Abstract: A dry toner having Zapon Yellow 141 as a charge control agent, dispersed moderately in the toner. Zapon Yellow 141 is about 95% by weight Solvent Yellow 81 and about 5% by weight Solvent Orange 56.

Abstract: Selected points in a copier are monitored by signal lines connected to a computer. If a signal is detected on a signal line, the time of occurrence is stored in the computer's memory at a location associated with the point that caused the signal. Eventually an array of the times of operation of each monitored point will be stored. The computer then calculates the difference between the times stored for selected pairs of the monitored points and stores these, as intervals, in additional locations of the memory. The intervals are combined to give calculated statistical results (mean, deviation, etc.) each of which is then compared against predetermined values normal for correctly operating copiers also stored in the memory. The results of the comparison set error flags if the limits are exceeded indicating possible future copier failures.

Abstract: A developer material comprising toner particles and coated carrier beads for use in developing images in an electrostatographic device is disclosed. The toner particles are initially classified according to a size distribution wherein less than 15% by weight are greater than 16 microns, between 7 and 15% by weight are less than 5 microns, the remainder being from 5 to 16 microns; and wherein the median particle size by weight is from 8 to 12 microns.The carrier beads have a core with a coating thereon. The coating is a mixed resin system comprising 5 to 55% by weight polytetrafluoroethylene, 5 to 55% by weight fluorinated polyethylene-propylene, and 40% to 80% by weight of a poly(amide-imide) resin which is stable up to at least 600.degree. F., triboelectrically negative (with respect to the herein described toner), nonspalling, essentially nonfriable and dispersible with the other resin components. Also, preferably the coating includes a pigment, such as TiO.sub.2, dispersed in the resin system.

Abstract: A toner material for use in developing images in an electrostatographic device is disclosed. The toner particles are initially classified according to a size distribution wherein less than 15% by weight are greater than 16 microns, between 7 and 15% by weight are less than 5 microns the remainder being from 5 to 16 microns and wherein the median particle size by weight is from 8 to 12 microns. The toner is used in a developer mix with carrier particles, and preferably the toner carrier mix is equilibrated such that the action of the developer mix and the machine provide a toner particle size distribution wherein less than 12% by weight are greater than 16 microns, between 15 and 30% by weight are less than 5 microns, the remainder being from 5 to 16 microns, and wherein the median particle size by weight is between 6.5 and 9.5 microns. An equilibrated toner particle distribution is also disclosed.

Abstract: A magnetic-brush developer for use in an electrophotographic machine wherein the magnetic brush is used to transport toner-coated carrier particles to an elevated development zone from a pickup zone. A path for so moving the carrier is provided between the magnetic brush roll and an overflow plate, the lower end of which also serves as a doctoring blade. The carrier is moved to the top of the roll where a doctoring blade limits the amount of carrier entering the development zone. Excess carrier is accumulated in an expanded spatial area near the doctoring blade and returned to the vicinity of the pickup zone by falling back between the overflow plate and the housing. An area is provided near the doctoring blade at the top of the roll where no magnetic field is present. The overflow plate is made of non-magnetic material.

Abstract: An auger fed magnetic brush developer wherein two parallel augers continuously recirculate the developer mix and cause the mix to be enriched with toner prior to its being returned to the magnetic brush roll.A supply auger communicates with the brush roll along its entire length and directly elevates the mix to a lower part of the brush roll's surface. This supply auger includes four flutes of a pitch equal to one-half the length of the brush roll. This auger flute arrangement insures that a uniform supply of mix is presented to the brush roll along its entire length. In addition, this supply auger construction insures that a uniform supply of enriched mix is presented to the brush roll along its entire length, since the gradually depleting carrier tends to be presented to the brush roll a minimum number of times, for example three, prior to its exiting one end of the supply auger.The carrier exiting the supply auger enters a turnaround compartment whereat new toner is added.