Ultrathin Contact-Imaging Camera for Fingerprint Imaging using Microlens Array and Multiple Block Layers

We reports an ultrathin camera for contact fingerprint imaging. The ultrathin camera consists of inverted type microlens array (MLA) and multiple block layers (MBLs) on CMOS image sensor arrays. The MBLs consist of alternating transparent and black multi-layers of SU8/black SU-8, which reduce the optical crosstalk between neighboring microlenses as well as control the field of view (FOV) of each microlens by adjusting the aperture diameter of the block layer. Contact fingerprint image was successfully reconstructed by stitching the partial images from the individual optical channels. This contact-imaging camera can be utilized in fingerprint imaging underneath LED or OLED displays for biometric authentication.