Patent US1353953A successfully refreshed from Google Patents.
Patent US3843915A successfully refreshed from Google Patents.
US3843915A
Expired / Lapsed
US
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Servo-motor control system including a two phase digital shaft position detector
Assignee: NCR Voyix Corp
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Filing: 1973-02-02
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Granted: 1974-10-22
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Expires: 1993-02-02
Abstract
Abstract Apparatus for providing digital signals indicating the direction and amount of rotation of a stepping motor which apparatus utilizes a code element having at least two code tracks positioned thereon such that each track is located at a different radius from the center of the code element. The code element is rotated past an index point by any rotating device. Means are provided for reading the code in each track and for providing pulse signals indicative of the code in each track. Logic means are utilized for counting the number of pulses from one or both provided signals to determine the amount of code element rotation with respect to the index point, and for comparing the relative occurrence of pulses in at least two provided signals to determine the direction of rotation of the code element.
Inventors
- 👤 J Helmbold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:59
CPC Classifications
B; B41; B41J; B41J11/00; B41J11/36; B41J11/42; B41J29/00; B41J29/38; G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/36; G01D5/363; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/21; G05B19/23; G05B2219/00; G05B2219/30; G05B2219/37; G05B2219/37175; G05B2219/41; G05B2219/41326; G05B2219/42; G05B2219/42168
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
335 words
Apparatus for providing signals indicating the direction and incremental rotation of a shaft comprising in combination: a. a code element coupled to said shaft, said code element having a transition code thereon; b. means for detecting and converting the code into a first and a second electrical signal, respectively, which signals have states corresponding to the transition code; c. logic means for receiving said first and said second electrical signal and for providing a first and a second output signal having corresponding states, said logic means also providing a third and a fourth output signal indicating the state of said first and said second output signals respectively a fixed time interval later; d. means responsive to said third and fourth output signals for providing a first and a second transition signal wherein said first transition signal is indicative of the occurrence of a preselected state of said third signal preceding a preselected state of said fourth signal, and said second transition signal is indicaTive of the occurrence of a preselected state of said fourth signal preceding a preselected state of said third signal; e. first gate means receiving said first and said second output signal for providing an indexing signal upon each coincidence of said first and said second output signals; f. a second and third coincidence gate means for receiving said first, and said second output signals, respectively, said first and said second transition signals, respectively, and both of said third and fourth ouput signals, to provide a first direction signal at the output of said second coincidence gate when all signals received by said second coincidence gate are of one state and a second opposite direction signal at the output of said third coincidence gate when all signals received by said third coincidence gate are of one state; and g. means for counting each of said indexing signals in an order determined by said first and second direction signals such that the accumulated count is proportional to the total rotation of said shaft.
Claim 2
Dependent Claim
335 words
Apparatus for providing signals indicating the direction and incremental rotation of a shaft comprising in combination: a. a code element coupled to said shaft, said code element having a transition code thereon; b. means for detecting and converting the code into a first and a second electrical signal, respectively, which signals have states corresponding to the transition code; c. logic means for receiving said first and said second electrical signal and for providing a first and a second output signal having corresponding states, said logic means also providing a third and a fourth output signal indicating the state of said first and said second output signals respectively a fixed time interval later; d. means responsive to said third and fourth output signals for providing a first and a second transition signal wherein said first transition signal is indicative of the occurrence of a preselected state of said third signal preceding a preselected state of said fourth signal, and said second transition signal is indicaTive of the occurrence of a preselected state of said fourth signal preceding a preselected state of said third signal; e. first gate means receiving said first and said second output signal for providing an indexing signal upon each coincidence of said first and said second output signals; f. a second and third coincidence gate means for receiving said first, and said second output signals, respectively, said first and said second transition signals, respectively, and both of said third and fourth ouput signals, to provide a first direction signal at the output of said second coincidence gate when all signals received by said second coincidence gate are of one state and a second opposite direction signal at the output of said third coincidence gate when all signals received by said third coincidence gate are of one state; and g. means for counting each of said indexing signals in an order determined by said first and second direction signals such that the accumulated count is proportional to the total rotation of said shaft.
Claim 3
Dependent Claim
53 words
The system according to claim 1 wherein said code element is comprised of a disc having apertures which define said code, and wherein said detecting means comprises photoelectric means for detecting the presence or absence of an aperture and for providing electrical signals indicative of the detected presence or absence of an aperture.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |