Method and apparatus to determine direction of motion in a sensor array of a touch sensing device

• US 8,085,252 B1
• Filed: 05/29/2008
• Issued: 12/27/2011
• Est. Priority Date: 05/29/2007
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Lee, Mark R., Hammer, Christopher R.
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Lin, Hang
• Application Number:
  US12/129,497
• Time in Patent Office: 1,307 Days
• Field of Search: 345/173, 345/174, 345/168, 178/18.03
• US Class Current: 345/174
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

Direction of motion in a sensor array of a touch sensing device may be determined using a rule-based algorithm. A presence of a conductive object on a sensing device may be detected. First, second, and third locations of the detected presence of the conductive object may be determined. The first location may be compared with the second location using the rule-based algorithm, and a first direction of motion of the conductive object may be recognized based on the comparison. The second location may be compared with the third location using the rule-based algorithm, and the same first direction of motion of the conductive object may be recognized based on the comparison.

Claims

1. A method to determine direction of motion in a sensor array of a touch sensing device, comprising:

detecting a presence of a conductive object on a sensing device;

determining a first location of the detected presence of the conductive object;

determining a second location of the detected presence of the conductive object;

comparing the second location to the first location using a rule-based logic algorithm;

recognizing a first direction of motion of the conductive object based on the comparison of the second location to the first location;

determining a third location of the detected presence of the conductive object;

comparing the third location to the second location using the rule-based logic algorithm; and

recognizing a continued first direction of motion of the conductive object based on the comparison of the third location to the second location,

wherein the rule-based logic algorithm includes;

if f[i]=0, then g[i]=0;

if f[i−

1]=f[i], then g[i]=0;

if f[i−

1]<

f[i], then g[i]=left; and

if f[i−

1]>

f[i], then g[i]=right;

where;

f[i]=current sample of sensor mask(t);

f[i−

1]=previous sample of sensor mask(t);

g[i]=output of direction detection algorithm; and

t=time.

2. The method of claim 1, further comprising:

determining a fourth location of the detected presence of the conductive object;

comparing the fourth location to the third location using the rule-based logic algorithm; and

recognizing a second direction of motion opposite the first direction of motion of the conductive object based on the comparison of the fourth location to the third location.

3. The method of claim 1, wherein the conductive object includes a finger.

4. A non-transitory machine-readable medium that provides instructions that, if executed by a machine, will cause the machine to perform operations comprising:

detecting a presence of a conductive object on a sensing device;

determining a first location of the detected presence of the conductive object;

determining a second location of the detected presence of the conductive object;

comparing the second location to the first location using a rule-based logic algorithm;

recognizing a first direction of motion of the conductive object based on the comparison of the second location to the first location;

determining a third location of the detected presence of the conductive object;

comparing the third location the second location using the rule-based logic algorithm; and

recognizing a continued first direction of motion of the conductive object based on the comparison of the third location to the second location,

wherein the rule-based logic algorithm includes;

if f[i]=0, then g[i]=0;

if f[i−

1]=f[i], then g[i]=0;

if f[i−

1]<

f[i], then g[i]=left; and

if f[i−

1]>

f[i], then g[i]=right;

where;

f[i]=current sample of sensor mask(t);

f[i−

1]=previous sample of sensor mask(t);

g[i]=output of direction detection algorithm; and

t=time.

5. An apparatus, comprising:

a sensing device having a plurality of sensor elements to detect a presence of conductive object on the sensing device; and

a processing device coupled to the sensing device, wherein the processing device is configured to;

detect a presence of a conductive object on a sensing device;

determine a first location of the detected presence of the conductive object;

compare the second location to the first location using a rule-based logic algorithm;

recognize a first direction of motion of the conductive object based on the comparison of the first and second locations;

determine a third location of the detected presence of the conductive object;

compare the third location to the second location using the rule based logic algorithm; and

recognize a continued first direction of motion of the conductive object based on the comparison of the second and third locations,

wherein the rule-based logic algorithm includes;

if f[i]=0, then g[i]=0;

if f[i−

1]=f[i], then g[i]=0;

if f[i−

1]<

f[i], then g[i]=left; and

if f[i−

1]>

f[i], then g[i]=right;

where;

f[i]=current sample of sensor mask(t);

f[i−

1]=previous sample of sensor mask(t);

g[i]=output of direction detection algorithm; and

t=time.

6. The apparatus of claim 5, wherein the processing device is further configured to:

determine a fourth location of the detected presence of the conductive object;

compare the fourth location to the third location using the rule-based logic algorithm; and

recognize a second direction of motion opposite the first direction of motion of the conductive object base on the comparison of the fourth location of the third location.

7. The apparatus of claim 5, wherein the processing device includes a capacitance sensor coupled to the plurality of the sensor elements, and wherein the capacitance sensor is configured to measure a capacitance on each sensor element.

8. The apparatus of claim 5, further comprising:

a component external to the processing device, wherein the processing device is configured to send data to the component when the direction of motion of the conductive object is recognized.

9. The apparatus of claim 8, wherein the component external to the processing device comprises a processor.

10. The apparatus of claim 8, wherein the component external to the processing device comprises a driver of a processor.

11. The apparatus of claim 8, wherein the component external to the processing device comprises an embedded controller.

12. The apparatus of claim 8, wherein the data includes at least one of a command and a signal.

13. The apparatus of claim 5, wherein the conductive object includes a finger.

14. The apparatus of claim 5, wherein the sensing device includes at least one of a single-dimension sensor array comprising the plurality of sensor elements and a multi-dimension sensor array comprising the plurality of sensor elements.

15. The apparatus of claim 5, wherein the sensing device includes at least one of a touch-sensor pad and a touch-sensor slider.

16. The apparatus of claim 5, wherein the sensing device is mounted on a mobile handset.

17. The apparatus of claim 6, wherein the processing device is configured to determine direction detection in a sequence where differing directions are recognized by a count balance rule.