Abstract:
A lighting device including at least one conversion element and a least one LED, which emits light into the conversion element. The light is then converted and emitted with a high radiant flux. The at least one LED emits light in the wavelength range of ≧220 nm to ≦800 nm and the at least one conversion element converts at least part of the light from the at least one LED to light in the wavelength range of &gt;300 nm to &lt;1000 nm. In some embodiments, the at least one conversion element includes a ceramic conversion material.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of light delivery devices, especially light delivery devices which are used for medical purposes, such as endoscopy. 
     BACKGROUND OF THE INVENTION 
     In endoscopy devices, light is delivered to a body lumen or body cavity, e.g. for diagnostic purposes as well as photodynamic therapy of atherosclerosis, malignant or benign tumor tissue, cancerous cells and other medical treatments. Devices of the prior art are disclosed in e.g. the US 2005/0165462, which is incorporated herein by reference. 
     Especially in endoscopy devices, which are used for diagnosis, a light source with a high flux density is used, such as Xenon lamps and halogen lamps. However, in prior art applications there is no possibility to change the color temperature of the light without deterioration of the light flux and/or light density. The term ‘color temperature’ is used in lieu of the definition of the correlated color temperature of a light source. 
     For example in halogen lamps it is possible to decrease the color temperature (increase the red emission relative to green and blue) by simply diminishing the light flux, but a shift towards the red while maintaining the light flux is impossible. 
     Such a change in color temperature on the other hand would allow a further facilitation of the diagnosis since it is known that e.g. by changing the color temperature the different tissues inside a patient&#39;s body, which is subjected to the endoscopy, appear differently on the picture made by the endoscopy camera. Therefore, it would be possible to improve the diagnosis by simply changing the color temperature and/or the spectral composition of the illumination. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a light delivery device, especially a light delivery device for medical purposes, which allows a change in color temperature while essentially maintaining or even improving the light flux and/or light density. 
     This object is achieved by a light-emitting device having the features of claim  1 . Accordingly, a light delivery device, especially for medical lighting purposes, is provided comprising at least one light emitting device comprising at least one first LED which emits light in the wavelength range of ≧220 nm to ≦550 nm and at least one conversion element placed towards the at least one first LED, which converts at least partly the light from the at least one first LED to light in the wavelength range of ≧300 nm to ≦1000 nm, where the at least one conversion element comprises a ceramic conversion material. 
     By doing so, it is possible to realize a light delivery device which for most applications in the present invention has one or more of the following advantages:
         Due to the ceramic conversion material, a high light flux density can be achieved, allowing the use of the light delivery device in a broad variety of applications, especially for endoscopical devices   Due to the ceramic conversion material it is possible to change the color temperature of the light delivery device especially towards the “red” without a deterioration in light flux.   Due to the ceramic conversion material it is possible to increase the light flux without changing the geometrical properties of light generation and emission, maintaining the efficiency of any light collection optics.       

     According to the invention, the light-emitting device comprises at least one first LED which emits light in the wavelength range of ≧220 nm and ≦1000 nm. LEDs with an emittance in this wavelength range have proven themselves in practice. 
     Preferably, those LEDs consist of a AlInGaN electroluminescent device with a phosphor conversion element attached, absorbing at least partially LED emitted light and reemit that light at a wavelength larger than the LED emission wavelength. 
     According to a preferred embodiment of the present invention, the light emitting device comprises at least one first LED which emits light in the wavelength range of ≧250 nm and ≦800 nm, more preferably ≧300 nm and ≦780 nm. 
     The term “ceramic material” in the sense of the present invention means especially a crystalline or polycrystalline compact material or composite material with a controlled amount of pores or which is porefree. 
     The term “polycrystalline material” in the sense of the present invention means especially a material with a volume density larger than 90 percent of the main constituent, consisting of more than 80 percent of single crystal domains, with each domain being larger than 0.5 μm in diameter and having different crystallographic orientations. The single crystal domains may be connected by amorphous or glassy material or by additional crystalline constituents. 
     According to a preferred embodiment of the present invention, the at least one conversion element has a refractive index n of ≧1.5 and ≦3 and the ratio A:E is ≧2:1 and ≦50000:1, where A and E are defined as follows:
         the at least one conversion element comprises at least one entrance surface where light emitted by the at least one LED can enter the conversion element, and at least one exit surface, where light can exit the at least one conversion element,   each of the at least one entrance surfaces having an entrance surface area, the entrance surface area(s) being numbered A 1  . . . A n  and each of the at least one exit surfaces having an exit surface area, the exit surface area(s) being numbered E 1  . . . E n  and the sum of each of the at least one entrance surface areas A being A=A 1 +A 2  . . . +A n  and the sum of each of the at least one exit surface areas E being E=E 1 +E 2  . . . +E n          

     By doing so, it is possible for most applications within the present invention to realize a lamp combining a high light flux with a greatly increased luminance compared to the LED. 
     According to a preferred embodiment of the invention, the light emitting device comprises at least one conversion element which comprises at least one entrance surface A where light emitted by the at least one LED can enter the conversion element. After absorption, light reemitted by the conversion element can leave through the entrance surface only with the fraction emitted within the escape cone of the material. The main fraction of the emitted light will be trapped within the conversion element and guided to an exit surface by total internal reflection. 
     In order to enhance this process, this at least one entrance surface has according to a preferred embodiment of the present invention a roughness Ra of ≧1 nm and ≦500 nm, preferably ≧10 nm and ≦100 nm and more preferably ≧20 nm and ≦40 nm. By this effect it is possible indeed to concentrate light at the exit surface E of the light conversion element. 
     According to a preferred embodiment of the present invention, the LEDs are in direct contact with the conversion elements but each have a lower refractive index than the conversion elements. 
     However, according to another preferred embodiment of the present invention, the LEDs and the conversion elements are placed at a distance from each other. In this case, preferably, the distance between the conversion elements and the LEDs is ≧1 μm and ≦100 mm, preferably ≧100 μm and ≦10 mm and more preferably ≧1 mm and ≦5 mm. 
     Besides the optical function of the separation of the LEDs and the conversion layer it is also advantageous and, insofar a further preferred embodiment of the present invention is concerned, to have a thermal decoupling of the conversion layer and the LEDs. In most applications, the efficiency of the conversion process decreases significantly for temperatures well above 100° C. In another preferred embodiment of this invention special cooling means are applied to the light-emitting device to dissipate heat generated within the conversion layer and the LED(s) to a heat sink outside the device, the LED(s) and the conversion element(s) being placed at a distance from each other preferably as described above. This cooling can be realized by forced air blowing and/or by liquid cooling, pumping a liquid around the conversion layer. In this preferred embodiment of the present invention the cooling means is therefore a liquid, preferably selected from a group comprising Water-, Oils, Propylene-, Ethylene-, Glycol based systems and mixtures thereof. In the latter case the refractive index of the liquid should be as low as possible to prevent light extraction of emitted light through the surface A of the conversion layer. The difference of the refractive index of the conversion layer n c  and the liquid n l  should be 0.1≦n c −n l ≦3, preferably 0.3≦n c −n l ≦2.5 and more preferably 0.5≦n c −n l ≦2. 
     According to the invention, the light that enters the conversion element is at least partly converted to light in the wavelength range of ≧300 nm and ≦1000 nm. By doing so, the light emitting device will emit light in a wavelength range, which is suitable for a broad variety of applications. According to a preferred embodiment of the present invention, the light that enters the conversion element is at least partly converted to light in the wavelength range of ≧350 nm and ≦880 nm, more preferably ≧380 nm and ≦780 nm. 
     According to a preferred embodiment of the invention, the conversion element comprises at least one exit surface, where light can exit the conversion element. In order to enhance this, according to a preferred embodiment of the present invention, the at least one exit surface is equipped with a refractive and/or diffractive structure or surface. This includes that the at least one exit surface is equipped with a scattering structure, a pyramide-like structure, a micro lens structure or a compound parabolic concentrator (CPC). The exit surface may contain one or a plurality of the indicated structures. The geometry of the exit structure can also be used to direct the emitted light from the exit surface to meet any requirement of an application. 
     According to a preferred embodiment of the invention, the at least one exit surface is optically directly coupled to a light guiding structure, by coupling the light conversion element to a light guide with a medium having an refractive index n c  close to the refractive index of either the conversion element n conv  or the light guide n g . The minimum of the difference of (abs(n c −n conv ) and abs(n c −n g ) is preferably &lt;0.3, more preferably &lt;0.1 and most preferably &lt;0.01. 
     According to a preferred embodiment of the invention, each of the at least one entrance surfaces has an entrance surface area, the entrance surface areas being numbered A 1  . . . A n  and each of the at least one exit surfaces has an exit surface area, the exit surface areas being numbered E 1  . . . E n  and the sum of each of the at least one entrance surface areas A n  is A=A 1 +A 2  . . . +A n  and the sum of each of the at least one exit surface areas E n  is E=E 1 +E 2  . . . +E n  and the ratio A:E, A and E being as defined above, is ≧2:1 and ≦50000:1. 
     By doing so, the light flux of the LED can be set within the preferred and desired range. According to a preferred embodiment of the present invention, the ratio A:E, A and E being as defined above, is ≧5:1 and ≦5000:1, more preferably ≧10:1 and ≦3000:1 yet more preferably ≧20:1 and ≦1000:1, and most preferably ≧50:1 and ≦500:1. 
     According to a preferred embodiment of the invention, the at least one conversion element has an refractive index n of ≧1.5 and ≦3. By doing so, it can be easily achieved that the efficiency of the LED is within a desired range. Especially, by setting the refractive index as described, the light that enters the conversion element as described will undergo total reflection at the sides/surfaces of the conversion element, which are no exit surfaces. The fraction of the light from the LEDs which is emitted through the exit surface (possibly after conversion) of the conversion element compared to the total emitted light can be as high as 
     
       
         
           
             
               1 
               - 
               
                 1 
                 
                   2 
                   ⁢ 
                   
                     n 
                     2 
                   
                 
               
             
             , 
           
         
       
     
     with n being the refractive index of the conversion element. This results in a very highly efficient light-emitting device. Preferably the at least one conversion element has a refractive index n of ≧1.5 and ≦2.8, more preferably ≧1.7 and ≦2.6 
     According to a preferred embodiment of the present invention, the transmittance for emitted light of the conversion element is ≧0.8 and ≦1. This greatly enhances the efficiency of the light-emitting device. Preferably, the transmittance of the conversion element is ≧0.9 and ≦1, more preferably ≧0.95 and ≦1. 
     According to a preferred embodiment of the present invention, the relation of the quantum efficiency at a temperature T compared to the quantum efficiency at 20° C. (thermal quenching) of the conversion element is ≧70% and ≦100% at 100° C., preferably ≧80% and ≦100% at 100° C. and most preferably ≧90% and ≦100% at 100° C. 
     According to a preferred embodiment of the present invention, the temperature at which the quantum efficiency of the conversion layer is reduced to 50% compared to the quantum efficiency at room temperature, (=TQ 50% -value), is ≧120° C. and ≦300° C., preferably 150° C.≦TQ 50% ≦350° C. and more preferably 180° C.≦TQ 50% ≦400° C. 
     According to a preferred embodiment of the present invention, the light delivery device comprises at least one further auxiliary LED which emits in the wavelength of ≧220 nm to ≦600 nm. 
     By doing so, it is possible in most applications within the present invention to very easily shift the color temperature of the light provided by the light delivery device without lowering the original light flux. 
     According to a preferred embodiment of the present invention, the auxiliary LEDs have (combined) a power of ≧2% to ≦100% of the first LED. In case that more than one first LED is present, it is preferred that the auxiliary LEDs have (combined) a power of ≧10% to ≦1000% of the combined first LEDs. 
     According to a preferred embodiment of the present invention, the auxiliary LEDs are mounted either individually or in a die package on a single supporting plate serving as a heat conductor and providing the electrical contacts for operation. The one or more supporting plates may also contain active electronic elements for LED protection, operation and control. In addition, according to a preferred embodiment of the present invention the auxiliary LEDs on a supporting plate are covered with optical structures to optimise the light output of the auxiliary LEDs. 
     In a further preferred embodiment of the present invention, the auxiliary LEDs are mounted on a supporting plate with a packing density of ≧0.05 and ≦0.5, preferably ≧0.1 and ≦0.3. The packing density is the ratio of the sum of the LED die surface areas divided by the surface area of the supporting plate. By doing so, it is possible to realize a light emitting device with particularly high lumen flux and superior luminance at a high power efficiency, which is achieved by effective cooling of the auxiliary LEDs, keeping the junction temperature below the specified values of the auxiliary LEDs. 
     According to a preferred embodiment of the present invention, the light from the at least one first LED is sent to the at least one conversion element in a preferred first light propagation direction and the light sent from the auxiliary LEDs towards the at least one conversion element has an angle towards the preferred first light direction of ≧65° and ≦115°, preferably ≧75° and ≦105° and most preferably ≧85° and ≦95°. 
     In such an arrangement it is possible in most applications within the present invention to ensure that the light that is emitted by the auxiliary LEDs is only or essentially used for conversion inside the conversion element, thereby allowing to “add” light of a certain wavelength. 
     According to a preferred embodiment of the present invention, the auxiliary LEDs are placed inside a support tube. 
     Preferably the part of the support tube, where no auxiliary LEDs are placed, is preferably covered with a highly reflective coating, preferably a mirror or a dielectric coating or a mixture thereof. By doing so, the efficiency of the conversion element(s) and the light emitting device can be enhanced further. The mirror is preferably applied by sputtering or evaporation in vacuum directly on the at least one further surface which is neither an exit nor an entrance surface. The mirror material is preferably selected from a group comprising silver, aluminum and/or mixtures thereof. The thickness of the mirror is preferably ≧50 nm and ≦1000 nm. 
     In such an arrangement it is possible in most applications within the present invention to ensure that the light that is emitted by the auxiliary LEDs is only or essentially used for conversion inside the conversion element, thereby allowing to “add” light of a certain wavelength and lowering the power requirements of the LEDs. 
     According to a preferred embodiment of the invention, the glass phase ratio of the ceramic conversion material is ≧2% to ≦5%, according to an embodiment of the present invention, ≧3% to ≦4%. It has been shown in practice that materials with such a glass phase ratio show the improved characteristics, which are advantageous and desired for the present invention. 
     The term “glass phase” in the sense of the present invention means especially non-crystalline grain boundary phases, which may be detected by scanning electron microscopy or transmission electron microscopy. 
     According to a preferred embodiment of the present invention, the surface roughness RMS (disruption of the planarity of a surface; measured as the geometric mean of the difference between highest and deepest surface features) of the surface(s) of the ceramic conversion material and/or the conversion element(s) is ≧0.001 μm and ≦1100 μm. According to one embodiment of the present invention, the surface roughness of the surface(s) of the ceramic conversion material and/or the conversion element(s) is ≧0.01 μm and ≦10 μm, according to another embodiment of the present invention ≧0.1 μm and ≦5 μm, according to yet another embodiment of the present invention ≧0.15 μm and ≦3 μm. and according to still another embodiment of the present invention ≧0.2 μm and ≦2 μm. 
     According to a preferred embodiment of the present invention, the specific surface area of the ceramic conversion material and/or the conversion element(s) is ≧10 −7  m 2 /g and ≦1 m 2 /g. 
     According to a preferred embodiment of the present invention, the ceramic conversion material is essentially made of material selected from the group of 
     (M I   1-x-y M II   x M III   y ) 3 (M IV   1-z M V   z ) 5 O 12 — where M I  is selected from the group comprising Y, Lu or mixtures thereof, M II  is selected from the group comprising Gd, La, Yb or mixtures thereof, M III  is selected from the group comprising Tb, Pr, Ce, Er, Nd, Eu or mixtures thereof, M IV  is Al, M V  is selected from the group comprising Ga, Sc or mixtures thereof, and 0≦x≦1, 0≦y≦0.1, 0≦z≦1, 
     (M I   1-x-y M II   x M III   y ) 2 O 3 — where M I  is selected from the group comprising Y, Lu or mixtures thereof, M II  is selected from the group comprising Gd, La, Yb or mixtures thereof, M III  is selected from the group comprising Tb, Pr, Ce, Er, Nd, Eu, Bi, Sb or mixtures thereof, and 0≦x≦1, 0≦y≦0.1, 
     (M I   1-x-y M II   x M III   y )S 1-z Se z — where M I  is selected from the group comprising Ca, Sr, Mg, Ba or mixtures thereof, M II  is selected from the group comprising Ce, Eu, Mn, Tb, Sm, Pr, Sb, Sn or mixtures thereof, M III  is selected from the group comprising K, Na, Li, Rb, Zn or mixtures thereof, and 0≦x≦0.01, 0≦y≦0.05, 0≦z≦1, 
     (M I   1-x-y M II   x M III   y )O— where M I  is selected from the group comprising Ca, Sr, Mg, Ba or mixtures thereof, M II  is selected from the group comprising Ce, Eu, Mn, Tb, Sm, Pr or mixtures thereof, M III  is selected from the group comprising K, Na, Li, Rb, Zn or mixtures thereof, and 0≦x≦0.1, 0≦y≦0.1, 
     (M I   2-x M II   x M III   2 )O 7 — where M I  is selected from the group comprising La, Y, Gd, Lu, Ba, Sr or mixtures thereof, M II  is selected from the group comprising Eu, Tb, Pr, Cc, Nd, Sm, Tm or mixtures thereof, M III  is selected from the group comprising Hf, Zr, Ti, Ta, Nb or mixtures thereof, and 0≦x≦1, 
     (M I   1-x M II   x M III   1-y M IV   y )O 3 — where M I  is selected from the group comprising Ba, Sr, Ca, La, Y, Gd, Lu or mixtures thereof, M II  is selected from the group comprising Eu, Tb, Pr, Ce, Nd, Sm, Tm or mixtures thereof, M III  is selected from the group comprising Hf, Zr, Ti, Ta, Nb or mixtures thereof, and M IV  is selected from the group comprising Al, Ga, Sc, Si or mixtures thereof, and 0≦x≦0.1, 0≦y≦0.1. 
     According to a preferred embodiment of the present invention, the conversion element comprises at least one further surface which is neither an exit nor an entrance surface and where at least one, preferably all of said further surface(s) are covered with a reflective coating, preferably a mirror or a dielectric coating or a mixture thereof. By doing so, the efficiency of the conversion element(s) and the light emitting device can be enhanced further. The mirror is preferably applied by sputtering or evaporation in vacuum directly on the at least one further surface, which is neither an exit nor an entrance surface. The mirror material is preferably selected from a group comprising silver, aluminum and/or mixtures thereof. The thickness of the mirror is preferably ≧50 nm and ≦1000 nm 
     A light emitting device according to the present invention may be of use in a wide variety of systems and/or applications, amongst them one or more of the following:
         medical lighting application systems,   endoscopes   devices for photodynamic therapy       

     The aforementioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pertinent field can be applied without limitations. 
     Additional details, features, characteristics and advantages of the object of the invention are disclosed in the subclaims, figures, examples and the following description of the respective figures and examples—which in an exemplary fashion—show several preferred embodiments and examples of a light delivery device according to the invention, wherein: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a very schematic cross-sectional partial view of a light delivery device according to a first embodiment of the present invention; 
         FIG. 2  shows a very schematic cross-sectional partial view of a light delivery device according to a first embodiment of the present invention; 
         FIG. 3  shows a schematic cross-sectional partial view of the embodiment of  FIG. 1  along line IV-IV in  FIG. 4   
         FIG. 4  shows a cross-sectional view of the conversion element of the light delivery device of  FIGS. 1 and 3  along line II-II in  FIG. 3   
         FIG. 5  shows a graph showing three emission spectra of a light delivery device according to a first example of the invention; 
         FIG. 6  shows an enlarged section of the graph of  FIG. 5 ; and 
         FIG. 7  shows a graph showing three emission spectra of a light delivery device according to a second example. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  shows a very schematic cross-sectional partial view of a light delivery device  1  according to a first embodiment of the present invention. The light delivery device  1  comprises a first LED  20 , a first converter substance  30 , which projects light towards the conversion element  10  through a collector lens  60 . From the conversion element  10 , the light is then partially converted and projected towards the optical fibre  70 . The optical fibre then may e.g. lead the light towards the tip of an endoscopy device (not shown in the Fig.). 
     In order to shift the color temperature of the LED, several auxiliary LEDs  40  are provided on a support tube  50 ; this part of the embodiment will be described in more detail in  FIG. 3 , which is an enlarged partial view of this part of the light delivery device. 
     As can be best seen from  FIG. 1 , the angle between the preferred light direction from the first LED (which in this embodiment is essentially horizontal) and the light sent out from the auxiliary LEDs (which in this embodiment is essentially vertical) is approximately 90°. 
       FIG. 2  shows a very schematic cross-sectional partial view of a light delivery device according to a first embodiment of the present invention. This second embodiment is identical with that of  FIG. 1  except that a second conversion element  15  is present. 
       FIG. 3  shows a schematic cross-sectional partial view the embodiment of  FIG. 1  along line IV-IV in  FIG. 4 . 
       FIG. 4  shows a cross-sectional view of the conversion element of the light delivery device of  FIGS. 1 and 3  along line II-II in  FIG. 3 . 
     As can be seen from  FIGS. 3 and 4 , the conversion element  10  is somewhat cylindrical in shape and preferably matches the optical fibre  70 . It is circumferentially surrounded by the support tube  50 , which holds several sets of auxiliary LEDs  40 . In this embodiment, four rows of auxiliary LEDs were used; however, it goes without saying that more (or less) auxiliary LEDs may be used, depending on the actual application. The inside surface of the support tube where no LEDs are located, is covered with a mirror. 
     Preferably, the auxiliary LEDs are arranged closely in groups, e.g. rows, leaving large contiguous areas of the supporting tube coated with a highly reflective coating. By doing so, the total amount of LED light absorbed by the conversion element is maximized. 
     The conversion element  10  has two entrance surfaces A 1 , A 2  (A 2  being the “side” of the cylinder that projects towards the LED  20 ), resulting in an A being A 1 +A 2 . Since there is only one exit surface with an exit surface area E 1 , the numeral E, being the sum of each of the at least one exit surface areas would simply be E=E 1 . The ratio of A:E is set to be ≧10:1 and ≦10000:1; in this example A:E would be approximately 400:1. However, it should be noted, that the embodiment in  FIGS. 3 and 4  is highly schematic and the ratio may be different for other applications. 
     The lighting device according to the invention is—in a merely exemplarily fashion—furthermore illustrated by the following examples together with the  FIGS. 5 to 7 : 
       FIG. 5  shows a graph showing three emission spectra of a light delivery device according to a first example of the invention,  FIG. 6  shows a enlarged section of the graph of  FIG. 5 . 
     EXAMPLE I 
     In Example I, a light delivery device with the setting of  FIG. 1  was used. The first LED (reference no.  20  in  FIG. 1 ) was a InGaN LED with a peak emission at 462 nm, the first converter substance (reference no.  30  in  FIG. 1 ) was a YAG:Ce ceramic material with the composition Y (3-x-y) Gd x Al 5 O 12 :Ce y  with x=0.3 and y=0.06. 
     The conversion element (reference no.  10  in  FIG. 1 ) was Y 2 O 3 :Eu with a 7% Europium doping and a density of 5.029 g/cm 3 . 
     The light delivery device furthermore comprises two sets of auxiliary LEDs (reference no.  40  in  FIG. 1 ), which are also InGaN LEDs. Each set of LEDs has a power of 100% of the first LED and a peak emission at 465 nm. 
       FIGS. 5 and 6  show the spectra of the light delivery device with the first LED only (“LED”), with one set of auxiliary LEDs switched on (“Aux 1 ”) and with both sets of auxiliary LEDs switched on (“Aux 2 ”). 
     The data of  FIGS. 5 and 6  are listed in Table I 
     
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE I 
               
               
                   
                   
               
               
                   
                 LED 
                 Aux1 
                 Aux2 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 380 
                 0.00188 
                 0.00238 
                 0.00288 
               
               
                   
                 382 
                 0.001739 
                 0.002239 
                 0.002739 
               
               
                   
                 384 
                 0.000654 
                 0.001154 
                 0.001654 
               
               
                   
                 386 
                 0.000711 
                 0.001211 
                 0.001711 
               
               
                   
                 388 
                 0.001233 
                 0.001733 
                 0.002233 
               
               
                   
                 390 
                 0.00117 
                 0.00167 
                 0.00217 
               
               
                   
                 392 
                 0.000811 
                 0.001311 
                 0.001811 
               
               
                   
                 394 
                 0.000946 
                 0.001446 
                 0.001946 
               
               
                   
                 396 
                 0.000838 
                 0.001338 
                 0.001838 
               
               
                   
                 398 
                 0.000623 
                 0.001123 
                 0.001623 
               
               
                   
                 400 
                 0.001035 
                 0.001535 
                 0.002035 
               
               
                   
                 402 
                 0.001292 
                 0.001792 
                 0.002292 
               
               
                   
                 404 
                 0.00122 
                 0.00172 
                 0.00222 
               
               
                   
                 406 
                 0.001175 
                 0.001675 
                 0.002175 
               
               
                   
                 408 
                 0.001278 
                 0.001778 
                 0.002278 
               
               
                   
                 410 
                 0.001367 
                 0.001867 
                 0.002367 
               
               
                   
                 412 
                 0.00144 
                 0.00194 
                 0.00244 
               
               
                   
                 414 
                 0.001532 
                 0.002032 
                 0.002532 
               
               
                   
                 416 
                 0.001929 
                 0.002429 
                 0.002929 
               
               
                   
                 418 
                 0.002528 
                 0.003028 
                 0.003528 
               
               
                   
                 420 
                 0.003352 
                 0.003852 
                 0.004352 
               
               
                   
                 422 
                 0.004891 
                 0.005391 
                 0.005891 
               
               
                   
                 424 
                 0.006672 
                 0.007172 
                 0.007672 
               
               
                   
                 426 
                 0.008475 
                 0.008975 
                 0.009475 
               
               
                   
                 428 
                 0.011025 
                 0.011525 
                 0.012025 
               
               
                   
                 430 
                 0.014129 
                 0.014629 
                 0.015129 
               
               
                   
                 432 
                 0.01841 
                 0.01891 
                 0.01941 
               
               
                   
                 434 
                 0.023055 
                 0.023555 
                 0.024055 
               
               
                   
                 436 
                 0.027142 
                 0.027642 
                 0.028142 
               
               
                   
                 438 
                 0.032944 
                 0.033444 
                 0.033944 
               
               
                   
                 440 
                 0.040675 
                 0.041175 
                 0.041675 
               
               
                   
                 442 
                 0.047448 
                 0.047948 
                 0.048448 
               
               
                   
                 444 
                 0.057997 
                 0.058497 
                 0.058997 
               
               
                   
                 446 
                 0.06568 
                 0.06618 
                 0.06668 
               
               
                   
                 448 
                 0.076898 
                 0.077398 
                 0.077898 
               
               
                   
                 450 
                 0.088318 
                 0.088818 
                 0.089318 
               
               
                   
                 452 
                 0.097781 
                 0.098281 
                 0.098781 
               
               
                   
                 454 
                 0.103529 
                 0.104029 
                 0.104529 
               
               
                   
                 456 
                 0.107177 
                 0.107677 
                 0.108177 
               
               
                   
                 458 
                 0.109494 
                 0.109994 
                 0.110494 
               
               
                   
                 460 
                 0.110901 
                 0.111401 
                 0.111901 
               
               
                   
                 462 
                 0.093512 
                 0.094012 
                 0.094512 
               
               
                   
                 464 
                 0.078426 
                 0.078926 
                 0.079426 
               
               
                   
                 466 
                 0.065164 
                 0.066119 
                 0.067074 
               
               
                   
                 468 
                 0.068973 
                 0.070108 
                 0.071243 
               
               
                   
                 470 
                 0.08761 
                 0.08811 
                 0.08861 
               
               
                   
                 472 
                 0.096669 
                 0.097169 
                 0.097669 
               
               
                   
                 474 
                 0.100671 
                 0.101351 
                 0.102031 
               
               
                   
                 476 
                 0.098311 
                 0.098811 
                 0.099311 
               
               
                   
                 478 
                 0.093635 
                 0.094135 
                 0.094635 
               
               
                   
                 480 
                 0.088668 
                 0.089168 
                 0.089668 
               
               
                   
                 482 
                 0.085616 
                 0.086116 
                 0.086616 
               
               
                   
                 484 
                 0.083357 
                 0.083857 
                 0.084357 
               
               
                   
                 486 
                 0.079624 
                 0.080124 
                 0.080624 
               
               
                   
                 488 
                 0.073583 
                 0.074083 
                 0.074583 
               
               
                   
                 490 
                 0.070694 
                 0.071414 
                 0.072134 
               
               
                   
                 492 
                 0.068335 
                 0.068835 
                 0.069335 
               
               
                   
                 494 
                 0.064839 
                 0.065339 
                 0.065839 
               
               
                   
                 496 
                 0.063057 
                 0.063557 
                 0.064057 
               
               
                   
                 498 
                 0.062375 
                 0.062875 
                 0.063375 
               
               
                   
                 500 
                 0.062363 
                 0.062993 
                 0.063623 
               
               
                   
                 502 
                 0.062725 
                 0.06337 
                 0.064015 
               
               
                   
                 504 
                 0.063773 
                 0.064273 
                 0.064773 
               
               
                   
                 506 
                 0.068184 
                 0.070894 
                 0.073604 
               
               
                   
                 508 
                 0.072833 
                 0.078278 
                 0.083723 
               
               
                   
                 510 
                 0.076638 
                 0.079698 
                 0.082758 
               
               
                   
                 512 
                 0.080117 
                 0.080647 
                 0.081177 
               
               
                   
                 514 
                 0.084271 
                 0.085041 
                 0.085811 
               
               
                   
                 516 
                 0.088583 
                 0.089083 
                 0.089583 
               
               
                   
                 518 
                 0.092116 
                 0.092726 
                 0.093336 
               
               
                   
                 520 
                 0.096028 
                 0.096528 
                 0.097028 
               
               
                   
                 522 
                 0.098354 
                 0.098854 
                 0.099354 
               
               
                   
                 524 
                 0.095827 
                 0.096327 
                 0.096827 
               
               
                   
                 526 
                 0.094712 
                 0.095212 
                 0.095712 
               
               
                   
                 528 
                 0.093644 
                 0.094144 
                 0.094644 
               
               
                   
                 530 
                 0.086809 
                 0.087309 
                 0.087809 
               
               
                   
                 532 
                 0.079557 
                 0.080057 
                 0.080557 
               
               
                   
                 534 
                 0.078023 
                 0.083963 
                 0.089903 
               
               
                   
                 536 
                 0.081832 
                 0.083412 
                 0.084992 
               
               
                   
                 538 
                 0.096771 
                 0.099706 
                 0.102641 
               
               
                   
                 540 
                 0.107926 
                 0.110741 
                 0.113556 
               
               
                   
                 542 
                 0.116971 
                 0.117571 
                 0.118171 
               
               
                   
                 544 
                 0.121157 
                 0.121782 
                 0.122407 
               
               
                   
                 546 
                 0.122688 
                 0.123223 
                 0.123758 
               
               
                   
                 548 
                 0.122018 
                 0.122573 
                 0.123128 
               
               
                   
                 550 
                 0.121649 
                 0.122704 
                 0.123759 
               
               
                   
                 552 
                 0.121918 
                 0.124548 
                 0.127178 
               
               
                   
                 554 
                 0.122846 
                 0.125451 
                 0.128056 
               
               
                   
                 556 
                 0.123639 
                 0.125474 
                 0.127309 
               
               
                   
                 558 
                 0.123114 
                 0.123614 
                 0.124114 
               
               
                   
                 560 
                 0.122137 
                 0.122637 
                 0.123137 
               
               
                   
                 562 
                 0.121608 
                 0.122568 
                 0.123528 
               
               
                   
                 564 
                 0.120783 
                 0.122688 
                 0.124593 
               
               
                   
                 566 
                 0.119735 
                 0.12131 
                 0.122885 
               
               
                   
                 568 
                 0.118723 
                 0.120298 
                 0.121873 
               
               
                   
                 570 
                 0.118546 
                 0.120606 
                 0.122666 
               
               
                   
                 572 
                 0.116935 
                 0.11762 
                 0.118305 
               
               
                   
                 574 
                 0.115054 
                 0.115614 
                 0.116174 
               
               
                   
                 576 
                 0.113432 
                 0.114262 
                 0.115092 
               
               
                   
                 578 
                 0.109946 
                 0.111191 
                 0.112436 
               
               
                   
                 580 
                 0.107852 
                 0.110017 
                 0.112182 
               
               
                   
                 582 
                 0.113155 
                 0.13106 
                 0.148965 
               
               
                   
                 584 
                 0.110682 
                 0.124317 
                 0.137952 
               
               
                   
                 586 
                 0.10715 
                 0.11296 
                 0.11877 
               
               
                   
                 588 
                 0.120096 
                 0.159521 
                 0.198946 
               
               
                   
                 590 
                 0.107076 
                 0.118441 
                 0.129806 
               
               
                   
                 592 
                 0.106777 
                 0.118612 
                 0.130447 
               
               
                   
                 594 
                 0.126511 
                 0.186606 
                 0.246701 
               
               
                   
                 596 
                 0.106581 
                 0.124741 
                 0.142901 
               
               
                   
                 598 
                 0.103291 
                 0.118781 
                 0.134271 
               
               
                   
                 600 
                 0.112167 
                 0.152797 
                 0.193427 
               
               
                   
                 602 
                 0.100955 
                 0.120695 
                 0.140435 
               
               
                   
                 604 
                 0.094712 
                 0.104957 
                 0.115202 
               
               
                   
                 606 
                 0.094031 
                 0.107736 
                 0.121441 
               
               
                   
                 608 
                 0.094532 
                 0.114652 
                 0.134772 
               
               
                   
                 610 
                 0.105648 
                 0.156603 
                 0.207558 
               
               
                   
                 612 
                 0.299 
                 0.799 
                 1.299 
               
               
                   
                 614 
                 0.175572 
                 0.397937 
                 0.60.620302 
               
               
                   
                 616 
                 0.134533 
                 0.268638 
                 0.402743 
               
               
                   
                 618 
                 0.088959 
                 0.124684 
                 0.160409 
               
               
                   
                 620 
                 0.077779 
                 0.093569 
                 0.109359 
               
               
                   
                 622 
                 0.074426 
                 0.088086 
                 0.101746 
               
               
                   
                 624 
                 0.075279 
                 0.096684 
                 0.118089 
               
               
                   
                 626 
                 0.074294 
                 0.099299 
                 0.124304 
               
               
                   
                 628 
                 0.073762 
                 0.103197 
                 0.132632 
               
               
                   
                 630 
                 0.073588 
                 0.107703 
                 0.141818 
               
               
                   
                 632 
                 0.098097 
                 0.193427 
                 0.288757 
               
               
                   
                 634 
                 0.060529 
                 0.075204 
                 0.089879 
               
               
                   
                 636 
                 0.055331 
                 0.062916 
                 0.070501 
               
               
                   
                 638 
                 0.052421 
                 0.058256 
                 0.064091 
               
               
                   
                 640 
                 0.049973 
                 0.054533 
                 0.059093 
               
               
                   
                 642 
                 0.047951 
                 0.052381 
                 0.056811 
               
               
                   
                 644 
                 0.045942 
                 0.050327 
                 0.054712 
               
               
                   
                 646 
                 0.044127 
                 0.048317 
                 0.052507 
               
               
                   
                 648 
                 0.042124 
                 0.045564 
                 0.049004 
               
               
                   
                 650 
                 0.040988 
                 0.045618 
                 0.050248 
               
               
                   
                 652 
                 0.048088 
                 0.072903 
                 0.097718 
               
               
                   
                 654 
                 0.039911 
                 0.050101 
                 0.060291 
               
               
                   
                 656 
                 0.03537 
                 0.038875 
                 0.04238 
               
               
                   
                 658 
                 0.034343 
                 0.039013 
                 0.043683 
               
               
                   
                 660 
                 0.031902 
                 0.034377 
                 0.036852 
               
               
                   
                 662 
                 0.031165 
                 0.035045 
                 0.038925 
               
               
                   
                 664 
                 0.034241 
                 0.048226 
                 0.062211 
               
               
                   
                 666 
                 0.02811 
                 0.030955 
                 0.0338 
               
               
                   
                 668 
                 0.0265 
                 0.0287 
                 0.0309 
               
               
                   
                 670 
                 0.025269 
                 0.027384 
                 0.029499 
               
               
                   
                 672 
                 0.023972 
                 0.026072 
                 0.028172 
               
               
                   
                 674 
                 0.02249 
                 0.02391 
                 0.02533 
               
               
                   
                 676 
                 0.0213 
                 0.022575 
                 0.02385 
               
               
                   
                 678 
                 0.020134 
                 0.021254 
                 0.022374 
               
               
                   
                 680 
                 0.019324 
                 0.020729 
                 0.022134 
               
               
                   
                 682 
                 0.01838 
                 0.019505 
                 0.02063 
               
               
                   
                 684 
                 0.017914 
                 0.019504 
                 0.021094 
               
               
                   
                 686 
                 0.017255 
                 0.01919 
                 0.021125 
               
               
                   
                 688 
                 0.021362 
                 0.034522 
                 0.047682 
               
               
                   
                 690 
                 0.017832 
                 0.024502 
                 0.031172 
               
               
                   
                 692 
                 0.014795 
                 0.01648 
                 0.018165 
               
               
                   
                 694 
                 0.017148 
                 0.026443 
                 0.035738 
               
               
                   
                 696 
                 0.013255 
                 0.015435 
                 0.017615 
               
               
                   
                 698 
                 0.0121 
                 0.01304 
                 0.01398 
               
               
                   
                 700 
                 0.011542 
                 0.012727 
                 0.013912 
               
               
                   
                 702 
                 0.011226 
                 0.012981 
                 0.014736 
               
               
                   
                 704 
                 0.011728 
                 0.015483 
                 0.019238 
               
               
                   
                 706 
                 0.013805 
                 0.023045 
                 0.032285 
               
               
                   
                 708 
                 0.026806 
                 0.066926 
                 0.107046 
               
               
                   
                 710 
                 0.029198 
                 0.076303 
                 0.123408 
               
               
                   
                 712 
                 0.013137 
                 0.024182 
                 0.035227 
               
               
                   
                 714 
                 0.018797 
                 0.043992 
                 0.069187 
               
               
                   
                 716 
                 0.008111 
                 0.009701 
                 0.011291 
               
               
                   
                 718 
                 0.00744 
                 0.008405 
                 0.00937 
               
               
                   
                 720 
                 0.006897 
                 0.007732 
                 0.008567 
               
               
                   
                 722 
                 0.006787 
                 0.007587 
                 0.008387 
               
               
                   
                 724 
                 0.006289 
                 0.006994 
                 0.007699 
               
               
                   
                 726 
                 0.005959 
                 0.006624 
                 0.007289 
               
               
                   
                 728 
                 0.005447 
                 0.006077 
                 0.006707 
               
               
                   
                 730 
                 0.005466 
                 0.006141 
                 0.006816 
               
               
                   
                 732 
                 0.005346 
                 0.005961 
                 0.006576 
               
               
                   
                 734 
                 0.004935 
                 0.005435 
                 0.005935 
               
               
                   
                 736 
                 0.004677 
                 0.005177 
                 0.005677 
               
               
                   
                 738 
                 0.004646 
                 0.005146 
                 0.005646 
               
               
                   
                 740 
                 0.004793 
                 0.005293 
                 0.005793 
               
               
                   
                 742 
                 0.004545 
                 0.0056 
                 0.006655 
               
               
                   
                 744 
                 0.004599 
                 0.006199 
                 0.007799 
               
               
                   
                 746 
                 0.003901 
                 0.004401 
                 0.004901 
               
               
                   
                 748 
                 0.003995 
                 0.00496 
                 0.005925 
               
               
                   
                 750 
                 0.003715 
                 0.004215 
                 0.004715 
               
               
                   
                 752 
                 0.003625 
                 0.004125 
                 0.004625 
               
               
                   
                 754 
                 0.003318 
                 0.003818 
                 0.004318 
               
               
                   
                 756 
                 0.003133 
                 0.003633 
                 0.004133 
               
               
                   
                 758 
                 0.003193 
                 0.003693 
                 0.004193 
               
               
                   
                 760 
                 0.00308 
                 0.00358 
                 0.00408 
               
               
                   
                 762 
                 0.003095 
                 0.003595 
                 0.004095 
               
               
                   
                 764 
                 0.002751 
                 0.003251 
                 0.003751 
               
               
                   
                 766 
                 0.002666 
                 0.003166 
                 0.003666 
               
               
                   
                 768 
                 0.002573 
                 0.003073 
                 0.003573 
               
               
                   
                 770 
                 0.002335 
                 0.002835 
                 0.003335 
               
               
                   
                 772 
                 0.002312 
                 0.002812 
                 0.003312 
               
               
                   
                 774 
                 0.001938 
                 0.002438 
                 0.002938 
               
               
                   
                 776 
                 0.001862 
                 0.002362 
                 0.002862 
               
               
                   
                 778 
                 0.001972 
                 0.002472 
                 0.002972 
               
               
                   
                 780 
                 0.001951 
                 0.002451 
                 0.002951 
               
               
                   
                   
               
             
          
         
       
     
     Further data of Example I are given in Table II: 
     
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE II 
               
               
                   
                   
               
               
                   
                 LED 
                 Aux1 
                 Aux2 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 CCT [K] 
                 4491 
                 3481 
                 2865 
               
               
                   
                 Ra 
                 80 
                 88 
                 85 
               
               
                   
                 uv 
                 0.011 
                 0.002 
                 0.009 
               
               
                   
                 x 
                 0.3662 
                 0.4043 
                 0.4331 
               
               
                   
                 y 
                 0.3923 
                 0.3857 
                 0.3807 
               
               
                   
                 LE [lmW] 
                 343 
                 334 
                 327 
               
               
                   
                 R1 
                 77.7 
                 94.2 
                 97 
               
               
                   
                 R2 
                 89.4 
                 99 
                 92.1 
               
               
                   
                 R3 
                 95.6 
                 93.9 
                 87.6 
               
               
                   
                 R4 
                 72.6 
                 88.4 
                 94.7 
               
               
                   
                 R5 
                 76.1 
                 92.1 
                 97 
               
               
                   
                 R6 
                 85.8 
                 93.2 
                 80.9 
               
               
                   
                 R7 
                 83.6 
                 82.1 
                 76.2 
               
               
                   
                 R8 
                 57.2 
                 61.9 
                 56.5 
               
               
                   
                 R9 
                 14.9 
                 9.9 
                 7.2 
               
               
                   
                 R10 
                 73.8 
                 96.1 
                 88.9 
               
               
                   
                 R11 
                 68.6 
                 88 
                 96.7 
               
               
                   
                 R12 
                 57.3 
                 79.8 
                 76.2 
               
               
                   
                 R13 
                 80.6 
                 96.9 
                 94.7 
               
               
                   
                 R14 
                 97.4 
                 98.8 
                 96 
               
               
                   
                   
               
             
          
         
       
     
     It can be clearly seen that a shift of the color temperature over approx. 1600K is possible without any deterioration of the lighting properties, such as the color rendering index Ra of the light delivery device. 
       FIG. 7  shows a graph with three emission spectra of a light delivery device according to a second example of the invention. 
     EXAMPLE II 
     In Example II, a light delivery device with the setting of  FIG. 1  was used. The first LED (reference no.  20  in  FIG. 1 ) was an InGaN LED with a peak emission at 462 nm, the first converter substance (reference no.  30  in  FIG. 1 ) was a YAG:Ce ceramic material with the composition Y (3-x-y) Gd x Al 5 O 12 :Ce y  with x=0.3 and y=0.06. 
     The conversion element on Example II is CaS:Eu with 0.1% Europium. 
     The light delivery device furthermore comprises two sets of auxiliary LEDs (reference no.  40  in  FIG. 1 ), which are also InGaN LEDs emitting at 450 nm. Each set of LEDs has a “strength” of 50% of the first LED. 
       FIG. 7  shows the spectra of the light delivery device with the first LED only (“LED”), with one set of auxiliary LEDs switched on (“Aux 1 ”) and with both sets of auxiliary LEDs switched on (“Aux 2 ”). 
     The data of  FIG. 7  are listed in Table III: 
     
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE III 
               
               
                   
                   
               
               
                   
                 LED 
                 Aux 1 
                 Aux 2 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 380 
                 0.002731 
                 0.002811 
                 0.002891 
               
               
                   
                 382 
                 0.00246 
                 0.00254 
                 0.00262 
               
               
                   
                 384 
                 0.002295 
                 0.002375 
                 0.002455 
               
               
                   
                 386 
                 0.002183 
                 0.002263 
                 0.002343 
               
               
                   
                 388 
                 0.0021 
                 0.00218 
                 0.00226 
               
               
                   
                 390 
                 0.002063 
                 0.002143 
                 0.002223 
               
               
                   
                 392 
                 0.001984 
                 0.002064 
                 0.002144 
               
               
                   
                 394 
                 0.001932 
                 0.002012 
                 0.002092 
               
               
                   
                 396 
                 0.001891 
                 0.001971 
                 0.002051 
               
               
                   
                 398 
                 0.001885 
                 0.001965 
                 0.002045 
               
               
                   
                 400 
                 0.001894 
                 0.001974 
                 0.002054 
               
               
                   
                 402 
                 0.001904 
                 0.001984 
                 0.002064 
               
               
                   
                 404 
                 0.001916 
                 0.001996 
                 0.002076 
               
               
                   
                 406 
                 0.00201 
                 0.00209 
                 0.00217 
               
               
                   
                 408 
                 0.002198 
                 0.002278 
                 0.002358 
               
               
                   
                 410 
                 0.002487 
                 0.002567 
                 0.002647 
               
               
                   
                 412 
                 0.00291 
                 0.00299 
                 0.00307 
               
               
                   
                 414 
                 0.003532 
                 0.003612 
                 0.003692 
               
               
                   
                 416 
                 0.004441 
                 0.004521 
                 0.004601 
               
               
                   
                 418 
                 0.005643 
                 0.005723 
                 0.005803 
               
               
                   
                 420 
                 0.007188 
                 0.007268 
                 0.007348 
               
               
                   
                 422 
                 0.009126 
                 0.009206 
                 0.009286 
               
               
                   
                 424 
                 0.011543 
                 0.011623 
                 0.011703 
               
               
                   
                 426 
                 0.014461 
                 0.014541 
                 0.014621 
               
               
                   
                 428 
                 0.017876 
                 0.017956 
                 0.018036 
               
               
                   
                 430 
                 0.021857 
                 0.021937 
                 0.022017 
               
               
                   
                 432 
                 0.026492 
                 0.026572 
                 0.026652 
               
               
                   
                 434 
                 0.031853 
                 0.031933 
                 0.032013 
               
               
                   
                 436 
                 0.037928 
                 0.038008 
                 0.038088 
               
               
                   
                 438 
                 0.044757 
                 0.044837 
                 0.044917 
               
               
                   
                 440 
                 0.052341 
                 0.052421 
                 0.052501 
               
               
                   
                 442 
                 0.06054 
                 0.06062 
                 0.0607 
               
               
                   
                 444 
                 0.069068 
                 0.069148 
                 0.069228 
               
               
                   
                 446 
                 0.0776 
                 0.07768 
                 0.07776 
               
               
                   
                 448 
                 0.085827 
                 0.085907 
                 0.085987 
               
               
                   
                 450 
                 0.093335 
                 0.093415 
                 0.093495 
               
               
                   
                 452 
                 0.099715 
                 0.099795 
                 0.099875 
               
               
                   
                 454 
                 0.104735 
                 0.104815 
                 0.104895 
               
               
                   
                 456 
                 0.108405 
                 0.108485 
                 0.108565 
               
               
                   
                 458 
                 0.110776 
                 0.110856 
                 0.110936 
               
               
                   
                 460 
                 0.111859 
                 0.111939 
                 0.112019 
               
               
                   
                 462 
                 0.111729 
                 0.111809 
                 0.111889 
               
               
                   
                 464 
                 0.110624 
                 0.110704 
                 0.110784 
               
               
                   
                 466 
                 0.10875 
                 0.10883 
                 0.10891 
               
               
                   
                 468 
                 0.106153 
                 0.106233 
                 0.106313 
               
               
                   
                 470 
                 0.102863 
                 0.102943 
                 0.103023 
               
               
                   
                 472 
                 0.099002 
                 0.099082 
                 0.099162 
               
               
                   
                 474 
                 0.094808 
                 0.094888 
                 0.094968 
               
               
                   
                 476 
                 0.090407 
                 0.090487 
                 0.090567 
               
               
                   
                 478 
                 0.085859 
                 0.085939 
                 0.086019 
               
               
                   
                 480 
                 0.081277 
                 0.081357 
                 0.081437 
               
               
                   
                 482 
                 0.076808 
                 0.076888 
                 0.076968 
               
               
                   
                 484 
                 0.072592 
                 0.072672 
                 0.072752 
               
               
                   
                 486 
                 0.068674 
                 0.068754 
                 0.068834 
               
               
                   
                 488 
                 0.06512 
                 0.0652 
                 0.06528 
               
               
                   
                 490 
                 0.062011 
                 0.062091 
                 0.062171 
               
               
                   
                 492 
                 0.059401 
                 0.059481 
                 0.059561 
               
               
                   
                 494 
                 0.057342 
                 0.057422 
                 0.057502 
               
               
                   
                 496 
                 0.055892 
                 0.055972 
                 0.056052 
               
               
                   
                 498 
                 0.055102 
                 0.055182 
                 0.055262 
               
               
                   
                 500 
                 0.054976 
                 0.055056 
                 0.055136 
               
               
                   
                 502 
                 0.055448 
                 0.055528 
                 0.055608 
               
               
                   
                 504 
                 0.056473 
                 0.056553 
                 0.056633 
               
               
                   
                 506 
                 0.057981 
                 0.058061 
                 0.058141 
               
               
                   
                 508 
                 0.059874 
                 0.059954 
                 0.060034 
               
               
                   
                 510 
                 0.06208 
                 0.06216 
                 0.06224 
               
               
                   
                 512 
                 0.064504 
                 0.064584 
                 0.064664 
               
               
                   
                 514 
                 0.067104 
                 0.067184 
                 0.067264 
               
               
                   
                 516 
                 0.069813 
                 0.069893 
                 0.069973 
               
               
                   
                 518 
                 0.072572 
                 0.072652 
                 0.072732 
               
               
                   
                 520 
                 0.075336 
                 0.075416 
                 0.075496 
               
               
                   
                 522 
                 0.078019 
                 0.078099 
                 0.078179 
               
               
                   
                 524 
                 0.08058 
                 0.08066 
                 0.08074 
               
               
                   
                 526 
                 0.082985 
                 0.083065 
                 0.083145 
               
               
                   
                 528 
                 0.085209 
                 0.085289 
                 0.085369 
               
               
                   
                 530 
                 0.087237 
                 0.087317 
                 0.087397 
               
               
                   
                 532 
                 0.089072 
                 0.089152 
                 0.089232 
               
               
                   
                 534 
                 0.090731 
                 0.090811 
                 0.090891 
               
               
                   
                 536 
                 0.092226 
                 0.092306 
                 0.092386 
               
               
                   
                 538 
                 0.093548 
                 0.093628 
                 0.093708 
               
               
                   
                 540 
                 0.094726 
                 0.094806 
                 0.094886 
               
               
                   
                 542 
                 0.09578 
                 0.09586 
                 0.09594 
               
               
                   
                 544 
                 0.0967 
                 0.09678 
                 0.09686 
               
               
                   
                 546 
                 0.097504 
                 0.097584 
                 0.097664 
               
               
                   
                 548 
                 0.098204 
                 0.098284 
                 0.098364 
               
               
                   
                 550 
                 0.098803 
                 0.098883 
                 0.098963 
               
               
                   
                 552 
                 0.099295 
                 0.099375 
                 0.099455 
               
               
                   
                 554 
                 0.099666 
                 0.099746 
                 0.099826 
               
               
                   
                 556 
                 0.099941 
                 0.100021 
                 0.100101 
               
               
                   
                 558 
                 0.10014 
                 0.100253 
                 0.100366 
               
               
                   
                 560 
                 0.100248 
                 0.100352 
                 0.100457 
               
               
                   
                 562 
                 0.100278 
                 0.100419 
                 0.10056 
               
               
                   
                 564 
                 0.100233 
                 0.10041 
                 0.100586 
               
               
                   
                 566 
                 0.10013 
                 0.100255 
                 0.10038 
               
               
                   
                 568 
                 0.099938 
                 0.100226 
                 0.100514 
               
               
                   
                 570 
                 0.099644 
                 0.099935 
                 0.100225 
               
               
                   
                 572 
                 0.099263 
                 0.099655 
                 0.100047 
               
               
                   
                 574 
                 0.09881 
                 0.099252 
                 0.099693 
               
               
                   
                 576 
                 0.098291 
                 0.098948 
                 0.099605 
               
               
                   
                 578 
                 0.097708 
                 0.09838 
                 0.099052 
               
               
                   
                 580 
                 0.097084 
                 0.098111 
                 0.099137 
               
               
                   
                 582 
                 0.096427 
                 0.097766 
                 0.099105 
               
               
                   
                 584 
                 0.095733 
                 0.097249 
                 0.098765 
               
               
                   
                 586 
                 0.094989 
                 0.096655 
                 0.098321 
               
               
                   
                 588 
                 0.094207 
                 0.096499 
                 0.098791 
               
               
                   
                 590 
                 0.093417 
                 0.096078 
                 0.098739 
               
               
                   
                 592 
                 0.092576 
                 0.096145 
                 0.099715 
               
               
                   
                 594 
                 0.091684 
                 0.095957 
                 0.100231 
               
               
                   
                 596 
                 0.090785 
                 0.095981 
                 0.101177 
               
               
                   
                 598 
                 0.089914 
                 0.09634 
                 0.102765 
               
               
                   
                 600 
                 0.089023 
                 0.097329 
                 0.105635 
               
               
                   
                 602 
                 0.088138 
                 0.097263 
                 0.106389 
               
               
                   
                 604 
                 0.087334 
                 0.097683 
                 0.108031 
               
               
                   
                 606 
                 0.086558 
                 0.099057 
                 0.111555 
               
               
                   
                 608 
                 0.08584 
                 0.101103 
                 0.116365 
               
               
                   
                 610 
                 0.085138 
                 0.102026 
                 0.118914 
               
               
                   
                 612 
                 0.084485 
                 0.104488 
                 0.12449 
               
               
                   
                 614 
                 0.083873 
                 0.107333 
                 0.130793 
               
               
                   
                 616 
                 0.08323 
                 0.109446 
                 0.135663 
               
               
                   
                 618 
                 0.082661 
                 0.113232 
                 0.143802 
               
               
                   
                 620 
                 0.082144 
                 0.116123 
                 0.150101 
               
               
                   
                 622 
                 0.081627 
                 0.118431 
                 0.155235 
               
               
                   
                 624 
                 0.08123 
                 0.122007 
                 0.162784 
               
               
                   
                 626 
                 0.080804 
                 0.124579 
                 0.168354 
               
               
                   
                 628 
                 0.08048 
                 0.128565 
                 0.176649 
               
               
                   
                 630 
                 0.080106 
                 0.132753 
                 0.1854 
               
               
                   
                 632 
                 0.079787 
                 0.135032 
                 0.190277 
               
               
                   
                 634 
                 0.079415 
                 0.140028 
                 0.200642 
               
               
                   
                 636 
                 0.078916 
                 0.141712 
                 0.204508 
               
               
                   
                 638 
                 0.078449 
                 0.145427 
                 0.212405 
               
               
                   
                 640 
                 0.077836 
                 0.146472 
                 0.215107 
               
               
                   
                 642 
                 0.077139 
                 0.150875 
                 0.224611 
               
               
                   
                 644 
                 0.076284 
                 0.150698 
                 0.225112 
               
               
                   
                 646 
                 0.075289 
                 0.150925 
                 0.226561 
               
               
                   
                 648 
                 0.074195 
                 0.152055 
                 0.229916 
               
               
                   
                 650 
                 0.072828 
                 0.150963 
                 0.229098 
               
               
                   
                 652 
                 0.071378 
                 0.149344 
                 0.227309 
               
               
                   
                 654 
                 0.069852 
                 0.149852 
                 0.229852 
               
               
                   
                 656 
                 0.068139 
                 0.145939 
                 0.223738 
               
               
                   
                 658 
                 0.066397 
                 0.143834 
                 0.221272 
               
               
                   
                 660 
                 0.064552 
                 0.138972 
                 0.213393 
               
               
                   
                 662 
                 0.062615 
                 0.136383 
                 0.210151 
               
               
                   
                 664 
                 0.060556 
                 0.133304 
                 0.206053 
               
               
                   
                 666 
                 0.0584 
                 0.129308 
                 0.200216 
               
               
                   
                 668 
                 0.056123 
                 0.125063 
                 0.194003 
               
               
                   
                 670 
                 0.053743 
                 0.120684 
                 0.187625 
               
               
                   
                 672 
                 0.05133 
                 0.113789 
                 0.176248 
               
               
                   
                 674 
                 0.049083 
                 0.108819 
                 0.168556 
               
               
                   
                 676 
                 0.046732 
                 0.103957 
                 0.161182 
               
               
                   
                 678 
                 0.044451 
                 0.097638 
                 0.150824 
               
               
                   
                 680 
                 0.042273 
                 0.091529 
                 0.140785 
               
               
                   
                 682 
                 0.040124 
                 0.086984 
                 0.133844 
               
               
                   
                 684 
                 0.038025 
                 0.083943 
                 0.129862 
               
               
                   
                 686 
                 0.035843 
                 0.076383 
                 0.116923 
               
               
                   
                 688 
                 0.033855 
                 0.073202 
                 0.112548 
               
               
                   
                 690 
                 0.031863 
                 0.068753 
                 0.105643 
               
               
                   
                 692 
                 0.029922 
                 0.062992 
                 0.096063 
               
               
                   
                 694 
                 0.028121 
                 0.059684 
                 0.091248 
               
               
                   
                 696 
                 0.026411 
                 0.055107 
                 0.083803 
               
               
                   
                 698 
                 0.024817 
                 0.0518 
                 0.078783 
               
               
                   
                 700 
                 0.023267 
                 0.04813 
                 0.072993 
               
               
                   
                 702 
                 0.021803 
                 0.044705 
                 0.067606 
               
               
                   
                 704 
                 0.020463 
                 0.041375 
                 0.062287 
               
               
                   
                 706 
                 0.019186 
                 0.038765 
                 0.058343 
               
               
                   
                 708 
                 0.017968 
                 0.035719 
                 0.05347 
               
               
                   
                 710 
                 0.016772 
                 0.033093 
                 0.049414 
               
               
                   
                 712 
                 0.015685 
                 0.030275 
                 0.044866 
               
               
                   
                 714 
                 0.014667 
                 0.029027 
                 0.043387 
               
               
                   
                 716 
                 0.013678 
                 0.026584 
                 0.039491 
               
               
                   
                 718 
                 0.012728 
                 0.02487 
                 0.037012 
               
               
                   
                 720 
                 0.011838 
                 0.021897 
                 0.031956 
               
               
                   
                 722 
                 0.011087 
                 0.020362 
                 0.029638 
               
               
                   
                 724 
                 0.010336 
                 0.018908 
                 0.02748 
               
               
                   
                 726 
                 0.009658 
                 0.017608 
                 0.025558 
               
               
                   
                 728 
                 0.00902 
                 0.015997 
                 0.022974 
               
               
                   
                 730 
                 0.008502 
                 0.014717 
                 0.020931 
               
               
                   
                 732 
                 0.007991 
                 0.013938 
                 0.019885 
               
               
                   
                 734 
                 0.007478 
                 0.012436 
                 0.017395 
               
               
                   
                 736 
                 0.007028 
                 0.012045 
                 0.017063 
               
               
                   
                 738 
                 0.00659 
                 0.010689 
                 0.014789 
               
               
                   
                 740 
                 0.006218 
                 0.010233 
                 0.014248 
               
               
                   
                 742 
                 0.005813 
                 0.009442 
                 0.013072 
               
               
                   
                 744 
                 0.005459 
                 0.008447 
                 0.011434 
               
               
                   
                 746 
                 0.005142 
                 0.007815 
                 0.010488 
               
               
                   
                 748 
                 0.004859 
                 0.007119 
                 0.009379 
               
               
                   
                 750 
                 0.004616 
                 0.007121 
                 0.009627 
               
               
                   
                 752 
                 0.004355 
                 0.006159 
                 0.007964 
               
               
                   
                 754 
                 0.004116 
                 0.006123 
                 0.008129 
               
               
                   
                 756 
                 0.003899 
                 0.005788 
                 0.007677 
               
               
                   
                 758 
                 0.003704 
                 0.005228 
                 0.006752 
               
               
                   
                 760 
                 0.003509 
                 0.00523 
                 0.006952 
               
               
                   
                 762 
                 0.00331 
                 0.004353 
                 0.005396 
               
               
                   
                 764 
                 0.003101 
                 0.004161 
                 0.005221 
               
               
                   
                 766 
                 0.002911 
                 0.003969 
                 0.005027 
               
               
                   
                 768 
                 0.002731 
                 0.003769 
                 0.004806 
               
               
                   
                 770 
                 0.002567 
                 0.003607 
                 0.004647 
               
               
                   
                 772 
                 0.002475 
                 0.003363 
                 0.004251 
               
               
                   
                 774 
                 0.002384 
                 0.003092 
                 0.0038 
               
               
                   
                 776 
                 0.002342 
                 0.002933 
                 0.003525 
               
               
                   
                 778 
                 0.002329 
                 0.002724 
                 0.003118 
               
               
                   
                 780 
                 0.002339 
                 0.002902 
                 0.003465 
               
               
                   
                   
               
             
          
         
       
     
     Further data of Example II are given in Table IV: 
     
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE IV 
               
               
                   
                   
               
               
                   
                 LED 
                 Aux1 
                 Aux2 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 CCT [K] 
                 4881 
                 3895 
                 3180 
               
               
                   
                 Ra 
                 88 
                 93 
                 83 
               
               
                   
                 uv 
                 0.004 
                 0.008 
                 0.016 
               
               
                   
                 x 
                 0.3494 
                 0.3788 
                 0.4035 
               
               
                   
                 y 
                 0.3632 
                 0.3579 
                 0.3535 
               
               
                   
                 LE [lm/W] 
                 297 
                 254 
                 226 
               
               
                   
                 R1 
                 86.3 
                 92 
                 78.4 
               
               
                   
                 R2 
                 94.1 
                 94.2 
                 85 
               
               
                   
                 R3 
                 96.4 
                 96.1 
                 97 
               
               
                   
                 R4 
                 80.1 
                 97.2 
                 85.9 
               
               
                   
                 R5 
                 83.8 
                 93.4 
                 79.5 
               
               
                   
                 R6 
                 88.3 
                 94.3 
                 83 
               
               
                   
                 R7 
                 90.9 
                 96.4 
                 92.4 
               
               
                   
                 R8 
                 80.2 
                 84.1 
                 65 
               
               
                   
                 R9 
                 50.1 
                 58.2 
                 16.2 
               
               
                   
                 R10 
                 82.5 
                 92.9 
                 73 
               
               
                   
                 R11 
                 76.5 
                 97.7 
                 84.7 
               
               
                   
                 R12 
                 62.9 
                 79.4 
                 66.8 
               
               
                   
                 R13 
                 88.6 
                 92.1 
                 78.6 
               
               
                   
                 R14 
                 97.9 
                 96.4 
                 96.6 
               
               
                   
                   
               
             
          
         
       
     
     It can be clearly seen that a shift of the color temperature over approx. 1700K is possible without any deterioration in the lighting properties, such as the Ra of the light delivery device. 
     In both examples it is possible to simply “add” red light, i.e. the spectra in the wavelength range of 380 to 580 nm are more or less identical for “LED”, “Aux 1 ” as well as “Aux 2 ”. 
     It should be noted that in both examples the light flux even increases by switching on the LED groups Aux 1  and Aux  2 . If a constant flux is required, the first LED may be dimmed when the Aux 1  and Aux 2  LEDs are switched on. In this case the color temperature will be decreased even further with the full power of the Aux 1  and Aux 2  LEDs added. It is evident that the light flux of all LEDs can be tuned to any desired value between the maximum power applicable to the LED package and zero. Power can be modified either by increasing and decreasing the DC voltage and current or by application of fast current and voltage pulses at a frequency &gt;10 Hz and modifying the ratio of the on and off-time of the power. 
     The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this patent application and the patents/applications incorporated by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is by way of example only, and is not intended to be limiting. The invention&#39;s scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed.