System and method of controlling an electropermanent magnet at a trackpad

Patent metadata

Field	Value
Publication number	US-11023077-B2
Application number	US-201916450269-A
Country	US
Kind code	B2
Filing date	Jun 24, 2019
Priority date	Jun 24, 2019
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

An information handling system may include a processor to receive input from a trackpad at the information handling system, from a user; and an electropermanent magnet control system to control the activation of an electropermanent magnet (EPM) magnetically couplable to the trackpad to influence the force of actuation.

First claim

What is claimed is:

1. An information handling system, comprising:
a processor to receive user input from a trackpad at the information handling system; and
an electropermanent magnet control system to control the activation of an electropermanent magnet (EPM) magnetically couplable to a diveboard structure of the trackpad to set a resistive actuation force for a click input to the trackpad, where a pulse of current in a first direction aligns the magnetic field of a low-coercivity magnet with a proximate high-coercivity magnet for an increased magnetic state and a pulse of current in a second direction switches magnetic field of the low-coercivity magnet counter to the high-coercivity magnet magnetic field.

2. The information handling system of claim 1 , wherein the EPM is a multi-level EPM comprising a high-coercivity magnet and a plurality of lower coercivity magnets.

3. The information handling system of claim 1 , wherein the electropermanent magnet control system receives user input descriptive of a setting for the resistive actuation force of the trackpad used by the user to actuate the trackpad.

4. The information handling system of claim 1 , wherein the electropermanent magnet control system controls the resistive actuation force of the trackpad used by the user to actuate the trackpad by selectively aligning each of a magnetic field of a plurality of low-coercivity magnets with a magnetic field of a high-coercivity magnet within the EPM to generate a magnetic field over the trackpad.

5. The information handling system of claim 1 , wherein the trackpad comprises a permanent magnet operatively coupled to a flange formed on the trackpad such that the permanent magnet is disposed over the EPM by the flange.

6. The information handling system of claim 1 , wherein the EPM is a multi-level EPM comprising a plurality of low-coercivity magnet to set polarity levels of the EPM to magnetically interact with the trackpad comprising a permanent magnet having a permanent magnet polarity.

7. The information handling system of claim 1 , wherein the electropermanent magnet control system detects an errant touch of the trackpad and selects a magnetic level of a multi-level EPM to interact with the diveboard structure of the trackpad such that the resistive actuation force increases to prevent inadvertent click inputs.

8. A trackpad system, comprising:
a substrate having a touch sensing layer to receive input from a user;
a switch to detect deflective movement of the substrate as a user actuates the trackpad system;
a permanent magnet operatively coupled to a portion of the substrate having a permanent magnet polarity; and
an electropermanent magnet (EPM) including a low-coercivity magnet having an electrically conductive wire coiled around the low-coercivity magnet to receive a first electrical current pulse to adjust the polarity of the low-coercivity magnet relative to the permanent magnet to generate an EPM magnetic flux to interact with the permanent magnet to set a resistive actuation force for a click input to the trackpad, where a pulse of current in a first direction aligns the magnetic field of the low-coercivity magnet with a proximate high-coercivity magnet for an increased magnetic state and a pulse of current in a second direction switches magnetic field of the low-coercivity magnet counter to the high-coercivity magnet magnetic field.

9. The trackpad system of claim 8 further comprising:
the EPM having a plurality of low-coercivity magnets each having an electrically conductive wire coiled around the low-coercivity magnet to receive electrical current pulses to adjust the polarity of the low-coercivity magnets relative to the permanent magnet polarity.

10. The trackpad of claim 9 , wherein the polarities of the low-coercivity magnets are selectively aligned opposite to the permanent magnet polarity in order to increase, incrementally, the resistive actuation force used by the user to actuate the trackpad depending on the number of low-coercivity magnets oppositely aligned.

11. The trackpad system of claim 8 further comprising:
a flange formed on the substrate onto which the permanent magnet is operatively coupled to dispose the permanent magnet to magnetically interface with the EPM.

12. The trackpad system of claim 8 , wherein the EPM is coupled to a chassis of an information handling system associated with the trackpad.

13. The trackpad system of claim 8 , comprising a number of flanges formed on the substrate onto which the permanent magnets are operatively coupled wherein the flanges overhang a past an edge of a housing of the trackpad to prevent the trackpad from rising above the housing.

14. A method of controlling a multilevel electro-permanent magnet (EPM) of a trackpad assembly of an information handling system, comprising:
at the multilevel EPM comprising a plurality of low-coercivity magnets- and a plurality of electrically conductive wires each coiled around a low-coercivity magnet:
selecting a magnetic level from a plurality of magnetic levels for the multilevel EPM by applying a selected number of current pulses to the plurality of electrically conductive wires to select a number of the plurality of low-coercivity magnets for polarity alignment with a high coercivity magnet or the EPM or to oppose polarity alignment of the high-coercivity magnet disposed on the trackpad assembly to set the magnetic level of the multilevel EPM, where the selected magnetic level may be used to adjust resistive actuation force for a click input to the trackpad assembly, where a pulse of current in a first direction aligns the magnetic field of one or more of the plurality of the low-coercivity magnets with the high-coercivity magnet for an increased magnetic state and a pulse of current in a second direction switches magnetic field of the one of a plurality of low-coercivity magnets counter to the high-coercivity magnet magnetic field.

15. The method of claim 14 , comprising determining if an intentional touch is detected at the trackpad assembly and:
when an intentional touch is detected, receiving input from the trackpad assembly at a processor of the information handling system; and
when an errant touch is detected, preventing any input from the trackpad assembly to be received at a processor of the information handling system.

16. The method of claim 15 , wherein detecting the errant touch occurs when a sensor in a palm rest near the trackpad assembly detects a touch or proximity of a user's hand.

17. The method of claim 14 , wherein application of any current to any electrically conductive wire causes an attractive force to be exerted onto a diveboard structure of the trackpad assembly to generate the resistive actuation force when the multilevel EPM is disposed under the c-cover of an information handling system.

18. The method of claim 15 , wherein detecting the errant touch occurs when a touch sensor layer of the trackpad assembly detects a touch indicating a palm or side of user's hand.

19. The method of claim 15 , wherein detecting the errant touch causes a selection of a magnetic level of the multi-level EPM to lock the trackpad assembly in an up position to prevent an errant click.

20. The method of claim 15 , wherein detecting the errant touch causes the multi-level EPM to set the polarity of the plurality of low-coercivity magnets to oppose a permanent magnet disposed on the trackpad assembly to lock in an up position.

Assignees

• Dell Products Lp

Inventors

• Morrison Jason S
• Regimbal Laurent A

Classifications

• G06F3/045

  using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact · CPC title

• H01H2215/05

  electromechanical · CPC title

• G06F3/03547

  Touch pads, in which fingers can move on a surface · CPC title

• H01F7/04 Primary

  Means for releasing the attractive force · CPC title

• G06F3/016

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