Method and apparatus for recording a single video frame

A method of developing a single frame video signal from a video signal consisting of successive frames, each of said successive frames consisting of two interlaced fields, and recording said single frame video signal on a recorder having a moving magnetic medium and a single stationary transducer, said transducer defining an endless recording track on said medium during a complete cycle of movement of said magnetic medium, comprising the steps of:

• applying a single field signal to said transducer and recording said single field signal on said recording track,
• sensing the recorded single field signal with said transducer and supplying said single field signal to a memory,
• storing said single field signal in said memory,
• reading out said single field signal from said memory and reapplying said single field signal to said transducer, and
• rerecording said single field signal on said recording track at a position on said track corresponding to the time delay between two interlaced fields, whereby said single field signal is recorded twice on said recording track and positioned so that the two recordings of said single field signal are interlaced to comprise a single frame signal.

A method of developing a single frame video signal from a video signal consisting of successive frames, each of said successive frames consisting of two interlaced fields and each of said fields consisting of a plurality of lines, and recording said single frame video signal on a recorder having a moving magnetic medium and a single stationary transducer, said transducer defining an endless recording track on said medium as said medium moves past said transducer, comprising the steps of:

• a. applying a single field signal to said transducer and recording said single field signal on said recording track,
• b. sensing a portion of the recorded single field signal with said transducer, said portion including an integer number of said plurality of lines,
• c. storing the sensed portion of said single field signal,
• d. rerecording said sensed portion of said single field signal on said medium at a location on said recording track with respect to the portion of the sensed portion of said single field signal corresponding to the time delay between the initiation of two successive fields, and
• e. repeating steps (b), (c) and (d) for successive portions of said single field signal until said single field signal is rerecorded in its entirety on said recording track in a position such that said single field signal comprises the interlaced fields of a video frame signal.

A stop-action recorder for recording a video signal and for providing at a frame rate to a monitor a video frame composed of two interlaced fields, without the motion jitter that results from spatial displacement of a subject during the time between display of the two interlaced fields, comprising:

• video source means for providing a signal to be recorded;
• disc means, including a magnetic disc and a magnetic pick-up and record head adjacent said magnetic disc, for recording a video signal;
• means for rotating said disc at the rate of one revolution per frame;
• memory means for storing a signal applied thereto;
• switch means for applying one of said two interlaced field signals to said disc means to be recorded on said magnetic disc during one-half revolution of said disc;
• means, connected to said head, for reproducing said one of said two interlaced field signals recorded on said magnetic disc and for applying the reproduced field signal to said memory means;
• and
• means, connected to said memory means, for reapplying said reproduced field signal to said switch means whereby said one of said two interlaced fields is rerecorded by said disc means such that, in a subsequent display of the signal recorded on said disc means, a frame composed of two identical interlaced fields will be shown by a video monitor.