Components
A CD player has three major mechanical components : a drive motor, a lens system, and a tracking mechanism. The drive motor (also called spindle) rotates the disc between 200 and 500 revolutions per minute. The tracking mechanism moves the lens system along the spiral tracks in which information is encoded, and the lens reads the information using a laser beam, typically produced by a laser diode. The laser reads information by focusing a beam on the CD, which is reflected back to a sensor. The sensor detects changes in the beam, and interprets these changes to read the data. This data is processed, and eventually converted to sound using a digital-to-analog converter (DAC).
A subcode is located in "lead-in" area of the disc, which is located in a inner ring of the disc, and contains roughly five kilobytes of available space. It is first information that the player reads, when the disc is loaded in the player, and contains information on the total number of audio tracks, the running time on the CD, the running time of each track, and other information.
The "lead out" area in the end (the outer peripheral) of the disc tells the player that disc has come to an end.
Read more about this topic: Compact Disc Player
Famous quotes containing the word components:
“Hence, a generative grammar must be a system of rules that can iterate to generate an indefinitely large number of structures. This system of rules can be analyzed into the three major components of a generative grammar: the syntactic, phonological, and semantic components.”
—Noam Chomsky (b. 1928)