Force touch button emulation

• US 9,927,905 B2
• Filed: 08/19/2015
• Issued: 03/27/2018
• Est. Priority Date: 08/19/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Smith, John Stephen
• Primary Examiner(s): XAVIER, ANTONIO J
• Application Number:
  US14/830,279
• Publication Number:
  US 20170052622A1
• Time in Patent Office: 951 Days
• Field of Search: None
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

Disclosed herein is an electronic device having a force sensing device. The force sensing device receives a continuous force input which is translated into a discrete event. In order to more accurately determine when the discrete event is to occur, the electronic device includes a two low-pass filters that concurrently receive a force signal from the force sensing device. The first low-pass filter has a first bandwidth and the second low-pass filter has a second bandwidth that is greater than the first bandwidth. The two low-pass filters filter the force signal to provide a user interface with a precise feel for slower more deliberate input while also providing fast response times for stronger, shorter input.

Claims

1. A method for determining a type of input received on a surface of an electronic device, the method comprising:

receiving a continuous force signal from a force sensing device;

providing the continuous force signal to a first low-pass filter having a first bandwidth;

concurrently providing the continuous force signal to a second low-pass filter having a second bandwidth that is greater than the first bandwidth;

determining, within a first time period, whether the continuous force signal exceeds a first threshold associated with the first low-pass filter; and

determining, within a second time period, whether the continuous force signal exceeds a second threshold associated with the second low-pass filter, wherein the second time period is shorter than the first time period and the second threshold is higher than the first threshold.

2. The method of claim 1, further comprising triggering a button press event when the continuous force signal exceeds the first threshold within the first time period.

3. The method of claim 2, further comprising triggering a button release event when the continuous force signal falls below a third threshold that is associated with the first low-pass filter, the third threshold being less than the first threshold.

4. The method of claim 1, further comprising triggering a button press event when the continuous force signal exceeds the second threshold within the second time period.

5. The method of claim 4, further comprising triggering a button release event when the continuous force signal falls below a fourth threshold that is associated with the second low-pass filter, the fourth threshold being less than the second threshold.

6. The method of claim 1, wherein the first low-pass filter attenuates a first amount of noise and wherein the second low-pass filter attenuates a second amount of noise.

7. The method of claim 6, wherein the second amount of noise is less than the first amount of noise.

8. The method of claim 1, further comprising issuing an interrupt to an operating system of the electronic device when the continuous force signal exceeds the first threshold.

9. The method of claim 1, further comprising issuing an interrupt to an operating system of the electronic device when the continuous force signal exceeds the second threshold.

10. An electronic device comprising:

a force sensing device;

a processing unit; and

a memory coupled to the processing unit, the memory for storing instructions which, when executed by the processing unit, causes the processing unit to determine a type of input received on a surface of the electronic device, the method comprising;

receiving samples of a continuous force signal from the force sensing device;

performing a first low-pass filtering of the samples of the continuous force signal with a first low-pass filter having a first bandwidth by averaging a first number of previous samples of the continuous force signal;

concurrently with performing the first low-pass filtering, performing a second low-pass filtering of the samples of the continuous force signal using a second low-pass filter having a second bandwidth, the second bandwidth greater than the first bandwidth, by averaging a second number of previous samples of the continuous force signal that is different than the first number;

receiving a first output from the first low-pass filtering at a first output rate;

receiving a second output from the second low-pass filtering at a second output rate;

wherein the second output rate is higher than the first output rate;

determining, within a first time period, whether the continuous force signal exceeds a first threshold associated with the first low-pass filter;

determining, within a second time period, whether the continuous force signal exceeds a second threshold associated with the second low-pass filter, wherein the second time period is shorter than the first time period and the second threshold is higher than the first threshold; and

determining the type of input associated with the continuous force signal based on the first output and the second output.

11. The electronic device of claim 10, wherein the force sensing device comprises a strain sensor.

12. The electronic device of claim 10, wherein the force sensing device comprises a capacitive sensor.

13. The electronic device of claim 10, wherein the force sensing device is associated with a display stack of the electronic device.

14. The electronic device of claim 10, wherein force sensing device is associated with a mechanical input device.

15. The electronic device of claim 10, wherein the discrete event is a button press event.

16. The electronic device of claim 10, further comprising instructions for determining when the continuous force signal falls below a third threshold associated with the output from the first low-pass filtering or a fourth threshold associated with the output from the second low-pass filtering, wherein the third threshold is less than first threshold and the fourth threshold is less than second threshold.

17. A method for translating a continuous force signal into a discrete event, the method comprising:

receiving the continuous force signal from a force sensing device;

concurrently providing the continuous force signal to a first low-pass filter and a second low-pass filter;

sampling output from the first low-pass filter at a first rate;

sampling output from the second low-pass filter at a second rate; and

issuing a command associated with the output from the first low-pass filter when the output from the first low-pass filter exceeds a first threshold; and

issuing a command associated with the output from the second low-pass filter when the output from the second low-pass filter exceeds a second threshold that is greater than the first threshold.

18. The method of claim 17, wherein the first low-pass filter has a first bandwidth and the second low-pass filter has a second bandwidth that is greater than the first bandwidth.

19. The method of claim 17, wherein the output of the first low-pass filter comprises an average of the last N number of samples of the continuous force signal.

20. The method of claim 19, wherein the output of the second low-pass filter comprises an average of the last M number of samples of the continuous force signal, wherein M is less than N.