Abstract: Loading mechanism for a disk drive is designed to load and to center any one of several disk cartridges having various thicknesses so that the disk within the cartridge is registered in a predetermined plane of rotation. A pair of guide rails, upper and lower, is mounted at each side of the insertion path for the cartridge. The upper and lower rails are movable relative to each other and relative to the frame of the disk drive. This allows the rails to separate to receive individual diskette cartridges having different thicknesses. After a cartridge is inserted, the loading mechanism will move the cartridge to a reference position where the disk within the cartridge is in the plane of rotaiton. The separation of the guide rails controls the reference position to which the cartridge is moved.

Abstract: This invention relates to enhancing the apparent resolution of electrophotographic printers. This is accomplished by writing a gray of half-tone halo along the periphery of images written on the photoconductor. When the image with its half-tone halo is developed, transferred and fixed by steps in the electrophotographic process, the printed image has a substantially smooth contour. In effect, the gray halo placed around the image merges with the black interior of the image when the image is developed, transferred and fixed. To prevent the image from appearing to be too thick after its contour has been smoothed by the use of the half-tone halo, the number of black picture elements used to write the image on the photoconductor are reduced. Also, the width of image segments making up the image may be adjusted by changing the level of gray used to write the half-tone halo.