Fully Integrated Ultrathin Camera for Contact Fingerprint Imaging

Abstract

We reports a fully integrated ultrathin camera with lens plate on CMOS image sensor for contact fingerprint imaging. The ultrathin camera consists of inverted type microlens array (MLA) and multiple block layers (MBLs) on CMOS image sensor. The MBLs consist of alternating transparent and black multiple layers of SU8/black SU-8 and reduce the optical crosstalk between neighboring images and control the field of view (FOV) of each microlens by adjusting the aperture diameter of the block layer. Contact fingerprint image was successfully captured by using frustrated total internal reflection method and reconstructed to one large image by stitching the partial images from the individual optical channels. This ultrathin camera can be utilized in various miniaturized optical devices including mobile or endoscopes.