An optical device that modifies a conventional anisotropic lens array to enable the viewer to perceive a repertoire of preselected images over a first range of angles of regard or to see through the device to a scene beyond the device without distortion. The preselected images in one orientation gives...http://www.google.com.tw/patents/US6324009?utm_source=gb-gplus-share專利 US6324009 - Optically anisotropic micro lens window for special image effects featuring periodic holes
