| 摘要 |
PURPOSE:To eliminate the need for a crystal filter required for the prevention of moire by shaping a protection plate in a plane at its one surface, and fine quadrangular pyramids closely at its other surface, and also meets specific requirements. CONSTITUTION:An image pickup element 14 which has plural picture elements in order to pick up an image formed through a lens and the protection plate 4 for protecting it are provided, and the protection plate 4 has the plane as one surface and fine quadrangular pyramids closely on the other surface. Then, the protection plate 4 is fitted to the image pickup element 14 in one body so that both sides of the quadrangular base of each quadrangular pyramid are parallel to the horizontal and vertical directions of picture elements on the image pickup surface 5. The shape of the protection plate 4 satisfies an expression. In the expression, L is the distance between the protection plate 4 and image pickup surface 5, l is the pitch of picture elements, N is the refractive index of the protection plate 4; and (d) is the length of one side of the quadrangular base of each quadrangular pyramid, and theta is the inclination of the oblique sides of the quadrangular pyramid. |
