Motion sensor for detecting bending or pivoting

• US 8,395,109 B2
• Filed: 05/25/2010
• Issued: 03/12/2013
• Est. Priority Date: 05/25/2010
• Status: Active Grant

• Current Assignee: The Jim Henson Company
• Original Assignee: The Jim Henson Co., Inc. (Highlight Communications AG)
• Inventors: Muravsky, Glenn
• Primary Examiner(s): Luu, Thanh
• Assistant Examiner(s): Naphas, Renee
• Application Number:
  US12/787,335
• Publication Number:
  US 20110292049A1
• Time in Patent Office: 1,022 Days
• Field of Search: 250/221, 250/227.11, 250/227.12, 250/227.14, 333/241, 333/242
• US Class Current: 250/231.1
• CPC Class Codes: G06F 3/014 Hand-worn input/output arrangements, e.g. data gloves
• CPC Class Codes: G06F 3/0362 with detection of 1D translations or rotations of an operating part of the device, e.g. scroll wheels, sliders, knobs, rollers or belts

Abstract

A motion sensor having a coiled member, light emitter, and light detector. The coiled member is bendable in response to lateral forces applied thereto. The coiled member defines an internal open ended channel having a first end opposite a second end. The emitter is adjacent the first end and emits light into the channel. At least a portion of that light travels through the channel toward the second portion. An amount of light reaching the detector is determined at least in part by how much the coiled member is bent. The detector is adjacent the second end and receives light from the channel. The detector is configured to transmit a signal indicating an amount of light received. The signal may be used by a motion capture system to animate a computer generated animation. Multiple motion sensors may be incorporated into a glove and positioned to detect bending of finger joints.

Claims

1. A motion sensor comprising:

a helically coiled member defining an internal open ended channel having a first open end portion opposite a second end portion and allowing the transmission of light therebetween, the helically coiled member being bendable when a lateral force is applied thereto;

a light emitter adjacent the first open end portion positioned to emit light into the channel for at least a portion of the light to travel through the channel toward the second open portion, at least a portion of the light traveling through the channel being reflected by the helically coiled member into the channel when the helically coiled member is bent; and

a light detector adjacent the second open end portion positioned to receive light that traveled through the channel, an amount of light received by the light detector varying depending at least in part on an amount by which the helically coiled member has been bent, and the light detector being further configured to transmit a signal indicating the amount of light received by the light detector.

2. The motion sensor of claim 1, wherein the amount of light received by the light detector is a linear function of the amount by which the helically coiled member has been bent.

3. The motion sensor of claim 1, wherein the channel is defined by an inwardly facing portion of the helically coiled member and the inwardly facing portion is other than planar.

4. The motion sensor of claim 1, wherein the channel is unobstructed to permit the transmission of light therethrough.

5. The motion sensor of claim 1, wherein the light emitter comprises a plurality of light emitting portions each configured to be selectively illuminated such that at least in some instances only one of the light emitting portions is illuminated.

6. The motion sensor of claim 5, further comprising:

a processor configured to selectively illuminate the light emitting portions and associate the amount of light received by the light detector with one of the light emitting portions that emitted the light detected.

7. The motion sensor of claim 1, wherein the channel is divided into a plurality of longitudinally extending sub-channels by one or more non-transparent dividing walls,

each sub-channel extends from a location toward the first open end portion to a location toward the second open end portion of the channel, and

the light emitter comprises a light emitting portion for each sub-channel, each light emitting portion emitting light into only a corresponding one of the sub-channels.

8. The motion sensor of claim 1, wherein the light emitter is configured to emit light having a plurality of different wavelengths,

the light detector is configured to detect light having each of the different wavelengths, and

the light detector is configured to transmit a signal indicating an amount of light detected for each of the different wavelengths.

9. The motion sensor of claim 1, wherein the light emitter emits a first color light, a second color light, and a third color light;

the light detector is configured to detect the first color light, the second color light, and the third color light, to distinguish the first color light from the second color light, to distinguish the first color light from the third color light, and to distinguish the second color light from the third color light, and

the light detector is further configured to transmit a signal indicating an amount of the first color light detected, an amount of the second color light detected, and an amount of the third color light detected.

10. The motion sensor of claim 9, wherein the light emitter comprises:

a first light emitting portion configured to emit the first color light;

a second light emitting portion configured to emit the second color light; and

a third light emitting portion configured to emit the third color light.

11. The motion sensor of claim 1, wherein the helically coiled member comprises a reflective coating.

12. The motion sensor of claim 1, wherein the light emitter is an infrared light emitting diode or a coherent laser light emitter.

13. A bend sensor for use with a motion capture system, the bend sensor comprising:

an elongated coil spring configured to deflect laterally in response to a laterally applied force and defining a longitudinally extending internal light transmitting channel;

a light emitter adjacent one end of the coil spring positioned to emit light into the internal channel of the coil spring, at least a portion of the light being reflected by the coil spring into the internal channel when the coil spring is deflected laterally; and

a light detector adjacent the other end of the coil spring positioned to receive light from the internal channel of the coil spring, an amount of light received from the internal channel of the coil spring varying depending at least in part on an amount by which the coil spring has been deflected laterally, and the light detector being further configured to transmit a signal to the motion capture system indicating an the amount of light received by from the internal channel of the coil spring.

14. A system for use with a first member configured to pivot relative to a second member, the system comprising:

a bend sensor comprising a helically coiled member having an interior channel, a first end couplable to the first member, and a second end couplable to the second member, the bend sensor further comprising a light emitter coupled to one of the first and second ends, and a light detector coupled to the other of the first and second ends, the light emitter emitting light into the interior channel, the helically coiled member being configured to bend laterally when (i) the first end is coupled to the first member, (ii) the second end is coupled to the second member, and (iii) the first member is pivoted relative to the second member, the helically coiled member being further configured to reflect at least a portion of the light into the interior channel when the helically coiled member is bent, an amount of light from the light emitter traveling through the interior channel and reaching the light detector varying based at least in part on an amount by which the helically coiled member is bent, the light detector being configured to transmit a signal encoding an indication of an amount of light received by the light detector; and

a motion capture system configured to receive the signal transmitted by the light detector, identify a bend amount associated with the indication of the amount of light received by the light detector encoded in the signal, and animate a computer generated animation based on the bend amount.

15. The system of claim 14, wherein the bend amount is determinable as a linear function of the indication of the amount of light received by the light detector encoded in the signal, and the motion capture system calculates the bend amount using the linear function.

16. The system of claim 14, wherein the motion capture system comprises a lookup table associating bend amounts with indications of amounts of light received by the light detector, and

the motion capture system looks up the indication of the amount of light received by the motion capture system in the lookup table to identify the bend amount associated with the indication of the amount of light received by the light detector encoded in the signal.

17. The system of claim 14, wherein the signal transmitted by the light detector is an analog signal, and the system further comprises a circuit configured to amplify the analog signal before the signal is transmitted to the motion capture system.

18. The system of claim 14, wherein the signal transmitted by the light detector is an analog signal, and the system further comprises an analog to digital converted configured to convert the analog signal into a digital signal before the signal is transmitted to the motion capture system.

19. A glove for use with a hand comprising a plurality of joints, the glove comprising:

a bend sensor for each of the plurality of joints, each bend sensor being positionable adjacent a selected one of the joints and configured to transmit a signal indicating by how much the selected one of the joints is bent, each bend sensor comprising;

a spring coiled about an interior channel, the spring being configured to bend when the selected one of the joints is bent;

a light emitter positioned to emit light into the interior channel of the spring, at least a portion of the light being reflected by the spring into the interior channel when the spring is bent; and

a light detector positioned to receive light from the interior channel of the spring, an amount of light received by the light detector varying depending at least in part on an amount by which the spring has been bent, and the light detector being further configured to transmit a signal indicating the amount of light received by the light detector.

20. The glove of claim 19, further comprising an outer surface, wherein the bend sensors are coupled to the outer surface of the glove by one or more outer coverings.

21. The glove of claim 19, wherein the one or more outer coverings are opaque.

22. The glove of claim 19, wherein the spring further comprises a first end portion coupled to the glove to one side of the selected one of the joints, a second end portion coupled to the glove to an opposite side of the selected one of the joints, and a bendable intermediate portion between the first and second end portions, the bendable intermediate portion being configured to bend when the selected one of the joints is bent.

23. The glove of claim 19, further comprising:

a circuit corresponding to each of the bend sensors coupled to the glove, each of the circuits being configured to receive and amplify the signal transmitted by the light detector of the bend sensor corresponding to the circuit.

24. The glove of claim 19, further comprising:

a circuit corresponding to each of the bend sensors coupled to the glove, each of the circuits being configured to receive and digitize the signal transmitted by the light detector of the bend sensor corresponding to the circuit.