SYSTEMS AND METHODS FOR IMAGE FILTERING IN SENSOR DEVICES

• US 20140267080A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Vandermeijden, Tom, Eryilmaz, Erol
• Granted Patent: US 9,383,861 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment

Abstract

A processing system for an input device includes a sensor module, a filter module, and a determination module. The sensor module is configured to drive a plurality of transmitter electrodes with transmitter signals; receive, with a plurality of receiver electrodes, resulting signals comprising effects corresponding to the transmitter signals; and produce a first sensor image based on the resulting signals. The filter module is configured to produce a transformed sensor image by applying a spatial filter to the first sensor image. The determination module is configured to positional information and/or the validity of a baseline for the input device based on the transformed sensor image.

Claims

1. A processing system for an input device, the processing system comprising:

a sensor module comprising sensor circuitry, the sensor module configured to drive a plurality of transmitter electrodes with transmitter signals;

receive, with a plurality of receiver electrodes, resulting signals comprising effects corresponding to the transmitter signals; and

produce a first sensor image based on the resulting signals; and

a filter module, wherein the filter module is configured to produce a transformed sensor image by applying a spatial filter to the first sensor image;

a determination module configured to determine at least one of positional information and a validity of a baseline for the input device based on the transformed sensor image.

2. The processing system of claim 1, wherein the spatial filter is a high-pass spatial filter applied in a reduced accuracy mode.

3. The processing system of claim 2, wherein the spatial filter is a 2×

2 spatial filter.

4. The processing system of claim 1, wherein the spatial filter is a two-axis gradient sweep filter.

5. The processing system of claim 1, wherein the determination module determines that the baseline is invalid if an input object is detected in the transformed sensor image.

6. The processing system of claim 1, wherein the processing system is configured to perform aggressive relaxation when an input object is detected in the transformed sensor image.

7. The processing system of claim 4, wherein the filter module is configured to apply the spatial filter substantially simultaneously with the determination module determining the validity of the baseline.

8. A method for an input device, comprising:

driving a plurality of transmitter electrodes with transmitter signals;

receiving, with a plurality of receiver electrodes, resulting signals comprising effects corresponding to the transmitter signals;

producing a first sensor image based on the resulting signals;

producing a transformed sensor image by applying a spatial filter to the first sensor image; and

determining at least one of positional information and a validity of a baseline for the input device based on the transformed sensor image.

9. The method of claim 8, wherein the spatial filter is a high-pass spatial filter applied in a reduced accuracy mode.

10. The method of claim 8, wherein the spatial filter is a two-axis gradient sweep filter.

11. The method of claim 8, further including determining that the baseline is invalid if an input object is detected in the transformed sensor image.

12. The method of claim 8, further including performing aggressive relaxation when an input object is detected in the transformed sensor image.

13. The method of claim 8, further including applying the spatial filter substantially simultaneously with determining the validity of the baseline.

14. A sensor device comprising:

a plurality of transmitter electrodes;

a plurality of receiver electrodes;

a processing system communicatively coupled to the plurality of transmitter electrodes and the plurality of receiver electrodes, the processing system configured to;

drive a plurality of transmitter electrodes with transmitter signals;

receive, with a plurality of receiver electrodes, resulting signals comprising effects corresponding to the transmitter signals;

produce a first sensor image based on the resulting signals; and

produce a transformed sensor image by applying a spatial filter to the first sensor image; and

determine at least one of positional information and a validity of a baseline for the input device based on the transformed sensor image.

15. The sensor device of claim 14, wherein the spatial filter is a high-pass spatial filter applied in a reduced accuracy mode.

16. The sensor device of claim 14, wherein the spatial filter is a 2×

2 spatial filter.

17. The sensor device of claim 14, wherein the spatial filter is a two-axis gradient sweep filter.

18. The sensor device of claim 14, wherein the determination module determines that the baseline is invalid if an input object is detected in the transformed sensor image.

19. The sensor device of claim 14, wherein the processing system is configured to perform aggressive relaxation when an input object is detected in the transformed sensor image.

20. The sensor device of claim 14, wherein the filter module is configured to apply the spatial filter substantially simultaneously with the determination module determining the validity of the baseline.