SIMPLE ITB STEERING RIB APPLICATOR

Abstract

This invention provides a steering rib for an ITB. These steering rib or ribs are applied to the ITB by placing the rib around a cylindrical fixture. The rib is held in place by a vacuum that is applied to the rib to hold it against the fixture until the rib is adhered to the inside surface of an ITB. Once the rib or ribbing is adhered to the ITB, a series of apertures directs compressed air against the rib and the ITB to release them from the fixture.

Description

This invention relates to an electrophotographic color system and more specifically to an intermediate transfer belt used in these systems.

BACKGROUND

In one electrophotographic color system, an array or series of different color imaging stations are aligned above an endless intermediate transfer belt (ITB). Each imaging station contains a raster output scanner (ROS), photoreceptor drum, development station, and cleaning station. The ROS emits an electronic beam (laser) which impinges on the rotating photoconductive drum, thereby causing that location on the drum to undergo a change in electrical charge. As the drum continues to rotate past the development station, toner particles of a color which is unique to that imaging station will attach to the drum at the location charged by the ROS. This colored image is then transferred from the drum to an intermediate transfer belt (ITB) that is passing by, and in contact with, that photoreceptor drum. As the intermediate belt passes by the different imaging stations (each usually containing a different color) it picks up subsequent color layers from the drums to create a complete color image which is then transferred to media.

Systems using intermediate transfer belt (ITB) architectures in the lower cost markets have identified passive belt tracking as a low cost alternative to active steering. Where as actively steered systems require a closed-loop control system consisting of multiple sensors, motors, and various other hardware and software components, the passively steered systems work on mechanics alone. One method for passive steering is through the use of belt steering or guide ribs. These ribs are adhered to the belt's surface and provide a mating surface with notched rollers, or the like, within the belt module. This interface keeps the belt (ITB) aligned as it rotates, preventing lateral movement, and in turn, ensuring proper image-on-image and image-on-paper registration.

SUMMARY OF THE INVENTION

This invention provides a method and device for aiding in the application of one or more steering ribs to the inside circumference of an intermediate transfer belt. The device consists of a drum or cylinder onto which the self-adhesive ribbing material placed and held via vacuum. The ITB is then slid over the cylinder or drum and located with respect to the ribbing. At this point the vacuum is removed and a puff of air is applied, transferring the ribbing material to the transfer belt. The process would be repeated to apply a rib on the other end or other ITB location if desired. This cylindrical apparatus with vacuum and air apertures greatly simplifies application of the steering rib and improves quality and uniformity.

The sequence of operation of the method of this invention is as follows: (1) Vacuum is applied to the lower plenum of the cylindrical fixture. (2) A precut strip of pressure sensitive adhesive coated urethane steering rib is placed over the lower plenum. (3) Once in place, the scrim paper can be removed from the outside surface of the ribs, exposing the adhesive on the outside surface of the steering rib. (4) Compressed air is applied to the upper plenum and the ITB belt is placed around the cylindrical fixture and slid down until it engages completely with the base. (5) Vacuum is applied to the upper plenum, securing the belt in place. (6) Vacuum is removed from the lower plenum and compressed air is applied, forcing the outside surface of the ribbing against the inner circumference of the belt. (7) The belt is then removed; the process can be repeated to apply ribbing to the opposite end of the belt as necessary.

While polyurethane ribs are a preferred material, any suitable material can be used for the steering rib such as other plastics, papers, tapes, and the like. Also, external connections to a source of vacuum and compressed air are located in the ribbing application fixture, or sources of compressed air can be located within the fixture if more convenient.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a color imaging system using an embodiment of an intermediate transfer belt of this invention.

FIG. 2 illustrates a domed ribbing application fixture with an external connection to vacuum and compressed air used in the present invention.

FIG. 3 illustrates a ribbing application fixture without a dome and with an internal source of vacuum and compressed air that can be used in the present invention.

FIG. 4 illustrates an embodiment of a ribbing application fixture of this invention with the intermediate transfer belt positioned on it ready for the ribbing material to be applied.

FIG. 5 is a perspective view of the ribbing application fixture of FIG. 4.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PREFERRED EMBODIMENTS

In FIG. 1, a color imaging system 1 is illustrated having an array of raster output scanners (ROS) 2 and their associated photoreceptor drums 5 aligned above an endless intermediate transfer belt 3. Each ROS emits a different image beam 4 on a photoconductive drum 5 to charge the drum's surface where the image for that color will be located. As the drum 5 rotates, the charged regions pick up toner of the color for that particular imaging station and transfer this color image to the surface of the belt 3 so that each colored image is deposited in relation to the previous deposited image. At the end of the process, all six deposited images (that are color developed at each station) are precisely aligned to form the final color image which is eventually transferred to media. The arrows 7 indicate the rotation direction of drum 5 and belt 3. The steering ribs 8 of this invention are shown on the inside surface of the ITB belt 3.

Rollers 19 of FIG. 1 mate with steering ribs 8 to move the intermediate transfer belt 3 precisely around the structure of system 1. Rollers 19 can have an abrasive surface or projections that mate with the ribs 8 to ensure there is no belt 3 slippage and precise movement of the belt for good image-to-image alignment.

This type of color system having an array of ROS units is generally described in U.S. Pat. No. 6,418,286 and is incorporated by reference into this disclosure.

The cylindrical fixture 9 of this invention consists primarily of the following parts: The domed upper portion 10 of the fixture 9 allows for quick and easy alignment of the belt 3 (shown in FIG. 4) around the fixture 9. Below the dome 10 is an air plenum 11 which provides a constant cushion of air between the fixture 9 and belt 3 during the loading and unloading process. The air and vacuum is provided by external air and vacuum intake 12. Beneath the air plenum is a vacuum channel 13 into which the ribbing material 8 is located. The channel 13 helps to locate the ribbing 8 while vacuum from channel 13 holds it in place. During the application process, this chamber is subsequently pressurized in order to force the ribbing material 8 along the internal circumference of the belt 3. Finally, the base 14 provides a hard stop to which the belt 3 and ribbing edges are aligned. The term “cylindrical” fixture includes round and oval cylinders or any other fixtures having round surfaces.

FIG. 3 illustrates an embodiment of an application fixture 9 without a dome 10 and without an external air and vacuum intake 12. In this embodiment any suitable vacuum generating and compressed air means 15 are located within the air plenum 11. A vacuum channel 13 having vacuum outlet 16 and compressed air outlets 17. (OK)

In FIG. 4 for clarity dotted lines are not shown or used but rather the fixture 9 is shown in solid lines. FIG. 5 is a perspective view of an embodiment of a fixture 9 of this invention. The sequence of the operation of the application of the steering ribs 8 is as follows: (1) Vacuum is applied to the lower plenum 13 (2) A precut strip of pressure sensitive adhesive coated urethane 8 (or other suitable material such as plastic tapes) is placed into the channel 13. (3) Once in place, the scrim paper can be removed from the external surface of rib 8 exposing the adhesive on the outer surface of the ribbing 8, (4) Compressed air is applied to the upper plenum 11 and the belt 3 is placed around the fixture and slid down until it engages completely with the base 14. (5) Vacuum is applied to the upper plenum 11 securing the belt in place. (6) Vacuum is removed from the lower plenum 13 and compressed air is applied, forcing the ribbing 8 against the inner circumference 18 of the belt 3, (7) The belt 3 is then removed while applying compressed air to the upper plenum 11; the process can be repeated to apply ribbing to the opposite end of the belt 3 as necessary. A portion of the steering rib 8 is cut away to show the location of lower plenum 13 and vacuum outlet aperture 16. The ribs 8 can be placed on both ends of the belt 3 or on only one end or at any location on the inner surface 18 of belt 3.

In summary, the present invention provides a novel electrophotographic marking system, a method of applying a steering rib to an ITB and a novel rib application fixture.

The electrophotographic marking system comprises an intermediate transfer belt (ITB). Thus belt has on its inner surface at least one steering rib, which is configured to guide and steer the ITB during a marking step. The rib or ribs are configured to mate with an aligned abraded or notched roller or surface to keep the belt aligned as it rotates, thus ensures minimum lateral movement during image-on-image registration. These ribs are provided on the ITB by placing the ribs with an adhesive on its outer surface around and on the circumference of a cylindrical fixture and positioning the ITB on the cylindrical fixture over the ribbing and thereby adhering the ribs to an inside surface of the ITB. The steering rib has an adhesive on its external side to facilitate attachment to the inner surface of the belt. The steering rib is composed of a material selected from the group consisting of plastics, paper, and fiberglass with an adhesive on its outer surface. The steering rib, in a preferred embodiment, comprises a polyurethane material. The steering rib is located on two edge portions of the ITB. The steering rib in one embodiment is located on one edge portion of said belt.

This invention also provides a method of applying a steering rib to an ITB of an electrophotographic marking system. This method comprises providing a cylindrical ribbing application fixture, providing in the fixture a base structure, above the base structure is positioned a lower plenum, and above the lower plenum is positioned an upper plenum, then applying a vacuum to the lower plenum to thereby hold in place a precut strip of the ribbing that is positioned around the lower plenum, exposing to an inner surface of the ITB to an outer surface of the steering rib with an adhesive located on the outer surface of the ribbing, removing the vacuum from the lower plenum and applying compressed air to release the ribbing from the fixture, forcing the ribbing with adhesive against an inner circumference of said belt, and removing the belt with the ribbing from the application fixture.

In one embodiment the vacuum is applied to the lower plenum via apertures in the lower plenum. The compressed air is applied to the upper plenum via apertures in the upper plenum. The vacuum and the compressed air are supplied to the fixture from a source external to the fixture or in another embodiment the vacuum and the compressed air are supplied to the fixture from a source internal to the fixture. The ribbing in one embodiment is applied to one inner side of the ITB. In another embodiment, the ribbing is applied to two or more inner locations on the ITB. The ribbing in a preferred embodiment comprises a polyurethane material. The lower plenum and the upper plenum comprise a cylindrical or drum-like structure having a dome in one embodiment positioned above the upper plenum for easy sliding of an ITB over the dome and around the drum. In a second embodiment, the dome is not used on the fixture. Also provided herewith is a cylindrical ribbing application fixture for applying a ribbing to an ITB comprising a base structure. Above the base structure is positioned a cylindrical lower plenum; positioned above the lower plenum and contiguous therewith is a cylindrical upper plenum. The lower plenum has a plurality of vacuum apertures around its circumference, these apertures are configured to apply a vacuum to the ribbing to hold the ribbing in place around the lower plenum before the ribbing is adhered to the ITB. The upper plenum has a plurality of air apertures around its circumference, which are configured to apply compressed air against an inner surface of the ITB to thereby release the ITB from the fixture after the ribbing is adhered to the ITB.

In one embodiment the vacuum and the compressed air are supplied to the fixture from a source outside the fixture. In another embodiment the vacuum and the compressed air are supplied to the fixture from a source internal to the fixture. The lower plenum is configured to receive the ribbing around its circumference and wherein the apertures in the lower plenum are configured to supply a vacuum that holds the ribbing against the lower plenum prior to the ribbing being adhered to the ITB. Obviously, the fixture of this invention is configured to apply the ribbing against an inner surface of all sizes of ITB.

It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that 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.

Claims

1. An electrophotographic marking system, said system comprising an intermediate transfer belt (ITB),

said belt comprising on its inner surface at least one steering rib,

said steering rib configured to guide and steer said ITB during a marking step,

said ribs configured to mate with an aligned notched roller or surface to keep said belt aligned as it rotates and ensures minimum lateral movement during image on image registration,

said ribs provided on said ITB by placing said ribs with an adhesive on its outer surface around and on a cylindrical fixture, positioning said ITB on said cylindrical fixture over said ribbing and thereby adhering said ribs to an inside surface of said ITB.

2. The marking system of claim 1 wherein said steering rib has an adhesive on its external side to facilitate attachment to said inner surface of said belt.

3. The marking system of claim 1 wherein said steering rib is composed of a material selected from the group consisting of plastics, paper, and fiberglass.

4. The marking system of claim 1 wherein said steering rib comprises a polyurethane material.

5. The marking system of claim 1 wherein said steering rib is located on two edge portions of said belt.

6. The marking system of claim 1 wherein said steering rib is located on one edge portion of said belt.

7. A method of applying a steering rib to an ITB of an electrophotographic marking system, said method comprising:

providing a cylindrical ribbing application fixture,

providing in said fixture a base structure,

above said base structure is positioned a lower plenum,

and above said lower plenum is positioned an upper plenum,

applying a vacuum to said lower plenum to thereby hold a precut strip of said ribbing that is positioned around said lower plenum,

exposing to an inner surface of said ITB an outer surface of said steering rib with an adhesive located on said outer surface of said ribbing,

applying compressed air to said upper plenum,

applying vacuum to said upper plenum, securing the belt in place,

removing said vacuum to said lower plenum forcing said ribbing with said adhesive against an inner circumference of said belt,

removing said vacuum from said upper plenum,

reapplying compressed air to said upper plenum,

and removing said belt with said ribbing from said application fixture.

8. The method of claim 7 wherein said vacuum and said compressed air are applied to said lower plenum via apertures in said lower plenum.

9. The method of claim 7 wherein said vacuum and said compressed air are applied to said upper plenum via apertures in said upper plenum.

10. The method of claim 7 wherein said vacuum and said compressed air are supplied to said fixture from a source external to said fixture.

11. The method of claim 7 wherein said vacuum and said compressed air are supplied to said fixture from a source internal to said fixture.

12. The method of claim 7 wherein said ribbing is applied on one inner side of said ITB.

13. The method of claim 7 wherein said ribbing is applied to two or more inner locations on said ITB.

14. The method of claim 7 wherein said ribbing comprises a polyurethane material.

15. The method of claim 7 wherein said lower plenum and said upper plenum comprise a cylindrical or drum-like structure having a dome positioned above for easy sliding of an ITB over said dome and around said drum.

16. A cylindrical ribbing application fixture for applying a ribbing to an ITB comprising:

a base structure,

above said base structure is positioned a cylindrical lower plenum,

positioned above said lower plenum and contiguous therewith is a cylindrical upper plenum,

said lower plenum having a plurality of apertures around its circumference, said apertures configured to apply a vacuum to said ribbing to hold said ribbing in place around said lower plenum and said apertures configured to apply said compressed air to said ribbing to apply said ribbing to said ITB,

said upper plenum having a plurality of apertures around its circumference, said apertures configured to apply compressed air against an inner surface of said ITB to thereby aiding in the loading and release of said ITB from said fixture after said ribbing is adhered to said ITB and said apertures configured to apply vacuum to said ITB to secure it in place during the ribbing application process.

17. The fixture of claim 16 wherein said vacuum and said compressed air are supplied to said fixture from a source outside said fixture.

18. The fixture of claim 16 wherein said vacuum and said compressed air are supplied to said fixture from a source internal to said fixture.

19. The fixture of claim 16 where said lower plenum is configured to receive said ribbing around its circumference, and wherein said apertures in said lower plenum are configured to supply a vacuum that holds said ribbing against said lower plenum.

20. The fixture of claim 16 configured to apply said ribbing against an inner surface of all sizes of ITB.