System and method for determining user input using dual baseline modes

• US 10,254,873 B2
• Filed: 05/05/2011
• Issued: 04/09/2019
• Est. Priority Date: 05/05/2011
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Vandermeijden, Tom
• Primary Examiner(s): Suglo, Janet L
• Application Number:
  US13/101,915
• Publication Number:
  US 20120283972A1
• Time in Patent Office: 2,896 Days
• Field of Search: 702 65, 702179, 702104, 702182, 702189, 702190
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184

Abstract

The embodiments described herein provide devices and methods that facilitate improved performance. In one embodiment, an input device comprises a plurality of capacitive sensor electrodes and a processing system coupled to the electrodes and configured to operate the electrodes to sense in a sensing region. Specifically, the processing system is configured to determine information about input objects in the sensing region based on comparisons of preliminary values with corresponding baseline values. The processing system is further configured to selectively operate in a first mode and a second mode. While operating in the first mode, the processing system selectively changes a baseline value of the plurality of baseline values by a first amount in response to that baseline value being below a corresponding preliminary value. This selective changing of baseline values occurs even when the processing system determines that an input object is in the sensing region.

Claims

1. A processing system for use with a capacitive input device of the type having a plurality of capacitive sensor electrodes and configured to sense in a sensing region, the processing system comprising:

sensor electrode circuitry configured to operate the plurality of capacitive sensor electrodes to produce pluralities of preliminary values, each preliminary value corresponding to an individual measured capacitance associated with a corresponding capacitive pixel and obtained using a sensor electrode of the plurality of sensor electrodes, the pluralities of preliminary values comprising a first plurality of preliminary values and a second plurality of preliminary values, the second plurality of preliminary values obtained after the first plurality of preliminary values; and

a determination module configured to determine information about input in the sensing region based on comparisons of the pluralities of preliminary values with corresponding baseline values of a plurality of baseline values, wherein the determination module is configured to selectively operate in a first mode and a second mode such that;

while operating in the first mode, the determination module individually compares a baseline value of the plurality of baseline values with a corresponding preliminary value of the first plurality of preliminary values, and selectively changes the baseline value by a first amount when the baseline value is different from the corresponding preliminary value to obtain an updated baseline, wherein, in the first mode, the selectively changing the baseline value is performed even when the processing system determines that an input object is in the sensing region; and

while operating in the second mode, the determination module does not selectively change the baseline value by the first amount when the baseline value and the corresponding preliminary value are different and when the processing system determines that the input object is in the sensing region,

wherein the determination module is configured to switch from operating in the first mode to operating in the second mode in response to one of an external signal and a determination that no input objects are in the sensing region,

wherein the determination module is further configured to;

determine a difference between a corresponding baseline value in the updated baseline and a corresponding preliminary value in the second plurality of preliminary values to obtain a plurality of measured values,

detect, from the plurality of measured values, the input object in the sensing region, and

provide, to an electronic system, positional information of the input object based on detecting the input object.

2. The processing system of claim 1, wherein while operating in the first mode, the determination module selectively changes the baseline value of the plurality of baseline values by the first amount in response to the baseline value being different from the corresponding preliminary value of the pluralities of preliminary values even when the processing system determines that the input object is in the sensing region by:

selectively increasing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being below the corresponding preliminary value of the pluralities of preliminary values.

3. The processing system of claim 2, wherein while operating in the first mode the determination module is further configured to:

selectively decrease the baseline value in response to the baseline value being above the corresponding preliminary value of the pluralities of preliminary values.

4. The processing system of claim 1, wherein while operating in the first mode, the determination module selectively changes the baseline value of the plurality of baseline values by the first amount in response to the baseline value being different from the corresponding preliminary value of the pluralities of preliminary values even when the processing system determines that the input object is in the sensing region by:

selectively decreasing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being above the corresponding preliminary value of the pluralities of preliminary values.

5. The processing system of claim 4, wherein while operating in the first mode the determination module is further configured to:

selectively increase the baseline value in response to the baseline value being below the corresponding preliminary value of the pluralities of preliminary values.

6. The processing system of claim 1, wherein the first amount is constant.

7. The processing system of claim 1, wherein while operating in the second mode the determination module is configured to change each baseline value in response to drift over time caused environmental changes.

8. The processing system of claim 1, wherein the determination module is configured to determine the first amount dynamically based on a determined number of input objects in the sensing region.

9. The processing system of claim 1, wherein the determination module is further configured to switch from operating in the first mode to operating in the second mode in response to a determined period of time, wherein the determined period of time is based on one of:

a predetermined period of time;

empirical user data;

a usage model; and

system resources.

10. An input device comprising:

a plurality of capacitive sensor electrodes; and

a processing system coupled to the plurality of capacitive sensor electrodes, the processing system configured to;

operate the plurality of capacitive sensor electrodes to sense in a sensing region and produce pluralities of preliminary values, each preliminary value corresponding to an individual measured capacitance associated with a corresponding capacitive pixel and obtained using a capacitive sensor electrode of the plurality of capacitive sensor electrodes, the pluralities of preliminary values comprising a first plurality of preliminary values and a second plurality of preliminary values, the second plurality of preliminary values obtained after the first plurality of preliminary values;

determine information about input in the sensing region based on comparisons of the pluralities of preliminary values with corresponding baseline values of a plurality of baseline values;

selectively operate in a first mode and a second mode, wherein;

while operating in the first mode, the processing system individually compares a baseline value of the plurality of baseline values with a corresponding preliminary value of the first plurality of preliminary values, and selectively changes the baseline value by a first amount when the baseline value is substantially different from the corresponding preliminary value to obtain an updated baseline, wherein, in the first mode, the selectively changing the baseline value is performed even when the processing system determines that an input object is in the sensing region; and

while operating in the second mode, the processing system does not selectively change the baseline value by the first amount when the baseline value is different from the corresponding preliminary value and when the processing system determines that the input object is in the sensing region; and

determine a difference between a corresponding baseline value in the updated baseline and a corresponding preliminary value in the second plurality of preliminary values to obtain a plurality of measured values;

detect, from the plurality of measured values, the input object in the sensing region; and

provide, to an electronic system, positional information of the input object based on detecting the input object,

wherein the processing system is configured to switch from operating in the first mode to operating in the second mode in response to at least one of a determination that no input objects are in the sensing region and external control signal from a controller.

11. The input device of claim 10, wherein while operating in the first mode, the processing system selectively changes the baseline value of the plurality of baseline values by the first amount in response to the baseline value being different from the corresponding preliminary value of the pluralities of preliminary values even when the processing system determines that the input object is in the sensing region by:

selectively increasing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being below the corresponding preliminary value of the pluralities of preliminary values.

12. The input device of claim 10, wherein while operating in the first mode, the processing system selectively changes the baseline value of the plurality of baseline values by the first amount in response to the baseline value being different from the corresponding preliminary value of the pluralities of preliminary values even when the processing system determines that the input object is in the sensing region by:

electively decreasing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being above the corresponding preliminary value of the pluralities of preliminary values.

13. The input device of claim 10, wherein the processing system is configured to determine the first amount dynamically based on a determined number of input objects in the sensing region of the input device.

14. The input device of claim 10, wherein the determination module is further configured to switch from operating in the first mode to operating in the second mode in response to a determined period of time, wherein the determined period of time is based on one of:

a predetermined period of time;

empirical user data;

a usage model; and

system resources.

15. A method for determining input to and implemented by a capacitive input device of the type having a plurality of capacitive sensor electrodes and configured to sense in a sensing region, the method comprising:

determining information about input in the sensing region based on comparisons of pluralities of preliminary values with corresponding baseline values of a plurality of baseline values, each preliminary value corresponding to an individual measured capacitance associated with a corresponding capacitive pixel and obtained using a capacitive sensor electrode of the plurality of capacitive sensor electrodes, the pluralities of preliminary values comprising a first plurality of preliminary values and a second plurality of preliminary values, the second plurality of preliminary values obtained after the first plurality of preliminary values; and

selectively operating the capacitive input device in a first mode and a second mode, wherein;

while operating in the first mode, individually comparing a baseline value of the plurality of baseline values with a corresponding preliminary value of the first plurality of preliminary values, and selectively changing the baseline value by a first amount when the baseline value is different from the corresponding preliminary value, wherein, in the first mode, the selectively changing the baseline value is performed even when an input object is determined to be in the sensing region;

while operating in the second mode, not selectively changing the baseline value by the first amount when the baseline value is different from the corresponding preliminary value and when an input object is determined to be in the sensing region; and

determining a difference between a corresponding baseline value in the updated baseline and a corresponding preliminary value in the second plurality of preliminary values to obtain a plurality of measured values,

detecting, from the plurality of measured values, the input object in the sensing region, and

providing, to an electronic system, positional information of the input object based on detecting the input object,

wherein the capacitive input device is configured to switch from operating in the first mode to operating in the second mode in response to one of an external signal and a determination that no input objects are in the sensing region.

16. The method of claim 15, wherein while operating in the first mode selectively changing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being different from the corresponding preliminary value of the pluralities of preliminary values even when the input object is in the sensing region by:

selectively increasing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being below the corresponding preliminary value of the pluralities of preliminary values.

17. The method of claim 15, wherein while operating in the first mode selectively changing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being different from the corresponding preliminary value of the pluralities of preliminary values even when the input object is in the sensing region by:

selectively decreasing the baseline value of the plurality of baseline values by the first amount in response to the baseline value being above the corresponding preliminary value of the pluralities of preliminary values.

18. The method of claim 15, further comprising dynamically determining the first amount based on a determined number of input objects in the sensing region.

19. The method of claim 15, further comprising switching from operating in the first mode to operating in the second mode.

20. The method of claim 15, wherein the determination module is further configured to switch from operating in the first mode to operating in the second mode in response to a determined period of time, wherein the determined period of time is based on one of:

a predetermined period of time;

empirical user data;

a usage model; and

system resources.