CN201118978Y

CN201118978Y - Electret microphone

Info

Publication number: CN201118978Y
Application number: CNU2007201724951U
Authority: CN
Inventors: 刘昌兵; 方涛; 周成军
Original assignee: AAC Acoustic Technologies Shenzhen Co Ltd
Current assignee: AAC Technologies Holdings Shenzhen Co Ltd
Priority date: 2007-10-22
Filing date: 2007-10-22
Publication date: 2008-09-17
Anticipated expiration: 2017-10-22

Abstract

The utility model relates to an electret microphone, which comprises an outer casing, a circuit board, a vibration diaphragm, a washer and a back pole plate, wherein, a plurality of punched holes are arranged along the peripheral side position of the back pole plate for the passing of the sound air current outside, and for holding more electronic charges on the back pole plate.

Description

Electret microphone

[technical field]

The utility model relates to a kind of microphone, relates in particular to a kind of electret microphone.

[background technology]

Development along with wireless telecommunications, Global Mobile Phone Users is more and more, the user not only is satisfied with conversation to the requirement of mobile phone, and want high-quality communication effect can be provided, especially at present the development of mobile multimedia technology, the speech quality of mobile phone becomes more important, and the microphone of mobile phone is as the voice pick device of mobile phone, and its design quality directly influences speech quality.In addition, more and more to the microminiaturization development, how the element on it as microphone, still can keep superperformance to mobile phone in ever-reduced volume, really be important problem.

Microphone at present commonly used mainly contains Electret Condencer Microphone and MEMS (microelectromechanical-systems) microphone, and Electret Condencer Microphone is comparatively extensive because of application with low cost, and main flow is electret microphone in the Electret Condencer Microphone.

Fig. 1 has shown a kind of structure of the back pole plate microphone relevant with the utility model.This back pole plate microphone 10 ' mainly comprises lid 11 ', be contained in diaphragm group 12 ' in the lid 11 ', pad 13 ', relative with diaphragm group 12 ' and by the back pole plate 14 ' of pad 13 ' separation, the dead ring 15 ' in order to accommodate back pole plate 14 ', the connecting ring 16 ' and the circuit board 17 ' of electric connection back pole plate 14 '.Lid 11 ' is provided with continuant orifice 110 ' to accept outside sound source, and diaphragm group 12 ' comprises diaphragm 121 ' and the diaphragm ring 122 ' that supports diaphragm 121 '.Diaphragm ring 122 ' electrically connects by lid 11 ' and circuit board, and back pole plate 14 ' is followed insulation between the lid 11 ' by dead ring 15 ' and diaphragm group 12 ', and is connected in circuit board 17 ' by connecting ring 16 '.Therefore, by above-mentioned electrical connection, can realize capacity effect between back pole plate 14 ' and the diaphragm group 12 '.

What should be specifically noted that is that back pole plate 14 ' is provided with electret.Electret is a kind of dielectric that can keep the electric polarization state for a long time, and this dielectric is a kind of high molecular polymer, is distributed with free charge on the electret.Owing to be distributed with free charge on the electret, so between the two poles of the earth of the capacitor that forms between vibrating diaphragm group 12 ' and the back pole plate 14 ', the quantity of electric charge has just been arranged, when sound wave makes diaphragm 121 ' vibration and when producing displacement, changed the capacitance of capacitor, the change of capacitance makes the output of capacitor produce corresponding alternating electric field, just formed the signal of telecommunication corresponding, so just finished the function of acoustic-electric conversion with acoustic signals.

Can find out that on scheming back pole plate 14 ' position is therebetween offered some through holes 140 ', these through holes 140 ' can be beneficial to the sound air communication and cross back pole plate 14 ', are convenient to the vibration of diaphragm 121 '.Yet through hole 140 ' is opened in the middle part of back pole plate 14 ', with diaphragm 121 ' over against area on the quantity of electric charge reduce, influence the effect of acoustic-electric conversion, in addition, middle perforate, back pole plate 14 ' strength reduction, in the microphone assembling process, breakage easily.

Therefore, be necessary to provide a kind of new electret microphone to overcome above-mentioned deficiency.

[utility model content]

The purpose of this utility model is to provide a kind of new electret microphone, and it can improve the acoustic-electric converting sensitivity, and can promote the microphone part strength.

The purpose of this utility model is achieved in that

A kind of electret microphone, it comprises back pole plate, back pole plate is provided with main body and by the vertically extending side of main body, by being recessed to form some breach to body interior on the side, makes that side is a concavo-convex interval shape.

As a kind of improvement of the present utility model, back pole plate is cylindric, and breach is enclosed to form by the two relative sagittal planes and the flexure plane of smooth connection sagittal plane.

Compared with prior art, the utlity model has following advantage: effective charge is more on the back pole plate, and intensity is higher.

[description of drawings]

Fig. 1 is the perspective exploded view of the existing electret microphone relevant with the utility model.

Fig. 2 is the three-dimensional exploded view of the utility model electret microphone.

Fig. 3 is the schematic perspective view of the back pole plate of the utility model electret microphone.

[embodiment]

Describe the concrete structure of the utility model electret microphone in detail below in conjunction with accompanying drawing.

Please refer to Fig. 2 and Fig. 3, the utility model electret microphone 10 comprises shell 11, vibrating diaphragm group 12, pad 13, back pole plate 14, dead ring 15, connecting ring 16 and circuit board 17.

Shell 11 is provided with roof 110 and by roof 110 vertically extending sidewalls 111, the host cavity (not icon) of other elements is accommodated in roof 110 and sidewall 111 common formation one, is provided with tone-entering hole 112 in order to accept the external voice signal on roof 110.

Vibrating diaphragm group 12 shapes and shell shape coupling is provided with the periphery 120 of ring-type and is fixed on diaphragm 121 on the periphery 120, that is, and and the intermediate void position of diaphragm 121 closed circular peripheries 120.

Pad 13 is the ring bodies of shape and vibrating diaphragm group 12 couplings, and this ring bodies is enclosed by inner edge 131 and outside 132 and forms.

Back pole plate 14 shapes and vibrating diaphragm group 12 couplings, it is provided with the side 141 that main body 140 reaches perpendicular to main body 140, by forming some breach 142 to main body 140 inner recess on the side 141, makes side 141 be concavo-convex interval shape.In addition, this breach 142 comprises the plane radially 1420 and the smooth flexure plane 1421 that is connected in plane 1420 of two opposing parallel.

Dead ring 15 is provided with the side wall of ring-type, selects a position that one groove 151 is set.

Connecting ring 16 is an electric conductor, perhaps is provided with conductive coating.

Circuit board 17 is provided with base portion 170, and conductive layer 171 is set on the base portion 170, and other is provided with some electronic components 172 and connects by other circuit on the circuit board 17.

After 10 assemblings of the utility model electret microphone, the matching relationship of each element is as follows:

Connecting ring 16 is placed on the base portion 170 of circuit board 17, and electrically connects with conductive layer 171, and back pole plate 14 is placed on the connecting ring 16, and both are electrically connected mutually; Dead ring 15 also is placed on the base portion 170 of circuit board 17, and is in the outside of connecting ring 16; Pad 13 is placed on the dead ring 15, and places vibrating diaphragm group 12 on the pad 13, and shell 11 is housed in above-mentioned all elements in the host cavity, and shell 11 has current-carrying part and is electrically connected to vibrating

diaphragm group

12,17 electric connections equally of shell 11 and circuit board.Therefore, back pole plate 14 is electrically connected to circuit board 17 by connecting ring 16, and vibrating diaphragm group 12 is electrically connected to circuit board 17 by shell 11, separates by pad 13 between vibrating diaphragm group 12 and the back pole plate 14, has promptly formed the sound sensing element of tool capacity effect.

Back pole plate 14 is provided with electret.Electret is a kind of dielectric that can keep the electric polarization state for a long time, and this dielectric is a kind of high molecular polymer, is distributed with free charge on the electret.Owing to be distributed with free charge on the electret, so between the two poles of the earth of the capacitor that forms between vibrating diaphragm group 12 and the back pole plate 14, the quantity of electric charge has just been arranged, when sound wave makes diaphragm 121 vibration and when producing displacement, changed the capacitance of capacitor, the change of capacitance makes the output of capacitor produce corresponding alternating electric field, just formed the signal of telecommunication corresponding, so just finished the function of acoustic-electric conversion with acoustic signals.

The breach of offering on the back pole plate 14 142 is beneficial to the air flows that acoustic pressure causes, thereby is convenient to diaphragm 121 vibrations.In fact, diaphragm 121 can vibrate smoothly, the air of microphone inside needs circulation, thereby require breach 142 to be covered fully by pad 13, other requires to form circulation of air between breach 142 and the groove 151, that is, both communicate, because the circulation of air that diaphragm 121 vibrations cause will be passed to the outside via groove 151 at the tone-entering hole 112 by shell 11 by the breach of offering on the back pole plate 14 142.This principle is same as the prior art.

The side of back pole plate 14 is offered breach 142, both be convenient to circulation of air, electret major part on the main body 140 of back pole plate 14 is over against vibrating diaphragm group 12 simultaneously, can promote the sensitivity of acoustic-electric conversion again, in addition, breach 142 is opened in periphery, can guarantee the intensity of back pole plate 14, and sagittal plane 1420 and flexure plane 1421 that breach 142 is provided with can guarantee the stress minimum that back pole plate 14 produces when being subjected to external force, improve intensity.

Need to prove; each element of the utility model microphone; its shape is not limited to that present embodiment is described and accompanying drawing is painted; as long as satisfy the electret microphone basic functional principle; and the periphery of back pole plate is offered the breach of circulation of air, all belongs in the utility model scope required for protection.

The above only is a better embodiment of the present utility model; protection range of the present utility model does not exceed with above-mentioned execution mode; as long as the equivalence that those of ordinary skills do according to the utility model institute disclosure is modified or changed, all should include in the protection range of putting down in writing in claims.

Claims

1. electret microphone, it comprises back pole plate, it is characterized in that: back pole plate is provided with main body and by the vertically extending side of main body, by being recessed to form some breach to body interior on the side, makes that side is a concavo-convex interval shape.

2. electret microphone as claimed in claim 1 is characterized in that: back pole plate is cylindric, and breach is enclosed to form by the two relative sagittal planes and the flexure plane of smooth connection sagittal plane.