EP2273184A1 - Lighting device for clean room - Google Patents

Abstract

The device has a bonnet (3) provided parallel to a support plate (2). Electroluminescent diodes (5) are provided as a light source. The support plate places the electroluminescent diodes in a position. The support plate and the bonnet form an envelope structure for closing the device. The envelope structure provides two principal external opposite faces. Side walls (31) connect the principal faces by forming an obtuse angle with an extension virtual plane, where the obtuse angle is ranged between 115 and 160 degrees. The bonnet is made of plastic, glass, aluminum and/or incorporating steel of optics transparency. The device is made of a polymeric coating material i.e. polyurethane.

Description

The invention relates to a lighting device for a clean room.

A clean room or commonly called a "clean room" a few years ago, is a place in which the concentration of airborne particle is massaged. Its construction is carried out so as to minimize the introduction, production and retention of particles inside the room and in which other characteristic parameters such as temperature, humidity and pressure are controlled as it appropriate.

It is important that, in addition to the design of efficient air handling equipment, all materials (partitions, floors, ceilings) and other movable equipment be appropriately designed and compatible with the required class level of the building. use of the clean room.

The lighting devices of a clean room therefore require such a design requirement. Different types of luminaires are known to be installed in clean rooms, those recessed in the ceiling or those placed against the ceiling, the latter being more exceptional because they generate greater risks of retention of contamination.

The invention is more particularly concerned with, but not limited to, lighting devices arranged in a wall. Indeed, the built-in devices are not retained here because they require specific arrangements combined with a significant workload for their installation, with drilling of reservations in the ceiling which weaken the ceiling structure and which are sometimes at the origin of contaminations due to leaks at the peripheral seal line between the device and the ceiling cutout.

The usual models arranged in wall light illuminate from fluorescent tubes and consist of a sealed housing whose rear part, facing the ceiling, houses the ignition means, while the light sources occupy the front part facing the environment of the room. The housing is fixed by fixing means passing through the ceiling.

These known devices are bulky, however, having a height relative to the ceiling of the order of 80 to 100 mm, which does not promote the flow of air in the room. They can thus be real barriers when in particular the air blowing mouths, useful for the air renewal of the room, are arranged nearby.

The resistance to the air flow resulting from these devices generates air disturbances generating locally so-called dead zones, at which no air mixing is present. These dead zones create zones of retention of the contamination, which constitutes a real danger in the control of the contamination of the local.

Furthermore, in case of defect of the light source or the ignition circuit, the replacement subsequently imposes a necessarily decontaminating intervention of the room, which involves time, energy and also a cost. In order to reduce the maintenance of these lights, the document WO 03/036159 teaches the use of electroluminescent lamps (LED or "LED" in English) instead of fluorescent tubes, these light sources are much more robust over time. However, these disclosed lighting devices are intended for filtering ceilings which do not correspond to the ceilings or surfaces for which the devices of the invention are intended, in particular, because they are dedicated to ceiling structures whose entire ceiling must be filtering to correspond to dust classes ISO 1 to ISO 5.

Other lighting devices that use LEDs, such as patent applications, are also known. US20080084693A1 , US20080304250A1 , W02009018433 .

The purpose of the invention is therefore to propose a clean room lighting device that involves reduced maintenance and has a small footprint in order not to disturb the aeraulic in the implantation room and not to generate retention zones. contamination, the device may further, depending on its arrangement within the room, meet the requirements of the various dust classes (classes ISO 1 to ISO 9).

According to the invention, the clean room lighting device comprises light-emitting diodes as light sources, a support plate for said diodes, the diodes preferably being mounted on a printed circuit, itself reported on the support plate, and an opposing hood parallel to the support plate, the support plate and the cover forming a sealed and sealed envelope structure for the device, and this structure having two opposite external faces, parallel and plane, and respectively corresponding to, the application face and attachment of the device against a reception surface, and the illumination face, the dimension separating these external faces being very substantially less than the other two dimensions of the faces. The device is characterized in that the envelope structure comprises side walls connecting the two main faces forming with the virtual plane of extension of the main face of application and attachment, an obtuse angle, preferably between 115 and 160 °.

According to one characteristic, the support plate of the diodes has a flat outer surface and provided with means capable of ensuring the attachment of the device directly against the reception surface for which the device is intended.

Thus, the device, using light emitting diodes, saves longevity time and overcomes the disadvantage of recurrent maintenance of the prior art. Moreover, because of the flatness of the outer face of application and attachment of the device (without any constituent element protruding from this face) and its attachment to direct destination (plating without gap) against a surface of Ceiling type home, no fixing strut is needed, avoiding an additional area of risk of contamination retention. In addition, its projecting volume from the ceiling providing an extremely flat shape combined with side walls pan inclined at obtuse angles from the ceiling, is completely compatible with the aeraulic flow established in the clean room and ease of cleaning required for such a room.

By external and internal means in the following description, the qualifiers relating to the elements of the device which are, respectively, with respect to the external environment of the device, and arranged inside the device.

The device advantageously has a height corresponding to the dimension extending transversely to the plane of the support plate, between 7 and 12 mm. In addition, the device advantageously has dimensions such that the ratio between the smallest dimension extending transversely to the plane of the support plate and one of the other two dimensions is less than 0.06.

This height reduced to at most 12 mm, whereas the prior art fluorescent tube devices laid down apply a height of about 80 mm, leads to extremely compact devices, not opposing the flows of look like a clean room.

According to another feature, the side walls of the structure have a curved surface towards the outside of the structure. In particular, the envelope structure having a parallelepiped shape, the junction edges of the side walls with the main lighting face are rounded concavity turned towards the inside of the device, preferably the concavity having a radius of curvature of at least 3 mm.

The cover forms a single piece obtained by thermoforming, or injection or machining, or is achieved by the assembly of two parts.

In the case of an assembly of two parts, an alternative embodiment may be to obtain separately, firstly the side walls in the form of a frame, and secondly, a facade substrate constituting the main face of illumination from the hood, each of the parts being obtained by thermoforming, or injection or machining, then to assemble these parts by welding, gluing or other means adapted to the nature of the materials composing them.

In another variant embodiment of assembly of two parts, the side walls and the facade substrate form two unitary and symmetrical half-shells, the junction plane of these two half-shells being parallel to the smallest dimension of the hood and transversal to one of the large dimensions. The assembly of the half-shells is achieved by welding, gluing or other means adapted to the nature of the materials composing them.

The cover is based on plastic material (s), possibly composite, or glass, or aluminum and / or steel incorporating transparent optics, and can be covered on all or part of its outer face intended to be facing the external environment of the device, a protective coating made of a polyurethane or other type of polymer material.

The external main illumination face corresponding to the external main face of the cover has a roughness coefficient of less than or equal to 0.8 μm, preferably less than 0.4 μm.

Advantageously, the device comprises a peripheral frame associated with the internal face of the cover, this frame being able to be secured to the cover when the cover is molded, and against which the support plate of the LEDs is made integral, the frame thus allowing the attachment of plate to the hood, and may participate in fixing the device against the surface for which it is intended.

The device may be in the form of a one-piece assembly and is intended to be fixed to a reception surface by fastening means cooperating by clipping with said device. Alternatively, it may be such that the cover is made removable from the support plate, the support plate being intended to be fixed beforehand against a reception surface by appropriate fixing means of the type by screwing or clipping, the cover being secured to the plate by mutual cooperation means arranged inside said device, for example male-female clipping means.

The device is preferably intended to be fixed against a ceiling, which advantageously requires no imposing reservation in the ceiling to the dimensions of the device as in the prior art. Only a reduced hole is required for the passage of the power supply cables and control LEDs, thus minimizing the risk of leaks in its attachment with said ceiling. In addition, this type of arrangement does not deteriorate the rigidity of the ceiling structure.

The device can of course be placed in a wall against a vertical surface type wall or other wall. It may also respond according to such an arrangement dust classes ISO 1 to ISO 4.

• La figure 1 représente une vue en perspective et de dessus d'un dispositif d'éclairage selon l'invention;
• La figure 2 est une vue partielle de côté de la figure 1 ;
• La figure 3 est une vue partielle en coupe de la figure 1 ;
• La figure 4 est une vue partielle de la face externe du capot du dispositif selon une variante de réalisation ;
• Les figures 5a et 5b illustrent un mode de fixation du dispositif;
• Les figures 6a et 6b illustrent une variante de fixation du dispositif ;
• La figure 7 est une vue schématique en coupe partielle d'une variante de réalisation du dispositif.

The present invention is now described with the aid of examples which are only illustrative and in no way limit the scope of the invention, and from the attached illustrations, in which:

• The figure 1 represents a perspective view from above of a lighting device according to the invention;
• The figure 2 is a partial side view of the figure 1 ;
• The figure 3 is a partial sectional view of the figure 1 ;
• The figure 4 is a partial view of the outer face of the hood of the device according to an alternative embodiment;
• The Figures 5a and 5b illustrate a method of fixing the device;
• The Figures 6a and 6b illustrate a variant of attachment of the device;
• The figure 7 is a schematic partial sectional view of an alternative embodiment of the device.

The figure 1 illustrates according to the invention, a lighting device 1 as a whole having a substantially parallelepipedal and flat envelope structure directly intended to be associated, for example with a clean room ceiling.

This structure is flat and homogeneous surface both on its outer surface 10 intended to be affixed against the ceiling and on its opposite outer side 11 intended to illuminate. With regard to the figure 2 , the device has a height h, dimension intended to be transverse to the ceiling and separating the two opposite general faces 10 and 11, between 7 and 12 mm.

The term "height" means the magnitude relative to the dimension intended to be normal to the receiving surface for which the device in the mounted position is intended.

The other dimensions, length and width of the parallelepiped, depend on the use and the location for which the device is intended. The devices may be of square section, with a side for example of 600 mm or 300 mm, or of rectangular section, for example of length 600 mm and width 200 mm.

Thus, the ratio between the height and the width or the length of the device remains less than 0.06.

• assurer son plaquage total contre le plafond sans présence d'interstices qui risqueraient sinon de fournir des zones de rétention de contamination ;
• garantir une libre circulation du flux d'air sur sa face 11 et ses parois latérales en regard de l'environnement de la salle sans gêner les écoulements aérauliques imposés dans la salle.

The extremely flat shape of the device and its height not exceeding 12 mm thus induce in the mounted position in a clean room several advantages including:

• ensure its total plating against the ceiling without any gaps that could otherwise provide contamination retention areas;
• guarantee a free flow of air on its face 11 and its side walls with respect to the environment of the room without impeding the flow aeraulic imposed in the room.

The lighting device illustrated in more detail by the sectional view of the figure 3 comprises a plate 2 for supporting light sources and constituting the back of the device intended to be advantageously directly affixed against the ceiling, and a cover 3 closing the device and forming its facade intended to be opposite the environment of the clean room .

The support plate 2 comprises an outer face 20 facing the outside of the device and an opposite inner face 21 facing the inside of the device, this inner face carrying a printed circuit 4 for example of the isolated metal support type (said "SMI") on which are disposed the light sources 5 formed of light emitting diodes (LEDs) and whose regulation is provided by said circuit 4. The circuit 4 is fixed to the inner face 21 of the plate by screwing and / or bonding, in particular using a thermal adhesive.

The circuit 4 may also be in the form of a plurality of arrays equipped with a multitude of LEDs.

The elements that are the support plate 2 provided with the LEDs and the cover 3 can form a one-piece assembly by the assembly method used, for example by molding, or be removable relative to each other. .

The plate 2 is made of a rigid material chosen in particular from: aluminum, painted steel, copper, an alloy of copper and aluminum, a combination of aluminum and steel.

Plate 2 comprises as illustrated on the figure 2 means 22 for fixing the device against the reception surface, a ceiling. These means are for example here holes that will house fastening means associated with the ceiling. These means could equally well be fastening or fixing projecting means adapted to cooperate with the reception surface.

The cover 3 comprises a substrate 30 extending parallel to the plate 2 and side walls 31 which extend in the direction of a plane containing the plate.

According to the invention and in an illustrated manner on the Figures 2 and 3 , the edges 32 connecting the substrate 30 to the walls 31 are rounded, the concavity being turned towards the inside of the device. This concavity has a radius of curvature of at least 3 mm.

The substrate 30 and the walls 31 may form a unitary piece or alternatively form two separate pieces which are associated with each other to provide a unitary assembly.

In the latter case, when the substrate 30 is independent of the walls 31, they preferably establish a frame 34, as illustrated in FIG. figure 4 provided with a flange 33 extending in the plane of the substrate 30 to provide surface continuity at the rounded-edge edge 32. The flange 33 may comprise a shoulder on which comes to rest the periphery 30A of the substrate 30 which is fixed by gluing or welding according to the types of materials used for the substrate and said frame.

In yet another variant, not illustrated, the walls could be made integral with the plate 2, the cover being intended to be attached against them.

According to the invention and as illustrated on the figure 2 , the side walls 31 have with the virtual plane of extension of the plate 2, and therefore with the ceiling against which the device will be applied, an angular orientation at an obtuse angle α, or present in a complementary manner, an acute angle with the plate 2. In particular, this angle α may be at least 115 °, preferably between 115 and 160 ° The angle is adapted according to the dimensions, height, length and width, imposed on the device.

The low height of the device (less than 12 mm) to which are added the inclination of the walls 31 and the rounded edge edges 32 ensures not to obstruct the flow of air flowing around the device, but instead participates in the stability of the aeraulic flows which advantageously follow the curves of the device.

According to the invention, it is moreover important that the external face 11 of the device corresponding to the external face of the cover 3 opposite the environment of the room is devoid of any asperities. Also it has a coefficient of roughness Ra less than or equal to 0.8 microns, preferably less than 0.4 microns.

As visible on the figure 3 , the support plate 2 carrying the LEDs is associated with the cover 3 via a peripheral frame 6 arranged on the internal face 35 of the cover and the height of which corresponds to the sufficient separation space between the plate 2 and the substrate 30 to accommodate the OF THE.

Depending on the nature of the materials chosen for the peripheral frame 6 and the cover 3 (facade substrate 30 and side walls 31), the frame may be an integral part of the hood or only part of the hood, that is to say be manufactured respectively in one piece with the entire hood (substrate and side walls), or coincides with the only side walls 31 of the hood. The facade substrate, the side walls and the frame can be obtained by plastic injection with particular materials.

The cover 3 is obtained in particular by a method using thermoforming, or injection molding or machining. It can be formed from transparent plastic material (s), and possibly composite material for its side walls for example. As a variant, it may be made of glass, or any other material that, however, incorporates transparent optical elements for the substrate 30 facing the LEDs.

As already said, the substrate 30 may be manufactured independently of the side walls 31 and be secured thereto later.

By way of examples for the plastics material of the cap, and without being limiting, mention may be made of polycarbonate (PC), polymethylmethacrylate (PMMA), high-density polyethylene (HDPE), polyethylene terephthalate (PET), polyethylene glycol (PETg).

For a material other than glass or plastic, the cover, in particular its side walls 31, are for example treated or painted aluminum, painted steel, or bare steel type 300 or 400 series.

Whatever the nature of the constituent material (s) of the cover, the latter can be covered on its outer surface with a polyurethane coating which has the advantage of protecting the outer face of the cover against various cleaning, disinfection or of sterilization implemented in the clean room.

The inner peripheral frame 6 is preferably made of plastic or composite material and is obtained by injection molding or extrusion molding. Its constituent material may be polyamide, polycarbonate (PC) or any other injectable or extrudable thermoplastic resin.

As expressed above, the peripheral frame 6 is made integral with the cover 3 or at least the side walls 31. For this purpose, it is for example manufactured in one piece by molding with the side walls 31 and optionally the substrate 30.

In a particular embodiment, the peripheral frame 6 is designed to associate the support plate 2 LEDs to the cover 3 to provide a lighting device in a one-piece form. Fixing the plate 2 is for example made by screwing its periphery to the frame 6.

Still in this embodiment, the frame 6 also makes it possible to participate in fixing the device to the ceiling.

So with regard to Figures 5a and 5b , the frame 6 has at its face 60 opposite the substrate 30 recesses 61, one of which is visible in the figures. These recesses are for example four in number being distributed at each corner of the parallelepiped forming the device. They cooperate with facing holes 22 arranged in the thickness of the plate 2, so as to receive fastening means 7 of the spring clip type which have been previously fixed to the ceiling 8. The fastening means 7 have been advantageously positioned by means of a template or by any suitable method such as by the use of a laser pointer.

In the variant of Figures 6a and 6b relative to the fixing of the lighting device, it is not monobloc but its cap 3 is made removable vis-à-vis the support plate 2 carrying the LEDs by means of mutual cooperation 90 and 91, the type male and female clips, arranged on the respective inner faces 35 of the cover and 21 of the plate.

The peripheral frame 6 is not necessarily necessary and is not present here, the clipping means 91 being for example co-molded with the walls 31 of the hood. However, alternatively, the peripheral frame 6 is integrated in the device because, made functional not only for the association of the plate 2 to the hood, but also for fixing the device to the ceiling. Thus, the frame has recesses, opposite which the plate 2 has orifices, clipping elements being mounted in the device through the orifices of the plate and being retained in the recesses of the frame. The clipping elements having been mounted prior to fixing the device to the ceiling, it remains, for fixing the device, that clip the latter on mutual cooperation elements integrated ceiling.

Fixing this device to the ceiling 8 is as follows: the plate 2 is first fixed to the ceiling by screwing for example, then the cover 3 is attached against the plate 2 by clipping.

Moreover, regardless of the design variant of the lighting device, monoblock or not, sealing means are provided to ensure a seal against dust and moisture inside the device.

The free ends or slices 36 of the side walls 31 of the cover may or may not be flush with the external face of the plate 2. In the latter case, shown in FIG. figure 7 to avoid the retention of contaminants in the residual space between the device and its receiving surface 8, a seal 92 such as sealant is provided on the edges 36 of the hood

The clean room lighting device of the invention is therefore designed to avoid disruption of the flow of air flowing into the clean room. The device does not obstruct airflow or cause turbulence. There is no risk of contamination retention. It also benefits from a longevity of the device by the use of LEDs.

Claims (10)

Clean room lighting device (1) comprises light-emitting diodes (5) as lighting sources, a support plate (2) for said diodes, and an opposing hood (3) parallel to the support plate , the support plate (2) and the cover (3) forming a closed envelope structure for the device, and this structure having two opposite external main faces (10, 11), parallel and plane, and respectively corresponding to, the face of application and fixation of the device against a reception surface, and the lighting face, the dimension separating these external faces being very substantially smaller than the two other dimensions of the faces, characterized in that the envelope structure comprises lateral walls (31) connecting the two main faces (10, 11) forming, with the virtual extension plane of the main application and fixing face (10), an obtuse angle, preferably between 115 and 160 ° . Device according to claim 1, characterized in that the cover (3) is secured to the plate (2) by mutual cooperation means (90, 91) arranged inside said device. Device according to claim 2, characterized in that the mutual cooperation means comprise clipping means. Device according to any one of the preceding claims, characterized in that it has a height corresponding to the dimension extending transversely to the plane of the support plate, between 7 and 12 mm, or such that the ratio between this height and one of the other two dimensions is less than 0.06. Device according to any one of the preceding claims, characterized in that the side walls (31) of the structure have a curved surface towards the outside of the structure. Device according to any one of the preceding claims, characterized in that the edges (32) connecting the side walls (31) with the main lighting face (11) are rounded concavity turned towards the inside of the device, preferably the concavity having a radius of curvature of at least 3 mm. Device according to any one of the preceding claims, characterized in that the cover (3) is based on plastic material (s), possibly composite, or glass, or aluminum and / or steel incorporating transparent optics, and can be covered on all or part of its external lighting face (11) intended to be opposite the external environment of the device, a protective coating of polyurethane or other type of polymer material. Device according to any one of the preceding claims, characterized in that the external main illumination face (11) designed to face the external environment of the device, has a roughness coefficient of less than or equal to 0.8 μm preferably less than 0.4 μm. Device according to any one of the preceding claims, characterized in that it comprises a peripheral frame (6) associated with the inner face (35) of the cover, this frame being able to be secured to the cover when the hood is molded, and against which is secured to the support plate (2). Device according to any one of the preceding claims, characterized in that it is intended to be fixed against a wall or other type of ceiling or vertical surface.

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