JPH10326067A - Image forming device - Google Patents

Abstract

(57) Abstract: An image forming apparatus for transferring a toner image formed on a photoreceptor surface to transfer paper and removing a transfer residual toner adhered to the photoreceptor surface after the transfer by a cleaning blade. Is stably abutted on the photoreceptor surface for a long period of time. SOLUTION: A coating layer of a tetrafluoroethylene resin is formed in a longitudinal end region H of a cleaning blade 19,
A polyvinylidene fluoride resin powder is fixed to the surface of the coat layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image bearing member having a surface on which a toner image is formed, a transfer device for transferring the toner image to a transfer material, and a toner image remaining on a surface of the image bearing member after the toner image is transferred. A cleaning device for removing the transfer residual toner and cleaning the surface of the image carrier, wherein the cleaning device extends long in a direction substantially perpendicular to the moving direction of the surface of the image carrier, and has a front end in the width direction thereof. An edge portion has a cleaning blade made of an elastic body that scrapes off transfer residual toner adhered to the image carrier surface by pressing against the image carrier surface,
The cleaning blade relates to an image forming apparatus formed to be longer than the width of the image forming area such that each end in the longitudinal direction is located outside the image forming area on the surface of the image carrier. is there.

[0002]

2. Description of the Related Art Electronic copiers, printers, facsimile machines,
Alternatively, an image forming apparatus of the above-described type configured as a multifunction peripheral having at least these two functions has been conventionally known.

In this type of image forming apparatus, the cleaning blade of the cleaning device is pressed against the image carrier, and the transfer residual toner adhered to the surface of the image carrier can be efficiently scraped and removed. While using, it is possible to form a high quality toner image on the surface of the image carrier. Moreover, since the cleaning blade is formed longer than the width of the image forming area on the surface of the image carrier, and each end of the cleaning blade in the longitudinal direction is located outside the image forming area, the cleaning blade cleans the image carrier. Even if the above operation is continuously performed, it is possible to prevent the untransferred toner from sneaking around each end of the cleaning blade and scattering the toner.

However, when the cleaning blade is configured in this manner, each end region in the longitudinal direction comes into pressure contact with a non-image forming region of the image carrier, that is, a surface portion of the image carrier on which the transfer residual toner does not adhere. Therefore, the frictional force acting on the cleaning blade in this region from the surface of the image carrier becomes larger than the frictional force acting on the central region in the longitudinal direction of the cleaning blade. Since the transfer residual toner is fed into the longitudinal central region of the cleaning blade, the toner functions as a lubricant,
Although the frictional force between the cleaning blade and the surface of the image carrier in the central area is relatively small, the toner is not fed into each end area in the longitudinal direction of the cleaning blade. This increases the frictional force received from the surface of the image carrier.

For this reason, especially when the cleaning blade is new or in a high-temperature environment, the cleaning blade stick-slips at the boundary between each longitudinal end region of the cleaning blade and the central region therebetween. A phenomenon in which the leading edge portion is damaged or a cleaning blade is involved may occur, and there is a fear that cleaning failure on the surface of the image carrier may occur.

[0006] In order to prevent such inconveniences, many proposals have been made and put into practical use (for example, JP-A-61-240269, JP-A-1-23).
5986, JP-A-6-194917 and JP-A-6-258995).

The configuration according to the conventional proposal reduces the frictional force acting between each non-image forming area outside the image forming area on the surface of the image carrier and the leading edge of the cleaning blade pressed against the non-image forming area. It is to let.

For example, there is a known method in which a low friction lubricant such as wax is applied to the leading edge of a cleaning blade which is pressed against a non-image forming area on the surface of an image carrier, and a wax coating layer is formed on the leading edge. It is. However, when this coat layer is thickened, a step is formed at the boundary between the leading edge where the coat layer is formed and the leading edge where the coat layer is not formed, and this part is slightly separated from the surface of the image carrier, A gap is formed here. For this reason, the toner passes through this gap, resulting in poor cleaning of the surface of the image carrier. For this reason, the coat layer must be thinned to a thickness close to the particle size of the toner to be used. However, such a thin coat layer may peel off from the cleaning blade early and lose its function. In particular, under severe environmental conditions, if a new cleaning blade is used and the image forming operation is continuously performed, the coating layer made of a low friction material is peeled off early, and the stick-slip of the cleaning blade gradually increases, There is a possibility that cleaning failure occurs suddenly at the boundary portion of the cleaning blade, and that the cleaning blade may be involved from this portion.

Further, a configuration has been proposed in which a case made of a low-friction material is provided at each end region in the longitudinal direction of the cleaning blade. However, according to this configuration, a step is formed at the edge of the case. The end edge portion of the image bearing member is discontinuously abutted on the surface of the image carrier, and the fine particle toner may pass through the gap formed in the step, and the cleaning property of the surface of the image carrier may be deteriorated.

Further, a configuration has been proposed in which a pattern toner image is forcibly fed to the leading edge of the cleaning blade, thereby lowering the coefficient of friction at each longitudinal end portion of the cleaning blade. It takes time until the cleaning blade wraps around each end region in the longitudinal direction, and during that time, it is difficult to expect a great effect in preventing the cleaning blade from being involved.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a cleaning blade in which each end region in the longitudinal direction and each of these end regions are formed. An object of the present invention is to provide an image forming apparatus of the type described at the beginning, which can maintain a lubricating effect with the surface of the image carrier to be pressed against for a long period of time and can ensure high cleaning performance on the surface of the image carrier.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an image forming apparatus of the type described at the beginning, wherein the cleaning blade has a longitudinal edge with respect to a leading edge of the cleaning blade. A low-friction lubricating substance is coated on the surface of the image carrier to form a coating layer of the substance on the front edge portion, and the fine particle lubricating powder applied to the surface of the image carrier is rotated with rotation of the image carrier, and the leading edge is coated with the lubricant. The present invention proposes an image forming apparatus characterized in that the image forming apparatus is fixed to the surface of a coat layer formed in a portion.

At this time, in the image forming apparatus according to the first aspect, it is advantageous that the low friction lubricating substance is an ethylene tetrafluoride resin.

Further, in the image forming apparatus according to claim 1 or 2, it is advantageous that the fine particle lubricating powder is a polyvinylidene fluoride resin powder (claim 3).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, and conventional disadvantages will be more specifically clarified with reference to the drawings.

FIG. 1 is a schematic partial cross-sectional view showing an image forming apparatus configured as a copying machine from the front side. In the image forming apparatus shown here, a drum-shaped photosensitive member 1 as an example of an image carrier is rotatably mounted around a central axis on a machine frame of the image forming apparatus main body not shown in FIG. The photoconductor 1 is supported and rotated at a constant speed in the clockwise direction (the direction of arrow A) in FIG. 1 during the image forming operation.
The photoreceptor 1 has a photoconductive layer such as OPC on its surface.

When the photoreceptor 1 rotates, its surface is uniformly charged to a predetermined polarity by a charging device including a charging roller 2 which rotates while contacting the surface. During the image forming operation, a high voltage is applied to the charging roller 2, whereby charges are uniformly applied to the surface of the photoconductor. In this example, it is assumed that the surface of the photoconductor is negatively charged.

The charged surface is irradiated with a light image L from an original (not shown) through an optical system. The surface of the photoreceptor is thus exposed, and an electrostatic latent image corresponding to a document image is formed here by the intensity of light at this time. The negative charge on the surface of the photoreceptor that is strongly exposed to light disappears or is weakened, and the portion where the initial charge remains is formed as an electrostatic latent image. This electrostatic latent image is
When the toner image passes through, the toner image is visualized as a toner image by the powdery toner.

The developing device 3 shown in FIG. 1 has a developing case 4 containing a developer D, and a developing roller 5 rotatably supported inside the developing case 4. Is transported with the developer carried thereon, and the electrostatic latent image formed on the photoconductor 1 is visualized as a toner image by the transported developer. In the developing device 3 of this example, a powdery two-component developer having a toner and a carrier is used as the developer D, and the friction between the toner and the carrier causes
The toner is positively charged and the carrier is negatively charged, and the toner is electrostatically transferred to the electrostatic latent image to visualize the latent image.

Light is irradiated from above the toner image on the photoreceptor 1 by a pre-transfer neutralization lamp 6. As a result, the transfer efficiency of a toner image described later is improved.

On the other hand, a transfer paper 8 which is an example of a transfer material is fed from the paper supply unit 7, and the transfer paper 8 waits once when the leading end thereof reaches the registration roller 9, and temporarily waits for the transfer paper. 8 is fed in the direction of arrow B by the registration roller 9 at a timing matching with the toner image on the photoconductor 1,
It is fed onto the transfer belt 10 traveling in the direction of arrow C.

The leading end of the transfer paper 8 is the photosensitive member 1 and the transfer belt 1
When the roller enters the nip with zero, the bias roller 1
1, a voltage opposite to that of the toner, that is, a negative voltage in this example, is applied. As a result, a charge having a polarity opposite to that of the toner on the photoconductor is applied to the transfer belt 10, whereby the toner image on the photoconductor is transferred onto the transfer paper 8. The toner image formed on the surface of the photoconductor is transferred onto the surface of the transfer paper 8 by a transfer device including the bias roller 11 and the transfer belt 10.

The transfer belt 10 is wound around a drive roller 12 and a driven roller 13 and driven to rotate in the direction of arrow C. The transfer paper 8 on which the toner image has been transferred is carried on the transfer belt 10 and conveyed. Then, after leaving the transfer belt 10, the transfer belt 10 is conveyed between a pair of fixing rollers of the fixing device 14.
Here, the toner image transferred onto the transfer paper 8 is fixed on the transfer paper 8 by the action of heat and pressure. Thus, the transfer paper 8 is discharged out of the apparatus as copy paper.

A cleaning member 15 made of, for example, a polyurethane blade is pressed against the surface of the transfer belt 10 on the drive roller side, whereby toner and paper dust attached to the surface of the transfer belt 10 are scraped off. The surface of the transfer belt 10 is coated with a fluorine-based resin such as polyvinylidene fluoride, for example, so that the coefficient of friction with respect to the cleaning member 15 is reduced. The toner and paper dust removed from the transfer belt 10 are stored in a receiving portion 16 located below.

After transfer of the toner image, transfer residual toner that has not been transferred to the transfer paper 8 adheres to the surface of the photoreceptor, and the transfer residual toner is removed by the cleaning device 17 to clean the surface of the photoreceptor. You. The cleaned photoreceptor surface is initialized by receiving a charge removing action by a charge removing device 18 composed of a lamp, and the above-described operation is subsequently performed to transfer a toner image onto the next transfer paper.

As described above, the illustrated image forming apparatus includes:
An image carrier comprising a photoreceptor 1 having a toner image formed on the surface thereof; a transfer device for transferring the toner image to a transfer material; and a transfer residual toner remaining on the image carrier after the transfer of the toner image is removed. And a cleaning device 17 for cleaning the surface of the image carrier. Instead of the illustrated transfer device, a transfer device including, for example, a transfer roller that rotates while being in contact with the surface of the image carrier or a corona discharger that is disposed separately from the surface of the image carrier can be used.

The cleaning device 17 of the present embodiment includes a cleaning blade 19 made of an elastic material such as polyurethane rubber, a cleaning case 20, and a case 2.
The cleaning blade 19 has a toner discharge member 21 disposed at the bottom of the image bearing member 0, as shown in FIG. The cleaning blade 20 extends in a direction substantially orthogonal to the width direction, and has a base end in the width direction fixed to the cleaning case 20. Thus, the transfer residual toner adhering to the surface of the image carrier is scraped off. At this time, paper dust and the like attached to the surface of the photoconductor 1 are also removed.

The transfer residual toner scraped and removed from the surface of the photoconductor 1 by the cleaning blade 19 is
The toner that has fallen to the bottom of the cleaning case 20 and is conveyed toward the back by the toner discharge member 21 that is disposed at the bottom of the cleaning case 20 and that is driven to rotate, is formed on the back side wall of the cleaning case 20. The toner is discharged from the cleaning case through a toner discharge port (not shown). The discharged toner is sent to a waste toner tank (not shown) through a transport pipe (not shown) or returned to the developing device 3 shown in FIG. 1 to be reused here.

Further, the toner discharge member 21 is
3 is configured as a screw conveyor having a spiral blade 24 fixed therearound. The toner discharge member 21 is rotatably disposed at the bottom of the cleaning case 20 and is provided on the image forming apparatus main body. The driving device (not shown) is driven to rotate, for example, in a counterclockwise direction in FIG. 1, thereby conveying the toner out of the cleaning case as described above. It is also possible to use a toner discharging member other than the illustrated embodiment, for example, a toner discharging member of a type in which a linear body such as a wire is wound in a coil shape, and this is rotated to transport the toner.

By the way, on the surface of the photoreceptor 1, a toner image is formed in an axial region indicated by a reference symbol X in FIG. 2, and no toner image is formed in each outer region E in the axial direction. This area X is an image forming area in the axial direction of the image carrier, and each outer area E is a non-image forming area in the axial direction of the image carrier.

Here, as can be seen from FIG. 2, each end 25 of the cleaning blade 19 in the longitudinal direction is located outside the image forming area X on the surface of the image carrier composed of the photoconductor 1. Is formed longer than the width of the image forming area X. Assuming that the length of the cleaning blade 19 is F, the length F is set to be larger than the image forming area X.

By setting the length of the cleaning blade 19 as described above, the cleaning blade 19
It is possible to prevent the transfer residual toner on the photoconductor from sneaking toward each end 25 of the cleaning blade 19 and scattering the toner even if the operation of continuously cleaning the photoconductor 1 is performed. Become.

However, as described above, since the untransferred toner is not fed into the leading edge portion 22 of the cleaning blade 19 which is in pressure contact with the non-image forming area E, the leading edge portion is left untouched. The frictional force received from the surface of the photoreceptor 1 increases, whereby the cleaning blade portion comes into contact with the photoreceptor surface so as to be hooked, and cannot be stably contacted. There was a risk that entangling of the blade would occur. In particular, when the cleaning blade 19 is arranged in the counter direction with respect to the moving direction of the photosensitive member surface (the direction of the arrow A) as shown in FIG. 1, the portion of the cleaning blade 19 that is pressed against the non-image forming area E. Large external force acts on the surface, and the above-described problem is likely to occur.

Therefore, in the image forming apparatus of this embodiment,
As shown in FIG. 2, a low-friction lubricating substance is applied to each end region H in the longitudinal direction of the cleaning blade 19 on the leading edge portion 22 of the cleaning blade, and the tip edge portion 22 is coated with the substance. The fine particle lubricating powder having the layer formed thereon and applied to the surface of the image carrier made of the photoreceptor 1 is applied to the above-mentioned leading edge portion 22 with the rotation of the image carrier.
A configuration was adopted in which the layer was fixed to the surface of the coat layer formed on the substrate.

It is conventionally known to apply a low-friction lubricating substance to the leading edge of a cleaning blade.
As described above, with this configuration alone, the coating layer of the applied substance was separated at an early stage, and the original function was inevitably lost. On the other hand, in the image forming apparatus of this example, not only the low-friction lubricating substance is applied to the leading edge portion, but also fine-particle lubricating powder is applied to the surface of the image carrier, and the surface of the image carrier is contacted through the image carrier. The powder was fixed to the coating layer formed on the leading edge portion 22 of the cleaning blade, thereby preventing the peeling of the coating layer for a long time. The more specific configuration will be clarified while introducing experimental examples performed by the present inventors.

In this experimental example, the cleaning blade 1
As No. 9, a polyurethane material having a rebound resilience of 30 to 50%, a rubber hardness of 70 degrees, an amount G of protrusion from the tip of the cleaning case 20 shown in FIG. 1 of 10 mm, and a total length F (FIG. 2) of 326 mm was used. The width of the image forming area X of the photoreceptor 1, that is, the length in the axial direction is 300 mm. The developing roller 5 is shorter than the entire length F of the cleaning blade 19.

When the above-described cleaning blade 19 is used, the transfer residual toner is not sent to each end region having a length of 13 mm. However, when a new cleaning blade 19 is set and the image forming operation is started, Photoconductor 1
The transfer residual toner adhered on the cleaning blade 19
When a certain amount of toner spreads toward each end 25 of the cleaning blade 19 immediately after reaching the leading edge portion 22 of the cleaning blade 19, the cleaning blade portion where the frictional force on the photoreceptor 1 increases at the beginning of the image forming operation Is an end region H (FIG. 2) having a length of about 10 mm from each end 25 toward the center in the longitudinal direction.

Therefore, in this experimental example, a low-friction lubricating substance is applied to each end region H in the longitudinal direction of the cleaning blade 19 in advance on the front edge 22 of the cleaning blade 19, A coating layer was formed on the portion No. 22. In this example, low-molecular-weight tetrafluoroethylene resin PTFE (trade name of Daikin Industries, Ltd .: Lubron) was used as the low friction lubricating substance.

Rubron is a powder having a particle diameter of about 0.2 μm and a melting point of about 310 ° C. This is dispersed in an organic solvent (butyl acetate, butyl alcohol, HCFC-141b, etc.), and this is aerosolized for cleaning. Blade 1
9, a coating layer 26 is formed on the leading edge 22 of each end region H as shown in FIG.
The thickness of the coat layer 26 is about 1 to 10 μm. FIG.
As shown in FIG. 5, the above-mentioned substance is applied to the end region H, which is the end surface 19A of the cleaning blade 19 and the surface extending across the surface 19B of the cleaning blade 19 facing the photoreceptor 1. Thus, the coat layer 26 is formed on the leading edge portion 22. In FIG. 2, the coat layer 26 is shown with diagonal lines.

As shown in FIG. 8, the coat layer 26 described above is used.
When the thickness of the coating layer is larger than 10 μm,
Then, a large gap S is formed at the boundary between the cleaning blade 19 and the leading edge portion 22 where the cleaning blade 19 is not applied, and the untransferred toner passes therethrough, and the cleaning performance of the photoconductor 1 is reduced. Moreover, when the thickness of the coating layer 26 is large, the coating layer 26 is easily cracked, and the coating layer 26 is easily peeled from the surface of the cleaning blade 19. On the other hand, as shown in FIG.
When the thickness is set to 0 μm, the gap S is hardly formed, and the leakage of the toner can be prevented.

Here, an image forming operation is performed while rotating the photoreceptor by using the urethane rubber cleaning blade on which the above-mentioned coating layer is not formed, and the surface temperature of the photoreceptor is raised. Then, the cleaning blade comes into contact with the photoreceptor surface while being caught, whereby the blade is entangled or the cleaning performance of the photoreceptor is extremely deteriorated.

On the other hand, when a coating layer is formed on the leading edge 22 of each end region H of the cleaning blade 19 as described above, even if the temperature is increased to 100.degree. On the other hand, the photosensitive member 1 was pressed against the photosensitive member 1 in a stable state, and good cleaning performance was obtained. Therefore, as long as the coat layer 26 is not peeled off, even if the cleaning blade 19 is used under severe conditions, high cleaning performance of the photoconductor 1 can be maintained.

However, the leading edge 22 of the cleaning blade 19, on which the low molecular weight tetrafluoroethylene resin coating layer 26 is formed as described above, is pressed against the surface of the photoreceptor 1 to perform an image forming operation using the new toner. When I went, 1
The coat layer peeled off after about 000 sheets of copy paper were obtained,
Thereafter, the stick-slip of the cleaning blade increased, and the cleaning blade was involved. This is because, as shown in FIG.
The toner particles do not sufficiently function as a lubricant because the toner particles easily separate from the leading edge portion 22 of the cleaning blade 19, and the coat layer 26 directly contacts the surface of the photoreceptor, As shown in FIG.
This is because the coat layer near the edge of the surface 19B of the cleaning blade 19 is peeled off. The portion indicated by reference numeral 27 in FIG. 11 is a portion from which the coat layer has been peeled off. Also, if the toner contains, for example, an abrasive made of silica,
The coating layer is also peeled off by the polishing action of the abrasive.

Therefore, the cleaning blade 19 on which the coating layer 26 is formed is incorporated as shown in FIG.
The fine particle lubricating powder was applied to the surface of the photoconductor 1, and the photoconductor 1 was rotated in this state. Here, as the fine particle lubricating powder, polyvinylidene fluoride resin powder, which is the same fluororesin powder as Rubron: PVDF (trade name of Penfault Inc .: Kainer) was used. When such a powder is initially applied to the surface of the photoconductor corresponding to each end region H of the cleaning blade 19 or the entire surface thereof, and the photoconductor 1 is rotated, the fine particle lubricating powder becomes as shown in FIG. To
Once stopped at the leading edge of the cleaning blade 19, it passes through the leading edge 22 by a small amount, and is again moved to the leading edge 22 of the cleaning blade 19.
And finally, the fine particle lubricating powder
2 was fixed to the surface of the coat layer 26 formed.

As described above, when the fine particle lubricating powder is fixed to the surface of the coating layer 26 of the leading edge portion 22 in a filming manner with the rotation of the photoreceptor 1, they are fixed very firmly. Therefore, when the image forming operation is performed in this state, the coat layer 26 is pressed against the surface of the photoreceptor 1 via the substance of the fine particle lubricating powder adhered thereto, and the external force applied to the coat layer 26 is greatly reduced. For this reason, the coating layer 26 of the low-friction lubricant material formed on the leading edge 22 in the longitudinal end region H of the cleaning blade 19 is maintained for a long time, and the coating layer 26 and the powder material adhered thereto are maintained. The cleaning blade 19 is stably pressed against the surface of the photoreceptor 1 for a long period of time. It is possible to prevent the cleaning blade 19 from contacting the surface of the photoconductor so as to be caught, or to prevent the cleaning blade 19 from being caught in the cleaning blade 19, thereby ensuring high cleaning performance of the photoconductor 1 over a long period of time.

In particular, when the low-friction lubricating substance is made of rubron made of ethylene tetrafluoride resin as described above, it is applied to each end region H of the cleaning blade 19 to form the coating layer 26 on the surface. As shown schematically in FIG. 4, rubron particles appear, and a minute gap S1 is formed between the particles. In this state, the surface of the photoreceptor is coated with a poly (vinylidene fluoride) resin to form the photoreceptor 1
Is rotated, the kainer passes through the gap S1 at the leading edge shown in FIG. 4, and the kainer reaches the leading edge 22 again. Finally, as shown schematically in FIG. Then, the kainer is fixed to the leading edge portion 22 with the gap S1 filled. For this reason, the fixed Kyner is extremely firmly fixed to the coat layer 26, and the coat layer 2
6 is effectively prevented from peeling.

In the experiment, in order to remove paper dust adhering to the leading edge portion 22 of the cleaning blade 19 during the image forming operation, a certain short time after the image forming operation is completed.
When the photoconductor 1 was rotated in the direction opposite to the arrow A (FIG. 1), the coating layer 26 did not fall from the leading edge portion 22 and the coating layer was not peeled off after about 4000 copies were made. I couldn't. In this manner, the cleaning blade 19 can stably come into contact with the surface of the photoreceptor without contacting the surface of the photoreceptor under any normal environment, and high cleaning performance can be maintained.

When about 5,000 image forming operations are performed after the new cleaning blade is started to be used,
Cleaning blade 19 corresponding to non-image forming area E
Since the fine powder toner gradually spreads to the front edge portion 22 of the cleaning blade 19, that is, the longitudinal edge region H of the cleaning blade 19, the front edge portion of the longitudinal edge region H can always hold the fine powder toner. become. In addition, the rebound resilience of the leading edge of the cleaning blade is also reduced, and the contact angle at which the longitudinal end region H of the cleaning blade contacts the photosensitive member 1 is reduced, whereby the cleaning blade 19 is less likely to be involved. Therefore, the coating layer 26 is not used until 5000 copies are made after the new cleaning blade 19 is used.
If the cleaning blade is not peeled off, the cleaning blade does not normally get caught.

By the way, as shown in FIG.
The developer D is stored in the developing case 4 and is carried while being carried on the surface of the developing roller 5. At this time, a sealing member is usually used so that toner does not scatter from the longitudinal end of the developing roller 5. Is provided.

FIGS. 6 and 7 show an example of the sealing member 28. The sealing member 28 is made of, for example, a urethane rubber sheet, and as shown in FIG. 7, a notch 29 is formed at the center in the longitudinal direction. Each end has a side seal portion 30, and each side seal 30 has
As shown in FIG. 6, the base end 31 of the seal member 28 is fixed to the outer surface of the distal end of the developing case 4 in contact with the surface of the photoconductor 1. The relative positions of the seal member 28 and the developing roller 5 are as shown in FIG. 7, and the developing roller 5 faces the photoconductor 1 through the cutout portion 29 of the seal member 28, and executes the developing operation as described above. At this time, the sealing member 2
8 prevents the toner from scattering outside the developing case due to the contact of the side seal portions 30 with the surface of the photoreceptor.

On the other hand, the developing case 4 above the developing roller 5
In order to prevent the toner from adhering to the inner surface, a sheet 32 to which the toner is less likely to adhere is adhered to the inner surface. At that time, in the conventional developing device, the sheet 3
2 is configured such that the tip 32a is pressed against the entire length of the seal member 28 and presses the seal member 28 against the surface of the photoreceptor. When the fine particle lubricating powder is applied to the surface and passed through the leading edge of the cleaning blade 19, and the lubricating powder again reaches the leading edge 22 of the cleaning blade, the fine particle lubricating powder is applied to the side seal of the seal member 28. There is a risk of being blocked by the part 30. In this case, it becomes difficult to adhere the fine particle lubricating powder to the coat layer 26 formed on the leading edge 22 of the cleaning blade 19.

Therefore, in the image forming apparatus of this embodiment,
In the side seal portion 30 indicated by the symbol Y in FIG.
As shown in FIG. 6, even if the leading end 32 a of the sheet 32 is slightly separated from the seal member 28 and the pressure from the developer acts on the side seal 30, the side seal 30
Are configured to contact the photosensitive member 1 with a weak force. Therefore, the fine particle lubricating powder on the photoreceptor is not blocked by the side seal portion 30 and can be sent to the cleaning blade 19 without any trouble.

Here, as a comparative example with the above-described configuration,
An example of a conventional configuration will be described. Referring to FIG. 10 as well, heretofore, a configuration in which a wax is applied to each end region H in the longitudinal direction of the cleaning blade 19 shown here to form a film has been adopted. At this time, the thickness of the film cannot be increased for the reason described above with reference to FIG. 11
As shown in the figure, there was a risk that the original function would be lost.

When the transfer residual toner T stays while moving near the leading edge of the cleaning blade 19,
The abrasive action of the silica added to the toner further accelerates the wear of the wax film. In addition, as described above with reference to FIGS. 6 and 7, in the conventional developing device, the side seal portion 30 of the seal member 28 contacts the surface of the photoreceptor with a large pressure. For example, urethane rubber constituting the surface of the cleaning blade 30 migrates to the surface of the photoreceptor, thereby increasing the friction coefficient of the surface. As a result, the rubber of the cleaning blade is exposed early and the effect of the wax film is lost.

The present invention can be widely applied to image forming apparatuses other than those shown in the drawings. For example, in addition to an image forming apparatus having an image carrier formed of a belt-shaped photosensitive member, a cleaning blade, a fur brush, a cleaning brush, and the like. The present invention can be applied to an image forming apparatus or the like having a cleaning device using a cleaning member such as a roller.

Further, the present invention can be applied to an image forming apparatus in which a toner image formed on a photoreceptor is primarily transferred to an intermediate transfer member and the toner image is secondarily transferred to a final transfer material such as transfer paper. . In this case, the intermediate transfer member constitutes a transfer material to which the toner image formed on the surface of the image carrier made of the photosensitive member is transferred, or the intermediate transfer member forms a toner image on the surface thereof. An image carrier is formed. In the latter case, the transfer device serves to transfer the toner image on the image carrier formed of the intermediate transfer member to a transfer material such as transfer paper, and the cleaning device adheres to the surface of the image carrier formed of the intermediate transfer member. This is for removing the transfer residual toner.

[0057]

According to the first aspect of the present invention, a coating layer is formed by applying a low-friction lubricating substance to the leading edge of each end region in the longitudinal direction of the cleaning blade.
By combining a configuration in which the fine particle lubricating powder is fixed to the coat layer via the surface of the image carrier, the coat layer can be maintained for a long time, and the cleaning blade can be rolled up and the cleaning property of the image carrier surface can be reduced. Generation can be prevented for a long time.

According to the configuration of the second and third aspects, the above-described operation and effect can be further ensured.

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional view illustrating an example of an image forming apparatus.

FIG. 2 is an explanatory diagram showing a relative positional relationship between a photoconductor and a cleaning blade.

FIG. 3 is an explanatory view showing a state in which a cleaning blade is coated with a low-friction lubricating substance and fine particle lubricating powder is fixed on the coating layer.

FIG. 4 is an explanatory diagram schematically showing an enlarged front end portion of the cleaning blade when a low friction lubricating substance is coated on the cleaning blade.

FIG. 5 is an explanatory diagram schematically showing an enlarged view of a state in which fine particle lubricating powder is fixed to a coat layer.

FIG. 6 is a partial cross-sectional view of the developing device, showing a state in which a side seal portion of the seal member is in contact with the surface of the photoconductor.

7 is an explanatory diagram showing a state of the seal member when viewed from the right side in FIG. 6, together with a developing roller.

FIG. 8 is a diagram showing a problem when a coat layer is too thick.

FIG. 9 is an explanatory diagram showing a state when the thickness of a coat layer is made appropriate.

FIG. 10 is an explanatory view showing a problem when the fine particle lubricating powder is not fixed on the coat layer and a conventional problem.

FIG. 11 is an explanatory view showing a problem when the fine particle lubricating powder is not fixed on the coat layer and a conventional problem.

[Explanation of symbols]

 17 Cleaning Device 19 Cleaning Blade 22 Front Edge 25 End 26 Coat Layer H End Area T Toner X Image Forming Area

Claims (3)

[Claims] An image carrier on which a toner image is formed, a transfer device for transferring the toner image to a transfer material, and a transfer residual toner remaining on the image carrier after the transfer of the toner image is removed. A cleaning device for cleaning the surface of the image bearing member, the cleaning device extending long in a direction substantially perpendicular to the moving direction of the surface of the image bearing member, and having a leading edge portion in the width direction of the image bearing member. A cleaning blade made of an elastic body that scrapes off transfer residual toner adhered to the surface of the image carrier by pressing against the surface, and each of the cleaning blades has an image forming area on the surface of the image carrier, each of which has a longitudinal end; In the image forming apparatus formed to be longer than the width of the image forming area so as to be located outside of the cleaning blade, the cleaning blade may perform cleaning with respect to a leading edge portion of the cleaning blade. A low-friction lubricating substance is applied to each end region in the longitudinal direction of the blade, a coating layer of the substance is formed on the leading edge portion thereof, and the fine particle lubricating powder applied to the surface of the image bearing member is coated with an image bearing member. An image forming apparatus characterized in that the image forming apparatus is fixed to a surface of a coat layer formed on the front edge portion with rotation. 2. The image forming apparatus according to claim 1, wherein the low friction lubricating substance is an ethylene tetrafluoride resin. 3. The image forming apparatus according to claim 1, wherein the fine particle lubricating powder is a polyvinylidene fluoride resin powder.