Abstract:
A second microphone device of a mobile terminal, and more particularly, a second microphone device of a mobile terminal for preventing various limitations caused by mounting of a second microphone, is provided. The second microphone device includes an ear jack connector having an insertion space, a microphone hole connected at one end to the insertion space, and a second microphone connected at the other end of the microphone hole, thereby improving ambient noise removal performance of the mobile terminal without adversely affecting its appearance.

Description:
PRIORITY 
     This application is a continuation application of a prior application Ser. No. 13/527,041 filed on Jun. 19, 2012, which claimed the benefit under 35 U.S.C. §119(a) of a Korean patent application filed on Jul. 8, 2011 in the Korean Intellectual Property Office and assigned Serial No. 10-2011-0067639, the entire disclosure of each of which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the reduction of ambient noise during a voice conversation using a mobile terminal. More particularly, the present invention relates to a second microphone device of a mobile terminal that enhances the reduction of ambient noise. 
     2. Description of the Related Art 
     As mobile terminals become more sophisticated, users expect additional features as well as a high level of call quality. To address the issue of call quality, technologies that include a second microphone for removal of ambient noise are often applied to mobile terminals. 
       FIG. 1  is a perspective view of a mobile terminal having a second microphone device according to the related art, and  FIG. 2  is a perspective view of the mobile terminal of  FIG. 1  from a different angle according to the related art. 
     Referring to  FIG. 1  and  FIG. 2 , a main microphone  102  receives the voice of a user, transforms the received voice to an electrical signal, and transfers the electrical signal. The main microphone  102  is generally installed on the bottom of a mobile terminal  101 . A second microphone device  100  is located on the mobile terminal to assist in achieving optimum performance by removing ambient noise other than the user&#39;s voice. Therefore, as shown in  FIG. 2 , the second microphone device  100  is installed on the top of the mobile terminal  101  in a direction opposite to the bottom of the mobile terminal  101  where the main microphone  102  is installed. However, the second microphone device  100  may not be installed on the top of the mobile terminal  101  in some cases, due to an undesirable appearance of the terminal caused by a microphone hole  120  exposed to the outside of the mobile terminal  101  and due to limitations of mounting conditions of the mobile terminal  101 . For example, the top of the mobile terminal  101  already includes an ear jack connector  110  for use in connection of an earpiece so that an additional hole for the second microphone  100  is even more unsightly and would require additional processing costs when creating the additional hole. 
     Accordingly, a second microphone device of a mobile terminal may be embodied in some cases by using a receiver hole  103 , which is provided for a speaker that outputs a voice of a corresponding person to the user, or at a rear or side of the mobile terminal. However, in any of these cases, because an object such as an ear, a hand or the face of the user closely contacts a second microphone hole installed in the receiver hole  103  or at the rear or side of the mobile terminal, there may be a problem that ambient noise may not be received by the second microphone device of the mobile terminal, thereby decreasing an ambient noise removal performance. 
     SUMMARY OF THE INVENTION 
     Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a mobile terminal having a second microphone device for removal of ambient noise. Another aspect of the present invention is to provide a mobile terminal having a second microphone device for removal of ambient noise without impairing the appearance of the mobile terminal. 
     In accordance with an aspect of the present invention, a second microphone device of a mobile terminal is provided. The second microphone device includes an ear jack connector having an insertion space for insertion of an earphone plug, a microphone hole connected at one end to the insertion space, and a second microphone connected at the other end of the microphone hole. 
     According to the present invention, because a microphone hole of a second microphone is connected to an insertion space into which an earphone plug can be inserted, the appearance of the mobile terminal is not impaired and the removal of ambient noise may be achieved. 
     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 view of a mobile terminal having a second microphone device according to the related art. 
         FIG. 2  is a perspective view of the mobile terminal of  FIG. 1  from a different angle according to the related art. 
         FIG. 3  is a perspective view of a mobile terminal having a second microphone device according to an exemplary embodiment of the present invention. 
         FIG. 4  is a cross-sectional view of the second microphone device cut along the line A-A′ in the mobile terminal of  FIG. 3  according to an exemplary embodiment of the present invention. 
         FIG. 5  is a cross-sectional view of the second microphone device cut along the line B-B′ in the second microphone device of  FIG. 4  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 their 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. 
       FIG. 3  is a perspective view of a mobile terminal having a second microphone device according to an exemplary embodiment of the present invention,  FIG. 4  is a cross-sectional view of the second microphone device cut along the line A-A′ in the mobile terminal of  FIG. 3  according to an exemplary embodiment of the present invention, and  FIG. 5  is a cross-sectional view of the second microphone device cut along the line B-B′ in the second microphone device of  FIG. 4  according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 3  through  FIG. 5 , a second microphone device  200  of a mobile terminal  201  includes an ear jack connector  210 , a microphone hole  220 , and a second microphone  230 . 
     The ear jack connector  210  has an ear jack plug  211 , a housing  212 , and a contact terminal  213 . The ear jack plug  211  fixes an earphone plug (not shown), and electrically connects a terminal of the earphone plug and the contact terminal  213  of the ear jack connector  210 . The ear jack plug  211  has an insertion space  215  into which the earphone plug, passing through an insertion hole  214 , is inserted. The housing  212  fixes the ear jack plug  211  and the contact terminal  213 , and protects them from the outside. In an exemplary implementation, the housing  212  is formed by molding. The contact terminal  213  electrically connects the ear jack plug  211  and a terminal (not shown) of a Printed Circuit Board (PCB)  260 . 
     The microphone hole  220  is a hole through which ambient noise is received and transferred to the second microphone  230 . The microphone hole  220  is connected at one end to the insertion space  215  of the ear jack plug  211 , and at the other end to a sound reception portion  231  of the second microphone  230 . The microphone hole  220  may be formed by a tube  221  that passes through holes formed in the ear jack plug  211  and the housing  212  and is connected to the second microphone  230 , as shown in  FIG. 4 , or may be formed by only a hole passing through the ear jack plug  211  and the housing  212 . 
     The second microphone  230  is a component that receives ambient noise through the microphone hole  220 , transforms it to an electrical signal, and transfers the electrical signal to a controller (not shown). A soundproof member  240  is formed on an outer surface of the second microphone  230  except at the sound reception portion  231 . The soundproof member  240  prevents noise that is generated inside the mobile terminal from being transferred to the second microphone  230 . In an exemplary implementation, the soundproof member  240  may be formed of rubber. An outer surface of the second microphone  230  on which the sound reception portion  231  is formed is surrounded by the soundproof member  240  except at the sound reception portion  231 , and is attached to the ear jack connector  210  by the soundproof member  240  between the surface of the second microphone  230  and the ear jack connector  210 . Additionally, the second microphone  230  is mounted on the PCB  260 , on which the ear jack connector  210  is also mounted. A terminal  250  of the second microphone  230  protrudes from the second microphone  230  towards a mounting surface  261  of the PCB  260 , and is connected to a terminal (not shown) of the PCB  260 . In this exemplary embodiment of the present invention, the second microphone  230  operates during a receiver communication mode. Therefore, because the earphone plug is removed from the ear jack plug  211  in the receiver communication mode, a passage through which ambient noise may enter is secured for the second microphone  230 . 
     According to an exemplary embodiment of the present invention, the microphone hole  220  of the second microphone  230  is connected to the insertion space  215  into which an earphone plug is inserted. Therefore, the appearance of the mobile terminal  201  is not impaired because the microphone hole  220  does not appear at the outside of the mobile terminal  201 . Additionally, in comparison with the related art in which a second microphone device is embodied using a receiver hole  203 , removal of ambient noise may be improved because a part of the body of a user does not block a passage through which ambient noise enters. 
     Additionally, the microphone hole  220  is not directly connected to the outside of the mobile terminal  201 , but is indirectly connected to the outside of the mobile terminal  201  through the insertion space  215  of the ear jack plug  211 . Therefore, in comparison with a mobile terminal of the related art, influx of foreign material to the second microphone  230  may be reduced. 
     While the invention has been shown and described with reference to certain exemplary 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.