Abstract:
The invention relates to a light module comprising a backlit surface element, a light source flatly applied to said surface element or connected thereto and to a light system comprising a plurality of said light modules.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to a light module with a backlit surface element in accordance with the preamble of patent claim  1  and to a light system for forming a backlit area. 
       PRIOR ART 
       [0002]    Backlighting a surface element has been known for years from, for example, advertisement boards, traffic signals and direction signs. Recently, however, there has been a demand for individual backlighting of individual subsurface elements, which are assembled to form a mosaic area. This has been observed to an increased extent in the sanitation sector, in which targeted backlighting of individual tiles of a tiled area is desired. In order to backlight the respective tiles, US 2005/0116667 A1, for example, proposes, in FIG. 46, backlighting the individual tiles by means of a light-emitting diode (LED) which has been inserted into a mount. One disadvantage with this solution, however, is the fact that uniform, flat backlighting of the tiles is not achieved by means of the LED. A further disadvantage is the fact that the LED and the mount have a relatively high physical height. 
       DESCRIPTION OF THE INVENTION 
       [0003]    The invention is based on the object of providing a light module with a backlit surface element which allows substantially uniform illumination of a surface element and has a low physical height. Furthermore, it is the object of the invention to provide a light system for forming a backlit area. 
         [0004]    These objects are achieved by a light module having the features as claimed in patent claim  1  or by a light system having the features as claimed in patent claim  10 . Particularly advantageous embodiments of the invention are described in the dependent patent claims. 
         [0005]    The light module according to the invention has a surface element, which is backlit by means of a light source. According to the invention, the light source bears flat against the surface element or is connected to it. The flat arrangement of the light source on the surface element means that the latter is backlit over the whole area and in particular uniformly. As a result, a very good backlighting effect can be achieved since the surface element does not have only one LED directed at it as in the above-described prior art. Furthermore, an advantage of the solution according to the invention is the fact that the mount for holding the light source is no longer required, with the result that the light module has a very low physical height. 
         [0006]    The light system according to the invention has a large number of light modules according to the invention. In this case, the light system can be matched to any desired mosaic areas in particular 
         [0000]    as a result of the flexible relative arrangement of the light modules in relation to one another and as a result of the free shaping of the light modules. 
         [0007]    The light source is preferably an electroluminescence light foil or a corresponding organic LED surface light. 
         [0008]    In order to avoid damage to the light source, it can be covered at the rear by a protective layer, for example a vapor barrier. 
         [0009]    In order to fix the light module on a fixing surface, it may be advantageous if the protective layer is covered at the rear by a backing layer, for example made from plastic. 
         [0010]    In order to be able to connect adjacent light modules electrically to one another, each light module can have at least one plug. This is preferably fixed in the backing layer and can protrude at the side or at the rear, i.e. in the direction of the fixing surface. If the plugs extend in the direction of the fixing surface it is advantageous if a connecting body can be inserted into a receptacle of the fixing surface, which connecting body can be used to produce the electrical contact between the plugs of the adjacent light modules. 
         [0011]    In order to enable individual driving of the light modules, they can have a switch, which is preferably arranged in the region of intersecting conductor tracks for looping through the current from one light module to the next light module and is protected against damage in the backing layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention will be explained below with reference to preferred exemplary embodiments. In the drawings: 
           [0013]      FIG. 1  shows a plan view of a light system according to the invention; 
           [0014]      FIG. 2  shows an enlarged side view of a light module from  FIG. 1 ; 
           [0015]      FIG. 3  shows an enlarged cross section through two interconnected light modules in accordance with a first exemplary embodiment; and 
           [0016]      FIG. 4  shows an enlarged cross section through two interconnected light modules in accordance with a second exemplary embodiment. 
       
    
    
     PREFERRED EMBODIMENTS OF THE INVENTION 
       [0017]      FIG. 1  show a very simplified plan view of a light system  2  according to the invention with a large number of light modules  4   a ,  4   b ,  4   c ,  4   d  according to the invention, which in their entirety form a mosaic area  6  of surface elements  8   a ,  8   b ,  8   c ,  8   d  which can be backlit, gaps or joins shown between the individual light modules  4   a  to  4   d  being illustrated as being very enlarged. The light modules  4   a  to  4   d , as explained in particular with reference to  FIG. 2 , can have any desired shapes and materials and can be combined with one another in a flexible manner, with the result that this light system  2  is suitable for forming any desired mosaic areas  6 . 
         [0018]    The light modules  4   a  to  4   d  are electrically connected to the directly adjacent light modules  4   a  to  4   d  via in each case one plug-type connection  10   a  to  10   d . The light module  4   b  is connected to a ballast  14  via a power supply line  12 , which ballast  14  is electrically connected to a current source (not illustrated). In order to loop through the current from one light module to an adjacent light module, for example from the light module  8   b  to the light module  8   c , the light modules  4   a  to  4   d  preferably have conductor tracks  16   a ,  16   b  which are indicated by dashed-dotted lines and which run in the interior of said light modules. The conductor tracks  16   a ,  16   b  are electrically connected in each case at least with one end section to a plug-type connection  10   a  to  10   d  and are arranged approximately at a 90° angle with respect to one another, with the result that an area of intersection or overlap is created. In the area of intersection of the conductor tracks  16   a ,  16   b , the light modules  4   a  to  4   d  each have a switch  18  which acts as a distribution cross and by means of which the supply of current to the respective light module  4   a  to  4   d  can be interrupted, with the result that the light modules  4   a  to  4   d  can be driven or addressed individually. The actuation of the respective switch  18  takes place via a signal, which is likewise transmitted via the conductor tracks  16   a ,  16   b  as well as the current. 
         [0019]    As is illustrated by way of example with reference to the light module  4   b  in  FIG. 2 , the surface elements  8   a  to  8   d  are each an integral part of the light modules  4   a  to  4   d . As shown by  FIG. 1 , they have a tile-like design and substantially consist of a transparent material such as glass or plastic, for example. However, they can also consist of a different material such as ceramic, marble or slate, 
         [0000]    the layer thickness or layer height being selected to be thin such that these materials also act in a light-transmissive manner. In principle, the configuration and the material are freely selectable and depend on the respective mosaic area  6  to be formed. Likewise, the plug-type connections  10   a  to  10   d  can be formed at any desired sections of the light modules  4   a  to  4   d  and their number can be freely selected, with the result that the light modules  4   a  to  4   d  are combined with one another or can be arranged in relation to one another in any desired manner. 
         [0020]    In each case one light source  22  is arranged flat on an inner surface  20  of the surface elements  8   a  to  8   d . The light source  22  is preferably an electroluminescence foil (EL foil) or an organic LED surface light (OLED surface light) and is connected directly to the surface element  8   a  to  8   d , with it extending ideally over the entire inner surface  20 . The direct connection can take place, for example, via a suitable adhesive or artificial resin. The light source  22  can also be arranged on an outer surface of the surface elements  8   a  to  8   d  which is remote from the inner surface  20 , however. It is, however, also conceivable for the light source  22  to be applied detachably to the inner surface  20 , so that it can be exchanged easily and quickly. 
         [0021]    The supply of electricity to the light source  22  takes place in the case of the light module  4   b  via the power supply line  12 , which, as has already been described in  FIG. 1 , is connected to the ballast  14 . As a result of the direct arrangement of the light sources  22  on the respective surface elements  8   a  to  8   d  and their flat extent, very low physical heights can be realized. Thus, for example, light modules  4   a  to  4   d  with a total physical height h of less than 5 mm 
         [0000]    are possible, with the result that, when the light modules  4   a  to  4   d  are positioned on a fixing surface  24 , they do not protrude very much. 
         [0022]    A protective layer  28  for avoiding damage to the light source  22  is applied to a large surface  26 , which is remote from the inner surface  20 , of the light source  22 , i.e. on the rear. As a result of the hygroscopic properties of the light source  22 , it is advantageous if the protective layer  28  is in the form of a vapor barrier, with the result that in particular the life of the light source  22  can be extended. 
         [0023]    In order to arrange the light modules  4   a  to  4   d  on the fixing surface  24 , for example a wall, a rear side  44 , which is remote from the light source  22 , of the protective layer  28  is covered by a preferably plastic-like backing layer  30 , onto which, for example, mortar can be applied in order to fix the respective light module  4   a  to  4   d  to the wall. The light modules  4   a  to  4   d  therefore each have a sandwich-like construction, with the light source  22  being arranged in a particularly protected manner by meant of the direct arrangement on the respective surface elements  8   a  to  8   d  and the covering at the rear by means of the protective layer  28 , which in turn is covered by the backing layer  30 . The risk of damage to the light source  22  can be further reduced if the backing layer  30  surrounds at least the protective layer  28  and the light source  22  in the form of a casing. 
         [0024]    As shown in  FIGS. 3 and 4 , the plug-type connections  10   a  to  10   d  are each formed by at least two plugs  32   a ,  32   b , which are electrically connected in each case 
         [0000]    to the light source  22  of their light module  4   a  to  4   d . In order to protect the plugs  32   a ,  32   b  from damage, at least sections of them are embedded in the backing layer  30  and terminate flush with it at the rear ( FIG. 2 ). Likewise, the switches  18  are embedded in the backing layer  30  (not illustrated). The plugs  32   a ,  32   b  are arranged in the edge region of the light modules  4   a  to  4   d  and can be in the form of female or male plugs, in the embodiment in the form of male plugs  32   a  electrical connections or data transmission connections  34   a ,  34   b  protruding at the side, i.e. in the direction of an adjacent light module  4   a  to  4   d , or at the rear, i.e. in the direction of the fixing surface  24  ( FIGS. 3 and 4 ). 
         [0025]    The lateral extent of the connections  34   a ,  34   b  of the male plug  32   a  have the advantage, as shown in  FIG. 3 , that on interaction with the female plug  32   b  of an adjacent light module  4   c , the plugs  32   a ,  32   b  can be directly electrically and mechanically connected to one another by means of being pushed together laterally, with the result that the number of electrical interfaces for looping through the current is minimized. 
         [0026]    The use of two male plugs  32   a ,  32   c  with a rear-side extent of their connections  34   a ,  34   b ,  34   c ,  34   d  has the advantage, as shown in  FIG. 4 , that the light modules  4   a  to  4   d  can be fixed detachably to the fixing surface  24  by means of their connections  34   a ,  34   b ,  34   c ,  34   d , with the result that additional auxiliary means for fixing them to the fixing surface  24  can be dispensed with. For this purpose, a plate-like connecting body  36  is arranged in a receptacle  42   
         [0000]    of the fixing surface  24 , which connecting body  36  has corresponding holes  38   a ,  38   b ,  38   c ,  38   d  for the releasable engagement of the connections  34   a  to  34   d . In order to produce an electrical connection between the light modules  4   a  to  4   d  and the respective plugs  32   a ,  32   c , the connections  34   a  to  34   d , in the inserted state, make contact, by means of their respective free end section, with a corresponding electrical contact element  40 , which is accommodated in the connecting body  36  and delimits the holes  38   a  to  38   d  at the bottom. 
         [0027]    The invention discloses a light module with a backlit surface element, against which a light source bears flat or is connected to it, and a light system with a large number of such light modules.