separate pixel segments from the LED pixel device. However it is also possible to provide the scored line as areas where the thickness of the circuit board have been reduced and thereby allowing a human to manually beak the circuit board along the scored lines and thereby remove excess pixel segments. Such scored line can also be provided by providing a number of holes along the scored lines in the printed circuit board. The holed reduces the strength of the printed circuit board along the scored lines enabling a human to break the circuit board along the scored lines. Further the LED pixel devices according the present invention can be embodies as a double-sided circuit board where the LED pixels are embodied at a first side of the double sided circuit boards and where the pixel segment detection means and controlling means are provided the second side of the double-sided circuit boards. This makes it possible to provide a nice looking LED pixel device where the LED pixel can be arrange in an array at the first side and where the controlling means and detection means can be hidden at the second (back side).

Fig. 5a and 5b illustrates respectively a back side and front side of a LED Pixel device 501 according to the present invention. The LED pixel device 501 functions in a similar manner as the LED pixel devices as described in the previous figures. In this embodiment the LED pixel device 501 is embodied on a double sided circuit board 502, which have been provide with a number of scored lines 51 3a-513d. The scored lines 51 3a-513d define a number of pixel segments 507a-507h. In this embodiment the LED pixels 505a-505z are arranged on the front side of the circuit board 502 and each are embodied as 3 in 1 LED having a red die, green die and blue die. The controlling means 503 and pixel segment detection means have been arranged on the back side of the circuit board. The LED device comprises also power supply and input/output means as described above, however these have been omitted from the drawing for the sake of simplicity.

In this embodiment the pixel segment detection means comprises two detection circuits coupled to analog to digital converters (not shown from simplicity) integrated into the controlling means 503. Each detection circuit comprises a power supply, a first electric load 535, a second electric load and voltage detection means (analog to digital converter integrated in controlling means). The first electric load 335 and the second electric load are coupled in series and a voltage VCC is applied across the first and second electric load by the power supply. The voltage detection means is adapted to detect the voltage across the second electric load.

The second electric load of the first detection circuit comprises a number of segment electric loads 541 a-541 d coupled in parallel, where each of the segment electric loads are arranged at a respective one of the pixel segments 507a-507d. As described above the size of the second electric load changes if some of the pixel segments 507a-507d are disconnected from the LED pixel device and the controlling means can be adapted to determine which of pixel segments that are connected to the LED pixel device based on the obtained voltage across the second electric load. In this embodiment the second electric load comprises also a pull down electric load 543 arrange on the controller segment 51 1 . The pull down electric load 543 ensures that a current runs through the detection circuit in the case that all the pixel segments 507a- 507d have been disconnected, whereby it is prevented the a floating potential is created. Similar the second electric load of the second detection circuit comprises a number of segment electric loads 541 e-541 h coupled in parallel (drawing contains 2x 541 d, one of them needs to be 541 f), where each of the segment electric loads are arranged at a respective one of the pixel segments 507e-507h, further the second detection circuit comprises also a pull-down electric load 543.

It can be seen that the pixel segments 507a-507h surrounds the controller segment 51 1 . It is noticed that further pixel segments also can be provided and arranged around the shown pixel segments, whereby they will surrounds the page segments 507a-507h. Further it is noticed that additional detection circuits also can be provided. The electric loads can be any component known in the art of electronics and capable of creating an electric load, for instance resistor, capacitors, inductors, transformers, diodes, transistors etc., however in this embodiment the electric loads are embodied as resistors.

Fig. 6 illustrates another embodiment of the LED pixel device 601 according to the present invention. Like the LED pixel device described above this LED pixel device comprise controlling means 603 adapted to control a number of LED pixels 605a, 605b....605n as known in the art of LED pixel devices. Further an internal power supply 621 receives electrical power from an external power supply 623 (not shown) for instance the power grid or a battery source. Electrical power is received by the internal power supply 621 which adapts and distributes electrical power through internal power lines 625 (dotted lines) to the subsystems of the LED pixel device. The internal power system can be constructed in many different ways and the illustrated power lines is for simplicity illustrated as one system where all components are connected to the same power line. However the skilled person realizes that some of the components in the LED pixel device need different kind of power, which can be distributed through a number of sub-systems.

The LED pixel device comprises further input/output means 628 adapted to receive and generate an input/output signal 630. The input/output signal may be any signal capable of carrying information and where the LED pixel device also is allowed to send information and can for instance be a DMX/RDM signal, an Ethernet signal etc.,

In this embodiment the LED pixel device is embodies as a flexible LED pixel string comprises a number, n, of LED pixel segments 607a - 607n. The LED pixels segments are interconnected by a flexible cable 645 comprising a multiple number of conductors. The multiple numbers of conductors comprises at least one power line adapted to provide power to the LED pixel segments and at least one data line adapted to provide data to the LED pixel segments. Each LED pixel segment 607a-607n comprises a number of LEDs and driving means 608a-608n for driving the LEDs based on data received through the data line. Further it is to be understood that the power line provides power for both the LEDs and the driving means. In the illustrated embodiment each LED pixel segment comprises a red LED, a green LED and a blue LED, which makes it possible to generate a large number of colors based on additive color mixing as known in the art of LED display systems. However other combinations of number and colors can be provided.

The flexible LED pixel string comprises a connector 647 and the connector 647 comprises a number of contacts electronic connected to the number of conductors and the connector is adapted to connect the flexible LED pixel string to a controller segment 61 1 . The controller segment 61 1 is adapted to provide power (through power line 625) and data (through data line 609) to the flexible LED pixel string through the connector 647. In the illustrated embodiment the connector 647 is a male connector where the contacts are adapted to fit mating female contacts of a female connector (not shown) at the controller segment 61 1 . It is noticed that any type of connectors can be used and that the flexible LED pixel string connector 647 also can be a female connector while the data and power feeder connector is a male connector. Further it is noticed at the flexible LED pixel string also can be connected directly the controller segment without using a dis-connectable connector. In this embodiment the detection means comprises a detection circuit, where the detection circuit comprises a power supply, a first electric load 635 and a second electric load and voltage detection means 639. The first electric load 635 and the second electric load are coupled in series and a voltage VCC is applied across the first and second electric load by the power supply and the voltage detection means 639 is adapted to detect the voltage across the second electric load. The second electric load comprises a number of segment electric loads 641 a-641 n coupled in parallel to one of the conductors 649 of the flexible cable 645. As illustrated the conductor 649 is arrange along the flexible cable and through each of the pixel segment 607b and each of the segment electric loads is arranged at one of the pixel segments 607a-607n. The pixel segments can be embodied as circuit boards which can be integrated into a housing and the pixel segments can be attached directly to the flexible cable or the pixels segments can be inserted between different flexible cable sections for instance by soldering the ends of flexible cable sections to the pixel segments.

The pixel detection means makes it possible to detect which of the pixel segments that are connected to the controller segment. As a result the length of flexible LED pixel string can be adjusted by separating pixel segments from the LED pixel string. The separation can for instance be made by cutting the flexible cable 645 between two of the LED pixel segments 607a-607n as illustrated by scissors 651 . In this embodiment the controlling means 603 can determine which of the pixel segments 641 a-641 n that are connected to the LED pixel device based on the detected voltage across the second electric load, as described above. Further also as describe above the detection means can be based on memory means or other identification means arrange at the pixel segments where the controlling means is adapted to detect the different segments.

The electric loads can be any component known in the art of electronics and capable of creating an electric load, for instance resistor, capacitors, inductors, transformers, diodes, transistors etc.

The flexible cable 645 can for instance be embodied as a 6-wire ribbon-cable (AWG20) which is soldered straight onto the PCBs of the pixels segments. Alternatively a click on mechanism which comprises electric pins that can be pinched through the jacket of the conductors, and in this way attach the pixel segments to the flexible cable. Other kinds of flexible cables can also be provided.

In the figures the first electric load and the second electric load have been arranged such that the first electric load has been arranged closest the potential VCC. However it is noticed that the order of first electric load and the second electric load may be changed so that the second electric load may be arranged closest to the potential VCC and it is noticed that the pixel setting determining means easily by the skilled person can be adjusted to account for this changed

Fig. 7 illustrates a block diagram of a display system 700 according to one aspect of the present invention. The display system 700 comprises a number of LED pixel devices where LED pixel device 761 is LED pixel screen with a large number of LED pixels (+1 000), LED pixel device 763 is a LED pixel device with 25 LED pixels and where LED pixel device 701 is a LED pixel device according to the present invention and similar to the once described above. The display system comprises a central controller 765 which is connected to the LED pixel devices via a communication system as illustrated by the dotted lines 767. The central controller can be embodied as a media server or light controller capable of sending pixel data and/or video data to the LED pixel devices. Further the central controller 765 is adapted to receive data from the LED pixels device through the communication system. The communication system can be embodied as any known communication system and based on any known communication protocols E.g. an Ethernet based system (both wired and/or wireless), serial protocols, DMX/RDM based protocols, Artnet etc. The central controller can comprise a number of video inputs capable of receiving any video signal or format and provide the content to the pixels of the display system. The central controller can in additional be coupled to other kinds of displays for instance high or medium resolution LED video screens, projector or the like or a number of light fixtures. The LED pixel device 701 is similar to the LED pixel device described above and comprises thus controlling means 703 adapted to control a number of LED pixels (not shown). Further an internal power supply (not shown) receives electrical power from an external power supply for instance the power grid or a battery source. The LED pixel device comprises further input/output means 728 adapted to receive an input signal from the central controller 765. Further the input/output means 728 generates and sends an output signal to the central controller as described above. The LED pixel device 701 comprises, like the LED pixel devices described above, a number of LED pixel segments 707a - 707n, each comprising at least one LED pixel 705a-705n. Also the LED pixel device comprises pixel segment detection means adapted to detect which of the pixel segments that are connected to the LED Pixel device 701 . In the illustrated embodiment the detection means comprises a detection circuit a power supply, a first electric load 735 and a second electric load and voltage detection means (analog to digital converter integrated in controlling means 703). The first electric load 735 and the second electric load are coupled in series and a voltage VCC is applied across the first and second electric load by the power supply. The voltage detection means is adapted to detect the voltage across the second electric load and the controlling means is adapted to determine which of the pixels segments that are connected based the obtained voltage across the second electric load. This is possible as the voltage across the second electric load changes according to which of the pixel segments that are connected to the LED Pixel device.

The LED device 701 is adapted to generate an output signal and send the output signal to the central controller. The output signal is indicative of the pixel setting of the LED device 701 , where the pixel setting is indicative of the number of pixels that the LED deceive comprises and optionally also how the pixels are arranged in relation to each other. The pixel setting can be generated based on the pixel segment detection means, as the pixel segment detection means can detect which of the pixels segments that are connected to the LED pixel device and the controlling means can be adapted to determine the pixel setting based this detection. The central controller is adapted to control the LED pixel device 701 based on the received output signal (from the LED pixel device 701 ), for instance the central controller can be adapted to adjust the pixel data that it sends to the LED pixel device 701 based on the output signal. Further the control controller can be adapted to map the pixel based on the received pixel setting.

This set up makes it possible during the installation of the LED pixel devices to adjust size of the LED pixel devices by removing the pixels segments from the LED pixel device and the central controller can the automatic "collect" the new pixel setting and adjust the controlling and pixel mapping based on the new pixel settings. The central controller can for instance comprise a pixel mapping user interface where the pixels of the display system is shown on a graphical user interface and the central controller can be adapted to adjust the pixel mapping user interface based on the "collected pixel settings of the LED pixel devices.

The central controller can be a media server or may be any computer based server capable of controlling content to LED pixel devices and/or light fixtures. Further the central controller may be embodied any light controller known in the art range in for complex controllers with many functions to simple light controllers with les functions and light controllers can also be embodied as PC, laptops, tablets, smart phones etc.

Fig. 8 illustrates a block diagram of a display system 800 according to one aspect of the present invention. The display system is similar to the display system illustrated in fig.7 and similar elements are labeled with the same reference numbers and will not be described further. The display system comprises a data and power feeder 869 the data and power feeder is connected to the central controller through a first communication system based on a first communication protocol. For instance a broadband and high speed Ethernet system. The data and power feeder 869 is connected to a number of LED pixel devices through a second communication system based on a second communication protocol e.g. based on a DMX/RDM protocol. The data and power feed is further adapted to supply power the LED devices for instance in in dedicated power conductors integrated with the communication conductors of the second communication system. However it is noticed that power and communication signals also can be provided through the same conductor. The data and power feed can also be adapted receive the output signal indicative of the pixel setting of the LED device from LED pixel device 701 and sends the pixel setting to the central controller, which the can be adapted to adjust its' controlling of the LED pixel device based on the converted output signal in as similar way as described above.

Claims

1 . A LED pixel device comprising:

• a number of LED pixels arranged at a plurality of interconnected pixel segments;

· controlling means connected to said pixel segments, said controlling means being adapted to control said number of LED pixels;

at least one of said pixel segments is disconnectable from said LED pixel device and said controlling means characterized in that said LED pixel device comprises pixel segment detection means adapted to detect which of said pixel segments that are connected to said LED pixel device and said controlling means and in that said controlling means is adapted to control said number of LED pixels based on said pixel segment detection means.

2. A LED pixel device according to claim 1 characterized in that said pixel device comprises output means adapted to generate an output signal and in that said output signal being generated based on said pixel segment detection means and being indicative of which of said plurality of segments that are connected to said LED device and said controlling means.

3. A LED pixel device according to claims 1 -2 characterized in that said LED pixel device comprises input means receiving an input signal, where said input signal being indicative of pixel data related to said LED pixels and wherein said controlling means is adapted to control said number of LED pixels based on said pixel data.

4. A LED pixel device according to claims 1 -3 characterized in that said pixel segment detection means comprises at least one detection circuit, where said detection circuit comprises a power supply, a first electric load and a second electric load, wherein said second electric load comprises a number of segment electric loads coupled in parallel, where said segment electric loads being arranged at said number of pixel segments.

5. A LED pixel device according to claim 4 characterized in that said pixel segment detection means comprises voltage detection means adapted to detect the voltage across said second electric load and in that said pixel segment detection means is adapted to determine which of said pixel segments that are connected to said LED device and said controlling means based on said voltage detection means.

6. A LED Pixel device according to claims 1 -5 characterized in that at least a part of said LED pixel device being embodied as a printed circuit board, where said printed circuit board being dived into a number of printed circuit board segments, where at least one of said printed circuit board segments constitutes a LED pixel segment, and where said printed circuit board comprises a number of a scored lines enabling at least one of said printed circuit board segments to be disconnected and separated from said LED pixel device.

7. A LED pixel device according to claim 6 characterized in that at least one of said circuits board segments comprises said controlling means.

8. A display system comprising a central controller and number of LED pixel devices, where said control controller and said number of LED pixel devices are connected through at least one communication system, said number of LED pixel devices comprises a number of LED pixels and said central controller being adapted to control said LED pixels of said LED pixel devices by sending pixel data to said LED pixel devices through said communication system characterized in that at least one of said LED pixel devices is a configurable LED pixel device comprising:

• a number of LED pixels arranged at a number of interconnected pixel segments; where at least one of said pixel segments is disconnectable from said configurable LED pixel device, • pixel segment detection means adapted to detect which of said pixel segments that are connected to said configurable LED pixel device, and in that said central controller is adapted to control said number of LED pixels of said configurable LED device based on said pixel segment detection means.

9. A display system according to claim 8 characterized in that said configurable LED pixel devices comprises output means adapted to generate an output signal, where said output signal is generated based on said pixel segment detection means and in that said controlling means is adapted to generate said pixel data to said configurable LED pixel device based on said pixel segment detection means.

10. A display system according to claim 9 characterized in that said output signal generated by said output means of said configurable LED pixel device is indicative of the pixel setting of said configurable LED pixel device.

1 1 . A method of controlling a LED pixel device where said LED pixel device comprises:

· a number of LED pixels arranged at a number of interconnected pixel segments, where at least one of said pixel segments is disconnectable from said LED pixel device;

• controlling means connected to said number of pixel segments, said controlling means being adapted to control said number of LED pixels; said method comprises the steps of:

• configuring said LED pixel device by separating at least one of said interconnected pixel segments from said LED pixel device,

• controlling the LED pixels of the remaining pixel segments using said controlling means;

characterized in that said step of controlling said LED pixel device comprises the step of: • detecting which of said pixel segments that are connected to said LED pixel device; and

• controlling said LED pixels based on said detection of which pixel segments that are connected to said LED pixel device.

12. A method of controlling a LED pixel device according to claim 1 1 characterized in that said step of detecting which of said pixel segments that are connected to said LED pixel device comprises the step of:

• applying voltage across a first electric load and a second electric load, · obtaining a voltage across a said second electrical load, where said second electric load comprises a number of parallel coupled segment electric loads, where each of said segment electric loads is arrange on one of said pixel segments,

• determining which of said pixel segments that are connected to said controlling means based on said obtained voltage across said second electric load.