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US 2015/0352859 A1Published application
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.
Claims20
A system of scanning beams, comprising:
- a scan optics module, wherein the scan optics module is configured according to a compensatory lens-distortion function, wherein the scan optics module is configured to compensate for a pin-cushion distortion and use only spherical lens elements, wherein the scan optics module receives multiple light beams at an approach angle and propagates the multiple light beams, such that the multiple light beams are substantially straight and parallel to each other as the multiple light beams scan across a first portion of an imaging surface;
- a light source module containing multiple light sources positioned to direct the multiple light beams to a raster polygon, wherein the light sources are positioned at an incident approach angle that is in a plane defined by the rotational axis of the raster polygon, wherein each incident beam is at a different incident approach angle, wherein the incident approach angle is greater than 0 degrees;
- the raster polygon having a first facet position and a second facet position wherein the first facet position and the second facet position is inclined at a different angle with respect to the raster polygon rotational axis, wherein each facet position reflects the multiple light beams and establishes distinct sets of reflected multiple light beams, wherein each set of reflected multiple light beams are substantially straight and parallel to each other, wherein the raster polygon rotates with a rotating axis tilt, wherein the raster polygon rotating axis tilt is tilted towards the scan optics module, wherein the tilt axis is based on an approach angle and pupil distance between a raster polygon mirror and the scan optics module, wherein the tilt axis is selected whereby two or more sets of reflected scan lines are symmetrical;
- a display screen, wherein the display screen images a portion of an image at a first portion of the screen from the first set of multiple light beams, wherein the display screen images a distinct second portion of an image at a distinct second portion of the screen from the second set of multiple light beams, and wherein the beams scanned across the first and second regions are substantially straight.
1 more element
A system, comprising:
- scan optics;
- a laser module;
- a raster polygon mirror;
- and
- a display screen, wherein the raster polygon mirror is disposed at an angle relative to the display screen, wherein the raster polygon mirror is rotatable, wherein the scan optics is disposed between the display screen and the raster polygon mirror, wherein the scan optics comprises a plurality of lenses and wherein each lens has a convex side facing the display screen.
2 more elements
A two-dimensional scanning system comprising:
- an imaging surface;
- multiple light sources configured to generate multiple light beams, each beam for illuminating a distinct portion of the imaging surface;
- a rotatable raster polygon that has multiple reflective facets and is positioned in an optical path between the multiple light sources and the imaging surface to direct the multiple light beams 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 plurality of scan lenses positioned in an optical path between the rotatable raster polygon and the imaging surface and configured to introduce barrel distortion of multiple scan lines that the multiple light beams follow across the imaging surface as the rotatable raster polygon rotates, wherein each scan lens has a convex surface facing an imaging surface;
- wherein the rotational raster polygon is positioned at a tilt angle inclined toward the imaging surface;
- wherein an approach angle of the multiple light beams is selected to position a convergence point of the multiple laser beams proximate a reflective facet of the rotatable raster polygon;
- wherein the multiple light beams reflected from a first facet of the rotatable raster polygon is along a first optical path through a first portion of the scan lens at a first incident angle and are incident on the imaging surface at a first vertical position;
- and
- wherein the multiple light beams reflected from a second facet of the rotatable raster polygon is along a second optical path through a second portion of the scan lens at a second incident angle different from the first incident angle and are incident on the imaging surface at a second vertical position different from the first vertical position.
7 more elements
Dependencies are inferred from the claim text.