System for operating one or more lasers to project a visible line onto a grass-covered surface
First Claim
1. An apparatus for providing at least one temporary visible reference line on a non-smooth surface within the view of at least one video camera, comprising:
- a first laser source disposed at a first elevated location relative to the surface, said first laser source being operative to emit a first laser beam having a wavelength of between 400 nm and 750 nm and to sweep said first laser beam along a selectable path upon the surface so as to form a temporary visible line thereon;
a second laser source disposed at a second elevated location relative to the surface, said second laser source being operative to emit a second laser beam having a wavelength of between 400 nm and 750 nm and to sweep said second laser beam across the selected path so as to form, with said first laser beam, a composite temporary visible line; and
a controller comprising a synchronization module operatively associated with the first and second laser sources and adapted to synchronize a sweep frequency rate, at which said first laser beam and said second laser beam are swept across the surface, to a scan rate of at least one camera arranged to receive an image of the composite temporary line.
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Accused Products
Abstract
An apparatus for providing at least one temporary visible line on a surface within the view of at least one video camera. The system comprises a first laser source disposed at a first elevated, stationary location relative to the surface, and a second laser source disposed at second elevated, stationary location relative to the surface. The output of each laser source is synchronously deflected so as to repetitively sweep each output beam across the same region of the surface and thereby project a visible composite line that is, for example, transverse to the lateral sidelines of an athletic field. A controller comprising a synchronization module synchronizes the sweep frequency rate, at which the beams sweep the surface, to a scan rate of at least one camera arranged to receive an image of the composite temporary line.
26 Citations
20 Claims
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1. An apparatus for providing at least one temporary visible reference line on a non-smooth surface within the view of at least one video camera, comprising:
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a first laser source disposed at a first elevated location relative to the surface, said first laser source being operative to emit a first laser beam having a wavelength of between 400 nm and 750 nm and to sweep said first laser beam along a selectable path upon the surface so as to form a temporary visible line thereon;
a second laser source disposed at a second elevated location relative to the surface, said second laser source being operative to emit a second laser beam having a wavelength of between 400 nm and 750 nm and to sweep said second laser beam across the selected path so as to form, with said first laser beam, a composite temporary visible line; and
a controller comprising a synchronization module operatively associated with the first and second laser sources and adapted to synchronize a sweep frequency rate, at which said first laser beam and said second laser beam are swept across the surface, to a scan rate of at least one camera arranged to receive an image of the composite temporary line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
a third laser source disposed at a third elevated, stationary location relative to the surface and at the same lateral side of the surface as said first laser source, said third laser source being operative to emit a third laser beam having a wavelength of between 400 nm and 750 nm and to sweep said third laser beam along a selectable path upon the surface; a fourth laser source disposed at a fourth elevated, stationary location relative to the surface and at the same lateral side of the surface as said second laser source, said fourth laser source being operative to emit a second laser beam having a wavelength of between 400 nm and 750 nm and responsive to input signals received from the controller to sweep said fourth laser beam across the selected path so as to form, with said third laser beam, a composite temporary line, wherein said controller is adapted to synchronize a sweep frequency rate at which said third laser source and said fourth laser source sweep the surface of the athletic field to a scan rate of the at least one camera, and wherein said controller is adapted to select between operation of said first and second laser sources as a pair and operation of said third and fourth laser sources as a pair depending on whether a temporary line is to be formed within a first region of the surface or within a second region of the surface.
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13. The apparatus according to claim 1, wherein said composite temporary line is a straight line having a length of about fifty three yards and a width of from about four to about eight inches.
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14. The apparatus according to claim 1, wherein a visible line formed upon the surface by said first laser source is a first series of individual line segments and a visible line formed upon the surface by said second laser source is a second series of individual line segments, said first and second laser sources being operable to form collinear, offset line segments with overlapping edges, whereby said composite temporary line is visible as a contiguous solid line along a substantial portion of its length.
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15. A method of projecting at least one temporary visible reference line onto a non-smooth surface characterized by a tendency to scatter incident visible light in random and non-uniform manner, comprising the steps of:
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receiving, in a first receiving step, a first line projection command;
operating a first laser source and a second laser source each disposed at different locations above the non-smooth surface so as to project, across only a first portion of the non-smooth surface, only a single composite visible line in accordance with the first line projection command;
receiving, in a second receiving step, a second line projection command; and
in a second operating step, operating the first and second laser sources so as to project, across only a second portion of the non-smooth surface, only a single composite line in accordance with the second line projection command. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification