JP2001125403A - Serial multicolor copying machine provided with electrode system intermediate transfer belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode system intermediate transfer belt for transferring and receiving a toner image in a stable condition in a copying machine. SOLUTION: As to the copying machine; the electrode system intermediate transfer belt 80 for transferring and receiving the toner image is provided with a resistance base body 84 for forming a lowermost layer, a semiconductor uppermost layer 88 formed above the resistance lowermost layer 84, and a series of conductive electrode 86 formed between the layers 84 and 88 in order to adjust an image transfer electric field inside the copying machine, so that the splashes of toner and the rupture of a nipping voltage before transfer can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

DESCRIPTION OF RELATED APPLICATIONS This application is based on US Provisional Patent Application No. 60 / 156,694, filed September 30, 1999.

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an electrophotographic printing machine, and more particularly, to an electrode type intermediate device for adjusting an image transfer electric field by reducing the problems of toner splash and voltage destruction of a nip before transfer. A tandem multicolor copier comprising a transfer belt, thereby ensuring better and more stable multicolor image transfer.

[0003]

2. Description of the Related Art In an electrophotographic printing machine, a photoconductive member is charged to a substantially uniform potential to make its surface photosensitive. The charged portion of the photoconductive member is exposed to a light image of the original document being copied. Exposure of the charged photoconductive member selectively removes charge in the irradiated area. Thereby, an electrostatic latent image is recorded on the photoconductive member corresponding to the information area included in the document being copied.

After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by contacting the latent image with a developing material containing charged toner particles, for example, black toner particles. The developing material can be a single component containing only charged toner particles, or as a binary component containing carrier particles and toner particles, when the toner particles are mixed or mixed with the carrier particles. It can be made to be electrically charged. In either case, contacting the developing material with the latent image forms a toner image on the photoconductive member, which is later transferred to copy paper. Next, the copy sheet is separated from the photoconductive member, and the toner powder is supplied onto the copy sheet via a fixing device, where the toner powder is heated and permanently adheres to the copy sheet. As a result, a black and white copy of the original document is formed.

In a multicolor electrostatographic printing press using a multicolor toner, the process of forming each color image is substantially the same as the above-described black and white printing process using only a black toner. However, rather than forming a single latent image on the photoconductive surface, several single color latent images corresponding to the color-by-color light images of the original document are recorded on the photoconductive surface. Each single color electrostatic latent image is developed with a plurality of toner particles in a complementary color relationship. This process is
It can be performed in a single process or in multiple processes, during which multiple cycles of image formation are performed on each colored image using each complementary colored toner particle. Are repeated to form a color toner image. In this process, the toner images of different colors can be superposed and transferred on the intermediate transfer belt or transferred in a serial arrangement.

In order to perform excellent and effective multicolor toner image transfer from a photoconductive drum to an intermediate transfer member, a transfer gap or a nip voltage destruction (pre-nip) which always hinders image transfer. A high electric field during transfer without breakdown is required. Restrictions that may affect such image transfer include (a) toner material (toner adhesion, toner pile height, etc.), (b) paper factors such as paper roughness, And (c) image attributes (eg, lines,
Halftone, solid line). Further, for such excellent and effective transfer and its stability, the material of the intermediate transfer member must have a lateral resistance greater than 1 × 10 ⁸ Ω-cm and a resistance of 10 × 10 ⁸ Ω-cm.
It is required to have a volume resistance of less than ¹² Ω-cm.

Conventionally, an intermediate transfer member with a non-electrode belt is a separate external conductive component or electrode that is biased, such as high and low resistance contact brushes,
Using a conductive blade, or a conductive contact roller, this electrode is located on the bottom side of the transfer belt to create a transfer electric field. However, these conventional intermediate transfer members may be partially ineffective if contaminants that insulate them are present, and may require a cleaning device to restore reliable contact and charging characteristics. In other words, a deskewer may be needed. Also, conventional intermediate transfer members, such as non-electrode belts, typically require a large contact area to improve charge transfer between the contacting bias component and the intermediate member. As a result, in the case of the intermediate transfer belt (ITB), undesirable dragging of the belt, particularly due to elastic belt elongation, tends to occur, which may cause a problem in superimposing images.

[0008]

According to one aspect of the present invention, there is provided an electrode-type intermediate transfer belt for transferring and receiving a toner image in a copying machine in a stable manner.

[0009]

According to the present invention, there is provided an electrode-type intermediate transfer belt comprising a resistive substrate forming a lowermost layer, a semiconductive uppermost layer formed above the resistive lowermost layer, and a resistive lowermost layer. A series of conductive electrodes formed between the semiconductive top layer, the series of conductive electrodes modulating the image transfer electric field within the copier, thereby reducing toner splash and pre-transfer nip voltage breakdown. It is possible to reduce.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, a serial multicolor electrophotographic copier is indicated generally by the reference numeral 200, which includes a frame 202 and a number of toner image units, for example, Reference numbers 20, 3 as a whole
It comprises four toner image units designated 0, 40, 50. Although a plurality of toner image units are shown as four, it is needless to say that any number of such toner image units can be equally implemented, and furthermore, can be considered as such.

As shown, each toner image unit 2
Reference numerals 0, 30, 40, and 50 are almost the same, and the only difference between the toner image units is the color of the toner and the developing material used in each unit. For example, toner image unit 20 uses cyan toner and developing material, and units 30, 40, and 50 use magenta, yellow, and black toner and developing material, respectively. Where units 20, 30, 40 and 50 are roughly similar, they will be described in detail together, particularly with reference to unit 20.

A photoconductive drum 12 having a photoconductive surface 13 is mounted on the toner image units 20, 30, 40, 50, and the various photoconductive drums 12 are arranged around their movement path. To advance a continuation of photoconductive surface 13 via an electrostatographic processing station,
It rotates in the direction of arrow 14. Initially, a portion of the photoconductive surface 13 passes below the corona generator 24, 34, 44, 54, which causes the portion of the photoconductive surface 13 to have a relatively high and substantially uniform potential. To be charged.

Next, the charged portion of photoconductive surface 13 is advanced through an imaging station, which is generally designated by the reference numeral 25,
The latent image forming unit including the raster output scanner (ROS) assembly 75 discharges each part of the charging unit imagewise and records the electrostatic latent image on this part. As shown, the latent image forming unit 26 may include a raster input scanner (RIS) assembly 71 for scanning a multicolor original document 27 placed on a transparent platen 31. The RIS assembly 71 includes a document illumination lamp, optics, a mechanical scanning device, and a charge-coupled device (these are not shown but are well known). This allows
The RIS assembly 71 scans the document 27 and converts the original image on the document into electronic image data organized as a series of raster scan lines. The electronic image data includes data indicating the density of the primary colors, for example, the densities of red, green, and blue at each point of the image on the document 27.

[0014] Alternatively, the electronic image data is output by a suitable source. The electronic data is transmitted to an image processing system (IPS) 73 having control electronics for generating and managing an image data flow to a raster output scanner (ROS) 75. The ROS 75 outputs the electronic image data as a series of raster scanning lines by modulating the laser beams 26, 36, 46, and 56. The ROS 75, as shown, controls the laser beams 26, 36, 4 based on which serial color image is to be formed by which image unit.
6, 56 are selectively output to the image units 20, 30, 40, and 50, respectively. Laser beams 26, 3
6, 46, 56 are focused on the photoconductive surface 13 of drum 12 using mirrors and lenses as shown. In this way, an electrostatic image of each required color separation image is recorded on photoconductive surface 13 of drum 12.

Next, the charged portion of the photoconductive surface 13 having the latent image is moved to developing units 28, 38, 48, 58, which are suitably charged toner and developer of the desired color. In the case of the toner image unit 20, for example, the toner image unit 20 contains a cyan toner and a developing material, and supplies the latent image to form a toner color separation image of a final multicolor toner image. Of course, as noted above, the specific colors of the toner and developing material will be different for each toner image unit 20, 30, 40, 50, and it is possible to alter the specific sequence or order for the use of different color toners. is there.

As shown, the toner image unit 2
For each of 0, 30, 40 and 50, the latent image is converted into a toner color separated image by the developing units 28, 38, 48 and 58 as described above, for example, in the case of the toner image unit 20, a cyan toner color separated image. After development, the toner color separation image is generally designated by reference numeral 2
It is moved to the transfer station indicated by 9, 39, 49, 59. Transfer stations 29, 39, 49,
At 59, the toner image is transferred onto the electrode-based intermediate transfer belt 80 according to the present invention (described in detail below) in a superimposed, accurately superimposed state.

Accordingly, the cyan toner image is formed and transferred by the toner image unit 20 itself. The magenta toner image is similarly formed by the toner image unit 30 and transferred to the previously formed and transferred toner image in a state of being accurately superimposed. The yellow toner image was similarly formed by the toner image unit 40 and transferred in a precisely superimposed superposition, and the black toner image was similarly formed by the toner imaging unit 50 and accurately superimposed. It is transferred in a superimposed state.

After the toner color image is transferred to the electrode type intermediate transfer belt 80 of the present invention, the residual toner and the residual developing material remaining on or adhering to the surface 13 of each drum 12 are removed, for example, by the cleaning device 22. 32, 42, and 52. The cleaning devices 22, 32, 42, and 52 are cleaning rollers formed of a suitable synthetic resin that is driven in a direction opposite to the direction of movement of the continuous transfer drum 12 so as to clean the surface of the drum 12 cleanly. Is provided. To assist this effect, a carrier may be supplied on the surface of the cleaning roller via a pipe. As described above, a wiper blade may be used to finish cleaning the surface 13 of the drum 12 in preparation for forming and transferring another color toner image.

As described above, after all the different toner color separation images have been formed and transferred onto the intermediate transfer belt 80 to form a composite multicolor toner image, the electrode-type intermediate transfer belt 80 The multicolor toner image is advanced to, for example, a transfer or transfix station 82. At the transfer or transfix station, the composite multicolor toner image is transferred from the electrode-based intermediate transfer belt onto copy paper 64, where it is heated and fused by heated fusing rollers 83, or the composite multicolor toner The image is transferred from the electrode-type intermediate transfer belt onto copy paper 64 for later fusing. After such transfixation or fusing, the substrate or copy sheet 64 is advanced to a catch or copy receiver 70 for later removal from the body 200 by an operator. After the composite multicolor toner image of the electrode-type intermediate transfer belt 80 is transferred or fixed on the copy paper 64, the residual toner and the residual developing material remaining on or adhered to the electrode-type intermediate transfer belt 80 are, for example, a cleaning device 72. Removed by. The cleaning device 72 includes a cleaning roller formed of a suitable synthetic resin that is driven in a direction opposite to the moving direction of the electrode-type intermediate transfer belt 80.

Referring now to FIGS. 1 and 2, the electrode-based intermediate transfer belt 80 of the present invention improves the adjustment and tolerance of the transfer electric field, and further includes the transfer gap, toner splash during transfer, and pre-transfer. It is particularly suitable for reducing nip field potential breakdown. Overall, the present invention provides better and more stable toner color separation from photoconductive drum 12 to electrode-based intermediate transfer belt 80 and from electrode-based intermediate transfer belt 80 to a copy substrate, such as copy paper 64. Achieve image transfer.

As described above, conventionally, an intermediate transfer member provided with a non-electrode belt has a biased external conductive component or electrode, such as a high-resistance and low-resistance contact brush, Using a conductive blade or a conductive contact roller, this electrode is located on the bottom side of the transfer belt to create a transfer electric field. However, these conventional intermediate transfer members may be partially ineffective if contaminants that insulate them are present, and may require a cleaning device to restore reliable contact and charging characteristics. That is, it may require a de-scummer. Also, conventional intermediate transfer members, such as non-electrode belts, typically require a large contact area to improve charge transfer between the contacting bias component and the intermediate member. Thereby, the intermediate transfer belt (ITB)
In this case, undesired belt dragging tends to occur, particularly due to elastic belt stretching, which can result in overlay problems.

The electrode type intermediate transfer belt 80 of the present invention is advantageous in overcoming the disadvantages of the conventional non-electrode type ITB,
This reduces problems and concerns about contamination and belt elongation,
Alternatively, the transfer electric field can be effectively adjusted.
As shown, the electrode-type intermediate transfer belt 80 includes an insulating base 84 including an insulating material such as polyester or polyimide. The insulating substrate 84 exposes at least a portion of each of the electrodes so that at least a portion of each of the electrodes along one or both end surfaces of the belt is used to apply a charging potential for adjusting a transfer electric field. It has a width slightly shorter than the length of the electrode.

As shown, the electrode-type intermediate transfer belt 80 has many conductive electrodes 86 formed on a resistive substrate 84. The electrodes are arranged in a pattern and are arranged transversely to the path and transversely or axially across the resistive substrate. The length of the electrode is
Depending on the width of the substrate, and ultimately the width of the electrode-type intermediate transfer belt, it can be up to about 20 inches (50 cm). Each electrode comprises a conductive material, such as copper, and is approximately 10
Preferably, it has a width of mil (2.5 mm). It is preferable that the interval between the electrodes, that is, the pitch, is also set to 10 mil. The electrodes themselves are printed, vacuum metallized,
Or it can be manufactured by any other suitable process. Importantly, the electrodes 86 eliminate high resistance contact with the belt and make the contact conductor for biasing the belt a smaller contact conductor for a smaller transfer nip. Make it possible.

The covering of the resistive layer or the semiconductive layer 88 is formed so as to cover the conductive electrode 86, and covers the conductive electrode 86. This coating layer is desirably a semiconductive layer that is dielectrically thin, has insulating properties, that is, has a sufficiently high specific resistance, has a thickness of less than 12 μm, and has a resistance of more than 10 ¹¹ Ω-cm. Low resistance of the resistive substrate (even if it meets transverse resistance requirements to avoid electrode printout) creates a belt short circuit problem to electrically weak areas on the photoconductor Because of the possibility, it is desirable to provide a resistance coating layer.

The coating layer is also desirable for realizing characteristics such as separation of toner or optimization of frictional force.
If heat transfer fusing is used in the intermediate transfer stage between the intermediate transfer member and the paper, it is relatively thick (greater than 5 mils (0.13 mm)) and conformable for high quality transfer fusing on coarser paper It is desirable to provide a coating layer.
Heat transfer fusing eliminates the concerns of electrostatic migration associated with coating layers having low resistivity and wet paper, which allows for lower resistance coating layers. Also, by providing a thicker coating layer that is desirable for conformability during transfer fusing, higher resistance to arcing between the intermediate transfer member and the photoconductor is achieved for coating layers having lower resistivity. And therefore the resistivity of the coating layer when applying transfixing is 1
Until 0 ⁸ Ω-cm can be reduced.

Experimentally, one embodiment of the electrode-based intermediate transfer belt 80 is a W.C. H. Br
Manufactured from printed material using a process developed by Ady, Milwaukee, Wyoming. This manufacturing process uses a line pattern of Br
and printing using special inks developed by Ady. The specialty inks are described, for example, in U.S. Pat. No. 4,714,631, which includes a water-soluble polymer, a solubility enhancer added within the polymer, and a rough surface in the ink layer after drying. Consisting of solid particle pigments for producing The resulting printed electrode pattern has multiple lines of 10 mil (0.25 mm) width at 10 mil (0.25 mm) intervals. The ink is approximately 18 "(45.7 cm) wide x 9" (2
(2.9 cm) length, supplied by silkscreening in a manner that repeats the process in segments. The substrate was 5 mil (0.13
mm) resistive polycarbonate and 5 mil (0.
13 mm) of polyethylene (PET).

After printing with the special ink as described above,
The printed material was placed in a vacuum chamber, first coated with about 0.01 μm of copper, and then vaporized with nickel to provide a wear-resistant nickel plating 94. Thus, the metal was deposited over the substrate and the inked areas to form a metallized film. Next, the metallized film is placed in a water tank equipped with a high pressure spray to remove the ink, where the ink removes itself and all the metal covering it, and is placed directly on the film surface. The metallized electrode pattern was left. A continuous electrode pattern can likewise be produced by means of a rotary flexographic process and by means of a conductive ink.

When the thickness 90 of the intermediate belt is smaller than the electrode pitch 92, the belt base 84 has a sufficient lateral resistance (re
It is necessary to provide a film having a sufficient lateral resistance between the conductive electrodes 86 in order to prevent the electrode from burning during transfer.
For a general 6 mil (0.15 mm) thick belt,
It has been found that the lateral resistance between the electrodes in all regions must be lower than 5 × 10 ¹⁰ Ω-cm to avoid electrode burning. On the other hand, the maximum allowable resistance depends on the shape of the electrode, the process speed, and the size of the transfer nip. A thicker coating layer 88 on the belt, such as a 10 mil (0.25 mm) conformable coating (when used in an intermediate heat transfer fusing system) provided on a rigid, thicker than 6 mil (0.15 mm) insulating substrate 84.
Is believed to relax some of the transverse resistance requirements to allow the use of resistive substrates having a resistivity much higher than 5 × 10 ¹⁰ Ω-cm. The lower resistance between the electrodes 86 is determined by the requirement to minimize the lateral current to a practical level. A typical lower limit is 10 ⁷ Ω
-Cm or greater, with a preferred lower limit being approximately 10 < ⁸ > [Omega] -cm or greater.

According to the design of the electrode type belt, the belt and the electric field adjusting bias members 23, 33, 43, despite the problem of local contamination at the bottom of the belt (for example, due to toner).
And 53 are possible. The high resistance coating layer also avoids the problem of electrostatic migration associated with highly wet paper. Electrode-based intermediate transfer belt 80 with electrodes 86 and semiconductive layer 88 provides additional advantages regarding electric field tuning due to the tolerance of the system with improved lateral conduction. The simplification of electrical contact can be facilitated by the use of completely electrode-based surfaces. The structure is suitable for charge adjustment and insensitive to dirt.

In summary, a serial multicolor copier is provided with an electrode-type intermediate transfer belt for transferring and receiving a toner image in a stable manner by enabling adjustment of the image transfer electric field. It has. This transfer electric field adjustment reduces the problem of toner splashing and pre-transfer nip voltage destruction and ensures better and more stable multicolor image transfer. The electrode-type intermediate transfer belt of the present invention includes a resistive substrate forming a lowermost layer, a semiconductive uppermost layer formed above the resistive lowermost layer, and a resistive lowermost layer and a semiconductive uppermost layer. It comprises a series of conductive electrodes formed, the series of conductive electrodes making it possible to adjust the image transfer electric field in the copier, thereby reducing toner splashing and pre-transfer nip voltage breakdown. Each electrode of the series of electrodes is formed with a width of about 10 mil (0.25 mm) and a distance of about 10 mil (0.25 mm) from an adjacent electrode. The space between adjacent electrodes is filled with a layer of resistive material to prevent lateral conduction and electrode burning.
A series of conductive electrodes are formed on an insulating substrate and covered with a layer of resistive material.

Although the present invention has been described in relation to particular embodiments, it is evident that many substitutions, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to embrace all such permutations, modifications, and variations that fall within the spirit and scope of the appended claims.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a serial type multicolor copying machine having an electrode type intermediate transfer belt according to the present invention.

FIG. 2 is a partially enlarged sectional view showing an electrode type intermediate transfer belt according to the present invention.

[Explanation of symbols]

 Reference Signs List 12 photoconductive drum 13 photoconductive surface 20, 30, 40, 50 toner image unit 22 cleaning device 23, 33, 43, 59 electric field adjusting bias member 24, 34, 44, 54 corona generating device 28, 38, 48, 58 Developing unit 29, 39, 48, 59 Transfer station 71 Raster input scanner assembly 73 Image processing system 75 Raster output scanner assembly 80 Electrode-type intermediate transfer belt 82 Transfer fixing station 83 Heat fixing roller 84 Belt substrate 86 Conductive electrode 88 Resistance layer , Semiconductive layer 94 abrasion resistant nickel plating

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Abraham Sheerian, New York, USA 14580 Webster Lisanikarane 809 (72) Inventor Joseph Manmino, United States of America 14526 Penfield Bella Drive 59 (72) Inventor Edward El Schroeder Jr. USA 14612 Rochester Glensideway 53, New York 53 (72) Inventor Michael Dee Thompson USA 14620 Rochester Rockingham Street 112 (72) Inventor Donald Jay Robertson USA 14450 Fair, New York Port Country Corner Lane 11

Claims (3)

[Claims] 1. A method comprising: (a) a frame; and (b) a plurality of toner image forming units attached to the frame, wherein each of the plurality of toner image forming units comprises: (i) a mobile device having a charge supporting surface; A photoreceptor capable of: (ii) a charging device for providing a uniform charge on the charge bearing surface; and (iii) a uniform charging device for electrostatically forming a color separation latent image on the charge bearing surface. An exposure device for imagewise removing charge from selected portions of the charged surface; and (iv) mounted on the frame to form a toner color separation image of the final multicolor toner image. A developing device for supplying a developing material containing charged toner particles of a corresponding color onto the color separation latent image; and (c) a fixing device, and attached to the frame,
A final multicolor image finishing assembly having an electrode-based intermediate transfer belt for forming a transfer nip with each of the plurality of toner image-forming units while forming an image transfer electric field; and wherein the electrode-based intermediate transfer belt comprises a toner A multicolor copier comprising a series of conductive electrodes to enable each of said image transfer electric fields to be adjusted to reduce bounce and nip voltage breakdown prior to transfer. 2. The method according to claim 1, wherein the electrode-type intermediate transfer belt is movable in a processing direction in a path, and each of the series of conductive electrodes is formed to extend in a direction transverse to the path. The multicolor copying machine according to claim 1. 3. An electrode-type intermediate transfer belt for transferring and receiving a toner image in a copying machine, comprising: (a) a resistive substrate forming a lowermost layer; and (b) a resistive lowermost layer of the resistive lowermost layer. A semiconductive top layer formed thereon; and (c) the resistive layer to enable adjustment of the image transfer field in the copier, thereby reducing toner splatter and pre-transfer nip voltage breakdown. An electrode type intermediate transfer belt comprising a series of conductive electrodes formed between a lowermost layer and the semiconductive uppermost layer.