FR2763742A1 - Single unit compact fluorescent lamp - Google Patents

Abstract

The compact fluorescent lamp is supplied directly from the mains via an electronic circuit fitted in the base (4) of the lamp itself. The fluorescent tube is wound in a coil (1) and enclosed in a protective outer sleeve (2). The outer sleeve is held clear of the fluorescent soil by spacers (3) distributed along the length of the lamp. The lamp is cooled by allowing air to enter the interior of the protective outer sleeve through holes (8) formed at the edge where the outer sleeve joins the lamp base (4). The equalisation of pressures inside and outside the outer sleeve improve the mechanical strength of the outer sleeve, making handling safer.

Description

 The present invention relates to lighting sources commonly known as "compact fluorescent" or "CFL" lamps <compact fluorescent lamps which have an integrated ballast and can thus operate independently on the sector.

 Devices of this kind. as they are presently described by the prior art have the drawbacks listed below.

Firstly, if we consider the safety of use, in the majority of cases, the use of such a product presents undeniable dangers for the user.

Indeed, even if the instructions strictly forbid it, the thin glass tube which constitutes the discharge chamber most often serves as a handle for screwing the lamp onto the luminaire.

As the internal pressure existing in this tube is very different from the atmospheric pressure, an awkward gesture is enough for the lamp to implode in the hand with all the risks of injury, burns and electrocution that this implies.

Secondly, if we consider the risks of intoxication of the user, in the hypothesis which has just been mentioned, mercury vapor and highly toxic wphosphoresW can then spread in the confined atmosphere that we proposed to light.

Third, Considering the ease of maintenance, due to the fragility of such a tube, it is impossible to clean all of the surface without danger.

Thus, when this type of lamp is exposed to intense pollution, as is the case in a kitchen, a dirty opaque layer is deposited there which, by thickening, reduces each day more the light emitted as well as the advantages that the user could be entitled to expect such a bright source.

Fourthly, if we consider the luminous efficacy of current compact fluorescent lamps, this is further hampered by the fact that these lamps include a base made of opaque molded material which, unlike conventional incandescent lamps , prohibits any emission of light in the area corresponding to a wide solid angle, coaxial with the fixing socket, this reducing the good distribution of the emitted photons.

Fifth, if we consider pollution, in addition to the fact that highly toxic products may be randomly released into the environment, said lamp is made of a plastic material which, most often is non-recyclable and is added to global pollution.

 Devices according to the prior art have attempted to correct these drawbacks.

Certain compact fluorescent lamps produced by Japanese manufacturers provide a solution to these drawbacks.

This solution comes down to fitting the above fluorescent tube into a polycarbonate globe. which effectively protects from the risks stated above.

Indeed, it is necessary to give a large volume to this type of globe in order not to cause the excessive heating of the aforesaid fluorescent tube, heating which would lead to a drastic reduction in the light output and the lifetime characterizing the latter.

However, building a robust large-scale globe in thin glass is illusory, this is why, it is necessary to use, to do this, either a thick and too heavy tempered glass, or plastic material called wpolyearbonatew which brings lightness and and excellent impact resistance.

The major drawbacks resulting from such a solution are: a prohibitive additional cost, an increase in non-recyclable materials and an unacceptable increase in volume.

It is for these low economic reasons that the large manufacturers of compact fluorescent lamps currently leave the user at the mercy of a product that can prove dangerous for him and our environment.

 The device according to the invention makes it possible to eradicate, without additional cost, the drawbacks listed above.

Figure 1, attached, illustrates the device, object of the invention, in an axial section.

This section, made along a longitudinal plane, shows the straight sections 1a ... 1k of the fluorescent tube 1 which, according to this embodiment, is shaped according to a spiraloid.

The fluorescent tube 1 rests at the bottom of the flared part of the envelope sheath 2 which consists of a translucent material, which can advantageously be glass.

The fluorescent tube 1 is held in place in said envelope sheath 2 by means of the drops of glue 3a, 3b, 3c and 3d, which ensure, in addition to effective fixing of said fluorescent tube, protection against any hard impact between the latter and said envelope sheath.

The translucent envelope sheath 2 narrows in its lower part Until constituting the truncated-cylindrical sleeve 4 which conforms to the prescriptions of the standards concerning the standard devices of type wu27 ", wu22", etc ...

allowing the connection of the lamps to the luminaires supplied by the sector.

The external surface of the sleeve 4 is coated with a conductive metallic layer.

This metallic thin layer is obtained by vacuum metallization or any other method ensuring good adhesion of the conductive particles on the surface of said sleeve which is molded in an insulating material such as glass.

The metallized zone 6 of the socket 4 takes the place of a central block of type E27 or of blocks of type B22.

 This metallized zone 6 is separated from the metallized zone covering the frusto-cylindrical part of the sleeve 4 by a non-metallized zone which guarantees a bypass distance respecting the standards in the matter.

 One or more holes pass through the wall of the material constituting the sheath 2 in zone 6.

 Likewise, at least, a bore 5 will be made in the material constituting the sheath 2, at the level of the aforesaid frusto-cylindrical part.

 These different holes will allow the passage and the welding on the peripheral metallization, of wires coming from the central part of the socket 4, which contains a device 7 called "electronic ballast", capable, from the AC sector, of supplying the voltage d priming and the maintenance current required by the discharge tube 1.

 Thus, the external surface of the end 4 of the envelope sheath 2, serving as a standardized socket, receives, at least, two metallization zones corresponding respectively to the holes 5 and 6, this allowing the inputs of the electronic module 7 to be connected to the sector, after connection of said socket.

 At the lower part of the fluorescent tube 1 are made in the wall of the material constituting the sheath-envelope 2, one or more calibrated nozzles 8a and 8b, which have the function of ensuring the flow by natural convection of a given heat transfer air flow, as soon as the heating caused by the operation of said fluorescent tube begins to be felt in this confinement.

 By suitably calculating the area of the nozzles 8a and 8b as well as their location, it is then possible to obtain almost perfect regulation of the operating temperature of the fluorescent tube 1, which makes it possible to expect optimal light output therefrom.

 Indeed, as we know, the luminous efficacy of this kind of fluorescent tube depends essentially on the effects of ambient temperature on its operating temperature.

 For this reason, with the device according to the invention it is possible to preset the total area of the nozzles 8a and 8b according to the climatic conditions of use.

 In this way, it is possible to maintain the operating temperature of the fluorescent tube 1 at a substantially constant value in a place having a given annual average temperature.

 Thus, when the lamp according to the invention is fixed in a vertical position, the mass of air circulating per unit of time inside the cylinder constituting the sheath envelope 2, under the effect of natural convection, will be substantially stable and will depend practically only on the section of the nozzles 8a and 8b.

 Therefore, it is advantageous to keep a maximum section at the opening 9 of the envelope sheath.

 In fact, such an arrangement makes it possible, during assembly of the lamp according to the invention, to insert the preassembled device in block in the envelope thus formed.

 Under these conditions, after welding of the wires leading to the pads 5 and 6, overmolding of the module 7 inside the socket 4 and placing drops of glue 3a, 3b, 3c and 3d, the assembly of said lamp is completed.

 Thus constructed, the device according to the invention provides excellent protection to the fluorescent tube 1 which no longer runs the risk of being grasped directly by the user with the consequences that we know.

 The operating temperature of the fluorescent tube 1 can be substantially maintained at a value optimizing the light output.

 The light emission can be carried out in all directions, especially, if care is taken to overmold the module 7 with a resin, not opaque, but translucent.

 In fact, the device according to the invention, especially if it is constructed from a glass envelope sheath 2, has only a minimum of opaque zones liable to hinder the path of the photons emitted by the tube 1.

 Figure 2, attached, illustrates a second embodiment of the device, object of the invention.

 According to this embodiment, the envelope sheath 2 consists of two separate parts 2a and 2b which are assembled together on their joint plane 10 which can be provided with lips allowing their self-assembly.

 Before said assembly, the upper part of the fluorescent tube 1 is fixed by the drops of glue 3e, 3f, 3g and 3h in the upper part 2a of the envelope sheath 2.

 This makes it possible to rigorously position the fluorescent tube 1.

 In fact, this kind of fluorescent tube, spiraled or simply of a standard curved type, is difficult to fix in its lower part, the mechanical dimensions of which are impossible to hold due to the rather imprecise welding of the preheating cathodes.

 Maintaining thus, from above, the fluorescent tube 1 which is thus suspended inside the part 2a, makes it possible to solve this problem while making it possible to free the emissive surface of said fluorescent tube as well as possible.

 Therefore, it is then possible to provide a large air gap between the lower part of the fluorescent tube 1 and the upper face of the module 7, which induces the following advantages.

 On the one hand, the light emitted by the lower part of the fluorescent tube is better dispersed in space.

 On the other hand, the space existing between the hottest part of said fluorescent tube and the electronic module 7 makes it possible to reduce the heating by conduction and by convection thanks to the air circulation caused by the nozzles 8a and 8b.

 In order to perfect this result, it is advantageous to stick on the electronic module 7 a reflective plate 11, which has the function of eliminating a large part of the infrared emitted by the lower part of the fluorescent tube 1.

 According to this embodiment, the circular opening 9 described above is replaced by one or more nozzles 8c and 8d whose total section is calculated to ensure, in relation to the lower nozzles 8a and 8b, sufficient air transit for the inside the sheath wraps 2å / 2b.

 Thus, the envelope sheath consists of at least two separate parts 2a and 2b, the first of which maintains the fluorescent tube 1 in its upper end and the second, in its lower end, the electronic module 7, nozzles 8a and 8b of section suitable being provided in said lower end while other nozzles 8c and 8d of suitable section are provided in said upper end.

 The nozzles 8c and 8d can be replaced by a single circular opening of sufficiently small diameter so that the fluorescent tube 1 can be easily bonded.

 This embodiment remains, moreover, quite similar to the first and has the same advantages compared to the prior art.

 The device, object of the invention, as just described solves the problems encountered with the products manufactured according to the prior art.

 Thus, the fluorescent tube 1 escapes direct contact with the user's hand thanks to the envelope sheath 2 whose diameter is small enough to offer good mechanical strength, including when the thickness of the latter is small.

 In this way the risks of injury by implosion of said fluorescent tube are eliminated, the risks of burns, the risks of electrocution and the risks of projection of toxic materials.

 Likewise, the fluorescent tube 1 is sheltered from air currents which destabilize its discharge current, which allows it to operate under a substantially regulated temperature, which makes it possible to hope for a luminous flux and a duration maximum life.

 On the other hand, this device makes it possible to obtain a better distribution of light in the space going hand in hand with a significant reduction in the heating of the electronic module 7, the reliability of which can thus be seriously improved.

In addition, the device according to the invention can lend itself to all kinds of decorative variants, in particular by coloring the glass or the translucent material constituting the envelope sheath 2.

This allows for example to use, for the glass or the translucent material constituting the parts 2a and 2b respectively, different colors.

In the same way, it is possible to deposit on the wall of said envelope sheath advertising graphics that the light emitted by the fluorescent tube 1 will enhance.

In addition, if the device according to the invention is made of glass, an economical and recyclable material, the pollution due to the proliferation of this type of inexpensive lamp will only increase mFdlocreDent planetary pollution.

The device according to the invention, as just described, can be lent to the economical manufacture of high-performance luminaires, disposable or not.

 It goes without saying, and as it follows from the above, the present invention is in no way limited to the modes of application and embodiment more particularly envisaged, it embraces, on the contrary, all the variants.

Claims (14)

 1. Autonomous device, called "compact fluorescent lamp", comprising a fluorescent tube 1, the ignition voltage and the maintenance current are delivered by an electronic module 7 housed in the base of said device, which comprises a standardized socket 4 allowing the connection of said electronic module to the AC sector, characterized in that the fluorescent tube 1 is fixed inside a translucent envelope sheath which is provided, at one of its ends, with an opening 9 or nozzles 8c and 8d and, at the other of its ends, calibrated nozzles 8a and 8b, the cross section of which is suitably chosen makes it possible to regulate the flow of heat-carrying air passing through said casing, so that it serves, on the one hand mechanical protection for the fluorescent tube 1 and on the other hand thermal protection capable of regulating its operating temperature.  2. Device according to claim 1, characterized in that the envelope sheath 2 is constituted by a single piece of translucent material.  3. Device according to claim 2, characterized in that the envelope sheath is constituted by a piece of glass.  4. Device according to claim 1, characterized in that said envelope sheath consists of at least two separate parts 2a and 2b, the first of which maintains in its upper end the fluorescent tube 1 and the second, in its lower end, the module electronic 7, nozzles 8a and 8b of suitable section being provided in said lower end while other nozzles 8c and 8d of suitable section are provided in said upper end.  5. Device according to claim 2, characterized in that the parts 2a and 2b are made of glass.  6. Device according to claim 2, characterized in that the fluorescent tube 1 is fixed in the upper end of the part 2a by means of a bonding making it possible to maintain it according to rigorous dimensions.  7. Device according to claims 1, 2, 3, 4, 5 and 6, characterized in that the electronic module 7 is overmolded by casting or injection of a plastic resin inside the end 4 of said sheath which envelope is conformed according to a standardized socket for connection to the AC network.  8. Device according to claim 7, characterized in that the face of the electronic module 7, facing the fluorescent tube 10, is provided with a plate capable of reflecting the infrared radiation emitted by said fluorescent tube.  9. Device according to claims 1, 2, 3, 4, 5, 6, 7 and 8, characterized in that the external surface of the end 4 of the envelope sheath 2, serving as a standardized socket, receives, at least, two metallization zones corresponding respectively to the holes 5 and 6, this allowing the inputs of the electronic module 7 to be connected to the sector, after connection of said socket.  10. Device according to claims 1, 2, 3, 4, 5, 6, 7, 8 and 9, characterized in that the glass or the translucent material constituting the above sheath envelope is colored.  11. Device according to claim 10, characterized in that the glass or the translucent material constituting the parts 2a and 2b are colored differently.  12. Device according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11, characterized in that the wall of the aforesaid sheath envelope receives advertising graphics.  13. Device according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12, characterized in that the fluorescent tube 1 is shaped in a spiral.  14. Device according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, it and 12, characterized in that the fluorescent tube 1 is of a standard curved type.