JPH04138488A - Cleaning device - Google Patents

Abstract

PURPOSE:To obtain a clear and improved image without stain caused by toner by thrusting the stagnating toner stuck to the surface of the image carrier from the upper face part at both sides to a center part along the blade edge of both side surface parts. CONSTITUTION:The blade member 12 consists of a plane part 121 and both side surface parts 122, 122 where both the wings are bent and the lower edge surface of the plane part 121 forms a linear edge part 12. Also at the lower edge surface of both side surface parts 122, 122, curved edge parts 12B, 12B are formed and they have a shape abutting on the curves b, b on a circumferential surface of the upper stream side in a revolving direction in the vicinity of both sides of a cylindrical surface of a photosensitive body drum 100. Accordingly a residual toner T peeled with a linear edge part 12A is pushed away and moves to both side parts on the circumferential surface of the photosensitive body 100. But the residual toner T in the vicinity of both sides of the circumferential surface of the photosensitive drum 100 is cought with the curved edge parts 12B at the more upper stream side than the linear edge part 12A and it is pushed away toward the linear edge part 12A along the curved face. Hence the dropping and the scattering of the residual toner are prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a copying machine and a printer that form a toner image on an image carrier using an electrophotographic method and transfer it onto a transfer material to obtain an image. The present invention relates to a cleaning device for a facsimile machine, etc., and specifically relates to a cleaning device that removes residual toner on an image carrier using a cleaning blade.

[Conventional technology]

Generally, electrostatic recording devices such as transfer-type electrophotographic copying machines use a rotating drum or rotating belt type image carrier having a photoconductive photosensitive layer on the outer circumferential surface, and the image carrier is rotated. Meanwhile, an electrostatic latent image is formed on the photosensitive layer and developed with toner, and the resulting toner image is transferred to recording paper. After the transfer is completed, the residual toner on the outer peripheral surface of the image carrier is removed and cleaned by a cleaning device, and an electrostatic latent image is formed again, and a new image is transferred.

As is well known, the cleaning device operates by pressing (including contacting) a blade member or other cleaning member against the surface of the image carrier.

For example, a blade cleaning method is a typical leaning method. In the blade cleaning method, the edge of the blade member is brought into pressure contact with the circumferential surface of the image carrier to forcibly remove toner adhering to the circumferential surface. This cleaning method is widely adopted because it has a simple structure and a high cleaning effect.

In this blade cleaning method, there are two types of blade application methods: a counter type (leading type) and a trail type, which differ in the fulcrum position and the blade contact angle.

[Problems to be Solved by the Invention] In the case of the above-mentioned counter type blade cleaning method, it is characterized in that it is particularly effective in removing residual toner from the image carrier, but on the other hand, the tip surface of the blade is located in the direction of rotation of the image carrier. The blade rotates to peel off and remove the residual toner and push it out, but at the same time, this residual toner is pushed toward both ends along the pressure contact surface of the blade and falls from both ends of the image carrier to the outside. - There are problems such as scattering, contaminating the image bearing member and surrounding members, and interfering with the next image formation.

Therefore, conventionally, a wide blade having a width equal to or larger than the cleaning width is used, but it is not possible to sufficiently prevent toner from falling from both ends of the image carrier. Further, when such a wide blade is used, there is a problem that the width and size of the cleaning device housing and the recording device main body are increased, which further increases the cost of the blade and the device.

[Means for solving problems]

The present invention has been made in view of the above-mentioned drawbacks of the prior art.When removing residual toner by pressing a cleaning blade against the surface of an image carrier, the toner accumulated on the surface of the image carrier is removed. To prevent toner from being pushed to both ends along the blade surface and causing toner contamination around the image carrier, we have developed a cleaning means that can effectively remove residual toner from the surface of the image carrier, and improve cleaning performance. It is an object of the present invention to provide a cleaning device for an electrostatic recording device that can be maintained and improved to obtain clear and excellent images.

The above object is to provide a cleaning device for removing residual toner adhering to the surface of a rotating image carrier by peeling it off by pressure contact with a cleaning blade, in which an edge surface of the cleaning blade in pressure contact with the image carrier is attached to a cylindrical surface of the image carrier. It is formed by a linear edge portion at the lower edge of the center of the cleaning blade that can be pressed against the surface generatrix, and a curved edge portion at the lower edge of both end surfaces that protrudes from both ends in the longitudinal direction of the cleaning blade, and the curved edge portion is used to carry an image. This is achieved by a cleaning device characterized in that it is shaped so as to come into contact with the upstream circumferential surface of the body in the rotational direction.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 to 4.

FIG. 1 is an enlarged sectional view of a cleaning device according to the present invention;
FIG. 2 is a perspective view of the image carrier and the cleaning blade.

The image carrier 100 that has completed the image formation and transfer reaches the cleaning device 10, where the cleaning action removes and removes the residual toner on the circumferential surface of the image carrier, and then the image carrier 100 is cleaned.
Entering the next rotation cycle, image formation and transfer processes are performed again.

The cleaning device IO has a cleaning device housing 1
1 is used as a container, and a blade member 12 as a cleaning member whose tip end is urged to come into pressure contact with the circumferential surface of the photosensitive drum (image carrier) 100 is built into the container. , the screw 13 is installed at a position where it can directly receive and accommodate most of the toner that is peeled off and falls.
The developer receiver containing the developer receiver includes a portion 14. This screw I3 is driven to rotate and sends the toner guided by the toner guide member 15 into the developer receiver portion 14.

The cleaning blade 12 is made of hard urethane rubber, has a length substantially corresponding to the width of the image body 100, and is held between L-shaped blade holders 16A and 16B. This blade holder 16A, 16
B can be rotated and adjusted in the horizontal direction about the rotation support shaft 17. In addition, this blade holder 16A,
The support member 18 to which the support member 16B is attached rotates in the vertical direction about the rotation support shaft 19, and the pressing force can be adjusted. By these two rotational adjustments (17, 1, 9),
The edge portion 12A of the blade member 12 is connected to the photoreceptor drum 10.
It is parallel to the axis of rotation of 0 and can be brought into contact with the circumferential surface with a -like pressure. In this way, the elastic force of the blade member 12 is utilized to provide the best cleaning effect for residual toner.
In addition, the blade member 12 is pressed against and fixed to the circumferential surface of the photoconductor drum 100 so as not to damage the circumferential surface of the photoconductor drum 100.

FIG. 3(A) is a perspective view of the blade member 12;
FIG. 3(B) is a plan view thereof, and FIG. 3(C) is a developed front view of the blade member.

In these figures, the blade member 12 consists of a flat part 121 having a large area in the center and bent end face parts 122, 122 on both sides of the flat part 121.

FIG. 4 is a perspective view showing a blade pressure contact curve on the circumferential surface of the image carrier.

The lower edge surface of the flat portion 121 has a linear edge portion 12A.
, and are pressed in parallel to a generatrix (shown in the drawings - dotted chain line) a that is parallel to the rotation axis of the cylindrical surface of the photosensitive drum 100 shown in FIG.

Further, curved edge portions 12B, 12B are formed on the lower edge surfaces of the both end portions 122, 122, and curved edges ( The dashed dot line) b connected to the bus line a shown in the figure forms a shape that comes into contact with b.

The cleaning blade 12 having the above shape is attached to hard blade holders 16A and 1 having approximately the same cross section.
It is clamped and fixed by 6B.

When the photosensitive drum 100 rotates to remove and clean the residual toner T after image formation, the cleaning blade 1
The residual toner T peeled off by the linear edge portion 12A of the central plane portion 121 of 2 is pushed away and moves to both ends of the circumferential surface of the photoreceptor drum 100; The residual toner T in the vicinity is removed by the curved edge portion 12B of the curved portion 122 of the both end surfaces 122 of the cleaning blade 12, and is removed from the linear edge portion 1.
It is collected on the upstream side of 2A and is pushed along the curved surface toward the straight edge portion 12A.

In this way, the residual toner on the circumferential surface near both ends of the photosensitive drum 100 moves toward the center, so it does not fall or scatter to the outside from both ends.

FIG. 5 is a sectional view of a belt-shaped photoreceptor process cartridge 20 equipped with a cleaning device according to the present invention.

Inside the casing 2 of the process cartridge 20, which is removable into an image forming apparatus (not shown), there are a plurality of developing devices 23a.
, 23b, 23c, and 23d, a cleaning device 22, and a charger 2A are housed therein.

Further, a driving roller 26 is provided on the upper part of the casing 21.
A photoreceptor belt 25 stretched between the roller 27 and the driven roller 27 is disposed. The photoreceptor belt 25 has a visible belt surface coated with a photosensitive layer such as an organic photoconductive layer, and is rotated in the direction of the arrow.

The process cartridge 20 is loaded into an image forming apparatus, and the entire surface is charged by a charger 24, image is exposed by a laser writing system unit, development is performed by developing devices 23(a) to (cl), and transferred to a transfer material by a transfer device (not shown). The remaining toner on the photoreceptor belt 25 is removed by pressure contact with the cleaning blade 221 of the cleaning device 22 after completing the entire toner image transfer process.

That is, the cleaning device 2 is attached to the circumferential surface of the photoreceptor belt 25 wound around the cylindrical surface of the driven roller 27.
The cleaning blade 221 in 2 is pressed into contact with the cleaning blade 221 so as to be able to freely approach and separate. The cleaning blade 221 consists of the linear edge portion 221A and curved edge portions 221B, 221B formed at both ends thereof.

In this embodiment as well, the curved edge portions 221B are in pressure contact with the upstream side of the rotation of the belt near both ends of the photoreceptor belt 25.
, 221B, the residual toner near both ends is gathered toward the center, so that it does not fall from both ends of the photoreceptor belt 25.
It will not scatter.

In addition, in the above-mentioned embodiment, after forming a color toner image on the photoreceptor belt 25 as an image forming process, -
In the previous section, we described an image forming method in which toner images are transferred onto a transfer material and then cleaned. It is also applicable to monochrome printers.

In the above embodiment, a counter type (leading type) was described as a type in which the tip of the cleaning blade 12 comes into contact with the circumferential surface of the image carrier 100.
The present invention is not limited to this, but can also be applied to a trail type as a method of applying the blade.

〔Effect of the invention〕

As explained above, in the cleaning device of the present invention, when residual toner is removed by pressing the cleaning blade against the surface of the image carrier, the toner pool adhering to the surface of the image carrier is removed along the blade edges on both end surfaces. This prevents residual toner from falling and scattering from both ends of the surface of the image carrier and causing toner contamination around the image carrier. It is possible to provide an electrostatic recording device that can remove residual toner well and produce clear and excellent images without toner stains.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a cleaning device according to the present invention, Fig. 2 is a perspective view of an image carrier and a cleaning blade, Fig. 3 is a perspective view, plan view, and developed front view of the cleaning blade, and Fig. 4 is an image FIG. 5 is a perspective view showing a blade pressure contact curve on the circumferential surface of a carrier, and FIG. 5 is a sectional view of a belt-shaped photoreceptor process cartridge equipped with a cleaning device according to the present invention. lO...Cleaning device 11...Casing 12...
・Blade member (cleaning blade) 12A...
Straight edge portion 12B...Curved edge portion 121.
... Plan view 122 ... Both end surfaces 16A,
16B...Blade holder 17...Rotation shaft
18... Support member 19... Rotation shaft 20... Process cartridge 21... Casing 22... Cleaning device 25... Photoreceptor belt 26... Drive roller 27
...Followed roller 100...Photosensitive drum (image carrier) a...Cylindrical surface generating line b...Blade pressure contact curve T near both ends of the cylindrical surface...Residual toner

Claims (1)

[Claims] In a cleaning device that removes residual toner adhering to the surface of a rotating image carrier by peeling it off by pressure contact with a cleaning blade, an edge surface of the cleaning blade that is in pressure contact with the image carrier is in pressure contact with a cylindrical surface generatrix of the image carrier. The cleaning blade is formed by a linear edge portion at the lower edge of the center of the cleaning blade, and a curved edge portion at the lower edge of both end faces extending to both ends in the longitudinal direction of the cleaning blade. A cleaning device characterized in that it is shaped so as to come into contact with a circumferential surface on the upstream side in the direction.