JPH0990847A - Lubricant supplying device for image carrier in electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable always supplying adequate amount of lubricant on a surface of an image carrier, as for the lubricant supplying device to the image carrier in the electrophotographic device. SOLUTION: A surface roughness of a roller 30, expressed as Rz in ten points average surface roughness is made >=3μm<=20μm. Moreover, with regard to the roller 30, pressing pressure W corresponding to the surface roughness Rz, is applied to the roller 30. In other words, the pressing pressure W (Ncm<2> ), is made 0.02/Rz<W<0.5/Rz. Then, the solid lubricant 35 is shaved by the rotation of the roller 30, a specific amount of the lubricant is stuck on the roller 30, the lubricant is transferred by the rotary brash 27 and applied on a photoreceptor 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be applied to an electrophotographic apparatus using a laser, such as a copying machine, a printer and a facsimile. More specifically, the present invention relates to a device for supplying a lubricant to an image carrier, which supplies a lubricant to an image carrier such as a photoconductor that forms an image on a surface thereof by using toner in such an electrophotographic apparatus.

[0002]

2. Description of the Related Art Conventionally, for example, a lubricant supplying device for a photoconductor of a copying machine is provided with a rotary brush 3 between a photoconductor 1 and a solid lubricant 2 as shown in FIG. Respectively contact the photoconductor 1 and the solid lubricant 2, and at the time of supplying the lubricant, rotate the rotary brush 3 to rub the solid lubricant 2, and the lubricant adhered to the rotary brush 3 is applied to the surface of the photoconductor 1. There is a structure that is applied.

By supplying the lubricant to the photoconductor 1 in this way, the friction coefficient of the surface of the photoconductor 1 is lowered, whereby the cleaning blade 4 pressed against the photoconductor 1 is worn and the cleaning performance is deteriorated. Of the toner is prevented, and the toner is excessively attached to the surface of the photoconductor 1 to prevent the background portion where an image is not formed from being contaminated with the toner.

[0004]

However, when the solid lubricant 2 is consumed, the contact pressure of the rotary brush 3 against the solid lubricant 2 weakens according to the decrease in the solid lubricant 2. Therefore, the lubricant rubbed off by the rotary brush 3 over time. Less, and as a result,
There has been a problem that the amount of lubricant supplied to the photoconductor 1 is gradually reduced, and it is not possible to constantly supply an appropriate amount of lubricant.

Therefore, an object of the present invention is to always be able to supply an appropriate amount of lubricant to the surface of an image bearing member such as a photoreceptor.

[0006]

Therefore, the present invention described in claim 1 has, for example, the following features:
The solid lubricant 35 is pressed against the rotary roller 30, the rotary roller 30 is rotated to scrape off the solid lubricant 35, and the lubricant adhering to the rotary roller 30 is transferred by a coating member such as the rotary brush 27. In the lubricant supplying device 25 for the image carrier in the electrophotographic apparatus for applying to the image carrier such as the photoconductor 11, the surface roughness of the rotating roller 30 is
The ten-point average surface roughness Rz is 3 μm or more and 20 μm or less,
The pressing pressure W [Ncm ² ] of the solid lubricant 35 against the rotary roller 30 is 0.02 / Rz <W <0.5 / Rz.
It is characterized by

When the rotary roller 30 having a surface roughness Rz = 3 μm is used, the rotary roller 30 is used.
Against 0.02 / 3 <W <0.5 / 3
cm ² ]. Then, the solid lubricant 35 is scraped by the rotation of the rotating roller 30, a certain amount of the lubricant is attached on the rotating roller 30, and the lubricant is applied to the surface of the image carrier by the applying member.

According to a second aspect of the present invention, for example, as shown in the following embodiment, in the lubricant supply device 25 according to the first aspect, the surface of the rotary roller 30 after being processed into a roller shape, It is characterized in that fine particles are adhered by using an adhesive to increase the interval between the irregularities on the surface of the rotating roller 30.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 is a schematic configuration diagram of a recording unit of a laser printer including the lubricant supply device according to the first aspect.

Reference numeral R in the drawing indicates a recording unit. The recording unit R includes a drum-shaped photoconductor 11 that is an image carrier. Around the photoconductor 11, a charging device 12, a developing device 13, a transfer charger 14,
A separation charger 15, a cleaning device 16, and a static eliminator 17 are arranged. An optical writing device 18 is provided above the photoconductor 11.

Then, at the time of recording, the paper P is sent out from a paper supply unit (not shown), and is conveyed to the lower side of the photoconductor 11 at a timing by a registration roller (not shown).

The photoconductor 11 rotates in the clockwise direction shown by the arrow. At this time, the surface of the photoconductor 11 is uniformly charged by the charging device 12, and the surface of the photoconductor 11 is irradiated with laser light. An electrostatic latent image is formed on. Subsequently, when the toner passes through the position of the developing device 13, the developing device 13 attaches toner to visualize the electrostatic latent image on the photoconductor 11. Then, the visible image is conveyed to the lower side of the photoconductor 11 and the paper P is conveyed.
The image is transferred by the transfer charger 14 onto the upper surface of the. After transfer,
The separation charger 15 removes the charge to separate the paper P from the photoconductor 11. After separation, the paper P is conveyed to a fixing device (not shown), where the transfer image is fixed, and then the paper P is discharged to an external paper discharge unit.

On the other hand, after the image transfer, the toner remaining on the surface of the photoconductor 11 is removed by the cleaning blade 20 of the cleaning device 16. Further, the surface of the photoconductor 11 is destaticized by the destaticizing charger 21 of the destaticizing device 17, and is irradiated with the destaticizing lamp 22 to be electrostatically initialized to prepare for the next use.

By the way, in the above-mentioned laser printer,
Although not shown in FIG. 5, the lubricant supply device is arranged, for example, at the upstream position in the rotation direction of the photoconductor 11 in the cleaning device 16.

FIG. 1 shows a lubricant supply device designated by the reference numeral 25. The lubricant supply device 25 has an outer case 25a.
A rotating brush 27 is provided inside. The rotating brush 27 is formed, for example, by arranging a large number of bristles 27b of polyester fiber in a brush shape on the outer circumference of a tube shaft 27a made of aluminum. Both ends of the tube shaft 27a are rotatably supported by the outer case 25a, arranged in parallel with the central axis of the photoconductor 11, and the tips of the bristles 27b are brought into contact with the surface of the photoconductor 11.

Therefore, the rotary roller 30 is provided on the side of the rotary brush 27 opposite to the photoconductor 11. Rotating roller 30
Is made of stainless steel, for example, and has a roughened surface. Both ends of the roller shaft 30a are rotatably supported by the outer case 25a and arranged in parallel with the tube shaft 27a, and the tips of the bristles 27b are brought into contact with the surface.

On the surface of the rotary roller 30, the solid lubricant 35 is pressed from the upper side in FIG. 1, while the tip side of the blade 40 is pressed to the lower side. Solid lubricant 3
As 5, there is used, for example, a material having zinc stearate as a main component, which is melted and then cooled and solidified to form a horizontally long rectangular material. As the blade 40, for example, a blade made of thick plate-shaped rubber that is long in the roller shaft 30a direction is used.

Further, above the solid lubricant 35, a long box-like member 31 having an upper side thereof is provided, and the outer case 2 is provided.
Support with 5a. Then, the lower ends of a plurality of compression springs 29 provided inside the box-shaped member 31 are pressed against the upper surface of the solid lubricant 35, and the solid lubricant 35 is pressed against the rotary roller 30 with a predetermined pressing pressure W. .

In the above-mentioned lubricant supply device 25, therefore, the rotary brush 27 and the rotary roller 30 are rotated when the lubricant is supplied, and the solid lubricant 35 is scraped by the rotary roller 30 to rotate the solid lubricant 35. A lubricant is attached to the surface of the roller 30.
Then, the lubricant adhering to the rotating roller 30 is transferred by the rotation of the rotating brush 27 and applied on the surface of the photoconductor 11.

On the other hand, when the lubricant is supplied, the rotating roller 30
Toner is transferred from the photoconductor 11 via the rotating brush 27 and adheres to the surface thereof. Then, the toner attached to the rotating roller 30 is removed by the blade 40.

By the way, if the rotating roller 30 is a relatively fine one having a ten-point average surface roughness Rz of less than 3 μm as the above-mentioned rotating roller 30, the fine irregularities on the surface rotate. Since the lubricant adhered to the roller 30 is covered, the solid lubricant 35 cannot be effectively scraped due to the unevenness of the surface, and the scraped amount is reduced. As a result, for example, as shown in FIG. 2 showing the relationship between the lubricant supply amount to the photoconductor 11 and the number of prints, as the number of prints increases with time, the lubricant supply amount S decreases, and when the number of prints reaches a certain value. It falls below the lower limit of the appropriate amount range.

On the other hand, if the rotary roller 30 having a relatively rough surface roughness Rz of 20 μm or more is used, the solid lubricant 35 is excessively cut when the solid lubricant 35 is scraped, and the lubricant is supplied. The amount easily exceeds the upper limit of the appropriate amount range. If the surface is rough like that, the blade 4
The wear of 0 is severe and the life is remarkably shortened.

Therefore, in the lubricant supply device 25 according to the above-mentioned claim 1, the surface roughness after processing into the roller shape as the rotating roller 30 is 10 μm or more in terms of ten-point average surface roughness Rz 2 μm or more 2
The thickness of 0 μm or less is used.

Incidentally, the scraping amount of the solid lubricant 35 corresponds to the surface roughness Rz of the rotary roller 30, and the pressing pressure W of the solid lubricant 35 against the rotary roller 30 is also applied.
It corresponds to a large part. That is, those surface roughness R
The larger the z and the pressing pressure W, the larger the scraping amount of the solid lubricant 35. Accordingly, a relatively large pressing pressure W is applied to the rotating roller 30 having a small surface roughness Rz, and conversely, a comparison is made to the rotating roller 30 having a large surface roughness Rz. It is considered desirable to apply a very small pressing pressure W.

Therefore, in the lubricant supply device 25, a pressing pressure W corresponding to each surface roughness Rz is applied to the rotary roller 30 for each rotary roller 30 processed into a roller shape. Then, specifically, when determined by an experiment, the pressing pressure W [Ncm ² ] against the rotating roller 30 is
0.02 / Rz <W <0.5 / Rz.

However, when using the rotary roller 30 of Rz = 3 μm, for example, 0.02 / 3 <W <0.5 /
A compression spring 29 having a spring force corresponding to the pressing pressure W is used so that the pressing pressure W [Ncm ² ] of 3 is applied to the rotating roller 30. Then, the solid lubricant 3 is urged by the compression spring 29.
5 is pressed against the rotating roller 30. Then, the solid lubricant 35 is scraped by the rotation of the rotary roller 30, a certain amount of lubricant is attached on the rotary roller 30, and the lubricant is applied to the surface of the photoconductor 11 by the rotary brush 27.

By the way, FIG. 3 shows an example of the surface condition of the rotary roller 30 (Rz = 3 μm to 20 μm) after being processed into a roller shape. Depending on the rotating roller 30, there are many parts a having a very small unevenness interval a on the surface as shown in the figure. If such a rotating roller 30 is used as it is, in some cases, the scraped amount of the solid lubricant 35 may be reduced due to the minimal portion a of the unevenness interval.

Therefore, in the invention described in claim 2, fine particles are attached to the surface of the rotary roller 30 after being processed into a roller shape by using an adhesive so that the interval between the irregularities on the surface of the rotary roller 30 becomes large. To do.

In this case, for example, ceramic particles are used as the particles. After processing into a roller shape, fine particles are attached to the surface of the rotary roller 30 using an adhesive. For example, an adhesive is applied to the surface of the rotating roller 30, and fine particles are electrostatically blown and adhered on the adhesive,
Further coat with an adhesive. Then, the spaces between the irregularities of the minimal portion a are covered with fine particles and an adhesive to increase the interval between the irregularities on the surface as shown in FIG. Then, the surface (Rz = 3 μm to 20 μm) of the rotating roller 30 is formed into a rough surface having irregularities with relatively large steps.

Then, when the rotary roller 30 is rotated, the convex portion m on the surface of the rotary roller 30 can surely scrape off the lubricant by a constant amount.

Further, in this case, it is preferable to appropriately change the particle size of the fine particles adhering to the surface according to the uneven state of the minimum portion a formed on the rotating roller 30.

In the above embodiments, the photoconductor 11 is used as the image carrier. However, the image carrier is not limited to such a photoconductor, and for example, an intermediate transfer belt, that is, after transferring each color image on the photoconductor individually to form a color image, the color image is transferred onto a sheet at a time. A transfer belt or the like may be used.

[0033]

Therefore, according to the invention described in claim 1, as the rotating roller, a roller having an appropriate surface roughness of 3 μm to 20 μm in terms of ten-point average surface roughness Rz is used. Appropriate pressing pressure W [Ncm ² ] corresponding to each surface roughness of each rotating roller, ie 0.02 / R
Since a pressing pressure of z <W <0.5 / Rz is applied to the rotating roller, the amount of lubricant scraped off by the rotating roller is always kept constant, and as a result, an appropriate amount of lubricant is always applied to the surface of the image carrier. Can be made available.

According to the second aspect of the present invention, since the fine particles are attached to the surface of the rotary roller after being processed into a roller shape by using an adhesive, the interval between the irregularities on the surface of the rotary roller is increased. Due to the unevenness on the surface, the solid lubricant can be more surely scraped off by a fixed amount, and as a result, an appropriate amount of the lubricant can always be more reliably supplied to the surface of the image carrier.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a lubricant supply device according to an embodiment of the invention described in claim 1.

FIG. 2 is a graph showing a relationship between the number of prints and a lubricant supply amount when a rotating roller having a surface roughness Rz of less than 3 μm is used.

FIG. 3 is a state explanatory view showing an example of a surface state of a rotary roller having a surface roughness Rz of 3 μm to 20 μm after being processed into a roller shape.

FIG. 4 is a state explanatory view showing a surface state of a rotary roller in which fine particles are adhered to the surface with an adhesive in the embodiment of the invention described in claim 2;

FIG. 5 is a schematic configuration diagram of a recording unit of a laser printer including the lubricant supply device.

FIG. 6 is a schematic configuration diagram showing a conventional lubricant supply device.

[Explanation of symbols]

 11 Photoreceptor (Image Carrier) 25 Lubricant Supply Device 27 Rotating Brush 30 Rotating Roller 35 Solid Lubricant Rz Surface Roughness W Pressing Pressure

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Arai 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (2)

[Claims] 1. A solid lubricant is pressed against a rotary roller, the rotary roller is rotated to scrape off the solid lubricant, and the lubricant adhering to the rotary roller is transferred by a coating member and applied to an image carrier. In a device for supplying a lubricant to an image carrier in an electrophotographic apparatus, a surface roughness of the rotating roller is 10 μm or more and a surface roughness Rz of 3 μm or more and 20 μm or less, and a pressing pressure of the solid lubricant to the rotating roller is set. W [N
cm ² ] is 0.02 / Rz <W <0.5 / Rz, and a lubricant supply device for an image carrier in an electrophotographic apparatus. 2. The electrophotography according to claim 1, wherein fine particles are attached to the surface of the rotary roller after being processed into a roller shape by using an adhesive to increase the interval between the irregularities on the surface of the rotary roller. Lubricant supply device for the image carrier in the apparatus.