JP2004163503A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent soiling of a primary transfer electrode layer by toner fed along a seam by a cleaning blade. <P>SOLUTION: In an image forming apparatus provided with an endless state image carrier belt or a transfer material carrying belt (1) to which a cleaning blade is abutted and which is connected at the seam (2) provided with an electrode layer (3) on one side end part, the seam is formed inclined with respect to the belt width direction which is perpendicular to the rotational direction of the belt so that the seam of the electrode layer part is located on the upstream side in the rotational direction of the belt. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus having an endlessly formed image carrier belt or transfer material conveying belt.
[0002]
[Prior art]
For example, in an endless intermediate transfer belt connected by a seam, the seam is inclined with respect to a belt width direction perpendicular to the rotation direction of the belt, so that a step at the seam stretches a belt such as a driving roller. It is known that unevenness in speed and vibration generated when the vehicle gets over a running roller can be reduced to suppress image unevenness (Patent Document 1).
[0003]
In addition, by making the seam oblique to the belt width direction, it is possible to prevent the bounce generated when the seam portion passes through the cleaning blade and improve the cleaning performance, and to reinforce the seam portion. It is also known that by attaching the members obliquely, it is possible to suppress the speed unevenness due to the joint portion (Patent Document 2).
[0004]
[Patent Document 1] JP-A-8-305112
[Patent Document 2] JP-A-9-146386
[Problems to be solved by the invention]
Although it is possible to improve image unevenness by making the seam oblique to the belt width direction, the oblique direction is not shown in the above-mentioned Patent Documents 1 and 2. However, when a primary transfer electrode layer for supplying a bias voltage for transferring a toner image on a photoreceptor is provided at an end of the belt and a blade for cleaning the belt surface is in contact with the belt, When the seam is inclined with respect to the belt width direction, a force is applied to the toner scraped off by the blade and sent downstream along the seam along the seam. Therefore, when the seam is inclined with respect to the belt width direction so that the seam portion of the primary transfer electrode layer is located on the downstream side with respect to the belt rotation direction, the toner sent along the seam by the cleaning blade may be at the belt end. This causes the primary transfer electrode layer of the portion to be soiled and causes transfer failure.
[0007]
[Means for Solving the Problems]
An object of the present invention is to provide an image forming apparatus provided with an endless image carrier belt or a transfer material transport belt that is contacted by a cleaning blade and joined by a seam having an electrode layer at one end. It is an object of the present invention to prevent the primary transfer electrode layer from being stained by toner sent along a seam by a cleaning blade, and to reliably apply a primary transfer bias.
For this purpose, the present invention provides an image forming apparatus provided with an endless image carrier belt or a transfer material transporting belt which is contacted with a cleaning blade and joined at one end by a seam having an electrode layer. Is formed at an angle with respect to the belt width direction perpendicular to the belt rotation direction so as to be on the upstream side with respect to the belt rotation direction.
Further, the present invention has a multilayer structure in which the belt is formed with a conductive layer and a semiconductive layer sequentially on a substrate, and the electrode layer is formed from the conductive layer surface at a portion where the semiconductive layer at one end of the belt is not formed. It is characterized in that it is formed over the semiconductive layer surface.
Further, the present invention is characterized in that an elastic electrode roller is disposed in contact with the electrode layer, and a transfer bias voltage is applied through the electrode roller.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a plan view showing an intermediate transfer member belt of the present embodiment, FIG. 2 is a cross-sectional view showing the intermediate transfer member belt, and FIG. 3 is a cross-sectional view illustrating a belt seam portion.
[0009]
The intermediate transfer belt 1 is endlessly formed by being joined at a diagonal seam 2 having a predetermined angle with respect to a belt width direction perpendicular to the belt traveling direction (rotation direction). There is a characteristic in the inclination direction. That is, the seam 2 is inclined with respect to the belt width direction such that the seam of the electrode layer portion is located upstream with respect to the belt rotation direction (in the illustrated example, from the bottom to the top of the drawing).
[0010]
When the inclination direction of the seam with respect to the belt width direction is set in this manner, the seam portion of the primary transfer electrode layer first contacts the tip of the cleaning blade (not shown), and the seam of the other portion sequentially contacts the cleaning blade. Finally, the joint end opposite to the primary transfer electrode layer contacts the cleaning blade. Therefore, the toner scraped off by the cleaning blade is sent from the primary transfer electrode layer side to the opposite side along the seam, thereby preventing the primary transfer electrode layer portion from being stained.
[0011]
As shown in FIG. 2, the intermediate transfer belt 1 of this embodiment has a conductive layer 5 made of aluminum or the like provided on a substrate 4 made of PET, and a semiconductive layer (paint) 6 formed on the surface thereof. A part where the semiconductive layer is not applied is formed in a band shape at an end portion thereof, and the primary transfer electrode layer 3 is formed on the exposed surface of the conductive layer 5, and a part thereof is semiconductive. It is formed so as to extend to the surface of the layer 6. The primary transfer electrode roller 10 contacts the primary transfer electrode layer 3, and a transfer bias voltage is applied to the conductive layer 5.
[0012]
As shown in FIG. 3, the seam 2 of the intermediate transfer belt is joined from the back side of the substrate 4 by a welded portion 7 formed by ultrasonic welding. When viewed microscopically, the electrode layer and the conductive layer are separated from each other at the seam 2, and the electrode roller 10 comes into contact with the separated electrode layer over the separated electrode layer.
[0013]
【Example】
FIG. 4 is an overall perspective view showing the intermediate transfer body unit, FIG. 5 is a cross-sectional view of a main part illustrating the intermediate transfer body belt, and FIG. 6 is a perspective view illustrating the primary transfer electrode roller.
[0014]
A drive roller 11 is provided at an end of the intermediate transfer body unit to drive the intermediate transfer body belt 1, and a primary transfer electrode layer 3 is formed at a belt end, and contacts the primary transfer electrode layer 3. And a primary transfer electrode roller 10 that rotates. The intermediate transfer belt 1 is rotated in a predetermined direction by a driving roller 11 and a driven roller 12, is given a constant tension by a tension roller 13, and is made of metal for determining a nip between the primary transfer backup roller 14 and the backup roller 14. Are provided. Further, a cleaning blade 16 for cleaning the belt surface comes into contact with a portion facing the driven roller 12.
[0015]
As shown in the enlarged view of FIG. 6, a primary transfer electrode layer 3 is formed at an end of the intermediate transfer body belt 1, and a primary transfer electrode roller 10 made of elastic rubber is provided at a position facing the driven roller 12. Is formed and a voltage of 220 V is applied.
[0016]
Hereinafter, the present embodiment will be described in more detail.
Through the steps of charging, exposing, and developing, the toner image reaches the primary transfer unit as the photosensitive member (not shown) on which the toner image is formed rotates. In the primary transfer section, the primary transfer backup roller 14 provided at a position facing the photoconductor is brought into contact with the photoconductor side by a force such as a spring, and the intermediate transfer belt and the photoconductor are contacted at a constant pressure by this force. .
[0017]
In this embodiment, the intermediate transfer member is provided with a PET film of 0.15 mm on the base material, a conductive layer such as an aluminum vapor-deposited layer on the surface thereof, and a semiconductive paint applied on the surface thereof to a thickness of 0.02 mm. A region where no paint is applied is provided at the end of the belt, and a carbon electrode layer having a width of 5 mm is provided on the surface of the conductive layer.
[0018]
The intermediate transfer member is formed by joining sheets in a belt shape, and the joint is formed by applying a PET film from the back side and joining them by ultrasonic welding. The seam has an angle with respect to the belt width direction perpendicular to the belt rotation direction, and the seam on the side with the carbon electrode layer is on the upstream side in the belt rotation direction. A primary transfer electrode roller 10 is arranged on the surface of the carbon electrode layer at a position facing the driven roller, and is configured to be driven to rotate by rotation of the intermediate transfer member.
[0019]
A bias voltage is applied to the primary transfer electrode roller 10 from a primary transfer high-voltage power supply (not shown), and the bias voltage is applied to the primary transfer electrode roller and the carbon electrode layer at the end of the intermediate transfer member, thereby performing intermediate transfer. Applied to the conductive layer of the body, the intermediate transfer body is uniformly charged. The toner image that has reached the primary transfer portion is nipped between the photosensitive member and the intermediate transfer member, and is primarily transferred onto the intermediate transfer member by the primary transfer bias applied to the conductive layer. This transfer is performed on the toner images sequentially formed on the photoconductor, and the colors are matched on the intermediate transfer body. At this time, the secondary transfer roller and the cleaner (not shown) do not disturb the toner image on the intermediate transfer member, and are kept separated.
[0020]
The primary transfer of the final color toner image onto the intermediate transfer member is started, and the superimposed image portion reaches the secondary transfer portion as the intermediate transfer member rotates. At this time, the transfer paper (not shown) is guided to the secondary transfer unit, the secondary transfer roller is brought into contact with the paper, and the toner images are collectively transferred to the transfer paper. The residual toner that has not been subjected to the secondary transfer reaches the cleaning portion of the intermediate transfer member, and the cleaning blade 16 abuts at this timing to scrape off the residual toner on the intermediate transfer member. Most of the scraped toner is collected into the cleaning housing (not shown), but some of the toner stays at the edge of the cleaning blade. In this state, when the diagonally joined seam reaches the position of the cleaning blade, the toner retained at the edge is sent obliquely along the diagonal seam. At this time, since the seam portion of the primary transfer electrode layer is arranged on the upstream side of the oblique seam, the seam is not contaminated by the obliquely fed toner. The toner sent obliquely is scraped off and sealed by a seal provided at the end of the cleaner, and is prevented from scattering outside the cleaner.
[0021]
【The invention's effect】
As described above, according to the present invention, the toner scraped off by the cleaning blade is sent to the downstream side in the belt rotation direction along the seam, but the seam portion of the primary transfer electrode layer is moved to the upstream side in the belt rotation direction. Therefore, the contamination of the primary transfer electrode layer by the toner sent in the direction of the seam by the cleaning blade can be prevented, and the primary transfer bias can be reliably applied.
[Brief description of the drawings]
FIG. 1 is a plan view showing an intermediate transfer member belt of the present embodiment.
FIG. 2 is a sectional view showing an intermediate transfer member belt.
FIG. 3 is a cross-sectional view illustrating a belt joint portion.
FIG. 4 is an overall perspective view showing an intermediate transfer unit.
FIG. 5 is a cross-sectional view illustrating a main part of the intermediate transfer belt.
FIG. 6 is a perspective view illustrating a portion of a primary transfer electrode roller.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Intermediate transfer belt, 2 ... Joint, 3 ... Primary transfer electrode layer, 4 ... Substrate, 5 ... Conductive layer, 6 ... Semiconductive layer, 10 ... Primary transfer electrode roller, 11 ... Drive roller, 12 ... Follower Roller, 13: tension roller, 14: backup roller, 15: support roller, 16: cleaning blade.

Claims (3)

In an image forming apparatus provided with an endless image carrier belt or a transfer material conveying belt joined by a seam having an electrode layer on one side end where a cleaning blade abuts, the seam of the electrode layer portion is in the belt rotation direction. An image forming apparatus in which a seam is formed so as to be inclined with respect to a belt width direction perpendicular to the belt rotation direction so as to be on the upstream side. The belt has a multilayer structure in which a conductive layer and a semiconductive layer are sequentially formed on a substrate, and the electrode layer straddles from the conductive layer surface of a portion where the semiconductive layer is not formed at one end of the belt to the semiconductive layer surface. The image forming apparatus according to claim 1, wherein the image forming apparatus is formed by cutting. 3. The image forming apparatus according to claim 1, wherein an elastic electrode roller is disposed in contact with the electrode layer, and a transfer bias voltage is applied via the electrode roller.

Images