Magnetic head tracking control system

An apparatus for reproducing information signals recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong at which each of said tracks has a positional signal recorded therein, said means for producing the first signal including means for detecting a time base error of said positional signal as reproduced by said transducer means.
• means for producing a second signal which corresponds to the value ##EQU6## in which n is the ratio of the speed of advancement of the record medium during reproducing to said recording speed, d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less n-1;
• means for producing a control signal on the basis of the relation of said first and second signals;
• and
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means.

An apparatus for reproducing information signals recorded in successive parallel tracks extending obliquely on a magnetic tape while the latter is advanced longitudinally of the tape at a predetermined recording speed, said apparatus comprising:

• a guide drum of which at least a portion is rotatable with said tape extending helically about at least a part of the periphery of said drum and being adapted to be longitudinally advanced;
• transducer means including a magnetic movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means mounting said head on said rotatable portion of the guide drum so as to rotate therewith and thereby scan along a selected one of the tracks positioned in proximity thereto by advancement of the tape, said transducer deflecting means being operative for deflecting said head in a direction which is transverse to the direction along said tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said head to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path, including deflection signal generating means for generating a deflection signal in correspondence to the deflection of said transducer means in said transverse direction from a rest position, oscillating means for providing a dither oscillation signal which, on application to said transducer deflection means, causes said transducer means to oscillate in said transverse direction about a null position, envelope detecting means for detecting the envelope of the output of said transducer means as the latter moves along a track and oscillates in said transverse direction, means for synchronously demodulating said detected envelope from said envelope detecting means including multiplier means having inputs receiving said detected envelope from the envelope detecting means and said deflection signal, respectively, so as to obtain a tracking error signal representative of the deviation of said null position of the transducer means from the center of the track considered in said transverse direction, and means for adding said tracking error signal and said dither oscillation signal in said drive signal for said transducer deflecting means;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong;
• means for producing a second signal which corresponds to the value ##EQU7## in which n is the ratio of the speed of advancement of the record medium during reproducing to said recording speed, d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1;
• means for producing a control signal on the basis of the relation of said first and second signals;
• and
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means.

An apparatus for reproducing information signals recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong;
• means for producing a second signal which corresponds to the value ##EQU8## in which n is the ratio of the speed of advancement of the record medium during reproducing to said recording speed, d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1;
• means for producing a control signal on the basis of the relation of said first and second signals;
• means for applying said control signal to said transducer deflection means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means;
• summing integrator means receiving said drive signal and control signal at respective inputs thereof;
• and
• adder means combining the output of said integrator means with said drive signal;
• and in which said first signal is derived from said adder means.

An apparatus for reproducing information signals recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong which is at said concluding end;
• means for detecting the speed of advancement of the record medium during reproducing and providing therefrom a signal corresponding to a ratio n of the speed of advancement of the record medium during reproducing to said recording speed;
• means for producing a second signal which corresponds to the value ##EQU9## in which d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1, said means for producing said second signal includes means receiving said signal corresponding to the ratio n and including invertive multiplier means for providing therefrom a signal which, when applied to said transducer deflecting means is effective to deflect said transducer means by (-1/2n+1/2) times the pitch between adjacent tracks on the record medium, a plurality of comparators each having a first input receiving said first signal and a second input, a plurality of different bias voltage sources through which the output of said invertive multiplier means is applied to said second inputs of the respective comparators, and means for combining the compared outputs of said comparators;
• means for producing a control signal on the basis of the relation of said first and second signals;
• and
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means.

An apparatus for reproducing video signals including horizontal and vertical synchronizing signals and being recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded video signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong;
• means for producing a second signal which corresponds to the value ##EQU10## in which n is the ratio of the speed of advancement of the record medium during reproducing to said recording speed, d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1;
• means for producing a control signal on the basis of the relation of said first and second signals;
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means;
• means responsive to the reproduced horizontal synchronizing signals for detecting said speed of advancement of the record medium during reproducing;
• and
• means responsive to said means for detecting said speed of advancement to provide to said second signal producing means a signal corresponding to said ratio n.

An apparatus for reproducing information signals recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks which are recorded with a predetermined pitch therebetween, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for producing a signal corresponding to a ratio n of the speed of advancement of the record medium during reproducing to said recording speed;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path including a bias voltage source, and adding means for applying the bias voltage from said source to said signal corresponding to the ratio n so as to obtain a signal corresponding to a deflection of (n-1) pitches of said transducer means when applied to said transducer deflecting means;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong;
• means for producing a second signal which corresponds to the value ##EQU11## in which d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1;
• means for producing a control signal on the basis of the relation of said first and second signals;
• and
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means.

An apparatus for reproducing information signals recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path;
• means for detecting said speed of advancement of the record medium during reproducing and providing therefrom a signal corresponding to a ratio of the speed of advancement of the record medium during reproducing to said recording speed;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong which is at said concluding end;
• means for producing a second signal which corresponds to the value ##EQU12## in which n is said ratio of the speed of advancement of the record medium during reproducing to said recording speed, d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1, including means for producing a signal corresponding to said integer m from said signal corresponding to the ratio n, multiplier means for multiplying by 1/2 said signal corresponding to the ratio n, and adder means for adding said signal corresponding to the integer m to the output of said multiplier means;
• means for producing a control signal on the basis of the relation of said first and second signals;
• and
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means.

An apparatus for reproducing information signals recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks, each of said tracks further having a positional signal recorded therein at a predetermined position therealong, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at predetermined position therealong;
• said means for producing the first signal including a source of external reference signals comparable with said positional signals, and means for comparing each of said positional signals reproduced by said transducer means with a respective one of said external reference signals and providing a corresponding detected time base error signal as a function of said deflection of said transducer deflecting means at said predetermined position;
• means for producing a second signal which corresponds to the value ##EQU13## in which n is the ratio of the speed of advancement of the record medium during reproducing to said recording speed, d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1;
• means for producing a control signal on the basis of the relation of said first and second signals;
• and
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means.

An apparatus for reproducing information signals recorded in successive parallel tracks on a record medium while the latter is advanced at a predetermined recording speed in a direction of an angle to the direction along said tracks, said apparatus comprising:

• transducer means movable along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the recorded information signals;
• transducer deflecting means for deflecting said transducer means in a direction which is transverse to said direction along the tracks;
• means for supplying a drive signal to said transducer deflecting means so as to cause said transducer means to follow a desired one of the tracks in moving from the beginning end to the concluding end of said path;
• means for producing a first signal which corresponds to the deflection of said transducer deflecting means needed to cause the transducer means to follow said desired one of the tracks at a predetermined position therealong;
• means for producing a continuously variable second signal which corresponds to the value ##EQU14## in which n is the ratio of the speed of advancement of the record medium during reproducing to said recording speed, d is the percentage of the distance along each track from said beginning end to said predetermined position therealong, and m is an integer that is no greater than n and no less than n-1;
• means for producing a control signal on the basis of the relation of said first and second signals;
• and
• means for applying said control signal to said transducer deflecting means so as to determine the position of said transducer means at said beginning end of the scanning path and, thereby, the next desired track to be followed by the transducer means.