BACKGROUND ART In general, microphones are divided into an omnidirectional microphone and a directional microphone according to directional characteristics. The directional microphones are divided into a bi-directional microphone and a unidirectional microphone. The bi-directional microphone is used for regenerating sufficiently front incident sound and rear incident sound and attenuating lateral incident sound in order to represent a 8-shaped polar pattern for a sound source. In addition, the bi- directional microphone is widely used in the place such as a noisy stadium since it has a superior near field characteristic. The unidirectional microphone maintains an output value in response to the broad front incident sound, and attenuates an output value resulted from a rear incident sound source in order to improve an S/N ratio for the front incident sound source. The unidirectional microphone is used as a voice recognition device since it has an articulate characteristic.

The directional microphone has the directional characteristic using a phase difference between front sound and rear sound by forming a sound hole on a case and a PCB. However, when the directional microphone is mounted on a main PCB of a cellular phone, the microphone is mounted on a microphone mounting area provided on a cellular phone case having a complicated shape and then is connected to the main PCB through a jumper cable or an FPC. Namely, the internal space of the cellular phone case formed around the microphone has an irregular shape since the cellular phone case has the complicated structure to integrate various shapes of components.

Accordingly, in order to mount the directional microphone in the cellular phone, the structure for mounting the microphone should be designed in the cellular phone case. In addition, it is hard to obtain correctly a directional effect since acoustic field is irregularly formed by the complicated internal structure of the cellular phone case.

DISCLOSURE OF THE INVENTION Accordingly, it is an object of the present invention to provide a holder kit for directional condenser microphone having paths for rear sound and lateral sound in order to obtain a prominent directional characteristic even after the directional condenser microphone is mounted in a cellualr phone case.

In orde to achieve the above object, the present invention provides a holder kit for directional condenser microphone comprising a holder housing having a shape of a cylinder which is formed with an internal space for receiving a condenser microphone, the holder housing including one side having an open part into which the condenser microphone is inserted, the other side having a sound hole for transferring front sound and supporting part for supporting the inserted condenser microphone, and a lateral side having sound paths for transferring rear sound by barrier ribs and a through-hole through which a connection member passes; the connection member for connecting the inserted condenser microphone to an external circuit ; and a holder cap having a shape of a cylinder which is formed with a bottom side having an open part, an upper side having a hole for collecting the rear sound, and the lateral side having a hole through which the connection member passes, the holder cap covering the holder housing.

Preferably, the holder cap may further comprise a chamber space for collecting the rear sound through the sound paths of the housing.

Preferably, the connection member may be an FPCB having a negative electrode pattern. and a positive electrode pattern, wherein the negative electrode pattern is wider than the positive electrode pattern to shield EMI noise collected to the rear direction.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the invention will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which: Fig. 1 is an exploded perspective view illustrating a holder kit for directional condenser microphone in accordance with the present invention; Figs. 2 to 3 are views illustrating the status to which a holder kit for directional condenser microphone of the present invention is applied; Fig. 4 is a sectional view illustrating the status to which a holder kit for

directional condenser microphone of the present invention is applied; Figs. 5 to 6 are perspective views illustrating a holder cap in Fig. 1 ; Fig. 7 is a detailed view illustrating an FPCB in Fig. 1 ; and Figs. 8 to 9 are perspective views illustrating a holder housing in Fig. 1.

BEST MODES FOR CARRYING OUT THE INVENTION Reference will now be made in detail to the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Fig. 1 is an exploded perspective view illustrating a holder kit for directional condenser microphone in accordance with the present invention.

Referring to Fig. 1, the holder kit 100 of the present invention comprises a housing 130 for receiving a microphone 20, an FPCB (Flexible Printed Circuit Board) 120 for connecting the microphone 20 within the housing 130 to an external circuit, and a holder cap 110 for wholly covering a holder including the microphone 20 whithin the housing 130, shielding rear reflection sound from the outside, obtaining a chamber of the rear sound through the front side, and decreasing noise due to vibration, thereby to enhance a directioncal characteristic of the microphone within the housing 130.

A windscreen (not shown) made of a conductive non-woven fabric can be attached to a front side of the housing 130 in order to prevent plosive and enhance an EMI characteristic. As the windscreen has the conductivity, which is made by adding conductive materials to the non-woven fabric such as polyester, the windscreen shields the plosive of the low frequency band and the EMI noise collected from the outside.

Figs. 2 to 3 are views illustrating the status to which a holder kit for directional condenser microphone of the present invention is applied, and Fig. 4 is a sectional view illustrating the status to which a holder kit for directional condenser microphone of the present invention is applied.

Referring to Figs 2 to 4, after the microphone 20 is inserted into the housing 130, the housing 130 is covered with the holder cap 110 so that a through-groove 132 (shown in Fig. 8) of the housing is positioned to correspond to a through-hole 116 (shown in Fig. 5) of the holder cap 110. Then, an FPCB 120 is inserted into the through-hole 116 (shown in Fig. 5) of the holder cap 110 so that solder pads 124a,

124b of the FCB 120 are connected to connection terminals 24a, 24b (shown in Fig.

5) of the microphone 20 within the housing 130. As described above, the holder cap 110 of the present invention protects the microphone 120 within the housing 130 from the vibration. Further, the holder cap 110 provides a chamber space 30 for the rear sound and collects the rear sound to the chamber space 30 through sound paths 133-1 to 133-4 of the housing 130 in order to enhance the directional characteristic.

Figs. 5 to 6 are perspective views illustrating a holder kit for directional condenser microphone of Fig. 1.

Referring to Figs. 5 to 6, the holder cap 110 of the present invention is formed with a shape of a cylinder inlcuding an upper surface 112 having a hole 114 for collecting the rear sound, a lateral surface 111 having a through-hole 116 for drawing the FPCB 120, a bottom surface having an open part for receiving the housing. A hole 113 for collecting the rear sound is formed at an edge between the upper surface 112 and the lateral surface 111.

The holder cap 110 comprises a predetermined space into which the housing 130 is inserted. In addition, a projection 115 is formed in the inside of the cap 110 in order to form the chamber space 30. The holder cap 110 is made of plastics, resin, metal, and silicon in order to shield the rear reflection sound from the outside. Further, the holder cap 110 provides the holes 113,114 for collecting the rear sound and the chamber of the rear sound through the front side, and decreases the noise due to the vibration.

Fig. 7 is a detailed view of an FPCB of Fig. l. The FPCB 120 is formed with a thin substrate 121 having a positive electrode pattern 123 and a negative electrode pattern 122. Each of the electrode patterns 121,123 is provided with the solder pads 124a, 124b for contacting with the connection terminals 24a, 24b of the microphone. A hole 125 for collecting the rear sound is formed at a position corresponding to a sound hole that is formed on a PCB of the microphone.

In the FPCB 120, as the area of the negative electrode pattern 122 is larger than the area of the positive electrode pattern 123 to shield the EMI noise collected to the rear direction, the EMI noise is attenuated by interfering and sinking out of the EMI noise passing through the hole 125 which is formed at the negative pattern 122 to collect the rear sound. In addition, FET cracks are prevented by the solder pads 124a, 124b.

Figs. 8 to 9 are perspective views illustrating a housing for the directional microphone in Fig. 1.

Referring to Fig. 8 to 9, the housing 130 is formed with a shape of a cylinder comprising an opening part. The housing 130 has a bottom surface 137 for supporting the inserted condenser microphone 20, and an internal space into which the condenser microphone 20 is inserted. A hole 136 is formed at a center of the bottom surface 137 of the housing 130 in order to transfer the front sound to the condenser microphone. Four through-holes 133-la to 133-4a and three auxiliary holes 138 are formed around the hole 138 of the bottom surface 137 in order to transfer the rear sound. In addition, barrier ribs 135 are installed at a lateral part 131 of the housing 130 in order to form four sound paths 133-1 to 133-4 for transferring the rear sound. A rib 135a is formed at an end of the barrier rib 135 in order to prevent the movement of the condenser microphone 20. A through-hole 132 is formed at the lateral side of the housing in order to draw the FPCB 120 for connecting electrically the condenser microphone 20 to an external main PCB. The holder housing 130 is made of materials such as resin, plastics, rubber, and metal. In the preferred embodiment of the present invention, the cylindrical housing is described to mount the cylindrical condenser microphone, however the housing can be formed with various shapes according to shapes of microphones.

INDUSTRIAL APPLICABILITY As described above, the holder kit for the directional condenser microphone of the present invention provides directivity of static characteristic since the same acoustic field is provided by transferring sound waves to the front, the rear, and the lateral directions of the condenser microphone even if the holder housing is mounted in the structure of the cellular phone case having a larger size compared to the holder housing. In addition, the present invention removes the noise due to the vibration using the holder cap and enhances the directional characteristic by providing the sound chamber for the read sound collected through the sound path of the housing.