A solid-state image pickup device for imaging an object using a CCD image sensor. The solid-state image pickup device includes a half wave plate between first and second birefringence plates 2 and 4 shifting the optical path of the image pickup light the radiation of which is interrupted by on/off control...http://www.google.ca/patents/US5369266?utm_source=gb-gplus-sharePatent US5369266 - High definition image pick-up which shifts the image by one-half pixel pitch
