Lensless close-up imaging with Fresnel zone aperture

Lensless light-field imaging technology using a Fresnel zone aperture (FZA) enables the development of extremely thin cameras with a function of refocusing after image capture. We propose two close-up technologies for lensless technology to image objects at short distances of millimeter order: fringe scan and fly-eye FZA technologies. Our fringe scan technology successfully cancels an artifact appearing at distances of millimeter order between an object and the FZA. Our fly-eye FZA technology expands the narrow field of view caused by the characteristics of the chief ray angle of image sensors. Our experimental results indicate that these technologies enable us to capture images of objects set 2 mm from the FZA. Our close-up technologies can expand the application scope of lensless technology, such as for inspection tools in limited spaces by taking advantage of the small tool size.