WO1999012161A1

WO1999012161A1 - Data storage device integrating magnetic tape and drive

Info

Publication number: WO1999012161A1
Application number: PCT/US1998/018112
Authority: WO
Inventors: Kenneth Sheppard; George Driskell
Original assignee: Verbatim Corp
Current assignee: Verbatim Corp
Priority date: 1997-09-02
Filing date: 1998-08-31
Publication date: 1999-03-11
Anticipated expiration: 2000-03-02

Abstract

A chassis (50) mounts two tape reels (71, 72) that hold a magnetic tape (90) wound in opposite directions on the respective tape reels. A resilient belt (111) transfers rotation of a capstan roller (140) to exterior portions (91, 92) of the magnetic tape wound on the reels. This moves the magnetic tape from reel to reel along a tape path that includes a magnetic read/write transducer (100) and at least a pair of tape guides (151, 152). A flexible belt (110) transfers rotation of a drive shaft (81) of a drive motor (80) to the capstan roller. Alternatively, the capstan roller is mounted directly to the drive shaft of the drive motor and the additional resilient belt is eliminated. The data storage device is preferably mounted inside a housing unit (213) that seals out contaminants and shields the magnetic tape from electro-magnetic interference.

Description

DATA STORAGE DEVICE INTEGRATING MAGNETIC TAPE AND DRIVE

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to devices for reading, writing, and storing data in a magnetic medium. More particularly, the present invention relates to devices for reading, writing, and storing data on a magnetic tape for use by a computer system.

Description of the Related Art There are many conventional devices for reading, writing and storing data in a magnetic medium for use by a computer system. For example, the conventional hard disk drive stores data magnetically in a plurality of data storage tracks on a hard disk. The data storage tracks are typically wider than required by the magnetic resolution of the hard disk due to a difficulty of precisely positioning a magnetic read/write transducer in the hard disk drive radially with respect to the hub of the hard disk. This difficulty limits the data storage capacity of conventional hard disk drives. Further, the conventional hard disk typically must be accelerated up to the constant rotational speed of, for example, 3600 revolutions per minute, the magnetic read write transducer positioned radially over a selected data storage track on the hard disk, and the hard disk rotated so that a selected data storage sector is under the magnetic read/write transducer before any reading or writing of data on the hard disk can occur, and frequent repositioning of the magnetic read write transducer is typically required. These steps can require several milliseconds and limit the data access times and throughput of current hard disk drives. Due to these limitations, other storage mediums such as magnetic tape are often employed for storing large volumes of digital data of, for example, more than a gigabyte. One conventional device for backing up computer system memory is the quarter-inch cartridge (QIC) tape drive and standardized QIC tape cartridge. The QIC tape drive comprises a tape drive housing having an opening for receiving a standardized QIC tape cartridge, with the tape drive housing holding a magnetic read/write transducer and a drive motor. The QIC tape cartridge comprises a base plate mounting a pair of tape reels. A length of magnetic tape runs from reel to reel along a tape path that includes a plurality of tape guides. A plurality of belt rollers and a capstan roller position a resilient belt along a belt path that includes exterior portions of the magnetic tape wound on each tape reel. In normal operation, the QIC tape cartridge is inserted into the opening in the tape drive housing and a capstan shaft coupled to the drive motor engages and rotates the capstan roller which in turn moves the resilient belt along the belt path and, hence, the magnetic tape from reel to reel along the tape path. The magnetic read/write transducer in the tape drive housing engages a segment of the magnetic tape at a location along the tape path of the tape cartridge for reading or writing data on the magnetic tape, with the tape guides holding the magnetic tape in alignment with the magnetic read/write transducer within the dimensional tolerances of the sliding- fit engagement of the cartridge in the tape drive housing.

Conventional QIC tape drives and cartridges are often employed for backing up hard disk drives and computer system memory for several reasons. The tape reels of QIC tape cartridges are relatively light compared to hard disks and can be accelerated up to an appropriate rate of speed for write operations very quickly. The magnetic read/write transducers of conventional QIC tape drives typically require fewer repositionings than those of hard disk drives. Consequently, QIC tape drives and cartridges are generally better at performing backups of computer system memory than hard disk drives.

Unfortunately, the conventional QIC tape drive and tape cartridge cannot fully utilize the data storage capacity of the magnetic tape used in the cartridges. Some space on the magnetic tape is needed between the data storage tracks to prevent cross-talk of data. Further, it is difficult to precisely align the magnetic tape in the tape cartridge with the magnetic read/write transducer in the tape drive housing because vibration can shift the data storage track on the magnetic tape out of alignment with the magnetic read/write transducer, for example, within dimensional tolerances of the sliding- fit engagement of the QIC tape cartridge within the tape drive housing. Also, alignment and spacing between the capstan shaft and the capstan roller is imprecise, resulting in slippage of the capstan roller and instantaneous tape speed variations. The QIC tape cartridges generally require a cover for keeping contamination off the magnetic tape, with the cover incorporating a movable gate that makes the magnetic tape accessible to the magnetic read/write transducer. However, this movable gate can also allow dirt to enter the QIC tape cartridge and contaminate the magnetic tape. Complete grounding and shielding of the conventional QIC tape cartridge within the conventional QIC tape drive is difficult, and, consequently, electro-magnetic noise such as 60-cycle hum from alternating currents (AC) in the tape drive may corrupt data on the magnetic tape.

Thus, there is a need for an improved data storage device that can more fully utilize the data storage capacity of magnetic tape than is currently possible with conventional QIC tape drives and QIC tape cartridges. Such a data storage device should preferably provide an alignment between a magnetic tape and a magnetic read/write transducer that is relatively fixed and vibration free when reading or writing data on the tape. Preferably, the magnetic tape should be shielded from possible sources of dirt and other contamination, and all components of the data storage device should preferably be conductively grounded together to prevent electronic noise from corrupting data stored on the magnetic tape.

SUMMARY OF THE INVENTION

The present invention provides a data storage device for reading, writing and storing data on a magnetic tape. The data storage device comprises a chassis that mounts a magnetic read/write transducer and a pair of tape reels that hold a length of magnetic tape and allow the magnetic tape to be bidirectionally moved reel to reel using a resilient belt that engages portions of the magnetic tape on each tape reel. A drive motor mounted to the chassis provides rotational force for driving the resilient belt. Because the drive motor and tape reels are mounted to the same chassis, the relative spacing of the drive motor and tape reels remains fixed during operation of the data storage device within much closer tolerances than are possible with slide- fit cartridges within an associated tape drive. Unlike QIC tape drives and cartridges wherein movement of the QIC tape cartridge in the QIC tape drive housing can affect the instantaneous tape speed, the present invention can provide stable tape speed when reading or writing data on the tape, but also allows for variations in tape speed occurring, for example, while the tape reels are attaining full speed. Because the magnetic read/write transducer is mounted to the same chassis as the tape reels, the magnetic tape can be very precisely positioned over the magnetic read/write transducer. Because of this highly precise positioning capability, complex servo- tracking schemes can be realized and extremely high tracking densities obtained.

The present invention also eliminates the need for the movable gate of the conventional QIC tape cartridges by shielding the magnetic tape, tape reels, drive motor, resilient belt or belts, and magnetic read/write transducer within a single housing unit. Using a single housing unit substantially eliminates the possibility of contaminants reaching the magnetic tape, which, in turn, prevents wear of the magnetic tape and the magnetic read/write transducer. The housing unit keeps away from the magnetic tape sources of electro-magnetic corruption, such as time- varying fields from nearby electrical wires or magnets. Preferably, the housing unit is fabricated of metal or other conductive material to shield the magnetic tape from external electro-magnetic fields and aid in cooling of internal component. Magnetic metals and alloys, such as iron and various steels, provide improved shielding from some varieties of magnetic fields and is thus preferably included in the housing unit for some applications of the present invention. The present invention provides an ideal storage medium for backing up both hard disk drives and computer system memory. Storage capacities greater than two gigabytes are readily obtainable with a current basic embodiment of the present invention. Other embodiments can provide ten gigabytes or more of storage capacity from a single tape of about 1000 feet or more. The improved throughput of the present invention relative to current QIC tape drives and cartridges is beneficial for backing up computer system memory and allows a greater volume of data to be saved more quickly than in conventional QIC devices.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an illustration of one embodiment of a data storage device of the present invention for reading, writing and storing data on magnetic tape.

Fig. 2 is an illustration of a side view of the data storage device of Figure 1. Fig. 3 is an illustration of a top view of an alternate embodiment of a data storage device of the present invention including an additional tape guiding and tensioning structures.

Fig. 4 is an illustration of a partial side view of the data storage device of Figure 3.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to Figure 1, there is shown one embodiment of a data storage device 501 of the present invention for reading, writing, and storing data on a magnetic tape 90. The data storage device 501 incorporates a chassis 50 having a top surface 51 that mounts a pair of tape reels 71, 72 in spaced relationship using pins 66, 67 respectively. One end of the magnetic tape 90 is wound clockwise on tape reel 71 , and an opposite end of the magnetic tape 90 is wound counter-clockwise on tape reel 72. The magnetic tape 90 is bidirectionally moved from reel 71. 72 to reel 72, 71 along a tape path that includes a magnetic read/write transducer 100 for reading and writing data on the magnetic tape 90, a sensor 190 for determining when the ends of the magnetic tape 90 are approached during operation of the data storage device 501, and a pair of tape guides 151, 152 for positioning the magnetic tape 90 on the magnetic read/write transducer 100. The tape reels 71, 72 and the tape path are positioned relative to a common plane to prevent wrinkling of the magnetic tape 90.

A drive motor 80 mounted to the top surface 51 of the chassis 50 generates rotational force for moving the magnetic tape 90 from reel 71, 72 to reel 72, 71 along the tape path. More particularly, a drive shaft 81 of the drive motor 80 extends through the chassis 50 to engage a flexible belt 110 beneath the chassis 50. The flexible belt 110 transfers rotation of the drive shaft 81 to a capstan roller 140 comprising a bottom roller 141 disposed beneath the chassis 50 coaxially mounted on shaft 143 to a top roller 143 disposed above the chassis 50. The shaft 142 is supported in a bearing mounted in the chassis 50 and transfers rotation of the bottom roller 141 to the top roller 143. An additional flexible and resilient belt 111 transfers rotation of the top roller 143 to exterior portions 91, 92 of the magnetic tape 90 wound on tape reels 71, 72 respectively. Bidirectional rotation of the drive shaft 81 is thus transferred through the two flexible belts 110, 111 to move the magnetic tape 90 bidirectionally from reel 71, 72 to reel 72, 71 along the tape path and deliver the magnetic tape 90 under tension from one of the tape reels 71, 72 to the other of the tape reels 72, 71. The diameter of each roller 141, 143 is selected in conjunction with a speed range of the drive motor 80 to provide an appropriate tape speed range. Alternate embodiments of the present invention mount both rollers 141, 143 either below or above the chassis 50, or alternatively, mount the drive motor 80 beneath the chassis 50 and extend the drive shaft 81 through the chassis to mount and directly drive the top roller 143.

To hold the magnetic tape 90 in tension, the flexible resilient belt 111 follows a belt path that includes the top roller 143, the exterior portions 91, 92 of the magnetic tape 90, and a pair of rotatable belt rollers 121, 122 mounted with pins 131, 132 to the top surface 51 of the chassis 50. The belt rollers 121, 122 provide appropriate tensioning of the resilient belt 111 in the belt path, and consequently appropriate tensioning of the magnetic tape 90 in the tape path, in the conventional manner of QIC tape cartridges, which involves some slippage of the resilient belt 111 over the magnetic tape 90 wound on the tape reels 71, 72. By driving the bottom roller 141 in the data storage device 501 more stably than the capstan roller of QIC tape cartridges is driven, the present invention substantially eliminates instantaneous tape speeds variations that can be encountered in conventional QIC tape drives operating with standardized slide-in tape cartridges.

To precisely position the capstan roller 140, tape reels 71, 72 and belt rollers 121, 122 along a common plane, the data storage device 501 includes a spring plate 170. The spring plate 170 is mounted to the various pins 66, 67, 131, 132 and the capstan shaft 142. The spring plate 170 acts as a leaf spring to project downward force on and reduce vertical play of the tape reels 71, 72, the belt rollers 121, 122, and the capstan roller 140. The spring plate 170 also includes holes through which screws 224, 225 are inserted and screwed into the chassis 50. The screws 224, 225 provide an adjustable level of load on the spring plate 170, and hence provide an adjustable vertical preloading of the capstan roller 140, the tape reels 71 , 72 and the belt rollers 121, 122 onto the top surface 51 of the chassis 50. Additional control over such preloading and over disposing the rollers 121, 122, 140 and reels 71, 72 along a common plane can be provided using washers and spacers as needed. The sensor 190 in the tape path beneficially prevents ends of the magnetic tape 90 from coming off the tape reels 71, 72. The magnetic tape 90 travels through a slot 191 in the sensor 190. The sensor 190 projects a light onto one surface of the magnetic tape 90 in the slot 191. The magnetic tape 90 includes a plurality of holes spaced a various locations near each end of the tape 90 that allow the light to travel through the tape 90. When an end of the magnetic tape 90 is approached during operation of the data storage device 501, the holes successively come into alignment with the projected light, and the projected light thus travels through the magnetic tape 90 and is registered by the sensor 191. The sensor can thus determine when an end of the magnetic tape 90 is approached and accordingly stop rotation of the tape reels 71, 72 to prevent the tape 90 from coming off a reel 11, 12.

Conventional QIC tape drives and cartridges also include a light sensor. However, in conventional QIC tape drives and cartridges, a prism is also required to project light through the QIC tape because the tape is disposed in the QIC cartridge. Further, the present invention allows for the use of any form of sensor that can detect that an end of the tape 90 is approaching because the magnetic tape 90 does not need to be compatible with conventional QIC tape drives. Thus, for example, hole patterns other than those conventionally included in conventional QIC tape can be used in alternate embodiments of the present invention.

The magnetic read/write transducer 100 comprises a plurality of magnetic read/write heads mounted together side by side in a servo-tracking device 102 in a conventional manner of QIC tape drives. Each read/write head can read and write data in a data storage track that extends along the length of the magnetic tape 90, and the transducer 100. Alignment and engagement of the magnetic tape 90 with the magnetic read/write heads is very precise because the transducer 100 and the tape reels 71, 72 are mounted to the same chassis 50, and consequently, the present invention allows for a greater number of data storage tracks and read/write heads than is currently possible with QIC tape drives and cartridges. The servo- tracking device 102 allows the magnetic read/write transducer 100 to read and write track centering signals on the magnetic tape 90 and to center each read/write head, or assembled group of such heads, relative to the width of the magnetic tape 90 in response to the track centering signals for precise alignment with one or more corresponding data storage tracks. The magnetic read/write transducer 100 can be designed to engage the magnetic tape 90 during reading or writing of data to the tape 90, and to disengage from the tape 90 during rewinding or forwarding the magnetic tape 90 for preventing wear and stretching of the magnetic tape 90. In an alternative embodiment of the present invention, the magnetic read/write transducer 100 is mounted in fixed position to the chassis, and the servo-tracking device 102 is omitted. In some embodiments of the present invention, one or more read/write heads can be shifted across the width of the magnetic tape 90 to access a plurality of data storage tracks on the tape 90.

The data storage device 501 includes a power port 170, a bus port 180, and electronic circuitry 101. The power port 170 delivers electrical power to the data storage device 501 for running the drive motor 80, magnetic read/write transducer 100, and electronic circuitry 101. The bus port 180 receives and transmits control signals and data to and from electronic circuitry (not shown) outside of the housing, such as a computer, in the conventional manner of QIC tape drives. The electronic circuitry 101 processes received control signals, generates control signals for output, and appropriately controls the operation of the drive motor 80 and the magnetic read/write transducer 100 for reading and writing data on the magnetic tape 90 and moving the magnetic tape 90 bidirectionally from reel 71, 72 to reel 72, 71.

The chassis 50 is preferably fabricated of non-magnetic metal, such as aluminum or zinc alloy. This provides great rigidity for keeping all components of the data storage device 501 in proper alignment and prevents the chassis 50 from becoming magnetized. Further, the metallic chassis 50 allows all components of the data storage device 501 to be conductively grounded together, aids in cooling such components, and provides electrostatic shielding of the magnetic tape 90.

The data storage device 501 is preferably contained within a housing unit 213 including an electrically conductive material for minimizing electromagnetic corruption of data on the magnetic tape 90 or magnetic read/write transducer 100 and for shielding internal components from dust particles, dirt, or other contaminants. The chassis 50 is mounted to a bottom unit 212 of the housing unit 213 by a plurality of metal screws 226, 227, 228, 229.

Referring now to Figure 2, there is shown a side view of the data storage device 501 that also illustrates a top unit 211 of the housing unit 213 which covers the chassis and the bottom unit 212. Both the bottom unit 212 and the top unit 211 are preferably constructed of metal. The housing unit 213 can be fabricated of magnetic metals and alloys, such as iron, steels, and the like, to provide improved shielding from some varieties of electro-magnetic interference. In alternative embodiments of the present invention, these units 211, 212 are constructed of a polymeric material such as plastic to absorb mechanical vibrations and coated with a layer of electrically conductive material to shield the internal components from electro-magnetic corruption. In another alternative embodiment of the present invention, a housing unit is formed directly to the chassis 50 to hermetically seal the internal components from external debris. These various illustrated and alternative housing units prevent the contamination and the corruption of data on magnetic tape commonly encountered in conventional QIC tape drives and standardized tape cartridges.

Referring now to Figures 3 and 4, there are shown a top view and a partial side view respectively of an alternate embodiment of a data storage device 601 of the present invention. The data storage device 601 includes a chassis 50, with a top surface 51, a pair of tape reels 71, 72, pins 66, 61 mounting the tape reels 71, 72 to the chassis, a magnetic read/write transducer 100, a servo-drive device 102 for the transducer 100, electronic circuitry 101 (not shown), a magnetic tape 90 wound bidirectionally on the tape reels 71, 72, a pair of tape guides 151, 152, a drive motor 80 having a drive shaft 81, a capstan roller 140, a flexible belt 110 and a flexible resilient belt 111, a pair of rotatable belt rollers 121, 122 mounted with pins 131, 132 to the top surface 51 of the chassis 50, and a housing unit 213 including a bottom unit 212 and a top unit 211 (not shown), and a spring plate 170, and other necessary components (not shown) of the data storage device 501 illustrated in Figures 1 and 2. However, the structure, functionality, and relative positioning of the various components differs from those Figures 1 and 2 as follows.

The spring plate 170 used in data storage device 601 is not mounted to the capstan shaft 143. Rather, screws 166, 167 mount the spring plate 170 to holes in pins 66, 67 respectively. An additional screw 168 mounts the spring plate 170 to the chassis 50 and provides downward force on the spring plate 170 to adjust preload and play of the tape reels 71, 72 and belt rollers 121, 122 respectively. The spring plate 170 of data storage device 601 is more rigid than that of data storage device 501 for more precisely limiting vertical play of the rollers 121, 122 and reels 71, 72. Thrust washers 171 , 172 disposed between the spring plate 170 and the tape reels 71, 72 respectively provide additional control over preloading and play of the tape reels 71, 72. The data storage device 601 includes an additional tape guide 153. The magnetic read/write transducer 100 is mounted between, adjacent, and substantially equidistant from the tape guide 152 and the additional tape guide 153. This configuration of tape guides 152, 153 is beneficial for improving engagement and alignment of the magnetic read/write transducer 100 with the magnetic tape 90. The remaining tape guide 151 beneficially prevents the tape path away from the capstan 140.

In the data storage device 501 of Figures 1-2, the flexible resilient belt 111 provides tension to the magnetic tape 90. This tension derives from rotational force supplied through the capstan 140 from the drive motor 80 and is determined in part by slippage of the flexible resilient belt 111 over the magnetic tape 90 wound on the tape reels 71, 72. Rotation of the capstan 140 at less than a full operational rate of speed can result in insufficient tension in the magnetic tape 90 for optimal read and write performance.

To address this issue, the data storage device 601 includes a tape tensioning device that provides control over the tension in the magnetic tape 90 and augments the tension supplied thereto by the flexible resilient belt 111. The tape tensioning device comprises a top swing arm 250 having a first end 260 mounted to a shaft 260 and a second end rotably mounting a tape roller 270. The shaft 260 is rotably mounted to the top surface 51 of the chassis 50 and extends through and beneath the chassis 50 to mount a bottom swing arm 251 that rotates in common with the top swing arm 250. A drive device 280 mounted beneath the chassis 50 provides rotational force for altering the rotational attitude of the bottom swing arm 251, and hence also the top swing arm 250, over a range of angles sufficient to allow the tape roller 270 to engage and apply a tension to the magnetic tape and to disengage from the magnetic tape 90.

The drive device 280 comprises a tension spring 281 and a solenoid 282. The tension spring 281 is coupled in tension to the chassis 50 and the bottom swing arm 251 and provides force to disengage the tape roller 270 from the magnetic tape 90. The solenoid 282 is coupled to the chassis 50 and disposed for drawing the bottom swing arm 251 into the solenoid 282 in opposition to the force provided by the tension spring 281. In operation, solenoid 282 provides sufficient force both to overcome force provided by the spring 281 and to suitably engage the tape roller 270 with the magnetic tape 90. The electronic circuitry 101 controls the drive device 280 and thus controls the tension provided to the magnetic tape 90. Different varieties of control are possible. In a basic variety, the electronic circuitry 101 fully engages the tape roller 270 with the magnetic tape 90 while the reels 71, 72 are rotated at less than a full rate of speed. This provides a selected additional tension to the magnetic tape 90 for read and write operations Once the reels 71, 72 attain the full rate of speed, the flexible resilient belt 111 provides such tension to the tape 90, and the electronic circuitry 101 disengages the tape roller 270 from the magnetic tape 90. The electronic circuitry 101 also disengages the tape roller 270 from the magnetic tape 90 when the reels 71, 72 are not rotating to reduce stretching of the magnetic tape and to improve wear of both the magnetic tape 90 and the magnetic read write transducer 100. In an alternative variety of control, the electronic circuitry 101 adjusts engagement of the tape roller 270 with the magnetic tape 90 variably over a range of engagement angles of the top swing arm 250. The electronic circuit 101 increases engagement of the tape roller 270 with the magnetic tape 90 in an indirect relationship with the rotational speed of the capstan roller 140. This provides variable tension to the magnetic tape 90 and allows the total tension in the magnetic tape 90 to be maintained at a substantially constant level or alternatively to be fine tuned for optimal read and write performance. The tape roller 270 can also be entirely disengaged from the magnetic tape 90 as before to reduce stretching of the magnetic tape 90. Referring now to Figure 4, there is shown a partial side view of the data storage device 601. Figure 4 illustrates the positioning of the thrust washer 172 and of screw 167 mounted in pin 67. The thrust washer 171 and screw 166 are similarly mounted, (not shown). The present invention therefore provides a high quality data storage device for reading, writing and storing data on a magnetic tape, and substantially eliminates numerous problems encountered in conventional QIC tape drives and cartridges, including damage to magnetic tape and other system components by dust and other contaminants, corruption of data on magnetic tape by electro-magnetic interference, capstan slippage, and relative movement between the conventional QIC tape cartridge and the associated tape drive, and variations in tape tension caused by variations in capstan speed. Consequently, the present invention provides greater data storage and throughput for reading and writing data on a magnetic tape and allows more data to be stored on a magnetic tape than is currently possible with conventional standardized QIC tape drives and cartridges.

Claims

What is claimed is:

1. A data storage device including a length of magnetic tape and an endless resilient belt, comprising: a chassis; rotatable first and second reels mounted in spaced relationship on the chassis with the magnetic tape disposed between the first reel and the second reel; a magnetic read/write transducer mounted to the chassis for reading and writing data on the magnetic tape; a plurality of tape guides mounted to the chassis for positioning the magnetic tape with respect to the transducer, with the magnetic tape passing between the reels along a tape path that includes the transducer and the tape guides; a plurality of rotatable belt rollers mounted in spaced relationship on the chassis for positioning the resilient belt in contact with exterior portions of the magnetic tape wound on each of the reels; a rotatable capstan roller mounted to the chassis for moving the resilient belt along a belt path that includes the capstan roller, the belt rollers, and the exterior portions of the magnetic tape wound on each of the reels for moving the magnetic tape between the reels along the tape path in response to rotation of the capstan roller; and a drive motor mounted to the chassis and disposed for rotating the capstan roller.

2. The data storage device of claim 1, wherein the capstan roller is mounted to a drive shaft of the drive motor.

3. The data storage device of claim 1, additionally comprising a second endless belt engaging the drive shaft for transferring rotation of the drive shaft to the capstan roller.

4. The data storage device of claim 3, wherein the capstan roller comprises a first roller coaxially mounted with a second roller on a capstan shaft, with the second endless belt engaging the second roller for rotating both the second and first rollers, and with the first roller engaging the endless resilient belt disposed along the belt path for moving the magnetic tape between the reels along the tape path in response to rotation of the drive shaft.

5. The data storage device of claim 4, wherein the first roller is disposed on one side of the chassis and the second roller is disposed on another side of the chassis, and additionally comprises a capstan shaft extending through a bearing mounted in the chassis and having opposite ends coaxially mounting the first roller to the second roller for transferring rotation of the second roller to the first roller.

6. The data storage device of claim 1, wherein at least one of the tape guides is mounted to the chassis and includes a recessed middle portion for positioning the magnetic tape within the tape path.

7. The data storage device of claim 1 wherein the magnetic read/write transducer and the magnetic tape are engaged for at least one of reading and writing data on the magnetic tape and disengaged for at least one of rewinding and forwarding the magnetic tape.

8. The data storage device of claim 1, additionally comprising an enclosing housing unit that contains and shields from contaminants the chassis, the reels, the magnetic tape, the transducer, the tape guides, the resilient belt, the belt rollers, the capstan roller, and the drive motor.

9. The data storage device of claim 8, wherein the housing unit is fabricated of an electrically conductive material for shielding the magnetic tape from electro-magnetic fields arising external to the housing unit.

10. The data storage device of claim 1, wherein the housing unit includes a magnetic metal for improved shielding of the magnetic tape from magnetic fields arising external to the housing unit.

11. The data storage device of claim 1 , wherein the transducer comprises a plurality of magnetic read/write heads mounted together in spaced relationship, each head disposed for reading and writing data in one of a plurality of data storage tracks on the length of magnetic tape.

12. The data storage device of claim 1, wherein the magnetic tape includes a plurality of track centering signals and the transducer reads the track centering signals and in response centers each head on a data storage track on the magnetic tape.

13. The data storage device of claim 1 wherein the reels and the tape path are disposed relative to a substantially common plane for preventing wrinkling of the magnetic tape.

14. The data storage device of claim 1, further comprising: a swing arm having a first end rotably mounted to the chassis and a second end; and a tape roller rotably mounted to the second end of the swing arm and applying a tension to the magnetic tape dependent on a rotational attitude of the swing arm; and a drive device for controlling the rotational attitude of the swing arm.

15. The data storage device of claim 14, wherein the tape roller applies variable tension to the magnetic tape for improved tracking of the magnetic tape by the magnetic read/write transducer.

16. The data storage device of claim 14, wherein the tape roller engages with the magnetic tape while the reels attain full speed for improved reading and writing of data on the tape.

17. The data storage device of claim 1, further comprising:

a plurality of pins mounting the reels and the belt rollers to the chassis; and

a plate coupled to the pins above the reels and the belt rollers for reducing play of the reels and the belt rollers on the pins.

18. The data storage device of claim 17, wherein the plate is substantially semi-rigid and elastic and preloads the reels and the belt rollers against the chassis for reducing play of the reels and the belt rollers on the pins.

19. The data storage device of claim 17, further comprising a plurality of thrust washers disposed between the plate and the reels and preloading the reels against the chassis for reducing play of the reels on the pins.

20. The data storage device of claim 17, further comprising at least one screw disposed to fasten the plate to the chassis and supply force for preloading the belt rollers against the chassis.

21. The data storage device of claim 11 , wherein the transducer shifts the plurality of heads between sets of the data storage tracks on the magnetic tape allowing at least one head to read and write data in a plurality of data storage tracks on the magnetic tape.