What is the Working Principle of a DVD Player?

A DVD player is very similar to a CD player. It has a laser assembly that shines the laser beam onto the surface of the disc to read the pattern of bumps . The DVD player decodes the MPEG-2 encoded movie, turning it into a standard composite video signal. The player also decodes the audio stream and sends it to a Dolby decoder, where it is amplified and sent to the speakers.

The drive consists of three fundamental components :

● Drive Motor : It is used to spin the disc. The drive motor is precisely controlled to rotate between 200 and 500 rpm, depending on which track is being read.

● Laser and a Lens System : The light from this laser has a smaller wavelength (640 nanometers) than the light from the laser in a CD player (780 nanometers), which allows the DVD laser to focus on the smaller DVD pits.

● Tracking Mechanism : It can move the laser assembly so the laser beam can follow the spiral track. The tracking system has to be able to move the laser at micron resolutions.