Abstract:
A speaker module of a portable terminal and a method of execution of a speakerphone mode using the same are provided. The speaker module includes a nondirectional microphone, a directional microphone, at least one speaker, and a controller. The nondirectional microphone is applied to one side of the portable terminal. The directional microphone is applied to another side of the portable terminal. The at least one speaker is installed in the same direction near the directional microphone. When the portable terminal is in a speakerphone mode, the controller controls to detect voice signal levels and/or frequency characteristics input to the two microphones, sets a transmission/reception mode of the portable terminal, and mute-processes a corresponding microphone.

Description:
PRIORITY 
     This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed in the Korean Intellectual Property Office on Nov. 25, 2009 and assigned Serial No. 10-2009-0114310, the entire disclosure of which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a microphone and speaker integrated speaker module. More particularly, the present invention relates to a speaker module of a portable terminal and a method of execution of a speakerphone mode in the portable terminal to prevent an echo phenomenon between a speaker and a microphone in the speakerphone mode. 
     2. Description of the Related Art 
     Due to recent developments in the mobile communication industry, portable terminals have progressed rapidly. Because conventional portable terminals were simply used for wireless communication between two users located at a long distance, the portable terminals supported only a receiver having close contact with a user&#39;s ear generated a relative low sound pressure. The conventional portable terminals were not in need of a speaker (e.g., a loud speaker) generating a high sound pressure to enable a user to listen to a called party&#39;s voice even at a long distance. 
     Recent portable terminals have been developed with several functions. As an internal/external flash memory capacity of the portable terminals increase, the portable terminals have the ability to support a function of reproduction of music and video, for example, reproduction of MPEG Audio Layer-3 (MP3), an Audio Video Interleave (AVI) file and the like, watching TeleVision (TV), and the like. The portable terminals have now become portable multimedia devices beyond a function of simple voice communication. 
     On the other hand, when a user makes a voice call, it is inconvenient to use the receiver. As a result, portable terminal manufacturers have developed speaker modules having various forms and functions that coincide with the portable terminals form and function. The portable terminal manufacturers have provided efforts to design slim portable terminals to meet consumers&#39; desire while applying the speaker module to the portable terminals. 
     With the efforts provided by the portable terminal manufacturers, the size of the portable terminals have been reduced by integrating and installing an internal antenna radiator, a speaker, a microphone, and a vibrator on one housing or carrier, and mounting a unified housing having the integrated devices installed on a main board of the portable terminal. 
     On the other hand, in order to prevent an echo phenomenon in a speakerphone mode between the speaker and the microphone, which is installed adjacent to the speaker, another microphone is installed for speakerphone use in a position spaced a preset distance apart from the speaker. Although a stereo speaker is used in the multimedia function operation, only one speaker installed in the position spaced apart from the microphone for speakerphone use is used in the speakerphone mode in order to solve the echo problem. 
     However, the above described construction of the portable terminal does not provide a slimness design and design applicability because the installation of two microphones in the portable terminal impose limitations on positioning, and using only one speaker can inconvenience a user due to low sound volume during a phone call. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a speaker module of a portable terminal and a method of execution of a speakerphone mode in the portable terminal using a speaker adjacent to a microphone in the speakerphone mode. 
     Another aspect of the present invention is to provide a speaker module of a portable terminal and a method of execution of a speakerphone mode in the portable terminal using a stereo speaker all the time by increasing applicability of two microphones. 
     A further aspect of the present invention is to provide a speaker module of a portable terminal and a method of execution of a speakerphone mode in the portable terminal to avoid noise or an echo phenomenon in a speakerphone mode when a speaker is arranged near two microphones, and to prevent space or design limitations caused by a microphone installation position. 
     The above aspects are provided by a speaker module of a portable terminal and a method of execution of a speakerphone mode using the same. 
     According to an aspect of the present invention, a speaker module of a portable terminal is provided. The speaker module includes a nondirectional microphone, a directional microphone, at least one speaker, and a controller. The nondirectional microphone is applied to one side of the portable terminal. The directional microphone is applied to another side of the portable terminal. The at least one speaker is installed in the same direction near the directional microphone. When the portable terminal is in a speakerphone mode, the controller controls to detect voice signal levels and/or frequency characteristics input to the two microphones, sets a transmission/reception mode of the portable terminal, and mute-processes the corresponding microphone. 
     According to another aspect of the present invention, a method of execution of a speakerphone mode using a speaker module of a portable terminal having a nondirectional microphone applied in front of the portable terminal, a directional microphone applied in rear of the portable terminal, at least one speaker, and a controller for controlling the two microphones based on a transmission/reception state when the portable terminal is in a speakerphone mode is provided. The method includes determining if the portable terminal is in the speakerphone mode, when the portable terminal is in the speakerphone mode, determining if the nondirectional microphone and the directional microphone simultaneously recognize a receiving voice signal level, and when two microphones simultaneously recognize the receiving voice signal level, mute-processing the two microphones and enabling only the speaker. 
     The method may further include determining if only the nondirectional microphone recognizes a transmitting voice signal level, and enabling the nondirectional microphone and mute-processing the directional microphone, if only the nondirectional microphone recognizes the transmitting voice signal level. 
     Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective diagram illustrating a portable terminal with two microphones according to an exemplary embodiment of the present invention; 
         FIG. 2  is a perspective diagram illustrating a nondirectional antenna in a front part of a portable terminal according to an exemplary embodiment of the present invention; 
         FIG. 3  is a perspective diagram illustrating a directional antenna in a rear part of a portable terminal according to an exemplary embodiment of the present invention; 
         FIG. 4  is a circuit diagram illustrating a construction of a portable terminal with two microphones according to an exemplary embodiment of the present invention; and 
         FIG. 5  is a flow diagram illustrating a procedure for executing a speakerphone mode of a portable terminal with two microphones according to an exemplary embodiment of the present invention. 
     
    
    
     Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
     The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
     It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. 
     By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide. 
       FIG. 1  is a perspective diagram illustrating a portable terminal with two microphones according to an exemplary embodiment of the present invention. 
     A bar type portable terminal is illustrated in  FIG. 1 . However, the present invention is applicable to a variety of portable terminals capable of applying a speaker module and performing a speakerphone function. The portable terminals, for example, perform various opening/closing operations such as a folder type portable terminal, a slide type portable terminal and the like. 
     Referring to  FIG. 1 , the portable terminal  100  includes a display unit  111  installed in front of a body  110 , a receiver  112  installed at the top of the display unit  111 , and one microphone (MIC)  113  installed at the bottom of the display unit  111 . The MIC  113  is a first MIC  113  installed in the portable terminal  100  and is a nondirectional MIC. The display unit  111  may be a touch screen. 
     The portable terminal  100  includes a speaker module installed at the bottom of the portable terminal. The speaker module is constructed on a carrier mounting an antenna radiator that is installed at the bottom of a main board. The speaker module includes the first MIC  113  installed in front, and a second MIC  13  (illustrated in  FIG. 3 ) and a speaker  12  (illustrated in  FIG. 3 ) installed in the rear. The speaker  12  may be a mono speaker or a stereo speaker. 
     In an exemplary embodiment of the present invention, in a case where the portable terminal  100  is in a speakerphone mode, the two MICs  113  and  13  are selectively controlled for operation or non-operation. Although the speaker  12  is installed together with the second MIC  13  and operates all the time, an obstacle phenomenon such as echo and the like does not take place. A detailed construction of the speaker  12  installed together with the second MIC  13  is described below. 
       FIG. 2  is a perspective diagram illustrating a nondirectional antenna in a front part of a portable terminal a according to an exemplary embodiment of the present invention.  FIG. 3  is a perspective diagram illustrating a directional antenna in a rear part of a portable terminal according to an exemplary embodiment of the present invention. 
     Referring to  FIGS. 2 and 3 , the speaker module according to an exemplary embodiment of the present invention may include two MICs  113  and  13 , a speaker  12 , and an antenna radiator  11  together on one carrier  10 . The carrier  10  is installed at the bottom of the main board  14 . The two MICs  113  and  12 , the speaker  12  and the antenna radiator  11  are mounted on the carrier  10 . When the carrier  10  is installed in the main board  14  of the portable terminal, the antenna radiator  11 , the two MICs  113  and  13 , and the speaker  12  may simultaneously electrically connect with each other. However, the antenna radiator  11 , the two MICs  113  and  13 , and the speaker  12  may be constructed to electrically connect to a suitable place of the main board  14  by a separate flexible printed circuit. 
     Referring to  FIG. 2 , the first MIC  113  is installed in front of the carrier  10  (i.e., in a front direction (F) of the portable terminal). The first MIC  113  is a nondirectional MIC. 
     Also, the second MIC  13  is installed in the rear of the carrier  10  (i.e., in a rear direction (R) of the portable terminal). The second MIC  13  is a directional MIC. The speaker  12  is installed at one side of the second MIC  13 . In an exemplary embodiment of the present invention,  FIG. 2  illustrates the speaker module with one speaker  12 . However, the present invention is not limited thereto. For example, two stereo speakers may be installed in the speaker module for an effective multimedia function of the portable terminal. However, the second MIC  13  may be installed in the same direction as a radiation direction of the speaker  12 , and the second MIC  13  may be installed in a position capable of, in a speakerphone mode operation, receiving and detecting a voice signal from the speaker  12  based on an operation angle range of the second MIC  13 . 
     Also, the speaker module unifies and installs the two MICs  113  and  13  and the speaker  12  on one carrier  10 . However, it is not required that the antenna radiator  11  and a vibrator (not illustrated) be additionally installed if there is available space on the carrier  10 . 
       FIG. 4  is a circuit diagram illustrating a construction of a portable terminal with two MICs according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 4 , two MICs  113  and  13 , a receiver  112 , and a speaker  115  each connect to a transmit/receive end of a controller  101  including a codec. The two MICs  113  and  13  may use different basebands designed by two Analog to Digital Converters (ADCs), respectively. The two MICs  113  and  13  may have a similar structure that is well known in the art. 
       FIG. 5  is a flow diagram illustrating a procedure for executing a speakerphone mode of a portable terminal with two MICs according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 5 , in step  501 , a controller detects a user&#39;s key input and determines if a speakerphone mode is entered. If it is determined that the speakerphone mode is entered, the controller proceeds to step  503  and determines if a first (1st) MIC and a second (2nd) MIC simultaneously recognize a receiving voice signal level. Here, the receiving voice signal level represents a called party&#39;s voice signal level transmitted through a speaker. The controller determines if a current receiving voice signal level is equal to or greater than a preset receiving voice signal level. If the two MICs both receive the preset receiving voice signal level or a receiving voice signal level greater than the preset receiving voice signal level, the controller proceeds to step  505  and determines that the key input is a speakerphone mode and mute-processes the two MICs. Then, the controller proceeds to step  507  and performs a speakerphone reception mode. Accordingly, a speaker echo phenomenon caused by the MIC may be prevented. For example, the speaker echo phenomenon may be prevented because the 1st MIC, a nondirectional MIC, may detect a preset voice signal level, and the 2nd MIC, a directional MIC, may detect a voice signal level received from the speaker installed in the same direction as the 2nd MIC, if the portable terminal is in a state in which a called party&#39;s voice is transmitted from the speaker. The current receiving voice signal level is compared with the preset receiving voice signal level and the controller determines whether to mute the two MICs. The controller may consider not only the voice signal level but also a frequency characteristic. 
     On the other hand, if it is determined in step  503  that the 1st MIC and the 2nd MIC do not detect the receiving voice signal level, the controller proceeds to step  509  and determine if only the 1st MIC recognizes a transmitting voice signal level. Also, the determination may be performed by a comparison with a preset voice signal level. In this case, the 2nd MIC, the directional MIC, may receive a relatively weak voice signal level because a sender&#39;s voice is input weakly. Accordingly, the controller proceeds to step  511  and enables only the 1st MIC and mute-processes the 2nd MIC that is no longer needed. The controller then proceeds to step  513  and performs a speakerphone transmission mode. 
     Although not illustrated, in a case where a user and a called party simultaneously talk to each other, the controller may detect preset subdivided voice signal levels, determine a difference between the voice signal levels detected in the 1st MIC and the 2nd MIC, and determine the speakerphone transmission/reception mode. That is since recent portable terminals provide transmission/reception mode conversion of 20 ms possible, exemplary embodiments of the present invention also provide transmission/reception mode conversion possible in a Double Talk (DT) mode. 
     A speaker module according to the exemplary embodiments of the present invention can perform a speakerphone function with a microphone installed near a speaker, without noise or an echo phenomenon caused by the microphone. Also, by installing the speaker and at least two microphones as one module, a portable terminal have a slim design. 
     While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.