CN2303418Y - Low distortion and low noise mouth-piece - Google Patents
Low distortion and low noise mouth-piece Download PDFInfo
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- CN2303418Y CN2303418Y CN 97220840 CN97220840U CN2303418Y CN 2303418 Y CN2303418 Y CN 2303418Y CN 97220840 CN97220840 CN 97220840 CN 97220840 U CN97220840 U CN 97220840U CN 2303418 Y CN2303418 Y CN 2303418Y
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Abstract
The utility model relates to a low noise mouthpiece. The utility model is provided with a shell, sound pickups arranged in the shell, and a suppression circuit which is used for eliminating the noise and the noise signals. The utility model is characterized in that a sound passing hole is arranged at the position where the shell faces one direction, and a plurality of sound pickups which are deployed according the regulated distances are arranged in the shell; delay circuits are arranged correspondingly to the sound pickups, and thus, the sound signals obtained from the same sound source can be received according to the sound pickups; low noise signals can be output. Because the sound generated from the sound source can enters the mouthpiece only facing one direction, the phase difference of the sound signals received by the two sound pickups is 180 DEG or 0 DEG, the distortion of the differential mode signals extracted from the sound signals received from the two sound pickups is quite low; thus, the low distortion and low ambient noise of the mouthpiece can be reached; besides, the low distortion and low noise mouthpiece with spacing reception, orientating spacing reception, and positioning reception can be realized.
Description
The utility model relates to a kind of low-distortion and low-noise microphone, particularly relates to a kind of low-distortion and low-noise microphone with a plurality of pick-ups.
At present, though existing pickup transmitter has various ways, performance is also different, but voice signal that various microphones send sound source and environmental noise signal be same to be received and not to have a selectivity, and just the way that installs the directional reception microphone cover additional by the receiving sensitivity that lowers microphone lowers environmental noise.Because the signal to noise ratio of the sound that actual environment noise and source of sound send is more or less the same, so the sound that often causes environmental noise to disturb source of sound to send.Taked for this reason, will carry out in recording studio such as recording, the phonetic entry of carrying out speech recognition of computer then can only be carried out in ad hoc speech room.Therefore, in daily life, press for a kind of low-distortion and low-noise microphone.
The existing microphone that can eliminate environmental noise, be that two pick-ups are settled back-to-back, sound wave is delivered by both direction and is entered two pick-ups, utilizes received voice signal phase place opposite, and the employing adder circuit is cancelled each other this two-way common-mode signal and obtained the low environment noise.But in fact two pick-ups phase difference of receiving the acoustical signal of same source of sound is not just to differ 180 degree or differ 0 degree, thereby, may cause the acoustical signal distortion.The utility model people's CN92112907.6 patent of invention discloses a kind of low-distortion and low-noise microphone, two pick-ups in same microphone cover, settling, adopt subtracter that the voice signal that is received is subtracted each other and reach the reduction environmental noise, owing to also be that sound input port by separately receives sound, exist the acoustical signal distortion equally, can not reach the problem of desirable signal to noise ratio.
The utility model has been made invention in order to address the above problem exactly, and therefore, the purpose of this utility model provides a kind of low-distortion and low-noise microphone.Microphone of the present utility model has not only been realized low distortion low environment noise owing to have a plurality of pick-ups and only be provided with a source of sound inlet port, but also can realize that spacing receives, the function that directed spacing receives and the location receives.
To achieve these goals, according to low-distortion and low-noise microphone of the present utility model, possess a microphone enclosure is arranged, be arranged at a plurality of pick-ups in the above-mentioned microphone enclosure, and the common-mode signal suppression circuit that is used to abate the noise, it is characterized in that, the position facing one direction of above-mentioned shell has sound wave and passes through the hole, and be provided with a plurality of above-mentioned pick-ups in the enclosure with predetermined distance configuration, with above-mentioned each pick-up relative set delay circuit, thereby receive the acoustical signal that same sound source signal obtains according to above-mentioned each pick-up, output low noise signal.
Because the sound that sound source is sent, can only enter microphone from a direction, the voice signal that two pick-ups receive passes through delay circuit, make the two paths of signals phase difference be 180 the degree or be 0 the degree, thereby the distortion of the difference mode signal that extracts from the voice signal that two pick-ups receive is very low, thereby can reach the low distortion low environment noise of microphone.And can realize that spacing receives, the low-distortion and low-noise microphone that directed spacing receives and the location receives.
Fig. 1 is the profile and the end view of the low-noise microphone of expression embodiment 1 of the present utility model;
Fig. 2 is the profile and the end view of the border noise microphone of expression embodiment 2 of the present utility model;
Fig. 3 is the profile of the low-noise microphone of expression embodiment 3 of the present utility model;
Fig. 4 is the profile of the low-noise microphone of expression embodiment 4 of the present utility model;
Fig. 5 is the profile of the low-noise microphone of expression embodiment 5 of the present utility model;
Fig. 6 is the profile of the low-noise microphone of expression embodiment 6 of the present utility model;
Fig. 7 is the profile of the low-noise microphone of expression embodiment 7 of the present utility model;
Fig. 8 is the profile of the low-noise microphone of expression embodiment 8 of the present utility model;
Fig. 9 is the profile of the low-noise microphone of expression embodiment 9 of the present utility model;
Figure 10 is a kind of delay circuit figure that uses in the explanation microphone of the present utility model;
Figure 11 is the another kind of delay circuit figure that uses in the explanation microphone of the present utility model;
Figure 12 is another the delay circuit figure that uses in the explanation microphone of the present utility model;
Figure 13 is another the delay circuit figure that uses in the explanation microphone of the present utility model;
Figure 14 is a kind of delay circuit figure that also has that uses in the explanation microphone of the present utility model;
Figure 15 is a kind of delay circuit figure that uses in the explanation microphone of the present utility model;
Figure 16 is the another kind of delay circuit figure that uses in the explanation microphone of the present utility model;
Figure 17 is another the delay circuit figure that uses in the explanation microphone of the present utility model;
Figure 18 is the single-ended positive feedback low pass of expression second order voltage controlled voltage source constant delay filter circuit figure;
Figure 19 is the logical constant delay filter circuit figure of the single-ended positive and negative tape feed of expression second order voltage controlled voltage source;
Figure 20 is the single-ended positive feedback high pass of expression second order voltage controlled voltage source constant delay filter circuit figure;
Figure 21 is an expression feedforward biquadratic all-pass filter circuit diagram;
Figure 22 is the active feedback amplifier all-pass filter of expression;
Figure 23 is an expression switching capacity filter all-pass filter circuit diagram;
Figure 24 is expression equalization filter circuit figure;
Figure 25 represents not Qiu equalization filter circuit figure now;
Figure 26 is the step low-pass constant delay filter circuit circuit diagram that expression has equalizer;
Figure 27 is the delay circuit circuit diagram of expression bucket chain delay circuit and charge coupled device;
Figure 28 is the digital delay circuit circuit diagram of expression;
Figure 29 a and 29b are respectively the end view and the front views of the structure of location receiving system.
Below, with reference to each accompanying drawing, embodiment of the present utility model is described in detail.Fig. 1 shows the profile of the low-distortion and low-noise microphone of embodiment 1 of the present utility model.As seen from Figure 1, low-distortion and low-noise microphone of the present utility model possesses: cylindrical shell 1, protecgulum 2, bonnet 3, pick-up sleeve pipe the 4, the 1st pick-up 5a, the 2nd pick-up 5b, the 3rd pick-up 5c, fixedly earthquake washer 8, back crash roll 9 and lead-out wire 10.The shell of this microphone is assembled by cylindrical shell 1, protecgulum 2 and bonnet 3.The size of shell is by the diameter and the length decision of cylindrical shell 1.Shell is columnar, also can adopt the shell of other shapes.Only be provided with through hole on the position facing one direction of shell, the protecgulum 2 of shell can be provided with one or more through hole (12), so that the pick-up that sound wave can only be installed in a direction propagates into cylindrical shell 1.In the shell of this microphone.Be provided with pick-up sleeve pipe 4 along cylindrical shell 1 axis direction.The sleeve pipe of circular or other shape that the metal that this pick-up sleeve pipe 4 can be a kind of two ends or an end opening, plastic or other material are made, inner tandem disposes a plurality of pick-ups, for example, be provided with the 1st pick-up 5a, the 2nd pick-up 5b and the 3rd pick-up 5c.Bonnet 3 one sides of pick-up sleeve pipe 4 are provided with fixedly that earthquake washer 8 is set to pick-up sleeve pipe 4 outsides, are provided with crash roll 9 simultaneously between pick-up sleeve pipe 4 and bonnet 3.The rear end of sleeve pipe is fixed in the shell by earthquake washer.Fixedly earthquake washer 8 and crash roll 9 plays a pick-up sleeve pipe 4 on the one hand and is fixed in the cylindrical shell 1, and prevent the effect of the bump vibrations that each pick-up in the pick-up sleeve pipe in use is subjected to, on the other hand, also have and prevent that sound from propagating into the effect of its inner set pick-up from 3 ones of bonnets.Fixedly earthquake washer 8 and crash roll 9 are constituted also and can be made of other material by elastomeric material, as: immobilization material of non-elastic material, fixedly pick-up sleeve pipe use or the like.If it is good not need to carry out shockproof processing of pick-up or pick-up shockproof effect, and shell is good at sound through hole scope part soundproof effect in addition except the position of sound through hole, also can not use earthquake washer, crash roll and quakeproof bracket.As long as from sound through hole 12 arrives the way of sound receiving terminal of each pick-up, channel of acoustic wave is arranged, just can as required pick-up be fixed on the required in the enclosure fixing position by bonding or various fixed mechanisms.
Between three pick-ups that are provided with in this pick-up sleeve pipe 4, be provided with window by sound, here, the sound wave that imports into from a direction between the 1st pick-up 5a and the 2nd pick-up 5b and the 2nd pick-up 5b and the 3rd pick-up 5c, is respectively equipped with window 6a and 6b, so that can be sent to respectively in each pick-up.And as shown in the figure, the sound of the 1st pick-up 5a, the 2nd pick-up 5b and the 3rd pick-up 5c receives end face all towards same direction,, all faces toward the direction of sound transmission here.In addition, the lead-in wire 10 that is connected to pick- up 5a, 5b and 5c passes bonnet 3 output signals, so that to the signal processing that abates the noise of output.Two pick-ups or the more pick-up that also can be provided with in this pick-up sleeve pipe 4.
In addition, where necessary, can install directed cover 11 additional, in order to the effect of strengthening receiving the directionality of sound and eliminating ambient noise in the front of protecgulum 2.The protecgulum 2 of shell has one or more through hole 12, and shown in Fig. 1 b, this through hole 12 can radially distribute.Certainly, also can adopt the guard form.In order to prevent that better sound from importing into the pick-up from the back side, the back side of pick-up can be provided with sound insulation packing ring 13a, 13b.And, the distance that is installed in a plurality of pick-up arrival sound through holes in the pick-up sleeve pipe 4 of microphone of the present utility model can not be identical, distance between them, with microphone to the distance of source of sound, the signal of the sound that sends of the source of sound that needs to receive and the sound of environmental noise is more relevant than the type of, pick-up etc.In general, source of sound is near more to the distance of microphone during use, and then required distance can be more little between two pick-ups; The sound that the source of sound that need to receive sends is bigger than more with the signal of the sound of environmental noise, and then the distance between two pick-ups also can be more little; Pick-up receives the more highly sensitive of sound, and then the distance between the pick-up can be leaned on more closely; And then, little as the background noise of common-mode signal suppression circuit, but also near point of the distance between two pick-ups then.Self-evident, in order to do the size of microphone forr a short time, should under the prerequisite of guaranteed performance, make the distance between pick-up as much as possible little.For example, establish if the distance of microphone of the present utility model and source of sound less than 5cm, then the distance between two pick-ups gets final product about 4～20mm scope greatly.Also have, the distance between the pick-up is near more, and then common-mode signal is just big more and then difference mode signal is also low more, and corresponding environmental noise is also low.In contrast, environmental noise is also big, and in other words, the effect that reduces environmental noise reduces.The sound wave difference mode signal size that receives between the acoustic signals that receives by each pick-up relatively and two pick-ups can be obtained the distance between source of sound and the microphone, thereby can realize that set a distance receives.
The pick-up that receiving sensitivity is low, noise is high will use receiving sensitivity height, pick-up that noise is low in the microphone, because will make signal to noise ratio increase as far as possible.In same microphone of the present utility model, use the every performance in same type two or more the pick-up will compare near consistent.
Fig. 2 is the profile and the end view of the low-distortion and low-noise microphone of expression embodiment 2 of the present utility model.
As seen from Figure 2, low-distortion and low-noise microphone of the present utility model possesses: cylindrical shell 1, protecgulum 2, bonnet 3, pick-up bearing 15 and 16, the 1st pick-up 5a, the 2nd pick-up 5b, the 3rd pick-up 5c, fixedly earthquake washer 8, crash roll 9 and lead-out wire 10.The microphone structure of present embodiment 2 is except replacing pick-up sleeve pipes 4 to support the 1st pick-up 5a and the 2nd pick-up 5b with pick-up bearing 15,16 respectively, all identical with embodiment 1.The shell of this microphone is assembled by cylindrical shell 1, protecgulum 2 and bonnet 3.The size of shell is by the diameter and the length decision of cylindrical shell 1.Shell is columnar, also can adopt the shell of other shapes.The protecgulum 2 of shell can be provided with one or more through hole 12, so that the pick-up that sound wave can only be installed in a direction propagates into cylindrical shell 1.Tandem disposes a plurality of pick-ups in this microphone, for example the 1st pick-up 5a, the 2nd pick-up 5b and the 3rd pick-up 5c.Install and fix ring 14 in protecgulum 2 one side appropriate locations, pick-up bearing 15a, position then are installed successively adjust packing ring 17, fixedly tongue 18a, pick-up bearing 15b, fixedly tongue 18b and fixing earthquake washer 8, the 1st pick-up 5a is installed in above-mentioned pick-up bearing 15a respectively again, the 2nd pick-up 5b is installed in pick-up bearing 15b and fixedly in the earthquake washer 8 the 3rd pick-up 5c is being installed.Also have, crash roll 9 fixedly is being installed between earthquake washer 8 and the bonnet 3 at the back side of the 3rd pick-up 5c.Fixedly earthquake washer 8 and crash roll 9 play on the one hand the 3rd pick-up 5c are fixed in the cylindrical shell 1, and prevent the effect of the bump vibrations that pick-up in use is subjected to, on the other hand, also have and prevent that sound from propagating into the effect of its inner set pick-up from 3 ones of bonnets.And shown in Fig. 2 a, the sound of the 1st pick-up 5a, the 2nd pick-up 5b and the 3rd pick-up 5c receives end face all towards same direction, that is, and and facing to the direction of sound transmission.In addition, the lead-in wire 10 that is connected to pick-up 5a, 5b and 5c passes bonnet 3 output signals, so that to the signal processing that abates the noise of output.Two pick-ups or the more pick-up that also can be provided with in this microphone.
The structure of relevant pick-up bearing then, is described.This pick-up bearing 15,16 shown in Fig. 2 b, has: ring 22 and back-up block 23 in outer trembleuse cup pad 19, interior trembleuse cup pad 20, bearing outer shroud 21, the bearing.Outer trembleuse cup pad 19 is assemblied on cylindrical shell 1 inwall.The housing of pick-up then is assemblied in the interior trembleuse cup pad 20.Be provided with by one or more back-up block 23 between trembleuse cup pad 19 and the interior trembleuse cup pad 20 outside, connect and supporting bearing outer shroud 21 and the interior ring 22 of bearing.This bearing outer shroud 21 fills up in 20 with bearing shake ring.Be provided with by one or more back-up block 23 between trembleuse cup pad 19 and the interior trembleuse cup pad 20 outside, connect and to support bearing outer shroud 21, and encircle 22 in the bearing.Space in this bearing outer shroud 21 and the bearing between the ring 22 is separated into the channel of acoustic wave 24 that one or more transmits sound wave by back-up block 23.Thereby, after transmitting the sound wave of coming in and arrive the 1st pick-up 5a by 2 through holes of protecgulum 12, can pass channel of acoustic wave 24a and be sent to the 2nd pick-up 5b, pass channel of acoustic wave 24b again and pass to the 3rd pick-up 5c.The several sections of pick-up bearing is according to using needs that multiple various combination can be arranged, but intermediate support block 23 and channel of acoustic wave 24 must be arranged in every kind of different combination, back-up block 23 is made by elastomeric material or other material, as: immobilization material of non-elastic material, fixedly pick-up use or the like.If it is good not need to carry out shockproof processing of pick-up or pick-up shockproof effect, and shell is good at sound through hole scope part soundproof effect in addition except the position of sound through hole, also can not use earthquake washer, crash roll and quakeproof bracket.As long as from the sound through hole arrives the way of sound receiving terminal of each pick-up, channel of acoustic wave is arranged, just can as required pick-up be fixed on the required in the enclosure fixing position by bonding or various fixed mechanisms.
The relation of the distance in the present embodiment 2 between each pick-up, source of sound and environmental noise similarly to Example 1, therefore, its explanation is omitted.
Fig. 3 shows the profile of the low-distortion and low-noise microphone of embodiment 3 of the present utility model.As seen from Figure 3, with Fig. 1 a relatively its different be in: increased pick-up bearing 15a, and fixed, can or only use the pick-up sleeve pipe with pick-up bearing 15a when specifically implementing at the 1st this pick-up bearing 15a of pick-up 5a place and pick-up sleeve pipe 4.Cancelled the 3rd pick-up 5c, be exactly, the 1st pick-up 5a and the 2nd pick-up 5b only have been set in this picks up sleeve pipe 4; And the sound of the 1st pick-up 5a and the 2nd pick-up 5b receives end face all towards the sound source direction of propagation, respectively offers some sound respectively near pick-up sleeve pipe 4 tube walls sound receives end face and enters the hole.
Fig. 4 shows the profile of the low-distortion and low-noise microphone of embodiment 4 of the present utility model.As seen from Figure 4, with Fig. 1 a relatively its different be in: increased pick-up bearing 15a, and fixed, can or only use the pick-up sleeve pipe with pick-up bearing 15a when specifically implementing at the 1st this pick-up bearing 15a of pick-up 5a place and pick-up sleeve pipe 4.Cancelled the 3rd pick-up 5c, be exactly, the 1st pick-up 5a and the 2nd pick-up 5b only have been set in this picks up sleeve pipe 4; And the 1st pick-up 5a sound receiving terminal is facing Sounnd source direction, and the sound receiving terminal of the 2nd pick-up 5b is facing the sound source direction of propagation, and offers some sound near pick-up sleeve pipe 4 tube walls sound receives end face and enter the hole.Briefly, face in the opposite direction with different being in of the embodiment 3 shown in Fig. 3 in the sound receiving terminal of the 1st pick-up 5a and the 2nd pick-up 5b.
Fig. 5 shows the profile of the low-distortion and low-noise microphone of embodiment 5 of the present utility model.As seen from Figure 5, with Fig. 1 a relatively its different be in: increased pick-up bearing 15a, and fixed, can or only use the pick-up sleeve pipe with pick-up bearing 15a when specifically implementing at the 1st this pick-up bearing 15a of pick-up 5a place and pick-up sleeve pipe 4.Cancelled the 3rd pick-up 5c, be exactly, the 1st pick-up 5a and the 2nd pick-up 5b only have been set in this picks up sleeve pipe 4; And, the 1st pick-up 5a sound receiving terminal is facing the sound source direction of propagation, and the sound receiving terminal of the 2nd pick-up 5b is facing Sounnd source direction, be exactly, the sound of the 1st pick-up 5a and the 2nd pick-up 5b receives that end face is relative to be put, and on pick-up sleeve pipe 4 tube walls, offer some sound and enter the hole, this sound enters the hole should receive the end at the 1st pick-up sound, if at other position then a later delay time should equal sound wave enters the time difference that the hole is sent to two pick-ups respectively from sound.Briefly, face in the opposite direction with different being in of the embodiment 3 shown in Fig. 3 in the sound receiving terminal of the 1st pick-up 5a and the 2nd pick-up 5b.
Fig. 6～9 show the profile of the low-noise microphone of embodiment 6～9 of the present utility model.The main difference point of the above embodiments 1～5 and present embodiment 6～9 is that the former a plurality of pick-ups are that tandem is one in front and one in back settled, and two pick-ups of the latter one in front and one in back dispose about being side by side.And the operation principle of the reduction environmental noise of microphone is identical.The profile of the low-noise microphone of embodiment 6 of the present utility model, as shown in Figure 6: in the cylindrical shell 1 of this microphone pick-up sleeve pipe 4 is installed.Before and after in the pick-up sleeve pipe 4 two pick-ups are installed side by side, that is, and the 1st pick-up 5a and the 1st pick-up 5b.One end of the sealing of cylindrical shell 1 has lead-in wire 10, and the other end has protecgulum 2, is provided as the sound through hole 12 that common sound enters the hole on it.In addition, where necessary, can install directed cover 11 additional, in order to the effect of strengthening receiving the directionality of sound and eliminating ambient noise in the front of protecgulum 2.The position of sound through hole 12 only is at shell position facing one direction, can be on the extended line of the connecting line of the intersection point of two pick-up axis extended lines arranged side by side and microphone cover protecgulum and this connecting line, and with the position of the perpendicular line segment of this connecting line on, or on other position that needs, can be one or more hole.The 1st arranged side by side pick-up 5a and the sound receiving terminal of the 2nd pick-up 5b be towards Sounnd source direction, that is, and and towards protecgulum 2 directions.
The outside of the stiff end of pick-up sleeve pipe 4 is with fixedly, and earthquake washer 8 is fixed in the shell., this fixedly earthquake washer 8 as the sound insulation of a pick-up of the least significant end that does not need sound wave to pass through and shockproof usefulness.At the 1st and the 2nd pick-up back side shockproof sound insulation pad 9a and 9b can be set.Fixedly earthquake washer 8 can be integral in conjunction with making with shockproof pad 9a and 9b.Pick-up bearing 15 is set in case of necessity can allows sound wave arrive the position that is installed on aftermost pick-up sound receiving terminal in the microphone sleeve pipe, pick-up or pick-up sleeve pipe are fixed in the shell.Can be only during concrete enforcement with pick-up bearing 15a or only use the pick-up sleeve pipe, also can the two all use.Equally, if do not need to carry out the shockproof processing of pick-up or the pick-up shockproof effect is good and shell except the position of sound through hole, the part soundproof effect beyond sound through hole scope is good, also can not use earthquake washer, crash roll and quakeproof bracket.As long as from sound arrives the way of sound receiving terminal of each pick-up by the hole, channel of acoustic wave is arranged, just can as required pick-up sleeve pipe or pick-up be fixed on the required in the enclosure fixing position by bonding or various fixed mechanisms.
The 1st pick-up sound receiving terminal and the 2nd pick-up sound receiving terminal are all towards pick-up sleeve pipe protecgulum 2, the sound wave that source of sound sends enters cavity before the pick-up from the protecgulum hole 12 of microphone cover 11, perhaps by sonic transmissions pipe 16, sonic transmissions pipe connector leads to being in charge of 16a and being in charge of 16b of each pick-up.Above-mentioned cavity can cut off the cavity that is divided into the independent use of each pick-up by microphone cover.
The profile of the low-noise microphone of embodiment 7 of the present utility model, as shown in Figure 7.Be with the main difference point of Fig. 6, the 1st pick-up 5a arranged side by side of present embodiment and the sound receiving terminal of the 2nd pick-up 5b are towards opposite with the foregoing description 6, towards direction of sound propagation, promptly, towards bonnet 3 directions, therefore before the receiving terminal of the 1st pick-up 5a and the 2nd pick-up 5b, separate and establish sound wave on sleeve pipe 4 tube walls at certain space place and enter hole 6a and 6b, so that can make sound wave arrive the receiving terminal of pick-up.The receiving terminal at the 1st and the 2nd pick- up 5a and 5b of the stiff end of pick-up sleeve pipe 4, outside also are with fixedly earthquake washer 8 and crash roll 9, and the pick-up back side also is provided with crash roll 9c and 9d simultaneously, and pick-up is fixed in the sleeve pipe 4.Pick-up sleeve pipe 4 outer being provided with can allow sound wave arrive the pick-up bearing 15 that is installed on the pick-up sound receiving terminal in the sleeve pipe.Can be only during concrete enforcement with pick-up bearing 15a or only use the pick-up sleeve pipe, also can the two all use.
The profile of the low-noise microphone of embodiment 8 of the present utility model, as shown in Figure 8.Be with the main difference point of Fig. 6, the 1st pick-up 5a sound receiving terminal arranged side by side of present embodiment is towards towards Sounnd source direction, promptly, towards protecgulum 2 directions, and the 2nd pick-up 5b is towards direction of sound propagation, that is, and and towards bonnet 3 directions, therefore on sleeve pipe 4 end faces of the 1st pick-up 5a receiving terminal, correspondingly be provided with and establish sound wave on sleeve pipe 4 tube walls that separate the certain space place before the receiving terminal of sound inlet port and the 2nd pick-up 5b and enter hole 6b, so that can make sound wave arrive the receiving terminal of pick-up.The receiving terminal at the 1st and the 2nd pick- up 5a and 5b of the stiff end of pick-up sleeve pipe 4, outside also are with fixedly earthquake washer 8 and crash roll 69, and the back side of the 2nd pick-up 5b also is provided with crash roll 9d simultaneously, and pick-up is fixed in the sleeve pipe 4.Pick-up sleeve pipe 4 outer being provided with can allow sound wave arrive the pick-up bearing 15 that is installed on the pick-up sound receiving terminal in the sleeve pipe.Can be only during concrete enforcement with pick-up bearing 15a or only use the pick-up sleeve pipe, also can the two all use.
The profile of the low-distortion and low-noise microphone of embodiment 9 of the present utility model, as shown in Figure 9.Be with the main difference point of Fig. 8, the 1st pick-up 5a sound receiving terminal arranged side by side of present embodiment is towards towards direction of sound propagation, promptly, towards bonnet 3 directions, and the 2nd pick-up 5b is towards Sounnd source direction, that is, and and towards protecgulum 2 directions, therefore separate before the receiving terminal of the 1st pick-up 5a and the 2nd pick-up 5b and establish sound wave on sleeve pipe 4 tube walls at certain space place and enter hole 6a and 6b, so that can make sound wave arrive the receiving terminal of pick-up.The receiving terminal at the 1st and the 2nd pick- up 5a and 5b of the stiff end of pick-up sleeve pipe 64, outside also are with fixedly earthquake washer 8 and crash roll 9, and the back side of the 1st pick-up 5a also is provided with shockproof sound insulating pad 9c simultaneously, and pick-up is fixed in the sleeve pipe 4.Pick-up sleeve pipe 4 outer being provided with can allow sound wave arrive the pick-up bearing 15 that is installed on the pick-up sound receiving terminal in the sleeve pipe.Can be only during concrete enforcement with pick-up bearing 15a or only use the pick-up sleeve pipe, also can the two all use.
Above, the structure in the utility model microphone has been described, the configuration mode of a plurality of pick-ups particularly has been described, below, the advantage of its different configuration directions is done simple declaration.
1) two pick-up sound receiving terminals are all towards the direction of pick-up protecgulum, the benefit of An Zhiing is like this, distance between two pick-up sound receiving terminals has only the height of a microphone more, and distance is closer, is beneficial to the signal to noise ratio that improves signal and environmental noise.And, through after the delay circuit delays, the phase difference of two acoustic signals that pick-up received just in time differs 0 degree, behind the subtraction circuit through following common mode inhibition circuit, two-way just subtracts each other can deduct common-mode signal, but common-mode rejection ratio depends on the common-mode rejection ratio of differential amplifier, only selects for use the higher differential amplifier of common-mode rejection ratio just can obtain the ratio of high signal and environmental noise.
According to microphone of the present utility model only on the shell at facing one direction position, promptly, have only a direction to have sound wave to enter the hole, the interior a plurality of pick-ups of shell are received enter the sound wave that the hole enters from same sound wave, add delay circuit like this, behind the common mode inhibition circuit, just can make sound waveform low distortion or undistorted.
When in the enclosure, perhaps in the pick-up sleeve pipe before and after tandem ground or front and back when a plurality of pick-up is installed side by side, the sound receiving terminal of pick-up in microphone towards, can in the scopes of 360 degree, change.But because sonic transmissions speed is well below the electric wave transmission speed, simultaneously because in order to obtain maximum common-mode rejection ratio, the phase difference of the acoustic signals of two pick-up receptions preferably differs 180 degree or differs 0 degree, when the sound wave signal of telecommunication that carries out so afterwards postpones, time of delay can be shorter, therefore preferably differ 180 degree or differ 0 degree for the phase difference that reaches the acoustic signals that two pick-ups receive, so that carrying out common-mode signal suppresses, extract difference mode signal, between two pick-up sound receiving terminals towards preferably relative or opposite towards.Otherwise utilize signal delay and phase-shift circuit and delay time and phase shift make it just in time to differ 0 the degree or 180 the degree.At this moment, pick-up recited above adopts:
2) preceding pick-up sound receiving terminal is towards the direction of pick-up cover protecgulum, back pick-up sound receiving terminal is towards the direction of pick-up cover bonnet, like this by putting through after the delay circuit delays, the phase difference of the acoustic signals of two pick-up receptions just in time differs 180 degree, just subtract each other through two-way behind the adder circuit of common mode inhibition circuit again and can deduct common-mode signal, common-mode rejection ratio does not rely on the common-mode rejection ratio of differential amplifier, need not select for use the very high differential amplifier of common-mode rejection ratio just can obtain the ratio of high signal and environmental noise.
3) preceding pick-up sound receiving terminal is towards the direction of pick-up cover bonnet, and back pick-up sound receiving terminal is towards the direction of pick-up cover protecgulum, and the acoustic signals distortion of reception is smaller, sound source is sounded signal and the ratio of environmental noise signal is higher.
In microphone of the present utility model, can use two or more pick-up, when using plural pick-up, placement relation between the 2nd and the 3rd pick-up, though be related to the placement relation between the 1st and the 2nd pick-up, also can be inequality, for example, the the 1st and the 2nd pick-up sound receiving terminal is towards the direction of pick-up protecgulum, and the 2nd and the 3rd pick-up sound receiving terminal is also towards the direction of pick-up bonnet.Again for example, the 1st and the 2nd pick-up is that tandem ground is placed, and the 2nd and the 3rd pick-up was both placed on tandem ground, also can place side by side etc.Therefore multiple different compound mode can be arranged.In addition, along with two pick-ups towards change fixedly earthquake washer, sound wave also to make corresponding changes by pipe support, pick-up sleeve pipe etc. by pipe, sound wave, also to change towards different combinations in the time of delay of late-class circuit and circuit with pick-up sound receiving terminal.
The utility model is with reference to the list of references in following reference book and the book: " modern mechanism handbook (first volume volume two) " (Meng Xianyuan chief editor China Machine Press in June, 1994 front page), " mechanism's reference manual " (C.H Ke Refunikefu work Meng Xianyuan translates China Machine Press's 1981 front pages), " the practical design of Machine Design atlas " (gloomy foreign three works of rattan are congratulated and translated China Machine Press's 1990 front pages mutually) are waited book, can adopt book various theories of mechanics and mechanical structure and the algorithm described in the list of references in the book that neutralize as required.Concrete theory of mechanics and mechanical structure and algorithm can change according to concrete application purpose.
Below, in conjunction with Figure 10～27, the delay circuit that uses in the microphone of the present utility model is described.
Not when the 2nd pick-up when becoming the position of 0 degree or 180 degree with the 1st pick-up, under the certain condition of delay time, can be by regulate the phase difference of input speech signal by the control phase regulating circuit, making it just in time to differ is 0 degree or 180 degree, perhaps.When phase difference is that 0 circuit of common mode inhibition when spending can adopt subtraction circuit (differential amplifier circuit), when phase difference is that 180 circuit of common mode inhibition when spending can adopt adder circuit.
Should equal the time of delay of delay circuit to make two pick-up sound receiving terminals effectively to receive the time of the transmission of sound wave between two pick-ups of voice signal.
Because gain (amplification) coefficient of the delay circuit that adds can be greater than, be equal to or less than 1, if equal 1, not influence of amplification coefficient for the two-way microphone circuit, if less than 1, just equal to have inserted a loss,, just equal to have strengthened the amplification coefficient of this one-level if greater than 1, at this moment can perhaps increase one-level amplification or attenuator circuit and compensate by regulating the amplification coefficient that the two-way prime is amplified respectively.
Various have the circuit of common-mode signal inhibit feature all can adopt, comprise various differential amplifier circuits, various subtraction circuit, adder circuit, two paths of signals is made phase phasic difference 180 degree of two paths of signals through phase transition or 0 degree enters the adder circuit addition then or subtraction circuit subtracts each other, two paths of signals is cancelled each other curb common-mode signal or the like circuit.Wherein differential amplifier circuit common-mode signal inhibit feature is the strongest.Curb common-mode signal, the difference mode signal of the voice signal that the just two-way microphone that remains is received.Because two pick-ups have certain range difference distance in microphone, the distance of microphone and source of sound is very approaching, distant with the source of sound distance of environmental noise, therefore the voice signal power of two pick-up receptions is very big according to the ratio difference of the range difference distance of source of sound, the source of sound of two pick-ups and ambient noise is very little apart from great distances ratio difference in the microphone, because it is very little that the distance between two pick-ups and the distance of the source of sound of ambient noise signal are compared difference, therefore the strong and weak ratio difference of the voice signal of two pick-up receptions is very little, and the distance of the sound that sends of the source of sound that sends the environmental noise signal and microphone is more little more than routine difference more, and is also just low more through using the common-mode signal circuit to curb the difference mode signal that common-mode signal takes out.And the distance of microphone and source of sound is near more, and the strong and weak ratio difference of the voice signal of two pick-up receptions is big more, and the difference mode signal that curbs the common-mode signal taking-up through use common-mode signal circuit is also just high more.This common-mode signal suppression circuit can adopt: 1, the null-type bridge circuit that utilizes commonly used is cancelled out each other two paths of signals in the telephone set network; 2, make two paths of signals phase phasic difference 180 degree utilize adder circuit to carry out phase cancellation then; 3, utilize subtraction circuit that synchronous two paths of signals is subtracted each other mutually as with differential amplifier circuit etc.
Figure 10 is a kind of delay circuit figure that uses in the explanation microphone of the present utility model.This delay circuit is made of delay circuit and subtraction circuit (differential amplifier).The output of a pick-up M1 of one route is received partiting dc capacitor C2, the output of capacitor C 2 is received the input of delay circuit ID2, the output of delay circuit ID2 is received partiting dc capacitor C4, the other end of capacitor C 4 is received resistance R 2, and negative (-) end and connecting resistance R3 that the other end of resistance R 2 is received common-mode signal suppression circuit U1 arrive ground.Another road, an output by another pick-up M2 is received partiting dc capacitor C1, the output of capacitor C 1 is received the input of delay circuit ID1, the output of delay circuit ID1 is received partiting dc capacitor C3, the other end of capacitor C 3 is received resistance R 1, and the other end of resistance R 1 is received just (+) input of common-mode signal suppression circuit U1.Just (+) input of feedback resistance R4 one termination U1, the other end is received the output of U1.The output of common-mode signal suppression circuit U1 is received partiting dc capacitor C5 and output audio signal.Power supply VCC powers to the 1st and the 2nd pick-up M1 and M2 respectively by constant-current source H1 and H2.Constant-current source H1 and H2 also can adopt devices such as resistance.
When in a housing, a plurality of pick-ups being set, its sound receiving terminal is all when pick-up protecgulum direction or bonnet direction, pick-up in the microphone of the present utility model is different with the source of sound distance, and the voice signal that roughly the same pick-up M1 of performance and pick-up M2 gather, pass through partiting dc capacitor C1 and C2 respectively, enter delay circuit ID1 and/or ID2, adding delay circuit is tandem placements because of these above-mentioned two pick-ups, between its sound receiving terminal certain distance is arranged, promptly, with source of sound range difference is arranged, sound needs the regular hour from the sound receiving terminal that the sound receiving terminal of a pick-up passes to another pick-up, thereby two pick-ups can not receive voice signal synchronously, cause and to carry out correct common-mode signal inhibition by the sound signal of telecommunication that common-mode signal suppression circuit receives two pick-ups, and produce the sound signal waveform distortion.If the voice signal that the same source of sound synchronization of two pick-up receptions sends, postpone through delay circuit ID1, the time that postpones equals to make two pick-up sound receiving terminals effectively to receive the time of the transmission of sound wave between two pick-ups of voice signal, the voice signal that sends of the same source of sound synchronization that receives of two pick-ups then, after the sound signal of telecommunication that pick-up M1 receives postpones through delay circuit ID1, can arrive common-mode signal suppression circuit (subtraction circuit synchronously with the sound signal of telecommunication that pick-up M2 receives, circuit such as differential amplifier) just (+) of U1, negative (-) two inputs, and carry out correct common-mode signal by the voice signal that common-mode signal suppression circuit receives two pick-ups and suppress, take out difference mode signal.If the voice signal that the source of sound that two pick-ups are received sends, postpone through delay circuit ID1 and ID2 respectively, the time difference of Yan Chiing should equal to make two pick-up sound receiving terminals effectively to receive the time of the transmission of sound wave between two pick-ups of voice signal so.The signal that receives from two pick-ups, the two paths of signals amplification quantity should be identical during to just (+) of common-mode signal suppression circuit U1, negative (-) two inputs, after the signal of microphone reception amplifies delay circuit delays through two-way respectively like this, the phase difference of two paths of signals is 0 degree when arriving the input of common-mode signal suppression circuit, the voice signal that two pick-ups is received by common-mode signal suppression circuit carries out the common-mode signal inhibition, obtain the difference mode signal of voice signal, can not produce the sound signal waveform distortion.
Delay circuit can adopt various types of phase-frequency responses and volt frequency response that the circuit of big flatness should be arranged, be that time of delay is consistent as far as possible on each Frequency point of whole passband with amplification coefficient, the filter that excursion is very little, the employed filter of delay circuit, will make detailed description as an example below: 1. the delay circuit of various suitable active filters or compound filter passive filter or passive filter and active filter or various suitable bucket chain formula postpone the various types of delay circuits of various kinds of (BBD) or the pale pinkish purple device of electric charge (CCD) and independent digital signal delay circuit or the like non-filtering wave by prolonging time circuit.
2. the various types of analog signal delay circuits of various kinds, perhaps various suitable digital signal delay circuits.The delay circuit of compound filter active filter or passive filter or passive filter and active filter can be single order or multistage low pass filter, all-pass filter, band pass filter, high pass filter or the like.Low pass filter, band pass filter, high pass filter can have the Bei Saier filter according to the device of the computational methods of filter circuit and use is different, Gauss-Chebyshev transition filter, Bu Dehuazi-Thomson transiens filter, switching capacity filter, single order and multistage low pass constant delay filter, the logical constant delay filter of band, high pass constant delay filter, all-pass filter, active feedback amplifier all-pass filter, the switching capacity filter all-pass filter, the equalization filter circuit, Qiu's equalization filter circuit now not, low pass constant delay filter circuit with equalizer, all-pass and constant delay filter, the all-pass filter of active feedback amplifier, Dai Liyang Nice type, Mao Xitazi type all-pass and constant delay filter, switching capacity constant delay filter (as MAX281) etc.
Through the voice signal after the delay circuit time-delay, synchronously through partiting dc capacitor C3 and C4, enter the input of two circuit of the differential amplifier circuit of forming by amplifier U1 and resistance R 1, R2, R4, R5, suppress common-mode signal and extract difference mode signal, and level application circuit is further handled after making this difference mode signal output to other via partiting dc capacitor C5.
Differential amplifier circuit is a kind of subtraction circuit in the present embodiment, but can adopt the differential amplifier of other types, for example, with the differential amplifier that is in series, with the differential amplifier etc. that is in parallel, also can adopt other by transistor or by operational amplifier or the subtraction circuit formed by digital circuit.
The performance of a plurality of pick-ups unanimity of should trying one's best is arranged, and a plurality of pick-ups add that the amplification coefficient that its prime is amplified before the input stage that adds the arrival common mode inhibition circuit behind the delay circuit should be roughly the same.If the amplification of pick-up M1 adds the amplification coefficient behind the delay circuit, add greater than the amplification of pick-up M2 then to equal the amplification coefficient of delay circuit two distances between the pick-up and to have increased.On the contrary, if the amplification of pick-up M1 adds the amplification coefficient behind the delay circuit, add the amplification coefficient of delay circuit less than the amplification of pick-up M2, the distance that then equals two pick-ups has reduced.So by the voice signal that same source of sound sends, the amplification of process pick-up M1 adds the amplification signal behind the delay circuit, the amplification that should as far as possible equal pick-up M2 adds the amplification signal of delay circuit.
Figure 11 illustrates the another kind of delay circuit figure that uses in the microphone of the present utility model.This delay circuit is made of delay circuit and adder circuit.The output of one route pick-up M3 is received partiting dc capacitor C2, and the output of capacitor C 2 is received the input of delay circuit ID2, and the output of delay circuit ID2 is received partiting dc capacitor C4, and the other end of capacitor C 4 is received resistance R 6.Partiting dc capacitor C1 is received by the output of pick-up M4 in another road, and the output of capacitor C 1 is received the input of delay circuit ID1, and the output of delay circuit ID1 is received partiting dc capacitor C3, and the other end of capacitor C 3 is received resistance R 5.Just (+) end of resistance R 5, R6, R7 and common-mode signal suppression circuit U2 is connected, and negative (-) terminating resistor R8 of common-mode signal suppression circuit U2 is to ground.The other end of resistance R 7 is received the output of common-mode signal suppression circuit U2.The output of common-mode signal suppression circuit U2 connects partiting dc capacitor C5 output audio signal.Just (+) input of feedback resistance R7 one termination U2, the other end is received the output of U2.The output of common-mode signal suppression circuit U2 is received partiting dc capacitor C5 and output audio signal.Power supply VCC powers to pick-up M3 and M4 respectively by constant-current source H1 and H2.
Above-mentioned constitutes sound receiving terminal opposing or tandem in opposite directions or the microphone of placing side by side that delay circuit is applicable to pick-up by delay circuit and adder circuit.The voice signal that the same source of sound synchronization that two pick-up M3 and M4 receive sends, simultaneously through after the delay circuit time-delay, enter the input of the adder circuit of forming by amplifier U2 and resistance R 5, R6, R7 and R8 through partiting dc capacitor C3 and C4, suppress common-mode signal and extract difference mode signal.Resulting difference mode signal outputs to other back level application circuit through capacitor C 5 and further handles.
Adder circuit can adopt by transistor or by operational amplifier or the positive adder be made up of digital circuit in the present embodiment, or anti-phase adder.This adder circuit also can be used for other needs adder circuit to carry out the microphone circuit that common-mode signal suppresses.
Figure 12 is another the delay circuit figure that uses in the explanation microphone of the present utility model.This delay circuit is made of delay circuit, phase-shift circuit and subtraction circuit (differential amplifier).Figure 12 compares with the delay circuit of Figure 10, just inserts the phase-shift circuit of new interpolation and the input of U2 is put upside down between partiting dc capacitor C3 and resistance R 1.No longer describe for same section, and only explain with regard to phase-shift circuit.This phase-shift circuit is made of amplifier U4 and resistance R 12, R13 and R14.One of resistance R 12 and negative feedback resistor R13 terminates to negative (-) end of U4, and the other end of feedback resistance R13 is connected with the output of U4 and partiting dc capacitor C7, the other end output signal of capacitor C 7.Just (+) input of amplifier U4 is through resistance R 14 ground connection.This delay circuit is applicable to pick-up receiving terminal opposing or tandem in opposite directions or the microphone of placing arranged side by side.The voice signal that the same source of sound synchronization of two pick-up receptions sends, after the delay circuit time-delay, wherein one road signal is through phase-shift circuit, with sound electrical signal phase phase shift 180 degree, promptly, the process delay circuit that original two pick-ups are received differs the sound signals of telecommunication of 180 degree through after the phase shifts, it differs that to become be 0 degree when arriving the input of common-mode signal suppression circuit, enter by amplifier U1 and resistance R 1 via partiting dc capacitor C3 and C4 again, R2, R3, two inputs of the differential amplifier circuit that R4 forms suppress common-mode signal and extract difference mode signal.This difference mode signal outputs to other back level application circuit through partiting dc capacitor C5 and further handles.
The back that phase-shift circuit not only can be placed on delay circuit in the present embodiment also can be configured in delay circuit circuit front.This phase-shift circuit can be by the transistor operational amplifier, and perhaps digital circuit is formed.Above-mentioned circuit phase shift 180 degree, but also can use the phase-shift circuit that in the scope of 360 degree, carries out phase shift as required.
Figure 13 is another the delay circuit figure that uses in the explanation microphone of the present utility model.This delay circuit is made of delay circuit, phase-shift circuit and adder circuit.Figure 13 compares with the delay circuit of Figure 11, just inserts the phase-shift circuit of new interpolation and the input of U2 is put upside down between partiting dc capacitor C3 and resistance R 5.No longer describe for same section, and only explain with regard to phase-shift circuit.This phase-shift circuit is made of amplifier U4 and resistance R 12, R13 and R14.One of resistance R 12 and negative feedback resistor R13 terminates to negative (-) end of U4, and the other end of negative feedback resistor R13 is connected with the output of U4 and partiting dc capacitor C7, the other end output signal of capacitor C 7.Just (+) input of amplifier U4 is through resistance R 14 ground connection.
This delay circuit is applicable to that the sound receiving terminal of each pick-up in the housing is together towards the tandem of pick-up protecgulum direction or bonnet direction or the microphone of placing side by side.
The voice signal that the same source of sound synchronization of two pick-up receptions sends, after the delay circuit time-delay, wherein one road signal enters the phase-shift circuit of being made up of amplifier U4 and resistance R 12, R13, R14 through partiting dc capacitor C3, the sound electrical signal phase is carried out phase shift 180 degree, make that original two pick-ups receive through differing of delay circuit be the sound signal of telecommunication of 0 degree after phase shift, differ when arriving the input of common-mode signal suppression circuit and become 180 degree.This signal enters the input of the adder circuit of being made up of amplifier U2 and resistance R 5, R6, R7, R8 again through partiting dc capacitor C7 and C4, suppress common-mode signal and extract difference mode signal.This difference mode signal outputs to other back level application circuit through partiting dc capacitor C5 and further handles.
The back that phase-shift circuit not only can be placed on delay circuit in the present embodiment also can be configured in delay circuit circuit front.This phase-shift circuit can be by the transistor operational amplifier, and perhaps digital circuit is formed.Above-mentioned circuit phase shift 180 degree, but also can use the phase-shift circuit that in the scope of 360 degree, carries out phase shift as required.
Figure 14 is the circuit that a kind of delay circuit that uses in the microphone of the present utility model of explanation and digital common mode inhibition circuit separate.This circuit by delay circuit, mould/number conversion circuit, central processing unit carries out the common mode inhibition computing and the D/A switch circuit constitutes.As seen from Figure 14, all same from pick-up M1 and M2 with Figure 10 to capacitor C 4 and C3 connected mode.Then, respectively the voice signal of gathering is input to pre-process circuit ID4 and ID3 as required, outputs to mould/number conversion circuit D1 after handling through pre-process circuit, analog signal conversion is become digital signal.Digital signal after mould/number conversion circuit D1 will change outputs to digital signal processing circuit D2, carries out common-mode signal and suppresses computing, removes common-mode signal and extracts difference mode signal.The difference mode signal that numeral common-mode signal suppression circuit D2 extracts outputs to D/A switch circuit D3, is this conversion of signals analog signal, outputing to other back level application circuit through partiting dc capacitor C5 further handles, also can carry out further digital processing computing by digital signal processing circuit, as: carry out digital filtering, speech recognition etc.By the way, this digital common-mode signal suppression circuit for example can be made up of central processor CPU and peripheral circuit, or is made up of digital processing unit (DSP) and peripheral circuit.Equally, digital signal processing circuit for example also can be made up of central processing unit and peripheral circuit, or be made up of digital processing unit and peripheral circuit, can also be made up of other digital circuit that can finish this computing.
Figure 15 is a kind of delay circuit figure that uses in the explanation microphone of the present utility model.This delay circuit is made of preamplifying circuit, delay circuit and subtraction circuit (differential amplifier).Compare by Figure 15 and Figure 10, this delay circuit is actually two-way and all adds delay circuit and subtraction circuit as can be seen, has just increased preamplifying circuit and each feedback resistance electric capacity respectively in parallel.
Pick-up M2 is connected with C9 one end with partiting dc capacitor C8 respectively with M1, and the other end of capacitor C 9 and C8 is connected with the positive input terminal of pre-amplifier respectively, carries out the prime signal and amplifies.Series resistor R15 and R16 between just (+) input of U5 in this pre-amplifier and U6, and the node ground connection between resistance R 15 and the R16; Be connected with capacitor C in parallel 10 and resistance R 17 between negative (-) input of U5 and the output, bearing between (-) input and the output of same U6 is connected with capacitor C in parallel 11 and resistance R 18; And be connected with variable resistor P1 between negative (-) input of U5 and U6.The output of U5 and U6 is connected isolation capacitance C1 and C2 respectively, and output signal is delivered to delay circuit ID1 and/or ID2, and, the identical no longer repeat specification of remainder with Figure 12.After extracting difference mode signal from U1, output to other back level application circuit through partiting dc capacitor C5 and further handle.
Figure 16 is a kind of delay circuit figure that uses in the explanation microphone of the present utility model.This delay circuit is made of preamplifying circuit, delay circuit and adder circuit.Compare by Figure 16 and Figure 11, this delay circuit is actually two-way and all adds delay circuit and adder circuit as can be seen, has just increased preamplifying circuit and each feedback resistance electric capacity respectively in parallel.
Pick-up M4 is connected with C9 one end with partiting dc capacitor C8 respectively with M3, and the other end of capacitor C 9 and C8 is connected with the positive input terminal of pre-amplifier respectively, carries out the prime signal and amplifies.Series resistor R15 and R16 between just (+) input of U5 in this pre-amplifier and U6, and the node ground connection between resistance R 15 and the R16; Be connected with capacitor C in parallel 10 and resistance R 17 between negative (-) input of U5 and the output, bearing between (-) input and the output of same U6 is connected with capacitor C in parallel 11 and resistance R 18; And be connected with variable resistor P1 between negative (-) input of U5 and U6.The output of U5 and U6 is connected isolation capacitance C1 and C2 respectively, and output signal is delivered to delay circuit ID1 and/or ID2, and, the identical no longer repeat specification of remainder with Figure 13.After extracting difference mode signal from U2, output to other back level application circuit through partiting dc capacitor C5 and further handle.
The utility model can be with reference to the list of references in following reference book and the book: " Fundamentals of Electronic Technology-simulation part " (Huazhong Institute of Technology electronics teaching and research room compiles Kang Huaguang chief editor Higher Education Publishing House and publishes in March, 1979 front page), " application of analog integrated circuit " (Chen Xiuzhong chief editor Higher Education Publishing House publishes in September, 1988 front page), " simulation and digital circuit " (Peng Long merchant Deng Yamei Yao Chang peace chief editor Sichuan science tech publishing house publishes in January, 984 front page), " integrated operational amplifier principle and application " (Li Qingquan writes Science Press's in February, 1980 front page in yellow Changning), sensor application and circuit thereof selected (Zhang Fuxue writes the Electronic Industry Press and publishes in June, 1992 front page).Can adopt various principles and algorithm and the circuit theory described in the list of references in the book neutralization book as required.Concrete circuit and application circuit can change according to concrete application purpose.
Figure 17 is a kind of mould/number delay circuit figure that uses in the explanation microphone of the present utility model.This mould/number delay circuit by preamplifying circuit, mould/number conversion, carry out digital delay and carry out digital common-mode signal suppression circuit constituting.Compare by Figure 17 and Figure 14, this modulus delay circuit is actually the independent delay circuit of cancellation as can be seen, directly carries out digital delay and digital common mode inhibition.
Pick-up M4 is connected with C9 one end with partiting dc capacitor C8 respectively with M3, and the other end of capacitor C 9 and C8 is connected with the positive input terminal of pre-amplifier respectively, carries out the prime signal and amplifies.Series resistor R15 and R16 between just (+) input of U5 in this pre-amplifier and U6, and the node ground connection between resistance R 15 and the R16; Be connected with capacitor C in parallel 10 and resistance R 17 between negative (-) input of U5 and the output, bearing between (-) input and the output of same U6 is connected with capacitor C in parallel 11 and resistance R 18; And be connected with variable resistor P1 between negative (-) input of U5 and U6.The output of U5 and U6 is connected isolation capacitance C1 and C2 respectively, and output signal is delivered to pre-process circuit ID4 and ID3, outputs to mould/number conversion circuit D1 after handling through pre-process circuit, and analog signal conversion is become digital signal.Digital signal after mould/number conversion circuit D1 will change outputs to digital signal processing circuit D2, carries out digital delay and carries out common-mode signal inhibition computing, removes common-mode signal and extracts difference mode signal.The difference mode signal that numeral common-mode signal suppression circuit D2 extracts outputs to D/A switch circuit D3, is this conversion of signals analog signal, outputing to other back level application circuit through partiting dc capacitor C5 further handles, also can carry out further digital processing computing by digital signal processing circuit, as: carry out digital filtering, speech recognition etc.Capacitor C 10 and C11 are used separately as the frequency compensation of two previous amplifier circuits.Pre-amplifier also can be used in other microphone circuit.
This digital delay and digital common-mode signal suppression circuit for example can be made up of central processor CPU and peripheral circuit, or are made up of digital processing unit (DSP) and peripheral circuit.Same digital signal processing circuit for example also can be made up of central processing unit and peripheral circuit, or be made up of digital processing unit and peripheral circuit, can also be made up of other the various digital circuits that can carry out this digital delay and digital common mode inhibition process.
Below, further illustrate among Figure 10-18 the delay circuit of independent use.
And, can between above-mentioned capacitor C 1 and C3, a kind of single-ended positive feedback low pass of second order voltage controlled voltage source (VCVS) constant delay filter as shown in figure 18 be set.This low pass constant delay filter constitutes: resistance R 19, R20, capacitor C 14, C15 form step low-pass RC filter network, and form second-order low-pass filter with operational amplifier U7.The amplification coefficient of this low pass filter can be adjusted by resistance R 21 and R22.
And, RC network in the above-mentioned low pass constant delay filter can be selected the RC or the RCL network of other types for use, and form other low-pass filter circuit with operational amplifier, for example, single-ended positive feedback low pass filter, single-ended negative feedback low pass filter, feedforward biquadratic low pass filter etc.Can have by the algorithm difference: Bezier low pass filter, Gaussian approximation filter, the approximate filter of Chebyshev and Gauss's one Chebyshev transiens filter, Bu Dehuazi-Thomson transiens filter etc.Can also adopt single order or multistage filter.
And, can between above-mentioned capacitor C 1 and C3, the logical constant delay filter of a kind of single-ended positive and negative tape feed of second order voltage controlled voltage source (VCVS) as shown in figure 19 be set.The formation of the logical constant delay filter of this band is: resistance R 23, R24, R25 and capacitor C 16 are formed Order RC bandpass filtering network with C17, and form the single-ended positive feedback second-order bandpass filter of voltage controlled voltage source with operational amplifier U8.
And, can between above-mentioned capacitor C 1 and C3, a kind of single-ended positive feedback high pass of second order voltage controlled voltage source constant delay filter as shown in figure 20 be set.This high pass constant delay filter constitutes: resistance R 67, R68 and capacitor C 45 are formed Order RC high-pass filtering network with C46, the node of capacitor C 46 and resistance R 68 is connected with the positive input terminal of amplifier U19, and the node of resistance R 69 and R70 is connected with the negative input end of U19.The amplification coefficient of above-mentioned bivalent high-pass filter is adjusted by resistance R 69 and R70.The sound signal of telecommunication is from the output output of amplifier U19, and (C3) outputs to the next stage circuit via isolation capacitance.
And, can between above-mentioned capacitor C 1 and C3, a kind of feedforward biquadratic all-pass filter as shown in figure 21 be set.This all-pass filter circuit constitutes: an end of resistance R 27 is connected with negative (-) end of amplifier U9; As the resistance R 28 of feedback resistance and capacitor C 19 in parallel after, connect with amplifier U9 bear between (-) input and the output; Be connected with resistance R 30 between the negative terminal of amplifier U9 and the output of U11; Be connected with capacitor C 11 between the negative input end of amplifier U11 and the output; Resistance R 33 is connected between the negative input end and resistance R 27 of amplifier U11, and resistance R 34 is connected between the negative input end and resistance R 27 of amplifier U10; Resistance R 29 is connected between the negative input end of the output of amplifier U9 and amplifier U10, and resistance R 31 is connected between the negative input end of the output of amplifier U10 and amplifier U11; And resistance R 32 is connected between the negative input end and output of amplifier U10.
Also can use the all-pass filter of other types as required, for example, single order, multi-stage filter, passive filter or active filter and combination thereof.
And, can between above-mentioned capacitor C 1 and C3, a kind of active feedback amplifier all-pass filter as shown in figure 22 be set.This all-pass filter is made of active feedback amplifier: resistance R 35 and R36, capacitor C 21 and active feedback amplifier U12, one end ground connection of resistance R 35, its other end is received the pin 1 and 3 of active feedback amplifier U12, capacitor C 21 and R36 are connected in series the pin 4 and 7 of active feedback amplifier all-pass filter, and its pin 2 is a signal input part.Resistance R 35 and capacitor C 21 are used to regulate effective transfer function of filter, and resistance R 36 is used for providing pure effective input impedance in active feedback amplifier U12 frequency range.Active feedback amplifier U12, active feedback amplifier has all kinds, for example, can use model AD830 and LTC1193.
And, can between above-mentioned capacitor C 1 and C3, a kind of switching capacity filter all-pass filter as shown in figure 23 be set.This all-pass filter is made of resistance programming switching capacity universal active filter: resistance R 37 and R38 are serially connected with the conduct of switching capacity filter U13 and import between the HP and Vout end of IN end, and resistance R 37 and R38 serial connection node connect the LP end of U13 and meet power supply VCC through resistance R 39; Resistance R 40, R41, R42 and R43 are connected to the conduct of switching capacity filter U13 and import between the HP and Vout end of IN end, each node between resistance R 40, R41, R42 and the R43 serial connection, and the BP+ ground and the BP-that are connected in U13 successively hold.Switching capacity filter has all kinds, and for example, resistance programming switching capacity universal active filter for example, can adopt model RU5621A.
And, can between above-mentioned capacitor C 1 and C3, a kind of equalization filter circuit as shown in figure 24 be set.The formation of this filter circuit is: a termination capacitor C1 of resistance R 47, and the positive input terminal of another termination amplifier U14, feedback resistance 48 two ends are connected to positive input terminal and the output of U14 respectively; Capacitor C 22, R44, R46 and R45 are concatenated into ring, and R44 is connected with the output of U14 with node between R46, and R45 is connected with the negative input end of U14 with node between R46, between the node of resistance R 45 and capacitor C 23 and the ground and connecting resistance R43 and capacitor C 22.Above-mentioned resistance R 43, R44, R45, R46 and capacitor C 22 are formed RC with C23 and are delayed the isostatic compensation network.This circuit can join to be needed in the balanced weighing apparatus delay circuit of delaying, as joins in the low pass Bessel filter circuit, also can be used as independent circuit and the series connection of other filter circuit or in parallel the use, is used for the distortion that the channel frequency characteristic is delayed in equilibrium.
And, can between above-mentioned capacitor C 1 and C3, a kind of not Qiu as shown in figure 25 equalization filter circuit now be set.Not Qiu now the formation of equalization filter circuit be: the positive input terminal of a termination amplifier U15 of resistance R 53, feedback resistance 54 two ends are connected to positive input terminal and the output of U15 respectively; Resistance R 49, R50, capacitor C 25, C24 are concatenated into loop, and its each interelement node is connected to the negative input end of resistance R 53, capacitor C 26, amplifier U15 and resistance R 52, resistance R 51 successively; And resistance R 51 is connected with the node of capacitor C 26 and the output of U15, and another termination capacitor C 27 of resistance R 52 is to ground.Above-mentioned resistance and electric capacity are formed RC and are delayed the isostatic compensation network.This circuit can join to be needed in the balanced weighing apparatus delay circuit of delaying, and also can be used as independent circuit and the series connection of other filter circuit or in parallel the use, is used for the distortion that frequency characteristic is delayed in equilibrium.
And, can between above-mentioned capacitor C 1 and C3, a kind of step low-pass constant delay filter circuit with equalizer as shown in figure 26 be set.This step low-pass constant delay filter circuit and Figure 24 with equalizer compares, in fact be: the positive input terminal that series resistor R19 and R20 is connected in amplifier U14, between the output of the intermediate node of resistance R 19 and R20 and amplifier U14, connect capacitor C 15, and connect capacitor C 14 between the positive input terminal of amplifier U14 and the ground, to delay isostatic compensation network annexation constant and above-mentioned resistance R 43, R44, R45, R46 and capacitor C 22 and C23 form RC.
So, in same filter circuit, the equalization filter of delaying is arranged again, can balanced delay the distortion of frequency characteristic with regard to existing second-order low-pass filter.This circuit can also be formed multistage constant delay filter together with other all kinds filtering wave by prolonging time device.
And, can be between above-mentioned capacitor C 1 and C3, be provided with a kind of as shown in figure 27 bucket chain delay circuit (BBD) and the delay circuit of charge-coupled device (CCD).The delay circuit that should be made up of bucket chain delay circuit or charge coupled device constitutes: input coupling capacitance C28 receives the input 14 of U16, supply power voltage Vcc is by supplying with the bias voltage of the input 14 of U16 after resistance R 55 and the potentiometer R59 dividing potential drop, pin 10 is connected to the power supply circuits of Vcc, supply power voltage Vcc is by supplying with the Vdd of the pin 5 of U16 after resistance R 57 and the R58 dividing potential drop, the U16 clock of supplying with from pin 1 input monophasic pulses if drives, the delay time of the clock frequency decision U16 of driving pulse.The signal process time-delay back of importing is passed through resistance R 60 grounding shunts from pin 8 and pin 9 outputs behind the process balanced potentiometer P1, and by capacitor C 29 outputs.
Can change the time of time-delay by the clock signal frequency that the change drive clock is input to this delay circuit input.Bucket chain delay circuit and charge coupled device delay circuit all are the electric charge coupled simulation shift registers that is made of CMOS.Two kinds of circuit are internal charge coupled simulation shift-register circuit structure difference, and using method is also roughly the same, but the noise of charge coupled device is lower than the bucket chain delay circuit.Delay circuit U16 can use the bucket chain delay circuit and the charge coupled device delay circuit of the various models of all kinds, for example, can use model SAD512D.
And, can between above-mentioned capacitor C 1 and C3, a kind of digital delay circuit as shown in figure 28 be set.This digital delay circuit constitutes: the filter network that input coupling capacitance C31 forms by LPF input pin 27 and the output pin 28 of resistance R 61, R62, R63, R64, C43, C34, C35 and digital delaying circuit U18, receive the negative input of operational amplifier U17, the pin 19 that the output of U17 is received digital delaying circuit U18 enters, and U18 terminates to the normal phase input end of U17 by input pin 25, output pin 26 output signals.The master control logic of U17 deposits in and takes out by the data of address pin 1,8,9,10,11,12,13,14 and data pin 5 and control pin 2,3,4,6,7 control storage U19.The digital signal that is demodulated to is deposited among the U19, take out behind the time-delay certain hour, after ovennodulation, output to subordinate's circuit through coupling capacitance C32 from pin 31 outputs.The U18 internal clock generator has been formed clock oscillation circuit by pin 22, pin 23 and C37, C44, R65 and crystal oscillator Z1.By the delay time control circuit of pin 18, pin 20, pin 21 control U18 inside, so that the length of control delay time.But the delay time of this integrated circuit (IC) chip is long, has time of delay third gear: 12.3ms, 13.4ms and 24.6ms can supply conversion.Need the design of change delay time.
Above, described delay circuit is an example with two pick-ups, when increase pick-up one by one, during as three pick-ups, delay circuit then, the pre-amplifier output of the 2nd pick-up should be divided into two, the amplification quantity of the every road output circuit all output amplification quantity with the pre-amplifier of the 1st pick-up or the 3rd pick-up is the same, time of the 1st pick-up circuit time-delay is equaled the delay time of the 1st pick-up to the 2 pick-ups, road signal with the output of the 2nd pick-up enters the common mode inhibition circuit jointly then, extract and look into the mould signal, again difference mode signal is postponed, equal time of delay from the time of delay of the 2nd pick-up to the 3 pick-ups, another road output signal of the 2nd pick-up is postponed, equal time of delay from the time of delay of the 2nd pick-up to the 3 pick-ups, the signal after another road process delay and the signal of the 3rd pick-up output are advanced people's common mode inhibition circuit jointly, extract difference mode signal, to enter common-mode signal suppression circuit jointly through the 1st pick-up after the time-delay and the difference mode signal between the difference mode signal between the 2nd pick-up and the 2nd pick-up and the 3rd pick-up again, extract difference mode signal.When having four pick-ups, can be to subtract each other the time of delay of the 1st pick-up and the time of delay of the 2nd pick-up, after postpone again, subtract each other the time of delay of the time of delay of the 3rd pick-up and the 4th pick-up, signal after delaying time the 1st and the 2nd again and the 3rd and the 4th signal subtraction.
The utility model can be with reference to the list of references in following reference book and the book: " active filter precise design handbook " (D.E.JOHNSON, J.R.JOHNSON, AND H.P.MOORE New Jersey 1980 Li Guorongs translate Electronic Industry Press in March, 1984), " active filter " (China Railway Press's in October, 1979 front page is compiled by telecommunications system of Northern Transportation University), " Hi-Fi audio device handbook " (the KTK audiovisual studio is write Sichuan Province science tech publishing house in March, 1992 Chengdu front page.Can adopt various principles and algorithm and the circuit theory described in the list of references in the book neutralization book as required.Concrete circuit and application circuit can change according to concrete application purpose.
Below, illustrate that microphone of the present utility model receives the principle of the low environment noise sound that nearest source of sound sends.The voice signal sound that source of sound sends can only be to enter microphone from an end, utilize two pick-ups to receive, carrying out signal delay with digital circuit, to make the voice signal phase difference that successively receives be 180 degree or 0 degree, two voice signals that pick-up receives, extract difference mode signal by digital common mode inhibition, deliver to D/A output then, or output to computer.
Below, illustrate that microphone of the present utility model can determine that sound source arrives the principle of microphone distance.Utilize two pick-ups to receive the voice signal that source of sound sends, add digital filtering method with postponing to add common mode inhibition, leach the voice signal of a pick-up reception in two pick-ups and each sound wave in the difference mode signal respectively, each sound wave of the same waveform as that the same time receives in right latter two voice signal carries out the comparison of watt level, calculate big or small ratio between the two, both ratio tables of voice signal that contrast is sent according to the source of sound of certain distance practical measurement or that calculate just can be known the source of sound that sends this sound wave and the actual range of microphone.In fact can almost completely extract the sound that sends at the source of sound with a certain distance from microphone this moment.If but on this distance when having a plurality of sources of sound to sound signal, the directional microphone cover that just can only rely on microphone to install additional is previously roughly distinguished.
Below, illustrate that microphone of the present utility model can eliminate the principle of most noises.Utilization is provided with three above pick-ups and receives the voice signal that source of sound sends in a microphone, earlier add common mode inhibition and take out difference mode signal between per two pick-ups with delay, use digital filtering method then, leach each sound wave in the voice signal in the two-way difference mode signal respectively, each sound wave of the same waveform as of the same time reception in the two-way difference mode signal carries out the comparison of watt level then, calculate big or small ratio between the two, both ratio tables of voice signal that contrast is sent according to the source of sound of certain distance practical measurement or that calculate just can be known the source of sound that sends this sound wave and the actual range of microphone.In same microphone three or three above pick-ups of this utilization receive the method that voice signal that source of sound sends is handled, and are actually the sound that will send from the nearest source of sound of microphone and extract, and environmental noise almost completely can be eliminated.Because by postponing to add the difference mode signal between two pick-ups of common mode inhibition taking-up, therefore the voice signal that sends from the nearest source of sound of microphone in this difference mode signal is the strongest, and the voice signal that the distant environmental noise source of sound of distance sends is just very weak, by filter difference mode signal is carried out filtering, even the acoustic signals of the same frequency that two sources of sound can not be sent distinguishes, because this moment the environmental noise signal to compare difference very big with the voice signal that send in the keynote source, even superposeed the environmental noise signal in the voice signal that send in the keynote source, also very low to the voice signal influence that send in the keynote source, so that can ignore fully, this is to be to be beyond one's reach with other method.This method can determine that also sound source arrives the microphone distance
Figure 29 a and 29b are respectively the end view and the front views of the structure of location receiving system.
The microphone 25,27,28 of location receiving system is a mid point 29 from jointing, connects by the linking arm 30,32,33 that stretches out to the outside respectively.Stretch out linking arm 31 forward or backward from mid point 29 and connect microphone 26, outwardly directed three microphone linking arms 30,32,33 can be isometric.If not isometric, then each location reception microphone is on scalene three summits exactly.These three microphones distance each other can be adjusted according to the source of sound of required reception and the distance between the microphone, but distance between each microphone and position should relative fixed, if change, the computational methods of the digital processing program of the voice signal that microphone receives are carried out in corresponding change simultaneously later on.Spendable above-mentioned microphone of the present utility model in the receiving system of this location.When using as above-mentioned when having the microphone of directional microphone cover, because laterally reaching the perpendicular positioning precision must be decided by the positioning accuracy of microphone cover itself, the longitudinal separation precision can decide by the calculating of central processing unit, and the positioning accuracy of the directional microphone cover of mechanical structure is not too high, so the direction positioning accuracy of this microphone is weaker a little.When using two this microphones, the positioning accuracy in these two microphone orientations can decide by the calculating of central processing unit, but not the positioning accuracy in the orientation will be decided by the positioning accuracy of the directional microphone cover of mechanical structure.When using three this microphones that are triangularly arranged, the positioning accuracy in the microphone orientation can decide by the calculating of central processing unit, and the front and back positioning accuracy will be decided by the positioning accuracy of the directional microphone cover of mechanical structure.Equally, when using more than three, promptly a plurality of above-mentioned microphones of the present utility model are pressed the space array configuration, and the positioning accuracy on three dimensions can decide by the calculating of central processing unit.
Utilize the microphone that the structure of certain space array configurations is arranged more than three to position the handling process of reception, carry out two voice signals that pick-ups reception source of sound sends in each microphone respectively, with postponing to add digital filtering method, leach each sound wave in the voice signal that two pick-ups receive respectively, each sound wave of the same waveform as that the same time receives in the voice signal that right latter two pick-up receives carries out the comparison of watt level, calculate big or small ratio between the two, contrast is according to both ratio tables of voice signal that the source of sound of certain distance practical measurement or that calculate sends, and just can know the source of sound that sends this sound wave and the actual range of microphone.At this moment, in fact can almost completely extract the sound that sends at source of sound from the microphone minimum distance.To locate the identical sound wave of waveform that each microphone receives in the microphone that has certain space array configurations structure more than three in the receiving system again and carry out the comparison that each microphone receives apart from difference, contrast is according to each microphone relative position of practical measurement, calculates this ratio and just can know the source of sound that sends this sound wave and the concrete relative position of microphone.
The utility model can be with reference to the list of references in following reference book and the book: " sonar signal processing-principle and equipment " (Li Guibin that afterwards improves oneself write Maritime Press in December, 1986) " digital filter analysis and design " (A. Anthony work Cheng Xiangjun translates Shaanxi science tech publishing house in April, 1984 front page) " signal, system and the signal processing first volume, volume two " (Wu Xiangqi writes Electronic Industry Press's in August, 1996 front page).Can adopt various principles and algorithm and the circuit theory described in the list of references in the book neutralization book as required.Concrete circuit and application circuit and algorithm can change according to concrete application purpose.
Above, with reference to each accompanying drawing, describe most preferred embodiment of the present utility model in detail, still, should not think that the utility model only only limits to each above-mentioned embodiment.Those skilled in the art, inspiration by the various embodiments described above, be not difficult low-distortion and low-noise microphone of the present utility model is made various improvement, change or replacement, therefore, these improvement, change or replacement, should not think to have broken away from design of the present utility model, or appended claims book institute restricted portion.
Claims (24)
1, a kind of low-distortion and low-noise microphone, possess a shell is arranged, be arranged at a plurality of pick-ups in the above-mentioned shell, and the common-mode signal suppression circuit that is used to abate the noise, it is characterized in that above-mentioned shell only has and has through hole at position facing one direction, and be provided with a plurality of above-mentioned pick-ups in the enclosure, with above-mentioned each pick-up relative set delay circuit, thereby receive the acoustical signal that same sound source signal obtains, output low noise signal according to above-mentioned each pick-up.
2, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned a plurality of pick-up series connection are fixed in the pick-up sleeve pipe, have sound wave near the above-mentioned casing wall the receiving terminal of above-mentioned pick-up and enter window.Above-mentioned pick-up sleeve pipe is fixed in the shell.
3, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned a plurality of pick-ups are fixing with the series connection of pick-up bearing respectively, and above-mentioned bearing has sound wave sound through hole.
4, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned a plurality of pick-up series connection are fixing in the enclosure.
According to claim 2 or 3 described low-distortion and low-noise microphones, it is characterized in that 5, above-mentioned a plurality of pick-ups have the 1st pick-up and the 2nd pick-up at least, the above-mentioned the 1st with the receiving terminal of the 2nd pick-up towards identical.
According to claim 2 or 3 described low-distortion and low-noise microphones, it is characterized in that 6, above-mentioned a plurality of pick-ups have the 1st pick-up and the 2nd pick-up at least, the above-mentioned the 1st and the receiving terminal of the 2nd pick-up towards on the contrary.
7, low-distortion and low-noise microphone according to claim 1, it is characterized in that, above-mentioned a plurality of pick-up parallel connections are fixed in the sleeve pipe of pick-up, have sound wave near the above-mentioned pick-up casing wall the receiving terminal of above-mentioned pick-up and enter window, and above-mentioned pick-up sleeve pipe is fixed in the shell.
8, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned a plurality of pick-up parallel connections are fixed in the shell.The receiving terminal centre that arrives above-mentioned pick-up from the sound through hole has channel of acoustic wave.
9, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned a plurality of pick-ups are fixed in the shell by shockproof bearing parallel connection, and above-mentioned bearing has sound wave sound passage.
According to each described low-distortion and low-noise microphone of claim 1 to 9, it is characterized in that 10, above-mentioned shell only has through hole on position facing one direction.
11, arrive described low-distortion and low-noise microphone according to claim 7 or 8, it is characterized in that, the position of described sound through hole is on shell position facing one direction, on the extended line of the connecting line of the intersection point of two pick-up axis extended lines arranged side by side and microphone cover protecgulum and this connecting line, and with the perpendicular line segment of this connecting line on.
According to claim 7 or 8 described low-distortion and low-noise microphones, it is characterized in that 12, above-mentioned a plurality of pick-ups have the 1st pick-up and the 2nd pick-up at least, the above-mentioned the 1st with the receiving terminal of the 2nd pick-up towards identical.
According to claim 7 or 8 described low-distortion and low-noise microphones, it is characterized in that 13, above-mentioned a plurality of pick-ups have the 1st pick-up and the 2nd pick-up at least, the above-mentioned the 1st and the receiving terminal of the 2nd pick-up towards on the contrary.
14, according to claim 7 or 8 described low-distortion and low-noise microphones, it is characterized in that, be provided with in the protecgulum of above-mentioned shell sound by the pipe, its minute tube opening be positioned at the top of pick-up receiving terminal.
15, low-distortion and low-noise microphone according to claim 1 is characterized in that, from sound arrives the way of sound receiving terminal of each pick-up by the hole channel of acoustic wave is arranged.
16, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned delay circuit, common-mode signal suppression circuit are to connect adder circuit by delay circuit to constitute.
17, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned delay circuit, common-mode signal suppression circuit are to connect subtraction circuit by delay circuit to constitute.
18, low-distortion and low-noise microphone according to claim 1 is characterized in that, above-mentioned delay circuit, common-mode signal suppression circuit are to constitute by connecting delay circuit, phase-shift circuit and adder circuit successively.
19, low-distortion and low-noise microphone according to claim 1, it is characterized in that, above-mentioned delay circuit, common-mode signal suppression circuit be by connect delay circuit, mould/number conversion circuit successively, central processing unit carries out the common mode inhibition computing and the D/A switch circuit constitutes.
20, low-distortion and low-noise microphone according to claim 16 is characterized in that, above-mentioned delay circuit, common-mode signal suppression circuit be before adder, be provided with preamplifying circuit.
21, low-distortion and low-noise microphone according to claim 17 is characterized in that, above-mentioned delay circuit, common-mode signal suppression circuit are to be provided with preamplifying circuit before subtracter.
According to claim 16 or 17 described low-distortion and low-noise microphones, it is characterized in that 22, above-mentioned delay circuit, common-mode signal suppression circuit are to be made of delay circuit and digital common-mode signal suppression circuit.
23, according to each described low-distortion and low-noise microphone of claim 16 to 22, it is characterized in that above-mentioned delay circuit is a low pass constant delay filter, the logical constant delay filter of band, high pass constant delay filter, all-pass filter, active feedback amplifier all-pass filter, the switching capacity filter all-pass filter, the equalization filter circuit, Qiu's equalization filter circuit now not, low pass constant delay filter circuit with equalizer, the delay circuit of bucket chain delay circuit (BBD) and charge-coupled device (CCD), and independent digital delay circuit.
According to each described low-distortion and low-noise microphone of claim 16 to 22, it is characterized in that 24, above-mentioned filter delay circuit is the multi-stage filter circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 97220840 CN2303418Y (en) | 1997-07-25 | 1997-07-25 | Low distortion and low noise mouth-piece |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 97220840 CN2303418Y (en) | 1997-07-25 | 1997-07-25 | Low distortion and low noise mouth-piece |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2303418Y true CN2303418Y (en) | 1999-01-06 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 97220840 Expired - Lifetime CN2303418Y (en) | 1997-07-25 | 1997-07-25 | Low distortion and low noise mouth-piece |
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| Country | Link |
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| CN (1) | CN2303418Y (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101848288A (en) * | 2010-04-19 | 2010-09-29 | 北京东微世纪科技有限公司 | Simulation noise reduction system and method for microphone |
| CN102395066A (en) * | 2011-11-10 | 2012-03-28 | 中兴通讯股份有限公司 | Microphone device capable of conducting adapterization from long distance |
| CN104361893A (en) * | 2014-10-24 | 2015-02-18 | 江西创成电子有限公司 | Mobile phone noise reduction device and noise reduction method thereof |
| CN108419159A (en) * | 2017-02-09 | 2018-08-17 | 钰太芯微电子科技（上海）有限公司 | The vehicle-mounted direction pickup apparatus of one kind and its automobile |
| CN111223254A (en) * | 2018-11-23 | 2020-06-02 | 无锡科晟光子科技有限公司 | Sound alarm sensor with high accuracy |
-
1997
- 1997-07-25 CN CN 97220840 patent/CN2303418Y/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101848288A (en) * | 2010-04-19 | 2010-09-29 | 北京东微世纪科技有限公司 | Simulation noise reduction system and method for microphone |
| CN102395066A (en) * | 2011-11-10 | 2012-03-28 | 中兴通讯股份有限公司 | Microphone device capable of conducting adapterization from long distance |
| CN102395066B (en) * | 2011-11-10 | 2018-05-01 | 中兴通讯股份有限公司 | A kind of microphone apparatus of remote pickup |
| CN104361893A (en) * | 2014-10-24 | 2015-02-18 | 江西创成电子有限公司 | Mobile phone noise reduction device and noise reduction method thereof |
| CN108419159A (en) * | 2017-02-09 | 2018-08-17 | 钰太芯微电子科技（上海）有限公司 | The vehicle-mounted direction pickup apparatus of one kind and its automobile |
| CN111223254A (en) * | 2018-11-23 | 2020-06-02 | 无锡科晟光子科技有限公司 | Sound alarm sensor with high accuracy |
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