Light source apparatus and endoscope system

Abstract

A fluorescent type of green light source of a semiconductor in a light source apparatus for an endoscope includes a blue excitation light source device and green emitting phosphor. The blue excitation light source device emits blue excitation light. The green emitting phosphor is excited by the blue excitation light, and emits green fluorescence. A dichroic filter in a dichroic mirror cuts off the blue excitation light from an emission spectrum of mixed light of the blue excitation light and green fluorescence from the fluorescent type of green light source. Thus, illumination light with the emission spectrum of a target can be stably supplied without influence of the blue excitation light to a light amount of blue light from a blue light source of a semiconductor.

What is claimed is: 
     
         1 . A light source apparatus for supplying a light guide device of an endoscope with light, comprising:
 a blue semiconductor light source for emitting blue light of a blue wavelength range;   a fluorescent type of a green semiconductor light source, having a blue excitation light source device and green emitting phosphor, said blue excitation light source device emitting blue excitation light of a violet to blue wavelength range overlapping on said blue wavelength range of said blue light, said green emitting phosphor being excited by said blue excitation light for emitting green fluorescence of a green wavelength range;   a wavelength cut-off filter component, disposed between said blue excitation light source device and said light guide device, for cutting off said blue excitation light.   
     
     
         2 . A light source apparatus as defined in  claim 1 , further comprising a path coupler for coupling two light paths from said blue and green semiconductor light sources together. 
     
     
         3 . A light source apparatus as defined in  claim 2 , wherein said wavelength cut-off filter component is disposed on said path coupler, or disposed between said path coupler and said green semiconductor light source. 
     
     
         4 . A light source apparatus as defined in  claim 2 , wherein said path coupler includes optics disposed at an intersection point between said two light paths;
 said wavelength cut-off filter component is a dichroic filter formed on said optics.   
     
     
         5 . A light source apparatus as defined in  claim 1 , further comprising a driver for simultaneously driving said blue and green semiconductor light sources for vessel enhancement imaging, to output mixed light of said blue light and said green fluorescence. 
     
     
         6 . A light source apparatus as defined in  claim 1 , further comprising a driver for alternately driving said blue and green semiconductor light sources for vessel enhancement imaging, sequentially to output said blue light and said green fluorescence. 
     
     
         7 . Alight source apparatus as defined in  claim 1 , further comprising a driver, connected to said blue and green semiconductor light sources, and changeable between simultaneous lighting and field sequential lighting;
 wherein in said simultaneous lighting, said driver simultaneously drives said blue and green semiconductor light sources for vessel enhancement imaging, to output mixed light of said blue light and said green fluorescence;   in said field sequential lighting, said driver alternately drives said blue and green semiconductor light sources for vessel enhancement imaging, sequentially to output said blue light and said green fluorescence.   
     
     
         8 . Alight source apparatus as defined in claim.  1 , wherein said blue semiconductor light source emits said blue light with a peak wavelength of at least one of 405, 415, 430 and 460 nm. 
     
     
         9 . Alight source apparatus as defined in claim.  1 , further comprising:
 a measurement sensor for measuring a light amount of said blue light or said green fluorescence emitted by at least one of said blue and green semiconductor light sources;   an optical path device for guiding part of said blue light or said green fluorescence to said measurement sensor;   a light source controller for controlling power supplied to said blue or green semiconductor light source according to a measurement result of said measurement sensor.   
     
     
         10 . Alight source apparatus as defined in  claim 9 , wherein said measurement sensor and said optical path device are associated with said green semiconductor light source, and said light source controller adjusts said power supplied to said blue excitation light source device according to said measurement result. 
     
     
         11 . A light source apparatus as defined in  claim 9 , further comprising a band pass filter, disposed upstream of said measurement sensor, for receiving light emitted by said green semiconductor light source and reflected by said optical path device, and cutting off light with a wavelength different from said green wavelength range of said green fluorescence. 
     
     
         12 . A light source apparatus as defined in  claim 9 , wherein said wavelength cut-off filter component is a wavelength cut-off filter of a plate shape disposed between said green semiconductor light source and said optical path device. 
     
     
         13 . A light source apparatus as defined in  claim 9 , wherein said optical path device includes a transparent glass plate, disposed downstream of said blue or green semiconductor light source, for reflecting said part of said blue light or said green fluorescence by Fresnel reflection, to guide said part to said sensor. 
     
     
         14 . A light source apparatus as defined in  claim 1 , further comprising a rotatable disk having said green emitting phosphor formed on a surface thereof;
 wherein said blue excitation light source device emits said blue excitation light toward said rotatable disk being rotated at an eccentric point thereof.   
     
     
         15 . An endoscope system including an endoscope having a light guide device for guiding light, and a light source apparatus for supplying said light guide device with said light, said endoscope system comprising:
 said light source apparatus including:   a blue semiconductor light source for emitting blue light of a blue wavelength range;   a fluorescent type of a green semiconductor light source, having a blue excitation light source device and green emitting phosphor, said blue excitation light source device emitting blue excitation light of a violet to blue wavelength range overlapping on said blue wavelength range of said blue light, said green emitting phosphor being excited by said blue excitation light for emitting green fluorescence of a green wavelength range;   a wavelength cut-off filter component, disposed between said blue excitation light source device and said light guide device, for cutting off said blue excitation light.