A retarder stack for transforming at least partially polarized light includes a first retarder and a second retarder. The first retarder has a first retardance and a first orientation and the second retarder has a second retardance and a second orientation both orientations with respect to the partially...http://www.google.es/patents/US6452646?utm_source=gb-gplus-sharePatente US6452646 - Optical retarder stack formed of multiple retarder sheets
Optical retarder stack formed of multiple retarder sheets
