US 11,886,641 B2
Method and apparatus for finger position tracking and haptic display using conductive islands
James E. Colgate, Evanston, IL (US); and Michael A. Peshkin, Evanston, IL (US)
Assigned to Northwestern University, Evanston, IL (US)
Filed by Northwestern University, Evanston, IL (US)
Filed on Aug. 30, 2022, as Appl. No. 17/898,734.
Application 17/898,734 is a continuation of application No. 16/924,818, filed on Jul. 9, 2020, granted, now 11,442,546, issued on Sep. 13, 2022.
Application 16/924,818 is a continuation of application No. 15/178,283, filed on Jun. 9, 2016, granted, now 10,739,853, issued on Aug. 11, 2020.
Claims priority of provisional application 62/173,732, filed on Jun. 10, 2015.
Prior Publication US 2022/0413618 A1, Dec. 29, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 3/01 (2006.01); G06F 3/041 (2006.01); G06F 3/044 (2006.01); G09B 21/00 (2006.01)
CPC G06F 3/016 (2013.01) [G06F 3/044 (2013.01); G06F 3/0416 (2013.01); G06F 3/0446 (2019.05); G06F 3/04164 (2019.05); G09B 21/003 (2013.01)] 19 Claims
OG exemplary drawing
 
1. 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 positive trace operatively connected to the surface haptic display, wherein the positive trace includes a plurality of first rows;
a negative trace operatively connected to the surface haptic display, wherein the negative trace includes a plurality of second rows;
wherein the plurality of first rows of the positive trace and the plurality of second rows of the negative trace are interdigitated;
a control device configured to apply positive voltage signals to the positive trace and to apply negative voltage signals to the negative trace; and
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 disposed in an area under the fingertip is charged via a capacitive coupling to the positive trace, and at least another of the adjacent conductive islands disposed in the area under the fingertip is charged via capacitive coupling to the negative trace.