APPARATUS AND METHOD FOR OPTICAL GESTURE RECOGNITION

• US 20100150399A1
• Filed: 12/12/2008
• Published: 06/17/2010
• Est. Priority Date: 12/12/2008
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Holcombe, Wayne T., Svajda, Miroslav
• Granted Patent: US 8,660,300 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 40/28 Recognition of hand or arm movements, e.g. recognition of deaf sign language static hand signs G06V40/113

Abstract

An optical gesture recognition system is shown having a first light source and a first optical receiver configured to receive reflected light from an object when the first light source is activated and output a first measured reflectance value corresponding to an amplitude of the reflected light. A processor is configured to receive the first measured reflectance value and to compare the first measured reflectance value at first and second points in time to track motion of the object and identify a gesture of the object corresponding to the tracked motion of the object.

Claims

1. An optical gesture recognition system, the system comprising:

a first light source;

a first optical receiver configured to receive reflected light from an object when the first light source is activated and output a first measured reflectance value corresponding to an amplitude of the reflected light; and

a processor configured to receive the first measured reflectance value, where the processor is further configured to compare the first measured reflectance value at first and second points in time to track motion of the object and identify a gesture of the object corresponding to the tracked motion of the object.

2. The optical gesture recognition system of claim 1, where the system further comprises:

a second light source; and

the processor is further configured to independently activate the first and second light sources and capture the first measured reflectance value for each of the first and second light sources at each of the first and second points in time in order to track the motion of the object and identify the gesture of the object utilizing the first measured reflectance values captured for both the first and second light sources.

3. The optical gesture recognition system of claim 2, where the first and second light sources and the optical receiver are disposed in predetermined relative positions to one another along a first axis.

4. The optical gesture recognition system of claim 2, where the system further comprises:

a third light source; and

the processor is further configured to independently activate the first, second, and third light sources and capture the measured reflectance values for each of the first, second, and third light sources at each of the first and second points in time in order to track the motion of the object and identify the gesture of the object utilizing the first measured reflectance values for the first, second and third light sources.

5. The optical gesture recognition system of claim 4, where the first, second and third lights sources and the optical receiver are disposed in predetermined relative positions to one another and the processor is configured to track motion of the object in at least two dimensions.

6. The optical gesture recognition system of claim 2, where the first and second light sources comprises a first light emitting diode.

7. The optical gesture recognition system of claim 2, where the first and second light sources have different illumination characteristics and the processor is further configured to activate the first and second light sources and track motion of the object on the basis of the different illumination characteristics of the first and second light sources.

8. The optical gesture recognition system of claim 7, where each of the first and second light sources has a corresponding illumination cone region, where the illumination cone regions partially overlap in space and where the processor is configured to track motion of the object based on reflectance detected in each of the illumination cone regions.

9. The optical gesture recognition system of claim 1, where the processor is integrated with the optical receiver.

10. The optical gesture recognition system of claim 1, where the first light source and optical receiver are mounted on a common base.

11. The optical gesture recognition system of claim 1, where the first light source and the optical receiver are integrated in an optical data transceiver.

12. The optical gesture recognition system of claim 4, where the system further comprises:

a fourth light source; and

the processor is further configured to independently activate the first, second, third and fourth light sources and capture the measured reflectance values for each of the first, second, third and fourth light sources at each of the first and second points in time in order to track the motion of the object and identify the gesture of the object utilizing the first measured reflectance values for the first, second, third and fourth light sources.

13. The optical gesture recognition system of claim 12, where the first and second light sources and the optical receiver are disposed in predetermined relative positions to one another along a first axis, the third and fourth light sources and the optical receiver are disposed in predetermined relative positions to one another along a second axis, and the processor is configured to track motion of the object in at least two dimensions.

14. The optical gesture recognition system of claim 1, where the system further comprises:

a second optical receiver configured to receive reflected light from an object when the first light source is activated and output a second measured reflectance value corresponding to an amplitude of the reflected light; and

the processor is further configured to capture the second measured reflectance value at each of first and second points in time in order to track the motion of the object and identify the gesture of the object utilizing the first and second measured reflectance values from the first and second points in time.

15. The optical gesture recognition system of claim 14, where the first and second optical receivers and the first light source are disposed in predetermined relative positions to one another along a first axis.

16. The optical gesture recognition system of claim 14, where the system further comprises:

a third optical receiver configured to receive reflected light from an object when the first light source is activated and output a third measured reflectance value corresponding to an amplitude of the reflected light; and

the processor is further configured to capture the third measured reflectance value at each of first and second points in time in order to track the motion of the object and identify the gesture of the object utilizing the first, second and third measured reflectance values from the first and second points in time.

17. The optical gesture recognition system of claim 16, where the first, second and third optical receivers and the first light source are disposed in predetermined relative positions to one another and the processor is configured to track motion of the object in at least two dimensions.

18. The optical gesture recognition system of claim 1, where the system further comprises:

a second light source;

a second optical receiver configured to receive reflected light from an object when the second light source is activated and output a second measured reflectance value corresponding to an amplitude of the reflected light; and

the processor is further configured to independently activate the first and second light sources and capture the first and second measured reflectance values for each of the first and second light sources at each of the first and second points in time in order to track the motion of the object and identify the gesture of the object utilizing the first and second measured reflectance values captured for both the first and second light sources.

19. A method for gesture recognition in an optical system, the method comprising the steps of:

measuring an amplitude of reflected light from an object at a first point in time to obtain a first measured reflectance value;

measuring an amplitude of reflected light from an object at a second point in time to obtain a second measured reflectance value;

comparing the first and second measure reflectance values to determine the relative motion of the object; and

identifying a gesture corresponding to the relative motion of the object.

20. The method of claim 19, where:

the step of measuring an amplitude of reflected light from an object at a first point in time to obtain a first measured reflectance value further comprises measuring an amplitude of reflected light for first and second reflections at the first point in time to obtain the first measure reflectance value; and

the step of measuring an amplitude of reflected light from an object at a second point in time to obtain a second measured reflectance value further comprises measuring an amplitude of reflected light for the first and second reflections at the second point in time to obtain the second measure reflectance value.

21. The method of claim 19, where the step of comparing the first and second measure reflectance values to determine the relative motion of the object includes calculating an approximate position of the object at the first and second points in time in at least two dimensions.

22. The method of claim 19, where:

the step of measuring an amplitude of reflected light from an object at a first point in time to obtain a first measured reflectance value further comprises measuring an amplitude of reflected light for first, second and third reflections at the first point in time to obtain the first measure reflectance value; and

the step of measuring an amplitude of reflected light from an object at a second point in time to obtain a second measured reflectance value further comprises measuring an amplitude of reflected light for the first, second and third reflections at the second point in time to obtain the second measure reflectance value.

23. An optical gesture recognition system, the system comprising:

means for measuring amplitude of reflected light from an object at a first point in time to obtain a first measured reflectance value and at a second point in time to obtain a second measured reflectance value;

means for comparing the first and second measure reflectance values to determine relative motion of the object; and

means for identifying a gesture corresponding to the relative motion of the object.