Scene adaptive endoscopic illuminator with fluorescence illumination

A method of providing illumination for an endoscope, comprising:

• coupling first illumination light into a proximal end of a light guiding element for an endoscope centered along a first angle relative to the light guiding element;
• illuminating a central area of a field of view of the endoscope from a distal end of the light guiding element with the first illumination light;
• while coupling the first illumination light, coupling second illumination light into the light guiding element centered along a second angle substantially different from the first angle;
• illuminating a peripheral area of the field of view with the second illumination light;
• adjusting an illumination level of the second illumination light relative to that of the first illumination light to improve evenness of illumination in the field of view;
• coupling third illumination light, of a different spectral band than that of the first and second illumination light, into the proximal end of the light guiding element centered along the first angle;
• illuminating a central area of a field of view of the endoscope from the distal end of the light guiding element with the third illumination light;
• while coupling the third illumination light, coupling fourth illumination light into the light guiding element centered along a substantially different angle than the first angle;
• illuminating a peripheral area of the field of view with the fourth illumination light;
• and
• adjusting an illumination level of the fourth illumination light relative to that of the third illumination light to improve evenness of illumination in the field of view.

An endoscopic imaging system comprising:

• an endoscope comprising a shaft, a light guide extending along at least a portion of the shaft to a distal end of the shaft, and a light input;
• a light source comprising:
• a first illumination element providing first illumination light into the light input, which is emitted by the light guide to illuminate a central area of a field of view of the endoscope;
• a second illumination element providing second illumination light to the light input and arranged relative to the first illumination element such that the second illumination light enters the light input at a substantially different angle from the first illumination light, which is emitted by the light guide to illuminate a peripheral area of the field of view, the second illumination element having an illumination level adjustable separately from that of the first illumination element;
• a third illumination element providing third illumination light, of a different spectral band than that of the first and second illumination light, into the light input, the third illumination light emitted by the light guide to illuminate a central area of a field of view of the endoscope;
• and
• a fourth illumination element providing fourth illumination light of the same spectral band as the third illumination light to the light input and arranged relative to the third illumination element such that the fourth illumination light enters the light input at a substantially different angle from the third illumination light and is emitted by the light guide to illuminate a peripheral area of the field of view, the fourth illumination element having an illumination level adjustable separately from that of the third illumination element.