JP2004109882A - Photoreceptor damping member, photoreceptor, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping member of a photoreceptor having the form of efficiency reducing noise generated in the electrifying and cleaning processings of the photoreceptor and facilitating the recycle of components as well and to provide the photoreceptor with less noise having the damping member in such a form in the inside. <P>SOLUTION: The photoreceptor 1 is composed by forming a photosensitive layer on the surface of a thin cylindrical base body 30. The photoreceptor 1 is provided in the inside with the damping member 50 composed of an elastic body in a cylindrical shape having a tapered hole and a fixing member 51 having a shape roughly matched with the tapered hole of the damping member 50 to be inserted to the tapered hole of the damping member 50 for fixing the damping member 50 to the inner surface of the photosensitive body 1 by friction force. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus using an electrophotographic process, and more particularly, to a photosensitive member including a charging member, a vibration damping member that reduces noise caused by a cleaning member coming into contact with the photosensitive member, and an image mounted with the photosensitive member. It relates to a forming apparatus.
[0002]
[Prior art]
One of image forming processes executed in an image forming apparatus such as a copying machine, a facsimile, a printer, and a printing machine includes a charging process. This process is a process of uniformly charging the photoreceptor serving as the latent image carrier, and as a method, there is charging by corona discharge or contact charging.
The corona discharge method is a method in which a corona charger is disposed at a predetermined interval from a photoconductor, and a corona discharge is performed by applying a high voltage to a charger wire. In this method, a discharge product such as ozone or nitrogen oxide is generated at the time of discharge, and this product causes environmental deterioration. In recent years, a contact charging method that can apply a low voltage and does not cause the above-described problem has been developed. It is being adopted.
In the contact charging method, a conductive roller, brush or blade is brought into contact with a photoconductor, and a voltage is applied between the two to inject electric charge into the photoconductor. In the case of the contact charging system, application of a low voltage can be completed, and although there is no generation of a discharge product, since it is in direct contact with the photoreceptor, the adhered matter such as toner remaining on the photoreceptor easily reverse-transfers. . In addition, if the charging member is left for a long time, a part of the charging member that is in contact with the photoconductor is deformed due to permanent deformation, and when the charging process is performed again, the contact state with the photoconductor is reduced. May change. As a result, the uniform contact with the photoreceptor is impaired, which may lead to uneven charging.
[0003]
For this reason, a technique has been proposed in which a minute predetermined distance is maintained between the photoconductor and the charging member to form a so-called non-contact charging range between the photoconductor and the charging member. I have.
That is, as a charging method intermediate between non-contact charging and contact charging, the photosensitive member and a charging member (a member having a suitable conductivity and elasticity, such as a brush, a roller-like brush, a roller, a blade, and a belt) are used. In recent years, a method of providing a minute gap and applying a direct current (DC) or a direct current (AC) superimposed DC voltage to perform charging (proximity charging) has begun to be adopted in recent years. As a configuration example of this proximity charging method, for example, when a charging member is a roller, a film having a predetermined thickness is wound around both peripheral surfaces in the axial direction of the charging roller, and a minute gap is provided according to the thickness of the film. There is. It is important that the small gap is maintained at a predetermined size in order not to change the charging characteristics. In other words, assuming that the gap is maintained, uniform charging can be achieved by applying a DC voltage that is relatively easy to set, but if the gap changes to be larger than the predetermined interval, The charging potential changes in accordance with the increase. For this reason, conventionally, even when a gap change occurs by superimposing an AC voltage on a DC voltage, uniform charging characteristics are obtained.
[0004]
As the photoreceptor, a conductive metal core made of a relatively lightweight material, specifically, a cylinder having a thin aluminum structure is used. In such a photoconductor, noise may be generated during operation. That is, devices for performing respective processes of charging, writing, development, transfer, and cleaning are arranged to face each other around the photoconductor. Among these devices, particularly, the charging device and the cleaning device often become noise sources of the photoconductor.
As is clear from the charging conditions described above, since the AC voltage is superimposed on the DC voltage in the charging device, the thin cylindrical portion tends to resonate when the AC voltage is applied. Propagates noise to surrounding areas.
Some cleaning devices have a blade that comes in contact with the photoconductor, and the blade repeatedly vibrates in the thin cylindrical part by repeatedly dragging the photoconductor and returning to the original position, causing the photoconductor to resonate. This will generate noise.
[0005]
Conventionally, in order to solve the noise of the photoreceptor as described above, a proposal has been made that the photoreceptor is formed of a solid, that is, a cylindrical and rigid support, or two or more elastic bodies and a cylindrical member are exposed to light. There have been proposals for installation inside a body (for example, see Patent Documents 1 and 2). However, in the former case, the use of a solid metallic base increases the cost and increases the weight of the photoreceptor considerably. Problems such as scratching are likely to occur. In the latter case, a complicated damping member is used, resulting in an increase in cost.
Further, it has been proposed that a cylindrical sliding contact member having a slit and a constricted portion extending in the longitudinal direction of the photosensitive drum is provided inside the photosensitive drum (see Patent Document 3). Because of its shape, it is difficult to remove it from the photosensitive drum, and it is not suitable as an easy-to-recycle form that is desired in recent years from the viewpoint of resource saving.
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 7-72641 [Patent Document 2]
JP-A-11-184308 [Patent Document 3]
JP 2000-315036 A
[Problems to be solved by the invention]
In view of the above problems, the present invention efficiently reduces noise generated during charging and cleaning of a photoreceptor, and has a configuration in which a photosensitive member has a form in which components can be easily recycled. An object of the present invention is to provide a photoreceptor having a vibration damping member therein and low noise. Further, another object is to provide an image forming apparatus in which the photoconductor is mounted and noise is reduced.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1 is a vibration damping member provided inside a cylindrical photoconductor, wherein the vibration damping member is a cylindrical elastic body having a tapered hole. It is in.
According to a second aspect of the present invention, there is provided a vibration damping member provided inside a cylindrical photoconductor, wherein the vibration damping member is a cylindrical elastic body having a drum-shaped hole.
According to a third aspect of the present invention, in the vibration damping member according to the first or second aspect, the loss tangent tan δ of the vibration damping member is 0.5 or more.
[0009]
According to a fourth aspect of the present invention, there is provided a photoreceptor obtained by forming a photosensitive layer on the surface of a thin cylindrical substrate, wherein the photoreceptor is formed of a cylindrical elastic body having a tapered hole. A photosensitive member having a member and a fixing member having a shape substantially coinciding with the vibration damping member, being inserted into a tapered hole of the vibration damping member, and fixing the vibration damping member to the inner surface of the photosensitive body by frictional force. Body.
The invention according to claim 5 is the photoconductor according to claim 4, wherein the loss tangent tan δ of the vibration damping member is 0.5 or more.
According to a sixth aspect of the present invention, in the photoreceptor according to the fourth or fifth aspect, the inner diameter of the cylindrical base of the photoreceptor is D, the outer diameter of the damping member is D ', and the taper of the damping member is The large diameter of the hole is D1, the small diameter of the tapered hole is D2, the large diameter of the fixing member is d1, the small diameter of the fixing member is d2, and the outside of the vibration damping member when the fixing member is inserted into the vibration damping member. When the diameter is D ", the photosensitive member satisfies D1 <d1, D2 <d2, and D">D> D '.
The invention according to claim 7 is the photoconductor according to claim 6, wherein D1-d1 <D2-d2.
[0010]
The invention according to claim 8 is the photoconductor according to any one of claims 4 to 7, wherein the fixing member is formed integrally with a flange at one end of the photoconductor.
According to a ninth aspect of the present invention, in the photoreceptor according to any one of the fourth to seventh aspects, the photoreceptor includes a shaft for performing positioning in the image forming apparatus main body with high accuracy. A shaft is a photoreceptor that also serves as the fixing member.
[0011]
According to a tenth aspect of the present invention, there is provided a photoreceptor obtained by forming a photosensitive layer on a surface of a thin cylindrical substrate, wherein the photoreceptor is formed of a cylindrical elastic body having a drum-shaped hole. The photosensitive member is fixed to the inner surface of the photoreceptor by frictional force by means of flanges at both ends of the photoreceptor having fixing portions having shapes substantially corresponding to both ends of a drum-shaped hole. Body.
An eleventh aspect of the present invention is the photoconductor according to the tenth aspect, wherein the loss tangent tan δ of the vibration damping member is 0.5 or more.
According to a twelfth aspect of the present invention, in the photoconductor according to the tenth or eleventh aspect, the photoconductor has an inner diameter D of the cylindrical base of the photoconductor, an outer diameter D ′ of the vibration damping member, The large diameter of the drum-shaped hole of the vibration damping member is D1, the small diameter of the drum-shaped hole is D2, the large diameter of the flange fixing part is d1, the small diameter of the flange fixing part is d2, and the vibration damping member has the fixing part. When the outer diameter of the vibration damping member when the flange is inserted is D ",
The photosensitive member satisfies D1 <d1, D2 <d2, and D ″>D> D ′.
According to a thirteenth aspect of the present invention, in the photoreceptor according to the twelfth aspect, the photoreceptor satisfies D1-d1 <D2-d2.
[0012]
According to a fourteenth aspect of the present invention, there is provided a photoconductor, a charging unit for uniformly charging the surface of the photoconductor, an exposure unit for writing an electrostatic latent image on the photoconductor surface, and an electrostatic device on the photoconductor. An image forming apparatus comprising: developing means for supplying toner to a latent image to make it visible, and transfer means for transferring the toner image on the photoreceptor to transfer paper or an intermediate transfer body. An image forming apparatus comprising the photoconductor according to any one of claims 4 to 13.
According to a fifteenth aspect of the present invention, there is provided a process wherein the photoreceptor according to any one of the fourth to thirteenth aspects and an at least one unit selected from a charging unit, a developing unit, and a cleaning unit are integrally supported. This is an image forming apparatus including a cartridge.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
1 is a configuration diagram of a full-color image forming apparatus, FIG. 2 is an enlarged view of an image forming apparatus in the image forming apparatus shown in FIG. 1, and FIG. 3 is a front view of a charging device in the image forming apparatus shown in FIG.
In FIG. 1, the image forming apparatus 20 includes the following devices. An image forming device 21C, 21Y, 21M, 21Bk for forming an image for each color according to a document image, a transfer device 22 disposed opposite to each image forming device 21C, 21Y, 21M, 21Bk, and an image forming device A manual feed tray 23 as a transfer paper supply unit for supplying various transfer papers to a transfer area where the devices 21C, 21Y, 21M, 21Bk and the transfer device 22 face each other, a paper feed cassette 24, a manual feed tray 23 or a paper feed cassette 24 A registration roller 31 that supplies the transfer paper conveyed from the printer according to the timing of image formation by the image forming devices 21C, 21Y, 21M, and 21Bk, and a fixing device 40 that fixes the transfer paper after transfer in the transfer area. .
The image forming apparatus 20 includes plain paper (hereinafter simply referred to as plain paper) generally used for copying, 90K paper such as OHP sheets, cards, and postcards, thick paper having a basis weight of about 100 g / m ² or more, and envelopes. Any of so-called special sheets having a larger heat capacity than paper (hereinafter simply referred to as special sheets) can be used as transfer paper.
[0014]
Each of the image forming apparatuses 21C, 21Y, 21M, and 21Bk performs development of each color of cyan, yellow, magenta, and black, and uses different toner colors. The configuration of 21C will be described as a representative of each of the imaging devices 21C, 21Y, 21M, and 21Bk.
The image forming apparatus 21C is provided in the rotation direction A of the photosensitive drum 25C, which is constituted by a thin cylindrical substrate having an outer diameter of 30 mm, an inner diameter of 28.5 mm, and a peripheral wall thickness of 0.75 mm as an electrostatic latent image carrier. A known configuration including a charging device 27C, a developing device 26C, and a cleaning device 28C arranged in this order and receiving exposure light 29C between the charging device 27C and the developing device 26C is used. The same applies to the other image forming apparatuses 21Y, 21M, and 21Bk shown in FIG. In the image forming apparatus 20 shown in FIG. 1, since the transfer device 22 extends obliquely, the space occupied by the transfer device 22 in the horizontal direction can be reduced.
[0015]
Each of the image forming apparatuses 21C, 21Y, 21M, and 21Bk has a unit configuration shown in FIG. 2 and is provided in the image forming apparatus 20. In FIG. 2, the image forming apparatus includes a photosensitive drum 25C (for convenience, the image forming apparatus 21C will be described, and the reference numerals are denoted by 25C related to the image forming apparatus 21C), a charging device 27C, and a cleaning device 28C. Have been.
As shown in FIG. 3, the charging device 27C uses a roller-shaped metal core, and its peripheral surface near both ends in the axial direction has a thickness for providing a predetermined minute interval with the photosensitive drum 25C. Is wound. The charging device 27C is pressed and urged toward the photosensitive drum 25C by a spring 27C3 provided on the rotating shaft 27C2, and the film 27C1 comes into contact with the peripheral surface of the photosensitive drum 25C, so that the charging device 27C A gap G is set between the peripheral surface and the peripheral surface.
The charging device 27C applies, for example, DC-700V to the metal core by a constant voltage control, and applies an AC voltage to the core metal by a constant current control. In this way, uniform charging by air discharge is performed.
[0016]
In FIG. 2, a cleaning device 28C includes a cleaning blade 28C1 that contacts the photosensitive drum 25C to scrape off residual toner, a brush 28C2 that collects toner scraped off by the cleaning blade 28C1, and a toner that is collected by the brush 28C2. And a waste toner conveying means 28C3 composed of a screw auger for conveying the toner toward the waste toner container.
The cleaning mechanism is also provided in the charging device 27C, and the cleaning mechanism of the charging device 27C uses a pad member 27C4 that comes into contact with the films 27C1 wound on both ends in the axial direction of the cored bar. The cleaning by the charging device 27C is performed to prevent the toner or the like adhered to the photosensitive drum 27C from being reversely transferred to the film because the film 27C1 is always in contact with the photosensitive drum 25C. In addition, the contact state between the film 27C1 and the photosensitive drum 25C is prevented from being changed by the reversely transferred toner or dust, and the facing distance between the photosensitive drum 25C and the charging device 27C is always kept constant. I have.
[0017]
4 to 7 are diagrams illustrating an embodiment of the present invention.
FIG. 4 shows the configuration of the photoreceptor 1. A substrate 30 having a photosensitive layer on the surface is provided with flanges 40 and 41 at both ends and a cylindrical vibration damping member 50 having a tapered hole. The fixing member 51 has a shape substantially coinciding with the tapered hole of the vibration damping member, and includes the fixing member 51 inserted into the tapered hole of the vibration damping member. The vibration damping member 50 is an elastic body, particularly an elastic body such as butyl rubber having a loss tangent tan δ of 0.5 or more.
5 to 7 are views showing the shapes of the base 30, the vibration damping member 50, and the fixing member 51, respectively. Here, the inner diameter of the base is D, the outer diameter of the damping member is D ', the large diameter of the tapered hole of the damping member is D1, the small diameter of the tapered hole of the damping member is D2, the large diameter of the fixed member is d1, and the diameter of the fixed member is d1. When the small diameter is d2, the configuration is such that D1 <d1, D2 <d2, and D> D '. For this reason, after the damping member 50 is inserted into the base 30, by inserting the fixing member 51 into the tapered hole of the damping member 50, the outer diameter of the damping member 50 increases to D ″, and D ″> D By satisfying the above condition, the substrate 30 comes into close contact with the inner surface and is fixed by friction.
[0018]
After the photoreceptor 1 has deteriorated with the use of the image forming apparatus, the flanges 40 and 41 are removed from the base 30, and then the vibration damping member 50 can be easily removed from the base 30 by removing the fixing member 51. Yes, it can be installed on a new substrate and reused. In this way, the configuration is suitable for recycling parts.
[0019]
In addition, as the shapes of the damping member 50 and the fixing member 51, in addition to the above-mentioned relational expression, D1-d1 <D2-d2, the assemblability when installing the damping member 50 on the base 30 is improved. . This is because when D1-d1 = D2-d2, when the fixing member 51 is inserted, the outer diameter is increased at one time in the longitudinal direction of the vibration damping member, so that the resistance at the time of insertion increases. For this reason, by setting D1−d1 <D2−d2, the diameter is gradually increased from the small diameter side to the large diameter side, so that the assembly becomes easy.
[0020]
FIG. 8 is a diagram showing another embodiment of the present invention. In the embodiment described above, the fixing member 51 is used separately from the flanges 40 and 41 on both sides of the base 30. However, in the embodiment shown in FIG. 43 are integrally formed. The relationship between the inner diameter of the base 30, the large diameter and the small diameter of the tapered hole of the damping member 50, and the large diameter and the small diameter of the fixing portion 43 of the flange 42 is as described above. By thus forming the fixing portion 43 integrally with the flange 42 on one side, it is possible to reduce the number of components and cost.
[0021]
FIG. 9 is a diagram showing still another embodiment of the present invention. Particularly, in an image forming apparatus or the like for forming a color image, since the positioning of the photoconductor in the main body must be highly accurate, a photoconductor having a shaft formed of a rigid body such as a metal is often used. In the embodiment shown in FIG. 9, a fixing portion is formed integrally with a shaft 60 provided on the photoconductor, and the outer diameter of the vibration damping member 50 is enlarged to be fixed to the base 30. The relationship between the inner diameter of the base 30, the large diameter and the small diameter of the tapered hole of the damping member 50, and the large diameter and the small diameter of the fixed portion of the shaft 60 are as described above. In the present embodiment, the positioning accuracy can be improved, and the vibration damping member 50 can be fixed and reused.
[0022]
FIG. 10 is a diagram showing still another embodiment of the present invention. In the embodiment shown in FIG. 10, the damping member 52 has a drum-shaped hole, and the flanges 46 and 48 at both ends of the base 30 are inserted into the hole shape of the damping member 52, respectively. Are fixed. The relationship between the inner diameter of the base 30, the large diameter and small diameter of the hole of the vibration damping member 52, and the large diameter and small diameter of the fixing portions 47 and 49 of the flanges 46 and 48 is as described above. With this configuration, after the vibration damping member 52 is inserted into the base 30, the flanges 46 and 48 are simply inserted and fixed to the base 30, and the vibration damping member 52 is also fixed within the base 30. Further, by removing the flanges 46 and 48, the vibration damping member 52 can be easily removed from the base 30, which is a configuration very suitable for parts recycling.
[0023]
In the image forming apparatus 20 equipped with the photoreceptor of the present invention described above, the charging device 27 performs charging by applying an AC superimposed DC voltage to a charging roller provided at a small interval with respect to the photoreceptor 25. Although it is a system, resonance can be suppressed by a vibration damping member provided inside the base of the photoconductor 25, and noise can be reduced. The cleaning device 28 is a mechanism for cleaning the surface of the photoconductor 25 with a blade by sliding the photoconductor 25. The vibration is suppressed by a vibration damping member provided inside the base of the photoconductor 25, and the noise is reduced. Can be.
[0024]
【The invention's effect】
As described above, according to the present invention, the shape of the vibration damping member provided inside the photoconductor and the shape of the fixing member fixing the vibration damping member are specified, so that the vibration damping member can be easily mounted inside the photoconductor, and the charging of the photoconductor can be performed. Further, it is possible to provide a vibration damping member capable of efficiently reducing noise generated in a cleaning process, and a photosensitive member. Further, the photoreceptor of the present invention makes it possible to easily remove the vibration damping member and to make the configuration very suitable for recycling parts. Further, the image forming apparatus provided with the photoconductor of the present invention is an image forming apparatus in which noise during charging and cleaning is reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a full-color image forming apparatus according to the present invention.
FIG. 2 is an enlarged view of an image forming apparatus in the image forming apparatus shown in FIG.
FIG. 3 is a front view of a charging device in the image forming apparatus shown in FIG.
FIG. 4 is a view showing one embodiment of a photoreceptor of the present invention.
FIG. 5 is a view showing the shape of a photoconductor substrate.
FIG. 6 is a diagram illustrating a shape of a vibration damping member.
FIG. 7 is a diagram showing a shape of a fixing member.
FIG. 8 is a view showing another embodiment of the photoconductor of the present invention.
FIG. 9 is a view showing another embodiment of the photoconductor of the present invention.
FIG. 10 is a view showing another embodiment of the photoconductor of the present invention.
[Explanation of symbols]
Reference Signs List 1 photoconductor 22 transfer device 25 photoconductor 26 developing device 27 charging device 28 cleaning device 29 exposure device 30 bases 40, 41, 42, 44, 45, 46, 48 flanges 43, 47, 49 fixing portion 50 damping member 51 fixing Member 60 axis

Claims (15)

A vibration damping member provided inside the cylindrical photoconductor,
The vibration damping member is a cylindrical elastic body having a tapered hole. A vibration damping member provided inside the cylindrical photoconductor,
The vibration damping member is a cylindrical elastic body having a drum-shaped hole. The vibration damping member according to claim 1 or 2,
The damping member has a loss tangent tan δ of 0.5 or more. A photosensitive member formed by forming a photosensitive layer on the surface of a thin cylindrical substrate,
The photosensitive member is a vibration damping member made of a cylindrical elastic body having a tapered hole,
A fixing member having a shape substantially matching the tapered hole of the vibration damping member, being inserted into the tapered hole of the vibration damping member, and fixing the vibration damping member to the inner surface of the photoconductor by frictional force. A photoreceptor characterized by being provided. The photoconductor according to claim 4,
The photosensitive member, wherein the vibration damping member has a loss tangent tan δ of 0.5 or more. The photoconductor according to claim 4, wherein
In the photoconductor, the inner diameter of the cylindrical base of the photoconductor is D, the outer diameter of the vibration damping member is D ', the large diameter of the tapered hole of the vibration damping member is D1, the small diameter of the tapered hole is D2, and the fixing member is When the large diameter is d1, the small diameter of the fixing member is d2, and the outside diameter of the vibration damping member when the fixing member is inserted into the vibration damping member is D ″,
A photoconductor, wherein D1 <d1, D2 <d2, and D ″>D> D ′. The photoconductor according to claim 6,
The photoconductor, wherein D1-d1 <D2-d2. The photoconductor according to any one of claims 4 to 7,
The photoconductor, wherein the fixing member is formed integrally with a flange at one end of the photoconductor. The photoconductor according to any one of claims 4 to 7,
The photoconductor is provided with a shaft for performing high-precision positioning in the image forming apparatus main body,
The photosensitive member, wherein the shaft also serves as the fixing member. A photosensitive member formed by forming a photosensitive layer on the surface of a thin cylindrical substrate,
The photosensitive member is provided with a vibration damping member made of a cylindrical elastic body having a drum-shaped hole therein,
The photoreceptor is characterized in that the vibration damping member is fixed to the inner surface of the photoreceptor by a frictional force by flanges at both ends of the photoreceptor having fixing portions having shapes substantially corresponding to the shapes of both ends of a drum-shaped hole. . The photoconductor according to claim 10,
The photosensitive member, wherein the vibration damping member has a loss tangent tan δ of 0.5 or more. The photoconductor according to claim 10,
In the photoconductor, the inner diameter of the cylindrical base of the photoconductor is D, the outer diameter of the vibration damping member is D ', the drum-shaped hole large diameter of the vibration-damping member is D1, the drum-shaped hole small diameter is D2, When the large diameter of the flange fixing portion is d1, the small diameter of the flange fixing portion is d2, and the outer diameter of the vibration damping member when the flange having the fixing portion is inserted into the vibration damping member is D ″,
A photoconductor, wherein D1 <d1, D2 <d2, and D ″>D> D ′. The photoconductor according to claim 12,
The photoconductor, wherein D1-d1 <D2-d2. A photoreceptor, charging means for uniformly charging the surface of the photoreceptor, exposing means for writing an electrostatic latent image on the photoreceptor surface, and supplying toner to the electrostatic latent image on the photoreceptor for visualization An image forming apparatus comprising: developing means for forming an image; and transfer means for transferring the toner image on the photoconductor to transfer paper or an intermediate transfer body,
An image forming apparatus comprising the photoconductor according to any one of claims 4 to 13. 14. An image, comprising a process cartridge integrally including the photosensitive member according to claim 4 and at least one unit selected from a charging unit, a developing unit, and a cleaning unit. Forming equipment.

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