Abstract: An apparatus (100) for measuring toner concentration in a developer contained in a developer housing (10) includes a developer sample container (102) that receives a portion of developer extracted from the developer housing (10). A spectrophotometer (112) measures spectrophotometric data for the portion of the developer in the developer sample container (102). A processor (116) estimates the toner concentration based on the measured spectrophotometric data and a pre-determined relationship (118) between the spectrophotometric data and the toner concentration. A method (200) for estimating the toner concentration in a developer comprising a toner and a carrier includes measuring (220) a color characteristic of the developer, comparing (222) the measured color characteristic with a pre-determined relationship between the color characteristic and the toner concentration, and estimating (226) the toner concentration based on the comparing.

Abstract: An electrophotographic printing machine, wherein an electrostatic latent image recorded on a photoconductive member is developed to form a visible image thereof, the electrophotographic printing machine including a system, for removing contaminants from toner in a developer housing, the system including a filter system, positioned in a path of flowing developer material, the filter system having a screen for permitting developer material to travel therethrough while inhibiting contaminants from traveling therethrough when vibrated; the screen being inclined to the path of flowing developer material a vibration driver, operatively connected to the screen, for vibrating the screen.

Abstract: An electrophotographic printing machine, wherein an electrostatic latent image recorded on a photoconductive member is developed to form a visible image thereof, the electrophotographic printing machine including a system, for removing contaminants from toner in a developer housing, the system including a filter system, positioned in a path of flowing developer material, the filter system having a screen for permitting developer material to travel therethrough while inhibiting contaminants from traveling therethrough when vibrated; the screen being inclined to the path of flowing developer material a vibration driver, operatively connected to the screen, for vibrating the screen.

Abstract: An apparatus (100) for measuring toner concentration in a developer contained in a developer housing (10) includes a developer sample container(102) that receives a portion of developer extracted from the developer housing (10). A spectrophotometer (112) measures spectrophotometric data for the portion of the developer in the developer sample container (102). A processor (116) estimates the toner concentration based on the measured spectrophotometric data and a pre-determined relationship (118) between the spectrophotometric data and the toner concentration. A method (200) for estimating the toner concentration in a developer comprising a toner and a carrier includes measuring (220) a color characteristic of the developer, comparing (222) the measured color characteristic with a predetermined relationship between the color characteristic and the toner concentration, and estimating (226) the toner concentration based on the comparing.

Abstract: A toner transport apparatus for electrographic printing machines that uses the distance between a toner storage container holding a supply of toner material and a developer housing to admix the toner with the developer. A first flexible auger transports the toner from the toner storage container to the developer housing and a second flexible auger transports some of the toner and developer from the developer housing back to the toner hopper where it is mixed with fresh toner.

Abstract: A process for producing a color toner or developer composition includes selecting at least two different color toners, in the form of toner pellets, mixing the color toner pellets to form a mixture, and grinding the color toner pellets to produce a final powdered toner composition of a specific customer selectable color. The powdered color toner composition may then be mixed with additional additives and/or developer carrier particles to produce a developer composition.

Abstract: An apparatus for transporting and tracking a belt arranged to move in a predetermined path and for controlling lateral movement of the belt from the predetermined path comprises a stationary non-rotating arcuate tracking shoe with a belt defining surface for supporting a belt thereon and including vertically oriented flanges at each side of said path defining surface and extending from said path defining surface outwardly to provide belt edge guides. When driving the belt around the tracking shoe the velocity of the belt in the axial direction of the tracking shoe is zero when the belt touches an edge guide. Therefore, the friction force acting on the belt from the tracking shoe in the axial direction approaches zero, thereby helping to keep the total system force applied at the edge guide less than the minimum force necessary to produce buckling of the side of the belt.