JPH0634135B2 - Blade device, cleaning device, and image forming device - Google Patents

Description

The present invention relates to a blade device, a cleaning device, and an image forming apparatus.

In particular, the present invention is such that the elastic cleaning member is brought into contact with the surface to be cleaned so as to face the direction of movement of the surface to be cleaned, and then the contact side of the cleaning member is shortened by reducing the free length from the holding portion to the contact portion. It is characterized in that it has a thin wall thickness to reduce the increasing pressure contact force against the surface to be cleaned.

An example of a conventional cleaning device is shown in FIGS. 1 and 2 below. In both FIGS. 1 and 2, the toner is removed from the surface of the photoconductor of the electrophotographic copying machine by using a blade.

First, FIG. 1 shows a case where a rectangular elastic blade 1 is brought into contact along the moving direction of the photoconductor 2 (direction a).
In this case, the vertical reaction force N received by the blade 2 from the photoconductor 1a and the combined reaction force R of the frictional force F between the two 1a and 2 are in the direction of separating the blade 2 from the photoconductor 1a. As a result, the toner blocking force is weak and toner particles often enter under the blade, and if they enter in one place, they tend to easily spread to the entire length of the blade, and once the blade is removed, the tip of the blade is removed. It was necessary to clean the edges.

Therefore, as shown in FIG. 2, a rectangular elastic blade 2 is contacted so as to face the moving direction of the photoconductor 1a (the direction of the arrow b), and on the obtuse angle side where the blade 2 and the photoconductor 1a intersect. To perform cleaning. Then, a part of the synthetic reaction force R is stored as elastic strain of the blade, and the other part acts as an effective cleaning force, and the blade 2 moves in the wedge-shaped space between the holder 3 and the photosensitive member 1a, that is, in the direction of the frictional force F. Since the toner is pushed, the toner blocking ability is remarkably large as compared with the known example shown in FIG. 1, so that the toner hardly gets under the blade and is sufficiently removed. In this way, when the blade 2 faces and abuts in the moving direction of the photoconductor 1a,
Cleaning performance is improved. However, the direction of the frictional force F is the direction in which the blade 2 is reversed. Therefore, in order to prevent this reversal phenomenon, the blade 2 must have a thickness or a free length greater than or equal to a predetermined value, which has been an obstacle to downsizing the cleaning device. That is, if the free length of the blade is shortened, the pressure contact force of the blade with respect to the photoconductor increases, and the risk of damage to the photoconductor increases. As a countermeasure against this, it is conceivable to reduce the thickness of the elastic blade, but the holding force at the holding portion is not evenly distributed, and there is a possibility that the deformation becomes large at the time of pressing and the cleaning property deteriorates. . That is, blade 2
When the blade 1 has a constant thickness and the blade 3 has a free end with respect to the holder 3, the stress of displacement of the blade 2 is at the point Q ₁
And the point 1 is concentrated on the point Q ₂ , and the blade 1 is likely to be displaced from this portion and also to be inverted.

Therefore, an object of the present invention is to provide a compact blade device, a cleaning device, and an image forming apparatus.

Another object of the present invention is to provide a blade device, a cleaning device, and an image forming apparatus in which the length from the holding portion of the cleaning member to the contact portion that contacts the surface to be cleaned is shortened.

Still another object of the present invention is to make the cleaning member contact the surface to be cleaned with a good pressure contact force, even though the length from the holding portion of the cleaning member to the contact portion for contacting the surface to be cleaned is made short. An object of the present invention is to provide a blade device, a cleaning device, and an image forming apparatus that are in contact with each other.

Another object of the present invention is to provide a blade device, a cleaning device, and an image forming apparatus capable of expanding the selection range of the material of the cleaning member.

Still another object of the present invention is to provide a blade device, a cleaning device, and an image forming apparatus having high peel strength between the holding member and the blade.

The present invention for achieving this object, a blade, and a holding member that holds one end of the blade, the blade end of the side opposite to the side held by the holding member is a contacted body. In a blade device that abuts, the holding member holds the blade so that both ends of the blade are sandwiched between the blades, and is a surface from the abutting side end of the blade toward the holding member, facing the abutted body. The surface on the contacting side is a substantially flat surface, the contact side end is a parallel part having a smaller wall thickness than the holding side, and the residue on the contacted body is removed. In the cleaning device, a blade for contacting the contacted body to remove the residue on the contacted body, a holding member for holding one end of the blade, and a residue removed from the contacted body A guide member for guiding the inside of the cleaning device, The holding member holds the blade so that both ends of the holding member are sandwiched between the blades, and the surface facing the holding member from the contact side end of the blade is substantially the surface facing the contacted body. Is a flat surface,
The contact side end of the blade is a parallel part having a thinner wall thickness than the holding side, and in an image forming apparatus for forming an image on a recording material, an image carrier and a blade contacting the image carrier. And a holding member for holding an end portion of the blade on the side opposite to the side in contact with the image bearing member, and holding the blade so that the holding member sandwiches both end surfaces thereof with the blade, The surface from the contact side end of the blade toward the holding member, the surface on the side facing the image carrier is a substantially flat surface, and the contact side end of the blade is thicker than the holding side. It is characterized in that it is a thin parallel part.

Next, the present invention will be described in more detail with reference to examples.

FIG. 3 is an explanatory view of essential parts of an electrophotographic copying apparatus to which the present invention is applied.

In the figure, 1 is an image carrier, which is an example in which a photosensitive member 1a having a photoconductive substance such as Se or OPC is supported in a drum shape. The drum-shaped image carrier 1 is pivotally supported by the shaft 1b and rotates in the arrow C direction. Further, 22 is a corona discharger, which is a photosensitive member 1.
a Surface is uniformly charged. Reference numeral 3 denotes an optical means such as an array of short-focus optical elements, which irradiates the photoconductor 1a with a light image according to the original image. Further, a developing device 4 develops the electrostatic latent image formed on the photoconductor 1a in response to the light image irradiation. In addition, 4a is a magnet roller, and 4b is a scraper for controlling the spikes on the roller 4a. A timing roller 5 serves to feed the transfer material 8 fed from a sheet feeding means (not shown) to the transfer position in synchronization with the development on the photoconductor 1a. Reference numeral 6 is a transfer material guide guide, and 7 is a transfer corona discharger, which applies a transfer corona to the back surface of the transfer material 8 to perform development transfer to the transfer material 8 fed to the transfer position 7a. Further, 9 is a conveyor belt, which guides the transfer material after completion of transfer to a fixing means (not shown). Further, 10 is a cleaning device according to an embodiment of the present invention. Reference numeral 11 denotes a cleaning blade to which an embodiment of the present invention is applied, which is made of an elastic material such as urethane rubber or plastic. And the photoconductor 1
The front end side 11a that comes into contact with a is thin. Further, the rear end side 11b of the blade 11 is held by adhesion to the blade holder portion 10 ₁ provided in the cleaning housing 10a. Further, 12 is an elastic guide sheet, which is in light contact with the surface of the photoconductor 1a, allows the residual toner on the photoconductor 1a to pass through, and the toner scraped off from the photoconductor 1a by the blade 11 is removed from the photoconductor 1a. Leads away. Further, 13 is a rotary blade, which is a rotary shaft 13
It is axially supported by a, and rotates in the direction of arrow d to guide the toner scraped off from the surface of the photoconductor 1a by the blade 11 to the inner side 10c of the partition wall 10b. The cleaning housing 10a has an opening 10d on the side facing the photoconductor 1a, and accommodates the toner scraped off by the blade 11 without scattering.

Now, FIG. 4 is an enlarged side view of this cleaning blade portion.

First, the elastic cleaning blade 11 is made of rubber or plastic having appropriate elasticity as described above, and its shape is L-shaped. And this blade 11
Like the blade 1 shown in FIG. 2, it is held by the holder portion 10 ₁ so as to face and abut the rotation direction (arrow c direction) of the photoconductor 1a. That is, the contact angle formed by the tangent line of the surface of the photoconductor 1a and the plate 1 at the edge contact point E is set to be an acute angle. This holder part 10
The blade 11 of ₁ is held by adhering the three surfaces e, f, g of the blade portion 11 abutting the holder portion 10 ₁ or any one of the surfaces to the holder portion 10 ₁ with an adhesive, a double-sided tape or the like. . And this holder part 10 ₁
The wall thickness t ₁ of the holding portion 11 ₁ of the blade 11 held by
When the blade 11 was sandwiched held by the holder unit 10 _1, or the blade 11 to the tip even if uneven holding unit 11 ₁ of receiving clamping force or the like upon tightened with screws or the like to the holder portion 10 ₁ The thickness is set so that the non-uniform force is not transmitted, and the holding portion 11 ₁ is not easily deformed when the blade 11 is pressed against the photoconductor 1a.

And, the blade 11 of the present embodiment has an L-shaped shape in which the tip side is partially cut away, and the thickness t ₂ of the tip portion 11 ₂ is thinner than the thickness t ₁ of the holding portion 11 ₁ . Holder part 10 ₁
When the free length L from the side end h to the tip i is shortened as compared with the conventional _one , the wall thickness is set to sufficiently reduce the increase in pressure particularly in the vicinity of the holding portion 11 ₁ (free length l ₂ ) having the wall thickness t ₁ .

As a result, the free length l ₂ of the thin-walled tip portion 11 ₂ itself is shortened, so that even if the wall thickness t ₂ is thinned, the blade 11 will be extremely thin.
The waist of the blade 11 is not weakened, and the tip 11 _{2 of the} blade 11 is
It is possible to maintain the pressed state with the photosensitive member 1a with a desired contact force. Further, in the case of the blade 11 of this embodiment,
When it comes into contact with the photoconductor 1a, the stress concentration is Q ₁ , Q ₂ , Q.
Dispersed in the ₃ part, the blade does not easily turn over.

With such a configuration, the cleaning performance equivalent to that of the conventional apparatus can be realized with the extremely compact apparatus.

As a more specific example, t ₂ = 1 mm, l ₁ = 2 mm, l ₂ = 2
Cleaning was performed using rubber having a Young's modulus of 52 kg / cm ² with mm, l ₃ = 3 mm and t ₁ = 2 mm. For comparison, a conventional rectangular plate-shaped body made of the same material with a thickness of 2 mm and a free length of 1
When cleaning was performed with a 6 mm blade, the same cleaning properties as those of the conventional example could be obtained. In this case, the free length of the blade could be reduced to about 1/4 as compared with the conventional example.

FIG. 5 is a partial sectional view showing another specific example based on the embodiment of the present invention.

In the illustrated example, the thickness holding portion 11 ₁ of the elastic cleaning blade 11 is configured to be held from the side opposite to the side where the blade 11 contacts the photoconductor 1a. Reference numeral 14 denotes a blade holder, which adheres and holds the surface 11 ₃ of the blade 11 opposite to the photoconductor 1.

The dimensional relationship of each part of the blade is the same as described above.

FIG. 6 shows still another embodiment of the present invention. This embodiment is a substantially T-shaped blade in which a holding portion 15a of the elastic cleaning blade 15 is provided with a cutout portion 15b. Then, the thickness T ₂ of the tip portion 15c of the blade 15 is set to the holding portion 15a.
Is thinner than the thickness T _{1 of} . Further, the holder 16 is brought into contact with the cutout portion 15b so that the blade 15a
It is bonded to the surface and the surface b. Also in this embodiment, the free length l ₁ of the tip portion 15c of the blade 15 is shortened to reduce the size of the cleaning device, the blade 1
It is possible to maintain an appropriate abutting force of No. 5 on the photoconductor 1a.

Further, another embodiment of the present invention is shown in FIGS. 7 (A) and 7 (B).

FIG. 7 (A) is a side view of the blade, and FIG. 7 (B) is a perspective view of the cleaning device. The blade is provided over substantially the entire width of the cleaning device so that it abuts over the entire width of the surface to be cleaned of the photoconductor. Has been.

In this embodiment, a support plate 17 made of aluminum, brass or the like and a polyurethane rubber are cast into a mold and integrally molded, and then a blade 18 is formed.
The tip A is cut. The support plate 17 and the blade 18 are integrally formed so that the contact angle θ ₁ of the blade 18 with respect to the photoconductor 1a is about 15 ° to 35 ° when mounted at a predetermined position in the main body of the copying machine. is there. In this embodiment, a bent blade 18 is used, and the support plate 17 is fitted in the center of the holding portion 18a.
The thickness t ₁ of the tip portion 18b is smaller than the thickness t _{4 of} 8a. The angle θ ₂ between the holding portion 18a and the tip portion 18b of the blade 18 is about 90 ° or more.

With such a shape, a blade with the dimensions of each part as follows is used, the contact angle is about 20 ° to 30 °, and the unit length is about 25 g.
As a result of the test, the test pieces were brought into contact with each other so as to face each other in the moving direction of / cm, and no problems occurred even when copying 10,000 blades. The dimensions of each part are t ₁ = 1.5 mm, t ₂
= T ₃ = 1.0 mm, t ₄ = 3.5 mm, l ₁ = 6.0 mm, l ₂ =
2.0 mm, l ₃ = 8.0 mm, the rubber hardness of the blade is about 6
It was set to 3 ° (JIS A).

Still another embodiment is shown in FIGS. 8 and 9.

In this embodiment as well, as in the previous embodiment, the support plate 19 and the blade 20 are integrally molded.

In this embodiment, the two surfaces a and b forming the edge portion E of the blade 20 that contacts the photosensitive member are flat surfaces, and the angle θ ₁ formed by both surfaces is about 90 °. Also, this blade 20 is b
It has a curved surface 21 facing the support plate 19 from the rear end face F opposite to the edge E of the surface, the thickness t ₁ between the EFs is minimum, and the thickness t of the support plate 19 side holding portion 21 is t. ₂ is the maximum.
That is, the blade 20 has a curved surface 21 on the side opposite to the side where the blade 20 contacts the surface of the photoconductor, and which extends from the surface of the photoconductor toward the support plate 19 side from the contact side.

Where t ₁ = 1.0 mm, t ₂ = 2.0 mm, t ₃ = 1.5 mm,
A blade molded with a rubber hardness of about 60 ° (JIS A) with l ₁ = 6.0 mm and l ₂ = 0.5 to 1.0 mm is placed facing the moving direction of the photoconductor at a unit length of 25 g / cm. When contacted and cleaned, no problems occurred when copying 10,000 sheets.

In this example, even if there is no curvature between the GFs of the blades, for example, even in a straight state, the same test result was obtained at the above set pressure.

FIG. 9 shows the state of the force received by the blade 20 when cleaning the photoconductor using this embodiment.

In the present embodiment, as shown in the drawing, cleaning is performed on the obtuse angle side where the blade 20 and the photoconductor 1a intersect.
Therefore, the normal force N that the blade 20 receives from the photoconductor 1a
Then, a part of the combined reaction force R of the frictional force F between the both 1a and 20 is stored as elastic strain of the blade 20, and the other part acts as an effective cleaning force. Therefore, the cleaning property can be improved as compared with the case where the blade is brought into contact along the movement of the photoconductor. Moreover, the blade 20 of this embodiment
Then, Q ₁ because there was a thickness change in the direction of the synthetic drag R
· Since Q stress of ₂ to stressed thing is distributed along the Q _n → Q _m without concentrating on this portion, there is no change point of inversion, it is always difficult to inversion.

Further, there is known a method of bringing the edge of the cleaner blade into contact with the image carrier with a knife edge structure. However, due to its manufacturing, it is difficult to obtain parallelism of the edge traverse line, and the pressure at the tip of the edge is weak, and if the rubber is deflected to a predetermined pressure, the edge will hit the belly and the pressure will not be applied at the leading edge, When an image carrier having a large coefficient is used, the tip may turn over. The edge of this embodiment is composed of two planes, the angle between both surfaces is about 90 °, and the edge has a thickness in the direction of the vertical direction force component from the photoconductor due to the contact portion pressure. There are few problems such as.

The hardness (JISA) of the elastic blade is preferably 30 ° or more, and the hardness of 60 ° to 95 ° (JISA) is optimal, but the hardness is not limited to this. In addition, the blade and the support may be joined together by any suitable method such as adhesion, integral molding, screwing or piveting. Further, the blade may be attached to the cleaning housing or any other suitable part.

The image forming apparatus is an electrophotographic copying machine / micro device or a recording machine. The surface to be cleaned is the surface of an image bearing member such as a photosensitive drum or a porcelain drum, the surface of a fixing roller, or the surface of a member to which a developer is attached.

As described above, the present invention can provide a compact blade device, a cleaning device, and an image forming apparatus having high peel strength between a holding member and a blade.

Further, the present invention provides a blade device, a cleaning device, and an image forming apparatus that can provide sufficient cleaning performance by providing the blade so as to face the surface to be cleaned even though the blade is made small.

[Brief description of drawings]

1 and 2 are cross-sectional views showing a conventional cleaning blade, FIG. 3 is a cross-sectional view of an essential part of an electrophotographic copying machine to which the present invention is applicable, and FIG. 4 is an embodiment of the present invention. 5 and 6 are side views of a cleaning blade to which another embodiment of the present invention is applied, and FIG. 7 (A) is a side view of a cleaning blade to which another embodiment is applied. FIG. 7 (B) is a perspective view of the cleaning device, and FIGS. 8 and 9 are side views of a cleaning blade to which another embodiment is applied. In the figure, reference numeral 10a indicates a cleaning housing, 10 ₁ indicates a holder portion, 1 indicates a drum-shaped image carrier, 10 indicates a cleaning device, 11 indicates a cleaning blade, 11 ₁ indicates a holding portion, 11 ₂ indicates a tip portion. , 15 ... cleaning blade, 15a ... holding part, 16 ... holder, 18 ... blade, 18a ... holding part, 19 ... support plate, 20 ... blade.

Claims (3)

[Claims] 1. A blade, and a plate-shaped holding member for holding one end of the blade, wherein the blade end opposite to the side held by the holding member is a contacted body. In the abutting blade device, the holding member holds the blade so that both end portions of the blade are sandwiched between the blades, and the blade is a surface from the abutting side end portion of the blade toward the holding member. A blade device characterized in that the surface on the side facing the contacted body is a substantially flat surface, and the contact side end portion is a parallel portion having a thinner wall thickness than the holding side. . 2. A cleaning device for removing a residue on a contacted body, comprising: a blade for contacting the contacted body to remove the residue on the contacted body; and one end portion of the blade. It has a plate-shaped holding member for holding, and a guide member for guiding the residue removed from the abutted body into the cleaning device, and the holding portion has its both end portions sandwiched by the blade. To hold the blade, the blade is a surface from the contact side end of the blade to the holding member, the surface of the side facing the contacted body is a substantially flat surface, A cleaning device, wherein the abutting side end of the blade is a parallel part having a smaller wall thickness than the holding side. 3. An image forming apparatus for forming an image on a recording material, comprising: an image carrier, a blade contacting the image carrier, and an end of the blade opposite to a side contacting the image carrier. And a plate-shaped holding member for holding the holding member, the holding member holds the blade so that both ends of the holding member are sandwiched by the blade, and the blade holds from the contact side end of the blade. A surface facing the member, the surface on the side facing the image carrier is a substantially flat surface, and the abutting side end of the blade is a parallel part having a thinner wall thickness than the holding side. Image forming apparatus characterized in that