constant linear velocity (CLV)

Constant Linear Velocity (CLV) is a recording/playback method of compact discs( CD) in which the angular acceleration is constant. The recording speed changes depending on the track position. The readout speed is constant, which is achieved by varying rotational speed.

To ensure a constant data transfer rate, the spindle motor must run faster when reading out inner tracks than when reading out tracks in the outer area. The speed ratio between the inner track and the outer track is about 1:3.5 for compact discs (CDs).

When recording television signals using the CLV process, the television fields are always recorded with the same track length on concentric circles. The innermost recording track contains a complete television frame with a vertical blanking interval, as in the Constant Angular Velocity ( CAV) process. The tracks following to the outside contain more and more fields; the outermost track contains six. The CLV process, which cannot be used for still image displays, has a much better track utilization compared to the CAV process and therefore a playing time of 60 minutes of video.