Current sensor output measurement system and method

• US 8,866,795 B1
• Filed: 08/29/2012
• Issued: 10/21/2014
• Est. Priority Date: 07/28/2008
• Status: Active Grant

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Xu, Yansun, Trisnadi, Jahja, Carlisle, Clinton, Zeng, Ke-Cai, Spurlock, Brett, Sanders, Steve
• Primary Examiner(s): Chow, Van
• Application Number:
  US13/598,464
• Time in Patent Office: 783 Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/0338 Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
• 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 3/03547 Touch pads, in which fingers can move on a surface

Abstract

Finger navigation methods, devices and systems are disclosed. In one embodiment the system comprises a light source configured to radiate a light beam towards a tactile surface. The system also comprises a photo detector module configured to sense speckle beams emitted by a target surface navigating the tactile surface in response to light hitting the target surface. The system further comprises a processor configured to track a movement of the target surface with respect to the tactile surface based on output from the photo detector module and a conductor structure for capacitive sensing of the target surface with respect to the tactile surface. The conductor structure is configured to determine a plurality of navigational functionalities based on the capacitive sensing of the target surface with respect to the tactile surface, including at least one of single click, double click, and scrolling.

Claims

1. A finger navigation sensor system, comprising:

a light source configured to radiate a light beam towards a tactile surface;

a photo detector module configured to sense speckle beams from a target surface navigating the tactile surface in response to light hitting the target surface;

a processor configured to report tracking data on movement of the target surface with respect to the tactile surface based on output from the photo detector module; and

a conductor structure for capacitive sensing of the target surface with respect to the tactile surface,

wherein the target surface comprises a human finger and wherein the conductor structure is configured to detect based on the capacitive sensing of the human finger with respect to the tactile surface, single click, double click, and scrolling.

2. The system of claim 1, wherein the processor is further configured to block reporting of tracking data provided a measured size of a liftoff of the target surface with respect to the tactile surface is more than a threshold value.

3. The system of claim 2, wherein the measured size of the liftoff of the target surface is determined by measuring an energy level of the speckle beams received at the photo detector module.

4. The system of claim 2, wherein the measured size of the liftoff of the target surface is determined by measuring a capacitance formed between the target surface and the conductor structure.

5. The system of claim 1 wherein the conductor structure comprises an aperture configured to allow the light beam to radiate towards the tactile surface and the speckle beams to reach the photo detector.

6. The system of claim 1, wherein the tactile surface comprises a transparent optical component.

7. The system of claim 1, wherein the photo detector module comprises a photo diode array (PDA).

8. A finger navigation sensor system, comprising:

a light source configured to radiate a light beam towards a tactile surface;

a photo detector module configured to sense speckle beams from a target surface navigating the tactile surface in response to light hitting the target surface;

a processor configured to track a movement of the target surface with respect to the tactile surface based on output from the photo detector module provided a measured size of a liftoff of the target surface with respect to the tactile surface is less than a threshold value;

a conductor structure for capacitive sensing of the target surface with respect to the tactile surface, wherein the target surface comprises a human finger and wherein the conductor structure is configured to detect based on the capacitive sensing of the human finger with respect to the tactile surface, single click, double click, and scrolling; and

wherein the measured size of the liftoff of the target surface is determined by measuring an energy level of the speckle beams received at the photo detector module.

9. The system of claim 8, wherein the tactile surface comprises a transparent optical component.

10. The system of claim 8, wherein the photo detector module comprises a photo diode array (PDA).

11. The system of claim 8, wherein the conductor structure comprises an aperture configured to allow the light beam to radiate towards the tactile surface and the speckle beams to reach the photo detector.

12. The system of claim 11, wherein the conductor structure comprises two conductor units coupled to a capacitive sensor associated with the processor.

13. The system of claim 8, wherein the light source comprises a laser light source and a light emitting diode (LED).

14. An electronic device, comprising:

a tactile surface for interfacing with a target surface; and

a finger navigation sensor system comprising;

a light source configured to radiate a light beam towards the tactile surface;

a photo detector module configured to sense speckle beams from the target surface navigating the tactile surface in response to light hitting the target surface;

a processor configured to track a movement of the target surface with respect to the tactile surface based on output from the photo detector module provided a measured size of a liftoff of the target surface with respect to the tactile surface is less than a threshold value; and

a conductor structure formed below the tactile surface for capacitive sensing of the target surface with respect to the tactile surface,

wherein the measured size of the liftoff of the target surface is determined by measuring a capacitance formed between the target surface and the conductor structure,

wherein the target surface comprises a human finger and wherein the processor is further configured to determine based on the capacitive sensing of the human finger with respect to the tactile surface, single click, double click, and scrolling.

15. The device of claim 14, further comprising an opaque insulator layer having a precision aperture for passing light radiated towards the tactile surface.

16. The device of claim 14, wherein the processor is configured to perform a proximity determination of the target surface with respect to the tactile surface based on the capacitive sensing of the target surface.

17. The device of claim 14, wherein the processor is configured to determine a plurality of navigational functionalities based on the sensed speckle beams.

18. The device of claim 14, wherein the light comprises a laser light and a LED light.

19. The device of claim 14, wherein the photo detector module and the processor are integrated within a programmable device.