JP3829542B2 - Cleaning device for image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cleaning device used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine that forms an image using electrophotographic technology. More specifically, the present invention relates to a cleaning device that removes residual toner on an image carrier that carries a toner image.
[0002]
[Prior art]
In general, an image forming apparatus using an electrophotographic technique includes a photosensitive member (an example of an image carrier) having a photosensitive layer on an outer peripheral surface, a charging unit that uniformly charges the outer peripheral surface of the photosensitive member, and the charging unit. An exposure unit that selectively exposes the outer peripheral surface charged uniformly by the above-described method to form an electrostatic latent image, and toner that is a developer may be applied to the electrostatic latent image formed by the exposure unit. Developing means for forming a visual image (toner image), transferring means for transferring the toner image developed by the developing means to a transfer medium such as paper, and the outer surface of the photosensitive member after transfer, contacting the surface of the photosensitive member And a cleaning device provided with a removing means for removing the remaining toner (residual toner). As the transfer means, in order to transfer the toner image on the photoconductor to a recording medium such as paper, the toner image formed on the photoconductor is transferred (primary transfer) and is carried thereon. Further, an intermediate transfer member (an example of an image carrier) that further transfers (secondary transfer) to a recording medium is also known, and this intermediate transfer member also remains on the surface after toner image transfer A cleaning device for removing toner (residual toner) is provided.
[0003]
As a conventional cleaning device, for example, as shown in FIG. 4A, the toner image is held on the image carrier 1 in contact with the surface 1a of the image carrier 1 that carries the toner image and rotates in the direction of the arrow. A cleaning blade (hereinafter also simply referred to as a blade) 2 as a removing means for removing the toner T, and a toner that comes into contact with the image carrier 1 below the removing means and is removed from the image carrier surface 1a by the removing means 2 A sheet including a sheet 3 for scooping T and a case 4 to which the sheet 3 and the removing means 2 are attached is known.
According to such a cleaning device, the toner T remaining on the image carrier 1 is scraped off by the blade 2 after passing through the contact portion C1 between the image carrier 1 and the rake sheet 3. It will be removed. The toner T thus scraped off is scooped by the scooping sheet 2 so that it basically does not leak to the side of the image carrier 1 and stain the inside of the apparatus.
By the way, the rake sheet 3 is usually made of a relatively soft material (for example, thermoplastic urethane) so as not to damage the surface of the image carrier 1, but the rake sheet has a relatively high linear expansion coefficient. Therefore, if no measures are taken, the warpage occurs at high temperature and high humidity, and a gap is partially generated at the contact portion with the image carrier 1, and the toner is transferred from the gap to the image carrier 1. Leak to the side and dirty inside the device.
Therefore, conventionally, in order to prevent the above-mentioned warp, a relatively hard material (for example, for example, along the lower part 3a as shown in FIG. The plate member 5 made of polyethylene terephthalate or the like is once attached with an adhesive 6, and the connecting member of the rake sheet 3 and the plate member 5 is bonded to the mounting surface 4a of the case 4 as shown in FIG. It was affixed with Agent 7. When the rake sheet is directly attached to the case, the rake sheet is attached to the case made of a relatively hard material in a state where the rake sheet is sufficiently pulled or stretched at a high temperature.
[0004]
[Problems to be solved by the invention]
In the conventional cleaning device described above, the rake sheet 3 is pressed against the image carrier 1 by the case 4 via a plate-like member made of a material harder than the rake sheet 3, or from a material harder than the rake sheet 3. In this case, the contact with the rake sheet 3 and the image carrier 1 due to manufacturing errors of the rake sheet 3 and the image carrier 1 (that is, the contact between the rake sheet 3 and the image carrier 1) (ie, The deviation of the contact force in the contact line direction) may not be satisfactorily absorbed only by the flexibility of the rake sheet 3, and as a result, a part of the contact part (contact line direction) between the rake sheet 3 and the image carrier 1 There was a risk that a static gap would occur.
Moreover, since it was necessary to stick the rake sheet to the plate-like member 5 or the case 4 in a state where the rake sheet is sufficiently pulled or stretched at a high temperature, there is also a problem that the assemblability is poor.
That is, in the conventional cleaning device, there is a problem that it is not always easy to secure the adhesion between the scooping sheet and the image carrier and the assemblability is also poor.
[0005]
An object of the present invention is to provide a cleaning device for an image forming apparatus that can solve the above-described problems and can improve the adhesion between a rake sheet and an image carrier and can also improve assemblability. There is.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the cleaning device for an image forming apparatus according to claim 1, wherein the toner image on the image carrier is transferred by contacting the surface of the image carrier, which is a rotating body carrying the toner image. a blade for removing the toner remaining on an image bearing member after a rake sheet in contact with the image bearing member at below the blade, scoop toner removed from the image bearing member surface with a blade, the rake sheet And a cleaning device comprising a case to which the blade is attached,
The scooping sheet is pressed against the image carrier by a sponge through a support member made of a sponge , and the support member has the toner removed on the upper surface of the support member by the blade. The support member is deposited on the contact portion between the image carrier and the blade and directly below the contact portion .
[0007]
[Function and effect]
According to the cleaning device for an image forming apparatus according to claim 1, the toner remaining on the image carrier after the toner image on the image carrier, which is a rotating body carrying the toner image, is transferred. The removed toner is scooped with a rake sheet.
The rake sheet is configured to be pressed against the image carrier by a case via a support member made of a material softer than the rake sheet. Therefore, a manufacturing error of the rake sheet and the image carrier is temporarily assumed. Even if unevenness of contact property (that is, contact force in the contact line direction) occurs between the rake sheet and the image carrier due to, for example, the unevenness of the rake sheet is not only the flexibility of the rake sheet. It is also absorbed by a support member made of a softer material.
Therefore, a partial gap at the contact portion between the rake sheet and the image carrier is less likely to occur, and as a result, the adhesion between the rake sheet and the image carrier is improved.
Further, as a result of improving the adhesion as described above, it is not necessary to attach the rake sheet to the support member in a state where the rake sheet is sufficiently pulled or stretched at a high temperature. For example, the rake sheet and the support member may be simply attached.
Therefore, the assemblability is also improved.
As described above, according to the cleaning device for an image forming apparatus of the first aspect, the adhesion between the scooping sheet and the image carrier can be improved and the assembling property can be improved.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a schematic front sectional view showing an essential part of a first embodiment of a cleaning device for an image forming apparatus according to the present invention.
In FIG. 1, reference numeral 10 denotes a photoconductor as an image carrier, which is rotationally driven in a direction indicated by an arrow by an appropriate driving means (not shown).
Around the photosensitive member 10, along with the rotation direction, a charging unit, a developing unit, a transfer device, and a cleaning device 20 (not shown) are arranged.
[0009]
The cleaning device 20 is a cleaning blade that scrapes off the toner (residual toner) that remains and adheres to the outer peripheral surface of the photoconductor 10 after the toner image on the photoconductor 10 is transferred to the transfer target by the transfer device (not shown). (Example of removing means) 21 and a sheet 22 that scoops and falls off the toner T that is scraped off by the blade 21.
The upper portion of the blade 21 is attached to the case 26 by an appropriate attachment means (not shown), and the tip (edge) 21 a is in contact with the surface of the photoconductor 10.
The scooping sheet 22 comes into contact with the photoconductor 10 below the contact portion C between the blade 21 and the photoconductor 10, and scoops off the toner scraped off by the blade 21.
The rake sheet 22 is attached to the case 26 via a support member 23, and is pressed against the photoconductor 10 via the support member 23 by the case 26.
In this embodiment, the rake sheet 22 and the support member 23 are fixed by, for example, an adhesive 24a, and the coupling member of the rake sheet 22 and the support member 23 is fixed to the mounting surface 26b of the case 26 by, for example, an adhesive 24b. It is. The bottom surfaces of the rake sheet 22 and the support member 23 are only placed on the support surface 26a of the case 26, and can be moved in the left-right direction in the figure with respect to the support surface 26a.
The rake sheet 22 is made of a soft material (for example, thermoplastic polyurethane) so as not to damage the surface 11 of the photoreceptor 10, and the support member 23 is made of a material that is softer than the rake sheet 22, for example, rubber. , Sponge (foam (for example, urethane foam)) and the like.
The rake sheet 22 and the support member 23 extend in a direction perpendicular to the paper surface, and are provided over the entire length below the contact portion C between the photoreceptor 10 and the blade 21.
The case 26 is made of a hard material, for example, a hard synthetic resin.
The cleaning device is configured as a unit by a case 26 and is detachably attached to a frame (not shown) of the image forming apparatus main body.
[0010]
According to the image forming apparatus cleaning apparatus as described above, the following effects can be obtained.
The toner T remaining on the image carrier 10 after the toner image on the image carrier 10 which is a rotating body carrying the toner image is transferred is removed by the removing means 21, and the removed toner T is removed. The scoop sheet 22 is scooped.
Since the rake sheet 22 is pressed against the image carrier 10 by the case 26 via the support member 23 made of a material softer than the rake sheet 22, the rake sheet 22 and the image carrier are temporarily provided. Even if the contact property (that is, the contact force in the direction of the contact line (direction perpendicular to the paper surface of FIG. 1)) is uneven between the rake sheet 22 and the image carrier 10 due to a manufacturing error of the body 10 or the like. This bias is absorbed not only by the flexibility of the rake sheet 22 but also by the support member 23 made of a softer material than the rake sheet 22.
Therefore, a partial gap at the contact portion C <b> 1 between the rake sheet 22 and the image carrier 10 is less likely to occur, and as a result, the adhesion between the rake sheet 22 and the image carrier 10 is improved.
Further, as a result of improving the adhesion as described above, it is not necessary to attach the rake sheet 22 to the support member in a state where the rake sheet 22 is sufficiently pulled or stretched at a high temperature. The member 23 is simply pasted.
Therefore, the assemblability is also improved.
As described above, according to the image forming apparatus cleaning device, the adhesion between the rake sheet 22 and the image carrier 10 can be improved, and the assemblability can be improved.
[0011]
<Second Embodiment>
FIG. 2 is a schematic front sectional view showing an essential part of a second embodiment of the image forming apparatus cleaning apparatus according to the present invention. In the figure, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals.
This embodiment differs from the first embodiment in the shape of the support member 23, the shape of the case 26, the coupling structure between the rake sheet 22 and the support member 23, and the mounting structure to the case 26. The other points remain the same.
The support member 23 of this embodiment is configured to have a shorter height and a slightly smaller thickness than those of the first embodiment, and the upper and lower portions of the rake sheet 22 are exposed. In this way, it is fixed to the rake sheet 22 with an adhesive 24a. The lower portion 22a of the rake sheet 22 is fixed to the mounting surface 26b of the case 26 with an adhesive 24b, and the lower surface of the support member 23 is brought into contact with the support surface 26a of the case 26.
In this embodiment, since the lower surface of the support member 23 is in contact with the support surface 26a of the case 26, a moment M as shown in the figure acts, whereby the rake sheet 22 is pressed against the photoconductor 10.
Also according to this embodiment, the same operational effects as those of the first embodiment can be obtained.
[0012]
<Third Embodiment>
FIG. 3 is a schematic front sectional view showing an essential part of a third embodiment of the image forming apparatus cleaning apparatus according to the present invention. In the figure, the same or corresponding parts as those in the second embodiment are given the same reference numerals.
This embodiment differs from the second embodiment in that the thickness of the support member 23 is increased (similar to that of the first embodiment), and the blade 21 is formed on the upper surface thereof. The toner T thus scraped off is deposited on the contact portion C between the image carrier 10 and the blade 21 and the portion U immediately below the contact portion C, and other points are not changed.
According to this embodiment, in addition to the operational effects of the first embodiment, the following operational effects can be obtained.
That is, since the toner T scraped off by the blade 21 is always deposited on the contact portion C between the image carrier 10 and the blade 21 and directly below U, the toner T acts as a lubricant and will be described below. Thus, the blade 21 is less likely to bend.
More specifically, since the toner scraped off by the blade 21 is accumulated at the contact portion C between the image carrier 10 and the blade 21 and the portion U immediately below the contact portion C, the rotating image carrier 10 and the cleaning blade 21 The toner is always supplied to the contact portion C without being affected by the image pattern. Since the toner acts as a lubricant, the presence of this toner reduces the frictional force between the blade 21 and the surface of the image carrier 10, resulting in an increase in the contact pressure and / or contact angle of the blade 21. Even in such a case, the blade 21 is less likely to bend.
Further, the cleaning blade 21 removes the toner by a so-called stick-slip behavior, but according to this embodiment, the frictional force between the blade 21 and the surface of the image carrier 10 is reduced. The behavior is stabilized, and as a result, the cleaning performance is further improved.
Also in the first embodiment, the thickness of the support member 23 is increased, and the toner T is deposited on the upper surface of the support member 23 on the contact portion C and the lower portion U. Therefore (the deposited toner T is not shown in FIG. 1), the above-described effects can be obtained.
[0013]
【Example】
The rake sheet 22 is a thermoplastic urethane sheet having a thickness of about 0.1 to 0.2 mm.
The support member 23 is a sponge (for example, urethane foam) having a thickness of about 3 to 6 mm.
[0014]
Although the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments or examples, and can be appropriately modified within the scope of the gist of the present invention.
For example,
(1) As a removing means for removing the toner remaining on the image carrier, an appropriate means (for example, a fur brush) can be employed in addition to the cleaning blade.
{Circle around (2)} In the above embodiment, the case where the image carrier is a photosensitive member has been described. However, the present invention can also be applied when the image carrier is an intermediate transfer member. In the above embodiment, the case where the image carrier (photosensitive member) has a cylindrical shape has been described. However, the present invention can also be applied when the image carrier has a belt shape.
(3) In the above embodiment, the rake sheet 22 and the support member 23 are integrally formed by the adhesive layer 24a. However, they can be integrally formed by welding.
[0015]
【The invention's effect】
According to the cleaning device for an image forming apparatus of the first aspect, the adhesion between the scooping sheet and the image carrier can be improved and the assembling property can also be improved.
[0016]
[Brief description of the drawings]
FIG. 1 is a schematic front sectional view showing a main part of a first embodiment of a cleaning device for an image forming apparatus according to the present invention.
FIG. 2 is a schematic front sectional view showing a main part of a second embodiment of a cleaning device for an image forming apparatus according to the present invention.
FIG. 3 is a schematic front sectional view showing an essential part of a third embodiment of a cleaning device for an image forming apparatus according to the present invention.
4A and 4B are explanatory diagrams of the prior art.
[Explanation of symbols]
T toner 10 photoconductor (image carrier)
11 Surface 21 Cleaning blade (removal means)
22 rake sheet 23 support member 26 case

Claims (1)

In contact with the surface of the image bearing member is a rotating member for bearing a toner image, and the blade to which the toner image on the image bearing member to remove toner remaining on the image bearing member after the transfer, from the blade A cleaning device comprising a sheet that contacts the image carrier at the bottom and scoops the toner removed from the surface of the image carrier with a blade , and a case to which the scoop sheet and the blade are attached,
The scooping sheet is pressed against the image carrier by a sponge through a support member made of a sponge , and the support member has the toner removed on the upper surface of the support member by the blade. A cleaning device for an image forming apparatus, which is a support member deposited on a contact portion between an image carrier and a blade and directly below the contact portion .

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