EP3827196B1 - Illuminated sign having an electrical cable with a vertical structure - Google Patents

Description

Technical field and prior art

The present invention relates to the field of lighting apparatus, and in particular that of illuminated signs.

The object of the present invention relates more particularly to a qualitative lighting device both in terms of lighting and control of the operating temperature as well as to the manufacturing process associated therewith.

The present invention will find numerous advantageous applications, in particular for signs such as, for example, shop signs which are generally made to measure and individually or in small quantities.

Other advantageous applications could also be envisaged for the design of other lighting devices of the lighting and/or light decoration type.

• une illumination homogène ;
• une bonne résistance mécanique et une bonne fiabilité ; et
• un faible encombrement et une faible épaisseur.

The characteristics sought for a good quality illuminated sign are as follows:

• homogeneous illumination;
• good mechanical strength and good reliability; And
• small size and low thickness.

Today, to obtain good luminous homogeneity and a low thickness for a sign, light-emitting diodes or LEDs (acronym for "Light-Emitting Diode") are preferably used.

An LED source can be implemented in several ways when manufacturing an illuminated sign.

Until now, this manufacturing is directly related to electronic products and components available in the market by manufacturers.

Conventionally, LEDs are offered in particular in the form of a chain, ribbons, plates or even individually, each type of LED can be used to manufacture a different type of illuminated sign depending on the need and the manufacturing method used. .

In the figures 1a-1b and 1c annexed to this description, the case of a letter "G" 120 millimeters high in " Times new roman " font to be illuminated is taken by way of example and will be described according to the main manufacturing methods used until now.

According to the first example of the picture 1a , the letter "G" is produced here using the so-called "module" method.

This method is the most used; it mainly consists of arranging LED modules in series in order to achieve the desired shape.

However, the Applicant submits that this method is not satisfactory because it does not always make it possible to illuminate small shapes in a homogeneous manner.

In the example of the "G" in 120 millimeters illustrated here, it is not possible to arrange the modules in the thinnest parts: the lighting obtained is therefore not optimal.

In the second example of the figure 1b , an LED ribbon is inserted on the support to form the letter “G”. The insertion of such an LED strip makes it possible to place light in much smaller shapes.

The distribution of the LED points is however not homogeneous as can be seen by figure 1b . In addition, the LED strip is subject to strong stresses (torsions, heat, cuts, etc.).

For these reasons, this so-called "LED strip" method is generally not synonymous with good quality signs.

It is possible to obtain better results in terms of lighting using a third method called “individual LEDs”. This method illustrated in figure 1c is however little used given the labor required to apply it to different and varied shapes.

For each desired shape, the resistors and the LEDs must be wired appropriately to form a tailor-made electrical circuit where each LED point is optimally placed.

For this method, it is therefore necessary to plan a significant additional time for the design of the electrical circuit and the layout of all the components.

The fourth method known so far is the so-called "printed circuit" method (not illustrated here). This method consists of creating a printed circuit that contains all the LEDs and resistors of the individual method but in an industrial way.

This method is very effective for large series signs, but it requires the development of the printed circuit, the production of a negative for printing the copper plates and heavy tools for the industrial process.

These tools are not suitable for unit production or small series that characterize illuminated signs.

All of the above methods have in common that they are difficult to industrialize in the case of unit production, as is generally the case in the production of illuminated signs.

A large part of the cost is therefore related to labor.

Whether it is to arrange modules (module method), insert ribbons (LED ribbon method), solder individual LEDs (individual LED method) or even create a printed circuit containing all the LEDs and resistors (method printed circuits), to date there is no simple method for automating the insertion of LED components into a form Documents DE4310440 A1 , DE10144206 A1 And EP 1 167 867 A2 describe lighting devices according to the prior art.

The Applicant therefore submits that the design of the illuminated signs proposed until now does not allow both homogeneous lighting, a controlled operating temperature and a reduced manufacturing cost in particular.

Object and summary of the present invention

The object of the present invention is to improve the situation described above.

The present invention therefore aims to remedy the various drawbacks mentioned above by proposing an innovative circuit structure and electrical wiring allowing the design of a lighting device offering tailor-made and unique light shapes and offering homogeneous and of good quality.

The object of the present invention relates, according to a first aspect, to a luminous lighting device comprising a plurality of light sources positioned on the front face of a support plate.

Preferably, the light sources are positioned according to a determined layout plan to form a predetermined lighting pattern.

According to the present invention, the light sources each have at least a first and a second electric terminals.

In a first embodiment, not covered by the claims, light sources are used each having first and second terminals respectively presenting first and second conductive rods of different lengths.

In a second embodiment of the present invention, light sources of the SMD LED type are used to be mounted on the surface of the plate (CMS type technology - for "Surface Mounted Component"). In this mode, the first and second terminals of each of the sources do not have conductive rods. The surface of the component supporting the terminals is substantially flat: the first and second terminals are simple contactors forming a connection pin.

According to the present invention, the support plate comprises an upper conductive layer and a lower conductive layer, the upper and lower layers being electrically insulated from each other by an intermediate insulating layer.

According to the present invention, the first and second electrical terminals of each light source are electrically connected respectively to the upper and lower layers by vertical wiring, or vice versa.

It is understood here that the upper and lower layers are connected to the same electric generator.

The sandwich structure provided in the context of the present invention with two conductive layers separated from each other by an insulating layer makes it possible to design a qualitative lighting device in terms of lighting and operating temperature control while being simple to to implement.

This structure differs from that proposed with the individual LED method in particular in that, according to the present invention, the two terminals of each light source are connected respectively between the upper and lower layers forming two separate horizontal planes electrically insulated from one of the 'other.

It is understood here that all of the light sources are therefore wired simultaneously by supplying the light sources with two horizontal and superposed layers of conductive materials.

Contrary to the method of individual LEDs, the wiring of the light sources is not done on a horizontal plane thanks to an electrical circuit, but on a vertical plane by establishing through the intermediary of the LED components an electrical contact of the two independent conductive layers at two different heights.

In one embodiment, not covered by the claims, the first and second terminals respectively have first and second rods of different lengths.

In one case, the first rod of the first terminal is shorter than the second rod of the second terminal. In this case, the first terminal is electrically connected to the upper layer and the second terminal is electrically connected to the lower layer.

In the other case, it will be understood that the first rod of the first terminal is longer than the second rod of the second terminal. In this case, the first terminal is electrically connected to the lower layer and the second terminal is electrically connected to the upper layer.

According to the invention, the support plate comprises, for each light source, a first hole opening into the front facade and at least partially passing through the upper layer.

In an advantageous embodiment, not covered by the claims, the first hole is dimensioned to receive the first or second electrical terminal (the one electrically connected to the upper layer) in order to establish an electrical contact point between the light source and the top layer.

It is understood here that such a first hole is dimensioned to receive the first or the second conductive rod of the light source.

According to the present invention, a light source is used whose first and second terminals do not have conductive rods. Terminals are flat.

To establish a point of electrical contact between the source and the upper layer, this embodiment uses an electrical bridge; such an electrical bridge makes it possible to establish an electrical connection between one of the flat terminals of the light source and the upper layer.

A specific plate structure is implemented here for this other mode.

According to the invention, the plate comprises on the front facade a first insulating layer; this conductive upper layer is therefore sandwiched between the insulating intermediate layer and the first insulating layer.

According to the invention, the first hole passes through the first insulating layer to emerge in the front facade.

According to the invention, a first electrical bridge is housed inside said first hole, said first electrical bridge electrically connecting the upper layer to the front facade to establish on the front facade a point of electrical contact between the first or second electrical terminal of the light source and the top layer.

Preferably, the first electric bridge is electrically insulated by an insulating sheath.

The assembly formed by the hole and the electrical bridge forms an electronic via. Such a via is thus in the form of a so-called metallized hole making it possible to establish an electrical connection between the two conductive layers of the plate.

According to the invention, the support plate comprises, for each light source, a second hole opening into the front face of the plate and passing through the upper layer, the insulating layer and at least partially the lower layer.

In the embodiment implementing electrical terminals having conductive rods of different lengths, the second hole is dimensioned to receive the second or first electrical terminal (the one electrically connected to the lower layer) in order to establish an electrical contact point between the light source and the lower layer.

It is understood here that such a second hole is sized to receive the second or first conductive rod of the light source.

In the other embodiment implementing flat electrical terminals, there is the implementation of an electronic via to electrically connect one of the terminals of the light source to the lower layer.

In this mode, the plate thus comprises on the rear face of the plate a second insulating layer; said conductive lower layer is thus sandwiched between the insulating intermediate layer and the second insulating layer.

According to the invention, a second electrical bridge is housed inside the second hole, said second electrical bridge electrically connecting said lower layer to the front facade to establish on the front facade a point of electrical contact between the second or first electrical terminal of the light source and the lower layer.

Preferably, the second electric bridge is electrically insulated by an insulating sheath.

Thus, in the embodiment implementing LEDs of the SMD LED type with flat terminals for surface mounting of the CMS type, the present invention provides for the implementation of an electronic card with a grid allowing a plurality of possibilities of predefined locations. Each potential location for an LED makes it possible to make the connection between the upper layer by means of two electrical contact points insulated between them and the two conductive layers, called central layers, of the electronic card. These links are made using electronic vias internal to the card.

In this mode with a multilayer structure having five layers, the two central conductive layers (positive and negative) have the function of distributing the electrical charge evenly over the whole of said electronic card: the presence of these two central conductive layers allows to distribute the electric charge.

Preferably, it is also possible to provide vertical wiring from these two conductive layers to an additional layer on the rear face. It thus becomes possible to select positive contact zones and negative contact zones on this layer to possibly facilitate wiring or even to carry out future tests. Advantageously, fixing means having conductivity properties are implemented at each of the electrical contact points to fix each of the light sources solidly on the support plate while ensuring electrical conductivity between each of the sources and respectively the upper layers. and lower.

According to a preferred variant embodiment, the fastening means comprise a conductive glue.

Preferably, this conductive adhesive is an epoxy type adhesive mixed with conductive particles of the type, for example silver or tin in particular.

According to another variant embodiment, the fastening means comprise a weld.

Such welding is therefore implemented at each of the electrical contact points so as to ensure an integral assembly between each of the sources and the upper and lower layers while ensuring electrical conductivity.

Advantageously, the first and second electrical terminals of each of the light sources are electrically insulated respectively from the lower and upper layers, or vice versa.

According to the invention, provision is also made for the support plate to have a third hole, called a blind hole, opening out on the front facade and passing through the upper layer and at least partially the insulating layer.

In this mode, the blind hole is preferably substantially centered on the second hole and has a larger diameter than the second hole so as to electrically insulate the upper layer and the second or first electrical terminal which is electrically connected to the lower layer.

It is understood here that the second and third holes are co-axial and that the third hole, which is shallower than the second hole, has a larger diameter than the latter so as to electrically insulate the upper layer and the electrical terminal which is electrically connected with the lower layer

Advantageously, the apparatus according to the present invention comprises electrical power supply means respectively connected to the upper and lower layers to supply direct current to each of the light sources.

In a preferred embodiment, provision is made for the support plate to comprise a fiberglass panel covered with two copper plates. In this mode, the panel is used insulating layer and the two copper plates serve as upper and lower layers respectively.

Preferably, the light sources comprise at least one light-emitting diode of the LED type and/or an individual module receiving a light-emitting diode of the LED SMD (for " Surface Mounted Device" ) type .

Preferably, each light source is in the form of an electronic component configured to withstand a voltage of 12 Volts and comprising an individual LED and a micro-resistor, encapsulated in a resin capsule.

The object of the present invention relates, according to a second aspect, to a method of manufacturing a luminous lighting device comprising a plurality of light sources positioned on the front face of a support plate, each light source having at least a first and a second electrical terminals.

• une fourniture d'une plaque support comprenant en façade avant, une première couche isolante, une couche supérieure conductrice, une couche inférieure conductrice et une couche intermédiaire isolante isolant électriquement lesdites couches supérieure et inférieure, ladite couche supérieure conductrice étant prise en sandwich entre la couche intermédiaire isolante et la première couche isolante;
• une première étape d'usinage au cours de laquelle on usine ladite plaque support de manière à former un premier trou traversant au moins partiellement ladite couche supérieure et ladite première couche isolante pour déboucher en façade avant ;-
  une deuxième étape d'usinage au cours de laquelle on usine ladite plaque support de manière à former un deuxième trou traversant au moins partiellement ladite couche inférieure, ladite couche isolante, ladite couche supérieure et ladite première couche isolante pour déboucher en façade avant;
• une troisième étape d'usinage au cours de laquelle on usine ladite plaque support de manière à former un troisième trou, dit borgne, traversant au moins ladite couche supérieure et au moins partiellement ladite couche isolante pour déboucher en façade avant, ledit trou borgne étant sensiblement centré sur ledit deuxième trou et présentant un diamètre supérieur audit deuxième trou de manière à isoler électriquement ladite couche supérieure et ladite deuxième ou première borne électrique électriquement reliée à la couche inférieure;
• une étape de raccordement électrique au cours de laquelle les première et deuxième bornes électriques de chaque source lumineuse sont électriquement reliées respectivement aux couches supérieure et inférieure et sont électriquement isolées respectivement des couches inférieure et supérieure, ou inversement, par une mise en oeuvre respectivement :
  1. a) d'un premier pont électrique isolé électriquement et logé à l'intérieur dudit premier trou raccordant ladite couche supérieure à la façade avant pour établir en façade avant un point de contact électrique entre ladite première ou deuxième borne électrique de ladite source lumineuse et ladite couche supérieure; et
  2. b) d'un deuxième pont électrique isolé électriquement et logé à l'intérieur dudit deuxième trou raccordant ladite couche inférieure à la façade avant pour établir en façade avant un point de contact électrique entre ladite deuxième ou première borne électrique de ladite source lumineuse et ladite couche inférieure.

According to the present invention, the method comprises the following steps:

• a supply of a support plate comprising, on the front face, a first insulating layer, an upper conductive layer, a lower conductive layer and an intermediate insulating layer electrically insulating said upper and lower layers, said upper conductive layer being sandwiched between the layer insulating intermediate and the first insulating layer;
• a first machining step during which said support plate is machined so as to form a first hole at least partially passing through said upper layer and said first insulating layer to emerge on the front facade;
  a second machining step during which said support plate is machined so as to form a second hole at least partially passing through said lower layer, said insulating layer, said upper layer and said first insulating layer to emerge in the front facade;
• a third machining step during which said support plate is machined so as to form a third hole, called a blind hole, passing through at least said upper layer and at least partially said insulating layer to emerge on the front facade, said blind hole being substantially centered on said second hole and having a diameter greater than said second hole so as to electrically isolate said upper layer and said second or first electrical terminal electrically connected to the lower layer;
• an electrical connection step during which the first and second electrical terminals of each light source are electrically connected respectively to the upper and lower layers and are electrically insulated respectively from the lower and upper layers, or vice versa, by an implementation respectively:
  1. a) a first electrical bridge electrically insulated and housed inside said first hole connecting said upper layer to the front facade to establish on the front facade a point of electrical contact between said first or second electrical terminal of said light source and said top layer; And
  2. b) a second electric bridge electrically insulated and housed inside said second hole connecting said lower layer to the front facade to establish on the front facade a point of electrical contact between said second or first electrical terminal of said light source and said lower layer.

This manufacturing technique thus makes it possible to implement light sources of the type, for example LED, individually on a support, this in an automatable manner.

In an embodiment (here called the first embodiment) not covered by the claims and implementing a light source having electrical terminals in the form of conductive rods of different lengths, provision can be made during this machining that the first hole is preferably dimensioned to receive the first or second electrical terminal (here the shorter conductive rod) in order to establish an electrical contact point between the light source and the upper layer.

In another advantageous embodiment (here called the second mode) implementing a light source having flat electrical terminals (SMD LEDs for example), the support plate further comprises a first insulating layer covering the upper conductive layer In this mode , the support plate is provided during this factory machining so that the first hole passes through said first insulating layer.

During this machining, provision is made in the first mode for the second hole to be preferably sized to receive the second or first electrical terminal in order to establish a point of electrical contact between the light source and the lower layer.

Advantageously, the electrical connection step comprises the implementation at each of the electrical contact points of fixing means (of the type, for example, a solder or a conductive glue of the epoxy type mixed with conductive particles of the type, for example silver or tin) to securely fix each of the sources on the support plate while ensuring electrical conductivity between each of the sources and respectively the upper and lower layers.

There is also provided in the method a preliminary step, not forming part of the present invention, of generating a computer file comprising in particular a determined layout plan making it possible to position the light sources correctly and optimally according to predefined criteria for form a predetermined lighting pattern.

The object of the present invention relates, according to a third aspect, to the use of a luminous lighting device such as that described above for a luminous sign.

• la difficulté de répartir les sources lumineuses de manière optimale pour un éclairage homogène ;
• l'impossibilité d'inclure un module LED dans une forme étroites (moins de 10mm) et de la raccorder électriquement ;
• l'augmentation de la température de fonctionnement des sources lumineuses dans le cas où elles sont fortement concentrées (particulièrement pour le ruban LED) ;
• le temps nécessaire avec les méthodes existantes pour choisir l'emplacement de chaque source lumineuse (chaque module, le tracé du ruban LED ou encore le placement de chaque LED et de chaque résistance) ;
• le temps nécessaire au raccordement électrique de toutes ces méthodes, soudure, câblage, etc. ;
• la difficulté d'automatiser les placements et soudures pour des produits sur-mesure ;
• la nécessité d'avoir des séries de pièces identiques pour envisager une production industrielle.

Thus, the present invention, by its various structural and functional technical characteristics, proposes a new design of luminous sign with vertical wiring making it possible to solve the various problems encountered until now with the existing solutions, namely:

• the difficulty of distributing the light sources in an optimal manner for homogeneous lighting;
• the impossibility of including an LED module in a narrow form (less than 10mm) and of connecting it electrically;
• the increase in the operating temperature of the light sources in the case where they are highly concentrated (particularly for the LED ribbon);
• the time required with existing methods to choose the location of each light source (each module, the layout of the LED strip or the placement of each LED and each resistor);
• the time required for the electrical connection of all these methods, welding, wiring, etc. ;
• the difficulty of automating placements and welding for made-to-measure products;
• the need to have series of identical parts to envisage industrial production.

Brief description of the appended figures

• la figure 2 représente de façon schématique une vue en coupe d'un appareil d'éclairage présentant une plaque support sur laquelle des sources lumineuses de type LED sont câblées selon un premier exemple de réalisation, non couvert par les revendications.
• la figure 3 représente de façon schématique une vue de dessus d'un appareil d'éclairage présentant une plaque support sur laquelle des sources lumineuses de type LED sont câblées selon un exemple de réalisation conforme à la figure 2 ;
• la figure 4 représente une vue schématique de dessus d'une plaque support conforme à la figure 2 sans source lumineuse ;
• les figures 5A et 5B représentent chacune de façon schématique une vue en coupe d'un appareil d'éclairage présentant une plaque support sur laquelle des sources lumineuses de type LED sont câblées selon un deuxième exemple de réalisation de la présente invention ;
• la figure 6 représente un organigramme d'un procédé de fabrication d'une appareil d'éclairage selon un exemple de réalisation de la présente invention.

Other characteristics and advantages of the present invention will become apparent from the description below, with reference to the figures 2 to 6 appended which illustrate two examples of embodiments devoid of any limiting character and on which:

• there figure 2 schematically represents a sectional view of a lighting device having a support plate on which light sources of the LED type are wired according to a first embodiment, not covered by the claims.
• there picture 3 schematically shows a top view of a lighting device having a support plate on which light sources of the LED type are wired according to an example embodiment in accordance with the figure 2 ;
• there figure 4 shows a schematic top view of a support plate in accordance with the picture 2 without light source;
• THE figure 5A And 5B each represent schematically a sectional view of a lighting device having a support plate on which light sources of the LED type are wired according to a second embodiment of the present invention;
• there figure 6 shows a flowchart of a method of manufacturing a lighting device according to an exemplary embodiment of the present invention.

Detailed description according to an advantageous embodiment

The manufacture of a luminous sign according to two embodiments will now be described in the following with reference jointly to the figures 2 to 6 .

As a reminder, one of the objectives of the present invention is to design a luminous sign making it possible to respond to the problem of producing a tailor-made and unique luminous form offering qualitative lighting, that is to say homogeneous and limiting the heat of functioning.

The two examples described here will each relate to the design of an illuminated sign; however, it will be understood that the invention can be implemented for any lighting or light decoration product, and in particular any lighting device which requires a made-to-measure and unique shape.

The manufacturing method which has been developed in the context of the present invention and which will be described in the remainder of the description makes it possible to implement individual light sources of the LED type on a support in an automatable manner.

We will speak here of an LED source in the general sense.

The concept underlying the present invention consists of a manufacturing method aimed at wiring all of the light sources 20, here LEDs, simultaneously by supplying the LED sources with two superposed layers of conductive materials.

In the example described here, individual LED components suitable for 12 Volts are used, and not 3.3 Volt LEDs as is generally the case with existing signs.

Such an LED component is in the form of a resin capsule comprising the LED as such and a micro-resistor. Such a component is thus configured to support a voltage of 12 Volts.

The process implemented is closest to the method of individual LEDs, which makes it possible to obtain the most qualitative product in terms of lighting and control of the operating temperature.

However, unlike this method, the wiring of each LED source is no longer done on a horizontal plane thanks to an electrical circuit, but on a vertical plane by establishing electrical contact between the two independent conductive layers at two different heights.

In the first exemplary embodiment illustrated in figure 2 , it is intended to use light sources of the LED type with conductive rods of different lengths.

In this first example, during an initial supply step S1, there is a panel of glass fibers covered on either side with a conductive plate, for example made of copper.

Also referred to as a sandwich panel.

Thus, it is understood that the fiberglass panel, which is made of an insulating material, constitutes an insulating layer 13 acting as an electrical insulator between an upper conductive layer 11 and a lower conductive layer 12 (the copper plates).

In the second exemplary embodiment illustrated in figure 5A And 5B , it is intended to use light sources of the LED SMD type with flat electrical terminals.

In this second example, a PCB-type multilayer panel is used with, as for the first example, an intermediate insulating layer 13 acting as electrical insulation between an upper conductive layer 11 and a lower conductive layer 12 and two insulating layers 17 and 18 sandwiching the whole 11-12-13. Layers 12 and 12 are so-called central layers.

This multilayer structure has many advantages such as ensuring optimal distribution of the electrical charge on the two central layers 11 and 12 to be able to wire all the LEDs without creating heating points as well as the possibility of creating strips for find the + and the - in bands on the lower layer.

As illustrated in figure 2 And 5A-5B , the LED sources (or more generally the light sources) will be positioned on the front face 10a of the support plate 10, that is to say on the upper layer 11 side.

It is desirable that the two layers 11 and 12 which are at different heights be electrically connected to each other. More precisely, the two layers 11 and 12 are wired to the same electric generator 40.

In each of the two examples described here, a vertical wiring structure is provided in which the two terminals 21 and 22 of each LED 20 are electrically connected with each of the two layers 11 and 12 respectively.

Thus, as shown in figure 2 Or 5 , an electrical connection step S5 is provided during the manufacturing process during which the first 21 and second 22 electrical terminals of each light source 20 are electrically connected respectively to the upper 11 and lower 12 layers.

To produce such a so-called vertical wiring, the manufacturing process provides beforehand for specific machining of the support plate 10.

In the two examples described, the plate will be machined so that each LED source 20 can come into contact with one of the two conductive layers 11 or 12 selectively.

In particular, three machining steps S2, S3 and S4 are provided which will make it possible to design a vertical wiring for each LED source 20.

In the two examples described, provision is preferably made for the use of a numerically controlled cutting machine of the CNC type which will machine the support plate 10 in a specific manner.

This CNC machine will be controlled automatically or semi-automatically thanks in particular to a layout plan generated during a step S0. During this step S0, a computer file intelligible by the CNC machine will be generated according in particular to the desired shape and to various predetermined constraints. This file then contains the layout plan with in particular the position and orientation of each LED source.

In each of the two examples described here, the support plate 10 is therefore machined during a step S2 to form a first hole 14 according to the layout plan (orientation and position, in particular).

In the example shown in figure 2 , this first hole 14 is machined so as to emerge on the front panel 10a and at least partially pass through the upper layer 11.

In the example described here, this first hole 14 is also sized to receive the first electrical terminal 21, here the shortest conductive rod.

In the example shown in figure 5A And 5B , the terminals 21-22 of the light source 20 are flat. Provision is here made for this first hole 14 to be machined so as to emerge on the front face 10a and at least partially pass through the upper layer 11 and the first insulating layer 17.

Next, the plate is machined during a step S3 to form a second hole 15, still according to the layout plan.

In the example shown in figure 2 , this second hole 15 is machined so as to emerge on the front panel 10a and pass through the upper layer 11, the insulating layer 13 and at least partially the lower layer 12.

In the example described here, this second hole 15 is sized to receive the second electrical terminal 22.

In the example shown in figure 5A And 5B , this second hole 15 is machined so as to emerge on the front panel 10a and pass through the first insulating layer 17, the upper layer 11, the insulating layer 13 and at least partially the lower layer 12.

Finally, during a step S4, the support plate 10 is machined so as to form a third hole 16, called a blind hole.

As illustrated in figure 2 Or 5A-5B , this blind hole 16 is machined so as to emerge on the front facade 10a and pass through the upper layer 11 and at least partially the insulating layer 13 (and the first insulating layer 17 for the example of the figure 5 )

In the example described here, this blind hole 16 is centered on the second hole 15 (co-axial with the latter) and has a diameter greater than that of the second hole 15.

There is also the same blind hole 16 in the embodiment of the Figures 5A-5B .

These machining operations are repeated according to the layout plan for each LED source. Thus, it is understood that by making according to the layout plan these holes 14, 15 and 16 with different diameters and depths, it is possible to reach the conductive layers 11 and 12 in order to establish an electrical connection with each terminal 21 and 22 conductor of LED source 20.

The machining of the blind hole 16 makes it possible to isolate the longest pole from the lower layer.

When positioning the LED sources 20, the holes 14, 15 and 16 made during the machining operations S2, S3 and S4 are therefore used. The LED sources 20 are then arranged one by one on the support plate 10 at the location defined during machining. The LED sources 20 are therefore placed upside down so as to have their conductive poles accessible and in contact with the sandwich panel 10.

It should be noted here that there are many LED components compatible with this manufacturing process, all through-hole LEDs of 3 or 5 millimeters in diameter but also individual micromodules receiving an SMD type LED.

In the first example described here and illustrated in figures 2, 3 and 4 , the electrical connection S5 is therefore made by inserting the first terminal 21 of the source 20 into the first hole 14 (the shortest conductive rod). In this way, an electrical contact point 21a is established between the light source 20 and the upper layer 11.

In this configuration and as illustrated in figure 2 , it is understood that the first terminal 21 of the LED source 20 is electrically isolated from the lower layer 12.

When connecting S5, the second terminal 22 (the longest conductive rod) of the source 20 is then inserted into the second hole 15 in order to establish an electrical contact point 22a between the light source 20 and the lower layer 12.

Thanks to the diameter of the blind hole 16, the second terminal 22 of the LED source 20 is electrically insulated from the upper layer 11.

At each electrical contact point 21a and 22a (that is to say twice per LED), a drop of conductive glue is then deposited during the electrical connection S5.

In the example described here, an epoxy-type glue is used mixed with microparticles of conductive material based on silver or tin, for example.

There is therefore half of the drops which is in contact with the upper layer and the other half which is in contact with the lower layer.

Preferably, this glue must be prepared with the right conductivity so as not to oppose excessive electrical resistance and with the right viscosity so as not to move during handling.

After laying and drying S6 of the adhesive, during a step S7 the two conductive layers 11 and 12 are supplied with the aid of electrical supply means 40 with direct current to supply all the LED sources 20 in shunt.

In the example described here, the LED sources used are 3.3 Volt LEDs. In this example, it is preferable to supply these two layers with direct current of 3.3 volts.

It is also possible to use LED sources which are directly designed to be supplied with 12 Volts. In this case, it is possible to supply this electrical assembly directly with 12V.

In the second example described here and illustrated in Figures 5A-5B , the electrical contact points 21a and 22a between the conductive layers 11 and 12 and the source are implemented by electrical bridges 19a and 19b which are introduced respectively into the first 14 and second 15 holes. Once the bridges 19a and 19b have been introduced into each of the respective holes, a resin is poured into each of said holes 14 and 15. This resin then forms an insulating sheath making it possible to ensure electrical insulation of the bridges.

The electrical contact points 21a and 22a between the terminals of the electrical source 20 and each of the layers 11 and 12 are thus implemented on the front panel 10a via bridges. In this second example, the electrical connection of each of the terminals 21 and 22 of the light source with the layers 11 and 12 is made by welding. Such soldering can be implemented, for example, by depositing an addition of solder cream type material and then placing it in the oven to secure the terminals to the plate.

In each of the examples, the LED sources are then placed on the support plate 10 machined beforehand to receive each LED with a predefined position and orientation.

This position and this orientation of the LED sources 20 is defined according to a layout plan during an initial step S0. Such a plan can be computer generated with dedicated computer software depending on the shape of the desired lighting.

Once the plan has been generated, one or more plates are prepared forming a panel of the sandwich type having on its lower and upper surface a conductive material and at its core an insulating material. This plate is pierced during machining to supply the LED sources 20 with the positive or negative conductive layer.

The advantage of also having a first and an example insulating layer sandwiching the assembly is to ensure an optimal distribution of the electrical charge on the two central layers in order to be able to wire all the LEDs without creating warm-up points. This multilayer configuration also makes it possible to create bands to find the + and the - by bands on the lower layer.

Then, drops of conductive glue 31 are placed on the support plate 10 for each point of contact 21a and 22a with the LED 20.

The two parts are then assembled to obtain a complete electrical circuit supplying all the LED sources of the shape at once. Each LED is therefore individually powered by shunt.

Arranging the LEDs is like arranging imperfect circles in a shape. This part can therefore be subject to computer automation by providing the machine with constraints of spacing with the edge of the shape and of spacing between the circles, in other words, between the LEDs.

The layout plan can therefore be generated by computer automatically or semi-automatically from the drawing of the shape to be produced.

It is therefore no longer necessary to manually decide the location of each element such as modules, LEDs or resistors, nor to decide on the electrical wiring that will connect these electrical components together.

All of the manufacturing steps described in the part can be automated to a greater or lesser degree. It is therefore possible to benefit from all the advantages of the individual placement method while greatly reducing the labor required to achieve it.

The robotization of this manufacture should make it possible to place this production in countries with high labor costs and therefore to bring production closer to the centers of consumption of this product. This also leads to lower transport costs and times.

Finally, the manufacturing process also makes it possible to accelerate the manufacture of signs and therefore to have a competitive advantage in terms of production time compared to the competition which produces these products by hand.

It should be noted that this detailed description relates to a particular embodiment of the present invention, but that in no case does this description have any limiting character to the subject of the invention; on the contrary, it aims to remove any possible imprecision or any misinterpretation of the following claims.

It should also be noted that the reference signs placed between parentheses in the following claims are in no way limiting; these signs have the sole purpose of improving the intelligibility and understanding of the following claims as well as the scope of the protection sought.

Claims (9)

1. Lighting fixture (100) comprising a plurality of light sources (20) positioned at the front (10a) of a support plate (10), said light sources (20) each having at least a first (21) and a second (22) electrical terminals,

   wherein said support plate (10) comprises:

   - at the front (10a), a first insulating layer (17),

   - an upper conductive layer (11),

   - a lower conductive layer (12), and

   - an intermediate insulating layer (13) electrically insulating said upper (11) and lower (12) layers;

   said upper conductive layer (11) being sandwiched between the intermediate insulating layer (13) and the first insulating layer (17),

   wherein said first (11) and second (12) electrical terminals are electrically connected respectively to the upper (11) and lower (12) layer and are electrically insulated respectively from the lower (12) and upper (11) layers, or conversely,

   wherein said support plate (10) includes, for each light source (20),

   a) a first hole (14) traversing at least partially said upper layer (11) and said first insulating layer (17) before opening onto the front (10a);

   b) a second hole (15) traversing at least partially said lower layer (12), said insulating layer (13), said upper layer (11) and said first insulating layer (17) before opening onto the front (10a); and

   c) a third, so-called blind, hole (16), traversing at least said upper layer (11) and at least partially said insulating layer (13) before opening onto the front (10a), said blind hole (16) being substantially centred on said second hole (15) and having a greater diameter than said second hole (15) so as to electrically insulate said upper layer (12) and said second (22) or first (11) electrical terminal electrically connected to the lower layer (12),

   which comprises:

   a first electrical bridge (19a, 19b) electrically insulated and housed inside said first hole (14), electrically connecting said upper layer (11) to the front (10a) to establish at the front an electrical contact point (21a, 22a) between said first (21) or second (22) electrical terminal of said light source (20) and said upper layer (11); and

   a second electrical bridge (19a, 19b) electrically insulated and housed inside said second hole (15), electrically connecting said lower layer (12) to the front (10a) to establish at the front (10a) an electrical contact point (22a, 21a) between said second (22) or first (21) electrical terminal of said light source (20) and said lower layer (12).
2. Fixture (100) according to claim 1, wherein said first electrical bridge (19a, 19b) is electrically insulated by an insulating sheath.
3. Fixture (100) according to any one of the preceding claims, wherein said plate (10) comprises at the back (10b) a second insulating layer (18), said lower conductive layer (12) being sandwiched between the intermediate insulating layer (13) and said second insulating layer (18).
4. Fixture (100) according to any one of the preceding claims, wherein said second electrical bridge (19a, 19b) is electrically insulated by an insulating sheath.
5. Fixture (100) according to any one of the preceding claims, characterised in that fastening means (30) having conductivity properties are used at the level of each of the electrical contact points (21a, 22a) to secure each of said sources (20) on said support plate (10) while ensuring electrical conductivity between each of said sources (20) and respectively the upper (11) and lower (12) layers.
6. Fixture (100) according to claim 5, wherein said fastening means (30) include:

   - an epoxy type conductive adhesive (31) mixed with conductive particles such as for example silver or tin in particular; or

   - a solder.
7. Fixture (100) according to any one of the preceding claims, characterised in that it includes electrical power supply means (40) respectively connected to the upper (11) and lower (12) layers to supply each of said light sources (20) with direct current.
8. Method for manufacturing a lighting fixture (100) comprising a plurality of light sources (20) positioned at the front (10a) of a support plate (10), each light source (20) having at least a first (21) and a second (22) electrical terminals, said method including the following steps:

   - providing (S1) a support plate (10) comprising, at the front (10a), a first insulating layer (17), an upper conductive layer (11), a lower conductive layer (12) and an intermediate insulating layer (13) electrically insulating said upper (11) and lower (12) layers, said upper conductive layer (11) being sandwiched between the intermediate insulating layer (13) and the first insulating layer (17);

   - a first machining step (S2) during which said support plate (10) is machined so as to form a first hole (14) traversing at least partially said upper layer (11) and said first insulating layer (17) before opening onto the front (10a);

   - a second machining step (S3) during which said support plate (10) is machined so as to form a second hole (15) traversing at least partially said lower layer (12), said insulating layer (13), said upper layer (11) and said first insulating layer (17) before opening onto the front (10a);

   - a third machining step (S4) during which said support plate (10) is machined so as to form a third, so-called blind, hole (16) traversing said upper layer (11) and at least partially said insulating layer (13) before opening onto the front (10a), said blind hole (16) being substantially centred on said second hole (15) and having a greater diameter than that of the second hole (15) so as to electrically insulate said upper layer (11) and said second (22) or first (11) electrical terminal electrically connected to the lower layer (12),

   - an electrical connection step (S5) during which the first (21) and second (22) electrical terminals of each light source (20) are electrically connected respectively to the upper (11) and lower (12) layers and are electrically insulated respectively from the lower (12) and upper (11) layers, or conversely, by implementing respectively:

   a) a first electrical bridge (19a, 19b) electrically insulated and housed inside said first hole (14), electrically connecting said upper layer (11) to the front (10a) to establish at the front an electrical contact point (21a, 22a) between said first (21) or second (22) electrical terminal of said light source (20) and said upper layer (11); and

   b) a second electrical bridge (19a, 19b) electrically insulated and housed inside said second hole (15), electrically connecting said lower layer (12) to the front (10a) to establish at the front (10a) an electrical contact point (22a, 21a) between said second (22) or first (21) electrical terminal of said light source (20) and said lower layer (12).
9. Use of a lighting fixture (100) according to any one of claims 1 to 7 for an illuminated sign.

Images