Keycap Vibration Measurement: Quantifying Press and Rebound Dynamics

The pressing feel of a keycap depends not only on the actuation travel and pressing force but also on the structural stiffness, rebound speed, and vibration characteristics of the keycap. For lightweight, small-sized keycaps, installing contact sensors may alter their original mass and dynamic response, so a non-contact approach is required to obtain true motion data.

Haytham monocular 3D high-speed visual strain gaugeUsing monocular 3D DIC digital image correlation technology with high-speed image acquisition, the pressing, bottoming-out, rebound, and residual vibration of the keycap at the moment of a keystroke are completely recorded. The system can acquire the 3D displacement, motion trajectory, and vibration response at different positions on the keycap surface, and analyze the maximum press depth, rebound time, local deformation differences, and vibration decay patterns.

Compared with recording only single-point displacement, keycap vibration measurement presents the overall motion state of the keycap and identifies problems such as tilted pressing, local deformation, or uneven rebound, converting the subjective "feel experience" into comparable and analyzable quantitative data.

This method can be used for testing laptop keyboards, mechanical keyboards, membrane keys, and other precision key structures, providing data support for keycap structure design, material selection, feel optimization, and reliability verification.