US3917987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voice coil motor control system
Assignee: Fujitsu Ltd
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Filing: 1974-12-23
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Granted: 1975-11-04
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Expires: 1994-12-23
Abstract
Abstract A voice coil motor control system includes a lower curve function generator for providing a lower distance-speed function for the motor indicating the motor acceleration stop point. An upper curve function generator provides an upper distance-speed curve function for the motor to follow and stops the motor at a desired position by following the upper distance-speed curve. The lower curve function generator and the upper curve function generator provide the lower distance-speed curve function in proportional relation with the upper distance-speed curve function.
Inventors
- 👤 Yuji Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:50
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1436; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553; G11B5/5547; H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356; H02P; H02P25/00; H02P25/02; H02P25/032; H02P25/034
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
141 words
A voice coil motor control system for controlling a voice coil motor for moving an object, the voice coil motor control system comprising distance means for providing an output signal in accordance with the distance between the actual position of the object and the desired position of the object; lower curve means for providing a speed signal for the motor indicating the stop point of acceleration in accordance with a lower curve function of the difference means; upper curve means for providing a speed signal for the motor to follow in accordance with an upper curve function in proportional relation with the lower curve function of the lower curve means; and control means for varying the control period of the motor between the lower curve function and the upper curve function in accordance with the output signal of the distance means.
Claim 2
Dependent Claim
141 words
A voice coil motor control system for controlling a voice coil motor for moving an object, the voice coil motor control system comprising distance means for providing an output signal in accordance with the distance between the actual position of the object and the desired position of the object; lower curve means for providing a speed signal for the motor indicating the stop point of acceleration in accordance with a lower curve function of the difference means; upper curve means for providing a speed signal for the motor to follow in accordance with an upper curve function in proportional relation with the lower curve function of the lower curve means; and control means for varying the control period of the motor between the lower curve function and the upper curve function in accordance with the output signal of the distance means.
Claim 3
Dependent Claim
73 words
A voice coil motor control system as claimed in claim 1, further comprising comparator means connected between the lower curve means and the upper curve means and the motor for comparing the speed of movement of the motor with the speed signal related to the upper curve function and the speed signal related to the lower curve function and controlling the operation of the motor in accordance with the results of the comparison.
Claim 4
Dependent Claim
42 words
A voice coil motor control system as claimed in claim 2, further comprising absolute value circuit means connected between the motor and the comparator means for providing the absolute value of the speed of movement of the motor to the comparator means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |