INPUT DEVICE WITH FORCE SENSING

• US 20130099802A1
• Filed: 12/09/2011
• Published: 04/25/2013
• Est. Priority Date: 10/25/2011
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Hsieh, Lin-Hsiang, Schediwy, Richard R.
• Granted Patent: US 9,041,418 B2
• Time in Patent Office: Days
• US Class Current: 324/661
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• 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 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: H03K 17/975 using a capacitive movable element
• CPC Class Codes: Y10T 29/49126 Assembling bases

Abstract

Devices and methods are provided that facilitate improved input device performance. The devices and methods utilize a first substrate with proximity sensor electrodes and at least a first force sensor electrode disposed on the first substrate. A second substrate is physically coupled to the first substrate, where the second substrate comprises a spring feature and an electrode component. The electrode component at least partially overlaps the first force sensor electrode to define a variable capacitance between the first force sensor electrode and the electrode component. The spring feature is configured to facilitate deflection of the electrode component relative to the first force sensor electrode to change the variable capacitance. A measure of the variable capacitance may be calculated and used to determine force information regarding the force biasing the input device.

Claims

1. An input device comprising:

a first substrate;

proximity sensor electrodes disposed on the first substrate, the proximity sensor electrodes configured to detect objects in a sensing region;

a first force sensor electrode disposed on the first substrate; and

a second substrate physically coupled to the first substrate, the second substrate comprising a spring feature and an electrode component, wherein the electrode component at least partially overlaps the first force sensor electrode to define a variable capacitance between the first force sensor electrode and the electrode component, and wherein the spring feature is configured to facilitate deflection of the electrode component relative to the first force sensor electrode to change the variable capacitance.

2. The input device of claim 1 wherein the second substrate comprises a conductive layer, and wherein the conductive layer is patterned to define the spring feature and the electrode component.

3. The input device of claim 1 wherein the proximity sensor electrodes and the first force sensor electrode are disposed on different layers of the first substrate.

4. The input device of claim 1 wherein the second substrate is physically coupled to the first substrate with a spacing layer, wherein the spacing layer is patterned to not overlap at least a portion of the electrode component and provide a spacing between the electrode component and the first force sensor electrode.

5. The input device of claim 4 wherein the spacing layer comprises a conductive feature configured to ohmically couple the second substrate to a contact disposed on the first substrate.

6. The input device of claim 1 wherein the second substrate further comprises an attachment feature, and wherein the attachment feature is defined in part by a slot formed in the second substrate, wherein the attachment feature is configured deform in response to a force applied to the first substrate.

7. The input device of claim 1 further comprising a casing, wherein the casing comprises a force transmission element, the force transmission element configured to facilitate deflection of the electrode component in response to force applied to the first substrate.

8. The input device of claim 7 wherein the casing further comprises an mating feature, the mating feature configured to be coupled to the attachment feature of the second layer, and wherein the mating feature and the force transmission element of the casing are dimensioned such that the force transmission element applies a force to the electrode component when the casing is physically coupled to the second substrate.

9. The input device of claim 1 further comprising a processing system, the processing system communicatively coupled to the proximity sensor electrodes, the electrode component and the first force sensor electrode, wherein the processing system is configured to determine a capacitance value of the variable capacitance and to determine force information from the capacitance value.

10. The input device of claim 9 further comprising a second force sensor electrode disposed on the first substrate, and wherein the electrode component of the second substrate at least partially overlaps the second force sensor electrode, and wherein the first force sensor electrode comprises a transmitter electrode and wherein the second force sensor electrode comprises a receiver electrode.

11. A method of forming an input device comprising:

providing a first substrate;

disposing a plurality of sensor electrodes on the first substrate, the plurality of sensor electrodes configured to detect objects in a sensing region;

disposing a first force sensor electrode on the first substrate;

patterning a second substrate to define a spring feature and an electrode component in the second substrate, the spring feature configured to facilitate deflection of the electrode component; and

physically coupling the second substrate to the first substrate such that the electrode component at least partially overlaps the first force sensor electrode to define a variable capacitance between the first force sensor electrode and the electrode component and such that deflection of the electrode component feature relative to the first force sensor electrode changes the variable capacitance.

12. The method of claim 11 wherein the second substrate comprises a metal layer, and wherein the metal layer is patterned by a technique selected from a group consisting of laser cutting, stamping and chemical etching.

13. The method of claim 11 further comprising providing a spacing layer wherein the second substrate is physically coupled to the first substrate with the spacing layer, wherein the spacing layer is patterned to not overlap at least a portion of the electrode component and provides a spacing between the electrode component and the first force sensor electrode.

14. The method of claim 11 further comprising patterning a slot in the second substrate to define an attachment feature, wherein the feature is configured deform in response to a force applied to the first substrate.

15. The method of claim 11 further comprising coupling a casing to the second substrate, wherein the casing comprises a force transmission element, the force transmission element configured to facilitate deflection of the electrode component in response to force applied to the first substrate.

16. The method of claim 15 wherein the casing further comprises a mating feature, the mating feature configured to be coupled to the attachment feature of the second substrate, and wherein the mating feature and the force transmission element of the casing are dimensioned such that the force transmission element applies a force to the electrode component when the casing is physically coupled to the second substrate.

17. An input device comprising:

a substrate;

a plurality of proximity sensor electrodes disposed on the substrate, the proximity sensor electrodes configured to detect objects in a sensing region;

a transmitter force sensor electrode and a receiver force sensor electrode disposed on the substrate;

a conductive layer physically coupled to the first substrate, the conductive layer patterned to define at least one attachment component in the conductive layer, at least one spring feature in the conductive layer and at least one electrode component in the conductive layer, wherein the electrode component at least partially overlaps the transmitter force sensor electrode and the receiver sensor electrode to define a variable capacitance between the transmitter force sensor electrode, the receiver sensor electrode and the electrode component, and wherein the spring feature is configured to facilitate deflection of the electrode component relative to the transmitter force sensor electrode and the receiver sensor electrode to change the variable capacitance; and

a casing, the casing comprising an mating element and a force transmission element, the mating element configured to be coupled to the attachment component of the conductive layer, and wherein the mating element and the force transmission element are dimensioned such that the force transmission element applies preload force to the electrode component when the attachment element is coupled to the attachment component and such that the force transmission element transmits additional force to electrode component in response to force applied by a user.

18. The input device of claim 17 further comprising a processing system communicatively coupled to the transmitter force sensor electrode and the receiver force sensor electrode, the processing system configured to determine a capacitance value of the variable capacitance and to determine force information from the capacitance value.

19. The input device of claim 18 wherein the processing system is further communicatively coupled to the plurality of proximity sensor electrodes, and wherein the processing system is further configured to operate the plurality of proximity sensor electrodes to sense objects in a sensing region.

20. The input device of claim 17 further comprising a slot in the conductive layer, wherein the slot defines at least in part the attachment component, and wherein the attachment feature is configured deform in response to a force applied to the substrate.