Method and apparatus for controlling magnitude and frequency of vibrotactile sensations for haptic feedback devices. A haptic feedback device, such as a gamepad controller, mouse, remote control, etc., includes a housing, an actuator coupled to the housing, and a mass. In some embodiments, the mass can...http://www.google.com.hk/patents/US7561142?utm_source=gb-gplus-share專利 US7561142 - Vibrotactile haptic feedback devices
