Patent Application
20120107027
The present disclosure relates generally to fuser release fluid control in imaging systems. More particularly, the present disclosure describes an apparatus, method, and system useful for reducing oil ghosting in imaging systems.
The fuser release fluid distribution on the surface of a roll or belt in an imaging system can have detrimental effects on image quality if not properly controlled. For example, if release fluid (for example, oil) is not evenly distributed on the portion of a surface (for example, a fuser roll or belt) that comes in contact with the media, oil ghosting can result in the form of a gloss band on the media. Oil ghosting can result from excess oil on, for example, the inter document zone (IDZ) of the fuser surface that exists between sheets of media, or on the outside paper path (OPP) area of the fuser surface when switching to wider media.
An apparatus for redistributing release agent on a fuser surface of an image forming device is provided. The apparatus has a fuser surface for contacting a sheet of media having an image formed thereon by the image forming device, the fuser surface moving in a traveling direction; and a flexible blade for redistributing the release agent on the fuser surface from a first post-fusing distribution to a second distribution, the flexible blade contacting the release agent on the fuser surface at a contact area and pressing the release agent against the fuser surface to redistribute the release agent from the first post-fusing distribution to the second distribution, wherein the flexible blade is adapted to redistribute the release agent such that the second distribution is more uniform across the fuser surface than the first post-fusing distribution.
The following figures form part of the present specification and are included to further demonstrate certain aspects of the disclosed features and functions, and should not be used to limit or define the disclosed features and functions. Consequently, a more complete understanding of the present embodiments and further features and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, wherein:
It is to be noted, however, that the appended drawings illustrate only typical embodiments of the disclosed subject matter and are, therefore, not to be considered limiting of the scope of the disclosed subject matter, as the disclosed subject matter may admit to other equally effective embodiments.
Illustrative embodiments are described in detail below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of the present disclosure.
The disclosed embodiments may include an apparatus for redistributing release agent on a fuser surface of an image forming device. The apparatus has a fuser surface for contacting a sheet of media having an image formed thereon by the image forming device, the fuser surface moving in a traveling direction; and a flexible blade for redistributing the release agent on the fuser surface from a first post-fusing distribution to a second distribution, the flexible blade contacting the release agent on the fuser surface at a contact area and pressing the release agent against the fuser surface to redistribute the release agent from the first post-fusing distribution to the second distribution. The flexible blade is adapted to redistribute the release agent such that the second distribution is more uniform across the fuser surface than the first post-fusing distribution.
The disclosed embodiments may further include an image forming device. The image forming device has a media transport path for transporting a sheet of media having an image formed thereon; a fuser surface for contacting the sheet of media, the fuser surface moving in a traveling direction; and a flexible blade for redistributing release agent on the fuser surface from a first post-fusing distribution to a second distribution, the flexible blade contacting the release agent on the fuser surface at a contact area and pressing the release agent against the fuser surface to redistribute the release agent from the first post-fusing distribution to the second distribution. The flexible blade is adapted to redistribute the release agent such that the second distribution is more uniform across the fuser surface than the first post-fusing distribution.
The disclosed embodiments may further include a method of redistributing release agent on a fuser surface of an image forming device. The method includes providing a fuser surface for contacting a sheet of media having an image formed thereon by the image forming device; moving the fuser surface in a traveling direction; contacting a release agent present on the fuser surface with a flexible blade such that the flexible blade redistributes the release agent on the fuser surface from a first post-fusing distribution to a second distribution, the flexible blade contacting the release agent on the fuser surface at a contact area and pressing the release agent against the fuser surface to redistribute the release agent from the first post-fusing distribution to the second distribution, wherein the flexible blade redistributes the release agent such that the second distribution is more uniform across the fuser surface than the first post-fusing distribution.
Oil ghosting can show up as a gloss band which is caused by excess release agent (for example, oil) left on a fusing surface. This can happen in the inter document zone (the area between sheets of media) and/or outside the paper path. In the inter document zone (IDZ) there is no paper to transfer the release agent to, which results in the fusing surface being left with excess release agent. Also, long runs of narrow media can result in excess release agent collecting outside the paper path causing an undesirable gloss differential when switching to wider media. For ease of description, the term “oil” will be used to refer to release agents of all types.
Exemplary embodiments of the disclosure propose the use of a flexible blade (such as a T-blade) to remove part of the excess oil and smooth the oil layer so that oil ghosting will be mitigated to a point at which it is not detectable. This type of blade is similar to a blade that is used to remove water from cars, trucks, windows, mirrors, etc.
Applicants' tests show that when the blade is properly aligned and pressed against the fusing surface with an adequate force, oil ghosting can be eliminated.
Testing was performed using a T-blade made of silicone. However, other materials can be used as long as the material is flexible, can withstand the high temperatures that exist in an image fusing system, and are compatible with the release agent. In the particular case where the release agent is silicone oil and the fusing temperatures are above 180 degrees Celsius, a material such as Viton® will be suitable.
As used herein, the term “image forming device” encompasses any apparatus, such as a digital copier, bookmaking machine, multifunction machine, and the like, that performs a print outputting function for any purpose. The image forming device can be used to produce prints from various types of media, such as coated or uncoated (plain) paper sheets, at high speeds. The media can have various sizes and weights.
As discussed above, a release agent is applied to fuser surface 110 during the operation of the image forming device. The release agent can be, for example, a silicone oil. The release agent builds up unevenly on fuser surface 110, especially in the IDZ and OPP, after images are fused to the media. To improve the image quality, an apparatus for redistributing release agent 200 is provided to redistribute the release agent more uniformly across the face of fuser surface 110. In the example shown in
Apparatus 200 includes, in this example, a blade assembly 300, as shown in
In embodiments, the fuser surface has an overall width in a transverse direction that is perpendicular to the travelling direction. Oil may be applied to a portion of the fuser surface that is less than the overall width of the fuser surface. As a result, blade 310 may have a length that is less than the overall width of the fuser surface or it may have a length that is equal, or greater than, the overall width of the fuser surface. For example, blade 310 may have a length substantially equal to the width of the oiled portion of the fuser surface. Embodiments may include a blade or blades that contact the fuser surface only at areas of the fuser surface that are not used to fuse images to media, such as, for example, areas at the edges of the fuser surface which are outside of the image area.
Exemplary embodiments of the disclosure position blade 310 such that it drags on fuser surface 110 while fuser surface 110 is supported on the hard surface of an internal roll (for example, roll 140 or 150). However, other embodiments can position blade 310 at a location where fuser surface 110 is not supported on the hard surface of an internal roll. The release agent removed by blade 310 can be collected in a pan 210 which can then be returned to the oil system. The oil return can, for example, go to the ram, to the oil bottle or to a separate oil waste bottle. Different orientations of the T-blade relative to fuser surface 110 can be used. For example, position A in
As mentioned above, embodiments of the disclosure can be used in devices having fuser rolls as well as those (such as the embodiment shown) using a fuser belt. However, because a fuser belt typically has a greater perimeter than a fuser roll, a fuser belt provides more locations at which apparatus 200 can be beneficially located. A fuser belt provides more locations (than a fuser roll) at which apparatus 200 can be placed so that a blade such as blade 310 is positioned above a collection pan such as pan 210. Also, providing one or more rolls such as rolls 120, 140, 150 having a large diameter provides an increased area over which apparatus 200 can be placed and still be located above a pan such as pan 210.
The viscosity of the oil usually decreases with increased temperature. This property can be used to produce better results depending on whether even spreading of the oil is desired or removal of the oil is desired. If even spreading of the oil is desired, the oil can spread by the blade at a point just after the oil has been heated (to reduce viscosity). The oil can be heated by heating the fuser surface through one of the rolls, for example, or some other heating device. If removal of the oil is desired, a higher viscosity is desirable. To obtain a higher viscosity, the oil can be scraped by the blade at a point on the fuser surface that is allowed to cool (or is not heated).
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
