Systems and methods for illumination and imaging of a target
An imaging device may include a first illumination port to output first light having a first illumination distribution at a target to illuminate the target, a second illumination port to output second light having a second illumination distribution at the target to illuminate the target, the second illumination distribution being substantially similar to the first illumination distribution at the target, the second illumination port being spaced apart from the first illumination port, the first and second illumination distributions being simultaneously provided to the target and overlapping at the target. The illumination from the first and second ports may be matched to a same aspect ratio and field of view coverage as the imaging field of view.
1. A processor to image a target, the processor to, within a period:
turn on an excitation light source to generate an excitation pulse to illuminate the target;
turn on a white light source to generate a white pulse to illuminate the target such that the white pulse does not overlap the excitation pulse and the white pulse is generated at least twice within the period;
expose an image sensor for a fluorescent exposure time during the excitation pulse;
expose the image sensor for a visible exposure time during at least one white pulse;
detect outputs from the image sensor;
compensate for ambient light; and
output a resultant image,
wherein, to compensate for ambient light, the processor is to:
expose a first set of sensor pixel rows of the image sensor for a fraction of the fluorescent exposure time; and
expose a second set of sensor pixel rows of the image sensor for all of the fluorescent exposure time.
2. The processor as claimed in claim 1 , wherein the fraction of the exposure time equals a width of the excitation pulse.
3. The processor as claimed in claim 1 , wherein the visible exposure time is for one white pulse within the period.
4. The processor as claimed in claim 1 , wherein the visible exposure time is for two white pulses within the period.
5. The processor as claimed in claim 1 , wherein, to compensate for ambient light, the processor is to:
expose the image sensor for a background exposure time when target is not illuminated at least once within the period.
6. A method for imaging a target, within a period, the method comprising:
generating an excitation pulse to illuminate the target;
generating a white pulse to illuminate the target such that the white pulse does not overlap the excitation pulse and the white pulse is generated at least twice within the period;
exposing an image sensor for a fluorescent exposure time during the excitation pulse;
exposing the image sensor for a visible exposure time during at least one white pulse;
detecting outputs from the image sensor;
compensating for ambient light including
exposing a first set of sensor pixel rows of the image sensor for a fraction of the fluorescent exposure time; and
exposing a second set of sensor pixel rows of the image sensor for all of the fluorescent exposure time; and
outputting a resultant image.
7. The method as claimed in claim 6 , wherein compensating for ambient light includes:
exposing the image sensor for a background exposure time when target is not illuminated at least once within the period.
8. The method as claimed in claim 6 , wherein generating the excitation pulse includes providing uniform, anamorphic illumination to the target.
9. The method as claimed in claim 8 , wherein providing uniform, anamorphic illumination to the target includes overlapping illumination from at least two illumination ports.
10. The method as claimed in claim 6 , wherein exposing the image sensor for the fluorescent exposure time includes providing a wavelength-dependent aperture upstream of the image sensor during the exposure, the wavelength-dependent aperture to block visible light outside a central region.
11. The method as claimed in claim 9 , wherein overlapping illumination from at least two illumination ports includes steering illumination from at least two illumination ports in accordance with a change of working distance.
12. A processor to image a target, the processor to, within a period:
turn on an excitation light source to generate an excitation pulse to illuminate the target;
turn on a white light source to generate a white pulse to illuminate the target such that the white pulse does not overlap the excitation pulse and the white pulse is generated at least twice within the period;
expose an image sensor for a fluorescent exposure time during the excitation pulse;
expose the image sensor for a visible exposure time during at least one white pulse, wherein a number of visible exposure times is less than a number of white pulses;
detect outputs from the image sensor;
compensate for ambient light; and
output a resultant image.
13. The processor as claimed in claim 12 , wherein to generate the excitation pulse, the processor is to provide uniform, anamorphic illumination to the target.
14. The processor as claimed in claim 13 , wherein to provide uniform, anamorphic illumination to the target, the processor is to steer illumination from at least two illumination ports in accordance with a change of working distance such that illumination from the at least two illumination ports overlaps at the target.