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US 4,304,459 AGranted
Reflective holographic scanning system insensitive to spinner wobble effects
AssigneeXerox Corporation
InventorCharles J. Kramer
Life of this patent
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Abstract
A holographic scanning system includes a reflective type holographic spinner having a plurality of diffraction gratings on its surface. A reconstruction wavefront incident on a non-grating surface of the spinner is reflected into a corrective optical element which displaces and redirects the wavefront so that it is incident at the grating at an angle corrected for the effects of spinner wobble.
Claims13
A holographic scanning system including a reflection holographic spinner having on its surface at least one holographic facet;
- a source of coherent light which directs a reconstruction light wavefront, onto a portion of said spinner surface adjacent said facet at a first angle of incidence, .theta..sub.i said reconstruction wavefront being reflected from said surface;
- an optical element disposed in the path of said reflected wavefront, said element acting to condition said wavefront and redirect it onto said holographic facet at a second angle of incidence, said facet diffracting said wavefront at a first order diffraction angle .theta..sub.d,
- means for rotating said spinner so that said facet is rotated across said reconstruction wavefront producing a corresponding translation of the diffracted wavefront, and
- means for focusing said diffracted wavefront, whereby a scan line is generated at an image plane which is substantially invariant to the presence of spinner wobble during rotation.
1 more element
Dependencies are inferred from the claim text.