Two dimensional optical position indicating apparatus
First Claim
1. An optical position indicating apparatus comprising a light source, detector means for detecting presence of light and producing an electrical output in response thereto;
- reflecting means for reflecting light from said light source across a target zone; and
retroreflecting means for reflecting said light incident thereupon along a path substantially coincident with the path of incidence of said light;
said retroreflecting means comprising a plurality of retroreflective assemblies, said reflecting means and said plurality of retroreflective assemblies being substantially disposed about said target zone in an arrangement whereby light emitted from said light source reflects from at least one of said reflecting means and said plurality of retroreflective assemblies and converges at said detector means;
limiting means for limiting said detector means to a finite viewing range;
said detector means being rotatable to effect scanning of said target zone said detector means being capable of measuring angular displacement from a reference whereby the presence of an opaque object within said target zone will register upon said detector means as a plurality of shadows as said detector means scans said target zone thereby resulting in absence of said electrical output for each of said plurality of shadows;
whereby the location of said opaque object within said target zone can be determined in two dimensions by geometric calculations involving angular displacements of said plurality of shadows.
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Accused Products
Abstract
An optical position indicating apparatus having a light source, a detector for detecting the presence of light and producing an electrical output in response thereto, a reflecting structure for reflecting light from the light source across a target zone, and, a retroreflecting structure for reflecting the light incident thereupon along a path substantially coincident with the path of incidence of the light. The retroreflecting structure comprises a plurality of retroreflective assemblies, the reflecting structure and the plurality of retroreflective assemblies are substantially disposed about the target zone and a limiting structure limits the detector to a finite viewing range so that rotation of the detector effects scanning of the target zone. The detector is capable of measuring angular displacement from a reference so that presence of an opaque object within the target zone will register upon the detector as a plurality of shadows thereby resulting in absence of electrical output from the detector for each of the plurality of shadows, whereby the location of the opaque object within the target zone can be determined in two dimensions by geometric calculations involving angular displacements of the plurality of shadows.
127 Citations
14 Claims
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1. An optical position indicating apparatus comprising a light source, detector means for detecting presence of light and producing an electrical output in response thereto;
- reflecting means for reflecting light from said light source across a target zone; and
retroreflecting means for reflecting said light incident thereupon along a path substantially coincident with the path of incidence of said light;
said retroreflecting means comprising a plurality of retroreflective assemblies, said reflecting means and said plurality of retroreflective assemblies being substantially disposed about said target zone in an arrangement whereby light emitted from said light source reflects from at least one of said reflecting means and said plurality of retroreflective assemblies and converges at said detector means;
limiting means for limiting said detector means to a finite viewing range;
said detector means being rotatable to effect scanning of said target zone said detector means being capable of measuring angular displacement from a reference whereby the presence of an opaque object within said target zone will register upon said detector means as a plurality of shadows as said detector means scans said target zone thereby resulting in absence of said electrical output for each of said plurality of shadows;
whereby the location of said opaque object within said target zone can be determined in two dimensions by geometric calculations involving angular displacements of said plurality of shadows. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- reflecting means for reflecting light from said light source across a target zone; and
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11. An optical position indicating apparatus comprising a light source;
- detector means for detecting presence of light and producing an electrical output in response thereto;
a plurality of reflective means for distributing light emitted from said light source across a target zone, said target zone being at least partially bordered by said reflective means; and
a light directing means for directing light from said light source across said target zone and for directing return light received from said target zone to said detector means;
said target zone being substantially rectangular; and
said light source, said detector means and said light directing means being positioned at a first corner of said target zone and said plurality of reflecting means comprising a first reflector assembly adjacent a second corner of said target zone, said second corner being positioned opposite said first corner;
a second reflector assembly defining a second side of said target zone adjacent said second corner, and a third reflector assembly defining a third side of said target zone opposite said first reflector assembly;
said second reflector assembly and said third reflector assembly being comprised of retroreflective material. - View Dependent Claims (12, 13, 14)
- detector means for detecting presence of light and producing an electrical output in response thereto;
Specification