JPH07104626A - Cleaning blade - Google Patents

Abstract

PURPOSE:To eliminate excessive friction between a cleaning blade and the image non-formed area of a photoreceptor while maintaining a toner sealing effect and to prevent the deformation of both ends of the cleaning blade and the irregular rotation of the photoreceptor by removing the corner edges of both ends of the cleaning blade. CONSTITUTION:Notched parts 41 formed by removing the corner edge are provided at both ends of the cleaning blade 4 which is brought into press-contact with the photoreceptor and performs cleaning to remove toner. The length of the corner edge brought into press-contact with the surface of the photoreceptor is obtained by (T) subtracting the length of the notched part 41 from the length of the cleaning blade 4 in a width direction, and expressed as cleaning width. The cleaning width is longer than the length of a sleeve roller, that is, a range where the toner remains on the photoreceptor. Thus, the cleaning blade 4 mantains a cleaning effect in the cleaning of the image formed area of the photoreceptor without the lowering of the effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning blade for scraping toner from a photoconductor to clean the photoconductor in an image forming apparatus.

[0002]

2. Description of the Related Art A conventionally known cleaning blade for scraping off toner from a photosensitive member for cleaning will be described with reference to FIG. FIG. 1 does not show one device, but four types of cleaning blades and one
FIG. 5 is a schematic diagram showing a relationship between a pair of photoconductor peripheral members (photoconductor 5, sleeve roller 7, paper 8) and a length in the photoconductor width direction with respect to an image or the like formed on the photoconductor. In FIG. 1, cleaning blades 1 to 3 show a part of a conventional cleaning blade, and cleaning blade 4 shows a part of a cleaning blade according to the present invention described later. The cleaning blades 1 to 4 are shown only on the side facing the photoconductor 5. Further, the sleeve roller 7 is provided in a developing device (not shown), and converts the latent image formed on the photoconductor 5 by exposure means (not shown) into a toner image.
The sheet 8 is a sheet for transferring the image formed on the photoconductor 5. The maximum area where the image of the photoconductor 5 can be formed is defined as an image forming area. Usually, it is difficult to form a stable photosensitive layer that contributes to image formation on both ends of the photoconductor. For this reason, the photosensitive member 5 uses only the central portion having a stable photosensitive layer for image formation, and both end portions where the photosensitive layer is unstable become the non-image forming regions 6 not used for image formation. There is. The length of the image forming area in the width direction of the photoconductor 5 is set so as to correspond to the length a of the paper 8.

The conventional cleaning blade 1 shown in FIG. 1 will be described below. The length of the cleaning blade 1 is slightly longer than the length b of the sleeve roller 7. And the length b of this sleeve roller 7
Is slightly longer than the length a of the sheet 8. That is, the distance from the edge of the image forming area to the edge of the cleaning blade 1 is extremely short. Therefore, the toner on both ends of the image forming area scraped off by the cleaning blade 1 during cleaning is cleaned by the cleaning blade 1.
It is easy to spill from both ends of the non-image forming area 6 and toner sealing is difficult. Then, the spilled toner may move again to the image forming area after cleaning. Therefore, the cleaning blade 1 is likely to have an adverse effect on both ends of the image in the main scanning direction.

The cleaning blade 2 solves the problems of the cleaning blade 1. The length of the cleaning blade 2 is substantially equal to the length of the photoconductor 5 in the width direction, and unlike the case of the cleaning blade 1, the corner edge is pressed against the entire width of the photoconductor 5 in the width direction. Therefore, in the image forming apparatus including the cleaning blade 2, even if the toner in the image forming area scraped off by the corner edge during the cleaning is spilled to the non-image forming area 6, the toner is cleaned. Therefore, in the image forming apparatus including the cleaning blade 2, the toner spilled on the non-image forming area 6 does not adversely affect both ends of the image in the main scanning direction. However, the cleaning blade 2 has a problem that the blade is deformed so that the blade is turned up at both ends. As described above, both ends of the photoconductor 5 are the non-image forming areas 6 that are not used for image formation. Therefore, since the toner does not adhere to the non-image forming area 6, the frictional force applied to the corner edge pressed against the non-image forming area 6 becomes large, and the blade is deformed so as to turn up from both ends of the corner edge as starting points. Resulting in. Further, when the frictional force between both ends of the corner edge and the photoconductor 5 becomes large, uneven rotation of the photoconductor 5 occurs. The deformation of the cleaning blade 2 from both ends of the corner edge is caused by the photoconductor 5 and the cleaning blade 2.
Is more likely to occur when the sleeve roller 7 is new, and more likely to occur when the sleeve roller 7 is new. As a cleaning blade in which both ends of the cleaning blade 2 are prevented from being deformed, there is known a cleaning blade having a blade length longer than the width in the width direction of the photoconductor 5, like the cleaning blade 3. However, in the case of the cleaning blade 3,
It is possible to prevent the deformation of both ends of the blade,
There is a problem in that the size of the entire device is increased.

Further, as a conventional cleaning blade in which both ends of the cleaning blade are prevented from being deformed, Japanese Patent Laid-Open No. 3277/1987 discloses a cleaning blade in which both ends in the width direction of the photosensitive member are obliquely cut. . Further, Japanese Utility Model Laid-Open No. 57-13960 discloses a cleaning blade in which all the corner edges of the cleaning blade pressed against the photoconductor are removed in the widthwise direction of the photoconductor.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the cleaning blade disclosed in Japanese Patent Publication No. 77, not only the corner edge but also other blade portions contacting both ends of the photoconductor are removed, and the cleaning blade is pressed against only the image forming area of the photoconductor. Similar to the cleaning blade 1 in FIG. 1, toner sealing is difficult and there is a problem that the image is easily adversely affected. Further, the cleaning blade disclosed in Japanese Utility Model Laid-Open No. 57-13960 has a problem that the cleaning performance for cleaning the toner remaining on the photoconductor is deteriorated by removing all the corner edges.

An object of the present invention is to solve the above problems,
It is an object of the present invention to provide a cleaning blade that has a toner sealing effect and does not adversely affect an image, and can prevent both ends of the blade from being deformed.

[0008]

In order to achieve the above-mentioned object, the present invention provides a cleaning blade for cleaning the toner adhering to the surface of the photoconductor which is pressed against the surface of the photoconductor which moves relatively. And has a length substantially equal to the width of the photoconductor, and is formed into a plate shape having a predetermined thickness,
Of the corner edges pressed against the surface of the photoconductor, the corner edges at both ends in the width direction of the photoconductor are removed to reduce the frictional force at this portion.

[0009]

The cleaning blade according to the present invention removes both ends of the corner edge which is pressed against the non-image forming area 6, thereby maintaining the toner sealing effect and keeping the two ends of the cleaning blade and the photosensitive member. Minimize the frictional force generated between them. As a result, both ends of the cleaning blade clean the toner on the edge of the photoconductor without curling up.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First, the cleaning member 9 provided with the cleaning blade 4 according to the present invention will be described with reference to FIG.
FIG. 2 is a cross-sectional view of the photoconductor 5 and the cleaning member 9 that is pressed against the photoconductor 5 to clean it. The cleaning member 9 includes a toner storage portion 91 that stores toner collected from the photoconductor 5,
A support member 92 attached to the upper part of the toner storage portion 91 for supporting the cleaning blade 4, and a toner storage portion 91.
And a seal member 93 that prevents toner from spilling out of the toner storage portion 91 attached to the lower part of the. The photoconductor 5 is exposed by an exposing unit (not shown) to form a latent image. The latent image formed on the photoconductor 5 is
The toner supplied from the sleeve roller 7 forms a visible image. This toner image is transferred onto the paper by a transfer mechanism (not shown). The toner remaining on the photoconductor 5 after the transfer is collected by the above-mentioned cleaning member 9 which is pressed against the surface of the photoconductor 5. The cleaning member 9 may be of a counter type in which the cleaning blade 4 is pressed against the uncleaned surface of the photoconductor 5 rotating in the direction of arrow h at an obtuse angle as shown in FIG. It may be a trailing type in which it is pressed against an acute angle.

Next, the cleaning blade 4 will be described with reference to FIGS. 1, 3 and 4. FIG. 3 is a perspective view of the cleaning blade 4, and FIG. 4 is a schematic view of the cleaning blade 4 in pressure contact with the photosensitive member 5 as viewed from the rotation axis direction of the photosensitive member 5 during cleaning. As shown in FIGS. 1 and 3, the cleaning blade 4 which is pressed against the photosensitive member 5 of the cleaning blade 4 to clean the toner has notches 41 with the corner edges removed at both ends. The length of the cutout portion 41 is about 10 mm. The length of the corner edge pressed against the surface of the photoconductor 5 is the length in the width direction of the cleaning blade 4 minus the length of the notch 41, and is represented by the cleaning width c. The cleaning width c is longer than the length b of the sleeve roller 7. That is, it is longer than the range in which the toner can remain on the photoconductor 5. As a result, the cleaning blade 4 maintains the cleaning effect for cleaning the image forming area of the photoconductor 5 without lowering it. Further, the corner edge after removing the notch portion 41 only partially overlaps with the non-image forming area 6 where the friction is large. That is, the portion of the corner edge pressed against the non-image forming area 6 can be small, and the non-image forming area 6
The friction between the cleaning blade 4 and both ends of the cleaning blade 4 is reduced.

Further, as shown in FIG. 4, when the cleaning blade 4 is pressed against the photoconductor 5, the cutout 41 is in contact with the photoconductor 5 at least at one side 41a forming the cutout 41. Therefore, even when the toner moves from the image forming area of the photoconductor 5 to the non-image forming area 6 or the toner is scattered from the developing device to the non-image area 6, the toner on the non-image area 6 And the toner does not remain on the photoconductor 5.
The notch 41 may be opposed to the surface of the photoconductor 5 with a very small gap such that toner cannot pass through.

Next, the notch 41 is shown in FIGS. 5a to 5d.
Will be explained. 5a to 5d are perspective views of the ends of the cleaning blade 4, respectively. In the case of the cleaning blade 4 shown in FIG. 5a, the corner edges are cut at an angle of 45 degrees with respect to the two surfaces forming the edge. When the width P of the cut off portion is 50 μm or more, the effect of preventing the deformation of both ends of the cleaning blade 4 appears, and the larger the width of P is, the more effective the deformation is prevented. However, if P is not about 1 mm or less, the gap between the surface of the photoconductor and the cleaning blade becomes large, and the toner sealing effect deteriorates. Therefore, the notch portion 41 is configured so that P is about 50 μm to 1 mm. The shape after removing the corner edges may be a curved surface as shown in FIG. 5b. Further, as shown in FIG. 5c, the shape may be adapted to the curvature of the surface of the photoconductor. In this case, both ends of the cleaning blade 4 and the surface of the photoconductor are in close contact with each other, the toner sealing effect is high, and excessive friction does not occur. Furthermore, as shown in FIG. 5d, the corner edge may be removed obliquely toward the end of the cleaning blade 4. Furthermore, the notches 41 may be formed at both ends of the cleaning blade 4 by grinding with a grinder or cutting with a cutter or the like after manufacturing the blade. Further, it is also possible to use a casting method in which the notch 41 can be formed.

[0014]

As is apparent from the above-mentioned invention, the cleaning blade according to the present invention eliminates the corner edges at both ends, thereby maintaining the toner sealing effect and the space between the cleaning blade and the non-image forming area of the photoreceptor. Therefore, it is possible to prevent deformation of both end portions of the cleaning blade and uneven rotation of the photosensitive member without excessive friction.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a relationship between a conventional cleaning blade and an image forming area on a photoconductor in a main scanning direction.

FIG. 2 is a cross-sectional view of a photosensitive member 5 and a cleaning member 9 that contacts the photosensitive member 5 to clean the photosensitive member 5.

FIG. 3 is a perspective view of a cleaning blade 4.

FIG. 4 is a schematic view of a state in which the cleaning blade 4 is pressed against the photoconductor 5 as viewed from the rotation axis direction of the photoconductor 5.

5 is a perspective view of an end portion of the cleaning blade 4. FIG.

[Explanation of symbols]

 4: Cleaning blade 5: Photosensitive member 6: Non-image forming area 9: Cleaning member 41: Notch

Claims (2)

[Claims] 1. A cleaning blade, which is pressed against a surface of a relatively moving photoconductor to clean toner adhering to the surface of the photoconductor, and has a length substantially equal to the width of the photoconductor. Of the corner edges that are formed in the shape of a plate with a certain thickness and are pressed against the surface of the photoconductor, the corner edges at both ends of the photoconductor in the width direction are removed to reduce the frictional force at this part. blade. 2. The length of the central portion of the corner edge after removing both ends is longer than the length of the image forming area on the surface of the photoconductor in the width direction of the photoconductor. Cleaning blade.