(1) Field of the Invention
This invention relates to an optical pickup calibrating apparatus in a disc player and a fabricating method of the same, and more particularly to an apparatus in which a guiding rod supporting the optical pickup is calibrated up and down to have the optical pickup focusing on the surface of a disc.
(2) Description of Related Art
In a rapid progress of personal computer industry, computer peripheral products, such as hard disks, disc players, scanners, and printers, have been broadly used in modern offices. Among these peripheral products, the disc player using compact disc (CD) featuring an enormous storing capacity, various data formats acceptable, and long period data storage is a most popular choice. In addition, the development of digital versatile disc (DVD) with a storage capacity up to 17 Giga byte (GB) improves high quality video and audio applications for disc players.
Referring to FIG. 1, a traditional disc player has a spindle motor 10, an optical pickup 20, and a driving apparatus 30. A disc (not shown in this figure), such as CD or DVD, is loaded on the spindle motor 10 and rotated by the spindle motor 10. The driving apparatus 30 is utilized to position the optical pickup 20 for helping the optical pickup 20 proceeding precise tracking and focusing on the disc to access data.
The driving apparatus 30 has a guiding rod 32, a sled motor (not shown), and a guiding shaft 34. The guiding rod 32 and the guiding shaft 34 are substantially parallel with each other and extended from the location of the spindle motor 10. The opposite edges of the optical pickup 20 are supported on the guiding rod 32 and the guiding shaft 34, respectively. By starting the sled motor to rotate the guiding shaft 34, the optical pickup 20 is positioned along the guiding rod 32. That is, the tilt event of the guiding rod 32 and the guiding shaft 34 implies the laser emitting direction of the optical pickup 20.
There are a huge amount of optical pits formed on the disc for storing data. The laser emitting direction of the optical pickup 20 had better be perpendicular to the surface of the disc for accessing data correctly. However, some small errors in the laser emitting direction are unpreventable in the fabrication process, and may significantly affect the performance of the optical pickup 20. For calibrating such errors, an optical pickup calibrating apparatus is usually formed together in the disc player for precisely adjusting the laser emitting direction of the optical pickup 20 to promote the yield.
Referring to FIGS. 2A and 2B, the traditional optical pickup calibrating apparatus has a base 410, a holder 420, a curved elastic sheet 430, a first screw 440, a second screw 450, and an adjusting screw 460. The holder 420 is screw-fixed on the base 410 by using the first screw 440 to hold one of the both ends 32a of the guiding rod 32. The curved elastic sheet 430 is screw-fixed on the base 410 by using the second screw 450. The curve elastic sheet 430 has a free end applying forces on the guiding rod 32 to prevent the guiding rod 32 from vibrating. The adjusting screw 460 is assembled on the base 410 and has a portion protruding over the base 410 just below the guiding rod 32. By rotating the adjusting screw 460 to change the length of the protruding portion, the tilt of the guiding rod 32 can be calibrated.
As mentioned above, the traditional optical pickup calibrating apparatus includes six parts, the base 410, the holder 420, the curved elastic sheet 430, the first screw 440, the second screw 450, and the adjusting screw 460, incorporate to calibrate the tilt of the guiding rod 32. Some corresponded assembling steps to complete the optical pickup calibrating apparatus within the disc player are necessary. Since the mechanism of the optical pickup calibrating apparatus is quite complicated, the yield of the disc player will definitely decrease and some additional fabrication cost will be unpreventable.
Accordingly, how to simplify the mechanism of the optical pickup calibrating apparatus for increasing the reliability of the disc player and also reducing the fabrication cost has become important designing issues of disc players nowadays.