Development process and apparatus

Claim 1

An improved process for causing the development of electrostatic latent images on an imaging member, comprising providing a development zone ranging in length of from about 0.5 centimeters to about 5 centimeters, which development zone is encompassed by a tensioned deflected flexible imaging member and a transporting member wherein the flexible imaging member is comprised of a supporting substrate, a photogenerating layer, and a transport layer comprised of electrically active diamine molecules dispersed in an inactive resinous binder, the diamine molecules being of the formula ##STR1## wherein X is selected from the group consisting of (ortho) CH 3 , (meta) CH 3 , (para) CH 3 , (ortho) C1, (meta) C1, (para) C1, causing the deflected flexible imaging member to move at a speed of from about 5 cm/sec to about 50 cm/sec, causing the transporting member to move at a speed of from about 6 cm/sec to about 100 cm/sec, said deflected flexible imaging member and said transporting member moving at different speeds, the ratio of the velocity of the transporting member to the flexible imaging member being greater than zero and less than 1 with the development time ranging from 0.83 seconds to about 5·10 3 seconds, maintaining a distance between the flexible imaging member and the transporting member of from about 0.05 millimeters to about 1.5 millimeters, adding insulating developer particles to the development zone, which particles are comprised of electrically insulating toner particles, and electrically insulating magnetic carrier particles, the flexible imaging member being deflected by the electrically insulating developer particles, wherein the deflection of the flexible imaging member caused by the insulating developer particles contained in the development zone is in the form of an arc of from about 10° to about 50°, contained in the development zone, introducing a high electric field in the development zone, wherein the developer particles contained in the development zone are agitated, and the insulating toner particles migrate from one layer of carrier particles to another layer of carrier particles in the development zone, the carrier particles rotating in one direction and subsequently in another direction, whereby toner particles are continuously made available immediately adjacent the deflected flexible imaging member, said process being accomplished in the absence of a magnetic field.