Abstract: A removable, sealable, magnet-less cartridge for use in a reproduction apparatus of the type having a control device to control the apparatus, a photoreceptor to receive toner through a photoreceptor path and to transfer the toner onto imaged portions of the photoreceptor, and a developer transporter of the magnetic type to carry toner in a magnetic brush to the imaged portions of the photoreceptor and to return unspent toner therefrom.

Abstract: A rotary magnetic media scanner for magnetic media player-recorders having a plurality of disk elements where each element is arranged in a simple disk configurations to facilitate manufacture. The disk elements are comprised of high magnetic permeable material and a low magnetic permeable material. The regions made of high magnetic permeable material define magnetic paths which generally have either axial or radial symmetry. Each of the elements form a portion of a complete magnetic circuit. When each of the elements are stacked together, they form a complete magnetic path operable for delivering a magnetic signal read from a tape medium to an electrical transducer and further to an amplifier circuit.

Abstract: An invention for positioning information tracks that are on a recording medium so that the scan path of a replay transducer is aligned with respect to those tracks has been discovered. The invention relieves tracking systems of the requirements of having dedicated servo heads, servo tracks, embedded servo recordings or preformatting procedures. A replay transducer "looks" for a synchronization mark on a data track to arrive at a prescribed time determined in a calibration step. The correct arrival time of the synchronization mark assures the correct positioning of the data track with respect to the scan path. Alternatively, an early or late arrival time signals an incorrect position and triggers a correction adjustment to the recording medium advancement mechanism.

Abstract: This system moves magnetic tape past the read/write head at a constant velocity by separately servo controlling the source reel motor and the take-up reel motor. Separate fine encoders are associated with each reel, each encoder providing multiple pulses for each revolution of the respective reel. Two radius calculation circuits each receive pulses from a respective one of the encoders and each calculate therefrom the radius values of tape on both of the reels. A radius information selector then selects, for use in controlling the motors, that set of radius values which is calculated by the calculation circuit which is receiving encoder pulses at the greater sampling rate. Separate servo circuits drive the two motors at respective angular velocities determined by utilizing the selected set of radius values. In each drive circuit, the associated tape radius is multiplied by the actual reel angular velocity, as indicated by the time duration between consecutive pulses from the encoder associated with that reel.