Computer input devices

Abstract

A sensing system for a computer input device. The sensing system comprises an actuator to attach to a key top or button. The actuator is moveable along an axis or hinged. The sensing system further comprises a biasing element to exert a biasing force on the actuator directed along the axis. The sensing system further comprises an actuator motion sensor associated with the actuator. The actuator motion sensor comprises a passive resonant circuit configured to be moved by the actuator and having a resonant frequency, an active resonant circuit configured to excite the passive resonant circuit atthe resonant frequency, a sensor driver to drive the active resonant circuit with an RF drive signal at the resonant frequency, and a detector to detect a level of RF signal from a driven actuator motion sensor for sensing a position and/or velocity of the actuator.

Description

technical field [0001] The present invention relates to sensing systems for computer input devices such as keyboards (eg, QWERTY keyboards), game controllers, and computer mice. Background technique [0002] Computer keyboards typically use mechanical switches or similar contact devices to sense the single stroke position of a key, where the closing of the switch is used to detect a key press event and the opening of the switch is used to detect a key release event. Therefore, these mechanical switches have a binary (on / off) response. Furthermore, the physical depression of the key at the actuation (switching) point depends on the mechanical configuration of the switch, and it is not possible to change the actuation point without changing the switch itself. However, in different situations or different operators will prefer different actuation points corresponding to more or less key presses (actuation distance). For example, for typing, long actuation distances are genera...

AI Technical Summary

Problems solved by technology

It uses light reflectivity as the basis for the position sensor, but this method, and optical methods in general, suffer from several limitations, including: a highly nonlinear response to the detected position; sensitivity to temperature changes and changes in ambient light; and to dirt , dust or moisture contamination susceptibility

Also, optics and supporting electronics can be expensive

[0009] Capacitive position sensors are sensitive to electromagnetic interference, operator hand position, and temperature, making their use as position sensors in analog switches impractical

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