A Flexible FOV Capsule Endoscope Design Based on Compound Lens

This paper proposes a capsule endoscope (CE) with a flexible large field of view (FOV) that imitates the compound eyes of insects, like those of a fly. Thirty-one ball lenses are demonstrated to cover 175° viewing area for constructing the compound lens. The ball lens used in the CE is responsible for 40° view to form the image on a curve image plane. A fiber array is applied to fit the curve image plane to improve the field curvature aberration and deliver the image into an image sensor. Such a compound lens can share image aberrations into the multiple ball lenses, keep high relative illumination (RI), and make the adjustment of the FOV possible. With a 45 × 45 fiber array, a ray tracing is simulated to verify that the proposed CE is feasible. The results show that the CE can capture 175° viewing area though the compound lens with ball-lens-based design.