Abstract:
A removable data cartridge is protected from air-transported particles such as dust, excessive moisture, contaminants, and the like by filtering or otherwise conditioning the airflow at initial startup. The recording media in the data cartridge is initially spun at a rate of speed higher than the operating speed for a brief period of time. By spinning the media at the increased speed, any particles in the cartridge will be removed by the filters. After the initial cleaning period, the spin speed of the media is reduced to a normal operating level.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates to computer storage products, and more particularly to initial cleaning of removable storage cartridges using a high speed startup.  
       BACKGROUND  
       [0002]     A typical disk drive for receiving removable storage cartridges has an actuator that carries read/write heads for communicating with a disk. Linear actuators translate back and forth along a radial axis of the disk. Rotary actuators usually consist of a structural arm that pivots on a voice coil motor and carries read/write heads on a distal end.  
         [0003]     When the storage cartridge is not in use, it has a casing surrounding a storage disk which provides protection against dust or contaminants. However when the disk is installed in a drive and accelerated to high speeds for fast access by read/write heads in the drive, an incredible amount of air turbulence is created. Therefore, protection and stabilization of the storage medium on the disk becomes a very serious problem. Some improvements have been obtained by incorporating an inner seal around portions of the periphery of the storage cartridge. See, for example U.S. patent application Ser. No. 09/346,485 entitled A SHUTTERLESS DATA RECORDING CARTRIDGE AND SEAL, which is incorporated herein by reference. See also U.S. Pat. No. 6,466,406 entitled DATA STORAGE CARTRIDGE HAVING ONE OR MORE SURFACE RECESSES FOR IMPROVED INTERNAL AIR CIRCULATION, which is incorporated herein by reference.  
         [0004]     Higher storage density on disk storage media has made the prevention and control of dust infiltration a very important factor. Also undesirable particles dislodged or otherwise transported through the air because of the various moving parts within the cartridge and associated drive may abrade and corrupt the storage media or the read/write heads.  
         [0005]     U.S. Pat. No. 4,885,652 to Leonard, et al. discloses a generally square disk cartridge for a recording disk includes at least one air filter in a corner of the cartridge and a circular rib adjacent the disk and between the disk and the filter. The cartridge may also include a radial rib connected to the circular rib to enhance air flow to the filter. Air filters may be located in each of the corners of the cartridge with associated circular and radial ribs to induce air flow to each filter.  
         [0006]     U.S. Pat. No. 4,969,061 to Patterson et al. discloses a cartridge with a flexible storage disk that rotates against a Bernoulli surface with a passage in communication with a differential pressure region such that air moves through the passage. A filter is positioned in the passage to remove particulate materials from the air.  
         [0007]     U.S. Pat. No. 5,615,070 to Bordes discloses a cartridge disk that includes an electrostatic filter in the shell enclosure that is strategically placed to clean the air circulated within the cartridge disk during operation. One part of the filter is placed in an air inlet centrally-mounted in the cover piece of the shell enclosure near a rotation axis of the hard disk platter. A second part of the filter is positioned in an outlet port and sandwiched between the cover piece and the base piece of the shell enclosure.  
         [0008]     What is needed is a system that enhances the removal of particulates in a removable data cartridge. Preferably, the system would clean the cartridge quickly on startup to minimize the risk of particulates causing damage during operation.  
       SUMMARY  
       [0009]     A removable data cartridge is protected from air-transported particles such as dust, excessive moisture, contaminants, and the like by filtering or otherwise conditioning the airflow at initial startup. The recording media in the data cartridge is initially spun at a rate of speed higher than the operating speed for a brief period of time. By spinning the media at the increased speed, any particles in the cartridge will be removed by the filters at a faster rate than they would filtered at normal operating speed. After the initial cleaning period, the spin speed of the media is reduced to a normal operating level. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0010]     These and other features and advantages of the invention will become more apparent upon reading the following detailed description and upon reference to the accompanying drawings.  
         [0011]      FIG. 1A  shows a perspective view of an embodiment of the invention in a removable storage cartridge constructed to receive a linear actuator.  
         [0012]      FIG. 1B  is a top planar view of the removable storage cartridge of  FIG. 1A  with certain storage disk components shown in phantom.  
         [0013]      FIG. 2  shows another embodiment of the invention in a removable storage cartridge constructed to receive a rotary actuator.  
         [0014]      FIG. 3  is an embodiment of the invention showing a partially cutaway view of a drive having a storage disk inserted therein, with a rotary actuator in loaded position and also showing in phantom the rotary actuator in unloaded position.  
         [0015]      FIG. 4  is a block diagram of the controls for a drive/disk combination employing the features of the invention.  
         [0016]      FIG. 5  is a top schematic view showing an embodiment of an airflow unit with an inlet immediately upstream from a read/write actuator.  
         [0017]      FIGS. 6A and 6B  is a top schematic view showing another embodiment with a plurality of airflow units located in selected positions outside of the perimeter of a rotating storage disk.  
         [0018]      FIG. 7  is a cutaway perspective view showing a different version of an airflow unit displaced from a head access hole in the cartridge.  
         [0019]      FIG. 8  shows the structure of  FIG. 7  from a side perspective view.  
         [0020]      FIG. 9  is a top view of the structure of  FIG. 7 .  
         [0021]      FIG. 10  is a flowchart showing the process for increasing particulate removal at startup. 
     
    
     DETAILED DESCRIPTION  
       [0022]     Referring to  FIGS. 1A and 1B , an exemplary data storage cartridge  11  for incorporating an embodiment of the invention includes an outer shell or housing  12  with an upper half  14  and lower half  16  defining a head access opening  25  for receiving a linear actuator from a disk drive.  
         [0023]     A data medium such as storage disk  20  and a hub  22  are rotatably mounted inside the outer shell  12 . The head access opening  25  permits read/write heads from the drive to move back and forth along a radius R as the storage disk rotates, and thus be selectively positioned proximate upper and/or lower recording surfaces of the storage disk  20  for read/write accessing from and to the storage medium on the disk. A shutter  26  located along side edge  12   a  slides away from the head access opening  25  upon insertion of the storage cartridge into a disk drive. Otherwise the shutter is in a normally closed position to protect the storage disk from contaminants or other undesirable interference or contacts.  
         [0024]      FIG. 2  illustrates a different embodiment of an exemplary data storage cartridge  11  of the type for receiving a rotary actuator from a disk drive. The storage cartridge including a top shell  13  connected to sidewalls  15  and front wall  17 , and including a bottom shell  9  connected to side walls  21  and front wall  23 . The top and bottom shells are connected through a rear pivot  29  to form a drive head opening  25  when the shells are in open position for receiving a storage disk  27 . (See U.S. Pat. No. 6,268,982, which is incorporated by reference.)  
         [0025]      FIG. 3  shows an exemplary rotary actuator  31  with an actuator arm  35  holding a read/write head  42  in loaded position over a storage disk  27 . A loading ramp  80  facilitates the loading and unloading movement of an actuator holding the read/write heads. A voice coil motor  30  enables rotary movement of the actuator to an unloaded position shown in phantom at  31   a.    
         [0026]      FIG. 4  schematically shows the various operational relationships for moving the actuator of the disk drive between a loaded and unloaded position. More particularly the voice coil motor  30  is coupled to the actuator  31  and is in electrical communication with a microprocessor  32  and a computer programmable memory  73  that has programmed code for controlling the operation of the microprocessor  32 .  
         [0027]     The disk drive has a mechanical or electrical sensor  74  to detect when a disk cartridge is inserted into the disk drive. An eject system  76  for ejecting the disk cartridge from the disk drive is activated by an eject button  80 .  
         [0028]     When a disk cartridge is inserted into the disk drive, the sensor detects its presence and communicates this information to the microprocessor. The programmed memory causes the microprocessor to power the voice coil motor so that the actuator is rotated from an unloaded position to a loaded position.  
         [0029]     In  FIG. 5 , a removable storage cartridge  11  comprises a data storage medium in the form a circular disc  27  housed within a cartridge housing  10 . A drive head opening  25  in the housing  10  provides an access path to allow an actuator head to be moved back and forth into proximity with the storage medium  27 . The actuator head  42  mounted on an actuator  31  is carried by a disk drive  8 .  
         [0030]     The storage medium is coupled by any suitable structure (such as through a hub) to a rotator or motor  18  in the drive  8  that rotates the storage medium in the removable cartridge. As the medium is rotated an air flow is created as shown by arrow  90 . Due to blockage caused by the actuator head support assembly  31 , a high pressure zone  91  is generated upstream of the actuator. Also due to the blockage, the high pressure zone helps to expel air from the cartridge as shown by arrows  92 . Similarly actuator blockage creates a low pressure zone  93  downstream from the actuator that induces air inflow as shown by arrows  94 . The airflows indicated by  92 ,  94  are mechanisms for air exchange between the cartridge and the drive and carry possible airborne contaminants.  
         [0031]     The present embodiment includes an induction vent  95 , preferably located hear a high pressure zone, and an exhaust vent  96  preferably located near a low pressure zone. A conditioning system  50  is disposed in a passage  52  connecting the induction vent  95  and the exhaust vent  96 . Air enters the induction vent  95  passes through the conditioning system  50  and is reprocessed and reconditioned. The reprocessed and reconditioned air is re-introduced at the exhaust slot vent  96 . The air conditioning system  50  may include any suitable air conditioning, filtration, processing system, or the like.  
         [0032]     In  FIGS. 6A and 6B , a removable storage cartridge  11  comprises a data storage medium in the form of a circular disc  27  housed within a cartridge housing  10 . A drive head opening  25  in the housing provides an access path to allow an actuator head to be moved back and forth into proximity with the storage medium  27 . The actuator head  42  is mounted on an actuator  31  that is carried by a disk drive  8 .  
         [0033]     The storage medium is coupled by any suitable structure to a rotator or motor  18  in the drive  8  to rotate the storage medium in the removable cartridge. As the medium is rotated an air flow is created as shown by arrow  90 .  
         [0034]     Referring to  FIG. 6A , when the actuator is near an outer periphery  37  of the disk, the wake from the flow over the actuator results in dynamic pressure loss in the flow downstream of the actuator and produces a hydrodynamic blockage in a first recirculation filter unit at location  1 L. However, a second recirculation filter or air-conditioning unit at location  1 M is not in the wake for this perimeter actuator position and is still effective.  
         [0035]     Referring to  FIG. 6B , when the actuator is near a center portion  36  of the disk, the wake from the flow over the actuator results in dynamic pressure loss in the flow downstream of the actuator and produces a hydrodynamic blockage in the second recirculation filter unit at  1 M. However, the first unit at location  1 L is not in the wake for the center portion head position and is still effective. Consequently when the filter at location  1 L is ineffective, the filter at location  1 M is effective and vice-versa. The effectiveness of the filtration system is therefore less sensitive to actuator position by using such plurality of filter units uniquely located.  
         [0036]     A similar scheme applies at the drive level as well. When the actuator is near the center, airflows in and out of the cartridge are set up as shown at locations  1 N and  1 P, for first and second filters, respectively. The flow direction at  1 N and  1 P is dependent on actuator position on the disk, so drive level filters can complement each other at locations  1 N and  1 P for different actuator position similar to the previously described filter unit positions.  
         [0037]     Reference is now made to  FIGS. 7, 8  and  9 . Shown is only a portion of a cartridge of the invention. In this embodiment, a filter or air conditioning unit with an enlarged inlet  98 , and an upwardly oriented filter outlet  99  is mounted in a cartridge that has a housing  10  with a head access opening  25 .  
         [0038]     The cartridge has a circular storage medium  27  (shown in part in  FIG. 9  and  FIG. 10 ) with a center  36 , a periphery  37 , and a data storage surface  38 . The medium  27  may have a storage surface on both sides  38 . The storage medium  27  is protected within the housing  10 . Referring in particular to  FIG. 10 , the housing  10  is structured to provide an access path through access opening  25  to allow the head  42  of the actuator  31  to be moved back and forth into proximity with the data storage surface  38  of the medium. The storage medium  27  is rotated by a drive rotator or motor  18  around the center  36  when the removable cartridge is mounted in the drive.  
         [0039]     The housing  10  includes a panel  19  that is generally parallel to and extending over the storage medium  27 . Rotation of the storage medium induces an air flow in the direction of rotation  90  over the data storage surface of the medium. An air processing or conditioning unit  50  is located across the air flow in at least part of the region between the center  36  and the periphery  37  of the rotating medium  27  and between the data storage surface  38  of the medium  27  and the panel  19 . Only one panel  19  and conditioning unit  50  is shown, but there may a panel and conditioning unit associated with the other data storage surface  38 . Preferably, the air processing unit is directed over most of this region with where the air processing unit extends between a location near the center and a location adjacent the periphery of the rotating medium and extends between a location adjacent to the data storage surface of the medium and a location adjacent to the panel.  
         [0040]     To increase the particle capturing surface of the filter and minimize the tendency of particle laden air to flow around the conditioning unit, the air processing unit is preferably angled, preferably with a leading edge  97  directed in a direction into the air flow at the location adjacent the surface of the medium.  
         [0041]     In any embodiment of the invention, variously shaped and sized airflow conditioning units can be incorporated for use with variously sizes and shapes of storage disks installed in different orientations with a disk drive in order to enjoy the benefits of the invention. It is believed that the direction control of air passing through the airflow units helps to diminish the air exchange from outside the cartridge. In this regard, structures in air flow path, such as induction and exit vents, flow passages, cartridge and drive walls, may include aerodynamic contours to help handle and direct air currents efficiently. Any of the aspects or embodiments of the invention can be used alone or used with other aspects or embodiments of the invention or other air conditioning/filtering systems for more effective air conditioning and filtering.  
         [0042]      FIG. 10  illustrates a process  100  for cleaning the data storage cartridge  11  according to the present invention. The process  100  begins at a START block  105 . Proceeding to block  110 , the process  100  spins the storage medium  27  at a first speed. This first speed is a higher speed than the normal operating speed of the data storage cartridge  11 . For example, if the normal operating speed of the data storage cartridge  11  is 4200 rpm, the first speed may be 5000 rpm, or any other speed greater than 4200 rpm.  
         [0043]     Proceeding to block  115 , the process  100  maintains the storage medium  27  spinning at the first speed for a set period of time. During this time period, the increased speed of the storage medium  27  increases the pressure differential across the filter to improve the removal of the particulates.  
         [0044]     After the designated time period, the process  100  proceeds to block  120  where the speed of the storage medium  27  is reduced to the normal operating speed. At this point, the high speed cleanup will have significantly reduced the amount of particulates in the data storage cartridge  11 , thereby increasing the reliability of the cartridge. The process  100  then terminates in END block  125 .  
         [0045]     The process  100  can be run anytime the cartridge needs to be cleaned, and would typically be set to run each time the cartridge is inserted into the drive. Thus, the cartridge will be automatically cleaned using the dual-speed process at startup.  
         [0046]     Numerous variations and modifications of the invention will become readily apparent to those skilled in the art. Accordingly, the invention may be embodied in other specific forms without departing from its spirit or essential characteristics.