WO2001082276A1

WO2001082276A1 - Led display device

Info

Publication number: WO2001082276A1
Application number: PCT/FR2001/001125
Authority: WO
Inventors: Simon Elkrief; Jean-Marc Fuselier; Jean-Christophe Lafut
Original assignee: Simon Elkrief; Fuselier Jean Marc; Lafut Jean Christophe
Priority date: 2000-04-26
Filing date: 2001-04-12
Publication date: 2001-11-01
Also published as: AU5232301A; FR2808379A1

Abstract

The invention concerns a display device controlled by switching on a plurality of light emitting diodes (3) forming a display screen, comprising a support structure for the diodes (3) and means for controlling them. The invention is characterised in that the support structure comprises one or several masts (7) oriented along parallel longitudinal axes and bearing each at least a module (5) provided with an outer surface forming a display screen portion. The invention is useful for making large size display screens.

Description

LIGHT EMITTING DIODE DISPLAY DEVICE

The present invention relates to a display device by controlling the ignition of a plurality of light-emitting diodes making up a screen.

The device of this type comprises a support structure for the diodes and means for their control.

Screens composed of a multiplicity of diodes are mainly known for the formation of large screens, in particular screens for shows.

However, the invention may find its application in other fields and in particular for advertising billboards or even for the formation of a stage for a show stage allowing the production of light effects. The use of light emitting diodes for the production of screens is already known.

In this context, document FR-2,472,795 discloses a linear display device comprising a plurality of light-emitting diodes arranged in line on an insulating support carrying connections connected to the contact pads of said diodes.

The device is characterized in that the insulating support is in the form of an elongated bar, each of the lateral faces of which is provided with networks of connections, the end of these connections overhanging the face of the support carrying the diodes.

Display devices according to the prior art have various drawbacks.

First, they consist of complex assemblies with a heavy and bulky support structure.

These support structures are also non-modular, which does not allow the shape and size of the screen to change according to the desired application.

Another disadvantage of current devices is that the control of the diodes and their supply is effected by multiple connections.

This results in a very high wiring cost and clearly insufficient reliability. In addition, many electrical wires and cables are present in an installation, which generates heating and electromagnetic interference.

From the point of view of human intervention, current devices take a long time to install and troubleshoot and do not exclude the risk of errors when wiring.

The current devices also exhibit significant heating at the level of the diode supports and do not allow good evacuation of the heat energy released by the latter.

There is a risk of overheating or, at the very least, premature wear of the components.

The invention overcomes the drawbacks of currently known techniques.

In this sense, one of the first objectives of the invention is to propose a modular structure for a display device.

To do this, the invention has the advantage of presenting a set of masts and modules attached to the masts which allows easier fixing and rapid adaptation to the desired application.

In particular, depending on the number of masts and modules, the size and shape of the screen can be varied as desired.

Another object of the invention is to produce a unitary assembly in terms of connections and mechanical structure. It is therefore particularly compact and thin, and therefore very rigid.

In this context, the invention allows mounting of the support structure and a connection for controlling the ignition of the diodes in a single phase. The intervention of installers is therefore faster and limits the risk of error.

In this context, it will also be noted that, according to the invention, the display device requires very little manual wiring, most of the connection being carried out automatically during the assembly phase of the mechanical support structure. The fitter is not in direct contact with the power lines because the modules are connected by manipulation of the structure of the module.

Another object of the invention is to allow efficient cooling of the structure. To do this, the device comprises different cooling means and can combine cooling by convection and by circulation of a fluid such as a liquid or a gas such as air.

Furthermore, the support for light-emitting diodes is such that heating is limited to this level. Other objects and advantages will appear during the description which follows, which however is not limitative of the invention.

The present invention relates to a display device by controlling the ignition of a plurality of light-emitting diodes making up a screen, comprising a support structure for the diodes and means for their control, characterized in that the support structure comprises one or more masts oriented along parallel longitudinal axes and each carrying at least one module with an outer face forming a portion of the screen.

The display device presented here can be produced in the following variants: - it includes protruding and re-entrant assembly profiles formed in correspondence on each mast and the modules that it carries, to couple them,

- the assembly profile of the module is formed on the face opposite to the external face, - the modules include a metal shell receiving one or more diode support cards by its opening,

- two opposite sides of the shell are closed by metal flanges,

- it comprises at least two superimposed masts and means for relative positioning of the masts constituted by at least one pin fitting into housings formed opposite on the lower mast and the upper mast,

the mast (s) are hollow and receive at least part of the control means,

the control means include: for each mast, means for distributing the power and data between the various modules,

- for each module, means of distributing power and data within the module,

- male / female connectors cooperating between said mast and module distribution means,

the distribution means are printed circuit cards,

the means for distributing the power and data of the mast are housed in its internal volume and maintained by means of longitudinal grooves and the male / female connectors of the modules and each mast cooperate through openings made in the mast,

- the hull has fins for convection cooling,

- each mast has fins for convection cooling,

- it includes an assembly of forced ventilation attached to the mast to create an air flow within the support structure, - the masts comprise channels forming a cooling circuit by circulation of a fluid,

- It includes, for each module, a sealing plate attached to the outer face and provided with as many holes as the module has diodes.

The attached drawings are given as indicative and non-limiting examples. They represent a preferred embodiment according to the invention. They will allow the invention to be easily understood.

Figure 1 is an exploded view of the display device according to the invention in a particular embodiment.

Figure 2 is a view of a module according to the invention. FIG. 3 shows possible constituent parts of the invention in two of its variants.

FIG. 4 illustrates a sealing element of the module in a preferred embodiment. The formation of images or light effects on a screen is carried out in the context of the invention by means of a plurality of light-emitting diodes 3.

These diodes are carried by a support structure in order to compose a screen according to a preferably flat surface.

To control the switching on or off of the diodes individually, control means are present.

Referring to FIG. 1, it can be seen that the light-emitting diodes 3 are positioned on elements in the form of plates here called motherboard 1 and daughter board 2.

This arrangement on two types of cards 1, 2 makes it possible to position control components 4 for lighting the diodes and these diodes 3 on the same face.

Daughter cards 2 are reported on motherboard 1.

The latter is itself fixed on a module marked 5.

This constitutes a unitary element corresponding to a part of the screen to be formed.

By superimposing or juxtaposing modules, a screen of the desired shape and size is produced.

To carry the modules and allow their superposition and juxtaposition, masts 7 are present. The masts 7 are essentially elongated in shape, made from beams, for example made of extruded aluminum.

The masts 7 constitute the supporting structure of the assembly and will be oriented vertically along their longitudinal axis to compose a vertical screen or horizontally to compose a luminous floor. Means for mechanical connection and for connection of power and data transfer are present between the masts 7 and each module 5 carried by the mast 7.

We describe below more precisely, on the one hand the modules, and on the other hand, the masts and their interaction. As it appears more precisely in FIG. 2, the modules are preferably constituted by a shell 6 having an opening constituting the external face 32 of the module 5.

It is by this external face 32 that the motherboard 1 carrying a plurality of daughter cards 2 is attached.

The outer face 32 is that which appears to the observer when the screen is formed.

Preferably, the shell 6 is made of extruded aluminum and cut to the desired length. To close the sides of the shell 6 at the level of the cuts made, preferably flanges 8 of suitable shape will be formed.

The formation of such flanges 8 is shown in FIG. 2.

In order to be carried by a mast 7, the module 5 has a fixing face provided with an assembly profile 10a. Preferably, the assembly profile 10a is located on the face opposite to the outer face 32.

As it appears in FIG. 1, the profile 10a has a shape substantially corresponding to that of a profile 10b formed on the mast, at one of its outer walls. Depending on the application, elements can be added to module 5.

In this context, FIG. 3 shows under the reference 25, the use of a sun visor attached at the level of the external face 32 in order to limit the influence of natural or artificial external light sources.

As part of the application to a light floor, the module 5 can be overcome with a slab 26, for example in transparent glass.

Furthermore, a sealing plate 24 can be positioned at the level of the external face 32 in order to protect the interior volume of the modules 5 from bad weather or humidity.

In this context, a sealing plate 24, for example made of silicone, is formed and has a plurality of holes 28 made corresponding to the location of the light-emitting diodes 3.

According to a preferred variant, the diameter of the holes 28 is slightly less than the diameter of the diodes 3 so that the sealing plate is applied perfectly to the surface of the diodes and thus prevents any passage of air or liquid. A textile belt 27 makes it possible, optionally, to reinforce the periphery of the plate 24.

The support structure according to the invention also comprises one or more masts 7, an example of which is shown in FIG. 1. It is essentially a substantially elongated element in the form of a beam capable of receiving and supporting one or more modules 5 as previously described.

In the context of the formation of a vertical screen, the masts 7 are aligned on a horizontal beam. The latter can be adjusted by cylinders vis-à-vis the ground to ensure the horizontality of the screen.

In addition, mast fixing systems 7 are provided on the beam to hold them and adjust their spacing. Advantageously, these fixing systems allow pivoting of the masts 7 for mounting (or maintenance) of the modules 5 with a horizontal mast and then lifting. Furthermore, all of the masts 7 are preferably fixed against a reinforcing structure such as a wall or scaffolding.

One of the outer walls of the mast 7 comprises the assembly profile 10b mentioned above, the shape of which is produced in a corresponding and complementary manner to that of the assembly profile 10a formed on the module 5. It can be seen, in the variant of the Figure 1, assembly profiles 10a and 10b respectively projecting and re-entering.

The module 5 is fixed to the mast by insertion of the profile 10a in the profile 10b and then by fixing by current means, in particular by screwing or any other embedding means. Without departing from the scope of the invention, the mast 7 may comprise two assembly profiles, on opposite walls, to receive two modules 5 with a view to forming two screens on either side of the masts 7.

To facilitate handling of the modules 5, these may have handles 13 attached to the face opposite to the outer face 32. A rod 34 advantageously ensures the centering of the module 5 on the mast 7.

To limit the weight of the masts 7 and for the purposes of making the electrical connection, the masts 7 are preferably hollow and have a cavity marked 31. Openings 17 are formed at the locations of the modules 5 to be positioned.

Of course, the height of the masts and that of the modules 5 is not limited.

To make a screen of great width, it will suffice to multiply the number of masts 7 by positioning them one next to the other at a spacing adjusted according to the width of the modules 5.

In the height direction, several modules 5 can be superimposed on the same mast 7.

In order not to use tall masts 7 for easier handling, it is possible to stack at least two masts 7.

For this purpose, relative positioning means of the superimposed masts 7 are present.

According to a preferred embodiment, these positioning means are constituted by at least one pin 21 capable of being inserted in housings 22 formed both on the lower mast and the upper mast opposite.

Furthermore, a seal 20 will preferably be interposed between the two masts 7.

As indicated above, the invention has the advantage of combining, in the same assembly steps, the formation of the support structure and the connection means.

This connection is necessary to supply electrical energy to each diode 3 from a general electrical network.

It also ensures the transfer of the essentially digital signals for controlling the ignition of the diodes 3. The control means will comprise, in this sense, two separate buses, one for supplying electrical energy, up to a power supply unit 33 in each module 5; the other for control signals.

In this context, a preferred variant of the invention consists in forming hollow masts 7 which receive at least part of the control means. The control means are received at the level of the cavity 31 visible in FIG. 1.

Preferably, the control means comprise several members.

Some are secured to modules 5, others are secured to mast 7. Furthermore, intermediate connection means between these different means are also formed.

In this sense, FIG. 1 shows means 15a for distributing the power and data between the various modules 5. These means 15a are present for each mast 7.

Preferably, the means 15a are integrated into the heart of the mast 7 and held by means of one or more grooves 16.

The means for controlling the ignition of the diodes also comprise, for each module, means 15b for distributing the power and data within this module 5.

Preferably, the means 15a, 15b are constituted by printed circuit cards.

The electrical connection between the means 15a and the means 15b is produced by means of connectors 14a, 14b cooperating between said means 15a, 15b. Male / female type connectors will be formed, one 14b being carried by the module 5, the other 14a being carried by the means 15a housed in the mast 7.

The cooperation of male and female connectors 14a, 14b ensures a leak-tightness of the device.

Of course, it is necessary to provide an opening in the mast 7 in order to allow the passage of the connectors 14a, 14b.

It is for this purpose that openings 17 are provided.

Another characteristic of the invention is to allow efficient cooling of the entire display device.

In this context, preferably, the shell 6 comprises a plurality of fins 23 allowing cooling by convection.

The presence of these fins is particularly important given that the shell 6 is placed near the motherboards 1 and daughterboards 2 supporting the diodes.

It is at this level that a significant heating is produced.

Furthermore, it is possible to form fins 30 on each mast 7 and in particular on the face opposite to the assembly profile 10b.

An additional convection cooling is thus operated.

It will also be noted that, according to the configuration in FIG. 1, the module 5 has a shape that is substantially flared towards the outer face 32, which makes it possible to free up a circulation space for an air flow at the rear of the screen. Depending on certain climatic and general operating conditions, it may be necessary to use a ventilation assembly 19 allowing forced ventilation.

The presence of a forced ventilation assembly 19 attached to the mast 7 by the face having fins 30 has been shown diagrammatically in FIG. 1.

This maintains an air flow within the support structure.

Furthermore, it can be seen that air circulation is possible in the vertical direction, a space at the rear of the screen being perfectly reserved.

Furthermore, within the module and the mast, the air is able to circulate through the cavity 31 and in the interior volume of the module.

A fan fixed on a support may be used to produce the ventilation assembly 19.

Air passages formed in the shell 6 allow air circulation in the thickness direction of the device. The hot air generated in front of the device can thus be expelled towards the rear, a cooler area.

The formation of a shell 6, flanges 8 and mast 7 made of aluminum or other metallic material allows heat to be removed by conduction in the thickness of the device. Continuity of conduction is ensured by the large module 5 / mast 7 contact surface.

It can be fixed to the mast 7 by means of a pin marked 18.

In order to further strengthen the cooling means, it is possible to form channels 29a, 29b, oriented substantially in the long direction of the masts 7 at the heart of these.

An example of embodiment of the channels 29a, 29b is presented in FIG. 1.

By connecting the lower part or upper part of the mast 7 the channels 29a, 29b, a circuit is produced allowing the circulation of a cooling fluid. Furthermore, it is possible to connect the channels 29a, 29b of several masts 7 placed contiguously so as to produce a single circuit for the entire display device whatever its length.

A heat transfer fluid such as water may be used. As an indication, it is indicated that a computer system can allow control of the entire display device.

To this end, the computer system will produce data in an image format which can be converted into a frame usable by the control means. This conversion can be carried out at an interface present at the output of the computer system.

Preferably, this interface leads to a single frame transferable to the means 15a present in each mast 7.

In terms of connection, a cable tray will run along the structure thus formed by aligning the masts to convey the electrical power supply and the control signals.

REFERENCES

1. Motherboard

2. Daughter card 3. Diodes

4. Control component

5. Module

6. Hull

7. Mast 8. Flange 9. Groove 10a, 10b. Assembly profiles

11. Hood

12. Means of supply 13. Handles

14a, 14b. connector

15a, 15b. Means of power and data distribution

16. Grooves

17. Opening 18. Pin

19. Forced ventilation assembly

20. Seal

21. Pawn

22. Housing 23. Fins

24. Sealing plate

25. Sun visor

26. Slab

27. Belt 28. Hole

29a, 29b. Circulation channels

30. Fin

31. Cavity

32. Outside face 33. Power supply

34. Centering pin

Claims

1. Display device by controlling the ignition of a plurality of light-emitting diodes (3) making up a screen, comprising a support structure for the diodes (3) and means for their control, characterized in that the support structure comprises one or more masts (7) oriented along parallel longitudinal axes and each carrying at least one module (5) provided with an external face (32) forming a portion of the screen; that it comprises assembly profiles (10a, 10b) projecting and returning formed in correspondence on each mast (7) and the modules (5) which it carries, to couple them; that the assembly profile (10a) of the module (5) is formed on the face opposite to the outer face (32).

2. Display device according to claim 1, characterized in that the modules (5) comprise a metal shell (6) receiving one or more support cards (1, 2) of the diodes (3) by its opening.

3. Display device according to claim 2 characterized in that two opposite sides of the metal shell (6) are closed by metal flanges (8).

4. Display device according to any one of claims 1 to 3, characterized in that it comprises at least two masts (7) superimposed and means for relative positioning of the masts (7) constituted by at least one pin (21) fitting into housings (22) formed opposite on the lower mast and the upper mast.

5. Display device according to any one of claims 1 to 4, characterized in that the mast or masts (7) are hollow and receive at least part of the control means.

6. Display device according to any one of claims 1 to 5, characterized in that the control means comprise:

- for each mast (7), means (15a) for distributing the power and data between the various modules (5), - for each module (5), means (15b) for distributing the power and data within the module (5),

- male / female connectors (14a, 14b) cooperating between said means (15a, 15b) for distributing the mast (7) and the module (5).

7. Display device according to claim 6, characterized in that the distribution means (15a, 15b) are printed circuit cards.

8. Display device according to claim 6 or 7, characterized in that the means (15a) for distributing the power and data from the mast

(7) are housed in its internal volume and held by longitudinal grooves (9) and by the fact that the male / female connectors (14a, 14b) of the modules (5) and each mast (7) cooperate through 'openings (17) made in the mast (7).

9. Display device according to claim 2 in combination with any one of the other claims, characterized in that the shell (6) has fins (23) for convection cooling.

10. Display device according to any one of claims 1 to 9, characterized in that each mast (7) has fins (30) for cooling by convection.

11. Display device according to any one of claims 1 to 10, characterized in that it comprises a forced ventilation assembly (19) attached to the mast (7) to create a flow of air within the support structure.

12. Display device according to any one of claims 1 to 1 1, characterized in that the masts (7) have channels (29a, 29b) forming a cooling circuit by circulation of a fluid.

13. Display device according to any one of claims 1 to 12, characterized in that it comprises, for each module (5), a sealing plate (24) attached to the external face (32) and provided with as many holes (28) as the module (5) comprises diodes (3).