Media transport performance measurements

Claim 3

The method set forth in claim 1 wherein said time metering includes using a periodic signal generator having a periodicity substantially less than expected elapsed time between two of said predetermined transitions and register means for accumulating digital representations of the number of counts between said transitions.

Claim 4

The method set forth in claim 1 wherein the distance indication is represented by succession of squarewaves with said ones of transitions being of all the same direction of change and during each said measurement holding said relative motion at a substantially constant velocity.

Claim 5

The method including making a first measurement as set forth in claim 1 and also making a second measurement while substantially altering the velocity in accordance with predetermined criteria and then subsequently comparing the two distance D measurements for evaluating relative motion during constant velocity and during changing velocity.

Claim 6

The method set forth in claim 4 wherein one of said articles is a magnetic tape and a second article is a tape-moving member engaging the tape for transport, said transducer being spaced from the tape-moving member and being in cooperative relationship in the tape for sensing magnetic marks thereon and further including tachometer means on said tape-transporting member for indicating displacement of the member and supposed displacement of said tape, the improved method further including: transporting said tape past the transducer by rotation of said member at a relatively constant velocity such that said marks are sensed by said transducer and simultaneously metering member movement; and subsequently varying the velocity of said tape-transporting member in decelerating/accelerating modes and simultaneously metering the distance between said marks and then comparing metered distance as indicated by the two modes of operation and indicating tape slip with respect to said member during accelerating/decelerating modes in accordance with differences in said measurements.

Claim 7

The method set forth in claim 5 wherein said first and second marks are pseudo records recorded on the tape by said transducer each having EOR and BOR end portions, moving the tape in the first direction substantially at constant velocity past the transducer, sensing EOR of the first record, metering the tape transport until detection of BOR of the second record both under constant velocity, and in deceleration/acceleration modes in both directions of motion and comparing the acceleration/deceleration modes in both directions with the distance indicated by the constant velocity measurement and indicating tape slip in both directions of motion in accordance with said measurement.

Claim 8

The method including recording said first mark on a magnetic member while transporting said magnetic member at a substantially constant velocity, stop the recording, and then substantially simultaneously decelerating the tape to a stop condition and recording said second mark after said tape has been stopped, and subsequently measuring the distance between said marks recorded in the above-described manner as set forth in claim 1.

Claim 9

Transport performance measurements wherein relative motion is effected between an article and a member with relative motion being indicated by transitions between electrical states of an electrical signal, each distance between two successive predetermined ones of said transitions representing a predetermined and relatively fixed distance, said transitions and said relative motions being asynchronous, said article having first and second marks thereon and said transport having means for sensing said marks when in a predetermined relationship to said member; effecting relAtive motion and sensing said electrical transitions during said motion; including the following steps: upon sensing a first of said marks, metering time in small increments until detection of a first one of said transitions, logging said time; repeatedly metering time between successive ones of said transitions and logging same; and finally, metering time between a last one of said transitions and said second mark, then in a digital machine computing the average time between two successive ones of said transitions as being representative of actual distance of relative motion between two of said transitions in the time domain, then dividing the partial metered times by said average time and summing the quotient with the number of transitions, and finally multiplying distance of relative motion between two successive ones of said transitions.

Claim 10

Transport performance measurements wherein relative motion is effected between an article and a member with relative motion being indicated by transitions between electrical states of an electrical signal, each distance between two successive predetermined ones of said transitions representing a predetermined and relatively fixed distance, said transitions and said relative motions being asynchronous, said article having first and second marks thereon and said transport having means for sensing said marks when in a predetermined relationship to said member; effecting relAtive motion and sensing said electrical transitions during said motion; including the following steps: upon sensing a first of said marks, metering time in small increments until detection of a first one of said transitions, logging said time; repeatedly metering time between successive ones of said transitions and logging same; and finally, metering time between a last one of said transitions and said second mark, then in a digital machine computing the average time between two successive ones of said transitions as being representative of actual distance of relative motion between two of said transitions in the time domain, then dividing the partial metered times by said average time and summing the quotient with the number of transitions, and finally multiplying distance of relative motion between two successive ones of said transitions.

Claim 11

The method set forth in claim 8 wherein said article is a flexible magnetic media and said member is a transducer capable of sensing and recording electrical signals on, to, and from said media and further means driving the tape in either direction across said transducer and displacement-indicating means in said driving means generating said transitions, the method further including: causing said media to be transported across said transducer and recording a pseudo record set of signals on said media and establishing reference points with respect to said pseudo record and metering distance between said reference points in accordance with claim 8.

Claim 12

The method set forth in claim 9 wherein said media is transported at a relatively constant velocity between all of said reference points both during recording and measurement.

Claim 13

The method set forth in claim 10 wherein said media is transported past said transducer after recording of said marks at least twice, a first one in accordance with claim 10 and a second time wherein the velocity is subjected to deceleration/acceleration modes for indicating media slip during such modes with respect to transport of the media at substantially constant velocity.

Claim 14

The method set forth in claim 11 further including reversing the direction of motion from said measurements and subjecting said media to deceleration/acceleration motions between at least two of said reference points for ascertaining media slippage in both directions of motion by comparing measurements during said deceleration/acceleration modes with respect to the distance indicated during the constant velocity measurement.

Claim 15

The method set forth in claim 12 further including completely stopping the media during said deceleration/acceleration modes.

Claim 16

The method set forth in claim 13 wherein an additional reference mark is established while said media is stopped whereby media transport during deceleration or acceleration mode is separately identifiable.

Claim 17

Media measurements for indicating distance between two signal portions on said media separated a distance sufficient such that a tachometer indicating displacement of said media is required to cycle through several signal cycles representing displacement, including the following steps in combination: metering elapsed time from a first signal portion until occurrence of a predetermined displacement signal while transporting said media past a transducer, then storing such elapsed time measurement, counting displacement signals until detection of said second signal portion, measuring time between successive ones of said displacement signal while counting said displacement signals, storing the elapsed time between the last-counted displacement signal and said second signal portion, computing the average velocity in a digital machine based upon a number of displacement signals and the total measured time between the first and last displacement signal, and combining said velocity displacement count and said metered time at the end portions adjacent said signal portions and generating signals indicating tHe distance between said signal portions.

Claim 18

Media measurements for indicating distance between two signal portions on said media separated a distance sufficient such that a tachometer indicating displacement of said media is required to cycle through several signal cycles representing displacement, including the following steps in combination: metering elapsed time from a first signal portion until occurrence of a predetermined displacement signal while transporting said media past a transducer, then storing such elapsed time measurement, counting displacement signals until detection of said second signal portion, measuring time between successive ones of said displacement signal while counting said displacement signals, storing the elapsed time between the last-counted displacement signal and said second signal portion, computing the average velocity in a digital machine based upon a number of displacement signals and the total measured time between the first and last displacement signal, and combining said velocity displacement count and said metered time at the end portions adjacent said signal portions and generating signals indicating tHe distance between said signal portions.

Claim 19

The method set forth in claim 15 wherein said media is moved in a forward direction and a pseudo data signal record precedes said first signal portion and succeeds said second signal portion.

Claim 20

The method set forth in claim 15 wherein said media measurement is in a direction wherein said pseudo record is disposed between said first signal portion and said second portion such that the length on the media of said record is precisely measured.

Claim 21

The method set forth in claim 15 wherein said displacement signal is a periodic square-wave having a periodicity in accordance with the velocity of the media motion with transitions in a given direction being reference transitions and all said time measurements being made with respect to said reference transitions and said signal portions.

Claim 22

The method set forth in claim 16 wherein said media is moved between a pair of spools with each spool capable of containing substantially all of said media, initially recording a plurality of pseudo records on said tape each having said signal portions and separated by IBG''s bordered by said signal portions, measuring a selected number of said distances between said signal portions at spaced points along said media such that distribution of the media between said spools is different for each of said measurements and performing such measurements at a relatively constant velocity, and repeating said measurements while subjecting the media to deceleration/acceleration modes between said signal portions being measured and then comparing the indicated displacements between said signal portions during said deceleration/acceleration modes with corresponding measurements made a constant velocity for indicating tape performance at different media distributions between said spools.

Claim 23

The method set forth in claim 19 wherein during said deceleration/acceleration modes, a single deceleration and a single acceleration from and to said constant velocity and a stop condition is performed between selected ones of said signal portions.

Claim 24

The subject matter set forth in claim 20 wherein said deceleration/acceleration mode is selected such that only deceleration or acceleration is performed between selected ones of said signal portions.

Claim 25

The method of claim 21 wherein said signal portions are recorded at least during some of said acceleration or deceleration modes.

Claim 26

The method set forth in claim 15 wherein said media transport is a reel-to-reel transport and said displacement-indicating signals are from a tachometer associated with rotation of one of said reels.

Claim 27

The subject matter of claim 15 wherein said media transport is a reel-to-reel transport and having a media with a reference track thereon plus an additional track having said signal portions and said measurement including combining said signals from said reference track, said signal portions and a tachometer indicating signal from a driving portion of said transport.

Claim 28

A magnetic tape system including a magnetic tape handler having driving means for moving tape past a transducer and the transducer capable of exchanging signals with the tape, a tachometer in the driving means indicating driving means operation and producing a series of signal-state changes indicative of displacement, programmable control circuit means operatively associated with said transducer and said driving means and including program means for establishing data signals, IBG''s, and control signals on said tape and receiving said signal-state changes from said driving means and being further operative to effect detection of said signals on said tape while transporting the tape by said driving means, and said program means being jointly responsive to signals from said tape and said signal-state changes for evaluating performance of said tape transport in that distances between said data signals forming an IBG are precisely measured by counting said transiTions and metering elapsed time between data signals and predetermined ones of said transitions and including means combining said counts with elapsed times for indicating actual IBG length.

Claim 29

A magnetic tape system including a magnetic tape handler having driving means for moving tape past a transducer and the transducer capable of exchanging signals with the tape, a tachometer in the driving means indicating driving means operation and producing a series of signal-state changes indicative of displacement, programmable control circuit means operatively associated with said transducer and said driving means and including program means for establishing data signals, IBG''s, and control signals on said tape and receiving said signal-state changes from said driving means and being further operative to effect detection of said signals on said tape while transporting the tape by said driving means, and said program means being jointly responsive to signals from said tape and said signal-state changes for evaluating performance of said tape transport in that distances between said data signals forming an IBG are precisely measured by counting said transiTions and metering elapsed time between data signals and predetermined ones of said transitions and including means combining said counts with elapsed times for indicating actual IBG length.