In: Computer Science
There is a common misperception that the pits and lands in optical discs represent zeros and ones. Research the function performed by the pits and lands in CD, DVD, and Blu-ray discs and explain how they are interpreted. Recordable discs do not use pits and lands. Research these discs and describe how they convey zeros and ones. Be sure to thoroughly cite the sources of your research.
1). ANSWER :
GIVENTHAT :
i).CDs, DVDs and Blu-Ray disks and optical media like these have pits and lands. The microscopic sections in the optical discs store the binary information in the form of 0's and 1's and using this data is stored in the disc.
ii).A land is reflective and thus reflects the laser when the laser tries to read from the optical disc to register the signal as a 1, and when the same laser light hits the pit, it registers a 0. To write 0's and 1's on the optical discs the laser bin is turned on for writing 1 and the laser beam is not turned on for writing the 0.
iii).The change in the height between the pits and lands result in the difference in the intensity in the light that is reflected.
iv).A common misperception that the pits and lands in optical discs represent Zeros and ones, but not pits and lands themselves do not directly represent the 0's and 1's rather the Non-return-to-zero, inverted (NRZI) encoding is used, such that the change from pit to land or land to pit indicates a one while no change detects a zero.