Method and apparatus for slow-motion playback of digital video signals

US5166834A · kind A · utility

Assignee

• BTS Broadcast Television Systems GmbH · DE

Inventors

• Roland Mester · Darmstadt, DE
• Berthold Eiberger · Darmstadt, DE

Key dates

• Filing date: Sep 4, 1990
• Grant date: Nov 24, 1992
• Expiry date: Sep 4, 2010

Classification

• Technology area (CPC G): Physics
• CPC primary: G11B2220/90
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

For reliable playback of digital video signals in slow-motion operation over a wide range of slow-motion speeds, auxiliary playback heads are positioned closely behind normal playback heads and offset by half a track width therefrom. Each of the playback heads have a circuit for regenerating clock and data signals which includes a PLL circuit and all of the PLL circuits have an output for the signal that shows whether the PLL circuit is locked in or not. The lock-in signals are supplied to first address inputs of an ROM which has a principal output showing whether the normal playback heads or the auxiliary playback heads have the larger number of locked-in PLL circuits and the group of playback heads having that larger number of locked-in PLL circuits is selected for having the data and clock signal outputs passed on to playback channels for further processing. The control of the switching circuit is improved by having auxiliary outputs of the ROM fed back to second address inputs thereof.