Z-CLV - All About All

Constant linear velocity (Redirected from Z-CLV)

Constant Linear Velocity (CLV) refers to how information is written to or read from a rotating data disk. A typical example can be seen in one of the differences between an LP record and a compact audio disc (CD). With an LP, the disc always spins at a Constant Angular Velocity (CAV) of 33 rpm, so the surface of the record groove passes the needle at slower linear rate as the needle moves toward the center of the disc. This is because when LPs were first developed, motor speed control was not nearly as accurate as it is today; constant linear velocity was harder to control.

With a CD, the motor speed decreases from 495 to 212 rpm as the read head moves away from the center, to keep the disc moving past the read head at a constant linear velocity (CLV) of 1.2 m/s. A DVD has as many 24 zones of different linear velocity. This zoning has given rise to the notion of zoned constant linear velocity (ZCLV).