Patent ID: 6326998
Filing Date: 2001-12-04
Classification: G02B

Abstract:
Imaging apparatus for focusing image light upon an array of photosites and for limiting the maximum spatial frequency of the image light that falls upon the array of photosites, said imaging apparatus comprising:an image sensor having a two-dimensional array of photosites;an optical section through which the image light passes;an optical filter including an array of four shaped features placed in mutually spaced relation in the optical section such that all incoming rays leading to an image point on the image sensor pass through the four features in order to blur the image light and limit the spatial frequencies to values below the Nyquist frequency of the sensor; andwherein the optical section includes a stop region and the optical filter, though not placed at the stop or at an image of the stop, is placed at a position with some field dependence and correction is provided therefor with the pitch of the image sensor chosen so that the bundle of rays that lead to an image point on the sensor passes through at least one full period of the four shaped features in the array.