CN105049976A

CN105049976A - Method for noise reduction, headset and terminal

Info

Publication number: CN105049976A
Application number: CN201510456834.8A
Authority: CN
Inventors: 刘浩东; 徐昌荣; 朱顺吉
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2015-07-30
Filing date: 2015-07-30
Publication date: 2015-11-11
Anticipated expiration: 2035-07-30
Also published as: CN105049976B

Abstract

The embodiment of the invention provides a method for noise reduction, a headset and a terminal. The headset comprises noise-reducing microphones used for collecting at least two paths of noise signals; a signal processing circuit used for modulating the at least two paths of noise signals onto different spectrums so as to obtain frequency division multiplexing signals; a transmitting and receiving circuit used for transmitting the frequency division multiplexing signals to a terminal through a microphone pin of the headset and also used for receiving noise reduction signals which are transmitted by the terminal based on the frequency division multiplexing signals, wherein the noise reduction signals are used for noise reduction of the at least two paths of noise signals; and a loudspeaker used for playing the noise reduction signals transmitted by the terminal. Therefore, arrangement of a noise reduction module inside the headset is unnecessary in the embodiment of the invention, the design of the headset can be simplified on the premise of realizing the noise reduction, and the portability of the headset is consequently improved.

Description

A kind of method of Noise reduction, earphone and terminal

Technical field

The embodiment of the present invention relates to the communications field, and more specifically, relates to a kind of method of Noise reduction, earphone and terminal.

Background technology

Three kinds of noise reduction measures that reduction noise adopts usually are, sound source place noise reduction, in communication process noise reduction and at Ren Erchu noise reduction, wherein, be active mode at source of sound place noise reduction, its general principle is: all sound is all made up of certain frequency spectrum, if can find a kind of sound, its frequency spectrum is just the same with the noise that will eliminate, just this noise cancellation just contrary (namely differing 180 °), just can fall by phase place.

The sound how obtaining offsetting noise is just in the key of source of sound place noise reduction, in current techniques, adopt active noise reduction (ActiveNoiseCanceling, referred to as " ANC ") earphone realizes noise reduction, and detailed process is: first detect by the microphone be placed in earphone the environmental noise that ear can hear; Again noise signal is reached Dolby circuit, Dolby circuit calculates de-noising signal in real time; Send after the de-noising signal obtained and playback Signal averaging from earphone, realize the suppression of noise.

In existing ANC earphone, except the playback loudspeaker (earphone used for mobile phone also have the microphone of a call/recording) the same with common headphones, increase the noise that two, left and right noise reduction microphone removes to collect left and right two ears in addition newly, and by the data-signal process (DigitalSignalProcess for the treatment of noise, referred to as " DSP ") built-in chip type is in earphone, therefore the powerup issue considering dsp chip is also needed, such as internal battery, charging chip and charging inlet etc.

Existing ANC earphone, owing to earphone needing integrated dsp chip for generating de-noising signal and battery, power management module, drawbacks such as there is system complexity, technology controlling and process cost when producing in enormous quantities is higher, use and maintain complexity, earphone volume is large.

Summary of the invention

The embodiment of the present invention provides a kind of method of Noise reduction, earphone and terminal, under the prerequisite realizing noise reduction, can simplify the design of earphone, thus improve the portability of earphone.

First aspect, provides a kind of earphone, and this earphone comprises:

Noise reduction microphone, for gathering at least two-way noise signal;

Signal processing circuit, for by this at least two-way noise signal be modulated to different frequency spectrums, obtain frequency-division multiplex singal;

Transmission circuit, this frequency-division multiplex singal is sent to terminal for the microphone pin by this earphone, this transmission circuit also for, receive the de-noising signal that this terminal sends according to this frequency-division multiplex singal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

This loud speaker, for playing this de-noising signal that this terminal sends.

In conjunction with first aspect, in the first possible implementation of first aspect, this earphone also comprises:

Power circuit, for obtaining the voltage that this terminal provides from this microphone pin, and provides power supply according to this voltage to this noise reduction microphone.

In conjunction with the first possible implementation of first aspect or first aspect, in the implementation that the second of first aspect is possible, this signal processing circuit specifically for, by this, at least two-way noise signal and reference clock signal are modulated on different frequency spectrums, obtain this frequency-division multiplex singal, this reference clock signal is for this at least two-way noise signal of aliging.

In conjunction with first aspect and above-mentioned implementation thereof, in the third possible implementation of first aspect, this earphone also comprises:

Call/recording microphone wind, for gathering voice signal;

This signal processing circuit specifically for, by this at least two-way noise signal and this voice signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal.

In conjunction with first aspect and above-mentioned implementation thereof, in the 4th kind of possible implementation of first aspect, this earphone also comprises:

Noise reduction control circuit, for determining whether this terminal supports active noise reduction, and when determining that this terminal supports active noise reduction, sends the control signal being used to indicate acquisition noise signal to this noise reduction microphone;

Wherein, this noise reduction microphone specifically for, according to this control signal, gather this at least two-way noise signal.

In conjunction with the 4th kind of implementation of first aspect, in the 5th kind of possible implementation of first aspect, this noise reduction control circuit specifically for, when the voltage that this terminal obtained from this microphone pin provides exceedes preset voltage value, determine this terminal support active noise reduction;

This transmission circuit also for, by this microphone pin, to this terminal send be used to indicate the first previously arranged signal that active noise reduction also supported by this earphone.

In conjunction with the 4th kind of implementation of first aspect, in the 6th kind of possible implementation of first aspect,

This transmission circuit also for, to this terminal send for inquiring the second previously arranged signal whether supporting active noise reduction;

This transmission circuit also for, receive the 3rd previously arranged signal that this terminal sends according to this second previously arranged signal, the 3rd previously arranged signal be used to indicate this terminal support active noise reduction;

This noise reduction control circuit specifically for, according to the 3rd previously arranged signal that this transmission circuit receives, determine this terminal support active noise reduction.

In conjunction with first aspect and above-mentioned implementation thereof, in the 7th kind of possible implementation of first aspect, this earphone also comprises:

Transducer, for pick-up transducers measuring-signal;

This signal processing circuit specifically for, by this at least two-way noise signal be modulated on different frequency spectrums from this sensor measurement signal, obtain this frequency-division multiplex singal.

In conjunction with first aspect and above-mentioned implementation thereof, in the 8th kind of possible implementation of first aspect, this noise reduction microphone is numeric type microphone, and this earphone also comprises:

D/A converting circuit, is treated to analog signal for this frequency-division multiplex singal this signal processing circuit obtained;

Wherein, this transmission circuit specifically for, send this analog signal by this microphone pin to this terminal.

In conjunction with first aspect and above-mentioned implementation thereof, in the 9th kind of possible implementation of first aspect, the protection bandwidth of this frequency-division multiplex singal is not less than preset value.

In conjunction with first aspect and above-mentioned implementation thereof, in the tenth kind of possible implementation of first aspect, this transmission circuit specifically for, reception this de-noising signal while, also receive this terminal send useful audio signal;

This loud speaker specifically for, broadcasting this de-noising signal while, also play this useful audio signal.

Second aspect, provides a kind of terminal, and this terminal comprises:

Transmission circuit, for being received the frequency-division multiplex singal that earphone sends by the microphone interface of terminal, wherein, this frequency-division multiplex singal is get by least two-way noise signal of the noise reduction microphone collection on this earphone being modulated on different frequency spectrums, and this microphone interface is connected with the microphone pin of this earphone;

Signal processing circuit, obtains this at least two-way noise signal for this frequency-division multiplex singal of demodulation;

Dolby circuit, for determine according to this signal processing circuit this at least two-way noise signal generate de-noising signal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

This transmission circuit also for, send this de-noising signal to this earphone.

In conjunction with second aspect, in the first implementation of second aspect, this frequency-division multiplex singal be by by this at least two-way noise signal and reference clock signal be modulated on different frequency spectrums and get, this reference clock signal is for this at least two-way noise signal of aliging;

This signal processing circuit also for, obtain this reference clock signal by this frequency-division multiplex singal of demodulation, and to align this at least two-way noise signal according to this reference clock signal.

In conjunction with second aspect and above-mentioned implementation thereof, in the second implementation of second aspect, this frequency-division multiplex singal be by by this at least two-way noise signal to be modulated on different frequency spectrums from the voice signal of the call on this earphone/recording microphone elegance collection and to get;

Signal processing circuit also for, obtain this voice signal by this frequency-division multiplex singal of demodulation;

This terminal also comprises:

Speed signal processing circuit, for the treatment of this voice signal.

In conjunction with second aspect and above-mentioned implementation thereof, in the third implementation of second aspect, this terminal also comprises:

Control circuit, for when determining that active noise reduction supported by this earphone, continues to provide to this earphone the voltage exceeding preset voltage value by the microphone interface of this terminal.

In conjunction with the third implementation of second aspect, in the 4th kind of implementation of second aspect,

This control circuit specifically for, when this terminal is connected with earphone, in preset time period, provided the voltage exceeding preset voltage value to this earphone by the microphone interface of this terminal;

This transmission circuit also for, receive this earphone that is used to indicate that this earphone sends and support the first previously arranged signal of active noise reduction;

This control circuit is used for, and according to this first previously arranged signal, determines that active noise reduction supported by this earphone.

In conjunction with the third implementation of second aspect, in the 5th kind of implementation of second aspect, this transmission circuit specifically for, before receiving this frequency-division multiplex singal, receive this earphone send for inquiring the second previously arranged signal whether supporting active noise reduction;

This control circuit is used for, and according to this second previously arranged signal, determines that active noise reduction supported by this earphone;

This transmission circuit also for, send to this earphone and be used to indicate this terminal and support the 3rd previously arranged signal of active noise reduction.

In conjunction with second aspect and above-mentioned implementation thereof, in the 6th kind of implementation of second aspect, this frequency-division multiplex singal be by by this at least two-way noise signal to be modulated on different frequency spectrums from the sensor measurement signal of the transducer collection on this earphone and to get;

Signal processing circuit also for, by this frequency-division multiplex singal of demodulation, obtain this sensor measurement signal;

This terminal also comprises:

Sensor signal processing circuit, for the treatment of this sensor measurement signal.

In conjunction with second aspect and above-mentioned implementation thereof, in the 7th kind of implementation of second aspect, this frequency-division multiplex singal that this transmission circuit receives is analog signal;

This signal processing circuit specifically for, before this frequency-division multiplex singal of demodulation, analog-to-digital conversion process is carried out to this frequency-division multiplex singal and obtains corresponding digital signal.

In conjunction with second aspect and above-mentioned implementation thereof, in the 8th kind of implementation of second aspect, the protection bandwidth of this frequency-division multiplex singal is not less than preset value.

In conjunction with second aspect and above-mentioned implementation thereof, in the 9th kind of implementation of second aspect, this transmission circuit specifically for, when sending this de-noising signal to this terminal, also send useful audio signal to this terminal.

The third aspect provides a kind of method of Noise reduction, and the method comprises:

At least two-way noise signal is gathered by the noise reduction microphone on earphone;

By this at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal;

This frequency-division multiplex singal is sent to terminal by the microphone pin of this earphone;

Receive the de-noising signal that this terminal sends according to this frequency-division multiplex singal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

Play this de-noising signal that this terminal sends.

In conjunction with the third aspect, in the first implementation of the third aspect, this by this at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal, comprising:

By this at least two-way noise signal and reference clock signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal, this reference clock signal is for this at least two-way noise signal of aliging.

In conjunction with the third aspect and above-mentioned implementation thereof, in the second implementation of the third aspect, the method also comprises:

By the call on this earphone/recording microphone elegance collection voice signal;

This by this at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal, comprising:

By this at least two-way noise signal and this voice signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal.

In conjunction with the third aspect and above-mentioned implementation thereof, in the third implementation of the third aspect, at least two-way noise signal should be gathered by the noise reduction microphone on earphone, comprise:

Determine whether this terminal supports active noise reduction;

When determining that this terminal supports active noise reduction, by this at least two-way noise signal of the noise reduction microphone collection on this earphone.

In conjunction with the third implementation of the third aspect, in the 4th kind of implementation of the third aspect, this determines whether this terminal supports active noise reduction, comprising:

When the voltage that this terminal obtained from this microphone pin provides exceedes preset voltage value, determine that this terminal supports active noise reduction;

The method also comprises:

By this microphone pin, send to this terminal and be used to indicate the first previously arranged signal that active noise reduction also supported by this earphone.

In conjunction with the third implementation of the third aspect, in the 5th kind of implementation of the third aspect, this determines whether this terminal supports active noise reduction, comprising:

Send for inquiring the second previously arranged signal whether supporting active noise reduction to this terminal;

Receive the 3rd previously arranged signal that this terminal sends according to this second previously arranged signal, the 3rd previously arranged signal is used to indicate this terminal and supports active noise reduction;

According to the 3rd previously arranged signal, determine that this terminal supports active noise reduction.

In conjunction with the third aspect and above-mentioned implementation thereof, in the 6th kind of implementation of the third aspect, the method also comprises:

By the transducer pick-up transducers measuring-signal on this earphone;

By this at least two-way noise signal be modulated on different frequency spectrums from this sensor measurement signal, obtain this frequency-division multiplex singal.

In conjunction with the third aspect and above-mentioned implementation thereof, in the 7th kind of implementation of the third aspect, this noise reduction microphone is numeric type microphone, should send this frequency-division multiplex singal, and comprising by the microphone pin of this earphone to terminal:

This frequency-division multiplex singal is carried out digital-to-analogue conversion, obtains the analog signal that this frequency-division multiplex singal is corresponding;

The frequency-division multiplex singal after this digital-to-analogue conversion is sent to this terminal by this microphone pin.

In conjunction with the third aspect and above-mentioned implementation thereof, in the 8th kind of implementation of the third aspect, the protection bandwidth of this frequency-division multiplex singal is not less than preset value.

In conjunction with the third aspect and above-mentioned implementation thereof, in the 9th kind of implementation of the third aspect, the de-noising signal that this terminal of this reception sends according to this frequency-division multiplex singal, comprising:

Receive the de-noising signal that this terminal sends according to this frequency-division multiplex singal, and receive the useful audio signal of this terminal transmission;

This de-noising signal that this terminal of this broadcasting sends, comprising:

Play this de-noising signal, and play this useful audio signal.

Fourth aspect provides a kind of method of Noise reduction, and the method comprises:

The frequency-division multiplex singal of earphone transmission is received by the microphone interface of terminal, wherein, this frequency-division multiplex singal is get by least two-way noise signal of the noise reduction microphone collection on this earphone being modulated on different frequency spectrums, and this microphone interface is connected with the microphone pin of this earphone;

This frequency-division multiplex singal of demodulation obtains this at least two-way noise signal;

According to this at least two-way noise signal generate de-noising signal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

This de-noising signal is sent to this earphone.

In conjunction with fourth aspect, in the first implementation of fourth aspect, this frequency-division multiplex singal be by by this at least two-way noise signal and reference clock signal be modulated on different frequency spectrums and get, this reference clock signal is for this at least two-way noise signal of aliging;

The method also comprises:

By this frequency-division multiplex singal of demodulation, obtain this reference clock signal, and to align this at least two-way noise signal according to this reference clock signal;

According to this at least two-way noise signal generate de-noising signal, comprising:

According to alignment after this at least two-way noise signal generate this de-noising signal.

In conjunction with fourth aspect and above-mentioned implementation thereof, in the second implementation of fourth aspect, this frequency-division multiplex singal be by by this at least two-way noise signal to be modulated on different frequency spectrums from the voice signal of the call on this earphone/recording microphone elegance collection and to get;

The method also comprises:

By this frequency-division multiplex singal of demodulation, obtain this voice signal;

By this voice signal of speed signal processing circuit process of this terminal.

In conjunction with fourth aspect and above-mentioned implementation thereof, in the third implementation of fourth aspect, the method also comprises:

Determine whether this earphone supports active noise reduction;

When determining that active noise reduction supported by this earphone, continue to provide to this earphone the voltage exceeding preset voltage value by the microphone interface of this terminal.

In conjunction with the third implementation of fourth aspect, in the 4th kind of implementation of fourth aspect, this determines whether this earphone supports active noise reduction, comprising:

When this terminal is connected with earphone, in preset time period, provided the voltage exceeding preset voltage value to this earphone by the microphone interface of this terminal;

Receive the first previously arranged signal being used to indicate this earphone support active noise reduction that this earphone sends according to this voltage;

According to this first previously arranged signal, determine that active noise reduction supported by this earphone.

In conjunction with the third implementation of fourth aspect, in the 5th kind of implementation of fourth aspect, this determines whether this earphone supports active noise reduction, comprising:

Receive this earphone send for inquiring the second previously arranged signal whether supporting active noise reduction;

According to this second previously arranged signal, determine that active noise reduction supported by this earphone;

Send to this earphone and be used to indicate the 3rd previously arranged signal that this terminal supports active noise reduction.

In conjunction with fourth aspect and above-mentioned implementation thereof, in the 6th kind of implementation of fourth aspect, this frequency-division multiplex singal be by by this at least two-way noise signal to be modulated on different frequency spectrums from the sensor measurement signal of the transducer collection on this earphone and to get;

The method also comprises:

By this frequency-division multiplex singal of demodulation, obtain this sensor measurement signal;

By this sensor measurement signal of sensor signal processing circuit process of this terminal.

In conjunction with fourth aspect and above-mentioned implementation thereof, in the 7th kind of implementation of fourth aspect, this frequency-division multiplex singal that this earphone sends is analog signal;

This frequency-division multiplex singal of this demodulation obtains this at least two-way noise signal, comprising:

Analog-to-digital conversion process is carried out to this frequency-division multiplex singal and obtains corresponding digital signal;

The frequency-division multiplex singal of demodulation after analog-to-digital conversion, obtains this at least two-way noise signal.

In conjunction with fourth aspect and above-mentioned implementation thereof, in the 8th kind of implementation of fourth aspect, the protection bandwidth of this frequency-division multiplex singal is not less than preset value.

In conjunction with fourth aspect and above-mentioned implementation thereof, in the 9th kind of implementation of fourth aspect, this sends this de-noising signal to this earphone, comprising:

This de-noising signal and useful audio signal is sent to this earphone.

5th aspect provides a kind of system of Noise reduction, and this system comprises earphone that above-mentioned first aspect provides and the terminal that above-mentioned second aspect provides.

Based on technique scheme, in embodiments of the present invention, at earpiece side acquisition noise signal, noise signal is sent to end side; Carry out noise reduction process in end side, generate the de-noising signal be used for noise signal noise reduction, de-noising signal is sent to earphone, is played out by the loud speaker of earphone, thus realize noise reduction.Therefore, in embodiments of the present invention, without the need to arranging Dolby circuit in earphone, under the prerequisite realizing noise reduction, the design of earphone can be simplified, thus improving the portability of earphone.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme of the embodiment of the present invention, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 shows the schematic block diagram of the earphone provided according to the embodiment of the present invention.

Fig. 2 shows another schematic block diagram of the earphone provided according to the embodiment of the present invention.

Fig. 3 shows schematic diagram noise signal being carried out to frequency division multiplexing that the embodiment of the present invention relates to.

Fig. 4 shows a schematic block diagram again of the earphone provided according to the embodiment of the present invention.

Fig. 5 shows a schematic block diagram again of the earphone provided according to the embodiment of the present invention.

Fig. 6 shows a schematic block diagram again of the earphone provided according to the embodiment of the present invention.

Fig. 7 shows the indicative flowchart of the method for the Noise reduction provided according to the embodiment of the present invention.

Fig. 8 shows another indicative flowchart of the method for the Noise reduction provided according to the embodiment of the present invention.

Fig. 9 shows a schematic block diagram again of the earphone provided according to the embodiment of the present invention.

Figure 10 shows a schematic block diagram again of the earphone provided according to the embodiment of the present invention.

Figure 11 shows the schematic block diagram of the terminal provided according to the embodiment of the present invention.

Figure 12 shows an indicative flowchart again of the method for the Noise reduction provided according to the embodiment of the present invention.

Figure 13 shows an indicative flowchart again of the method for the Noise reduction provided according to the embodiment of the present invention.

Figure 14 shows the schematic block diagram of the system of the Noise reduction provided according to the embodiment of the present invention.

Figure 15 shows another schematic block diagram of the system of the Noise reduction provided according to the embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

The earphone that the embodiment of the present invention relates to, comprise receiver (also can be referred to as earplug or earmuff), receiver comprises loud speaker.Earphone is connected with terminal by earphone cord, and such as, earphone cord comprises four-part form pin, and this four-part form pin can insert the four-part form audio interface of terminal.

The terminal that the embodiment of the present invention relates to can be various audiogenic device, and this terminal comprises four-part form audio interface, after being connected with the four-part form pin of earphone, power supply can be provided for earphone, drive loud speaker (also can be referred to as loudspeaker) and the microphone of earphone, this four-part form audio interface is such as active 3.5mm jack.Particularly, this terminal can be portable or table type electronic equipment, such as, can be the various handheld terminals such as mobile phone, panel computer, music player or recorder, and be not limited only to communication terminal.

Should also be understood that the noise signal related in the embodiment of the present invention is specially intermediate frequency and low-frequency noise signal, this frequency range contains the daily most of noise faced of user, the repeated noise etc. of such as most typical aeroengine, or train, subway.

Fig. 1 shows the schematic block diagram of the earphone 100 provided according to the embodiment of the present invention, and as shown in Figure 1, this earphone 100 comprises:

Noise reduction microphone 110, for gathering at least two-way noise signal;

Signal processing circuit 120, for by this at least two-way noise signal be modulated to different frequency spectrums, obtain frequency-division multiplex singal;

Transmission circuit 130, this frequency-division multiplex singal is sent to terminal for the microphone pin by this earphone, this transmission circuit 130 also for, receive the de-noising signal that this terminal sends according to this frequency-division multiplex singal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

Loud speaker 140, for playing this de-noising signal that this terminal sends.

In embodiments of the present invention, at earpiece side acquisition noise signal, noise signal is sent to end side; Carry out noise reduction process in end side, generate the de-noising signal be used for noise signal noise reduction, de-noising signal is sent to earphone, is played out by the loud speaker of earphone, thus realize noise reduction.Therefore, in embodiments of the present invention, without the need to arranging Dolby circuit in earphone, under the prerequisite realizing noise reduction, the design of earphone can be simplified, thus improving the portability of earphone.

In addition, in embodiments of the present invention, in the process of earphone to terminal transmitted noise signal, be a road frequency-division multiplex singal by multipath noise signal transacting, utilize passage corresponding to the microphone pin of earphone that this frequency-division multiplex singal is sent to end side and carry out subsequent treatment, the embodiment of the present invention, on the basis of traditional four-section type headset pin, achieves and sends multipath noise signal to terminal simultaneously, can improve the effect of noise reduction.

Should understand, this noise reduction microphone (hereinafter referred to as MIC) 110 is for gathering the noise signal of the surrounding environment that ear can be heard, particularly, this noise reduction microphone 110 for gathering the noise signal within the scope of predeterminated frequency, to realize optionally eliminating the ambient noise of different frequency range or shielding.

Should also be understood that this noise reduction microphone 110 is arranged on earphone, particularly, near the left and right receiver that can be arranged in earphone, or be integrated in the receiver of left and right, comprise loud speaker in receiver, particularly, if the schematic diagram of the earphone shown in 2 200.Particularly, such as this noise reduction microphone is two noise reduction MIC, and one of them noise reduction MIC is distributed in the outside of the left receiver of earphone, and another noise reduction MIC is distributed in the outside of the right receiver of earphone.Again or, as shown in Figure 2, this noise reduction microphone is four noise reduction MIC, and wherein two noise reduction MIC are distributed in outside and inner side (space namely between headset earpiece and ear) of the left receiver of earphone respectively, and another two noise reduction MIC are distributed in outside and the inner side of the right receiver of earphone respectively.Should also be understood that in embodiments of the present invention, this noise reduction microphone can also comprise the noise reduction MIC of greater number, and wherein part noise reduction MIC is distributed near left receiver, and another part noise reduction MIC is distributed near right receiver.Should also be understood that the noise reduction MIC adopting a greater number gathers ambient noise signal, more comprehensively can obtain the periotic ambient noise of people, thus follow-uply can realize noise reduction better.

Further, be distributed in the noise reduction MIC of receiver inside, also for obtaining the audio signal that the receiver after noise reduction process is play, for the signal feedback needed for follow-up noise reduction algorithm, so that noise reduction algorithm can carry out corresponding dynamic conditioning and signal estimation.

Should also be understood that in embodiments of the present invention, also can only utilize a noise reduction MIC to obtain a road noise signal.Such as, earphone has been installed a noise reduction MIC, such as this noise reduction MIC to be positioned at apart from left receiver with right receiver apart from identical position.Earphone Jiang Gai mono-tunnel noise signal sends to terminal, terminal generates the de-noising signal identical with this noise amplitude signal, phase place is contrary, this de-noising signal that earphone receiving terminal sends, and is equivalent to left and right receiver and receives same de-noising signal, should be understood that and also can realize decrease of noise functions.

Should also be understood that the earphone in the embodiment of the present invention can, for In-Ear earphone, also can be headphone.Corresponding, the receiver of earphone also can be referred to as earplug or earmuff.The receiver of In-Ear earphone is earplug, and the receiver of headphone can be referred to as earmuff.

Particularly, Fig. 2 shows the schematic diagram of headphone 200, and as shown in Figure 2, this earphone 200 comprises:

Noise reduction microphone 210, for gathering the ambient noise signal of surrounding, particularly, gather at least two-way noise signal, particularly, Fig. 2 schematically provides four noise reduction MIC, wherein two are positioned at outside and the inner side of left receiver, and two other is positioned at outside and the inner side of right receiver.Alternatively, in embodiments of the present invention, this noise reduction microphone also can be integrated in headset earpiece.

Left and right receiver 220, for playing audio signal, comprises loud speaker (also can be referred to as loudspeaker) respectively in this left and right receiver 220.Should be understood that the loud speaker 140 shown in Fig. 1 is arranged in headset earpiece.

Signal processing circuit 230, for the treatment of the noise signal that noise reduction microphone 210 gathers, is treated to the frequency-division multiplex singal on a road, is sent to terminal by the microphone pin of earphone cord 240.

Earphone cord 240, one end of earphone cord 240 comprises four-part form pin 250, and this four-part form pin 250 comprises L channel L pin, R channel R pin, ground connection G pin and microphone M pin.

Earphone is connected with terminal by the four-part form pin 250 of earphone cord, particularly, this four-part form pin 250 is for being connected with the four-part form audio interface of terminal, terminal drives left and right loudspeaker and the microphone of earphone respectively by L channel L pin, R channel R pin and microphone M pin, particularly, in the figure 2 example, terminal drives four noise reduction microphones and a call/recording microphone wind by M pin.

Should be understood that noise reduction microphone in the embodiment of the present invention 110 corresponds to the noise reduction microphone 210 in Fig. 2, loud speaker 140 corresponds to the loud speaker comprised in the receiver 220 shown in Fig. 2.Particularly, be send frequency division composite signal by the M pin of four-part form pin 250 to terminal, be also the de-noising signal sent by M pin receiving terminal to transmission circuit 130.Signal processing circuit 120 in the embodiment of the present invention can correspond to the signal processing circuit 230 shown in Fig. 2.

Should also be understood that Fig. 2 is only example and non-limiting, such as, the four-part form pin shown in Fig. 2 comprises L pin, R pin, G pin and M pin successively, and wherein, the order of G pin and M pin can also be exchanged, and the embodiment of the present invention is not construed as limiting this.

Signal processing circuit 120 for by noise reduction microphone collection this at least two-way noise signal be modulated to different frequency spectrums, obtain frequency-division multiplex singal.This at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal.Particularly, according to default spectrum allocation may information, by this at least two-way noise signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal, this default spectrum allocation may information comprises the corresponding relation of the multiplexing signal of needs and Reusespectrum.Such as, the process at least two-way noise signal being modulated to frequency-division multiplex singal is: be modulated on the first sub-band of Reusespectrum by the first via noise signal A at least two-way noise signal by the frequency spectrum a at noise signal A place originally, is modulated on the second sub-band of Reusespectrum by the second tunnel noise signal B by the frequency spectrum b at noise signal B place originally.In the present embodiment, particularly, this default spectrum allocation may information includes the corresponding relation of frequency spectrum a and the first sub-band, and the corresponding relation of frequency spectrum b and the second sub-band.Accordingly, in end side, according to this default spectrum allocation may information, demodulation is carried out to this frequency-division multiplex singal, particularly, demodulation is carried out to the signal on the first sub-band in this frequency-division multiplex singal, by the signal recuperation on the first sub-band on frequency spectrum a, thus obtain this first via noise signal A; Demodulation is carried out to the signal on the second sub-band, by the signal recuperation on this second sub-band on frequency spectrum b, thus obtains this second tunnel noise signal B.

Will also be understood that, in embodiments of the present invention, by noise reduction microphone collection this at least two-way noise signal be modulated on different frequency spectrums, specifically refer to by this at least two-way noise signal be modulated on the different frequency spectrum of the spectral range of passage corresponding to the microphone pin of earphone.

Particularly, such as this noise reduction microphone 110 is four noise reduction microphones, arrangement on earphone as shown in Figure 2, namely this at least two-way noise signal be four tunnel noise signals, respectively by being positioned at inside left horn, outside, inside right horn, the noise reduction MIC acquisition noise signal in outside, suppose the data of this noise signal Zhong Mei road, four tunnels noise signal be only limitted to 2.5kHz bandwidth within data, then Wei Gai tetra-tunnel noise signal carries out the concrete condition of spectrum allocation may as shown in Figure 3:

The de-noising signal (signal 2 as shown in Figure 3) that noise reduction MIC outside left horn gathers is assigned to: 28kHz ~ 34kHz;

The de-noising signal (signal 3 as shown in Figure 3) that noise reduction MIC inside left horn gathers is assigned to: 38kHz ~ 44kHz;

The de-noising signal (signal 4 as shown in Figure 3) that noise reduction MIC outside right horn gathers is assigned to: 48kHz ~ 54kHz;

The de-noising signal (signal 5 as shown in Figure 3) that noise reduction MIC inside right horn gathers is assigned to: 58kHz ~ 64kHz.

Alternatively, in embodiments of the present invention, the protection bandwidth of this frequency-division multiplex singal is not less than preset value.

Particularly, this preset value can be arranged according to real needs, and the protection bandwidth of such as this frequency-division multiplex singal is 4kHz, and the embodiment of the present invention is not construed as limiting this.

Should be understood that the protection bandwidth of frequency-division multiplex singal refers to the spectrum intervals in this multiplexed signals between adjacent two paths of signals, the signal of the transmission that this protection bandwidth can ensure on different frequency range does not interfere with each other.Particularly, as shown in Figure 3, the protection bandwidth such as arranging the data of each road signal is not less than 4kHz.

Transmission circuit 130 for, receive the de-noising signal that this terminal sends according to this frequency-division multiplex singal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction.

Should be understood that terminal is by this frequency-division multiplex singal of demodulation, this at least two-way noise signal can be recovered, and then generate corresponding de-noising signal.

Particularly, such as, suppose in earpiece side, the process at least two-way noise signal being modulated to frequency-division multiplex singal is: be modulated on the first sub-band by the first via noise signal A at least two-way noise signal by the frequency spectrum a at noise signal A place originally, is modulated on the second sub-band by the second tunnel noise signal B by the frequency spectrum b at noise signal B place originally.In end side, demodulation is carried out to this frequency-division multiplex singal, particularly, demodulation is carried out to the signal on the first sub-band in this frequency-division multiplex singal, by the signal recuperation on the first sub-band on frequency spectrum a, thus obtain this first via noise signal A; Demodulation is carried out to the signal on the second sub-band, by the signal recuperation on this second sub-band on frequency spectrum b, thus obtains this second tunnel noise signal B.

Terminal demodulates out, at least after two-way noise signal, generates identical with this noise amplitude signal, the de-noising signal that phase place is contrary, and namely this de-noising signal can be cut down and even offsets this noise signal.

It should be noted that, the first via noise signal A supposing at least two-way noise signal is the noise signal around the left receiver of earphone, and the second tunnel noise signal B at least in two-way noise signal is the noise signal around the right receiver of earphone.Alternatively, terminal can generate L channel de-noising signal based on first via noise signal A, generates R channel de-noising signal based on the second tunnel noise signal B.

Alternatively, terminal also based on this at least two-way noise signal, can generate a de-noising signal, then same de-noising signal is used as L channel de-noising signal and R channel de-noising signal simultaneously.

Alternatively, in embodiments of the present invention, this signal processing circuit 120 specifically for, by this, at least two-way noise signal and reference clock signal are modulated on different frequency spectrums, obtain this frequency-division multiplex singal, this reference clock signal is for this at least two-way noise signal of aliging.

Such as, this at least two-way noise signal comprise the two-way noise signal being arranged in two noise reduction microphones near the left receiver of earphone and gathering, this two-way noise signal is after spectrum modulation, likely because modulation algorithm error etc. bring phase deviation, namely, in frequency-division multiplex singal, there is phase deviation in this two-way noise signal.Terminal receives this frequency-division multiplex singal, and this two-way noise signal obtained after the demodulation also exists phase deviation, can cause generating de-noising signal accurately.In order to avoid this problem, when earpiece side carries out frequency division multiplexing process to multipath noise signal, namely reference clock signal is provided, make terminal when JieDuHuaYu II Decoction division multiplex signal according to this reference clock signal, the noise signal that there is phase deviation can be revised, thus obtain de-noising signal accurately.

Particularly, as shown in Figure 3, be assigned to reference to clock signal (signal 6 as shown in Figure 3): 70kHz.

Should be understood that Fig. 3 is only example and non-limiting, in practical operation, the Frequency point of the protection bandwidth adopted in frequency division multiplexing process and each road signal all can adjust accordingly according to algorithm requirements, not obligates here.

Alternatively, in embodiments of the present invention, this transmission circuit 130 of noise reduction specifically for, reception this de-noising signal while, also receive this terminal send useful audio signal;

This loud speaker 140 specifically for, broadcasting this de-noising signal while, also play this useful audio signal.

Should be understood that this useful audio signal is the audio signal that user needs to listen to, such as, this useful audio signal is the audio signal such as music or conversation signal.Thus this de-noising signal and useful audio signal play out by headset earpiece, and user just can hear comparatively pure music or conversation signal.

Alternatively, in embodiments of the present invention, this earphone 100 also comprises:

Clock circuit, for providing reference clock signal to noise reduction microphone 110, makes multiple noise reduction microphone based on this at least two-way noise signal of identical reference clock signal collection.

Alternatively, as shown in Figure 4, in embodiments of the present invention, this earphone 100 also comprises:

Power circuit 150, for obtaining the voltage that this terminal provides from this microphone pin, and provides power supply according to this voltage to this noise reduction microphone.

Particularly, for earphone shown in Fig. 2, this power circuit 150 obtains voltage that terminal provides (particularly for the microphone pin (hereinafter referred to as M pin) of the four-part form pin from earphone cord, microphone bias voltage can be referred to as), this power circuit 150 provides power supply based on the voltage obtained from terminal to noise reduction microphone 110, namely for driving noise reduction microphone 110.

Should be understood that this power circuit 150 also for powering to signal processing circuit 120.

Particularly, this power circuit 150 is the power supply circuits in this signal processing circuit 120.

In embodiments of the present invention, earpiece side is responsible for acquisition noise signal, is sent to end side and carries out noise reduction process, and therefore, earpiece side is without the need to arranging Dolby circuit, and nature is without the need to solving the powerup issue of Dolby circuit; Secondly, what adopt in the embodiment of the present invention is four-section type headset pin, terminal can be utilized to the power supply of the microphone pin in four-part form pin to drive noise reduction microphone and the signal processing circuit for frequency division multiplexing process, thus earphone inside eliminates the power module with larger volume and weight, simplify the design of earphone, simplify the volume of earphone, manufacturing cost and the maintenance cost of earphone can have been reduced, also can improve the portability of earphone.

Should be understood that in embodiments of the present invention, this earphone can be also handset earphone, namely comprises call/recording MIC (also can be referred to as chest wheat).When user uses this call/recording MIC, such as recording or with other user's communications, to when at least two-way noise signal carries out frequency division multiplexing process, also comprise the frequency division multiplexing to this call/recorded audio signals.

Alternatively, as shown in Figure 5, in embodiments of the present invention, this earphone 100 also comprises:

Call/recording microphone wind 160, for gathering voice signal;

This signal processing circuit 120 specifically for, by this at least two-way noise signal and this voice signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal.

Particularly, this call/recording microphone wind 160 is such as the microphone 260 shown in Fig. 2, also can be referred to as chest wheat or headset, for user's communication or recording.

This signal processing circuit 120 specifically for, by voice signal frequency division multiplexing together with at least two-way noise signal, be defined as a road multiplexed signals, suppose to converse/bandwidth of operation of data of voice signal that recording MIC exports is 20kHz, for the frequency spectrum of the data allocations of the voice signal of MIC output of conversing or record is: 0 ~ 24kHz, as in Fig. 3 being the frequency spectrum that signal 1 distributes.For noise signal distributes frequency spectrum as described above, repeat no more here.

Should understand, in embodiments of the present invention, call/recorded audio signals and multipath noise signal are sent to terminal by frequency-division multiplex singal by earphone in the lump, accordingly, in end side by carrying out demodulation to frequency-division multiplex singal, this call/recorded audio signals and multipath noise signal can be recovered, carry out noise reduction process for noise signal, call/recorded audio signals is sent to relevant audio-frequency signal processing module, and such as codec chip processes.Therefore, in embodiments of the present invention, while realizing active noise reduction, can't affect the business that user normally uses call/recording microphone to divide, two kinds of events can be carried out simultaneously, do not interfere with each other, thus can improve satisfaction of users.

Should also be understood that in embodiments of the present invention, earphone comprises two kinds of mode of operations, and one is normal mode of operation, and one is noise reduction mode of operation.Wherein, in a normal mode of operation, earphone does not have decrease of noise functions, plays out from terminal received audio signal from receiver namely merely, and can not provide noise signal to terminal, particularly, the noise reduction MIC in earphone can not work.Under noise reduction mode of operation, earphone is powered to noise reduction MIC, and noise reduction MIC works, acquisition noise signal, and carries out frequency division multiplexing process to noise signal, and the multiplexed signals after process is sent to terminal.

Earphone, when determining that terminal supports active noise reduction, just can be held noise reduction mode of operation, otherwise be in normal mode of operation.

Alternatively, as shown in Figure 6, in embodiments of the present invention, this earphone 100 also comprises:

Noise reduction control circuit 170, for determining whether this terminal supports active noise reduction, and when determining that this terminal supports active noise reduction, sends the control signal being used to indicate acquisition noise signal to this noise reduction microphone;

Wherein, this noise reduction microphone 110 specifically for, according to this control signal, gather this at least two-way noise signal.

Particularly, by transmitting the signal of making an appointment between earphone and terminal, inform whether the other side oneself supports active noise reduction.

Alternatively, in embodiments of the present invention, this noise reduction control circuit 170 specifically for, when the voltage that this terminal obtained from this microphone pin provides exceedes preset voltage value, determine this terminal support active noise reduction;

This transmission circuit 130 also for, by this microphone pin, to this terminal send be used to indicate the first previously arranged signal that active noise reduction also supported by this earphone.

Particularly, after earphone is connected with terminal, terminal lifting is to the MIC bias voltage of earphone, such as, the default MIC bias voltage value of common headphones is 2.7v (preset voltage value corresponding in the embodiment of the present invention), the terminal in the embodiment of the present invention for the MIC bias voltage that earphone provides be 5V.When headset detection is to when exceeding the MIC magnitude of voltage of preset voltage value, determine that distant terminal can support active noise reduction.

Should also be understood that in the embodiment of the present invention, terminal also has noise reduction mode of operation and normal mode of operation, and terminal is also when determining that active noise reduction supported by opposite end earphone, opens noise reduction mode of operation, otherwise is in normal mode of operation.Therefore, after earphone supports active noise reduction function according to the MIC bias voltage determination distant terminal exceeding preset voltage value, also need to send for representing that this earphone can support decrease of noise functions to distant terminal, and indicating terminal opens the first reservation signal of noise reduction mode of operation.

Particularly, this first reservation signal is a special audio signal, the clean audio signal such as very much do not had for this nature of 1k, 8k or 16k.Should be understood that this first reservation signal is all known for earphone and terminal.

Particularly, take terminal as mobile phone be example, composition graphs 7, describes the handshake procedure S161 from the angle of mobile phone, in S11, mobile phone detects that four-section type headset is in place, and namely mobile phone is connected with earphone; In S12, mobile phone provides the MIC bias voltage of 5V to earphone by four-part form audio interface, should be understood that mobile phone only need provide the MIC bias voltage of 2.7V for common headphones (namely not having the earphone of decrease of noise functions); In S13, mobile phone open recording channel, to audio signal processing circuit, starts to detect previously arranged signal; In S14, mobile phone judges whether to receive previously arranged signal, and particularly, this previously arranged signal is the clean audio signal that this nature of 1k, 8k or 16k does not have very much, when determining to receive, forwards S15 to, otherwise forwards S16 to; In S15, according to the previously arranged signal that earphone sends, determine that active noise reduction supported by this earphone, then the MIC bias voltage provided for earphone is continued to remain on 5V, and enter noise reduction mode of operation.

Particularly, take terminal as mobile phone be example, composition graphs 8, describes the handshake procedure S161 from the angle of earphone, and in S21, the four-part form pin of earphone inserts the four-part form audio interface of mobile phone, and namely earphone is connected with mobile phone; In S22, earphone judges that whether MIC bias voltage that mobile phone provides is higher than 2.7V, if so, forwards S23 to, otherwise forwards S24 to; In S23, the MIC bias voltage that earphone determination mobile phone provides is higher than 2.7V, be such as 5V, then determine that active noise reduction supported by this mobile phone, send previously arranged signal (previously arranged signal corresponding in S14 in Fig. 3) to this mobile phone, and enter noise reduction mode of operation, i.e. acquisition noise signal, frequency division multiplexing noise signal, to mobile phone transmitted noise signal, and receive the mixed signal of mobile phone transmission, and play this mixed signal; In S24, the MIC bias voltage that earphone determination mobile phone provides not higher than 2.7V, is then determined that this mobile phone does not support active noise reduction, is entered normal mode of operation, namely with the identity work of common headphones.

Should be understood that 2.7V and 5V related in Fig. 7 and Fig. 8 is only example and non-limiting.

After mobile phone detects that earphone cord four-part form pin inserts the four-part form audio interface of mobile phone, mobile phone encoding and decoding (codec) chip can be biased (HSMICBIAS) voltage (being such as lifted to 5V from 2.7V) by lifting ear microphone momently, and open recording channel, detect and whether can receive the first previously arranged signal, if after HSMICBIAS voltage lifting a period of time, mobile phone codec chip does not detect the first previously arranged signal, what then think current insertion is common headphones, then 2.7V is returned in HSMICBIAS voltage drop, follow-uply this earphone will be used as common headphones process.

If mobile phone codec chip is by after the lifting of HSMICBIAS voltage, interlock circuit in DSP module in earphone detects HSMICBIAS voltage and raises, then determine that active noise reduction supported by this mobile phone, this earphone also can switch to noise reduction mode of operation by normal mode of operation, namely DSP module 130 is powered to noise reduction MIC, and carries out frequency division multiplexing process to the noise signal that noise reduction MIC gathers.Meanwhile, earphone can send the first previously arranged signal to mobile phone, indicate earphone for active earphone with this, prompting mobile telephone set also can open noise reduction mode of operation, particularly, this first previously arranged signal is such as a special audio signal, the clean audio signal such as very much do not had for this nature of 1k, 8k or 16k.

Should be understood that earphone can continue for some time and send this first previously arranged signal to mobile phone, such as, continue to send 0.5s.

After mobile phone receives this first previously arranged signal, then determine that this earphone is ANC earphone, then mobile phone is also operated in noise reduction mode of operation, namely carries out noise reduction process to the frequency-division multiplex singal (analog signal) that earphone sends.

Will also be understood that, after earphone is connected with mobile phone, namely after earphone cord four-part form pin inserts the four-part form audio interface of mobile phone, the HSMICBIAS voltage that mobile phone provides is in 2.7V always, not lifting, then this earphone is only operated in normal mode of operation, and carry out work as a common headphones, namely this earphone does not have decrease of noise functions.

Should understand, in embodiments of the present invention, ANC earphone is before unlatching active noise reduction mode of operation, first handshake procedure can be carried out with the terminal be connected, namely whether mutual certification the other side supports active noise reduction function, and is all supporting on the basis of active noise reduction both sides, performs the step of active noise reduction, realize active noise reduction, thus provide the useful voice signal after noise reduction process for user.

Alternatively, in embodiments of the present invention, this first previously arranged signal comprises the signal of supersonic band.

Particularly, in handshake procedure between above-mentioned earphone and terminal, the audio mixing frequency of the first previously arranged signal related to and the transmitting time of audio mixing mode and this first previously arranged signal and duration, respective handling can be done according to actual conditions, such as: by the mode of frequency division multiplexing, utilize the signal of supersonic band other signals subsidiary, make the algorithm of mobile phone terminal to carry out Thin interbed, therefore determine that this earphone is ANC earphone.

Should be understood that other high-frequency signals can also be utilized to generate this first previously arranged signal to other signals subsidiary, and the embodiment of the present invention is not construed as limiting this except utilizing the signal of supersonic band other signals subsidiary to generate this first previously arranged signal.

Should be understood that transmission circuit 130 sends this frequency-division multiplex singal by the microphone pin of this earphone to terminal, so that this terminal obtains this at least two-way noise signal according to this frequency-division multiplex singal demodulation.

Alternatively, in embodiments of the present invention, this transmission circuit 130 also for, to this terminal send for inquiring the second previously arranged signal whether supporting active noise reduction;

This transmission circuit 130 also for, receive the 3rd previously arranged signal that this terminal sends according to this second previously arranged signal, the 3rd previously arranged signal be used to indicate this terminal support active noise reduction;

This noise reduction control circuit 170 specifically for, according to the 3rd previously arranged signal that this transmission circuit receives, determine this terminal support active noise reduction.

Alternatively, in embodiments of the present invention, this second previously arranged signal comprises the signal of supersonic band, the audio signal of this second previously arranged signal behaviour ear None-identified.

Particularly, this second reservation signal is a special audio signal, the clean audio signal such as very much do not had for this nature of 1k, 8k or 16k.The audio signal of the 3rd previously arranged signal behaviour ear None-identified, the 3rd prearranged signals is such as ultrasonic wave audio signal.Should be understood that this second reservation signal and the 3rd reservation signal are all known for earphone and terminal.

Should be understood that and described above is earphone and terminal is opening the handshake procedure before noise reduction mode of operation.Other means can also be adopted to realize this handshake procedure, and the embodiment of the present invention is not construed as limiting this.

In embodiments of the present invention, earphone acquisition noise signal, and noise signal is supplied to terminal processes, the de-noising signal sent by receiving terminal, is played out de-noising signal by receiver, thus reaches the object of active noise reduction.Therefore, in embodiments of the present invention, earphone is inner without the need to arranging the module of noise reduction process, under the prerequisite realizing noise reduction, can simplify the design of earphone, thus improve the portability of earphone.

Alternatively, in embodiments of the present invention, this noise reduction microphone 110 is numeric type microphone, and this earphone 100 also comprises:

D/A converting circuit 190, is treated to analog signal for this frequency-division multiplex singal this signal processing circuit obtained;

Wherein, this transmission circuit 130 specifically for, send this analog signal by this microphone pin to this terminal.

Should understand, noise reduction microphone 110 in the embodiment of the present invention also can be analogue type MIC, but before its noise signal (analog signal) gathered carries out frequency division multiplexing process, after needing first this noise signal to be converted to digital signal, then carry out follow-up process.

Alternatively, the noise reduction microphone 110 in the embodiment of the present invention is analogue type MIC.

Particularly, namely this at least two-way noise signal be analog signal.

Wherein, this signal processing module 120 specifically for, first to this at least two-way noise signal carry out modulus process, obtain the digital signal that at least two-way noise signal is corresponding; Then in numeric field, frequency division multiplexing process is carried out to this digital signal that at least two-way noise signal is corresponding, then digital-to-analogue conversion is carried out to the frequency-division multiplex singal obtained, obtain corresponding analog signal, send this analog signal to terminal.

In embodiments of the present invention, except comprising at least except two-way noise signal in the frequency-division multiplex singal that earphone sends to terminal, can also including but not limited to other sensor signals, such as earphone is at the measuring-signal of level sensor.Should be understood that sensor measurement signal can be sent to terminal by frequency-division multiplex singal by a channel, terminal can obtain this sensor measurement signal after crossing frequency-division multiplex singal demodulation to this, thus can obtain more information about environment residing for earphone.

Alternatively, as shown in Figure 9, in embodiments of the present invention, this earphone 100 also comprises:

Transducer 180, for pick-up transducers measuring-signal;

This signal processing circuit 120 specifically for, by this at least two-way noise signal be modulated on different frequency spectrums from this sensor measurement signal, obtain this frequency-division multiplex singal.

Particularly, such as this transducer 180 be earphone at level sensor, whether this sensor measurement signal can indicate earphone to be worn on ear, such as, can measure the distance between receiver and ear.Alternately, this transducer 180 can also be accelerometer, gyroscope or other transducers for measuring human body sport parameter.

This signal processing circuit 120 specifically for, by this, at least two-way noise signal and this sensor measurement signal are modulated on different frequency spectrums, such as the frequency spectrum of the data allocations of this sensor measurement signal is: 78kHz ~ 88kHz, as in Fig. 3 being the frequency spectrum that signal 7 distributes.

Should understand, in end side, obtain this demodulation according to this frequency-division multiplex singal demodulation and obtain sensor measurement signal, when the distance of the receiver distance ear determining earphone exceeds threshold value, when namely determining that earphone leaves ear, then stop to send audio signal (suppose before this, terminal sends audio signal to earphone always) to earphone; Otherwise terminal keeps sending audio signal to earphone.

Should be understood that in embodiments of the present invention, this sensor measurement signal can also be the signal that other transducers gather, such as infrared sensor etc.

Therefore, in embodiments of the present invention, by sending sensor measurement signal to terminal, terminal can be allowed to know the more information about environment residing for earphone, thus the communication between terminal and earphone can be adjusted neatly, in real time.

Alternatively, in embodiments of the present invention, signal processing circuit 120, power circuit 150, noise reduction control circuit 170, D/A converting circuit 190, call/recording microphone wind 160 and for providing the clock circuit of reference clock signal for noise reduction microphone 110, it can be separate circuit, also can be integrated in a functional module, embodiment of the present invention contrast is not construed as limiting.

Figure 10 shows the schematic diagram of the earphone 300 provided according to the embodiment of the present invention, and this earphone 300 comprises:

Noise reduction microphone 310, for gathering at least two-way noise signal, this noise reduction microphone 310 is numeric type microphone;

Integrated treatment circuit 320, comprising:

Call/recording microphone wind 321, for gathering voice signal;

Power circuit 322, for obtaining the voltage that this terminal provides from this microphone pin, and provides power supply according to this voltage to this noise reduction microphone 310 and call/recording microphone wind 321;

Clock circuit 323, provides reference clock signal for giving this noise reduction microphone 310.

Noise reduction control circuit 324, for determining whether the terminal be connected with earphone supports active noise reduction, and when determining that this terminal supports active noise reduction, control this noise reduction microphone 310 acquisition noise signal, particularly, determine whether the terminal be connected with earphone supports that the method for Noise reduction and the noise reduction control circuit 170 in foregoing embodiments determine whether the terminal be connected with earphone supports that the method for Noise reduction is similar, repeats no more here.

Signal processing circuit 325, for by this at least two-way noise signal be modulated to different frequency spectrums from this voice signal, obtain frequency-division multiplex singal;

D/A converting circuit 326, carries out digital-to-analogue conversion for the frequency-division multiplex singal obtained this signal processing circuit 325, obtains the analog signal of this frequency-division multiplex singal;

Transmission circuit 330, for sending to terminal the frequency-division multiplex singal (analog signal) that this integrated treatment circuit 320 determines by the microphone pin of this earphone, this transmission circuit 330 also for, receive the de-noising signal that this terminal sends according to this frequency-division multiplex singal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

Should be understood that transmission circuit 330 sends this frequency-division multiplex singal to terminal, so that this terminal obtains this at least two-way noise signal according to this frequency-division multiplex singal demodulation.

Loud speaker 340, for playing this de-noising signal that this terminal sends.

Alternatively, as shown in Figure 10, this integrated treatment circuit 320 also comprises random asccess memory SRAM327, for storing data and information, and such as program.

Figure 11 shows the schematic block diagram of the terminal 400 provided according to the embodiment of the present invention, and as shown in figure 11, this terminal 400 comprises:

Transmission circuit 410, for being received the frequency-division multiplex singal that earphone sends by the microphone interface of terminal, wherein, this frequency-division multiplex singal is get by least two-way noise signal of the noise reduction microphone collection on this earphone being modulated on different frequency spectrums, and this microphone interface is connected with the microphone pin of this earphone;

Wherein, at least two-way noise signal such as respectively by be arranged on earphone noise reduction MIC gather two-way noise signal.

Signal processing circuit 420, obtains this at least two-way noise signal for this frequency-division multiplex singal of demodulation;

Dolby circuit 430, for determine according to this signal processing circuit this at least two-way noise signal generate de-noising signal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

Particularly, this de-noising signal is identical with the amplitude of this noise signal, and phase place is contrary, thus can offset this noise signal.The generative process of this de-noising signal can not repeat see prior art the present embodiment.

This transmission circuit 410 also for, send this de-noising signal to this earphone.

In embodiments of the present invention, terminal demodulates noise signal from the frequency-division multiplex singal that earphone sends, and generates the de-noising signal contrary with this noise signal phase place, then sends this de-noising signal to earphone.Therefore, in embodiments of the present invention, in end side process noise signal, and generating de-noising signal, making earphone inner without the need to arranging the module of noise reduction process, under the prerequisite realizing noise reduction, the design of earphone can be simplified, thus improve the portability of earphone.

Particularly, such as terminal is mobile phone, and this signal processing module 420 is arranged in the codec chip of mobile phone.

Should be understood that in embodiments of the present invention, this at least two-way noise signal be specially two-way noise signal, or the noise signal of four tunnel noise signals or greater number, the embodiment of the present invention is not construed as limiting this, the quantity of the noise reduction MIC installed according to earpiece side and determining.

Should also be understood that earphone is connected with the four-part form audio interface of terminal by the four-part form pin of earphone cord, carry out work.

Particularly, transmission circuit 410, by the four-part form audio interface of terminal and the four-part form pin of earphone cord, receives this frequency-division multiplex singal that earphone sends.

Particularly, signal processing circuit 420 for, generate the mechanism of frequency-division multiplex singal based on earpiece side based on noise signal, this frequency-division multiplex singal of demodulation obtains this at least two-way noise signal.Particularly, such as in earpiece side, according to presetting spectrum allocation may information, by will at least two-way noise signal be modulated on different spectral to obtain this frequency-division multiplex singal, then in end side, can based on this default spectrum allocation may information, this frequency-division multiplex singal of demodulation is to obtain this at least two-way noise signal.

Such as, in earpiece side, the process at least two-way noise signal being modulated to frequency-division multiplex singal is: be modulated on the first sub-band of Reusespectrum by the first via noise signal A at least two-way noise signal by the frequency spectrum a at noise signal A place originally, is modulated on the second sub-band of Reusespectrum by the second tunnel noise signal B by the frequency spectrum b at noise signal B place originally.In the present embodiment, particularly, this default spectrum allocation may information includes the corresponding relation of frequency spectrum a and the first sub-band, and the corresponding relation of frequency spectrum b and the second sub-band.Accordingly, in end side, according to this default spectrum allocation may information, demodulation is carried out to this frequency-division multiplex singal, particularly, demodulation is carried out to the signal on the first sub-band in this frequency-division multiplex singal, by the signal recuperation on the first sub-band on frequency spectrum a, thus obtain this first via noise signal A; Demodulation is carried out to the signal on the second sub-band, by the signal recuperation on this second sub-band on frequency spectrum b, thus obtains this second tunnel noise signal B.

Particularly, earpiece side, to the description of at least frequency division multiplexing process composition graphs 2 as detailed above of two-way noise signal, repeats no more here.

Dolby circuit 430, for determine according to this signal processing circuit this at least two-way noise signal generate de-noising signal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction, particularly, this de-noising signal is identical with the amplitude of noise signal, and phase place is contrary.

Particularly, such as, when at least two-way noise signal got from earpiece side comprises the noise signal C near a left receiver in road, and a noise signal D near the right receiver in road, at this moment, according to the de-noising signal c that noise signal C generates, send from L channel, according to the de-noising signal d that noise signal D generates, send from R channel.

This transmission circuit 410 specifically for, send this de-noising signal by the left channel interface of earphone connecting line and right channel interface to this earphone.

Alternatively, in embodiments of the present invention, this transmission circuit 410 specifically for, when sending this de-noising signal to this terminal, also send useful audio signal to this terminal.Should be understood that this useful audio signal is the audio signal that user needs to listen to, such as, this useful audio signal is the audio signal such as music or conversation signal.Thus this de-noising signal and useful audio signal play out by headset earpiece, and user just can hear comparatively pure music or conversation signal.

Alternatively, in embodiments of the present invention, this frequency-division multiplex singal be by by this at least two-way noise signal and reference clock signal be modulated on different frequency spectrums and get, this reference clock signal is for this at least two-way noise signal of aliging;

This signal processing circuit 420 also for, obtain this reference clock signal by this frequency-division multiplex singal of demodulation, and to align this at least two-way noise signal according to this reference clock signal.

In embodiments of the present invention, this earphone can be handset earphone, namely comprises call/recording MIC (also can be referred to as chest wheat).When user uses this call/recording MIC, such as recording or with other user's communications, to when at least two-way noise signal carries out frequency division multiplexing process, also comprise the frequency division multiplexing to this call/recorded audio signals.

Alternatively, in embodiments of the present invention, this frequency-division multiplex singal be by by this at least two-way noise signal to be modulated on different frequency spectrums from the voice signal of the call on this earphone/recording microphone elegance collection and to get;

Signal processing circuit 420 also for, obtain this voice signal by this frequency-division multiplex singal of demodulation;

This terminal 400 also comprises:

Speed signal processing circuit 440, for the treatment of this voice signal.

In embodiments of the present invention, terminal has noise reduction mode of operation and normal mode of operation, and terminal is when determining that active noise reduction supported by opposite end earphone, opens noise reduction mode of operation, otherwise is in normal mode of operation.Wherein, in a normal mode of operation, terminal acquiescence only from call/recorded audio signals that earphone reception call/recording MIC (i.e. chest wheat) collects, only provides common MIC bias voltage to earphone.Under noise reduction mode of operation, terminal can promote the MIC bias voltage of earphone, and such as common MIC bias voltage is 2.7V, at this moment improves the MIC bias voltage of 5V.Simultaneously, think that what receive from earpiece side is according to presetting the frequency-division multiplex singal of spectrum allocation may modulates information, and then according to this default spectrum allocation may information, from frequency-division multiplex singal, demodulation obtains noise signal (or also demodulation obtains call/recorded audio signals, or sensor measurement signal), generating contrary with this noise signal phase place is de-noising signal, and is sent to earpiece side.

In embodiments of the present invention, earphone also comprises two kinds of mode of operations, and one is normal mode of operation, and one is noise reduction mode of operation.Wherein, in a normal mode of operation, earphone does not have decrease of noise functions, plays out from terminal received audio signal from receiver namely merely, and can not provide noise signal to terminal, particularly, the noise reduction MIC in earphone can not work.Under noise reduction mode of operation, earphone is powered to noise reduction MIC, and noise reduction MIC works, acquisition noise signal, and carries out frequency division multiplexing process to noise signal, and the multiplexed signals after process is sent to terminal.

Namely this terminal and this earphone are all, when confirming that opposite end possesses active noise reduction function, just can open noise reduction mode of operation.

Alternatively, in embodiments of the present invention, this terminal also 400 to comprise:

Control circuit 450, for when determining that active noise reduction supported by this earphone, continues to provide to this earphone the voltage exceeding preset voltage value by the microphone interface of this terminal.

Alternatively, in embodiments of the present invention, this control circuit 450 specifically for, when this terminal is connected with earphone, in preset time period, provided the voltage exceeding preset voltage value to this earphone by the microphone interface of this terminal;

This transmission circuit 410 also for, receive this earphone that is used to indicate that this earphone sends and support the first previously arranged signal of active noise reduction;

This control circuit 450 for, according to this first previously arranged signal, determine this earphone support active noise reduction.

Be mobile phone below with terminal for example describes the technical scheme that the embodiment of the present invention provides.After mobile phone detects that earphone cord four-part form pin inserts the four-part form audio interface of mobile phone, mobile phone encoding and decoding (codec) chip can be biased (HSMICBIAS) voltage (being such as lifted to 5V from 2.7V) by lifting ear microphone momently, and open recording channel, detect and whether can receive the first previously arranged signal, if after HSMICBIAS voltage lifting a period of time, mobile phone codec chip does not detect the first previously arranged signal, what then think current insertion is common headphones, then 2.7V is returned in HSMICBIAS voltage drop, follow-uply this earphone will be used as common headphones process.

If mobile phone codec chip is by after the lifting of HSMICBIAS voltage, interlock circuit in DSP module in earphone detects HSMICBIAS voltage and raises, then determine that active noise reduction supported by this mobile phone, this earphone also can switch to active noise reduction pattern by general mode, namely DSP module 130 is powered to noise reduction MIC, and carries out frequency division multiplexing process to the noise signal that noise reduction MIC gathers.Meanwhile, earphone can send the first previously arranged signal to mobile phone, indicate earphone for active earphone with this, prompting mobile telephone set also can open active noise reduction pattern, particularly, this first previously arranged signal is such as a special audio signal, the clean audio signal such as very much do not had for this nature of 1k, 8k or 16k.

After mobile phone receives this first previously arranged signal, then determine that this earphone is ANC earphone, then mobile phone is also operated in active noise reduction pattern, namely carries out noise reduction process to the reasonable signal (analog signal) that earphone sends.

Will also be understood that, after earphone is connected with mobile phone, namely after earphone cord four-part form pin inserts the four-part form audio interface of mobile phone, the HSMICBIAS voltage that mobile phone provides is in 2.7V always, not lifting, then this earphone is only operated in general mode, and carry out work as a common headphones, namely this earphone does not have decrease of noise functions.

Alternatively, in embodiments of the present invention, this transmission circuit 410 specifically for, before receiving this frequency-division multiplex singal, receive this earphone send for inquiring the second previously arranged signal whether supporting active noise reduction;

This control circuit 450 for, according to this second previously arranged signal, determine this earphone support active noise reduction;

This transmission circuit 410 also for, send to this earphone and be used to indicate this terminal and support the 3rd previously arranged signal of active noise reduction.

Particularly, this second reservation signal is a special audio signal, the clean audio signal such as very much do not had for this nature of 1k, 8k or 16k.Should be understood that this second reservation signal and the 3rd reservation signal are all known for earphone and terminal.

Alternatively, in embodiments of the present invention, this frequency-division multiplex singal be by by this at least two-way noise signal to be modulated on different frequency spectrums from the sensor measurement signal of the transducer collection on this earphone and to get;

Signal processing circuit 420 also for, by this frequency-division multiplex singal of demodulation, obtain this sensor measurement signal;

This terminal 400 also comprises:

Sensor signal processing circuit 460, for the treatment of this sensor measurement signal.

Particularly, this sensor measurement signal is such as the signal of earphone sensor measurement in place.

Alternatively, in embodiments of the present invention, this sensor measurement signal is used to indicate the range information between the receiver of this earphone and people's ear;

This S250, according to this sensor measurement signal, correspondingly processes, and comprising:

S251, when according to this sensor measurement signal, when the distance determining between the receiver of this earphone and people's ear is more than threshold value, stops to play this mixed signal to this earphone.

Particularly, earphone such as, install an earphone at level sensor, by this sensor measurement signal of this earphone sensor measurement in place, whether this sensor measurement signal can indicate earphone to be worn on ear, such as, can measure the distance between receiver and ear.

To this at least two-way noise signal, this sensor measurement signal and reference clock signal carry out the process of frequency division multiplexing process as indicated above, repeat no more here.

Should be understood that in embodiments of the present invention, this sensor measurement signal can also be the signal that other transducers gather, such as accelerometer, gyroscope or other sensors for measuring human body sport parameter.

Alternatively, in embodiments of the present invention, this frequency-division multiplex singal that this transmission circuit receives is analog signal;

This signal processing circuit 420 specifically for, before this frequency-division multiplex singal of demodulation, analog-to-digital conversion process is carried out to this frequency-division multiplex singal and obtains corresponding digital signal.

Figure 12 shows the indicative flowchart of the method 500 of the Noise reduction provided according to the embodiment of the present invention, and such as the method 500 can be performed by the earphone 100 in above-described embodiment, and as shown in figure 12, the method 500 comprises:

S510, gathers at least two-way noise signal by the noise reduction microphone on earphone;

Particularly, such as noise reduction microphone 110 as shown in Figure 1 gathers this at least two-way noise signal.

S520, by this at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal;

S530, sends this frequency-division multiplex singal by the microphone pin of this earphone to terminal;

Should be understood that this terminal can obtain this at least two-way noise signal according to this frequency-division multiplex singal demodulation.

S540, receives the de-noising signal that this terminal sends according to this frequency-division multiplex singal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

S550, plays this de-noising signal that this terminal sends.

In S510, particularly, acquisition this at least two-way noise signal also can be four tunnel noise signals, six tunnel noise signals or more multipath noise signal, the embodiment of the present invention is not construed as limiting this.Particularly, such as, this at least two-way noise signal be four tunnel noise signals, accordingly, earphone is installed 4 noise reduction MIC, wherein two are distributed in outside and inner side (space namely between receiver and ear) of left receiver respectively, and two other is distributed in outside and the inner side of right receiver respectively, thus gathers 4 tunnel noise signals by these four noise reduction MIC.Should be understood that the noise reduction MIC of employing four noise reduction MIC or greater number gathers ambient noise signal, more comprehensively can obtain the periotic ambient noise of people, thus follow-uply can realize noise reduction better.

Should also be understood that in embodiments of the present invention, earphone can be In-Ear earphone, also can be headphone.Corresponding, the receiver of earphone also can be referred to as earplug or earmuff.The receiver of In-Ear earphone is earplug, and the receiver of headphone can be referred to as earmuff.

S520, by this at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal.Particularly, according to default spectrum allocation may information, by this at least two-way noise signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal, this default spectrum allocation may information comprises the corresponding relation of the multiplexing signal of needs and Reusespectrum.Such as, the process at least two-way noise signal being modulated to frequency-division multiplex singal is: be modulated on the first sub-band of Reusespectrum by the first via noise signal A at least two-way noise signal by the frequency spectrum a at noise signal A place originally, is modulated on the second sub-band of Reusespectrum by the second tunnel noise signal B by the frequency spectrum b at noise signal B place originally.In the present embodiment, particularly, this default spectrum allocation may information includes the corresponding relation of frequency spectrum a and the first sub-band, and the corresponding relation of frequency spectrum b and the second sub-band.Accordingly, in end side, according to this default spectrum allocation may information, demodulation is carried out to this frequency-division multiplex singal, particularly, demodulation is carried out to the signal on the first sub-band in this frequency-division multiplex singal, by the signal recuperation on the first sub-band on frequency spectrum a, thus obtain this first via noise signal A; Demodulation is carried out to the signal on the second sub-band, by the signal recuperation on this second sub-band on frequency spectrum b, thus obtains this second tunnel noise signal B.

Alternatively, in embodiments of the present invention, S520 by this at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal, comprising:

S521, by this at least two-way noise signal and reference clock signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal, this reference clock signal is for this at least two-way noise signal of aliging.

Particularly, as shown in Figure 3, when earpiece side frequency division multiplexing, be assigned on the frequency spectrum of 70kHz with reference to clock signal (signal 6 as shown in Figure 3), accordingly, terminal demodulates this reference clock signal from the frequency spectrum of 70kHz, aligns, and then generate noise signal exactly according to this reference clock signal to demodulation multipath noise signal out.

As shown in Figure 3, particularly, be assigned to reference to clock signal (signal 6 as shown in Figure 3): 70kHz.

Alternatively, in embodiments of the present invention, this noise reduction microphone is numeric type microphone, and S530 sends this frequency-division multiplex singal by the microphone pin of this earphone to terminal, comprising:

S531, carries out digital-to-analogue conversion by this frequency-division multiplex singal, obtains the analog signal that this frequency-division multiplex singal is corresponding;

S532, sends the frequency-division multiplex singal after this digital-to-analogue conversion by this microphone pin to this terminal.

Should be understood that this noise reduction microphone can be also simulation microphone, then in S520, first will two-way noise signal analog-to-digital conversion be at least digital signal, then multiply digital signals is modulated on different spectral, generates frequency-division multiplex singal, carrying out follow-up process.

Alternatively, in embodiments of the present invention, S540 receives the de-noising signal that this terminal sends according to this frequency-division multiplex singal, comprising:

S550 plays this de-noising signal that this terminal sends, and comprising:

Play this de-noising signal, and play this useful audio signal.

Particularly, this useful audio signal is such as the audio signal such as music or conversation signal.Thus this de-noising signal and useful audio signal play out by headset earpiece, and user just can hear comparatively pure music or call.

Alternatively, in embodiments of the present invention, the method 500 also comprises:

S560, by the call on this earphone/recording microphone elegance collection voice signal;

S520 by this at least two-way noise signal be modulated on different frequency spectrums, obtain frequency-division multiplex singal, comprising:

S522, by this at least two-way noise signal and this voice signal be modulated on different frequency spectrums, obtain this frequency-division multiplex singal.

Particularly, by voice signal frequency division multiplexing together with at least two-way noise signal, be defined as a road multiplexed signals, suppose to converse/bandwidth of operation of data of voice signal that recording MIC exports is 20kHz, for the frequency spectrum of the data allocations of the voice signal of MIC output of conversing or record is: 0 ~ 24kHz, as in Fig. 3 being the frequency spectrum that signal 1 distributes.For noise signal distributes frequency spectrum as described above, repeat no more here.

Alternatively, in embodiments of the present invention, S510 gathers at least two-way noise signal by the noise reduction microphone on earphone, comprising:

S511, determines whether this terminal supports active noise reduction;

S512, when determining that this terminal supports active noise reduction, by this at least two-way noise signal of the noise reduction microphone collection on this earphone.

Alternatively, in embodiments of the present invention, S511 determines whether this terminal supports active noise reduction, comprising:

S511A, when the voltage that this terminal obtained from this microphone pin provides exceedes preset voltage value, determines that this terminal supports active noise reduction;

The method 100 also comprises:

S570, by this microphone pin, sends to this terminal and is used to indicate the first previously arranged signal that active noise reduction also supported by this earphone.

Particularly, as shown in Figure 4 and Figure 5, description as detailed above, repeats no more here.

S511B, sends for inquiring the second previously arranged signal whether supporting active noise reduction to this terminal;

S511C, receives the 3rd previously arranged signal that this terminal sends according to this second previously arranged signal, and the 3rd previously arranged signal is used to indicate this terminal and supports active noise reduction;

S511D, according to the 3rd previously arranged signal, determines that this terminal supports active noise reduction.

S580, by the transducer pick-up transducers measuring-signal on this earphone;

S523, by this at least two-way noise signal be modulated on different frequency spectrums from this sensor measurement signal, obtain this frequency-division multiplex singal.

Particularly, in S520 frequency division multiplexing process, for the frequency spectrum of the data allocations of sensor measurement signal is: 78kHz ~ 88kHz, as in Fig. 3 being the frequency spectrum that signal 7 distributes.

Should be understood that the earphone 300 that the method 500 of the Noise reduction provided according to the embodiment of the present invention also can be provided by above-described embodiment realizes.

Figure 13 shows the indicative flowchart of the method 600 of the Noise reduction provided according to the embodiment of the present invention, and the terminal 400 that the method 600 such as can be provided by foregoing embodiments performs, and as shown in figure 13, the method comprises:

S610, the frequency-division multiplex singal of earphone transmission is received by the microphone interface of terminal, wherein, this frequency-division multiplex singal is get by least two-way noise signal of the noise reduction microphone collection on this earphone being modulated on different frequency spectrums, and this microphone interface is connected with the microphone pin of this earphone;

Such as, this noise reduction microphone is two noise reduction microphones, near the left and right receiver being arranged on earphone respectively, for gathering the noise signal that ear can be heard.

S620, this frequency-division multiplex singal of demodulation obtains this at least two-way noise signal;

S630, according to this at least two-way noise signal generate de-noising signal, this de-noising signal be used for this at least two-way noise signal carry out noise reduction;

S640, sends this de-noising signal to this earphone.

Should be understood that earphone is connected with the four-part form audio interface of terminal by the four-part form pin of earphone cord, carry out work.

In S620, this frequency-division multiplex singal of demodulation obtains this at least two-way noise signal, particularly, such as in earpiece side, according to presetting spectrum allocation may information, by will at least two-way noise signal be modulated to obtain this frequency-division multiplex singal on different spectral, then in end side, can based on this default spectrum allocation may information, this frequency-division multiplex singal of demodulation is to obtain this at least two-way noise signal.

Particularly, earpiece side, to the description of at least frequency division multiplexing process composition graphs 3 as detailed above of two-way noise signal, repeats no more here.

Alternatively, in embodiments of the present invention, this frequency-division multiplex singal that this earphone sends is analog signal;

This frequency-division multiplex singal of S620 demodulation obtains this at least two-way noise signal, comprising:

S621, carries out analog-to-digital conversion process to this frequency-division multiplex singal and obtains corresponding digital signal;

S622, the frequency-division multiplex singal of demodulation after analog-to-digital conversion, obtains this at least two-way noise signal.

Alternatively, in embodiments of the present invention, S640 sends this de-noising signal to this earphone, comprising:

This de-noising signal and useful audio signal is sent to this earphone.

Particularly, useful audio signal is such as music or conversation signal etc.Alternatively, in S640, by useful audio signal being superposed with de-noising signal, obtaining mixed signal, sending to earphone.

This frequency-division multiplex singal of demodulation, obtains this at least two-way noise signal and this reference clock signal, and to align this at least two-way noise signal according to this reference clock signal;

S630, according to this at least two-way noise signal generate de-noising signal, comprising:

This frequency-division multiplex singal of demodulation, obtains this at least two-way noise signal and this voice signal;

Described method 600 also comprises:

S650, by this voice signal of speed signal processing circuit process of this terminal.

Alternatively, in embodiments of the present invention, the method 600 also comprises:

S660, determines whether this earphone supports active noise reduction;

S670, when determining that active noise reduction supported by this earphone, continues to provide to this earphone the voltage exceeding preset voltage value by the microphone interface of this terminal.

Alternatively, in embodiments of the present invention, S660 determines whether this earphone supports active noise reduction, comprising:

S661, when this terminal is connected with earphone, provides the voltage exceeding preset voltage value in preset time period to this earphone by the microphone interface of this terminal;

S662, receives the first previously arranged signal being used to indicate this earphone support active noise reduction that this earphone sends according to this voltage;

S663, according to this first previously arranged signal, determines that active noise reduction supported by this earphone.

Detailed process description as detailed above, repeats no more here.

S664, receive this earphone send for inquiring the second previously arranged signal whether supporting active noise reduction;

S665, according to this second previously arranged signal, determines that active noise reduction supported by this earphone;

S666, sends to this earphone and is used to indicate the 3rd previously arranged signal that this terminal supports active noise reduction.

This frequency-division multiplex singal of demodulation, obtains this at least two-way noise signal and this sensor measurement signal;

The method 600 also comprises:

S680, by this sensor measurement signal of sensor signal processing circuit process of this terminal.

Particularly, such as, this transducer on earphone is that earphone is at level sensor, by this sensor measurement signal of this earphone sensor measurement in place, whether this sensor measurement signal can indicate earphone to be worn on ear, such as, can measure the distance between receiver and ear.

Should be understood that in embodiments of the present invention, this sensor measurement signal can also be the signal that other transducers gather, such as, be accelerometer, gyroscope or other sensors for measuring human body sport parameter.

As shown in figure 14, the embodiment of the present invention also provides a kind of system 700 for active noise reduction, and this system comprises the earphone 710 and terminal 720 that embodiment above provides.

Particularly, the earphone 100, earphone 200 or the earphone 300 that provide for foregoing embodiments of this earphone 710; The terminal 400 that terminal 720 provides for foregoing embodiments.

This earphone 710 is connected with the four-part form audio interface of terminal by the four-part form pin on earphone cord with terminal 720.

Particularly, as shown in figure 15, noise reduction MIC acquisition noise multipath noise signal in the earphone 710 that the embodiment of the present invention provides, signal processing module 711 is (corresponding to the signal processing circuit 120 that foregoing embodiments describes, or integrated treatment circuit 320) by carrying out frequency division multiplexing process to this noise signal, obtain frequency-division multiplex singal, then send this frequency-division multiplex singal by the data feedback channel 722 of terminal 720 to this terminal 720.Signal processing module 721 (signal processing circuit 420 corresponding to foregoing embodiments describes) in this terminal 720 is by this frequency-division multiplex singal of demodulation, recover this noise signal, and generate the de-noising signal contrary with this noise signal phase place, send mixed signal to earphone 710 finally by down going channel 723 simultaneously, this mixed signal comprises de-noising signal, can also include by audio signal, such as music or voice signal.Alternatively, this mixed signal is the signal after useful audio signal superposes with de-noising signal.

As from the foregoing, in the system that the embodiment of the present invention provides, active noise reduction can be realized.And the processing module do not comprised in the earphone that provides of the embodiment of the present invention for generating de-noising signal, also without the need to solving the powerup issue of this processing module, compared to existing ANC earphone, under the prerequisite realizing active noise reduction, the structure of earphone can be simplified widely, reduce its volume, reduce production cost, also can improve the reliability of earphone.

In addition, in embodiments of the present invention, the processing module being used for generating de-noising signal is placed as end side, the chip ability that end side is powerful can be utilized, better performance can be possessed, and autgmentability is better.Such as this terminal is mobile phone, and mobile phone side software of can directly upgrading, directly obtains the lifting of performance, and can adopt the earphone of this technology by adaptive many moneys.Therefore, the scheme of the active noise reduction that the embodiment of the present invention provides, compared to prior art, its application is more flexible.

In embodiments of the present invention, the combination of earphone 300 and terminal 500 can realize active noise reduction.And the processing module do not comprised in the earphone 300 that provides of the embodiment of the present invention for generating de-noising signal, also without the need to solving the powerup issue of this processing module, compared to existing ANC earphone, under the prerequisite realizing active noise reduction, the structure of earphone can be simplified widely, reduce its volume, reduce production cost, also can improve the reliability of earphone.

Should also be understood that the differentiation that first, second, third, fourth and the various numeral number that relate to only are carried out for convenience of description herein, be not used for limiting the scope of the embodiment of the present invention.Should be understood that character "/" herein, general expression forward-backward correlation is to the relation liking a kind of "or".

Should understand, in various embodiments of the present invention, the size of the sequence number of above-mentioned each process does not also mean that the priority of execution sequence, and the execution sequence of each process should be determined with its function and internal logic, and should not form any restriction to the implementation process of the embodiment of the present invention.

Those of ordinary skill in the art can recognize, in conjunction with unit and the algorithm steps of each example of embodiment disclosed herein description, can also realize with the combination of electronic hardware or computer software and electronic hardware.These functions perform with hardware or software mode actually, depend on application-specific and the design constraint of technical scheme.Professional and technical personnel can use distinct methods to realize described function to each specifically should being used for, but this realization should not thought and exceeds scope of the present invention.

Those skilled in the art can be well understood to, and for convenience and simplicity of description, the specific works process of the system of foregoing description, device and unit, with reference to the corresponding process in preceding method embodiment, can not repeat them here.

In several embodiments that the application provides, should be understood that disclosed system, apparatus and method can realize by another way.Such as, device embodiment described above is only schematic, such as, the division of described unit, be only a kind of logic function to divide, actual can have other dividing mode when realizing, such as multiple unit or assembly can in conjunction with or another system can be integrated into, or some features can be ignored, or do not perform.Another point, shown or discussed coupling each other or direct-coupling or communication connection can be by some interfaces, and the indirect coupling of device or unit or communication connection can be electrical, machinery or other form.

The described unit illustrated as separating component or can may not be and physically separates, and the parts as unit display can be or may not be physical location, namely can be positioned at a place, or also can be distributed in multiple network element.Some or all of unit wherein can be selected according to the actual needs to realize the object of the present embodiment scheme.

In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, also can be that the independent physics of unit exists, also can two or more unit in a unit integrated.

If described function using the form of SFU software functional unit realize and as independently production marketing or use time, can be stored in a computer read/write memory medium.Based on such understanding, the part of the part that technical scheme of the present invention contributes to prior art in essence in other words or this technical scheme can embody with the form of software product, this computer software product is stored in a storage medium, comprising some instructions in order to make a computer equipment (can be personal computer, server, or the network equipment etc.) perform all or part of step of method described in each embodiment of the present invention.And aforesaid storage medium comprises: USB flash disk, portable hard drive, read-only memory (ROM, Read-OnlyMemory), random access memory (RAM, RandomAccessMemory), magnetic disc or CD etc. various can be program code stored medium.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; change can be expected easily or replace, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of described claim.

Claims

1. an earphone, is characterized in that, comprising:

Noise reduction microphone, for gathering at least two-way noise signal;

Signal processing circuit, for described at least two-way noise signal is modulated to different frequency spectrums, obtains frequency-division multiplex singal;

Transmission circuit, described frequency-division multiplex singal is sent to terminal for the microphone pin by described earphone, wherein said transmission circuit also for, receive the de-noising signal that described terminal sends according to described frequency-division multiplex singal, described de-noising signal is used for carrying out noise reduction to described at least two-way noise signal;

Loud speaker, for playing the described de-noising signal that described terminal sends.

2. earphone according to claim 1, is characterized in that, described earphone also comprises:

Power circuit, for obtaining the voltage that described terminal provides from described microphone pin, and provides power supply according to described voltage to described noise reduction microphone.

3. earphone according to claim 1 and 2, it is characterized in that, described signal processing circuit specifically for, described at least two-way noise signal and reference clock signal are modulated on different frequency spectrums, obtain described frequency-division multiplex singal, described reference clock signal is at least two-way noise signal described in aliging.

4. earphone according to any one of claim 1 to 3, is characterized in that, described earphone also comprises:

Call/recording microphone wind, for gathering voice signal;

Described signal processing circuit specifically for, described at least two-way noise signal and described voice signal are modulated on different frequency spectrums, obtain described frequency-division multiplex singal.

5. earphone according to any one of claim 1 to 4, is characterized in that, described earphone also comprises:

Noise reduction control circuit, for determining whether described terminal supports active noise reduction, and when determining that described terminal supports active noise reduction, sends the control signal being used to indicate acquisition noise signal to described noise reduction microphone;

Wherein, described noise reduction microphone specifically for, according to described control signal, at least two-way noise signal described in collection.

6. earphone according to claim 5, is characterized in that, described noise reduction control circuit specifically for, when the voltage that the described terminal obtained from described microphone pin provides exceedes preset voltage value, determine described terminal support active noise reduction;

Described transmission circuit also for, by described microphone pin, send to described terminal and be used to indicate the first previously arranged signal that active noise reduction also supported by described earphone.

7. earphone according to claim 5, is characterized in that,

Described transmission circuit also for, send for inquiring the second previously arranged signal whether supporting active noise reduction to described terminal;

Described transmission circuit also for, receive described terminal according to described second previously arranged signal send the 3rd previously arranged signal, described 3rd previously arranged signal be used to indicate described terminal support active noise reduction;

Described noise reduction control circuit specifically for, according to described 3rd previously arranged signal that described transmission circuit receives, determine described terminal support active noise reduction.

8. earphone according to any one of claim 1 to 7, is characterized in that, described earphone also comprises:

Transducer, for pick-up transducers measuring-signal;

Described signal processing circuit specifically for, described at least two-way noise signal is modulated on different frequency spectrums from described sensor measurement signal, obtains described frequency-division multiplex singal.

9. earphone according to any one of claim 1 to 8, is characterized in that, described noise reduction microphone is numeric type microphone, and described earphone also comprises:

D/A converting circuit, is treated to analog signal for the described frequency-division multiplex singal described signal processing circuit obtained;

Wherein, described transmission circuit specifically for, send described analog signal by described microphone pin to described terminal.

10. earphone according to any one of claim 1 to 9, is characterized in that, the protection bandwidth of described frequency-division multiplex singal is not less than preset value.

11. earphones according to any one of claim 1 to 10, is characterized in that, described transmission circuit specifically for, reception described de-noising signal while, also receive described terminal send useful audio signal;

Described loud speaker specifically for, broadcasting described de-noising signal while, also play described useful audio signal.

12. 1 kinds of terminals, is characterized in that, comprising:

Transmission circuit, for being received the frequency-division multiplex singal that earphone sends by the microphone interface of terminal, wherein, described frequency-division multiplex singal is get by least two-way noise signal of the noise reduction microphone collection on described earphone being modulated on different frequency spectrums, and described microphone interface is connected with the microphone pin of described earphone;

Signal processing circuit, at least two-way noise signal described in obtaining for frequency-division multiplex singal described in demodulation;

Dolby circuit, for described in determining according to described signal processing circuit at least two-way noise signal generate de-noising signal, described de-noising signal is used for carrying out noise reduction to described at least two-way noise signal;

Described transmission circuit also for, send described de-noising signal to described earphone.

13. terminals according to claim 12, it is characterized in that, described frequency-division multiplex singal is get by described at least two-way noise signal and reference clock signal being modulated on different frequency spectrums, and described reference clock signal is at least two-way noise signal described in aliging;

Described signal processing circuit also for, obtain described reference clock signal by frequency-division multiplex singal described in demodulation, and according to the alignment of described reference clock signal at least two-way noise signal.

14. terminals according to claim 12 or 13, it is characterized in that, described frequency-division multiplex singal is get by described at least two-way noise signal being modulated on different frequency spectrums from the voice signal of the call on described earphone/recording microphone elegance collection;

Signal processing circuit also for, obtain described voice signal by frequency-division multiplex singal described in demodulation;

Described terminal also comprises:

Speed signal processing circuit, for the treatment of described voice signal.

15., according to claim 12 to the terminal according to any one of 14, is characterized in that, described terminal also comprises:

Control circuit, for when determining that active noise reduction supported by described earphone, continues to provide to described earphone the voltage exceeding preset voltage value by the microphone interface of described terminal.

16. terminals according to claim 15, is characterized in that,

Described control circuit specifically for, when described terminal is connected with earphone, in preset time period, provided the voltage exceeding preset voltage value to described earphone by the microphone interface of described terminal;

Described transmission circuit also for, receive the described earphone that is used to indicate that described earphone sends and support the first previously arranged signal of active noise reduction;

Described control circuit is used for, and according to described first previously arranged signal, determines that active noise reduction supported by described earphone.

17. terminals according to claim 15, is characterized in that,

Described transmission circuit specifically for, before receiving described frequency-division multiplex singal, receive described earphone send for inquiring the second previously arranged signal whether supporting active noise reduction;

Described control circuit is used for, and according to described second previously arranged signal, determines that active noise reduction supported by described earphone;

Described transmission circuit also for, send to described earphone and be used to indicate the 3rd previously arranged signal that described terminal supports active noise reduction.

18. according to claim 12 to the terminal according to any one of 17, it is characterized in that, described frequency-division multiplex singal is get by described at least two-way noise signal being modulated on different frequency spectrums from the sensor measurement signal of the transducer collection on described earphone;

Signal processing circuit also for, by frequency-division multiplex singal described in demodulation, obtain described sensor measurement signal;

Described terminal also comprises:

Sensor signal processing circuit, for the treatment of described sensor measurement signal.

19., according to claim 12 to the terminal according to any one of 18, is characterized in that, the described frequency-division multiplex singal that described transmission circuit receives is analog signal;

Described signal processing circuit specifically for, before frequency-division multiplex singal described in demodulation, analog-to-digital conversion process is carried out to described frequency-division multiplex singal and obtains corresponding digital signal.

20., according to claim 12 to the terminal according to any one of 19, is characterized in that, the protection bandwidth of described frequency-division multiplex singal is not less than preset value.

21., according to claim 12 to the terminal according to any one of 20, is characterized in that, described transmission circuit specifically for, when sending described de-noising signal to described terminal, also send useful audio signal to described terminal.

The method of 22. 1 kinds of Noise reductions, is characterized in that, comprising:

Described at least two-way noise signal is modulated on different frequency spectrums, obtains frequency-division multiplex singal;

Described frequency-division multiplex singal is sent to terminal by the microphone pin of described earphone;

Receive the de-noising signal that described terminal sends according to described frequency-division multiplex singal, described de-noising signal is used for carrying out noise reduction to described at least two-way noise signal;

Play the described de-noising signal that described terminal sends.

23. methods according to claim 22, is characterized in that, are describedly modulated on different frequency spectrums by described at least two-way noise signal, obtain frequency-division multiplex singal, comprising:

Described at least two-way noise signal and reference clock signal are modulated on different frequency spectrums, obtain described frequency-division multiplex singal, described reference clock signal is at least two-way noise signal described in aliging.

24. methods according to claim 22 or 23, it is characterized in that, described method also comprises:

By the call on described earphone/recording microphone elegance collection voice signal;

Described described at least two-way noise signal is modulated on different frequency spectrums, obtains frequency-division multiplex singal, comprising:

Described at least two-way noise signal and described voice signal are modulated on different frequency spectrums, obtain described frequency-division multiplex singal.

25. methods according to any one of claim 22 to 24, is characterized in that, describedly gather at least two-way noise signal by the noise reduction microphone on earphone, comprising:

Determine whether described terminal supports active noise reduction;

When determining that described terminal supports active noise reduction, at least two-way noise signal described in being gathered by noise reduction microphone on described earphone.

26. methods according to claim 25, is characterized in that, describedly determine whether described terminal supports active noise reduction, comprising:

When the voltage that the described terminal obtained from described microphone pin provides exceedes preset voltage value, determine that described terminal supports active noise reduction;

Described method also comprises:

By described microphone pin, send to described terminal and be used to indicate the first previously arranged signal that active noise reduction also supported by described earphone.

27. methods according to claim 25, is characterized in that, describedly determine whether described terminal supports active noise reduction, comprising:

Send for inquiring the second previously arranged signal whether supporting active noise reduction to described terminal;

Receive the 3rd previously arranged signal that described terminal sends according to described second previously arranged signal, described 3rd previously arranged signal is used to indicate described terminal and supports active noise reduction;

According to described 3rd previously arranged signal, determine that described terminal supports active noise reduction.

28. methods according to any one of claim 22 to 27, it is characterized in that, described method also comprises:

By the transducer pick-up transducers measuring-signal on described earphone;

Described at least two-way noise signal is modulated on different frequency spectrums from described sensor measurement signal, obtains described frequency-division multiplex singal.

29. methods according to any one of claim 22 to 28, it is characterized in that, described noise reduction microphone is numeric type microphone, and the described microphone pin by described earphone sends described frequency-division multiplex singal to terminal, comprising:

Described frequency-division multiplex singal is carried out digital-to-analogue conversion, obtains the analog signal that described frequency-division multiplex singal is corresponding;

Sent through described analog signal to described terminal by described microphone pin.

30. methods according to any one of claim 22 to 29, it is characterized in that, the protection bandwidth of described frequency-division multiplex singal is not less than preset value.

31. methods according to any one of claim 22 to 30, is characterized in that the de-noising signal that the described terminal of described reception sends according to described frequency-division multiplex singal comprises:

Receive the de-noising signal that described terminal sends according to described frequency-division multiplex singal, and receive the useful audio signal of described terminal transmission;

The described de-noising signal that the described terminal of described broadcasting sends, comprising:

Play described de-noising signal, and play described useful audio signal.

The method of 32. 1 kinds of Noise reductions, is characterized in that, comprising:

The frequency-division multiplex singal of earphone transmission is received by the microphone interface of terminal, wherein, described frequency-division multiplex singal is get by least two-way noise signal of the noise reduction microphone collection on described earphone being modulated on different frequency spectrums, and described microphone interface is connected with the microphone pin of described earphone;

At least two-way noise signal described in frequency-division multiplex singal described in demodulation obtains;

Generate de-noising signal according to described at least two-way noise signal, described de-noising signal is used for carrying out noise reduction to described at least two-way noise signal;

Described de-noising signal is sent to described earphone.

33. methods according to claim 32, it is characterized in that, described frequency-division multiplex singal is get by described at least two-way noise signal and reference clock signal being modulated on different frequency spectrums, and described reference clock signal is at least two-way noise signal described in aliging;

At least two-way noise signal described in frequency-division multiplex singal described in described demodulation obtains, comprising:

Frequency-division multiplex singal described in demodulation, at least two-way noise signal and described reference clock signal described in acquisition, and according to described reference clock signal alignment at least two-way noise signal;

Described in described basis, at least two-way noise signal generates de-noising signal, comprising:

According to alignment after described at least two-way noise signal generate described de-noising signal.

34. methods according to claim 32 or 33, it is characterized in that, described frequency-division multiplex singal is get by described at least two-way noise signal being modulated on different frequency spectrums from the voice signal of the call on described earphone/recording microphone elegance collection;

Frequency-division multiplex singal described in demodulation, at least two-way noise signal and described voice signal described in acquisition;

Described method also comprises:

By voice signal described in the speed signal processing circuit process of described terminal.

35. methods according to any one of claim 32 to 34, it is characterized in that, described method also comprises:

Determine whether described earphone supports active noise reduction;

When determining that active noise reduction supported by described earphone, continue to provide to described earphone the voltage exceeding preset voltage value by the microphone interface of described terminal.

36. methods according to claim 35, is characterized in that, describedly determine whether described earphone supports active noise reduction, comprising:

When described terminal is connected with earphone, in preset time period, provided the voltage exceeding preset voltage value to described earphone by the microphone interface of described terminal;

Receive the first previously arranged signal being used to indicate described earphone support active noise reduction that described earphone sends according to described voltage;

According to described first previously arranged signal, determine that active noise reduction supported by described earphone.

37. methods according to claim 35, is characterized in that, describedly determine whether described earphone supports active noise reduction, comprising:

Receive described earphone send for inquiring the second previously arranged signal whether supporting active noise reduction;

According to described second previously arranged signal, determine that active noise reduction supported by described earphone;

Send to described earphone and be used to indicate the 3rd previously arranged signal that described terminal supports active noise reduction.

38. methods according to any one of claim 32 to 37, it is characterized in that, described frequency-division multiplex singal is get by described at least two-way noise signal being modulated on different frequency spectrums from the sensor measurement signal of the transducer collection on described earphone;

Frequency-division multiplex singal described in demodulation, at least two-way noise signal and described sensor measurement signal described in acquisition;

Described method also comprises:

By sensor measurement signal described in the sensor signal processing circuit process of described terminal.

39. methods according to any one of claim 32 to 38, is characterized in that, the described frequency-division multiplex singal that described earphone sends is analog signal;

Analog-to-digital conversion process is carried out to described frequency-division multiplex singal and obtains corresponding digital signal;

The frequency-division multiplex singal of demodulation after analog-to-digital conversion, at least two-way noise signal described in acquisition.

40. methods according to any one of claim 32 to 39, it is characterized in that, the protection bandwidth of described frequency-division multiplex singal is not less than preset value.

41. methods according to any one of claim 32 to 40, is characterized in that, describedly send described de-noising signal to described earphone, comprising:

Described de-noising signal and useful audio signal is sent to described earphone.

42. 1 kinds, for the system of active noise reduction, is characterized in that, comprise the earphone according to any one of claim 1 to claim 11 and the terminal according to any one of claim 12 to claim 21.