Servosystem for recorder-reproducer apparatus utilizing frequency and phase synchronizing

Claim 2

In a recorder-reproducer system having a member rotatable in a given direction including means for providing a control signal whose frequency and phase are indicative of the velocity and phase of said rotatable member, an arrangement for synchronizing the operation of said rotatable member with a reference signal, comprising: means responsive to said control signal and said reference signal for providing an error signal indicative of the frequency and phase difference therebetween; power sensitive drive means for rotating said member; power control means coupled to said drive means and responsive to said error signal to cause said drive means to rotate said member in a given direction at a velocity and phase so as to reduce said difference; and means coupled to said power control means and active upon said power being reduced to a given value in response to said error signal, to apply power to said drive means in a manner establishing a rotation-urging force in said drive means, said force acting in a direction opposite said given direction causing the magnitude of the velocity of said member in said given direction to be reduced in accordance with said error signal.

Claim 3

The invention according to claim 1; wherein said power-sensitive drive means is a plural phase motor having at least first and second inputs, said power control means includes means for generating and applying sequentially phased substantially constant level pulse energizing signals to the respective inputs of said drive means, said control means further including means for varying the width of said energizing signals in accordance with said error signal, means for comparing the value of the width of said energizing signals with a predetermined value, and means for transposing two of said energizing signal inputs to said drive means upon said width of said energizing signals being less than said predetermined value.

Claim 4

The invention according to claim 2, wherein; said level of energizing signals applied to said drive means is limited by said control means to a value which causes said drive means to rotate at a speed which is substantially less than the synchronous speed of said drive means, and said control means includes means for symmetrically varying the duty cycle of each of said energizing signals so as to maintain a given timed phased relation among said energizing signals.

Claim 5

In a headwheel servo system including means for providing a control signal indicative of the phase and frequency of said rotating headwheel, and detecting means responsive to said control signal and a reference signal for providing an error signal indicative of the difference therebetween, the combination comprising: signal-generating means coupled to said detecting means and responsive to said reference signal for providing a plurality of pairs of pulse signal outputs; said generating means including means for establishing a given phasing sequence of each of said pair of signals with respect to other of said pairs of signals and said reference signal, and means for symmetrically width modulating said signals in accordance with said error signal; pulse-width-sensitive means coupled to said generating means for providing a signal indicative of the pulse width condition of said generating means outputs, polyphase energizable motor means for rotating said headwheel; means including switching means coupled between said signal generating means and said motor means for applying selected ones of said generating means outputs to said motor means; and means for controlling said switching means in response to the output of said pulse-width-sensitive means.

Claim 6

In a headwheel servo system including means for providing a control signal indicative of the phase and frequency of said rotating headwheel, and detecting means responsive to said control signal and a reference signal for providing an error signal indicative of the difference therebetween, the combination comprising: signal-generating means coupled to said detecting means and responsive to said reference signal for providing a plurality of pairs of pulse signal outputs; said generating means including means for establishing a given phasing sequence of each of said pair of signals with respect to other of said pairs of signals and said reference signal, and means for symmetrically width modulating said signals in accordance with said error signal; pulse-width-sensitive means coupled to said generating means for providing a signal indicative of the pulse width condition of said generating means outputs, polyphase energizable motor means for rotating said headwheel; means including switching means coupled between said signal generating means and said motor means for applying selected ones of said generating means outputs to said motor means; and means for controlling said switching means in response to the output of said pulse-width-sensitive means.

Claim 7

The invention according to claim 4, wherein; said switching means is operable in a first mode in which one member of each of said signal pairs is coupled to respective inputs of said motor means, and a second mode in which the other signal member Of two or said signal pairs is coupled to a motor input other than the input to which said one member of said pair was applied.

Claim 8

The invention according to claim 4 wherein the width-modulating means of said signal-generating means includes means for providing inverse variation of the width of said signal pairs.

Claim 9

In combination with a recorder-reproducer system having a rotatable headwheel including signal transducer means, apparatus for synchronizing the rotation of said headwheel with a reference signal of a given frequency and phase, comprising: means for providing a second signal whose frequency and phase are indicative of the velocity and phase of said headwheel; third means responsive to said reference signal for providing first and second outputs, said one output comprising a first plurality of pulse trains each having a frequency which is a first given multiple of said reference signal frequency, said other output comprising a second plurality of pulse trains each having a frequency which is a second given multiple of said reference signal, each of said pulse trains being sequentially phased with respect to said reference signal; detecting means responsive to said second signal and said reference signal for providing an error signal indicative of the frequency and phase difference therebetween; fifth means coupled to said first output of said third means and responsive to said error signal for providing a plurality of pairs of pulse trains, including means causing the pulse width of the members of each of said pulse train pairs to vary inversely in accordance with variations of said error signal; pulse-width-monitoring means responsive to the output of said fifth means for providing an output signal indicative of the pulse width of a given member of each of said signal pairs being less than a given width; switching means having inputs coupled to said second and third means for providing an output comprising selected ones of the output of said fifth means and the second output of said third means; means coupled to the output of said monitoring means for controlling the selective operation of said switching means; gating means coupled to the output of said switching means for providing from the second output of said third means an output having pulse widths in accordance with the selected ones of the output of said fifth means; and means responsive to the output of said gating means for controlling the rotation of said headwheel.

Claim 10

In combination with a recorder-reproducer system having a rotatable headwheel including signal transducer means, apparatus for synchronizing the rotation of said headwheel with a reference signal of a given frequency and phase, comprising: means for providing a second signal whose frequency and phase are indicative of the velocity and phase of said headwheel; third means responsive to said reference signal for providing first and second outputs, said one output comprising a first plurality of pulse trains each having a frequency which is a first given multiple of said reference signal frequency, said other output comprising a second plurality of pulse trains each having a frequency which is a second given multiple of said reference signal, each of said pulse trains being sequentially phased with respect to said reference signal; detecting means responsive to said second signal and said reference signal for providing an error signal indicative of the frequency and phase difference therebetween; fifth means coupled to said first output of said third means and responsive to said error signal for providing a plurality of pairs of pulse trains, including means causing the pulse width of the members of each of said pulse train pairs to vary inversely in accordance with variations of said error signal; pulse-width-monitoring means responsive to the output of said fifth means for providing an output signal indicative of the pulse width of a given member of each of said signal pairs being less than a given width; switching means having inputs coupled to said second and third means for providing an output comprising selected ones of the output of said fifth means and the second output of said third means; means coupled to the output of said monitoring means for controlling the selective operation of said switching means; gating means coupled to the output of said switching means for providing from the second output of said third means an output having pulse widths in accordance with the selected ones of the output of said fifth means; and means responsive to the output of said gating means for controlling the rotation of said headwheel.

Claim 11

The invention according to claim 7 wherein said switching means is operable in one mode thereof to transpose two of said plurality of outputs of said fifth means.

Claim 12

The invention according to claim 7, wherein; said third means includes means for providing a fixed phase relation between said reference signal and the center of each pulse of said first and second outputs of said third means, and said fifth means includes means for symmetrically varying the pulse widths of the output of said fifth means to provide said output with said fixed phase relation of the output of said third means.