KR20100058281A - Microphone unit and portable device including the same - Google Patents

Abstract

PURPOSE: A microphone unit and a portable terminal unit including the same are provided to improve the overall sound quality of an audio transmission part by effectively blocking time division multiple access noise. CONSTITUTION: An integrated circuit(3) includes an amplifier unit(4) and a filter unit(6). The amplifier unit amplifies electric signal with weak signal level from a main body(1). The filter unit filters a noise which is inserted in the amplified electric signal. The amplifier unit includes a field effect transistor and an op amplifier. The filter unit includes the juxtaposition structure of an inductor and a capacitor.

Description

A microphone unit and a portable terminal including the same {Microphone Unit And Portable Device including the same}

The present invention relates to a microphone unit and a portable terminal including the same, and more particularly, to a microphone unit capable of filtering noise in a specific frequency range by adding a resonance filter to the microphone unit and a portable terminal including the same.

Recently, portable terminals have been widely used based on mobility. In particular, mobile communication terminals capable of making voice calls while moving among the portable terminals are very popular portable terminals used by more than 85% of the nation.

The above-described mobile communication terminal includes a configuration of a radio frequency unit, a controller including a modem, an audio processor for voice output and collection, and a display unit for providing a call screen for voice call support. In particular, the microphone unit for collecting voice in the audio processing unit is required to be small in size in order to be disposed in the mobile communication terminal.

In order to satisfy such a small requirement, the mobile communication terminal uses an electret condenser microphone (ECM) using a condenser microphone, particularly an electret.

The conventional ECM is provided with a diaphragm or the like inside a case made of metal such as aluminum, steel, or brass, and generates an electric signal by changing an external sound of an electric field formed by the diaphragm and the electret. The ECM-mounted substrate processes this electrical signal and converts it to a signal in the audible region, and then records, outputs, or transmits the signal. To this end, the interior of the ECM includes a FET (Field Effect Transister) for amplifying the primary electrical signal generated by the electret and the diaphragm. Such a conventional microphone unit has a problem in that an electric field formed by the diaphragm and the electret is vulnerable to noise generated from an external environment and a mobile communication terminal, thereby generating a lot of noise.

Accordingly, an object of the present invention is to provide a microphone unit and a portable terminal including the same, which can minimize the influence on the collected audio while reducing noise generated in a specific frequency band.

A microphone unit according to a preferred embodiment of the present invention for achieving the above object, the body portion for converting the physical signal transmitted through the sound hole into an electrical signal; And a substrate unit having an amplifier for amplifying the electrical signal and a filter unit for filtering the amplified signal, wherein the filter unit includes a resonance filter capable of filtering the amplified signal in a specific frequency band. It features.

A mobile terminal according to an embodiment of the present invention for achieving the above object, the radio frequency unit for forming a communication channel; An input unit generating a key input signal for forming the call channel; A microphone unit for collecting an audio signal to be transmitted according to the call channel formation; And a controller configured to control the radio frequency unit, the input unit, and the microphone unit to transmit the collected audio signals between call channel formations, wherein the microphone unit converts a physical signal transmitted through a sound hole into an electrical signal. And a body part, a substrate part having an amplifier for amplifying the electrical signal, and a filter part for filtering the amplified signal, wherein the filter part includes a resonance filter capable of filtering the amplified signal in a specific frequency band. It is characterized by including.

According to the microphone unit and the portable terminal including the same according to an embodiment of the present invention, it is possible to minimize the noise of the required frequency band while minimizing the influence of the collected audio.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation according to the embodiment of the present invention will be described, and the description of other parts will be omitted so as not to disturb the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and the inventors are appropriate to the concept of terms in order to explain their invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a view schematically showing the appearance of a mobile terminal according to an embodiment of the present invention.

Referring to FIG. 1, a portable terminal 100 according to an exemplary embodiment of the present invention includes a display unit 130, an input unit 110, and a microphone unit 120. The portable terminal 100 may further include a configuration of a radio frequency unit, a speaker, a power supply unit, and a control unit for controlling the above-described functions to substantially support the mobile communication function. The display unit 130 outputs a screen corresponding to an application program executed according to a user request, for example, a standby screen and a screen required according to the use of a terminal. In addition, the input unit 110 may be implemented as a keypad or a touch screen to receive numeric or text information from a user and set various functions. In the case of a touch screen, the input unit 110 may display image and coordinate values corresponding to a plurality of input keys and function keys. When the touch event occurs, the touch event may be transmitted to the controller. The function keys may include a direction key, a side key, and an accelerator key set for performing a specific function. The microphone unit 120 collects an external audio signal and transmits the external audio signal to the controller. When the voice call is performed, the microphone unit 120 may be activated. The microphone unit 120 will be described in more detail with reference to FIG. 2.

2 is a view schematically showing a microphone unit according to an embodiment of the present invention.

Referring to FIG. 2, the microphone unit 120 according to the present invention includes a substrate portion 2 having a body portion 1 and an integrated circuit 3.

The body 1 converts external sound into a primary electrical signal. To this end, the body 1 is provided with components such as diaphragms, electrets, and cases. This body portion 1 transmits the primary electrical signal generated by the diaphragm and electret to the substrate portion 2 by conductive means. Detailed description of the body portion 1 will be described with reference to FIG. 5 to be described later.

The substrate unit 2 amplifies the primary electrical signal provided from the body unit 1, extracts an audio frequency band signal from the amplified primary electrical signal, and converts the secondary electrical signal. The substrate unit 2 provides the converted secondary electric signal to an external device or a circuit. To this end, the substrate portion 2 includes a printed circuit board 5, an integrated circuit 3 mounted on the printed circuit board 5, and a signal line 8 connected to the integrated circuit 3. An equivalent circuit corresponding to the substrate portion 2 will be described with reference to FIG. 3 to explain the operation of the substrate portion 2 of the present invention.

3 is an equivalent circuit diagram of the configuration of the substrate unit 2 according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the integrated circuit 3 according to the present invention includes an amplifier 4 and a filter 6. The amplifier 4 amplifies an electric signal having a weak signal level transmitted from the body 1, and the filter unit 6 filters noise inserted into the amplified electric signal. To this end, the amplifier 4 includes an amplifier such as a field effect transistor (FET) and an OP amplifier, and the filter unit 6 may have a structure in which a capacitor and an inductor are arranged in parallel. In more detail, when an external audio signal is transmitted through the sound hole formed in the body portion 1, the ECU formed of the diaphragm and the electret disposed inside the body portion 1 may be separated from the electret according to the vibration of the diaphragm. The change causes a change in capacitance distribution. When the distribution of capacitance distribution is transmitted to the integrated circuit 3, the amplifier 3 included in the integrated circuit 3 amplifies the signal and transfers the signal to the filter unit 6. The filter unit 6 may remove noise of a specific frequency band of the amplified signal using the second resonance filter. To this end, the filter unit 6 may include a first inductor connected in series with the amplifier 3, a first capacitor connected in parallel between the amplifier 3 and the first inductor, and a first capacitor connected in parallel with the first capacitor. A second inductor and a second capacitor arranged in parallel between the first inductor and the second inductor may be provided. As the filter unit 6 is arranged in the form of pi, the signal output from the amplifier 3 may be filtered in two places. At this time, the pie type filter unit 6 is a band of 824 ~ 915Mhz where the time division multiple access (TDMA) noise mainly occurs in a specific frequency region, for example, GSM communication module, and the TDMA noise according to the DCS / PCS communication module Capacitors and inductors are available to filter the 1705 ~ 1901Mhz band that occurs. Accordingly, it can be seen that the filter unit of the present invention filters noise in two regions as shown in FIG. 4.

As described above, the microphone unit according to an embodiment of the present invention is generated due to a structure in which the distance between the microphone unit and the antenna becomes closer due to the slimming of the portable terminal and the limitation of the antenna position and the communication method peculiar to the GSM or PCS terminal. TDMA noise inflow can be effectively prevented. In addition, since the microphone unit of the present invention does not use a resistance element in the filter unit configuration, the attenuation of the original signal is eliminated, thereby preventing linear noise amplification due to the compensation for the attenuation, thereby improving the overall sound quality of the audio transmission part. have.

5 is a view showing in detail the microphone unit according to an embodiment of the present invention.

5, the body portion 1 of the electret condenser microphone according to the present invention includes a case 20, a diaphragm 22, a spacer ring 23, a bipolar plate 24, a conductive base ring 25 and An insulating base ring 26 is provided.

The case 20 has an inner space in which the diaphragm 22, the spacer ring 23, the bipolar plate 24, the conductive base ring 25 and the insulating base ring 26 are accommodated. The case 20 not only protects the internal enclosure from external shocks, but also shields external noise to ensure normal operation of the ECM and prevents the flow of internal enclosures. Here, the case 20 may accommodate the substrate portion therein according to the bonding method of the substrate portion. That is, when the substrate portion 2 and the body portion 1 are coupled by the curling process, the case 20 accommodates the substrate portion therein and is coupled by a method such as resistance welding, laser welding, or adhesion. The case 20 may be coupled in such a manner that the substrate portion closes the opening of the case 20 without accommodating the substrate portion therein. In addition, the case 20 electrically connects the diaphragm 22 and the substrate. To this end, the case 20 is made of a polygonal or circular pillar of one side of the open shape, the sound hole 27 is formed in the unopened portion of the sound. The case 20 is made of a metal having good conductivity, such as aluminum (Al), copper (Cu), or an alloy using them to shield noise, and gold (Au) to improve electrical conductivity and prevent corrosion. Or it may be used in the form of plating nickel (Ni).

The diaphragm 22 forms an electric field together with the bipolar plate 33, and vibrates by the sound pressure of the sound introduced through the sound hole to change the electric field formed between the bipolar plate 33. The diaphragm 22 is composed of a diaphragm 22b and a polar ring 22a. The vibrating membrane 22b may be nickel (Ni), silver (Ag), gold (Au), or the like to impart conductive properties to a film such as polyethylene terephthalate (PET) having a thickness of several micrometers so that it may easily vibrate even a minute sound pressure. It is produced by sputtering a metal. The polar ring 22a fixes and supports the vibration membrane 22b, secures a vibration space of the vibration membrane 22b, and forms a conductive path of the vibration membrane 22b together with the case 20.

The spacer ring 23 is positioned between the diaphragm 22 and the bipolar plate 24 to form a space such that the diaphragm 22 and the bipolar plate 24 are arranged in parallel at a predetermined distance. Do it. In addition, the spacer ring 23 allows the diaphragm 22 and the bipolar plate 33 to be electrically insulated, and is manufactured using a material having good insulating properties such as an acrylic resin.

The back plate 24 forms an electric field together with the diaphragm 22 to convert an acoustic signal into a primary electric signal. To this end, the bipolar plate 24 is composed of an electret polymer film 24a and a bipolar column 24b. The electret polymer film 24a is charged semi-permanently and forms an electric field by the charge. The electret polymer film 24a is produced by injecting charge through a charge injector after pressurizing and heat-sealing a polymer film such as PTFE (Poly Tetra Fluoro Ehtylene), PFA (Perfluoroalkoxy), or FEP (Fluoroethylenepropylene). . And the anode 24b is manufactured using metals, such as copper, bronze, brass, and phosphor bronze.

The conductive base ring 25 provides a conductive path between the bipolar plate 24 and the substrate portion, and supports and fixes the objects in the case 20. The conductive base ring 25 forms and maintains a space between the bipolar plate 24 and other internal objects and the substrate, thereby preventing contact between the integrated circuit and other objects mounted therein.

The insulating base ring 26 is disposed between the bipolar plate 24 and the case 20 to insulate the bipolar plate 24 and the case 20 and to fix the diaphragm 22. The insulating base ring 26 is manufactured in a cylindrical shape having a space formed therein, and an outer surface of the pillar contacts the case 20, and houses the bipolar plate 24 and the conductive base ring 25 in the inner space. Such an insulating base ring 26 is made of a material having good insulating and strength characteristics.

While the present invention has been described with reference to several preferred embodiments, these embodiments are illustrative and not restrictive. As such, those of ordinary skill in the art will appreciate that various changes and modifications can be made according to equivalents without departing from the spirit of the present invention and the scope of rights set forth in the appended claims.

1 is a view schematically showing the appearance of a portable terminal according to an embodiment of the present invention;

2 is a view schematically showing the appearance of a microphone unit according to an embodiment of the present invention;

3 is a view showing an equivalent circuit of a microphone unit according to an embodiment of the present invention;

4 is a graph illustrating filtering performance of a microphone unit according to an embodiment of the present invention;

5 is a view showing an example of the body portion configuration of the microphone unit of the present invention.

Claims (8)

A body unit converting the physical signal transmitted through the sound hole into an electrical signal; And a substrate part having an amplifier part for amplifying the electrical signal and a filter part for filtering the amplified signal. The filter unit microphone unit, characterized in that it comprises a resonance filter for filtering a specific frequency band of the amplified signal. The method of claim 1, The filter unit A microphone unit, characterized in that two capacitors and two inductors are arranged in a pie form. The method of claim 1, The filter unit A first inductor connected in series with the amplifier, a first capacitor connected in parallel between the amplifier and the first inductor, a second inductor connected in parallel with the first capacitor, and between the first inductor and the second inductor And a second capacitor arranged in parallel. The method of claim 1, The filter unit Microphone unit characterized in that the 824 ~ 915Mhz band and 1705 ~ 1901Mhz band filtering. A radio frequency unit forming a communication channel; An input unit generating a key input signal for forming the call channel; A microphone unit for collecting an audio signal to be transmitted according to the call channel formation; And a controller configured to control the radio frequency unit, the input unit, and the microphone unit to transmit the collected audio signal between call channel formations. The microphone unit And a body part for converting the physical signal transmitted through the sound hole into an electrical signal, a substrate part having an amplification part for amplifying the electrical signal, and a filter part for filtering the amplified signal, wherein the filter part is the amplified signal. And a resonant filter capable of filtering in a specific frequency band. The method of claim 5, The filter unit A portable terminal, characterized in that two capacitors and two inductors are arranged in a pie form. The method of claim 5, The filter unit A mobile terminal, characterized by filtering the 824 ~ 915Mhz band and 1705 ~ 1901Mhz band. The method of claim 5, The radio frequency unit A portable terminal, comprising: a TDMA (Time Division Multiple Access) communication module.

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