FR2739524A1 - Strip pcb for LED illumination panel - Google Patents

Abstract

The pcb has an elongated shape and a number of conducting paths present on one of its surfaces. Two power supply conducting bands (15,16), one negative and one positive, are placed along the pcb edges. The pcb is divided into a number of sectors (11-13) each sector receiving a number of electrical components. Each sector receives three LEDs (30) connected in series with a resistor (31).

Description

"Printed circuit strip for light emitting diodes,
support profile for such a strip, luminaire and light panel "
The subject of the present invention is a printed circuit strip for light-emitting diodes, more specifically a printed circuit strip adapted to receive projecting on one face a row of diodes, which is crossed by the tails of these diodes, and on the other face of which are established the conductive tracks necessary for serving them advantageously, these diodes are associated with current limiting resistors which the conductive tracks take into account; preferably, the assembly is capable of wave welding.

 Given the many possible applications of such a bar, it is necessary to be able to have many bars of different lengths, which increases the cost price.

 The object of the present invention is to propose a bar of the above type which can be marketed according to an extremely reduced or even unitary range, by arranging it so that it is breakable.

 Thus, according to the invention, a printed circuit strip, for light-emitting diodes, having conductive tracks which include two said supply strips, a positive supply strip and a negative supply strip, extending parallel along of the bar and extended, respectively, by short transverse sections pierced with holes and by conductive blocks also pierced with holes, said short sections and said conductive blocks being regularly distributed, carries cutting marks delimiting sectors, one of the end sectors at least comprising two electrical supply pads.

 Advantageously, each sector is arranged to receive n light-emitting diodes and a resistor connected in series.

 Preferably, in each sector, between the supply strips, there are successively provided with n tracks: a first track with end studs aligned with the holes in the positive feed strip; a second track with end studs, one of which is located transversely to a stud of the first track and is aligned longitudinally with the studs of the negative power strip, and the other of which is aligned longitudinally with the positive power strip pads; an n th track with end studs pierced with holes, one of which is located transversely to the stud of the track which precedes it and is aligned longitudinally with the studs of the negative power strip and the other of which is aligned longitudinally with the pads of the positive feed strip and is located transversely to the right of a hole in the negative feed strip.

 The two supply pads receive an electrical connector, preferably of the male type.

 Thus, thanks to this modular sector arrangement, the range can be extremely reduced, for example to three bars of different lengths; the intermediate lengths are obtained by cutting said three bars to the desired length.

 Preferably, each sector is provided with supply pads; this makes it possible to multiply the possibilities and to only industrialize a single bar of a given length: the bars of shorter length are obtained as previously, and the bars of longer length are obtained by placing one or more bars in series industrialized, each end sector having two supply pads, one sector supporting a male connector, the other sector a corresponding female connector.

 The invention also relates to a profile intended to support, in a simple manner, a printed circuit strip carrying light-emitting diodes.

 According to the invention, an assembly profile, for a printed circuit strip carrying light-emitting diodes, has a cross section in the general shape of a U defining two wings connected, in the vicinity of one of their ends, by a partition and having internally opposite, from said partition, a boss and a tongue defining a groove suitable for receiving said printed circuit strip; advantageously, each wing internally has a panel so that a slot is defined suitable for receiving a transparent plate; the ends in the vicinity of which the partition is disposed each have a return extending in the direction of one another and defining a T-shaped notch open towards the outside.

 Advantageously, the wings each have, internally, two semi-circular lips arranged transversely between said tongue and said face.

 Preferably, each section of the profile is internally provided with a recess.

 Another object of the present invention is to propose a luminaire of simple production, taking advantage of the printed circuit strip of the present invention, equipped with light-emitting diodes, supported by the profile, also of the present invention; such a longilinear luminaire can be used for direct or indirect lighting.

 Thus, according to the invention, a luminaire comprising a printed circuit strip carrying light-emitting diodes held in a support is characterized in that said printed circuit strip is of the above type and said support is an assembly profile of the above type advantageously, said profile is adapted to also support a plate made of a transparent thermal insulating and self-extinguishing material.

 The present invention also aims to provide a light panel of simple construction, taking advantage of the printed circuit strip of the present invention for lighting by the edge of a transparent or translucent plate, hereinafter referred to as transparent plate , of which at least one of the faces carries a drawing or a text underlined by the diffusion and the reflection of the light wave which, sent by the light-emitting diodes, crosses the plate; The advantage of such lighting is that it is compact, at very low voltage and that it leads to very low consumption; its lifespan is high; moreover, its implementation is simple and the security problems are reduced to a minimum.

 According to the invention, a light panel comprising a printed circuit strip carrying light-emitting diodes, a transparent plate bearing an inscription and intended to be illuminated by the edge by said light-emitting diodes, is characterized in that said printed circuit strip is of the above type; preferably, said strip and said transparent plate are supported by a profile element, said profile being of the above type; each section of the profile being internally provided with a recess, the plate is crossed by pins whose ends take place in the recesses.

 To better understand the object of the invention, we will now describe, by way of example, purely illustrative and not limiting, an embodiment shown in the accompanying drawings.

On these drawings
- Figure 1 is a plan view of the printed circuit strip according to the invention viewed from the conductive tracks side
- Figure 2 is a plan view of a sector of the bar of Figure 1 seen from the component side
- Figure 3 is a plan view of the bar of Figure 1 side view components
- Figure 4 is a partial plan view of the bar of Figure 1 showing an end sector seen from the component side
- Figure 5 illustrates the coupling of two bars of Figure 1
- Figure 6 is a side view showing a support profile according to the invention
- Figure 7 is a partially sectional view of a light panel according to the invention;
- Figure 8 is a view along VIII-VIII of Figure 7
- Figures 9 and 1 1 are plan views of end caps of the profile of Figure 6
- Figure 10 is a view along X of Figure 7
- Figure 1 2 shows a variant end sector with respect to Figure 1.

 Referring to Figures 1 to 4, we see the bar 10 diode holder constituted by an elongated element of the printed circuit.

 On one of its faces, illustrated in FIG. 1, we see the conductive tracks of the printed circuit; these include two bands 1 5 and 16, said supply, respectively positive and negative, extending parallel over substantially the entire length of the strip 1 O; the positive feed strip 1 5 is extended, on its side which faces the negative feed strip 16, by short transverse sections at the end of which are studs pierced with holes 1 7 passing through the bar 10; said transverse sections are regularly distributed along the positive feed strip 1 5, each end of which also includes such a transverse section.

 The negative supply strip 1 6 has, on the side which faces the positive supply strip 15, regularly spaced conducting blocks each having two holes 19, 29 aligned longitudinally, one of the two holes, here the hole 19 , being placed in line with a hole 1 7 of the positive feed strip 1 5; such a block is provided at one end of the negative supply strip 16, its other end comprising a short transverse section having a hole 1 8 disposed in line with the end hole 1 7 of the positive supply strip 1 5.

 The bar 10 comprises two end sectors 1 1 and 1 3 and intermediate sectors 1 2; these sectors are delimited by cutting marks 1 4 traced on the face of the bar 10 adapted to receive electrical components, as shown in Figure 3 in which is shown, for example, a bar 10 to six sectors.

 Each sector is arranged to receive three light-emitting diodes, in the example shown, connected in series with a resistor; to do this, as shown in FIGS. 1 and 2, between the positive 1 5 and negative 1 6 supply strips are provided three tracks a first track 20 with end studs drilled with holes 23, 24 aligned with the holes 17 positive feed strip 15; a second track 21 with end studs pierced with holes 25, 26 one of which, the hole 25, is located transversely to the right of the hole 24 of the first track 20 and is aligned longitudinally with the holes 19, 29 of the strip negative feed 16, and the other, the hole 26, is aligned longitudinally with the holes 17 of the positive feed strip 1 5; a third track 22 with end studs pierced with holes 27, 28 one of which, the hole 27, is situated transversely to the right of the hole 26 of the second track 21 and is aligned longitudinally with the holes 19, 29 of the strip negative feed 16, and the other, hole 28, is longitudinally aligned with holes 1 7 of the positive feed strip 1 5 and is located transversely to the right of hole 29 of the negative feed strip 1 6.

 Each sector is thus adapted to support by welding three light-emitting diodes 30 through its holes 24-25, 26-27, 28-29 respectively, and a resistor 31 between the hole 23 and the hole 17 placed between the holes 23 and 26; the hole 1 9 and the hole 1 7 which faces it transversely are adapted to be connected to an electrical supply cable for supplying the positive supply strips 1 5 and negative 1 6.

 According to the example described, three diodes are in series with a resistance of course, depending on the applications, two diodes can be provided, or else four or more diodes.

 As will be understood, by cutting a strip 10 along one of the references 14, it is possible to obtain bar elements of different lengths adapted to the needs.

 More precisely, the bar 10 which has just been described makes it possible, by being industrialized only along a single length, for example with six sectors as shown in FIG. 3, to obtain any desired length: the shorter lengths are obtained by cutting the bar 10, and the longer lengths by placing two or more bars 10 in series, as shown in FIG. 5; this is obtained by taking advantage of the presence of the supply holes 17, 1 8 of the sector 1 1 and 17, 1 9 of the sector 1 3; the holes 17, 1 8 of the sector 1 1 carry a connector 33, advantageously of the male type, adapted to cooperate with a complementary connector, here of the female type, provided at the end of an electrical supply cable 32, as shown in Figure 4; by making the holes 17, 1 9 of the sector 1 5 carry a connector 133, FIG. 5, complementary to the connector 33, it is possible to put a strip 10 in series with one or more strips or a strip element.

 For certain applications, it may not be necessary to put bars in series and industrialize a range of two or three lengths, the longest of which is: in this case, the holes 17, 1 8 at the end of the end sector 11, and the sections of track which feed them, are deleted, as shown in FIG. 12.

 Figure 6 shows, in cross section, a profile 40 adapted to support a bar such as that which has just been described.

 The cross section of the profile 40 has a general U-shape defining two wings 50, 51 connected, in the vicinity of one of their ends, by a partition 43; each of said ends has a return, respectively 57, 58, so that a T-shaped notch 41 is defined, open towards the outside, said returns 57, 58 extending in the direction of one another.

 From the partition 43, the wings 50, 51 have internally opposite a boss 42, a tongue 44, two semi-circular lips 47, a flap 49 provided with a recess 52.

 Between the bosses 42 and the tongues 44 are defined longitudinal grooves 46 intended to slide the bar (or the element) 10, FIG. 8 showing the bar 10 thus installed.

 The panels 49 are at a transverse distance from each other defining an insertion slot for a plate made of transparent material, advantageously of poly (methyl methacrylate), that the profile 40 is intended to partially overlap for lighting by the edge of said plate by light emitting diodes 30; such a plate 60 is visible in FIGS. 7 and 8. The plate to be lit 60 is provided with pins 56 which pass through it and whose length corresponds to the transverse distance between the bottoms of the recesses 52 of the profile 40, so that the plate 60 is slidably mounted on the profile 40: FIG. 8 shows the plate 60 thus mounted in the profile 40. The assembly of the plate 60 and the profile 40 using the pins 56 has the advantage, by mounting the pins 56 with a slight play in the holes in the plate 60 which they pass through, to allow the plate 60 to expand due to the heat, however slight, given off by the light-emitting diodes and, therefore, to prevent the plate does not crack or break.

 To complete the assembly of the profile 40, of the bar 10 and of the plate 60, end pieces 61, 62, visible in FIGS. 11 and 9 respectively, close the profile 40 at each of its ends; the two semi-circular lips 47 of each wing 50, 51 define semicylindrical wells 48 into which self-tapping screws 64, FIG. 10 can be screwed, which allow the end pieces 61, 62 and the profile 40 to be secured by screwing; thus, the elements mounted to slide in the profile 40 are held longitudinally.

 It is possible, as shown in the figures, to take advantage of the longitudinal guides 45 of the profile 40, defined between the partition 43 and the bosses 42, in order to slide therein a strip 54 made of electrically insulating material to protect against contact optionally between the partition 43 and the electrical components of the strip 10, when the profile 40 is made of a metallic material, such as for example aluminum.

 According to a variant not shown, the strip 54 can be replaced by a simple adhesive, glued for example on the inner face of the partition 43 or on the concerned face of the bar 1 0.

 We can also take advantage of the space 59 between the flaps 49 and the semi-circular lips 47 to slide a plate, such as the plate 55 of FIG. 8, in a transparent thermal insulating and self-extinguishing material, such as than a polycarbonate for example, so as to be able to use the assembly according to the invention indoors, and thus meet the standards existing on the subject, the PMMA being combustible as well as the components of the bar 10. Furthermore, the wafer 55 is used for holding the plate 60 relative to the profile 40 by taking up the mounting clearances and / or the manufacturing tolerances: by using a plate 55 of sufficient thickness, the plate 60 is maintained by taking support, one side, on the lower edge, with respect to FIGS. 6 or 8, of the recess 52 and, on the other side, on the lower lip 47 by means of said plate 55.

 When such a plate 55 is used, it can, according to a variant not shown, be glued to the edge of the plate 60 to maintain it, in which case the pins 56 and the recesses 52 can be removed, the width of the plate 55 being greater than the thickness of the plate 60.

 By providing the plate 60 with an inscription 63, FIG. 7, it can be seen that, thanks to the invention, it is easy to produce a light panel inexpensively as a function of the space required for the inscription 63, the strip 10 is cut to length, whether or not fitted with components, diodes 30 and resistors 31; in the second case, these components are mounted on the bar element thus cut to length, as well as the male end connector; the bar or said bar element, the plate 60, optionally the insulating strip 54 and the transparent plate 55, are installed in the profile 40 beforehand, also, cut to length as well as the strip 54 and the plate 55; the ends 61, 62 are then put in place.

 It should be noted that, thanks to the sliding mounting of the bar 10 in the profile 40 serving as its housing, the maintenance operations are facilitated, the possible change of bar advantageously being able to be carried out without any particular tool.

 The fixing of the light panel thus formed can be done by any suitable conventional means capable of cooperating with the T-shaped notch 41 of the profile 40; I'embout 62 has a notch 65 clearing access to the notch 41 for easy implementation of said means, the light panel being assembled; The notch 41 can, for example, cooperate with a corresponding T-profile fixed directly vertically to a wall or a partition, the panel being placed as a flag, or by means of a bracket, the panel being placed parallel to the wall or partition; it is also possible to suspend said panel from hangers carrying at their ends nuts which have been taken captive in the notch 41.

 The invention allows many applications; it is possible to create luminous information, signage, decoration and advertising panels. The inscription, such as the inscription 63, can of course be carried out in different ways: engraving, painting, attached adhesive; it can represent letters, words, patterns.

 It is also possible to produce lighting devices, direct or indirect, from the profile according to the invention in which a transparent plate is not inserted; thus, such a lighting device or luminaire comprises the assembly profile 40 in which a printed circuit strip 10 carrying light-emitting diodes has been mounted, the profile 40 also supports, thanks to the spaces 59, a plate 55 in one transparent thermal insulating and self-extinguishing material.

Claims (11)

 1. Assembly profile, for a printed circuit strip carrying light-emitting diodes, having a cross section in the general shape of a U defining two wings (50, 51) connected, in the vicinity of one of their ends, by a partition (43) and having internally opposite, from said partition (43), a boss (42) and a tongue (44) defining a groove suitable for receiving said printed circuit strip.  2. Profile according to claim 1, characterized in that each wing (50, 51) has internally a pan (49) so that is defined a slot adapted to receive a transparent plate (60).  3. Profile according to one of claims 1 or 2, characterized in that the ends in the vicinity of which is disposed the partition (43) each have a return (57, 58) extending towards one of the other and defining a T-shaped notch (41) open towards the outside.  4. Profile according to one of claims 1 to 3, characterized in that the wings (50, 51) each have, internally, two semi-circular lips (47) disposed transversely between said tongue (44) and said pan ( 49).  5. Profile according to one of claims 2 to 4, characterized in that each pan (49) is internally provided with a recess (52).  6. Profile according to one of claims 1 to 5, characterized in that the printed circuit strip has conductive tracks which include two strips (15, 16) said supply, a positive supply strip (15) and a negative supply strip (16), extending parallel along the strip (10) and extended, respectively, by short transverse sections pierced with holes (17) and by conductive blocks also pierced with holes (19 , 29), said short sections and said conducting blocks being regularly distributed, the printed circuit strip carrying cutting marks (14) delimiting sectors (11, 12, 13), one (11) of the end sectors at least comprising two electrical supply pads.  7. Profile according to claim 6, characterized in that each sector (11, 12, 13) is arranged to receive n light-emitting diodes (30) and a resistor connected in series.  8. Profile according to claim 7, characterized in that in each sector, between the supply strips (15, 16), there are successively provided with n tracks: a first track (20) with end studs pierced with holes ( 23, 24) aligned with the holes (17) of the positive supply strip (15); a second track (21) with end studs pierced with holes (25, 26) one of which (25) is located transversely to the right of a hole (24) in the first track (20) and is aligned longitudinally with the holes (19, 29) of the negative supply strip (16), and the other (26) of which is aligned longitudinally with the holes (17) of the positive supply strip (1 5); an n th track (22) with end studs pierced with holes (27, 28) one of which (27) is situated transversely to the right of the hole (26) of the track (21) which precedes it and is aligned longitudinally with the holes (19, 29) of the negative supply strip (16) and the other (28) of which is aligned longitudinally with the holes (17) of the positive supply strip (15) and is located transversely to the right of a hole (29) in the negative power strip (16).  9. Profile according to one of claims 6 to 8, characterized in that said two supply pads receive an electrical connector (33).  10. Profile according to one of claims 6 to 8, characterized in that each sector (11, 12, 13) is provided with supply pads.  11. Luminaire comprising a printed circuit strip carrying light-emitting diodes held in a support, characterized in that said support is the assembly profile (40) according to one of claims 1 to 10.  1 2. Luminaire according to claim 11, characterized in that said profile (40) is adapted to also support a plate (55) in a transparent thermal insulating and self-extinguishing material.  1 3. Luminous panel comprising a printed circuit strip carrying light-emitting diodes, a transparent plate bearing an inscription and intended to be illuminated by the edge by said light-emitting diodes, in which said strip and said transparent plate are supported by a profiled element , characterized in that said profile (40) is according to one of claims 1 to 10.  1 4. Panel according to claim 13, characterized in that the profile is according to claim 5 and the plate is crossed by pins (56) whose ends are received by the recesses (52).