1. Field of the Invention
The present invention relates to an optical disc drive, and more particularly, to an optical disc drive which can prevent damage by static electricity not only in a closed state of a tray but also in an open state thereof.
2. Description of the Related Art
In general, optical disc drives record or reproduces information by radiating light onto a recording medium such as CDs (compact discs) and DVDs (digital versatile discs). The optical disc drive includes various structures to discharge static electricity to prevent malfunction or failure of elements due to the static electricity.
FIGS. 1 and 2 show an example of a static electricity discharge structure employed in a conventional optical disc drive. FIG. 1 shows that a tray 30 of the conventional optical disc drive is closed while FIG. 2 shows that the tray 30 is open. The optical disc drive is disclosed in U.S. Pat. No. 5,684,775.
Referring to FIG. 1, the conventional optical disc drive includes a chassis 33 formed of metal, the tray 30 coupled to the chassis 33 to be inserted into the chassis 33 or pulled out of the chassis 33 by being guided by a guide rail 42, and a bezel 35 provided at a front side of the tray 30. An eject button 43 to unlock the tray 30 when inserted in the chassis 33 and locked is provided at the bezel 35. An eject switch 52, which is pressed by the eject button 43, and a circuit board 50, where the eject switch 52 is installed, are provided at a front surface portion of the tray 30 facing the eject button 43. A metal plate member 60 to guide current by static electricity toward the chassis 33 is provided at a rear surface of the bezel 35 facing the front surface portion of the tray 30. The metal plate member 60 is attached to the rear surface of the bezel 35 by a pair of bosses 36 and 37 protruding from the rear surface of the bezel 35.
In a state in which the tray 30 of the optical disc drive having the above structure is inserted in the chassis 33, when the eject button 43 is pressed using a finger tip 17 to open the optical disc drive, as shown in FIG. 1, a discharge of static electricity 80 may be generated by friction between the finger tip 17 and the eject button 43. The static electricity 80 passes through a gap 70 between the bezel 35 and the eject button 43, as indicated by an arrow shown in FIG. 1, to proceed toward a cover portion 61 of the metal plate member 60 located around the eject switch 52. Then, the static electricity 80 is transferred to the chassis 33 via contact leads 64 and 65 at both ends of the metal plate member 60 and discharged through a ground (not shown). Thus, the static electricity 80 is prevented from flowing into the circuit board 50 via the eject switch 52.
However, referring to FIG. 2, when the optical disc drive is in an open state as the tray 30 is pulled out of the chassis 33, since the contact leads 64 and 65 of the metal plate member 60 do not contact the chassis 33, a discharge path of the static electricity is blocked so that the static electricity may flow into the circuit board 50 to malfunction or damage the optical disc drive.