JP2002365973A - Apparatus for applying lubricant to image carrier, process cartridge having the same, and image forming apparatus - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a lubricant coating apparatus in which the amount of coating on an image carrier does not become excessive in an early stage of use. SOLUTION: In order to achieve a first object, a photosensitive drum 15, a solid lubricant 3, and a brush for applying the lubricant 3 to the photosensitive drum 15 by contacting the lubricant 3 and the photosensitive drum 15 respectively. In the apparatus for applying a lubricant to the photosensitive drum 15 in the image forming apparatus having the roller 4, the shape of the lubricant 3 is changed so that the area of the surface in contact with the brush roller 4 is It is characterized by being formed so as to be changed by coating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for applying a lubricant to an image carrier in an electrophotographic image forming apparatus, a process cartridge having the same, and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as a cleaning means provided in an electrophotographic image forming apparatus, a simple configuration has been adopted.
Further, from the viewpoint of low cost, a blade cleaning method as shown in FIG. 13 is widely adopted. In FIG. 13, reference numeral 101 denotes a photosensitive drum serving as an image carrier which is driven to rotate in the direction of an arrow, and reference numeral 102 denotes a cleaning unit.

The cleaning means 102 includes a waste toner collecting container 103, a support member 104 attached to the container 103, an elastic blade 105 held by the container 103, and a toner collecting sheet 106.

The elastic blade 105 is made of polyurethane rubber or the like, and is in contact with the surface of the photosensitive drum 101 in a so-called counter direction. This makes it possible to reliably scrape off the transfer residual toner remaining on the photosensitive drum 101.

In recent years, there has been an increasing demand for finer output images, and as a means for satisfying these requirements, a substantially spherical toner capable of obtaining more uniform charging characteristics and a fine particle toner having a smaller particle size have been proposed. Is being adopted.

However, it is known that it is very difficult to remove these toners from the surface of the photosensitive drum 101 when using substantially spherical toner or fine particle toner as compared with conventional toners.

The reason is that when the photosensitive drum 101 is driven to rotate, the elastic blades 105 contact the surface of the photosensitive drum 101.
This is because the substantially spherical toner and the fine particle toner easily pass through a slight gap between the surface of the photosensitive drum 101 and the elastic blade 105 generated at this time.

In order to solve this problem, the photosensitive drum 10
Means of increasing the contact pressure of the elastic blade 105 with respect to 1 is used, but at this time, the frictional force between the photosensitive drum 101 and the elastic blade 105 naturally increases, thereby preventing damage and wear of each member. It is necessary.

On the other hand, for example, as shown in FIG.
A solid lubricant 107 fixedly disposed, and lubricant application to an image carrier having an application roller 108 which is a lubricant application member that contacts each of the lubricant 107 and the photosensitive drum 101 and rotates in a predetermined direction. By mounting the device, it is possible to prevent damage and wear of each member.

This means is particularly effective in suppressing a phenomenon called "blade squealing" which occurs when the frictional force between the surface of the photosensitive drum 101 and the elastic blade 105 increases and the elastic blade causes irregular amplitude movement. Show the effect.

As the solid lubricant, fatty acid metal salts such as zinc stearate and calcium stearate are generally used.

[0012]

However, in a configuration such as the above-mentioned lubricant applying apparatus, a solid droplet lubricant fixed and arranged is brought into contact with each of the lubricant and the image carrier to apply the lubricant to the image carrier. Since the rubbing is performed directly using a coating member to be coated, the coating amount on the image carrier tends to increase particularly in the early stage of use.

In addition, the amount of coating tends to increase, particularly at the central portion in the longitudinal direction of the image carrier, in relation to the method of supporting the image carrier and the coating member.

On the other hand, when the amount of application to the image carrier is extremely large, the frictional force between the surface of the photosensitive drum and the elastic blade is increased due to the excessive amount of the lubricant, and the torque required for rotationally driving the photosensitive drum is increased. Has a problem of rising.

Accordingly, a first object of the present invention is to provide a lubricant coating device in which the amount of coating on an image carrier does not become excessive in the early stage of use.

A second object of the present invention is to provide a lubricant applying apparatus in which the amount of application on the central portion of the image bearing member does not become excessive.

A third object of the present invention is to prevent the amount of the lubricant applied to the image bearing member from becoming excessive by changing the area and hardness of the surface in contact with the lubricant application member. It is to provide a lubricant applying device to be controlled.

[0018]

In order to achieve the first object, an image carrier, a solid lubricant, and a lubricant that is brought into contact with each of the lubricant and the image carrier to contact the image carrier. An application member for applying the lubricant to the image carrier in the image forming apparatus having the lubricant, the shape of the lubricant, the area of the surface in contact with the application member, the application of the lubricant to the image carrier It is formed so as to change according to. Further, it can also be achieved by forming the lubricant such that the hardness of the surface in contact with the application member is changed by applying the lubricant to the image carrier.

In order to achieve the second object, an image carrier, a solid lubricant, and a coating member which contacts the lubricant and the image carrier to apply the lubricant to the image carrier, In the apparatus for applying a lubricant to an image carrier in an image forming apparatus having the above configuration, the shape of the lubricant is formed such that the area of the surface in contact with the application member changes in the longitudinal direction of the lubricant.
In addition, the lubricant, the hardness of the surface on the side in contact with the application member,
It can also be achieved by forming the lubricant so as to change in the longitudinal direction.

The third object is achieved by using a lubricant having the above-mentioned shape and hardness to control the amount of the lubricant applied to the image carrier.

[0021]

[First Embodiment] A first embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a main part of an image forming apparatus according to the present embodiment, FIGS. 2 and 3 are configuration diagrams of a lubricant, and FIG. 4 is a diagram illustrating an application amount to an image carrier by a lubricant application device. .

In an electrophotographic image forming apparatus,
The electrostatic latent image formed on the image carrier is visualized as a toner image by a developing device. In an image forming apparatus that forms a color image by superimposing toner images of a plurality of colors, an image forming apparatus 11 using an intermediate transfer member as shown in FIG. It has been proposed and put into practical use. By adopting the intermediate transfer member, it is possible to improve the media flexibility without depending on the sheet size, the sheet thickness and the like.

The image forming process will be described.

The image forming apparatus 11 is connected to a host 12 such as a personal computer or a work station.
Image data is received via a video interface in response to a print request from the host 12. This image data is separated into four colors of yellow, magenta, cyan, and black, and a charging, exposure, and development process is sequentially performed for each color to form a toner image. Transfer) and batch transfer (secondary transfer) to a medium such as a sheet to obtain a full-color image.

Reference numeral 1 denotes a photosensitive drum as a first image carrier which is driven to rotate at a predetermined peripheral speed in the direction of the arrow. The surface of the photosensitive drum 15 is uniformly charged by a charging roller 16 as charging means. The charging roller 16 is pressed against the surface of the photosensitive drum 15 with a predetermined pressing force, and is rotated by the rotation of the photosensitive drum 15. Next, scanning is performed by the exposure unit 13 that is ON / OFF controlled according to the image data of the first color (yellow), and an electrostatic latent image of the first color is formed.

The first color electrostatic latent image is developed and visualized by a yellow developing device 14a containing yellow toner. The developing device 14 will be described later. The visualized first toner image is transferred to a photosensitive drum 15 as a first image carrier.
Is transferred to the surface of the intermediate transfer member 5 as a second image bearing member which rotates and fluctuates in the direction of the arrow at a peripheral speed substantially equal to the peripheral speed of the photosensitive drum 15 (primary transfer). ) Is done. The toner remaining on the photosensitive drum 15 without being transferred during the primary transfer is scraped and collected by a cleaning blade 6 provided in a cleaning device 7 pressed against the photosensitive drum 15.

Subsequently, the above process is repeated three times, each time a second toner image developed with magenta toner,
The third toner image developed with the cyan toner and the fourth toner image developed with the black toner are sequentially transferred to the surface of the intermediate transfer member 5 and laminated to form a color image.

The full-color toner image on the intermediate transfer member 5 is
The transfer belt 9 electrostatically collectively transfers (secondarily transfers) the sheet P fed from the sheet force set 8 or the like. Thereafter, the full-color toner image transferred to the sheet P is permanently fixed in the fixing device 10, and is discharged from the discharge unit to the outside of the apparatus, thereby obtaining a desired print image.

Next, the toner will be described.

The toner is a non-magnetic one-component developer, but can be applied to a magnetic toner and a crushed toner. In this embodiment, a substantially spherical toner whose transfer efficiency is greatly improved is used. Specifically, SF-
1 is 100 to 180, and SF-2 is 100 to 140.

The SF-1 and SF-2 are manufactured by Hitachi, Ltd.
Using an E-SEM (S-800), 100 toner images are randomly sampled, and the image information is obtained via an interface using an image analyzer (Lusex3, manufactured by Nicole).
And analyze it, and define the value obtained by the following equation.

SF-1 = ｛(MXLNG) ² / ARE
A｝ * (π / 4) * 100 SF-2 = ｛(PER1) ² / AREAl * (π / 4)
* 100 (MXLNG: absolute maximum length, AREA: toner projection area, PER1: peripheral length) The shape factor SF-1 of this toner indicates a spherical degree, and is 100
As the size increases, the shape gradually changes from a sphere to an irregular shape.
SF-2 indicates the degree of unevenness. As the value increases from 100, the unevenness of the toner surface becomes more conspicuous.

The toner may be produced by any method as long as the toner has the shape factor described above. For example, a conventional pulverized toner surface may be subjected to a plastic spheroidizing treatment by thermal and mechanical stress. Further, a method of directly producing a toner by a turbid polymerization method, a dispersion polymerization method of directly producing a toner by using a water-based inducing solvent in which a monomer obtained is soluble and insoluble in a polymer, or a water-soluble polar initiator is used. It is also possible to use an emulsion polymerization method typified by a soap-free polymerization method of directly polymerizing in the presence of an agent to form a toner.

In the present embodiment, as the polymerized toner, the spherical coefficient of spherical SF-1 is relatively easily adjusted to 100 to 180.
SF-2 can be controlled to 100 to 140, and a fine particle toner having a sharp particle size distribution of 4 to 8 μm can be obtained. The turbid polymerization method under normal pressure or under pressure is used, and styrene and n- Butyl acrylate, a salicylic acid metal compound as a charge control agent, a saturated polyester as a polar resin, and a colorant were added to produce colored turbid particles having a weight average particle size of about 7 μm.

Next, the cleaning device 7 which is a process cartridge provided with the cleaning blade 6 and the lubricant application mechanism used in this embodiment will be described with reference to FIG.

In FIG. 2, 6 is a cleaning blade, 1 is a toner collecting sheet, and 2 is a waste toner collecting container. As described above, a small amount of toner remaining on the surface of the photosensitive drum after the primary transfer is removed from the photosensitive drum by the cleaning blade 6 constituting the cleaning device 7, and the cleaning device 7 is removed by the waste toner collecting sheet 1. Is stored in the waste toner collecting container 2 without being scattered outside.

The cleaning blade 6 is made of polyurethane rubber integrally held at the tip of the sheet metal 5 and has a predetermined penetration amount that can obtain a sufficient effect on the photosensitive drum even when the above-mentioned substantially spherical toner is used. The contact is made under the conditions of δ and the set angle θ.

Inside the cleaning device 7, a solid lubricant 3 fixedly arranged upstream of the cleaning blade 6 in the rotation direction of the photosensitive drum 15, and a brush roller 4 is rotated so as to contact the lubricant 3 and the photosensitive drum 15. It is installed to be movable. The brush roller 4 is driven to rotate at a predetermined speed in the direction of the arrow,
The lubricant 3 scraped off by the brush roller 4 is applied to the photosensitive drum 15
Applied on top. In this embodiment, the brush roller 4 is used, but a rotatable elastic body may be used.

In this embodiment, zinc stearate is used as a solid lubricant. In addition, relatively higher fatty acids such as iron stearate, copper stearate, magnesium palmitate, calcium palmitate, manganese oleate, and lead oleate can be used.

The solid lubricant fixedly arranged as shown in the conventional example has a strong tendency to apply a large amount to the image carrier, especially in the early stage of its use. Therefore, in the present embodiment, as shown in FIG. 2, the area of the surface in contact with the brush roller 4 as an application member is small in the initial stage of use, and as the use increases, the lubrication of the image carrier is reduced. The solid lubricant 3 having a shape in which the area of the surface in contact with the brush roller 4 is increased by wear of the lubricant due to application of the lubricant.

By adopting such a shape, the tendency that the amount of application to the image carrier is large in the early stage of use can be eliminated, and the contact pressure of the cleaning blade is increased by using a substantially spherical toner. In this case, it is possible to prevent the members from being damaged or worn due to the frictional force between the photosensitive drum 15 and the cleaning blade 6.

The solid lubricant having the above-mentioned shape is formed by cutting a conventional lubricant by cutting, but may be formed by a mold.

As shown in FIG. 4, the decrease in the weight of the solid lubricant per unit usage time was defined as the amount of application to the image carrier per unit time. It can be seen that the initial coating amount on the image bearing member is appropriately reduced.

As a shape for changing the area of the surface in contact with the application member, a shape as shown in FIG. 3 can be selected.

In the present embodiment, an example in which the photosensitive drum 15 is used as the image carrier has been described. However, for example, the lubricant of the present invention can also be used for an intermediate transfer member carrying a toner image visualized by a developing device. The applicator can be used.

With the above configuration, it is possible to prevent an excessive amount of the lubricant from being applied to the image carrier in the early stage of use of the lubricant applying device.

[Second Embodiment] Next, a second embodiment of the image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 5 is a configuration diagram of the lubricant application device according to the present embodiment, and FIG. 6 is a diagram illustrating the amount of application to the image carrier by the lubricant application device. The same parts as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, another embodiment of a lubricant applying apparatus in which the amount of the lubricant applied to the image carrier in the early stage of its use is not excessive will be described.

The hardness of a solid lubricant such as zinc stearate can be selected, and is generally represented by pencil hardness. With a hard lubricant, the amount of lubricant worn by the application member for applying the lubricant to the image carrier is smaller, and the amount of the lubricant applied to the image carrier is reduced.

As shown in FIG. 5, in this embodiment, the hardness of the lubricant is changed a plurality of times in the direction perpendicular to the surface in contact with the application member. In particular, in order to prevent the amount of application to the image carrier in the early stage of use from becoming excessive, a lubricant having a high hardness may be selected in the early stage of use. Here, a lubricant having a hardness B and a hardness 2B is used, but it goes without saying that the lubricant can be appropriately selected.

FIG. 6 shows the decrease in the weight of the solid lubricant per unit time used as the amount of application to the image carrier per unit time. It can be seen that the use of the solid lubricant of the present embodiment reduces the amount of application to the image carrier in the initial stage of use.

Such a lubricant having a plurality of hardnesses is
It can be created by bonding, or it can be created by a mold.

With the above configuration, it is possible to prevent an excessive amount of the lubricant from being applied to the image carrier in the early stage of use of the lubricant applying device.

[Third Embodiment] Next, a third embodiment of the image forming apparatus according to the present invention will be described with reference to the drawings. 7 is a configuration diagram of the lubricant application device according to the present embodiment, FIG. 8 is a configuration diagram of the lubricant, and FIG. 9 is a diagram illustrating an application amount of the lubricant application device to the image carrier. The same parts as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, there is shown a form of a lubricant applying apparatus in which the amount of applied lubricant at the longitudinal end of the image carrier does not become excessive.

As shown in FIG. 7, in this embodiment, the area of the surface in contact with the lubricant application member in the longitudinal direction is changed. Wide at the center and narrow at both ends.

FIG. 9 shows the decrease in the weight of the solid lubricant per unit usage time as the amount of application to the image carrier per unit time. It can be seen that the use of the solid lubricant of this embodiment reduces the amount of application to the image carrier at both ends appropriately.

As the shape for changing the area of the surface in contact with the coating member, a shape as shown in FIG. 8 can be appropriately selected.

With the configuration described above, it is possible to prevent an excessive amount of the lubricant from being applied to the image carrier at the initial stage of use of the lubricant applying apparatus.

[Fourth Embodiment] Next, a fourth embodiment of the image forming apparatus according to the present invention will be described with reference to the drawings. Figure
10 is a configuration diagram of the lubricant application device according to the present embodiment, and FIG. 11 is a diagram illustrating an application amount of the lubricant application device to the image carrier. The same parts as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, another embodiment of the lubricant applying apparatus is described, in which the amount of applied lubricant at the longitudinal end of the image carrier is not excessive.

As shown in FIG. 10, in the present embodiment, the hardness of the surface in contact with the lubricant applying member in the longitudinal direction is changed. Choose a harder lubricant at both ends than at the center. Here, a lubricant having a hardness of 2B is used at the center and a lubricant having a hardness B is used at both ends, but it goes without saying that a lubricant can be appropriately selected.

FIG. 11 shows the decrease in the weight of the solid lubricant per unit time used as the amount of application to the image carrier per unit time. It can be seen that the use of the solid lubricant of this embodiment reduces the amount of application to the image carrier at both ends appropriately.

With the above configuration, it is possible to prevent an excessive amount of application to the image carrier at the initial stage of use of the lubricant applying apparatus.

[Fifth Embodiment] Next, a fourth embodiment of the image forming apparatus according to the present invention will be described with reference to the drawings. Figure
FIG. 12 is a configuration diagram of a lubricant application device according to the present embodiment.
The same parts as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, as described in the first to fourth embodiments, the area or hardness of the surface on the side in contact with the lubricant application member contacts the lubricant application member. The amount of application to the image carrier is controlled by appropriately selecting the vertical direction of the side surface and the longitudinal direction of the image carrier.

For example, at the beginning of its use, and
At both ends, if the amount of application to the image carrier is excessive, the area of the surface of the both ends that is in contact with the coating member is made smaller than the central portion, and the coating member is used in the initial stage of its use. The area of the surface in contact with the image bearing member is small, and as the use increases, the shape may be increased so that the lubricant is worn by the application of the lubricant to the image bearing member.

Further, the hardness of the lubricant on the side in contact with the coating member at both ends is made harder than that of the central part, and the lubrication of the image bearing member is increased as the use increases from the beginning of use. A lubricant having a hardness such that a surface of soft hardness appears due to wear of the lubricant due to application of the lubricant may be used.

The same effect can be achieved by appropriately selecting the area or hardness of the surface on the side in contact with the lubricant application member and appropriately selecting the same.

The lubricant having the above-mentioned shape and hardness can be prepared by the method described in the first to fourth embodiments. Also, as shown in FIG. 12, various kinds of lubricants can be formed by combining small pieces of lubricant having various hardnesses and various areas in the longitudinal direction and the direction perpendicular to the surface in contact with the application member. it can.

With the above configuration, the amount of application on the image carrier can be controlled.

[0072]

As described above, the shape of the lubricant is formed such that the area of the surface in contact with the coating member is changed by the application of the lubricant to the image carrier. Further, the lubricant is formed such that the hardness of the surface in contact with the application member changes with the application of the lubricant to the image carrier. Thus, it is possible to prevent an excessive amount of application to the image carrier in the early stage of use.

Further, the shape of the lubricant is formed such that the area of the surface in contact with the application member changes in the longitudinal direction of the lubricant. Further, the lubricant is formed such that the hardness of the surface in contact with the application member changes in the longitudinal direction of the lubricant.
Thereby, it is possible to prevent the amount of application to the central portion of the image carrier from becoming excessive.

Further, by changing the area and hardness of the surface in contact with the lubricant applying member, it is possible to prevent the amount of the lubricant applied to the image carrier from becoming excessive.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of an image forming apparatus according to a first embodiment.

FIG. 2 is a configuration diagram of a lubricant application device.

FIG. 3 is a configuration diagram of a lubricant.

FIG. 4 is a diagram illustrating an amount of application to an image carrier by a lubricant application device.

FIG. 5 is a configuration diagram of a lubricant application device according to a second embodiment.

FIG. 6 is a diagram illustrating an amount of application to an image carrier by a lubricant application device.

FIG. 7 is a configuration diagram of a lubricant application device according to a third embodiment.

FIG. 8 is a configuration diagram of a lubricant.

FIG. 9 is a diagram showing the amount of application to an image carrier by a lubricant application device.

FIG. 10 is a configuration diagram of a lubricant application device according to a fourth embodiment.

FIG. 11 is a diagram showing the amount of application to an image carrier by a lubricant application device.

FIG. 12 is a configuration diagram of a lubricant application device according to a fifth embodiment.

FIG. 13 is a configuration diagram of a conventional cleaning device and a lubricant applying device.

[Explanation of symbols]

 δ: Intrusion amount θ: Set angle P: Sheet 1: Waste toner collecting sheet 2: Waste toner collecting container 3: Lubricant 4: Brush roller 4a: Yellow developing device 5: Intermediate transfer member 6: Cleaning blade 7: Cleaning device 8 Sheet power set 9 Transfer belt 10 Fixing device 11 Image forming device 12 Host 13 Exposure means 14 Developing device 14a Yellow developing device 15 Photosensitive drum 16 Charging roller

Claims (13)

[Claims] An image carrier in an image forming apparatus, comprising: an image carrier; a solid lubricant; and a coating member that contacts the lubricant and the image carrier to apply the lubricant to the image carrier. In the image forming apparatus, the lubricant has a shape in which an area of a surface on a side in contact with the coating member changes by applying the lubricant to the image carrier. A device for applying lubricant to the image carrier. 2. An image carrier in an image forming apparatus, comprising: an image carrier; a solid lubricant; and an application member that contacts the lubricant and the image carrier to apply the lubricant to the image carrier. An image carrier in the image forming apparatus, wherein a hardness of a surface of the lubricant contacting the application member is changed by applying the lubricant to the image carrier. Lubricant application device to the. 3. An image carrier in an image forming apparatus, comprising: an image carrier; a solid lubricant; and a coating member that contacts the lubricant and the image carrier to apply the lubricant to the image carrier. In the lubricant applying apparatus, the lubricant may be applied to an image carrier in an image forming apparatus, wherein an area of a surface in contact with the applying member changes in a longitudinal direction of the lubricant. Lubricant application device. 4. An image carrier in an image forming apparatus, comprising: an image carrier; a solid lubricant; and a coating member that contacts the lubricant and the image carrier to apply the lubricant to the image carrier. Wherein the hardness of the surface of the lubricant contacting the application member changes in the longitudinal direction of the lubricant, and the lubricant is applied to the image carrier in the image forming apparatus. apparatus. 5. The lubricant applying apparatus according to claim 1, wherein an amount of the lubricant applied to the image bearing member is controlled. 6. The lubricant according to claim 1, wherein the lubricant is formed by combining small pieces of lubricant having a plurality of hardnesses and an area of a surface in contact with the application member. Lubricant application device. 7. The lubricant applying device according to claim 1, wherein the applying member is a rotatable elastic body or a brush. 8. The lubricant applying device according to claim 1, wherein the image carrier is an electrostatic latent image carrier. 9. The image carrier according to claim 1, wherein the image carrier is a toner image carrier visualized by a developing device.
9. The lubricant applying device according to any one of items 1 to 8. 10. The lubricant applying device according to claim 1, wherein the lubricant is formed by a mold. 11. The lubricant applying device according to claim 1, wherein the lubricant is formed by cutting. 12. A process cartridge on which the lubricant applying device according to claim 1 is mounted. 13. An image forming apparatus comprising the lubricant applying device according to claim 1.