Taction v. Apple Patent Infringement Workbench
Testing actuator design against the two asserted Taction axial magnetic suspension and active braking patents.
Limitation: Resonant actuator ($f_0 \le 180\text{ Hz}$) with active counter-phase electrical pulse dampening ringdown to $<15\text{ ms}$.
Limitation: Linear magnetic mass array producing transient rise time $<10\text{ ms}$ with peak $>2.5\text{ G}$ using voice coil flux steering.
Engineering Physics & Legal Context (Taction vs. Apple Taptic Engine)
In mobile hardware, traditional eccentric rotating mass (ERM) motors suffer from sluggish rise times (>40 ms) and lingering spin-down that feels mushy. Linear Resonant Actuators (LRA) and planar magnetic voice coils solve this by oscillating a suspended tungsten/neodymium mass along a guided axis.
The Patent Dispute: Taction Technology alleged Apple’s Taptic Engine incorporated patented active braking (firing an inverted electrical wave immediately after the drive pulse to cancel kinetic inertia) and axial planar magnetic suspensions that achieve sub-10ms tactile clicks without overshoot. The jury awarded $5.7 billion based on an estimated $5.00/unit royalty across iPhone and Apple Watch shipments.
Workaround Strategy: Actuators can evade the patent claim limitations by shifting resonance outside the claimed frequency band ($>220\text{ Hz}$), employing non-electrical viscous mechanical damping fluids, or using passive elastomeric end-stops instead of active closed-loop counter-pulses.