Abstract:
Methods for preparing for analysis of surface contamination of magnetic tape, in one embodiment, submerses and passes a continuing length of the magnetic tape through a covered water bath; and subsequent to the submersing step, wipes the continuing length of the magnetic tape while covered. The preparation is conducted, in one embodiment, with a covered enclosure configured to enclose a water bath to a level at least submersing guide(s) and a continuing length of the magnetic tape passed by the guide(s). A wiping arrangement is configured to wipe the continuing length of magnetic tape subsequent to the submersion in the water bath. Further, the covered enclosure comprises openings therein to pass the continuing length of magnetic tape.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    Commonly assigned copending U.S. Patent Application Ser. No. (TUC920100107US1), filed on even date herewith, relates to the cleaning of the surfaces of magnetic tape. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to magnetic tape, and more particularly, to preparation for the analysis of contaminants of the magnetic tape. 
       BACKGROUND OF THE INVENTION 
       [0003]    Magnetic tape comprises an important media for the storage of data, including the long term storage and archiving of data. The presence of ionic materials on the surface of magnetic tape is becoming increasingly important due to the potential corrosion caused by ionic species. Some examples comprise chlorine, fluorine, iodine and bromine salts, and phosphates and sulfates. These corrosion species commonly come from environmental sources and deposit onto the tape surface that can then cause corrosion to the tape, and to surfaces and components of a tape drive that the tape is used in. 
         [0004]    A magnetic tape is long, for example, 600 meters, so that analysis of a portion of a tape may not provide information regarding the remainder of the tape. 
       SUMMARY OF THE INVENTION 
       [0005]    Methods and apparatus are provided for extraction of surface contaminants of magnetic tape. 
         [0006]    In one embodiment, the method comprises submersing and passing a continuing length of the magnetic tape through a covered water bath; and subsequent to the submersing step, wiping the continuing length of the magnetic tape while covered. 
         [0007]    In a further embodiment, the continuing length of the magnetic tape, measured as the length of magnetic tape submerged in the covered water bath, is less than 1/1000 of total length of the magnetic tape. 
         [0008]    In another embodiment, the submersing and passing step comprises a speed of longitudinal passing of the magnetic tape of between 0.01 meters per second and 0.3 meters per second. 
         [0009]    In a further embodiment, the speed comprises substantially 0.2 meters per second. 
         [0010]    In another embodiment, the wiping step comprises wiping both sides (front and back) of the magnetic tape. 
         [0011]    In a further embodiment, the wiping step comprises wiping both sides of the magnetic tape simultaneously in a squeegee action. 
         [0012]    In a still further embodiment, the wiping step comprises passing the continuing length of magnetic tape between opposed brushes, the brushes contacting respectively the front and the back of the magnetic tape. 
         [0013]    In a further embodiment, the brushes comprise polymer brushes. 
         [0014]    In another embodiment, the water bath is heated to a temperature of between room temperature and 70 degrees Celsius. 
         [0015]    In still another embodiment, subsequent to the wiping step, the continuing length of magnetic tape is dried externally of the covered water bath. 
         [0016]    In another embodiment, a system for extracting surface contaminants of magnetic tape, comprises at least one guide configured to pass a continuing length of magnetic tape thereby; a covered enclosure configured to enclose the at least one guide and a water bath to a level at least submersing the guide(s), and submersing a continuing length of the magnetic tape passed by the guide(s); and a wiping arrangement configured to wipe the continuing length of magnetic tape subsequent to the submersion in the water bath. 
         [0017]    In a further embodiment, the covered enclosure comprises openings therein to pass the continuing length of magnetic tape. 
         [0018]    For a fuller understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a diagrammatic illustration of a system configured to extract surface contaminants from a magnetic tape; 
           [0020]      FIGS. 2A and 2B  are illustrations of respectively, a container and cover of the system of  FIG. 1 ; 
           [0021]      FIG. 3  is a flow chart depicting an exemplary method of operating the system of  FIGS. 1 and 2 ; 
           [0022]      FIGS. 4A and 4B  are illustrations of an embodiment of the guide and support apparatus of the system of  FIGS. 1 and 2 ; and 
           [0023]      FIGS. 5A and 5B  are illustrations of an alternative embodiment of the guide and support apparatus of the system of  FIGS. 1 and 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    This invention is described in preferred embodiments in the following description with reference to the Figures, in which like numbers represent the same or similar elements. While this invention is described in terms of the best mode for achieving this invention&#39;s objectives, it will be appreciated by those skilled in the art that variations may be accomplished in view of these teachings without deviating from the spirit or scope of the invention. 
         [0025]    Referring to  FIGS. 1 ,  2 A and  2 B, an example of a system  10  is illustrated which is configured to extract and concentrate surface contaminants from a magnetic tape  12  of a tape cartridge  14 . The surface contaminants of interest comprise ionic materials that are becoming increasingly important due to the potential corrosion caused by these ionic species. The corrosion species commonly come from environmental sources and deposit onto the tape surface and then can cause corrosion to surfaces and components of magnetic tape drives employed to write and read data with respect to the magnetic tape. The system  10  is configured to provide a non-destructive extraction of the surface contaminants from substantially an entire spool of magnetic tape of tape cartridge  14  using a small volume of water and to concentrate the extracted materials for detection and analysis of the ionic materials. 
         [0026]    The extraction system  10  comprises a container  15  and a guide system  18  of at least one guide  20  configured to pass a continuing length  25  of magnetic tape  12 . The guide system  18  is configured to guide and pass the continuing length of tape  25  within a water bath  27 , submersing the magnetic tape in the water bath. 
         [0027]    The magnetic tape may be supported and directed by additional guides such as guides  30  and  31 , supported by support  32 , which are configured to guide the magnetic tape  25  within the container  15 , and by guides  33  and  34  outside the container  15 . The guides may comprise bearings with or without flanges, or may comprise cylindrical surfaces with or without flanges, to guide the magnetic tape along the tape path, as will be discussed. 
         [0028]    A cover  35  is placed so as to cover the water bath  27  and the guides  30  and  31  that are within the container  15 . The cover  35  minimizes the water loss from water bath  27  due, for example, to splashing and evaporation. 
         [0029]    Submersion of the continuing length of magnetic tape  25  in the water bath  27  dissolves the ionic materials, thereby extracting the materials from the magnetic tape into the water bath. 
         [0030]    A wiping arrangement  40 , or wiper, for example comprising opposed brushes  42  and  43 , is configured to contact respectively the front and back of the magnetic tape as the continuing length of magnetic tape exits the water bath. The magnetic tape passes between the opposed brushes  42 ,  43  subsequent to submersion in the water bath  47 , while the magnetic tape is within the covered enclosure  15 ,  35 . The wiping arrangement  40 , or wiper, thereby wipes both sides of the magnetic tape to reduce the likelihood that water is carried from the bath  27  on the tape. In one example, the brushes of wiper  40  wipe both sides of the magnetic tape simultaneously in a squeegee action. 
         [0031]    The magnetic tape is directed through a notch in the cover  35  and guide  34  directs the magnetic tape  12  through a drier  50 . The drier  50  is external to the water bath enclosure and may, for example, be an air drier configured to dry both sides of the magnetic tape  12 . The temperature of the air drier does not exceed 70 degrees Celsius, and the drying is primarily from the movement of the air blowing onto the tape surface. Air driers are known to those of skill in the art. Drier  50  is intended to further dry the magnetic tape and to eliminate the possibility that the tape surfaces would become stuck once the magnetic tape is rewound in the tape cartridge  14 . 
         [0032]    A drive system  60  pulls the magnetic tape in a longitudinal path extending from the tape cartridge  14 , through the water bath  27 , submerging the continuing length of magnetic tape  25  in the water bath, through wiping arrangement  40 , and through external drier  50 . The drive system  60  is arranged to move the tape longitudinally from the tape cartridge  14  with a tension sufficient to maintain the magnetic tape  12  against the guides  33 ,  30 ,  20 ,  31  and  34  without the development of slack. The entire spool of magnetic tape from tape cartridge  14  is thus submerged in water bath  27  to extract the ionic materials into the water bath and the wiping arrangement  40 , for example comprising opposed brushes  42  and  43 , ensures that the extracted ionic materials remain in the water bath, concentrating the ionic materials in the small amount of water comprising the water bath. The concentration allows a subsequent analysis of the ionic materials. 
         [0033]    Once substantially the entire length of magnetic tape has passed through the water bath  27 , the magnetic tape is withdrawn from enclosure  15  and is rewound into the tape cartridge  14 , for example, by the drive system  60 . 
         [0034]    Referring additionally to  FIG. 3 , the method for extracting the ionic materials comprises, in step  70 , threading the magnetic tape  12  into the guide system  18 , and through the wiping arrangement  40  and drier  50 . In the illustrated example, the magnetic tape is also threaded along guides  33 ,  30  and along guide  20  of guide system, and threaded along guide  31  and through the brushes  42 ,  43  of wiping arrangement, or wiper,  40 , and along guide  34  and through the drier  50  to drive system  60 . 
         [0035]    Water is placed in the container  15  to form the water bath  27 , and, in one example, in step  75 , the unit comprising guide system  18  and support  32  and guides  30  and  31  are placed within the container  15  while the cover  35  is off and placed at the proper depth in the water bath  27  so as to submerse guide  20  and length of magnetic tape  25  in the water bath. Brushes  42  and  43  are not submersed. Referring to  FIGS. 1 and 2B , the support  32  and guide system  18  are supported by a back bracket which may be attached to the rear of the container  15 , for example above the water bath. The notch  76  is arranged to clear the back bracket, while notch  77  is arranged to clear the vertical portion  78  of the support  32 . Further notches  79  and  80  are arranged to clear the magnetic tape as it enters and exits the container  15 , respectively. 
         [0036]    The water bath  27  may be heated to a temperature of between room temperature and 70 degrees Celsius, either preheated before being placed in container  15 , or container  15  may comprise a heating element to heat the water bath. 
         [0037]    Referring to  FIGS. 1 ,  2 A,  2 B and  3 , in step  82 , cover  35  is placed at the container  15  so as to cover at least the water bath  27 . In the example, the cover is placed on the top of the container  15 , covering the water bath  27 , length of magnetic tape  25  and wiper  40 . 
         [0038]    In step  84 , the continuing length of magnetic tape  25  is drawn by drive system  60  along the guides to pass the continuing length of magnetic tape through the water bath  27 , submerging the continuing length of magnetic tape in the water bath, then from the water bath through wiper  40  and from the container  15  through the external drier  50 . 
         [0039]    The drive system  60  passes the magnetic tape in the longitudinal direction of the tape at a speed of between  0 . 01  meters per second and  0 . 3  meters per second. In a specific embodiment, the speed comprises substantially  0 . 2  meters per second. 
         [0040]    Thus, the continuing length of magnetic tape is submersed and passed through a covered water bath; and, subsequent to the submersing step, the magnetic tape is wiped while the magnetic tape is covered. 
         [0041]    The entire spool of magnetic tape  12  from tape cartridge  14  is thus drawn through the water bath, the water bath extracting the ionic materials that are present on the surface of the magnetic tape into the water bath. A magnetic tape  12  is long, for example, 600 meters, so that passing a continuing length of the magnetic tape  25 , which comprises less than 1/1000 of total length of the magnetic tape  12 , through the water bath  27  results in extracting and concentrating the ionic materials in the water bath. The small size of the water bath  27  through which the tape is passed concentrates the ionic materials for analysis to determine the ionic species that contaminated the magnetic tape  12 . As discussed above, some examples comprise chlorine, fluorine, iodine and bromine salts, and phosphates and sulfates. These corrosion species commonly come from environmental sources and deposit onto the tape surface that can then cause corrosion to the tape, and to surfaces and components of a tape drive that the tape is used in. 
         [0042]    Once the magnetic tape  12  has been passed through the water bath, it may be removed from container  15  and rewound back into tape cartridge  14 . 
         [0043]      FIGS. 4A and 4B  illustrate one embodiment of the guide system, support, guides and bracket that may be employed in the system  10  of  FIG. 1 . Guides  93 ,  90 ,  89 ,  91  and  94  correspond to guides  33 ,  30 ,  20 ,  31  and  34  respectively of  FIG. 1 . The guides  93 ,  90 ,  89 ,  91  and  94  comprise roller bearing guides which may comprise flanges to guide the magnetic tape. Examples of such roller bearing guides are known to those of skill in the art. The wiper  40  is also illustrated. The wiper and guides are supported by a bracket  98  that may be attached through slot  99  to the rear of the container  15  of  FIG. 1 . 
         [0044]      FIGS. 5A and 5B  illustrate an alternative embodiment of the guide system, support, guides and bracket that may be employed in the system  10  of  FIG. 1 . Guides  103 ,  100 ,  109 ,  101  and  104  correspond to guides  33 ,  30 ,  20 ,  31  and  34  respectively of  FIG. 1 . The guides  103 ,  100 ,  109 ,  101  and  104  comprise cylindrical surfaces, such as pins which may comprise flanges to guide the magnetic tape. Examples of such cylindrical surfaces, partial or full, are known to those of skill in the art. The wiper  40  is also illustrated. The wiper and guides are supported by a bracket  110  that may be attached through slot  111  to the rear of the container  15  of  FIG. 1 . 
         [0045]    Referring to  FIG. 1 , drive system  60  may comprise any suitable means for winding the magnetic tape  12  on a take up reel, passing the magnetic tape through the water bath  27  and through the wiper  40  and drier  50  with a small amount of tension on the magnetic tape  12  to maintain the magnetic tape in the tape path. One example comprises a drive motor and take up reel of a magnetic tape drive. 
         [0046]    Those of skill in the art will understand that changes may be made with respect to the methods discussed above, including changes to the ordering of the steps. Further, those of skill in the art will understand that differing specific component arrangements may be employed than those illustrated herein. 
         [0047]    While the preferred embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims.