Haptic display with simultaneous sensing and actuation
Touch interface devices having systems and methods for producing multi-point haptics utilizing simultaneous sensing and actuation are disclosed. In a first configuration, two layers of electrodes are used, including a top layer for haptics near a touch surface of an insulating substrate and a bottom layer for sensing at the bottom surface of the insulating substrate, with the two electrode sets have substantially the same pattern as one another. In a second configuration, a single array of electrodes is used near a touch surface of an insulating substrate and serves as both surface haptic devices and sensing devices.
1. A touch interface having simultaneous sensing and actuation comprising:
an insulating substrate having a front surface and a rear surface;
a plurality of electrodes disposed on the rear surface arranged in a first pattern;
a plurality of electrodes disposed on the front surface arranged in a second pattern that mirrors the first pattern, wherein the electrodes on the front surface have a substantial mutual capacitance with corresponding mirrored electrodes on the rear surface,
wherein when a transmitted signal is applied to at least one of the electrodes on the rear surface, the transmitted signal passes through the insulating substrate via the mutual capacitance to the at least one electrode on the front surface such that when a user's finger is disposed contiguous with the front surface the finger modulates a strength of reception of the transmitted signal from the at least one electrode on the front surface to at least one other electrode on the front surface as a received signal;
wherein the received signal passes through the insulating substrate via the mutual capacitance to at least one electrode on the rear surface so that a location of the user's finger is determined from the strength of reception of the received signal.
2. The touch interface of claim 1 wherein the first pattern is substantially identical to the second pattern.
3. The touch interface of claim 1 wherein the plurality of electrodes on the front surface are transparent.
4. The touch interface of claim 1 wherein at least one haptic actuation signal is applied to at least one electrode.
5. The touch interface of claim 4 wherein two different haptic actuation signals are applied to at least two electrodes, wherein when the user's finger closes a circuit among the plurality of electrodes disposed on the front surface, such that an electrostatic friction force acts on the user's finger to create a haptic effect.
6. The touch interface of claim 5 wherein the two different haptic actuation signals combine such that the haptic effect is substantially independent of the state of coupling of the user's body to ground.
7. The touch interface of claim 1 wherein the substrate is planar.
8. The touch interface of claim 1 wherein the substrate is transparent.
9. The touch interface of claim 8 wherein the substrate further comprises a sheet of glass or plastic.
10. The touch interface of claim 1 wherein the haptic effect provided by the electrodes on the front surface is a change in friction.
11. The touch interface of claim 1 wherein the haptic effect is independently controllable at more than one touch location.
12. The touch interface of claim 1 wherein the electrodes on the rear surface provide measurements of positions of more than one touch location.
13. The touch interface of claim 1 wherein electrical signals are sent to at least one of the one or more of the electrodes in the set of electrodes on the front surface to produce a haptic effect.
14. The touch interface of claim 1 wherein electrical signals are sent to at least one of the one or more of the electrodes in the set of electrodes on the rear surface to measure a touch location.
15. The touch interface of claim 1 wherein the set of electrodes on the rear surface remain functional when the one or more electrodes of the set of electrodes on the front surface is damaged.
16. The touch interface of claim 1 wherein the set of electrodes on the front surface and the set of electrodes on the rear surface are arranged in substantially similar and aligned patterns with each presenting an array having two or more lines of different electrodes that present intersection locations.
17. The touch interface of claim 16 wherein the set of electrodes on the front surface and the set of electrodes on the rear surface are arranged in substantially similar and aligned patterns presenting an array having three lines of different electrodes that present a tri-intersection pattern.
18. The touch interface of claim 17 wherein the tri-intersection provides disambiguation of ghost images of touch locations relative to actual finger touch locations when the touch interface is used with multi-finger sensing.
19. The touch interface of claim 17 wherein the tri-intersection provides disambiguation of at least one finger touch location of a first individual relative to at least one finger touch location of a second individual when the touch interface is used with multi-user sensing.