EP1256972A2 - Flat lighting device with a mirror surface - Google Patents

Abstract

The device (1) has a base plate and a front plate joined to an at least partly transparent vessel with an internal ionisable filling, whereby in a partial region of the vessel at least one of the two plates is at least partly provided with a mirror surface and an unmirrored part area of the vessel is formed to implement the illumination function.

Description

Technical field

The invention relates to a flat lighting device, except one Lighting function also has a mirror function, i.e. the lighting device can also be used as an illuminated mirror.

State of the art

Illuminable mirrors are usually realized in that outside the actual mirror surface, for example laterally or above the Mirror surface, one or more separate lights are arranged. The principally shallow installation depth of a mirror is due to the dimensions of the separate luminaire (s) used for the lighting not usable. Suitable lights typically include at least a lamp including lamp holder and any associated Lamp reflector, a lamp housing or a lamp cover and in the case of the use of discharge lamps, for example fluorescent lamps, additionally an electrical control gear.

Presentation of the invention

It is an object of the present invention to provide an improved illuminable To provide mirrors.

This task is accomplished with a flat lighting device Features of claim 1 solved. Particularly advantageous configurations can be found in the dependent claims.

In departure from the structure described above, conventional illuminable The invention proposes mirrors made up of several separate components a flat lighting device with an integrated mirror surface in front.

The lighting device according to the invention is based on a flat lamp, comprising a base plate and a front plate that at least one partially transparent vessel connected to it inside has an ionizable filling.

The connection can be realized for example by means of a frame, which is arranged between and connected to the two plates. In this way, the frame also defines the mutual distance between the both essentially plan plates. The frame usually runs along the edge areas of both panels around the entire area Use both plates as completely as possible for the formation of the vessel to be able to.

The frame can be dispensed with if at least one of the two Plates are suitably convex in their edge area, so the two Form the assembled plates without a frame.

According to the invention, only a partial area of the vessel is used to implement the Lighting function trained. This sub-area preferably extends along at least part of the edge region of the vessel. In the rest The area of the vessel is at least one of the two plates at least partially provided with a mirror surface.

Optionally, the vessel can also be divided into two or more chambers, which are the areas designed for the mirror and lighting functions separate the flat lighting device from each other. To this It is possible to change the ionizable filling to that for the lighting function to restrict the trained area, i.e. only the corresponding one (s) Chamber (s) with the ionizable intended for the discharge Filling to fill. This is particularly the case with relatively expensive fillings, for example Xenon, beneficial. The chamber enclosing the mirror surface can be filled with a cheaper gas (mixture), for example Nitrogen or dried air.

The flat lamp of the lighting device according to the invention is particularly preferred of the type of dielectric barrier discharge lamp, also called dielectric barrier discharge lamp. With this flat lamp type is at least a part of the electrodes from the filling of the discharge vessel separated by a dielectric. The electrodes are for that either arranged on the outer surface of the discharge vessel as in the EP 0 839 436 B1 discloses, wherein the wall of the discharge vessel itself as said dielectric acts. Or the electrodes are on the inner surface of the discharge vessel, in which case the electrodes are additionally covered with a dielectric layer as in the WO 98/43277 discloses. The electrodes are usually in the form of conductor tracks Structures formed on the inner surface, for example Screen printing are applied. Similarly, these are strip-like Electrodes printed with the dielectric layer. For more details for this, reference is made to WO 99/66538.

This type of lamp is preferred in accordance with that disclosed in EP 0 0733 266 B1 pulsed operating processes because it is particularly efficient has proven compared to the conventional mode of operation of dielectric disabled discharges with sinusoidal AC voltage. In any case the polarity of neighboring electrodes is selected alternately. As a result, the discharge burns between adjacent electrodes.

A partial area of at least one of the two plates, for example a partial area the inner surface of the base plate, is with the mirror surface mentioned Mistake. While this mirrored section in a conventional manner acts as a mirror, the non-mirrored section is used for the realization the lighting function, i.e. used as a lamp. For this purpose the non-mirrored section with the above-mentioned electrode structure and printed on the dielectric layer. Only takes place in this section during operation the gas discharge takes place alone or in connection with a on the wall of the discharge tube applied phosphor layer generated light required for the lighting function.

Another advantage is that the lighting device is easy to clean, because the entire front, i.e. Mirror area including lamp area is limited by the flat one-piece front panel.

The area of the mirrored partial area typically corresponds to more than 50%, better more than 60%, preferably more than 70%, particularly preferred more than 80% of the front surface of the front panel, on the one hand for the Use a sufficiently large mirror surface with respect to that for the whole To be able to provide the lighting device required area. on the other hand the area of the non-mirrored section that functions as a lamp be large enough to provide sufficient and as uniform to ensure shadow-free lighting. From that point of view it has proven itself if the area functioning as a lamp is more than 5%, better approx. 10% or more corresponds to the front surface of the front plate.

Description of the drawings

Figur 1a

eine erfindungsgemäße Beleuchtungsvorrichtung mit Spiegelfläche in Draufsicht,

Figur 1b

eine Schnittdarstellung entlang der Linie AB der Beleuchtungsvorrichtung aus Fig. 1a,

Figur 1c

eine Ausschnittsvergrößerung eines Teilbereiches C der Darstellung aus Fig. 1b.

In the following, the invention is explained in more detail using the example of such a dielectric barrier flat lamp, since this appears to be particularly suitable due to the easily automated manufacturing steps, including the printing steps. Nevertheless, conventional flat lamps are expressly included. Show it:

Figure 1a

a lighting device according to the invention with a mirror surface in plan view,

Figure 1b

2 shows a sectional illustration along the line AB of the lighting device from FIG. 1 a,

Figure 1c

an enlarged section of a portion C of the illustration of Fig. 1b.

Figures 1a to 1c schematically show a plan view, a sectional view along the line AB and an enlarged section of a section C of a lighting device 1 according to the invention, comprising a rectangular base plate 2, such a front plate 3, a frame 4 and two partitions 5a, 5b. The components 2 to 5 mentioned are all made of glass.

The one running around the edges of base plate 2 and front plate 3 Frame 4 connects these two plates 2, 3 to a flat vessel. The two partitions 5a, 5b divide this vessel 2, 3, 4 into three cuboid Chambers 6 to 8. The two outer chambers 6, 8 are the same size, elongated and extend along two opposite narrow sides the flat lighting device 1. Each of the two outer chambers 6, 8 serves as a discharge vessel in each case an elongated partial flat lamp, i.e. ultimately to implement the lighting function. Further explanations this will follow below. The middle chamber 7 is significantly larger as the two outer chambers 6, 8 and serves as a mirror. To this The purpose is the inner surface of the base plate 2 in the area of the middle chamber 7 vaporized with a mirror surface 9. The mirror surface 9 corresponds approximately 90% of the base area of the front panel 3.

The two outer chambers 6, 8 are filled with xenon at a cold filling pressure of approx. 10 kPa. Due to the use of relatively expensive xenon, the subdivision of the vessel into chambers 6 - 8 has the advantage that the amount of xenon required can be limited to these chambers 6, 8 which act as discharge vessels. If such cost considerations are irrelevant, spatial division into chambers can also be dispensed with and the entire vessel 2, 3, 4 filled with xenon. Within each outer chamber 6, 8, strip-like electrodes 10 made of silver solder are printed on the inner surface of the base plate 2 and are covered with a glass solder layer 11 acting as a dielectric barrier. A phosphor layer 12 is applied to the inner surface of the front panel 2 within each outer chamber 6, 8. The phosphor layer 12 consists of a three-band phosphor mixture with which white light can be generated. In this case, the phosphor layer 12 converts the ultraviolet radiation (UV) generated during discharge within each outer chamber 6, 8 into visible light. The UV radiation here is molecular band radiation with a maximum at approximately 172 nm, which is emitted by Xe ² * excimers formed in the discharge. The total area of the phosphor layer 12 corresponds to approximately 10% of the base area of the front plate 3. Essentially the entire remaining part of the base area, ie approximately 90%, functions as a mirror due to the mirror surface 9. When the device according to the invention explained above is switched on, diffuse, uniform illumination is achieved.

In the exemplary embodiment explained above, two are Lamp acting, in the plan view of Fig. 1a strip-shaped sections used. However, there are of course only one or more as two such sub-areas glowing in operation encompassed by the invention. For example, it can be advantageous to increase the illuminance be, in the embodiment of Fig. 1a at the top of the lighting device to provide a further partial area functioning as a lamp, i.e. a total of three such subareas or additionally on lower edge of such a partial area, i.e. a total of four. This has opposite an alternatively pure widening of the strip-shaped partial areas the advantage of cheaper lighting distribution. You also have to the sub-areas mentioned are not necessarily strip-shaped but can rather have almost any contours. However taking into account the desired size and shape of the mirror surface. In this context it should be mentioned that the basic form of the invention Lighting device, i.e. ultimately the shape of the two plates, by no means has to be rectangular. Rather, there are also numerous Forms conceivable, the choice of forms being essentially aesthetic Aspects are likely to be decisive.

Claims (10)

Flat lighting device (1), comprising a base plate (2) and a front panel (3) leading to an at least partially transparent Are connected to the vessel, which has an ionizable filling inside having at least one in a partial area of the vessel of the two plates (2) at least partially with a mirror surface (9) is provided and with an unmirrored portion of the vessel for the realization of a lighting function is formed. The lighting device according to claim 1, wherein the non-mirrored Partial area is provided with electrodes (10). The lighting device according to claim 2, wherein the electrodes (10) in the form of a structure similar to a conductor track on the wall of the vessel is arranged. Lighting device according to claim 2 or 3, wherein at least one Part of the electrodes (10) through a dielectric (11) from the ionizable Filling are separated. Lighting device according to one of the preceding claims, the vessel wall in the for the realization of the lighting function trained partial area at least partially with a Phosphor layer (12) is provided. Lighting device according to one of the preceding claims, one or more partition walls (5a, 5) between the plates (2, 3) 5b) are arranged such that the vessel in two or more chambers (6, 7, 8) is divided and thereby the mirrored part of the non-mirrored section is separated. Lighting device according to one of the preceding claims, wherein the two plates (2, 3) by one between the two plates (2, 3) arranged and along the edge areas of both plates (2,3) surrounding frame (4) are connected. Lighting device according to one of the preceding claims, wherein the mirror surface (9) prefers more than 50%, better more than 60% more than 70%, particularly preferably more than 80% of the front surface corresponds to the front panel (3). Lighting device according to one of the preceding claims, where the trained for the implementation of the lighting function Partial region (12) along at least part of the edge region of the Lighting device (1) extends. Lighting device according to claim 9, wherein the portion of the portion (12) more than 5%, better about 10% or more of the front surface of the Front plate (3) corresponds.

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