2-d straight-scan on imaging surface with a raster polygon
AssigneePrysm, Inc.
InventorsHanxiang BAI, Roger A. HAJJAR
Life of this patent
Estimating the term…
Abstract
A 2-D scanning system uses a fast-rotating raster-polygon as a single scanning component to produce straight scan lines over a 2-D image surface. An approach angle of incident light beams to the raster-polygon is selected to minimize pin-cushion distortion of scan lines introduced by polygon scanning on the image surface, and a tilt angle of the rotational axis of the raster-polygon is selected to position said polygon-scanning distortion symmetrically on the image surface. In addition, scan optics are configured to generate a predetermined amount of barrel distortion of scan lines on the image surface to compensate for pin-cushion distortion introduced by polygon scanning.
Claims21
A scanning system comprising:
- an imaging surface;
- a light-source configured to generate at least one light beam for illuminating a portion of the imaging surface;
- a rotatable raster polygon that has multiple reflective facets and is positioned in an optical path between the light source and the imaging surface to direct the at least one light beam to the imaging surface with the reflective facets, wherein the reflective facets are each inclined at a different angle with respect to a rotational axis of the rotatable raster polygon;
- and
- a scan lens positioned in an optical path between the rotatable raster polygon and the imaging surface and configured to introduce barrel distortion of a scan line that the light beam follows across the imaging surface as the rotatable raster polygon rotates.
The scanning system of claim 11, wherein scan lines of the first set of scan lines are interleaved between scan lines of the second set of scan lines.
A method of constructing a scanning system that includes an imaging surface, a light-source configured to generate at least one light beam for illuminating a portion of the imaging surface, and a rotatable polygon mirror positioned in an optical path between the light source and the imaging surface to direct the at least one light beam to the imaging surface, the method comprising:
- determining pin-cushion scan-line distortion of a scan line followed by the at least one light beam across the imaging surface as the rotatable polygon mirror rotates;
- and
- positioning a scan lens in an optical path between the rotatable polygon mirror and the imaging surface,
- wherein the scan lens is configured to introduce barrel scan-line distortion of the scan line that compensates for the pin-cushion scan-line distortion of the scan line such that the scan line is a substantially straight line on the imaging surface, and
- wherein the rotatable raster polygon mirror has multiple reflective facets that are each inclined at a different angle with respect to a rotational axis of the rotatable polygon mirror.
Dependencies are inferred from the claim text.