Dual earphone using both bone conduction and air conduction

1. An earphone set using both bone conduction and air conduction, comprising:

a dual earphone allowing a user to selectively hear sound from the front or rear side of the earphone set;

a case cover provided at an end of the dual earphone;

a cylindrical reinforcing frame assembled on one side of the case cover;

a finishing ring mounted on an outer peripheral surface of the cylindrical reinforcing frame;

a top cover assembled on one side of the cylindrical reinforcing frame and the finishing ring and having an extension projection at one side thereof;

a rubber ear cap assembled at a front end of the extension projection to be inserted into an ear hole of a user; and

a bone conduction vibrator provided inside the dual earphone.

2. The earphone set according to claim 1 , wherein the extension projection is inclined from the center of a body of the dual earphone in a range from 20 to 40 degrees so that the dual earphone is easily inserted into the ear hole of the user.

3. The earphone set according to claim 2 , wherein a locking groove is formed on an outer peripheral surface of the extension projection to preventing the rubber ear cap from being easily separated from the front end of the extension projection after the rubber ear cap is assembled.

4. The earphone set according to claim 2 , further comprising a damper ear cap provided at a front end of the extension projection and having a hole formed at a center of the damper ear cap so that the user hears sounds using air conduction.

5. The earphone set according to claim 1 , wherein at least one vent hole is further formed in the top cover so that the user hears sounds using both bone conduction and air conduction.

6. The earphone set according to claim 1 , wherein the bone conduction vibrator includes:

bottom cover assembled on an inner peripheral surface of the cylindrical reinforcing frame, and from which a shaft integrally protrudes from the center of the bottom cover;

n inside cushion mounted on an outer peripheral surface of the shaft to reduce mechanical shock noise;

voice coil assembled at one end of the bottom cover;

a yoke assembled in a center shaft at an outer peripheral surface of the voice coil, and having a chamfering portion formed at a corner of the yoke;

magnet and a plate assembled inside the yoke and on an outer peripheral surface of the center shaft respectively;

weight plate and a vibrating plate assembled on one side of the yoke and on an outer peripheral surface of the center shaft respectively; and

printed circuit board, a piezoelectric damper, and a piezoelectric element sequentially assembled on one side of the inside cushion.

7. The earphone set according to claim 6 , wherein a catching groove for preventing separation of the inserted bottom cover is further formed on one side of the frame and a support protrusion for preventing separation of the inserted vibrating plate is further formed on an opposite side of the frame.

8. The earphone set according to claim 1 , wherein a hole for inserting a cable is formed on one side of the case cover or a groove for preventing separation of the case cover from the ear hole of the user is formed on an outer peripheral surface of the case cover.

9. The earphone set according to claim 1 , wherein piezoelectric module cases are disposed between the finishing ring and the top cover to attach and detach a piezoelectric element when a cable is inserted into the piezoelectric module cases.

10. The earphone set according to claim 9 , wherein a first piezoelectric element fixing member is formed on an inner peripheral surface of each piezoelectric module case and a second piezoelectric element fixing member fixes an outer peripheral surface of the piezoelectric element.