Video signal recording method and apparatus for field-segment recording

Claim 2

A video signal recording method, characterized in recording a field composed of scanning lines of a video signal by recording N respectively different sets, each comprising substantially l/N scanning lines of the field, on N respective diagonal tracks of a magnetic tape, where N is an integer equal to or greater than 2, each said set containing one in each of successive groups of N scanning lines of said input video signal field, whereby each of said N diagonal tracks has recorded thereon a set of said scanning lines extending from substantially the commencement to the end of said field.

Claim 3

A recording method according to claim l, in which each of said fields is recorded on said N tracks by executing N successive recording scans across said tape.

Claim 4

A recording method according to claim 2, in which said video signal is produced by combining a luminance signal having a relatively wide bandwidth and first and second chrominance signals each having a comparatively narrow bandwidth, by: arranging successive portions of each of said chrominance signals in a line-ordered sequence in accordance with corresponding ones of said scanning lines; performing time-axis compression of said sequentially arranged chrominance signal portions to produce time-compressed chrominance signals, and; multiplexing said time-compressed chrominance signals with said luminance signal.

Claim 5

A recording method according to claim 3 in which each of said scanning lines includes a flyback interval, and in which said multiplexing is executed by inserting said time-compressed chrominance signals into said flyback intervals.

Claim 8

A method of recording according to claim 5, in which said video signal is produced by combining a luminance signal having a relatively wide bandwidth and first and second chrominance signals each having a comparatively narrow bandwidth, by: arranging successive portions of each of said chrominance signals in a line-ordered sequence in accordance with corresponding ones of said scanning lines; performing time-axis compression of said sequentially arranged chrominance signal portions to produce time-compressed chrominance signals, and; multiplexing said time-compressed chrominance signals with said luminance signal.

Claim 9

A method of recording according to claim 6, in which N is made equal to two, whereby two of said tracks are simultaneously recorded in parallel during each of said recording scans across said tape, and in which multiplexing of said time-compressed chrominance signals and said time-expanded luminance signal and division into two channel signals are executed such that only portions of said first chrominance signal are recorded at a first set of mutually adjoining positions on said two tracks and only portions of said second chrominance signal are recorded at a second set of mutually adjoining positions on said two tracks.

Claim 10

A recording method according to claim 7, in which each of said scanning lines includes a flyback interval, and in which said multiplexing is executed by inserting said time-compressed chrominance signals into said flyback intervals.

Claim 11

A video signal recording method characterized in: executing interlace scanning of a target plate of a video camera to produce a video signal comprising successive fields each composed of a fixed number of scanning lines; recording successive ones of said video signal fields on respective diagonal tracks of a magnetic tape, and; during subsequent playback of said magnetic tape, executing processing of said fields in a playback signal to combine at least two of said fields in a line-sequential alternating manner, to synthesize one field of a playback video signal.

Claim 12

A video signal recording method characterized in: executing interlace scanning of a target plate of a video camera to produce a video signal comprising successive fields each composed of a fixed number of scanning lines; recording successive ones of said video signal fields on respective diagonal tracks of a magnetic tape, and; during subsequent playback of said magnetic tape, executing processing of said fields in a playback signal to combine at least two of said fields in a line-sequential alternating manner, to synthesize one field of a playback video signal.

Claim 13

l0. A video signal recording and playback apparatus for recording and playback of an input video signal consisting of successive scanning lines, comprising; recording circuit means for recording a field of said input video signal on N diagonal tracks of a magnetic tape, where N is an integer equal to or greater than 2, by recording N respectively different sets of said scanning lines on respective ones of said tracks, each said set containing substantially l/N of the scanning lines in said field, composed of one in each of successive groups of N scanning lines of said field, and; playback circuit means for executing playback of said field after recording on said magnetic tape, by processing playback signals derived from said N tracks to combine said N sets of scanning lines into a sequence which is identical to a sequence of scanning lines in said input video signal field.

Claim 14

l0. A video signal recording and playback apparatus for recording and playback of an input video signal consisting of successive scanning lines, comprising; recording circuit means for recording a field of said input video signal on N diagonal tracks of a magnetic tape, where N is an integer equal to or greater than 2, by recording N respectively different sets of said scanning lines on respective ones of said tracks, each said set containing substantially l/N of the scanning lines in said field, composed of one in each of successive groups of N scanning lines of said field, and; playback circuit means for executing playback of said field after recording on said magnetic tape, by processing playback signals derived from said N tracks to combine said N sets of scanning lines into a sequence which is identical to a sequence of scanning lines in said input video signal field.

Claim 15

A recording and playback apparatus according to claim l0, in which said recording circuit means comprise: first analog to digital conversion means for converting said input video signal to a digital video signal; first memory means and first memory control means for receiving said digital video signal, to store successive scanning lines of said field in said first memory means and thereafter successively read out as output signal data said N sets of M/N scanning lines from said first memory means; first digital to analog conversion means for converting said output signal data from said first memory means to an analog recording signal, and; at least one pair of electromagnetic recording/playback heads mounted peripherally on a rotary drum, spaced apart by l80°, connected for recording said analog recording signal on said magnetic tape such that said N sets of scanning lines are recorded on respective ones of said N diagonal tracks; and in which said playback circuit means comprise: said recording/playback heads, connected for playback of said analog recording signal from said N tracks; second analog to digital conversion means for converting an analog playback signal from said playback head to a digital playback signal; second memory means and second memory control means for storing said digital playback signal as data in said second memory means, and for thereafter reading out from said second memory means as an output signal the contents of said digital playback signal arranged in said sequence of scanning lines of the input video signal, and; second digital to analog conversion means for performing digital to analog conversion of said output signal from said second memory means.

Claim 16

A recording and playback apparatus according to claim ll, and further comprising means for converting said analog recording signal to a frequency modulated signal for recording by said heads, and means for executing frequency demodulation of output signals produced from said heads during playback operation, to produce said analog playback signal.

Claim 17

A recording and playback apparatus according to claim l0, in which N is equal to 4 or greater, and further comprising time axis expansion means for converting said input video signal into N/2 channel signals in which the duration of each of said scanning lines is expanded to become N/2 times that of each scanning line of said input video signal, and in which said N/2 channel signals are recorded in parallel on N/2 tracks of said magnetic tape by said recording circuit means, and moreover comprising time-axis compression means for compressing the duration of each scanning line of playback signals from said N/2 tracks to that of said input video signal, for combining said playback signals into a single channel signal.

Claim 18

A recording and playback apparatus according to claim l3, in which said input video signal comprises a luminance signal and first and second chrominance signals respectively supplied in parallel and in which said time-axis expansion means performs time axis expansion of said luminance signal, and further comprising means for performing time axis compression of successive portions of each of said chrominance signals respectively corresponding to successive ones of said scanning lines, multiplexing means for multiplexing said chrominance signals following said said time axis compression thereof with said luminance signal after said time expansion of the luminance signal, demultiplexing means for separating said first and second chrominance signals from said playback signals, and second time-axis expansion means for performing time axis expansion of each of said chrominance signals thus separated.

Claim 19

A video signal recording and playback apparatus, comprising: A video camera having a target plate and means for executing interlace scanning of said target plate with an interlace ratio of 2N:l, where N is an integer equal to or greater than 2, for producing an input video signal consisting of successive scanning lines arranged as successive frames, each said frame comprising 2N fields; recording circuit means for recording successive ones of said 2N fields of each frame of the input video signal on respective ones of 2N diagonal tracks on a magnetic tape, and; playback circuit means for producing playback signals from said tracks and for rearranging a sequence of scanning lines in said playback signals to produce an output video signal having a 2:l interlace ratio.

Claim 20

A video signal recording and playback apparatus, comprising: A video camera having a target plate and means for executing interlace scanning of said target plate with an interlace ratio of 2N:l, where N is an integer equal to or greater than 2, for producing an input video signal consisting of successive scanning lines arranged as successive frames, each said frame comprising 2N fields; recording circuit means for recording successive ones of said 2N fields of each frame of the input video signal on respective ones of 2N diagonal tracks on a magnetic tape, and; playback circuit means for producing playback signals from said tracks and for rearranging a sequence of scanning lines in said playback signals to produce an output video signal having a 2:l interlace ratio.

Claim 21

A recording and playback apparatus according to claim l5, in which said recording means comprise at least one pair of recording/playback heads mounted peripherally on a rotary drum and spaced apart by l80°, connected such as to alternately record successive ones of said fields of the input video signal on successive ones of said tracks, and in which said playback circuit means comprise: said pair of recording/playback heads, connected such as to alternately produce playback signals from successive ones of said tracks; analog to digital conversion means for converting said playback signals to a digital playback signal; memory means and memory control means for storing said digital playback signal as data in said memory means, and for thereafter reading out from said second memory means, as a digital output signal, the contents of said digital playback signal with a sequence of scanning lines therein rearranged to provide an interlace ratio of 2:l, and; digital to analog conversion means for performing digital to analog conversion of said digital output signal.

Claim 22

A recording and playback apparatus according to claim l6, and further comprising means for converting said input video signal to a frequency modulated signal to be recorded by said recording/playback heads, and means for executing frequency demodulation of output signals from said heads during playback operation to produce said playback signals.