0
TECHNICAL PAPERS

Measurement of Stiffness and Damping Characteristics of Computer Keyboard Keys

[+] Author and Article Information
Mark Nagurka

Department of Mechanical and Industrial Engineering,  Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, USAmark.nagurka@marquette.edu

Richard Marklin

Department of Mechanical and Industrial Engineering,  Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, USArichard.marklin@marquette.edu

J. Dyn. Sys., Meas., Control 127(2), 283-288 (Jun 01, 2005) (6 pages) doi:10.1115/1.1902823 History:

To determine the stiffness and damping of computer keyboard keys, a computer-controlled test rig that can measure computer key displacement, velocity, and contact force has been designed. The test rig, consisting of a single-axis stage carrying a probe for contacting keys, has been used to collect contact force and motion data as computer keys are depressed and released at constant velocities up to 80mms. Keys that employ a rubber-dome under their caps to achieve the necessary compliance and toggling action were tested. The results demonstrate a nonlinear stiffness force versus displacement characteristic at a given speed and the presence of damping-type forces that increase with key depression speed at a given displacement. In particular, the results indicate that the peak force at the 80mms rate of depression increases relative to the quasistatic (0.5mms) force level by over 12% for the “Enter,” “K,” and “Spacebar” keys. This paper describes the hardware and software configuration, and presents sample results of the stiffness and damping characteristics of keys during depression-return stroke tests.

FIGURES IN THIS ARTICLE
<>
Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic of rubber-dome key mechanism and photograph of rubber domes

Grahic Jump Location
Figure 2

Relationship between key force and key displacement, adapted from ISO/DIS 9241/4.2 standard (ISO, 1998 (14))

Grahic Jump Location
Figure 3

Test rig: (a) side view; and (b) photograph

Grahic Jump Location
Figure 4

Test device actuation and measurement block diagram showing subsystems

Grahic Jump Location
Figure 5

Force-displacement of depression and release of rubber-dome keys at 0.5 and 80mm∕s speeds for (a) “Enter,” (b) “K,” and (c) “Spacebar”

Grahic Jump Location
Figure 6

Peak and trough forces of three rubber-dome keys as a function of depression speed

Grahic Jump Location
Figure 7

Damping force as a function of depression speed of rubber-dome keys at the peak force displacement for (a) “Enter,” (b) “K,” and (c) “Spacebar”

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In