US3764087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic tape drive
Assignee: Unisys Corp
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Filing: 1971-06-11
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Granted: 1973-10-09
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Expires: 1991-06-11
Abstract
Abstract Apparatus is disclosed for maintaining, at a constant preselected value, the velocity at which a magnetic tape moves from a supply reel, past an electromagnetic read or write head, and onto a take-up reel during motorized rotation of one of the reels. A motor rotates one of the reels. A motor control applies a motor control signal to the motor and comprises apparatus for causing the motor control signal to have a non-linear component which is inversely proportional to the diameter of the tape on one of the reels. The non-linear signal component causes the motor to rotate the reel at a velocity inversely proportional to increasing tape diameter and thereby maintain a substantially constant linear velocity of tape. Preferably, the apparatus for causing the non-linear signal component comprises a sensing apparatus providing a series of signals, the accumulated number of which is indicative of the number of revolutions of one of the reels as tape passes between reels. A counter counts the series of signals and forms a representative digital output signal. A digital to analog converter converts the digital signal to an analog signal. A circuit is connected to the converter which modifies the analog signal and forms the above-defined non-linear signal component. Also, preferably apparatus is provided for causing another signal component in the motor control signal which is inversely proportional to angular velocity of the driven reel so as to maintain the angular velocity of the reel constant for a given value of non-linear signal.
Inventors
- 👤 E Paananen
- 👤 L Csengery
- 👤 R Barry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:37
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; G11B15/26; G11B15/32; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/912
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
231 words
In a magnetic tape transport having a read or write head for tape connected between supply and take-up reels, apparatus for transporting the tape between the reels past the head at a substantially constant linear velocity comprising: a. controllable means responsive to an applied control signal for driving and thereby rotating a driven one of said reels; and b. control means for applying a non-linear control signal, which is inversely proportional to the diameter of tape on said driven reel to said controllable means and comprising 1. means for providing a series of signals corresponding to the number of revolutions of said driven reel; 2. a counter for counting said series of signals and for providing digital output signals representative of the accumulated count and representative of the number of layers of tape wound on said driven reel; 3. a digital to analog converter for converting said digital signals to an analog signal; and 4. means coupled to said digital to analog converter for forming said control signal and comprising means for modifying said analog signal to a non-linear signal which is inversely proportional to the diameter of tape on said driven reel; said controllable means being responsive to said non-linear signal for driving said driven reel at an angular velocity which is substantially directly proportional to said non-linear signal and thereby maintain a substantially constant linear velocity of said tape.
Claim 2
Dependent Claim
231 words
In a magnetic tape transport having a read or write head for tape connected between supply and take-up reels, apparatus for transporting the tape between the reels past the head at a substantially constant linear velocity comprising: a. controllable means responsive to an applied control signal for driving and thereby rotating a driven one of said reels; and b. control means for applying a non-linear control signal, which is inversely proportional to the diameter of tape on said driven reel to said controllable means and comprising 1. means for providing a series of signals corresponding to the number of revolutions of said driven reel; 2. a counter for counting said series of signals and for providing digital output signals representative of the accumulated count and representative of the number of layers of tape wound on said driven reel; 3. a digital to analog converter for converting said digital signals to an analog signal; and 4. means coupled to said digital to analog converter for forming said control signal and comprising means for modifying said analog signal to a non-linear signal which is inversely proportional to the diameter of tape on said driven reel; said controllable means being responsive to said non-linear signal for driving said driven reel at an angular velocity which is substantially directly proportional to said non-linear signal and thereby maintain a substantially constant linear velocity of said tape.
Claim 3
Dependent Claim
33 words
a counter for counting said series of signals and for providing digital output signals representative of the accumulated count and representative of the number of layers of tape wound on said driven reel;
Claim 4
Dependent Claim
33 words
a counter for counting said series of signals and for providing digital output signals representative of the accumulated count and representative of the number of layers of tape wound on said driven reel;
Claim 5
Dependent Claim
29 words
means for sensing the angular velocity of said driven reel and means for forming a second signal component in said control signal inversely proportional to said sensed angular velocity.
Claim 6
Dependent Claim
29 words
means for sensing the angular velocity of said driven reel and means for forming a second signal component in said control signal inversely proportional to said sensed angular velocity.
Claim 7
Dependent Claim
65 words
first photodetection means for sensing the amount of light impinging thereon, the source of light and first photodetection means being positioned on opposite sides of one of such reels of tape, the first photodetection means being partially masked by the reel of tape as tape is wound on such reel thereby providing an output signal corresponding to the diameter of tape wound on such reel;
Claim 8
Dependent Claim
65 words
first photodetection means for sensing the amount of light impinging thereon, the source of light and first photodetection means being positioned on opposite sides of one of such reels of tape, the first photodetection means being partially masked by the reel of tape as tape is wound on such reel thereby providing an output signal corresponding to the diameter of tape wound on such reel;
Claim 9
Dependent Claim
10 words
a light source on one side of the member; and
Claim 10
Dependent Claim
10 words
a light source on one side of the member; and
Claim 11
Dependent Claim
42 words
In a magnetic tape transport according to claim 1 wherein said controllable means comprises: a. a motor; b. a drive chain connected to said motor for rotation of the driven wheel; and wherein said means for providing a series of signals comprises:
Claim 12
Dependent Claim
26 words
a second photodetection means responsive to said source of light for establishing a reference signal equal to the maximum possible vAlue of said output signal; and
Claim 13
Dependent Claim
26 words
a second photodetection means responsive to said source of light for establishing a reference signal equal to the maximum possible vAlue of said output signal; and
Claim 14
Dependent Claim
15 words
a digital to analog converter for converting said digital signals to an analog signal; and
Claim 15
Dependent Claim
15 words
a digital to analog converter for converting said digital signals to an analog signal; and
Claim 16
Dependent Claim
86 words
In a magnetic tape transport having a read or write head for tape connected between supply and take-up reels, apparatus for transporting the tape between the reels past the head at a substantially constant linear velocity comprising: a. controllable means responsive to an applied control signal for driving and thereby rotating a driven one of said reels; and b. control means for applying a non-linear control signal, which is inversely proportional to the diameter of tape on said driven reel to said controllable means and comprising
Claim 17
Dependent Claim
86 words
In a magnetic tape transport having a read or write head for tape connected between supply and take-up reels, apparatus for transporting the tape between the reels past the head at a substantially constant linear velocity comprising: a. controllable means responsive to an applied control signal for driving and thereby rotating a driven one of said reels; and b. control means for applying a non-linear control signal, which is inversely proportional to the diameter of tape on said driven reel to said controllable means and comprising
Claim 18
Dependent Claim
57 words
photodetection means on the other side of the member, the member thereby operating to mask the light from the light source to the photodetection means at all times when the aperture is not correctly aligned, and the photodetection means being operative to generate a signal each time the light source, aperture and photodetection means are in alignment.
Claim 19
Dependent Claim
57 words
photodetection means on the other side of the member, the member thereby operating to mask the light from the light source to the photodetection means at all times when the aperture is not correctly aligned, and the photodetection means being operative to generate a signal each time the light source, aperture and photodetection means are in alignment.
Claim 20
Dependent Claim
69 words
In a magnetic tape transport having a read or write head for tape connected between supply and take-up reels, apparatus for transporting the tape between the reels past the head at a substantially constant linear velocity comprising: a. controllable means responsive to an applied control signal for driving and thereby rotating one of said reels; b. control means for applying said control signal to said controllable means and comprising:
Claim 21
Dependent Claim
69 words
In a magnetic tape transport having a read or write head for tape connected between supply and take-up reels, apparatus for transporting the tape between the reels past the head at a substantially constant linear velocity comprising: a. controllable means responsive to an applied control signal for driving and thereby rotating one of said reels; b. control means for applying said control signal to said controllable means and comprising:
Claim 22
Dependent Claim
58 words
means for detecting and amplifying any difference between said output signal and said reference signal to form the non-linear signal; said controllable means being responsive to said non-linear signal for driving said driven reel at an angular velocity which is substantially directly proportional to said non-linear signal and thereby maintain a substantially constant linear velocity of said tape.
Claim 23
Dependent Claim
58 words
means for detecting and amplifying any difference between said output signal and said reference signal to form the non-linear signal; said controllable means being responsive to said non-linear signal for driving said driven reel at an angular velocity which is substantially directly proportional to said non-linear signal and thereby maintain a substantially constant linear velocity of said tape.
Claim 24
Dependent Claim
76 words
means coupled to said digital to analog converter for forming said control signal and comprising means for modifying said analog signal to a non-linear signal which is inversely proportional to the diameter of tape on said driven reel; said controllable means being responsive to said non-linear signal for driving said driven reel at an angular velocity which is substantially directly proportional to said non-linear signal and thereby maintain a substantially constant linear velocity of said tape.
Claim 25
Dependent Claim
76 words
means coupled to said digital to analog converter for forming said control signal and comprising means for modifying said analog signal to a non-linear signal which is inversely proportional to the diameter of tape on said driven reel; said controllable means being responsive to said non-linear signal for driving said driven reel at an angular velocity which is substantially directly proportional to said non-linear signal and thereby maintain a substantially constant linear velocity of said tape.
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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) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |