Aeon Imaging has developed a unique approach to imaging that uses the row-by-row exposure of a 2D CMOS rolling shutter camera as a flexible electronic aperture.

Unlike a global shutter, which integrates charge evenly across the entire active sensor area during the exposure time, rolling shutter CMOS cameras integrate light over one or more pixel rows at a time. Light that reaches the sensor, but is outside the active rolling shutter read area, is not captured, and therefore cannot reduce contrast.

With the flexible electronic aperture, confocal imaging is made possible by temporally and spatially synchronizing the rolling shutter with an illumination line at the target. Unlike similar confocal imaging systems, our approach does not require de-scanning, nor a separate mechanical aperture such as a pinhole or slit.

Some key advantages this approach offers are:

• Real-time adjustments to the confocal aperture width. This permits software-based image adjustment to balance the trade-off between maximizing image contrast and signal to noise ratio.
• Highly accurate and repeatable adjustments to the offset of the confocal aperture with respect to the illumination line. Spatial offsets are at the pixel-level (several micrometers, depending on the camera) and temporal offsets are on the order of a microsecond. Both can be set on a frame-to-frame basis through software, providing a unique advantage over mechanical aperture-based systems.