JP4332837B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus having an endless image carrier belt or a transfer material transport belt.
[0002]
[Prior art]
For example, in an endless intermediate transfer belt that is joined at a seam, the seam is inclined with respect to the belt width direction perpendicular to the belt rotation direction so that the step of the seam stretches the belt such as a drive roller. It is known that unevenness in speed and vibration generated when getting over a running roller can be reduced and image unevenness can be suppressed (Patent Document 1).
[0003]
In addition, by slanting the seam with respect to the belt width direction, it is possible to improve the cleaning performance by preventing the bounce that occurs when the seam passes the cleaning blade. It is also known that unevenness in speed due to a joint portion can be suppressed by bonding members diagonally (Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 8-305112
[Patent Document 2]
JP-A-9-146386 [0006]
[Problems to be solved by the invention]
Although it is possible to improve image unevenness by making the seam oblique with respect to the belt width direction, the oblique direction is not shown in Patent Document 1 and Patent Document 2. However, when a primary transfer electrode layer for supplying a bias voltage for transferring a toner image on the photoreceptor is provided at the belt end, and a blade for cleaning the belt surface is in contact with the belt, When the seam is slanted with respect to the belt width direction, a force that is sent downstream with respect to the belt rotation direction along the seam acts on the toner scraped by the blade. 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 on the downstream side with respect to the belt rotation direction, the toner sent along the seam by the cleaning blade is This causes the primary transfer electrode layer of the portion to become dirty and cause transfer failure.
[0007]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention is intended to solve the above-described problems, and an image forming apparatus provided with an endless image carrier belt or transfer material conveying belt that is brought into contact with 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 soiled by the toner sent along the seam by the cleaning blade and to reliably apply the primary transfer bias.
Therefore, the present invention provides an image forming apparatus including an endless image carrier belt or a transfer material transport belt which is contacted by a cleaning blade and joined by a seam having an electrode layer at one end thereof. Is characterized in that a seam is formed so as to be inclined with respect to the belt width direction perpendicular to the belt rotation direction so as to be upstream of the belt rotation direction.
In the present invention, 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 is formed from the surface of the conductive layer where the semiconductive layer at one end of the belt is not formed. It is formed over the surface of the semiconductive layer.
Further, the present invention is characterized in that an elastic electrode roller in contact with the electrode layer is disposed, and a transfer bias voltage is applied through the electrode roller.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 1 is a plan view showing an intermediate transfer belt according to the present embodiment, FIG. 2 is a cross-sectional view showing the intermediate transfer belt, and FIG. 3 is a cross-sectional view illustrating a belt joint portion.
[0009]
The intermediate transfer body belt 1 is formed in an endless shape by joining at an oblique seam 2 having a predetermined angle with respect to the belt width direction perpendicular to the belt traveling direction (rotation direction). There is a characteristic in the inclination direction. That is, the inclination of the joint 2 with respect to the belt width direction is inclined so that the joint of the electrode layer portion is on the upstream side with respect to the belt rotation direction (in the illustrated example, from the lower side to the upper side in the drawing).
[0010]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention is intended to solve the above-described problems, and an image forming apparatus provided with an endless image carrier belt or transfer material conveying belt that is brought into contact with 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 soiled by the toner sent along the seam by the cleaning blade and to reliably apply the primary transfer bias.
For this purpose, the present invention provides an image carrier belt or transfer material conveying belt having an electrode layer to which a bias voltage is applied to one end of a belt surface connected endlessly by a seam and applied to the belt surface. In the image forming apparatus including at least a cleaning blade in contact, a joint portion having the electrode layer among the joints is first brought into contact with the cleaning blade, and a joint portion in another portion is sequentially brought into contact with the cleaning blade, and finally The seam is formed so as to be inclined with respect to the belt width direction perpendicular to the belt rotation direction so that the seam end opposite to the electrode layer is in contact with the cleaning blade.
In the present invention, 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 is a conductive layer in a portion where the semiconductive layer is not formed at one end of the belt. It is characterized by being formed across the surface from the surface of the semiconductive layer.
Further, the present invention is characterized in that the seams are joined from the back side by ultrasonic welding.
Further, the present invention is characterized in that the electrode layer and the conductive layer are separated at the joint portion.
Further, the present invention is characterized in that an electrode roller contacting the electrode layer is disposed and a transfer bias voltage is applied through the electrode roller.
In the invention, it is preferable that the electrode roller is an elastic electrode roller that is in contact with and straddles between the electrode layers of the joint portion.
[0011]
As shown in FIG. 2, the intermediate transfer belt 1 of the present embodiment is provided with a conductive layer 5 such as aluminum on a substrate 4 made of PET, and a semiconductive layer (paint) 6 formed on the surface 3. The layer structure is such that a part where the semiconductive layer is not applied is formed in a strip shape at the end, 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 joint 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 at the joint 2 and the electrode roller 10 is in contact with the separated electrode layers.
[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 for explaining the intermediate transfer body belt, and FIG. 6 is a perspective view for explaining a portion of the primary transfer electrode roller.
[0014]
A drive roller 11 is provided at the 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 the end of the belt and is in contact with the primary transfer electrode layer 3. A primary transfer electrode roller 10 that rotates is provided. The intermediate transfer belt 1 is rotated in a predetermined direction by a driving roller 11 and a driven roller 12 and is given a constant tension by a tension roller 13. The intermediate transfer belt 1 is made of metal for determining the nip between the primary transfer backup roller 14 and the backup roller 14. The support roller 15 is provided. Further, a cleaning blade 16 that cleans the surface of the belt abuts against a portion facing the driven roller 12.
[0015]
As shown in the enlarged view of FIG. 6, the primary transfer electrode layer 3 is formed on the end of the intermediate transfer belt 1, and the primary transfer electrode roller 10 made of elastic rubber is located at a position facing the driven roller 12. And a voltage of 220V is applied.
[0016]
Hereinafter, this embodiment will be described in more detail.
Through the charging, exposure, and development steps, the toner image reaches the primary transfer portion as the photoconductor (not shown) on which the toner image is formed rotates. In the primary transfer portion, the primary transfer backup roller 14 provided at a position facing the photoconductor is brought into contact with the photoconductor side with a force such as a spring, and the intermediate transfer belt and the photoconductor are brought into contact with each other with a constant pressure. .
[0017]
In this embodiment, the intermediate transfer member has a PET film of 0.15 mm on the substrate, a conductive layer such as an aluminum vapor deposition layer on the surface, and a semiconductive paint is applied to the surface with a thickness of 0.02 mm. In addition, an area where no paint is applied is provided at the belt end, and a carbon electrode layer is provided with a width of 5 mm on the surface of the conductive layer.
[0018]
The intermediate transfer member is obtained by joining sheet-like materials in a belt shape, and the joint is obtained 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 where the carbon electrode layer is located is the upstream side in the belt rotation direction. On the surface of the carbon electrode layer, a primary transfer electrode roller 10 is disposed at a position facing the driven roller, and is configured to rotate following the 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 source (not shown), and this bias voltage is intermediate transferred via the primary transfer electrode roller and the carbon electrode layer at the end of the intermediate transfer body. The intermediate transfer member is uniformly charged by being applied to the conductive layer of the body. 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 a primary transfer bias applied to the conductive layer. This transfer is performed on the toner images sequentially formed on the photosensitive member, and color matching is performed on the intermediate transfer member. At this time, since the secondary transfer roller and the cleaner (not shown) do not disturb the toner image on the intermediate transfer member, they are kept in a separated state.
[0020]
The primary transfer of the toner image of the final color is started on the intermediate transfer member, and the superposed image portion reaches the secondary transfer portion as the intermediate transfer member rotates. At this timing, a transfer paper (not shown) is guided to the secondary transfer portion, and the secondary transfer roller is brought into contact therewith, so that the toner images are collectively transferred onto the transfer paper. 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 comes into contact with the cleaning portion in synchronization with this, and scrapes the residual toner on the intermediate transfer member. Most of the scraped toner is collected into a cleaning housing (not shown), but a part of the toner stays at the edge of the cleaning blade. In this state, when the joint portion diagonally joined reaches the position of the cleaning blade, the toner staying at the edge portion is obliquely fed along the oblique joint portion. At this time, since the joint portion of the primary transfer electrode layer is disposed on the upstream side of the oblique seam, the primary transfer electrode layer is not contaminated by the obliquely fed toner. The obliquely fed toner is scraped off and sealed by a seal installed at the end of the cleaner, thereby preventing scattering to the outside of 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 upstream of the belt rotation direction. Therefore, the primary transfer electrode layer can be prevented from being soiled by the toner sent in the direction of the seam by the cleaning blade, and the primary transfer bias can be reliably applied.
[Brief description of the drawings]
FIG. 1 is a plan view illustrating an intermediate transfer belt according to an exemplary embodiment.
FIG. 2 is a cross-sectional view showing an intermediate transfer belt.
FIG. 3 is a cross-sectional view illustrating a belt joint portion.
FIG. 4 is an overall perspective view showing an intermediate transfer body unit.
FIG. 5 is a cross-sectional view of a main part for explaining an 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 ... Seam, 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 (6)

At least an image carrier belt or a transfer material conveyance belt having an electrode layer to which a bias voltage is applied to one end of a belt surface joined endlessly by a seam, and a cleaning blade in contact with the belt surface In the image forming apparatus, the joint portion having the electrode layer among the joint portions is first brought into contact with the cleaning blade, the joint portions in other portions are sequentially brought into contact with the cleaning blade, and finally the joint portion on the opposite side to the electrode layer is finally provided. 2. The image forming apparatus according to claim 1, wherein the joint is formed so as to be inclined with respect to a belt width direction perpendicular to the belt rotation direction so that the end portion contacts the cleaning blade . The belt conductive layer on a substrate, a multilayer structure in which a semiconductive layer are sequentially formed, the electrode layer is the belt side end portion and the surface of the conductive layer from the semiconductive layer surface of the portion semiconductive layer is not formed The image forming apparatus according to claim 1, wherein the image forming apparatus is formed so as to straddle the screen. The image forming apparatus according to claim 1, wherein the joint is joined from the back side by ultrasonic welding. The image forming apparatus according to claim 1, wherein the electrode layer and the conductive layer are separated at a portion of the joint. Place the contacting electrode roller to the electrode layer, the image forming apparatus according to any one of claims 1 to 4, characterized in that applying a transfer bias voltage via the electrode roller. The image forming apparatus according to claim 5, wherein the electrode roller is an elastic electrode roller that abuts across the electrode layer at the joint.

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