Winding – tensioning – or guiding – Unwinding and rewinding a machine convertible information... – Including threading
Reexamination Certificate
1999-08-31
2001-04-17
Nguyen, John Q. (Department: 3653)
Winding, tensioning, or guiding
Unwinding and rewinding a machine convertible information...
Including threading
C242S332800, C360S071000, C360S095000
Reexamination Certificate
active
06216970
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates in general to magnetic media tape and tape drives, and in particular to reducing the mechanical distortion created in the magnetic tape at the take-up reel interface.
2. Background Art
One type of magnetic media tape on single reel tape cartridges is typically threaded into and unthreaded from a tape drive with a leading portion such as a leader block or leader tape. Occasionally, these systems experience a mechanical embossment or distortion when they are loaded into the take-up reel. This problem is more frequent with thin, high capacity magnetic tapes. The distortion typically occurs near the interface between the drive hub and the leader portion wherever there is an unsupported region or gap (see FIGS.
1
-
4
). Ideally, the outer edge of the leader portion is substantially flush with the outer diameter of the reel hub and centered in its throat. However, in the prior art, there is a misalignment range of approximately +/−100 microns.
As shown in
FIGS. 1 and 2
, a small but significant embossment
11
,
13
, respectively (shown exaggerated for ease of understanding), is formed in subsequent layers of the thin magnetic tape
15
wrapped around the hub
17
on top of the leader block
19
at a uniform tension. Embossments
11
,
13
form on top of the edges of the leader block
19
, and on top of the throat edges of hub
17
, respectively.
A third type of discontinuity is shown in FIG.
3
. Here, a larger than normal gap
12
is formed to one side of leader block
19
when it is not centered in the throat of hub
17
. Gap
12
leads to the formation of an embossment
14
in tape
15
. In
FIG. 4
, a reel
16
has a slit
18
for receiving a piece of leader tape
20
that is spliced to the end of magnetic tape
22
with a strip of adhesive tape
24
. In this configuration, two discontinuities can be formed in magnetic tape
22
: an embossment
26
at the throat of slit
18
, and/or an embossment
28
at or near adhesive tape
24
. Each of these discontinuities can result in recording errors in the tape where data is recorded. An improved method for reducing mechanical distortion in magnetic tape is needed.
SUMMARY OF THE INVENTION
A tape cartridge assembly contains a spool of magnetic tape with a leader block on one end. The leader block inserts into take-up reel and the tape is initially wound at a higher than normal tension to create a small band of tightly wound tape on the reel. The band eliminates the effect of any mechanical distortion created by the leader block. The remainder of the tape is wound on top of the tight band at normal tension to form an outer band of distortion-free magnetic tape.
REFERENCES:
patent: 4477851 (1984-10-01), Delziel et al.
patent: 4519553 (1985-05-01), Campbell et al.
patent: 5581419 (1996-12-01), Kobayashi
Byrne Dennis H.
Chliwnyj Alex
Felsman Bradley Vaden Gunter & Dillon, LLP
International Business Machines - Corporation
Martin Robert B.
Nguyen John Q.
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