Retro-reflective disc target having exposed retro-reflective beads
Inventors
Chen, Larry • Willms, David • Balkos, Athanasios Tommy • White, Shaulaine
Assignees
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Publication Number
US-12498509-B2
Publication Date
2025-12-16
Expiration Date
Abstract
A retro-reflective marker comprising a bare retro-reflective layer; a protective layer with a near-infrared (NIR) wavelength specific anti-reflective coating; and a border with an NIR absorbent coating.
Core Innovation
The invention relates to a retro-reflective marker/disc target that is wipeable and configured for optical tracking. The retro-reflective marker uses a retro-reflective layer comprising retro-reflective beads exposed to air, combined with a near-infrared (NIR) filter that includes an NIR wavelength specific anti-reflective coating.
To suppress direct reflection and improve contrast in the tracked system, the marker includes a border having an NIR absorbent coating. The border covers a portion of the NIR filter or the protective layer and defines an aperture for the retro-reflective marker. In multilayer arrangements, the retro-reflective layer is positioned as a bottom layer, the NIR filter or protective layer is positioned as a second layer with the NIR wavelength specific anti-reflective coating, and the border is positioned as a top layer.
The invention further includes a destructive-interference based NIR anti-reflective coating and, in some embodiments, an anti-smudge coating to support wipeable operation while maintaining accuracy. The marker includes structural assembly features such as a mounting base and a retaining ring, including threaded or snap-fit connection, to maintain relative positioning of the retro-reflective layer, protective layers, border, and mounting components.
Claims Coverage
The document provides four independent claims. Each independent claim centers on a retro-reflective marker with air-exposed retro-reflective beads combined with an NIR wavelength specific anti-reflective coating and an NIR absorbent border that covers part of an optical filter or protective layer while defining an aperture.
Air-exposed retro-reflective beads with NIR filter anti-reflective coating and NIR absorbent border aperture
A retro-reflective marker comprising a retro-reflective layer comprising retro-reflective beads, wherein the retro-reflective beads are exposed to air; a near-infrared (NIR) filter with an NIR wavelength specific anti-reflective coating; and a border having an NIR absorbent coating, the border covering a portion of the NIR filter and defining an aperture for the retro-reflective marker.
Visibly opaque protective layer with NIR wavelength specific anti-reflective coating and NIR absorbent border aperture
A retro-reflective marker comprising a retro-reflective layer comprising retro-reflective beads, wherein the retro-reflective beads are exposed to air; a visibly opaque protective layer with a near-infrared (NIR) wavelength specific anti-reflective coating; and a border having an NIR absorbent coating, the border covering a portion of the protective layer and defining an aperture for the retro-reflective marker.
NIR absorbent polyimide ring border with aperture over protective layer
A retro-reflective marker comprising a retro-reflective layer comprising retro-reflective beads, wherein the retro-reflective beads are exposed to air; a protective layer with a near-infrared (NIR) wavelength specific anti-reflective coating; and a border having a ring shaped geometry and comprising an NIR absorbent polyimide film, the border covering a portion of the protective layer and defining an aperture for the retro-reflective marker.
Cylindrical mounting base with destructive-interference NIR anti-reflective coating and anti-smudge coating
A marker comprising a cylindrical mounting base; a retro-reflective layer adjacent to the cylindrical mounting base and comprising retro-reflective beads, wherein the retro-reflective beads are exposed to air; a visibly opaque protective layer configured to provide a near-infrared (NIR) filter above the retro-reflective layer; a NIR anti-reflective coating adjacent to a top surface of the visibly opaque protective layer and adjacent to a bottom surface of the visibly opaque protective layer, the NIR anti-reflective coating being operable to provide destructive interference of incident waves; an anti-smudge coating adjacent to the NIR anti-reflective coating adjacent to the top surface of the visibly opaque protective layer; a border having a ring shaped geometry and comprising an NIR absorbent film, the ring shaped geometry defining an aperture for the marker; and a retaining ring configured to maintain relative positioning of the retro-reflective layer, the visibly opaque protective layer, the retaining ring mounting to the cylindrical mounting base.
Overall, the independent claims collectively cover a retro-reflective marker/disc target that combines air-exposed retro-reflective beads with an NIR wavelength specific anti-reflective coating and an NIR absorbent border or ring defining an aperture, with further claim-specific structural configurations including visibly opaque protective layer implementations, ring-shaped NIR absorbent polyimide film borders, and a cylindrical mounting base with a destructive-interference NIR anti-reflective coating plus an anti-smudge coating and retaining ring.
Stated Advantages
Reduce direct-reflection errors.
Improve accuracy.
Improve contrast by suppressing stray light.
Wipeable operation while maintaining accuracy.
Documented Applications
Used in an optical tracking system for estimating marker pose and tracked object pose (position and orientation).
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