Video disk signal recording system with cyclical speed control

Claim 2

In a video signal recording system for recording upon circular tracks of an endless magnetic recording medium a television signal consisting of synchronizing pulses and video signals in which the horizontal synchronizing pulses in first fields are out of phase relative with those in second fields, a video signal recording system comprising a. television signal sampling means for sampling the television signal of each first field to be recorded upon the circular track of the endless magnetic recording medium in such a way that at least the horizontal synchronizing pulse phase difference component may be cut off at the end of said first field to be recorded, thereby to define a sampling interval, b. recording means for recording the sampled television signal of one field on each of the circular tracks of the endless magnetic recording medium, c. driving means for rotating the endless magnetic recording medium at a period equal to the sampling interval, d. speed control means connected to said recording medium driving means for varying the rotational period of said driving means in such a way that the rotational period of said driving means may be increased by about two times the phase difference between the horizontal sync pulses of the first sampled, and the second, not-sampled, field during the duration of each of said second not-sampled field between each said first sampled field, whereby the starting points of the recording of said first, sampled, fields upon the circular tracks on the endless magnetic recording medium may coincide to occupy the same place in space.

Claim 3

A video signal recording system according to claim 1 wherein said sampling means includes a. a counter for counting the horizontal synchronizing pulses in each field of the television signal, said counter being reset upon counting said horizontal synchronizing pulses in each field, b. sampling signal generating means coupled to said counter which is set by the vertical synchronizing pulse in the television signal and is reset by the reset output of said counter, and c. transmission gate means coupled to said sampling signal generating means for permitting the transmission of the television signal for a predetermined time interval in response to the output of said sampling pulse generating means.

Claim 4

A video signal recording system according to claim 1 wherein said speed control means includes a. pulse generating means for generating during one rotation of the endless magnetic recording medium control pulses the number of which is greater than the number of horizontal synchronizing pulses in each of said sampled fields by at least one pulse, and b. phase comparator means coupled to said pulse generating means for comparing the phase of the reference signal corresponding to the horizontal synchronizing pulse in the television signal with the phase of said control pulses generated by said pulse generating means, and generating the output which corresponds to the phase difference between said reference signal and control pulses, said phase comparator means imparting the additional energy to said driving means so as to vary the rotational speed of said endless magnetic recording medium in such a way that the rotational period of the endless magnetic recording medium may be increased by at least two times said phase difference between said horizontal synchronizing pulses when there exits said phase difference output.

Claim 5

A video signal recording system according to claim 3 wherein said pulse generating means includEs a. first and second groups of pulse generating elements which are arrayed around the circles and rotated in unison with the endless magnetic recording medium, the number of said first group of pulse generating elements being equal to the number of horizontal synchronizing pulses in each field of the television signal and the number of said second group of pulse generating elements being different from said number of said first group of pulse generating elements by at least one, b. first and second sensing heads disposed in opposed relation with said first and second groups of pulse generating elements respectively for sensing said pulse generating elements so as to generate electrical signals, c. frequency division means for stepping down the vertical synchronizing pulse frequency by one half, and d. switching means connected to said frequency division means for alternately conducting first and second output lines in response to the signals from said frequency division means, said first and second output lines being connected to said first and second sensing heads respectively, said switching means being also connected to said phase comparator means, whereby said endless magnetic recording medium may be rotated in response to the pulses generated by said first and second groups of pulse generating elements for recording the sampled field of the television signal.

Claim 6

A video signal recording system according to claim 4 wherein the pulse generating elements of said second group are disposed in non-uniformly spaced apart relation with each other in the sections corresponding to the starting point and intermediate section of the circular recording track of said endless magnetic recording medium, whereby the rotational period of the endless magnetic recording medium may be varied so as compensate for the inertia thereof.

Claim 7

In a video signal recording system for recording upon an endless magnetic recording medium selected television signals corresponding to predetermined fields including the video signal and synchronizing signals of said fields, the horizontal synchronizing pulses in each field of the television signal being out of phase, a video signal recording system, comprising a. television signal sampling means including sampling signal generating means for sampling the video signals in a predetermined sequence in response to the vertical synchronizing pulses in said synchronizing pulses in the television signal, said television signal sampling means sampling in response to the sampling signal from said sampling signal generating means the television signal including the video signals of the predetermined fields and the associated synchronizing pulses of the predetermined fields, b. recording means coupled to said sampling means for recording upon the circular tracks on the magnetic recording medium the television signal of the predetermined fields sampled by said sampling means, c. driving means for driving the magnetic recording medium relative to said recording means at a rotational period less than a duration of each field, and d. control means coupled to said driving means for varying the driving speed of said driving means, said control means including i. first pulse generating means for generating two kinds of control pulse trains having different numbers of pulses respectively during said rotational period of said magnetic recording medium which is driven with respect to said recording means ii. frequency division means for stepping down into one half the vertical synchronizing pulse frequency in the television signal, iii. switching means coupled to said pulse generating means and to said frequency division means for outputting either of said two kinds of pulse trains in response to the signal from said frequency division means, iv. second pulse generating means for generating pulses having the same pulse period and pulse duration or width with those of one of said two kinDs of pulse trains generated by said first pulse generating means, and v. comparator means coupled to said switching means and to said second pulse generating means for comparing the period of the relative displacement between said magnetic recording medium and said recording means and the phases of the pulses from said switching circuit and said second pulse generating circuit, said control means being interconnected between said comparator means and said drive means for imparting to said driving means the energy corresponding to the output from said comparator means so as to vary said relative speed between said magnetic recording medium and said recording means, thereby coinciding the starting points of the respective recordings of respective fields of the television signal to be sampled and recorded upon the magnetic recording medium.

Claim 8

In a video signal recording system for recording upon an endless magnetic recording medium selected television signals corresponding to predetermined fields including the video signal and synchronizing signals of said fields, the horizontal synchronizing pulses in each field of the television signal being out of phase, a video signal recording system, comprising a. television signal sampling means including sampling signal generating means for sampling the video signals in a predetermined sequence in response to the vertical synchronizing pulses in said synchronizing pulses in the television signal, said television signal sampling means sampling in response to the sampling signal from said sampling signal generating means the television signal including the video signals of the predetermined fields and the associated synchronizing pulses of the predetermined fields, b. recording means coupled to said sampling means for recording upon the circular tracks on the magnetic recording medium the television signal of the predetermined fields sampled by said sampling means, c. driving means for driving the magnetic recording medium relative to said recording means at a rotational period less than a duration of each field, and d. control means coupled to said driving means for varying the driving speed of said driving means, said control means including i. first pulse generating means for generating two kinds of control pulse trains having different numbers of pulses respectively during said rotational period of said magnetic recording medium which is driven with respect to said recording means ii. frequency division means for stepping down into one half the vertical synchronizing pulse frequency in the television signal, iii. switching means coupled to said pulse generating means and to said frequency division means for outputting either of said two kinds of pulse trains in response to the signal from said frequency division means, iv. second pulse generating means for generating pulses having the same pulse period and pulse duration or width with those of one of said two kinDs of pulse trains generated by said first pulse generating means, and v. comparator means coupled to said switching means and to said second pulse generating means for comparing the period of the relative displacement between said magnetic recording medium and said recording means and the phases of the pulses from said switching circuit and said second pulse generating circuit, said control means being interconnected between said comparator means and said drive means for imparting to said driving means the energy corresponding to the output from said comparator means so as to vary said relative speed between said magnetic recording medium and said recording means, thereby coinciding the starting points of the respective recordings of respective fields of the television signal to be sampled and recorded upon the magnetic recording medium.

Claim 9

A video signal recording system according to claim 6 wherein a. said driving means drives the magnetic recording medium at a period shorter than a duration of each field of the television signal, and b. said first pulse generating means in said control means includes i. first and second disks drivingly coupled to said drive means so as to rotate at the same rotational period as the magnetic recording medium, a plurality of pulse signal generating elements being disposed around the periphery of each of said first and second disks, the number of said pulse signal generating elements disposed in said first disk being different from that of said pulse signal generating elements in said second disk, and ii. sensing means disposed in opposed relation with respect to said peripheries of said first and second disks for sensing said pulse signal generating elements thereof so as to generate the control pulses.

Claim 10

A video signal recording system according to claim 7 wherein said pulse signal generating elements on said first disk are disposed in equiangularly spaced apart relation, and said pulse signal generating elements on said second disk corresponding to the starting point of the magnetic recording medium are spaced apart from each other by a distance equal to the spacing between the pulse signal generating elements on said first disk, and those corresponding to the intermediate portion or section of said magnetic recording medium are spaced apart from each other by a distance shorter than said spacing between said pulse signal generating elements on said first disk, so that the rotational period of the magnetic recording medium may be delayed so as to compensate the inertia thereof.

Claim 11

A video signal recording system according to claim 7 wherein said frequency division circuit comprises a flip-flop, and said switching means comprises a pair of logic AND gate means connected to said sensing means and said flip-flop.

Claim 12

A video signal recording system according to claim 7 wherein said pulse signal generating elements arrayed on said first disk are equal in number to the horizontal synchronizing pulses in each field of the television signal, and said second pulse generating means generates the control pulses which are substantially identical to the horizontal synchronizing pulses.