Capacitive stereoscopic image sensing

• US 9,898,148 B2
• Filed: 05/27/2015
• Issued: 02/20/2018
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Tanemura, Tetsuo, Lu, Wei, Araki, Shunsuke
• Primary Examiner(s): Rosario, Nelson
• Assistant Examiner(s): Lin, Chun-Nan
• Application Number:
  US14/723,218
• Publication Number:
  US 20160349871A1
• Time in Patent Office: 1,000 Days
• Field of Search: 345174
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• 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
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• 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
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

This disclosure generally provides an input device with near-field and far-field receiver electrodes. Using resulting signals captured by these receivers, the input device generates a near-field capacitive image and a far-field capacitive image. In one embodiment, the near-field capacitive image contains information identifying a location of an input object in a first plane in free space, while the far-field capacitive image contains information identifying a location of the input object in a second plane in free space. Further, the first and second planes may be parallel planes where the first plane is closer to an input surface of the input device than the second plane. In one embodiment, the input device compares the information in the near-field and far-field images in order to determine a state of the input object.

Claims

1. An input device, comprising:

a plurality of near-field receiver electrodes;

a plurality of far-field receiver electrodes;

a plurality of transmitter electrodes, wherein the near-field receiver electrodes, the far-field receiver electrodes, and the transmitter electrodes are disposed on one or more substrates and configured to sense input objects in a sensing region; and

a processing system configured to;

drive a sensing signal onto the transmitter electrodes;

generate a near-field capacitive image of the sensing region based on resulting signals received from the near-field receiver electrodes,

generate a far-field capacitive image of the sensing region based on resulting signals received from the far-field receiver electrodes,

in response to detecting moisture in the sensing region, stop compensating for noise when processing the resulting signals received from the far-field receiver electrodes and increase a noise compensation level used when processing the resulting signals received from the near-field receiver electrodes, and

determine a state of an input object interacting with the sensing region by comparing the near-field capacitive image describing the input object with the far-field capacitive image describing the input object.

2. The input device of claim 1, wherein each of the near-field receiver electrodes has a different geometry than each of the far-field receiver electrodes, wherein determining the state comprises at least one of:

(i) determining an angle of orientation between the input object and an input surface of the input device and (ii) determining a type of the input object from a plurality of different predefined input object types.

3. The input device of claim 1, wherein the near-field and far-field receiver electrodes are disposed on a same side of one of the substrates.

4. The input device of claim 3, wherein the processing system is configured to process capacitive signals from the near-field receiver electrodes and the far-field receiver electrodes simultaneously.

5. The input device of claim 1, wherein a geometry of the near-field receiver electrodes results in the near-field capacitive image containing input object information associated with a first plane in free space, and a geometry of the far-field receiver electrodes results in the far-field capacitive image containing input object information associated with a second plane in free space that is parallel to the first plane, wherein the first plane is closer to an input surface of the input device than the second plane.

6. The input device of claim 1, wherein the processing system is configured to:

track a location of the moisture in the sensing region using the far-field capacitive image generated when noise compensation is stopped, and

superimpose the far-field capacitive image onto the near-field capacitive image to identify a location of the input object in the sensing region relative to the location of the moisture, wherein the near-field capacitive image is generated when noise compensation is increased in response to detecting the moisture.

7. The input device of claim 1, wherein the state of the input object defines a location of a first portion of the input object relative to the sensing region and a location of a second portion of the input object relative to the sensing region, wherein the first portion of the input object is closer to the sensing region than the second portion, and

wherein the processing system is configured to determine an angle of orientation between the input object and an input surface of the input device based on the respective locations of the first and second portions of the input object relative to the sensing region.

8. The input device of claim 1, wherein the processing system, while determining the state of the input object, is further configured to:

detect an activation of a display using the near-field capacitive image;

modify, based on detecting the activation of the display, a compensation technique used to process the resulting signals received by the far-field receiver electrodes; and

determine whether the input object is proximate to the sensing region using the modified compensation technique, wherein the input object is a body part of a user.

9. The input device of claim 1, wherein the state of the input object defines a type of the input object based on comparing a first size value of the input object derived from the near-field capacitive image to a second size value of the input object derived from the far-field capacitive image.

10. The input device of claim 1, wherein the state of the input object defines a motion performed by the input object based on comparing a plurality of near-field capacitive images and a plurality of far-field capacitive images to identify a changing offset between locations of the input object in the plurality of near-field capacitive images and locations of the input object in the plurality of far-field capacitive images.

11. A method, comprising:

driving a sensing signal on a plurality of transmitter electrodes;

receiving resulting signals from a plurality of near-field receiver electrodes;

receiving resulting signals from a plurality of far-field receiver electrodes;

generating a near-field capacitive image of a sensing region of an input device based on resulting signals received from the near-field receiver electrodes;

generating a far-field capacitive image of the sensing region based on resulting signals received from the far-field receiver electrodes;

in response to detecting moisture in the sensing region, stop compensating for noise when processing the resulting signals received from the far-field receiver electrodes and increasing a noise compensation level used when processing the resulting signals received from the near-field receiver electrodes; and

determining a state of an input object interacting with the sensing region by comparing the near-field capacitive image describing the input object with the far-field capacitive image describing the input object.

12. The method of claim 11, wherein a geometry of the near-field receiver electrodes results in the near-field capacitive image containing input object information associated with a first plane in free space, and a geometry of the far-field receiver electrodes results in the far-field capacitive image containing input object information associated with a second plane in free space that is parallel to the first plane, wherein the first plane is closer to an input surface of the input device than the second plane, wherein determining the state comprises at least one of:

(i) determining an angle of orientation between the input object and the input surface of the input device and (ii) determining a type of the input object from a plurality of different predefined input object types.

13. The method of claim 11, wherein the resulting signals received from the far-field and the near-field receiver electrodes are received simultaneously.

14. The method of claim 11, wherein the near-field capacitive image contains input object information associated with a first plane in free space and the far-field capacitive image contains input object information associated with a second plane in free space that is parallel to the first plane, wherein the first plane is closer to an input surface of the input device than the second plane.

15. A processing system, comprising:

a connection interface configured to couple to a plurality of transmitter electrodes, a plurality of near-field receiver electrodes, and a plurality of far-field receiver electrodes disposed within a sensing region;

a sensor module configured to;

drive sensing signals onto the plurality of transmitter electrodes,

receive resulting signals from the plurality of near-field receiver electrodes, and

receive resulting signals from the plurality of far-field receiver electrodes; and

a determination module configured to;

generate a near-field capacitive image based on the resulting signals received from the near-field receiver electrodes,

generate a far-field capacitive image of the sensing region based on resulting signals received from the far-field receiver electrodes,

in response to detecting moisture in the sensing region, stop compensating for noise when processing the resulting signals received from the far-field receiver electrodes and increase a noise compensation level used when processing the resulting signals received from the near-field receiver electrodes, and

determine a state of an input object interacting with the sensing region by comparing the near-field capacitive image describing the input object to the far-field capacitive image describing the input object.

16. The processing system of claim 15, wherein the determination module is configured to:

track a location of the moisture in the sensing region using the far-field capacitive image generated when noise compensation is stopped, and

superimpose the far-field capacitive image onto the near-field capacitive image to identify a location of the input object in the sensing region relative to the location of the moisture, wherein the near-field capacitive image is generated when noise compensation is increased in response to detecting the moisture.

17. The processing system of claim 15, wherein a geometry of the near-field receiver electrodes results in the near-field capacitive image containing input object information associated with a first plane in free space, and a geometry of the far-field receiver electrodes results in the far-field capacitive image containing input object information associated with a second plane in free space that is parallel to the first plane, wherein the first plane is closer to an input surface of an input device than the second plane, wherein determining the state comprises at least one of:

(i) determining an angle of orientation between an input object and the input surface of the input device and (ii) determining a type of the input object from a plurality of different predefined input object types.

18. The processing system of claim 17, wherein the determination module is configured to identify a location of a first portion of the input object in the first plane based on the input object information in the near-field capacitive image and identify a location of a second portion of the input object in the second plane based on the input object information in the far-field capacitive image.

19. The processing system of claim 18, wherein the first portion of the input object is located a greater distance from the input surface of the input device, relative to a direction perpendicular to the input surface, than the second portion of the input object.

20. The processing system of claim 17, wherein the near-field capacitive image and the far-field capacitive image both contain input object information describing a location of the input object at a same point of time.