Abstract:
An actuating and display plate for a flushing device consists of a non-conductive transparent material, wherein the plate has at least one viewing window, behind which are disposed: an infrared light source, a proximity sensor, which works on a light-reflection basis and is sensitive to the wavelength zone and with which the flushing device can be triggered, and a display light source within the visible light zone. On the plate is provided a back coating, which has a transmission in the range between 2 percent and 15 percent for the visible light zone ( 22 ) and a transmission of more than 60 percent for the near-infrared light zone ( 24 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an actuating and display plate for a flushing device, wherein the plate consists of a non-conductive transparent material, wherein the plate has at least one viewing window, and wherein behind the viewing are disposed: at least one infrared light source, at least one proximity sensor, which works on a light-reflection basis and is sensitive to the wavelength zone of the infrared light source and with which the flushing device can be triggered, and at least one display light source within the visible light zone. 
       PRIOR ART 
       [0002]    From EP 1 961 876, a device for electrically triggering a toilet flushing system is known, wherein the actuating plate is a glass plate or a plate made of a non-conductive material. Behind the plate are sensor keys of capacitively working sensors, which contactlessly detect the approach of the hand of a user. The sensor system of the capacitive sensor keys is stuck on the rear side of the actuating plate. 
         [0003]    EP 1 867 613 discloses, from the field of kitchens, a combined actuating and display plate which has, moreover, a rear, opaque coating that leaves a window open. This window is provided with a likewise rear precious metal coating, which in the visible light for the range of wavelengths from 400 nanometres to 750 nanometres is said to have a transmission in the range of 1 to 21% and a scatter of 0 to 1%. 
         [0004]    In addition, in this viewing window region behind the glass ceramic plate, a lighting means is provided in order to be able to provide the user with a confirmation of the activation of the capacitive sensor likewise disposed behind the glass ceramic plate. 
         [0005]    AT 009 069 U1 discloses an actuating and display plate of a flushing fitting having the features of the preamble of claim  1 , which actuating and display plate has a viewing window behind which is provided a proximity sensor, working on a light-reflection basis, with which the fitting can be triggered. The infrared sensor is said, on the one hand, to be capable of detecting the approach of a user to the fitting and, on the other hand, the sensor is capable of discerning when the fitting is due to be triggered. For this, the triggering is achieved via an infrared distance measurement. In addition, behind the viewing window is provided an optical lighting means, with which the operating state or the triggered function is displayed to the user of the fitting. The viewing window is in this case transparent, and symbols and signal fields provided for the display, which if need be are imprinted or stuck on the actuating and display plate, are likewise transparent. 
       REPRESENTATION OF THE INVENTION 
       [0006]    Starting from this prior art, it is one object of the invention to define a combined actuating and display plate which ensures an improved optical display, whilst safeguarding the functional capability of the contactless triggering. 
         [0007]    According to the invention is provided an actuating and display plate for a flushing device, wherein the plate consists of a non-conductive transparent material, wherein the plate has at least one viewing window, and wherein behind the viewing window are disposed: at least one infrared light source, at least one proximity sensor, which works on a light-reflection basis and is sensitive to the wavelength zone of the infrared light source and with which the flushing device can be triggered, and at least one display light source within the visible light zone, wherein a back coating of the plate, which has a transmission in the range between 1 percent and 15 percent for the visible light zone and a transmission of more than 60 percent for the near-infrared light zone, is provided. 
         [0008]    The glass plate per se offers the foundation for contactless and hence hygienic triggering and is, in terms of its size, the basis of a wide variety of options for the display and the different triggering operations. By virtue of the fact that in this context a single back coating is provided, a homogeneous display, which safeguards the opaqueness of the sensor system hidden behind the glass plate and, at the same time, ensures the display by virtue of a display lighting means disposed behind the glass plate, can be realized. 
         [0009]    A transmission of this coating in the range between 1 percent and 15 percent for the visible light zone allows a clearly visible display for a user even under adverse light conditions, without too high a transmission, as in a fully transparent glass plate without coating, showing details of the sensor system. 
         [0010]    In the prior art of AT 009 069 U1, as in other embodiments of sensors in this field, the glass plates provided for this are kept very small in terms of their surface, which spatially precludes, for example, an arrangement of a plurality of sensors for the triggering or display of two different flush water quantities. As a result of the small surface area, the quantity of light which enters through the plate is automatically limited and it is difficult for the user to see through. The prior art according to EP 1 867 613 also then uses an opaque region to limit the incident scattered light. 
         [0011]    Here an object of the invention is to define a large-area actuating and display plate which, nevertheless, allows no look-through onto electronics disposed behind it. For this, the coating is chosen in the said transmission range. 
         [0012]    For the use of this actuating and display plate having a single coating for contactless detection by an optical contactless distance measurement, it is then a basic feature that the transmission of the coating in the region of the near-infrared wavelength zone is at least 60%, so that the transmittance of the coated plate for infrared light is sufficiently great for infrared distance measurement in both directions. The transmission takes place once for the emitted rays of the infrared light source in one direction, and then for the rays, reflected by the user, in the other direction through the plate. 
         [0013]    The transmission behaviour of the actuating plate is crucial for the correct representation of the lighting elements and for the infrared sensor system. On the one hand, a maximum transparency in the IR-zone is realized, on the other hand the transmission in the visible zone must not exceed predetermined values in order to prevent components behind the actuating plate from becoming visible to the user. 
         [0014]    Further embodiments are defined in the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Preferred embodiments of the invention are described below with reference to the drawings, which serve merely for illustration and should not be interpreted in a restrictive sense. In the drawings: 
           [0016]      FIG. 1  shows a transmission spectrum of a coating for use in an illustrative embodiment of the invention, and 
           [0017]      FIG. 2  shows a schematic perspective view of an illustrative embodiment of an actuating and display plate according to the invention. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0018]      FIG. 1  shows a transmission spectrum of a coating for an actuating and display plate  100  according to the invention, represented in  FIG. 2 . 
         [0019]    The value of the transmission  10  in the thereto possible range between 0 and 100 percent is represented on the axis of ordinate relative to the wavelength  20  for a range from ultraviolet into infrared. The axis of abscissas is divided into five zones  21 ,  22 ,  23 ,  24  and  25 . 
         [0020]    According to the invention, in respect of the coating, two wavelength zones are essential, in which the transmission behaviour must lie within a specific range. This is the visible light zone  22 , this visible light zone being defined between 400 nanometres and 700 nanometres for the human eye. In the case of a restricted colour display, this zone can also be restricted to sub-zones, for example between 400 and 550 nanometres, from 500 to 700 nanometres, in order to utilize more blue or red displays, or having a restricted range from 500 to 600 nanometres. 
         [0021]    The second essential wavelength zone is the infrared zone  24  of a wavelength from about 800 nanometres to 2000 nanometres, wherein the normally used infrared light sources deliver a radiation in the range between 850 nanometres and 920 nanometres. Furthermore, in  FIG. 1 , the ultraviolet zone is provided with the reference numeral  21 , whilst the far infrared zone is provided with the reference numeral  25 . The transition zone between the visible light zone  22  and the infrared zone  24  is provided with the reference numeral  23 . The lower limit of this zone  23  can be altered according to the definition of the upper end of the visible light zone  22 . The zone  21  thus relates to the value of the transmission with a wavelength of less than 400 nanometres, or less than 500 nanometres according to the above illustrative embodiments. The far zone  25  thus relates to the value of the transmission with a wavelength of greater than 2000 nanometres, or greater than 920 nanometres according to the above illustrative embodiments. Finally, the transition zone  23  relates to the value of the transmission with a wavelength of greater than 700 nanometres, or greater than 550 or 600 nanometres, and less than 800 nanometres, or less than 850 nanometres according to the above illustrative embodiments. The combinations are fluid and dependent on the chosen coating. 
         [0022]    In  FIG. 1 , with the curve  39 , a curve modelled on the real transmission characteristic is plotted, which curve has been employed, in trials, in prototypes of the invention. 
         [0023]    According to the invention, a transmission between 1 and 15% for the visible light zone  22  shall be provided in respect of the coating. This transmission is represented by the transmission band limited by the lower limit curve  31  and the upper limit curve  32  and is shaded. In particular, a transmission between 2 and 10% can be provided. Advantageously, transmissions of more than 5% are present only in small part-zones of the critical wavelength zone  22 . In the represented illustrative embodiment, a corresponding wavelength part-zone  38  with a higher transmission is found in the wavelength zone close to the ultraviolet. Such a part-zone  38  is a wavelength zone over no more than 150 nanometres in total, advantageously over no more than 100 nanometres in total, in which the transmission curve comprises between 5 and 15 percent. In the trials conducted by the Applicant, coatings were used which produce such zones  38  of up to 70 nanometres in the region of the short-wave visible zone and up to 70 nanometres in the region of the long-wave visible zone, i.e. for example between 400 and 450 nanometres and between 650 and 700 nanometres. 
         [0024]    With this transmission in the zone  22 , the user of the inventive device is guaranteed to have sufficient perception of the light source, as a display means, disposed behind the actuating plate; conversely, the transmission, in turn, is not so high that the user can recognize, apart from the lighting means, other elements in the installation frame of the display and actuating plate. Preferably, the background of the installation frame is designed or coloured in particular as grey or black, at least not white. If there is no installation frame forming the background, but this is a wall part of a building, then this shall preferably be kept dark. 
         [0025]    In the two boundary zones  21  and  25  of the ultraviolet and infrared, it is indicated with the shading between 0 percent and 100 percent that the transmission behaviour of the coating in these zones can be freely chosen; in particular, it can resemble the transmission behaviour of the adjoining zones. 
         [0026]    In the transition zone  23  between the visible light zone  22  and the infrared zone  24 , a steady transition of the transmission behaviour is advantageously provided, although, here too, this transmission can in principle be freely chosen; in particular, it can be zero; this zone can also be relatively small and comprise just a few nanometres. A steep transition flank of this kind is preferred. In another, non-represented illustrative embodiment having a different coating, the zone  23  extends between 700 and 850 nanometres and steadily rises therein from about 10% transmission to 65% transmission. A zone  38  of enhanced transmission then exists at the upper wavelength zone end  22 . 
         [0027]    The transmission behaviour in the infrared zone  24  is characterized by its lower limit of 60%. It is essential for a correct detection of the actuation that the infrared light emitted by the sensor light source and reflected back by the user is transmitted to the extent of no less than 60% in order to obtain an adequate response. The transmission in this zone  23  is upwardly open and can amount to up to 100% of the light entering the coating. 
         [0028]      FIG. 2  shows in very schematic representation an actuating plate  100 , behind which a coating is here represented as a separate surface  101 , the thickness of the coating being negligible in relation to the thickness of the supporting actuating plate  100 . The coating  101  can comprise, in particular, a display window  102  and a sensor window  103 , which windows can be separated by a masking  104 . The masking signifies a light-impermeable coating, which in particular lets through neither visible light nor IR light. 
         [0029]    Such a coating  104  further has the advantage that it is available as a very strongly adherent coating, which can simultaneously offer a base surface for fastening the actuating plate onto a mounting frame. For this, boundary regions, disposed on the margin of the plate, can be provided. In contrast to the representation of  FIG. 2 , the opaque coating is not then disposed on a continuous coating  101  but directly on the glass plate  100 . Naturally it is possible to provide different arrangements of display windows  102  and sensor windows  103  as long as a light source in the visible light zone is provided as the display lighting, as well as a pair, comprising a sensor light source and sensor detector, which is designed to emit and detect infrared light. 
         [0030]    The advantageously present, closed rear space of the actuating unit having the actuating plate according to the invention can easily be the rear space of a wall in which the display and actuating plate is installed, or a separate installation frame can be provided, the surface colour of which is then preferably dark. 
         [0031]    It is further possible for the actuating and display plate to have a coating which has a mirroring effect for the viewer. This can be constituted by the said coating having the transmission behaviour of  FIG. 1 . In other words, the feature that the further or the same coating shows a reflection shall be realized, of course, only for the wavelength zone  22  which is essential for the viewer; insofar as this reflection occurs only for incident light in part-zones of the wavelength zone  22 , a colour effect is obtained. The reflection can lie within the visible zone, in particular in the range from 30 to 50 percent, a reduced overall transmission being obtained if an additional coat is applied to the inventive coating. The values of the coating  101  should then be seen in total. 
         [0032]    A combined coating of this kind can be an interference filter coating on Borofloat glass, which, given high reflection, produces a damping of 5% in the visible zone up to 700 nanometres and, from 800 nanometres, allows a transmission of over 60%. 
         [0033]    The actuating plate can also be provided with a splinter protection film, which has no effect on the transmission and reflection behaviour. 
       REFERENCE SYMBOL LIST 
       [0000]    
       
           10  transmission 
           20  wavelength 
           21  ultraviolet zone 
           22  visible light zone 
           23  transition zone 
           24  near-IR zone 
           25  far IR-zone 
           31  lower limit curve 
           32  upper limit curve 
           38  zone of enhanced transmission 
           39  real transmission curve 
           100  actuating and display plate 
           101  coating 
           102  display window region 
           103  sensor window region 
           104  opaque coating