What happens to the CD when we insert it in the CD drive?

Question

Does it spin, or does the lens spin. Isn't it scratched? How does the whole procedure work? Thanks.

Answer 1

When you insert a CD into the CDROM, it stays on a 'hanger' that holds it in the centre and spins it. Most CDROMs have 52x or 56x as their maximum speed. Then the lens moves moves up and down the CD, that is, from inside to outside and vice versa. (From the inner circle where the hangers holds it to spin it to the outer edge of the CD. The lens reads the CD by emitting laser light onto the CD to read its contents. Thats why its not advisable to open up a CD while its reading a CD because of the laser light.
Note that if a CD has scratched, the scratch creates a shadow onto the CD when the laser lights onto it blocking the lens from reading that particular point thus causing read or cyclic redundancy or data error.
Also note that the CD is suspended like 2cm from the lens by the hanger which also spins it.

Answer 2

The CD spins and it is read by the laser lens which starts in the middle and works it way to the edge of the disc on a mechanical arm. The speed at which the disc spins varies depending which area of the disc is being read. The disc should not be scratched as no part of the playing surface should get touched by the player once inserted.

Answer 3

The CD spins and a laser is reflected onto the lens. Nothing physically touches the surface of the CD, so it doesn't get scratched.

Answer 4

the CD spins and gets hit by a small laser light. The reflections from that light are captured by the CD player and converted into music or data.

Answer 5

The disc spins, and the lens travels up and down a track perpendicular to the disc. It does not get scratched because the spindle lifts the disc it clear of the tray first (I think).

Answer 6

It spins. The lens fires a laser which reads the surface. The surface contains pits and grooves and it is these that the laser reads.

Answer 7

A Compact Disc is made from a 1.2 mm thick disc of almost pure polycarbonate plastic and weighs approximately 16 grams. A thin layer of Super Purity Aluminium (or rarely gold, used for its data longevity, such as in some limited-edition audiophile CDs) is applied to the surface to make it reflective, and is protected by a film of lacquer. The lacquer is normally printed directly and not with an adhesive label. Common printing methods for compact discs are screen-printing and offset printing. CD data is stored as a series of tiny indentations (pits), encoded in a tightly packed spiral track moulded into the top of the polycarbonate layer. The areas between pits are known as 'lands'. Each pit is approximately 100 nm deep by 500 nm wide, and varies from 850 nm to 3.5 μm in length. The spacing between the tracks, the pitch, is 1.6 μm. A CD is read by focusing a 780 nm wavelength semiconductor laser through the bottom of the polycarbonate layer. The difference in height between pits and lands leads to a phase difference between the light reflected from a pit and that from its surrounding land. By measuring the intensity with a photodiode, it is possible to read the data from the disc. The pits and lands themselves do not directly represent the zeros and ones of binary data. Instead, Non-return-to-zero, inverted encoding is used: a change from pit to land or land to pit indicates a one, while no change indicates a zero. This in turn is decoded by reversing the Eight-to-Fourteen Modulation used in mastering the disc, and then reversing the Cross-Interleaved Reed-Solomon Coding, finally revealing the raw data stored on the disc.

Pits are much closer to the label side of a disc so that defects and dirt on the clear side can be out of focus during playback. Discs consequently suffer more damage because of defects such as scratches on the label side, whereas clear-side scratches can be repaired by refilling them with plastic of similar index of refraction.

AND AFTER ALL THAT, I REALISE I HAVEN'T ANSWERD UR QUESTION LOL!!!

Answer 8

a lense inside you cd drive reeds data on the disk. The disk spins around as the lense reeds the data on that disk. The lense moves up and down to get closer to the centre or edge of the disk depending where the data is.

for more information visit...

http://en.wikipedia.org/wiki/Cd_drive

Answer 9

it spins