Speckle based sensor for three dimensional navigation

• US 20050024624A1
• Filed: 07/31/2003
• Published: 02/03/2005
• Est. Priority Date: 07/31/2003
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Gruhlke, Russell W., Dlaz, Dennis C.
• Granted Patent: US 7,205,521 B2
• Time in Patent Office: Days
• US Class Current: 356/3.10
• CPC Class Codes: G01P 3/36 Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light G01P3/68 takes precedence; gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams G01C19/64
• CPC Class Codes: G01S 17/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• 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: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

Motion of a speckle pattern is employed to provide for navigation in three dimensions. Non-speckle optical navigation methods may also be used to provide for two dimensional surface navigation with speckle being used to provide for navigation in the third dimension.

Claims

1. An optical navigation system comprising:

a light source for providing a light beam having a first wavelength incident onto a target surface;

a coherent source for providing a divergent beam having a second wavelength incident onto said target surface;

a first detector for receiving a first reflection of said light beam from said target surface; and

a second detector for receiving a second reflection of said divergent beam from said target surface to allow the determination of the position of said first and said second detector with respect to said target surface from signals generated by said first and said second detectors in response to said first and said second reflections.

2. The system of claim 1 wherein said second reflection is comprised of a speckle pattern.

3. The system of claim 1 where said coherent source comprises a VCSEL.

4. The system of claim 1 further comprising a wavelength filter for passing said second wavelength and disposed with respect to said second detector such that said second detector receives only said second reflection.

5. The system of claim 1 further comprising a focusing lens positioned between said coherent source and said target surface.

6. The system of claim 1 further comprising a collimating lens positioned between said first source and said target surface.

7. The system of claim 1 further comprising a lightpipe disposed between said target surface and said second detector to increase the collection efficiency of said second reflection.

8. The system of claim 1 further comprising a collection lens disposed between said target surface and said detector to increase the collection efficiency of said second reflection.

9. The system of claim 1 further comprising a third detector to receive said second reflection.

10. The system of claim 1 wherein said second detector comprises detector strips alternating with non detector strips.

11. An optical navigation system comprising:

a coherent source for providing a first portion of a beam comprising a first wavelength and a second portion of a beam comprising a second wavelength onto a target surface;

a first detector for receiving a first reflection of said first portion of said beam from said target surface; and

a second detector for receiving a second reflection of said second portion of said beam from said target surface to allow the determination of the position of said first and said second detector with respect to said target surface from signals generated by said first and said second detectors in response to said first and said second reflections.

12. The system of claim 11 wherein said coherent source comprises a first and a second narrowband wavelength filter to produce said first and said second portions of said beam.

13. The system of claim 11 wherein said coherent source comprises a VCSEL.

14. The system of claim 11 wherein said second reflection is comprised of a speckle pattern.

15. The system of claim 11 further comprising a focusing lens operable to focus said second portion of said beam at position between said coherent source and said target surface.

16. The system of claim 11 further comprising a collimating lens operable to collimate said first portion of said beam.

17. The system of claim 11 further comprising a lightpipe disposed between said target surface and said second detector to increase the collection efficiency of said second reflection.

18. The system of claim 11 further comprising collection lens disposed between said target surface and said detector to increase the collection efficiency of said second reflection.

19. The system of claim 12 further comprising a third narrowband wavelength filter for passing said second wavelength and disposed with respect to said second detector such that said second detector receives only said second reflection.

20. The system of claim 11 further comprising a third detector to receive said second reflection.

21. An optical navigation system comprising:

a coherent source for providing a light beam incident onto a target surface;

a first detector for receiving a first portion of a reflection of said light beam from said target surface; and

a second detector for receiving a second portion of said reflection of said light beam from said target surface to allow the determination of the position of said first and said second detector with respect to said target surface from signals generated by said first and said second detectors in response to said first and said second portions of said reflections.

22. The optical navigation system of claim 21 wherein said coherent source is positioned at an angle between five and twenty degrees with respect to said target surface.

23. The optical navigation system of claim 21 further comprising an aperture positioned between said second detector and said target surface to limit the field of view of said second detector.

24. The optical navigation system of claim 21 wherein said first detector is a correlation detector.