BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a perspective view of a case of a conventional rectangular-box-shaped condenser microphone;
FIG. 2 is a perspective view of a case of a rectangular-box-shaped condenser microphone according to an embodiment of the present invention;
FIG. 3 is a perspective view illustrating an assembled state of a rectangular-box-shaped condenser microphone according to an embodiment of the present invention;
FIG. 4 is a side sectional view of the rectangular-box-shaped condenser microphone illustrated in FIG. 3;
FIG. 5 is a perspective view of a sealing pad according to an embodiment of the present invention; and
FIG. 6 is a side sectional view of a rectangular-box-shaped condenser microphone according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of 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. 2 is a perspective view of a case of a rectangular-box-shaped condenser microphone according to an embodiment of the present invention, FIG. 3 is a perspective view illustrating an assembled state of a rectangular-box-shaped condenser microphone according to an embodiment of the present invention, and FIG. 4 is a side sectional view of the rectangular-box-shaped condenser microphone illustrated in FIG. 3.
Referring to FIGS. 2 to 4, the rectangular-box-shaped condenser microphone includes a metal case 102, a polar ring 104a, a diaphragm 104, a spacer 106, an insulating base 108, a backplate 110 with a sound hole 110a, a conductive base 112, a rectangular-ring-shaped sealing pad 114, and a printed circuit board (PCB) 116. The metal case 102 has a rectangular box shape with one side open, such that parts are received therein. In the rectangular-box-shaped metal case 102, edge portions of curling surfaces 102c are chamfered for the purpose of easy curling. The polar ring 104a and the diaphragm 104 are assembled in the metal case 102. The rectangular-ring-shaped sealing pad 114 is used for preventing sound leakage. A conductive pattern and a protruding connection terminal 116a are formed in the PCB 116.
Referring to FIG. 2, the metal case 102 has a rectangular box shape with one side open, and four edges 102b of the open side are chamfered. Therefore, during the curling process, the end portions 102 of the adjacent surfaces do not overlap each other. The sound hole 102a is formed in the bottom surface of the case. The sound hole 102a may be formed in the PCB 116, instead of the case 102, depending on a sound entry structure of the condenser microphone.
The diaphragm 104 and the backplate 110 are disposed to face each other, with the insulating spacer 106 being interposed therebetween. The diaphragm 104 can be vibrated by external sound. The diaphragm 104 is electrically connected to the PCB 116 through the polar ring 104a and the metal case 102. The backplate 110 and the conductive base 112 are electrically isolated from the metal case 102 by the insulating base 108. Since such a structure has been well known to those skilled in the art, further description will be omitted.
Referring to FIG. 5, the rectangular-ring-shaped sealing pad 114 prevents sound of the condenser microphone from leaking out. The sealing pad 114 is formed of a flexible material, for example, rubber or resin. The sealing pad 114 is mounted into the metal case 102 and then the PCB 116 is put into the metal case 102. Thereafter, when the metal case 102 is curled, the sealing pad 114 is pressed to seal the gap between the metal case 102 and the PCB 116. When the sealing pad 114 is pressed by the curling process, its height is reduced from t1 to t2.
As illustrated in FIG. 3, the condenser microphone assembled in the above-mentioned way can be easily curled because the edge portions 102c of the adjacent surfaces of the case 102 do not overlap one another. The protruding connection terminal 116a makes it easy to perform an SMD process. Two or more connection terminals may be formed in the PCB 116. The curling surface 102c of the case 102 may be used as a ground terminal.
FIG. 6 is a side sectional view of a rectangular-box-shaped condenser microphone according to another embodiment of the present invention.
Referring to FIG. 6, the rectangular-box-shaped condenser microphone includes a metal case 102, a polar ring 104a, a diaphragm 104, a spacer 106, an insulating base 108, a backplate 110 with a sound hole 110a, a conductive base 112, a rectangular-ring-shaped sealing pad 114, and a PCB 116. The metal case 102 has a rectangular box shape with one side open, such that parts are received therein. In the rectangular-box-shaped metal case 102, edge portions 102b of curling surfaces 102c are chamfered for the purpose of easy curling. The polar ring 104a and the diaphragm 104 are assembled in the metal case 102. The rectangular-ring-shaped sealing pad 114 is used for preventing sound leakage. A conductive pattern, a protruding connection terminal 116a, and a sound hole 116b are formed in the PCB 116.
A significant difference between the two condenser microphones is that the condenser microphone of FIG. 6 has the sound hole 116b in the PCB 116, while the condenser microphone of FIG. 4 has the sound hole 102a in the case 102. Further description about other elements will be omitted for avoiding the duplication.
As described above, the electret condenser microphone according to the embodiments of the present invention can be easily curled by chamfering the edge portions of the rectangular-box-shaped case. Furthermore, sound characteristics of the electret condenser microphone can be improved by sealing the gap between the case and the PCB using the sealing pad.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Patent Application
20080056523
