阅读说明：本技术 具有斜切尖端的熔凝器剥离机构 (Fuser release mechanism with beveled tip ) 是由 D·F·卡希尔 R·D·博波 M·H·艾伦 于 2019-09-24 设计创作，主要内容包括：一种熔凝器设备(60)包括第一滚子(62)和第二滚子(64),所述第一滚子和第二滚子成夹(66)的关系以运输在其之间的接收件部件(42)。剥离机构(300)包括具有长形的、薄的、柔性的切削指(312)的切削组件,其中切削指的尖端(344)被用具有相应扫掠角的第一斜切表面和第二斜切表面(340、341)斜切,沿着切削指的上部表面形成锋利的边缘(342)。安装机构(314)以操作的关系将所述切削指定位到所述第一滚子,其中切削指的底部表面在从切削指的尖端间隔开的接触点(347)处接触所述第一滚子的表面,使得沿着切削指的第一表面的锋利的边缘以在50和120微米之间的距离(D)从第一滚子的所述表面间隔开。(A fuser apparatus (60) includes a first roller (62) and a second roller (64) in a nip (66) relationship to transport a receiver member (42) therebetween. The exfoliation mechanism (300) includes a cutting assembly having an elongate, thin, flexible cutting finger (312) in which a tip (344) of the cutting finger is beveled with first and second beveled surfaces (340, 341) having respective sweep angles, forming a sharp edge (342) along an upper surface of the cutting finger. A mounting mechanism (314) positions the cutting finger to the first roller in operative relationship with a bottom surface of the cutting finger contacting a surface of the first roller at a contact point (347) spaced from the tip of the cutting finger such that the sharpened edge along the first surface of the cutting finger is spaced from the surface of the first roller by a distance (D) between 50 and 120 microns.)

1. A fuser apparatus, comprising:

a first roller and a second roller in a nip relationship to transport the receiver member therebetween and to permanently fuse the marking particles to the receiver member under the application of heat and pressure; and

a stripping mechanism for stripping the receiver member from the first roller, the stripping member comprising one or more cutting assemblies, each cutting assembly comprising:

an elongated, thin, flexible cutting finger having a tip, a first surface, a second surface, and a centerline extending in a length direction, wherein the tip of the cutting finger is beveled with a first bevel surface and a second bevel surface forming a sharp edge along the first surface of the cutting finger, the tip of the cutting finger having a tip angle between 10 degrees and 45 degrees, wherein the first bevel surface bevels the tip on a first side of the centerline and the second bevel surface bevels the tip on a second side of the centerline, wherein a first line of intersection between the first bevel surface and the second surface is oriented at a first sweep angle relative to a line orthogonal to the centerline and a second line of intersection between the second bevel surface and the second surface is oriented at a second sweep angle relative to the line orthogonal to the centerline, the first sweep angle and the second sweep angle have values between 5 degrees and 30 degrees; and

a mounting mechanism for positioning the cutting finger to the first roller in operative relation such that the second surface of the cutting finger contacts a surface of the first roller at a contact point spaced from the tip of the cutting finger such that the sharpened edge along the first surface of the cutting finger is spaced from the surface of the first roller by a distance of between 50 microns and 120 microns.

2. The fuser apparatus of claim 1, wherein the contact point corresponds to an intersection point between the second surface of the cutting finger and the first and second chamfered surfaces.

3. The fuser apparatus of claim 1, wherein the first roller is a support roller and the second roller is a heated fuser roller.

4. The fuser apparatus of claim 1, wherein the first roller is a heated fuser roller and the second roller is a support roller.

5. The fuser apparatus of claim 1, further comprising a release agent management system that applies a release agent to the first roller or the second roller.

6. The fuser apparatus of claim 5, wherein the mounting mechanism positions the cutting finger such that release agent on the surface of the first roller does not flow onto the first surface of the cutting finger when the first roller is rotated.

7. The fuser device of claim 1, wherein the difference between the tip angle and an angle of attack formed between the second surface of the cutting finger and a tangential plane of the first roller at the point of contact is between 5 and 15 degrees.

8. The fuser apparatus of claim 1, wherein the first chamfered surface and the second chamfered surface are planar surfaces.

9. The fuser apparatus of claim 1, wherein the first chamfered surface and the second chamfered surface are non-planar surfaces.

10. The fuser apparatus of claim 9, wherein the first chamfered surface and the second chamfered surface have a stepped thickness profile.

11. A paper transportation system, comprising:

a first roller and a second roller in a sandwiched relationship to transport the receiver member therebetween; and

a stripping mechanism for stripping the receiver member from the first roller, the stripping member comprising one or more cutting assemblies, each cutting assembly comprising:

an elongated, thin, flexible cutting finger having a tip, a first surface, a second surface, and a centerline extending in a length direction, wherein the tip of the cutting finger is beveled with a first bevel surface and a second bevel surface forming a sharp edge along the first surface of the cutting finger, the tip of the cutting finger having a tip angle between 10 degrees and 45 degrees, wherein the first bevel surface bevels the tip on a first side of the centerline and the second bevel surface bevels the tip on a second side of the centerline, wherein a first line of intersection between the first bevel surface and the second surface is oriented at a first sweep angle relative to a line orthogonal to the centerline and a second line of intersection between the second bevel surface and the second surface is oriented at a second sweep angle relative to the line orthogonal to the centerline, the first sweep angle and the second sweep angle have values between 5 degrees and 30 degrees; and

a mounting mechanism for positioning the cutting finger to the first roller in operative relation such that the second surface of the cutting finger contacts a surface of the first roller at a contact point spaced from the tip of the cutting finger such that the sharpened edge along the first surface of the cutting finger is spaced from the surface of the first roller by a distance of between 50 microns and 120 microns.

12. A fuser apparatus, comprising:

a first roller and a second roller in a nip relationship to transport the receiver member therebetween and to permanently fuse the marking particles to the receiver member under the application of heat and pressure; and

a stripping mechanism for stripping the receiver member from the first roller, the stripping member comprising one or more cutting assemblies, each cutting assembly comprising:

an elongated, thin, flexible cutting finger having a first surface, a second surface, and at least one raised protrusion protruding from the second surface spaced from a tip of the cutting finger, wherein the tip of the cutting finger is beveled with at least one beveled surface forming a sharp edge along the first surface, the tip of the cutting finger having a tip angle of less than 25 degrees; and

a mounting mechanism for positioning the cutting finger to the first roller in operative relation such that the at least one raised protuberance projecting from the second surface of the cutting finger contacts a surface of the first roller at a point of contact such that the sharpened edge along the first surface of the cutting finger is spaced from the surface of the first roller by a distance of between 50 microns and 120 microns.

13. The fuser apparatus of claim 12, wherein the first roller is a support roller and the second roller is a heated fuser roller.

14. The fuser apparatus of claim 12, wherein the first roller is a heated fuser roller and the second roller is a support roller.

15. The fuser apparatus of claim 12, further comprising a release agent management system that applies a release agent to the first roller or the second roller.

16. The fuser apparatus of claim 15, wherein the mounting mechanism positions the cutting finger such that release agent on the surface of the first roller does not flow onto the first surface of the cutting finger when the first roller is rotated.

17. The fuser device of claim 12, wherein the difference between the tip angle and an angle of attack formed between the second surface of the cutting finger and a tangential plane of the first roller at the point of contact is between 5 and 15 degrees.

18. The fuser apparatus of claim 12, wherein said cutting finger has a centerline extending in a length direction, wherein said cutting finger is beveled with a first beveled surface and a second beveled surface, wherein said first beveled surface bevels said tip on a first side of said centerline and said second beveled surface bevels said tip on a second side of said centerline, wherein a first line of intersection between said first beveled surface and said second surface is oriented at a first sweep angle relative to a line orthogonal to said centerline and a second line of intersection between said second beveled surface and said second surface is oriented at a second sweep angle relative to said line orthogonal to said centerline, said first and second sweep angles having values between 5 and 30 degrees.

19. The fuser apparatus of claim 12, wherein the at least one chamfered surface is a planar surface.

20. The fuser apparatus of claim 12, wherein the at least one chamfered surface is a non-planar surface.

21. The fuser apparatus of claim 20, wherein the at least one chamfered surface has a stepped thickness profile.

22. A paper transportation system, comprising:

a first roller and a second roller in a sandwiched relationship to transport the receiver member therebetween; and

a stripping mechanism for stripping the receiver member from the first roller, the stripping member comprising one or more cutting assemblies, each cutting assembly comprising:

an elongated, thin, flexible cutting finger having a first surface, a second surface, and at least one raised protrusion protruding from the second surface spaced from a tip of the cutting finger, wherein the tip of the cutting finger is beveled with at least one beveled surface forming a sharp edge along the first surface, the tip of the cutting finger having a tip angle of less than 25 degrees; and

a mounting mechanism for positioning the cutting finger to the first roller in operative relation such that the at least one raised protuberance projecting from the second surface of the cutting finger contacts a surface of the first roller at a point of contact such that the sharpened edge along the first surface of the cutting finger is spaced from the surface of the first roller by a distance of between 50 microns and 120 microns.

Technical Field

This invention pertains to the field of electronic image printing and more particularly to receiver media stripping mechanisms for fuser devices.

Background

Electrophotography is a useful process for printing an image on a receiver (or "imaging substrate"), such as a piece of paper or another planar medium (e.g., glass, fabric, metal, or other object) or sheet (sheet) as will be described below. In this process, an electrostatic latent image is formed on the photoreceptor by: the photoreceptor is uniformly charged and then the selected uniformly charged regions are discharged to produce an electrostatic charge pattern (i.e., a "latent image") corresponding to the desired image.

After latent image formation, the charged toner particles are brought into the vicinity of the photoreceptor and attracted to the latent image to develop the latent image into a toner image. Note that, depending on the composition of the toner particles (e.g., clean toner), the toner image may not be visible to the naked eye.

After the latent image is developed on the photoreceptor into a toner image, the appropriate receiver is brought into juxtaposition with the toner image. A suitable electric field is applied to transfer the toner particles of the toner image to the receiver to form the desired printed image on the receiver. The imaging process is typically repeated many times with a reusable photoreceptor.

The receiver is then removed from its operative association with the photoreceptor and subjected to heat or pressure to permanently fix (i.e., "fuse") the printed image to the receiver. Multiple print images (e.g., separate images of different colors) can be overlaid on the receiver before fusing to form a multi-color print image on the receiver.

Contact fusing systems consist of a heated surface where the image and support medium are pressed against until the toner is sufficiently melted to adhere to the support medium. The heated fusing surface can be a roller or a heated fusing belt. The media and toner are pressed against the fuser surface with a pressure roller or pressure belt. The roller or belt can be heated or unheated.

For printing systems where the toner used does not include an additive (e.g., a release wax) to prevent the toner from adhering to the fuser surface, a release fluid (e.g., oil) is typically applied to the fuser surface before the media is fused. For printing systems that print on cut sheets of media, the interframe space separates consecutive sheets. Some of the release fluid applied to the fusing surface during this inter-frame gap will be transferred to the pressure roller surface. In many printing systems, a contact cutter (skive) is used to peel the media from the pressure roller. In such a case, any relief fluid delivered to the pressure roller can be cut by the contact cutter and collected on its surface. The released fluid on the cutter surface may then be transferred to the back side of the subsequent sheet of media. This can lead to unwanted artifacts (artifacts), particularly when printed in a double-sided (i.e., double-sided) printing mode. In this case, any release fluid delivered to the backside of the substrate in the fusing subsystem may wet the imaging surface when the second side image is printed by the imaging module. The released fluid on the imaging surface may then lead to a higher or lower print density in the corresponding image area, which can produce undesirable image artifacts. Such artifacts may persist in many sheets of media until the release fluid is removed from the imaging surface. Even in a single-sided printing mode, dripping of the release fluid on the surface of the media may result in differential gloss artifacts, or may be transferred to adjacent media pieces in the output tray to create visible surface artifacts.

There is also a need for a stripping mechanism for a fuser apparatus that effectively strips receiver media from a fuser roller without causing the receiver media to be contaminated with a different degree of release agent.

Disclosure of Invention

The present invention proposes a fuser apparatus including:

a first roller and a second roller in a sandwiched relationship to transport the receiver member therebetween and to permanently fuse the marking particles to the receiver member under the application of heat and pressure; and

a stripping mechanism for stripping a receiver member from a first roller, the stripping member comprising one or more cutting assemblies, each cutting assembly comprising:

an elongated, thin, flexible cutting finger having a tip, a first surface, a second surface, and a centerline extending in a length direction, wherein the tip of the cutting finger is beveled with a first bevel surface and a second bevel surface, forming a sharp edge along the first surface of the cutting finger, the tip of the cutting finger having a tip angle between 10 degrees and 45 degrees, wherein the first chamfer surface chamfers the tip on a first side of the centerline and the second chamfer surface chamfers the tip on a second side of the centerline, wherein a first intersection line between the first chamfer surface and the second surface is oriented at a first sweep angle (sweep angle) with respect to a line normal to the centerline, and a second intersection line between the second chamfer surface and the second surface is oriented at a second sweep angle relative to a line normal to the centerline, the first sweep angle and the second sweep angle having values (magnetites) between 5 degrees and 30 degrees; and

a mounting mechanism for positioning the cutting finger to the first roller in operative relationship such that the second surface of the cutting finger contacts the surface of the first roller at a contact point spaced from the tip of the cutting finger such that the sharpened edge along the first surface of the cutting finger is spaced from the surface of the first roller by a distance of between 50 microns and 120 microns.

The invention has the following advantages: cutting refers to having well controlled tip clearance across a wide range of operating conditions.

This has the additional advantage that any release agent on the surface of the roller is guided to the side and prevented from flowing onto the receiver side of the cutting finger where it can subsequently be transferred to the receiver. This has the result that image artefacts which may result when the release agent is transferred to the receiver are reduced.

Drawings

FIG. 1 is a front cross-section of an electrophotographic printer suitable for use with the various embodiments;

FIG. 2 is a front cross-section of one of the print modules of the electrophotographic printer of FIG. 1;

FIG. 3 illustrates a schematic side view of a fuser module according to an exemplary embodiment;

FIG. 4 illustrates a bottom view of an exemplary cutting finger according to a first configuration;

FIG. 5 shows a cross-sectional side view of the cutting finger of FIG. 4 in an operative position relative to a fuser module pressure roller;

6A-6C illustrate a cutting finger installed in an exemplary mounting mechanism;

FIG. 7 illustrates the cutting assembly including two cutting fingers 312 in an operative position relative to the fuser module pressure roller;

8A-8C illustrate different exemplary shapes of chamfer surfaces;

FIG. 9 illustrates an exemplary beveled fixture useful for forming beveled surfaces on cutting fingers;

10A-10B illustrate bottom views of exemplary cutting fingers according to a second configuration;

FIG. 11 is a cross-sectional side view of the cutting finger of FIG. 10A in an operative position relative to a fuser module pressure roller; and

fig. 12A-12C illustrate several exemplary raised geometries for the cutting finger of fig. 10A-10B.

It is to be understood that the drawings are for purposes of illustrating the concepts of the invention and may not be to scale. Identical reference numerals have been used, where possible, to designate identical features that are common to the figures.

Detailed Description

The invention includes combinations of the embodiments described herein. References to "a particular embodiment" and the like relate to features presented in at least one embodiment of the invention. Separate references to "one embodiment" or "a particular embodiment" or the like do not necessarily refer to the same embodiment or embodiments; however, such embodiments are not mutually exclusive, unless so indicated or readily apparent to those of ordinary skill in the art. The use of the singular or plural reference to the word "method" or "methods" and the like is not limiting. It should be noted that the word "or" is used in this disclosure in a non-exclusive sense unless explicitly stated otherwise or required by the context.

As used herein, the terms "parallel" and "perpendicular" have a tolerance of ± 10 °.

As used herein, a "sheet" is a discrete piece of media, such as receiver media (described below) for an electrophotographic printer. The sheet has a length and a width. The sheet is folded along a fold axis (e.g., positioned at the center of the sheet along the length dimension and extending the entire width of the sheet). The folded sheet contains two "lobes," each being that portion of the sheet on one side of the fold axis. The two sides of each leaf are referred to as "pages". The "face" refers to one side portion of the sheet, whether before or after folding.

As used herein, "toner particles" are particles of one or more materials that are transferred to a receiver by an Electrophotographic (EP) printer to produce a desired effect or structure (e.g., a printed image, texture, pattern, or overlay) on the receiver. As is known in the art, the toner particles can be milled or chemically prepared from larger solids (e.g., precipitated from a solution of pigment and dispersant using an organic solvent). The toner particles can have a range of diameters (e.g., less than 8 pm, about 10-15 pm, up to about 30 pm, or more), where "diameter" preferably relates to a volume-weighted median diameter (volume-weighted median diameter) as determined by a device such as a Coulter Multisizer. When practicing this invention, it is preferable to use larger toner particles (i.e., those having a diameter of at least 20 pm) in order to obtain a desired toner pile height that will enable macroscopic toner relief structures (relief structures) to be formed.

"toner" refers to a material or mixture that contains toner particles and can be used to form an image, pattern, or coating when placed on an imaging member that includes a photoreceptor, photoconductor, or electrostatically charged or magnetic surface. The colorant can be transferred from the imaging member to the receiver. The toner is also referred to in the art as marking particles, dry ink, or developer, but it is noted that "developer" is used herein differently, as described below. The colorant can be a dry mixture of particles or a suspension of particles in a liquid colorant matrix.

As already mentioned, the coloring agent includes coloring agent particles; it can also include other types of particles. The particles in the colorant can be of various types and have various characteristics. Such properties can include absorption of incident electromagnetic radiation (e.g., particles containing colorants such as dyes or pigments), absorption of moisture or gases (e.g., desiccants or getters), inhibition of bacterial growth (e.g., biocides, particularly useful in liquid-toner systems), adhesion to a receiver (e.g., adhesives), electrical conductivity or low magnetic reluctance (e.g., metal particles), electrical resistivity, texture, gloss, remanence, fluorescence, resistance to corrosive agents, and other properties of additives known in the art.

In a one-component or one-component development system, "developer" refers only to the toner. In these systems, none, some, or all of the particles in the colorant can be magnetic themselves. However, the developer in the one-component system does not include magnetic carrier particles. In a two-member, or multi-member development system, the "developer" refers to a mixture comprising toner particles and magnetic carrier particles, which can be conductive or non-conductive. The toner particles can be magnetic or non-magnetic. The carrier particles can be larger than the toner particles (e.g., 15-20 pm or 20-300 pm in diameter). The magnetic field is used to move the developer in these systems by applying a force on the magnetic carrier particles. The developer is moved into the vicinity of the imaging member or the conveying member by a magnetic field, and toner or toner particles in the developer are conveyed from the developer to the member by an electric field, as will be described further below. The magnetic carrier particles are not intentionally placed on the component by the action of an electric field; only the colorant is intentionally placed. However, magnetic carrier particles, as well as other particles in the toner or developer, can be inadvertently transported to the imaging member. The developer can include other additives known in the art, such as those listed above for the colorant. The colorant and carrier particles can be substantially spherical or non-spherical.

Electrophotographic processes can be implemented in devices including printers, copiers, scanners and facsimile machines, as well as analog or digital devices, all of which are referred to herein as "printers". The various embodiments described herein are useful for electrostatic image printers, such as electrophotographic printers that employ a coloring agent developed on an electrophotographic receiver, and ion image (ionographic) printers and copiers that do not rely on an electrophotographic receiver. Electrophotography and ion imaging are types of electrostatic imaging methods (printing using electrostatic fields), which are a subset of electronic imaging methods (printing using electric fields). The invention can be practiced using any type of electronic image printing system, including electrophotographic and ion image printers.

Digital copy printing systems ("printers") typically include a digital front end processor (DFE), a print engine (also referred to in the art as a "marking engine") for applying toner to a receiver, and one or more post-press finishing systems (e.g., a UV coating system, a glosser system, or a laminator system). The printer is capable of reproducing a desired black-and-white or color image onto the receiver. The printer is also capable of producing a selected toner pattern on the receiver that does not directly correspond to the visible image (e.g., surface texture).

The DFE receives an input electronic file (such as a postscript command file) made up of images from other input devices (e.g., a scanner, digital camera, or computer-generated image processor). In the context of the present invention, an image can include a photographic rendition of a scene as well as other types of visual content such as text or graphical elements. The image can also include non-visible content such as texture, gloss, or specific specifications for a protective overlay pattern.

The DFE can include various functional processors such as a Raster Image Processor (RIP), an image positioning processor, an image manipulation processor, a color processor, or an image storage processor. The DFE rasterizes an input electronic file into an image bitmap for printing by a print engine. In some embodiments, the DFE allows a human operator to set up parameters such as layout, font, color, paper type, or post-trim options. The print engine takes the rasterized image bitmap from the DFE and converts the bitmap into a form that can control the printing process from the exposure device to the transfer of the print image onto the receiver. The finishing system applies features (such as protection, glossing, or adhesion to the print). The finishing system can be implemented as an integrated component of the printing press or as a separate machine through which the printed products are fed after they have been printed.

The printer can also include a color management system that is responsible for the characteristics of the image printing process (e.g., an electrophotographic process) implemented in the print engine to provide known, consistent color reproduction characteristics. The color management system can also provide known color copies for different inputs, such as digital camera images or film images. Color management systems are well known in the art, and any such system can be used to provide color correction in accordance with the present invention.

In one embodiment of an electrophotographic modular printing machine useful with various embodiments (e.g., NEXPRESS SX3900 printer manufactured by Eastman Kodak Company of Rochester, New York), a color-toner print image is made in a plurality of color imaging modules arranged in series, and the print image is sequentially electrostatically transferred to a receiver adhered to a transport web that moves through the modules. The color-imparting agent includes a colorant (e.g., a dye or pigment) that absorbs visible light of a particular wavelength. Commercial machines of this type typically employ an intermediate transfer member in the respective module for transferring the visible image from the photoreceptor and the print image to the receiver. In other electrophotographic printers, each visible image is transferred directly to a receiver to form a corresponding printed image.

It is also known for electrophotographic printers to have the ability to place clean toner also using an additional imaging module. Providing a clean toner overcoat to the color print is desirable to provide features such as protecting the print from fingerprints, reducing certain visual artifacts, or providing desirable texture or surface finish characteristics. Clean toner uses particles similar to toner particles of a color development station without color material (e.g., dye or pigment) being introduced into the toner particles. However, a clean toner overcoat can increase cost and reduce the color gamut of the print; it is therefore desirable to provide the operator/user with the option to determine whether a clean toner overcoat will be applied to the entire print. A uniform layer of clean toner can be provided. Layers that vary inversely with the height of the toner stack can also be used to establish a horizontal toner stack height. The pigments of the respective colors are placed one above the other at respective locations on the receiver and the height of the stack of the colorants of the respective colors is the sum of the height of the colorants of each respective color. The uniform stack height provides a print with more uniform or even gloss.

Fig. 1-2 are front cross-sections illustrating portions of a typical electrophotographic printer 100 useful with various embodiments. The printing press 100 is adapted to produce an image on a receiver, such as a single color image (i.e., a monochrome image) or a multi-color image such as a CMYK or a five color (five color) image. The multi-color image is also referred to as a "multi-component" image. One embodiment involves printing using an electrophotographic print engine having five sets of single color image producing or image printing stations or modules arranged in tandem, but more or less than five colors can be combined on a single receiver. Other electrophotographic typewriter or printer devices can also be included. The various components of the printing press 100 are shown as rollers; other configurations (including straps) are also possible.

Referring to fig. 1, a printing press 100 is an electrophotographic printing apparatus having a plurality of electrophotographic image forming printing modules 31, 32, 33, 34, 35 arranged in series, also referred to as an electrophotographic imaging subsystem. Each printing module 31, 32, 33, 34, 35 produces a single color toner image for transfer to receiver 42 moving successively through the module using a respective transfer subsystem 50 (only one marked for clarity). In some embodiments, one or more of the printing modules 31, 32, 33, 34, 35 can print a colorless toner image that can be used to provide a protective overcoat or tactile image feature. The receiver 42 is transported into the printing press 100 from a supply unit 40 using a transport web 81, which supply unit 40 can comprise an active feed subsystem as known in the art. In various embodiments, the visual image can be sequentially transferred in the transfer subsystem 50 from the imaging roller directly to the receiver or from the imaging roller to one or more transfer rollers or belts and then to the receiver 42. Receiver 42 is, for example, a cut sheet of a selected section of mesh or a flat receiver medium, such as paper or transparent film.

In the illustrated embodiment, each receiver 42 is capable of having up to five single color toner images transferred thereon in registration to form a multicolored image during a single pass through five printing modules 31, 32, 33, 34, 35. As used herein, the term "multicolour" means that in the printed image, various combinations of five colours are combined to form other colours on the receiver at various locations on the receiver, and all five colours participate to form primary colour printing (process colours) in at least some of the subsets. That is, at a particular location on the receiver, each of the five colors of coloring agents can be combined with one or more of the other colors to form a color that is different from the color of the coloring agent combined at that location. In the exemplary embodiment, printing module 31 forms a black (K) print image, printing module 32 forms a yellow (Y) print image, printing module 33 forms a magenta (M) print image, and printing module 34 forms a cyan (C) print image.

Printing module 35 is capable of forming red, blue, green, or other fifth type of printed image, including images formed from clean toner (e.g., one lacking pigment). The basic colors of the four subtractive methods (cyan, magenta, yellow, and black) can be combined in various combinations of subsets thereof to form a representative spectrum of colors. The color gamut of the printer (i.e., the range of colors that can be produced by the printer) depends on the materials used and the processes used to form the colors. The fifth color can be added to improve the color gamut. In addition to increasing the color gamut, the fifth color can also be a specialized color toner or mottle color, such as used to make a proprietary logo or color (e.g., metallic, fluorescent, or pearlescent colors) that cannot be produced with CMYK colors alone, or a clean toner or colored toner. Colored colorants absorb less light than they transmit, but do contain pigments or dyes that shift the color (hue) of the light passing through them to a lighter color. For example, a bluing tint applied to a white paper will cause the white paper to appear bluish when viewed under white light, and will cause yellow printed under the bluing tint to appear greenish under white light.

Receiver 42a is shown after passing through printing module 31. The printed image 38 on receiver 42a includes unfused toner particles. Receiver 42a then proceeds from one of each of the respective printing modules 31, 32, 33, 34, 35 to fuser module 60 (i.e., a fusing or fixing assembly) to fuse printed image 38 to receiver 42a, following transfer of the respective printed images overlaid in registration. The transport web 81 transports the print-image-bearing receiver to the fuser module 60, which fuser module 60 generally secures the toner particles to the respective receiver by the application of heat and pressure. The receivers are disengaged one by one from the transport web 81 to allow them to be fed neatly into the fuser module 60. The transport web 81 is then reformed for reuse at a cleaning station 86 by cleaning and neutralizing the charge on the opposite surface of the transport web 81. A mechanical cleaning station (not shown) for removing or vacuuming the colorant off the transport web 81 can also be used independently of the cleaning station 86 or in conjunction with the cleaning station 86. The mechanical cleaning station can be arranged along the transport net 81 before or after the cleaning station 86 in the direction of rotation of the transport net 81.

In the illustrated embodiment, the fuser module 60 includes a heated fusing roller 62 and an opposing pressure roller 64, the heated fusing roller 62 and the opposing pressure roller 64 forming a fusing nip 66 therebetween. The pressure rollers 64 can also be referred to as support rollers. In one embodiment, the fuser module 60 further includes a release agent application sub-station 68 that applies a release fluid (e.g., silicone oil) to the fusing rollers 62. Alternatively, a waxy toner can be used without applying a release fluid to fuser roll 62. Other embodiments of contact and non-contact fuser can be employed. For example, solvent fixing uses a solvent to soften the toner particles so they are bonded to the receiver. Flash lamp fusing uses a short burst of high frequency electromagnetic radiation (e.g., ultraviolet light) to melt the toner. Radiation fixation uses low frequency electromagnetic radiation (e.g., infrared light) to melt the toner more slowly. Microwave fixing uses electromagnetic radiation in the microwave range to (primarily) heat the receiver, thereby causing the colorant particles to melt by heat conduction, so that the colorant is fixed to the receiver.

The fused receiver (e.g., receiver 42b carrying fused image 39) is transported in tandem along a path from fuser module 60 to output tray 69 or back to printing modules 31, 32, 33, 34, 35 to form an image on the backside of the receiver (i.e., to form duplex printing). Receiver 42b can also be transported to any suitable output accessory. For example, an auxiliary fuser or gloss assembly can provide a clean colorant overcoat. The printing press 100 can also include a plurality of fuser modules 60 to support applications such as overprinting (overprinting), as is known in the art.

In various embodiments, between the fuser module 60 and the output tray 69, the receiver 42b passes through the finisher 70. The finisher 70 performs various paper processing operations such as folding, stapling, hemming, collating, and bonding.

The printing press 100 includes a main press equipment Logic and Control Unit (LCU) 99 that receives input signals from various sensors associated with the printing press 100 and sends control signals to various components of the printing press 100. LCU 99 can include a microprocessor that incorporates suitable look-up tables and control software executable by LCU 99. It can also include a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a Programmable Logic Controller (PLC) with a program such as ladder logic, a microcontroller, or other digital control system. LCU 99 can include memory for storing control software and data. In some embodiments, sensors associated with the fuser module 60 provide appropriate signals to the LCU 99. In response to the sensor signals, the LCU 99 issues command and control signals that adjust the heat or pressure within the fuser nip 66 and other operating parameters of the fuser module 60. This allows the printer 100 to print on receivers having various thicknesses and surface finishes, such as glossy or matte.

Image data for printing by the printing press 100 can be processed by a raster image processor (RIP; not shown) which can include a color separation screen generator or a plurality of color separation screen generators. The output of the RIP can be stored in a frame or line buffer for color separation of the delivery of print data to each of a set of respective LED typewriters associated with the print modules 31, 32, 33, 34, 35 (e.g., color channels for black (K), yellow (Y), magenta (M), cyan (C), and red (R), respectively). The RIP or color separation screen generator can be part of the printing press 100 or remote from the printing press 100. The image data processed by the RIP can be obtained from a color document scanner or digital camera, or generated by a computer, or from a memory or network that typically includes image data representing successive images that need to be reprocessed into halftone image data for adequate representation by the printer. RIP is capable of performing image processing procedures (e.g. color correction) in order to obtain a desired color print. The color image data is separated into respective colors and transformed by the RIP into halftone dot image data of the respective colors (e.g., using a halftone matrix that provides desired screen angles and screen rules). The RIP can be a suitably programmed computer or logic device and is adapted to employ stored or calculated halftone matrices and templates for processing the separated color image data into converted image data (which is in the form of halftone information suitable for printing). These halftone matrices can be stored in a screen pattern memory.

Fig. 2 shows additional details of printing module 31 representing printing modules 32, 33, 34 and 35 (fig. 1). The photoreceptor 206 of the imaging assembly 111 includes a photosensitive layer formed on a conductive substrate. The photosensitive layer is an insulator in the substantial absence of light, such that an electrical charge remains on its surface. Upon exposure to light, the charge dissipates. In various embodiments, the photoreceptor 206 is part of or disposed above the surface of the imaging component 111, which imaging component 111 can be a disk, drum, or belt. The photoreceptor can comprise a homogenous layer of a single material, such as vitreous selenium or a composite layer containing the photoconductor and another material. Photoreceptor 206 can also contain multiple layers.

The charging subsystem 210 applies a uniform electrostatic charge to the photoreceptor 206 of the imaging assembly 111. In the exemplary embodiment, charging subsystem 210 includes a grid of lines 213 having a selected voltage. The additional necessary components provided for control can be assembled in the vicinity of the various processing elements of the respective printing module. The meter 211 measures the uniform electrostatic charge provided by the charging subsystem 210.

An exposure subsystem 220 is provided for selectively modulating the uniform electrostatic charge on photoreceptor 206 in an imagewise manner by exposing photoreceptor 206 to electromagnetic radiation to form a latent electrostatic image. The uniformly charged photoreceptor 206 is typically exposed to actinic radiation provided by selectively activating particular light sources in an LED array or laser arrangement that outputs light that is directed onto the photoreceptor 206. In embodiments using a laser device, a rotating polygon (not shown) is sometimes used to scan one or more laser beams across the photoreceptor in the fast scan direction. One pixel site (site) at a time is exposed and the intensity or duty cycle of the laser beam is varied at each spot site. In embodiments using an array of LEDs, the array can include a plurality of LEDs arranged next to each other along a line, all of the spot locations in a row of spot locations on the photoreceptor can be selectively exposed simultaneously, and the intensity or duty cycle of each LED can be varied over a line exposure time to expose each pixel location in the row during the line exposure time.

As used herein, an "engine pixel" is the smallest addressable unit on photoreceptor 206 that exposure subsystem 220 (e.g., a laser or LED) can expose with a selected exposure that is different from the exposure of another engine pixel. The engine pixels can overlap (e.g., to increase addressability along the slow scan direction). Each engine pixel has a corresponding engine pixel location, and the exposure applied to the engine pixel location is described by the engine pixel level.

Exposure subsystem 220 can be a write-white (write-white) or a write-black (write-black) system. In a write-white or "charged area development" system, exposure dissipates the charge on the area of the photoreceptor 206 to which toner should not adhere. The toner particles are charged to be attracted to the charge remaining on the photoreceptor 206. The exposed areas thus correspond to the white areas of the printed page. In a black-write or "discharged area develop" system, the toner is charged to be attracted to the bias voltage applied to the photoreceptor 206 and repelled from the charge on the photoreceptor 206. Thus, the toner adheres to the areas where the charge on the photoreceptor 206 has been dissipated by exposure. The exposed areas thus correspond to the black areas of the printed page.

In the illustrated embodiment, a gauge 212 is provided to measure the potential back exposed surface within the fragment area of the latent image that is sometimes formed in the non-image area on the photoreceptor 206. Other gauges and components (not shown) can also be included.

The development station 225 includes a toner housing 226 that can rotate or be stationary for applying toner of a selected color to the latent image on the photoreceptor 206 to produce a developed image on the photoreceptor 206 corresponding to the color of the toner placed at this printing module 31. The development stations 225 are electrically biased to develop the respective latent images by suitable respective voltages, which can be supplied by a power supply (not shown). The developer is supplied to the coloring case 226 by a supply system (not shown) such as a supply roller, an auger, or a belt. The toner is transported from the development station 225 to the photoreceptor 206 by electrostatic forces. These forces can include coulombic forces between the charged toner particles and the charged electrostatic latent image, and lorentz forces on the charged toner particles due to the electric field created by the bias voltage.

In some embodiments, the development station 225 employs a two-component developer that includes toner particles and magnetic carrier particles. The exemplary development station 225 includes a magnetic core 227 to cause magnetic carrier particles proximate the coloring shell 226 to form a "magnetic brush" as is known in the art of electrophotography. The magnetic core 227 can be stationary or rotating and can rotate at a speed and direction the same as or different from the speed and direction of the coloring housing 226. The magnetic core 227 can be cylindrical or non-cylindrical, and can include a single magnet or a plurality of magnets or magnetic poles disposed around the circumference of the magnetic core 227. Alternatively, the magnetic core 227 can include an array of solenoids that are driven to provide magnetic fields in alternating directions. The magnetic core 227 preferably provides a magnetic field having varying values and directions around the outer circumference of the coloring shell 226. The development station 225 can also employ a single member developer that includes a magnetic or non-magnetic toner without separate magnetic carrier particles.

The transport subsystem 50 includes a transport support member 113 and an intermediate transport member 112, the intermediate transport member 112 being for transporting the respective print image from the photoreceptor 206 of the imaging member 111 to a surface 216 of the intermediate transport member 112 via a first transport nip 201 and from there to the receiver 42, the receiver 42 receiving the respective toned print image 38 from each of the printing modules in a superimposed manner to form a composite image thereon. The printed image 38 is, for example, a separation of one color, such as cyan. Receiver 42 is transported by transport web 81. The transfer to the receiver is effected by an electric field provided to transfer the support member 113 through a power source 240, the power source 240 being controlled by the LCU 99. Receiver 42 can be any object or surface to which toner can be transferred from imaging component 111 by application of an electric field. In this example, receiver 42 is shown prior to entering second transfer nip 202, and receiver 42a is shown subsequent to the transfer of print image 38 onto receiver 42 a.

In the illustrated embodiment, the toner image is transferred from the photoreceptor 206 to the intermediate transfer member 112 and from there to the receiver 42. Registration of the separated toner images is achieved by registering the separated toner images on receiver 42, as is done with NEXPRESS SX 3900. In some embodiments, a single transfer member is used to sequentially transfer the toner image from each color channel to receiver 42. In other embodiments, the separated toner images can be transferred in registration directly from the photoreceptors 206 in the respective printing modules 31, 32, 33, 34, 25 to receiver 42 without the use of a transfer component. Any of the transfer processes may be suitable when practicing the present invention. An alternative method of transferring the toner image involves transferring the separate toner image in registration to a transfer member and then transferring the registered image to a receiver.

LCU 99 sends control signals to, among other things, charging subsystem 210, exposure subsystem 220, and corresponding development station 225 of each print module 31, 32, 33, 34, 35 (fig. 1). Each printing module can also have its own respective controller (not shown) coupled to the LCU 99.

Aspects of the invention will now be described with reference to fig. 3, which fig. 3 illustrates an exemplary fuser module 60. The fuser module 60 includes a fusing roller 62 and a pressure roller 64. Receiver 42 including unfused print image 38 is fed through transport web 81 into nip 66 between fuser roll 62 and pressure roll 64. Heated fuser roll 62 fuses the toner to receiver 42 to provide fused image 39. Receiver 42 with the fused image is then guided by paper guide 320 into exit roller 322.

In the illustrated embodiment, fusing roller 62 is an internally heated roller that includes a heating element (such as infrared heater lamp 324) to heat the surface of fusing roller 62. In other embodiments, the externally heated fusing roller 62 can be used in the case where heat is supplied to the fusing roller 62 from an external member (such as one or more heated rollers).

A fusing roller temperature sensor 302 senses the temperature of the surface of the fusing roller 62. The temperature is fed to a control system that controls the power of the heater lamp 324 to maintain the fusing roller 62 at a particular temperature.

In some embodiments, the pressure roller 64 can also include an optional heater lamp 326, although this is generally not necessary. An optional pressure roller cooler 315 can be used to cool the surface of the pressure roller 64. For example, the pressure roller cooler can be a hollow tube with a series of holes or slots to direct air onto the surface of the pressure roller 64. The power supplied by the heater lamp 326 and the flow of air through the pressure roller cooler 315 can be controlled in response to a signal from the pressure roller temperature sensor 304 to maintain the pressure roller 64 at a particular temperature.

The release agent application substation 68 comprises a release agent reservoir 336 containing a release agent 331. The releasing agent 331 is typically a silicone-based oil and is designed to prevent the toner from adhering to the fusing roller 62. In an exemplary embodiment, the release agent 331 is an organometallic functional polydimethylsiloxane. The core pad 330 is submerged in the release agent 331 and transfers the release agent 331 from the release agent reservoir 336 to the metering roller 332. The core pad 330 also functions to clean the surface of the metering roller 332. The metering roll 332 generally has a textured surface with a pattern of depressions. The metering blade 334 skives the surface of the metering roller 332 to provide a controlled amount of release agent 331 on the surface. The release agent 331 is then transferred from the metering roll 332 to the donor roll 338 and from there to the fusing roll 62.

Air cutters 316 direct a jet of air toward fuser nip 66. As receiver 42 exits fusing nip 66, an air jet of air reaches between fusing roller 62 and receiver 42 to separate receiver 42 from the surface of fusing roller 62. Air cutters 316 are sometimes referred to as air knives.

The stripping mechanism 300 includes one or more cutting assemblies 310. Each cutting assembly includes a cutting finger 312 mounted in a mounting mechanism 314. In the illustrated configuration, the cutting fingers 312 are contact cutters that contact the surface of the pressure roller 64 and are used to strip the receiver off the roller surface. Contact cutters have the advantage that: they are less expensive than air cutters, which strip the receiver from the roller surface with high velocity air. An unfortunate side effect of contact cutters is that they will peel away not only the receiver, but anything else that may be on the roller surface. This can include debris such as paper waste and toner particles, as well as any release agent 331 that may have been transferred to the roller surface. For conventional contact cutters, release agent 331 can collect on the receiver side of cutting finger 312 where it can be transferred to receiver 42. This may cause artifacts, particularly in the case of two-sided printing, in which case the receiver 42 makes a second pass through the printing press 100 (fig. 1). One way to circumvent this problem would be to have the cutting fingers 312 non-contact. However, a significant problem with operating a non-contact cutter is maintaining the required clearance between the tips of the cutting fingers 312 and the roller. Generally, the required gap should be no greater than the thinnest receiver 42 that needs to be peeled away. For machines that print combined paper down to 59 gsm, this gap needs to be about 70 pm. It is not possible to maintain such a small clearance without the ability of the cutter to follow the surface of the roller. As will be discussed later, the cutting finger 312 of the present invention has the particular feature of maintaining a particular tip clearance, while the particular feature on the cutting finger 312 maintains contact with the roller. This is effective to prevent the release agent 331 from accumulating on the paper side of the cutting finger 312.

A fuser roller cleaner assembly 305 is used to clean the surface of fuser roller 62 to remove residual toner particles after receiver 42 is separated from fuser nip 66. The fuser roll cleaner assembly 305 includes a cleaning web 306, which cleaning web 306 travels from a supply roll 307 around a web backing roll 309 to a tension roll 308. The cleaning web 306 is typically a fabric made of a synthetic polymer, such as aramid.

A pressure roller cleaner 303 is provided to clean the surface of the pressure roller 64. In the exemplary embodiment, pressure roller cleaner 303 is wrapped with a fabric made of a synthetic polymer (such as aramid or polyamide) and counter-rotates with respect to pressure rollers 64. Pressure roller cleaner 303 removes residual debris such as paper scraps and toner particles, and it also serves to uniformly spread any release agent 331 conveyed to pressure roller 64 in the inter-frame gap between the sheets of receiver 42.

Fig. 4 illustrates a bottom view of a cutting finger 312 according to an exemplary embodiment of the present invention. A cross-sectional side view of the cutting finger 312 is shown in fig. 5. The cutting fingers 312 are made of a thin, flexible material such as metal or plastic. The cutting fingers 312 have an extent in a length direction 343To a centerline 346 of the tip 344. The cutting finger 312 has an upper first surface 354 and a bottom second surface 356 facing the pressure roller 64. The thickness of the cutting fingers 312 is preferably between 120-500 microns, and more preferably between 200-300 microns. The width of the cutting fingers 312 is preferably between 2.5-20 mm, and more preferably between 10-15 mm. The tip 344 of the cutting finger 312 is rounded and beveled with first and second beveled surfaces 340, 341. The chamfered surfaces 340, 341 form a sharpened edge 342 along a first surface 354 of the cutting finger 312, the cutting finger 312 having a tip angle θ χ that is preferably between 10-45 degrees, and more preferably between 20-30 degrees. The first chamfered surface 340 chamfers the tip 344 on a first side of the centerline 346, and the second chamfered surface 341 chamfers the tip 344 on a second side of the centerline 346. A first line of intersection 348 between the first chamfer surface 340 and the second surface 356 is at a first sweep angle θ with respect to a line normal to the centerline 346_S1Oriented and a second intersection line 349 between the second chamfer surface 341 and the second surface 356 at a second sweep angle θ with respect to a line normal to the centerline 346_S2And (4) orientation. A first sweep angle and a second sweep angle theta_S1、θ_S2Preferably between 5-30 degrees and more preferably between 10-25 degrees. In the illustrated embodiment, the first sweep angle and the second sweep angle θ_S1、θ_S2The values of (a) are equal, however this is not a requirement. Chamfered surfaces 340, 341 act in a manner similar to the bow of a boat to push any release agent 331 on the roller surfaces to the side, preventing it from flowing up over tip 344 onto upper second surface 354 where it can then be transferred to receiver 42 (fig. 3). The illustrated cutting fingers 312 have mounting holes 358 to facilitate mounting to the mounting mechanism 314.

As can be seen in the enlarged detail a of fig. 5, the cutting fingers 312 contact the surface of the pressure roller 64 at contact points 347. The cutting fingers 312 are at an angle of attack of 0 relative to a tangent 350 to the roller surface_AAnd (4) orientation. The angle of attack is preferably in the range of 5-30 degrees. Angle of attack theta_AAnd tip angle θ χ are selected so that the sharpness at the tip of cutting finger 312The edge 342 is maintained at a tip gap T_GAway from the roller surface. In a preferred embodiment, the tip gap T_GBetween 50-120 μm, and more preferably between 70-100 μm. This is large enough to ensure that the release agent 331 (fig. 3) does not flow onto the first surface 354 of the cutting fingers 354, but small enough so that it can separate a thin receiver (e.g., as thick as 75 μm) from the roller surface. This requires tip angle θ χ to be greater than angle of attack 0_A. In the preferred embodiment θ χ - θ_AIs between 5-15 degrees. The tip offset distance TQ between sharp edge 342 and contact point 347 is preferably at least 25 μm. In an exemplary embodiment, the thickness of the cutting finger 312 is 254 μm, the width of the cutting finger 312 is 12 mm, the tip angle θ χ is 24 degrees, and the angle of attack is 0_AIs 14 degrees, sweep angle theta_SIs 10 degrees, which produces a tip clearance T of about 100 μm_G. This geometry has been found to produce good results over a wide range of media types and system conditions.

The cutting fingers 312 are pressed against the roller surface with a tip load TL which is preferably between 75-600 mN, and more preferably between 100-200 mN. In an exemplary embodiment, a tip load of TL =140 mN is used. In the illustrated embodiment, the tip load is controlled by reducing the thickness of the cutting fingers 312 in the thinned portion 360. In an exemplary configuration, the thickness of the cutting finger is about 254 μm, but it is reduced to about 100 μm in the thinned portion 360.

Fig. 6A-6C illustrate additional details of cutting assembly 310 according to an exemplary embodiment. Fig. 6A illustrates an isometric view of the cutting assembly 310, fig. 6B illustrates a top view of the cutting assembly 310, and fig. 6C illustrates a cross-sectional side view of the cutting assembly through the cutting line shown in fig. 6B. As can be seen in fig. 6B-6C, the mounting mechanism 314 has several different parts, including a cutting bracket 400, a cut-down member 410, a hold-down spring 415, and a hold-down pivot pin 420. To install the cutting finger 312, the rear end of the cutting press 410 is pressed downward, pivoting the cutting press 410 about the press pivot pin 420 and compressing the press spring 415. The cutting finger 312 can then be inserted with the mounting hole 358 (fig. 4) on the cutting finger 312 fitting over the mounting pin 405 on the cutting bracket 400. The rear end of cutting press 410 is then released, clamping cutting finger 312 between cutting bracket 400 and cutting press 410, with the front side of cutting press 410 pressing down on thinned portion 360 (fig. 4) of cutting finger 312. It will be apparent to those skilled in the art that any suitable type of mounting mechanism 314 known in the art in other embodiments can be used to mount the cutting finger 312 in an operative position relative to the pressure roller 64.

Fig. 7 illustrates an isometric view of the cutting assembly 310 mounted in an operative position relative to the pressure roller 64, according to an exemplary embodiment. In this configuration, the cutting assembly 310 includes two cutting fingers 312 mounted in corresponding mounting mechanisms 314 toward the center of the pressure roller 64. Cutting assembly 310 also includes wings 425 that raise the edge of receiver 42 away from pressure roller 64.

The chamfer surfaces 340, 341 formed at the tip 344 of the cutting finger 312 need not be planar surfaces. Fig. 8A-8C illustrate several exemplary cross-sectional profiles that can be used for the chamfer surfaces 340, 341. In the example of fig. 8A, the chamfer surface 340 is planar such that the cross-sectional profile is a straight line.

In the example of fig. 8B, the chamfered surface 340 is a non-planar curved surface such that the cross-sectional profile is a curved line. Such a curved surface can be formed, for example, if the chamfer surface 340 is manufactured by pressing a cutting finger against a grinding wheel. It is noted that in the case of curved chamfer surfaces, the lines of intersection 348, 349 (fig. 4) between the chamfer surfaces 340, 341 and the second side 356 of the cutting finger 312 may not be straight. In such a case, the sweep angle can be defined using a best-fit straight line through the curved intersection lines 348, 349.

In the example of fig. 8C, the chamfered surface 340 has a stepped thickness profile. For example, such a surface can be formed if the chamfered surface 340 is fabricated by using a series of etching processes to remove material near the tips 344 of the cutting fingers 312, with a mask for each etching process adjusted to expose more (or fewer) cutting fingers 312 to the etching process.

Since the chamfer surface 340 in the example of fig. 8b-8C is non-planar, the definition of the tip angle θ χ may be somewhat ambiguous. One method that can be used to define the tip angle θ χ is to determine the best-fit planar surface (as shown by the dashed lines in fig. 8 b-8C), and calculate the angle θ χ relative to the best-fit planar surface.

Fig. 9 illustrates an exemplary chamfer fixture 430 that can be used to fabricate the cutting finger 312 with planar chamfer surfaces 340, 341 as shown in fig. 8A. The cutting finger 312 is clamped into the chamfer fixture 430 using a clamp 435, with the tip 344 of the cutting finger 312 positioned in contact with the planar surface of the grinding stone 450. The example chamfer fixture 430 includes a sweep angle θ that can be adjusted to control the chamfer surfaces 340, 341_S1、θ_S2And a miter angle adjustment mechanism 445 that controls the tip angle θ χ formed by the miter surfaces 340, 341.

In an exemplary manufacturing process, non-chamfered cutting fingers 312 are clamped into chamfered fixture 430 with tips 344 just touching abrasive stones 450. The adjustment screw 460 is then adjusted to move the cutting finger 312 toward the grinding stone 450 by an amount corresponding to the amount of material to be removed by the beveling process. In an exemplary configuration, the beveling process removes between 0.5-1.0 mm of material. The grinding stone 450 is then vibrated back and forth along the direction of motion 455 until the desired amount of material is removed. In an exemplary process, the grinding stone 450 is moved manually by a human operator. In other configurations, a motorized transport system can be used to move the grinding stones 450 using an automated motion process.

After the first chamfer surface 340 is formed, the cutting fingers 312 can be repositioned to form a second chamfer surface 341 by making appropriate adjustments to the sweep angle adjustment mechanism 440.

In other embodiments, the grinding stone 450 in fig. 9 can be replaced with a grinding wheel or belt sander. With the tape sander configuration, the tip 344 of the cutting finger 312 is positioned against the sanded tape. The ground belt is transported along the belt path instead of moving the grinding stones 450 back and forth in a vibratory motion.

In the embodiment so far described, the point on the second surface 356 of the cutting finger 312 that corresponds to the intersection of the second surface 356 with the first and second chamfer surfaces 340, 341 makes contact with the pressure roller 64. An important feature of the cutting finger 312 is that the sharpened edge 342 at the tip 344 of the cutting finger 312 has a specific tip clearance T_GSpaced from the surface of the pressure roller 64. In the foregoing embodiments, tip clearance is controlled primarily by controlling tip angle θ χ and angle of attack O ^. Another feature is that the first and second chamfer surfaces 340, 341 help direct the flow of the release agent 331 over the surface of the roller so that it does not flow up onto the upper surface of the cutting finger 312. In other embodiments, these features can be provided in alternative ways.

An alternative embodiment of one such class is illustrated in fig. 10A-10B, fig. 11. One or more protrusions 510 are provided, the one or more protrusions 510 being spaced apart from the tip 344 of the cutting finger 312 by a distance D. Controlling tip gap T by distance D along with height H of protrusion(s) 510_G. Preferably, the tip gap T_GBetween 50-120 μm, and more preferably between 50-100 μm. In the exemplary configuration of fig. 10A, two protrusions 510 are provided on either side of the centerline 346. In the exemplary configuration of fig. 10B, a single protrusion 510 is provided, the single protrusion 510 being positioned on the centerline. The small contact points 347 between the surface of the pressure roller 64 and the protuberances 510 on the cutting finger 312 enable the release agent 331 to flow around the protuberances 510 and prevent the release agent 331 from flowing up onto the first surface 354 of the cutting finger 312 where it can be transferred to the receiver 42. Preferably the distance D is in the range of 3-8 mm, and the height.

In the example of fig. 10A-10B, a single chamfered surface 520 is provided, the single chamfered surface 520 forming the sharp edge 342 at the tip 344 of the cutting finger 312. An intersection line 522 formed between the chamfer surface and the second surface 356 of the cutting finger 312 is perpendicular to the centerline 346 extending in the length direction 343. The tip angle θ χ is preferably less than 25 degrees, and more preferably less than 15 degrees. In other embodiments, multiple chamfer surfaces (e.g., the first and second chamfer surfaces 340, 341 of fig. 4) can be used in combination with the protrusion 510 of fig. 10A-10B.

The protrusion 510 can have a variety of different shapes. For example, fig. 10A illustrates a protrusion 510 having a circular footprint, while fig. 10B illustrates a protrusion having a rounded triangular footprint. Likewise, the height profile of the protrusions 510 can also take on various shapes as illustrated by some exemplary shapes in fig. 12A-12C. In the example of fig. 12A, the protrusion 510 has a hemispherical profile. In the example of fig. 12B, the height profile of the protrusion 410 is elliptical. In the example of fig. 12C, the protrusion 510 has an asymmetric height profile.

The protrusions 510 can be fabricated using any suitable method known in the art. In some embodiments, the protrusions can be formed by using a stamping operation to locally deform the shape of the cutting fingers 312. In other embodiments, the cutting finger 312 includes a protrusion 510 that can be formed using a molding operation. In other embodiments, the protrusion 510 can be formed by starting with a thicker cutting finger 312 and using an etching process to reduce the thickness in the enclosed area away from the protruding protrusion 510.

In the exemplary embodiment discussed above, cutting finger(s) 312 are used to peel receiver 42 away from pressure roller 64 in fuser module 60. It will be apparent to those skilled in the art that in other embodiments the cutting finger(s) 312 can be used to peel the receiver 42 away from the fuser roller 62. In such a case, the cutting assembly 310 is reversed and positioned such that the cutting finger(s) 312 contact the surface of the fuser roller 62. The cutting finger(s) 312 of the present invention can also be used in other types of paper transport systems to peel a sheet of receiver media from the surface of any type of roller, such as a paper transport roller.

Parts list

31 printing module

32 printing module

33 printing module

34 printing module

35 printing module

38 printing images

39 fused image

40 supply unit

42 receiver

42a receiver

42b receiver

50 transport subsystem

60 fuser module

62 fusing roller

64 pressure roller

66 fusing clip

68 Release agent application substation

69 output tray

70 trimmer

81 transportation net

86 cleaning station

99 logic and control unit

100 printing machine

111 image forming unit

112 intermediate transfer member

113 transfer support member

201 first transfer nip

202 second conveying clamp

206 light sensor

210 charging subsystem

211 counter

212 counter

213 Grating

216 surface

220 exposure subsystem

225 develop subsystem

226 coloring shell

227 magnetic core

240 power source

300 peeling mechanism

302 fusing roller temperature sensor

304 pressure roller temperature sensor

303 pressure roller cleaner

305 fuser roll cleaner assembly

306 cleaning net

307 supply roll

308 tension roller

309 net support roller

310 cutting assembly

312 cutting finger

314 mounting mechanism

315 pressure roller cooler

316 air cutting member

320 paper guide

322 exit roller

324 heater lamp

326 heater lamp

330 core pad

331 releasing agent

332 metering roller

334 metering blade

336 release agent reservoir

338 donor Rollers

340 chamfered surface

341 chamfered surface

342 sharp edge

343 longitudinal direction

344 tip

346 center line

347 contact point

348 intersecting line

349 intersecting line

350 tangent line

354 first surface

356 second surface

358 mounting hole

360 thinned portion

400 cutting bracket

405 mounting pin

410 cutting press

415 pressing spring

420 hold down the pivot pin

425 wing part

430 beveling fixing piece

435 clamp

440 sweep angle adjustment mechanism

445 miter angle adjusting mechanism

450 grinding stone

455 direction of motion

460 adjusting screw

510 projection

520 chamfered surface

522 intersecting line

Distance D

Height H

T_GTip clearance

TL tip load

TQ tip offset

θ_S1Sweep angle

θ_S2Sweep angle

Angle theta chi tip

θ_A Angle of attack