Earphone

1. An earphone comprising:

a housing;

a reel mechanism pivotally disposed in the housing and having an accommodating space defined therein;

a speaker disposed in the accommodating space; and

a transmission wire wound on the reel mechanism;

wherein when the transmission wire is pulled or released and thereby drives the reel mechanism to rotate, the speaker rotates coaxially together with the reel mechanism.

2. The earphone of claim 1 , wherein the housing is formed by assembling a first cover and a second cover face to face, and the reel mechanism and the speaker are both disposed between the first cover and the second cover.

3. The earphone of claim 2 , wherein the first cover has a plurality of holes for outputting sound produced by the speaker.

4. The earphone of claim 2 , wherein the second cover has an ear hanger capable of being hung on a user's ear.

5. The earphone of claim 2 , wherein the second cover further comprises a control switch configured for allowing or blocking the rotation of the reel mechanism.

6. The earphone of claim 2 , wherein the reel mechanism has a through hole formed thereon and the second cover has a post disposed thereon, the post being receivable by the through hole so that the reel mechanism is rotatable to the second cover.

7. The earphone of claim 1 , wherein the reel mechanism has a slot for the transmission wire to be wound upon.

8. The earphone of claim 1 , wherein the reel mechanism further comprises a spring with a first end secured to the reel mechanism and an opposite second end secured to the housing.

9. The earphone of claim 1 , wherein the speaker comprises a main body and a plastic sheath engaged with the main body.

10. The earphone of claim 1 , wherein the speaker is secured in the accommodating space through latching engagement, gluing engagement, riveting engagement or bolting engagement.

11. An earphone comprising:

a housing;

a reel mechanism pivotally disposed in the housing; and

a speaker disposed in the housing and engaged with the reel mechanism, and having a transmission wire wound around the speaker;

wherein when the transmission wire is pulled or released, the speaker and the reel mechanism are driven to rotate together.

12. The earphone of claim 11 , wherein the housing is formed by assembling a first cover and a second cover face to face, and the reel mechanism and the speaker are both disposed between the first cover and the second cover.

13. The earphone of claim 12 , wherein the first cover has a plurality of holes defined therein for outputting sound produced by the speaker.

14. The earphone of claim 12 , wherein the second cover has an ear hanger capable of being hung on a user's ear.

15. The earphone of claim 12 , wherein the second cover further comprises a control switch configured for allowing or blocking the rotation of the reel mechanism.

16. The earphone of claim 12 , wherein the reel mechanism has a through hole formed thereon and the second cover has a post disposed thereon, the post being receivable by the through hole so that the reel mechanism is rotatable to the second cover.

17. The earphone of claim 11 , wherein the reel mechanism has an accommodating space defined therein and the speaker is disposed in the accommodating space.

18. The earphone of claim 17 , wherein the reel mechanism has a slot for the transmission wire to be wound upon.

19. The earphone of claim 11 , wherein the speaker is secured in the accommodating space through latching engagement, gluing engagement, riveting engagement or bolting engagement.

20. The earphone of claim 11 , wherein the reel mechanism further comprises a spring with a first end secured to the reel mechanism and an opposite second end secured to the housing.