Design of birefringence special-frequency filters for aliasing of CCD image sensors

Abstract

It is Well-known that if an input optical image of a CCD image sensor contails higher special-frequency components than Nyquist frequency, a spurious pattern named aliasing generates in the out-put image. To supress the aliasing, an opticalspecial-frequency filter of birefringence quartz plate is attached to the CCD. This paper describes the design of birefringence quartz filters and their characteristics. The frequency responce is not necessarily parfect but the accuracy of cut-off frequency is expected to br very high.