JP3486076B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image carrier on which a toner image is formed, a transfer device for transferring the toner image onto a transfer material, and a toner image remaining on the surface of the image carrier after the transfer. A cleaning device for removing the transfer residual toner and cleaning the surface of the image carrier, the cleaning device extending in a direction substantially orthogonal to the moving direction of the surface of the image carrier, and the tip in the width direction thereof. An edge portion has a cleaning blade made of an elastic body that is pressed against the surface of the image carrier to scrape off the residual toner remaining on the surface of the image carrier,
The cleaning blade relates to an image forming apparatus in which each end portion in the longitudinal direction is formed longer than the width of the image forming area on the surface of the image carrier so as to be located outside the image forming area. is there.

[0002]

2. Description of the Related Art Electronic copying machines, printers, facsimiles,
Alternatively, an image forming apparatus of the above type configured as a multi-function peripheral or the like having at least these two functions has been conventionally known.

In this type of image forming apparatus, since the cleaning blade of the cleaning device is brought into pressure contact with the image bearing member and the transfer residual toner adhering to the surface of the image bearing member can be efficiently scraped and removed, the image bearing member is repeatedly used. It is possible to form a high quality toner image on the surface of the image carrier while using it. Moreover, since the cleaning blade is formed to be longer than the width of the image forming area on the surface of the image carrier, and the respective longitudinal ends of the cleaning blade are 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 transfer residual toner from getting around to each end portion of the cleaning blade and scattering the toner.

However, when the cleaning blade is constructed in this way, each end area in the longitudinal direction comes into pressure contact with the non-image forming area of the image carrier, that is, the surface part 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 is larger than the frictional force acting on the central region in the longitudinal direction of the cleaning blade. Transfer residual toner is sent to the central area of the cleaning blade in the longitudinal direction, so that toner functions as a lubricant,
Although the frictional force between the cleaning blade and the surface of the image bearing member in this central region is relatively small, the toner is not sent to each end region in the longitudinal direction of the cleaning blade, so that the cleaning blade in this region is not fed. The frictional force received from the surface of the image carrier becomes large.

For this reason, especially when the cleaning blade is new or in an environment of high temperature, at the boundary between each longitudinal end area of the cleaning blade and the central area therebetween, sticking slip of the cleaning blade causes There is a possibility that the leading edge portion may be damaged or the cleaning blade may be caught, resulting in defective cleaning of the surface of the image carrier.

In order to prevent such a problem, many proposals have been made and put into practical use from the past (for example, Japanese Patent Laid-Open Nos. 61-240269 and 1-23).
5986, JP-A-6-194917 and JP-A-6-258995).

The configuration proposed in the prior art reduces the frictional force acting between each non-image forming area outside the image forming area on the surface of the image bearing member and the tip edge portion of the cleaning blade pressed against the non-image forming area. It is what makes me.

For example, a method is known in which a low-friction lubricant such as wax is applied to the tip edge portion of a cleaning blade that is in pressure contact with the non-image forming area on the surface of the image bearing member, and a wax coating layer is formed on the tip edge portion. Is. However, when this coating layer is thickened, a step is formed at the boundary between the leading edge portion where the coating layer is formed and the leading edge portion where this coating layer is not formed, and this portion is slightly separated from the image carrier surface, 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 has to be thinned to a thickness close to the particle size of the toner used. However, such a thin coat layer may peel off from the cleaning blade early and lose its function. When a new cleaning blade is used and the image forming operation is continuously performed under particularly severe environmental conditions, 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 may suddenly occur at the boundary portion of the cleaning blade, and the cleaning blade may be entangled from this portion.

Further, a structure has been proposed in which a case made of a low friction material is provided in each end region of the cleaning blade in the longitudinal direction. However, according to this structure, a step is formed at the edge of the case, so that the cleaning blade is formed. Since the leading edge portion of the sheet comes into contact with the surface of the image carrier in a discontinuous manner, the fine particle toner may pass through the gap formed in the stepped portion, and the cleaning property of the surface of the image carrier may deteriorate.

Further, a structure has been proposed in which a pattern toner image is forcibly sent to the tip edge portion of the cleaning blade, thereby lowering the friction coefficient of each end region in the longitudinal direction of the cleaning blade. It takes time for the cleaning blade to wrap around the respective end regions in the longitudinal direction, and until then, it is difficult to expect a great effect in preventing the cleaning blade from being caught.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art. The object of the present invention is to provide the end regions in the longitudinal direction of the cleaning blade and these end regions. An object of the present invention is to propose an image forming apparatus of the type described at the beginning, which can maintain a lubricating effect with the surface of the image carrier that is in pressure contact for a long period of time and can secure a high cleaning property for the surface of the image carrier.

[0012]

In order to achieve the above object, the present invention is directed to an image forming apparatus of the type described at the beginning, in which each end region in the longitudinal direction of the cleaning blade with respect to the leading edge part of the cleaning blade. A low-friction lubricant substance is applied to form a coating layer of the substance on the tip edge portion of the substance, and the fine particle lubricant powder applied to the surface of the image bearing member is added to the tip edge portion as the image bearing member rotates. There is proposed an image forming apparatus characterized by being fixed to the surface of a coat layer formed on a portion (claim 1).

In this case, in the image forming apparatus according to the first aspect, it is advantageous that the low friction lubricating substance is tetrafluoroethylene resin (the second aspect).

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

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings, and together with this, the conventional drawbacks will be clarified more specifically with reference to the drawings.

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

When the photosensitive member 1 rotates, its surface is uniformly charged to a predetermined polarity by a charging device composed of 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 so that the surface of the photoreceptor is uniformly charged. In this example, it is assumed that the surface of the photoconductor is negatively charged.

A light image L from a document (not shown) is applied to the charged surface through an optical system. In this way, the surface of the photoconductor is exposed, and an electrostatic latent image corresponding to the original image is formed here depending on the intensity of the light at this time. The negative charges on the surface of the photoconductor which are strongly exposed to light disappear or are weakened, and the part where the initial charge remains is formed as an electrostatic latent image. This electrostatic latent image is the developing device 3
When it passes through, the toner is visualized as a toner image by the powdery toner.

The developing device 3 shown in FIG. 1 has a developing case 4 accommodating a developer D and a developing roller 5 rotatably supported inside the developing case 4, and the peripheral surface of the developing roller 5 is rotationally driven. The developer is carried on and conveyed by the developer, and the electrostatic latent image formed on the photoconductor 1 is visualized as a toner image by the conveyed 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 due to friction between the toner and the carrier,
The toner is positively charged and the carrier is negatively charged, and the toner is electrostatically transferred to the electrostatic latent image and the latent image is visualized.

Light is emitted from the pre-transfer charge eliminating lamp 6 from above the toner image on the photosensitive member 1. As a result, the transfer efficiency of the toner image described later is improved.

On the other hand, a transfer paper 8 which is an example of the transfer material is fed from the paper feeding section 7, and the transfer paper 8 once stands by when the leading end of the transfer paper 8 reaches the registration roller 9, and the transfer paper 8 is transferred. 8 is fed in the direction of arrow B by the registration roller 9 at the timing of matching the toner image on the photoconductor 1.
It is fed onto the transfer belt 10 running in the direction of arrow C.

The leading edge of the transfer paper 8 is the photosensitive member 1 and the transfer belt 1.
When entering the nip portion with 0, at the same time, the bias roller 1
1, a voltage having a polarity 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 the transfer device including the bias roller 11 and the transfer belt 10.

The transfer belt 10 is wound around a driving roller 12 and a driven roller 13 and is rotationally driven in the direction of arrow C, and the transfer paper 8 on which a toner image is transferred is carried on the transfer belt 10 and carried. After being separated from the transfer belt 10, it is conveyed between the pair of fixing rollers of the fixing device 14,
The toner image transferred onto the transfer paper 8 is fixed on the transfer paper 8 by the action of heat and pressure. In this way, the transfer paper 8 is discharged outside the apparatus as copy paper.

A cleaning member 15 made of, for example, a blade made of polyurethane is pressed against the surface of the transfer belt 10 on the drive roller side, whereby toner and paper dust adhering 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 to reduce the coefficient of friction with respect to the cleaning member 15. The toner and paper dust removed from the transfer belt 10 are stored in the receiving portion 16 located below.

After the transfer of the toner image, the transfer residual toner that has not been transferred to the transfer paper 8 adheres to the surface of the photosensitive member. The transfer residual toner is removed by the cleaning device 17, and the surface of the photosensitive member is cleaned. It The surface of the photoconductor after cleaning is initialized by being subjected to the charge removing action by the charge removing device 18 including a lamp, the above-described operation is continuously performed, and the toner image is transferred onto the next transfer sheet.

As described above, the illustrated image forming apparatus is
An image carrier composed of the photoconductor 1 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 surface of the image carrier after the toner image is transferred are removed. 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 arranged apart from the surface of the image carrier can be used.

The cleaning device 17 of this embodiment includes a cleaning blade 19 made of an elastic material such as polyurethane rubber, a cleaning case 20, and a case 2 thereof.
As shown in FIG. 2, the cleaning blade 19 has a toner discharge member 21 disposed at the bottom of the image carrier 0, and the cleaning blade 19 has the toner discharge member 21 with respect to the moving direction (direction of arrow A) of the surface of the image carrier made of the photoconductor 1. The base end in the width direction extends in a direction substantially orthogonal to the width direction, and the base end in the width direction is fixed to the cleaning case 20, and the tip end part 22 in the width direction of the cleaning blade on the opposite side is pressed against the surface of the image carrier composed of the photoconductor 1. Then, the transfer residual toner adhering to the surface of the image carrier is scraped off. At this time, paper dust and the like adhering to the surface of the photoconductor 1 are also removed.

The transfer residual toner scraped off and removed from the surface of the photosensitive member 1 by the cleaning blade 19 is
The toner that has fallen to the bottom of the cleaning case 20 is conveyed toward the back side by the toner discharging member 21 that is disposed at the bottom of the cleaning case 20 and is rotationally driven, and is formed on the back side wall of the cleaning case 20. The toner is discharged from the toner discharge port (not shown) to the outside of the cleaning case. 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 for reuse.

The toner discharge member 21 is composed of the rotation center shaft 2
The toner discharge member 21 is rotatably arranged on the bottom of the cleaning case 20 and is provided in the image forming apparatus main body. A driving device (not shown) rotationally drives the device, for example, in the counterclockwise direction in FIG. 1, and thereby conveys the toner to the outside of the cleaning case as described above. It is also possible to use a toner discharging member other than the illustrated form, 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 rotationally driven to convey toner.

By the way, on the surface of the photoconductor 1, a toner image is formed in the axial direction area indicated by X in FIG. 2, and the toner image is not formed in the areas E on the respective outer sides in the axial direction. The area X is an image forming area in the axial direction of the image carrier, and the areas E on the respective outer sides are non-image forming areas in the axial direction of the image carrier.

As can be seen from FIG. 2, the cleaning blade 19 has its longitudinal end portions 25 located outside the image forming area X on the surface of the image carrier composed of the photoconductor 1. In addition, it is formed longer than the width of the image forming area X. When the length of the cleaning blade 19 is F, this length F is set larger than the image forming area X.

By setting the length of the cleaning blade 19 as described above, the cleaning blade 19 is
Even when the cleaning operation of the photoconductor 1 is continuously performed, it is possible to prevent the transfer residual toner on the photoconductor from reaching the respective end portions 25 of the cleaning blade 19 and scattering the toner. Become.

However, as described above, since the transfer residual toner is not sent to the portion of the leading edge portion 22 of the cleaning blade 19 that is in pressure contact with the non-image forming area E, the portion of the leading edge portion is not transferred. The frictional force received from the surface of the photoconductor 1 becomes large, and as a result, the cleaning blade portion comes into contact with the surface of the photoconductor so as to be caught, and cannot contact in a stable state. There was a possibility that the blade might be caught. In particular, when the cleaning blade 19 is arranged in the counter direction with respect to the moving direction of the photoconductor surface (the direction of arrow A) as shown in FIG. 1, the portion of the cleaning blade 19 that is in pressure contact with the non-image forming area E thereof. A large external force acts on the above, and the above-mentioned problems are likely to occur.

Therefore, in the image forming apparatus of this example,
As shown in FIG. 2, a low-friction lubricant substance is applied to each end region H in the longitudinal direction of the cleaning blade 19 with respect to the tip edge part 22 of the cleaning blade, and the substance is coated on the tip edge part 22. The fine particle lubricating powder that forms a layer and is applied to the surface of the image carrier composed of the photoconductor 1 is rotated by the rotation of the image carrier, and the leading edge portion 22
A structure is adopted in which it is fixed to the surface of the coat layer formed on.

It is well known in the art to apply a low-friction lubricant to the tip edge of the cleaning blade.
As described above, with this structure alone, the coating layer of the applied substance is liable to be peeled off early and the original function thereof may be lost. On the other hand, in the image forming apparatus of the present example, not only the low friction lubricating substance is applied to the front edge portion, but also the fine particle lubricating powder is applied to the surface of the image carrier, and the low-friction lubricant is applied to the surface of the image carrier. The powder was fixed to the coating layer formed on the tip edge portion 22 of the cleaning blade, and thereby the peeling of the coating layer was prevented for a long time. The more specific configuration will be clarified by introducing an experimental example conducted by the present inventor.

In this experimental example, the cleaning blade 1
As the material 9, polyurethane having a rebound resilience of 30 to 50%, a rubber hardness of 70 degrees, an amount G protruding 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 photoconductor 1, that is, the length in the axial direction thereof is 300 mm. The developing roller 5 is shorter than the total length F of the cleaning blade 19.

When the above-mentioned cleaning blade 19 is used, the untransferred toner is not sent to each end region having a length of 13 mm, but 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
A certain amount of toner immediately spreads to the respective end portions 25 of the cleaning blade 19 when reaching the leading edge portion 22 of the cleaning blade portion. Therefore, the frictional force to the photoconductor 1 becomes large 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 the tip edge portion 22 of the cleaning blade 19 in advance in each end region H in the longitudinal direction of the cleaning blade 19, and the tip edge portion 22 is applied. A coat layer was formed on the portion 22. In this example, a low molecular weight tetrafluoroethylene resin PTFE (trade name: Lubron manufactured by Daikin Industries, Ltd.) was used as the low-friction lubricant.

Lubron is a powder having a particle size of about 0.2 μm and a melting point of about 310 ° C., which is dispersed in an organic solvent (butyl acetate, butyl alcohol, HCFC-141b, etc.) and is made into an aerosol for cleaning. Blade 1
9 is applied by spraying, and the coating layer 26 is formed on the tip edge portion 22 of each of the end regions H as shown in FIG.
The film thickness of the coat layer 26 is about 1 to 10 μm. Figure 3
As shown in FIG. 4, the above-mentioned substance is applied to the end region H described above, which extends over the tip surface 19A of the cleaning blade 19 and the surface 19B of the cleaning blade 19 facing the photoconductor 1, and the boundary between the both surfaces is applied. The coat layer 26 is formed on the leading edge portion 22. In FIG. 2, the coat layer 26 is shown by hatching.

As shown in FIG. 8, the coat layer 26 described above is used.
If the thickness of the coating layer is larger than 10 μm, the coating layer 26
Then, a large gap S is formed in the boundary portion with the leading edge portion 22 of the cleaning blade 19 where this is not performed, and the transfer residual toner passes through this, and the cleaning property of the photoconductor 1 is deteriorated. Moreover, if the coat layer 26 has a large thickness, the coat layer 26 is likely to be cracked, and the coat layer 26 is likely to be separated from the surface of the cleaning blade 19. On the other hand, as shown in FIG. 9, the coat layer 26 has a thickness of 1
If it is set to 0 μm, the gap S is hardly formed, and the toner leakage can be prevented.

Here, an image forming operation is performed while rotating the photoconductor by using the urethane rubber cleaning blade which does not form the above-mentioned coat layer, and the temperature of the photoconductor surface is raised to about 80 ° C. In this case, the cleaning blade comes into contact with the surface of the photoconductor while being caught, which causes the blade to be caught and the cleaning property of the photoconductor to be extremely reduced.

On the other hand, if the coating layer is formed on the tip edge portion 22 of each end region H of the cleaning blade 19 as described above, the cleaning blade 19 will not contact the photoreceptor 1 even if the temperature is raised to 100 ° C. On the other hand, pressure contact was performed in a stable state, and good cleaning property for the photoconductor 1 was obtained. Therefore, as long as the coat layer 26 is not peeled off, the high cleaning property of the photoconductor 1 can be maintained even if the cleaning blade 19 is used under severe conditions.

However, as described above, the tip edge portion 22 of the cleaning blade 19 on which the low molecular weight tetrafluoroethylene resin coating layer 26 is formed is brought into pressure contact with the surface of the photosensitive member 1, and the image forming operation is performed using the new toner. When I went, 1
The coat layer peeled off after about 000 copy sheets were obtained.
After that, the stick-slip of the cleaning blade increased, and the cleaning blade was caught. This is because the transfer residual toner T
Has a large particle diameter, and such toner particles easily separate from the tip edge portion 22 of the cleaning blade 19, so that the toner does not sufficiently function as a lubricant, and the coat layer 26 directly contacts the surface of the photoconductor. As shown in FIG.
This is because the coating layer near the edge of the surface 19B of the cleaning blade 19 is peeled off. The part indicated by reference numeral 27 in FIG. 11 is the part where the coat layer is peeled off. Further, if the toner contains an abrasive such as silica,
The coating layer is also peeled off by the polishing action of this polishing agent.

Therefore, the cleaning blade 19 having the coat layer 26 formed thereon is assembled as shown in FIG.
A 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: PVDF (trade name: Kainer manufactured by Penfault Co., Ltd.), which is the same fluorine-based resin powder as Lubron, 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 of the photoconductor 1 and the photoconductor 1 is rotated, the fine particle lubricating powder is converted into a powder as shown in FIG. To
The cleaning blade 19 is once dammed by the leading edge portion, then passes through the leading edge portion 22 little by little, and again the leading edge portion 22 of the cleaning blade 19 is stopped.
Finally, the fine-particle lubricating powder finally comes into contact with the tip edge portion 2.
It adhered to the surface of the coat layer 26 formed in 2.

As described above, when the fine-particle lubricating powder is adhered to the surface of the coat layer 26 of the tip edge portion 22 in a filming manner as the photosensitive member 1 rotates, they are extremely firmly adhered. Therefore, when the image forming operation is performed in this state, the coat layer 26 is pressed against the surface of the photoconductor 1 through the substance of the fine particle lubricating powder adhered thereto, and the external force applied to the coat layer 26 is greatly reduced. Therefore, for a long period of time, the coating layer 26 of the low-friction lubricant substance formed on the tip edge portion 22 in the longitudinal end region H of the cleaning blade 19 is maintained, and the coating layer 26 and the powder substance adhered thereto are maintained. The cleaning blade 19 is pressed against the surface of the photoconductor 1 in a stable state for a long period of time in cooperation with the cleaning blade 19. The cleaning blade 19 can be prevented from coming into contact with the surface of the photoconductor so that the cleaning blade 19 is caught, and the trouble that the cleaning blade 19 is caught can be prevented, and high cleaning performance for the photoconductor 1 is assured for a long period of time.

In particular, when the low-friction lubricating material is made of rublon of tetrafluoroethylene resin as described above, when the coating layer 26 is formed by applying this to each end region H of the cleaning blade 19, the surface thereof is formed. As shown in FIG. 4 in an exaggerated manner, the particles of Lubron appear, and minute gaps S1 are formed between the particles. In this state, the surface of the photoreceptor is coated with a polyvinylidene fluoride resin kiner to form the photoreceptor 1.
When rotated, the kiner passes through the gap S1 at the tip edge portion shown in FIG. 4, reaches the tip edge portion 22 again, and finally, as shown schematically by hatching in FIG. , The kiner is fixed to the tip edge portion 22 while filling the gap S1. Therefore, the adhered kiner adheres to the coat layer 26 extremely firmly, and
The peeling of 6 is effectively prevented.

In the experiment, in order to remove the paper dust adhering to the tip edge portion 22 of the cleaning blade 19 during the image forming operation, after the image forming operation is completed, a certain short time is required.
When the photoconductor 1 was rotated in the direction opposite to the arrow A (FIG. 1), the coat layer 26 did not drop from the leading edge portion 22 and the peeling of the coat layer was recognized even after executing about 4000 copies. I couldn't do it. In this way, under any normal environment, the cleaning blade 19 does not abut on the surface of the photoconductor so as to be abutted in a stable state, and high cleaning performance can be maintained.

Incidentally, when an image forming operation of about 5,000 sheets is performed after starting to use a new cleaning blade,
Cleaning blade 19 corresponding to the non-image forming area E
Since the fine powder toner gradually spreads to the end edge portion 22 of the cleaning blade 19, that is, to the end area H in the longitudinal direction of the cleaning blade 19, the tip edge portion of the end area H in the longitudinal direction can always hold the fine powder toner. become. In addition, the impact resilience of the tip edge portion of the cleaning blade also decreases, and the contact angle at which the end portion H in the longitudinal direction of the cleaning blade contacts the photoconductor 1 becomes small, which makes it difficult for the cleaning blade 19 to be caught. Therefore, from the start of using the new cleaning blade 19 to the copying of 5000 sheets, the coat layer 26
If it does not peel off, the cleaning blade will not normally be caught.

By the way, as shown in FIG.
The developer D is accommodated in the developing case 4 and is carried on the surface of the developing roller 5, and at this time, a seal member is usually used to prevent the toner from scattering from the longitudinal end portion of the developing roller 5. Is provided.

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

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 of the sheet, a sheet 32 to which the toner hardly adheres is attached to the inner surface thereof. At that time, in the conventional developing device, the sheet 3
The tip 32a of No. 2 is pressed against the entire length of the seal member 28 and presses the seal member 28 against the surface of the photoconductor. However, when such a developing device is used, as described above, When the fine particle lubricating powder is applied to the surface and passed through the tip edge portion of the cleaning blade 19 and reaches the tip edge portion 22 of the cleaning blade again, the fine particle lubricant powder is the side seal of the seal member 28. There is a risk of being dammed by the portion 30. In this case, it becomes difficult to fix the fine particle lubricating powder to the coat layer 26 formed on the tip edge portion 22 of the cleaning blade 19.

Therefore, in the image forming apparatus of this example,
In the side seal portion 30 shown by reference numeral Y in FIG.
As shown in FIG. 6, even if the front end portion 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 portion 30, the side seal portion 30 is not formed.
Is configured to contact the photoconductor 1 with a weak force. Therefore, the side seal portion 30 does not block the fine particle lubricating powder on the photoconductor, and the fine powder can be sent to the cleaning blade 19 without any trouble.

Here, as a comparative example with the above-mentioned configuration,
An example of a conventional configuration will be described. Here again, referring to FIG. 10, conventionally, a configuration has been adopted in which wax is applied to each end region H in the longitudinal direction of the cleaning blade 19 shown here to form a film. At that time, the thickness of the film cannot be increased for the reason described above with reference to FIG. 8, and such a thin film can be formed in a very short time by rubbing the photoconductor for several minutes. 11
There was a risk of peeling as shown in, and losing its original function.

When the transfer residual toner T stays in the vicinity of the tip edge portion of the cleaning blade 19 while moving,
The abrasion of the wax film is further accelerated by the polishing action of silica added to the toner. Moreover, as described above with reference to FIGS. 6 and 7, in the conventional developing device, since the side seal portion 30 of the seal member 28 is in contact with the surface of the photoconductor with a large pressure, the side seal portion is For example, urethane rubber, which constitutes 30, is transferred to the surface of the photoconductor, and the friction coefficient of the surface is increased, which also causes the film on the tip edge portion of the cleaning blade to peel off early. 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, an image forming apparatus provided with an image carrier made of a belt-shaped photosensitive member, a cleaning blade, a fur brush, and a cleaning device. The present invention can be applied to an image forming apparatus having a cleaning device that also uses a cleaning member such as a roller without any trouble.

Further, the present invention can be applied to an image forming apparatus of a type in which a toner image formed on a photosensitive member 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 body constitutes a transfer material to which the toner image formed on the surface of the image carrier made of the photoconductor is transferred, or the intermediate transfer body forms a toner image on the surface. It constitutes an image carrier. In the latter case, the transfer device serves to transfer the toner image on the image carrier composed of the intermediate transfer member to a transfer material such as transfer paper, and the cleaning device attaches to the surface of the image carrier composed of the intermediate transfer member. It is used to remove the transfer residual toner.

[0057]

According to the structure described in claim 1, a structure in which a low-friction lubricating substance is applied to the tip edge portion of each end region in the longitudinal direction of the cleaning blade to form a coating layer,
The coat layer can be maintained for a long period of time by combining the constitution in which the fine particle lubricating powder is fixed to the coat layer through the surface of the image bearing member, and the entrainment of the cleaning blade and the deterioration of the cleaning property of the surface of the image bearing member can be prevented. Occurrence can be prevented for a long time.

According to the structures of claims 2 and 3, the above-mentioned effects can be further ensured.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional view showing 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 diagram showing a state in which a cleaning blade is coated with a low-friction lubricating substance and fine-particle lubricating powder is fixed to the coating layer.

FIG. 4 is an explanatory view schematically showing the leading edge portion of the cleaning blade when the cleaning blade is coated with a low friction lubricating substance.

FIG. 5 is a schematic enlarged view showing a state in which a 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 a seal member is in contact with a surface of a photoconductor.

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

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

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

FIG. 10 is an explanatory diagram showing a defect when the fine particle lubricating powder is not fixed on the coating layer and a conventional defect.

FIG. 11 is an explanatory diagram showing a defect when the fine particle lubricating powder is not fixed on the coating layer and a conventional defect.

[Explanation of symbols]

17 Cleaning device 19 cleaning blade 22 Tip edge 25 edge 26 coat layer H edge area T toner X image forming area

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Claims (3)

(57) [Claims] 1. 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 surface of the image carrier after transferring the toner image is removed. A cleaning device for cleaning the surface of the image carrier by means of the cleaning device, the cleaning device extending in a direction substantially orthogonal to the moving direction of the surface of the image carrier, and the leading edge portion in the width direction of the image carrier. The cleaning blade has an elastic body that is pressed against the surface and scrapes off the residual toner remaining on the surface of the image carrier, and the cleaning blade has an end portion in the longitudinal direction at each of the image forming areas on the surface of the image carrier. In an image forming apparatus that is formed longer than the width of the image forming area so as to be located on the outer side of the cleaning blade, the cleaning is performed with respect to the 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 to form a coating layer of the substance on the tip edge portion thereof, and the fine-particle lubricating powder applied to the surface of the image bearing member is applied to the surface of the image bearing member. An image forming apparatus characterized in that it is fixed to the surface of a coat layer formed on the leading edge portion in accordance with rotation. 2. The image forming apparatus according to claim 1, wherein the low friction lubricant is tetrafluoroethylene resin. 3. The image forming apparatus according to claim 1, wherein the fine particle lubricating powder is polyvinylidene fluoride resin powder.