Method and apparatus for reproducing video data stored on a magnetic tape in a manner facilitating search and slow-motion operation

US5237461A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Jurgen Heitmann · Zwingenberg, DE
• Rolf Loos · Eppertshausen, DE
• Roland Mester · Darmstadt, DE

Key dates

• Filing date: Aug 25, 1992
• Grant date: Aug 17, 1993
• Expiry date: Aug 25, 2012

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04N5/937
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

As many as three of the four heads spaced at 90.degree. intervals around the periphery of a head wheel may be in contact with the magnetic tape of a video recorder and reproducer at the same time. Oblique tracks are recorded on the tape record video date in blocks corresponding to sectors, each composed of the same numbers of lines, each track beginning with a video sector and ending with another video sector with small audio blocks inbetween. Four different sector designations succeed each other in turn. The video data of each block is preceded by an identification signal of which the two most significant bits designate the sector. The sector designations are separated from the outputs of each of the magnetic heads and control a PROM, the output of which controls a crosspoint switch to direct data blocks in accordance with the sector identification to four memories and the audio blocks to an audio memory. When reproduction is performed at a speed faster or slower than the recording speed, the control data for the switch normally still has enough redundance for correct switching but when the control data becomes inconsistent with the track pattern, an error is detected and the prev…