Abstract: An apparatus for developing a latent image recorded on a movable imaging surface, including: a reservoir for storing a supply of developer material including toner particles; a donor member being arranged to receive toner particles from the reservoir and to deliver toner particles to the image surface at locations spaced apart from each other in the direction of movement of the imaging surface thereby to develop the latent image thereon; and a humidification system, associated with the reservoir, for maintaining the supply of developer material at a predefined humidity.

Abstract: An apparatus for developing a latent image recorded on a movable imaging surface, including: a reservoir for storing a supply of developer material including toner particles; a donor member being arranged to receive toner particles from the reservoir and to deliver toner particles to the image surface at locations spaced apart from each other in the direction of movement of the imaging surface thereby to develop the latent image thereon; and a humidification system, associated with the reservoir, for maintaining the supply of developer material at a predefined humidity.

Abstract: A toner maintenance system for an electrophotographic developer unit, including a sump for storing a quantity of developer material comprised of toner material; a first member for transporting developer material from the sump, a viewing window, in communication with toner material, in the sump; an optical sensor, for measuring reflected light off the viewing window and toner material, and generating a signal indicative thereof. A toner concentration controller is adapted to receive a signal from the optical sensor and to generate an “Add Toner” signal to replenish toner material in the sump.

Abstract: A toner maintenance system for an electrophotographic developer unit, including a sump for storing a quantity of developer material a sump for storing a quantity of developer material comprised of toner material; a first member for transporting a mixture of developer material and toner particles from the sump, a viewing window, in communication with toner material, in the sump; an optical sensor, device for measuring reflected light off the viewing window and toner material, and generating a signal indicative thereof. A toner concentration controller is adapted to receive a signal from the sensor and to generate an “Add Toner” signal to replenish toner in the sump.