Image pickup device

Abstract

Abstract PURPOSE:To greatly suppress a spurious signal due to return distortion, by providing transparent flat plates of anisotropic materials having birefrigence characteristics in front of the photoelectric surface of an image pickup device, and inserting a quater-wavelength phase plate between the flat plates. CONSTITUTION:An image of a subject 1 is formed on the photoelectric surface of a solid-state image pickup device 6 through a lens 2. Between the lens 2 and solid-state image pickup device, anisotropic materials having birefrigence characteristics, e.g. crystal plates 3 and 5 are provided, and between those crystal plates 3 and 5, a phase plate 4 is arranged to nearly equalize the quantity of normal beams emitted from the crystal plate 5 to that of abnormal beams. Then, since the separation direction of the abnormal beams is different from that of the normal beams to the crystal plates 3 and 5, band limitation which is in a comb shape in any direction is performed, suppressing spurious signals in horizontal and vertical directions.

Inventors

• 👤 Masanobu Morishita
• 👤 森下　政信

Bibliographic Details