Image-based sensing of acceleration

• US 20070062284A1
• Filed: 09/22/2005
• Published: 03/22/2007
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Machida, Akihiro
• Granted Patent: US 7,293,459 B2
• Time in Patent Office: Days
• US Class Current: 73/513
• CPC Class Codes: G01P 15/093 by photoelectric pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1686 the I/O peripheral being an integrated camera
• CPC Class Codes: G06F 2200/1637 Sensing arrangement for detection of housing movement or orientation, e.g. for controlling scrolling or cursor movement on the display of an handheld computer
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion telephones including GPS signal receivers H04M2250/10

Abstract

A system includes a support, a pendular element, an elastic restraint, an image sensor, and a processing system. The elastic restraint couples the pendular element to the support and applies to the pendular element a restraining force that opposes movement of the pendular element in at least a first direction. The image sensor captures images of the pendular element. The processing system determines one or more movement measures describing movement of the support from comparisons of ones of the images captured by the image sensor. In another aspect, a pendular element is elastically coupled to a support. A restraining force that opposes movement of the pendular element in at least a first direction is applied to the pendular element. Images of the pendular element are captured. One or more movement measures describing movement of the support are determined from comparisons of ones of the captured images.

Claims

1. A system, comprising:

a support;

a pendular element;

an elastic restraint coupling the pendular element to the support and operable to apply to the pendular element a restraining force that opposes movement of the pendular element in at least a first direction;

an image sensor operable to capture images of the pendular element; and

a processing system operable to determine one or more movement measures describing movement of the support from comparisons of ones of the images captured by the image sensor.

2. The system of claim 1, wherein the pendular element comprises a tracking feature and the processing system is operable to determine the movement measures based at least in part on positions of the tracking feature in ones of the captured images.

3. The system of claim 2, wherein the tracking feature comprises a reference mark on a surface of the pendular element.

4. The system of claim 3, wherein the pendular element is transmissive of light in a specified wavelength range and the image sensor is operable to capture images of light in the specified wavelength range.

5. The system of claim 4, further comprising a window transmissive of light in the specified wavelength range that illuminates the image sensor through the pendular element.

6. The system of claim 1, wherein the elastic restraint comprises a first elastic element and a second elastic element that couple opposite sides of the pendular element to the support along an axis parallel to the first direction.

7. The system of claim 6, further comprising a third elastic element and a fourth elastic element that couple opposite sides of the pendular element to the support along an axis orthogonal to the first direction.

8. The system of claim 1, wherein the processing system is operable to determine the movement measures based on comparisons of positions of corresponding structure-related features in ones of the captured images.

9. The system of claim 1, wherein at least one of the movement measures corresponds to an acceleration of the support.

10. The system of claim 1, wherein at least one of the movement measures corresponds to a velocity of the support.

11. The system of claim 1, wherein at least one of the movement measures corresponds to a displacement of the support.

12. The system of claim 1, wherein at least one of the movement measures corresponds to a tilt orientation of the support relative to a gravitational field direction.

13. The system of claim 1, further comprising:

a housing containing the support, the pendular element, the elastic restraint, the image sensor, and the processing system;

a second image sensor in the housing; and

a lens system for focusing light from outside the housing onto the second image sensor;

wherein the processing system is operable to process the images captured by the second image sensor into respective image files.

14. The system of claim 13, wherein the processing system is operable to embed ones of the movement measures into corresponding ones of the image files.

15. The system of claim 13, wherein the processing system is operable to modify ones of the images captured by the second image sensor based on one or more of the movement measures.

16. The system of claim 13, wherein the processing system is operable to generate one or more signals modifying where the focused light is captured by the second image sensor based on one or more of the movement measures.

17. A method, comprising:

elastically coupling a pendular element to a support;

applying to the pendular element a restraining force that opposes movement of the pendular element in at least a first direction;

capturing images of the pendular element; and

determining one or more movement measures describing movement of the support from comparisons of ones of the captured images.

18. The method of claim 17, wherein the coupling, the applying, the capturing, and the determining are performed within a housing, and further comprising:

focusing light from outside the housing along a light path;

capturing images of the focused light in a capture plane; and

processing the captured images of the focused light into respective image files.

19. The method of claim 18, further comprising embedding ones of the movement measures into corresponding ones of the image files.

20. The method of claim 18, further comprising modifying ones of the captured images based on one or more of the movement measures.

21. The method of claim 18, further comprising modifying where the focused light is captured in the capture plane based on one or more of the movement measures.