JPH0895454A - Electrophotographic device - Google Patents

Abstract

PURPOSE: To prevent a cleaning blade from reversely rotating or squeaking by arranging a member whose frictional resistance is smaller than the surface of the cleaning blade so that is made to exist between the side end of the cleaning blade and the surface of a photoreceptor while keeping away from a toner adhering area. CONSTITUTION: A sheet member 24 consisting of PET(polyethylene terephthalate) sheet is provided at the end of the cleaning blade 21, and wound round the blade 21 so as to cover the tip of the blade 21, then both ends thereof are stuck to the lower surface of the blade 21 and the upper surface of a supporting member 23. Since the sheet member 29 whose frictional resistance is smaller than the photoreceptor 1 and the blade 21 is placed at the end of the blade 21, frictional force generated at the end of the blade 21 at the time of rotating the (J) photoreceptor 1 is reduced. Thus, the reverse rotation of the blade 21 is prevented and squeaking is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus provided with a blade type cleaning device for cleaning by cleaning a transfer residual toner by a cleaning blade disposed in contact with a photosensitive member.

[0002]

2. Description of the Related Art In an electrophotographic apparatus, transfer residual toner remaining on a photosensitive member after a transfer process is removed. As a cleaning device for removing the transfer residual toner, a blade type device having a simple structure and a sufficient cleaning ability has been widely used.

FIG. 5 is a diagram showing a main structure of an electrophotographic apparatus using a blade type cleaning device. In the figure, reference numeral 1 denotes a drum-shaped photosensitive member, which is rotationally driven in a direction indicated by an arrow by a rotational driving mechanism not shown.

2 is a blade type cleaning device,
It has a cleaning blade 21, a waste toner container 22 and a support member 23. The cleaning blade 21
It is fixed to the waste toner container 22 via the support member 23, and the tip thereof is in contact with the surface of the photoconductor 1. The waste toner container 22 collects and stores the toner scraped off the surface of the photoconductor 1 by the cleaning blade 21. A portion of the bottom surface of the waste toner container 22 below the contact position between the cleaning blade 21 and the photoconductor 1 serves as a receiving blade 22a for receiving the falling toner.

[0005]

By the way, the width of the cleaning blade 21 is set to be larger than the width of the toner adhering region of the photoconductor 1 as shown in FIG. Further, the width of the cleaning blade 21 is set smaller than the length of the photoconductor in terms of driving the photoconductor and sealing the waste toner. Therefore, almost no toner exists between the photoconductor 1 and the cleaning blade 21 in the area indicated by A in FIG.

In the blade type cleaning device, the toner existing between the photoconductor 1 and the cleaning blade 21 has a function as a lubricant, and reduces the friction between the photoconductor 1 and the cleaning blade 21. Therefore, strong friction occurs between the photoconductor 1 and the cleaning blade 21 in the area indicated by A in FIG.

Further, since the cleaning blade 21 is constrained by the support member 23, the moment generated in the cleaning blade 21 is only the bending moment My at the center portion in the width direction as shown in FIG. 7, but at both ends. In addition to the bending moment My, a bending moment Mx and torsion moments Mxy and Myx are also generated, which easily deforms.

Due to the above-mentioned two circumstances, the both ends of the cleaning blade 21 stick and stick more violently than other parts.
A slip movement occurs. Therefore, the cleaning blade 2
1 is a phenomenon in which the cleaning blade 21 falls in the rotation direction of the photoconductor 1,
Are extremely likely to occur at both ends of the cleaning blade 21 and the sound source (vibration source) without the cleaning blade 21 or the photoreceptor 1.
There was a problem that became.

The present invention has been made in view of such circumstances, and an object thereof is to prevent reversal at both ends of the cleaning blade and to prevent the cleaning blade or the photosensitive member from disappearing. To provide a photographic device.

[0010]

In order to achieve the above object, the present invention has a cleaning blade which comes into contact with the surface of a photoconductor, and which adheres to a predetermined toner adhesion region on the surface of the photoconductor. In an electrophotographic apparatus equipped with a blade type cleaning device for removing the toner with the cleaning blade, it is interposed between the side end portion of the cleaning blade and the surface of the photoconductor while avoiding the toner adhesion area. Then, a predetermined member having a smaller frictional resistance than the surface of the cleaning blade, such as a sheet-like member or a lubricant, is arranged by, for example, pasting or coating on at least one of the surface of the photoconductor and the cleaning blade.

[0011]

By taking such means, the friction between the side edge of the cleaning blade and the surface of the photoreceptor caused by the rotation of the photoconductor and the side edge of the cleaning blade avoids the toner adhesion area. It is reduced by a predetermined member interposed between and the surface of the photoconductor.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a main structure of an electrophotographic apparatus according to the first embodiment. The same parts as those in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

The electrophotographic apparatus of this embodiment basically has the same structure as the conventional electrophotographic apparatus shown in FIG. 5, but as shown in FIG. A sheet-shaped member 24 made of a (polyethylene terephthalate) sheet is provided. The sheet-like member 24 has an elongated rectangular shape and covers the tip of the cleaning blade 21.
While being wound around 1, the both ends thereof are adhered to the lower surface of the cleaning blade 21 and the upper surface of the support member 23, respectively (the hatched portions are adhered portions).

If the tension of the sheet-shaped member 24 is large, the cleaning blade 21 may be mechanically restrained and the function of the cleaning blade 21 may be impaired. Therefore, the sheet-shaped member 24 should have an appropriate degree of slack. However, if the slack of the sheet-shaped member 24 is too large, the sheet-shaped member 24 can move freely, which may induce toner leakage. Therefore, it is desirable to minimize the slack of the sheet-shaped member 24.

Further, since the contact portion between the photosensitive member 1 and the cleaning blade 21 is separated by the thickness of the sheet-like member 24, the sheet-like member 24 is as thin as possible within the range where the mechanical strength can be maintained. Better. If the thickness is 1 mm or less, the function of the cleaning blade 21 can be maintained.

Now, the width of the sheet-like member 24 is equal to that of the photosensitive member 1.
The sheet-like member 24 is set so as not to hang on the position facing the toner adhesion region. That is, as shown in FIG. 2, of the entire width of the cleaning blade 21, a portion B that does not face the toner adhering region of the photoconductor 1 is a portion to which the sheet-shaped member 24 can be attached. The maximum width is B. In addition, this B
In many cases, 5 mm or more is usually provided, but as a result of experiments, it is possible to prevent the cleaning blade 21 from reversing and reduce the gap by attaching the sheet-like member 24 to a portion 3 mm or more from the side edge of the cleaning blade 21. I understood. Therefore, the sheet-like member 24 does not have to have a width indicated by B, but a smaller width indicated by C (3 mm
≦ C <B) may be set.

Although not shown, the sheet member 24 is similarly attached to the other end of the cleaning blade 21.

In the electrophotographic apparatus constructed as described above, the sheet-like member 24 having a smaller frictional resistance than the cleaning blade 21 is interposed between the photoconductor 1 and the cleaning blade 21 at the end of the cleaning blade 21. Therefore, the frictional force generated at the end of the cleaning blade 21 when the photoconductor 1 rotates is reduced. As a result, the cleaning blade 21 is prevented from being turned over, and the clearance is reduced.

The photosensitive member 1 has a diameter of 30 mm and the length of the raw tube is 2.
An organic photoreceptor having a relatively high friction coefficient of 99.5 mm and an OPC coating width of 282 mm, a cleaning blade 21 made of urethane rubber having a hardness of 65 degrees, a width of 279 mm, and a free length of 1
0 mm, plate thickness 2 mm, cleaning angle 10 degrees, bite depth 1.2 mm, scorotron charging device,
Using an electrophotographic apparatus having a non-magnetic one-component developing device, a roller transfer transferring device, and a heat roll fixing device, it is possible to perform the test in an environment of 35 ° C. and 85%.
As a result of recording 000 sheets and confirming whether the cleaning blade 21 is reversed or not, and ascertaining the degree of the absence, the cleaning blade 21 is reversed when the sheet-shaped member 24 is not attached. It was confirmed that when the sheet-shaped member 24 was attached, the cleaning blade 21 did not reverse, and when the sheet-shaped member 24 was attached, the non-stickiness was remarkably reduced as compared with the case where the sheet-shaped member 24 was not attached. As the sheet-shaped member 24, a PET sheet having a width of 3 mm (Mylar manufactured by DuPont, thickness 0.025) is used.
mm) was used.

(Second Embodiment) FIG. 3 is a view showing the arrangement of the essential parts of an electrophotographic apparatus according to the second embodiment. The same parts as those in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

The electrophotographic apparatus of this embodiment basically has the same structure as the conventional electrophotographic apparatus shown in FIG. 5, but as shown in FIG. A sheet-shaped member 25 made of a (polyethylene terephthalate) sheet is provided. The sheet-shaped member 25 has an elongated rectangular shape, one end of which is adhered to the upper surface of the support member 23 and is extended along the upper surface of the cleaning blade 21 to the lower surface of the receiving blade 22a.
The other end is bonded to the lower surface of the receiving blade 22a (the hatched portion is the bonded portion).

The slack, thickness and width of the sheet member 25 are set in the same manner as in the first embodiment.

Thus, according to this embodiment, at the end of the cleaning blade 21, the sheet-like member 25 having a smaller frictional resistance than the cleaning blade 21 is interposed between the photoconductor 1 and the cleaning blade 21. The frictional force generated at the end of the cleaning blade 21 when the photoconductor 1 rotates is reduced. As a result, the cleaning blade 21 is prevented from being turned over, and the clearance is reduced.

As a result of conducting the same test as that of the first embodiment, the cleaning blade 21 was reversed when the sheet-shaped member 25 was not attached, whereas the sheet-shaped member 25 was not attached. It was confirmed that the cleaning blade 21 did not reverse when it was pasted, and that the stickiness when the sheet-shaped member 25 was pasted was significantly reduced compared to when it was not pasted.

Further, according to this embodiment, the sheet-like member 25
Is an opening formed between the cleaning blade 21 and the receiving blade 22a (opening of the toner container 22)
Since the sheet-like member 25 is closed, there is an advantage that the sheet-like member 25 also functions as a sealing material for preventing leakage of waste toner.

(Third Embodiment) FIG. 4 is a diagram showing a main structure of an electrophotographic apparatus according to the third embodiment. The same parts as those in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

The electrophotographic apparatus of this embodiment basically has the same structure as the conventional electrophotographic apparatus shown in FIG. 5, but a part of the surface of the photoconductor 1 (hatched in FIG. 4). The portion 11) is coated with a metal soap lubricant 11.

Here, the application area of the lubricant 11 is set as follows. That is, on the surface of the photoreceptor 1, the image area actually used for image formation is the lubricant 1
If 1 is applied, it may hinder the image formation. Therefore, the area indicated by D in FIG. 4 except this image area is the area to which the lubricant 11 can be applied. Then, the lubricant 11 may be applied to the entire applicable area, but since the width of the cleaning blade 21 is smaller than the length of the photoconductor, there is a portion where the cleaning blade 21 is not in contact with the both ends of the photoconductor 1. However, even if the lubricant 11 is applied to that portion, it is meaningless, so that the area indicated by E in FIG. 4 is an effective application area of the lubricant 11. As a result of an experiment, if the lubricant 11 is applied to a portion 3 mm or more from the side edge of the cleaning blade 21, the cleaning blade 2
It was found that the inversion of 1 can be prevented and the inversion can be reduced.
Therefore, the application area of the lubricant 11 does not have to have a width indicated by D, but a smaller width indicated by F (3 mm ≦ F <
It may be set to D).

Thus, according to this embodiment, at the end of the cleaning blade 21, the lubricant 11 having a smaller frictional resistance than that of the cleaning blade 21 is interposed between the photoconductor 1 and the cleaning blade 21. Cleaning blade 2 when photoconductor 1 rotates
The frictional force generated at the end of 1 is reduced. As a result, the cleaning blade 21 is prevented from being turned over, and the clearance is reduced.

As a result of conducting a test similar to that of the first embodiment, the cleaning blade 21 was inverted when the lubricant 11 was not applied, whereas the lubricant 11 was used. It was confirmed that in the case where the lubricant was applied, inversion of the cleaning blade 21 did not occur, and in the case where the lubricant 11 was applied, the thickness was remarkably reduced as compared with the case where the lubricant 11 was not applied.

The present invention is not limited to the above embodiments. For example, although the sheet-shaped members 24 and 25 are made of PET in the first and second embodiments, polystyrene, polyamide, polyethylene, fluorine resin, polypropylene, polycarbonate, PI (polyimide), PEEK ( Polyether ether ketone) or polyimide amide resin can be applied.

In the third embodiment, the lubricant 11 is made of metal soap, but in addition, hydrocarbon lubricants such as liquid paraffin, micro wax, low molecular weight polyethylene wax, stearic acid, lauric acid. Fatty acid type lubricants such as stearic acid amide, palmitic acid amide, methylene pistearamide, fatty acid amide type lubricants, ethylene glycol monostearate, butyl stearate, ester type lubricants such as hydrogenated castor oil, cetyl alcohol , Alcohol lubricants such as stearyl alcohol, metal soaps such as zinc stearate and lead stearate, silicones, chlorinated bifanyl, fluoroesters, polychlorotrifluoroethylene, phosphoric acid esters, polyphenyl ethers, polyglycol silicone Graft Po Mer synthetic lubricants such as fluorine-based graft polymer can be applied.

In the first and second embodiments, the sheet-like members 24 and 25 are replaced by the cleaning blade 2.
The sheet-shaped member may be attached to the surface of the photoconductor 1, or the sheet-shaped member may be attached to both the surface of the photoconductor 1 and the cleaning blade 21. good. The area where the sheet-shaped member is attached on the surface of the photoconductor 1 is similar to the area where the lubricant is applied in the third embodiment.

In the third embodiment, the lubricant 11 is applied to the surface of the photoconductor 1, but the lubricant may be applied to the cleaning blade 21, or the surface of the photoconductor 1 may be applied. A lubricant may be applied to both the cleaning blade 21 and the cleaning blade 21. The width of application of the lubricant on the cleaning blade 21 conforms to the width of the sheet-like members 24 and 25 in the first and second embodiments.

Besides, various modifications can be made without departing from the scope of the present invention.

[0037]

According to the present invention, the cleaning blade has a cleaning blade which comes into contact with the surface of the photoconductor, and the toner adhering to a predetermined toner adhesion region on the surface of the photoconductor is removed by the cleaning blade. In an electrophotographic apparatus equipped with a blade type cleaning device, it is interposed between a side end portion of the cleaning blade and the surface of the photoconductor in a state of avoiding the toner adhesion area, and is more frictional than the surface of the cleaning blade. Since a predetermined member such as a sheet-like member or a lubricant having a small resistance is arranged by, for example, pasting or applying, it is possible to prevent the cleaning blade or the photosensitive member from being reversed at both ends of the cleaning blade. It becomes an electrophotographic device.

[Brief description of drawings]

FIG. 1 is a diagram showing a main configuration of an electrophotographic apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a sticking position of a sheet-shaped member.

FIG. 3 is a diagram showing a main configuration of an electrophotographic apparatus according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a main configuration of an electrophotographic apparatus according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a main configuration of an electrophotographic apparatus using a conventional blade type cleaning device.

FIG. 6 is a photoconductor 1 and a cleaning blade 21 in FIG.
FIG.

FIG. 7 is a diagram illustrating a moment generated in the cleaning blade 21.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photoconductor 11 ... Lubricant 21 ... Cleaning blade 23 ... Support member 22a ... Receiving blade 24, 25 ... Sheet-shaped member

Claims (3)

[Claims] 1. A blade-type cleaning device having a cleaning blade that comes into contact with the surface of a photoconductor, and removing the toner adhering to a predetermined toner adhesion region on the surface of the photoconductor with the cleaning blade. In the electrophotographic apparatus, a predetermined member having a frictional resistance smaller than that of the surface of the cleaning blade is interposed between the side end portion of the cleaning blade and the surface of the photosensitive member while avoiding the toner adhesion area. An electrophotographic apparatus characterized in that the above is arranged. 2. The electrophotographic apparatus according to claim 1, wherein the predetermined member has a sheet shape and is attached to at least one of the surface of the photoreceptor and the cleaning blade. 3. The electrophotographic apparatus according to claim 1, wherein the predetermined member is a lubricant applied to at least one of the surface of the photoconductor and the cleaning blade.