CN102547520A - Capacitance microphone, and control system and control method for capacitance microphone - Google Patents
Capacitance microphone, and control system and control method for capacitance microphone Download PDFInfo
- Publication number
- CN102547520A CN102547520A CN2010106025432A CN201010602543A CN102547520A CN 102547520 A CN102547520 A CN 102547520A CN 2010106025432 A CN2010106025432 A CN 2010106025432A CN 201010602543 A CN201010602543 A CN 201010602543A CN 102547520 A CN102547520 A CN 102547520A
- Authority
- CN
- China
- Prior art keywords
- electric capacity
- distance
- signal
- face
- pad
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention relates to a capacitance microphone, and a control system and a control method for the capacitance microphone. The microphone comprises a capacitor and an output device, wherein the capacitor consists of two polar plates, and receives an acoustical signal; and the output device outputs an audio signal. The control system comprises a distance detection device, a control device and a power supply device, wherein the distance detection device detects a distance between the polar plate surfaces of the two polar plates of the capacitor, and transmits the distance to the control device; the control device compares the distance between the polar plate surfaces with a standard distance to generate a distance difference, generates a control signal corresponding to the distance difference, and transmits the control signal to the power supply device; the power supply device transmits an electrical signal to any polar plate of the capacitor according to the control signal to change voltage between the two polar plates of the capacitor and make the polar plate receiving the electrical signal move along a direction vertical to the polar plate surface of the other polar plate so as to change the distance between the polar plate surfaces of the two polar plates of the capacitor into the standard distance; and the standard distance is shorter than a critical standard between the polar plate surfaces of the two polar plates of the capacitor. By the technical scheme, the capacitor can work in a supercritical state.
Description
Technical field
The present invention relates to the microphone field, particularly relate to a kind of Electret Condencer Microphone and control system thereof and control method.
Background technology
In Electret Condencer Microphone, detect the voice signal of input through using the electric capacity that changes with voice signal.Fig. 1 is the structural representation of electric capacity.As shown in Figure 1, electric capacity is made up of two pole plates, and these two pole plates respectively have unique pad-face, and the pad-face of these two pole plates is relative.In use, keep certain spacing 101 to place relatively between two pad-faces, like this, this electric capacity just can store and discharge electric charge.
Fig. 2 is the mechanical structure sketch map of electric capacity.As shown in Figure 2, two pole plates of electric capacity at setovered respectively a certain amount of positive charge or negative electrical charge, be have a bias voltage between pole plate after because the effect of the electrostatic force that electric field produced between pole plate; Two pole plates have the trend of adhesive, simultaneously, because the composition material of pole plate has certain elasticity; Make pole plate that the elastic restoring force of resisting this adhesive arranged again when producing displacement; Displacement is big more, and elastic restoring force is also big more, and this resistance effect can equivalence be a spring; As shown in Figure 2, represent to produce the legend of the equivalent factor of this elastic force with spring 201.
Under the general condition, the elastic restoring force between pole plate is proportional to the displacement size of pole plate.But the size of the electrostatic force attraction between pole plate then be inversely proportional to the pole plate distance square.Therefore, thus the adhesive effect that when between pole plate, exists voltage to produce electrostatic force, and the displacement that pole plate has an adhesive trend produces an elastic restoring force offsetting electrostatic force.When the pole plate displacement reaches critical displacement; If the pole plate displacement continues to increase; The speed that increases greater than elastic restoring force of the speed that increases of electrostatic force then, this moment then elastic force with irresistible this adhesive effect, at this moment; Two pole plates will complete adhesive under the effect of electrostatic force, and the distance 101 between pole plate becomes 0.
Electrostatic force when the displacement of pole plate being reached critical condition here, is called as critical electrostatic force.Among the present invention, the stable state that the electrostatic force between the electric capacity two-plate is equaled critical electrostatic force is called the critical condition of electric capacity, and the distance between the pad-face of the electric capacity two-plate of critical condition is called critical distance; The stable state of electrostatic force subcritical electrostatic force is called the subcritical state of this electric capacity, and the stable state that electrostatic force is higher than critical electrostatic force is called the supercriticality of this electric capacity.
When having certain voltage between the two-plate of electric capacity, because the acting in conjunction of electrostatic force and pole plate elastic restoring force, there is certain relation in the distance between this voltage and two-plate.Fig. 3 is voltage and the graph of a relation of polar plate spacing between capacitor plate.As shown in Figure 3, abscissa is the voltage V between pole plate, the initial separation d when not having voltage between polar plate spacing d and the pole plate of ordinate when stablizing
0Ratio, among Fig. 3, when polar plate spacing d is initial separation d just
02/3rds o'clock, electric capacity is operated in critical condition 301, this moment, the voltage between pole plate reached maximum V
0, will be initial separation d just
02/3rds polar plate spacing be called critical gap; When polar plate spacing d greater than initial separation d
02/3rds o'clock, electric capacity is operated in subcritical state, the relation of voltage is shown in the solid line among the figure between polar plate spacing and pole plate, the elastic force effect that is enough to resist electrostatic force this moment guarantees not adhesive of two-plate; When polar plate spacing d less than initial separation d
02/3rds o'clock; Electric capacity is operated in supercriticality, between polar plate spacing and pole plate the relation of voltage shown in the dotted line among the figure, the elastic force effect that is not enough to resist electrostatic force this moment; Need add strength and act on pole plate, make the two not adhesive and can reach static balancing.Can find out that by Fig. 3 under subcritical state and supercriticality, the voltage between the electric capacity two-plate is all less than maximum V
0, and for each less than V
0Voltage, respectively have an orthostatic spacing d corresponding at supercriticality and subcritical state with it.
Electret Condencer Microphone utilizes electric capacity to receive voice signal; Make pole plate produce vibration; The storage and the blind forwarding that will vibrate then through electric charge are changed to audio signal output; The amplitude and the phase place of the voice signal that the amplitude of this audio signal and phase place receive with electric capacity respectively are directly proportional, and guarantee the output signal of microphone and the corresponding relation between the input signal like this.Simultaneously, microphone needs higher sensitivity, and promptly for given input audio signal, the output signal of microphone is stronger.And the power of Electret Condencer Microphone output signal is relevant with the change in electrical charge amount of microphone electric capacity, and for satisfying the sensitivity demand, the microphone that prior art provides has dual mode to adopt, and first kind of mode is for increasing the voltage between the electric capacity two-plate; The second way perhaps increases the oscillating region of pole plate for reducing the pole plate normal pitch, and to obtain bigger relative vibration, promptly pole plate is with the ratio of voice signal displacement oscillating region and pole plate normal pitch, thereby makes that the intensity of variation of capacitance size is more violent.Above-mentioned dual mode all can make the microphone capacitor plate in this process, store or the quantity of electric charge that discharges bigger, thereby the sensitivity that improves microphone.But; Above-mentioned dual mode all is the restriction that receives the electric capacity operating state; Prior art when manufacturing and designing microphone, requires the working point of its electric capacity to be positioned at subcritical state in order to prevent the two-plate adhesive collision of electric capacity; Promptly no matter whether microphone has the voice signal input; The electric capacity of being made up of two pole plates in the microphone all must be in subcritical state, the initial separation d that the maximum voltage the when voltage between its pole plate must be far smaller than critical condition, polar plate spacing must be when not having electric charge on the pole plate
02/3rds, this has limited the sensitivity of microphone, has also limited the highest signal to noise ratio that capacitance microphone can reach.
Summary of the invention
Topic provides a kind of Electret Condencer Microphone and control system and control method between technology to be solved by this invention, can make electric capacity wherein be operated in supercriticality.
It is following that the present invention solves the technical scheme of inscribing between above-mentioned technology: a kind of control system of Electret Condencer Microphone; Said Electret Condencer Microphone comprises: the electric capacity that is used to receive voice signal that is made up of two pole plates; The output device of output audio signal, this control system comprises: pitch measuring, control device and electric supply installation; Wherein,
Said pitch measuring is used for, and detects the distance between the pad-face of two pole plates of said electric capacity, and sends it to said control device;
Said control device is used for, and the distance between the pad-face of two pole plates of said electric capacity is compared with gauged distance, obtains range difference; Generate and the corresponding control signal of said range difference, and said control signal is sent to said electric supply installation;
Said electric supply installation is used for; According to said control signal, send the signal of telecommunication to the arbitrary pole plate of said electric capacity, this signal of telecommunication is used to change the voltage between two pole plates of said electric capacity; The pole plate that receives this signal of telecommunication is moved along the direction perpendicular to the pad-face of another pole plate; Thereby make the distance between the pad-face of two pole plates of said electric capacity become gauged distance, wherein, said gauged distance is less than the critical distance between the pad-face of two pole plates of said electric capacity.
The invention has the beneficial effects as follows: among the present invention,, supply control device distance to compare with gauged distance because pitch measuring can detect the distance between the pad-face of electric capacity two-plate; Obtain range difference, and generate and the corresponding control signal of this range difference, electric supply installation obtains arbitrary pole plate that the signal of telecommunication exports electric capacity to according to this control signal; Thereby this pole plate can be moved in the direction vertical with the pad-face of another pole plate according to the requirement of the signal of telecommunication, finally make the distance between the pad-face of two-plate become gauged distance; And; This gauged distance is less than the critical distance between the pad-face of two-plate, the polar plate spacing when promptly this gauged distance is operated in critical condition less than electric capacity, therefore; The present invention can make the electric capacity in the microphone be operated in supercriticality; Thereby can obtain higher sensitivity of microphone, bigger microphone capacitance, higher microphone signal to noise ratio.
On the basis of technique scheme, the present invention can also do following improvement:
Further, said electric supply installation is according to said control signal, and the signal of telecommunication that sends to arbitrary pole plate of said electric capacity is current signal or voltage signal.
Further, said pitch measuring comprises probe, an emission current testing circuit, wherein,
Said probe is positioned on the pad-face of arbitrary pole plate of said electric capacity; Distance between the pad-face of the peak of said probe and probe place pole plate is less than the gauged distance between the pad-face of two pole plates of said electric capacity;
Said emission current testing circuit is used for, the relative pole plate of detector probe place pole plate and the field emission current between the said probe; According to said emission current, obtain the distance between the pad-face of two pole plates of said electric capacity.
Further, said pitch measuring comprises two check-out consoles, capacitive detection circuit, wherein,
Said two check-out consoles are positioned on the pad-face of same pole plate of said electric capacity, and the plate face of said two check-out consoles is positioned at same plane and all parallel with the pad-face of self place pole plate; The gross area of the plate face of said two check-out consoles belongs to the area of the pad-face of pole plate less than self;
Said capacitive detection circuit is used for, and detects the electric capacity between said two check-out consoles; According to the capacitance between said two check-out consoles, obtain the distance between the pad-face of two pole plates of said electric capacity.
Further, the whole or part in said electric capacity, pitch measuring, control device, electric supply installation, the output device is positioned on the same integrated circuit; Or said electric capacity, pitch measuring, control device, electric supply installation, output device are different circuits.
Further, arbitrary pole plate of said electric capacity is processed by semi-conducting material.
Further, the bandwidth of the loop of said electric capacity, pitch measuring, control device and electric supply installation formation is less than the bandwidth of said voice signal; Said voice signal changes the distance between the pad-face of two pole plates of said electric capacity; Wherein,
Arbitrary pole plate of said electric capacity sends the output signal of telecommunication to said output device, and the amplitude of the said output signal of telecommunication and said voice signal are directly proportional the variable quantity of distance between the pad-face of said two pole plates;
Said output device is used for, output audio signal, and the amplitude of said audio signal and phase place are directly proportional with the amplitude and the phase place of the said output signal of telecommunication respectively.
Further, the bandwidth of the loop of said electric capacity, pitch measuring, control device and electric supply installation formation is more than or equal to the bandwidth of voice signal; Said voice signal changes the distance between the pad-face of two pole plates of said electric capacity; Wherein,
The amplitude of the audio signal of said output device output and phase place are directly proportional with the amplitude and the phase place of said electric supply installation to the signal of telecommunication of arbitrary pole plate transmission of said electric capacity respectively.
Further, said output device is further used for, and said audio signal is carried out analog-to-digital conversion, obtains digital audio and video signals; Export said digital audio and video signals.
In addition, the invention allows for a kind of Electret Condencer Microphone, this microphone comprises: electric capacity, output device and control system, wherein,
Said electric capacity is made up of two pole plates, is used to receive voice signal;
Said output device is used for output audio signal;
Said control system is above-mentioned any control system.
In addition, the invention allows for a kind of control method of Electret Condencer Microphone, this method comprises:
Electric capacity receives voice signal, and this voice signal changes the distance between the pad-face of two pole plates of said electric capacity; Output device output audio signal, the amplitude of said audio signal and phase place are directly proportional with the amplitude and the phase place of said voice signal respectively;
Detect the distance between the pad-face of two pole plates of said electric capacity, and itself and gauged distance are compared, obtain range difference; Generate and the corresponding control signal of said range difference;
According to said control signal; Arbitrary pole plate to said electric capacity sends the signal of telecommunication; This signal of telecommunication is used to change the voltage between two pole plates of said electric capacity; Thereby make the distance between the pad-face of two pole plates of said electric capacity become gauged distance, wherein, said gauged distance is less than the critical distance between the pad-face of two pole plates of said electric capacity.
Description of drawings
Fig. 1 is the structural representation of electric capacity;
Fig. 2 is the mechanical structure sketch map of electric capacity;
Fig. 3 is voltage and the graph of a relation of polar plate spacing between capacitor plate;
Fig. 4 is the structure chart of the control system of the Electret Condencer Microphone of the present invention's proposition;
Fig. 5 is the structure chart of pitch measuring first embodiment of the present invention's proposition;
Fig. 6 is the structure chart of pitch measuring second embodiment of the present invention's proposition;
Fig. 7 is for being the structure chart of control system first embodiment of Electret Condencer Microphone provided by the invention;
Fig. 8 is for being the structure chart of control system second embodiment of Electret Condencer Microphone provided by the invention;
Fig. 9 is the control method flow chart of Electret Condencer Microphone provided by the invention.
Embodiment
Below in conjunction with accompanying drawing principle of the present invention and characteristic are described, institute gives an actual example and only is used to explain the present invention, is not to be used to limit scope of the present invention.
Fig. 4 is the structure chart of the control system of the Electret Condencer Microphone of the present invention's proposition.As shown in Figure 4; This Electret Condencer Microphone comprises: the electric capacity that is used to receive voice signal that is made up of two pole plates; These two pole plates are shown in the label among Fig. 4 401 and 402, and the output device that is used for output audio signal that does not draw among Fig. 4, in addition; This control system comprises: pitch measuring 403, control device 404, electric supply installation 405; Here, pitch measuring 403, control device 404, electric supply installation 405 and electric capacity can constitute a loop, and this loop can be used for the stable distance between the pad-face of two pole plates of electric capacity at gauged distance; Wherein, the function of each several part is described below:
Pitch measuring 403 is used for, the distance between the pad-face of two pole plates 401,402 of detection electric capacity, and send it to said control device 404;
Here; The electric capacity of being made up of two pole plates 401 and 402 is the employed electric capacity of Electret Condencer Microphone provided by the invention; The pad-face of its two pole plates can be the plane; Can not the plane also, as long as the electric capacity of its composition can be realized function of the present invention, all within protection scope of the present invention.
It is the loop of gauged distance that pitch measuring 403, control device 404, electric supply installation 405 and electric capacity have been formed a control pad-face spacing jointly; This loop can be through degenerative mode; Be implemented under the microphone condition of work; To the control of distance between the pad-face of electric capacity two-plate, reach stable distance between the pad-face that makes two pole plates in the purpose of gauged distance.
Electric capacity in the microphone provided by the present invention; The function of its two pole plates can be exchanged; What promptly receive voice signal can be pole plate 401, also can be pole plate 402, and the pole plate of the signal of telecommunication that the reception electric supply installation provides both can be pole plate 401; Also can be pole plate 402, these situation be all within protection scope of the present invention.
Because concerning an electric capacity, when the certain voltage of biasing between two-plate, a certain amount of positive and negative charge has just distributed on the pad-face of two-plate; Thereby between the two-plate face, form certain electric field, the intensity of this electric field and the orientation independent of bias voltage, and only relevant with the size of bias voltage size and capacitance; Capacitance is big more, and the quantity of electric charge that then distributes on the pad-face of two pole plates is just many more, and electric field is also just strong more; Otherwise capacitance is more little, then electric field also just more a little less than; Therefore; The direction of the voltage of being setovered on two pole plates 401 and 402 among the present invention is not do requirement, still is the 402 upper offset positive voltages negative voltages of still setovering at pole plate 401 no matter promptly, all within protection scope of the present invention.
When voice signal is imported; Can be thereby that pole plate 401 detects sound with the capacitance that voice signal vibrates change electric capacity; Also can be thereby that pole plate 402 detects sound with the capacitance that voice signal vibrates change electric capacity, this dual mode be all within protection scope of the present invention.
Among the present invention, gauged distance is the length less than critical distance between the pad-face of electric capacity two-plate, if the distance between the pad-face of two- plate 401 and 402 is a gauged distance, means that then this electric capacity is operated in supercriticality.Control system among the present invention utilizes above-mentioned loop to guarantee that electric capacity is operated in supercriticality.When the distance between the pad-face of the pad-face of pole plate 401 and pole plate 402 was not equal to gauged distance, control device control electric supply installation 405 produced the signals of telecommunication, is used to change the voltage between two-plate; Thereby the electrostatic force between the change two-plate; Like this, just can control the pole plate that receives the signal of telecommunication, like the pole plate among Fig. 4 401; Being moved, is gauged distance thereby make the range recovery between two- plate 401 and 402.
This shows, among the present invention, because pitch measuring can detect the distance between the pad-face of electric capacity two-plate; Supply control device distance to compare, obtain range difference, and generate and the corresponding control signal of this range difference with gauged distance; Electric supply installation obtains arbitrary pole plate that the signal of telecommunication exports electric capacity to according to this control signal, thereby this pole plate can be moved in the direction vertical with the pad-face of another pole plate according to the requirement of the signal of telecommunication; Finally make the distance between the pad-face of two-plate become gauged distance, and this gauged distance is less than the critical distance between the pad-face of two-plate; Polar plate spacing when promptly this gauged distance is operated in critical condition less than electric capacity; Therefore, the present invention can make the electric capacity in the microphone be operated in supercriticality, thereby can obtain higher sensitivity of microphone; Bigger microphone capacitance, higher microphone signal to noise ratio.
Control system provided by the invention makes electric capacity steady operation that two- plate 401 and 402 constituted in supercriticality, means that the normal operating conditions of this Electret Condencer Microphone works in supercriticality for its electric capacity.And; With respect to the gauged distance between the pad-face of two- plate 401 and 402, the displacement that the pole plate that voice signal is caused the pressure effect of pole plate takes place on the direction perpendicular to pad-face is minimum, almost can ignore; Therefore; Though voice signal acts on pole plate it is subjected to displacement, this displacement is very little for the influence of the working point of the electric capacity of pole plate 401 and 402 compositions, and this electric capacity works in supercriticality always.
Because the present invention can make capacitor plate steady operation in the microphone in supercriticality, therefore, the restriction that the gauged distance among the present invention between two- plate 401 and 402 the pad-face can exceed prior art makes gauged distance less than initial maximum spacing d
02/3rds.And because sensitivity of microphone and this gauged distance are inversely proportional to, therefore, the present invention can effectively improve the sensitivity of microphone.Simultaneously; Under the identical situation of capacitance, because this gauged distance distance between two-plate in the prior art, therefore; The area of pole plate 401 and 402 pad-face can be much smaller than prior art among the present invention, thereby effectively reduces the production cost of Electret Condencer Microphone.
Equally; Because it is constant basically that the present invention can guarantee that the distance between the pad-face of two-plate can remain gauged distance; Therefore, with respect to prior art factors such as the absolute value of the manufacture crafts such as distance of the pad-face of two pole plates, tolerance are required very high, to guarantee the conforming situation of microphone property; The present invention has reduced the requirement to the pole plate manufacture craft, and this has also reduced the production cost of microphone.
The control signal that electric supply installation 405 sends according to control device; Arbitrary pole plate to electric capacity; Be pole plate 401 or 402, the signal of telecommunication of transmission can be voltage signal, also can be current signal; Change the voltage between pole plate 401 and 402 in this way; Can change the electrostatic force between these two pole plates, so just can control the pole plate that receives the signal of telecommunication that electric supply installation 405 sent towards or direction away from the pad-face of another pole plate on be subjected to displacement, thereby make the distance between the pad-face of two-plate become gauged distance.
In practical application, electric supply installation 405 can be both to the pole plate output voltage signal of electric capacity, again to its output current signal, promptly electric supply installation 405 can and be realized the displacement control to pole plate with dual mode.For example, if the spacing between the pad-face of pole plate 401 and 402 surpasses maximum spacing d
02/3rds, promptly electric capacity is in subcritical operating state, makes electric capacity be in the position of overcritical operating state for pole plate is moved to; Electric supply installation 405 can be at first to the pole plate output voltage signal; Make pole plate move to critical localisation gradually, even the spacing between the pad-face of two-plate is a critical distance, electric capacity arrives critical excitation; At this moment, the voltage between the two-plate has also reached the critical voltage V among Fig. 3
0, then, electric supply installation 405 switches to current signal to the signal of telecommunication of pole plate output; Continue to make the pole plate displacement, be decreased to gauged distance gradually thereby make shown in the dotted line of distance in Fig. 3 between the pad-face of two-plate, in this process; Voltage between the two-plate is also reducing gradually; Finally, electric supply installation 405 is controlled pole plate and is moved to the position that makes electric capacity reach overcritical operating state through to pole plate output voltage signal and current signal.Here the voltage signal that said reception electric supply installation 405 sends and the pole plate of current device can be arbitrary pole plate of electric capacity.
Among the present invention, the pitch measuring 403 that detects distance between the pad-face of two- plate 401 and 402 can have multiple implementation.
Fig. 5 is the structure chart of pitch measuring first embodiment of the present invention's proposition.As shown in Figure 5, this pitch measuring comprises probe 501, an emission current testing circuit 502, wherein,
Probe 501 is positioned on the pad-face of arbitrary pole plate of electric capacity; Distance between the pad-face of the peak of probe 501 and this probe place pole plate is less than the gauged distance between the pad-face of two pole plates of electric capacity;
Field emission current testing circuit 502 is used for, the relative pole plate of detector probe place pole plate and the field emission current between the probe 501; According to the field emission current, obtain the distance between the pad-face of two pole plates of electric capacity.
Here, probe 501 can be conductive devices, and its current potential is identical with the current potential of the pad-face of its place pole plate.
The existence of voltage between two pole plates of electric capacity; Can between the relative pole plate of probe tip and probe place pole plate, produce an emission current; The size of this emission current be and probe and above-mentioned relative pole plate between distance have known exponential relationship; Through measuring the size of this emission current, can obtain the distance between the relative pole plate of probe tip and its place pole plate, thereby utilize the probe tip height of the pad-face of its place pole plate relatively; And the distance between the relative pole plate of probe tip and its place pole plate, detect the distance between the pad-face that obtains two-plate.
Among the checkout gear embodiment shown in Figure 5, probe 501 can be more than one probe, and a plurality of probes are set, and can increase the reliability of this distance detection device.
Fig. 6 is the structure chart of pitch measuring second embodiment of the present invention's proposition.As shown in Figure 6, this pitch measuring comprises two check-out consoles 601 and 602, capacitive detection circuit 603, wherein,
Check-out console 601 and 602 is positioned on the pad-face of same pole plate of electric capacity, and two check-out consoles 601 and 602 plate face are positioned at same plane and all parallel with the pad-face of self place pole plate; The gross area that two check-out consoles 601 and 602 plate face are covered is less than the area of the pad-face of self place pole plate;
Capacitive detection circuit 603 is used for, and detects the electric capacity between two check-out consoles 601 and 602; According to the capacitance between two check-out consoles 601 and 602, obtain the distance between the pad-face of two pole plates of electric capacity.
Among the present invention; Because two check-out consoles 601 belong to the area of the pad-face of pole plate with the gross area that 602 plate face is covered less than self; Therefore, two check-out consoles 601 and 602 existence can not influence the function of sound detection of two electric capacity that pole plate constituted of electric capacity.
Two check-out consoles 601 and 602 are formed a new check-out console to electric capacity; This check-out console has known exponential relationship to the distance between the pad-face of the capacitance of electric capacity and pole plate 401 and 402; Through detecting the capacitance of this check-out console, can determine the distance between the pad-face of pole plate 401 and 402 to electric capacity.
The control system of Electret Condencer Microphone provided by the invention can make the electric capacity steady operation in supercriticality, and with respect to prior art, the oscillating region of the pole plate in its electric capacity has enlarged, thereby is with a wide range of applications.
Further, among the present invention, arbitrary pole plate of electric capacity, promptly pole plate 401 and/or 402 can be processed by semi-conducting material, is for example processed by semi-conducting materials such as silicon.
Fig. 7 is for being the structure chart of control system first embodiment of Electret Condencer Microphone provided by the invention.As shown in Figure 7, this microphone comprises: the electric capacity that is used to receive voice signal, output device 706, pitch measuring 703, control device 704, the electric supply installation 705 be made up of two pole plates 701 and 702.Wherein, Electric capacity and pitch measuring 703, control device 704, electric supply installation 705 are formed a loop; And the bandwidth of this loop is less than the bandwidth of voice signal, and voice signal can make two pole plates 701 of electric capacity and the distance between 702 the pad-face change; Loop wherein is used for, when microphone is worked, with the stable distance between the pad-face of two pole plates in the electric capacity at gauged distance;
Voice signal makes the arbitrary pole plate in the electric capacity be subjected to displacement in the direction perpendicular to its pad-face; Arbitrary pole plate of electric capacity sends the output signals of telecommunication to output device 706, and the amplitude of this output signal of telecommunication and voice signal are directly proportional the variable quantity of distance between the pad-face of two pole plates;
Pitch measuring 703 is used for, and detects two pole plates 701 of electric capacity and the distance between 702 the pad-face, and this distance is sent to control device 704;
Here, arbitrary pole plate of electric capacity may be used to receive voice signal, and with this voice signal vibration; Thereby change the distance between the pad-face of electric capacity two-plate, and therefore change the capacitance of electric capacity, like this; The positive and negative charge that is distributed on the pad-face of electric capacity two-plate also will correspondingly increase or reduce; Thereby on arbitrary pole plate of electric capacity, form a signal, this signal can be delivered to output device 706, supplies its output audio signal.
Loop among Fig. 7 is used for guaranteeing that the spacing of the pad-face of electric capacity two-plate is continuously the gauged distance less than critical distance; Thereby steady operation is in supercriticality; Like this; Utilize the Electret Condencer Microphone of control system shown in Figure 7 that excellent more performance can be provided, perhaps under the prerequisite that has with the identical performance of prior art, have lower cost.
As shown in Figure 7, thus electric capacity makes arbitrary pole plate at the reception voice signal, like pole plate 701, after being subjected to displacement, can will export the signal of telecommunication by pole plate 702 and send to output device 706, thus output audio signal.Since voice signal bandwidth be higher than the bandwidth of loop; Thereby audio signal bandwidth also just is higher than the loop bandwidth of loop; Like this; On this signal paths of this microphone output, do not form closed loop to the audio signal that produces from this microphone of voice signal input, this is an open cycle system.
Be that pole plate 702 sends the output signal of telecommunication to output device among Fig. 7, equally also can send the output signal of telecommunication to output device by pole plate 701, the intensity of this output signal of telecommunication is directly proportional with the displacement of the pole plate of electric capacity with the voice signal vibration.In this case, the function of remaining device is constant, equally also can make electric capacity be operated in supercriticality, reaches the object of the invention.
Fig. 8 is for being the structure chart of control system second embodiment of Electret Condencer Microphone provided by the invention.As shown in Figure 8; This microphone comprises: the electric capacity that is used to receive voice signal, pitch measuring 803, control device 804, electric supply installation 805 and the output device 806 that are made up of two pole plates 801 and 802; Wherein, Electric capacity and pitch measuring 803, control device 804, electric supply installation 805 have constituted a loop, and the bandwidth of this loop is more than or equal to the bandwidth of voice signal; Wherein,
The voice signal that electric capacity receives make arbitrary pole plate with the perpendicular direction generation audio frequency error displacement of pad-face, thereby the distance between the pad-face of two pole plates of electric capacity is changed; The amplitude of the audio signal of output device 806 outputs and phase place are directly proportional with the amplitude and the phase place of electric supply installation 805 to the signal of telecommunication of arbitrary pole plate transmission of electric capacity respectively.
Like this, above-mentioned loop just can generate and the corresponding control signal of this audio frequency error displacement, thereby the distance that arbitrary pole plate of electric capacity is moved between the pad-face that satisfies two-plate is the position of the condition of gauged distance; Specifically:
Pitch measuring 803 is used for, and detects two pole plates 801 of electric capacity and the distance between 802 the pad-face, and sends it to control device 804;
Like this; No matter be to power up in the process of charging electric charge at electric capacity; Still receive in the process of voice signal at electric capacity, arbitrary pole plate of electric capacity can send to the signal of telecommunication of self according to electric supply installation 805, is subjected to displacement in the direction vertical with the pad-face of another pole plate; Thereby make the distance between the pad-face of two-plate become gauged distance, this gauged distance is less than the critical distance between the pad-face of two-plate.
In the present embodiment, the bandwidth of loop means that more than or equal to the bandwidth of voice signal the reaction speed of this loop is not less than the speed of capacitor plate with the voice signal vibration; Therefore, when under the effect of pole plate at voice signal certain displacement taking place, loop can carry out feedback modifiers to it immediately; Making the range recovery between the pad-face of two-plate is gauged distance; Like this, with respect to embodiment shown in Figure 7, the resume speed of pole plate is faster in the present embodiment.
Different with the position of output device among Fig. 7, among the embodiment shown in Figure 8, the control signal that electric supply installation 805 utilizes control device 804 to provide; Arbitrary pole plate to electric capacity like pole plate 801, provides the signal of telecommunication; Carrying out displacement to control this pole plate, is gauged distance thereby make the range recovery between the pad-face of pole plate and 802, simultaneously; With this signal of telecommunication,, send to output device 806 again with the form of voltage signal or current signal; With the audio signal that makes output device 806 output amplitudes and phase place be directly proportional with the amplitude and the phase place of the signal of telecommunication respectively, thereby realize audio output function.Like this, voice signal is received by electric capacity, causes the displacement of its pole plate; Thereby changed the distance between the pad-face of pole plate 801 and 802, pitch measuring 803 detects after this distance, and it is offered control device 804; By control device 804 itself and gauged distance are compared, produce and the corresponding control signal of range difference, this control signal is just fed back to arbitrary pole plate of electric capacity by electric supply installation 805; Control it and be subjected to displacement, it is gauged distance that this displacement can make the range recovery between the pad-face of two-plate, simultaneously; Output device 806 is output intensity and the audio signal that the intensity of control signal is directly proportional also, this shows, from this microphone of voice signal input; To output device 806 output audio signals, this is a closed loop, thereby this microphone is the closed loop audio output system.
Among the embodiment shown in Figure 8; Arbitrary pole plate of electric capacity is with the displacement of voice signal generation audio frequency error; Its principle is the pressure that pole plate receives voice signal, and in the direction generation audio frequency error displacement vertical with pad-face, and the displacement of this audio frequency error displacement is directly proportional with the pressure of voice signal.
Among two embodiment that Fig. 7 and Fig. 8 provide; The static displacement scope of pole plate is far longer than prior art; Therefore, under the situation of the intensity generation unit change of voice signal, the Strength Changes of these two audio signals that embodiment exported is much larger than prior art; Under the constant situation of outside noise, the present invention has improved the signal to noise ratio of microphone greatly.
Among these two embodiment of Fig. 7 and Fig. 8; Whole or part in electric capacity, pitch measuring, control device, electric supply installation, the output device can be positioned on the same integrated circuit; Also can discretely be provided with, promptly electric capacity, pitch measuring, control device, electric supply installation, output device are different circuits.
In the embodiment shown in fig. 7, voice signal causes the pole plate vibration, and the scope of vibration is less than gauged distance, thereby this vibration can not influence the work of whole microphone.Equally; Among the embodiment shown in Figure 8; Because the feedback effect of loop is very fast, thereby the audio frequency error displacement of the caused pole plate of voice signal is littler than the Oscillation Amplitude among Fig. 7 embodiment, like this; The audio frequency error displacement of pole plate is also less than gauged distance, and this audio frequency error displacement can not influence the work of microphone yet.
In addition, the invention allows for a kind of Electret Condencer Microphone, this microphone comprises: electric capacity, output device and control system, wherein,
Said electric capacity is made up of two pole plates, is used to receive voice signal;
Said output device is used for output audio signal;
Said control system is above-mentioned control system.
This shows, in this microphone, the electric capacity that is used for receiving voice signal that constitutes by two pole plates; Received the control of control system, can steady operation in supercriticality, make two distances between pole plate remain gauged distance less than critical distance between pole plate; Therefore, with respect to microphone of the prior art, Electret Condencer Microphone provided by the invention has higher sensitivity of microphone; Bigger microphone capacitance, higher microphone signal to noise ratio.
Fig. 9 is the control method flow chart of Electret Condencer Microphone provided by the invention.As shown in Figure 9, this method comprises:
Step 901: electric capacity receives voice signal, and this voice signal changes the distance between the pad-face of two pole plates of electric capacity; Output device output audio signal, the amplitude of audio signal and phase place are directly proportional with the amplitude and the phase place of voice signal respectively.
Step 902: detect the distance between the pad-face of two pole plates of electric capacity, and itself and gauged distance are compared, obtain range difference; Generate and the corresponding control signal of range difference.
Step 903: according to control signal; Arbitrary pole plate to electric capacity sends the signal of telecommunication; This signal of telecommunication is used to change the voltage between two pole plates of electric capacity; Thereby make the distance between the pad-face of two pole plates of electric capacity become gauged distance, wherein, gauged distance is less than the critical distance between the pad-face of two pole plates of electric capacity.
Sequencing on each step in this method is not free; Step 901 can be carried out with step 902,903 simultaneously; Thereby make when electric capacity receives voice signal, output device output audio signal; Carry out the pad-face spacing and detect, generate control signal and utilize control signal to send the signal of telecommunication, thereby make the pad-face spacing revert to gauged distance, realize that finally the electric capacity steady operation is in supercriticality.
This shows that the present invention has the following advantages:
(1) among the present invention,, supply control device distance to compare with gauged distance because pitch measuring can detect the distance between the pad-face of electric capacity two-plate; Obtain range difference, and generate and the corresponding control signal of this range difference, electric supply installation obtains arbitrary pole plate that the signal of telecommunication exports electric capacity to according to this control signal; Thereby this pole plate can be moved in the direction vertical with the pad-face of another pole plate according to the requirement of the signal of telecommunication, finally make the distance between the pad-face of two-plate become gauged distance; And; This gauged distance is less than the critical distance between the pad-face of two-plate, the polar plate spacing when promptly this gauged distance is operated in critical condition less than electric capacity, therefore; The present invention can make the electric capacity in the microphone be operated in supercriticality; Thereby can obtain higher sensitivity of microphone, bigger microphone capacitance, higher microphone signal to noise ratio.
(2) because the present invention can guarantee that electric capacity steady operation in the microphone is in supercriticality; Therefore; The quiescent point of the electric capacity among the present invention is very stable; The displacement of pole plate can exceed the restriction of prior art, and the spacing of pad-face that makes two-plate is less than 2/3rds of initial maximum spacing, and the present invention can effectively improve the sensitivity of microphone.
(3) because the present invention can guarantee that the stable distance between the pad-face of two-plate is that gauged distance is constant basically; Therefore; Under the identical prerequisite of the capacitance of electric capacity; The area of the pad-face of two-plate can be much smaller than prior art among the present invention, thereby effectively reduces the production cost of Electret Condencer Microphone.
(4) among the present invention, the probe in the pitch measuring can be more than one probe, thereby improves reliability of the present invention.
(5) must improve the mode of sensitivity of microphone through the mode that improves the pole plate manufacture craft, reduces mismachining tolerance with respect to prior art; Among the present invention; The sensitivity of microphone can improve through electrical way; Thereby reduced requirement to the pole plate manufacture craft, also simplified the method that improves sensitivity of microphone simultaneously.
(6) in the prior art; Electric capacity in the microphone is operated in subcritical state, thereby the power of the audio signal of its output is less, and the present invention has then significantly improved the power of output audio signal on the microphone capacitor plate; Therefore, the present invention is with a wide range of applications.
The above is merely preferred embodiment of the present invention, and is in order to restriction the present invention, not all within spirit of the present invention and principle, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (11)
1. the control system of an Electret Condencer Microphone; Said Electret Condencer Microphone comprises: the electric capacity that is used to receive voice signal that is made up of two pole plates; The output device of output audio signal is characterized in that, this control system comprises: pitch measuring, control device and electric supply installation; Wherein,
Said pitch measuring is used for, and detects the distance between the pad-face of two pole plates of said electric capacity, and sends it to said control device;
Said control device is used for, and the distance between the pad-face of two pole plates of said electric capacity is compared with gauged distance, obtains range difference; Generate and the corresponding control signal of said range difference, and said control signal is sent to said electric supply installation;
Said electric supply installation is used for; According to said control signal, send the signal of telecommunication to the arbitrary pole plate of said electric capacity, this signal of telecommunication is used to change the voltage between two pole plates of said electric capacity; The pole plate that receives this signal of telecommunication is moved along the direction perpendicular to the pad-face of another pole plate; Thereby make the distance between the pad-face of two pole plates of said electric capacity become gauged distance, wherein, said gauged distance is less than the critical distance between the pad-face of two pole plates of said electric capacity.
2. control system according to claim 1 is characterized in that, said electric supply installation is according to said control signal, and the signal of telecommunication that sends to arbitrary pole plate of said electric capacity is current signal or voltage signal.
3. control system according to claim 1 and 2 is characterized in that, said pitch measuring comprises probe, an emission current testing circuit, wherein,
Said probe is positioned on the pad-face of arbitrary pole plate of said electric capacity; Distance between the pad-face of the peak of said probe and probe place pole plate is less than the gauged distance between the pad-face of two pole plates of said electric capacity;
Said emission current testing circuit is used for, the relative pole plate of detector probe place pole plate and the field emission current between the said probe; According to said emission current, obtain the distance between the pad-face of two pole plates of said electric capacity.
4. control system according to claim 1 and 2 is characterized in that, said pitch measuring comprises two check-out consoles, capacitive detection circuit, wherein,
Said two check-out consoles are positioned on the pad-face of same pole plate of said electric capacity, and the plate face of said two check-out consoles is positioned at same plane and all parallel with the pad-face of self place pole plate; The gross area of the plate face of said two check-out consoles belongs to the area of the pad-face of pole plate less than self;
Said capacitive detection circuit is used for, and detects the electric capacity between said two check-out consoles; According to the capacitance between said two check-out consoles, obtain the distance between the pad-face of two pole plates of said electric capacity.
5. control system according to claim 1 and 2 is characterized in that, the whole or part in said electric capacity, pitch measuring, control device, electric supply installation, the output device is positioned on the same integrated circuit; Or said electric capacity, pitch measuring, control device, electric supply installation, output device are different circuits.
6. control system according to claim 1 and 2 is characterized in that, arbitrary pole plate of said electric capacity is processed by semi-conducting material.
7. control system according to claim 1 is characterized in that, the bandwidth of the loop that said electric capacity, pitch measuring, control device and electric supply installation constitute is less than the bandwidth of said voice signal; Said voice signal changes the distance between the pad-face of two pole plates of said electric capacity; Wherein,
Arbitrary pole plate of said electric capacity sends the output signal of telecommunication to said output device, and the amplitude of the said output signal of telecommunication and said voice signal are directly proportional the variable quantity of distance between the pad-face of said two pole plates;
Said output device is used for, output audio signal, and the amplitude of said audio signal and phase place are directly proportional with the amplitude and the phase place of the said output signal of telecommunication respectively.
8. control system according to claim 1 is characterized in that, the bandwidth of the loop that said electric capacity, pitch measuring, control device and electric supply installation constitute is more than or equal to the bandwidth of voice signal; Said voice signal changes the distance between the pad-face of two pole plates of said electric capacity; Wherein,
The amplitude of the audio signal of said output device output and phase place are directly proportional with the amplitude and the phase place of said electric supply installation to the signal of telecommunication of arbitrary pole plate transmission of said electric capacity respectively.
9. according to claim 7 or 8 described microphones, it is characterized in that said output device is further used for, said audio signal is carried out analog-to-digital conversion, obtain digital audio and video signals; Export said digital audio and video signals.
10. an Electret Condencer Microphone is characterized in that, this microphone comprises: electric capacity, output device and control system, wherein,
Said electric capacity is made up of two pole plates, is used to receive voice signal;
Said output device is used for output audio signal;
Said control system is the described control system of the arbitrary claim of claim 1 to 9.
11. the control method of an Electret Condencer Microphone is characterized in that, this method comprises:
Electric capacity receives voice signal, and this voice signal changes the distance between the pad-face of two pole plates of said electric capacity; Output device output audio signal, the amplitude of said audio signal and phase place are directly proportional with the amplitude and the phase place of said voice signal respectively;
Detect the distance between the pad-face of two pole plates of said electric capacity, and itself and gauged distance are compared, obtain range difference; Generate and the corresponding control signal of said range difference;
According to said control signal; Arbitrary pole plate to said electric capacity sends the signal of telecommunication; This signal of telecommunication is used to change the voltage between two pole plates of said electric capacity; Thereby make the distance between the pad-face of two pole plates of said electric capacity become gauged distance, wherein, said gauged distance is less than the critical distance between the pad-face of two pole plates of said electric capacity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010602543.2A CN102547520B (en) | 2010-12-23 | 2010-12-23 | Electret Condencer Microphone and control system thereof and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010602543.2A CN102547520B (en) | 2010-12-23 | 2010-12-23 | Electret Condencer Microphone and control system thereof and control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102547520A true CN102547520A (en) | 2012-07-04 |
| CN102547520B CN102547520B (en) | 2016-04-06 |
Family
ID=46353255
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201010602543.2A Active CN102547520B (en) | 2010-12-23 | 2010-12-23 | Electret Condencer Microphone and control system thereof and control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102547520B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1372431A (en) * | 2001-02-20 | 2002-10-02 | Akg声学有限公司 | Electroacoustic telephone transmitter |
| US20050242800A1 (en) * | 2004-04-29 | 2005-11-03 | Zircon Corporation | Sensor auto-recalibration |
| CN1741685A (en) * | 2004-05-21 | 2006-03-01 | 桑尼奥公司 | Detection and control of diaphragm collapse in condenser microphones |
-
2010
- 2010-12-23 CN CN201010602543.2A patent/CN102547520B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1372431A (en) * | 2001-02-20 | 2002-10-02 | Akg声学有限公司 | Electroacoustic telephone transmitter |
| US20050242800A1 (en) * | 2004-04-29 | 2005-11-03 | Zircon Corporation | Sensor auto-recalibration |
| CN1741685A (en) * | 2004-05-21 | 2006-03-01 | 桑尼奥公司 | Detection and control of diaphragm collapse in condenser microphones |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102547520B (en) | 2016-04-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104836473B (en) | Acquire the generator and sound transducer of acoustic energy | |
| US8653717B2 (en) | Vibration power generator, vibration power generating device, and electronic device and communication device having vibration power generating device mounted thereon | |
| CN103595295B (en) | Magnetic/piezoelectric broadband vibration energy collector | |
| US20200413203A1 (en) | Piezoelectric type and capacitive type combined mems microphone | |
| CN1993000B (en) | Electro-acoustic actuator and method for manufacture | |
| CN111479179A (en) | Micro-electro-mechanical system | |
| CN102957992A (en) | Dual backplate microphone | |
| JP2011124891A (en) | Controller for capacitance type electromechanical conversion device, and method for controlling the same | |
| CN103200512A (en) | Glitch detection and method for detecting a glitch | |
| CN105491492B (en) | A kind of self calibration silicon microphone device and calibration method | |
| CN209897223U (en) | MEMS microphone | |
| CN111130341B (en) | Digital closed-loop control charge pump based on MEMS (micro-electromechanical system) capacitor | |
| US8564170B2 (en) | Vibration power generator, vibration power generation apparatus, and electric device and communication device with vibration power generation apparatus mounted thereon | |
| WO2016206939A1 (en) | Independently adjustabable charge pumps for differential microphones | |
| CN104065301A (en) | Piezoelectric static composite-type low-frequency vibration energy collector | |
| Lu et al. | A CMOS-MEMS CC-beam metal resoswitch for zero quiescent power receiver applications | |
| CN102547520A (en) | Capacitance microphone, and control system and control method for capacitance microphone | |
| CN100570371C (en) | Move the accelerometer of additional vibratory with minimizing owing to improved recurrence | |
| CN105634331A (en) | Magnetoelectric and piezoelectric combined generator | |
| EP2792162B1 (en) | Preventing electrostatic pull-in in capacitive devices | |
| Yang et al. | Investigation on behavior of the vibration-based piezoelectric energy harvester array in ultracapacitor charging | |
| CN103404170A (en) | Method for driving a condenser microphone | |
| Khbeis et al. | Development of a simplified hybrid ambient low frequency, low intensity vibration energy scavenger system | |
| CN101877484A (en) | Filter circuit | |
| CN101276691A (en) | Apparatus and method for drive controlling micro machine device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20180717 Address after: 261206 Fengshan Road, Fangzi District, Weifang, Shandong Province, No. 68 Patentee after: Shandong Gettop Acoustic Co.,Ltd. Address before: 100191 Beijing Haidian District Zhichun Road 23 quantum Ginza 1002 room Patentee before: Beijing Acuti Microsystems Co., Ltd. |