Abstract: A reproduction method and apparatus including a primary image forming member, and a substantially cylindrical intermediate image transfer member operatively associated with the primary image forming member whereby a marking particle image formed on the primary image forming member can be electrostatically transferred from the primary image forming member to the intermediate image transfer member (ITM). An endless web arrangement is provided in cooperative association with the ITM. The endless web arrangement includes an endless web and a plurality of support rollers about which the endless web is entrained. A transfer nip for transfer of an image to receiver member is defined between the ITM and the endless web. An electrical transfer field is provided for electrostatically transferring a marking particle image to a receiver member brought into intimate contact with the ITM in the nip.

Abstract: A method and apparatus for electrostatically transferring a toner image from a toner image bearing member (TIBM) to a receiver sheet is disclosed. A receiver sheet is moved within a nip defined between a transfer roller having a resistive outer layer and a toner image bearing member supporting a toner image. To provide for transfer, there is applied an electrical bias to the resistive layer from a conductive member located beneath the resistive layer and in electrical contact with the resistive layer. There are also applied to an outer surface of the resistive layer a first contact voltage to establish an post-nip electrical voltage distribution to a post-nip region of the transfer roller that is immediately downstream of an in-nip region. The post-nip electrical voltage distribution is accomplished by having the first contact voltage be applied at first points on the outer layer of the transfer roller, the first points being within or proximate the post-nip region.

Abstract: A corona charger for depositing an electrostatic charge on a charge retentive surface, without the creation of sheeting defects, the charger includes a coronode, and a power supply operating in cycles and providing in each of the cycles electrical power to the coronode to produce a net positive charging current with voltage to the coronode from the power supply operating in a portion of each cycle with a positive polarity to generate positive corona emissions. The power supply operates so that an AC component of the voltage provided by the power supply has a positive polarity in the range of about 60% to about 85% of each cycle. When operating in a broader range of greater than 50% but less than 100%, DC equivalent current to the coronode is controlled below a value causing sheeting.

Abstract: A method and apparatus for electrostatically transferring a toner image from a toner image bearing member to a receiver sheet is disclosed. A receiver sheet is moved within a nip defined between a transfer roller having a resistive outer layer and a toner image bearing member supporting a toner image. To provide for transfer, there is applied to the resistive layer a first contact voltage to establish a post-nip electrical voltage distribution to a post-nip region of the transfer roller that is immediately downstream of an in-nip region. The post-nip electrical bias is accomplished by having the first contact voltage be applied at first points on the outer layer of the transfer roller, the first points being within or proximate the post-nip region. There is also applied to the resistive layer a second contact voltage to establish a pre-nip electrical voltage distribution to a pre-nip region of the transfer roller immediately up-strean of the in-nip region.

Abstract: A small particle toner image is formed on a primary image member (11), such as a photoconductor; electrostatically transferred to an intermediate transfer member (22); and then electrostatically transferred to a receiving sheet. The intermediate transfer member includes a base of a relatively compliant material having an embedded coating of beads with a volume weighted average diameter of less than about 3 microns, and preferably between 0.5 and 1.0 micron. These beads cover at least 40% of the intermediate image member.

Abstract: This invention pertains to an AC charger (10) in which an AC voltage waveform applied to a corona wires (12) has a duty cycle of between 50% and 90%. This increases the efficiency of the charger without increasing the signal-to-noise ratio. In one embodiment, the AC voltage waveform is asymmetric.

Abstract: A series of single color toner images are formed on one or more image members and transferred in registry to an intermediate member to form multicolor images. A first multicolor image is transferred from the intermediate member to the first side of a copy sheet, the copy sheet is inverted and a second multicolor image is transferred to the second side of the copy sheet. Preferably, the first multicolor image is not fused prior to transfer of the second multicolor image to the copy sheet, and the two multicolor images are fused to the copy sheet simultaneously.

Abstract: Image transfer properties of an electrophotographic imaging element are improved by heterogeneously dispersing, as a separate phase within the photoconductive surface layer of the element, finely divided particles of an abhesive substance which is nonconductive and spreadable and to which toner particles adhere less strongly than to the composition of the surface layer in the abhesive substance. An example of the abhesive substance is a particulate low molecular weight telomer of tetrafluoroethylene.

Abstract: Primary charging of a moving electrographic photoconductor to a nominal potential level is achieved with low sensitivity to variation in system parameters, such as photoconductor capacitance, photoconductor velocity and/or charger efficiency. Separately-addressed, AC corona discharge units are arranged and predeterminedly biased to first substantially overcharge the photoconductor relative to the nominal potential and then discharge the photoconductor to exit at the nominal potential level.

Abstract: In-place primary charging of an electrophotographic imaging member is effected by a corona discharge device which employs variably-biased AC energization of its discharge electrode. During a charging period the potential level of the image member is detected by a sensor, and the bias level of electrode energizing source is varied from an initial value above the nominal primary charge potential toward the nominal potential in response to signals from the sensor.

Abstract: Apparatus for measuring the surface potential of moving electrostatically charged elements uses at least one electrically conducting detector mounted on the outer periphery of a grounded roller. An insulated ring secured around each end of the roller in an edge contacting relationship with the charged element under measurement provides a friction drive for the roller and maintains the detector in a spaced and non-contacting position from the charged element. As the roller is rotated, the detector is alternately exposed to the charged element and to a grounded shell arranged in a spaced and non-contacting manner from both the charged element and the roller and builds an A.C. voltage on a sampling capacitor. The output of the sampling capacitor is connected to a circuit which determines the envelope of the A.C. voltage and provides a differential D.C. voltage representative of the surface potential of the charged element. This D.C.