Maryam-09

Thursday, September 14, 2006

HOW CD BURN WORKS
An external writable CD drive, also called a CD burner: With this type of drive, you can take music or data files from your computer and make your own CDs.
CD burners marked by a cultural shift. The technology made it sutaible for the average person to gather songs and produce their own CDs. All the sudden music-mix makers hand their hands on the made of production everywhere.
Inside the CD player there is a little bit of computer technology involved about the data into understanding data blocks and sending to DAC or to the computer. DAC is "digital to analog converter."
The easy job of the CD player is to study the laser on the track of bumps. The laser beam passes through the flaxible layer,reflects off the aluminum layer and hits an opto-electronic device that detects change in light. The bumps reflect light differently than the "lands" (the rest of the aluminum layer). The opto-electronic device detects the change in reflectivity. The electonics in the drive interpret the change in reflectivility in order to read the bits that make up the bytes.
Keeping the laser beam centered on the data track is the hardest part. This centering is the job of the tracking system. The tracking system, as it plays the CD, has to continually move the laser outward. As the laser moves outward from the center of the disc, the bumps move past the laser faster --- this happens because the linear, or tangential, speed of the bumps is the same radius times the speed at which the disc is revolving (rpm). Therefore, as the laser moves outward, the spindle motor must slow the speed of the CD. That way, the bumps travel past the laser at a constant speed, and the data comes off the disc at a constant rate.
The CD player spins the disc while moving the laser assembly outward from the middle. To keep the laser scanning the data track at a constant speed, the player must slow the disc as the assembly moves outward.
The CD player has the job of finding and reading the data that are as bumps on the CD. Considering how small the bumps are, the CD player is an exceptionally precise piece of equipment. The drive consists of three fundamental components.

Group members: Maryam Sohrabi, Maryam Safdar Ali, Roxana Kazemi.

0 Comments:

Post a Comment

<< Home