Method for authenticating an object
View Patent ↗A method for authenticating an object that includes providing a label ( 12 ) with invisible indicia ( 14 ) printed with optically active material on a reflective substrate; providing a device that has a digital camera ( 18 ) having a light source ( 20 ), an image sensor ( 22 ), a first polarizing filter ( 24 ) having a first orientation, and a second polarizing filter ( 26 ) having a second orientation; illuminating the label with the light from the light source through the first polarizing filter; forming an image with the image sensor using reflected light from the label wherein the reflected light passes through the second polarizing filter prior to reaching the sensor; wherein the second polarizing filter makes the invisible indicia visible; and authenticating the object.
1. A method of authenticating an object comprising:
providing a label with invisible indicia on the object wherein at least a portion of the label rotates a polarization of incident light;
providing a digital camera having a light source, an image sensor, a first linear polarizer having a first orientation, and a second linear polarizer having a second orientation;
illuminating the label with light from the light source through the first linear polarizer;
forming an image with the image sensor using reflected light from the label wherein the reflected light passes through the second polarizer prior to reaching the sensor;
wherein the second linear polarizer makes the invisible indicia visible; and
authenticating the object.
2. The method of claim 1 wherein the second linear polarizer is orthogonal to the first orientation.
3. The method of claim 1 further comprising:
displaying, communicating, or printing the visible indicia.
4. The method of claim 1 wherein the indicia are machine readable or human readable.
5. The method of claim 1 wherein the indicia encode authentication information.
6. The method of claim 5 further comprising:
comparing the authentication information to a predetermined authentication code.
7. The method of claim 6 wherein the comparison is made by a user or a processor in the camera.
8. The method of claim 1 further comprising:
transmitting the visible indicia to a remote location for authentication; and
transmitting the authentication to the digital camera.
9. The method of claim 8 further comprising:
transmitting a coupon to the digital camera after authentication.
10. The method of claim 8 further comprising:
collecting information related to a sale of the object.
11. The method of claim 8 further comprising:
restocking the object based on a sale of the object.
12. The method of claim 8 further comprising:
transmitting a coupon to a cash register on completion of a sale of the object.
13. The method of claim 1 further comprising:
transmitting the visible indicia and a GPS location of the digital camera to a remote location for authentication;
authenticating the object based on the visible indicia and the GPS location; and
transmitting the authentication to the digital camera.
14. The method of claim 13 further comprising:
transmitting a coupon to the digital camera after authentication.
15. The method of claim 1 wherein the invisible indicia rotate a polarization of incident light differently from the surrounding label.
16. The method of claim 1 wherein the invisible indicia rotate the incident light greater than 0° and less than 180° and rotate the incident light differently from the surrounding label.
17. The method of claim 1 wherein the invisible indicia rotate a polarization of incident light.
18. The method of claim 1 wherein the label surrounding the invisible indicia rotate a polarization of incident light.
19. The method of claim 1 wherein the second orientation is parallel to the first orientation;
a first quarter-wave plate is positioned between the first linear polarizer and the label; and
a second quarter wave plate is positioned between the second linear polarizer and the label.
20. The method of claim 19 wherein the invisible indicia change a polarization of incident light.
21. The method of claim 19 wherein the label surrounding the invisible indicia change a polarization of incident light.
22. A method of authenticating an object comprising:
providing a light source;
providing an image sensor;
providing a first linear polarizer having a first orientation
providing a second linear polarizer having a second orientation;
illuminating a label on the object with light from the light source through the first linear polarizer;
wherein the label has invisible indicia which rotate a polarization of incident light;
forming an image with the image sensor using reflected light from the label wherein the reflected light passes through the second polarizer prior to reaching the sensor;
wherein the second linear polarizer makes the invisible indicia visible; and
authenticating the object.
23. A method of authenticating an object comprising:
illuminating a label on the object with light having a first linear polarization;
wherein the label has invisible indicia which rotate the first polarization of incident light to a second polarization;
passing the light from the label through a linear polarizer which passes light having the second linear polarization and makes the invisible indicia visible;
forming an image of the visible indicia; and
authenticating the object.
24. The method of claim 1 wherein the second orientation is 90° with respect to the first orientation;
a first quarter-wave plate is positioned between the first linear polarizer and the label; and
a second quarter wave plate is positioned between the second linear polarizer and the label.
25. The method of claim 24 wherein the invisible indicia change a polarization of incident light.
26. The method of claim 24 wherein the label surrounding the invisible indicia change a polarization of incident light.