Constant angular velocity

An advantage of CAV mode over CLV is that the drive mechanism is easier to engineer (and less expensive to build).

Gramophone records have always used CAV, including CEDs which provide video signals.

[specify] It allows for shorter access times because the rotation speed (angular velocity) does not need to be changed when the laser seeks across the disc, similarly to the magnetic head of a hard disk drive.

CAV was used in the LaserDisc format for interactive titles; it was also used with special editions of certain films.

[citation needed] If the used media (e.g. DVD-RAM variants) has a linear (writing) speed limitation that can not be attained with physically supported angular (rotation) speeds at the inner edge of the recordable area, the disc writing can start off with a constant angular velocity, until the increasing linear velocity has reached the writing speed limitation of the disc.

Comparison of several forms of disk storage showing tracks (not-to-scale); green denotes start and red denotes end. Note Apple 3.5–inch floppy disk drives used five speeds, increasing capacity by a fourth relative to simpler CAV drives.
* Some CD-R(W) and DVD-R(W)/DVD+R(W) recorders operate in ZCLV, CAA or CAV modes.
Dimensions of a standard-size (12 cm diameter) optical disc
Constant-angular-velocity (CAV) LaserDisc , showing the NTSC field setup and individual scan lines