In-ear minitype rare earth moving iron type loudspeaker
Technical field
The present invention selects rare-earth magnetic composite material and moving (magnetic) iron formula electroacoustic principle for use, processes in-ear minitype rare earth moving iron type loudspeaker.
Background technology
Loud speaker is to convert electrical energy into mechanical energy, again mechanical energy is converted to the electro-acoustic element of acoustic energy, and it is widely used in every field such as communication, broadcasting, education, daily life.Existing market is the widest with electrodynamic type (also claiming moving-coil type) loudspeaker applications, and loud speaker is narrow because of frequency band for electromagnetic type (also claiming reed), distortion big, lower tone seldom uses.Wear all kinds of easily wired, wireless headsets and hearing aids, more need extra small, the lamprophonic Microspeaker of volume.Now market Shang'er bei formula hearing aids uses the import minisize electromagnetic loud speaker of 6.35x4.34x3.02 (millimeter) mostly, its sound generating mechanism with by the superseded reed horn structure in market identical (" practical loudspeaker techniques handbook " book of writing with reference to Wang Yizhen).In-ear minitype rare earth moving iron type loudspeaker does not have coil-moving speaker to solve: should the few big technical barrier of inductance electromotive force in light weight, voice coil loudspeaker voice coil again of the voice coil loudspeaker voice coil number of turn.Hearing aids has specific (special) requirements to loud speaker: one. power little (microwatt level); Two. output impedance big (Shang kilohm); Three. highly sensitive, distortion is little; Four. volume is little, in light weight, and is suitable with earhole.In the in-ear minitype rare earth moving iron type loudspeaker, the solenoid that the number of turn is many, impedance is big is fixed, and sounding is little by weight, and the rare earth magnetic drive sound film that magnetic is strong vibrates to be realized.The present invention really easily solves an above-mentioned difficult problem, and the electroacoustic index of loud speaker is effectively promoted.
Summary of the invention
In-ear minitype rare earth moving iron type loudspeaker of the present invention; Different with the import minisize electromagnetic loud speaker that Shang'er bei formula hearing aids volume commonly used in market is 6.35x4.34x3.02 (millimeter), electromagnetic loudspeaker is replaced by the good dynamic speaker of tonequality because of lower tone.The in-ear minitype loud speaker, because environment for use is special, loud speaker must be accomplished: 1. volume little (less than earhole); 2. driving power little (microwatt level); 3. voice coil loudspeaker voice coil requires impedance high (solenoid must have thousands of circles); Four. highly sensitive, distortion is little.Above harsh conditions, dynamic speaker commonly used can't be realized at all.In-ear minitype rare earth moving iron type loudspeaker; Its electroacoustic conversion regime is neither electromagnetic type also is different from electrodynamic type; Iron formula that the present invention is called moving (magnetic); The conversion of its electroacoustic is little, in light weight by volume, the high rare earth magnetic of magnetic field intensity alternating electromagnetic field push away, draw effect down and sound membrane resonance sounding realize.Because the number of turn is many, the solenoid that impedance is big adopts fixed form, and sounding is by in light weight, and the rare earth magnetic drive sound film that magnetic is strong vibrates to be realized.Because of promoting the required tone currents very little (microampere order) of solenoid work, loud speaker just can produce little, the highly sensitive audio of distortion, is well suited for product employings such as hearing aids.The device of moving iron type loud-speaker can all be installed in the circular antimagnetic metal shell of 6 millimeters high 4 millimeters of diameters, really conforms to the interior loud speaker of hearing aids well and wants the characteristics that volume is extra small, audition is clear, placement is comfortable.
Description of drawings
Below in conjunction with accompanying drawing and embodiment the present invention is described further.
Accompanying drawing is a structural representation of the present invention.
Among the figure: 1. metal shell 2. locating rings 3. sound films 4. magnet rings 5. solenoids 6. beryllium film alloy-iron cores
Embodiment
Cementation the audio-electromagnetically member of being made up of solenoid (5) and cylindrical beryllium film alloy-iron core (6) on the metal shell of in-ear minitype rare earth moving iron type loudspeaker of the present invention (1) inner bottom surface, has will the bond sound film (3) of magnet ring (4) of locating ring (2) fixing above the solenoid (5).Magnet ring (4) is to be formed by the NdFeB magnetic powder of radial polarization and the compound punch process of plastic cement.Sound film (3) is positioned at the end face top of solenoid (5) interior beryllium film alloy-iron core (6).The gap of sound film (3) and beryllium film alloy-iron core (6) end face is confirmed by factors such as the magnetic field intensity experiment of surface area, shape, thickness, soft durometer, quality, elastic force and the magnet ring (4) of sound film (3), selects the next adaptive location of the locating ring (2) of optimum thickness.Make the sensitivity of loud speaker, resonance frequency, technical indicators such as acoustic pressure, tonequality are confirmed with reference to " practical loudspeaker techniques handbook " book computational methods and related experiment that Wang Yizhen writes.All device is installed in 6 millimeters of diameters, and in high 4 millimeters circular antimagnetic metal shell (1) chamber, sound spreads out of from top centre bore.