OPTICAL INSTRUMENT AND OPTICAL ELEMENT PROVIDING EXPANDED EXIT PUPIL

摘要

The invention provides an optical instrument including means (1, 2) to produce an optical image to be viewed by an observer including a diffractive element (7) located at an intermediate focal or image plane (4) of the optical instrument and comprising a pattern of a plurality of areas effective to cause diffraction interference in light passing through the optical instrument and thereby produce an expanded exit pupil (6) comprising a combination of a multiplicity of exit pupils displaced relative to one another transverse to an optical axis (3) of said instrument.