Abstract: An air-pulse generating device, a wearable sound device, a fanless blower, and an airflow producing method are disclosed. The air-pulse generating device includes a film structure, configured to be actuated to generate a plurality of air pulses at an ultrasonic pulse rate. The plurality of air pulses produces a net airflow toward one single direction.

Abstract: A driving circuit, configured to drive a venting device, includes a first node, a second node, and an amplifying circuit. The venting device, configured to be controlled to open a vent or seal the vent, includes a film structure, which includes a first flap and a second flap, and an actuator, which includes a first actuating portion disposed on the first flap and a second actuating portion disposed on the second flap. When the venting device is controlled to open the vent, the driving circuit generates a first voltage at the first node and generates a second voltage at the second node. When the venting device is controlled to seal the vent, the driving circuit generates a third voltage at both the first node and the second node. The first voltage is larger than the third voltage, and the third voltage is larger than the second voltage.

Abstract: A venting device is disposed within a wearable sound device or to be disposed within the wearable sound device. The venting device includes an anchor structure, a film structure and an actuator. The film structure includes an anchor end anchored on the anchor structure and a free end, and the film structure is configured to form a vent or close the vent. The actuator is disposed on the film structure. The film structure partitions a space into a first volume and a second volume, and the first volume and the second volume are connected via the vent when the vent is formed. The venting device is controlled by the controller to seal the vent when the controller determines to close the vent.

Abstract: A cantilever structure includes an anchor portion and a film structure. The film structure covers over a cavity and vibrates within the cavity. A length of the film structure is less than a width of the film structure. The anchor portion includes at least one protrusion protruding toward the cavity, and the film structure is anchored on the anchor portion with the at least one protrusion.

Abstract: A wearable sound device includes a venting module, configured to form at least one vent to connect a volume within the wearable sound device and ambient, and a sound producing device, configured to produce sound according to an equalized input signal. The venting module, including at least one venting device, operates among a plurality of statuses corresponding to a plurality of degrees of opening. A controller generates the equalized input signal according to a degree of opening among the plurality of degrees of opening, in order to counteract a roll off caused by the at least one vent.

Abstract: A feedback control system configured to drive a load is disclosed. The feedback control system includes an up-sampling circuit, configured to perform an un-sampling operation on a source signal and produce an up-sampled signal with an up-sampling frequency according to the up-sampled signal and a feedback signal from the load; a delta circuit, coupled to the up-sampling circuit and configured to produce a delta signal; a sigma circuit, configured to produce a density modulation signal according to the delta signal; and a driving device, configured to drive the load according to the density modulation signal with the up-sampling frequency.

Abstract: An acoustic device includes a first sound producing component and a back cavity structure. The first sound producing component has a first front side and a first back side, wherein the first sound producing component is a high frequency sound unit, and the first front side faces a sound propagating opening of the acoustic device. The back cavity structure is connected to the first back side of the first sound producing component. The first sound producing component produces a first acoustic wave from the first front side towards the sound propagating opening, and the first sound producing component produces a second acoustic wave from the first back side towards a back cavity of the back cavity structure. The back cavity structure is configured to flatten a peak or a dip of a frequency response of the first sound producing component.

Abstract: An acoustic device includes a first sound producing component and a back cavity structure. The first sound producing component has a first front side and a first back side, wherein the first sound producing component is a high frequency sound unit, and the first front side faces a sound propagating opening of the acoustic device. The back cavity structure is connected to the first back side of the first sound producing component. The first sound producing component produces a first acoustic wave from the first front side towards the sound propagating opening, and the first sound producing component produces a second acoustic wave from the first back side towards a back cavity of the back cavity structure. The back cavity structure is configured to flatten a peak or a dip of a frequency response of the first sound producing component.

Abstract: A linearity compensation method for a sound producing device (SPD) includes steps of: applying a test signal on a first SPD; obtaining an acoustic measurement result generated from the first SPD according to the test signal; generating a compensation curve according to the acoustic measurement result; and performing a linearity compensation operation on a second SPD according to the compensation curve.

Abstract: A wearable sound device includes a venting device including a film structure and an actuator and a driving circuit configured to be controlled by a controller and to drive the actuator, such that the film structure is controlled to form a vent or to seal the vent. The controller is coupled to a sensing device configured to generate a sensing result and determine whether to seal the vent according to the sensing result. The film structure partitions a space within the wearable sound device into a first volume and a second volume. The first volume is connected to or to be connected to an ear canal of a wearable sound device user. The second volume is connected to or to be connected to an ambient of the wearable sound device. The first volume and the second volume are connected via the vent when the vent is formed.

Abstract: A demodulation signal generator, coupled to an air-pulse generator comprising a flap pair, includes a resonance circuit. The resonance circuit produces a first demodulation signal and a second demodulation signal. The resonance circuit and the flap pair co-perform a resonance operation, such that the first demodulation signal and the second demodulation signal are generated via the co-performed resonance operation and have opposite polarity. The flap pair performs a differential movement to form an opening to perform a demodulation operation on a modulated air pressure variation.

Abstract: A venting device includes a first flap, which is configured to be actuated to swing upward during a rising time, and a second flap, which is disposed opposite to the first flap and configured to be actuated to swing downward during a falling time, a first actuating portion disposed on the first flap, and a second actuating portion disposed on the second flap. The venting device configured to form a vent is disposed within a wearable sound device or to be disposed within the wearable sound device. The vent is formed via applying a first voltage to the first actuating portion and applying a second voltage on the second actuating portion, such that the venting device gradually forms the vent.

Abstract: An air-pulse generating device includes a film structure including a flap pair. The film structure is actuated to perform a common mode movement, so as to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is actuated to perform a differential mode movement, so as to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation.

Abstract: A speaker system includes a first acoustic transducer, a second acoustic transducer and a spreading structure. The first acoustic transducer is configured to generate a first acoustic wave. The second acoustic transducer is configured to generate a second acoustic wave. The spreading structure is disposed over the first acoustic transducer and configured to guide the first acoustic wave to propagate through a sound passage formed within the spreading structure. A directionality of the first acoustic wave is spread at a sound outlet of the spreading structure after the first acoustic wave propagates through the sound passage in the spreading structure.

Abstract: A cell includes a membrane and an actuating layer. The membrane includes a first membrane subpart and a second membrane subpart, wherein the first membrane subpart and the second membrane subpart are opposite to each other. The actuating layer is disposed on the first membrane subpart and the second membrane subpart. The first membrane subpart includes a first anchored edge which is fully or partially anchored, and edges of the first membrane subpart other than the first anchored edge are non-anchored. The second membrane subpart includes a second anchored edge which is fully or partially anchored, and edges of the second membrane subpart other than the second anchored edge are non-anchored.

Abstract: The present invention discloses a feedback control system. The feedback control system comprises a plant, configured to produce an output according to a control signal; a first summing block, configured to produce a first difference between an input signal and a measured output signal; a first controller, configured to generate the control signal, such that the first difference decreases to be less than a first threshold or is less than the first threshold; wherein the first controller comprises a memory configured to store a table, and the table contains information of a plurality of transfer functions corresponding to a plurality of operating conditions; wherein the first controller determines an operating condition under which the plant operates, and chooses to utilize a transfer function corresponding to the operating condition to generate the control signal according to the transfer function and the first difference.

Abstract: A package structure includes a first substrate and a first device disposed on the first substrate. The first device includes at least one anchor structure, a film structure anchored by the anchor structure and an actuator configured to control the film structure to form a first vent temporarily. The film structure partitions a space into a first volume to be connected to an ear canal and a second volume connected to an ambient of a wearable sound device. The ear canal and the ambient are connected via the first vent when the first vent is opened. The first vent is opened by controlling a first membrane portion and a second membrane portion of the film structure, such that a difference between a first displacement of the first membrane portion and a second displacement of the second membrane portion is larger than a thickness of the film structure.

Abstract: A sound producing cell includes a membrane and an actuating layer. The membrane includes a first membrane subpart and a second membrane subpart, wherein the first membrane subpart and the second membrane subpart are opposite to each other. The actuating layer is disposed on the first membrane subpart and the second membrane subpart. The first membrane subpart includes a first anchored edge which is fully or partially anchored, and edges of the first membrane subpart other than the first anchored edge are non-anchored. The second membrane subpart includes a second anchored edge which is fully or partially anchored, and edges of the second membrane subpart other than the second anchored edge are non-anchored.

Abstract: A package structure includes a cover and a cell disposed within the cover. The cell includes a membrane, an actuating layer and an anchor structure. The membrane includes a first membrane subpart and a second membrane subpart, wherein the first membrane subpart and the second membrane subpart are opposite to each other in a top view. The actuating layer is disposed on the first membrane subpart and the second membrane subpart in the top-view direction. The membrane is anchored by the anchor structure. The first membrane subpart includes a first anchored edge which is fully or partially anchored, and edges of the first membrane subpart other than the first anchored edge are non-anchored. The second membrane subpart includes a second anchored edge which is fully or partially anchored, and edges of the second membrane subpart other than the second anchored edge are non-anchored.

Abstract: A driving circuit, configured to drive a venting device, includes a first node, a second node, and an amplifying circuit. The venting device, configured to be controlled to open a vent or seal the vent, includes a film structure, which includes a first flap and a second flap, and an actuator, which includes a first actuating portion disposed on the first flap and a second actuating portion disposed on the second flap. When the venting device is controlled to open the vent, the driving circuit generates a first voltage at the first node and generates a second voltage at the second node. When the venting device is controlled to seal the vent, the driving circuit generates a third voltage at both the first node and the second node. The first voltage is larger than the third voltage, and the third voltage is larger than the second voltage.