JPH04249285A - Cleaning device - Google Patents

Abstract

PURPOSE:To offer a long-life counter type blade cleaning device which maintains the high cleaning efficiency of a blade made of a rubber elastic material and reduces the wear of the surface of an image carrier. CONSTITUTION:In this blade cleaning device, the surface roughness of the surface of the blade 10 in contact with the surface of the image carrier 1 is 2-10mum when the blade has reference length L0.8mm and maximum height Rmax. Consequently, the desired effect is obtained and the picture quality of a recording image never decreases.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for removing toner adhering to the surface of an image carrier of an electrophotographic recording device, and more particularly, the present invention relates to a cleaning device for removing toner adhering to the surface of an image carrier of an electrophotographic recording device, and more particularly, a blade made of a rubber elastic material is moved from the edge portion where the front end surface and the surface intersect to the surface of the image carrier. The present invention relates to a so-called counter-type blade cleaning device that scrapes off toner adhering to the surface of the image carrier with the front end surface of the blade while holding the blade so that its side is in contact with the surface of the moving image carrier.

0002

BACKGROUND OF THE INVENTION Conventionally, the above-mentioned cleaning device has been constructed by forming a cylindrical sheet of urethane rubber on the inner surface of a cylindrical rotary mold by centrifugal molding, and cutting the sheet to form a blade. The blade was used so that the free forming surface opposite to the surface peeled from the mold surface of the sheet was used as the surface in contact with the image carrier surface.

[0003] The blade made of rubber elastic material is more flexible than the surface of the image carrier and conforms well to the surface of the image carrier.
There is no wear on the image bearing surface, urethane rubber has relatively good wear resistance, and the free-forming surface formed by centrifugal molding has R according to JISBO601, which can be measured by optical cutting method.
Since it has a surface roughness that is smoother than the surface roughness in which max is in the range of 2 to 100 μm, that is, a surface smoothness that cannot be obtained on the peeling surface from the mold surface, the free-forming surface is used as the contact surface to the image carrier surface. This is because it was believed that this would further prevent toner from entering between the contact between the blade and the image carrier, thereby improving the efficiency of scraping off the toner by the blade, and hence the cleaning efficiency.

0004

However, in the conventional cleaning device as described above, there is a problem in that the cleaning efficiency decreases relatively quickly. In order to solve this problem, if the rubber hardness of the blade is increased, a new problem arises in that the surface of the image carrier becomes more susceptible to wear and tear, thereby shortening the life of the image carrier.

The present invention has been made in order to solve the above-mentioned problems, and provides a blade cleaning device that improves the durability of the blade, that is, maintains high cleaning efficiency without increasing the rubber hardness of the blade. For the purpose of providing.

[0006]

[Means for Solving the Problems] As a result of detailed research into the causes of reduced cleaning efficiency, the inventor of the present invention found that the reduction in cleaning efficiency is caused by the edge where the front end surface of the blade intersects with the surface of contact with the image carrier surface. The occurrence of curling is largely related to the occurrence of curling, and the occurrence of curling is largely related to the contact friction between the blade and the image carrier. The above-mentioned curling is less likely to occur if the surface is rough enough to prevent toner from entering between the contact surfaces, and therefore the contact friction is small, rather than by a free-forming surface. Instead of making the contact surface with the image carrier surface rough, the contact friction is reduced by making the image carrier surface rough, thereby making the above-mentioned curl less likely to occur. It has been found that problems arise in that the image quality of the toner image deteriorates, and the image quality of the recorded image deteriorates due to a decrease in the transfer efficiency from the image carrier to the recording paper.

The present invention has been made based on the above-mentioned findings, and includes holding a blade made of a rubber elastic material such that the front surface side contacts the moving image carrier surface from the edge portion where the front end surface and the surface intersect. In a cleaning device that scrapes off toner adhering to the image carrier surface on the front end surface side of the blade, the reference length L0.8 of the surface of the blade is used.
The cleaning device is characterized in that the surface roughness indicated by the maximum height Rmax in mm is in the range of 2 μm or more and 10 μm or less, and this configuration achieves the above object.

[0008] The surface roughness is determined by Rmax according to JISBO601-1982, which is determined by the optical cutting method or the stylus method.
It is a value.

[0009]

[Operation] The cleaning device of the present invention has a counter type blade made of a rubber elastic material whose surface in contact with the image carrier surface has a surface roughness of 2 μm or more and 10 μm or less at Rmax with a reference length L0.8 mm. Compared to a cleaning device in which the free-forming surface of the centrifugal molding is used as the contact surface of the blade to the image carrier surface, the contact friction between the blade and the image carrier is small, so the working edge of the blade is less likely to curl. Toner hardly ever enters between the contact surfaces of the image carrier and the image carrier, thus maintaining high cleaning efficiency without increasing the rubber hardness of the blade.Improving the durability of the blade and extending the life of the image carrier. It will not be lowered.

[0010] When the surface roughness Rmax of the contact surface of the blade to the image carrier surface becomes smoother than 2 μm, the effect of improving the durability of the blade decreases markedly, and conversely, when it becomes rougher than 10 μm, the surface roughness Rmax becomes smoother than 2 μm. Toner other than the fine particles with a particle size of 5 μm or less used tends to enter between the contact surfaces of the blade and the image carrier, resulting in a decrease in cleaning efficiency from the beginning. The preferable surface roughness of the contact surface of the blade is 2 μm or more and 6 μm or less, and 6 μm or more.
If the diameter is less than .mu.m, even if the toner contains fine particles with a particle size of 5 .mu.m or less, the toner will not enter between the contact surfaces of the blade and the image carrier to cause scumming.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic side view showing an example of an electrophotographic recording apparatus using the cleaning device of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1.

In the figure, 1 is an a-Se type photoreceptor;
It has a photoreceptor layer such as a Si-based photoreceptor or an OPC photoreceptor, rotates in the direction of the arrow, and has its surface uniformly charged by a charger 2.
Image exposure 3 is applied to the charged surface to form an electrostatic image,
This is an image carrier on which the electrostatic image is developed into a toner image by a developing device 4. The developed toner image is transferred by a transfer device 5 to a recording paper fed so as to be in contact with the image carrier 1, and the recording paper is separated from the image carrier 1 by a separator 6 and transferred to a fixing device by a conveyor 7. After the toner image is fixed thereon, it is discharged outside the machine.

Reference numeral 8 holds a blade 10 made of a rubber elastic material such as urethane rubber by a holder 9, and brings one side surface 10a of the blade 10 into pressure contact with the surface of the image carrier 1 from the edge where it intersects with the front end surface 10b. As shown in FIG. This is a cleaning device that sends out to a conveying means.

In the blade 10, the surface roughness of the surface 10a that contacts the surface of the image carrier 1 is in the range of the maximum height Rmax of the reference length L0.8 mm from 2 μm to 10 μm, preferably from 2 μm to 6 μm. It is something. As a result, the life of the blade 10 for maintaining high cleaning efficiency is significantly extended compared to a conventional blade in which the free-forming surface of centrifugal molding is brought into contact with the image carrier surface.

Regarding this, a blade obtained from a urethane rubber sheet formed by conventional centrifugal molding has a surface roughness of Rm.
When the free-forming surface side, which is smoother than ax2μm, is used as the contact surface to the image carrier, the opposite surface roughness is R.
When compared with the case where the peeling surface side from the mold surface, which has a maximum diameter in the range of 2 μm to 6 μm, is used as the contact surface to the image carrier, in the former case, the initially high cleaning efficiency decreased in a short period of time. However, in the latter case, the same high cleaning efficiency was maintained for a much longer period of time. This result was the same not only when the toner had fine particles with a particle size of 5 μm or less removed, but also when the toner contained such fine particles in a proportion of 10% by weight or less. In addition, a similar comparison was made by changing the degree of finish on the inner surface of the rotary mold used for centrifugal molding, and it was found that for toner from which fine particles had been removed, the contact surface roughness of the blade to the image carrier was as described above up to Rmax 10 μm. However, if the toner contains fine particles, the cleaning efficiency will be lowered from the beginning. If the surface roughness of the contact surface of the blade with the image carrier becomes rougher than Rmax 10 μm, the cleaning efficiency from the beginning will decrease even for toner from which fine particles have been removed.

The image carrier to which the cleaning device of the present invention is applied may be one having an insulating surface layer on the photoreceptor layer, or an electrostatic image carrier having no photoreceptor layer and using a multi-stylus electrode or a screen photoreceptor on the insulating surface layer. An electrostatic image may be formed by a forming means or the like. Further, the toner may be non-magnetic toner or magnetic toner, and the developing device is not limited to a magnetic brush developing device. The blades of the cleaning device are not limited to those obtained from sheets formed by centrifugal forming, but may also be obtained from sheets formed by rolling rolls or press forming, and are not limited to those made of urethane rubber. .

[0018]

[Effects of the Invention] According to the cleaning device of the present invention, the life of the blade for maintaining high cleaning efficiency is extended, and the surface of the image carrier is less worn out, and the quality of recorded images is not degraded. An excellent effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an example of an electrophotographic recording apparatus using the cleaning device of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1.

[Explanation of symbols]

1...image carrier,
4...Developing device, 5...Transfer device,
6...Separator, 8...Cleaning device,
9...Holder, 10...Blade.

Claims (2)

[Claims] 1. A blade made of a rubber elastic material is held so that the front surface side contacts the moving image carrier surface from the edge where the front end surface and the surface thereof intersect, and the front end surface side of the blade is attached to the image carrier surface. In a cleaning device for scraping off toner, the reference length L0.
A cleaning device characterized in that the surface roughness indicated by the maximum height Rmax of 8 mm is in the range of 2 μm or more and 10 μm or less. 2. The cleaning device according to claim 1, wherein the rubber elastic material is urethane rubber.