US5216556A
Expired / Lapsed
US
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Method for optimized tape tension adjustment for a tape drive
Assignee: Quantum Corp
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Filing: 1991-04-26
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Granted: 1993-06-01
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Expires: 2011-04-26
Abstract
Abstract A method for adjusting the tension of a tape in a tape drive is disclosed. The tape is loaded into the tape drive. A test signal is then provided to record test information onto the tape while the tape tension is varied concurrently in a prescribed manner. The test information is read immediately to provide a test readback signal. The test readback signal is processed to determine a functional relationship between the test readback signal and the tape tension. An operating tape tension value is computed based upon the functional relationship. The operating tape tension is implemented on the tape drive in the form of a command signal to a motor means of the tape drive.
Inventors
- 👤 Mitchell R. Steinberg
- 👤 George A. Saliba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:36
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/43; G11B33/00; G11B33/10
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
124 words
A method for adjusting the tension of a tape in a tape drive, the method comprising the steps of: loading the tape into the tape drive; providing a test signal; recording test information from the test signal onto the tape while tape tension is concurrently varied in value in a prescribed manner; immediately reading the test information to obtain a test readback signal; processing the test readback signal to determine a functional relationship between the test readback signal and the tape tension; computing the value of an operating tape tension based upon the functional relationship between the test readback signal and the tape tension; and implementing the operating tape tension in the form of a command signal to motor means of the tape drive.
Claim 2
Independent Claim
124 words
A method for adjusting the tension of a tape in a tape drive, the method comprising the steps of: loading the tape into the tape drive; providing a test signal; recording test information from the test signal onto the tape while tape tension is concurrently varied in value in a prescribed manner; immediately reading the test information to obtain a test readback signal; processing the test readback signal to determine a functional relationship between the test readback signal and the tape tension; computing the value of an operating tape tension based upon the functional relationship between the test readback signal and the tape tension; and implementing the operating tape tension in the form of a command signal to motor means of the tape drive.
Claim 3
Dependent Claim
24 words
The method of claim 1 further including the step of preparing a designated scratch area on the tape prior to recording the test signal.
Claim 4
Dependent Claim
33 words
The method of claim 2 wherein the step of preparing the designated scratch area on the surface of the tape comprises erasure of data in the scratch area by a predetermined write signal.
Claim 5
Dependent Claim
33 words
The method of claim 1 wherein the test signal is a signal of fixed parameters and the step of recording the test information includes: varying the tape tension as a function of time.
Claim 6
Dependent Claim
21 words
The method of claim 4 wherein varying the tape tension includes increasing the tape tension as a linear function of time.
Claim 7
Dependent Claim
21 words
The method of claim 5 wherein a periodic disturbance of the tape tension is superimposed on the linear function of time.
Claim 8
Independent Claim
289 words
A method for providing drive signals to first and second motor means of a tape drive for adjusting the tape tension to compensate for changes in ambient conditions as well as variation in physical and functional characteristics of the tape drive and the tape, the method comprising the steps of: loading a tape into the tape drive; preparing a designated scratch area on the tape by erasing the designated scratch area on a first track with a pre-selected write signal by means of a forward write transducer while the tape is moving in the forward direction; upon reaching the end of the scratch area, reversing the direction of the tape motion and erasing the designated scratch area on a second track with a pre-selected write signal by means of a backward write transducer; providing a test signal of known parameters for recording test information onto the scratch area of the first track with the tape moving in the forward direction while concurrently varying the tape tension in a predetermined manner by supplying appropriate current commands to the first motor means and the second motor means; immediately reading the thus recorded test information for obtaining a test readback signal by means of a read transducer; sampling the test readback signal; processing the samples of the test readback signal to generate a table of the readback amplitude values versus the tape tension values; determining a reference readback signal amplitude value; determining an operating tape tension value with reference to the thus determined reference readback signal amplitude value; and controlling the current commands to the first motor means and the second motor means in response to the thus determined operating tape tension value for controlling the tape tension in the tape drive.
Claim 9
Independent Claim
289 words
A method for providing drive signals to first and second motor means of a tape drive for adjusting the tape tension to compensate for changes in ambient conditions as well as variation in physical and functional characteristics of the tape drive and the tape, the method comprising the steps of: loading a tape into the tape drive; preparing a designated scratch area on the tape by erasing the designated scratch area on a first track with a pre-selected write signal by means of a forward write transducer while the tape is moving in the forward direction; upon reaching the end of the scratch area, reversing the direction of the tape motion and erasing the designated scratch area on a second track with a pre-selected write signal by means of a backward write transducer; providing a test signal of known parameters for recording test information onto the scratch area of the first track with the tape moving in the forward direction while concurrently varying the tape tension in a predetermined manner by supplying appropriate current commands to the first motor means and the second motor means; immediately reading the thus recorded test information for obtaining a test readback signal by means of a read transducer; sampling the test readback signal; processing the samples of the test readback signal to generate a table of the readback amplitude values versus the tape tension values; determining a reference readback signal amplitude value; determining an operating tape tension value with reference to the thus determined reference readback signal amplitude value; and controlling the current commands to the first motor means and the second motor means in response to the thus determined operating tape tension value for controlling the tape tension in the tape drive.
Claim 10
Dependent Claim
69 words
The method of claim 7 wherein the step of determining the reference readback signal amplitude value further comprises: searching through the table of the readback amplitude values versus the tape tension values to determine the maximum readback signal amplitude; calculating a base amplitude value equal to a predetermined portion of the maximum readback signal amplitude; and finding a readback amplitude value in the table matching the base amplitude value.
Claim 11
Dependent Claim
22 words
The method of claim 8 wherein the base amplitude value is within a predetermined percentage range of the maximum readback signal amplitude.
Claim 12
Dependent Claim
20 words
The method of claim 8 wherein the base amplitude value is about ninety percent of the maximum readback signal amplitude.
Claim 13
Dependent Claim
65 words
The method of claim 8 wherein the step of determining the operating tape tension value further includes: locating within the table of the readback amplitude values versus the tape tension values a base tape tension value corresponding to the readback amplitude value matching the base amplitude value; and adding a predetermined offset to the base tape tension value to determine the operating tape tension value.
Claim 14
Dependent Claim
18 words
The method of claim 11 wherein the predetermined offset to the base tape tension is about 3 ounce-force.
Claim 15
Dependent Claim
64 words
The method of claim 7 wherein the step of processing the samples of the test readback signal further comprises: storing the samples of the test readback signal in the table inside a memory; filtering the stored samples of the test readback signal through a digital filter with a desired frequency response; and storing the filtered samples of the test readback samples in a table.
Claim 16
Dependent Claim
16 words
The method of claim 13 wherein the digital filter is a finite impulse response digital filter.
Claim 17
Dependent Claim
23 words
The method of claim 14 wherein the finite impulse response filter is a least squares approximation of the ideal low pass digital filter.
Claim 18
Dependent Claim
142 words
The method of claim 7 wherein the step of processing the samples of the test readback signal further comprises: storing the samples of the test readback signal in a first table inside a memory; filtering the stored samples of the test readback signal through a first digital filter having a low pass frequency response; storing the samples of the test readback signal filtered by the first digital filter in a second table; filtering the samples of the test readback signal stored in the first table through a second digital filter having a band pass frequency response; storing the samples of the test readback signal filtered by the second digital filter in a third table; and combining the samples of the test readback signal from the second table and the third table in a predetermined manner to determine the operating tape tension value.
Claim 19
Dependent Claim
100 words
The method of claim 7 wherein the method for adjusting the tension of the tape in the tape drive is first performed on a track with the tape moving in one direction to determine a forward value of the operating tape tension, and then repeated on a separate track with the tape moving in the backward direction to determine a backward value of the operating tape tension; the forward operating tape tension being implemented when the tape is advanced in the forward direction, and the backward operating tape tension being implemented when the tape is advanced in the backward direction.
Claim 20
Dependent Claim
56 words
The method of claim 7 wherein the method for adjusting the tension of the tape in the tape drive is performed on each track of a multiple channel tape drive, the operating tape tension for the tape drive being implemented based upon the selection from the set of operating tape tension values obtained for each track.
Claim 21
Independent Claim
140 words
An apparatus for adjusting the tension of a tape in a tape drive by control of the motor means thereof, the apparatus comprising: means for receiving the tape; means for providing a test signal; means for recording test information from the test signal onto the tape while tape tension is concurrently varied in value in a prescribed manner; means for immediately reading the test information to obtain a test readback signal; means for processing the test readback signal to determine a functional relationship between the test readback signal and the tape tension; means for computing the value of an operating tape tension based upon the functional relationship between the test readback signal and the tape tension; and means for controlling the motor means of the tape drive for implementing the operating tape tension in the form of a command signal.
Claim 22
Independent Claim
140 words
An apparatus for adjusting the tension of a tape in a tape drive by control of the motor means thereof, the apparatus comprising: means for receiving the tape; means for providing a test signal; means for recording test information from the test signal onto the tape while tape tension is concurrently varied in value in a prescribed manner; means for immediately reading the test information to obtain a test readback signal; means for processing the test readback signal to determine a functional relationship between the test readback signal and the tape tension; means for computing the value of an operating tape tension based upon the functional relationship between the test readback signal and the tape tension; and means for controlling the motor means of the tape drive for implementing the operating tape tension in the form of a command signal.
Claim 23
Dependent Claim
22 words
The apparatus of claim 19 comprising means for preparing a designated scratch area on the tape prior to recording the test signal.
Claim 24
Dependent Claim
17 words
The apparatus of claim 19 comprising means for varying the tape tension as a function of time.
Claim 25
Dependent Claim
22 words
The apparatus of claim 21 comprising means for superimposing a periodic disturbance on the tape tension varied as the function of time.
Claim 26
Independent Claim
290 words
An apparatus for providing drive signals to first and second motor means of a tape drive for adjusting the tape tension to compensate for changes in ambient conditions as well as variation in physical and functional characteristics of the tape drive and the tape, the apparatus comprising means for receiving a tape into the tape drive; means for preparing a designated scratch area on the tape by erasing the designated scratch area on a first track with a pre-selected write signal by means of a forward write transducer while the tape is moving in the forward direction; means for erasing the designated scratch area on a second track with a pre-selected write signal by means of a backward write transducer; means for providing a test signal of known parameters for recording test information onto the scratch area of the first track with the tape moving in the forward direction; means for immediately reading the thus recorded test information for obtaining a test readback signal by means of a read transducer; means for sampling the test readback signal; means for processing the samples of the test readback signal to generate a table of the readback amplitude values versus the tape tension values; means for varying the tape tension in a predetermined manner by supplying appropriate current commands to the first motor means and the second motor means; means for determining a reference readback signal amplitude value; means for determining an operating tape tension value with reference to the thus determined reference readback signal amplitude value; and means for controlling the current commands to the first motor means and the second motor means in response to the thus determined operating tape tension value for controlling the tape tension in the tape drive.
Claim 27
Independent Claim
290 words
An apparatus for providing drive signals to first and second motor means of a tape drive for adjusting the tape tension to compensate for changes in ambient conditions as well as variation in physical and functional characteristics of the tape drive and the tape, the apparatus comprising means for receiving a tape into the tape drive; means for preparing a designated scratch area on the tape by erasing the designated scratch area on a first track with a pre-selected write signal by means of a forward write transducer while the tape is moving in the forward direction; means for erasing the designated scratch area on a second track with a pre-selected write signal by means of a backward write transducer; means for providing a test signal of known parameters for recording test information onto the scratch area of the first track with the tape moving in the forward direction; means for immediately reading the thus recorded test information for obtaining a test readback signal by means of a read transducer; means for sampling the test readback signal; means for processing the samples of the test readback signal to generate a table of the readback amplitude values versus the tape tension values; means for varying the tape tension in a predetermined manner by supplying appropriate current commands to the first motor means and the second motor means; means for determining a reference readback signal amplitude value; means for determining an operating tape tension value with reference to the thus determined reference readback signal amplitude value; and means for controlling the current commands to the first motor means and the second motor means in response to the thus determined operating tape tension value for controlling the tape tension in the tape drive.
Claim 28
Dependent Claim
75 words
The apparatus of claim 23 wherein the means for determining the reference readback signal amplitude value further comprises: means for searching through the table of the readback amplitude values versus the tape tension values to determine the maximum readback signal amplitude; means for calculating a base amplitude value equal to a predetermined portion of the maximum readback signal amplitude; and means for finding a readback amplitude value in the table matching the base amplitude value.
Claim 29
Dependent Claim
69 words
The apparatus of claim 23 wherein the means for determining the operating tape tension value further comprises: means for locating within the table of the readback amplitude values versus the tape tension values a base tape tension value corresponding to the readback amplitude value matching the base amplitude value; and means for adding a predetermined offset to the base tape tension value to determine the operating tape tension value.
Claim 30
Dependent Claim
70 words
The apparatus of claim 23 wherein the means for processing the samples of the test readback signal further comprises: means for storing the samples of the test readback signal in a table inside a memory; means for filtering the stored samples of the test readback signal through a digital filter with a desired frequency response; and means for storing the filtered samples of the test readback samples in a table.
Claim 31
Dependent Claim
154 words
The apparatus of claim 23 wherein the means for processing the samples of the test readback signal further comprises: means for storing the samples of the test readback signal in a first table inside a memory; means for filtering the stored samples of the test readback signal through a first digital filter having a low pass frequency response; means for storing the samples of the test readback signal filtered by the first digital filter in a second table; means for filtering the samples of the test readback signal stored in the first table through a second digital filter having a band pass frequency response; means for storing the samples of the test readback signal filtered by the second digital filter in a third table; and means for combining the samples of the test readback signal from the second table and the third table in a predetermined manner to determine the operating tape tension value.
References Cited (Backward Citations)
US3947880A
Cited
US3633187A
Cited
US3781490A
Cited
US4389600A
Cited
US4552351A
Cited
US4656530A
Cited
US4807107A
Cited
US5032936A
Cited
US5125592A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-31 | 1996-11-30 | 1997-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-31 | 2000-11-30 | 2001-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-31 | 2004-11-30 | 2005-06-01 | $7700.00 | Window Closed / Lapsed |