GENERAL DIFFRACTIVE OPTICS METHOD FOR EXPANDING AND EXIT PUPIL

摘要

This invention describes a general diffractive optics method that uses a plurality of diffractive elements (14, 18, 22) on an optical substrate ( 12) for expandi ng the exit pupil of a display of an electronic device for viewing. The method is used for optical coupling in an optical device and it is characterized by extending of an exit pupil of an input optical beam in an output beam wherein the optical device comprises: an optical substrate ( 12) and in-coupling, (14), intermediate (18) and out-coupling (22) diffractive element disposed on the optical substrate, wherein periodic lines of intermediate diffractive element comprise an angle p with periodic lines of the in-coupling and of the out-coupling diffractive elements, respectively. The system supports a broad range of rotation angles (0 p 70°) and correspond! ng conical angles and remains geometrically accurate.