Magnetic field cancelling audio speakers and associated devices are disclosed. In one embodiment, a utility locator includes an audio speaker device with two loudspeaker drivers positioned and electrically connected to reduce emitted magnetic fields over a range of frequencies corresponding with locator sensing frequencies.

A drive circuit is provided, which is used for driving an electrostatic film actuator. The drive circuit includes an input end, an isolation capacitor and a diode. The input end is used for receiving an input signal. The isolation capacitor includes a first end and a second end. The first end is electrically connected to the input end, and the second end is electrically connected to the electrostatic film actuator. The diode is connected between a working voltage end and the second end in a forward-bias direction, and an output signal is generated at the second end to drive the electrostatic film actuator.

Ultrasonic transducers that include membrane films and perforated baseplates. An ultrasonic transducer includes a baseplate having a conductive surface with a plurality of apertures, openings, or perforations formed thereon or therethrough, and a membrane film having a conductive surface. The membrane film is positioned adjacent to the apertures, openings, or perforations formed on or through the baseplate. By applying a voltage between the conductive surface of the membrane film and the conductive surface of the baseplate, an electrical force of attraction can be created between the membrane film and the baseplate. Varying this applied voltage can cause the membrane film to undergo vibrational motion. The dimensions corresponding to the size and/or shape of the apertures, openings, or perforations formed on or through the baseplate can be varied so that different regions of the baseplate produce different frequency responses, allowing the net bandwidth of the ultrasonic transducer to be increased.

The invention relates to audio transducers, such as loudspeaker, microphones and the like, and includes improvements in or relating to: audio transducer diaphragm structures and assemblies, audio transducer mounting systems; audio transducer diaphragm suspension systems, personal audio devices incorporating the same and any combination thereof. The embodiments of the invention include linear action and rotational action transducers. For both types of transducer, rigid and composite diaphragm constructions and unsupported diaphragm periphery designs are described. Systems and methods for mounting the transducer to a housing, such as an enclosure or baffle are also described. Furthermore, hinge systems including: rigid contact hinge systems and flexible hinge systems are also disclosed for various rotational action transducer embodiments. Various applications and implementations are described and envisaged for the audio transducer embodiments including, for example, personal audio devices such as headphones, earphones and the like.

An earphone includes a resonance circuit that outputs an adjusted signal obtained by making a signal component of a predetermined frequency contained in an electric signal outputted from a sound source device larger than a signal component of another frequency, a fixed electrode that is fixed to a housing, a diaphragm that is provided facing the fixed electrode and that vibrates according to a potential difference generated between the diaphragm and the fixed electrode on the basis of the adjusted signal, a contact part that contacts a partial region of the diaphragm and presses the partial region against the fixed electrode, and a sound emitting part that emits sound generated by vibration of the diaphragm to the outside of the housing.

Disclosed is a display device, including a display panel and at least one thin film actuator. The display panel includes a front side and a rear side that are opposite to each other. The thin film actuator is arranged on the rear side, and the thin film actuator indirectly drives the display panel to vibrate through a vibrating cavity or a connecting structure.

According to embodiment, a transducer includes a microfabricated element integrated on a single die and an interface IC coupled to the microfabricated element. The microfabricated element includes an acoustic transducer and a temperature sensor, and the interface IC is electrically coupled to the acoustic transducer and the temperature sensor.

The invention relates to audio transducers, such as loudspeaker, microphones and the like, and includes improvements in or relating to hinge systems for rotational action audio transducers. The hinge systems of the invention being configured to operatively support a diaphragm in use, and comprising a hinge assembly having one or more hinge joints, wherein each hinge joint comprises a hinge element and a contact member. The contact member comprises a contact surface and the configuration is such that during operation each hinge joint is configured to allow the hinge element to move relative to the associated contact member, while maintaining a substantially consistent physical contact with the contact surface. The hinge assembly biases the hinge element towards the contact surface. Preferably the hinge assembly is configured to apply a biasing force to the hinge element of each joint toward the associated contact surface, compliantly. Various applications and implementations are described and envisaged for the audio transducer embodiments including, for example, personal audio devices such as headphones, earphones and the like.

Disclosed are an electrical-acoustic transformation device and an electronic device, including a moving coil electrical-acoustic transformation unit and a piezoelectric buzzer. The electrical-acoustic transformation device in the present invention has a moving coil sound generating structure and a piezoelectric sound generating structure. The piezoelectric plate compensates the high-frequency response of a vibrating system, realizing an electrical-acoustic transformation device with good performance and super wideband.

Disclosed is a structure for detecting the vibration displacement of a speaker, including: a vibration system having a movable pole plate; a magnetic circuit system; and a fixed pole plate provided under the vibration system and opposite to the movable pole plate, the movable pole plate and the fixed pole plate constituting a capacitor. Also disclosed is an acoustoelectric inter-conversion dual-effect device, further including an impedance transformer connected to the capacitor and including a field effect transistor and a diode. In the present invention, a movable pole plate of a capacitor is provided on a vibration system and a fixed pole plate is provided under the vibration system and fixed in position. When the vibration system vibrates, the change in capacitance is detected to calculate the actual displacement of the vibration system, which can reduce the power of the speaker device when the actual displacement of the vibration system exceeds a safety threshold. For an electronic device adopting such a speaker structure, the displacement of the vibration system of a speaker product can be detected in real time at the system end of the electronic device.