Abstract: An improved spindle motor is provided for rotatably driving one or more memory storage disks in a computer disk drive or the like. The spindle motor comprises a stator shaft having opposite ends anchored to a disk drive housing, and a cylindrical rotor hub supported by bearings from the stator shaft for relatively high speed rotation. The stator shaft carries an armature in magnetically coupled relation with a high strength unitary permanent magnet sleeve carried by the rotor hub, with the number of armature poles and permanent magnet poles being mismatched to achieve low cogging motor operation. The memory disks have central openings therein and are mounted about the rotor hub for rotation during motor operation.

Abstract: An overlapped document detector for a document handling apparatus comprises an air knife in the primary document path to separate overlapped documents and forward them along separate ones of two secondary paths. Optical detectors focused on each secondary path, detects documents to detect an overlapped condition. A vacuum is created to maintain the documents in their respective secondary paths for detection purposes.

Abstract: As documents are moved serially past a servo motor-driven endorser, it endorses a stamp upon each. A transport signal dependent on document speed, and an endorser signal generated by an optical tachometer mounted to the servo motor, provide input to a frequency comparator. The output of the comparator is a control signal which controls the servo motor speed to adjust the endorser rotational surface velocity to equalization with the document speed. Logic circuitry sets the endorser at a zero angular position. Responsive to an endorse command, the endorser is accelerated to document speed, receives ink from a supply roller, then endorses the passing document. A counter and a digital comparator in cooperation with the tachometer signal completion of the endorsement whereupon the endorser is decelerated and placed in the zero position.