Patent Description:
In an image forming apparatus using an electrophotographic method such as a copying machine and a printer, there is known a technique in which a toner conveying device conveying toner such as waste toner is disposed in a cleaning device.

In PTL <NUM>, a technique, for installing a comb-shaped agitator (swinging member) that swings between a shaft portion and a spiral blade (screw portion) of the conveying screw, to prevent the agglomeration of toner conveyed by the conveying screw in the cleaning device. For more details, the agitator includes a plurality of overhanging portions arranged side by side at intervals in the axial direction of the agitator and a plurality of bending portions (tip portions) that bend from the free end sides of the plurality of overhanging portions.

In the technique of PTL <NUM>, a comb-shaped swinging member that swings between a shaft portion and a screw portion of the conveying screw is provided to stir the toner in the devices, an effect of reducing the failure of the toner agglomeration in the devices can be greatly expected. <CIT> discloses a toner conveyance device comprising a conveyance screw and a toner crushing member.

However, in the technique such as PTL <NUM>, may cause a problem in which the swinging member (agitator) is caught in the conveying screw. If the above-described inconvenience occurs, failures such as device drive lock and damage of the swinging member may occur.

[PTL <NUM>]
Japanese Patent No. <CIT> (<CIT>).

An object of the present disclosure is to provide a toner conveyance device, a cleaning device, a process cartridge, and an image forming apparatus that can prevent the swinging member from being caught in the conveying screw and reduce the failure of toner agglomeration in the devices.

According to an aspect of the present disclosure, there is provided a toner conveying device according to the appended claims.

According to aspects of the present disclosure, there can be provided a toner conveying device, a cleaning device, a process cartridge, and an image forming apparatus that can prevent the swinging member from being caught in the conveying screw and reduce the failure of toner agglomeration in the devices.

Embodiments of the present disclosure are described in detail with reference to drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description thereof are simplified or omitted as appropriate.

First, with reference to <FIG> and <FIG>, a description is given of the overall configuration and operation of an image forming apparatus <NUM>. <FIG> is a schematic view illustrating a configuration of the image forming apparatus <NUM> according to an embodiment of the present disclosure. <FIG> is a cross-sectional view illustrating a configuration of a process cartridge 10Y (serving as an image forming unit) for yellow installed in the image forming apparatus <NUM> of <FIG>. It is to be noted that the four process cartridges 10Y, <NUM>, 10C, and 10BK (serving as image forming units) have substantially the same configuration except for the colors of toner used in image forming processes. Therefore, only the process cartridge 10Y is illustrated as a representative in <FIG>.

In <FIG>, the image forming apparatus <NUM>, which is illustrated as a tandem-type color copier in the present embodiment, includes a writing device <NUM>, a document feeder <NUM>, and a scanner <NUM> (serving as a document reading device). The writing device <NUM> emits a laser beam based on input image data. The document feeder <NUM> feeds a document D to the scanner <NUM>. The scanner <NUM> reads image data from the document D. The image forming apparatus <NUM> further includes a sheet feeder <NUM> (in this case, a plurality of sheet feeders <NUM>), a registration roller pair <NUM>, and the four process cartridges 10Y, <NUM>, 10C, and 10BK (serving as image forming units). The sheet feeder <NUM> accommodates a stack of sheets such as paper sheets. The registration roller pair <NUM> adjusts a conveyance timing of a sheet. The process cartridges 10Y, <NUM>, 10C, and 10BK form toner images of yellow, magenta, cyan, and black, respectively. The image forming apparatus <NUM> further includes primary transfer rollers <NUM> and an intermediate transfer belt <NUM>. The toner images formed on photoconductor drums <NUM> (see <FIG>) of the respective process cartridges 10Y, <NUM>, 10C, and 10BK are transferred to and overlapped one on another on the intermediate transfer belt <NUM> by the primary transfer rollers <NUM>, thereby forming a multicolor toner image. The image forming apparatus <NUM> further includes a secondary transfer roller <NUM>, a belt cleaning blade 19a, and a fixing device <NUM>. The secondary transfer roller <NUM> transfers the multicolor toner image on the intermediate transfer belt <NUM> onto the sheet. The belt cleaning blade 19a cleans the intermediate transfer belt <NUM>. The fixing device <NUM> fixes the multicolor toner image (unfixed image) on the sheet.

A description is provided below of the operation of the image forming apparatus <NUM> when forming a normal color image. The document feeder <NUM> feeds, with conveyance rollers, the document D from a document table onto an exposure glass <NUM> of the scanner <NUM>. Then, the scanner <NUM> optically reads image data from the document D set on the exposure glass <NUM>. The yellow, magenta, cyan, and black image data are transmitted to the writing device <NUM>. The writing device <NUM> irradiates the photoconductor drums <NUM> (serving as image bearers) of the corresponding process cartridges 10Y, <NUM>, 10C, and 10BK with laser beams L (serving as exposure light) based on the yellow, magenta, cyan, and black image data, respectively.

Meanwhile, the photoconductor drum <NUM> (see <FIG>) in each of the four process cartridges 10Y, <NUM>, 10C, and 10BK rotates in a predetermined direction (i.e., counterclockwise in <FIG>). A charging device <NUM> (see <FIG>) uniformly charges a surface of the photoconductor drum <NUM> at a position facing each other (charging process). As a result, a charging potential is formed on the surface of the photoconductor drum <NUM>. Subsequently, the surface of the photoconductor drum <NUM> charged reaches an irradiation position to receive the laser beam L. The writing device <NUM> emits laser beams L corresponding to four colors from four light sources according to the image data. The respective laser beams L pass through different optical paths for components of yellow, magenta, cyan, and black (exposure process).

The laser beam L for the yellow component is emitted to the surface of a first photoconductor drum <NUM> (serving as an image bearer) that is the first from the left among the photoconductor drums <NUM> of the four process cartridges 10Y, <NUM>, 10C, and 10BK in <FIG>. A polygon mirror that rotates at high velocity deflects the laser beam L for yellow so that the laser beam L scans the surface of the photoconductor drum <NUM> along the rotation axis direction of the photoconductor drum <NUM> (i.e., the main scanning direction). Thus, an electrostatic latent image corresponding to the yellow component is formed on the photoconductor drum <NUM> charged by the charging device <NUM>.

Similarly, the laser beam L for the magenta component is irradiated to the surface of a second photoconductor drum <NUM> of the process cartridge <NUM> that is the second from the left in <FIG>, to form an electrostatic latent image for magenta thereon. The laser beam L corresponding to the cyan image data is irradiated to the surface of a third photoconductor drum <NUM> that is the third from the left in <FIG>, to form an electrostatic latent image corresponding to the cyan image data. The laser beam L corresponding to the black image data is irradiated to the surface of a fourth photoconductor drum <NUM> that is the fourth from the left in <FIG>, to form an electrostatic latent image corresponding to the black image data.

Then, the surfaces of the photoconductor drums <NUM> having the respective electrostatic latent images reach positions opposed to the corresponding developing devices <NUM> (see <FIG>). The developing device <NUM> supplies toner of each color onto the surface of the photoconductor drum <NUM> and develops the electrostatic latent image on the photoconductor drum <NUM> into a visible toner image (development process). Subsequently, the surface of the photoconductor drum <NUM> after the development process reaches a position facing the intermediate transfer belt <NUM> (i.e., a primary transfer nip). The primary transfer rollers <NUM> are disposed at the positions where the photoconductor drums <NUM> face the intermediate transfer belt <NUM> and in contact with an inner circumferential surface of the intermediate transfer belt <NUM>, respectively. At the positions of the primary transfer rollers <NUM>, the toner images on the photoconductor drums <NUM> are transferred to and overlapped one on another on the intermediate transfer belt <NUM>, to form a multicolor toner image on the intermediate transfer belt <NUM> (primary transfer process).

After the primary transfer process, the surface of the photoconductor drum <NUM> passes through a discharge lamp and reaches a position opposite a cleaning device <NUM> (see <FIG>). At this position, a cleaning blade 14a (see <FIG>) removes adhesive material on the photoconductor drum <NUM>, such as toner (i.e., untransferred toner) adhering to the surface of the photoconductor drum <NUM>, and the removed toner is collected into the cleaning device <NUM> (cleaning process). The untransferred toner collected into the cleaning device <NUM> is conveyed by a conveying screw 15a (see <FIG>) toward the outside of the cleaning device <NUM>, and is then collected into a waste-toner container as waste toner. Then, the surface of the photoconductor drum <NUM> passes through the discharge lamp, and a series of image forming processes performed on the photoconductor drum <NUM> ends.

On the other hand, the multicolor toner image is formed on the intermediate transfer belt <NUM> by transferring and overlapping the respective single-color toner images on the photoconductor drums <NUM>. Then, the intermediate transfer belt <NUM> bearing the multicolor toner image moves clockwise in <FIG> to reach a position opposite the secondary transfer roller <NUM>. The secondary transfer roller <NUM> transfers the multicolor toner image borne on the intermediate transfer belt <NUM> onto the sheet (secondary transfer process). After the secondary transfer process, the surface of the intermediate transfer belt <NUM>, as an image bearer, reaches a position opposite the belt cleaning device <NUM>. The belt cleaning device <NUM> collects untransferred toner (adhesive material) adhering to the intermediate transfer belt <NUM> by the cleaning blade 19a. Thus, a series of transfer processes performed on the intermediate transfer belt <NUM> ends.

The sheet is fed from the sheet feeder <NUM> via a registration roller pair <NUM> to a secondary transfer nip between the intermediate transfer belt <NUM> and the secondary transfer roller <NUM>. More specifically, a sheet feed roller <NUM> feeds the sheet from the sheet feeder <NUM> that contains multiple sheets such as paper sheets, and the sheet is then guided by a conveyance guide to the registration roller pair <NUM> (serving as a timing roller pair). The sheet that has reached the registration roller pair <NUM> is conveyed toward the secondary transfer nip, timed to coincide with the arrival of the multicolor toner image on the intermediate transfer belt <NUM>.

The sheet on which the multicolor toner image has been transferred is conveyed to the fixing device <NUM> by a conveyance belt. The fixing device <NUM> includes a fixing belt and a pressure roller pressing against each other to form a fixing nip. In the fixing nip, the multicolor toner image is fixed on the sheet. After the fixing process, an output roller pair ejects the sheet as an output image outside a main body of the image forming apparatus <NUM>. Thus, a series of image forming processes ends.

With reference to <FIG>, the process cartridge 10Y is described in further detail below. As illustrated in <FIG>, in the process cartridge 10Y, the photoconductor drum <NUM> as the image bearer, the charging device <NUM> (charging roller), the developing device <NUM>, and the cleaning device <NUM> are combined together as a single unit. The cleaning device <NUM> includes a toner conveying device <NUM>.

The photoconductor drum <NUM> as the image bearer used in the present embodiment is an organic photoconductor to be charged to a negative polarity and includes a photosensitive layer formed on a drum-shaped conductive support member. For example, the photoconductor drum <NUM> is multilayered and includes a base layer serving as an insulation layer, the photosensitive layer, and a surface layer (i.e., a protection layer) are sequentially overlaid one on another on the conductive support member as a substrate. The photosensitive layer includes a charge generation layer and a charge transport layer. The photoconductor drum <NUM> is rotated counterclockwise in <FIG> by a drive motor.

With reference to <FIG>, the charging device <NUM> is a charging roller including a conductive core and an elastic layer of moderate resistivity overlaid on the conductive core. The charging device <NUM> applies a predetermined voltage, which includes an alternating-current (AC) voltage superimposed on a direct-current (DC), from a charging power source and uniformly charges the surface of the photoconductor drum <NUM> facing the charging device <NUM>.

The developing device <NUM> includes a developing roller 13a disposed opposite the photoconductor drum <NUM>, a first conveying screw 13b disposed opposite the developing roller 13a, a second conveying screw 13c disposed opposite the first conveying screw 13b via a partition, and a doctor blade 13d disposed opposite the developing roller 13a. The developing roller 13a includes multiple magnets and a sleeve that rotates around the magnets. The magnets are stationary and generate magnetic poles around the circumference of the developing roller 13a. The magnets generate a plurality of magnetic poles on the developing roller 13a (sleeve) to bear a developer G on the developing roller 13a. The developing device <NUM> stores a two-component developer G including toner T and carrier C.

The cleaning device <NUM> includes the cleaning blade 14a, an inlet seal 14b as a sealing member, a toner conveying device <NUM>, and so forth. The cleaning blade 14a contacts the photoconductor drum <NUM> as the image bearer and cleans the surface of the photoconductor drum <NUM>. The toner conveying device <NUM> conveys the untransferred toner collected in the cleaning blade 14a in the width direction that is the axial direction of the photoconductor drum <NUM> and a direction perpendicular to a plane in which <FIG> is drawn.

The cleaning blade 14a is a plate-shaped member made of rubber material such as urethane rubber, and is supported in a cantilever structure by a supporting plate (held in a case of the cleaning device <NUM>). The cleaning blade 14a contacts the surface of the photoconductor drum <NUM> at a predetermined angle and with a predetermined pressure. With this configuration, the adhesive material such as toner adhering to the surface of the photoconductor drum <NUM> are mechanically scraped off and collected into the cleaning device <NUM> by the cleaning blade 14a. Examples of the adhesive material adhering to the photoconductor drum <NUM> include paper dust arising from sheets, discharge products arising on the photoconductor drum <NUM> during electrical discharge by the charging device <NUM>, and additives to toner. According to the present embodiment, the cleaning blade 14a contacts the photoconductor drum <NUM> against the direction of rotation of the photoconductor drum <NUM>.

The inlet seal 14b as a sealing member is a substantially rectangular sheet-shaped member made of a rubber material such as polyurethane rubber, having flexibility, and having a thickness of about <NUM> to <NUM>. The inlet seal 14b is supported in a cantilever structure in a case of the cleaning device <NUM>. The inlet seal 14b is in contact with the surface of the photoconductor drum <NUM> on a downstream side of the cleaning blade 14a in a rotation direction of the photoconductor drum <NUM>. A flat surface of the inlet seal 14b is partially in contact with the surface of the photoconductor drum <NUM>. The inlet seal 14b functions as a sealing member so that the toner (untransferred toner) collected in the cleaning device <NUM> does not leak outside.

As illustrated in <FIG>, the conveying screw 15a is provided in the toner conveying device <NUM>. The conveying screw 15a includes a shaft portion 15a1 and a screw portion 15a2 spirally wound around the shaft portion 15a1. The conveying screw 15a rotates in a predetermined direction to convey toner (adhesive material such as untransferred toner collected inside the cleaning device <NUM>). When the conveying screw 15a is rotated in the direction indicated by arrows of <FIG> by the drive motor, the toner in the cleaning device <NUM> is conveyed in the axial direction (i.e., a direction perpendicular to a plane on which <FIG> is drawn and a direction indicated by broken arrow in <FIG>), and is discharged in a direction indicated by thick arrow in <FIG> toward a waste toner conveyance path <NUM> of the cleaning device <NUM>. The toner discharged to the waste toner conveyance path <NUM> is conveyed and collected by the waste toner conveying screw 40a toward the waste toner container. The conveying screw 15a receives driving force from the drive motor to rotate the photoconductor drum <NUM> via a gear train, and is driven to rotate counterclockwise in <FIG> in conjunction with the rotation of the photoconductor drum <NUM>. The conveying screw 15a includes the screw portion 15a2 that is formed with a pitch (screw pitch) X on the shaft portion 15a1. In the present embodiment, a swinging member 15b (see <FIG>) for preventing toner aggregation in the toner conveying device <NUM> (cleaning device <NUM>) is disposed, but this embodiment will be described later in detail.

The image forming processes, described above, are described in further detail below with reference to <FIG>. The developing roller 13a rotates clockwise indicated by arrow in <FIG>. In the developing device <NUM>, as the first and second conveying screws 13b and 13c, arranged via the partition, rotate as illustrated in <FIG>, the developer G is circulated in the longitudinal direction of the developing device <NUM>, being stirred with fresh toner T supplied from a toner supply unit <NUM> via the toner supply inlet. The longitudinal direction of the developing device <NUM> is perpendicular to the surface of the paper on which <FIG> is drawn. Thus, the toner T is triboelectric ally charged and attracted to the carrier C. The toner T is borne on the developing roller 13a together with the carrier C. The developer G borne on the developing roller 13a reaches a position opposite the doctor blade 13d. After having been adjusted to an appropriate amount at the position of the doctor blade 13d, the developer G on the developing roller 13a then comes to an opposing position to the photoconductor drum <NUM> (i.e., a development area).

In the development area, the toner T in the developer G adheres to the electrostatic latent image on the photoconductor drum <NUM>. The toner T adheres to the electrostatic latent image by a development electric field formed by a potential difference (i.e., a developing potential) between a latent image potential (i.e., an exposure potential) of an image area irradiated with the laser beam L and a developing bias applied to the developing roller 13a. Most of the toner T attached to the photoconductor drum <NUM> in the developing process is transferred onto the intermediate transfer belt <NUM>. Untransferred toner T adhered (remained) on the surface of the photoconductor drum <NUM> is collected in the cleaning device <NUM> by the cleaning blade 14a. Subsequently, the surface of the photoconductor drum <NUM> passes through the position of the discharge lamp. After these processes, a series of image forming processes of the photoconductor drum <NUM> is completed.

The toner supply unit <NUM> of the image forming apparatus <NUM> (main body) includes a replaceable toner bottle <NUM> and a toner hopper <NUM>. The toner hopper <NUM> holds and rotates the toner bottle <NUM> and supplies fresh toner T to the developing device <NUM>. Each toner bottle <NUM> contains fresh toner T (yellow toner in <FIG>). Spiral projections are disposed on an inner circumferential surface of the toner bottle <NUM>. The fresh toner T contained in the toner bottle <NUM> is supplied through the toner supply inlet to the developing device <NUM> as the toner T existing in the developing device <NUM> is consumed. The consumption of the toner T in the developing device <NUM> is detected either directly or indirectly using a magnetic sensor disposed below the second conveying screw 13c in the developing device <NUM>.

The configuration and operation of the toner conveying device <NUM> (cleaning device <NUM>) according to the embodiment of the present disclosure are described below. As described above with reference to <FIG>, the toner conveying device <NUM> includes a conveying screw 15a (screw portion 15a2 is spirally wound on the shaft portion 15a) which is rotated in the predetermined direction and conveys the toner. As illustrated in <FIG>, in the present embodiment, the swinging member 15b formed in a substantially comb form is disposed in the toner conveying device <NUM> (the cleaning device <NUM>). The swinging member 15b is a flexible sheet-shaped member made of PET (polyethylene terephthalate) and the forth, has a thickness of <NUM> to <NUM>, and is a swingable member that can swing between the shaft portion 15a1 and the screw portion 15a2 of the conveying screw 15a, with the rotation of the conveying screw 15a.

Specifically, as indicated by a double headed arrow in <FIG>, a free end (a portion other than a supporting portion 15b1 supported by the case of the device) of the swinging member 15b repeatedly moves alternately between a position to contact the screw portion 15a2 (the position indicated by a broken line in <FIG>) and a position to contact the shaft portion 15a1 (the position indicated by a solid line in <FIG>), in accordance with the rotation cycle of the conveying screw 15a. This is because, when viewed from the side of the swinging member 15b (an overhanging portion 15b2 and a tip portion 15b3 described below), the shaft portion 15a1 and the screw portion 15a2 alternately appear at the opposite position of the swinging member 15b with the rotation of the conveying screw 15a. The swinging movement of the swinging member 15b can also referred to <FIG>.

Referring to <FIG>, <FIG>, and so forth, the swinging member 15b includes a plurality of overhanging portions 15b2, and a plurality of tip portions 15b3 (bending portions). The plurality of overhanging portions 15b2 are arranged at intervals with respect to the axial direction of the conveying screw 15a. Each of the plurality of tip portions 15b3 is bent at a predetermined angle α from the free end side (boundary portion 15b4) of the overhanging portion 15b2 in the direction away from the shaft portion 15a1. The tip portion 15b3 of the swinging member 15b is formed so that the width of the tip portion 15b3 in the axial direction (which is the horizontal direction in <FIG> and the direction perpendicular to the plane on which <FIG> is drawn) gradually increases, at least, from a portion to contact the screw portion 15a2 toward the free end side.

In the present embodiment, the tip portion 15b3 of the swinging member 15b is formed so that the width of the tip portion 15b3 in the axial direction gradually increases from the boundary portion 15b4 with the overhanging portion 15b2 toward the free end side. More specifically, the tip portion 15b3 has side edges 15b30 extending from the boundary portion 15b4 with the overhanging portion 15b2 toward the free end side. Each of the side edges 15b30 is neither parallel nor perpendicular to the axial direction but continuously inclined in a direction approaching another tip portion 15b3 adjacent to the tip portion 15b3. As illustrated in <FIG>, the plurality of overhanging portions 15b2 and the plurality of tip portions 15b3 are symmetrically formed, and are formed at a pitch W (≠ X) different from the screw pitch X of the conveying screw 15a. The pitch W of the plurality of overhanging portions 15b2 and the plurality of tip portions 15b3 is different from the screw pitch X of the conveying screw 15a, so that the swinging movement of the plurality of tension portions 15b2 and the plurality of tip portions 15b3 does not occur at the same timing. In the present embodiment, the pitch W of the plurality of overhanging portions 15b2 and the plurality of tip portions 15b3 is formed so that the pitch W is larger than the screw pitch X of the conveying screw (W > X). As illustrated in <FIG>, the overhanging portion 15b2 is longer than the span from the supporting portion 15b1 (the portion attached to the case of the cleaning device <NUM>) to the shaft portion 15a1. Furthermore, the width of the overhanging portion 15b2 is shorter than the screw pitch X described above.

As illustrated in <FIG>, the swinging member 15b thus configured swings so as to alternately contact the shaft portion 15a1 and the screw portion 15a2, and reduces the failure of toner agglomeration in the toner conveying device <NUM> (or the cleaning device <NUM>).

As illustrated in <FIG> and <FIG>, the swinging member 15b is in a state in which the swinging member 15b is in contact with the shaft portion 15a1 of the conveying screw 15a (or in a state close to the shaft portion 15a1). As the rotation of the conveying screw 15a advances, as illustrated in <FIG>, the overhanging portion 15b2 of the swinging member 15b comes into contact with the screw portion 15a2 (outer peripheral portion) of the conveying screw 15a. At this time, the tip portion 15b3 of the swinging member 15b is closest to an area indicated by the broken line in <FIG> and loosen the toner in the area (to prevent toner agglomeration in the area. The area is close to the photoconductor drum <NUM> and far from the conveying screw 15a. Toner is likely to stay and agglomerate in the area. In the present embodiment, since the tip portion 15b3 is wider than the overhanging portion 15b2, the effect of loosening the toner is easily achieved.

Further, as the rotation of the conveying screw 15a proceeds from the state, as illustrated in <FIG>, <FIG>, the tip portion 15b3 of the swinging member 15b comes into contact with the screw portion 15a2 (outer peripheral portion) of the conveying screw 15a. At this time, since the tip portion 15b3 is formed so that the width of the tip portion 15b3 gradually increases at least from the portion to contact the screw portion 15a2 toward the free end side, the tip portion 15b3 and the screw portion 15a2 (outer peripheral portion) intersect the predetermined intersection angle θ. Accordingly, the swinging member 15b (the tip portion 15b3) is less likely to be caught in the conveying screw 15a than in the case that the above-described intersection angle θ is not generated. As a result, such a failure that the device is locked by the entrainment of the swinging member 15b or that the swinging member 15b is broken are restrained.

Further, as the rotation of the conveying screw 15a proceeds from the state, as illustrated in <FIG> and <FIG>, the tip portion 15b3 of the swinging member 15b comes into contact with (or approaches) the shaft portion 15a1 of the conveying screw 15a. Thereafter, the operation of the swinging member 15b described in <FIG> is repeated in accordance with the rotation cycle of the conveying screw 15a. Such a configuration can prevent the swinging member 15b from being caught in the conveying screw 15a and reduce the failure in which toner agglomerates in the cleaning device <NUM>.

Referring to <FIG>, in the present embodiment, the tip portion 15b3 of the swinging member 15b is formed so that each of the side edges 15b30, which extends from the boundary portion 15b4 with the overhanging portion 15b2 toward the free end side, contacts the screw portion 15a2 at approximately <NUM> degrees from the screw portion 15a2. As illustrated in <FIG>, when the tip portion 15b3 comes into contact with the outer peripheral portion of the screw portion 15a2, the intersection angle θ is set to be approximately <NUM> degrees. Such a configuration can more easily achieve an effect that the swinging member 15b (or the tip portion 15b3) is less likely to be caught in the conveying screw 15a. Note that the intersection angle θ is preferably approximately <NUM> degrees, but may be set to an angle (for example, about <NUM> degrees) that is not too small, in other words, an angle at which the swinging member 15b (or the tip portion 15b3) is not caught in the screw portion 15a2.

Referring to <FIG> and so forth, in the present embodiment, the tip portion 15b3 of the swinging portion 15b is bent at approximately <NUM> degrees from the free end side (boundary portion 15b4) of the overhanging portion 15b2 in a direction away from the shaft portion 15a1. That is, a bending angle α of the tip portion 15b3 is set to approximately <NUM> degrees. In such a configuration, as illustrated in <FIG>, the tip portion 15b3, which moves to the area surrounded by the broken line (area in which the agglomerated toner is likely to be generated), is less likely to be bent by the pressure of toner. Thus, an effect of loosening the toner is likely to be achieved. Further, the bending process of the swinging member 15b at the time of forming the tip portion 15b3 is simplified (and the workability of the bending is enhanced).

In the present embodiment, the swinging member 15b is formed so as to contact the conveying screw 15a along the axial direction. The swinging member 15b is disposed across the entire range in the axial direction of the conveying screw 15a illustrated in <FIG>. Such a configuration can reduce toner agglomeration across the entire range in the axial direction in which toner is conveyed by the conveying screw 15a.

Referring to <FIG>, in the present embodiment, when the tip portion 15b3 of the swinging member 15b is closest to the photoreceptor drum <NUM> (in other words, moves to a swinging position farthest from the shaft portion 15a1), the tip portion 15b3 is substantially parallel to a virtual line N passing through the axial center of the shaft portion 15a1 and the center of a virtual line segment M connecting the contact position between the photoconductor drum <NUM> and the cleaning blade 14a and the contact position between the photoconductor drum <NUM> and the inlet seal 14b , when viewed in a cross section perpendicular to the axial direction. Note that the center of the virtual line segment M is at a position equidistant with a distance A from both ends of the virtual line segment M. In such a configuration, as illustrated in part (b) of <FIG>, the tip portion 15b3, which moves to the area surrounded by the broken line (area in which agglomerated toner is likely to be generated), is less likely to be bent by the pressure of toner. Thus, an effect of loosening toner is likely to be achieved.

Referring to <FIG> and so forth, in the present embodiment, the supporting surface 14a1 of the cleaning blade 14a (the case surface on which the supporting plate of the cleaning blade 14a is fixed) and the supporting surface of the swinging member 15b (the case surface on which the supporting portion 15b1 of the cleaning blade 14a is affixed) are substantially parallel. In such a configuration, when the cleaning device <NUM> in which the toner conveying device <NUM> is installed is assembled in a manufacturing plant, the workability of assembling the cleaning blade 14a extending in the axial direction and the swinging member 15b is improved.

As described above, the swinging member 15b in the present embodiment is formed so that the overhanging portion 15b2 and the tip portion 15b3 are symmetrical in a direction perpendicular to the axial direction of the swinging member 15b. Therefore, in order to prevent the entrainment of the cleaning blade 14a to the photoconductor drum <NUM>, even when a "reverse mode" in which the photoconductor drum <NUM> is rotated in the reverse direction for a short time during non-image formation is performed and the transport screw 15a is also rotated in the reverse direction accordingly, the tip portion 15b3 of the swinging member 15b is less likely to caught in the conveying screw 15a for the same reason as in the normal rotation. Accordingly, a drive lock of the cleaning device <NUM> and a damage of the swinging member 15b are also prevented.

As described above, the toner conveying device <NUM> (or the cleaning device <NUM>) in the present embodiment includes the conveying screw 15a and the swinging member 15b. The conveying screw 15a has the shaft portion 15a1 and the screw portion 15a2 spirally wound around the shaft portion 15a1, and rotates in the predetermined direction to convey toner. The swinging member 15b is formed in a substantially comb form and can swing between the shaft portion 15a1 and the screw portion 15a2 with the rotation of the conveying screw 15a. The swinging member 15b includes the plurality of overhanging portions 15b2 and the plurality of tip portions 15b3. The plurality of overhanging portions 15b2 are arranged side by side at intervals in the axial direction of the conveying screw 15a. Each of the plurality of tip portions 15b3 is bent at a predetermined angle α from the free end of the corresponding overhanging portion 15b2 in a direction away from the shaft portion 15a1. The tip portion 15b3 of the swinging member 15b is formed so that the width of the tip portion 15b3 in the axial direction of the swinging member 15b gradually increases at least from the portion to contact the screw portion 15a2 toward the free end side. Such a configuration can prevent the swinging member 15b from being caught in the conveying screw 15a and reduce the failure that toner agglomerates in the cleaning device <NUM>.

In the above-described embodiments, the respective components (i.e., the photoconductor drum <NUM>, the charging device <NUM>, the developing device <NUM>, and the cleaning device <NUM>) of the image forming unit are combined together as the process cartridge <NUM> (i.e., the process cartridge 10BK) to make the image forming unit compact and to facilitate maintenance work. Alternatively, the cleaning device <NUM> may not be included in the process cartridge and can be independently installed (removably) in the image forming apparatus <NUM> (main body). In such a configuration, similar effects to those of the above-described embodiment and variations are also attained. It is to be noted that the term "process cartridge" used in the present disclosure means a removable unit including an image bearer and at least one of a charging device to charge the image bearer, a developing device to develop latent images on the image bearer, and a cleaning device to clean the image bearer that are united together, and is designed to be removably installed as a united part in the image forming apparatus <NUM> (main body).

In the above-described embodiment, the present disclosure is applied to the toner conveying device <NUM> included in the cleaning device <NUM> to remove the adhesive material on the photoconductor drum <NUM> as an image bearer. By contrast, the present disclosure is applied to the toner conveying device <NUM> included in the belt cleaning device <NUM> to remove the adhesive material on the intermediate transfer belt <NUM> as an image bearer. In the above-described embodiments, the present disclosure is applied to the toner conveying device <NUM> (the cleaning device <NUM>) included in the image forming apparatus <NUM> that performs multicolor image formation. Alternatively, the present disclosure can also be applied readily to the toner conveying device <NUM> (the cleaning device <NUM>) included in a monochrome image forming apparatus. In the above-described embodiment, the present disclosure is applied to the toner conveying device <NUM> included in the cleaning device <NUM>, but the application of the present disclosure is not limited thereto, and, for example, the present disclosure can be applied to all of the toner conveying device that conveys toner (including waste toner, and new toner or recycled toner, etc.), even in the toner conveying device <NUM> included in the developing device <NUM> and the toner supply unit <NUM>. Such cases also provide substantially the same effects as the effects described above.

Note that embodiments of the present disclosure are not limited to the above-described embodiments and it is apparent that the above-described embodiments can be appropriately modified within the scope of the technical idea of the present disclosure in addition to what is suggested in the above-described embodiments. Further, the number, position, shape, and so on of components are not limited to those of the present embodiment, and may be the number, position, shape, and so on that are suitable for implementing the present disclosure.

Claim 1:
A toner conveying device (<NUM>) comprising:
a conveying screw (15a) configured to rotate in a predetermined direction and convey toner, the conveying screw (15a) including:
a shaft portion (15a1); and
a screw portion (15a2) formed with a first pitch (X) and is spirally wound around the shaft portion (15a1); and
a swinging member (15b) of a substantially comb shape configured to swing between the shaft portion (15a1) and the screw portion (15a2) with rotation of the conveying screw (15a), the swinging member (15b) including:
a plurality of overhanging portions (15b2) arranged side by side at intervals in an axial direction of the conveying screw; and
a plurality of tip portions (15b3) , each one of which is bent at a predetermined angle from a free end side of a corresponding one of the plurality of overhanging portions (15b2) in a direction away from the shaft portion (15a1),
wherein a width of each one of the plurality of tip portions (15b3) in the axial direction of the conveying screw gradually increases at least from a portion to contact the screw portion toward a free end side of each one of the plurality of tip portions,
characterised in that
the plurality of overhanging portions (15b2) and the plurality of tip portions (15b3) are formed at a second pitch (W) which is larger than the first pitch (X) of the conveying screw (15a).