Abstract:
A holder for wide magnetic recording tape has a frame with four generally rectangular sides and an open top and an open bottom, with a frame height extending between the open top and the open bottom. Magnetic recording tape is wound in tape packs respectively on two hubs that are rotatably mounted between opposite sides of the frame. Because of the open structure of the frame, during a write/read operation the tape pack on one of the hubs can have a diameter which exceeds the height of the frame, thereby allowing substantially all of the magnetic recording tape to be wound on one of the hubs, if necessary.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a holder for wide magnetic recording tape. 
     2. Description of the Prior Art and Related Applications 
     The use of magnetic tape as a medium for data recording has the significant advantages of a relatively low cost and a relatively large recording surface area. Nevertheless, conventional magnetic tape has certain disadvantages associated therewith. 
     A first of these disadvantages is that tape is a sequential medium, which means that when a data transfer head is located at a beginning of a tape, it is necessary for the tape to be transported along its entire length in order to retrieve (or re-write) information at the end of the tape. 
     A second disadvantage is that, due to the desire and necessity of storing as much data as possible within an available tape area, the data transfer head technology as well as the recording media technology are pushed to their quality limits. 
     Moreover, many existing drives and cartridges must be designed within specified form factors, in order to satisfy standardization requirements. As an increasing number of functions become available, which are desired to be accommodated in a drive or on a tape, data storage area or other functions must be sacrificed to accommodate the new, additional functions, or some type of compromise must be reached in the overall design. 
     Among the more important market requirements which are expected in the near future for data storage on tape is that the need for higher storage capacity will continue to increase, at an even faster rate than previously. As discussed below, for example, the storage capacity of a currently available single cartridge is not sufficient for unattended backup during a longer period of time, and therefore so-called autoloader systems have been developed to automatically insert and remove a number of cartridges in a sequence. 
     Further market requirements are expected to be a need for faster time to access data, a need for an increased data transfer rate, a lower cost per MB (megabyte) and an overall improved quality and reduced cost. 
     As noted above, the limited data storage capacity of conventional cartridges has resulted in the development of autoloader systems. Conventional autoloader systems, however, are not a satisfactory solution to the problem of storing a large amount of data in an unattended backup procedure over a relatively long period of time. Several disadvantages exist with regard to currently available autoloader systems. 
     Because such autoloader systems make use of a large number of cartridges, the cartridges are made relatively small, and therefore have a limited space available for use for data storage. Typically, six to ten of such cartridges must be put in a magazine in order to have sufficient storage area (capacity). Because of the relatively small size of the cartridges, the drive is also made small, in order to match standardized form factors. The drive is disposed in a system housing, which also contains robotics, electronics and software needed for loading an unloading the cartridges. 
     The relatively large number of components, and therefore the relatively high cost, associated with conventional autoloader systems makes the use of such systems an unattractive alternative for a customer who merely wants long term data backup. 
     To address these problems, a tape cartridge and a drive for extremely wide tape are disclosed in co-pending U.S. application Ser. No. 691,165, filed Oct. 19, 2000, the teachings of which are incorporated herein by reference. The tape cartridge and drive described therein accommodate tape having an extremely wide width, such as a width that is greater than approximately 24 mm, or in a range between approximately 24 mm and approximately 127 mm. 
     The width of this extremely wide tape, therefore, is greater than that of a conventional magnetic recording tape by a factor of 6 to 10 times. Because the tape has this extremely wide width, the total tape length can be made significantly shorter while still making the same total area available for data storage. Making the tape shorter, however, requires less time for winding and unwinding the tape from the hubs on which it is carried in order to access data at a particular location on the tape. 
     It is important, however, that the housing for accommodating such extremely wide tape have the same, or substantially the same, form factor as conventional recording cartridges, so as to be accommodated in the openings for conventional tape cartridges in tape drives and auto loaders and magazines. This means that the axes of rotation of the tape hubs in cartridges for accommodating extremely wide tape will proceed parallel to a “longer” dimension of the cartridge housing, rather than perpendicular to the shortest dimension (height) as in a conventional cartridge housing. Given a length of extremely wide tape which is necessary to provide the same total area available for recording data on the tape as a conventionally sized tape, such a length of extremely wide tape can be accommodated in a housing having a height which is comparable to the height of a conventional tape cartridge only when the tape is substantially evenly distributed in respective tape packs on the two hubs in the housing. When any significant amount of extremely wide tape is wound onto one of the hubs, the diameter on the tape pack on that hub increases beyond the standard height of a conventional cartridge housing. 
     This problem could be addressed by simply providing a lesser length of extremely wide tape in the cartridge, so that even when all of the tape is wound on one tape hub in one tape pack, the diameter of that tape pack still would not exceed the height of a standard tape cartridge. 
     This would defeat one of the advantages of employing extremely wide tape, however, by decreasing the total area available for recording data. 
     To address this problem a tape cartridge is disclosed in co-pending U.S. application Ser. No. 09/859,328, filed May 16, 2001, which accommodates an amount of extremely wide tape therein having a total area available for data recording which is substantially the same as the area available for data recording in a conventional tape cartridge, and which has a form factor which is substantially the same as the form factor for a conventional tape cartridge. The tape cartridge disclosed in this co-pending application has a housing with two tape hubs rotatably mounted therein with wide magnetic recording tape wound thereon for winding and unwinding between the two hubs in a tape transport direction, with the housing being composed of first and second housing parts which are movable relative to each other in a direction perpendicular to the tape transport direction and which is also perpendicular to the rotational axes of the hubs, to accommodate an increase in diameter of the tape pack on one of the hubs which arises as the extremely wide tape is wound onto that hub. The housing thus can expand in the movement direction. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a holder for wide recording tape which accommodates a length of extremely wide recording tape having a reduced access time to data in comparison to conventional width recording tape with the same area available for data recording, and wherein the holder has a form factor which is substantially the same as that of a standard tape cartridge. 
     The above object is achieved in accordance with the principles of the present invention wherein the tape holder is formed by a four-sided frame in which two tape hubs are disposed, with wide magnetic recording tape wound thereon for winding and unwinding between the hubs in a tape transport direction. The frame therefore does not form a housing in the conventional sense because it does not have a top and a bottom which are permanently fixed to the sides of the frame. The frame may be provided with a top cover and a bottom cover for protecting the recording tape from dust and other contamination during storage, however, if such covers are used, they do not have a permanent connection to the frame, and are only held in place by a snap arrangement, so that during use of the frame in the drive, the covers are separated from the frame and therefore the frame is open at the top and at the bottom, and the diameter of the respective tape packs on the hubs is therefore not constrained by any fixed housing dimensions. 
     It is not necessary, however, to provide the frame with a top cover and a bottom cover, if the frame can be stored, when not in use in the drive, in a magazine or some other type of enclosure which serves for dust protection. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a perspective view of a wide tape holding frame constructed in accordance with the principles of the present invention. 
     FIG. 1A is a sectional view through one of the tape hubs in the wide tape holding frame in accordance with the invention. 
     FIG. 1B is a side view of one of the tape hubs in the wide tape holding frame in accordance with the invention. 
     FIG. 1C is an end view of one of the tape hub flanges in the wide tape holding frame in accordance with the invention. 
     FIG. 2 shows the wide tape holding frame of FIG. 1 with the top cover and the bottom cover separated from the frame. 
     FIG. 3 is an exploded view of the wide tape holding frame in accordance with the invention. 
     FIG. 4 is a section view through the wide tape holding frame of FIG.  1 . 
     FIG. 5 is a perspective view of a schematically illustrated wide tape drive. 
     FIG. 6 shows the wide tape holding frame in accordance with the invention in a schematically illustrated wide tape drive. 
     FIG. 7 shows the wide tape holding frame in accordance with the invention with the top and the bottom cover separated therefrom in the schematically illustrated wide tape drive. 
     FIG. 8 is a bottom view of the wide tape holding frame in accordance with the invention in a schematically illustrated wide tape drive. 
     FIG. 9 is sectional view through the wide tape holding frame and wide tape drive shown in FIG.  6 . 
     FIG. 10 a sectional view through the wide tape holding frame and wide tape drive shown in FIG.  7 . 
     FIG. 11 schematically illustrates the wide tape holding frame, without the top cover and the bottom cover, connected with two drive motors of the wide tape drive. 
     FIG. 12 is a sectional view of a drive shaft of one of the drive motors of the wide tape drive engaged in one of the tape hubs in the wide tape holding frame in accordance with the invention. 
     FIG. 13 is a perspective view from the rear of the wide tape frame in accordance with the invention, showing the write-preventing slide element. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The wide tape holding frame and cover assembly  1  shown in FIG. 1 has a rectangular frame  2  with a bottom cover  3  and a top cover  4 . One side of the frame  2  has a hinged access door  5 , which allows tape guides and a read/write head element to be inserted, as described in further below. This side of the frame  2  also has access openings  6  respectively in registration with tape hubs  7  that are rotatably mounted in the frame  2 . The access openings  6  allow respective drive shafts of a tape drive to be inserted into the tape hubs  7 , as also described in more detail below. 
     Each lateral side of the frame  2  has an opening  8  therein, which serves two purposes. The opening  8  serves as a gripper recess during loading of the cartridge into a drive, as described in more detail below, and also serves as an access opening for receiving projection  21  (see FIG. 3) on the bottom cover  3 , as also described in more detail below. 
     Each lateral side of the frame  2  also has grooves  9  which respectively receive projecting surfaces  25  of cartridge guides  34  of the drive  29  (see FIG.  5 ). The drive  29  is shown only schematically herein. Further details of the drive  29  are described in copending application “Wide Tape Drive for Wide Tape Holding Frame,” Rudi et al., Ser. No. 10/052,826 filed simultaneously herewith, the teachings of which are incorporated herein by reference. 
     Recesses  10  are also formed in the bottom cover  3  and the frame  2  which serve as notches for robotic handling of the frame  2 , with or without the covers  3  and  4 . 
     The side of the frame  2  in which the access door  5  and the access openings  6  are disposed also has sight openings  11 , the purpose of which is described below. 
     A cross-sectional view of the tape hub  7  is shown in FIG. 1A, with an exterior view being shown in FIG.  1 B. Each tape hub  7  has a shaft  12  with an internal bore  13  therein and flanges  18  and  19  at opposite ends. The flange  18  is disposed adjacent to the side of the frame  2  in which the access openings  6  are present, and has toothed projections  14  for engagement with the tape drive  29  in a known manner. 
     Each tape hub  7  further has a spring  15 , a thrust ball  16  and a thrust element  17 , which interact with a drive shaft of the tape drive  29  in the manner described in more detail below. The thrust element  17  also serves as a rotatable mount for the hub  7 , and is received in an opening in a side of the frame  2  opposite to the side containing the access opening  6 . The exterior of the projecting teeth  24  fit into the access opening  6  and serve to rotatably mount the opposite end of the tape hub  7 . 
     The flange  18  which, as noted above, is adjacent to the side of the frame  2  containing the access opening  6 , has a reflective surface  20  thereon which, when the oblong flanges  18  and  19  are oriented within the confines of the frame  2  (as shown in FIG. 3) is disposed behind the sight opening  11 . The reflective surface  20  has a different reflection characteristic from the remainder of the material of the flange  18 , such as by being a different color. A light transmitter/receiver arrangement (not shown) in the tape drive  19  thus can determine when the flange  18  (and thus the flange  19  as well) are oriented as shown in FIG. 3, or at an angle relative to that position to accommodate an increased diameter of tape wound on the hub  7 . 
     The frame  2  with the tape hubs therein can be used by itself in an environment which is suitably dust-free and contamination-free. The covers  3  and  4  are optional, for providing a complete enclosure the magnetic recording tape wound on the tape hubs  7 , when necessary. 
     The dimensions of the frame  2  with equal amounts of tape wound on the respective tape hubs  7  are approximately 4″×4″×0.8″. In a write/read operation mode, the maximum tape pack diameter can be approximately 0.9″. The frame  2  alternatively can have dimensions of 4″×5″. If the top and bottom covers  3  and  4  are used, the cartridge dimensions therewith are approximately 4″×4″×1″. The distance between the outside surfaces of the covers  3  and  4  in the write/read position (shown in FIG. 2) is approximately 1.6″. This means that the cartridge will fit into a standard form factor drive. 
     As shown in FIG. 13, a slide element  41  is movable back and forth in an opening  42  in the backside of the frame  2 . The element  41  has a tab  43  which, depending on position of the element  41 , is either flush with or recessed from a side surface of the frame  2 . The status (flush or recessed) of the tab  43  is detectable by suitable means (optical, sonic, etc.) in the drive  29 . Depending on the position of the slide element  41  in the opening  42 , which is manually set, the drive will enable or disenable writing of data on the tape  23 , thereby preventing an inadvertent alteration of previously recorded data. 
     The expanded assembly  1  is shown in FIG. 2, to illustrate the position of the components when it is in a drive (the surrounding drive not being shown in FIG. 2) for conducting a read or write operation. The top and bottom covers  3  and  4  have been separated by the frame  2  by an appropriate mechanism in the tape drive  29 . The initial position of the assembly  1  in the tape drive  29  is shown in FIG. 6, and the expanded position is shown in FIG.  7 . An appropriate mechanism in the guides  34  presses through the access opening  8  in each side of the frame  2 , thereby pressing against the projection  21  and releasing the bottom cover  3  from the frame  2 . The projection  21  is mounted on a flexible flap, which has a flange  26  at its end which engages an opening  28  in an inner flange  27  of the top cover  4 . When the projection  21  is pressed to release it from the access opening  8 , this also causes the flap to flex, thereby also releasing the flange  26  from the opening  28 , thereby freeing the top cover  4  from the frame  2  as well. 
     As can be seen in FIG. 2 as well as in the cross-sectional view in FIG.  4  and the exploded view in FIG. 3, the bottom cover  3  has tape guides  24  projecting inwardly therefrom, which hold the tape  23  in a position for engagement with the write/read head  38  (shown in FIG. 5) in the write/read mode. In the write/read mode only writing may take place, or only reading, or both. If the top and bottom covers  3  and  4  are not used, the tape guides  23  can be mounted to project inwardly from the frame  2 . The axle  22  for the access door  5  also can be seen as projecting inwardly from the bottom cover  3 . 
     In the expanded condition shown in FIG. 2, all of the tape  23  is wound onto one of the tape hubs  7 , with the flange.  65  thereof being rotated approximately perpendicularly to the position shown in FIG. 4, wherein equal amounts of tape  23  are wound on the two hubs  7 . The rotation of the flanges takes place during the initial startup of the transport motion of the tape  23 , with a small amount of friction being present at that time, which is all that is needed to rotate the flanges  18  and  19  by approximately one-quarter rotation. 
     As noted above, when the assembly  1  is inserted in the tape drive  29  it is engaged with guides  34  on opposite sides, via the grooves  9 . The guides  34  are rigidly mounted to a base plate  30 , to which drive motors  31  are also mounted. 
     As can be seen in FIG. 5, each of the motors  31  has a drive shaft  32 , and a toothed rim  33 , which engages the teeth  14  on the tape hub  7 . The read/write head  38  is moved along guide rods  36 , connected by a connector  37 , via a conical roller  40  by an actuator  39 , mounted to the plate  30 . 
     A plan view of the assembly  1  loaded into the tape drive  29  is shown in FIG. 8, and the arrangement without the covers, and without the plate  30 , is shown in FIG. 11, with all of the tape  25  being wound on one of the tape hubs  7 . 
     Sectional views of the assembly  1  loaded into the drive  29  are shown in FIG. 9 (before expansion) and FIG. 10 (after expansion). 
     The engagement of a drive shaft  32  of one of the drives  31  is shown in FIG.  12 . When fully inserted with the teeth engaged, the end of the drive shaft  32  presses against the spring  15 , which in turn rides against the thrust ball  16 . The thrust element  17  is mounted in the frame  2 , so that the thrust ball  16  is free to rotate between the spring  15  and the thrust element  17 , thereby maintaining radial alignment during rotation of the tape hub  7 . When the drive shaft  32  is removed, the spring  15  forces the flange  18  into the access opening  6 , thereby limiting rotation of the hub  7 . 
     Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.