Synchronization control system in video signal reproducing device

A video signal reproducing apparatus for use with a magnetic disk of the type that has synchronization signals stored thereon, and has a phase generate signal generating source at a portion thereof, the position of which having a predetermined relationship in phase with at least one of said stored synchronization signals on said disk, comprising:

• disk information detecting means, located opposing said disk, for reading information from said disk and producing output signals indicative of:
• 1) a phase generate signal from said phase generate signal generating source on said disk, 2) a video signal from said disk, and 3) said stored synchronization signals;
• drive means for causing relative positional movement between said magnetic disk and said information detecting means, said drive means having a controlling input and producing an output signal indicative of said relative positional movement;
• signal generating means, coupled to an output of said disk information detecting means, for producing a compound synchronization signal, comprising a vertical sync signal and a horizontal sync signal, synchronized with said video signal, and for producing a servo reference signal, synchronized with at least one of said sync signals in said compound synchronization signal;
• first switch means, coupled to receive said video signal and said compound synchronization signal as input signals, for selectively outputting one of said input signals responsive to a first control input;
• second switch means, coupled to receive said phase generate signal and at least one of said stored synchronization signals as inputs thereof, for selectively outputting one of said input signals as a first sync signal responsive to a second control input;
• phase detection and correction means, for receiving said first sync signal from said second switch means, and said servo reference signal and producing an output signal indicative of a difference therebetween, said output signal being used, along with said output signal of said drive means to control said drive means, and
• control means for:
• 1) commanding a switching between tracks of said disk operation, 2) producing and sending a signal to said first control input of said first switch means, said signal commanding an output of said composite synchronization signal during said switching of tracks operation, and 3) producing and sending a signal to said second control input of said second switch means, said signal commanding said second switch means to output said phase generate signal at least during periods of said switching between tracks operation.

A video signal reproducing device for use with a magnetic disk of the type that has a phase generate signal generating source at a portion thereof, the position of which having a predetermined relationship in phase with a synchronization of said disk, comprising:

• disk information detecting means, located opposing said disk, for reading information from said disk and producing output signals indicative of:
• 1) a phase generate signal from said phase generate signal generating source on said disk, and 2) a video signal from said disk;
• drive means for causing relative positional movement between said magnetic disk and said information detecting means, said drive means having a controlling input and producing an output signal indicative of said relative positional movement;
• signal generating means, coupled to an output of said disk information detecting means, for producing a compound synchronization signal comprising a vertical sync signal and a horizontal sync signal synchronized with said video signal, and for producing a servo reference signal, synchronized with at least one of said sync signals in said compound synchronization signal;
• switch means, coupled to receive said video signal and said compound synchronization signal as input signals selectively outputting one of said input signals responsive to a control input;
• phase detection and correction means, for receiving said phase generate signal and said servo reference signal and producing an output signal indicative of a difference therebetween, said output signal being used, along with said output signal of said drive means to control said drive means, and
• control means for commanding a switching between tracks of said disk operation, and producing and sending a signal to said control input of said switch means, said signal commanding an output of said composite synchronization signal during said switching of tracks.