JP4550535B2 - Image forming apparatus - Google Patents

Description

The present invention relates to a toner density control device in an image forming apparatus, and more particularly to a good toner replenishment control device in an image forming apparatus such as a copying machine, a printer, and a facsimile machine using an electrophotographic system.

In recent years, small particle size toners such as polymerized toners are widely used in image forming apparatuses in order to improve image quality. However, these small particle size toners have a problem that it is difficult to clean the toner remaining on the photoreceptor after the image is transferred onto the transfer paper by the photoreceptor cleaning means.
As a means for solving the above problem, there is used a method in which a lubricant is applied to a photosensitive member and the friction coefficient of the photosensitive member is lowered, thereby preventing chattering of a cleaning blade as a cleaning unit and improving a toner cleaning property.
As a method of applying the lubricant, a method of applying a solid lubricant by applying pressure to the applying means with a spring as in Patent Document 1 and Patent Document 2 has been proposed. (Figure 2)

As described above, when a lubricant is applied in order to improve the cleaning property, it is desirable that the application amount be continuously applied as much as possible. When the coating amount is small, the reduction in the frictional force of the photoreceptor is reduced, and the effect of improving the cleaning property is diminished. On the other hand, if the coating amount is too large, the consumption amount becomes excessive and the predetermined lubricant is used up quickly. In particular, in a small apparatus such as a process cartridge, the amount of lubricant that can be mounted is limited, so it is desirable to keep the application amount to the minimum amount that can maintain the function.
However, in a device that applies a solid lubricant by applying pressure with a spring, the amount of lubricant applied is the same as the amount of lubricant applied. There was a problem of decreasing. (Figure 3)
As a method for regulating the amount of lubricant applied, methods such as Patent Document 1 and Patent Document 2 in which the applied pressure is changed by a cam or solenoid have been proposed, but these are used for small process cartridges because the apparatus becomes complicated. It is not suitable to do. In addition, the cost increases.

JP-A-2002-24487 JP 2000-231298 A

The present invention provides a lubricant application apparatus that maintains the cleaning performance for a long time even in a small process cartridge by stably maintaining the coating amount of the solid lubricant for a long time by a simple and low-cost method, and It is an object of the present invention to provide an image forming apparatus including the above.

As means for solving the above problems, the present invention has the following features.
The lubricant application device according to the present invention includes a solid lubricant, a spring that presses the solid lubricant against the application unit, and a casing provided with the solid lubricant and the spring. in the lubricant coating apparatus for applying a lubricant to the photoreceptor, the lubricant applying device, wherein the protrusions on the inner wall of the housing have plurality, in the initial use state in contact the convex portion is in the solid lubricant becomes the resistance force of the solid lubricant is pressed by a spring Te, continued use, the solid lubricant is scraped, characterized in that movement to away from the convex portion.
In the process cartridge according to the present invention, at least a photosensitive member used for electrophotographic image formation is integrally supported, and the process cartridge can be attached to and detached from the image forming apparatus main body. An agent coating apparatus is provided.
In the image forming apparatus according to the present invention, the exposure and photosensitive member for bearing a latent image, said disposed in contact with or close to the photosensitive member, a charging device for charging the photoreceptor surface, the photoreceptor surface and an exposure device for writing an electrostatic latent image, transferring the developing device into a visible image with toner to the photosensitive member latent image formed on the surface, a visible image of the photoreceptor surface to a transfer member transferring a device, is disposed downstream of the transfer device, the image forming apparatus including a cleaning device, a cleaning the toner of the photoreceptor surface, characterized in that it comprises a lubricant coating apparatus according to the above.
The image forming apparatus according to the present invention includes the process cartridge described above.
The image forming apparatus according to the present invention is further characterized in that the toner used is a polymerized toner.

As described above, by means of the resolution, with a lubricant coating apparatus of the present invention is difficult to clean from the front surface of the photosensitive member 1, an image forming apparatus using an integral polymerized toner lubricant coating However, a stable lubricant application can be performed at low cost.
In addition, the process cartridge having the lubricant application device of the present invention is advantageous in terms of maintenance, and by simply replacing the process cartridge, it is possible to quickly recover from a failure caused by a part or device, and shorten the service time. Can be planned. Furthermore, making the electrophotographic photosensitive member easy to clean greatly contributes to the extension of the life of the process cartridge.

The configuration of the present invention will be described below. FIG. 1 is a schematic diagram of an image forming apparatus.
In the apparatus, a photosensitive member 1, a developing roller 2, a charging roller 3, a charging roller cleaning member 4, and a photosensitive member cleaning device 5 are arranged.
The toner image visualized on the photoreceptor 1 by a known process is transferred onto paper by the transfer roller 6 and fixed by a fixing device (not shown).
After the transfer process, a solid lubricant 8 such as zinc stearate is applied to the lubricant application roller 7 by a spring 9 by a lubricant application roller 7 such as a brush roller. Assists removal.
Transfer residual toner on the photosensitive member is the most by the photoconductor cleaning device 5, but is removed from the front surface of the photosensitive member 1, the toner of the traces which could not be removed adheres to the charging roller 3, further charging cleaning member 4 is removed from the surface of the charging roller 3.
When passing through the nip between the transfer roller 6 and the photoreceptor 1, a part of the paper dust adheres on the photoreceptor 1 . They are removed by the photoconductor cleaning device 5, but some of them pass through the cleaning means and adhere to and accumulate on the surface of the charging roller 3. These paper dusts are also removed from the surface of the charging roller 3 by the charging cleaning member 4 in the same manner as the toner.

Configuration of the solid lubricant coating unit is internal to the two springs 9 of the solid lubricant 8 is slidable a housing 10 internally is fixed to one end as shown in FIG. 2, against the solid lubricant 8 It urges the pressure due to ne 9 words, has a configuration which is pressed against the lubricant applying roller.
If the process cartridge is continuously used in this state, the contact portion of the solid lubricant 8 with the lubricant application roller 7 is gradually scraped. Then, as shown in FIG. 3, the spring 9 is in the extended state as compared with FIG. 2, so that the urging force against the solid lubricant 8 is weakened, and the lubricant application roller 7
As a result, the amount of the lubricant applied to the photosensitive member 1 is reduced.

In the present invention, a part of the housing 10 is provided with claw-like convex portions 10-1 as shown in FIG. The convex portion 10-1 is in contact with the upper portion of the solid-type lubricant 8, and has a resistance to pressure force F which is pressurized lubricant applying low La 7 by the solid lubricant 8 spring 9. That is, for an initial pressurizing force F1 by the play ne 9, the resistance force R is applied by the friction force of the convex portion 10-1, the pressing force F of the solid lubricant 8 against the lubricant applying roller 7 becomes F1-R .

If the process cartridge is continuously used in this state, the contact portion of the solid lubricant 8 with the lubricant application roller 7 is gradually scraped. Then, as shown in FIG. 5, a state where its upper portion is cut to a position which comes to barely contact position with the pawl-shaped protrusions 10-1 of the applied pressure by the field I 9 initial pressurizing force F1 F2 is further reduced by the moving distance of the solid lubricant 8 . Pressure force F to the lubricant applying row La 7 of the solid lubricant 8 in this state is the F2-R. If the use is further continued, as shown in FIG. 6, the solid lubricant 8 is finally separated from the convex portion 10-1. At this time, of course pressure against the lubricant applying row La 7 of the solid lubricant 8 is for resistance R by the projection portion 10-1 is eliminated, when the pressure field ne 9 at this position and F3 This is the term for F3 only.

Further, when continued use, the solid lubricants 8 is further cut, pressure against the pressure force F4 becomes due to play ne 9, also in the lubricant applying row La 7 of the solid lubricant 8 as in FIG. 7 F4 It becomes.
That is , when there is no projection 10-1 , the pressure applied to the lubricant application roller of the solid lubricant 8 is
F '= F1->F2->F3-> F4
By providing the convex portion 10-1 ,
F = F1-R → F2-R → F3 → F4
Then, the fluctuation of the applied pressure over time is corrected by the resistance force R, and the difference in applied pressure between the initial stage and the life of the process cartridge is reduced.

Since the mechanism of the present invention is simple and small, it can be used more effectively in process cartridges that are particularly required to be small.
Further, spheronization, because it is small particle size, rotates the toner between the cleaning blade of the photoconductor 1, for entering into the gap, is difficult to clean from the front surface of the photosensitive member 1, a lubricant coating is Even in an image forming apparatus using indispensable polymerized toner, it is possible to stably apply a lubricant at low cost.

An image forming apparatus including the process cartridge or the lubricant application device of the present invention will be described.
FIG. 8 is a schematic diagram showing the configuration of an embodiment of the image forming apparatus according to the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem type image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 12 made of an endless belt member is provided at a position facing each photoconductor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 that transfers the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 12 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 12.

A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 12 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 12. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is pressed against the support roller 16 via the intermediate transfer belt 12. 12 is transferred to the transfer paper. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .

The developing device 11 of the image forming unit 18 uses a developer containing the above toner. In the developing device 11, the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor 40 to develop the latent image on the photoconductor 40. By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.
Further, a process cartridge that is integrally supported with the photosensitive member 40 and is detachably formed on the main body of the image forming apparatus can be obtained. In addition, the process cartridge may include a charging unit, a developing device, and a cleaning unit.

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15, 16 is rotated by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 12 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer belt 12, these single color images are sequentially transferred to form a composite color image on the intermediate transfer belt 12.

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, the sheet is fed out from one of the paper cassettes 44 provided in the paper bank 43 in multiple stages, and the separation roller 45 Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 12, the sheet is fed between the intermediate transfer belt 12 and the secondary transfer device 22, and is transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 12 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 12 after the image transfer, so that the tandem image forming device 20 can prepare for the image formation again.

1 is a schematic diagram of an image forming unit showing an embodiment of the present invention. It is a schematic block diagram of a solid lubricant application apparatus. It is a figure which shows the state in which the solid lubricant of FIG. 2 was used. 1 is a schematic configuration diagram of a solid lubricant application device in which a claw-like convex part is provided in a part of a housing, and a pressing force F1 by a spring 9 and a frictional resistance R of the convex part act on the solid lubricant 8. FIG. ing. FIG. 5 is a diagram showing a state in which the solid lubricant of FIG. 4 is used, and the solid lubricant 8 is subjected to a pressing force F2 by a spring 9 and a frictional resistance R of a convex portion. FIG. 6 is a diagram showing a state in which the solid lubricant of FIG. 5 is further used, and only the pressing force F <b> 3 by the spring 9 works on the solid lubricant 8. FIG. 7 is a diagram showing a state in which the solid lubricant of FIG. 6 is further used, and only the pressing force F <b> 4 by the spring 9 works on the solid lubricant 8. 1 is a schematic configuration diagram of an image forming apparatus showing an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Developing roller 3 Charging roller 4 Charging roller cleaning member 5 Photoconductor cleaning device 6 Transfer roller 7 Lubricant application roller 8 Solid lubricant 9 Spring 10 Housing 10-1 Convex part 11 Developing device 12 Intermediate transfer belt 16 Support Roller 18 Image forming means 20 Tandem image forming device 21 Exposure device 22 Secondary transfer device 24 Secondary transfer belt 25 Fixing device 28 Reversing device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Photoconductor (latent image carrier)
43 Paper bank 44 Paper feed cassette 45 Separation roller 46 Paper feed path 47 Transport roller 48 Paper feed path 49 Registration roller 50 Paper feed roller 51 Manual feed tray 52 Separating roller 55 Switching claw 56 Discharge roller 57 Paper discharge tray 62 Primary transfer means 100 Copy Device main body 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (5)

Solid lubricant,
A spring that presses the solid lubricant against the application means;
A housing provided with the solid lubricant and a spring;
In a lubricant application device for applying a lubricant to a photoreceptor with the application means,
The lubricant application device is:
A plurality of convex portions are provided on the inner wall of the housing,
In an initial use state becomes the resistance force of the solid lubricant, wherein the convex portion is pressed by the spring in contact with the solid lubricant, Continued use, the solid lubricant is scraped, the convex portion moves Lubricant application device characterized by being separated from In a process cartridge that integrally supports at least a photoreceptor used for electrophotographic image formation and is detachable from the image forming apparatus main body,
The process cartridge includes the lubricant application device according to claim 1. A photoreceptor carrying a latent image;
Wherein disposed in contact or in proximity to the photosensitive member, a charging device for charging the photoreceptor surface,
An exposure device that exposes the surface of the photoreceptor and writes an electrostatic latent image;
A developing device into a visible image with toner to the photoreceptor surface to form a latent image,
A transfer device that transfers the visible image of the photoreceptor surface to a transfer member,
Is disposed downstream of the transfer device, the image forming apparatus and a cleaning device for cleaning the toner of the photoreceptor surface,
The image forming apparatus includes:
An image forming apparatus comprising the lubricant application device according to claim 1. The image forming apparatus according to claim 3,
The image forming apparatus includes:
An image forming apparatus comprising the process cartridge according to claim 2. The image forming apparatus according to claim 3 or 4,
The image forming apparatus includes:
An image forming apparatus, wherein the toner used is a polymerized toner.

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