Microprism for a capsule endoscope with wafer level optics

Capsule endoscopes are pill-sized devices that physicians can utilize for diagnosis of a patient's small intestine. For diagnostic requirements, excellent image quality, large field of view (FOV) and compact size are crucial. In this paper, a multi-camera capsule endoscope (MCCE) composed of two wafer level optic modules and microprism elements which can offer both a large FOV and clear image quality within limited space conditions is described. The properties of the microprism needed to ensure the necessary image quality are further discussed, including working efficiency, the ability to increase the FOV, and the inhibition of chromatic aberration. Finally, the functioning of the MCCE is verified through an optical simulation and preliminary experiments. The results show that the max half FOV of the MCCE could be increased from 28° to 37°, and the relative illumination could be kept at 80% without a dark corner effect. (paper)