| 20100118415 | OPTICAL PLATE FOR AN IMAGING CAMERA - An optical plate for an imaging camera is proposed that is used for further deepening the depth of field. The optical plate is orthogonal to the optical axis, that, in shape, (1) is an optical plate that has the same effective aperture diameter as the imaging camera and is attached in front thereof to deepen the depth of field, and on the incidence plane or exit plane, is equipped with first and second regions in the effective aperture, the first region being on the inside (or is an outside region), with a surface shape curvature that increases going from optical axis to periphery, and a thickness that becomes thicker going from the center to the periphery, that delays the phase of transmitted light more at the periphery than the center, the second region being on the outside (or is an inside region) which has a plane parallel plate shape. Also, (2) an optical plate having a shape that is a synthesis of first and second shapes of incidence plane or exit plane, the first shape being a concave shape with a surface shape curvature that increases going from optical axis to periphery, and a thickness that becomes thicker going from the center to the periphery, that delays the phase of transmitted light more at the periphery than the center, the second shape being a convex shape with a constant surface shape curvature having the function of shifting the focal point position from long distance to the short-distance side. | 05-13-2010 |
