RETROREFLECTORS PROVIDING INFORMATION ENCODED IN REFLECTED NON-VISIBLE LASER WHILE RETAINING VISIBLE LIGHT SAFETY PROPERTIES
Described are retroreflective marker devices, which encode information that can be read by optical sensors, such as LiDAR devices, and that do not detract from human safety. Also described are kits for retrofitting existing markers.
1 . A reflective marker device comprising:
a. a retroreflective surface and a lens covering the retroreflective surface to form a face;
b. the face comprising a plurality of regions, the plurality of regions comprising at least a region of a first type and a region of a second type;
c. the region of the first type comprising a first filter embedded in the lens, the first filter attenuating a light of a first laser having a first source and a wavelength outside a visible wavelength spectrum incident on the face; and
d. the region of the second type lacking the first filter and reflecting the light of the first laser incident on the face to the first source; wherein both the region of the first type and the region of the second type reflect light within the visible wavelength spectrum incident from the face to the first source; and wherein the light of the first laser incident on the face is reflected to the first source as a first pattern, the first pattern comprising encoded information.
2 . The reflective marker device of claim 1 , comprising at least 2 regions of the first type or the second type.
3 . The reflective marker device of claim 1 , wherein the lens comprises glass, polycarbonate, plastic, or any combination thereof.
4 . The reflective marker device of claim 1 , wherein the first filter comprises an absorptive dye, a polarizing filter, an interference filter, a physical filter, or any combination thereof.
5 . The reflective marker device of claim 1 , wherein the light of the first laser has a wavelength between 893 nm and 913 nm or between 1540 nm and 1560 nm.
6 . The reflective marker device of claim 1 , wherein the encoded information in the first pattern is spatially encoded.
7 . The reflective marker device of claim 6 , wherein the spatial encoding comprises two-dimensional encoding.
8 . The reflective marker device of claim 7 , wherein the two-dimensional encoding comprises a QR code, a pattern, an array, a shape, a number, a letter, a symbol, or any combination thereof.
9 . The reflective marker device of claim 6 , wherein the spatial encoding comprises three-dimensional encoding.
10 . The reflective marker device of claim 9 , wherein the three-dimensional encoding comprises a pattern, an array, a shape, a number, a letter, a symbol, or any combination thereof.
11 . The reflective marker device of claim 1 , wherein the encoded information is non-temporally encoded.
12 . The reflective marker device of claim 1 , comprising a plurality of faces, wherein at least two of the plurality of faces are non-coplanar.
13 . The reflective marker device of claim 12 , wherein the at least two non-coplanar faces are parallel.
14 . The reflective marker device of claim 12 , wherein the at least two non-coplanar faces are offset by an offset distance of about 0.01 inches to about 3 inches.
15 . The reflective marker device of claim 12 , wherein a distance between at least two of the non-coplanar faces encodes information.
16 . The reflective marker device of claim 1 , further comprising a region of a third type comprising a second filter embedded in the lens, the second filter attenuating a light of a second laser having a second source and a wavelength outside the visible spectrum and different than that of the first laser incident on the face and reflecting light having a wavelength within the visible spectrum incident from the face to the second source such that light of the second laser incident on the face is reflected to the second source as a second pattern, the second pattern comprising encoded information.
17 . The reflective marker device of claim 16 , wherein the second filter comprises an absorptive dye, a polarizing filter, an interference filter, a physical filter, or any combination thereof.
18 . The reflective marker device of claim 16 , wherein the light of the second laser has a wavelength between 893 nm and 913 nm or between 1540 nm and 1560 nm.
19 . The reflective marker device of claim 1 , wherein the device is passive.
20 . The reflective marker device of claim 1 , wherein the device is non-mechanical and nonelectronic.