Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism
Reexamination Certificate
2001-07-19
2004-10-12
Sniezek, Andrew L. (Department: 2651)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
C360S071000, C360S095000
Reexamination Certificate
active
06804077
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for quickly and consistently reinitializing a tape drive after a loss of power to the tape drive.
DESCRIPTION OF RELATED ART
Single reel tape cartridges are used to transport and store tape for reel-to-reel tape drives. A single reel tape cartridge is inserted into a tape drive and a mechanism is used to load the end of the tape into a take-up reel from the tape cartridge. Once the end of the tape is loaded into the take-up reel, the tape drive operates as a reel-to-reel tape drive. A motor is coupled to the takeup reel to rotate the take-up reel about the take-up reel axis and another motor is coupled to the single reel tape cartridge to rotate the reel of the tape cartridge about its axis.
The tape drive mechanism attaches to a tape leader pin, located at the end of the tape contained in the single reel tape cartridge. The hub filler uses a slot in the hub filler for receiving the tape leader pin. The hub filler is coupled to a guide arm that drives the hub filler between the single reel tape cartridge and the take-up reel. An example of a mechanism for driving the hub filler between the tape cartridge and the take-up reel is disclosed in U.S. Pat. No. 6,034,839.
FIG. 1
is a view of the tape drive mechanism disclosed in U.S. Pat. No. 6,034,839. The hub filler
300
enters into the cartridge
210
and attaches to the end of the tape. The hub filler
300
then moves along a guide rail
247
, driven by the guide arm
250
. Typically, the hub filler
300
attaches to the end of a tape in the tape cartridge
210
and the guide arm
250
moves the hub filler
300
along the guide rail
247
, trailing the tape across the read/write head
222
and into the take-up reel
242
. The hub filler
300
enters the take-up reel
242
through a channel
244
and into the hub
245
of the take-up reel
242
.
FIG. 2
is a top view of the tape drive mechanism, depicting the hub filler
300
in the take-up reel
242
with the tape
216
attached. The single reel tape cartridge
210
is positioned in the tape drive. The tape
216
is wound on a reel inside the cartridge
210
. The end of the tape
216
is attached to a leader pin
214
. The hub filler
300
has transported the end of the tape
216
along the guide rail
247
, driven by the guide arm
250
, from the cartridge
210
to the takeup reel
242
. During this transportation hub filler
300
pivots on axle
252
and is held to the guide rail
247
by pressure from a spring. The hub filler
300
also includes a catcher that attaches to the leader pin
214
when entering the cartridge
210
. The tape
216
is passed across the read/write head
222
and the end of the tape
216
is secured to the take-up reel
242
. The tape drive is then operated by rotation of the take-up reel
242
and the single reel of the cartridge
210
about their respective axes to move the tape
216
across the read/write head
222
. Motors are used to rotate the take-up reel
242
and the single reel of the cartridge
210
, controlling the speed of the tape
216
as it moves across the read/write head
222
. The hub filler
300
pivots on an axle
252
that is coupled to the guide arm
250
. This pivoting is necessary for the hub filler
300
to be guided on the guide rail
247
into the take-up reel
242
. Once the hub filler
300
is in the take-up reel
242
, with the tape
216
attached, the take-up reel
242
rotates to thereby unload the tape from the cartridge
210
. The hub filler
300
rotates with the take-up reel
242
on the axle
252
.
There are some concerns regarding the conventional tape drive described above. During the sequence of operations of a conventional tape drive mechanism there is a possibility of a power loss. When power is eventually restored to the tape drive, it is difficult for a controller that controls the mechanical operation of the conventional tape drive to determine what operation in the sequence of operations the conventional tape drive was performing at the time of power loss. In other words, the controller does not know, after the restoration of power, how to continue operation of the tape drive. When the conventional tape drive inevitably continues operation after restoration of power, there is a likelihood that the leader pin
214
will become disengaged from the hub filler
300
. This problem may exist when, at the time of power loss, the hub filler
300
was in between the tape cartridge
210
and take-up reel
242
. Such a circumstance will effectuate a “jam” in a tape drive and cause the tape drive to be temporarily inoperable. This circumstance is very inconvenient for the user of the “jammed” tape drive and may cause significant delays for the user.
Some conventional tape drives include sensors that sense the position of the mechanical parts of the tape drive mechanism after recovery of power. However, these sensing arrangements can be somewhat inaccurate and this inaccuracy can cause the tape drive mechanism to be “jammed”, as discussed above. Further, this sensing of the position of the mechanical parts after a power recovery often does not provide enough information to determine the direction the mechanical parts were moving when the power loss occurred. In other words, the conventional tape drive mechanism cannot consistently resume operation during reinitialization from where the tape drive mechanism was operating prior to power loss. This may cause an undesirable delay during reinitialization. Further, the hardware necessary for sensing the position of mechanical parts of the conventional tape drive takes up valuable space in the tape drive, which is undesirable in compact tape drives.
SUMMARY OF THE INVENTION
There is a need for a tape drive that can consistently resume operation during reinitialization after a power loss, with minimum time delay. There is also a need for a tape drive mechanism that can consistently resume operation during reinitialization after a power loss, but consumes minimal space.
These and other needs are met by embodiments of the present invention, which provide a method and apparatus of utilizing a non-volatile memory that stores the functional state of a tape drive throughout the operation thereof. Particularly, in embodiments of the present invention, the tape drive mechanism is arranged to store in the non-violatile memory the last instruction issued from a controller to the tape drive mechanism. This last issued instruction is further stored in relation to the sequence of instructions that the tape drive mechanism is performing at time of storage. Accordingly, if a power loss occurs during the operation of the tape drive mechanism according to an issued instruction, the tape drive is arranged to read the functional state of the tape drive mechanism from the non-volatile memory during reinitialization.
The present invention has the advantage of fast reinitializing after power loss. This is possible, since the last issued instruction in relation to the sequence of instructions that the tape drive mechanism was performing at the time of power loss is stored in the non-volatile memory. Accordingly, after a power loss, the tape drive mechanism can resume operation without significant delay during reinitialization. Hence, it is unnecessary for the tape drive to sense or attempt to determine where in the sequence of instructions the tape drive was at the time of power loss, based on the position of the mechanical parts of the tape drive mechanism.
Another advantage of the present invention over a conventional tape drive is that mechanical failure or “jamming” is less likely to occur. In embodiments of the present invention, the tape drive can resume operation at the same instruction in the sequence of instructions during reinitialization with a significant reduction, in comparison to a conventional tape drive, in the probability of mechanical failure or “jamming”. For instance, in a conventional tape drive, if a hub filler is transporting an end of tape with a leader pin attached, it is possible for the lead
Certance LLC
Sniezek Andrew L.
Thelen Reid & Priest LLP
LandOfFree
Method and apparatus for reinitializing a tape drive after a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for reinitializing a tape drive after a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for reinitializing a tape drive after a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3285405