Roller transfer apparatus

DETAILED DESCRIPTION This invention is directed to a transfer roller apparatus for use for example in an electrographic copier including a dielectric member adapted to carry electrostatically developed marking particle images, and the mechanism for applying an electrical bias thereto.
The transfer roller apparatus, employing a mechanism for accurately locating a receiver member on the periphery of the roller, includes a cylindrical roller, including a coaxial conductive core, mounted for rotation about its longitudinal axis and located such that its peripheral surface is in operative relation with the dielectric member.
An electrical bias is applied to the roller to establish a transfer field between the roller and the dielectric member to effect transfer of marking particle images from the dielectric member to a receiver member accurately located on the peripheral surface of the roller.
The bias is applied by connecting an electrical potential source to the roller through the conductive core.
A discontinuity in the transfer field is created in the area of the roller surface over which locating and tacking of a receiver member are effected.
The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiments presented below.