Microprocessor controlled reproducing apparatus having asynchronous reproducing capability

Claim 2

A servo system for controlling a magnetic tape recording and reproducing apparatus to permit asynchronous reproducing to selectively enable reproducing time compression and expansion relative to the normal speed reproducing time, said system comprising: servo means(36) for controlling the transverse movement of the transducing head relative to the longitudinal direction of the recorded tracks to accurately follow a track during reproducing of a track and to selectively automatically position the head to begin following the next desired track subsequently of the completion of the following of a track; a capstan servo (34) for moving the tape during reproducing, said capstan servo being capable of detecting recorded control track signals and including a programmable counting means (704) clocked by a high rate clock for providing a reference vertical sync output signal for use in providing closed loop control track lock operation, said counting means having a station reference vertical sync input which triggers said counting means when said reference vertical sync signal is applied thereto the counter output being synchronized to the station reference vertical sync signal when the same . is applied thereto; preceding means (30) for controlling the capstan servo means to isolate the reference vertical sync signal input from said counting means and for programming said counting means with a preselected count so that said counting means provides an alternate reference vertical sync signal to the capstan servo, which alternate reference vertical sync signal is delayed or advanced relative to the station reference vertical sync signal by a value that represents a precise difference between the count between successive station reference vertical sync signals and the count programmed therein.

Claim 3

A servo system as defined in Claim 1 wherein said precise difference comprises the frequency of the input clock signal which clocks said programmable counter divided by the predetermined number plus or minus the frequency of the input clock divided by the preselected count number.

Claim 4

A servo system as defined in Claim 2 wherein said preselected count value is proportional to the amount of time compression and expansion that is desired.

Claim 5

A servo system as defined in Claim 3 including means for providing said preselected count to said processing means.

Claim 6

Apparatus for controlling the operation of a recording and reproducing apparatus of the type which includes a rotatable scanning drum having a movable element on which transducing heads are mounted, which element is movable in a transverse direction relative to the longitudinal orientation of the recorded track, the servo system comprising: a servo means (36)for controlling the transverse movement of the transducing head to follow a track during reproducing and to selectively position the head at the completion of following of a track to begin following the next desired track, wherein the positioning of the head is proportional to the position thereof at a predetermined time relative to the angular position of the scanning drum; a capstan servo (34) for moving the tape during reproducing, said capstan servo being capable of detecting recorded control track signals on the recorded tape and to drive said capstan so that it is locked to a vertical sync signal in a closed servo loop, said capstan servo including a programmable counting means (704) having an output for providing said vertical sync signal, said output signal being synchronized to a station reference vertical / sync signal when the same is applied to said programmable counting means, the counting means output vertical sync being at a rate other than the rate of said station reference vertical sync signal, when the the station reference vertical sync is not applied thereto, said counting means being operable as a free-running counter in such event, with the vertical sync rate being determined by the count that is programmed therein; processing means for providing a count number to said programmable counting means of said capstan servo and for selectively applying or isolating the station reference vertical sync signal to said counting means, the frequency of said output vertical sync being proportional to the difference between the predetermined count when station reference vertical sync is applied thereto and the preselected count when said station reference vertical sync is not applied thereto, thereby expanding or compressing the speed of reproducing while maintaining control track lock.

Claim 7

Apparatus for controlling the operation of a recording and reproducing apparatus of the type which includes a rotatable scanning drum having a movable element on which transducing heads are mounted, which element is movable in a transverse direction relative to the longitudinal orientation of the recorded track, the servo system comprising: a servo means (36)for controlling the transverse movement of the transducing head to follow a track during reproducing and to selectively position the head at the completion of following of a track to begin following the next desired track, wherein the positioning of the head is proportional to the position thereof at a predetermined time relative to the angular position of the scanning drum; a capstan servo (34) for moving the tape during reproducing, said capstan servo being capable of detecting recorded control track signals on the recorded tape and to drive said capstan so that it is locked to a vertical sync signal in a closed servo loop, said capstan servo including a programmable counting means (704) having an output for providing said vertical sync signal, said output signal being synchronized to a station reference vertical / sync signal when the same is applied to said programmable counting means, the counting means output vertical sync being at a rate other than the rate of said station reference vertical sync signal, when the the station reference vertical sync is not applied thereto, said counting means being operable as a free-running counter in such event, with the vertical sync rate being determined by the count that is programmed therein; processing means for providing a count number to said programmable counting means of said capstan servo and for selectively applying or isolating the station reference vertical sync signal to said counting means, the frequency of said output vertical sync being proportional to the difference between the predetermined count when station reference vertical sync is applied thereto and the preselected count when said station reference vertical sync is not applied thereto, thereby expanding or compressing the speed of reproducing while maintaining control track lock.