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Anti-static sleeves for storage cartridges and removable media Disclosure Number: IPCOM000016258D
Original Publication Date: 2002-Oct-05
Included in the Prior Art Database: 2003-Jun-21

Publishing Venue



Removable storage media, such as magnetic tapes and optical disk cartridges, must be protected from dirt and other contaminants when not inside the host device (tape drive, optical drive, or library). Environmental protection is also required for more-advanced removable storage components which includes but is not limited to removable hard disk drives and solid-state memory devices. In essence, any removable component used for data storage should have a protective case or sleeve to prevent or reduce contamination when located outside the storage device in which it is used. This ensures more reliable performance by protecting both the media and storage device from deterioration caused by dirt and other contaminants. In the past, protective sleeves and cases have been designed with no precautions against another type of environmental condition. This condition is the accumulation or generation of static charges on the removable cartridge or component. Insertion of these charged cartridges or components can disrupt operation of the host device, and in some cases, cause permanent damage to electronics. In the case of removable magnetic tape or optical media, the host drive or library operation may be temporarily or permanently affected but generally would not result in permanent data loss or corruption on the media itself. However, for more complex removable components like hard disk drives, there is the potential for this permanent data loss to occur if no attention is paid to elimination of static electricity. An actual example of protective cartridge sleeves not preventing, but actually creating, the generation of static electricity can be found with the optical media used in the IBM 3995 Optical Library Dataserver. These 5.25-inch re-writable or WORM cartridges are placed in protective sleeves when shipped or stored outside the drive or library. These sleeves are typically made from a stiff paper material with no static dissipative properties, and they tightly enclose the cartridge to minimize entry of dust and dirt. Removal by hand of the cartridge from the sleeve has been shown to impart static charges with potentials as high as 13 kilovolts (kV) on the cartridge, depending on ambient humidity and presence of oils or other contaminants due to handling of the cartridge. When a charged cartridge is inserted into the 3995 library import/export slot, a resulting electrostatic discharge (ESD) transient occurs inside the library, thus causing a disruption to the library electronics and normal operation. This solution proposed by this disclosure is a sleeve designed to control unwanted static electricity buildup and generation on removable media and components. This design utilizes the permanent treatment of sleeves with an anti-static chemical or made from anti-static materials (see list below). In addition, the protective sleeve can be designed with attributes to reduce the static charging that occurs when the media is removed. This can be accomplished by reducing the friction or sliding contact between surfaces during removal. One method to reduce sliding contact (drag) is to minimize the vacuum creating when pulling the cartridge from the sleeve. This vacuum causes the sleeve to pull-in tightly against the cartridge and results in higher drag and higher static generation. This vacuum effect can be reduced by providing ways for air to enter the sleeve only when the cartridge is removed. A solution utilizing either static-dissipative materials and/or design must reduce the charge potential measured on the cartridge to a maximum of 1 kV to minimize the likelihood of an ESD-induced error. Applicable Anti-static Materials