JPH063411Y2 - Drum cleaning mechanism of electrophotographic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a drum cleaning mechanism of an electrophotographic apparatus for removing residual toner adhering to the surface of a photosensitive drum.

[Conventional technology]

In electrophotographic devices such as laser printers and copiers, the surface of a photosensitive drum is uniformly charged by a charging charger, and the charged drum surface is irradiated with an exposure beam to form a charged image.
This charged image is developed (visualized) by a developing device, and the visualized image is transferred to a sheet. After the transfer, the residual toner adhering to the drum surface is removed by the drum cleaning mechanism to form a charged image on the drum surface again.

[Problems to be solved by the invention]

As a drum cleaning mechanism for such an electrophotographic apparatus, for example, as shown in FIG. 6, a method in which a blade 102 is brought into contact with the surface of a photosensitive drum 101 to scrape off residual toner is generally used. Since the blade 102 was attached to the attachment member 104 with the screw 103 and the attachment member 104 was fixed to the frame (not shown), many attachment parts other than the blade were required, resulting in high cost.

Further, since the portion contacting the photosensitive drum 101 is only one portion at the tip of the blade, a sufficient cleaning effect cannot be obtained, and in order to enhance the cleaning effect, it is necessary to increase the contact pressure of the blade with respect to the drum, There is a problem that the life of the blade is shortened when the contact pressure is increased.

The present invention has been made in view of such circumstances, and an object thereof is to improve a cleaning effect and a life of a blade in a drum cleaning mechanism of an electrophotographic apparatus in which a blade is brought into contact with a drum surface to remove residual toner. And

[Means for solving problems]

In order to achieve the above object, the present invention provides a drum cleaning mechanism of an electrophotographic apparatus, comprising a blade for removing toner adhering to a photosensitive drum, and a blade holder for holding the blade. While forming a rectangular opening in the center of the plate-shaped body consisting of, the blade holder in the central portion of the blade is bent convexly with respect to the photosensitive drum, the upper edge of the opening and It is characterized in that a blade holding portion for contacting the lower edge with the surface of the photosensitive drum is provided.

[Action]

In the present invention, since the blade portion in contact with the drum surface is located at two places, the upper edge and the lower edge, the cleaning effect is improved, and it is not necessary to increase the contact pressure of the blade with the drum, so that the life of the blade can be extended. it can. Moreover, since the blade and the blade holder can be attached without using screws or the like, the number of parts can be reduced.

〔Example〕

Hereinafter, the present invention will be described based on embodiments shown in the drawings.

FIG. 1 is a side view of a drum cleaning mechanism showing an embodiment of the present invention. In the figure, reference numeral 1 is a blade formed of a plate-like elastic material such as rubber. The blade 1 is held at the tip of a blade holder 2, and its central portion is in contact with the surface of the photosensitive drum 3. A rectangular hole 4 is formed in the central portion of the blade 1 as shown in FIG. 2, and a pair of upper edge 5a and lower edge 5b are formed in the longitudinal edge portion of the rectangular hole 4. These upper edge 5a and lower edge 5b
Has a substantially symmetrical shape as shown in FIG.
Residual toner adhering to the surface of the photosensitive drum 3 is scraped off at the tips of a and 5b.

The blade holder 2 is made of synthetic resin, and the elastic force of the synthetic resin is used to press the blade 1 against the surface of the photosensitive drum 3. As shown in FIG. 4, a blade holding portion 6 having a dogleg shape is provided at the tip of the blade holder 2, and the blade 1 is elastically deformed and held in the blade holding portion 6. That is, the blade holding unit 6 bends the plate-shaped blade 1 in a convex shape with respect to the photosensitive drum 3 to form an upper edge 5 a and a lower edge 5 b of the rectangular hole 4.
Is in contact with the surface of the photosensitive drum 3. A toner discharge port 7 is formed on the blade holding surface of the blade holding portion 6,
Residual toner scraped off by blade 1 is removed by blade holder 2
The toner is discharged to the toner storage portion 8 formed in the central portion of the. In addition, an engaging portion 9 that engages with an engaging concave portion 11 provided in the left and right frames 10 of the photosensitive drum 3 is provided at a rear end portion of the blade holder 2, and the blade holder 2 is detachably fixed to the left and right frames 10. You can do it. In this embodiment, arc-shaped relief recesses 12 are formed at both ends of the blade 1 in the longitudinal direction as shown in FIG. 6, and the blade portions other than the upper edge 5a and the lower edge 5b are on the surface of the photosensitive drum 3. It does not come into contact.

In such a structure, the residual toner adhering to the surface of the photosensitive drum 3 is scraped off at two places, the upper edge 5a and the lower edge 5b of the blade 1, so that the residual toner is scraped off only at the edge portion of the blade. The cleaning effect can be significantly improved as compared with the conventional example. Further, since the contact pressure of the upper edge 5a and the lower edge 5b on the drum 3 is larger at the upper edge 5a, the life of the upper edge 5a is shorter than that of the lower edge 5b. Can extend the life of the. Further, in the present embodiment, the blade 1 is detachably held in the blade holding portion 6 of the blade holder 2, and the blade holder 2 is detachably fixed to the left and right frames 10, so that mounting parts such as screws are unnecessary, and the cost is reduced. Can be significantly reduced. In addition, the blade 1 can be easily manufactured only by forming the rectangular opening 4 in the center of the plate-shaped body made of an elastic material, and the manufacturing cost of the blade 1 can be reduced. Further, the plate-shaped blade 1 having the rectangular opening 4 in the center is bent convexly with respect to the photosensitive drum 4 by the blade holding portion 6 of the blade holder 2 so that the upper edge 5a and the lower edge 5a of the opening 4 are removed. By contacting the surface of the photosensitive drum 4, the toner attached to the photosensitive drum 4 can be more effectively removed by using the blade 1 formed in a plate shape.

[Effect of device]

As described above, according to the present invention, a blade is formed by forming a rectangular opening in the center of a plate-like body made of an elastic material, and the blade holder is formed so that the center of the blade is convex with respect to the photosensitive drum. By providing a blade holding part that bends to bring the upper edge and the lower edge of the opening into contact with the surface of the photosensitive drum, a blade having the upper edge and the lower edge can be easily made, and moreover, in a plate shape. The formed blade can be used to more effectively remove the toner attached to the photosensitive drum.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a side view of a drum cleaning mechanism, FIG. 2 is a plan view of a blade, and FIG. 3 is a sectional view taken along line II-II of FIG. 4 is a perspective view of the blade holder, FIG. 5 is a sectional view taken along line VV of FIG. 2, and FIG. 6 is an explanatory view showing a conventional example. 1 ... Blade, 2 ... Blade holder, 3 ... Photosensitive drum,
5a ... upper edge, 5b ... lower edge, 9 ... engaging portion, 10 ...
Left and right frames, 11 ... Engagement recesses.

Claims (1)

[Scope of utility model registration request] 1. A drum cleaning mechanism of an electrophotographic apparatus comprising a blade for removing toner adhering to a photosensitive drum and a blade holder for holding the blade, wherein the blade is a plate-shaped member made of an elastic material. A rectangular opening is formed in the center, and the blade holder is formed by bending the central portion of the blade in a convex shape with respect to the photosensitive drum so that the upper edge and the lower edge of the opening are formed by the photosensitive member. A drum cleaning mechanism for an electrophotographic apparatus, which is provided with a blade holding portion that contacts the surface of the drum.