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US 4,544,228 AGranted
Scanning method using a rotating prism
AssigneeSpectra-Physics, Inc.
InventorJoseph F. Rando
Life of this patent
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AssigneeSpectra-Physics, Inc.
InventorJoseph F. Rando
Estimating the term…
A scanning apparatus and method for scanning a beam of light incorporate an optical system in which a rotatable wheel has a plurality of light deflecting facets on the periphery of the wheel. The incoming light beam is reflected by a routing mirror or a routing beam splitter cube onto a front face of a facet as that facet is rotated in line with the routing element. The beam is deflected as it makes its first pass through the facet, and a porro prism redirects the deflected beam back through the rotating facet so that the beam makes two passes through each facet rotating past the routing element. The scanning action is produced by the rotation of the facet in the path of both passes of the beam through the facet. The net result cancels the angular motion of the beam in one direction and adds to the angular motion in the orthogonal direction. Scanning action as produced by one facet is repeated for each facet located on the periphery of the wheel.
A scanning apparatus for repeatedly scanning a beam of light in a single same direction and from the same starting point, said apparatus comprising,
The invention defined in claim 7 wherein the lens is a single meniscus lens located a distance away from the rotating prism facets and having curved surfaces chosen to minimize aberrations at the image plane.
A method of optimizing the straightness of a scanned line in an optical scanner of the kind having a rotating prism and routing means and reflecting means for causing a collimated monochromatic light beam to make two passes through the rotating prism and to produce the scanned line, said method comprising,
Dependencies are inferred from the claim text.