Miniature hard disk drive with EMI protection and single permanent magnet rotary actuator having an improved housing seal

A disk drive information storage device comprising:

• disk means for recording and reproducing information, said disk means having a diameter in the range of from about 45 mm to about 50 mm;
• a housing comprising a baseplate and a cover, said baseplate having a peripheral portion which includes a lip extending circumferentially around said peripheral portion, said lip terminating in a free edge, wherein said peripheral portion of said baseplate further includes a laterally extending ledge, said ledge defining a peripheral extent of said peripheral portion of said baseplate, and further wherein said lip is positioned within said peripheral extent of said baseplate, and wherein said cover includes a peripheral portion adapted to cooperate with the peripheral portion of said baseplate to provide an enclosure for said disk drive, wherein when said cover is positioned on said baseplate to form said enclosure a portion of said peripheral portion of said cover overlaps said lip at all locations around the periphery of said baseplate, said peripheral portion of said cover further including a free edge at the periphery thereof such that when said cover is engaged with said baseplate said free edge of said cover overlaps said free edge of said lip;
• a resilient seal positioned in contact with and interposed between a portion of said laterally extending ledge and a portion of said free edge of said cover at all locations around the peripheral portion of the baseplate when said cover is positioned on said baseplate to form said enclosure;
• a spin motor supported by said housing for rotating said disk means, said spin motor including a rotor for receiving said disk means and rotating said disk means about a first axis;
• and
• actuator means including a body portion rotatably supported on said housing for rotation about a second axis, said actuator means further including an actuator drive motor coupled to said body portion for providing rotary motion to said body portion, wherein said actuator drive motor is comprised of a coil coupled to said body portion, said coil having first and second sides, said actuator drive motor further including a single permanent magnet positioned on said first side of said coil and a flux plate having a first portion coupled to said magnet on said first side of said coil and a second portion which extends adjacent to said second side of said coil.