Touchpad with capacitive force sensing

Patent metadata

Field	Value
Publication number	US-10068728-B2
Application number	US-201113082293-A
Country	US
Kind code	B2
Filing date	Apr 7, 2011
Priority date	Oct 15, 2009
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

Described herein are techniques related to a touchpad with capacitive force sensing. The described techniques may determine the point or region of a user-engagement surface contacted by a user. In addition, the described techniques may also determine a force of the user's finger press on the user-engagement surface using one or more capacitance force-sensors. Furthermore, the described techniques may offer active tactile feedback (i.e., haptics) to the user's finger touching the user-engagement surface. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

First claim

What is claimed is:

1. A haptic force-sensing touchpad comprising:
a user-engagement surface presented for contact by a user;
a first spring plate operably associated with the user-engagement surface, wherein the first spring plate comprises a conductive layer;
a second spring plate operably associated with the first spring plate, wherein the second spring plate comprises:
a first capacitive force sensing strip disposed proximate a first edge of the second spring plate,
a second capacitive force sensing strip disposed proximate a second edge of the second spring plate, and
a conductive interior region disposed between the first capacitive force sensing strip and the second capacitive force sensing strip,
wherein the first spring plate and the second spring plate are spaced-apart with a defined gap therebetween;

a return mechanism operably associated with the first spring plate or the second spring plate;
a touch-sensing module operably associated with the user-engagement surface, the touch-sensing module being configured to determine an X/Y position of contact by the user with the user-engagement surface;
a capacitive force-sensing module operably associated with the user engagement surface, the capacitive force-sensing module being configured to determine a force applied to the user-engagement surface in response to a change in a variable capacitance between the first capacitive force sensing strip and the conductive layer; and
an active-feedback actuation mechanism operably associated with the user-engagement surface, the actuation mechanism configured to provide tactile feedback to the user in response to the force applied to the user engagement surface,
wherein the conductive interior region is configured to generate a haptic movement, when activated by the active-feedback actuation mechanism, between the first spring plate and the second spring plate, and
wherein the return mechanism is configured to restore, after the haptic movement, the defined gap between the first spring plate and the second spring plate.

2. A haptic force-sensing touchpad as recited in claim 1 , wherein the capacitive force-sensing module determines the force applied to the user engagement surface by the user's contact therewith by determining a z direction deflection of the user-engagement surface caused by the force applied to the user-engagement surface.

3. A haptic force-sensing touchpad as recited in claim 1 , wherein the touch-sensing module determines the X/Y position of the user's contact with the user-engagement surface by determining the force applied to the user-engagement surface by the user's contact therewith.

4. A haptic force-sensing touchpad as recited in claim 1 , further comprising a resistance mechanism operably associated with the user engagement surface and configured to resist a movement of the user engagement surface in at least one direction of Z.

5. A force-sensing apparatus comprising:
a user-engagement surface presented for contact by a user;
a first spring plate operably associated with the user-engagement surface, wherein the first spring plate comprises a conductive layer;
a second spring plate operably associated with the first spring plate, wherein the second spring plate comprises:
a first capacitive force sensing strip disposed proximate a first edge of the second spring plate,
a second capacitive force sensing strip disposed proximate a second edge of the second spring plate, and
a conductive interior region disposed between the first capacitive force sensing strip and the second capacitive force sensing strip,
wherein the first spring plate and the second spring plate are spaced-apart with a defined gap therebetween;

a capacitive force-sensing module operably associated with the user-engagement surface,
the capacitive force-sensing module being configured to determine a force applied to the user-engagement surface in response to a change in a variable capacitance between the first capacitive force sensing strip and the conductive layer; and
an active-feedback actuation mechanism operably associated with the user-engagement surface, the actuation mechanism configured to provide tactile feedback to the user in response to the force applied to the user-engagement surface by the user, wherein the conductive interior region is configured to generate haptic movement, when activated by the active-feedback actuation mechanism, between the first spring plate and the second spring plate.

6. A force-sensing apparatus as recited in claim 5 , further comprising a touch-sensing module operably associated with the user engagement surface and configured to determine an X/Y position of a contact by the user with the user-engagement surface.

7. A force-sensing apparatus as recited in claim 5 , wherein the capacitive force-sensing module is further configured to move the first spring plate or the second spring plate corresponding to a Z direction deflection of the user-engagement surface, the deflection being caused, at least in part, by the force applied to the user-engagement surface.

8. A force-sensing apparatus as recited in claim 5 , further comprising a resistance mechanism operably associated with the user engagement surface and configured to resist a movement of the user engagement surface in at least one direction of Z.

9. A force-sensing apparatus as recited in claim 5 , wherein the active-feedback actuation mechanism further comprises:
a return mechanism operably associated with the first spring plate or the second spring plate, wherein the return mechanism is configured to restore, after the haptic movement, the defined gap between the first spring plate and the second spring plate.

10. A force-sensing apparatus as recited in claim 5 , wherein the active-feedback actuation mechanism is further configured to provide the tactile feedback to the user in response to an increase in the force applied to the user-engagement surface by the user.

11. A method comprising:
receiving X/Y data from one or more touch sensors regarding a contact by a user on a user-engagement surface of an input apparatus;
based upon the received X/Y data, determining an X/Y position of the contact by the user on the user-engagement surface;
receiving Z data from one or more force sensors regarding deflection of a first spring plate from a second spring plate in a Z direction caused by a force applied to the user-engagement surface by the user's contact therewith, wherein the user engagement surface is operably associated with the first spring plate and the second spring plate;
based upon the received Z data, determining the force applied to the user-engagement surface by the user's contact therewith, wherein the force is determined from a change in a variable capacitance between a conductive layer in the first spring plate and a first capacitive force sensing strip proximate a first edge of the second spring plate;
triggering an active-feedback actuation mechanism of the input apparatus to provide tactile feedback to the user, wherein the triggering is performed in response to, at least in part, the determined force; and
generating, in response to triggering the active-feedback actuation mechanism and using a conductive interior region, haptic movement between the first spring plate and the second spring plate,
wherein the conductive interior region is disposed between the first capacitive force sensing strip and a second capacitive force sensing strip proximate a second edge of the second spring plate.

12. A method as recited in claim 11 , further comprising reporting the determined X/Y position and determined force to a host device of the input apparatus.

Assignees

• Huska Andrew P
• Krumpelman Douglas M
• Peterson Cody G
• Synaptics Inc

Inventors

• Huska Andrew P
• Krumpelman Douglas M
• Peterson Cody G

Classifications

• H01H2003/008

  with a haptic or a tactile feedback controlled by electrical means, e.g. a motor or magnetofriction · CPC title

• G06F3/016

  Input arrangements with force or tactile feedback as computer generated output to the user · CPC title

• H01H2215/05

  electromechanical · CPC title

• H01H13/85 Primary

  characterised by tactile feedback features · CPC title

• G06F3/0414

  using force sensing means to determine a position · CPC title