Illumination system, microscope comprising an illumination system and microscope method

1. An illumination system ( 10 ) for a fluorescence microscope ( 3 ) for observation of an object ( 17 ) containing at least one fluorophore ( 19 ), comprising:

an illumination device ( 9 ), the illumination device ( 9 ) having an emission spectrum ( 22 ) which comprises fluorescence excitation wavelengths ( 23 ) of the at least one fluorophore ( 19 ) and visible-light background illumination wavelengths ( 25 ) which differ from the fluorescence excitation wavelengths ( 23 ),

an illumination filter ( 41 ) for arrangement between the illumination device ( 9 ) and the object ( 17 ), the illumination filter ( 41 ) having at least one fluorescence excitation passband ( 93 ) which is limited to the fluorescence excitation wavelengths ( 23 ) and at least one background illumination passband ( 95 ) which comprises the visible-light background illumination wavelengths ( 25 ),

wherein the transmissivity ( 88 ) of the fluorescence excitation passband ( 93 ) is larger than the transmissivity ( 88 ) of the background illumination passband ( 95 ) and wherein the width ( 92 ) of the fluorescence excitation passband ( 93 ) is smaller than the width ( 92 ) of the background illumination passband ( 95 ), and

wherein the intensity of the visible-light background illumination wavelengths ( 25 ) has at least a local maximum ( 111 ) at a color ( 112 ) complementary to a color ( 112 ) of fluorescence emission wavelengths ( 23 a ) of the at least one fluorophore ( 19 ).

2. The illumination system ( 10 ) according to claim 1 , wherein the illumination device ( 9 ) comprises a plurality of modes of operation, wherein, in each of the plurality of modes of operation, the ratio of the energy in the visible-light background illumination wavelengths ( 25 ) to the energy in the fluorescence excitation wavelengths ( 23 ) is different.

3. The illumination system ( 10 ) according to claim 1 , wherein the illumination device ( 9 ) comprises a plurality of modes of operation, wherein, in each of the plurality of modes of operation, the distribution of energy across the visible-light background illumination wavelengths ( 25 ) is different.

4. The illumination system ( 10 ) according to claim 1 , further comprising an image processor ( 57 ) and a light source controller ( 75 ), the image processor ( 57 ) being configured to determine a color ( 112 ) of at least part of the object ( 17 ) and wherein the light source controller ( 75 ) is adapted to change the emission spectrum ( 22 ) of the light source ( 29 ) depending on the determined color ( 112 ) of at least part of the object ( 17 ).

5. The illumination system according to claim 1 , further comprising an intensity detector ( 61 ) for determining an intensity of a fluorescence emission ( 113 ) emitted from the at least one fluorophore ( 19 ) and for automatically adjusting an intensity of at least part of the visible-light background illumination wavelengths ( 25 ) depending on the determined intensity.

6. A microscope ( 1 ) comprising an illumination system ( 10 ) according to claim 1 .

7. The illumination system ( 10 ) according to claim 1 , wherein the illumination device ( 9 ) comprises at least two light sources ( 29 ) having different emission spectra ( 22 ).

8. The illumination system ( 10 ) according to claim 7 , wherein the emission spectrum ( 22 ) of one of the at least two light sources ( 29 ) comprises the fluorescence excitation wavelengths ( 23 ) and the emission spectrum ( 22 ) of another one of the at least two light sources ( 29 ) comprises the visible-light background illumination wavelengths ( 25 ).

9. The illumination system ( 10 ) according to claim 7 , wherein the fluorescence excitation wavelengths ( 23 ) of different fluorophores ( 19 ) are emitted by different light sources ( 29 ) of the at least two light sources ( 29 ).

10. The illumination system ( 10 ) according to claim 7 , further comprising a controller ( 56 ) configured to adapt at least one of the emission spectrum ( 22 ) and the intensity of the at least two light sources ( 29 ) independently of one another.

11. A microscope method for illumination of an object ( 17 ) comprising at least one fluorophore ( 19 ), the method comprising the steps of:

illuminating the object ( 17 ) with fluorescence excitation wavelengths ( 23 ) in the fluorescence excitation spectrum ( 20 ) of the at least one fluorophore ( 19 ) and with visible-light background illumination wavelengths ( 25 ) different from the fluorescence excitation wavelengths ( 23 ); and

attenuating the visible-light background illumination wavelengths ( 25 ) before the visible-light background illumination wavelengths ( 25 ) reach the object ( 17 );

wherein the intensity of the visible-light background illumination wavelengths ( 25 ) has at least a local maximum ( 111 ) at a color ( 112 ) complementary to a color ( 112 ) of fluorescence emission wavelengths ( 23 a ) of the at least one fluorophore ( 19 ).

12. The microscope method according to claim 11 , further comprising the step of automatically adjusting a distribution of energy across the visible-light background illumination wavelengths ( 25 ) depending on a fluorescence emission spectrum of the at least one fluorophore ( 19 ).

13. The microscope method according to claim 11 , further comprising the step of automatically adjusting an intensity in the visible-light background illumination wavelengths ( 25 ) depending on an intensity of light emitted in the fluorescence emission spectrum of the at least one fluorophore ( 19 ).

14. The microscope method according to claim 11 , further comprising the step of automatically adjusting an intensity in the visible-light background illumination wavelengths ( 25 ) depending on a color ( 112 ) of at least part of the object ( 17 ).