A DVD player reads data from a disc using a laser beam. Here is a simplified step-by-step process:
- The DVD disc is inserted into the player.
- The player's motor spins the disc at a constant speed.
- A laser beam is emitted from the DVD player's laser diode.
- The laser diode focuses the laser beam onto the surface of the DVD disc.
- The laser beam reflects off the disc's surface, specifically the data layer, which consists of pits and lands.
- While the disc is spinning, the laser beam scans the surface in a spiral pattern, starting from the inside and moving outward.
- As the laser beam interacts with the disc's surface, it measures the reflections. When it encounters pits (tiny indentations), it ****ters the light differently than when it encounters lands (flat areas). These variations in light reflection represent the binary data (0s and 1s) stored on the disc.
- The laser beam's reflections are captured by a photo-detector, which translates the varying reflections into electrical signals.
- The electrical signals are sent to a digital-to-analog converter (DAC), which converts the signals into digital data.
- The digital data is then processed by the DVD player's internal circuits to decode and play the audio, video, or other data stored on the disc.
This process allows the DVD player to read the encoded data and play videos, movies, or other content stored on the DVD disc.