JP2008138807A - Gear, drive device, process cartridge, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear capable of serving as a fan by discharging or sucking air with saved space and at low cost. <P>SOLUTION: This gear 100 for the fan comprises a gear body 101 having gear parts 101a, 101b formed around a common rotating shaft and a propeller part 102 held on the rotating shaft and rotated integrally with the rotating shaft and detachably mounted on the rotating shaft. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gear, a driving device, a process cartridge, and an image forming apparatus, and more particularly to a technique for enabling cooling in a narrow space.

JP 7-319370 A

  Conventionally, in order to protect a heat-sensitive portion from a heat source, a fan is provided to discharge the surrounding hot air, or air is sucked from outside the apparatus to cool it. For example, Patent Document 1 discloses an image forming apparatus provided with a cooling fan that discharges heat generated by a fixing device to the outside of the apparatus.

  However, when the apparatus main body is small, there is a problem that there may be no space for adding a fan. Further, the configuration in which the fan is driven via a gear train or a pulley and a belt has a problem that the number of parts increases and the cost increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gear that can exhaust or intake air in a space-saving and low-cost manner and can serve as a fan.
Another object of the present invention is to provide a drive device, a process cartridge, and an image forming apparatus provided with the gear.

According to the present invention, there is provided a gear main body having a plurality of gear portions formed around a common rotating shaft, and rotating integrally with the rotating shaft held by the rotating shaft, and the rotating shaft. It is solved by being constituted by a propeller part provided in a removable manner.

  Further, the plurality of gear portions have different numbers of teeth, and the plurality of gear portions are formed at different positions in the axial direction with respect to the rotation shaft, and are adjacently formed at different positions in the axial direction. It is preferable that the propeller portion is disposed between the two gear portions.

  Further, it is preferable that the propeller portion has a through hole having a predetermined shape as a mounting portion to the rotation shaft, and the gear main body is provided with a fitting portion corresponding to the through hole on the rotation shaft.

  The cross-sectional shape of the through hole and the fitting portion in a direction perpendicular to the rotation axis is circular, and the inner diameter of the through hole is larger than the outer diameter of the largest gear portion of the plurality of gear portions. Small is preferable.

Further, it is preferable that a flow hole through which an air flow passes is provided on an end surface of at least one gear portion of the plurality of gear portions.
In addition, it is preferable that a tapered portion whose axial thickness increases from the outer periphery toward the inner periphery is formed on the end surface on the propeller portion side of at least one gear portion of the plurality of gear portions.

  Further, according to the present invention, there is provided a gear according to any one of claims 1 to 6, wherein the gear includes a driving source and a gear that receives driving from the driving source, and the gear that receives driving from the driving source. Is preferable.

  The gear according to any one of claims 1 to 6, further comprising a gear driven via a transmission gear from a gear driven by the drive source, wherein the gear driven via the transmission gear. This is solved by the drive device characterized by this.

Preferably, a plurality of gears driven via the transmission gear are provided.
A first drive source, a second drive source, a gear according to any one of claims 1 to 6, wherein the first drive gear is driven by the first drive source, and The gear according to any one of claims 1 to 6, wherein the second drive gear receives driving from the second drive source, and the gear according to any one of claims 1 to 6, respectively. It is preferable to provide two gears driven by the second drive gear via the transmission gear.

  Further, it is preferable that the first drive gear, the second drive gear, and the two gears are arranged on a substantially straight line in a direction perpendicular to the rotation axis of the gear, with the rotation axes of the gears being parallel to each other.

  Further, according to the present invention, there is provided a process cartridge mounted with at least an image carrier and detachably attached to an image forming apparatus main body according to the present invention, wherein the process cartridge is a gear for driving the image carrier. The problem is solved by a process cartridge comprising the gear described in any one of the above items.

  In addition, according to the present invention, the above object is provided with the gear according to any one of claims 1 to 6, the drive device according to claims 7 to 11, or the process cartridge according to claim 12. The image forming apparatus is characterized by the above.

Preferably, the image carrier is driven by the gear according to any one of claims 1 to 6.
Further, it is preferable that a plurality of image carriers are provided, and each image carrier is driven by the gear according to any one of claims 1 to 6.

  A driving source for driving the image carrier for the black image; and an image carrier for forming a black image and an image carrier for forming an image of another color. It is preferable to separately provide a drive source for driving the image carrier for use.

  According to the gear of the present invention, a gear main body having a plurality of gear portions formed around a common rotating shaft, the gear main body being held by the rotating shaft and rotating integrally with the rotating shaft, Because it is composed of a detachable propeller unit, there is no need for a separate fan, and there is no need for gear trains, pulleys, belts, etc. to drive the fan. Alternatively, it is possible to realize a high-performance gear that can perform intake and can play the role of a fan at a low cost. In addition, a fan-shaped gear with a complicated shape can be created easily and at low cost. Furthermore, it is possible to form the gear body and the propeller portion from different materials.

  With the configuration of the second aspect, by arranging the propeller portion between the axial directions of the adjacent gear portions having different numbers of teeth, the propeller portion can be provided in a small space, and space saving can be realized.

  According to the configuration of the third aspect, the fitting portion provided on the rotating shaft and the through-hole of the propeller portion can be fitted together so that both can be fitted and mounted, and the gear with the fan can be configured at low cost.

According to the configuration of the fourth aspect, since the propeller portion is smaller than the outer diameter of the maximum diameter gear portion, the propeller can be used in a small space.
According to the configuration of the fifth aspect, since the flow hole through which the airflow passes is provided in the end face of at least one gear portion, the weight of the gear can be reduced and the flow of air generated in the propeller portion can be made smooth. it can.

According to the configuration of the sixth aspect, since the tapered portion is formed on the end face of at least one gear portion, the flow of air generated in the propeller portion can be made smooth.
According to the drive device of claim 7, since the gear driven by the drive source is the high-performance gear according to the present invention, even if the drive device has a limited space, the driven device can be driven without adding a fan separately. It is possible to cool the object easily and at low cost.

With the configuration of the eighth aspect, the plurality of driven objects can be effectively cooled by the high-performance gear according to the present invention.
With the structure of the ninth aspect, it is possible to effectively cool a large number of driven objects by the high-performance gear according to the present invention.

  According to the structure of the tenth aspect, for example, it is possible to suppress the consumption by dividing the driving source for a plurality of driven objects having different usage frequencies, and each driven object is effectively cooled by the high-performance gear according to the present invention. be able to. In addition, it is possible to provide a driving device particularly suitable for a color image forming apparatus including four image carriers.

According to the structure of the eleventh aspect, it is possible to provide a driving device particularly suitable for a tandem type color image forming apparatus in which four image carriers are arranged in series.
According to the process cartridge of the twelfth aspect, even if the process cartridge has no space, the image carrier and its peripheral devices can be effectively cooled by the high-performance gear according to the present invention. And cost reduction can be achieved.

  According to the image forming apparatus of the thirteenth aspect, the driven object can be effectively cooled by the highly functional gear according to the present invention, and the apparatus can be reduced in size and cost.

According to the structure of the fourteenth aspect, the image carrier can be cooled in a space-saving manner.
According to the configuration of the fifteenth aspect, in the apparatus configuration including a plurality of image carriers, the plurality of image carriers can be cooled in a space-saving manner.

  According to the configuration of the sixteenth aspect, it is possible to suppress wear by driving the image carrier for black images, which is frequently used, and the image carrier for other color images, by separate driving sources, and each image carrier. The space can be effectively cooled in a space-saving manner by the highly functional gear according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an example of a gear according to the present invention. The gear 100 shown in this figure is configured integrally with a gear body 101 having a first gear 101a and a second gear 101b as a gear with a fan, with a propeller 102 mounted. 2 shows the propeller 102 and FIG. 3 shows the gear 101 alone.

  As shown in FIG. 2, in the propeller 102 of this example, eight propeller blades 102b are implanted in a cylindrical base portion 102a having a through hole, and two claws are provided on the inner peripheral side of the base portion 102a. The part 102c is protrudingly provided.

  As shown in FIG. 3, the gear body 101 is a two-stage gear having a first gear 101a which is a large-diameter gear and a second gear 101b which is a small-diameter gear, and a part of the shaft portion is fitted with the propeller 102. Provided as a propeller fitting portion 101c. The propeller fitting portion 101c is formed with a claw fitting portion 101d into which the two claw portions 102c of the propeller 102 are fitted. Although only one claw fitting portion 101d is shown in the figure, a claw fitting portion 101d is also formed on the opposite side of the shaft. The propeller 102 is fitted into the gear body 101 by fitting the propeller 102 into the propeller fitting portion 101c of the gear body 101 and fitting the claw portion 102c into the claw fitting portion 101d. Is done.

  The propeller 102 is provided so as to be detachable from the gear main body 101. Thus, the fan-equipped gear 100 having a complicated shape can be easily configured by separately manufacturing and assembling the gear main body 101 and the propeller 102. In addition, the gear body 101 and the propeller 102 can be formed of different materials, and a fan-equipped gear can be realized easily and at low cost.

  Further, the relationship between the inner diameter of the cylindrical base portion 102a of the propeller 102 and the outer diameter of the propeller fitting portion 101c of the gear body 101 is set to such a size that both can be attached and detached and there is no backlash at the time of fitting. The air flow is made smooth.

  Further, the diameter (outer diameter) of the propeller 102 is smaller than the diameter (outer diameter) of the first gear 101a that is a large-diameter gear and larger than the diameter (outer diameter) of the second gear 101b that is a small-diameter gear. Is set. Thereby, the propeller 102 does not protrude outside the first gear 101a on the axial projection surface of the gear 100, and a space-saving gear with a fan can be realized (the gear 100 with a fan is used in a space-saving manner. be able to).

  The fan-equipped gear 100 of the present example has a configuration in which a propeller 102 is integrally provided between a large-diameter gear 101a and a small-diameter gear 101b, which are two-stage gears, so that a gear for driving the fan is not provided. Rows, pulleys, belts, etc. are not required, and space-saving and low-cost exhaust or intake can be achieved, and a high-performance gear that can function as a fan can be realized at low cost.

FIG. 4 is a front view showing another example of the gear main body 101.
The gear main body 101B shown in this figure is provided with a plurality of through holes (air circulation) 101f in the end surface portion 101e of the first gear 101a which is a large-diameter gear. Except for providing the through hole 101f, it is the same as the gear body 101 described above. The through hole 101f can be set as appropriate. In the gear main body 101B of the present example, by providing the through hole 101f in the end surface portion 101e of the first gear 101a, the weight can be reduced while maintaining the strength of the gear, and air can pass through the through hole 101f by the propeller 102. The flow of the generated air flow can also be made smooth.

FIG. 5 is a front view showing still another example of the gear main body 101.
In the gear body 101C shown in this figure, a tapered portion 101g having an axial thickness increasing from the outer periphery toward the inner periphery is formed on one end (propeller side) end surface of the first gear 101a which is a large-diameter gear. Yes. Except for providing the taper portion 101g, it is the same as the gear body 101 described above. In the gear main body 101C of the present example, the tapered portion 101g is provided on one end (propeller side) end surface of the first gear 101a, thereby increasing the strength of the gear (particularly the first gear 101a) and the air flow generated by the propeller 102. Can be made smooth.

Next, an embodiment of a drive device using a fan gear according to the present invention will be described.
FIG. 6 is a front view showing an example of a drive device according to the present invention, and FIG. 7 is a plan view thereof. In the driving device 200 shown in these drawings, four fan gears 100-1 to 100-4 are rotatably mounted and supported on a housing 201 of the driving device.

  In the drawing, the leftmost fan-equipped gear 100-1 is rotationally driven by a motor 202 attached to the opposite side surface of the housing 201. In the drawing, the right three fan-equipped gears 100-2 to 100-4 are the middle (center of the three) fan-equipped gear 100-3 by a motor 203 attached to the opposite side surface of the housing 201. Further, the fan-equipped gears 100-3 and 102-4 on both sides are rotationally driven from the fan-equipped gear 100-3 via the transmission gears 204a and 204b.

  An input gear (not shown) of a driven member is meshed with each second gear 101b of each of the fan-equipped gears 100-1 to 100-4. Drive the drive member. The driven member is, for example, a photosensitive pair of an image forming apparatus, and the driving apparatus 200 of this example including four fan gears 100-1 to 100-4 is a tandem type image forming apparatus including four photosensitive members. It can be used as a drive device for the image forming unit.

As the gear main body of each of the gears 100-1 to 100-4 with the fans, any of the gear main bodies 101, 101B, and 101C described with reference to FIGS.
In the driving apparatus 200 of the present example configured as described above, since 100-1 to 100-4 are configured as fan gears according to the present invention, driven members (for example, photoconductors) driven by the respective gears are used. There is no need to provide a separate cooling fan to cool the drum, etc., and there is no need for additional gear trains, pulleys and belts to drive the cooling fan, and space-saving and low-cost cooling is achieved. It becomes possible.

Next, a process cartridge using a gear with a fan according to the present invention in a drive system will be described.
FIG. 8 is a cross-sectional configuration diagram illustrating an example of a process cartridge including a fan gear according to the present invention. A process cartridge 300 shown in this figure is configured such that a photosensitive drum 301 and a charging device 302, a developing device 303, and a cleaning device 304 arranged around the photosensitive drum 301 are integrally configured as a cartridge that can be attached to and detached from an image forming apparatus main body (not shown). It is.

  In the process cartridge 300 of this example, a gear (not shown) press-fitted into the photosensitive drum 301 is directly driven by a drive gear (not shown). Further, the charging roller 302a of the charging device 302 and the developing roller 303a of the developing device 303 are driven from a gear press-fitted into the photosensitive drum 301 via a transmission gear (not shown), and the toner supply roller 303b is further driven from the developing roller 303a. It is configured to drive. Here, the fan gear 100 according to the present invention described above is used as a drive gear for directly driving the gear press-fitted into the photosensitive drum 301. As the gear body of the fan-equipped gear 100, any of the gear bodies 101, 101B, 101C described with reference to FIGS.

  When the process cartridge 300 is mounted on the image forming apparatus main body (not shown), the fan-equipped gear 100 mounted on the process cartridge is connected to the drive system of the image forming apparatus main body, and is driven by the drive source (motor) of the image forming apparatus main body. The photosensitive drum 301, the charging roller 302a, the developing roller 303a, and the toner supply roller 303b are driven.

  In the process cartridge 300 of this example, the fan-equipped gear 100 according to the present invention is used as a drive gear for directly driving the photosensitive drum 301. Therefore, even if the process cartridge has no space, the photosensitive drum 301 and its drum The surrounding charging roller 302a, developing roller 303a and the like can be cooled, and the cost is not increased.

  The basic configuration of the image forming apparatus to which the process cartridge 300 of this example is attached is the same as that of a conventionally known train photograph system, and therefore the illustration and description of the overall configuration of the image forming apparatus and the like are omitted. .

  Next, a tandem type image forming apparatus provided with a plurality of image carriers (photoconductors), which uses the drive device described in FIGS. 6 and 7 as a drive system for the plurality of image carriers, will be described. To do.

  FIG. 9 is a cross-sectional view showing a schematic configuration of a tandem color printer including four photosensitive drums as a plurality of image carriers. The color printer 1 has a configuration in which a paper feeding unit 2 is provided at the lower part of the apparatus main body, and an image forming unit 3 is disposed above the paper feeding unit 2. A paper discharge tray 60 is formed on the upper surface of the apparatus. As shown by the broken line in the drawing, the recording paper is transported from the paper feeding unit 2, the image formed by the image forming unit 3 is transferred onto the paper, fixed by the fixing device 50, and discharged. The paper is discharged to the tray 60. Manual feed (symbol: c) is possible from the side of the apparatus, and discharge (symbol: d) to the side of the apparatus is also possible.

  The image forming unit 3 is provided with a transfer conveyance belt 21 that is disposed so as to be inclined so that the paper feed side is on the bottom and the paper discharge side is on the top. Four image forming units 4M, 4C, 4Y, and 4Bk for magenta (M), cyan (C), yellow (Y), and black (Bk) are arranged in order from the bottom along the upper running side of the transfer conveyance belt 21. They are arranged side by side.

  Each of the image forming units 4M, 4C, 4Y, and 4Bk includes a photosensitive drum 5 as an image carrier, and a charging device, a developing device, a cleaning device, and the like are provided around the photosensitive drum 5. The developing device is a two-component developing device composed of toner and carrier, and applies the toner carried on the developing roller to the photosensitive drum 5. Laser light from the optical writing device 8 is applied to the photosensitive drum 5 from between the charging roller and the developing roller.

  The upper running side of the transfer / conveying belt 21 is configured such that only the upper predetermined range thereof is brought into contact with the black image forming unit 4Bk and can be separated from the image forming units 4M, 4C, and 4Y. That is, in the case of color printing, the transfer conveyance belt 21 is held in contact with the four-color image forming units 4M, 4C, 4Y and 4Bk (photosensitive drums thereof), and in the case of black monochrome printing, the image forming unit 4Bk ( The photosensitive drum 2) is kept in contact with the transfer / conveying belt 21 only.

  As described above, generally, in the case of black monochrome printing (monochrome mode) that is most frequently used, the transfer conveyance belt 21 is brought into contact with only the black image forming unit 4Bk (photosensitive drum), and image forming units of other colors are used. By separating the belt 21 from the photosensitive drums 4M, 4C, and 4Y, it is not necessary to operate the imaging units 4M, 4C, and 4Y that are not necessary for forming a monochrome image. The life of the parts related to 4C and 4Y, in particular, the photoconductor drum is not reduced.

  The driving device 200 described with reference to FIGS. 6 and 7 is used as a driving device for driving the photosensitive drums 5 of the four image forming units 4M, 4C, 4Y, and 4Bk of the present embodiment. The gears 100-1 to 100-4 with the fan of the driving device 200 described above are engaged with the gears press-fitted into the respective photosensitive drums 5 of the respective color image forming units, so that the respective photosensitive drums 5 are rotationally driven.

  As described above, in this example, as described above with reference to FIGS. 6 and 7, with the leftmost fan, only the black image forming unit 4Bk (the photosensitive drum) can be driven in the frequently used monochrome mode. The gear 100-1 is driven by the motor 202, and the other three-color image forming units 4M, 4C, and 4Y (photosensitive drums) of the three fan-equipped gears 100-2 to 100-4 are driven by another motor 203. It is comprised so that it may drive.

  In the tandem type color printer of this example in which image forming units 4M, 4C, 4Y, 4Bk for four colors are arranged in a narrow space, the present invention is used as a driving device for driving each photosensitive drum 5 as a driven body. By using the driving device 200 having a fan-equipped gear, it becomes possible to cool the respective photosensitive drums 5 and surrounding devices by the gear-equipped fan 100 even when there is no space for providing a separate cooling fan. Realizes space-saving and low-cost cooling.

  As mentioned above, although this invention was demonstrated by the example of illustration, this invention is not limited to this. For example, a gear having a plurality of gear portions is not limited to a two-stage gear, and the present invention can be applied to a gear having three or more gear portions. Further, the present invention can be applied not only to the drive gear but also to a transmission gear or an intermediate gear. The gear portion is not limited to external teeth but may be internal teeth. Furthermore, it is possible to use a gear having an appropriate form of gear within the scope of the present invention, such as a helical gear as well as a spur gear.

  Further, the number of propeller blades is arbitrary, and the shape and the like can be appropriately changed. Moreover, when providing a through-hole in the end surface of a gearwheel, the number and shape are also arbitrary. The through hole is not limited to the first gear, and may be provided in the second gear if possible, or may be provided in both. The same applies to the case where there are three or more gear portions.

Further, the number of propeller blades is arbitrary, and the shape and the like can be appropriately changed. The outer diameter of the propeller can also be set according to the present invention.
In the drive device, the number of gears with fans to be mounted, the drive mode, and the like can be changed as appropriate. The driven member is not limited to the image carrier (photosensitive member) of the image forming apparatus, and the gear with a fan and the driving device of the present invention can be used for driving an arbitrary device of an arbitrary device.

In the process cartridge, devices mounted on the cartridge are arbitrary, and for example, an image carrier (photoconductor) and a developing device can be appropriately changed.
In the image forming apparatus, an image forming method or the like is arbitrary, and is not limited to the direct transfer method, and may be an intermediate transfer method. Further, the number of image carriers (photosensitive members) is not limited to four and is arbitrary. A configuration in which a plurality of developing devices are arranged around one image carrier (photosensitive member) or a configuration using a revolver type developing device is also possible. The gear with a fan and the driving device of the present invention can also be used for a monochrome device. The image forming apparatus is not limited to a printer, and may be a copier, a facsimile machine, or a multi-function machine having a plurality of functions.

It is a perspective view which shows an example of the gear which concerns on this invention. It is a front view of the propeller part with which the gear is provided. It is a top view of the gear main body of the gear. It is a front view which shows another example of a gear main body. It is a front view which shows another example of a gear main body. It is a front view which shows an example of the drive device which concerns on this invention. FIG. It is a cross-sectional block diagram which shows an example of the process cartridge which concerns on this invention. 1 is a cross-sectional view illustrating a schematic configuration of a tandem type color printer according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color printer 4 Image forming unit 5 Photosensitive drum 21 Transfer conveyance belt 100 Gear 101, 101B, 101C Gear main body 101a 1st gear (large diameter gear)
101b Second gear (small diameter gear)
101f Through hole (air flow)
101g Taper part 102 Propeller 200 Drive device 202, 203 Motor (drive source)
204a, 204b Transmission gear 300 Process cartridge 301 Photosensitive drum

Claims (16)

A gear body having a plurality of gear portions formed around a common rotating shaft;
A gear comprising: a propeller portion which is held by the rotating shaft and rotates integrally with the rotating shaft and which is detachably provided on the rotating shaft. The plurality of gear portions have different numbers of teeth, and the plurality of gear portions are formed at different positions in the axial direction with respect to the rotating shaft, and adjacent two formed at different positions in the axial direction. The gear according to claim 1, wherein the propeller portion is disposed between the two gear portions. The propeller part has a through hole of a predetermined shape as a mounting part to the rotating shaft,
The gear according to claim 1, wherein the gear main body is provided with a fitting portion corresponding to the through hole on the rotating shaft. The cross-sectional shape of the through hole and the fitting portion in a direction perpendicular to the rotation axis is circular, and the inner diameter of the through hole is smaller than the outer diameter of the largest gear portion of the plurality of gear portions. The gear according to claim 3, wherein: The gear according to claim 1, wherein a flow hole through which an airflow is passed is provided in an end face of at least one gear portion of the plurality of gear portions. The taper portion whose axial thickness increases from the outer periphery toward the inner periphery is formed on an end surface of at least one gear portion of the plurality of gear portions on the propeller portion side. The gear according to 1. A driving source and a gear that receives driving from the driving source;
The gear which receives a drive from the said drive source is a gear of any one of Claims 1-6, The drive device characterized by the above-mentioned. A gear that is driven via a transmission gear from a gear that is driven by the drive source, and the gear that is driven via the transmission gear is the gear according to any one of claims 1 to 6. The drive device according to claim 7, wherein the drive device is characterized. The drive device according to claim 8, comprising a plurality of gears driven via the transmission gear. A first drive source and a second drive source;
The first driving gear according to any one of claims 1 to 6, wherein the first driving gear receives driving from the first driving source,
The second driving gear according to any one of claims 1 to 6, wherein the second driving gear receives driving from the second driving source.
A drive apparatus comprising: the gear according to any one of claims 1 to 6 and two gears driven by the second drive gear via a transmission gear. The first drive gear, the second drive gear, and the two gears are arranged substantially in a straight line in a direction perpendicular to the rotation axis of the gear, with the rotation axes of the gears being parallel to each other. The drive device according to claim 10. 7. A process cartridge having at least an image carrier mounted thereon and detachably attached to the image forming apparatus main body, comprising the gear according to claim 1 as a gear for driving the image carrier. Process cartridge characterized by. An image forming apparatus comprising the gear according to claim 1, the drive device according to claim 7, or the process cartridge according to claim 12. The image forming apparatus according to claim 13, wherein the image carrier is driven by the gear according to claim 1. The image forming apparatus according to claim 13, further comprising a plurality of image carriers, wherein each image carrier is driven by the gear according to claim 1. An image carrier for forming a black image and an image carrier for forming an image of another color;
16. The image forming apparatus according to claim 15, further comprising a drive source that drives the image carrier for the black image and a drive source that drives the image carrier for the other color image.

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