Abstract: The present disclosure relates to an EEG measuring device which is in close contact with a head of a subject while having an adjustable size to fit the head of the subject.

Abstract: A waterproof microspeaker includes: a frame; a magnetic circuit provided below the frame and including a yoke, inner and outer magnets, and a top plate; a voice coil located between the magnets and configured to vibrate by a magnetic field of the magnetic circuit and mutual electromagnetic force when an electric signal is applied; and a diaphragm housing provided above the frame. The diaphragm housing includes: a sidewall portion provided above the frame and having a predetermined height; an edge dome portion protruding upwardly or downwardly along an inner circumference of the sidewall portion; and a diaphragm provided inside the edge dome, allowing an upper end of the voice coil to be fixed thereto, and configured to generate sound by vibration of the voice coil. The diaphragm includes a polymeric material including metal or plastic and is inserted into an inner circumferential portion of the edge dome portion.

Abstract: A method for purifying a waste N-methyl-2-pyrrolidone (NMP) mixed solution according to an embodiment of the present disclosure includes using a base. The base according to an embodiment may be NaBH4. N-methylsuccinimide and ?-butyrolactone are simultaneously removed, and high-purity NMP can be recovered by applying a base to the waste NMP mixed solution.

Abstract: The present disclosure provides a microspeaker enclosure including a block formed of a porous material. The microspeaker enclosure including a block formed of a porous material includes a microspeaker, an enclosure case in which the microspeaker is mounted, the enclosure case including a back volume communicating with the microspeaker, a porous block installed in the back volume, having 3-nm pores having air adsorption performance and 6-nm pores serving as a passage for air circulation in a predetermined ratio, and including porous particles combined as a block, and a film attached to one surface of the porous block.

Abstract: Provided are a diaphragm for a high water pressure waterproof microspeaker and a high pressure waterproof microspeaker including the same. The diaphragm for a high pressure waterproof microspeaker, which is provided in a microspeaker to reproduce sound, includes a center diaphragm and a side diaphragm, includes a center diaphragm attachment portion having a ring shape with a perforated center overall and attached to an outer periphery of the center diaphragm, a frame attachment portion attached to a frame, and a dome portion located between the center diaphragm attachment portion and the frame attachment portion and protruding upwardly or downwardly. The center diaphragm attachment portion of the side diaphragm includes an upper attachment portion attached to an upper surface of the center diaphragm and a lower attachment portion attached to a lower surface of the center diaphragm.

Abstract: The present disclosure provides an earphone with a duct unit dividing a pressure equilibrium hole and a back hole. The earphone includes a driver unit including a frame, a magnetic circuit, a voice coil, a diaphragm configured to reproduce sound, and a pressure equilibrium hole configured to improve a pressure difference between front and rear sides of the driver unit, and a back hole configured to smooth vibration of the diaphragm. A housing allows the driver unit to be installed therein and includes a vent hole. A duct unit provided in the housing adjusts a size of a back volume in the housing and provides a flow path from the pressure equilibrium hole to the vent hole.

Abstract: Disclosed is an earbud including a head housing configured for insertion into a user's auricle and having a sound emitting hole, and a stick housing extending downward from the head housing, wherein the stick housing is inclined inward.

Abstract: Disclosed is a thermoelectric generator including a heat source contact, a heat sink contact, and a plurality of co-axial fibers. Each of the co-axial fibers include a core and a cladding disposed about the core. The plurality of co-axial fibers extend from the heat source contact to the heat sink contact. Thermoelectric generators are disclosed including hollow core doped silicon carbide fibers and doubly clad PIN junction fibers. Methods for forming direct PN junctions between oppositely doped fibers are additionally disclosed.

Abstract: Disclosed is a sound vibration sensor using a piezoelectric element having a cantilever structure. The sound vibration sensor includes a housing forming an exterior, a piezoelectric element having a cantilever structure installed in the housing, a support structure supporting a fixed end of the piezoelectric element, a weight attached to a free end of the piezoelectric element, and an energizing part configured to transmit an output from the piezoelectric element, wherein the sound vibration sensor comes into contact with a speaker's body, receives vibration of the body generated when the speaker utters a sound through the housing, and amplifies the vibration by the free end of the piezoelectric element to detect the voice vibration of the speaker using a piezoelectric characteristic of the piezoelectric element.

Abstract: A two-way receiver includes a cylindrical frame, a yoke dividing an internal space of the frame and including a cylindrical portion, a first flange portion formed at an outer periphery of the cylindrical portion, a connection wall bent downward from the first flange portion, a second flange portion formed at an outer periphery of the connection wall, and a communication hole formed by deleting a portion of the connection wall and second flange portion. A first speaker unit is installed above the yoke, and a second speaker unit below the yoke. A protector coupled to a lower portion of the frame protects the second speaker. A bass duct formed on an outer periphery of the first speaker unit has a sound emission hole for emitting a sound of the first speaker unit emitted to the communication hole of the yoke to a position spaced apart from the communication hole.

Abstract: Provided is an earphone having a pressure equilibrium structure capable of preventing a decrease in acoustic characteristics or sound pressure, while having a structure capable of achieving equilibrium within an ear canal. The earphone includes a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm, a front housing surrounding a front and a side surface of the receiver and including a sound tube, a rear housing attached to a rear of the receiver and coupled to the front housing, and a duct located between the diaphragm and the sound tube. An acoustic path through which sound is emitted is formed from the receiver to an end of the sound tube. The front housing or the rear housing includes a leakage hole. An inner end of the duct is connected to the acoustic path. An outer end of the duct is connected to the leakage hole.

Abstract: A hybrid receiver includes a dynamic driver including a frame, magnetic circuit, voice coil vibrated by the magnetic circuit and a mutual electromagnetic force, and a diaphragm to which the voice coil is attached to vibrate, a balanced armature driver including a housing, a magnetic circuit, a coil, an armature magnetized by a magnetic field of the coil to interact with the magnetic circuit, a rod vertically connected to the armature, and a diaphragm vibrated by the rod, and a bracket coupled to an upper portion of the diaphragm of the dynamic driver and having a sound emission port configured to emit sound of the dynamic driver. The bracket has a balanced armature driver accommodation space on an upper surface thereof. The balanced armature driver is disposed such that the diaphragm is parallel to the upper surface of the bracket. The housing has a sound emission hole above the diaphragm.

Abstract: Methods of making various fibers are provided including co-axial fibers with oppositely doped cladding and core are provide; hollow core doped silicon carbide fibers are provided; and doubly clad PIN junction fibers are provided. Additionally methods are provided for forming direct PN junctions between oppositely doped fibers are provided. Various thermoelectric generators that incorporate the aforementioned fibers are provided.

Abstract: Disclosed are a yoke assembly having a magnetic field aggregation structure and a two-way receiver having the same. The yoke assembly for a two-way receiver provided in a two-way receiver having two speaker units sharing a portion of a magnetic field, includes a yoke including a cylindrical portion having a circular bottom surface and a side wall and a flange portion extending externally from an upper end of the side wall of the cylindrical portion and a first magnetically permeable plate attached to an upper surface of the flange portion.

Abstract: A hybrid actuator includes a housing for defining an external appearance, a stator having a coil, a vibrator having a permanent magnet which vibrates due to a mutual electromagnetic force with the stator, an elastic member for elastically supporting the vibrator relative to the housing, and a piezoelectric element attached to one surface of the housing.

Abstract: Disclosed is a translation system using a sound vibration microphone capable of fundamentally blocking noise by detecting vibrations generated from a user's voice using a piezo element. The translation system using a sound vibration microphone includes a first earset including a sound vibration sensor and a speaker, a first wearable acoustic device including a microphone and a speaker and performing wireless communication with the first earset, and a first electronic communication device performing wireless communication with the first wearable acoustic device and performing communication with a translation server, wherein the first wearable acoustic device and the first electronic communication device are in a communicatable state.

Abstract: A receiver having a pressure equilibrium structure includes a magnetic circuit including a yoke, a permanent magnet coupled to the yoke, and a top plate attached to the permanent magnet, a voice coil configured to vibrate by mutual electromagnetic force with the magnetic circuit, a diaphragm allowing the voice coil to be attached thereto and vibrated by the voice coil to generate sound, and a protector coupled to an upper surface of the diaphragm and surrounding an outer side of the magnetic circuit with a gap from an outer periphery of the magnetic circuit, wherein the protector has a hole communicating with a gap portion with the magnetic circuit and an air path is formed by the hole of the protector and the gap between the magnetic circuit and the protector.

Abstract: Disclosed is a canal-type earphone having a pressure equilibrium structure. The canal-type earphone includes: a microspeaker including a frame, a magnetic circuit, a voice coil, and a diaphragm; an earphone housing including an accommodation space accommodating the microspeaker and a nozzle extending to one side of the accommodation space; a vent hole formed at the earphone housing, installed in at least one of portions located in front of the microspeaker in the nozzle and the accommodation space, and allowing air to flow outside and inside the earphone housing; and an eartip coupled to outside of the nozzle of the earphone housing.

Abstract: Disclosed is a receiver unit having a pressure equilibrium structure and a compensation structure for a low frequency, including a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm, an upper casing covering an upper portion and a side surface of the receiver and having a sound insulation hole, and a lower casing attached to a lower surface of the receiver and coupled to the upper casing, wherein a ventilation recess is provided on an outer surface of the upper casing to allow air to flow between an upper space of the upper casing and a lower space of the lower casing, the receiver includes a back hole, and the lower casing includes a duct connecting the back hole and the lower space of the lower casing.

Abstract: The present disclosure relates to a sound converting device, and in particular, a sound converting device having a near-infrared ray emission function, which allows a wearer to remain in a stable state by vagal nerve stimulation (VNS) and adjusts a stimulation effect on the wearer by adjusting an intensity of stimulation. A near-infrared ray emitted by an optical device of a light emitting unit has at least one of a set wavelength included in a reference wavelength range, a set frequency included in a reference frequency range, and a set light intensity included in a reference light intensity range, and the optical device operates to correspond to a set duty ratio included in a reference duty ratio.