Patent Abstract:
A luminous module for mounting in a household appliance has a housing that is embodied in such a way as to receive a luminous element. The luminous module further contains a first optical wave guide having a light admission surface via which light emitted by the luminous element enters the first optical wave guide, and a light output surface via which the light emerges from the luminous module. The housing is embodied in such a way as to alternatively receive a first luminous element and a second luminous element that is different from the first.

Full Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates to an illuminating module for mounting in a domestic appliance with a housing which is designed for receiving an illuminating element, and in which is arranged a first light conductor which has a light admission surface through which light escaping from the illuminating element enters the first light conductor, and which has a light exit surface from the light escapes from the illuminating module. 
     Such an illuminating module is disclosed in DE 100 64 118 A1, which describes a domestic appliance with a trademark in which the trademark consists of a structural element or an assembly of a transparent or translucent material, and which is connected to at least one light source fitted on the inside of the housing in such a manner that the outer surface of the trademark radiates light in the forward direction when the light source is switched on. The illuminating module of prior art must be produced specially for the application, which in a multiplicity of domestic appliance variants results in an equally large number of illuminating module variants to be specially produced. 
     SUMMARY OF THE INVENTION 
     The object of this invention is to indicate a universally low cost illuminating module for mounting in a domestic appliance. 
     This object is achieved by an illuminating module with the features of Claim  1 . 
     The illuminating module has a housing which is designed for receiving an illuminating element. In the housing is arranged a first light conductor of transparent or translucent material which has a light admission surface and a light exit surface. Light escaping from the illuminating element enters the light admission surface and is admitted to the first light conductor, and the light escapes from the light exit surface and from the illuminating module. Because the housing is designed for alternately receiving a first illuminating element and a second illuminating element that is different from the first element, the illuminating module can be equipped with an illuminating element that is optimised to the situation without its housing having to be modified. 
     In the illuminating module the first illuminating element may have at least one second light conductor. The illuminating module may therefore be used as a passive illuminating module on positions in a domestic appliance on which an electrical power supply is not desirable or not possible. 
     Furthermore, the second illuminating element may have a support plate, in particular a circuit circuit board, with at least one light source, so that light can be generated directly in the illuminating module. The illuminating module may therefore be used as an active illuminating module on positions on which a power supply is possible without problem. 
     At least one functional element is formed on the housing of the illuminating module. The functional element can be formed easily and inexpensively on the housing. The functional element can be formed particularly easily and inexpensively on the housing if the housing and the functional element are produced in one piece from the same plastic. 
     In particular, the functional element as a stop element with which the first light conductor and/or the first illuminating element and/or the second illuminating element is releasably secured in the housing and/or with which the illuminating module can releasably secured with a module receiving device. The illuminating module may therefore be equipped extremely easily with different first light conductors to enable different indications to be displayed. For example, the first light conductors are distinguished by differently designed light exit sides which display different symbols or letters which can be moulded into the light exit side, formed on the light exit side or impressed upon the light exit side. The different symbols or letters may also be formed at other points on the first light conductor instead of on the light exit side, e.g. on a side opposite the light exit side or in the volume of the first light conductor. On the insides of the housing at least one further stop element can be formed with which the first and/or the second illuminating element can be secured in the housing. The stop element is designed particularly advantageously so that both a circuit board with one or a plurality of light emitting diodes and, as an alternative to this, a second light conductor can be secured in the housing. On the one hand the illuminating module can be designed as an active illuminating module with its own light source, and on the other it can be designed as a passive illuminating module with light from a remote light source directed into the illuminating module. On the outside of the housing can be formed at least one further stop element with which the illuminating module can be secured in a module receiving device of the domestic appliance. The connection between the illuminating module and the module receiving device may therefore easily be loosened again and the illuminating module can be removed from the module receiving device so that it can be exchanged, for example, for another module or so that individual components of the illuminating module can be replaced. 
     The functional element is advantageously designed so that it is spring-mounted. In particular, the housing has a spring mounting for the first and/or second illuminating element so that the first and/or the second illuminating element can easily be mounted in the housing by bending the spring mounting from its position of test. 
     In a preferred embodiment the housing has at least one light reflecting inner surface. The luminosity of the illuminating module can therefore be increased since light which falls onto the reflecting inner surface of the housing is reflected instead of absorbed by it and is therefore continues to be available for radiation from the illuminating module. 
     The first light conductor is advantageously designed in the shape of a parallelepiped and, in particular, has a light exit surface which is perpendicular to the light admission surface. The first light conductor can therefore be manufactured inexpensively and assembled in the housing particularly easily. 
     According to a preferred embodiment the first illuminating element and/or the second illuminating element has direct contact with the light admission surface of the first light conductor, as a result of which the position of the coupling of the light from the first or second illuminating element into the first light conductor is extremely high. 
     In order to achieve as uniformly distributed light radiation over the light exit surface of the first light conductor as possible, the light exit surface and/or the surface of the first light conductor opposite the light exit surface has a structured surface. It is also possible to equip the light exit surface with a diffuser foil or to manufacture the first light conductor from diffuse material in order to obtain uniform light radiation. 
     The illuminating module can be secured releasably in a module receiving device of the domestic appliance, wherein the module receiving device is preferably arranged behind a screen of the domestic appliance. However, the module receiving device may also be arranged in front of or behind any other parts of the domestic appliance which are to be illuminated. For example, the module receiving device may be formed by stop hooks which are formed on the back of the screen and which engage in stop lugs of the illuminating module for mounting the illuminating module, which lugs are in turn formed on the housing of the illuminating module. 
     In particular, the screen may be a grip plate for an object that is movable on the domestic appliance, e.g. a detergent drawer or a door or a hood or flap of the domestic appliance. An optical display can be provided on these moving parts of the domestic appliance by using a second light conductor for feeding light into the illuminating module. An electrical connection for the illuminating module is difficult to obtain on these parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention and its embodiments are explained in greater detail in the following with reference to drawings, 
       in which 
         FIG. 1   a  shows a perspective view of an illuminating module without an illuminating element obliquely to the light exit surface; 
         FIG. 1   b ,  1   c  each show an enlarged section of the illuminating module according to the invention from  FIG. 1   a;    
         FIG. 2   a  shows the illuminating module from  FIG. 1   a  with a second light conductor as illuminating element; 
         FIG. 2   b  shows the second light conductor according to  FIG. 2   a;    
         FIG. 3   a  shows the illuminating module from  FIG. 1   a  with a circuit board fitted with four light emitting diodes as the illuminating element, and with a diffuser foil above the light exit surface; 
         FIG. 3   b  shows the circuit board according to  FIG. 3   a;    
         FIG. 4   a  shows a perspective view of the rear side of a screen of a domestic appliance with the assembled illuminating module according to  FIG. 3   a  viewed obliquely from the rear side of the illuminating module; 
         FIG. 4   b  shows a front view of the screen according to  FIG. 4   a;    
         FIG. 5   a  shows a front view of a domestic appliance with an assembled illuminating module according to  FIG. 2   a;    
         FIGS. 5   b,    5   c  each show a perspective view of a detergent dispenser tray of the domestic appliance according to  FIG. 5   a,  viewed oblique from above. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1   a  shows an illuminating module  1  according to the invention, with a housing  2  and with a first light conductor  3  arranged in housing  2 . The first light conductor  3  is designed in the shape of a parallelepiped, and has a light admission surface  4  and a light exit surface  5 , wherein light exit surface  5  is essentially perpendicular to light admission surface  4 . Housing  2  comprises the first light conductor  3  with a rear wall  6  opposite light exit surface  5  of the first light conductor  3 , with a first longitudinal wall  7  arranged adjacent to light admission surface  4 , with a second longitudinal wall  8  opposite this first longitudinal wall  7 , with a first transverse wall  9  connecting the first longitudinal wall  7  and the second longitudinal wall  8 , and with a second transverse wall  10  opposite the first transverse wall  9 . Housing  2  is designed so that it is open on light exit surface  5  of the first light conductor  3 . The internal sides of housing  2 , in particular that of rear wall  6  and the second longitudinal wall  8 , may be designed so that they are light reflecting. 
     On the first transverse wall  9  and on the opposite second transverse wall  10  are formed stop elements  11  with which the first light conductor  3  is retained in housing  2 . Furthermore, guiding elements  12  are formed on the first or second transverse wall  9 ,  10  for exact positioning of the first light conductor  3  in housing  2 , and rear wall  6  has pins  13  formed on it which engage through recesses of the first light conductor  3 , thereby determining the exact position of the first light conductor  3 . Stop elements  11 , guiding elements  12  and pins  13  are, in particular, formed in one piece on housing  2 . 
     Inside housing  2  a receiving region  14  for receiving an illuminating element is formed between light admission surface  4  of the first light conductor and the first longitudinal wall  7  of housing  2  arranged adjacent to it, which illuminating element is able to supply illuminating module  1  with light. Two stop elements  15 , for mounting the illuminating element, are formed on the first longitudinal wall  7  of housing  2 . An enlarged representation of stop element  15  is shown in  FIG. 1   b.  Stop element  15  is resiliently formed on housing  2  and has a stop nose  16  which is designed with an arc-shaped groove  17 . Furthermore, a sprung mounting  18  is formed on the first transverse wall  9  of housing  2 , which mounting can be bent from its position of rest when the illuminating element is assembled. Moreover, housing  2  has on its second transverse wall  10  a recess  19  through which the illuminating element can be threaded when mounted in receiving region  14 .  FIG. 1   c  shows an enlarged representation of the second transverse wall  10  with recess  19 . On the outside of the second transverse wall  10  are formed, above recess  19 , two retaining elements  20  with which an exact position of the illuminating element can be established in receiving region  14  when assembling the illuminating element in illuminating module  1 . 
       FIG. 2   a  shows illuminating module  1  according to  FIG. 1   a,  with a second light conductor  21  mounted in receiving region  14 , and  FIG. 2   b  shows the second light conductor  21 . The second light conductor  21  has a rod-shaped design and has a light coupling surface  22 , an end face  23  opposite light coupling surface  22  and a light uncoupling surface  24  arranged at right angles to light coupling surface  22  or end face  23 . The rear surface  25  of the second light conductor  21  opposite light uncoupling surface  24  has a curved design. Furthermore, the second light conductor  21  is divided into a light supply region  26  and a light discharge region  24 . wherein the second light conductor  21  has a first step  28  between both these regions  26 ,  27 , then on light supply region  26 , a first step  28  and perpendicular to this a second step  29  whereby the second light conductor  21  can be retained in receiving region  14  of housing  2 . The second light conductor  21  can be coated with a light reflecting and/or opaque coating, with the exception of light coupling surface  22  and light uncoupling surface  24 , so that light which enters light coupling surface  22  of the second light conductor  21  from a light source (not shown) can only escape again from light uncoupling surface  24 . 
     When the second light conductor is assembled in receiving region  14  of illuminating module  1  according to  FIG. 1   a  and  FIG. 2   a,  the second light conductor  21 , with its light supply region  27 , is threaded through recess  19  of housing  2  so that light supply region  27  projects laterally from housing  2 . Stop elements  15  are bent from the position of rest and the second light conductor  21  is pushed into receiving region  14  so that light uncoupling surface  24  comes into direct contact with light admission surface  4  of the first light conductor  3 . When the second light conductor is assembled stop elements  15  each solidly enclose the curved rear surface  25  of the second light conductor  21  with the arc-shaped groove  17  of their stop noses  16 . The second light conductor  21  rests with its end face  23  and its first step  28  against guiding elements  12  of housing  2  and with its second step  29  on second transverse wall  10  above recess  19 , and is in this manner fixed in receiving region  14  of housing  2 . 
     The second light conductor  21  may have its own housing and may be manufactured, for example, as a two-component injection moulding. Furthermore, the second light conductor  21  may be composed of a plurality of second individual light conductors which are held together by a common housing, for example, or are inserted individually in receiving region  14  of illuminating module  1 , and there retained. The second individual light conductors may be differently coloured in the case of light sources with the same light colouring. Moreover, the first light conductor  3  in housing  2  may also be composed of a plurality of first individual light conductors which are arranged with their light exit surfaces  5  adjacent to or behind each other, wherein the first individual light conductors may have different symbols and/or letters and/or colours. It is therefore possible to assign to each of the first individual light conductors a second individual light conductor, whereby each of the first individual light conductors can be supplied separately with light. 
       FIG. 3   a  shows illuminating module  1  according to  FIG. 1   a  with a support plate  30  fitted in receiving region  14  and  FIG. 3   b  shows support plate  30 . Support plate  30  is designed as a rod-shaped circuit board and is fitted in its light discharge region  31  with four light emitting diodes  32 . Support plate  30  has at one of its end a contact region  33  for electrical connections. Furthermore, support plate  30  is provided at its end opposite contact region  33  with a notch  34  and with a groove  35  between light discharge region  31  and contact region  33 . 
     When support plate  30  is assembled in receiving region  14  of illuminating module  1  according to  FIGS. 1   a  and  3   a,  support plate  30  is threaded with its contact region  33  through recess  19  of housing  2 , so that contact region  33  projects laterally from housing  2  for simple electrical contacting. Sprung mounting  18  is bent from its position of rest and support  30  is pushed into receiving region  14  so that light emitting diodes  32  are able to come into direct contact with light admission surface  4  of the first light conductor. When support plate  30  is assembled, mounting  18  is engaged in notch  34  of support plate  30  and support plate  30  is engaged with its groove  35  in transverse wall  10  above recess  19  between the two retaining elements  20 , so that support plate  30  is fixed in this manner in receiving region  14  of housing  2 . 
     Support plate  30  may be designed as a rigid or flexible circuit board. Light emitting diodes  32  are able to radiate light at different times and/or indifferent colours. Furthermore, the first light conductor  3  in housing  2  may be composed of a plurality of first individual light conductors which are arranged with their light exit surfaces  5  adjacent to or behind one another, wherein the first individual light conductors may have different symbols and/or letters and/or colours. It is therefore possible to assign a light emitting diode  32  to each of the first individual light conductors, whereby each of the first individual light conductors can be supplied separately with light. To obtain a light radiation that is distributed uniformly throughout light exit surface  5 , a diffuser foil  36  can be fitted over light exit surface  5  of the first light conductor  3 , which foil is fixed by pins  13 . As an alternative to this, the first light conductor  3  may be manufactured from material which diffusely disperses the admitted light. 
       FIG. 4   a  shows a perspective view of a screen  37  of the domestic appliance, with the assembled illuminating module  1  according to  FIG. 3   a,  viewed obliquely from the rear of illuminating module  1 . A module receiving device  38  is formed by three stop hooks  39  formed on screen  37  on the rear side of screen  37 . Stop hooks  39  grip by means of stop lugs  40 , which are formed on housing  2  of illuminating module  1 , whereby illuminating module  1  is retained in module receiving device  38  on the one hand, and can easily be released again from module receiving device  38  on the other. 
       FIG. 4   b  shows a front view of screen  37  according to  FIG. 4   a.  Screen  37  has recesses  38  in the form of an inscription through which the light of illuminating module  1  can be radiated. Recesses  38  can be filled with a transparent material or alternatively the inscription may be designed convexly so that it lies congruently to recesses  38  on light exit surface  5  of the first light conductor  3 , so that when illuminating module  1  is assembled in module receiving device  38  the convexly designed inscription penetrates recesses  38  of screen  37  and forms with screen  37  a flat front face. 
       FIG. 5   a  shows the upper front view of a washing machine  41 , with a grip plate  42  of a detergent dispenser tray  43  behind which illuminating module  1  according to  FIG. 2   a  is mounted. The position of illuminating module  1 , with the second light conductor  21 , is denoted by a dotted line. The second light conductor  21  is coupled with its light coupling surface  22 , to a light source  44  of washing machine  41  when detergent dispenser tray  43  is closed so that illuminating module  1  is supplied with light and the trademark “SIEMENS” is able to light up on grip plate  42  of detergent dispenser tray  43 . 
       FIG. 5   b  shows diagrammatically the detergent dispenser tray  43  when extended, so that a first chamber  45  for receiving detergent for the pre-wash, a second chamber  45  for receiving detergent for the main wash and a third chamber  45  for receiving fabric softener are visible. A second illuminating module  49  is secured behind rear wall  48  of detergent dispenser tray  43 . The second illuminating module  49  has a first light conductor  3  which consists of a first light radiating element  50  for the first chamber  45 , a second light radiating element  51  for the second chamber  46 , and a third light radiating element  52  for third chamber  47 , which are arranged adjacent to each other in illuminating module  49 . The second illuminating module  49  has a second light conductor  21 , which consists of a first light conducting element  53  for supplying light to the first light radiating element  50 , a second light conducting element  54  for supplying light to the second light radiating element  51 , and a third light conducting element  55  for supplying light to the third light radiating element  52 . The positions of the first, second and third light radiating elements  50 ,  51  and  52 , with the first, second and third light conducting elements  53 ,  54  and  55 , are denoted in  FIG. 5   b  by dotted lines. 
     Rear wall  48  of detergent dispenser tray  43  has a recess in the form of a symbol for pre-wash “I” for the first chamber  45 , a recess in the form of a symbol for main wash “II” for the second chamber  46 , and a recess in the form of a symbol for conditioning “*” for the third chamber  47 , through which recess light from illuminating module  49  can be radiated. When detergent dispenser tray  43  is open, the first light conducting element  53  couples to a first light source  56 , the second light conducting element  54  to a second light source  57 , and the third light conducting element  55  to a third light source  58 , so that the first, second and third light radiating elements  50 ,  51  and  52  can be supplied with light independently of each other. The first, second and third light sources  56 ,  57  and  58  may, for example, be differently coloured light emitting diodes, bulbs or in turn light conductors which transmit light from a remotely arranged light source. Depending on the set washing programme, the first, second and third light sources can be switched on by a washing machine control system (not shown) before the start of the washing programme when detergent dispenser tray  43  is fully open. The symbol for pre-wash “I” therefore now lights up on rear wall  48  of detergent dispenser tray  43  when a washing programme with pre-wash is selected, so that it is indicated to a user whether the first chamber  45  must be filled with detergent or not. The same applies to the display of the symbol for conditioner. 
       FIG. 5   c  shows an alternative design of detergent dispenser tray  43 . Light coupling surface  22 . Viewed from illuminating module  1  mounted behind grip plate  42  of detergent dispenser tray  43 , light coupling surface  22  is shown to the side of detergent dispenser tray  43 , in which light from the first, second and third light sources  56 ,  57  and  58  can couple when detergent dispenser tray  43  is closed. A screen  59 , slightly inclined relative to the front of washing machine  41 , is formed at the rear, upper end of detergent dispenser tray  43  in front of rear wall  48 . This screen, inclined relative to an observer, has for the first chamber  45  the recess in the form of the symbol for pre-wash “I”, for the second chamber  46  the recess in the form of the symbol for main wash “II”, and for the third chamber  47  the recess in the form of the symbol for conditioning “*”, so that the symbols are clearly visible to the user. The second illuminating module  49  is mounted behind this inclined screen  59 , so that when detergent dispenser tray  43  is open the light of the symbols is radiated in the direction of an observer standing in front of washing machine  41 . 
     LIST OF REFERENCE NUMBERS 
     
         
         
           
               1  Illuminating module 
               2  Housing 
               3  First light conductor 
               4  Light admission surface 
               5  Light exit surface 
               6  Rear wall of the housing 
               7  First longitudinal wall of the housing 
               8  Second longitudinal wall of the housing 
               9  First transverse wall of the housing 
               10  Second transverse wall of the housing 
               11  Stop element 
               12  Guiding element 
               13  Pin 
               14  Receiving region for an illuminating element 
               15  Stop element 
               16  Stop nose 
               17  Arc-shaped groove of the stop nose 
               18  Sprung mounting 
               19  Recess 
               20  Retaining element 
               21  Second light conductor 
               22  Light coupling surface 
               23  End face 
               24  Light uncoupling surface 
               25  Rear surface of the second light conductor 
               26  Light supply region 
               27  Light discharge region 
               28  First step 
               29  Second step 
               30  Support plate 
               31  Light discharge region 
               32  Light emitting diode 
               33  Contact region 
               34  Notch 
               35  Groove 
               36  Diffuser foil 
               37  Screen 
               38  Module receiving device 
               39  Stop hook 
               40  Stop lug 
               41  Washing machine 
               32  Grip plate 
               43  Detergent dispenser tray 
               44  Light source 
               45  First chamber 
               46  Second chamber 
               47  Third chamber 
               48  Rear wall of the detergent dispenser tray 
               49  Illuminating module 
               50  First light radiating element 
               51  Second light radiating element 
               52  Third light radiating element 
               53  First light conducting element 
               54  Second light conducting element 
               55  Third light conducting element 
               56  First light source 
               57  Second light source 
               58  Third light source 
               59  Inclined screen

Technology Classification (CPC): 3