Abstract:
A lightning device includes a component in which a light-emitting diode and adapter electronics are integrated. The component corresponds mechanically and : electrically to an electric light bulb, the adapter electronics converting the voltage usually delivered to a conventional electric light bulb into a voltage required by the light-emitting diode.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention is in the field of lightning devices.  
           [0003]    2. Description of the Background Art  
           [0004]    Miniature electric light bulbs are used in many appliances, including in hand-held medical diagnostic instruments. Their purpose is to illuminate the field to be viewed, for example body parts and body cavities, as brightly as possible.  
           [0005]    Because of the high demands placed on the intensity of the light, miniature electric light bulbs in most cases have a working life of just a few hours. They are also expensive and therefore represent an important cost factor. The high current consumption entails high costs for current supply, for example using chargers for chargeable batteries and using power packs, or high running costs are involved in operating with dry batteries.  
           [0006]    With the availability of light-emitting diodes, in particular diodes emitting white light, there are more and more applications in which electric light bulbs are being replaced by light-emitting diodes. These consume much less current and have a much longer working life than electric light bulbs. However, a disadvantage is that, in order to achieve an illumination equivalent to the illumination obtained using an electric light bulb, a plurality of light-emitting diodes is required (see DE 100 31 685 A1), and elaborate optical devices are in most cases needed in order to focus the light of the individual LEDs into a homogeneous luminous field. Another disadvantage is that light-emitting diodes are available only for certain operating voltages and, for this reason, electronic adaptation to conventional current supplies is necessary unless altogether different current supplies are required.  
         SUMMARY OF THE INVENTION  
         [0007]    The invention relates to lightening device comprising a light-emitting diode, in particular, in particular for use in medical diagnostic instruments.  
           [0008]    The object of the invention is therefore to make available lightning device comprising a light-emitting diode which has a similar mechanical construction and a similar electrical function to conventional light bulbs.  
           [0009]    According to the invention, this object is achieved by a lightning device in which a light-emitting diode (LED) and adapter electronics are integrated in such a way that the light-emitting diode can be operated using a standard type of power supply. The outer geometry of the lightning device comprising the light-emitting diode and adapter electronics is so configured that it fits into customary sockets.  
           [0010]    In this way it is possible to use existing devices with conventional current supplies and to utilize the advantages of the light-emitting diodes without limitation.  
           [0011]    In a preferred embodiment, a focussing optical system, in the simplest case a positive lens, is integrated into the transparent part of the housing of the lighting device. By this means it is possible to distribute the light more uniformly across the field to be illuminated, so that it is not necessary to use a plurality of light-emitting diodes and, instead, a single light-emitting diode is sufficient to illuminate the field. In this way light-emitting diodes can also be used in devices, in particular medical diagnostic instruments, in which there is only one seat or socket for the lighting means. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    Embodiments of the invention will now be described with reference to the attached drawings in which:  
         [0013]    [0013]FIG. 1 illustrates a known miniature electric light bulb having a screwable lamp socket and a condenser lens,  
         [0014]    [0014]FIG. 2 illustrates a known miniature electric light bulb having a pluggable lamp socket without optical system,  
         [0015]    [0015]FIG. 3 a miniature electric lighting device in accordance with the present invention having a screwable lamp socket and a condenser lens,  
         [0016]    [0016]FIG. 4 a miniature electric lighting device in accordance with the present invention having a pluggable lamp socket without optical system. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    The known miniature electric light bulb  10  shown in FIG. 1 comprises a light-proof cylindrical lamp housing  14  at the right end of which, as shown in FIG. 1, a screwable lamp socket  12  is arranged. Two lead wires  16 ,  18  are connected to lamp socket  12  in a known manner. A coiled glow filament  20  arranged within lamp housing  14  is connected to the ends of lead wires  16  and  18 , respectively. Filament  20  is arranged within a cone-shaped glass body  22 . Glass body  22  extends beyond the right end of cylindrical housing  14 , as shown in FIG. 1. The projecting end of glass body  22  is formed as lens cone  24 .  
         [0018]    The miniature electric light bulb  30  shown in FIG. 2 comprises a pluggable lamp socket  32  which is arranged at one end of a cylindrical lamp housing  34 . Within lamp housing  34 , a glass cone  42  is arranged in such a way that it projects beyond that end of lamp housing  34  which opposes lamp socket  32 . Within glass cone  42 , a coiled glow filament  40  is arranged which is connected to lead wires  36 ,  38 , the lead wires  36 ,  38  being connected to lamp socket  32 .  
         [0019]    A first embodiment of a miniature electric lighting device  50  in accordance with the present invention is illustrated in FIG. 3; miniature electric lighting device  50 , similar to miniature electric light bulb  10  of FIG. 1, comprises a screwable lamp socket  52  which is mounted to the right end of a cylindrical lamp housing  54 , as shown in FIG. 3. Within lamp housing  54 , adapter electronics  60  are arranged which are connected to lamp socket  52  through lead wires  56 ,  58 . At the end of adapter electronics  60  remote from lamp socket  52 , an LED (light emitting diode)  62  is arranged which is connected to adapter electronics  60 . The end of lamp housing  54  remote from lamp socket  52  is sealed by a condenser lens  64 , which condenser lens  64  divergently or convergently emits light emitted by LED  62 .  
         [0020]    The dimensions of lamp socket  52  and lamp housing  54  of miniature electric lighting device  50  in accordance with the present invention substantially correspond to the dimensions of lamp socket  12  and lamp housing  14  of the known miniature electric light bulb  10  shown in FIG. 1, so that in an illumination device known miniature electric light bulb  10  can be replaced by miniature electric lightning device  50  of the present invention.  
         [0021]    The miniature electric lightning device  70  shown in FIG. 4 comprises a pluggable lamp socket  72  corresponding to lamp socket  32  of known miniature electric light bulb  30  of FIG. 2. As shown in FIG. 4, lamp socket  72  is arranged at the right end of a lightproof cylindrical lamp housing  74 . Within lamp housing  74 , adapter electronics  80  are arranged which are connected to lamp socket  72  through lead wires  76 ,  78 . Connected to adapter electronics  80  is a LED  82 . The LED  82  comprises a dome-shaped illuminant body  84 , which on its end facing lamp socket  72  comprises a ring flange  90 , which ring flange  90  abuts against a ring flange  88  of lamp housing  74 , the ring flange  88  extending inwards. The dome-shaped body  84  of LED  82  extends through the left end of lamp housing  74 , as shown in FIG. 4.  
         [0022]    The dimensions of lamp housing  74  and lamp socket  72  of miniature electric light bulb  70  in accordance with the present invention substantially correspond to the dimensions of lamp housing  34  and lamp socket  32  of the known miniature electric light bulb  30  shown in FIG. 2, so that in an illumination device known miniature electric light bulb  30  can be replaced by miniature electric light bulb  70  of the present invention.