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US 5,311,107 AGranted
Method and apparatus for stopping DC motor by brake power corresponding to rotation frequency of motor and disk storage unit having such apparatus
AssigneesMitsubishi Electric Corporation, TEAC Corporation
InventorsHiroo Shimegi, Akira Mashimo, Hiroyuki Onda, Katsuya Enami, Hiroshi Takahashi
Life of this patent
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Abstract
A motor stopping apparatus detects a rotation frequency of a motor to which a load is attached, and applies break power in accordance with the rotation frequency to the motor until the motor is approximately stopped. The apparatus may be provided in a disk storage.
Claims11
A motor stopping method comprising the steps of:
- (a) detecting a rotation frequency of a motor to which a load is attached;
- and
- (b) applying braking power to the motor in accordance with the rotation frequency until the motor is approximately stopped;
- wherein said method further comprises the following steps, performed before said step (b):
- (c) rotating the motor with the load at a first rotation frequency;
- (d) applying an initial braking power to the motor;
- (e) measuring a period during which the rotation frequency of the motor is changed from the first rotation frequency to a second rotation frequency lower than the first rotation frequency;
- and
- (f) comparing the measured period with a predetermined reference period, the amount of braking power applied in step (b) being determined in accordance with the comparison.
6 more elements
A motor stopping apparatus comprising:
- rotation detecting means for detecting a rotation frequency of a motor to which a load is attached;
- direction detecting means for detecting a direction of rotation of the motor, said direction detecting means outputting a detecting result when a direction of rotation of the motor driving the load changes from a first direction to a second direction opposite to the first direction;
- and
- brake means, coupled to said rotation detecting means and direction detecting means, for applying braking power to the motor which corresponds to the rotation frequency detected by said rotation detecting means so that the braking power decreases as the rotation frequency of the motor decreases, said braking power being applied until said direction detecting means outputs the detecting result.
1 more element
A motor stopping apparatus comprising:
- rotation detecting means for detecting a rotation frequency of a motor to which a load is attached;
- direction detecting means, coupled to said rotation detecting means, for detecting a direction of rotation of the motor, said direction detecting means outputting a detecting result when a direction of rotation of the motor driving the load changes from a first direction to a second direction opposite to the first direction;
- load detecting means for detecting the weight of the load based on an alteration in the speed change characteristics of the motor due to the weight of the load;
- and
- brake means, coupled to said rotation detecting means, direction detecting means, and load detecting means, for applying brake power to the motor which corresponds to the rotation frequency detected by said rotation detecting means and the speed change of the load detected by said load detecting means until said direction detecting means outputs the detecting result;
- wherein said load detecting means comprises:
- time measuring means for measuring a first time period which represents how long it takes for the rotation frequency of the motor to change from a first rotation frequency to a second rotation frequency lower than the first rotation frequency in a case where said brake means applies a first braking power to the motor which has the load and is rotating at the first rotation frequency;
- and
- comparing means, coupled to the time measuring means, for comparing the first time period with a reference time period, said brake means applying braking power in accordance with a comparison result of said comparing means.
6 more elements
A disk storage unit comprising:
- a head for recording information on a disk and/or reproducing information therefrom;
- a motor which rotates the disk;
- and a motor control device which controls the operation of said motor, said motor control device comprising:
- rotation detecting means for detecting a rotation frequency of said motor;
- direction detecting means, coupled to said rotation detecting means and said brake means, for detecting a direction of rotation of the motor, said direction detecting means outputting a detecting result when a direction of rotation of the motor driving the disk changes from a first direction to a second direction opposite to the first direction;
- and
- brake means, coupled to said rotation detecting means and direction detecting means, for applying braking power to the motor which corresponds to the rotation frequency detected by said rotation detecting means so that the braking power decreases as the rotation frequency of the motor decreases, said braking power being applied until said direction detecting means outputs the detecting result.
4 more elements
A motor stopping method comprising the steps of:
- (a) detecting a rotation frequency of a motor to which a load is attached;
- and
- (b) applying braking power to the motor in accordance with the rotation frequency until the motor is approximately stopped;
- wherein said method further comprises the following steps, performed before said step (b);
- (c) experimentally rotating the motor with the load from a stop state to a first rotation frequency;
- (d) measuring a period required for the rotation frequency of the motor to reach the first rotation frequency;
- and
- (e) comparing the measured period with a predetermined reference period, the amount of braking power applied in step (b) being determined in accordance with the comparison.
5 more elements
Dependencies are inferred from the claim text.