Abstract:
A cleaning station for removing toner and particulates from a fusing member has first and second cleaning rollers rollingly engaging the fusing member. Each cleaning roller has a roller surface coated with a layer of tacky toner. Each roller further defines an internal receiver for collecting excess toner and particulates, and has an aperture forming a fluid passage between the reservoir and the surface of the roller. A synchronization assembly synchronizes the rotation of the rollers so the second cleaning roller cleans the portions of the fusing member uncleaned by the first cleaning roller due to the aperture in the surface of the first cleaning roller.

Description:
FIELD OF THE INVENTION 
     This invention relates to cleaning systems for electrostatographic printing machines, and more particularly this invention relates to a cleaning station engaging the fusing member of a printing machine. 
     BACKGROUND TO THE INVENTION 
     Electrostatic printers are known in which a toner image is fused or fixed to a substrate to form a final document. The fusing can occur after transfer of the toner image to the substrate, or transfer and fusing simultaneously occur in a transfuse process. In either arrangement the substrate is fed into a fusing nip where a combination of fusing members, such as fusing or transfuse belts or rollers, apply heat and pressure to the toner image and substrate to fix or fuse the toner image to the substrate. During the fusing process, toner particles from the toner image and debris from the substrate can adhere to the fusing member. These toner particles and other debris, contaminants, can transfer from the fusing member to subsequent documents resulting in print defects. In addition, build up of toner particles on the fusing member can degrade the quality of fusing of the toner image on subsequent documents. The build up of toner particles can also decrease the operational life of the fusing member. 
     Therefore it is preferred to clean the fusing members to remove toner particles and other particulate debris, such as dirt and fiber, that effect final print quality. 
     One prior cleaner employed a cleaning roller engaging the surface of a fuser roll to remove toner particles. Toner particles preferentially adhered to the cleaner roller. However, as excess toner particles accumulate on the cleaner roller, the toner layer on the surface of the cleaner roller can become uneven, resulting in uneven cleaning of the fusing member. The toner layer on the cleaner roller can become excessively thick, requiring maintenance to remove the excess toner of the toner layer. 
     In one alternative assembly, the cleaner roller is formed of a hollow cylinder and apertures are provided in the cylinder to permit excess toner to be driven inward through the openings. Excess toner therefore is collected on the inside of the cylinder, extending the period between servicing or the life of the cleaner roller. However, the openings can result in gaps in the cleaning surface of the roller, requiring multiple cycles to the fusing member to completely clean the surface of the fusing member by the cleaner roller. Therefore toner particles on the fusing member can continue to disrupt fusing, or be transferred to subsequent documents, before their removal. 
     SUMMARY OF THE INVENTION 
     Briefly stated, a cleaner station in accordance with the invention has a carousel or turret supporting a plurality of cleaner roller assemblies cleaningly engageable to a fusing member. The carousel is indexed to in turn position each cleaner roller assembly in contact with the fusing member for cleaning. Each cleaner roller assembly cleans the surface of the fusing member for a preestablished operational period, for example a preestablished number of pages. At termination of the preestablished operational period, the used cleaner roller assembly is moved out of engagement with the fusing member and a second cleaner roller assembly is brought into cleaning engagement with the fusing member. In a first embodiment, each cleaner roller assembly is formed of a continuous surface or solid surface cleaner roller rotatably mounted to the carousel. The cleaner roller in contact with the fusing member is heated within the tacky range of the toner employed in the printing apparatus. Toner particles and other particulates such as dirt and fiber adhere to the tacky toner layer formed on the cleaner roller and are thereby cleaner from the fusing member. The use of a solid surface cleaning roller allows for effective single pass cleaning of the fusing member. 
     In a further embodiment of a cleaning station in accordance with the invention, each cleaner roll assembly has a perforated cleaner roller. Each cleaner roller defines an internal reservoir. The cleaner roller in contact with the fusing member is heated within the tacky range of the toner employed in the printing apparatus. Toner particles and other particulates such as dirt and fiber adhere to the tacky toner layer and are thereby cleaned from the fusing member. Excess toner collected on the cleaner roller is forced into the reservoir to thereby extend the operational life of the perforated cleaner roller. 
     In a still further embodiment each cleaning assembly has a pair of rotatably mounted cleaning rollers. The first cleaning roller in the process direction of the fusing member is a perforated cleaner roller. The second cleaner roller has a solid surface and is positioned down stream in the process direction from the first cleaning roller. The cleaner roller in contact with the fusing member is heated within the tacky range of the toner employed in the printing apparatus. Toner particles and other particulates such as dirt and fiber adhere to the tacky toner layer and are thereby cleaned from the fusing member. The use of at least one solid surface cleaner roller allows for effective single pass cleaning of the fusing member. 
     The cleaner station in accordance with the invention is described in combination with a fusing member formed of a transfuse belt. The cleaner station is additionally applicable with other fusing members, such as transfuse rollers, fuser rollers and fuser belts. Single pass cleaning is particularly important for transfuse systems where toner images are cyclically transferred to and from the transfuse member, increasing the potential of stray toner particles adhering to the fusing member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic side view of a duplex cut sheet electrostatographic printer having a cleaning station in accordance with the invention; 
     FIG. 2 is an enlarged schematic side view of the transfer nips of the printer of FIG. 1; 
     FIG. 3 is an enlarged cross-sectional schematic site view of the cleaning station of FIG. 2; 
     FIG. 4 is an enlarged schematic view of the cleaner roller assembly of the cleaning station  58 ; 
     FIG. 5 is an enlarged schematic view of an alternate embodiment of the cleaner roller assembly of FIG. 3; 
     FIG. 6 is an enlarged schematic view of an additional alternate embodiment of the cleaner roller assembly of FIG. 3; 
     FIG. 7 is a graphical representation of residual toner as a function of transfuse member temperature; and 
     FIG. 8 is a graphical representation of crease as a function of transfuse member temperature for given representation of substrate temperature. 
     FIG. 9 is a side elevational view of one embodiment of the synchronizing mechansim of the invention herein; 
     FIG. 10 is a side elevational view of a second embodiment of the synchronizing mechanism of the invention herein; 
     FIG. 11 is an end view of a cleaning roll illustrating the spiral cut aperture connecting the surface of the roll with the interior chamber. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1 and 2, a multi-color cut sheet duplex electrostatographic printer  10  has an intermediate transfer belt  12 . The intermediate transfer belt  12  is driven over guide rollers  14 ,  16 ,  18 , and  20 . The intermediate transfer belt  12  moves in a process direction shown by the arrow A. For purposes of discussion, the intermediate transfer member  12  defines a single section of the intermediate transfer member  12  as a toner area. A toner area is that part of the intermediate transfer member which receives the various processes by the stations positioned around the intermediate transfer member  12 . The intermediate transfer member  12  may have multiple toner areas; however, each toner area is processed in the same way. 
     The toner area is moved past a set of four toner image producing stations  22 ,  24 ,  26 , and  28 . Each toner image producing station  22 ,  24 ,  26 ,  28  operates to place a color toner image on the toner image of the intermediate transfer member  12 . Each toner image producing station  22 ,  24 ,  26 ,  28  operates in the same manner to form developed toner image for transfer to the intermediate transfer member  12 . 
     The image producing stations  22 ,  24 ,  26 ,  28  are described in terms of a photoreceptive system, but it is readily recognized by those of skilled in the art that ionographic systems and other marking systems can readily be employed to form developed toner images. Each toner image producing station  22 ,  24 ,  26 ,  28  has an image bearing member  30 . The image bearing member  30  is a drum or belt supporting a photoreceptor. 
     The image bearing member  30  is uniformly charged at a charging station  32 . The charging station is of well-known construction, having charge generation devices such as corotrons or scorotrons for distribution of an even charge on the surface of the image bearing member  30 . An exposure station  34  exposes the charged image bearing member  30  in an image-wise fashion to form an electrostatic latent image at the image area. For purposes of discussion, the image bearing member defines an image area. The image area is that part of the image bearing member which receives the various processes by the stations positioned around the image bearing member  30 . The image bearing member  30  may have multiple image areas; however, each image area is processed in the same way. 
     The exposure station  34  preferably has a laser emitting a modulated laser beam. The exposure station  34  raster scans the modulated laser beam onto the charged image area. The exposure station  34  can alternately employ LED arrays or other arrangements known in the art to generate a light image representation that is projected onto the image area of the image bearing member  30 . The exposure station  34  exposes a light image representation of one color component of a composite color image onto the image area to form a first electrostatic latent image. Each of the toner image producing stations  22 ,  24 ,  26 ,  28  will form an electrostatic latent image corresponding to a particular color component of a composite color image. 
     The image area is advanced to a development station  36 . The developer station  36  has a developer corresponding to the color component of the composite color image. Typically, therefore, individual toner image producing stations  22 ,  24 ,  26 , and  28  will individually develop the cyan, magenta, yellow, and black that make up a typical composite color image. Additional toner image producing stations can be provided for additional or alternate colors including highlight colors or other custom colors. Therefore, each of the toner image producing stations  22 ,  24 ,  26 ,  28  develops a component toner image for transfer to the toner area of the intermediate transfer member  12 . The developer station  36  preferably develops the latent image with a charged dry toner powder to form the developed component toner image. The developer can employ a magnetic toner brush or other well known development arrangements. 
     The image area having the component toner image then advances to the pretransfer station  38 . The pretransfer station  38  preferably has a pretransfer charging device to charge the component toner image and to achieve some leveling of the surface voltage above the image bearing member  30  to improve transfer of the component image from the image bearing member  30  to the intermediate transfer member  12 . Alternatively the pretransfer station  30  can use a pretransfer light to level the surface voltage above the image bearing member  30 . Furthermore, this can be used in cooperation with a pretransfer charging device. The image area then advances to a first transfer nip defined between the image bearing member  30  and the intermediate transfer member  12 . The image bearing member  30  and intermediate transfer member  12  are synchronized such that each has substantially the same linear velocity at the first transfer nip  40 . The component toner image is electrostatically transferred from the image bearing member  30  to the intermediate transfer member  12  by use of a field generation station  42 . The field generation station  42  is preferably a bias roller that is electrically biased to create sufficient electrostatic fields of a polarity opposite that of the component toner image to thereby transfer the component toner image to the intermediate transfer member  12 . Alternatively the field generation station  42  can be a corona device or other various types of field generation systems known in the art. A prenip transfer blade  44  mechanically biases the intermediate transfer member  12  against the image bearing member  30  for improved transfer of the component toner image. The toner area of the intermediate transfer member  12  having the component toner image from the toner image producing station  22  then advances in the process direction. 
     After transfer of the component toner image, the image bearing member  30  then continues to move the image area past a preclean station  39 . The preclean station employs a pre clean corotron to condition the toner charge and the charge of the image bearing member  30  to enable improved cleaning of the image area. The image area then further advances to a cleaning station  41 . The cleaning station  41  removes the residual toner or debris from the image area. The cleaning station  41  preferably has blades to wipe the residual toner particles from the image area. Alternately the cleaning station  41  can employ an electrostatic brush cleaner or other well know cleaning systems. The operation of the cleaning station  41  completes the toner image production for each of the toner image producing stations  22 ,  24 ,  26 , and  28 . 
     The first component toner image is advanced at the image area from the first transfer nip  40  of the image producing station  22  to the first transfer nip  40  of the toner image producing station  24 . Prior to entrance of the first transfer nip  40  of the toner image producing station  24  an image conditioning station  46  uniformly charges the component toner image to reduce stray, low or oppositely charged toner that would result in back transfer of some of the first component toner image to the subsequent toner image producing station  24 . The image conditioning stations, in particular the image conditioning station prior to the first toner image producing station  22  also conditions the surface charge on the intermediate transfer member  12 . At each first transfer nip  40 , the subsequent component toner image is registered to the prior component toner images to form a composite toner image after transfer of the final toner image by the toner image producing station  28 . 
     The geometry of the interface of the intermediate transfer member  12  with the image bearing member  30  has an important role in assuring good transfer of the component toner image. The intermediate transfer member  12  should contact the surface of the image bearing member  30  prior to the region of electrostatic field generation by the field generation station  42 , preferably with some amount of pressure to insure intimate contact. Generally, some amount of pre-nip wrap of the intermediate transfer member  12  against the image bearing member  30  is preferred. Alternatively, the pre-nip pressure blade  44  or other mechanical biasing structure can be provided to create such intimate pre-nip contact. This contact is an important factor in reducing high electrostatic fields from forming at air gaps between the intermediate transfer member  12  and the component toner image in the pre-nip region. For example, with a corotron as the field generation station  42 , the intermediate transfer member  12  should preferably contact the toner image in the pre-nip region sufficiently prior to the start of the corona beam profile. With a field generation station  42  of a bias charging roller, the intermediate transfer member  12  should preferably contact the toner image in the pre-nip region sufficiently prior to the contact nip of the bias charging roller. “Sufficiently prior” for any field generation device can be taken to mean prior to the region of the pre-nip where the field in any air gap greater than about 50 μm between the intermediate transfer member  12  and the component toner image has dropped below about 4 volts/micron due to falloff of the field with pre-nip distance from the first transfer nip  40 . The falloff of the field is partly due to capacitance effects and this will depend on various factors. For example, with a bias roller this falloff with distance will be slowest with larger diameter bias rollers, and/or with higher resistivity bias rollers, and/or if the capacitance per area of the insulating layers in the first transfer nip  40  is lowest. Lateral conduction along the intermediate transfer member  12  can even further extend the transfer field region in the pre-nip, depending on the transfer belt resistivity and other physical factors. Using intermediate transfer members  12  having resistivity nearer the lower end of the preferred range discussed below and/or systems that use large bias rollers, etc., preference is larger pre-nip contact distances. Generally the desired pre-nip contact is between about 2 to 10 mm for resistivities within the desired range and with bias roller diameters between about 12 mm and 50 mm. 
     The field generation station  42  will preferentially use very conformable bias rollers for the first transfer nips  40  such as foam or other roller materials having an effectively very low durometer ideally less than about 30 Shore A. In systems that use belts for the imaging modules, optionally the first transfer nip  40  can include acoustic loosening of the component toner image to assist transfer. 
     In the preferred arrangement, “slip transfer” is employed for registration of the color image. For slip transfer, the contact zone between the intermediate transfer member  12  and the image bearing member  30  will preferably be minimized subject to the pre-nip restrictions. The post transfer contact zone past the field generation station  42  is preferentially small for this arrangement. Generally, the intermediate transfer member  12  can optionally separate along the preferred bias roller of the field generation station  42  in the post nip region if an appropriate structure is provided to insure that the bias roller does not lift off the surface of the image bearing member due to the tension forces of the intermediate transfer member  12 . For slip transfer systems, the pressure of the bias roller employed in the field generation station  42  should be minimized. Minimized contact zone and pressure minimizes the frictional force acting on the image bearing member  30  and this minimizes elastic stretch issues of the intermediate transfer member  12  between first transfer nips  40  that can degrade color registration. It will also minimize motion interactions between the drive of the intermediate transfer member  12  and the drive of the image bearing member  30 . 
     For slip transfer systems, the resistivity of the intermediate transfer member  12  should also be chosen to be high, generally within or even toward the middle to upper limits of the most preferred range discussed later, so that the required pre-nip contact distances can be minimized. In addition, the coefficient of friction of the top surface material on the intermediate transfer member should preferentially be minimized to increase operating latitude for the slip transfer registration and motion quality approach. 
     In an alternate embodiment the image bearing members  30 , such as photoconductor drums, do not have separate drives and instead are driven by the friction in the first transfer nips  40 . In other words, the image bearing members  30  are driven by the intermediate transfer member  12 . Therefore, the first transfer nip  40  imparts sufficient frictional force on the image bearing member to overcome any drag created by the development station  36 , cleaner station  41 , additional subsystems and by bearing loads. For a friction driven image bearing member  30 , the optimum transfer design considerations are generally opposite to the slip transfer case. For example, the lead in of the intermediate transfer member  12  to the first transfer zone preferentially can be large to maximize the friction force due to the tension of the intermediate transfer member  12 . In the post transfer zone, the intermediate transfer member  12  is wrapped along the image bearing member  30  to further increase the contact zone and to therefore increase the frictional drive. Increased post-nip wrap has a larger benefit than increased pre-nip wrap because there will be increased pressure there due to electrostatic tacking forces. As another example, the pressure applied by the field generation device  42  can further increase the frictional force. Finally for such systems, the coefficient of friction of the material of the top most layer on the intermediate transfer member  12  should preferentially be higher to increase operating latitude. 
     The toner area then is moved to the subsequent first transfer nip  40 . Between toner image producing stations are the image conditioning stations  46 . The charge transfer in the first transfer nip  40  is normally at least partly due to air breakdown, and this can result in non uniform charge patterns on the intermediate transfer member  12  between the toner image producing stations  22 ,  24 ,  26 ,  28 . As discussed later, the intermediate transfer member  12  can optionally include insulating topmost layers, and in this case non uniform charge will result in non uniform applied fields in the subsequent first transfer nips  40 . The effect accumulates as the intermediate transfer member  12  proceeds through the subsequent first transfer nips  40 . The image conditioning stations  46  “level” the charge patterns on the belt between the toner image producing stations  22 ,  24 ,  26 ,  28  to improve the uniformity of the charge patterns on the intermediate transfer member  12  prior to subsequent first transfer nips  40 . The image conditioning stations  46  are preferably scorotrons and alternatively can be various types of corona devices. As previously discussed, the charge conditioning stations  46  additionally are employed for conditioning the toner charge to prevent retransfer of the toner to the subsequent toner image producing stations. The need for image conditioning stations  46  is reduced if the intermediate transfer member  12  consists only of semiconductive layers that are within the desired resistivity range discussed later. As further discussed later, even if the intermediate transfer member  12  includes insulating layers, the need for image conditioning stations  46  between the toner image producing stations  22 ,  24 ,  26 ,  28  is reduced if such insulating layers are sufficiently thin. 
     The guide roller  14  is preferably adjustable for tensioning the intermediate transfer member  12 . Additionally, the guide roller  14  can, in combination with a sensor sensing the edge of the intermediate transfer member  12 , provide active steering of the intermediate transfer member  12  to reduce transverse wander of the intermediate transfer member  12  that would degrade registration of the component toner images to form the composite toner image. 
     Each toner image producing station positions component toner image on the toner area of the intermediate transfer member  12  to form a completed composite toner image. The intermediate transfer member  12  transports the composite toner image from the last toner image producing station  28  to pre-transfer charge conditioning station  52 . When the intermediate transfer member  12  includes at least one insulating layer, the pretransfer charge conditioning station  52  levels the charge at the toner area of the intermediate transfer member  12 . In addition the pre-transfer charge conditioning station  52  is employed to condition the toner charge for transfer to a transfuse member  50 . It preferably is a scorotron and alternatively can be various types of corona devices. A second transfer nip  48  is defined between the intermediate transfer member  12  and the transfuse member  50 . A field generation station  42  and pre-transfer nip blade  44  engage the intermediate transfer member  12  adjacent the second transfer nip  48  and perform the same functions as the field generation stations and pre-transfer blades  44  adjacent the first transfer nips  40 . However the field generation station at the second transfer nip  48  can be relatively harder to engage conformable transfuse members  50 . The composite toner image is transferred electrostatically and with heat assist to the transfuse member  50 . 
     The electrical, characteristics of the intermediate transfer member  12  are also important. The intermediate transfer member  12  can optionally be constructed of a single layer or multiple layers. In any case, preferably the electrical properties of the intermediate transfer member  12  are selected to reduce high voltage drops across the intermediate transfer member. To reduce high voltage drops, the resistivity of the back layer of the intermediate transfer member  12  preferably has sufficiently low resistivity. The electrical characteristics and the transfer geometry must also be chosen to prevent high electrostatic transfer fields in pre-nip regions of the first and second transfer nips  40 ,  48 . High pre-nip fields at air gaps of around typically &gt;50 microns between the component toner images and the intermediate transfer member  12  can lead to image distortion due to toner transfer across an air gap and can also lead to image defects caused by pre-nip air breakdown. This can be avoided by bringing the intermediate transfer member  12  into early contact with the component toner image prior to the field generating station  42 , as long as the resistivity of any of the layers of the intermediate transfer member  12  are sufficiently high. The intermediate transfer member  12  also should have sufficiently high resistivity for the topmost layer to prevent very high current flow from occurring in the first and second transfer nips  40 ,  48 . Finally, the intermediate transfer member  12  and the system design needs to minimize the effect of high and/or non-uniform charge buildup that can occur on the intermediate transfer member  12  between the first transfer nips  40 . 
     The preferable material for a single layer intermediate transfer member  12  is a semiconductive material having a “charge relaxation time” that is comparable to or less than the dwell time between toner image producing stations, and more preferred is a material having a “nip relaxation time” comparable or less than the transfer nip dwell time. As used here, “relaxation time” is the characteristic time for the voltage drop across the thickness of the layer of the intermediate transfer member to decay. The dwell time is the time that an elemental section of the transfer member  12  spends moving through a given region. For example, the dwell time between imaging stations  22  and  24  is the distance between imaging stations  22  and  24 , divided by the process speed of the transfer member  12 . The transfer nip dwell time is the width of the contact nip created during the influence of the field generation station  42 , divided by the process speed of the transfer member  12 . 
     The “charge relaxation time” is the relaxation time when the intermediate transfer member is substantially isolated from the influence of the capacitance of other members within the transfer nips  40 . Generally the charge relaxation time applies for regions prior to or past the transfer nips  40 . It is the classic “RC time constant”, that is ρkε o , the product of the material layer quantities dielectric constant k times resistivity ρ times the permitivity of vacuum ε o . In general the resistivity of a material can be sensitive to the applied field in the material. In this case, the resistivity should be determined at an applied field corresponding to about 25 to 100 volts across the layer thickness. The “nip relaxation time” is the relaxation time within regions such as the transfer nips  40 . If  42  is a corona field generation device, the “nip relaxation time” is substantially the same as the charge relaxation time. However, if a bias transfer device is used, the nip relaxation time is generally longer than the charge relaxation time. This is because it is influenced not only by the capacitance of the intermediate transfer member  12  itself, but it is also influenced by the extra capacitance per unit area of any insulating layers that are present within the transfer nips  40 . For example, the capacitance per unit area of the photoconductor coating on the image bearing member  30  and the capacitance per unit area of the toner image influence the nip relaxation time. For discussion, C L  represents the capacitance per unit area of the layer of the intermediate transfer member  12  and C tot  represents the total capacitance per unit area of all insulating layers in the first transfer nips  40 , other than the intermediate transfer member  12 . When the field generation station  42  is a bias roller, the nip relaxation time is the charge relaxation time multiplied by the quantity [1+(C tot /C L )]. 
     The range of resistivity conditions defined in the above discussion avoid high voltage drops across the intermediate transfer member  12  during the transfers of the component toner images at the first transfer nips  40 . To avoid high pre-nip fields, the volume resistivity in the lateral or process direction of the intermediate transfer member must not be too low. The requirement is that the lateral relaxation time for charge flow between the field generation station  42  in the first transfer nip  40  should be larger than the lead in dwell time for the first transfer nip  40 . The lead in dwell time is the quantity L/v. L is the distance from the pre-nip region of initial contact of the intermediate transfer member  12  with the component toner image, to the position of the start of the field generation station  42  within the first transfer nip  40 . The quantity v is the process speed. The lateral relaxation time is proportional to the lateral resistance along the belt between the field generating station  42  and the pre-nip region of initial contact, and the total capacitance per area C tot  of the insulating layers in the first transfer nip  40  between the intermediate transfer member  12  and the substrate of the image bearing member  30  of the toner image producing station  22 ,  24 ,  26 ,  28 . A useful expression for estimating the preferred resistivity range that avoids undesirable high pre-nip fields near the field generation stations  42  is: [ρ L VLC tot ]&gt;1. The quantity is referred to as the “lateral resistivity” of the intermediate transfer member  12 . It is the volume resistivity of the member divided by the thickness of the member. In cases where the electrical properties of the member  12  is not isotropic, the volume resistivity of interest for avoiding high pre-nip fields is that resistivity of the layer in the process direction. Also, in cases where the resistivity depends on the applied field, the lateral resistivity should be determined at a field of between about 500 to 1500 volts/cm. 
     Thus the preferred range of resistivity for the single layer intermediate transfer member  12  depends on many factors such as for example the system geometry, the transfer member thickness, the process speed, and the capacitance per unit area of the various materials in the first transfer nip  40 . For a wide range of typical system geometry and process speeds the preferred resistivity for a single layer transfer belt is typically a volume resistivity less than about 10 13  ohm-cm and a more preferred range is typically &lt;10 11  ohm-cm volume resistivity. The lower limit of preferred resistivity is typically a lateral resistivity above about 10 8  ohms/square and more preferred is typically a lateral resistivity above about 10 10  ohms/square. As an example, with a typical intermediate transfer member  12  thickness of around 0.01 cm, a lateral resistivity greater than 10 10  ohms/square corresponds to a volume resistivity of greater than 10 8  ohm-cm. 
     Discussion below will specify the preferred range of electrical properties for the transfuse member  50  to allow good transfer in the second transfer nip  48 . The transfuse member  50  will preferably have multiple layers and the electrical properties chosen for the topmost layer of the transfuse member  50  will influence the preferred resistivity for the single layer intermediate transfer member  12 . The lower limits for the preferred resistivity of the single layer intermediate transfer member  12  referred to above apply if the top most surface layer of the transfuse member  50  has a sufficiently high resistivity, typically equal to or above about 10 9  ohm-cm. If the top most surface layer of the transfuse member  50  has a somewhat lower resistivity than about 10 9  ohm-cm, the lower limit for the preferred resistivity of the single layer intermediate transfer member  12  should be increased in order to avoid transfer problems in the second transfer nip  48 . Such problems include undesirably high current flow between the intermediate transfer member  12  and the transfuse member  50 , and transfer degradation due to reduction of the transfer field. In the case where the resistivity of the top most layer of the transfuse member  50  is less than about 10 9  ohm-cm, the preferred lower limit volume resistivity for the single layer intermediate transfer member  12  will typically be around greater than or equal to 10 9  ohm-cm. 
     In addition, the intermediate transfer member  12  should have sufficient lateral stiffness to avoid registration issues between toner image producing stations  22 ,  24 ,  26 ,  28  due to elastic stretch. Stiffness is the sum of the products of Young&#39;s modulus times the layer thickness for all of the layers of the intermediate transfer member. The preferred range for the stiffness depends on various systems parameters. The required value of the stiffness increases with increasing amount of frictional drag at and/or between the toner image producing stations  22 ,  24 ,  26 ,  28 . The preferred stiffness also increases with increasing length of the intermediate transfer member  12  between toner image producing stations, and with increasing color registration requirements. The stiffness is preferably &gt;800 PSI-inches and more preferably &gt;2000 PSI-inches. 
     A preferred material for the single layer intermediate transfer member  12  is a polyamide that achieve good electrical control via conductivity controlling additives. 
     The intermediate transfer member  12  may also optionally be multi-layered. The back layer, opposite the toner area, will preferably be semi-conductive in the discussed range. The preferred materials for the back layer of a multi-layered intermediate transfer member  12  are the same as that discussed for the single layer intermediate belt  12 . Within limits, the top layers can optionally be “insulating” or semiconductive. There are certain advantages and disadvantages of either. 
     A layer on the intermediate transfer member  12  can be thought of as behaving “insulating” for the purposes of discussion here if the relaxation time for charge flow is much longer than the dwell time of interest. For example, a layer behaves “insulating” during the dwell time in the first transfer nip  40  if the nip relaxation time of that layer in the first transfer nip  40  is much longer than the time that a section of the layer spends in traveling through the first transfer nip  40 . A layer behaves insulating between toner image producing stations  22 ,  24 ,  26 ,  28  if the charge relaxation time for that layer is much longer than the dwell time that a section of the layer takes to travel between the toner image producing stations. On the other hand, a layer behaves semiconducting in the sense meant here when the relaxation times are comparable or lower than the appropriate dwell times. For example, a layer behaves semi conductive during the dwell time of the first transfer nip  40  when the nip relaxation time is less than the dwell time in the first transfer nip  40 . Furthermore, a layer on the intermediate transfer member  12  behaves semiconductive during the dwell time between toner image producing stations  22 ,  24 ,  26 ,  28  if the relaxation time of the layer is less than the dwell time between toner image producing stations. The expressions for determining the relaxation times of any top layer on the intermediate transfer member  12  are substantially the same as those described previously for the single layer intermediate transfer member. Thus whether or not a layer on the multilayered intermediate transfer member  12  behaves “insulating” or “semiconducting” during a particular dwell time of interest depends not only on the electrical properties of the layer but also on the process speed, the system geometry, and the layer thickness. 
     A layer of the transfer belt will typically behave “insulating” in most transfer systems if the volume resistivity is generally greater than about 10 13  ohm-cm. Insulating top layers on the intermediate transfer member  12  cause a voltage drop across the layer and thus reduce the voltage drop across the composite toner layer in the first transfer nip  40 . Therefore, the presence of insulating layers requires higher applied voltages in the first and second transfer nips  40 ,  48  to create the same electrostatic fields operating on the charged composite toner image. The voltage requirement is mainly driven by the “dielectric thickness” of such insulating layers, which is the actual thickness of a layer divided by the dielectric constant of that layer. One potential disadvantage of an insulating layer is that undesirably very high voltages will be required on the intermediate transfer member  12  for good electrostatic transfer of the component toner image if the sum of the dielectric thickness of the insulating layers on the intermediate transfer member  12  is too high. This is especially true in color imaging systems with layers that behave “insulating” over the dwell time longer than one revolution of the intermediate transfer member  12 . Charge will build up on such insulating top layers due to charge transfer in each of the field generation stations  42 . This charge buildup requires higher voltage on the back of the intermediate transfer member  12  in the subsequent field generation stations  42  to achieve good transfer of the subsequent component toner images. This charge can not be fully neutralized between first transfer nips  40  with image conditioning station  46  corona devices without also causing undesirable neutralization or even reversal of the charge of the transferred composite toner image on the intermediate transfer member  12 . Therefore, to avoid the need for unacceptably high voltages on the back of the intermediate transfer member  12 , the total dielectric thickness of such insulating top layers on the intermediate transfer member  12  should preferably be kept small for good and stable transfer performance. An acceptable total dielectric thickness can be as high as about 50 μm and a preferred value is &lt;10 μm. 
     The optimal top most layer of the intermediate transfer member  12  preferably has good toner releasing properties such as low surface energy, and preferably has low affinity to oils such as silicone oils. Materials such as PFA, TEFLON™, and various flouropolymers are examples of desirable overcoating materials having good toner release properties. One advantage of an insulating coating over the semiconductive backing layer of the intermediate transfer member  12  is that such materials with good toner releasing properties are more readily available if the constraint of needing them to also be semiconductive is removed. Another potential advantage of high resistivity coatings applies to embodiments that wish to use a transfuse member  50  having a low resistivity top most layer, such as &lt;&lt;10 9  ohm-cm. As discussed, the resistivity for the intermediate transfer member  12  of a single layer is preferably limited to typically around &gt;10 9  ohm-cm to avoid transfer problems in the second transfer nip  48  if the resistivity of the top most layer of the transfuse member  50  is lower than about 10 9  ohm-cm. For a multiple layer intermediate transfer member  12 , having a sufficiently high resistivity top most layer, preferably &gt;10 9  ohm-cm, the resistivity of the back layer can be lower. 
     Semiconductive coatings on the intermediate transfer member  12  are advantaged in that they do not require charge leveling to level the charge on the intermediate transfer member  12  prior to and between toner image producing stations  22 ,  24 ,  26 ,  28 . Semiconductive coatings on the intermediate transfer member are also advantaged in that much thicker top layers can be allowed compared to insulating coatings. The charge relaxation conditions and the corresponding ranges of resistivity conditions needed to enable such advantages are similar to that already discussed for the back layer. Generally, the semiconductive regime of interest is a resistivity such that the charge relaxation time is smaller than the dwell time spent between toner image producing stations  22 ,  24 ,  26 ,  28 . A more preferred resistivity construction allows thick layers, and this construction is a resistivity range such that the nip relaxation time within the first transfer nip  40  is smaller than the dwell time that a section of the intermediate transfer member  12  takes to move through the first transfer nip  40 . In such a preferred regime of resistivity the voltage drop across the layer is small at the end of the transfer nip dwell time, due to charge conduction through the layer. 
     The constraint on the lower limit of the resistivity related to the lateral resistivity apply to the semiconductive top most layer, to any semiconductive middle layers, and to the semiconductive back layer of a multiple layer intermediate transfer member  12 . The preferred resistivity range for each such layer is substantially the same as discussed for the single layer intermediate transfer member  12 . Also, the additional constraint on the resistivity related to transfer problems in the second transfer nip  48  apply to the top most layer of a multiple layer intermediate transfer member  12 . Preferably, the top most semiconductive layer of the intermediate transfer member  12  should be typically &gt;10 9  ohm-cm when the top most layer of the transfuse member  50  is typically somewhat less than 10 9  ohm-cm. 
     Transfer of the composite toner image in the second transfer nip  48  is accomplished by a combination of electrostatic and heat assisted transfer. The field generation station  42  and guide roller  74  are electrically biased to electrostatically transfer the charged composite toner image from the intermediate transfer member  12  to the transfuse member  50 . 
     The transfer of the composite toner image at the second transfer nip  48  can be heat assisted if the temperature of the transfuse member  50  is maintained at a sufficiently high optimized level and the temperature of the intermediate transfer member  12  is maintained at a considerably lower optimized level prior to the second transfer nip  48 . The mechanism for heat assisted transfer is thought to be softening of the composite toner image during the dwell time of contact of the toner in the second transfer nip  48 . The toner softening occurs due to contact with the higher temperature transfuse member  50 . This composite toner softening results in increased adhesion of the composite toner image toward the transfuse member  50  at the interface between the composite toner image and the transfuse member. This also results in increased cohesion of the layered toner pile of the composite toner image. The temperature on the intermediate transfer member  12  prior to the second transfer nip  48  needs to be sufficiently low to avoid too high a toner softening and too high a resultant adhesion of the toner to the intermediate transfer member  12 . The temperature of the transfuse member  50  should be considerably higher than the toner softening point prior to the second transfer nip to insure optimum heat assist in the second transfer nip  48 . Further, the temperature of the intermediate transfer member  12  just prior to the second transfer nip  48  should be considerably lower than the temperature of the transfuse member  50  for optimum transfer in the second transfer nip  48 . 
     The temperature of the intermediate transfer member  12  prior to the second transfer nip  48  is important for maintaining good transfer of the composite toner image. An optimum elevated temperature for the intermediate transfer member  12  can allow the desired softening of the composite toner image needed to permit heat assist to the electrostatic transfer of the second transfer nip  48  at lower temperatures on the transfuse member  50 . However, there is a risk of the temperature of the intermediate transfer member  12  becoming too high so that too much softening of the composite toner image occurs on the intermediate transfer member prior to the second transfer nip  48 . This situation can cause unacceptably high adhesion of the composite toner image to the intermediate transfer member  12  with resultant degraded second transfer. Preferably the temperature of the intermediate transfer member  12  is maintained below or in the range of the Tg (glass transition temperature) of the toner prior to the second transfer nip  48 . 
     The transfuse member  50  is guided in a cyclical path by guide rollers  74 ,  76 ,  78 ,  80 . Guide rollers  74 ,  76  alone or together are preferably heated to thereby heat the transfuse member  50 . The intermediate transfer member  12  and transfuse member  50  are preferably synchronized to have the generally same velocity in the transfer nip  48 . Additional heating of the transfuse member is provided by a heating station  82 . The heating station  82  is preferably formed of infra-red lamps positioned internally to the path defined by the transfuse member  50 . Alternatively the heating station  82  can be a heated shoe contacting the back of the transfuse member  50  or other heat sources located internally or externally to the transfuse member  50 . The transfuse member  50  and a pressure roller  84  define a third transfer nip  86  therebetween. 
     A releasing agent applicator  88  applies a controlled quantity of a releasing material, such as a silicone oil to the surface of the transfuse member  50 . The releasing agent serves to assist in release of the composite toner image from the transfuse member  50  in the third transfer nip  86 . 
     The transfuse member  50  is preferably constructed of multiple layers. The transfuse member  50  must have appropriate electrical properties for being able to generate high electrostatic fields in the second transfer nip  50 . To avoid the need for unacceptably high voltages, the transfuse member  50  preferably has electrical properties that enable sufficiently low voltage drop across the transfuse member  50  in the second transfer nip  48 . In addition the transfuse member  50  will preferably ensure acceptably low current flow between the intermediate transfer member  12  and the transfuse member  50 . The requirements for the transfuse member  50  depend on the chosen properties of the intermediate transfer member  12 . In other words, the transfuse member  50  and intermediate transfer member  12  together have sufficiently high resistance in the second transfer nip  48 . 
     The transfuse member  50  will preferably have a laterally stiff back layer, a thick, conformable rubber intermediate layer, and a thin outer most layer. Preferably the thickness of the back layer will be greater than about 0.05 mm. Preferably the thickness of the intermediate conformable layers and the top most layer together will be greater than 0.25 mm and more preferably will be greater than about 1.0 mm. The back and intermediate layers need to have sufficiently low resistivity to prevent the need for unacceptably high voltage requirements in the second transfer zone  48 . The preferred resistivity condition follows previous discussions given for the intermediate transfer member  12 . That is, the preferred resistivity range for the back and intermediate layer of a multiple layer transfuse member  50  insures that the nip relaxation time for these layers in the field generation region of the second transfer nip  48  is smaller than the dwell time spent in the field generation region of the second transfer nip  48 . The expressions for the nip relaxation times and the nip dwell time are substantially the same as the ones discussed for the single layer intermediate transfer member  12 . Thus the specific preferred resistivity range for the back and intermediate layers depends on the system geometry, the layer thickness, the process speed, and the capacitance per unit area of the insulating layers within the transfer nip  48 . Generally, the volume resistivity of the back and intermediate layers of the multi-layer transfuse member  50  will typically need to be below about 10 11  ohm-cm and more preferably will be below about 10 8  ohm-cm for most systems. Optionally, the back layer of the transfuse member  50  can be highly conductive such as a metal. 
     Similar to the multiple layer intermediate transfer member  12 , the top most layer of the transfuse member  50  can optionally behave “insulating” during the dwell time in the transfer nip  48  (typically &gt;10 12  ohm-cm) or semiconducting during the transfer nip  48  (typically 10 6  to 10 12  ohm-cm.) However, if the top most layer behaves insulating, the dielectric thickness of such a layer will preferably be sufficiently low to avoid the need for unacceptably high voltages. Preferably for such insulating behaving top most layers, the dielectric thickness of the insulating layer should typically be less than about 50 μm and more preferably will be less than about 10 μm. If a very high resistivity insulating top most layer is used, such that the charge relaxation time is greater than the transfuse member cycle time, charge will build up on the transfuse member  50  due to charge transfer during the transfer nip  48 . Therefore, a cyclic discharging station  77  such as a scorotron or other charge generating device will be needed to control the uniformity and reduce the level of cyclic charge buildup. 
     The transfuse member  50  can alternatively have additional intermediate layers. Any such additional intermediate layers that have a high dielectric thickness typically greater than about 10 microns will preferably have a sufficiently low resistivity such to ensure low voltage drop across the additional intermediate layers. 
     The transfuse member  50  preferably has a top most layer formed of a material having a low surface energy, for example silicone elastomer, fluoroelastomers such as Viton™, polytetrafluoroethylene, perfluoralkane, and other fluorinated polymers. The transfuse member  50  will preferably have intermediate layers between the top most and back layers constructed of a Viton™ or silicone with carbon or other conductivity enhancing additives to achieve the desired electrical properties. The back layer is preferably a fabric modified to have the desired electrical properties. Alternatively the back layer can be a metal such as stainless steel. 
     The transfuse member  50  can optionally be in the form of a transfuse roller (not shown), or is preferably in the form of a transfuse belt. A transfuse roller for the transfuse member  50  can be more compact than a transfuse belt and it can also be advantaged relative to less complexity of the drive and steering requirements needed to achieve good motion quality for color systems. However, a transfuse belt has advantages over a transfuse roller such as enabling large circumference for longer life, better substrate stripping capability, and generally lower replacement costs. 
     The intermediate layer of the transfuse member  50  is preferably thick to enable a high degree of conformance to rougher substrates  70  and to thus expand the range of substrate latitude allowed for use in the printer  10 . In addition the use of a relatively thick intermediate layer, greater than about 0.25 mm and preferably greater than 1.0 mm enables creep for improved stripping of the document from the output of the third transfer nip  86 . In a further embodiment, thick low durometer conformable intermediate and top most layers such as silicone are employed on the transfuse member  50  to enable creation of low image gloss by the transfuse system with wide operating latitude. 
     The use of a relatively high temperature on the transfuse member  50  prior to the second transfer nip  48  creates advantages for the transfuse system. The transfer step in the second transfer nip  48  simultaneously transfers single and stacked multiple color toner layers of the composite toner image. The toner layers nearest to the transfer belt interface will be hardest to transfer. A given separation color toner layer can be nearest the surface of the intermediate transfer member  12  or it can also be separated from the surface, depending on the color toner layer to be transferred in any particular region. For example, if a toner layer of magenta is the last stacked layer deposited onto the transfer belt, the magenta layer can be directly against the surface of the intermediate transfer member  12  in some color print regions or else stacked above cyan and/or yellow toner layers in other color regions. If transfer efficiency is too low, a high fraction of the color toners that are close to the intermediate transfer member  12  will not transfer but a high fraction of the same color toner layers that are stacked onto another color toner layer will transfer. Thus for example, if the transfer efficiency of the composite toner image is not very high, the region of the composite toner image having cyan toner directly in contact with the surface of the intermediate transfer member  12  can transfer less of the cyan toner layer than the regions of the composite toner image having cyan toner layers on top of yellow toner layers. The transfer efficiency in the second transfer nip  48  is &gt;95% therefore avoiding significant color shift. 
     With reference to FIG. 7 disclosing experimental data on the amount of residual toner left on the intermediate transfer member  12  as a function of the transfuse member  50  temperature. Curve  92  is with electric field, pressure and heat assist and curve  90  is without electric field assist but with pressure and heat assist. A very low amount of residual toner means very high transfer efficiency. The toner used in the experiments has a glass transition temperature range Tg of around 55° C. Substantial heat assist is observed at temperatures of the transfuse member  50  above Tg. Substantially 100% toner transfer occurs when operating with an applied field and with the transfuse member  50  temperature above around 165° C., well above the range of the toner Tg. Preferential temperatures will vary depending on toner properties. In general, operation well above the Tg is found to be advantageous for the heat assist to the electrostatic transfer for many different toners and system conditions. 
     Too high a temperature of the transfuse member  50  in the second transfer nip  48  can cause problems due to unacceptably high toner softening on the intermediate transfer member side of the composite toner layer. Thus the temperature of the transfuse member  50  prior to the second transfer nip  48  must be controlled within an optimum range. The optimum temperature of the composite toner image in the second transfer nip  48  is less than the optimum temperature of the composite toner image in the third transfer nip  86 . The desired temperature of the transfuse member  50  for heat assist in the second transfer nip  48  can be readily obtained while still obtaining the desired higher toner temperatures needed for more complete toner melting in the third transfer nip  86  by using pre-heating of the substrate  70 . Transfer and fix to the substrate  70  is controlled by the interface temperature between the substrate and the composite toner image. Thermal analysis shows that the interface temperature increases with both increasing temperature of the substrate  70  and increasing temperature of the transfuse member  50 . 
     At a generally constant temperature of the transfuse member  50  in the second and third transfer nips  48 ,  86 , the optimum temperature for transfer in the second transfer nip  48  is controlled by adjusting the temperature of the intermediate transfer member  12 , and transfuse in the third transfer nip  86  is optimized by preheating of the substrate  70 . Alternatively, for some toner formulations or operation regimes no preheating of the substrate  70  is required. 
     The substrate  70  is transported and registered by a material feed and registration system  69  into a substrate pre-heater  73 . The substrate pre-heater  73  is preferably formed a transport belt transporting the substrate  70  over a heated platen. Alternatively the substrate pre-heater  73  can be formed of heated rollers forming a heating nip therebetween. The substrate  70  after heating by the substrate preheater  73  is directed into the third transfer nip  86 . 
     FIG. 8 discloses experimental curves  94 ,  96  of a measure of fix called crease as a function of the temperature of the transfuse member  50  for different pre-heating temperatures of a substrate. Curve  94  is for a preheated substrate and a curve  96  for a substrate at room temperature. The results disclose that the temperature of the transfuse member  50  for similar fix level decreases significantly at higher substrate pre-heating curve  94  compared to lower substrate pre-heating curve  96 . Heating of the substrate  70  by the substrate pre-heater  73  prior to the third transfer nip  86  allows optimization of the temperature of the transfuse member  50  for improved transfer of the composite toner image in the second transfer nip  48 . The temperature of the transfuse member  50  can thus be controlled at the desired optimum temperature range for optimum transfer in the second transfer nip  48  by controlling the temperature of the substrate  70  at the corresponding required elevated temperature needed to create good fix and transfer to the substrate  70  in the third transfer nip  86  at this same controlled temperature of the transfuse member  50 . Therefore cooling of the transfuse member  50  prior to the second transfer nip  48  is not required for optimum transfer in the second transfer nip  48 . In other words the transfuse member  50  can be maintained at substantially the same temperature in both the second and third transfer nips  48 ,  86 . 
     Furthermore, the over layer, the intermediate and topmost layers, of the transfuse member  50  can be relatively thick, preferably greater than about 1.0 mm, because no substantial cooling of the transfuse member  50  is required prior to the second transfer nip  48 . Relatively thick intermediate and topmost layers of the transfuse member  50  allows for increased conformability. The increased conformability of the transfuse member  50  permits printing to a wider latitude of substrates  70  without a substantial degradation in print quality. In other words the composite toner image can be transferred with high efficiency to relatively rough substrates  70 . 
     In addition, the transfuse member  50  is preferably at substantially the same temperature in both the second and third transfer nips  48 ,  86 . However, the composite toner image preferably has a higher temperature in the third transfer nip  86  relative to the temperature of the composite toner image in the second transfer nip  48 . Therefore the substrate  70  has a higher temperature in the third transfer nip  86  relative to the temperature of the intermediate transfer member  12  in the second transfer nip  48 . Alternatively, the transfuse member  50  can be cooled prior to the second transfer nip  48 , however the temperature of the transfuse member  50  is maintained above, and preferably substantially above the Tg of the composite toner image. Furthermore, under certain operating conditions, the top surface of the transfuse member  50  can be heated just prior to the second transfer nip  48 . 
     The composite toner image is transferred and fused to the substrate  70  in the third transfer nip  86  to form a completed document  72 . Heat in the third transfer nip  86  from the substrate  70  and transfuse member  50 , in combination with pressure applied by the pressure roller  84  acting against the guide roller  76  transfer and fuse the composite toner image to the substrate  70 . The pressure in the third transfer nip  86  is preferably in the range of about 40-500 psi, and more preferably in the range 60 psi to 200 psi. The transfuse member  50 , by combination of the pressure in the third transfer nip  86  and the appropriate durometer of the transfuse member  50  induces creep in the third transfer nip to assist release of the composite toner image and substrate  70  from the transfuse member  50 . Preferred creep is greater than 4%. Stripping is preferably further assisted by the positioning of the guide roller  78  relative to the guide roller  76  and pressure roller  84 . The guide roller  78  is positioned to form a small amount of wrap of the transfuse member  50  on the pressure roller  84 . The geometry of the guide rollers  76 ,  78  and pressure roller  84  form the third transfer nip  86  having a high pressure zone and an adjacent low pressure zone in the process direction. The width of the low pressure zone is preferably one to three times, or more preferably about two times the width of the high pressure zone. The low pressure zone effectively adds an additional 2-3% creep and thereby improves stripping. Additional stripping assistance can be provided by stripping system  87 , preferably an air puffing system. Alternatively the stripping system  87  can be a stripping blade or other well known systems to strip documents from a roller or belt. Alternatively, the pressure roller can be substituted with other pressure applicators such as a pressure belt. 
     After stripping, the document  72  is directed to a selectively activatable glossing station  110  and thereafter to a sheet stacker or other well know document handing system (not shown). The printer  10  can additionally provide duplex printing by directing the document  72  through an inverter  71  where the document  72  is inverted and reintroduced to the pre-transfer heating station  73  for printing on the opposite side of the document  72 . 
     A cooling station  66  cools the intermediate transfer member  12  after second transfer nip  48  in the process direction. The cooling station  66  preferably transfers a portion of the heat on the intermediate transfer member  12  at the exit side of the second transfer nip  48  to a heating station  64  at the entrance side of the second transfer nip  48 . Alternatively the cooling station  66  can transfer a portion of the heat on the intermediate transfer member  12  at the exit side of the second transfer nip  48  to the substrate prior to the third transfer nip  86 . Alternatively the heat sharing can be implemented with multiple heating stations  64  and cooling stations  66  to improve heat transfer efficiency. 
     A cleaning station  54  engages the intermediate transfer member  12 . The cleaning station  54  preferably removes oil that may be deposited onto the intermediate transfer member  12  from the transfuse member  50  at the second transfer nip. For example, if a preferred silicone top most layer is used for the transfuse member  50 , some silicone oil present in the silicone material can transfer from the transfuse member  50  to the intermediate transfer member  12  and eventually contaminate the image bearing members  30 . In addition the cleaning station  54  removes residual toner remaining on the intermediate transfer member  12 . The cleaning station  54  also cleans oils deposited on the transfuse member  50  by the release agent management system  88  that can contaminate the image bearing members  30 . The cleaning station  54  is preferably a cleaning blade alone or in combination with an electrostatic brush cleaner, or a cleaning web. 
     A cleaning station  58  in accordance with the invention (see FIG. 3) engages the surface of the transfuse member  50  past the third transfer nip  86  to remove any residual toner and contaminants from the surface of the transfuse member  50 . The cleaning station  58  has a rotatable turret or carousel  280  supporting multiple cleaner roller assemblies  281 . The cleaner roller assemblies  281  are cleaningly engageable to transfuse member  50 . The cleaner roller assemblies are mounted to a rotatable turret or carousel. The carousel is indexed to in turn position each cleaner roller assembly in cleaning engagement with the fusing member for cleaning. In a first embodiment, each cleaner roll assembly  281  is formed of a rotatable solid surface cleaner roller  259 . The cleaner roller  259  is oriented orthogonal to the process direction of the transfuse member  50  and preferably extends across the substantially entire width of the transfuse member  50 . The cleaner roller  259  is preferably formed of a metal tube or cylinder. Alternatively the cleaner roller can be formed of cardboard or other high surface energy material. Partially melted toner forms a toner layer on the outer surface of the cleaner roller  259 . The toner layer becomes adhesive or sticky at an elevated temperature. The cleaner roller  259  of the cleaner roller assembly in contact with the fusing member is heated within the tacky range of the toner employed in the printing apparatus. The use of a solid surface cleaner roller  259  allows for effective single pass cleaning of the transfuse member  50 . The cleaner roller  259  is preferably not driven, but is an idler roller deriving rotational motion from frictional engagement of the toner layer  262  with the transfuse member  50 . 
     The cleaner roller  259  is supported at a preestablished first fixed distance from the surface of the transfuse member  50 . The cleaner roller  259  is held in pressure contact with the surface of the transfuse member  50 . The cleaner roller  259  is preferably positioned opposite guide roller  80 . Alternatively a pressure roller  261  is positioned opposite the first cleaner roller  259  to maintain adequate pressure between the transfuse member  50  and cleaner roller  259 . The cleaner roller  259  rollingly engages the transfuse member  50  and applies a pressure of 10-50 psi to the transfuse member  50 . 
     The cleaner roller  259  is preferably formed of a rigid, material such as steel, but can also be brass, aluminum stainless steel, cardboard, etc. The cleaner roller  259  is preferably heated by the transfuse member  50  to thereby maintain the toner layer  262  on the cleaning roller  259  in a partially melted state. The toner layer can alternatively be heated by an external heater. The operating temperature range of the toner layer  262  is sufficiently high to melt the toner, typically greater than 100° C. Too low a temperature of the toner layer  262  results in the toner and other contaminants failing to adhere to the cleaner roller  259 . The temperature range of the toner layer  262  cannot be allowed to get too elevated, greater than 180° C., in order to prevent toner layer splitting. The partially melted toner is therefore preferably maintained within an optimum temperature range of 100-180° C. The toner layer  262  is maintained in the optimum temperature range by the heat from the transfuse member  50 , in combination with additional heating provided by a cleaning heater  265 , if so required. 
     The cleaner roller  259  is preferably initially coated with the toner layer  262 . The toner layer  262  is then heated until within the optimum temperature range. Alternatively, the cleaner roller  259  is bare when brought into contact with the transfuse member  50 , having no initial toner layer. The cleaner roller  259  is heated in the optimum range and toner particles from the transfuse member  50  adhere to the cleaner roller  259 . The toner layer  262  is therefore formed from the excess toner particles on the transfuse member  50 . In addition, other particulates and contaminants on the transfuse member  50  adhere to the sticky toner layer  262  on the cleaner roller  259  and are removed from the transfuse member. 
     The cleaner roller  259 , preferably having a solid surface, cleans the surface of the transfuse member for a preestablished operational period, for example a preestablished number of pages. At the end of the preestablished operational period, the used cleaner assembly  281  is moved out of cleaning engagement with the transfuse member and a second clean cleaning assembly  281  is brought into cleaning engagement with the fusing member  50 . The cleaning station  58  in most operational environments cleans the transfuse member  50  in a single pass preparing the transfuse member  50  to receive a new composite toner image. 
     In a further embodiment of the cleaning station  58  in accordance with the invention, each cleaner roll assembly  281  has a perforated cleaner roll  260  in place of the solid surface roll  259 . (See FIG. 5) The perforated cleaner roller  260  is a tube or hollow cylinder defining an interior reservoir  264 . The perforated cleaner roller  260  has an aperture  266  passing through the roller surface. The aperture  266  can be a series of holes or preferably a single spiral wound cut extending axially along the length of the perforated cleaner roller  260 . 
     A sticky toner layer is maintained on the perforated cleaner roller  260  as described above. As the thickness of the toner layer  263  increases from the accumulation of toner particles from the transfuse member  50 , excess toner is squeezed into the interior reservoir  264  of the perforated cleaner roller  260 . The pressure between the perforated cleaner roller  260  and the transfuse member  50  drives the excess toner from the toner layer  263  into the interior reservoir  264 . The aperture  266  allows excess toner of the toner layer  263  to be squeezed or driven into the interior reservoir  264  of the cleaner roller  260  thereby maintaining the preferred thickness of the toner layer  263  on the surface of the cleaner roller  260 . As a result, excess toner and particulates are accumulated in the interior reservoir  264  extending the operational life of the individual cleaner assembly  281 , and therefore the operational life of the entire cleaning station  58  between routine service. The aperature forms a cleaning gap where the transfuse member will not be cleaned when the aperature passes over the surface of the transfuse member. 
     In a still further embodiment of the invention, each cleaning assembly  281  has spaced apart rotatably mounted solid surface and perforated cleaner rollers  259 ,  260 . (See FIG. 6) The perforated cleaner roller  260  is positioned first in the process direction of the transfuse member. A solid surface cleaner roller  259  is positioned down stream in the process direction from the perforated cleaner roller  260 . The cleaner rollers  260 ,  259  are each cleaningly engagable to the transfuse member  50 . The first and second perforated solid surface cleaner rollers  260 ,  259  functionally operate in the same manner as the perforated cleaner rollers  260  and solid surface cleaner rollers  259  described above. The perforated cleaner roller  260  has a relatively extended operational life due to excess toner and particulates being accumulated in the internal reservoir  264 . However the perforated cleaner roller  260  will not typically clean the entire surface of the transfuse member  50  in a single pass due to the aperture  266 . The solid surface cleaner roller  259  will typically clean the entire surface of the transfuse member  50 . The solid surface cleaner roller  259  will have an extended operational life due to the perforated cleaner roller  260  removing a high proportion of the toner and particulates contaminating the transfuse member  50 . Therefore the cleaner roller  281  assembly can provide single pass cleaning of the transfuse member and a relatively extended operational life. Single pass cleaning is particularly important for transfuse systems where toner images are cyclically transferred to and from the transfuse member, increasing the likelihood of stray toner particles adhering to the transfuse member. The operation of the turret to bring unused cleaner roller assemblies into contact with the transfuse member further extends the extended operational life of the cleaner assembly reduces the amount of required routine maintenance. 
     As shown in FIGS. 9 through 11, a pair of synchronized perforated cleaning rolls  259 ,  260  can be utilized to more effectively clean the transfuse member  50 . The synchronizing mechanism can be a gear train as shown in FIG. 9 having similar sized gears  302 ,  304  affixed to the cleaning rolls  259 ,  260  and mated through an idler gear  306  or as shown in FIG. 10, a drive belt  314  connecting identically sized drive pulleys  310 ,  312  attached to the cleaning rolls may be used. The synchronizing mechanism is required so that the spiral aperture  366  in each of the cleaning rolls  260  (FIG. 11) can be staggered from one another so that the transfuse member  50  can be cleaned by the combined single rotation of each cleaning roll. 
     The transfuse member  50  is driven in the cyclical path by the pressure roller  84 . Alternatively drive is provided or enhanced by driving the guide roller  74 . The intermediate transfer member  12  is preferably driven by the pressured contact with the transfuse member  50 . Drive to the intermediate transfer member  12  is preferably derived from the drive for the transfuse member  50 , by making use of adherent contact between intermediate transfer member  12  and the transfuse member  50 . The adherent contact causes the transfuse member  50  and intermediate transfer member  12  to move in synchronism with each other in the second transfer nip  48 . Adherent contact between the intermediate transfer member  12  and the toner image producing stations  22 ,  24 ,  26 ,  28  may be used to ensure that the intermediate transfer member  12  moves in synchronism with the toner image producing stations  22 ,  24 ,  26 ,  28  in the first transfer zones  40 . Therefore the toner image producing stations  22 ,  24 ,  26 ,  28  can be driven by the transfuse member  50  via the intermediate transfer member  12 . Alternatively, the intermediate transfer member  12  is independently driven. When the intermediate transfer member is independently driven, a motion buffer (not shown) engaging the intermediate transfer member  12  buffers relative motion between the intermediate transfer member  12  and the transfuse member  50 . The motion buffer system can include a tension system with a feedback and control system to maintain good motion of the intermediate transfer member  12  at the first transfer nips  40  independent of motion irregularity translated to the intermediate transfer member  12  at the second transfer nip  48 . The feedback and control system can include registration sensors sensing motion of the intermediate transfer member  12  and/or sensing motion of the transfuse member  50  to enable registration timing of the transfer of the composite toner image to the substrate  70 . 
     A gloss enhancing station  110  is preferably positioned down stream in the process direction from the third transfer nip  86  for selectively enhancing the gloss properties of documents  72 . The gloss enhancing station  110  has opposed fusing members  112 ,  114  defining a gloss nip  116  there between. The gloss nip  116  is adjustable to provide the selectability of the gloss enhancing. In particular, the fusing members are cammed whereby the transfuse nip is sufficiently large to allow a document to pass through with out substantial contact with either fusing member  112 ,  114  that would cause glossing. When the operator selects gloss enhancement, the fusing members  112 ,  114  are cammed into pressure relation and driven to thereby enhancement the level of gloss on documents  72  passed through the gloss nip  116 . The amount of gloss enhancement is operator selectable by adjustment of the temperature of the fusing members  112 ,  114 . Higher temperatures of the fusing members  112 ,  114  will result in increased gloss enhancement. U.S. Pat. No. 5,521,688, Hybrid Color Fuser, incorporated herein by reference, describes a gloss enhancing station with a radiant fuser. 
     The separation of fixing and glossing functions provides operational advantages. Separation of the fixing and glossing functions permits operator selection of the preferred level of gloss on the document  72 . The achievement of high gloss performance for color systems generally requires relatively higher temperatures in the third transfer nip  86 . It also typically requires materials on the transfuse member  50  having a higher heat and wear resistance such as Viton™ to avoid wear issues that result in differential gloss caused by changes in surface roughness of the transfuse member due to wear. The higher temperature requirements and the use of more heat and wear resistant materials generally result in the need for high oil application rates by the release agent management system  88 . In transfuse systems such as the printer  10  increased temperatures and increased amounts of oil on the transfuse member  50  could possibly create contamination problems of the photoreceptors  30 . Printers having a transfuse system and needing high gloss use a thick nonconformable transfuse member, or a relatively thin transfuse member. However, a relatively nonconformable transfuse member and a relatively thin transfuse member fail to have the high degree of conformance needed for good printing on, for example, rougher paper stock. 
     The use of the gloss enhancing station  110  substantially reduces or eliminates the need for gloss creation in the third transfer nip  86 . The reduction or elimination of the need for gloss in the third transfer nip  86  therefore minimizes surface wear issues for color transfuse member materials and enables a high life transfuse member  50  with readily available silicone or other similar soft transfuse member materials. It allows the use of relatively thick layers on the transfuse member  50  with resultant gain in operating life for the transfuse member materials and with resultant high conformance for imaging onto rougher substrates. It reduces the temperature requirements for the transfuse materials set with further gain in transfuse material life, and it can substantially reduce the oil requirements in the third transfer nip  86 . 
     The gloss enhancing station  110  is preferably positioned sufficiently close to the third transfer nip  86 , so the gloss enhancing station  110  can utilize the increased document temperature that occurs in the third transfer nip  86 . The increased temperature of the document  72  reduces the operating temperature needed for the gloss enhancing station  110 . The reduced temperature of the gloss enhancing station  110  improves the life and reliability of the gloss enhancing materials. 
     Use of a highly conformable silicone transfuse member  50  is an example demonstrated as one important means for achieving good operating fix latitude with low gloss. Critical parameters are sufficiently low durometer for the top most layer of the transfuse member  50 , preferably of rubber, and relatively high thickness for the intermediate layers of the transfuse member  50 , preferably also of rubber. Preferred durometer ranges will depend on the thickness of the composite toner layer and the thickness of the transfuse member  50 . The preferred range will be about 25 to 55 Shore A, with a general preference for about 35 to 45 Shore A range. Therefore preferred materials include many silicone material formulations. Thickness ranges of the over layer of the transfuse member  50  will preferably be greater than about 0.25 mm and more preferably greater than 1.0 mm. Preference relative to low gloss will be for generally thicker layers to enable extended toner release life, conformance to rough substrates, extended nip dwell time, and improved document stripping. In an optional embodiment a small degree of surface roughness is introduced on the surface of the transfuse member  50  to enhance the range of allowed transfuse material stiffness for producing low transfuse gloss. Especially with higher durometer materials and/or low thickness layers there will be a tendency to reproduce the surface texture of the transfuse member. Thus some surface roughness of the transfuse member  50  will tend toward low gloss in spite of high stiffness. Preference will be transfuse member surface gloss number &lt;30 GU. 
     A narrow operating temperature latitude for good fix with low gloss in transfuse has been demonstrated at relatively high toner mass/area conditions. Toner of size about 7 microns requiring toner masses about 1 mg/cm2 requires a temperature of the transfuse member  50  between 110-120° C. and preheating of the paper to about 85° C. to achieve gloss levels of &lt;30 GU while simultaneously achieving acceptable crease level below  40 . However, low mass/area toner conditions have shown increased operating transfuse system temperature range for fix and low gloss. The use of small toner having high pigment loading, in combination with a conformable transfuse member  50 , allows low toner mass/area for color systems therefore extending the operating temperature latitude for low gloss in the third transfer nip  86 . Toner of size about 3 microns requiring toner masses about 0.4 mg/cm2 requires a temperature of the transfuse member  50  between 110-150° C., and paper preheating to about 85° C., to achieve gloss levels of &lt;30 GU while simultaneously achieving acceptable crease level below 40. 
     The gloss enhancing station  110  preferably has fusing members  112 ,  114  of Viton™. Alternatively hard fusing members such as thin and thick Teflon™ sleeves/overcoatings on rigid rollers or on belts, or else such overcoatings over rubber underlayers, are alternative options for post transfuse gloss enhancing. The fusing members  112 ,  114 , preferably have an top most fixing layer stiffer than that used for the top most layer of the transfuse member  50 , with a high level of surface smoothness (surface gloss preferably &gt;50 GU and more preferably &gt;70 GU). The topmost surface can be alternatively textured to provide a texture to the documents  72 . The gloss enhancing station  110  preferably includes a release agent management application system (not shown). The gloss enhancing station can further include stripping mechanisms such as an air puffer to assist stripping of the document  72  from the fusing members  112 ,  114 . 
     Optionally the toner formulation may include wax to reduce the oil requirements for the gloss enhancing station  110 . 
     The gloss enhancing station  110  is described in combination with the printer  10  having an intermediate transfer member  12  and a transfuse member  50 . However, the gloss enhancing station  110  is applicable with all printers having transfuse systems producing documents  72  with low gloss. In particular this can include transfuse systems that employ a single transfer/transfuse member. 
     As a system example, the transfuse member  50  is preferably 120° C. in the third transfer nip  86 , and the substrate  70  is preheated to 85° C. The result is a document  72  having a gloss value 20-30 GU. The fusing members are preferably heated to 120° C. The temperature of the fusing members  112 ,  114  is preferably adjustable so different degrees or levels of glossing can be applied to different print runs dependent on operator choice. Higher temperatures of the fusing members  112 ,  114  increase the gloss enhancement while lower temperatures will the reduce the amount of gloss enhancement on the documents  72 . 
     The fusing members  112 ,  114  are preferably fusing rollers, but can alternatively the fusing members  112 ,  114  can be fusing belts. The top most surface of each fusing member  112 ,  114  is relatively non-conformable, preferably having a durometer above 55 Shore A. The gloss enhancing station  110  provides gloss enhancing past the printer  10  employing a transfuse system that operates with low gloss in the third transfer nip  86 . The printer  10  preferably forms documents  72  having 10-30 Gardner Gloss Units (GU) after the third transfer nip  86 . The gloss on the documents  72  will vary with toner mass per unit area. The gloss enhancing unit  110  preferably increases the gloss of the documents  72  to greater than about 50 GU on Lustro Gloss™ paper distributed by S D Warren Company.