Back to results
US 5,315,112 AGranted
Real time laser spot tracking in both horizontal and vertical axes
AssigneeXerox Corporation
InventorEllis D. Harris
Life of this patent
Estimating the term…
Abstract
An optical system in which arrays of pseudo-corner cube retro reflectors are used to provide optical feedback of the horizontal and vertical positions of a scanning beam. The arrays of reflectors are located above and below the path of the scanning beam near the photoreceptor. The horizontal and vertical position information is then used to correct the alignment of the scanning beam.
Claims10
In a raster scanner where a beam is scanned along a given path:
- a) first and second reflector means in the path of the scanning beam,
- b) said first reflector means being located on one side of the path of the scanning beam and said second reflector means being spaced from said first reflector means and located on the opposite side of the scanning beam, said spacing between said first and second reflector means being in a direction generally perpendicular to the path of the scanning beam,
- c) said first and second reflector means being arranged in such a manner that when the scanning beam is on center, each of said first and second reflector means will receive substantially equal portions of the beam and when the beam is off center, the portions of the beam received by said first and second reflector means will be unequal,
- d) first and second detector means arranged to receive beam reflections from said first and second reflector means, respectively,
- e) determining means operably connected to said first and second detector means for determining if said first and second reflector means receive equal or unequal portions of the beam, and
- f) means responsive to said determining means when said first and second detector means receive unequal portions of said scanning beam to correct the alignment of the scanning beam until said determining means determines the said first and second reflector means receives substantially equal portions of the scanning beam.
3 more elements
In a raster scanner where a beam is scanned along a given path:
- a) first and second reflector means in the path of the scanning beam and extending coextensive with a substantial portion of the scanning path of the beam,
- b) said first reflector means being located on one side of the path of the scanning beam and said second reflector means being spaced from said first means and located on the opposite side of the scanning beam, said spacing between said first and second reflector means being in a direction generally perpendicular to the path of the scanning beam,
- c) said first and second reflector means being arranged in such a manner that either one or both of said first and second means will receive a portion of the beam during the beam scan,
- d) first and second detector means arranged to receive beam reflections from said first and second reflector means, respectively, and
- e) determining means operably connected to said first and second detector means for determining the position of the beam from the beam reflected to said first and second detector means from said first and second reflector means.
2 more elements
Dependencies are inferred from the claim text.