JP2012037753A - Image forming device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize a lubricant application method with respect to a use state of a user.SOLUTION: The image forming device includes an image carrier 8, and a cleaning device 11 having a cleaning member 31 that is brought into contact with the surface of the image carrier 8 to clean foreign matters, a lubricant supplying member 43 for supplying the lubricant to the image carrier 8, and a frame member 30 supporting at least the cleaning member 31, the lubricant supplying member 43, and the image carrier 8. The frame member 30 includes areas 50 for disposing the lubricant supplying member 43 at further downstream side and further upstream side in the rotation direction of the image carrier 8 than the cleaning member 31. The lubricant supplying member 43 may be disposed either of the areas.

Description

  The present invention relates to an image forming apparatus using an electrophotographic process, and more particularly to a coating method of a lubricant on a photoreceptor of the image forming apparatus.

In an image forming apparatus using an electrophotographic process, an image is formed by subjecting an image carrier (for example, a photoconductive photoreceptor) to a charging step, an exposure step, a development step, and a transfer step.
Residues such as residual toner and paper dust remaining on the surface of the photoreceptor after the transfer process are removed through a cleaning process.
Further, as a generally used cleaning method, a cleaning blade made of rubber or polyurethane that is inexpensive, has a simple mechanism, and has excellent cleaning properties is used.
In addition, it is known that a lubricant is applied to the photoconductor, for example, as described in Patent Document 1 in order to protect it from charging and a cleaning blade.
However, the use conditions of the image forming apparatus are uneven depending on the user, and it is difficult to optimize the method of applying the lubricant for the usage in the market.

Patent Document 1 describes that the amount of application is changed by changing the amount of a spring that presses a lubricant application member against the photoreceptor, but in terms of application of the lubricant, for example, As will be described later, there is a problem in that required cleaning performance and cost vary depending on the use condition by the user.
Generally, after cleaning with a cleaning blade, applying lubricant on the downstream side of the cleaning blade improves the cleaning performance and the life of the cleaning blade. However, the leveling of the lubricant after application is smoothed. If the lubricant is applied on the upstream side of the cleaning blade before cleaning with the cleaning blade, the cleaning blade also serves as a lubricant leveling member. Although the life of the cleaning blade is sacrificed, the cost can be reduced by eliminating the leveling member.
For example, in the case of a user who mainly outputs a low image area ratio such as a general office document composed of figures and texts, a high cleaning property is unnecessary and a method of applying a lubricant upstream of a cleaning member or Although it is possible to obtain sufficient functions with an inexpensive configuration such as a method that does not use a lubricant, it is expensive although it is an expensive configuration for users who mainly output high image areas such as posters and flyers A method of applying a lubricant having cleaning properties downstream of the cleaning member is required.

As described above, by changing the position where the lubricant application member is provided (changing the lubricant application method), the cleaning performance can be adjusted according to the use conditions of the user. It has been difficult to optimize the upstream side or the downstream side) with respect to the usage situation of the user. That is, adjustments such as changing the position of the lubricant application member in accordance with the use situation later are difficult at present.
SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an image forming apparatus that can change the position where a lubricant application member is provided and can optimize the lubricant application method with respect to the usage situation of the user in the market. The purpose is to do.

In order to solve the above problems, the invention of claim 1 is directed to an image carrier, a cleaning member that comes into contact with the surface of the image carrier to clean foreign matter, and lubrication that supplies a lubricant to the image carrier. And a cleaning device including at least the cleaning member, the lubricant supply member, and a frame that supports the image carrier, the frame provided with the lubricant supply member The image forming apparatus is characterized in that the region is provided on the upstream side and the downstream side in the rotation direction of the image carrier with respect to the cleaning member, and the lubricant supply member can be disposed in any of the regions.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, when the lubricant supply member is disposed in the region downstream of the cleaning member in the rotation direction of the image carrier, the cleaning is performed. An image in which the frame body is provided with a lubricant leveling member that is in contact with the image carrier and equalizes the thickness of the lubricant applied by the lubricant supply member downstream of the member in the rotation direction of the image carrier. Features a forming device.
According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, when the lubricant supply member is disposed in the region upstream of the cleaning member in the rotation direction of the image carrier, The image forming apparatus is characterized in that the cleaning member equalizes the thickness of the lubricant applied by the lubricant supply member.
According to a fourth aspect of the invention, there is provided the image forming apparatus according to any one of the first to third aspects, wherein the lubricant includes at least a fatty acid metal salt.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the lubricant is an image forming apparatus using at least an inorganic lubricant.
According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the image forming apparatus supplies a lubricant containing both a fatty acid metal salt and an inorganic lubricant to the image carrier. It is characterized by.
The invention according to claim 7 is the image forming apparatus according to claim 4 or 6, wherein the fatty acid metal salt is zinc stearate.
The invention according to claim 8 is the image forming apparatus according to claim 5 or 6, wherein the inorganic lubricant is boron nitride.
According to a ninth aspect of the invention, there is provided a process cartridge which is attached to and detached from the image forming apparatus according to any one of the first to eighth aspects and includes at least the image carrier and the cleaning device.

  With the above configuration, according to the present invention, the position of the lubricant supply member can be selected to be upstream or downstream of the cleaning member. Using a system in which the position of the lubricant supply member that can be extended in terms of cost is provided downstream of the cleaning member, the color cleaning device has a lubricant supply member that has a short life but can reduce costs. Since an optimal method such as using a method upstream of the cleaning member can be selected, the lubricant application method can be optimized for the usage situation of the user in the market.

1 is a longitudinal side view schematically showing a color printer which is an image forming apparatus according to an embodiment of the present invention. The perspective view which shows the state which open | released the side cover provided in the main body case shown in FIG. FIG. 3 is a first diagram illustrating an example of a process cartridge according to an embodiment of the present invention. FIG. 4 is a second diagram illustrating an example of a process cartridge according to the embodiment of the invention. FIG. 3 is a diagram illustrating an example of a process cartridge according to an embodiment of the present invention (part 3);

Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a longitudinal side view schematically showing a color printer which is an image forming apparatus according to an embodiment of the present invention.
In the main body case 2 of the color printer 1, a printer engine 3, an optical writing device 4 that emits a light beam, a paper feed cassette 5 that is a recording medium storage unit that stores a recording medium P that is a transfer target, a toner image Are provided with a fixing device 6 for fixing the recording medium P to which toner has been transferred, a waste toner collecting container 7 for collecting waste toner generated after transferring the toner image, and the like.
The printer engine 3 is a portion that forms a toner image and transfers the formed toner image to the recording medium P, and includes four photoconductors 8 (8Y, 8C, 8M, and 8K) that are image carriers, and each photoconductor 8. A charging roller 9 as a charging device, a developing device 10, and a black cleaning device as shown in FIG. 3 to be described later, with a lubricant supply member positioned downstream of the cleaning member 11K, as shown in FIG. Similarly, as shown in FIG. 4 described later, the position of the lubricant supply member in the color cleaning device is the cleaning device 11M (C, Y) upstream of the cleaning member, the primary transfer roller 12, the image carrier, and the transfer target. The intermediate transfer belt 13 includes a secondary transfer roller 14 that is a transfer device, an intermediate transfer belt cleaning device 15, and the like. Here, in the description of the present specification and drawings, Y, C, M, and K subscripts indicate yellow, cyan, magenta, and black colors, respectively, and these subscripts are omitted as necessary. .

In the example of the color printer as shown in FIG. 1, the number of operating parts at the time of image formation is reduced by having a monochrome image formation mode in which only the corresponding photosensitive member rotates and forms an image when performing image formation with single color toner. In addition, it is an energy saving and low running cost device. In particular, by having a black monochromatic image forming mode in which the output ratio of a single color is higher than that of other colors, the apparatus is greatly energy-saving and has a low running cost.
In general, the usage rate in the black single-color image forming mode, which is energy saving and low running cost, tends to be high, and the rotation time (use amount) of the black photoconductor 8K tends to be longer than that of other color photoconductors. is there.
Therefore, in the example of FIG. 1, the black cleaning device 11 </ b> K employs a method in which the lubricant supply member is positioned downstream of the cleaning member, which is costly but can extend the service life.

On the other hand, the MCY cleaning device 11 uses a system in which the lubricant supply member is upstream of the cleaning member, which has a shorter life than the above-described system but can be reduced in cost.
In this case, it is possible to greatly reduce the maintenance cost by extending the life of the MCY cleaning device and reducing the number of replacements in the market.
Regarding the MCY cleaning device, the usage ratio is reduced due to the relationship of the blank monochromatic image forming mode, so even with a configuration with a short life as described above, it is possible to have the same replacement timing as the black cleaning device, Only the device cost can be reduced without increasing the maintenance cost.

The photoconductor 8 is formed in a cylindrical shape and is connected to a drive motor (not shown), and rotates around a center line by a drive force from the drive motor. A photosensitive layer on which an electrostatic latent image is formed is provided on the outer peripheral surface of the photoreceptor 8.
The charging roller 9 is disposed in contact with the outer peripheral surface of the photoconductor 8 or is disposed with a small gap from the outer peripheral surface of the photoconductor 8. When a voltage is applied to the charging roller 9 from a power supply unit (not shown), corona discharge is generated between the charging roller 9 and the photoconductor 8, and the outer peripheral surface of the photoconductor 8 is made uniform. Charged.
The optical writing device 4 emits a light beam corresponding to the image data, and exposes the outer peripheral surface of the uniformly charged photoreceptor 8. By this exposure, an electrostatic latent image corresponding to the image data is formed on the outer peripheral surface of the photoreceptor 8.

The developing device 10 supplies toner to the photoreceptor 8. The supplied toner adheres to the electrostatic latent image formed on the outer peripheral surface of the photoconductor 8, and the electrostatic latent image on the outer peripheral surface of the photoconductor 8 is visualized as a toner image.
The intermediate transfer belt 13 is a loop-shaped belt formed of a resin film or rubber as a base, and is wound around a drive roller 16, an entrance roller 17, and a tension roller 18, and is driven by a drive motor (not shown). When the connected driving roller 16 is driven to rotate, it rotates in the direction of arrow A. The entrance roller 17 and the tension roller 18 are driven to rotate by the frictional force with the intermediate transfer belt 13 as the intermediate transfer belt 13 rotates in the direction of arrow A.
The primary transfer roller 12 is disposed on the inner peripheral surface side (inside the loop) of the intermediate transfer belt 13, and a toner image on each photoconductor 8 is formed by applying a transfer voltage to the primary transfer roller 12. The image is transferred onto the intermediate transfer belt 13. The toner images formed on the respective photoreceptors 8 are sequentially transferred and superimposed on the intermediate transfer belt 13, and a color toner image is formed on the intermediate transfer belt 13.

Each cleaning device 11 cleans the outer peripheral surface of the photoconductor 8 after the toner image is transferred to the intermediate transfer belt 13. By this cleaning, toner, paper dust, and the like remaining on the outer peripheral surface of the photoreceptor 8 after the toner image is transferred to the intermediate transfer belt 13 are collected as waste toner.
The color toner image formed on the intermediate transfer belt 13 is transferred to the secondary transfer roller 14 at the timing when the recording medium P is sent to the transfer position where the intermediate transfer belt 13 and the secondary transfer roller 14 are in contact with each other. When the working voltage is applied, it is transferred to the recording medium P. The recording medium P is fed from the sheet feeding cassette 5 and is conveyed by the conveyance roller 19 and the registration roller 20, and is transferred to the fixing device 6 after the toner image is transferred. The recording medium P to which the toner image has been transferred is subjected to fixing processing by applying heat and pressure in the fixing device 6, and the toner image melted by this fixing processing is fixed to the recording medium P. The recording medium P for which the fixing process has been completed is discharged onto a discharge tray 21 formed on the upper surface of the main body case 2.

The intermediate transfer belt cleaning device 15 cleans the outer peripheral surface of the intermediate transfer belt 13 after the color toner image is transferred to the recording medium P. By this cleaning, toner, paper dust, and the like remaining on the outer peripheral surface of the intermediate transfer belt 13 after the toner image is transferred are collected as waste toner.
The waste toner collection container 7 is a portion in which waste toner collected by the cleaning devices 11 and 15 is input from the cleaning devices 11 and 15 and the input waste toner is stored. The waste toner collection container 7 is detachably attached to the main body case 2, and is removed from the main body case 2 when the waste toner in the waste toner collection container 7 is almost full, and an empty waste toner collection container. 7 is attached.

  The photosensitive member 8 that is a component of the printer engine 3, the charging roller 9, the developing device 10 and the cleaning device 11 arranged around each photosensitive member 8 are unitized and housed in a case 22, and the process cartridge 23 ( 23Y, 23C, 23M, and 23K). Each process cartridge 23 is detachably mounted in the main body case 2. Since the photosensitive member 8, the charging roller 9, the developing device 10, and the cleaning device 11 are unitized as a process cartridge 23, replacement and maintenance work is facilitated, and the positional accuracy between the members is high. Therefore, the quality of the formed image can be improved. In this embodiment, the photosensitive member 8, the charging roller 9, the developing device 10, and the cleaning device 11 have been described by taking the process cartridge 23 as an example. However, there are various process cartridge configurations. For example, at least one of the charging roller 9, the developing device 10, and the cleaning device 11 and the photosensitive member 8 are housed in a case and unitized.

FIG. 2 is a perspective view showing a state in which the side cover 24 provided on the main body case 2 is opened.
By opening the side cover 24, the printer engine 3 and the waste toner collection container 7 appear, and the process cartridge 23, the intermediate transfer belt 13 and the waste toner collection container 7 can be replaced and other maintenance can be performed. The intermediate transfer belt 13, the rollers 16, 17, 18 and the cleaning device 15 are housed in a belt case 13a and unitized.

3, 4 and 5 are views showing examples of the process cartridge according to the embodiment of the present invention.
3, 4, and 5 use the same frame, and the lubricant installation locations 50 for installing the solid lubricant 40 are provided on both the upstream side (FIG. 3) and the downstream side (FIG. 4) of the cleaning blade 31, The solid lubricant 40 can be installed at either of the installation locations.
Also, the lubricant leveling blade 44 can be removed as shown in FIG.
Since the lubricant supply member (brush roller 44) can be arranged on either the upstream side or the downstream side of the image bearing member rotation direction of the cleaning member (cleaning blade 31), the application method depending on the use situation of the user can be selected. Can do.

  As a first example, in FIG. 3, the process cartridge includes a photoconductor 8, a cleaning blade 31 (cleaning member) that removes transfer residual toner and the like attached on the photoconductor 8, and a cleaning blade 31. The anti-scattering sheet 39 that prevents the transfer residual toner and the like scraped off in step 3, the powder transfer coil 32 that transfers the transfer residual toner, the solid lubricant 40, the solid lubricant holding member 41 that holds the solid lubricant, the solid The brush roller 43 (lubricant shaving and lubricant supply member) for shaving and applying the lubricant to the photoreceptor 8, the lubricant pressing spring 42 for pressing the solid lubricant against the brush roller 43, and the photoreceptor 8 are supplied. Lubricant leveling blade 44 (lubricant leveling member) for leveling the lubricant and applying the thin film, a charging roller pressing spring 36 for pressing the charging roller 9 against the photosensitive member 8, a charging low Charging cleaner roller 37 for cleaning the surface 9, a charging cleaner roller pressing spring 38 for pressing the charging cleaner roller 37 to the charging roller 9, a configuration in which a.

The rotation direction of the brush roller 43 in FIG. 3 is not limited, and the arrangement of the solid lubricant 40 is not limited.
In the case of the layout of FIG. 3, the solid lubricant 40 is applied downstream of the cleaning blade 31 and uses two blades (the cleaning blade 31 and the lubricant leveling blade 44).
In this configuration, the lubricant is supplied to the surface of the photoconductor 8 after being cleaned by the cleaning blade 31 by the lubricant supply member (brush roller 40), so that the lubricant is not affected by foreign matters such as transfer residual toner. It becomes possible to supply without.
As a result, the lubricant can be evenly supplied to the surface of the photoconductor 8 even under the condition of continuous output with a large image area where the transfer residual toner is the largest among the use conditions of the user, and the function of the cleaning blade 31 is impaired. In addition, it is possible to suppress the occurrence of streak-like smeared images in the sheet passing direction due to poor cleaning (higher cleaning function and higher reliability).
In addition, by applying the lubricant to the photoconductor 8 without unevenness, the life of the cleaning blade is also extended (longer cleaning life).
However, in order to apply the solid lubricant 40 downstream of the cleaning blade 31, the lubricant leveling blade 44 for leveling the thickness of the solid lubricant 40 is required, and the cost increases accordingly.

FIG. 4 shows a method in which the solid lubricant 40 is applied upstream of the cleaning blade 31, and one blade (cleaning blade 31) is used.
For users who mainly output low image area ratios such as general office documents, high cleaning performance is unnecessary, such as a method in which lubricant is applied upstream of the cleaning member or a method in which no lubricant is used. A sufficient function can be obtained with an inexpensive configuration.
That is, in the configuration of FIG. 4, since the cleaning blade 43 performs both cleaning and lubricant leveling after applying the lubricant by the cleaning roller 43, the lubricant leveling required in the case of FIG. However, although the blade 44 is not required and the cost is lower than that in FIG. 3, since the lubricant is not uniformly applied, the life of the cleaning blade 31 is reduced and the cleaning property is also reduced.

Further, FIG. 5 is a method in which a solid lubricant is not disposed, and the cleaning property is low, but the cost can be suppressed.
In this way, by selecting the lubricant application method according to how it is used, it is possible to supply the optimum process cartridge according to the use situation of the user, and it is inexpensive because the same frame can be used, In addition, an image forming apparatus excellent in maintainability can be provided.
Furthermore, since the method shown in FIGS. 3, 4, and 5 uses the same frame, the frame can be recycled and any lubricant application method can be reused.
Also, any of the configurations shown in FIGS. 3, 4, and 5 can be selected, and can be changed according to the use state of the user. For example, for a user who frequently uses monochrome printing, black can be configured as shown in FIG. 3 to improve cleaning performance, and color can be configured as shown in FIG. 4 to reduce costs. Further, in the case of a user who mainly outputs a large image area such as a poster or a flyer, the color ratio becomes high, so that the cleaning property can be improved by changing the configuration of all colors to the configuration of FIG.
The configuration of the present invention is effective even for a monochrome machine.

  For example, in the case where continuous output with a large image area, which tends to impair the cleaning function, is used, the maintenance cost and running cost can be reduced by extending the life with the configuration shown in FIG. Further, when a low image and intermittent output are frequently used as in a document output in a general office, the running cost can be reduced by suppressing the cost of the cleaning device with the configuration of FIG. 4 or 5. With the configuration of the present invention, it is possible to easily replace the cleaning device depending on the usage status of each user, and it is possible to obtain an optimal configuration according to the usage status of the user.

In this example, the solid lubricant and the solid lubricant holding plate are attached and integrated.
3 and 4, a solid lubricant is used, but the effect of the present invention is not limited to the solid lubricant. For example, the same effect can be obtained in a configuration in which a powder lubricant or a solid and powder lubricant is used in combination.
By using the following fatty acid metal salt or inorganic lubricant as the lubricant, it is possible to achieve high durability, high reliability, and long life of the cleaning property.
Examples of fatty acid metal salts include barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, zinc stearate , Zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, aluminum palmitate, palmitate Calcium acid, lead caprylate, lead caprate, zinc linolenate, cobalt linolenate, calcium linolenate, zinc ricinoleate, cadmium ricinoleate and mixtures thereof However, the present invention is not limited to this. Moreover, you may mix and use these. In the present invention, zinc stearate is most preferably used since it is particularly excellent in film formability on an image carrier.
When the lubricant contains a fatty acid metal salt, the effect of protecting the image carrier and reducing the cleaning failure is particularly great.

The inorganic lubricant in the present invention refers to an inorganic compound that cleaves and lubricates itself or causes internal slip. Specific examples include talc, mica, boron nitride, molybdenum disulfide, tungsten disulfide, kaolin, smectite, hydrotalcite compound, calcium fluoride, graphite, plate-like alumina, sericite, and synthetic mica. However, it is not limited to this. Among them, boron nitride is most preferable in the present invention because hexagonal mesh surfaces in which atoms are firmly combined overlap with each other at a wide interval, and the force acting between the layers is only weak van der Waals force. Used.
When an inorganic lubricant is contained in the solid lubricant, the effect of reducing deterioration with time of the blade, the effect of reducing deterioration with time of the charging roller, and the effect of reducing cleaning defects are particularly great.
Further, when boron nitride is used among the inorganic lubricants, the effect of reducing deterioration with time of the blade, the effect of reducing deterioration with time of the charging roller, and the effect of reducing cleaning defects are particularly great.
These inorganic lubricants may be surface-treated as necessary for the purpose of imparting hydrophobicity.

Further, a larger effect can be obtained by applying or attaching both the fatty acid metal salt and the inorganic lubricant. That is, since the deterioration over time of the image carrier and the peripheral parts of the image carrier can be improved together, a very great effect can be obtained in improving the life of the peripheral parts including the image carrier.
Further, by using zinc stearate as the fatty acid metal salt and boron nitride as the inorganic lubricant, a great effect can be obtained particularly in improving the life of peripheral parts including the image carrier.

DESCRIPTION OF SYMBOLS 1 Color printer, 2 Main body case, 3 Printer engine, 4 Optical writing device, 5 Paper feed cassette, 6 Fixing device, 7 Waste toner collection container, 8 Photoconductor, 9 Charging roller, 10 Developing device, 11 Cleaning device, 12 Primary transfer roller, 13 Intermediate transfer belt, 13a Belt case, 14 Secondary transfer roller, 15 Cleaning device, 16 Drive roller, 17 Inlet roller, 18 Tension roller, 19 Transport roller, 20 Registration roller, 21 Paper discharge tray, 22 Case , 23 process cartridge, 24 side cover, 30 frame, 31 cleaning blade, 32 powder conveying coil, 36 charging roller pressing spring, 37 charging cleaner roller, 38 charging cleaner roller pressing spring, 39 scattering prevention sheet, 40 solid lubricant , 41 Solid lubrication Holding member, 42 a lubricant pressure spring, 43 brush roller, 44 a blade

JP 2009-15034 A

Claims (9)

An image carrier;
A cleaning member that comes into contact with the surface of the image carrier and cleans foreign matter, a lubricant supply member that supplies a lubricant to the image carrier, and at least the cleaning member, the lubricant supply member, and the image carrier. A cleaning device including a supporting frame,
The frame includes regions for disposing the lubricant supply member on the upstream side and the downstream side in the rotation direction of the image carrier relative to the cleaning member, and the lubricant supply member is one of the regions. An image forming apparatus that can be arranged on a surface. The image forming apparatus according to claim 1.
When the lubricant supply member is disposed in the region downstream of the cleaning member in the rotation direction of the image carrier,
A lubricant leveling member that contacts the image carrier and equalizes the thickness of the lubricant applied by the lubricant supply member on the downstream side in the rotation direction of the image carrier relative to the cleaning member is formed on the frame body. An image forming apparatus characterized by being provided. The image forming apparatus according to claim 1.
When the lubricant supply member is disposed in the region upstream of the cleaning member in the rotation direction of the image carrier, the cleaning member equalizes the thickness of the lubricant applied by the lubricant supply member. An image forming apparatus.   4. The image forming apparatus according to claim 1, wherein the lubricant includes at least a fatty acid metal salt. 5.   4. The image forming apparatus according to claim 1, wherein at least an inorganic lubricant is used as the lubricant. 5.   4. The image forming apparatus according to claim 1, wherein a lubricant containing both a fatty acid metal salt and an inorganic lubricant is supplied to the image carrier.   7. The image forming apparatus according to claim 4, wherein the fatty acid metal salt is zinc stearate.   The image forming apparatus according to claim 5, wherein the inorganic lubricant is boron nitride. It is attached to and detached from the image forming apparatus according to any one of claims 1 to 8,
A process cartridge comprising at least the image carrier and the cleaning device.

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