A new subminiature impact actuator for mobile devices

This paper presents a new subminiature impact type actuator which creates the haptic sensation in a mobile device. Recently, linear resonance actuators (LRA) are widely used. One of the key differences between an LRA and a traditional eccentric motor is that the LRA generates the vibrotactile sensation through resonance for minimizing response time. The strategy of operation near the resonant frequency, however, brought a new issue for creating vibrotactile sensation which can be strong enough to feel in arbitrary frequency. In order to achieve this issue, we adopt an unstable structure to amplify impact force and to reduce response rate. Due to the impact with fast rising and falling time in the proposed impact actuator, the available strong impact vibration is created over wide frequency range from 0Hz to 100Hz. The impact vibration generated from the proposed actuator is suitable for reproducing realistic button sensation and creating various vibration patterns in mobile devices.