Sensing light

• US 20060243928A1
• Filed: 04/28/2005
• Published: 11/02/2006
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Blythe, Gregory W., Huddleston, Wyatt A., Blythe, Michael M., Thielman, Jeffrey L.
• Granted Patent: US 7,265,370 B2
• Time in Patent Office: Days
• US Class Current: 250/556
• CPC Class Codes: G01N 2021/4711 Multiangle measurement
• CPC Class Codes: G01N 2021/4735 Solid samples, e.g. paper, glass
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials

Abstract

A method and apparatus senses light reflected off of a surface of an object at angles with respect to incident light.

Claims

1. An apparatus comprising:

an object having a surface configured to reflect wavelengths of light which vary based upon an angle between first incident light and reflected light; and

at least one sensor configured to generate a first signal using a first light reflected from the surface at a first angle with respect to incident light and to generate a second signal using a second light reflected from the surface at a second angle with respect to second incident light.

2. The apparatus of claim 1, wherein the surface includes color shifting ink.

3. The apparatus of claim 1, wherein the at least one light sensor is configured to generate the first signal when receiving light at a first position and to generate the second signal when receiving light at a second position.

4. The apparatus of claim 3, wherein the at least one light sensor includes a first sensor at the first position and a second sensor at the second position.

5. The apparatus of claim 3, wherein the at least one light sensor includes a sensor configured to move between the first position and the second position.

6. The apparatus of claim 1 further comprising at least one light source configured to direct light at the surface from a first position and from a second position.

7. The apparatus of claim 6, wherein the at least one light source includes a first light source at the first position and a second light source at the second position.

8. The apparatus of claim 6, wherein the at least one light source includes a light source movable between the first position and the second position.

9. The apparatus of claim 1 further comprising:

a first indicator configured to indicate a first position for the surface at which the first signal is to be generated; and

a second indicator configured to indicate a second position for the surface at which the second signal is to be generated.

10. The apparatus of claim 9 further comprising:

a horizontal surface, wherein the object is configured to be rested upon the horizontal surface, selectively, at the first position and the second position;

a projector configured to generate an image on the horizontal surface including the first indicator and the second indicator wherein the projector is on a first side of the surface and wherein the object is configured to rest against a second side of the surface.

11. The apparatus of claim 1 further comprising:

a memory;

data stored in the memory; and

a processing unit configured to identify the object based upon the data and at least one of the first signal and the second signal.

12. The apparatus of claim 11, wherein the processing unit is configured to compare the first signal to the second signal to determine a relationship and to compare the relationship with the data.

13. The apparatus of claim 1 further comprising at least one light source configured to direct a first light having a first color at the surface and a second light having a second color at the surface, wherein the at least one light sensor is configured to generate the first signal based upon the first light after it has reflected off the surface and is configured to generate the second signal based upon the second light after it has reflected off the surface.

14. The apparatus of claim 1 further comprising a projector configured to project a first incident light at the surface and to subsequently project a second incident light at the incident surface, the second incident light having at least one characteristic different than the first incident light, wherein the projector includes a digital micromirror device and wherein the digital micromirror device is in a first state and the projector projects the first incident light and a second state when the projector projects the second incident light.

15. An apparatus comprising:

a memory;

data stored in the memory; and

a processing unit configured to identify an object using the data and light reflected off a surface at different angles with respect to associated incident light of the object.

16. The apparatus of claim 15 further comprising at least one sensor configured to generate a first signal based upon light reflected at a first angle off the surface and a second signal based upon light reflected at a second angle off the surface.

17. An object comprising:

a surface configured to reflect and alter light; and

an actuator configured to move the surface.

18. The object of claim 17 further comprising a trigger, wherein the actuator moves the surface in response to actuation of the trigger.

19. The object of claim 17, wherein the actuator is configured to continuously move the surface.

20. The object of claim 17, wherein the actuator is configured to periodically move the surface.

21. An apparatus comprising:

means for sensing light reflected off a surface of an object at different angles; and

means for identifying the object based upon the sensed reflected light.

22. A processor readable medium comprising:

instructions for sensing a first light reflected off an object'"'"'s surface at a first angle with respect to first incident light so as to have a first wavelength;

instructions for sensing a second light reflected off the object at a second angle with respect to second incident light so as to have a second wavelength; and

instructions for comparing the first light and the second light.

23. A method comprising:

sensing a first light reflected off an object surface at a first angle with respect to first incident light and having a first wavelength;

sensing a second light reflected off the object surface at a second angle with respect to second incident light and having a second wavelength; and

comparing the first light and the second light.

24. The method of claim 23 further comprising authenticating the object based upon the comparison of the first light and the second light.

25. The method of claim 23 further comprising:

sensing light reflected off the object surface while the object surface is at a first position; and

sensing light reflected off the object surface while the object surface is at a second position.

26. The method of claim 23 further comprising:

sensing light with at least one sensor at a first position; and

sensing light with the at least one sensor at a second position.

27. The method of claim 26, wherein sensing light at the first position and the second position includes moving a sensor between the first position and the second position.

28. The method of claim 23, wherein sensing light at the first position and at the second position includes sensing the light with a first sensor at a first position and with a second sensor at a second position.

29. The method of claim 23 further comprising reflecting light off of the object surface from at least one light source at a first position and at a second position.

30. The method of claim 29, wherein reflecting light from at least one light source at a first position and at a second position includes moving a light source between the first position and the second position.

31. The method of claim 29, wherein reflecting light from at least one light source at a first position and at a second position includes reflecting light off of the object from a first light source at the first position and a second light source at the second position.

32. The method of claim 23, wherein comparing the first light and the second light includes comparing the color of the first light with a color of the second light.

33. The method of claim 23, wherein the object surface includes color shifting ink.