Abstract: An apparatus in which at least a pair of developer rollers deposit toner particles on an electrostatic latent image recorded on a photoconductive member to render it visible. One of the rollers rotates at a first tangential velocity being spaced a first distance from the photoconductive member. The other roller rotates at a second tangential velocity being spaced a second distance from the photoconductive member. The second tangential velocity is greater than the first tangential velocity with the second distance being less than the first distance.

Abstract: A color process in which color copies of an original document containing color information are reproduced. Successive single color electrostatic latent images are developed with particles having a predetermined triboelectric charge thereon. These particles are transferred from the single color electrostatic latent images to a sheet of support material in a prescribed sequence. The sequence of transfer is such that each successive layer of toner particles transferred to the sheet of support material has a lesser triboelectric charge thereon than the preceeding layer transferred thereto. In this manner, back transfer from the sheet of support material to the electrostatic latent image is minimized.

Abstract: A reproduction machine having a cleaning brush mechanism for cleaning the photoreceptor surface of the machine has a detector mounted within the mechanism for sensing the presence of any transfer sheet which might accidently enter the mechanism. The cleaning brush mechanism includes a brush rotatably mounted within a housing, the preferred embodiment of the invention having a crystal pickup with a probe mounted adjacent to the periphery of the brush and adjacent to the entrance to the housing in the direction of rotation of the brush. A transfer sheet entering the housing will "accordian" or crumple, thus contacting the probe to generate a signal.

Abstract: An apparatus which develops an electrostatic latent image with electrostatically charged particles. The apparatus produces a magnetic field which forms a brush-like array of charged particles. A development electrode is operatively associated with the magnetic field to suppress the effect of local contrast enhancement.

Abstract: A device in which the quantity of particles stored in a container is monitored. The device is arranged to indicate when the supply of particles is beneath a predetermined level. A shaft member positioned in the particle storage container is rotated from a first position to a second position. When the level of particles therein is beneath the predetermined level, a magnetic torque overcomes the resistance offered by the particles to rotate the shaft from the first position to the second position indicating that additional particles should be added to the storage container.

Abstract: An apparatus in which an electrostatic latent image is developed with electrostatically charged particles. A brush-like array of charged particles is positioned closely adjacent to the electrostatic latent image. A portion of the charged particles are separated from the brush-like array thereof. The separated charged particles are moved into contact with the latent image to render it visible.The foregoing abstract is neither intended to define the invention disclosed in the specification, nor is it intended to be limiting as to the scope of the invention in any way.

Abstract: An electrophotographic printing machine and method of use therefor in which a plurality of light images of the same original document are formed. Each of the light images is of a different predetermined magnitude and irradiates a charged photoconductive member to record a plurality of electrostatic latent images thereof. The electrostatic latent images are developed with developer mixes having differing predetermined concentrations of toner particles therein. These developed powder images are transferred, in superimposed registration with one another, onto a common sheet of support material forming a high quality reproduction of the original document.

Abstract: A device in which a developability regulating apparatus employed in a multi-color electrophotographic printing machine is maintained substantially free from contaminating particles. This is achieved in the present invention by directing a substantially laminar fluid flow over the light source and photosensor used in the developability apparatus.