Systems and methods for controlling a resonant device for generating vibrotactile haptic effects

#This invention generally relates to haptic feedback device control. The present invention more particularly relates to systems and methods for controlling a resonant device.

#Electronic device manufacturers strive to produce a rich interface for users. Conventional devices use visual and auditory cues to provide feedback to a user. In some interface devices, kinesthetic feedback (such as active and resistive feedback) and/or tactile feedback (such as vibration, texture, and heat) is also provided to the user, more generally known collectively as “haptic feedback.” Haptic feedback can provide cues that enhance and simplify the user interface. Specifically, vibration effects, or vibrotactile haptic effects, may be useful in providing cues to users of electronic devices alerting the user to specific events, or in providing realistic feedback to create greater sensory immersion within a simulated or virtual environment.

#For example, cell phones are commonly equipped with auditory and visual cues indicating an incoming telephone call. Visual cues typically include flashing lights. Auditory cues typically include a series of tones, synthesized music, or, more recently, digitally-recorded music. However, in some instances, such visual and auditory cues may not be useful to a user of the cell phone. For example, a user in a movie theater will typically have the phone's audible ringer silenced and will have the phone in a pocket and be unable to view the visual cues. In such instances, vibrotactile haptic effects are desirable.

#These and other features, aspects, and advantages of the present invention are better understood when the following Detailed Description is read with reference to the accompanying drawings, wherein:

#FIG. 1 is a block diagram illustrating a system for controlling a resonant device in one embodiment of the present invention;

#FIG. 2 is a flowchart illustrating a method for braking an actuator in one embodiment of the present invention;

#Embodiments of the present invention provide systems and methods for controlling a resonant device.

#In one embodiment of the present invention, a cell phone has a resonant system for generating vibrations. The resonant system comprises a resonant actuator and is controlled by a processor that sends signals to the resonant system to activate and brake the actuator. For example, when the cell phone detects an incoming call, it generates a driving signal to drive the actuator at its resonant frequency to generate vibration, thereby alerting the user of the cell phone to the incoming call. Then to stop the vibrations, the cell phone generates a braking signal at the resonant frequency and approximately 180 degrees out of phase with the driving signal to brake the actuator and halt the vibrations.

#By activating and braking the actuator in sequence, the cell phone can generate a wide variety of vibrotactile haptic effects. For example, an incoming call may generate three short, strong vibrations in rapid succession. The cell phone can also generate vibrotactile effects synchronized to ring tones such that the vibrotactile haptic effects correspond to the low frequencies, or bass portions, of the ring tone. The vibrotactile haptic effects can be played in time with the ring tone such that the user can feel the bass portions of the ring tone through the vibrations.