CN200973120Y

CN200973120Y - Bi-microphone anti-noise transmitter

Info

Publication number: CN200973120Y
Application number: CN 200620128107
Authority: CN
Inventors: 徐海波; 徐忠义
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-11-13
Filing date: 2006-11-13
Publication date: 2007-11-07
Anticipated expiration: 2016-11-13

Abstract

The utility model relates to a designed improvement for the single microphone noise resistance telephone transmitter. The improved structure comprises an audio noise filtration circuit and a microphone circuit. The key design is that the audio noise filtration circuit adopts the integrated circuit chip ZY1421 and the peripheral matching capacitance element; the double-direction microphone circuit is combined by two microphones that are basically consistent in structure and technical indices and utilizes the matching resistance to connect in parallel between the power supply and the ground line; the collected audio signals are respectively led out from the two microphones and are then respectively led to the two input terminals of the chip ZY1421 through the capacitance. After the internal circuit processing, the voice signal after noise elimination is led out from the output terminal of the chip ZY1421.

Description

Dual microphone anti-noise transmitter

Technical field

The utility model belongs to the anti-noise technology in the communication field voice transfer, a kind of specifically design improvement of dual microphone anti-noise transmitter.

Background technology

Along with the develop rapidly of science and technology,, more and more entered our production, life and various social activities practice with the electronic product that audio-frequency information transmits.To the audio-frequency information that is transmitted, particularly the quality requirement of voice messaging is more and more higher.Any error of crucial language in the important social activities all can cause heavy losses without redemption.Yet the randomness of application scenario is unforeseen, and incident noise jamming brings worried to high-quality voice messaging and inconvenience almost can't overcome.Mobile phone, intercom and computer and all need suppress the audio transmission product of noise jamming, press for from the source raising of audio signal sample and enter effective audio signal anti-noise ability of transmission system, carry out communication, the quality that conveys a message and effect to improve these products of utilization.The dsp chip that produces is the microprocessor audio signal analysis treatment system of a complexity for this reason.Have certain effect, can improve the quality of audio transmission greatly.But its complex structure, cost costliness, the supporting software support of needs can't popularization and applications on common electronic product, the particularly product for civilian use.The ZY1421 chip is a kind of pure hardware circuit, does not need the software support in the use.The success of ZY1421 pronounciation processing chip a kind ofly lays the foundation at inhibition noise jamming voice entry system that can popularization and application on the performance, on the price for we design.

Summary of the invention

Goal of the invention of the present utility model provides a kind of structural design of dual microphone anti-noise transmitter, adapting to occasion to strong noise, or on the electronic product that voice accuracy and readability are had higher requirements.

Comprise in the structural design of the present utility model by two directional microphone circuit and the audio-frequency noise filtering circuit that is connected thereafter.Crucial design is that to have adopted a model be that the extremely supporting peripheral capacity cell of ZY1421 special chip is formed to the audio-frequency noise filtering circuit.Two directional microphone circuit are that the microphone by two structures and technical indicator basically identical makes up setting dorsad, is connected in parallel between power supply and the ground wire by means of build-out resistor in the space, the audio signal that is collected is drawn from two microphones respectively, cause two inputs of chip ZY1421 respectively by electric capacity, after the chip internal processing of circuit, eliminate the voice signal of noise and draw from the output of chip ZY1421.

In order further to adapt to of the space length requirement of chip ZY1421 internal circuit configuration to two microphone input signals; It is reflected at the phase difference value that vibration parameters promptly is an audio signal; One can be on two one of them microphone of directional microphone circuit in parallel postpones electric capacity, with adapt to the electronic product space narrow and small, can't reach requirement to two directional microphone installing space distances.

Two structures and the essentially identical full directional microphone of technical indicator when making up dorsad in the space, and do not require that sensitivity is just the same.Even there is the difference of 8dB also can obtain the adjustment of chip internal circuit.Because these two microphones have a certain physical distance the space, can be the signal in the far field (the noise source of sound is outside microphone 1m) of the near field of voice in the space (source of sound apart from microphone within the 15cm), noise and two input (INL that their delay time signal is sent into the ZY1421 chip, INR), promptly become noise input microphone owing to postpone that microphone of the access of electric capacity.The adjustment that postpones the circuit in electric capacity and the chip can be regarded as the processing that the noise that imports into is carried out, and is equivalent to the delay of two microphone space lengths.To guarantee ZY1241 chip judging to noise; The technique effect of handling and filtering.

The intensity of noise can obviously reduce in the audio frequency component after treatment, and it is that the design produces positive technique effect that distance has obtained strengthening with voice interior, that import from microphone at 15cm.Good effect of the present utility model also comprises the obvious lifting of directive property, effectively improves the filtering quality of transmitter background noise, and the noise that the microphone of particularly adjusting the distance surpasses 15-30cm has the obvious suppression effect.And cost is low, and supporting technical conditions are simple, and support that does not need software or the like has special meaning to popularization and application on the product for civilian use.

How further specify goal of the invention of the present utility model below in conjunction with accompanying drawing realizes.

Description of drawings

Fig. 1 is a structured flowchart of the present utility model.

Fig. 2 is the electrical schematic diagram of embodiment 1 of the present utility model

Fig. 3 is the electrical schematic diagram of embodiment 2 of the present utility model

Wherein 1 represent microphone circuit, 1A, 1B represent microphone, and 2 represent the audio-frequency noise treatment circuit, 2A represents prime audio-frequency noise treatment circuit, and 2B represents back level audio-frequency noise treatment circuit, and 2C represents delay circuit, U represents operational amplifier, and R1-R3 represents resistance, and C1-C15 represents electric capacity.

Embodiment

From accompanying drawing project organization of the present utility model as can be seen, comprise two microphone circuits 1 and the audio-frequency noise filtering circuit 2 that is connected thereafter that point to.It is that the extremely supporting peripheral capacity cell (C5-C8) of ZY1421 special chip is formed that crucial improvement has been to adopt in the audio-frequency noise filtering circuit 2 model.The microphone circuit 1 of two sensings is by the microphone (1A of two structures and technical indicator basically identical, 1B) make up dorsad in the space setting, be connected in parallel between power supply and the ground wire by means of build-out resistor (R1, R2), the audio signal that is collected is respectively from two microphone (1A, draw 1B), respectively by electric capacity (C1, C2) cause two inputs of chip ZY1421, eliminate the voice signal of noise and draw through C3 from the output of chip ZY1421.

In order further to adapt to the small space of electronic product, remedying the deficiency of two directional microphone space lengths, in two directional microphone circuit 1 one, microphone 1B have gone up a capacitor C 15 in parallel.

Embodiment 2 is in order to adapt to high-grade electronic product or the anti-noise of voice to be had the needs of the application scenario of requirements at the higher level.This embodiment sound intermediate frequency noise filtering circuit (2) further adopted two models be the two poles of the earth noise processing circuit of forming of the extremely supporting peripheral capacity cell of ZY1421 special chip (2A, 2B) and a delay circuit 2C be composited.Audio signal is from microphone (1A, cause two inputs of the ZY1421 special chip among the prime noise processing circuit 2A 1B), the voice signal that removes after handling through de-noising is divided into two-way after the output of this chip ZY1421 is drawn, the capacitor C 3 of leading up to directly is connected to the input of back utmost point noise processing circuit 2B chip ZY1421, deliver to another input of back utmost point noise processing circuit 2B chip ZY1421 after handle through delay circuit 2C on another road, the output of the chip ZY1421 of de-noising voice signal from the utmost point noise processing circuit 2B of back is drawn.

The phase-shift circuit that above-mentioned delay circuit 2C is made up of operational amplifier U, introduce from the input of operational amplifier U through capacitor C 1 through the audio signal of pre-treatment, from another input of audio frequency utmost point noise processing circuit 2B chip ZY1421 after resistance R 3, the capacitor C 4 of series connection are connected on of the output of operational amplifier U.Can further improve the technical indicator of anti-noise by adjustment to resistance R 3, capacitor C 4 numerical value.

Forward and backward level audio-frequency noise treatment circuit (2A, all be to adopt the capacity cell of the extremely peripheral coupling of chip ZY1421 to form 2B), two-way audio signal with phase difference is introduced from two inputs respectively, and the voice signal after the de-noising is sent from the output of back level audio-frequency noise treatment circuit (2B).

Microphone (1A, flexible sheet in structure 1B) should adopt with the lot number material, each microphone is connected with build-out resistor and is arranged between power supply and the ground wire, the audio signal of being gathered is from microphone (1A, 1B) with build-out resistor (R1, R2) junction draws that (C1 C2) delivers to prime audio-frequency noise treatment circuit (2A, 2B) two of chip ZY1421 inputs by electric capacity.

Claims

1, dual microphone anti-noise transmitter, form with the audio-frequency noise filtering circuit (2) that is connected thereafter by two directional microphone circuit (1), it is characterized in that it is that the extremely supporting peripheral capacity cell (C5-C8) of ZY1421 special chip is formed that audio-frequency noise filtering circuit (2) adopts a model, two directional microphone circuit (1) are by the microphone (1A of two structures and technical indicator basically identical, 1B) make up setting dorsad in the space, by means of build-out resistor (R1, R2) be connected in parallel between power supply and the ground wire, the audio signal that is collected is respectively from two microphone (1A, draw 1B), by electric capacity (C1, C2) cause two inputs of chip ZY1421, eliminate the voice signal of noise and draw through C3 from the output of chip ZY1421.

2,, it is characterized in that in two directional microphone circuit (1) that microphone (1B) gone up a capacitor C 15 in parallel according to the said dual microphone anti-noise of claim 1 transmitter.

3, according to the said dual microphone anti-noise of claim 2 transmitter, it is characterized in that it is the two poles of the earth noise processing circuit (2A that the extremely supporting peripheral capacity cell of ZY1421 special chip is formed that audio-frequency noise filtering circuit (2) adopts two models, 2B) and delay circuit (2C) form, audio signal is from microphone (1A, cause two inputs of the ZY1421 special chip in the prime noise processing circuit (2A) 1B), voice signal after remove handling through de-noising is divided into two-way from the output of this chip ZY1421 after drawing, one the tunnel after C3 directly is connected to the input of utmost point noise processing circuit (2B) chip ZY1421, deliver to another input of back utmost point noise processing circuit (2B) chip ZY1421 after handle through delay circuit (2C) on another road, the output of the chip ZY1421 of de-noising voice signal from back level noise processing circuit (2B) is drawn.

4, according to the said dual microphone anti-noise of claim 3 transmitter, it is characterized in that delay circuit (2C) is the phase-shift circuit that operational amplifier (U) is formed, directly introduce through the audio signal that prime is handled, be connected on another input of back grade noise processing circuit (2B) chip ZY1421 from the audio frequency of the output of operational amplifier (U) through resistance (R3), the electric capacity (C4) of series connection from an input of operational amplifier (U).

5, according to the said dual microphone anti-noise of claim 3 transmitter, it is characterized in that forward and backward level audio-frequency noise treatment circuit (2A, be to adopt the capacity cell of the extremely peripheral coupling of chip ZY1421 to form 2B), two-way audio signal with phase difference is introduced from the input of two chips respectively, and the voice signal after the de-noising is sent from the output of back level audio-frequency noise treatment circuit (2B).

6, according to the said dual microphone anti-noise of claim 1 transmitter, it is characterized in that microphone (1A, flexible sheet in structure 1B) should adopt with the lot number material, each microphone is connected with build-out resistor and is arranged between power supply and the ground wire, the audio signal of being gathered from microphone (1A, 1B) with build-out resistor (R1, R2) draw by electric capacity (C1 the junction, C2) deliver to prime audio-frequency noise treatment circuit (2A, 2B) two of chip ZY1421 inputs.