Circuit and method for determining motion with redundant comb-arrays

• US 8,547,336 B1
• Filed: 02/08/2011
• Issued: 10/01/2013
• Est. Priority Date: 02/16/2006
• Status: Active Grant

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Todoroff, Brian, Xu, Yansun
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): LAM, VINH TANG
• Application Number:
  US13/023,533
• Time in Patent Office: 966 Days
• Field of Search: 345156-167, 2502081-216
• US Class Current: 345/166
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
• CPC Class Codes: G06F 3/03549 Trackballs G06F3/03541 takes precedence

Abstract

An optical navigation system and method are provided. In one embodiment, the method includes: (i) generating for a first group of photosensitive elements a first quasi-sinusoidal signal at a first time, and a second quasi-sinusoidal signal at a second time in response to motion of light received thereon in a first direction; (ii) computing from the first and second quasi-sinusoidal signals a phase angle change; and (iii) computing from the first and second quasi-sinusoidal signals a radius value. Other embodiments are also described.

Claims

1. A method comprising:

generating for a first group of photosensitive elements a first quasi-sinusoidal signal at a first time, and a second quasi-sinusoidal signal at a second time in response to motion of light received thereon in a first direction;

computing from the first and second quasi-sinusoidal signals a phase angle change;

computing from the first and second quasi-sinusoidal signals a radius value;

generating for a second group of photosensitive elements a third quasi-sinusoidal signal at the first time, and at the second time a fourth quasi-sinusoidal signal in response to the motion of the light received thereon in the first direction;

computing from the third and fourth quasi-sinusoidal signals another phase angle change;

computing from the third and fourth quasi-sinusoidal signals another radius value; and

combining phase angle changes using radius-weighted-averaging to provide a single weighted average phase angle change resulting from the motion of the light in the first direction.

2. The method of claim 1, wherein the first and second groups of photosensitive elements are positioned at different locations within a two dimensional (2D) array of photosensitive elements.

3. The method of claim 1, wherein generating quasi-sinusoidal signals for the first and second groups of photosensitive elements further comprises generating for each group of photosensitive elements quasi-sinusoidal signals at the first and second time in response to motion of light in a second direction.

4. A method comprising:

generating for a first group of photosensitive elements a first quasi-sinusoidal signal at a first time, and a second quasi-sinusoidal signal at a second time in response to motion of light received thereon in a first direction;

generating for a second group of photosensitive elements a third quasi-sinusoidal signal at the first time, and at the second time a fourth quasi-sinusoidal signal in response to motion of light received thereon in the first direction;

computing from the first and second quasi-sinusoidal signals a first phase angle change,

and from the third and fourth quasi-sinusoidal signals a second phase angle change; and

combining the first and second phase angle changes to provide a single average phase angle change resulting from the motion in the first direction.

5. The method of claim 4, further comprising computing a signal strength value of the quasi-sinusoidal signals computing from the first and second quasi-sinusoidal signals a first radius value, and from the third and fourth quasi-sinusoidal signals a second radius value.

6. The method of claim 5, wherein combining the first and second phase angle changes comprises combining the first and second phase angle changes using radius-weighted averaging to provide a single weighted average phase angle change.

7. The method of claim 4, wherein the first and second groups of photosensitive elements are positioned at different locations within a two dimensional (2D) array of photosensitive elements.

8. The method of claim 4, wherein the first and second groups of photosensitive elements are positioned at within two different arrays of photosensitive elements.

9. The method of claim 4, wherein generating quasi-sinusoidal signals for the first and second groups of photosensitive elements further comprises generating for each group of photosensitive elements quasi-sinusoidal signals at the first and second time in response to motion of light in a second direction.