Digital display panel module and associated digital display panel

Abstract

A module for a digital display panel includes a circuit board, a first face of which presents a network of light emitting diodes. The module also includes a chassis fixed on a second face of the circuit board, and a water permeable connector mounted on the circuit board. The chassis includes a base around the water permeable connector, a top part of the base having at least one groove, wherein a seal is inserted. Further, the module includes a power supply unit fitted with a continuous voltage connector surrounded by a ferrite and fitted in the water permeable connector. The power supply unit is attached to the chassis so that a lower plate of the power supply unit co-operates with the seal of the base to ensure a seal around the water permeable connector and the DC voltage connector of the power supply unit.

Claims

1. A module fora digital display panel, the module comprising: an electronic board whose first face presents a network of light emitting diodes arranged in rows and columns with a substantially constant pitch; a chassis mounted on a second face of the electronic board, opposite the first face; and a water permeable connector mounted on the second face of the electronic board; wherein the chassis has a base surrounding the water permeable connector, a top part of the base having at least one groove wherein a seal is inserted, and wherein the module has a power supply box with a continuous voltage connector surrounded by a ferrite and inserted into the water permeable connector, with the power supply box being attached to the chassis so that a bottom plate of the power supply box cooperates with the seal of the base to ensure sealing around the water-permeable connector and the continuous voltage connector of the power supply box.

2. The module according to claim 1, wherein the mounting of the power supply box on the chassis is ensured by at least two screws passing through an opening of the bottom plate of the power supply box and screwed into mounting studs of the chassis.

3. The module according to claim 1, wherein the power supply box comprises a cover fixed on the bottom plate, a thermal resin being injected into the power supply box between the cover and the bottom plate.

4. The module according to claim 3, wherein the cover is made of aluminum.

5. The module according to claim 3, wherein the cover contains heat dissipation fins.

6. The module according to claim 1, wherein the power supply box comprises a sealed alternating connector intended to cooperate with a sealed alternating connector of a power supply cable.

7. The module according to claim 6, wherein the sealed alternating connector of the power supply box contains a plug to protect the sealed alternating connector when the power supply cable is not connected with the power supply box.

8. The module according to claim 1, wherein the top part of the base has two grooves and the seal has a first face with two lips entering the two grooves of the base and a second face having a hemicylindrical shape.

9. The module according to claim 1, wherein the chassis comprises a central grid, on which the base is mounted.

10. The module according to claim 1, where the digital display panel comprises a set of modules arranged in rows and/or columns.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The disclosed embodiments and their advantages will become more apparent from the following disclosure, given by way of a non-limiting example, supported by the attached figures wherein FIGS. 1 to 8 represent:

(2) FIG. 1: a schematic depiction of the back in perspective of a module according to one embodiment; and

(3) FIG. 2: an exploded layout of the module of FIG. 1;

(4) FIG. 3: a schematic representation in perspective of the circuit board of the module of FIG. 1;

(5) FIG. 4: a schematic representation in perspective of the chassis and of the circuit board of the module of FIG. 1;

(6) FIG. 5: a schematic representation from below of the chassis of the module of FIG. 1;

(7) FIG. 6: a schematic representation from below of a power box mounted on the chassis of FIG. 5;

(8) FIG. 7: a schematic representation in perspective of the power box of FIG. 6;

(9) FIG. 8: a partial, open representation in perspective of the power box of FIG. 6; and

(10) FIG. 9: a schematic section representation of the power box of FIG. 6.

DETAILED DESCRIPTION

(11) FIGS. 1 and 2 show a LED module, i.e. a module 10 containing an circuit board 11 with a first face showing a network of light emitting diodes (or LEDs) arranged in rows and columns with a substantially constant pitch. The pitch between two LEDs can vary depending on the application, for example the pitch can be 4, 6 or 8 mm. The assembly of the light emitting diodes is welded onto a first face of the circuit board 11. As shown in FIG. 3, this circuit board 11 has holes ending on a second face 12 of the circuit board 11 so that a chassis 13 can be attached.

(12) This chassis 13 has a center grid 15 that ensures the mechanical holding of circuit board 11 while allowing the thermal dissipation of the energy released by the light emitting diodes. On the edges of the frame 13, a mounting plate 14 is fitted. The purpose of this mounting plate 14 is to mount the module 10 to form a digital display panel. A digital display panel typically consists of several modules 10 that are placed in a row and/or in a column to form a large display surface.

(13) Typically, a module 10 can have dimensions of the order of 40 by 43 cm, and the display surface of a digital display panel can vary depending on the application, for example 6 m by 3 m, 4 m by 2 m, etc.

(14) The disclosed embodiments relate to a sealed LED module 10. As used herein, a “sealed” module is a module, which is capable of withstanding a low pressure water spray on all its faces. To ensure the sealing of the light emitting diodes, the front face of the circuit board 11, that is, the face intended to form the display surface, can be covered with a transparent resin.

(15) In the same way, the rear face 12 of the circuit board 11 can be covered with a heat resin configured to allow the heat dissipation of the electronic circuit and the LEDs mounted on the circuit board 11.

(16) To obtain the desired operation of a LED module 10, it is also necessary to route the power supply and the data to control the display surface. In the example in FIGS. 1 and 2, the data is transmitted through optical fibers 30 by a sealed connector or a sealing element around a water-permeable connector.

(17) More specifically, the present embodiments relate to a sealed power supply housing 17 for converting electrical energy from a cable 18 to a water permeable connector 16 soldered onto the circuit board 11. Classically, the transformation carried out in power supply box 17 corresponds to a continuous alternating conversion based on a voltage rectifier assembly.

(18) Typically, cable 18 can be connected to a low-voltage network, for example a 220 V alternating voltage network with a frequency of 50 Hz and a nominal current of 2 A. At the output of power box 17, a DC voltage connector 28 supplies the circuit board 11 with a DC voltage between 3 and 12 V and a current between 10 and 60 A. For example, the DC voltage connector 28 may have a voltage of 4.2 V and a current of 40 A.

(19) The mounting of the power supply unit 17 on the chassis 13 is ensured by screws passing through a bottom plate 25 of the power supply unit 17 cooperating with mounting studs 22 of the chassis 13. Furthermore, the continuous voltage connector 28 of the power supply unit 17 is inserted into the water permeable connector 16 welded onto the circuit board 11.

(20) To ensure sealing around these two connectors 16, 28, a receptacle 21 is provided on the chassis 13 around the water permeable connector 16.

(21) As shown in FIGS. 4 and 5, this flange 21 has a cylindrical shape and the top end of this cylindrical shape has at least one groove, wherein an O-ring 23 is placed. Preferably, the top end of the base 21 has two grooves, as shown in FIGS. 4 and 9. The seal 23 then has a first face with two lips entering the two grooves and a second face with a hemicylindrical shape.

(22) The sealing around the two connectors 16, 28 is ensured by cooperation between the lower plate 25 of the power unit 17 and the seal 23. Indeed, when the bottom plate 25 is screwed on the mounting studs 22 of the chassis 13, it compresses the seal 23 and ensures the sealing around the connectors 16, 28 so that it is possible to reduce the stresses on the connectors 16, 28 and to use connectors 16, 28 permeable to water.

(23) Furthermore, the reduction of mechanical stress on the DC voltage connector 28 of the power box 17 allows a ferrite 26 to be integrated around this DC voltage connector 28, i.e. to mount a ferrite coaxial with the DC voltage connector 28. To effectively limit electromagnetic interference with a ferrite 26 integrated in a power supply housing 17 of a LED module 10, it has been observed that a ferrite 26 with a height between 25 and 30 mm, an internal diameter between 15 and 20 mm and an external diameter between 25 and 30 mm is effective. To be able to use such a ferrite 26, the height of the power box 17 must be fitted. In the example in FIGS. 7 to 9, a cover 14 is used to obtain the desired height of the power supply unit 17 to integrate the ferrite 26. As shown in FIG. 9, the circuit board 33 of power box 17 is preferentially placed closest to the top face of the cover 14 to limit the absorption of the heat emitted for the circuit board 11 of module 10.

(24) The circuit board 33 of the power supply unit 17 is preferentially connected to a sealed alternative connector 19 so that the power supply cable 18 can be separated from the power supply unit 17. To do this, cable 18 has a sealed alternating connector 20 cooperating with the sealed alternating connector 19 of the power box 17. Preferably, connector 20 of cable 18 is a male connector and connector 19 on power box 17 is a female connector.

(25) Connector 19 of power box 17 can also be combined with a plug to protect connector 19 when cable 18 is not connected with the power box 17.

(26) To ensure sealing inside the supply unit 17, injection holes 27 are used to inject a heat resin when the cover 24 is attached to the bottom plate 25. Alternatively or in addition, the seal between the cover 24 and the bottom plate 25 can be ensured by a seal 34 squeezed at the interface between the cover 24 and the bottom plate 25, as shown in FIG. 9. Preferably, the cover 24 is made of aluminum and has fins to improve the heat dissipation of the power unit 17. The components that emit heat inside the power box 17 can therefore be embedded in the heat resin and the heat is led inside this resin to the cover 24, which diffuses this heat in the rear part of the LED module 10.

(27) The presently disclosed embodiments thus allow to obtain a sealed power supply unit 17 and allows a quick mounting on the LED module 10 by screwing the bottom plate 25 to the contact of the seal 23 mounted on the socket 21. Furthermore, the power supply unit 17 incorporates a ferrite 26 in order to limit electromagnetic interference while guaranteeing sealing because the ferrite 26 is integrated into the sealed unit of the power supply unit 17.