Abstract

A method of developing an electrostatic latent image using a developer including a mixture of electrically chargeable toner particles and high resistance magnetic carrier particles chargeable to a polarity opposite to that of the toner polarities, includes providing a developing zone where a developer carrying member for carrying the developer is opposed to an electrostatic latent image beaering member bearing the electrostatic latent image to be developed with a development clearance D, providing a layer of the developer on the developer carrying member, the developer layer having a thickness less than the clearance D, maintaining the magentic particles in the developer layer out of contact with the electrostatic latent image bearig member by magnetic field generating means disposed behind the developer carrying member, applying an external electric field in the developing zone wherein the electric field for vibrating the magnetic particles under influence of a magnetic field provided by the magnetic field generating means for intermittently contacting the magnetic particles to the latent image bearing member, and for reciprocating the toner particles in the developer layer between the latent image bearing member and the magnetic carrier particles in the developing zone to develop the electrostatic latent image.