Laser printing system with developable helicoid reflector
AssigneePolaroid Corporation
InventorsJohn R. Lewis, Andrew McCurdy, Arthur D. Gaudet
Life of this patent
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Abstract
Line scanning apparatus are especially compensated to limit beam divergence in one direction by embodying a specularly reflective developable helicoid. Beam divergence in the direction orthogonal to the aforementioned one direction is masked by a narrow slit extending longitudinally in the direction of the longitudinal center axis of the helicoid.
Claims16
Line scanning apparatus for use with a source of radiation that can be beamed thereat, to scan the beamed radiation across a radiation sensitive medium in a plurality of successive line scans, said apparatus comprising:
- a specularly reflective developable helicoid disposed for rotation about the longitudinal center axis thereof to receive an incident beam of radiation from the source in a direction generally parallel to said longitudinal center axis and reflect the incident beam of radiation in a direction outward of said longitudinal center axis toward the radiation sensitive medium wherein one rotation of said helicoid operates to displace the reflected beam of radiation in one direction parallel to said longitudinal center axis;
- and
- means for optically controlling said reflected radiation from said helicoid so as to limit the divergence of the reflected radiation in directions generally perpendicular to the longitudinal center axis of said helicoid.
Apparatus for line scanning a photosensitive medium comprising:
- a light source for providing a beam of collimated light;
- a specularly reflective developable helicoid disposed for rotation about the longitudinal center axis thereof to receive incident thereto said collimated light beam in a direction generally parallel to said longitudinal center axis and reflect said incident light beam in a direction outward of said longitudinal center axis toward the photosensitive medium wherein one rotation of said helicoid operates to displace the reflected beam of radiation in one direction parallel to said longitudinal center axis to provide one line scan across the photosensitive medium;
- drive means for rotating said helicoid and incrementally changing the positions of the photosensitive medium and said helicoid relative to each other subsequent to each of said line scans;
- and
- means for optically controlling said reflected light beam from said helicoid so as to limit the divergence of said reflected light beam in directions generally perpendicular to the longitudinal center axis of said helicoid.
Dependencies are inferred from the claim text.