constant angular velocity (CAV)
Recording and playback method for image plates. In the Constant Angular Velocity (CAV) process, the tracks are recorded on concentric circles, starting in the center of the picture plate.
Each circular track contains one television frame ( field), i.e. two fields(frames ). The picture is changed by changing the track within the vertical blanking interval. Since the circumference of the inner recording track is much smaller than that of the outer track, valuable recording space is wasted in the CAV process, which is ultimately reflected in the storage capacity. This comprises approx. 54,000 full frames, which corresponds to a playing time of 36 minutes.
The advantage of the CAV process lies in the still image playback that is only possible with this process. Since one frame corresponds to one revolution, the constant revolution speed is 25 rps.