Compact Disc Player - Pickup Mechanisms

Pickup Mechanisms

Two types of optical tracking mechanisms exist:

• the swing-arm mechanism, originally designed by Philips - the lens moves at the end of an arm, very much like the old turntables. Used in earliest Philips CD players.
• the radial mechanism, designed by Sony, which is the one used in most CD players nowadays - the lens moves on a radial rail. It is also known as 3-beam linear tracking.

The swing-arm mechanism has a distinctive advantage over the other in that it doesn't "skip" when the rail becomes dirty. The swing arm mechanisms tend to have a much longer life than their radial counterparts. The radial mechanism works best for CD-ROMs, though, as the speed of the disc increases.