How Does a DVD Player Work

The Digital Versatile Disc or the Digital Video Disc (DVD) is a compact disc with a large capacity. The maximum capacity of the DVD is 15 GB. DVD players are used in desktop computers, laptop computers, and television sets. The DVD players are used to read the data on the DVDs. Let us understand exactly how a DVD player works.

Components of a DVD Player

Motor
The motor is used to spin the DVD and the speed at which the disc is spun depends on the type of DVD you are playing in the DVD player. Also, the speed of the motor depends on the track that is read by the DVD player.

Laser assembly
The laser assembly is used to read the data, video and audio present on the DVD using the DVD player. The laser assembly consists of a laser beam and a light sensor. The laser beam is incident on the DVD and the laser sensor is used to read the reflected light from the DVD.

Tracking Mechanism
The tracking mechanism of the DVD player is used to move the laser beam in synchronization with the DVD so that the laser sensor can track the data on the DVD perfectly.

Reading the DVD

Data is stored on the DVD in the digital form, i.e. in 1s and 0s. The 1s and 0s are represented in the form of bumps and flats respectively. The DVD is made of aluminum and then plastic coated to reflect the laser beam. The laser assembly of the DVD player is used to project a laser beam on the DVD so that the bumps and flats on the DVD can be read. The laser beam is projected on the DVD and the motor spins the DVD in order to read it. Usually, the DVD players have an MPEG-2 decoder or MPEG-4 decoder, which decodes the encoded data read by the laser assembly.

The decoder decodes the data in the form of audio, video and data. The most crucial part of DVD reading is keeping the DVD centered on the data track. The tracking mechanism moves the laser radially outwards from the center of the disc. The synchronization is maintained by the formula which is given as follows:

Speed of the Tracking System = (Radius of the Disc) X (Speed of the Rotation of the Disc)

This speed is always maintained so that the data is collected at a constant rate. The dual layer DVD is also available. The second layer of the DVD starts on the outer side of the disc, so the tracking system does not have to move again to the center of the disc while reading the second layer. This eliminates the time delay in the data output.

The DVD player supports the following DVD formats and CD formats:

• DVD-R
• DVD+R
• DVD-RW
• DVD+RW
• DVD-RAM
• DVD-ROM
• CD-R
• CD-RW

The DVD players available, nowadays, are digital theater system (DTS) compatible. Some of the DVD players have the DTS decoder inside the player, but even if you have a DTS compatible receiver, you can enjoy the benefits of DTS. The DVD player has a Dolby digital decoder to decode the Dolby digital information. The DVD players that are available these days, have a remote control and a USB port. The USB port enables us to plug the USB flash drives (pen drives) to view movies, listen to music and view images. The ever-advancing technology is introducing many features to make the DVD players fully-equipped. Nowadays, even portable DVD players are available.