JP6201295B2 - Cleaning device and image forming apparatus - Google Patents

Description

The present invention relates to a cleaning device that cleans an object to be cleaned with powder adhered to the surface, and an image forming device that forms an image using powdered toner .

  A technique is known in which powder is conveyed in a direction along the axis of the auger using an auger having a spiral wing body around a shaft that is driven to rotate about the axis. For example, in an image forming apparatus that uses toner that is powder and attaches toner to a latent image due to a difference in electrostatic potential to form a visible image, transport of a two-component developer containing toner or toner and a magnetic carrier An auger is used.

  The auger disclosed in Patent Document 1 has a wing body spiraled around a shaft body, and the length over which the wing body projects from the cylindrical shaft body changes along the spiral. It is. Due to the change in the overhang length of the wing body, the shape when viewed in the axial direction is almost elliptical. That is, the overhang length of the wing body changes with a period of a central angle of 180 ° along the spiral.

JP 2006-119549 A

  An object of the present invention is to provide a cleaning device and an image forming apparatus using an auger that can suppress vibrations when driven to rotate about an axis.

In order to solve the above-mentioned problem, the invention according to claim 1 is arranged to face an image holding body on which an image is formed by adhesion of powdery toner or an intermediate transfer body to which the image is transferred, and the image A cleaning member that removes the toner adhering to the holding member or the intermediate transfer member to clean the surface of the image holding member or the intermediate transfer member; and the toner removed and collected by the cleaning member A conveying member that conveys the shaft , the conveying member being rotated around a central axis, and a predetermined central angle around the central axis that projects spirally from the outer peripheral surface of the axial member The length projected from the shaft body changes at a period of, and the shape when projected in the direction of the central axis of the shaft body has a plurality of maximum points of the projecting length in the circumferential direction. In front and back And a wing body in which the center length between adjacent maximum points in the projected shape is 120 ° or less, and the powder is conveyed. A cleaning device is provided which is disposed in a tubular conveyance path and is an auger in which the wing body comes into contact with the inner peripheral surface of the conveyance path by the deflection of the shaft body .

  According to a second aspect of the present invention, in the cleaning device according to the first aspect, the auger has a central angle that is a cycle in which the overhang length of the wing body changes is set larger than 90 ° and smaller than 540 °. Shall.

  The invention according to claim 3 is the cleaning device according to claim 1 or 2, wherein the blade body changes into a curved shape combining a sinusoidal curve or a quadratic curve in which the overhang length from the shaft body is continuous. It shall be.

According to a fourth aspect of the present invention, there is provided an image holding body on which a latent image is formed on a peripheral surface due to a difference in electrostatic potential, and developing a toner image by transferring powdery toner to the latent image on the image holding body. A developing device, a transfer device for directly transferring the toner image formed on the image carrier to a recording medium or transferring the toner image from the image carrier to an intermediate transfer member, and then transferring the toner image to the recording medium; and the image carrier Alternatively, the present invention provides an image forming apparatus having the cleaning device according to any one of claims 1 to 3 for removing and cleaning powdery toner adhering to an intermediate transfer member.

According to a fifth aspect of the present invention, there is provided an image carrier in which a latent image due to a difference in electrostatic potential is formed on an endless peripheral surface, and a toner image by transferring powdery toner to the latent image on the image carrier. A developing device that develops the toner image, a transfer device that directly transfers the toner image formed on the image carrier to a recording medium or transfers the toner image from the image carrier to an intermediate transfer member, and then to the recording medium; A cleaning device that removes and cleans the powdery toner adhering to the image carrier or the intermediate transfer member; and the toner collected by the cleaning device or the powdered toner discharged from the developing device; A transport path for transporting excess developer containing a magnetic carrier to the collection chamber; and an auger provided in the transport path for transporting the toner or the developer , wherein the auger is around a central axis. Driven to rotation And a length that projects from the shaft body in a cycle of a predetermined central angle around the central axis changes in the direction of the central axis of the shaft body. The projected shape has a plurality of maximum points of the overhang length in the circumferential direction, and the overhang length continuously decreases before and after the maximum point of the overhang length. A wing body whose center angle is 120 ° or less, and is disposed in a tubular conveyance path through which powder is conveyed, and the wing body is conveyed by the deflection of the shaft body An image forming apparatus that is in contact with an inner peripheral surface of a road is provided.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the auger has a central angle that is a cycle in which the overhang length of the wing body changes is set to be larger than 90 ° and smaller than 540 °. It shall be.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the fifth or sixth aspect, the wing body has a curved shape that is a combination of a sine curve or a quadratic curve in which an extension length from the shaft body is continuous. It shall change.

  In the cleaning device according to the first aspect of the present invention, it is possible to suppress vibration when the auger for transporting the toner is driven to rotate about the axis as compared with the case where this configuration is not provided.

  In the cleaning device according to the second aspect of the present invention, it is possible to improve the transportability of the powder as compared with the case where this configuration is not provided.

  In the cleaning device according to the third aspect of the present invention, the powder transportability can be improved compared to the case where the present configuration is not provided.

  In the image forming apparatus according to the fourth aspect of the present invention, it is possible to suppress vibration when the auger included in the cleaning device is rotationally driven around the axis, compared to the case where the present configuration is not provided.

  In the image forming apparatus according to the fifth aspect of the present invention, it is possible to suppress vibration when the auger for transporting the toner or developer is driven to rotate about the axis, as compared with the case where this configuration is not provided.

  In the image forming apparatus according to the sixth aspect of the present invention, the powder transportability can be improved as compared with the case where the present configuration is not provided.

  In the image forming apparatus according to the seventh aspect of the present invention, it is possible to improve the transportability of the powder as compared with the case where the present configuration is not provided.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a partial perspective view of an auger that can be used in the image forming apparatus shown in FIG. 1. FIG. 3 is a partial side view and an enlarged front view of the auger shown in FIG. 2. It is a schematic front view which shows the change of the length which the wing | blade body of the auger shown in FIG. 2 protrudes from a shaft body. It is a schematic front view which shows the change of the length which the wing body protrudes from a shaft body of the other example of the auger which can be used with the image forming apparatus of this invention . It is a schematic front view which shows the change of the length which the wing body protrudes from a shaft body of the other example of the auger which can be used with the image forming apparatus of this invention . It is a schematic front view which shows the change of the length which the wing body protrudes from a shaft body of the other example of the auger which can be used with the image forming apparatus of this invention . FIG. 4 is a schematic front view showing an example of an auger in which the length of the wing body changes and which is not applied to the image forming apparatus of the present invention . FIG. 7 is a schematic front view showing another example of an auger in which the length of the wing body changes and which is not applied to the image forming apparatus of the present invention . FIG. 7 is a schematic front view showing another example of an auger in which the length of the wing body changes and which is not applied to the image forming apparatus of the present invention . FIG. 6 is a schematic front view showing another example of an auger in which the length of the wing body changes, which is applied to the image forming apparatus of the present invention . FIG. 7 is a schematic front view showing another example of an auger in which the length of the wing body changes and which is not applied to the image forming apparatus of the present invention . FIG. 6 is a schematic front view showing another example of an auger in which the length of the wing body changes, which is applied to the image forming apparatus of the present invention . FIG. 2 is a schematic configuration diagram of a cleaning device for an intermediate transfer belt that is an embodiment of the present invention and can be used in the image forming apparatus illustrated in FIG. 1.

Hereinafter, embodiments of the invention according to the present application will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.
This image forming apparatus forms a color image using four colors of toner, and outputs an image of each color of yellow (Y), magenta (M), cyan (C), and black (K). The image forming units 10Y, 10M, 10C, and 10K of the type are provided, and an intermediate transfer belt 11 that functions as an intermediate transfer member is provided opposite to these. The intermediate transfer belt 11 is stretched so as to face each of the image forming units 10 by a plurality of roll-shaped members, and the circumferential surface thereof is driven to rotate. On the intermediate transfer belt 11, the toner images of the respective colors are superimposed and primarily transferred from the photosensitive drum 1 included in each image forming unit 10. On the downstream side of the position where primary transfer is performed in the circumferential movement direction of the intermediate transfer belt, a secondary transfer roll 21 for performing secondary transfer is disposed so as to face the intermediate transfer belt 11. At the secondary transfer position 22 where the secondary transfer roll 21 faces the intermediate transfer belt 11, the sheet-like recording medium is sent to the secondary transfer position 22 from the sheet storage portion 23 through the sheet conveyance path 24. Yes. A fixing device 25 for fixing the toner image on the recording medium by heating and pressing the toner image is provided downstream of the secondary transfer position 22 in the recording medium conveyance path. Further, a paper discharge holding unit (not shown) that holds the recording medium with the toner image fixed thereon is provided on the downstream side.
On the other hand, the toner remaining on the photosensitive drum 1 after the primary transfer is scraped off by the cleaning device 6 for the photosensitive drum and is sent into the storage chamber 32 by the conveyance path 31.

  The image forming unit 10 includes an image forming unit 10Y for forming a yellow toner image, an image forming unit 10M for forming a magenta toner image, and a cyan toner image in order from the upstream side in the circumferential movement direction of the intermediate transfer belt 11. An image forming unit 10C for forming and an image forming unit 10K for forming a black toner image are arranged. Each of the image forming units 10 has a photosensitive drum 1 that functions as an image holding member with an electrostatic latent image formed on the surface, and the photosensitive drum 1 is provided around each photosensitive drum 1. A charging device 2 that charges the surface of the photosensitive drum 1, an exposure device 3 that irradiates the charged photosensitive drum 1 with image light based on an image signal, and a latent image formed on the photosensitive drum. Are selectively transferred to the developing device 4 for forming a toner image, a primary transfer roll 5 for primary transfer of the toner image on the photosensitive drum 1 onto the intermediate transfer belt 11, and the photosensitive drum 1 after transfer. And a photosensitive drum cleaning device 6 for removing residual toner.

  The photoreceptor drum 1 is formed by laminating an organic photoreceptor layer on the peripheral surface of a metal cylindrical member, and the metal portion is electrically grounded. Moreover, a voltage may be applied.

The charging device 2 is a charging roll disposed in contact with the peripheral surface of the photosensitive drum 1 that is a member to be charged. A voltage is applied to the charging roll, and a minute gap between the charging roll and the photosensitive drum 1 is applied. The surface of the photosensitive drum 1 is charged by the electric discharge generated in the above.
In this embodiment, the charging roll that comes into contact with the photosensitive drum is used as described above, but it is also possible to use a blade-shaped member or a charging device that performs non-contact charging by corona discharge.

  The exposure device 3 uses an LED array in which LEDs blinking based on an image signal are arranged in the axial direction of the photosensitive drum 1, and irradiates light toward the surface of the photosensitive drum 1. . By this light irradiation, the electrostatic potential of the exposed portion of the charged photosensitive drum 1 is attenuated, and an electrostatic latent image corresponding to an image of each color is formed on the surface of the photosensitive drum 1. ing. An exposure device that scans the surface of the photosensitive drum with a blinking laser beam to form an electrostatic latent image can also be used.

  The developing device 4 uses a two-component developer containing toner and a magnetic carrier, and transfers the toner onto the photosensitive drum 1 at a position facing the photosensitive drum 1 to visualize the latent image. It is. Further, when the toner is consumed as the image is formed, the two-component developer containing only the toner or the toner and the magnetic carrier is replenished.

  The primary transfer roll 5 has an outer peripheral surface covered with a rubber material in which conductive particles are added to a metal core, and faces the photosensitive drum 1 for each of the image forming units 10Y, 10M, 10C, and 10K. It is arranged on the back side of the intermediate transfer belt 11 at the position. Then, a bias voltage for primary transfer is applied to the primary transfer roll 5, and an electric field for transfer is formed between the primary transfer roll 5 and the photosensitive drum 1. Thus, the toner image on the photosensitive drum 1 is electrostatically transferred to the passing intermediate transfer belt 11 at the primary transfer position where the photosensitive drum 1 and the primary transfer roll 5 face each other.

  The photosensitive drum cleaning device 6 is configured to remove toner remaining on the photosensitive drum 1 after transfer by a cleaning blade disposed in contact with the peripheral surface of the photosensitive drum 1. The toner removed from the photosensitive drum 1 is sent to the transport path 31, and the transport path 31 transports the fed toner toward the storage chamber 32. Further, when the developing device 4 supplies the two-component developer as the toner is consumed, the two-component developer discharged excessively is also fed into the conveying path 31 to clean the photosensitive drum. The toner discharged from the apparatus 6 is transported to the storage chamber 32 together with the toner.

The intermediate transfer belt 11 is formed by forming an endless film-like member in which a plurality of layers are stacked. Each layer is adjusted so as to have a predetermined surface resistivity by adding a substance such as carbon or an ion conductive substance to a resin material, for example.
Such an intermediate transfer belt 11 is supported by a rotationally driven drive roll 12, an adjustment roll 13 that adjusts the bias in the width direction of the intermediate transfer belt 11, and a position that faces the secondary transfer roll 21. It is stretched around a roll 14 and moves around in the direction of arrow A shown in FIG.

  The secondary transfer roll 21 contacts the intermediate transfer belt 11 and is disposed at a position facing the opposing roll 14 with the intermediate transfer belt 11 interposed therebetween. The intermediate transfer belt 11 rotates as it is driven to rotate. When a recording medium is fed between the intermediate transfer belt 11 and the secondary transfer roll 21, the recording medium is sandwiched and conveyed. A bias voltage for transfer is applied between the secondary transfer roll 21 and the opposing roll 14, and the toner image on the intermediate transfer belt 11 is transferred to the recording medium by the formed electric field.

  The fixing device 25 includes a heating roll 25a having a built-in heating source and a pressure roll 25b pressed against the heating roll 25a, and these are in contact with each other to form a nip portion. The recording medium to which the toner image has been transferred is fed into the nip portion, heated and pressed between the rotating heating roll 25a and the pressure roll 25b, and the toner image is pressed onto the recording medium. It has become.

  On the downstream side of the secondary transfer position 22 in the circumferential movement direction of the intermediate transfer belt 11 and on the upstream side of the position where the image forming unit 10 faces, a cleaning device 33 for the intermediate transfer belt is provided on the peripheral surface of the intermediate transfer belt 11. It is provided so as to face. By this intermediate transfer belt cleaning device 33, the toner remaining on the intermediate transfer belt 11 after the toner image is secondarily transferred is removed from the intermediate transfer belt 11 and collected. This toner is fed into the collection chamber 32 together with the toner or two-component developer conveyed through the conveyance path 31.

The conveyance path 31 is provided with an auger 40 that is rotationally driven around an axis inside a tubular member. The auger 40 can convey toner in the axial direction. The auger 40 has a wing body 42 that spirally protrudes from the circumferential surface of a shaft body 41 having a circular cross section, and is rotationally driven around an axis by a drive device 43. As a result, the toner in the transport path 31 having a tubular shape is transported to the collection chamber 32.
Note that when the conventional auger is driven to rotate, the shaft body may bend and deform due to the weight of the auger itself. That is, if it is supported at both ends, deflection occurs at the center. Accordingly, the auger may vibrate if the auger comes into contact with the peripheral surface in the conveyance path and the overhang length of the wing body of the auger changes.

FIG. 2 is a partial perspective view showing an example of the auger 40 that can be arranged in the conveyance path 31. FIG. 3 is a partial side view of the auger 40 and an enlarged front view, that is, a view of the auger 40 viewed in the axial direction.
In the auger 40, the overhang length of the wing body 42 from the shaft body 41 changes along the spiral, and the overhang length periodically changes at every predetermined center angle around the axis. In the auger 40, the maximum length 42a is changed from the maximum point 42a at which the overhang length is maximized to the maximum point 42a with a period of a central angle of 225 °. When the auger is viewed in the axial direction, as shown in FIG. 3B, the maximum points 42a at which the overhang length is maximum are distributed in the circumferential direction of the auger 40. The central angle between the maximum points 42a adjacent to each other on the diagram projected in the direction is 45 °.
The diameter of the shaft body 41 of the auger 40 is 6 mm, the maximum overhang length of the wing body 42 is 4 mm, the minimum overhang length is 2 mm, the spiral pitch is 12 mm, and 29 pitches are formed in the entire length of the auger 40. . That is, every time the spiral wing body 42 makes a round around the shaft body 41, the spiral wing body 42 advances 12 mm in the axial direction, and the wing body 42 spirals around the shaft body 41 29 times.

  In this auger 40, as shown in FIG. 4, the spiral wing body 42 has a projecting length that decreases along the spiral from a reference maximum point 42a (0) where the projecting length is maximum, and a reference maximum point 42a (0). The overhanging length becomes the maximum again at the maximum point 42a (1) where the central angle between the two points is 225 °. Further, the overhang length sequentially changes around the central axis along the spiral at a cycle of every 225 °, and the maximum points 42a (2), 42a (3), 42a (4), 42a (5) of the overhang length every 225 °. 42a (6) and 42a (7) appear, and the maximum point 42a (8) in the eighth period overlaps with the reference maximum point 42a (0) in FIG. 4 in which the auger 40 is projected in the axial direction. That is, every five rotations (360 ° × 5 = 225 ° × 8) around the axis along the spiral wing body 42, the maximum points 42a of the eight overhang lengths are projected every 45 ° in the axial direction. Will appear in the distribution.

  When toner that is powder is transported using such an auger 40, propulsive force in the axial direction is applied to the toner in contact with the wing body 42 by rotation of the auger 40, but the overhang length of the wing body 42 is increased. Due to the change, the range in which the driving force is applied to the toner fluctuates periodically. As a result, it is possible to transport the toner, which is aggregated and formed into a lump shape, so as to loosen fluctuations in the range in which the driving force is applied. Further, the variation in the range in which the driving force is applied acts to agitate the toner having deteriorated fluidity. Therefore, good transportability is achieved even for toner that tends to agglomerate or has decreased fluidity due to an increase in temperature or an increase in the number of toners charged with a reverse polarity. Can be obtained.

Further, the conveyance path 31 provided with the auger 40 has an inner circumferential surface so as to surround all or a part of the auger 40 in the circumferential direction, and in order to obtain good conveyance properties, the tip and inner surfaces of the wing body 42 are formed. It is desirable to reduce the distance from the peripheral surface. For this reason, when a deflection occurs in the rotationally driven auger, it comes into contact with the inner peripheral surface of the conveyance path 31. At this time, when the auger is projected in the axial direction, the wing body has a long extension area and a short extension around the central axis, and if the central angle of the short extension area is large, this part is downward. When faced, the auger will flex greatly with its own weight. Then, due to the rotation of the auger around the axis, the portion with a large overhang length and the portion with a small overhang repeatedly face the lower part of the inner peripheral surface of the transport path, and the axis vibrates up and down.
However, in the auger 40 used in the image forming apparatus according to the present invention, the maximum points 42a of the overhang length are distributed in the circumferential direction in the drawing projected in the axial direction, and the central angle between the adjacent maximum points is 45 ° ( 120 degrees or less), the maximum point 42a of the overhang length of the wing body 42 comes in contact with the lower part of the inner peripheral surface of the conveyance path 31 one after another and the auger 40 is deflected when rotated around the axis. However, the amount of displacement is reduced and the vibration of the auger 40 is suppressed.
It should be noted that the effect of the present invention can be achieved with any value as long as the central angle between adjacent maximum points is 120 ° or less, but it is more preferably 90 ° or less, and more preferably 72 ° or less. .

  The central angle at which the wing body overhang length of the auger periodically changes is not limited to 225 °, and the maximum point of the wing body overhang length is 120 ° or less in the shape projected in the axial direction. Any other angle can be used as long as the angle is distributed over the entire circumference at intervals of. However, it is desirable to set the central angle at which the overhang length periodically changes to a value greater than 90 ° and less than 540 ° in order to maintain good toner transportability.

  The change in overhang length may be a discontinuous point, that is, the overhang length changes with an angle, or the overhang length may change due to a step, but it changes with a smooth continuous curve. Is desirable. For example, when the central angle is the horizontal axis and the vertical axis is the overhang length, it is desirable that the change in the overhang length is a sine curve, a combination of quadratic curves, or the like.

Next, an example in which the center angle at which the overhang length of the wing body 42 periodically changes is different from the above-described 225 °, which is applicable to the image forming apparatus of the present invention, and the image forming apparatus of the present invention. An example excluded from application will be described.
In the auger that can be used in the image forming apparatus of the present invention, the central angle at which the overhang length of the wing body periodically changes is, for example, 270 °, 288 °, 216 °, 144 °, 240 °, 480 °, or 120 °. It can be.
FIG. 5 is a view showing the shape of the auger 50 in which the projecting length of the spiral wing body periodically changes at each central angle of 270 °, as viewed in the axial direction thereof. In the auger 50, the maximum point 52a (1), 52a (2), 52a (3), and the maximum point 52a (2), 52a (3), each time it rotates 270 ° along the spiral from the reference maximum point 52a (0) where the maximum protrusion length is obtained. 52a (4), and the maximum point 52a of the overhang length overlaps the reference maximum point 52a (0) every time the spiral rotates three times around the axis. When the auger 50 is viewed in the axial direction, the maximum point 52a of the overhang length exists every 90 ° along the circumferential direction.

  FIG. 6 is a diagram showing the shape of the auger 60 in which the projecting length of the spiral wing body periodically changes at each central angle of 288 °, as viewed in the axial direction thereof. In this auger 60, every time the base length 62a (0) at which the overhang length becomes maximum is rotated by 288 ° along the spiral, the maximum points 62a (1), 62a (2), 62a (3), 62a (4) and 62a (5), and the maximum point 62a of the overhang length overlaps the reference maximum point 62a (0) every time the spiral rotates four times around the axis. When the auger 60 is viewed in the axial direction, the maximum point 62a of the overhang length exists every 72 ° along the circumferential direction. Similarly, when the center angle, which is the period at which the overhang length changes, is 144 ° or 216 °, the maximum point of the overhang length exists every 72 ° along the circumferential direction.

As shown in FIG. 7, in the auger 90 having a central angle of 240 °, which is a cycle in which the overhang length changes, there are three maximum points 92a of the overhang length. In this auger 90, adjacent maximum points 92a exist every 120 ° along the circumferential direction. Further, even when the central angle, which is the period at which the overhang length changes, is 120 °, 480 °, there are three positions where the overhang length is maximum in the circumferential direction, and the center angles between adjacent maximum points are all 120. °.
In this way, the maximum point of the overhang length appears for each angle that becomes the greatest common divisor of 360 ° with the central angle that makes the overhang length change.

  On the other hand, the case where the central angle that is the period in which the overhang length changes is 180 ° or 360 ° is excluded from the scope of the present invention. Moreover, there is a range excluded from the present invention before and after the above value. The range excluded from the present invention before and after the above value will be described later.

In an auger with a central angle of 180 °, which is the period at which the overhang length changes, the maximum point 72a of the overhang length is at two locations in the circumferential direction when the auger 70 is viewed in the axial direction as shown in FIG. These central angles are larger than 180 °, that is, 120 °. Therefore, it is not possible to suppress the auger 70 from being greatly deflected when the range in which the overhang length between the maximum overhang points 72a is reduced is downward, and vibration is likely to occur.
Further, in the auger having a central angle of 360 °, which is a cycle in which the overhang length changes, the maximum point 82a of the overhang length is one place in the circumferential direction as shown in FIG. Accordingly, it is not possible to suppress the deflection generated in the auger 80 as in the case where the central angle is 180 °.

In the auger 100 in which the central angle with which the overhang length changes is around 180 °, for example, 179 °, the shape projected in the axial direction of the auger 100 is as shown in FIG. In this auger 100, the overhang length becomes the maximum again at a point 102a (1) rotated by 179 ° along the spiral of the wing body 102 from the reference maximum point 102a (0) where the overhang length of the wing body 102 becomes the maximum. The overhang length from the maximum point 102a (0) to the point 102a (2) where the central angle is 2 ° in the spiral direction (clockwise in FIG. 10) and the opposite direction (counterclockwise in FIG. 10) of the wing body 102 Is the maximum. Then, every time it circulates around the axis along the spiral of the wing body 102, the direction of the spiral of the wing body (clockwise in FIG. 10) is reversed from the reference maximum point 102a (0) and the maximum point 102a (1). The overhang length of the wing body 102 is maximized at a position 2 ° apart in the direction (counterclockwise in FIG. 10). If the wing body 102 of the auger 100 is provided with 29 pitches in the axial direction of the auger 100, that is, if the wing body 102 makes 29 laps around the axis, the wing body starts from the reference maximum point 102a (0). The maximum point 102a of the overhang length of the wing body 102 is distributed in a region a1 having a central angle of 58 ° in a direction opposite to the spiral direction of 102 and a region a2 having a central angle of 58 ° from the maximum point 102a (1). Regions a3 and a4 deviating from these ranges, and in the region having a central angle of 123 °, there is no point at which the overhang length is maximum, and the central angle between the maximum points exceeds 120 ° It becomes. Therefore, in the auger 100, it is difficult to suppress the vibration when the auger 100 is rotationally driven in a state where the auger is generated, and is excluded from the application in the image forming apparatus of the present invention .

  However, in the auger 110 having a central angle of 178 ° as a cycle in which the overhang length changes, the reference maximum point 112a (0) and the reference maximum point 112a (0) follow the spiral of the wing body 112 as shown in FIG. Thus, the overhang length of the wing body is maximized at the point 112a (1) rotated by 178 °. From these points 112a (0) and 112a (1), the maximum point 112a of the overhang length appears at a central angle of 4 ° in the direction opposite to the spiral direction of the wing body and is distributed in the regions a5 and a6 of 116 °. . Accordingly, the regions a7 and a8 where the maximum point 112a of the overhang length does not exist are regions having a central angle of 66 °, and the central angle between the adjacent maximum points 112a is 120 ° or less, and are included in the scope of the present invention. It will be a thing.

On the other hand, when the center angle, which is the period at which the overhang length changes, is in a range around 360 °, for example, 355 °, the shape projected in the axial direction of the auger 120 is as shown in FIG. In this auger 120, the overhang length becomes the maximum again at the maximum point 122a (1) rotated 355 ° along the spiral of the wing body 122 from the reference maximum point 122a (0) at which the overhang length of the wing body 122 becomes the maximum. The maximum point 122a of the overhang length exists every time the central angle is sequentially separated from the maximum point 122a (0) by 5 ° in the direction opposite to the spiral direction of the wing body. Therefore, when the wing body 122 is formed so as to rotate 29 times around the axis along the entire length of the auger 120, the maximum point 122a of the overhang length is distributed in a region a9 having a central angle of 145 °. Further, the maximum point 122a of the overhang length does not exist in the area a10 having a central angle of 215 ° other than this area, and is excluded from application in the image forming apparatus of the present invention .

However, in the auger 130 having a central angle of 345 ° as a cycle in which the overhang length changes, as shown in FIG. 13, every 15 ° of central angle from the reference maximum point 132a (0) in the direction opposite to the spiral direction of the wing body. The maximum point 132a at which the overhang length of the wing body 132 becomes the maximum appears and is distributed in a region of 435 °. Accordingly, the maximum point 132a of the overhang length is distributed over the entire circumference in the circumferential direction of the auger 130, and is included in the auger that can be used in the image forming apparatus of the present invention .

As described above, the auger whose center angle, which is the cycle in which the overhang length changes, is 180 ° or 360 °, that is, the angle at which the greatest common divisor with 360 is larger than 120, and the cycle in which the overhang length changes. An auger whose central angle is a value that is before and after the above value and that is excluded by the above conditions is excluded from the scope of the present invention. Then, the central angle, which is the period at which the overhang length changes, is a value at which the greatest common divisor with 360 is 120 or less, that is, the greatest common divisor is 120, 90, 60, 45, 40, 30, 20, 15, 12, The image forming apparatus according to the present invention is an auger that is an angle between a value that is 10, 8, 6, 4, 3, 2, etc., a value that is mutually prime with 360, and that is not included in the above excluded conditions. It can be used in.
Further, in the above description, the central angle that becomes the period at which the overhang length changes does not consider the case of having a fraction of 1 ° or less, but the center angle that becomes the period at which the overhang length changes has a fraction of 1 ° or less. It is possible to determine what is included in the scope of the present invention and what is excluded from the scope of the present invention in light of the above excluded conditions.

The auger described above is arranged in the conveyance path 31 and conveys the toner or the two-component developer, but a similar auger can be used in the cleaning device of the present invention .
FIG. 14 is a schematic configuration diagram of the cleaning device 33 for the intermediate transfer belt used in the image forming apparatus shown in FIG. 1 according to an embodiment of the present invention. In this intermediate transfer belt cleaning device 33, an auger according to the present invention is used, and (a) shows a vertical section in a direction along the circumferential movement direction of the intermediate transfer belt 11, and (b) The figure shows a vertical section along the width direction of the intermediate transfer belt 11.

The cleaning device 33 for the intermediate transfer belt includes a cleaning blade 34 that scrapes off residual toner that comes in contact with the peripheral surface of the intermediate transfer belt 11 and a housing that temporarily stores the toner collected from the intermediate transfer belt 11. 35 and an auger 36 disposed in the housing 35 so as to have an axis in the width direction of the intermediate transfer belt 11.
Similar to the auger 40 shown in FIGS. 2 and 3, the auger 36 has a wing body that spirally projects around a shaft body having a circular cross section. And the overhang | projection length from the shaft body of this wing | blade body changes along a spiral. The central angle, which is the cycle in which the overhang length of the wing body changes, can be determined in the same manner as the auger shown in FIGS. 2 and 3, and can be set to 225 °, 270 °, 288 °, for example. Therefore, the shape of the wing body projected in the axial direction of the shaft body has a plurality of maximum points in the circumferential direction where the overhang length of the wing body is maximum, and the shape projected in the axial direction is between the adjacent maximum points. Each of the central angles of the angle is 120 ° or less.

In the cleaning device 33, the toner scraped off from the intermediate transfer belt 11 by the cleaning blade 34 is temporarily stored in the housing 35, and the auger 36 is driven to rotate in the axial direction of the auger 36, that is, the width direction of the intermediate transfer belt 11. It is conveyed to. At this time, the toner includes a toner remaining without being transferred at the secondary transfer position, a toner scraped from a patch image transferred onto the intermediate transfer belt 11, and the like, and is liable to cause condensation and fluidity deterioration. However, it is smoothly conveyed in the axial direction by the auger 36.
By being conveyed by this auger 36, it is carried out from the housing 35 of the cleaning device 33 for the intermediate transfer belt, and sent into the storage chamber 32 through the toner dropping portion 37.

On the other hand, in the photosensitive drum cleaning device 6 that removes the toner remaining on the photosensitive drum 1 after the primary transfer of the toner image, the toner can be conveyed using the auger 6a similar to the above . The toner removed from the photosensitive drum 1 can be sent to the conveyance path 31. The toner sent to the transport path 31 is further transported by the auger 40 and sent to the storage chamber 32.

In the embodiment described above, the auger conveys the toner or the two-component developer, but the auger is not limited to the above-mentioned use, and is widely applied to the one that conveys powder. be able to. Needless to say, the present invention can also be applied to a material for conveying a fluid such as a kneaded material such as an auger used in a so-called extrusion molding apparatus. Further, the image forming apparatus using the powdered toner is not limited to the one used in the cleaning device or the transport path, and it is necessary to transport the powdered toner or the two-component developer. Can be used at the site. In particular, when the auger is used in an image forming apparatus, vibration when rotating around the central axis of the auger can be suppressed, so that image quality disturbance due to vibration can be suppressed.

1: Photosensitive drum, 2: Charging device, 3: Exposure device, 4: Developing device, 5: Primary transfer roll, 6: Cleaning device for photosensitive drum, 6a: Cleaning device for photosensitive drum Auger, 10: image forming unit, 11: intermediate transfer belt, 12: drive roll, 13: adjustment roll, 14: counter roll,
21: secondary transfer roll, 22: secondary transfer position, 23: sheet storage unit, 24: sheet conveyance path, 25: fixing device, 25a: heating roll, 25b: pressure roll,
31: Conveying path, 32: Storage chamber, 33: Cleaning device for intermediate transfer belt, 34: Cleaning blade, 35: Housing, 36: Auger, 37: Toner dropping part, 40, 50, 60, 70, 80, 90 , 100, 110, 120, 130: auger 41, 51, 61, 71, 81, 91, 101, 111, 121, 131: shaft of auger, 42, 52, 62, 72, 82, 92, 102, 112, 122, 132: auger wing body, 42a, 52a, 62a, 72a, 82a, 92a, 102a, 112a, 122a, 132a: maximum point of wing body overhang length,

Claims (7)

The toner that is disposed opposite to an image carrier on which an image is formed by adhesion of powdery toner or an intermediate transfer member to which the image is transferred, and adheres on the image carrier or the intermediate transfer member A cleaning member for removing the surface and cleaning the surface of the image carrier or the intermediate transfer member;
A conveying member that conveys the toner removed and collected by the cleaning member,
The conveying member is
A shaft driven to rotate around the central axis,
A shape when projecting in the direction of the central axis of the shaft body, the length projecting spirally from the outer peripheral surface of the shaft body, the length projecting from the shaft body changes at a predetermined central angle around the central axis However, there are a plurality of maximum points of the overhang length in the circumferential direction, the overhang length continuously decreases before and after the maximum point of the overhang length, and the central angle between the adjacent maximum points in the projected shape is Each of which has a wing body of 120 ° or less,
A cleaning device, wherein the cleaning device is an auger disposed in a tubular conveyance path through which powder is conveyed, wherein the blade body is in contact with an inner peripheral surface of the conveyance path by bending of the shaft body . 2. The cleaning device according to claim 1, wherein the auger is set such that a central angle that is a cycle in which the overhang length of the wing body changes is set to be larger than 90 ° and smaller than 540 ° . The cleaning device according to claim 1, wherein the wing body changes in a curved shape in which a protruding length from the shaft body is a combination of a continuous sine curve or a quadratic curve . An image carrier on which a latent image due to a difference in electrostatic potential is formed on the peripheral surface;
A developing device for transferring a powdery toner to a latent image on the image carrier and developing the toner image;
A transfer device for directly transferring the toner image formed on the image carrier to a recording medium or transferring the toner image from the image carrier to an intermediate transfer member and then transferring the toner image to the recording medium;
An image having a cleaning device according to any one of claims 1 to 3, wherein the cleaning is performed by removing powdery toner adhering to the image carrier or intermediate transfer member. Forming equipment. An image carrier on which a latent image is formed by an electrostatic potential difference on an endless peripheral surface;
A developing device for transferring a powdery toner to a latent image on the image carrier and developing the toner image;
A transfer device for directly transferring the toner image formed on the image carrier to a recording medium or transferring the toner image from the image carrier to an intermediate transfer member and then transferring the toner image to the recording medium;
A cleaning device for removing and cleaning powdery toner adhering to the image carrier or intermediate transfer member;
A transport path for transporting the toner collected by the cleaning device or excess developer discharged from the developing device and containing powdered toner and a magnetic carrier to a collection chamber;
An auger provided in the transport path and transporting the toner or the developer ,
The auger
A shaft driven to rotate around the central axis,
A shape when projecting in the direction of the central axis of the shaft body, the length projecting spirally from the outer peripheral surface of the shaft body, the length projecting from the shaft body changes at a predetermined central angle around the central axis However, there are a plurality of maximum points of the overhang length in the circumferential direction, the overhang length continuously decreases before and after the maximum point of the overhang length, and the central angle between the adjacent maximum points in the projected shape is Each of which has a wing body of 120 ° or less,
An image forming apparatus, wherein the image forming apparatus is disposed in a tubular conveyance path through which powder is conveyed, and the wing body is in contact with an inner peripheral surface of the conveyance path by bending of the shaft body .   The image forming apparatus according to claim 5, wherein the auger has a central angle that is a period in which a projecting length of the wing body is changed larger than 90 ° and smaller than 540 °.   The image forming apparatus according to claim 5, wherein the wing body changes in a curved shape in which a protruding length from the shaft body is a combination of a continuous sine curve or a quadratic curve. .

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