JP7536559B2 - CLEANING DEVICE AND IMAGE FORMING APPARATUS - Google Patents

Description

The present invention relates to a cleaning device and an image forming device equipped with a cleaning device.

Conventionally, electrophotographic image forming devices are known that include a transfer belt or photosensitive drum as an image carrier that carries a toner image, and a cleaning means that collects toner remaining on the transfer belt or photosensitive drum. The cleaning means includes a frame and a cleaning blade that is in contact with the transfer belt or photosensitive drum and serves as a collection member for collecting toner remaining on the transfer belt or photosensitive drum.

Patent Document 1 discloses the configuration of an image forming device that includes a cleaning means having a transport member that transports toner collected from a photosensitive drum by a cleaning blade, and a storage section that stores the toner collected by the cleaning means. In Patent Document 1, the toner collected by the cleaning blade accumulates inside the frame, and then reaches a transport member that is positioned above the cleaning blade in the direction of gravity. Then, when the toner reaches the transport member, the toner is transported to the storage section by the transport member that rotates under the driving force.

JP 2016-218435 A

However, the configuration of Patent Document 1, in which the toner is transported by a transport member disposed above the cleaning blade in the direction of gravity, raises the following concerns. That is, when the toner itself has low fluidity, or in an environment in which the fluidity of the toner is reduced, such as a high-temperature, high-humidity environment, the toner collected from the photosensitive drum may aggregate before reaching the transport member, which may result in a decrease in cleaning performance.

The present invention aims to prevent deterioration of cleaning performance in an image forming device that transports toner using a transport member that is positioned above a recovery member that contacts an image carrier and recovers toner in the direction of gravity.

The present invention relates to a cleaning device for recovering toner remaining on an image carrier that carries a toner image, the cleaning device including a recovery member that contacts the image carrier to recover toner remaining on the image carrier, a transport member that transports the toner recovered by the recovery member, the transport member being disposed above a position where the recovery member contacts the image carrier in the direction of gravity, a rotatable stirring member that has flexibility and stirs the toner recovered by the recovery member, and a storage section that can store the toner recovered from the image carrier by the recovery member, the storage section being disposed in front of the transport member. and a storage section that stores the stirring member, wherein the transport member extends in the width direction of the image carrier perpendicular to the movement direction of the image carrier and transports toner in the width direction by rotating, the storage section has a wall that contacts the rotating stirring member, and the stirring member has a first state in which the end side in contact with the wall is deformed toward the upstream side in the rotation direction of the stirring member, and a second state in which the deformation of the end side is released by moving away from the wall, and the toner is supplied toward the transport member by the recoil when moving from the first state to the second state .

As described above, the present invention makes it possible to suppress deterioration of cleaning performance in an image forming device that transports toner using a transport member that is positioned above a recovery member that contacts an image carrier to recover toner in the direction of gravity.

FIG. 1 is a schematic cross-sectional view illustrating a configuration of an image forming apparatus. FIG. 2 is a schematic perspective view illustrating a configuration of an intermediate transfer unit. FIG. 2 is a schematic diagram illustrating a configuration of a driving side of an intermediate transfer unit. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a cleaning unit. 5A and 5B are schematic diagrams illustrating toner transport in a cleaning unit. 5A and 5B are schematic diagrams illustrating the relationship between a stirring member and a recovery member.

The following describes an embodiment of the present invention with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiment may be changed as appropriate depending on the configuration and various conditions of the device to which the invention is applied, and the scope of the invention is not intended to be limited to the following embodiment.

Example 1
[Image forming apparatus]
FIG. 1 is a schematic cross-sectional view showing the configuration of an image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment is a so-called tandem type image forming apparatus having a plurality of image forming units Sa to Sd. The first image forming unit Sa forms an image using toner of each color, namely, yellow (Y), the second image forming unit Sb forms an image using toner of each color, magenta (M), the third image forming unit Sc forms an image using toner of each color, cyan (C), and the fourth image forming unit Sd forms an image using toner of each color, namely, black (Bk). These four image forming units are arranged in a row at regular intervals, and the configuration of each image forming unit has many parts that are substantially the same except for the color of the toner contained therein. Therefore, in the following description, unless a particular distinction is required, the suffixes a, b, c, and d given to the reference numerals to indicate that the element is provided for one of the colors will be omitted and the description will be given generally.

The image forming section S has a photosensitive drum 1, which is a drum-shaped photosensitive member, a charging roller 2 as a charging means for charging the photosensitive drum 1, a developing means 4, and a drum cleaning means 6 (cleaning device). In this embodiment, the photosensitive drum 1, the charging roller 2, the developing means 4, and the drum cleaning means 6 are integrated into a cartridge to constitute a process cartridge 19 that is detachable from the main body of the image forming device 100.

The photosensitive drum 1 is an image carrier that carries a toner image, and is rotated at a predetermined process speed in the direction of the arrow R1 shown in the figure. The developing means 4 contains toner as a developer (non-magnetic one-component developer in this embodiment) and has a developing roller 41 as a developing member for developing a toner image on the photosensitive drum 1 with the toner, and a developer coating blade (not shown) as a developer regulating member. The toner contained in the developing means 4 is carried by the developing roller 41 at a position where the developer coating blade and the developing roller 41 face each other, and is then transported to the opposing portion (developing portion) of the photosensitive drum 1 and the developing roller 41 as the developing roller 41 rotates.

The drum cleaning means 6 is a means for collecting toner adhering to the photosensitive drum 1. The drum cleaning means 6 has a cleaning member such as a fur brush or a cleaning blade that comes into contact with the photosensitive drum 1, and a waste toner container that contains the toner and other waste removed from the photosensitive drum 1 by the cleaning member.

The exposure means 3 can be configured as a laser scanner unit that scans laser light using a polygon mirror, or an LED array, but in this embodiment, a laser scanner unit is used. As will be described in detail later, the exposure means 3 forms an electrostatic latent image on the surface of the photosensitive drum 1 by irradiating the photosensitive drum 1 with a scanning beam 18 modulated based on an image signal.

When the image forming operation is started by the control means (not shown) receiving an image signal, the photosensitive drum 1 is rotated. During the rotation process, the photosensitive drum 1 is uniformly charged to a predetermined potential (charging potential) with a predetermined polarity (negative polarity in this embodiment) by the charging roller 2 to which a voltage is applied from a charging power source (not shown), and is irradiated with a scanning beam 18 from the exposure means 3 in response to the image signal. As a result, an electrostatic latent image corresponding to each color component image of the target color image is formed in each image forming section S. Next, the electrostatic latent image is developed at the development position by the developing roller 41 to which a voltage is applied from a development power source (not shown), and is visualized as a toner image on the photosensitive drum 1.

In this embodiment, the normal charging polarity of the toner contained in the developing means 4 is negative. In this embodiment, the electrostatic latent image is reversely developed using toner charged to the same polarity as the charging polarity of the photosensitive drum by the charging member, but the present invention can also be applied to an image forming device in which the electrostatic latent image is positively developed using toner charged to the opposite polarity to the charging polarity of the photosensitive drum.

The intermediate transfer belt 71 (image carrier) is an endless, movable intermediate transfer body, and is positioned so as to contact each photosensitive drum 1 of each image forming unit S, and is tensioned by three rollers, a drive roller 72, a tension roller 73, and a driven roller 74, which are tensioning members. The intermediate transfer belt 71 is tensioned under a predetermined tension applied by the tension roller 73, and moves in the direction of the arrow R2 shown in the figure due to the rotation of the drive roller 72, which rotates by receiving a driving force. The intermediate transfer belt 71 in this embodiment is composed of multiple layers, which will be described in detail later.

The toner image formed on the photosensitive drum 1 is primarily transferred to the intermediate transfer belt 71 as it passes through the primary transfer section N1 where the photosensitive drum 1 and the intermediate transfer belt 71 come into contact. At this time, a voltage of the opposite polarity to the normal charging polarity of the toner (positive polarity in this embodiment) is applied to the primary transfer roller 5 from a primary transfer power source (not shown). Thereafter, the toner remaining on the photosensitive drum 1 without being primarily transferred to the intermediate transfer belt 71 is removed from the surface of the photosensitive drum 1 by being collected by the drum cleaning means 6. Here, the primary transfer roller 5 is provided at a position corresponding to the photosensitive drum 1 via the intermediate transfer belt 71, and is a primary transfer member (contact member) that contacts the inner circumferential surface of the intermediate transfer belt 71.

In this way, the toner images of each color formed at each image forming section S are transferred in sequence to the intermediate transfer belt 71 in a superimposed manner at each primary transfer section N1. As a result, four toner images of colors corresponding to the desired color image are formed on the intermediate transfer belt 71.

In accordance with the formation of an electrostatic latent image on the photosensitive drum 1 by the exposure means 3, the transfer material P loaded in the paper feed cassette 11 as a storage section is fed by the paper feed roller 12 as a paper feed means and then conveyed to the conveying roller 13. Then, in accordance with the timing at which the four-color toner image carried on the intermediate transfer belt 71 reaches the secondary transfer section N2 formed by the contact between the secondary transfer roller 8 and the intermediate transfer belt 71, the transfer material P is conveyed to the secondary transfer section N2 by the conveying roller 13. After that, the four-color toner images carried on the intermediate transfer belt 71 are secondarily transferred all at once onto the surface of the transfer material P, such as paper or an OHP sheet, fed by the paper feed roller 12.

The secondary transfer roller 8 is in contact with the outer peripheral surface of the intermediate transfer belt 71 and is pressed with a pressure of 50 N against the drive roller 72, which is positioned opposite the secondary transfer roller 8 via the intermediate transfer belt 71, forming the secondary transfer section N2. The four color toner images carried by the intermediate transfer belt 71 are secondarily transferred all at once to the surface of the transfer material P as they pass through the secondary transfer section N2. At this time, a voltage of the opposite polarity (positive polarity in this embodiment) to the normal charging polarity of the toner is applied to the secondary transfer roller 8 from a secondary transfer power source (not shown).

The transfer material P onto which the four-color toner image has been transferred by the secondary transfer is then heated and pressurized in the fixing means 10, whereby the four colors of toner are melted, mixed, and fixed to the transfer material P. Any toner remaining on the intermediate transfer belt 71 after the secondary transfer is cleaned and removed by the cleaning means 9 (recovery means) provided downstream of the secondary transfer section N2 in the direction of movement of the intermediate transfer belt 71.

The cleaning means 9 is a recovery member that contacts the outer peripheral surface of the intermediate transfer belt 71 at a position opposite the drive roller 72, and has an elastic blade 91 made of urethane rubber or the like. The toner recovered from the surface of the intermediate transfer belt 71 by the cleaning blade 91 is transported toward a recovery container 75 provided in an area formed by the inner peripheral surface of the intermediate transfer belt 71, and is recovered in the recovery container 75. In the following description, the cleaning blade 91 is simply referred to as the blade 91. The blade 91 is disposed at a position opposite the drive roller across the intermediate transfer belt 71. The blade 91 contacts the intermediate transfer belt 71 in a counter direction to the movement direction of the intermediate transfer belt 71.

In the image forming device 100 of this embodiment, a full-color print image is formed through the above operations.

Here, in the image forming apparatus 100 of this embodiment, the transfer material P is transported vertically upward with respect to the secondary transfer section N2 in the direction of gravity. In this embodiment, as shown in FIG. 1, the cleaning means 9 is disposed above the drive roller 72 in the direction of gravity.

In addition, in the image forming device 100 of this embodiment, the intermediate transfer belt 71, cleaning means 9, and collection container 75 are integrated into a unit, and are configured as an intermediate transfer unit 7 that can be detached from the main body of the image forming device 100.

The image forming operation in the image forming apparatus 100 of this embodiment has been described above using an example in which an image is formed using four image forming units Sa to Sd. However, the image forming apparatus 100 can also form a single color or full color image by forming an image using a desired single or multiple (not all) image forming units S.

[Intermediate transfer unit]
Next, the configuration of the intermediate transfer unit 7 will be described with reference to Figures 2, 3, and 4. Figure 2 is a perspective view showing an outline of the intermediate transfer unit 7. Here, for ease of explanation, the intermediate transfer belt 71 is omitted. Figure 3 is a schematic diagram of the intermediate transfer unit 7 in Figure 2 as viewed from the direction of the arrow AA in the figure, and is a simplified exploded schematic diagram for explaining the configuration of the cleaning means 9. Also, Figure 4 is a schematic cross-sectional view of the intermediate transfer unit 7 in Figure 2 as viewed from the direction of the arrow BB in the figure.

As shown in FIG. 2, the intermediate transfer unit 7 supports the intermediate transfer belt 71 by three tension rollers: a drive roller 72, a tension roller 73, and a driven roller 74. The drive roller 72 is supported by bearings 721 at both ends so that it can rotate freely, and rotates when a predetermined rotational driving force is transmitted from the device body to one end in the direction of the rotation axis. In the following description, the side to which the drive force is transmitted is referred to as the drive side (the side indicated by the arrow AA in FIG. 2), and the opposite side is referred to as the non-drive side (the side indicated by the arrow BB in FIG. 2). In this embodiment, the drive roller 72 is a roller obtained by pressing a metal shaft such as SUS into both ends of a pipe with a diameter of about 25 mm, which is made of an aluminum core covered with rubber in which carbon is dispersed as a conductive agent.

In this embodiment, the tension roller 73 is an aluminum metal rod with a diameter of about 25 mm, and bearings 731 are provided at both ends of the tension roller 73 in the direction of its rotation axis. The bearings 731 are biased by compression springs 732, which bias both ends of the tension roller 73 and apply a predetermined tension to the intermediate transfer belt 71. The driven roller 74 is an aluminum metal rod like the tension roller 73, and both ends are supported by bearings 741 so that it can rotate freely.

The primary transfer roller 5 is provided at a position corresponding to the photosensitive drum 1 across the intermediate transfer belt 71. The primary transfer roller 5 is supported by bearings 151 at both ends in the direction of the rotation axis, and is biased toward the intermediate transfer belt 71 with a predetermined force by a compression spring 152 via the bearings 151, and rotates in response to the rotation of the intermediate transfer belt 71. In this embodiment, the primary transfer roller 5 is a roller made of a metal shaft such as SUS with a diameter of about 6 mm. At least one of the bearings 151 provided on both ends is made of a conductive material, and a positive voltage is applied to the primary transfer roller 5 from a primary transfer power source (not shown), thereby performing primary transfer of a toner image from the photosensitive drum 1 to the intermediate transfer belt 71.

The intermediate transfer belt 71 may be made of rubber, resin, or the like. In this embodiment, the intermediate transfer belt 71 is an endless belt-like film made of a resin material with medium resistance and a thickness of about 60 μm in the thickness direction perpendicular to the direction of movement of the intermediate transfer belt 71 and the direction of the rotation axis of each agency Corolla.

The frame 76 is the frame of the intermediate transfer unit 7 that supports each tension roller, and is made of a molded resin material. The bearings 151 at both ends that support the primary transfer roller 5, and the bearings 731 at both ends that support the tension roller 73 are supported by the frame 76 in a state in which they can move relative to the frame 76 in the pressure direction of each compression spring.

Support plates 77 and 78 are provided near the drive roller 72 supported by the frame 76, which rotatably support the drive roller 72 and driven roller 74 via the respective bearings. The support plates 77 and 78 are fixed to the frame 76 with screws or the like, positioned at both ends of the drive roller 72 in the direction of the rotation axis. In this embodiment, pressed metal sheets are used for the support plates 77 and 78.

As will be described in detail later, as shown in Figures 2 to 4, the cleaning means 9 has a blade 91 as a cleaning member and a recovery section 92 that recovers the toner removed from the intermediate transfer belt 71 by the blade 91. The blade 91 and the recovery section 92 are fixed in position to the support plate 77 and the support plate 78, respectively.

The toner removed from the intermediate transfer belt 71 by the blade 91 is temporarily stored inside the recovery section 92. Then, after being transported inside the recovery section 92, it is collected in the recovery container 75 through a toner transport path 761 provided on the drive side of the frame 76 shown in FIG. 3. The toner transport path 761 is sealed by fastening a transport path cover 762 with screws or the like, thereby preventing toner from leaking to the outside in the intermediate transfer unit 7.

The collection container 75 is made of molded resin parts, and is configured as a container with a sealed periphery by adhering multiple resin parts together. The collection container 75 is fixed to the frame 76 with screws or the like. The collection container 75 is also provided with a detection means (not shown), such as an optical sensor, for detecting when the toner in the container is full. This makes it possible to notify the user when it is time to replace the collection container 75. A collection container 75 that is full can be replaced with a new one by a serviceman or the user by replacing the intermediate transfer unit 7.

[Cleaning Means]
As shown in Figures 2 to 4, as already described above, the cleaning means 9 has a blade 91 as a cleaning member, and a collection section 92 for temporarily storing the toner removed from the intermediate transfer belt 71 by the blade 91 and transporting it to the collection container 75.

As shown in FIG. 4, the blade 91 has elastic urethane rubber 91a and a retaining metal plate 91b to which the urethane rubber 91a is adhered. With respect to the longitudinal direction of the urethane rubber 91a (the direction of the rotation axis of the drive roller 72), the length of the urethane rubber 91a is set to a width longer than the image forming area capable of carrying a toner image on the intermediate transfer belt 71. The blade 91 is also positioned in pressure contact with the intermediate transfer belt 71, and is capable of removing toner remaining on the intermediate transfer belt 71.

Here, to ensure the removal of toner, it is necessary to press the blade 91 against the intermediate transfer belt 71 with a predetermined pressure. In this embodiment, the aforementioned predetermined pressure is ensured by arranging the blade 91 opposite at least one of the multiple tension rollers that tension the intermediate transfer belt 71. More specifically, the blade 91 is arranged so as to be in contact with the drive roller 72 at a position downstream of the secondary transfer section N2 in the movement direction of the intermediate transfer belt 71 and above the drive roller 72 in the direction of gravity.

In the longitudinal direction of the blade 91, holes 91c for rotatably supporting the blade 91 and spring hooks 91d for attaching a pressure spring to press the blade 91 against the intermediate transfer belt 71 are provided at both ends of the holding plate 91b. The blade 91 engages with metal blade support shafts 77a and 78a that are crimped to the support plates 77 and 78, respectively, via the holes 91c at both ends, and is supported in a rotatable state that allows it to move freely toward and away from the intermediate transfer belt 71.

Furthermore, spring hooks 91d provided at both ends of blade 91 in the longitudinal direction and spring hooks 92b provided at both ends of recovery section 92 in the longitudinal direction engage with hooks 93a and 93b provided at both ends of tension spring 93 in the expansion/contraction direction, respectively. More specifically, as shown in Figs. 3 and 4, spring hook 91d engages with hook 93a, and spring hook 92d engages with hook 93b, so that spring hook 91d and spring hook 92d are spanned by tension spring 93. As a result, a moment is generated by tension spring 93 around hole 91c on blade 91, and blade 91 is pressed against intermediate transfer belt 71 with a predetermined pressure.

In the recovery section 92, in order to prevent the toner recovered from the intermediate transfer belt 71 from leaking from the frame 94 of the recovery section 92 to the outside, a plurality of sealing members (not shown) are attached to the frame 94 with double-sided tape or the like. In addition, in terms of the movement direction of the intermediate transfer belt 71, upstream of the cleaning section CL where the blade 91 and the intermediate transfer belt 71 come into contact, a sheet member 44 that contacts the intermediate transfer belt 71 to seal the gap between the recovery section 92 and the intermediate transfer belt 71 is provided. The sheet member 44 as a sealing member is arranged to extend in the width direction of the intermediate transfer belt 71. With these configurations, in this embodiment, the toner that is primarily recovered in the recovery section 92 is transported to the recovery container 75 without leaking from the cleaning means 9 to the outside.

<Toner Transport in Transport Section>
4, the recovery unit 92 has a toner storage unit 92c capable of temporarily storing the toner removed by the blade 91, and a screw 92d as a transport member for transporting the stored toner in the longitudinal direction of the blade 91. Furthermore, the recovery unit 92 in this embodiment includes a sheet member 92e (agitating member) provided inside the toner storage unit 92c and continuously provided over substantially the entire area of the recovery unit 92c in the longitudinal direction of the blade 91, and a rotating shaft 92a.

The sheet member 92e is a flexible sheet member such as PET having a thickness of about 80 μm, and is fixed to the rotating shaft 92a that is provided extending throughout the entire interior of the recovery section 92 in the longitudinal direction of the blade 91, and can rotate on the rotating shaft 92a. The rotating shaft 92a is made of a resin member and has at least one flat surface a1 parallel to the extension direction of the a of the rotating shaft 92, and one end side of the sheet member 92c is fixed to the flat surface a1 with double-sided tape or the like (not shown). When viewed from the rotation axis direction of the rotating shaft 92a, the sheet member 92e has one end side fixed to the flat surface a1 in the radial direction of the rotation trajectory Rm of the sheet member 92e, and the other end side opposite to the one end side is a free end. Here, the rotation trajectory Rm is the rotation trajectory of the extreme end of the free end of the sheet member 92e.

The rotating shaft 92a has a third gear 82 for rotational drive disposed on one end of the shaft in the direction of the rotation axis. As shown in FIG. 2, the third gear 82 rotates in the clockwise direction in FIG. 4 by sequentially receiving driving forces from a first gear 80 disposed on the shaft end of the driving roller 72 at one end of the driving roller 72 in the direction of the rotation axis, and a second gear 81 engaged with the first gear 80. Furthermore, as shown in FIG. 4, when viewed from the direction of the rotation axis of the rotating shaft 92a, the center of the rotation axis of the rotating shaft 92a is disposed above the blade 91 and below the center of the rotation axis of the screw 92d in the direction of gravity.

The toner removed from the intermediate transfer belt 71 by the blade 91 after passing through the secondary transfer section N2 accumulates in the recovery section 92 at the cleaning section CL where the blade 91 and the intermediate transfer belt 71 come into contact, and around the sheet member 44. Here, in the configuration of this embodiment, the toner accumulated in the recovery section 92 is supplied to the screw 92d while being stirred by the rotating sheet member 92e. The mechanism by which the sheet member 92e supplies the toner to the screw 92d will be described in detail later.

The screw 92d has a spiral transport section 60 for transporting the toner supplied by the sheet member 92e in the direction of the arrow BB in FIG. 2 relative to the rotation axis direction (longitudinal direction) of the screw 92d. The screw 92d is held by a cylindrical holding section 92f in the recovery section 92. The holding section 92f extends in the rotation axis direction of the screw 92d and holds the screw 92d. The holding section 92f is not provided in an area 92g (open section) facing the sheet member 92e so that the toner supplied from the sheet member 92e can reach the transport section 60 of the screw 92d.

The screw 92d has a fourth gear 83 for transmitting drive power at the end on the non-drive side in the direction of the rotation axis. The fourth gear 83 is engaged with the third gear 82 that drives the seat member 92e, and can be rotated by the drive power transmitted via the first gear 80, the second gear 81, and the third gear 82.

When viewed from the direction of the rotation axis of the screw 92d, the toner storage unit 92c has a wall portion 92h near the sheet member 92e that has an arc shape concentric with the arc shape of the rotation trajectory Rm of the sheet member 92e. When viewed from the direction of the rotation axis of the screw 92d, the toner storage unit 92c also has a wall portion 92i that has a linear shape that continues from the end of the wall portion 92h on the side closer to the screw 92d toward the screw 92d. In this embodiment, the wall portion 92h and the wall portion 92i are members that constitute the frame of the toner storage unit 92c.

Furthermore, in the configuration of this embodiment, when viewed from the rotation axis direction of the screw 92d, the toner storage section 92c has a wall portion 92h downstream of the cleaning section CL and upstream of the screw 92d in the rotation direction of the sheet member 92e. The wall portion 92h is disposed inside the rotation locus Rm in the radial direction of the rotation locus Rm of the outermost periphery of the screw 92d. And, when viewed from the rotation axis direction of the screw 92d, the region 92g is disposed downstream of the wall portion 92h and upstream of the cleaning section CL in the rotation direction of the sheet member 92e.

In addition, a portion of the urethane rubber 91a is also positioned so as to be interposed inside the rotation locus Rm in the radial direction of the rotation locus Rm. Meanwhile, the sheet member 44 is positioned outside the rotation locus Rm of the free end of the sheet member 92e in the radial direction. With these configurations, the sheet member 92e rotates while interfering with the wall portion 92h and part of the blade 91, and also rotates while maintaining a constant distance from the sheet member 44. As a result, the toner contained in the toner storage section 92c can be more effectively agitated and the toner can be supplied to the screw 92d.

Next, the agitation of toner by sheet member 92e and the supply of toner to screw 92d will be described with reference to Figures 5(a) and (b). Figure 5(a) is a schematic cross-sectional view illustrating the transport of toner when wall portion 92h and sheet member 92e are in contact with each other as viewed from the direction of the rotation axis of screw 92d. Figure 5(b) is a schematic cross-sectional view illustrating the transport of toner when wall portion 92h and sheet member 92e are no longer in contact with each other as viewed from the direction of the rotation axis of screw 92d.

As described above, the outermost periphery of the free end of the sheet member 92e rotates clockwise along the rotation locus Rm. As shown in FIG. 5A, a portion of the upper surface (top surface) of the urethane rubber 91a in relation to the direction of gravity is positioned radially inward of the rotation locus Rm, so the sheet member 92e rotates so as to interfere with the top surface of the urethane rubber 91a. In other words, the sheet member 92e rotates while scraping off the toner accumulated on the top surface of the urethane rubber 91a.

Furthermore, as shown in FIG. 5(a), since the wall portion 92h is disposed radially inward of the rotation locus Rm, the sheet member 92e rotates while scooping up toner along the wall portion 92h. At this time, of the toner accumulated on the sheet member 44, the toner accumulated radially inward from the rotation locus Rm is scooped up and transported by the sheet member 92e. On the other hand, the toner accumulated radially outward from the rotation locus Rm near the sheet member 44 continues to remain on the upper side of the sheet member 44 in the direction of gravity.

In this state, when more toner is collected by the blade 91, the toner surface remaining on the sheet member 44 rises in the direction of gravity due to being pushed by the toner removed from the intermediate transfer belt 71 by the blade 91. Then, when the toner surface reaches the inside of the rotation trajectory Rm, it is scooped up by the rotating sheet member 92e. As a result, the toner remaining on the sheet member 44 is successively replaced.

As shown in FIG. 5A, the wall portion 92h is disposed radially inward from the rotation trajectory Rm of the free end of the sheet member 92e, so when the sheet member 92e rotates in contact with the wall portion 92h, it rotates while deforming toward the upstream side in the rotation direction of the sheet member 92e. More specifically, the end side (free end side) in contact with the wall portion 92h rotates in a deformed state (first state) in which it is deformed toward the upstream side in the rotation direction of the sheet member 92e. As a result, the toner is scooped up as shown in FIG. 5A while being prevented from falling from the sheet member 92e.

Next, as shown in FIG. 5B, when the free end of the sheet member 92e moves from the wall portion 92h to the position of the wall portion 92i, the sheet member 92e separates from the wall portion 92h, and the deformation of the end side (free end side) that was in contact with the wall portion 92h is released, resulting in a free state (second state). At this time, some of the toner T scooped up by the sheet member 92e flies from the sheet member 92e toward the screw 92d through the region 92g due to the reaction force of the sheet member 92e trying to return from the deformed state of FIG. 5A to the free state of FIG. 5B. After reaching the screw 92d, the flying toner T is transported toward the toner transport path 761 by the transport section 60 of the rotating screw 92d. In addition, any toner that does not fly due to the reaction of the sheet member 92e returning to its free state falls onto the top surface of the urethane rubber 91a as shown by the arrow in Figure 5 (b), and is then scooped up again by the rotating sheet member 92e.

The toner T transported by the transport unit 60 in the direction of the arrow BB in FIG. 2 relative to the rotation axis direction of the screw 92d reaches the toner transport path 761. As shown in FIG. 3, the toner transport path 761 is formed with a slope angle equal to or greater than the angle at which the toner T falls under its own weight. As a result, the toner T transported to the toner transport path 761 by the rotation of the screw 92d is transported to the entrance 763 of the collection container 75 under the toner's own weight.

The toner T transported to the entrance 763 is then diffused and filled in the collection container 75 by a toner diffusion member (not shown) that is arranged in the collection container 75 to fill the inside of the collection container 75 with toner. As the toner diffusion member, for example, a member such as a screw or paddle that has a spiral transport section and can transport toner by rotating, or an arm member or slide member that can diffuse toner by expanding and contracting in the axial direction, can be used.

As described above, according to the configuration of this embodiment, the sheet member 92e can agitate the toner collected by the blade 91 from the intermediate transfer belt 71 to the collection section 92, and supply the toner toward the screw 92d, which is disposed above the blade 91 in the direction of gravity. More specifically, the toner storage section 92c has a wall portion 92h disposed inside the rotation trajectory of the outermost periphery of the sheet member 92e when viewed from the direction of the rotation axis of the screw 92d. When the sheet member 92e rotates in contact with the wall portion 92h, the sheet member 92e scoops up and transports the toner with its free end deformed. Then, when the sheet member 92e and the wall portion 92h are separated and the deformed state of the sheet member 92e is released, the toner scooped up by the sheet member 92e flies toward the screw 92d due to the reaction of the sheet member 92e returning from the deformed state to the free state. In this way, with the configuration of this embodiment, it is possible to efficiently agitate the toner contained in the toner container 92c and transport it toward the screw 92d, thereby preventing a decrease in the cleaning performance of the cleaning means 9.

Figure 6(a) is a schematic cross-sectional view seen from the direction of the rotation axis of the rotating shaft 92a, explaining the state before the toner near the cleaning section CL is scraped off by the sheet member 92e. Also, Figure 6(b) is a schematic cross-sectional view seen from the direction of the rotation axis of the rotating shaft 92a, explaining the state after the toner near the cleaning section CL is scraped off by the sheet member 92e.

As shown in FIG. 6(a), in this embodiment, when viewed from the direction of the axis of rotation of the rotating shaft 92a, each member is arranged so that the area formed by the rotation locus Rm of the sheet member 92e overlaps with the blade 91. In other words, when viewed from the direction of the axis of rotation of the rotating shaft 92a, at least a portion of the area (area Rt in this embodiment) on the free end side of the blade 91 in the belt conveying direction overlaps with the area formed by the rotation locus Rm. As a result, as shown in FIG. 6(b), as the sheet member 92e rotates, a portion of the toner remaining near the blade 91 is conveyed by the sheet member 92e and supplied to the screw 92d.

In this embodiment, the blade 91 and the sheet member 92e are configured to come into contact with each other. The sheet member 92e is also configured from a soft material such as a PET sheet. This allows the toner transport area of the sheet member 92e to be maximized while minimizing the impact caused by the contact between the blade 91 and the sheet member 92e.

Here, if the sheet member 92e is brought too close to the blade 91, the length of contact between the sheet member 92e and the blade 91 will be long, and the contact time of the sheet member 92e will be long and the bent posture at the time of contact will be large. As a result, the pressure applied to the blade 91 by the rotation of the sheet member 92e will increase, which may lead to a decrease in cleaning performance. For this reason, in this embodiment, the contact area T of the blade 91 that the sheet member 92e contacts due to the rotation of the sheet member 92e is set to 1 mm. In order to suppress the above-mentioned decrease in cleaning performance, it is more preferable to set the contact distance T to 2 mm or less.

Here, in the image forming apparatus 100 of this embodiment, the transfer material P is transported vertically upward with respect to the secondary transfer section N2 in the direction of gravity. Also, in this embodiment, as shown in FIG. 1, the cleaning means 9 is arranged above the drive roller 72 in the direction of gravity. However, the transport direction of the transfer material P and the members arranged opposite the cleaning means 9 are not limited to the configuration described in this embodiment. As long as the configuration has at least the cleaning means 9 with the screw 92d arranged above the cleaning section CL in the direction of gravity, it is possible to obtain the same effect by adopting the configuration of this embodiment.

In addition, in the image forming apparatus 100 of this embodiment, the intermediate transfer belt 71, cleaning means 9, and collection container 75 are integrated into a unit, and are configured as an intermediate transfer unit 7 that can be attached to and detached from the main body of the image forming apparatus 100. However, this is not limited to the above, and the intermediate transfer unit and the collection container may each be configured as separate units, and only the intermediate transfer unit or the collection container may be replaced with respect to the main body of the image forming apparatus 100.

In this embodiment, each configuration of the cleaning means 9 that collects toner remaining on the intermediate transfer belt 71 serving as an image carrier has been described. However, this is not limiting, and each configuration described in this embodiment can also be adopted for the cleaning means that collects toner remaining on the photosensitive drum serving as an image carrier. In this case, an image forming apparatus that is provided with a cleaning means having the configuration described in this embodiment may be configured to transfer a toner image from a photosensitive drum to an intermediate transfer body such as an intermediate transfer belt, or may be configured to transfer a toner image from a photosensitive drum to a transfer material such as paper. In either case, by adopting a configuration similar to that of this embodiment, it is possible to obtain the same effect.

9 Cleaning device 71 Intermediate transfer belt 91 Cleaning blade 92c Toner storage section 92d Screw 92e Sheet member 92h Wall section

Claims (19)

A cleaning device for recovering toner remaining on an image carrier that carries a toner image, comprising:
The cleaning device includes:
a recovery member that comes into contact with the image carrier to recover toner remaining on the image carrier; a transport member that transports the toner recovered by the recovery member, the transport member being located above a position where the recovery member and the image carrier come into contact in the direction of gravity; a rotatable stirring member that has flexibility and stirs the toner recovered by the recovery member; and a storage section that can store the toner recovered from the image carrier by the recovery member, the storage section housing the transport member and the stirring member,
the conveying member extends in a width direction of the image carrier perpendicular to a moving direction of the image carrier, and conveys the toner in the width direction by rotating;
the housing portion has a wall portion that comes into contact with the rotating stirring member,
The agitating member has a first state in which the end side in contact with the wall portion is deformed toward the upstream side in the rotation direction of the agitating member, and a second state in which the deformation of the end side is released by separating from the wall portion, and the cleaning device supplies toner toward the conveying member by the recoil when moving from the first state to the second state . The cleaning device according to claim 1, characterized in that, when viewed from the direction of the rotation axis of the conveying member, the center of the rotation axis of the stirring member is disposed below the center of the rotation axis of the conveying member in the direction of gravity. The cleaning device according to claim 1 or 2, characterized in that the storage section has a holding section that extends in the width direction and holds the conveying member, and an area in which the holding section is not formed, downstream of the wall section and upstream of the recovery member, in the rotation direction of the stirring member. The cleaning device according to any one of claims 1 to 3, characterized in that the rotation axis direction of the conveying member and the rotation axis direction of the stirring member are parallel. The cleaning device according to any one of claims 1 to 4, characterized in that the recovery member is a cleaning blade that is in contact with the image carrier in a counter direction to the moving direction of the image carrier. The cleaning device according to any one of claims 1 to 5, characterized in that the rotation direction of the conveying member is opposite to the rotation direction of the stirring member. An image forming apparatus comprising: a photoconductor; an endless intermediate transfer body carrying a toner image transferred from the photoconductor ; a recovery means for recovering toner remaining on the intermediate transfer body; a transfer member that contacts the intermediate transfer body to form a transfer section and transfers the toner image carried on the intermediate transfer body to a transfer material in the transfer section; and a first tension member and a second tension member that tension the intermediate transfer body,
the recovery means includes a recovery member that contacts the intermediate transfer body to recover toner remaining on the intermediate transfer body, a transport member that transports the toner recovered by the recovery member, the transport member being located above a position where the recovery member and the intermediate transfer body contact each other in the direction of gravity, a flexible stirring member that is rotatable and stirs the toner recovered by the recovery member, and a storage section that can store the toner recovered from the intermediate transfer body by the recovery member, the storage section housing the transport member and the stirring member,
the transport member extends in a width direction of the intermediate transfer body perpendicular to a moving direction of the intermediate transfer body, and transports the toner in the width direction by rotating;
When viewed from the rotation axis direction of the conveying member, the storage portion has a wall portion that is disposed downstream of the recovery member and upstream of the conveying member in relation to the rotation direction of the stirring member, and is disposed inside a rotation locus of an outermost periphery of the stirring member,
With respect to a moving direction of the intermediate transfer body, the recovery member is disposed downstream of the transfer unit and upstream of a position where the photoconductor and the intermediate transfer body come into contact with each other,
the transfer member is disposed at a position facing the first tension member with the intermediate transfer body therebetween,
the first tension member is a drive roller that rotates by receiving a driving force, the drive roller having a first gear at an end of a shaft in a direction of a rotation axis;
The image forming apparatus according to claim 1, wherein the stirring member and the conveying member are rotated by a driving force transmitted via the first gear . The image forming apparatus according to claim 7, characterized in that, when viewed from the direction of the rotation axis of the conveying member, the center of the rotation axis of the stirring member is disposed below the center of the rotation axis of the conveying member in the direction of gravity. The image forming apparatus according to claim 7 or 8, characterized in that the storage section has a holding section that extends in the width direction and holds the conveying member, and an area in which the holding section is not formed, downstream of the wall section and upstream of the recovery member, in the rotation direction of the stirring member. The image forming device according to claim 9, characterized in that the agitating member, when rotated, forms a first state in which the end side in contact with the wall portion is deformed toward the upstream side in the rotation direction of the agitating member, and a second state in which the deformation of the end side is released by moving away from the wall portion, and the toner scooped up by the agitating member is supplied to the conveying member through the region by the reaction force when moving from the first state to the second state. 11. The image forming apparatus according to claim 7, wherein a rotation axis direction of the conveying member and a rotation axis direction of the stirring member are parallel to each other. 12. The image forming apparatus according to claim 7, wherein the recovery member is a cleaning blade that is in contact with the intermediate transfer body in a counter direction to a moving direction of the intermediate transfer body. 13. The image forming apparatus according to claim 7, further comprising a developing unit that supplies toner to the photoconductor , the photoconductor being rotatable, and the electrostatic latent image being developed by the developing unit. 8. The image forming apparatus according to claim 7 , wherein the recovery member is disposed at a position facing the first tension member across the intermediate transfer body. 8. The image forming apparatus according to claim 7 , wherein the conveying member rotates in a direction opposite to the direction of rotation of the stirring member. 15. The image forming apparatus according to claim 7 , wherein the rotation direction of the stirring member is the same as the rotation direction of the drive roller. 17. The image forming apparatus according to claim 15, further comprising: a second gear that engages with the first gear; a third gear for rotating the stirring member, the third gear engaging with the second gear; and a fourth gear for rotating the conveying member, the fourth gear engaging with the third gear. 18. The image forming apparatus according to claim 14 , wherein the toner collected in the storage section by the collection member is transported by the transport member toward a collection container provided at a position separate from the storage section. 20. The image forming apparatus according to claim 18 , wherein the recovery container is provided within an area formed by an inner circumferential surface of the intermediate transfer body stretched by the first tension member and the second tension member.

Images