Pointing devices

• US 8,723,816 B2
• Filed: 09/03/2010
• Issued: 05/13/2014
• Est. Priority Date: 09/09/2009
• Status: Active Grant

• Current Assignee: STMicroelectronics Limited (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Limited (STMicroelectronics NV)
• Inventors: Raynor, Jeffrey, Laflaquiere, Arnaud
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): Edwards, Carolyn R
• Application Number:
  US12/876,055
• Publication Number:
  US 20110057906A1
• Time in Patent Office: 1,348 Days
• Field of Search: 345156-178
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/0339 Touch strips, e.g. orthogonal touch strips to control cursor movement or scrolling; single touch strip to adjust parameter or to implement a row of soft keys
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface

Abstract

A touch pad uses a plurality of optical mouse type sensors. The sensors are optimized for detection of motion along the predominant direction of a user'"'"'s finger as the finger is moved around the touch pad. A first one of the sensors functions to optically sense motion in a first direction, while a second one of the sensors functions to optically sense motion in a second, different, direction. The first and second directions are oriented a closed, for example, circular, path.

Claims

1. A touch pad pointing device comprising:

a mousing surface defining a closed path for a user pointer;

a first optical mouse sensor having an imaging region through which the closed path passes that is oriented in a first direction, the first optical mouse sensor configured to detect presence and motion of the user pointer at the imaging region in the first direction and generate a first motion signal indicative of the detected motion;

a second optical mouse sensor having an imaging region through which the closed path passes that is oriented in a second, different, direction, the second optical mouse sensor configured to detect presence and motion of the user pointer at the imaging region in the second direction and generate a second motion signal indicative of the detected motion; and

a detector provided to detect direction of motion of a user pointer along the closed path and to detect speed of motion along the closed path on the basis of relative timing of the first and second motion signals output from the first optical mouse sensor oriented in the first direction and the second optical mouse sensor oriented in the second direction.

2. The touch pad pointing device of claim 1, wherein the closed path is in the shape of a circle.

3. The touch pad pointing device of claim 1, wherein at least four optical mouse sensors are provided, defining at least four angularly equidistant touch zones.

4. The touch pad pointing device of claim 1, wherein the optical mouse sensors and the mousing surface operate to provide frustrated total internal reflection.

5. The touch pad pointing device of claim 3, wherein each of the sensors has the same address and a system controller is provided that has four separate ports.

6. The touch pad pointing device of claim 5, wherein the ports are I²C or SPI interfaces.

7. The touch pad pointing device of claim 1, wherein the optical mouse sensors have the same address and a system controller has a single port and a bus multiplexer.

8. The touch pad pointing device of claim 1, wherein each of the optical mouse sensors has different or programmable addresses and can share the same bus.

9. The touch pad pointing device of claim 1, wherein each of the optical mouse sensors comprises an optical proximity detector configured to detect both direction of motion and speed of motion.

10. The touch pad pointing device of claim 1, wherein each of the optical mouse sensors comprises a photodetector with a linear array of pixels.

11. The touch pad pointing device of claim 1, wherein reset periods of the optical mouse sensors are offset, such that the first optical mouse sensor is held in reset during an entire time period while a radiation source is illuminating a second optical mouse sensor.

12. The touch pad pointing device of claim 11, wherein the first optical mouse sensor is held in reset during an entire integration time period of the second optical mouse sensor.

13. The touch pad pointing device of claim 11, wherein the offset timing is carried out between two groups of optical mouse sensors.

14. The touch pad pointing device of claim 1, wherein imaging region for each optical mouse sensor is elongated in a direction of a predominant direction of the closed path passing through the imaging region.

15. The touch pad pointing device of claim 1, wherein each optical mouse sensor includes a sensor array having a non-square aspect ratio.

16. The touch pad pointing device of claim 1, wherein each optical mouse sensor includes a sensor array and wherein individual pixels in the sensor array have a non-square aspect ratio.

17. A method of sensing motion of a user pointer on a touch pad pointing device comprising:

optically sensing motion in a first direction at a first point along a closed path;

optically sensing motion in a second, different, direction at a second, different, point along the closed path;

wherein the closed path is defined by a mousing surface of the touch pad pointing device;

detecting a direction of motion of a user pointer along the closed path on the basis of a motion detection signal output from an optical mouse sensor located at each of the first and second points; and

detecting a speed of motion of the user pointer along the closed path on the basis of the relative timing of the motion detection signals output from said optical mouse sensors located at the first and second points.

18. The method of claim 17, wherein the closed path is in the shape of a circle.

19. The method of claim 17, further comprising optically sensing motion in at least four different directions at different detection points along the closed path, the detection points being angularly equidistant.

20. The method of claim 17, wherein the step of optically sensing motion comprises detecting a frustrated total internal reflection signal.

21. The method of claim 17, wherein the detection is carried out using an optical proximity detector of the optical mouse sensor.

22. The method of claim 17, wherein reset periods of at least two of the optical mouse sensors are offset, such that a first optical mouse sensor is held in reset during an entire time period while a radiation source is illuminating a second optical mouse sensor.

23. The method of claim 22, wherein the first optical mouse sensor is held in reset during an entire integration time period of the second optical mouse sensor.

24. The method of claim 23, wherein the offset timing is carried out between two groups of optical mouse sensors.

25. A touch pad pointing device, comprising:

a mousing surface defining a closed curved path for a user pointer;

a first optical frustrated total internal reflection sensor configured to make a detection of user pointer movement in a movement detection direction oriented in a first direction tangential to the closed curved path, said first optical frustrated total internal reflection sensor positioned at a first location along the closed path and further configured to output a first signal indicative of movement detection;

a second optical frustrated total internal reflection sensor configured to make a detection of user pointer movement in a movement detection direction oriented in a second direction tangential to the closed path, said first optical frustrated total internal reflection sensor positioned at a second, different, location along the closed curved path and further configured to output a second signal indicative of movement detection; and

a processing circuit coupled to receive the first and second signals and configured to detect movement of the user pointer and speed of movement of the user pointer along the closed curved path in response to relative timing of the first and second signals.

26. The device of claim 25 wherein each optical frustrated total internal reflection sensor comprising a plurality of sensor pixels arranged in an array.

27. The device of claim 25, wherein each optical frustrated total internal reflection sensor comprises an optical proximity detector.