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US 11,442,546 B2Granted
Method and apparatus for finger position tracking and haptic display using conductive islands
AssigneeNorthwestern University
InventorsJames E. Colgate, Michael A. Peshkin
Life of this patent
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Abstract
A touchscreen includes conductive islands that are capacitively coupled to conductive traces, where they may be used to provide capacitive sensing of the position of one or more fingers in contact with a touchscreen and/or to exert haptic forces on one or more fingers in contact with a touchscreen.
Claims18
A surface haptic display comprising:
- a front surface having a plurality of conductive islands disposed at a depth in close proximity to the front surface, and wherein each of the plurality of conductive islands are conductively isolated;
- a plurality of conductive traces operatively connected to the surface haptic display;
- and
- a control device configured to apply positive and negative voltage signals to the plurality of conductive traces,
- wherein each conductive island is substantially capacitively coupled to at least two of the conductive traces,
- wherein an attractive electrostatic force is generated on a fingertip contiguous with the front surface that increases a perceived friction force on the fingertip against movement of the fingertip parallel to the front surface when at least one of the conductive islands that is close to the fingertip is charged via a capacitive coupling of the at least one conductive island to the at least two conductive traces that are in proximity to the at least one conductive island,
- wherein the at least two conductive traces cancel or enhance the electrostatic attraction of the fingertip to the at least one conductive island,
- wherein application of a negative voltage signal to both of the at least two conductive traces is configured to enhance the electrostatic attraction of the fingertip to the at least one conductive island, and
- wherein application of a positive voltage signal to one of the at least two conductive traces and application of a negative voltage signal to the other of the at least two conductive traces is configured to cancel the electrostatic attraction of the fingertip to the at least one conductive island.
6 more elements
A method of generating haptic feedback on a surface haptic display, the method including the steps of:
- disposing a plurality of conductive islands at a first depth in close proximity to a front surface;
- conductively isolating each of the plurality of conductive islands;
- disposing a plurality of conductive traces at a second depth, each conductive island being substantially capacitively coupled to at least two of the conductive traces;
- generating an attractive electrostatic force on a fingertip contiguous with the front surface;
- and
- charging at least one of the conductive islands that is close to the fingertip via a capacitive coupling to the at least two conductive traces that are in proximity to the at least one conductive island and wherein the attractive electrostatic force on the fingertip contiguous with the front surface increases a perceived friction force on the fingertip against movement of the fingertip parallel to the front surface;
- and
- enhancing the electrostatic attraction of the fingertip to the at least one conductive island by applying one of positive voltage signals to the at least two conductive traces and negative voltage signals to the at least two conductive traces.
5 more elements
A haptic device comprising:
- a surface haptic display comprising a front surface;
- a plurality of conductive islands disposed at a depth in close proximity to the front surface, and wherein each of the plurality of conductive islands are conductively isolated;
- a plurality of conductive traces operatively connected to the surface haptic display, wherein each conductive island is substantially capacitively coupled to at least two of the conductive traces;
- and
- a control device configured to apply positive and negative voltage signals to the plurality of conductive traces,
- wherein an attractive electrostatic force is generated on a fingertip contiguous with the front surface that increases a perceived friction force on the fingertip against movement of the fingertip parallel to the front surface when at least one of the conductive islands that is close to the fingertip is charged via a capacitive coupling of the at least one conductive island to the at least two conductive traces that are in proximity to the at least one conductive island,
- wherein application of a positive voltage signal to both of the at least two conductive traces is configured to enhance the electrostatic attraction of the fingertip to the at least one conductive island, wherein application of a negative voltage signal to both of the at least two conductive traces is configured to enhance the electrostatic attraction of the fingertip to the at least one conductive island, and
- wherein application of a positive voltage signal to one of the at least two conductive traces and application of a negative voltage signal to the other of the at least two conductive traces is configured to cancel the electrostatic attraction of the fingertip to the at least one conductive island.
5 more elements
Dependencies are inferred from the claim text.