Abstract: A sound producing device includes a first sound producing cell, driven by a first driving signal and configured to produce a first acoustic sound on a first audio band, and a second sound producing cell, driven by a second driving signal and configured to produce a second acoustic sound on a second audio band different from the first audio band. A first membrane of the first sound producing cell and a second membrane of the second sound producing cell are Micro Electro Mechanical System fabricated membranes. The first audio band is upper bounded by a first maximum frequency; the second audio band is upper bounded by a second maximum frequency. A first resonance frequency of the first membrane is higher than the first maximum frequency of the first driving signal. A second resonance frequency of the second membrane is higher than the second maximum frequency of the second driving signal.

Abstract: A sound producing device includes a base and at least one chip disposed on the base. The chip includes at least one membrane and at least one actuator. The membrane includes a coupling plate and at least one spring structure connected to the coupling plate. The actuator is configured to receive a driving signal corresponding to an input audio signal to actuate the membrane, and the input audio signal and the driving signal have an input audio band which has an upper bound at a maximum frequency. The spring structure is situated between the coupling plate and the actuator. The membrane has a first resonance frequency higher than the maximum frequency.

Abstract: A sound producing device includes a base and at least one chip disposed on the base. The chip includes at least one membrane and at least one actuator. The membrane includes a coupling plate and at least one spring structure connected to the coupling plate. The actuator is configured to receive a driving signal corresponding to an input audio signal to actuate the membrane, and the input audio signal and the driving signal have an input audio band which has an upper bound at a maximum frequency. The spring structure is situated between the coupling plate and the actuator. The membrane has a first resonance frequency higher than the maximum frequency.

Abstract: A method for manufacturing an air pulse generating element is provided. First, a thin film layer including a membrane is provided, and then, a plurality of actuators are formed on the thin film layer. After that, a first chamber is formed between the thin film layer and a first plate and followed by patterning the thin film layer to form a plurality of valves, in which the membrane and the valves are formed of the thin film layer. Subsequently, a second chamber is formed between the thin film layer and a second plate, and a plurality of channels are formed in the first plate and the second plate.

Abstract: An air pulse generating element is disclosed. The air pulse generating element includes a front faceplate; a back faceplate; a front supporting element; a back supporting element; a folded membrane, configured to form a front chamber and a back chamber, and comprising a plurality of membrane units; wherein the plurality of membrane units are parallel and sequentially connected and an end of the folded membrane is connected to the back faceplate via the back supporting element and another end of the folded membrane is connected to the front faceplate via the front supporting element; and a plurality of valves controlling a plurality of air flow channels between the front chamber toward either a front space or a back space; wherein the plurality of membrane units are configured to perform horizontal deformation to squeeze air in and out of the front or back chamber with operations of the plurality of valves.

Abstract: A method for manufacturing an air pulse generating element is provided. First, a thin film layer including a membrane is provided, and then, a plurality of actuators are formed on the thin film layer. After that, a first chamber is formed between the thin film layer and a first plate and followed by patterning the thin film layer to form a plurality of valves, in which the membrane and the valves are formed of the thin film layer. Subsequently, a second chamber is formed between the thin film layer and a second plate, and a plurality of channels are formed in the first plate and the second plate.

Abstract: An air pulse generating element is disclosed. The air pulse generating element includes a front faceplate; a back faceplate; a front supporting element; a back supporting element; a folded membrane, configured to form a front chamber and a back chamber, and comprising a plurality of membrane units; wherein the plurality of membrane units are parallel and sequentially connected and an end of the folded membrane is connected to the back faceplate via the back supporting element and another end of the folded membrane is connected to the front faceplate via the front supporting element; and a plurality of valves controlling a plurality of air flow channels between the front chamber toward either a front space or a back space; wherein the plurality of membrane units are configured to perform horizontal deformation to squeeze air in and out of the front or back chamber with operations of the plurality of valves.

Abstract: An accelerometer includes a base, two elastic portions and two masses. The base includes a supporting portion. Each of the elastic portions is connected to the supporting portion. The supporting portion is located between the two masses, the two masses are connected to the two elastic portions respectively, and the base supports the two elastic portions and the two masses merely by the supporting portion. The two masses are adapted to produce movements to enable the two elastic portions to be elastically deformed.

Abstract: A structure of a trailer bed having a lower level trailer bed and an upper level trailer rack, wherein two sides of the lower level trailer bed utilize parallel pillars as support, the top end of the pillar is mounted with a substantially horizontal upper level trailer rack, the end of the lower level trailer bed is mounted with an elevating/retracting plate allowing a carrier car to going in and out, the upper level trailer rack is pivotally mounted with an elevating/retracting trailer bed module, and the height of the trailer bed is adjustable for ferrying various type of vehicles onto the trailer bed so as to provide safety in the course of transporting.

Abstract: A frame structure of an auto transport trailer is provided. The frame structure comprises a lower deck, a plurality of supporting rods arranged in parallel along the elongate sides of the lower deck, and a roughly horizontal upper deck supported by the supporting rods. The lower deck has a pair of foldable ramps at its rear end and the upper deck has a pair of lifting ramps hinged to its middle section. On the lower and upper decks, there are ramps that can be tilted at one end so that neighboring cars are somewhat overlapped vertically to reduce the length of the frame structure or to hold more cars.