Optical instrument and optical element providing expanded exit pupil
AssigneeVision Engineering Limited
InventorGraham Mercer
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Abstract
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.
Claims12
A diffractive element for use in an optical instrument, comprising a plurality of replications of a pattern of separated diffraction structures each effective to produce diffractive interference of polychromatic light passing through or reflected by the diffractive element, the plurality of diffraction structures including diffraction structures of different sizes and shape, and the plurality of replications are configured to produce a plurality of exit pupils which are displaced relative to one another transverse to an optical axis of the optical instrument such as to be viewable as a single, continuous expanded exit pupil and which have a light energy such that a light energy distribution across an extent of the expanded exit pupil is substantially uniform.
Dependencies are inferred from the claim text.