US4254368A
Expired / Lapsed
US
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Apparatus for driving a motor
Assignee: Hitachi Ltd
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Filing: 1980-01-17
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Granted: 1981-03-03
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Expires: 2000-01-17
Abstract
Abstract In an apparatus for driving a motor wherein a carrier or stage carrying a sample thereon is located and moved to a predetermined position by controlling the slow-up and slow-down speed of the motor at the start and prior to the stopping thereof, respectively, this invention provides for speed control of the motor in accordance with a function of arbitrary characteristic slope, the function being stored in the form of a succession of digital values which may be sequentially accessed by a counter control circuit responsive to a control command signal representing the on-off condition for the motor.
Inventors
- 👤 Satoshi Ido
- 👤 Nobuo Hamamoto
- 👤 Kazuo Ichino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:42
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/416; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/904; Y10S388/907; Y10S388/908; Y10S388/912; Y10S388/916
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
240 words
In an apparatus for driving a motor wherein a stage carrying a sample thereon is located and moved to a predetermined position in accordance with a selected speed characteristic including a function for slow-up and slow-down of the speed at the start and prior to the stopping of the motor, respectively, the improvement comprising: circuit means to provide a preset stage movement command signal, a control command signal shorter than said preset stage movement command signal by a predetermined slow-down time interval and a clock signal for determining slow-up and slow-down times; counting means responsive to said control command signal and said clock signal for counting in an "up" direction at a logical "1" level of said control command signal and in a "down" direction at a logical "0" level of said control command signal to produce a sequence of address signals; memory means for storing a speed control function of arbitrary characteristic shape in the form of a succession of digital values and for reading out said values in response to the output address signals of said counting means; converting means for converting the digital output of said memory means to a pulse train signal whose frequency varies in accordance with the digital values; gate circuit means for effecting an AND operation between said pulse train signal and said stage movement command signal; and driving means to drive said motor with an output signal obtained by said AND operation.
Claim 2
Dependent Claim
240 words
In an apparatus for driving a motor wherein a stage carrying a sample thereon is located and moved to a predetermined position in accordance with a selected speed characteristic including a function for slow-up and slow-down of the speed at the start and prior to the stopping of the motor, respectively, the improvement comprising: circuit means to provide a preset stage movement command signal, a control command signal shorter than said preset stage movement command signal by a predetermined slow-down time interval and a clock signal for determining slow-up and slow-down times; counting means responsive to said control command signal and said clock signal for counting in an "up" direction at a logical "1" level of said control command signal and in a "down" direction at a logical "0" level of said control command signal to produce a sequence of address signals; memory means for storing a speed control function of arbitrary characteristic shape in the form of a succession of digital values and for reading out said values in response to the output address signals of said counting means; converting means for converting the digital output of said memory means to a pulse train signal whose frequency varies in accordance with the digital values; gate circuit means for effecting an AND operation between said pulse train signal and said stage movement command signal; and driving means to drive said motor with an output signal obtained by said AND operation.
Claim 3
Dependent Claim
17 words
An apparatus for driving a motor according to claim 1, wherein said motor is a pulse motor.
Claim 4
Dependent Claim
92 words
An apparatus for driving a motor according to claim 2, wherein digital values representing said function stored in said memory means vary in value so as to produce a driving frequency which has an abrupt slope from a time corresponding to the zero frequency, which has a gentle slope in the vicinity of a self-start frequency of said pulse motor before and after arrival at said self-start frequency, which thereafter rises abruptly again, and which has a gentle slope in the vicinity of a maximum frequency before arrival at said maximum frequency.
Claim 5
Independent Claim
21 words
An apparatus for driving a motor according to claims 1 or 3, wherein said memory means comprises a read only memory.
Claim 6
Independent Claim
20 words
An apparatus for driving a motor according to claims 1 or 3, wherein said counting means comprises an up/down counter.
Claim 7
Independent Claim
27 words
An apparatus for driving a motor according to claims 1 or 3, wherein said converting means comprises a digital-to-analog converter connected in series with a voltage-to-frequency converter.
Claim 8
Independent Claim
92 words
An apparatus for driving a motor according to claims 1 or 3, wherein said counting means comprises an up-down counter, detecting means for detecting the maximum value count and minimum value count of said up-down counter, and additional gate circuit means for applying said clock signal to drive said up-down counter in the "up" direction until said maximum value count is detected by said detecting means and for applying said clock signal to drive said up-down counter in the "down" direction until said minimum value count is detected by said detecting 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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |