Capstan motor drive control device
AssigneeSony Corporation
InventorsYoshinori Kobayashi, Ryuji Watanabe
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Abstract
A capstan motor is controlled by a signal derived from a frequency generator that has been converted to a voltage that reflects the instantaneous change in velocity of the rotating motor. Acceleration of the motor is found by using a mean velocity obtained as a reciprocal of the pulsed signal from the frequency generator and then estimating the instantaneous velocity based on the derived acceleration. The estimated instantaneous velocity is converted to a drive voltage for the capstan motor so that the motor can be started and stopped with a respective constant acceleration and deceleration.
Claims7
A capstan motor drive control system comprising:
- period detection means for detecting a period of a pulsed input signal having a frequency which is a function of a rotational velocity of a capstan motor;
- correction means for determining a rate of change of a reciprocal of the period detected by said period detection means and employing said rate of change to produce a corrected reciprocal indicating on instantaneous frequency at a time of detection within said period, and
- converter means for converting the corrected reciprocal into an electrical voltage for controlling the rotational velocity of the capstan motor.
A drive control system comprising:
- pulse signal generating means for generating successive pulse signals having a frequency proportional to a velocity of a moving object;
- a memory storing a time of occurrence of a rising edge of each pulse;
- means for determining periods of said pulse signals supplied from said pulse signal generating means using stored times from said memory;
- corrector means for finding reciprocals of said periods representing a series of instantaneous velocities and a continuously updated instantaneous velocity;
- and
- means for converting the instantaneous velocity into a drive control voltage for controlling movement of the moving object.
A drive control method for a capstan motor comprising steps of:
- producing a series of pulse signals FG representing a rotational rate of the capstan motor;
- calculating a series of accelerations of the capstan motor based on the FG pulse signals;
- and
- controlling a drive voltage to the capstan motor as a function of the calculated accelerations for maintaining them at a substantially constant value during starting or stopping of the capstan motor.
A drive control method for a capstan motor comprising steps of:
- producing a series of pulse signals FG representing a rotational rate of the capstan motor;
- employing the FG pulse signals to calculate acceleration of the capstan motor at a time of starting thereof;
- and
- employing the calculated acceleration to control a capstan motor drive voltage for maintaining the acceleration of the capstan motor substantially constant during starting thereof.
A drive control method for a capstan motor comprising steps of:
- employing FG pulse signals to calculate acceleration of the capstan motor at a given time of starting thereof;
- storing the calculated acceleration;
- and
- controlling a drive voltage at a subsequent starting time immediately following said given starting time as a function of the stored acceleration for starting the capstan motor at a constant acceleration.
Dependencies are inferred from the claim text.