12 results about "Electret" patented technology

An electret (1) is produced by subjecting a composite oxide containing two or more metal elements to a polarization treatment. The composite oxide is a crystalline or non-crystalline oxide containing two different trivalent metal elements A and B and has a basic composition represented by the formula A3B5O12. The composite oxide has a band gap energy of 3 eV or more. Metal element A includes at least one element selected from trivalent rare-earth elements, and metal element B includes at least one element selected from trivalent typical elements.

An electret (1) is formed by subjecting an inorganic dielectric body (2) to a charging process. The inorganic dielectric body (2) is composed of a metal compound containing at least either Al or Mg, and the total mole fraction of Al and Mg among all the metal elements contained in the metal compound is greater than 50%. The metal compound may contain a metal oxide or a metal salt and may be an Al-containing oxide or salt, a Mg-containing oxide or salt, or a mixed oxide containing both Al and Mg.

The utility model belongs to loudspeaker technical field discloses a kind of electrostatic loudspeaker and electronic equipment, electrostatic loudspeaker includes shell, first polarity structure, second polarity structure, vibration structure. First polarity structure is equipped with at least one, first polarity structure is set in shell;Second polarity structure is equipped with at least one, second polarity structure is set in shell, and second polarity structure and first polarity structure are along first direction vibration structure alternately arranged;When one of the two of first polarity structure and second polarity structure includes electrode layer, the other of the two includes electret layer;First direction vibration structure is the thickness direction of shell;Vibration structure is set in shell, and vibration structure is conductor;The inner periphery of vibration structure is connected to second polarity structure, and the outer periphery of vibration structure is connected to shell. The electrostatic loudspeaker and electronic equipment provided by the utility model have long service life.

The utility model belongs to loudspeaker technical field discloses a kind of loudspeaker and electronic equipment, and loudspeaker includes shell and sounding unit, and the shell wall of shell is provided with first sound outlet;Sounding unit is equipped with second sound outlet, and second sound outlet is communicated with first sound outlet;Sounding unit includes fixed assembly, at least one diaphragm, at least one first polarity structure and at least one second polarity structure;Fixed assembly is installed in shell, and diaphragm is conductive structure, and diaphragm is correspondingly arranged with first polarity structure, and diaphragm is connected between fixed assembly and corresponding first polarity structure, and first polarity structure and second polarity structure are alternately arranged along first direction, and second polarity structure is equipped on both sides of first polarity structure;When one of first polarity structure and second polarity structure includes electrode layer, the other of both includes electret layer.The loudspeaker and electronic equipment provided by the utility model have good acoustic effect and long service life.

An object of the present disclosure is to provide, for example, a fluoropolymer electret material with hardness. The present disclosure relates to an electret material comprising a fluoropolymer, wherein the fluoropolymer comprises, as a main component, a monomer unit represented by formula (1):wherein R1 to R4 are each independently a fluorine atom, a fluoroalkyl group, or a fluoroalkoxy group; and the fluoropolymer has a mass average molecular weight of 1 million or more and 5 million or less, or 5000 or more and less than 20000.

This invention provides a thin-film electret electroacoustic conversion device, its manufacturing method, and a speaker. The thin-film electret electroacoustic conversion device includes a first electrode, an electret diaphragm, and a second electrode arranged sequentially along the thickness direction. Both the first and second electrodes are electrically isolated from the electret diaphragm. The electret diaphragm carries a permanent charge, which is distributed in a patterned array within its surface. The thin-film electret electroacoustic conversion device provided by this invention arranges the charge on the electret diaphragm in an array, so that when the electret diaphragm vibrates under the action of an electric field, it forms an arrayed vibration source. The sound waves emitted by the vibration source are transmitted within the thin film and simultaneously into the air outside the film. This avoids the concentration of the sound field perpendicular to the film direction caused by full-surface sound emission, resulting in a moderately diffused sound field distribution. This reduces the difficulty of sound effect setting and avoids the problem of significant sound effect degradation caused by angular setting deviations.

The application provides a flexible electret electromechanical sensor with micro-displacement amplification and a preparation method, and is used for solving the problems of insufficient weak signal detection sensitivity, lack of active micro-displacement amplification mechanism, poor environmental adaptability and insufficient conformal adhesion capability of the existing flexible electret electromechanical sensor. The sensor shell is provided with a first cavity in the upper part and a second cavity in the lower part. The first cavity and the second cavity are communicated through an airflow through hole. An electret film is sealingly arranged at the opening of the first cavity. A conformal film is sealingly arranged at the opening of the second cavity. When the conformal film is displaced and deformed, the gas in the second cavity is compressed. The gas in the second cavity flows to the first cavity through the airflow through hole. Under the action of the directional pressure boosting effect, the electret film is displaced and deformed more than the conformal film. The application realizes micro-displacement amplification through air pressure driving, and greatly improves the weak signal detection sensitivity.

The invention relates to a piezoelectric-electret synergistically coupled low-frequency vibration energy taking device, which belongs to the technical field of vibration energy taking and comprises a coupling beam base, a cantilever beam fixed end, a piezoelectric cantilever beam, a movable end insulating mass block, an electret bracket, an electret film and a copper electrode plate, the cantilever beam fixing end is fixedly connected with the coupling beam base, one end of the piezoelectric cantilever beam is connected with the cantilever beam fixing end, and the other end of the piezoelectric cantilever beam is fixedly connected with the movable end insulation mass block and the copper electrode plate; the electret film is fixedly connected with the electret bracket; the copper electrode plate and the electret film are oppositely arranged in a non-contact manner; the piezoelectric cantilever beam comprises a metal pole plate in the center, an upper piezoelectric layer and a lower piezoelectric layer; and the piezoelectric component and the electret electrostatic component are respectively connected with an energy management circuit.

An ultra-high charge density electret is disclosed. The ultra-high charge density electret includes a three-dimensional structure with multiple sidewalls. A porous silica film is formed on the multiple sidewalls, and the porous silica film is charged by multiple positive or negative ions.

A method for manufacturing a vibration power generation device includes: first silicon substrate patterning for patterning a first silicon substrate to form a first support portion and a fixed electrode finger; second silicon substrate patterning for patterning a second silicon layer of a second silicon substrate in which a first silicon layer and the second silicon layer are laminated to form a movable electrode finger and patterning the first silicon layer to form a second support portion and a movable portion; electret film forming for forming an electret film at one of the movable electrode finger and the fixed electrode finger; and bonding for bonding the first silicon substrate to the second silicon layer side of the second silicon substrate such that the movable electrode finger and the fixed electrode finger face each other.

The present application provides an electret-based electrostatic flat panel driver, comprising a transparent substrate, an anchor point arranged on the transparent substrate, a movable flat electrode connected to the anchor point through an elastic beam, a fixed electrode arranged on the upper surface of the transparent substrate and opposite to the movable flat electrode, used to drive the movable flat electrode to make at least one of the out-of-plane translational motion and the out-of-plane torsional motion, an emission electrode arranged on the lower surface of the movable flat electrode, used to receive the excitation light irradiated from the lower surface of the transparent substrate and release electrons, and an electret film formed by the charged film arranged on the upper surface of the fixed electrode and used to capture and fix the electrons released from the emission electrode to provide a bias voltage for the fixed electrode. The present application also provides a corresponding manufacturing method of the electrostatic flat panel driver. The electrostatic flat panel driver of the present application can be compatible with the electret into the electrostatic flat panel driver to reduce the electrostatic driving voltage.

This invention relates to the field of noise testing technology and discloses a semi-anechoic chamber measurement system for air conditioner noise testing, comprising: a conversion analysis unit, a co-calibration unit, an attenuation compensation unit, and a judgment unit. The conversion analysis unit obtains a reference conversion efficiency value through reference acoustic wave calibration, accurately capturing the correspondence between the initial sound pressure and capacitance. The thermally sensitive attenuation factor generated by the co-calibration unit comprehensively reflects the influence of temperature changes on the microphone diaphragm elastic modulus and electret charge attenuation, solving the problem of decreased conversion efficiency due to temperature rise. Meanwhile, the attenuation compensation unit obtains a dynamic capacitance response value sequence through inverse compensation, avoiding further attenuation of the amplitude of low-noise weak electrical signals. The judgment unit accurately determines the degree of elimination of temperature drift and electromagnetic coupling effects by analyzing electromagnetic coupling residual values ​​and mutual information redundancy, preventing the true sound pressure from being masked by interference signals and ensuring the accuracy of air conditioner noise test data.