JP5470144B2 - Toner transport device, toner cartridge and cleaning unit including the same - Google Patents

Description

  The present invention relates to a toner conveying device provided in an electrophotographic image forming apparatus, a toner cartridge provided with the toner conveying device, and a cleaning unit.

  In an electrophotographic image forming apparatus using a two-component developer, the toner in the developing unit is consumed and reduced by image formation, so that the toner concentration in the developer does not fall below a predetermined value. The toner is replenished.

  As a conventional toner cartridge that is detachably attached to the image forming apparatus, a toner storage unit that stores replenishment toner, a toner discharge port that discharges toner toward the developing unit, and a toner discharge unit that discharges toner from the toner storage unit. There has been proposed a toner cartridge including an auger screw that conveys toner to an outlet (see, for example, Patent Document 1).

  In addition, the toner transport device according to the related art 2 provided in the image forming apparatus includes a cylindrical toner transport path having a toner discharge port on the downstream side, and an auger screw rotatably provided inside the toner transport path. Thus, a toner conveying device has been proposed in which the spiral direction of the spiral blade of the auger screw is reversed (reverse spiral) on the most downstream side (see, for example, Patent Document 2).

JP 2006-235255 A JP 2008-32769 A

However, the toner cartridges described in the prior arts 1 and 2 may cause the following problems.
In the case of the toner cartridge described in the related art 1, a toner discharge portion having a narrow space is provided on the downstream side of the toner conveyance path, and the toner in the toner discharge portion is transported over a long distance or left for a long time. As a result, the fluidity is lowered and the particles tend to aggregate.
When the auger screw rotates in this state and the toner is transported to the downstream side of the toner transport path, the toner adheres and accumulates on the wall surface on the most downstream side of the toner transport path, and the deposited toner is transported one after another. The coming toner is pressed against the wall surface on the most downstream side to be in a consolidated state.
As a result, the toner deposited on the wall surface on the most downstream side gradually grows into a large lump, and finally a lock phenomenon occurs in which the rotation of the auger screw is stopped by the lump of toner.

In addition, in the case of the toner cartridge described in the related art 2, it is considered that it is possible to make it difficult to deposit toner on the wall surface on the most downstream side of the toner conveyance path, but the toner adheres to the reverse spiral portion of the auger screw and accumulates. To do.
Since the toner accumulated in the reverse spiral portion and the toner successively conveyed to the downstream side move in the opposite directions and collide with each other, the toner accumulated in the reverse spiral portion becomes a compacted state due to a sudden rise in pressure. .
As a result, the toner accumulated on the reverse spiral portion gradually grows into a large lump, and finally a lock phenomenon occurs in which the rotation of the auger screw is stopped by the lump of toner.

The inventors of the present invention have made extensive studies on the lock phenomenon of the prior arts 1 and 2, and found the following.
More specifically, the spiral blade of the conventional auger screw has an elongated trapezoidal or rectangular cross-sectional shape that gradually becomes thinner from the inner end toward the outer end on the rotating shaft side. It protrudes in the vertical direction, and its thickness is constant as a whole.
The shape of the spiral blade is suitable for transmitting the conveying force in the conveying direction along the rotation axis to the toner, and is not suitable for transmitting the force in the rotating direction to the toner.

When the toner is transported by rotating the auger screw, the toner is transported to the toner transport unit mainly receiving transport force in the transport direction along the rotation axis. Of the toner transported to the toner discharge portion, the toner below the rotation shaft tends to fall out of the toner discharge port due to its own weight. The agglomerated toner above is not discharged but goes straight on. Even with toner below the rotating shaft, the aggregated toner around the toner discharge port is difficult to be discharged.
Therefore, as in the prior arts 1 and 2, the toner is in a compacted state in the toner discharge portion and becomes a lump of toner, causing a lock phenomenon.

  The present invention has been made in view of the above problems, and includes a toner conveying device that does not cause a toner compaction state in the vicinity of a toner discharge port in a toner conveying path and prevents a lock phenomenon. An object is to provide a toner cartridge and a cleaning unit.

  Thus, according to the present invention, the toner conveyance path disposed inside, the toner introduction port disposed on the upstream side of the toner conveyance path for introducing the toner into the toner conveyance path from the outside, and the toner conveyance path A toner transport cylinder having a toner discharge port disposed downstream of the toner transport path for discharging the toner from the path to the outside; and the toner transport path rotatably provided in the toner transport cylinder. A screw shaft for conveying the toner from the upstream side to the downstream side, the screw shaft having a rotation shaft, a first surface inclined upstream from the inner end to the outer end of the rotation shaft side, and an upstream side A spiral blade attached to the rotary shaft having a second surface inclined to the side, and the spiral blade has a cross-sectional shape that gradually decreases from the inner end to the outer end on the rotary shaft side. And said Tona In a position facing the discharge opening, the toner conveying device thickness toward the downstream side has a thick portion which gradually thickened toner conveyance path (the first invention) is provided.

  According to another aspect of the present invention, the toner conveying device and a cartridge main body having a toner accommodating portion disposed adjacent to the toner conveying device are provided inside the cartridge main body, and the cartridge main body is provided on the outer surface side of the cartridge main body. A toner comprising: a shutter for opening and closing a toner discharge port; and a paddle member that is rotatably provided in the cartridge body and feeds the toner in the toner storage portion from the toner introduction port into the toner conveyance path. A cartridge (second invention) is provided.

  According to still another aspect of the present invention, a cleaning unit including the toner transport device and a blade member attached to an opening edge of the toner introduction port in the toner transport cylinder of the toner transport device ( 3rd invention) is provided.

  According to still another aspect of the present invention, a photosensitive drum on which an electrostatic latent image is formed on the surface, and toner is supplied to the electrostatic latent image on the surface of the photosensitive drum to form a toner image. A developing unit; the toner cartridge for supplying toner to the developing unit; a transfer unit that transfers a toner image on the surface of the photosensitive drum to a recording medium; and a fixing unit that fixes the toner image to the recording medium; An image forming apparatus (fourth invention) is provided.

  According to still another aspect of the present invention, a photosensitive drum on which an electrostatic latent image is formed on the surface, and toner is supplied to the electrostatic latent image on the surface of the photosensitive drum to form a toner image. A developing unit, a transfer unit that transfers a toner image on the surface of the photoconductive drum to a recording medium, a fixing unit that fixes the toner image on the recording medium, a waste toner collecting unit, and the blade member include the photoconductive drum. An image forming apparatus that removes residual toner on the surface of the photosensitive drum remaining after transfer by the cleaning unit and conveys the residual toner to the waste toner collecting unit. (5th invention) is provided.

According to the toner conveyance device of the present invention, the toner is conveyed from the upstream side to the downstream side of the toner conveyance path by rotating the spiral blade of the screw shaft. At this time, the toner on the upstream side mainly receives the conveying force in the direction along the rotation axis of the screw shaft.
When the toner is conveyed to the position of the thick portion of the spiral blade, a radial force that is a direction orthogonal to the rotation axis is gradually applied to the toner. This is because the thick-walled portion has a mountain-shaped or trapezoidal cross-sectional shape that gradually becomes thinner from the inner end toward the outer end, and has a thickness toward the downstream side of the toner conveyance path at a position facing the toner discharge port. This is because the thickness gradually increases.
Further, since the thick portion gradually increases toward the downstream side, the contact area between the thick portion and the toner gradually increases, and the rotational force of the thick portion is easily transmitted to the toner.
Furthermore, the shape and volume of the space between the thick portion and the inner peripheral wall of the toner discharge portion (for example, the space between the helical pitches above the rotation shaft) vary as the thick portion rotates.

Therefore, when transporting toner with reduced fluidity by the toner transport device of the present invention, in the toner discharge portion near the toner discharge port of the toner transport cylinder, the agglomerated toner around the rotating shaft is the thick portion of the spiral blade. Receiving the conveying force in the conveying direction, the radial force, and the rotating force in the circumferential direction of the rotation axis, and the shape and volume of the space between the thick wall portion and the inner peripheral wall of the toner discharge portion are changed. It is solved by and restores fluidity.
As a result, the toner whose fluidity around the rotating shaft has been recovered is smoothly pushed out from the toner discharge port without being in a compacted state as in the prior art, so that the screw shaft locking phenomenon is prevented. In particular, in the past, the aggregated toner above the rotating shaft, which is hard to be discharged, was likely to be in a compacted state. It is.

Further, according to the toner cartridge and the image forming apparatus provided with the toner conveying device, the screw shaft is prevented from being locked, so that the toner can be replenished stably to the developing unit. An image can be formed with an image density.
Further, according to the cleaning unit and the image forming apparatus provided with the toner conveying device, the screw shaft is prevented from being locked, so that the cleaning unit is filled with the removed toner (waste toner) and moves toward the photosensitive drum. The accident that the image forming apparatus overflows and the toner is contaminated can be prevented, and the cleaning function by the cleaning unit can be maintained.

FIG. 1 is an explanatory diagram showing the overall configuration of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a perspective view illustrating a configuration of a toner cartridge unit including a toner cartridge mounted on the image forming apparatus according to the first embodiment. FIG. 3 is a side sectional view of the toner cartridge according to the first exemplary embodiment. 4A is a side sectional view of the toner cartridge showing the sectional shape of the spiral blade in the screw shaft of FIG. 3, and FIG. 4B is a sectional view taken along the line AA of the toner cartridge in FIG. 4A. 4C is a cross-sectional view of the toner cartridge taken along line BB in FIG. 4A, and FIG. 4D is a cross-sectional view of the toner cartridge taken along line DD in FIG. 4A. . FIG. 5 is a side view illustrating a part of the screw shaft of the toner conveying device according to the first exemplary embodiment. 6A is a side cross-sectional view illustrating a part of the screw shaft of the toner conveying device according to the first exemplary embodiment, and FIG. 6B is a partial enlarged cross-sectional view of FIG. 6A. FIG. 7 is a side sectional view of the toner cartridge in the image forming apparatus according to the second embodiment. FIG. 8 is a side view illustrating a part of the screw shaft of the toner conveying device according to the second exemplary embodiment. FIG. 9 is a side cross-sectional view illustrating a part of the screw shaft of the toner conveying device according to the second exemplary embodiment. FIG. 10 is a side sectional view showing a part of the screw shaft of the toner conveying device in the image forming apparatus according to the third embodiment. FIG. 11 is a side sectional view showing a part of the screw shaft of the toner conveying device in the image forming apparatus according to the fourth embodiment. FIG. 12 is a schematic cross-sectional view of the toner conveying device in the image forming apparatus according to the fifth exemplary embodiment as viewed from the upstream side. FIG. 13 is a cross-sectional view illustrating a toner conveyance device according to the fifth exemplary embodiment.

The toner conveying device of the present invention can be used as a toner conveying mechanism in an electrophotographic image forming apparatus such as a monochrome or full-color copying machine, printer, facsimile machine, and multifunction machine having these functions.
More specifically, the toner conveying device of the present invention includes a toner conveying mechanism of a toner cartridge that is detachably (replaceable) attached to the main body of the image forming apparatus, and a cleaning unit that removes residual toner on the surface of the photosensitive drum. It can be used as a toner transport mechanism.

  The toner transport device includes a toner transport path disposed inside as described above, a toner introduction port disposed on the upstream side of the toner transport path in order to introduce toner into the toner transport path from the outside, A toner transport cylinder having a toner discharge port disposed downstream of the toner transport path for discharging the toner from the toner transport path to the outside; and the toner transport cylinder rotatably provided in the toner transport cylinder. A screw shaft that conveys the toner in the conveyance path from the upstream side to the downstream side.

The screw shaft has a rotating shaft and a spiral blade attached to the rotating shaft having a first surface inclined to the downstream side from the inner end to the outer end on the rotating shaft side and a second surface inclined to the upstream side. .
Here, in the spiral blade of the screw shaft, the second surface is an extrusion surface that transmits the conveyance force to the toner in the toner conveyance path.
The spiral blade has a cross-sectional shape (mountain shape or trapezoidal shape) that gradually becomes thinner from the inner end toward the outer end on the rotating shaft side, and toward the downstream side of the toner conveyance path at a position facing the toner discharge port. It has a thick portion where the thickness is gradually increased.
Here, although the thickness of the thick portion changes as described above, the cross-sectional shape maintains a mountain shape or a trapezoid shape. Therefore, although it depends on the rate of change in the thickness of the thick portion, the pitch of the spiral blades, and the like, the thick portion may have a portion that covers the rotating shaft.
Specifically, the toner conveying device may be configured as follows.

(1) In the thick portion of the spiral blade, the first surface is inclined with respect to the axis of the rotation shaft so as to gradually approach parallel to the downstream side of the toner conveyance path, and the rotation shaft The second surface is inclined so as to gradually approach parallel to the downstream axis of the toner conveyance path. In other words, the thickness of the thick portion changes in the direction of the first surface and the second surface. This configuration corresponds to Embodiment 1 described later.
In this way, the variation in the shape and volume of the space between the thick wall portion and the toner discharge portion can be increased, so that the effect of removing the aggregated toner can be enhanced.

(2) In the thick portion of the spiral blade, the first surface is inclined with respect to the axis of the rotation shaft so as to gradually approach parallel to the downstream side of the toner conveyance path, and the rotation shaft The second surface is inclined at a constant angle with respect to the axial center. In other words, the thickness of the thick portion changes only in the direction of the first surface. This configuration corresponds to Embodiment 2 described later.
In this way, since the inclination angle of the second surface, which is the extruded surface of the thick wall portion, with respect to the rotational axis is constant, the toner can be released while reducing the radial force, whereby the toner is Stress due to being pressed against the peripheral wall of the discharge portion can be reduced.

(3) In the case of (1) or (2), in the spiral blade, at the end portion on the most downstream side of the thick wall portion, adjacent to the first surface and perpendicular to the axis of the rotation shaft End faces are arranged. This configuration corresponds to Embodiments 1 and 2 described later.
In this way, the wall surface on the most downstream side of the toner conveyance path is covered with the vertical end surface, and the toner conveyance is finished on the first surface, so that the conveyance force in the downstream direction is not transmitted to the toner. It can be prevented from being pressed against the wall surface on the most downstream side, and toner accumulation on the wall surface on the most downstream side can be prevented.

(4) In the case of (1) to (3), the thick portion has a plurality of step portions arranged in a spiral direction on at least one of the first surface and the second surface. This configuration corresponds to Embodiments 3 and 4 described later.
In this way, the rotational force is easily transmitted to the toner around the rotation shaft by the plurality of step portions when the thick wall portion rotates, so that the toner discharge port can be smoothly discharged while effectively solving the agglomerated toner. And the stress caused by the toner being pressed against the peripheral wall of the toner discharge portion can be further reduced.
Examples of the stepped portion include a raised portion protruding from the surface on which the stepped portion is provided, a concave portion formed on the surface, or a combination of the convex portion and the concave portion. Examples of the convex portion include a dot shape, a ridge shape, and a small piece. Examples of the recess include a dot shape and a groove shape.
These convex portions and concave portions are preferably arranged so as to easily transmit the rotational force to the toner.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

(Embodiment 1)
FIG. 1 is an explanatory diagram showing the overall configuration of an image forming apparatus according to Embodiment 1 of the present invention.
As shown in FIG. 1, the image forming apparatus 100 according to the first embodiment includes four image forming units 55 (55a to 55d), and toner cartridges 200 (200a to 200d) to be described later provided in the image forming units 55. ).
In the first embodiment, a multicolor or single color image is displayed on a predetermined sheet (recording paper) based on image data included in an input command such as image data transmitted from the outside via a communication network or the like. However, as an image forming apparatus, a multi-color or single-color image is recorded on a recording medium according to image data transmitted from the outside and / or image data read from a document by a scanner. It may be a copier, a facsimile machine, or a multifunction machine having these functions.

<Overall configuration of image forming apparatus>
First, the overall configuration of the image forming apparatus 100 will be described in detail.
As shown in FIG. 1, the image forming apparatus 100 according to the first embodiment includes an exposure unit E, the four image forming units 55 (55a to 55d), the intermediate transfer belt 11, and the primary transfer roller 13 (13a to 13a). 13d), the secondary transfer roller 14, the fixing unit 15, the paper transport paths P1, P2, and P3, the paper feed cassette 16, the manual paper feed tray 17, the paper discharge tray 18, the toner cartridge unit 20, and the like. It has.
Each of the image forming units 55 (55a to 55d) includes a photosensitive drum 101 (101a to 101d) corresponding to an image carrier on which a latent image is formed by the exposure unit E, and a developing unit 102 (102a to 102d). The charging roller 103 (103a to 103d) and the cleaning unit 104 (104a to 104d) are provided.

The image data of the color image handled in the image forming apparatus 100 is image data corresponding to the four hues of black (K), cyan (C), magenta (M), and yellow (Y). Based on the image data, a visible image is formed by each of the image forming units 55 (55a to 55d).
Accordingly, in each image forming unit 55 (55a to 55d), the developing unit 102 (102a to 102d), the photosensitive drum 101 (101a to 101d), and the charging are formed so as to form four types of latent images corresponding to the respective colors. One roller 103 (103a to 103d), one transfer roller 13 (13a to 13d), and one cleaning unit 104 (104a to 104d) are provided.
The image forming units 55 (55a to 55d) are arranged in a line in the moving direction (sub-scanning direction) of the intermediate transfer belt 11.

  Since each image forming unit 55a to 55d has the same configuration, in this specification, each image forming unit is indicated by a unified reference numeral 55, and each photosensitive drum provided in each image forming part is designated by a unified reference numeral 101. The developing unit is indicated by a unified reference numeral 102, each charging roller is indicated by a unified reference numeral 103, each transfer roller is indicated by a unified reference numeral 13, and each cleaning unit is indicated by a unified reference numeral 104. The symbols a to d correspond to a for black, b for cyan, c for magenta, and d for yellow, and the above-mentioned means distinguished by these symbols constitute four image stations. Has been.

The exposure unit E, which is an exposure apparatus, includes a semiconductor laser, a polygon mirror 4, a first reflection mirror 7, a second reflection mirror 8, and the like (not shown), and image data for each hue of black, cyan, magenta, and yellow. Each of the photosensitive drums 101a to 101d is irradiated with a light beam such as a laser beam modulated by. On each of the photosensitive drums 101a to 101d, an electrostatic latent image is formed based on image data of each hue of black, cyan, magenta, and yellow.
In the present embodiment, the exposure unit E is a method using a laser scanning unit (LSU) including a laser irradiation unit and a reflection mirror. For example, an EL or LED writing head in which light emitting elements are arranged in an array. You may use the thing of the method using.

The photosensitive drum 101 is a substantially cylindrical image carrier disposed above the exposure unit E, and is controlled to rotate in a predetermined direction by a driving unit and a control unit (not shown).
The photosensitive drum 101 includes, for example, a base material made of a metal drum made of aluminum or the like, and amorphous silicon (a-Si), selenium (Se), or an organic optical semiconductor (OPC) laminated on the outer peripheral surface of the base material. ) And other thin film photoconductive layers. Note that the configuration of the photosensitive drum 101 is not particularly limited to this configuration.

The charging roller 103 is a contact-type charger that uniformly charges the surface of the photosensitive drum 101 to a predetermined potential.
In the first embodiment, as shown in FIG. 1, a contact-type roller-type charging roller 103 is used as a charger, but a charger-type or brush-type charger is used instead of the charging roller 103. Also good.

The developing unit 102 supplies toner to the surface of the photosensitive drum 101 on which the electrostatic latent image is formed, and develops the electrostatic latent image into a toner image.
Each of the developing units 102a to 102d contains black, cyan, magenta, and yellow toners, and the electrostatic latent images formed on the photosensitive drums 101a to 101d corresponding to the respective hues are black, cyan, It is visualized as a magenta and yellow toner image.

The cleaning unit 104 removes and collects the toner remaining on the surface of the photosensitive drum 101 after development and image transfer with a lubricant or the like.
The intermediate transfer belt 11 disposed above the photosensitive drum 101 is formed endlessly with a film having a thickness of about 100 to 150 μm, and is a driving roller disposed on the downstream side and the upstream side in the toner image transport direction. It is stretched between 11a and the driven roller 11b to form a loop-shaped movement path.
The photosensitive drum 101 facing the lower outer peripheral surface of the intermediate transfer belt 11 is arranged in the order of the photosensitive drum 101d, the photosensitive drum 101c, the photosensitive drum 101b, and the photosensitive drum 101a from the upstream side in the toner image conveying direction. .

On the lower inner peripheral surface side of the intermediate transfer belt 11, primary transfer rollers 13a to 13d that are in contact with the lower inner peripheral surface and press the lower outer peripheral surfaces against the photosensitive drums 101a to 101d are disposed. A contact position of the belt 11 with each of the photosensitive drums 101a to 101d is a primary transfer position.
The primary transfer rollers 13a to 13d transfer the toner images carried on the surfaces of the photosensitive drums 101a to 101d onto the intermediate transfer belt 11, and the primary transfer bias having a polarity opposite to the charging polarity of the toner is controlled by constant voltage control. Applied.
As a result, the toner images of the respective colors formed on the photosensitive drums 101a to 101d are sequentially transferred onto the outer peripheral surface of the intermediate transfer belt 11, and a full-color toner image is formed on the outer peripheral surface of the intermediate transfer belt 11. .

However, when image data of only a part of the hues of yellow, magenta, cyan, and black is input, a part of the four photosensitive drums 101a to 101d corresponding to the hue of the input image data. Only the photosensitive drum 101 forms an electrostatic latent image and a toner image.
For example, when forming a monochrome image, an electrostatic latent image and a toner image are formed only on the photosensitive drum 101a corresponding to the black hue, and only the black toner image is formed on the outer peripheral surface of the intermediate transfer belt 11. Transcribed.

Each of the primary transfer rollers 13a to 13d includes a shaft made of a metal (for example, stainless steel) having a diameter of 8 to 10 mm and a conductive elastic material (for example, EPDM, urethane foam, or the like) that covers the surface of the shaft. A high voltage is uniformly applied to the intermediate transfer belt 11 by a conductive elastic material.
In this embodiment, the primary transfer rollers 13a to 13d are used as the transfer electrodes, but brushes and the like can also be used.

At each primary transfer position, the toner image transferred onto the outer peripheral surface of the intermediate transfer belt 11 is conveyed to a secondary transfer position that is a position facing the secondary transfer roller 14 by the rotation of the intermediate transfer belt 11.
The secondary transfer roller 14 is pressed against the outer peripheral surface of the intermediate transfer belt 11 wound around the driving roller 11a at a predetermined nip pressure during image formation. In order to constantly obtain the nip pressure, either the secondary transfer roller 14 or the drive roller 11a is made of a hard material such as metal, and the other is a soft material such as an elastic roller (elastic rubber roller or foaming resin). Roller).

When the paper fed from the paper feed cassette 16 or the manual paper feed tray 17 passes through the secondary transfer position between the secondary transfer roller 14 and the intermediate transfer belt 11, the secondary transfer roller 14 is charged with toner. A high voltage having a polarity (+) opposite to the polarity (−) is applied.
As described above, the electrostatic latent images on the respective photosensitive drums 101a to 101d are visualized with toners corresponding to the respective hues to become toner images, and these toner images are stacked on the intermediate transfer belt 11. The Thereafter, the stacked toner images are conveyed to the secondary transfer position by the rotation of the intermediate transfer belt 11, and the toner images are transferred onto the paper conveyed to the secondary transfer position.

The toner remaining on the intermediate transfer belt 11 without being transferred to the sheet causes a color mixture of the toner in the next step, and is removed and collected by the intermediate transfer belt cleaning unit 12.
The intermediate transfer belt cleaning unit 12 is provided with, for example, a cleaning blade that contacts the intermediate transfer belt 11. This cleaning blade is disposed so as to contact the outer peripheral surface portion of the intermediate transfer belt 11 supported by the driven roller 11b.

The sheet on which the toner image is transferred as a visible image is guided to a fixing unit 15 including a heating roller 15a and a pressure roller 15b, and passes between the heating roller 15a and the pressure roller 15b to be heated and pressed. Receive. As a result, the toner image that becomes a visible image is firmly fixed on the surface of the paper.
Then, the sheet on which the toner image is fixed is discharged onto the discharge tray 18 by the discharge roller 18a.

In the image forming apparatus 100, a substantially vertical direction for feeding the paper stored in the paper cassette 16 to the paper discharge tray 18 between the secondary transfer roller 14 and the intermediate transfer belt 11 and via the fixing unit 15. A paper transport path P1 is provided.
In the paper transport path P1, a pickup roller 16a that feeds the paper in the paper cassette 16 one by one into the paper transport path P1, a transport roller r10 that transports the fed paper upward, and the transported paper is predetermined. A registration roller 19 that guides between the secondary transfer roller 14 and the intermediate transfer belt 11 at the timing and a paper discharge roller 18 a that discharges the paper to the paper discharge tray 18 are disposed.

Further, inside the image forming apparatus 100, a paper conveyance path P2 in which a pickup roller 17a and a conveyance roller r10 are arranged is provided between the manual paper feed tray 17 and the registration roller 19.
Further, a paper transport path P3 is formed between the paper discharge roller 18a and the upstream side of the registration roller 19 in the paper transport path P1.

The paper discharge roller 18a is provided so as to be rotatable in both forward and reverse directions. When forming a single-sided image for forming an image on one side of a sheet, and for forming a second-side image in double-sided image formation for forming an image on both sides of a sheet. Driven in the forward direction, the paper is discharged to the paper discharge tray 18.
On the other hand, when the first side image is formed in the double-sided image formation, the paper discharge roller 18a is driven in the normal rotation direction until the rear end of the paper passes through the fixing unit 15, and then the rear end of the paper is sandwiched. Driven in the reverse direction, the paper is guided into the paper transport path P3. As a result, the sheet on which the image is formed on only one side during the double-sided image formation is guided to the sheet conveyance path P1 with the front and back sides and the front and rear ends reversed.

The registration roller 19 feeds the sheet fed from the sheet cassette 16 or the manual feed tray 17 or conveyed via the sheet conveying path P3 at a timing synchronized with the rotation of the intermediate transfer belt 11. And the intermediate transfer belt 11.
For this reason, the registration roller 19 stops rotating when the operation of the photosensitive drum 101 and the intermediate transfer belt 11 is started, and the sheet fed or conveyed prior to the rotation of the intermediate transfer belt 11 has a leading edge. The movement in the paper conveyance path P1 is stopped in a state where it is in contact with the registration roller 19. Thereafter, the registration roller 19 is a position where the secondary transfer roller 14 and the intermediate transfer belt 11 are in pressure contact with each other, at a timing when the front end portion of the sheet and the front end portion of the toner image formed on the intermediate transfer belt 11 face each other. Start spinning.

  Note that in all of the image forming units 55a to 55d, the primary transfer rollers 13a to 13d press the intermediate transfer belt 11 against all of the photosensitive drums 101a to 101d when full-color images are formed. On the other hand, only the primary transfer roller 13a presses the intermediate transfer belt 11 against the photosensitive drum 101a during monochrome image formation in which image formation is performed only in the image forming unit 55a.

<Configuration of toner cartridge>
Next, the configuration of the toner cartridge 200 according to Embodiment 1 will be described in detail with reference to the drawings.
FIG. 2 is a perspective view illustrating a configuration of a toner cartridge unit including a toner cartridge mounted on the image forming apparatus according to the first embodiment.
3 is a side cross-sectional view of the toner cartridge according to the first exemplary embodiment, and FIG. 4A is a side cross-sectional view of the toner cartridge showing the cross-sectional shape of the spiral blade in the screw shaft of FIG. 4B is a cross-sectional view taken along the line AA of the toner cartridge in FIG. 4A, and FIG. 4C is a cross-sectional view taken along the line BB of the toner cartridge in FIG. FIG. 6 is a cross-sectional view of the toner cartridge in FIG.

As shown in FIGS. 2 to 4, the toner cartridge 200 includes a cartridge main body M, a toner conveying device G <b> 1 of the present invention and a paddle member 206 provided in the cartridge main body M.
More specifically, the toner cartridge 200 is formed in a sealed container shape that is long in one direction and has a toner housing cartridge body 201 having a toner discharge port 204a on one end in the longitudinal direction thereof, and is provided on the outer surface side of the cartridge body 201. And a shutter 203 for opening and closing the toner discharge port 204a, and a toner (in the cartridge main body 201, provided in a position that can rotate about the rotation axis in the longitudinal direction and overlaps the toner discharge port 204a). (Not shown) has a screw shaft 202 for conveying the toner discharge port 204a to the toner discharge port 204a, and a rotation shaft 206a parallel to the rotation shaft 202a of the screw shaft 202 in the cartridge main body 201. The toner in the cartridge main body 201 is transferred to the screw shaft 202 side. The paddle part for feeding into And a 206.

  In the toner cartridge 200, the cartridge main body 201 has a substantially rectangular parallelepiped portion 201a and a protruding portion 201b connected to one end in the longitudinal direction of the substantially rectangular parallelepiped portion 201a. Note that one end of the rotating shaft 202a of the screw shaft 202 in the cartridge main body 201 passes through the side wall of the protruding portion 201b and protrudes to the outside, and a drive gear 202c is attached to one end thereof.

As shown in FIG. 2, four toner cartridges 200 are mounted side by side in the toner cartridge holder 20x, and thus the toner cartridge unit 20 is configured.
The toner cartridge holder 20x has an upper opening container shape, and has four concave portions partitioned by a partition wall inside, and the toner cartridge 200 is accommodated in the four concave portions.
Further, a wall portion on both sides in the longitudinal direction of the concave portion of the toner cartridge holder 20x is formed with a window portion through which the drive gear 202c of each toner cartridge 200 is inserted and a notch portion in which the lock lever 20a is swingably attached. ing.
The toner cartridge 200 is fitted into the recess of the toner cartridge holder 20x, and the lock lever 20a of the toner cartridge holder 20x is lifted to move the cartridge body 201 to the right (in the direction of arrow F), thereby stopping the stopper plate 20b of the toner cartridge holder 20. Is held in a pressed state.

Further, a notch window (not shown) is formed on the bottom wall of the concave portion of the toner cartridge holder 20x from the position facing the toner discharge port 204a of each mounted toner cartridge 200 to the edge in the vicinity thereof. ing.
When the toner cartridge unit 20 is attached to the image forming apparatus, the toner cartridge 200 moves in a substantially horizontal direction with respect to the toner supply pipe 105, so that the shutter 203 is placed on the upper end of the toner supply pipe 105 that has passed through the notch window. When the shutter 203 moves in a substantially horizontal direction and the toner discharge port 204a is disposed at a position facing the toner supply pipe 105, the toner discharge port 204a is opened (see FIG. 1).
The image forming apparatus is provided with a gear that meshes with the drive gear on the paddle member 206 side and the drive gear on the screw shaft 202 side of each toner cartridge 200 to transmit the rotational force from the drive motor.

The cartridge main body 201 is a large volume space in which the paddle member 206 is disposed, and a small volume space in which the toner accommodating portion 201x in which most of the toner T is accommodated and the screw shaft 202 are disposed. A toner conveying path 201y is provided which is adjacent to and in communication with the toner container 201x and has a toner discharge port 204a disposed at one end in the longitudinal direction thereof.
One end portion of the toner conveyance path 201y in the longitudinal direction is an internal space of the protruding portion 201b of the cartridge body 201, and serves as a toner discharge portion 204 having a toner discharge port 204a.
That is, the cartridge main body 201 is formed in a shape in which the toner conveyance path 201y protrudes to one end side in the longitudinal direction from the toner accommodating portion 201x, and the toner discharge port 204a is one end in the longitudinal direction from the toner accommodating portion 201x. It is disposed in the protruding space of the toner conveyance path 201y protruding to the side.
Note that the bottom surfaces of the toner container 201x and the toner conveyance path 201y are formed in an arc shape.

The toner discharge port 204 a is a rectangular opening provided at the bottom of the toner discharge unit 204, and is an opening for discharging the toner carried by the screw shaft 202 to the outside of the toner cartridge 200.
The shutter 203 is a substantially square plate-like shutter that is slidably provided at a position where the toner discharge port 204a is closed, and opens the toner discharge port 204a when the toner cartridge 200 is mounted on the image forming apparatus. Is.
In a state before the toner cartridge 200 is attached to the image forming apparatus, the shutter 203 is elastically biased in a direction to close the toner discharge port 204a by a spring member (not shown), for example.

The paddle member 206 includes a rotating shaft 206a and a single rectangular stirring blade 206b attached to the rotating shaft 206a.
One end of the rotating shaft 206a penetrates through a side wall on one end side in the longitudinal direction of the cartridge main body 201 in the toner accommodating portion 201x, and a driving gear (not shown) is attached to one end thereof.
The other end of the rotation shaft 206a is rotatably fitted in and supported by a recess provided on the side wall on the other end side in the longitudinal direction of the cartridge main body 201 in the toner accommodating portion 201x.

The stirring blade 206b is made of a flexible sheet member such as a resin sheet (for example, a PET sheet) and a rubber sheet having both appropriate flexibility and rigidity, and its length is slightly shorter than the length of the toner container 201x. The width is a dimension that is in sliding contact with or close to the bottom surface of the toner storage unit 201.
The agitation paddle 206 releases the toner in the toner container 201x and feeds the released toner into the toner conveyance path 201y as the rotation shaft 206a rotates in the direction of arrow E.

[Configuration of toner transport device]
The toner conveying device G1 of the present invention has a basic structure including a toner conveying cylinder and a screw shaft that is rotatably provided in the toner conveying cylinder.
In the case of the first exemplary embodiment, the toner conveying device G1 is integrated with the cartridge main body 201 and is incorporated as a part of the configuration of the toner cartridge 200.

  More specifically, in the toner transport device G1, the toner transport cylinder constitutes a wall portion around the screw shaft 202 in the cartridge body 201, and the toner transport path 201y and the toner transport path 201y A toner introduction port arranged on the upstream side of the toner conveyance path 201y for introducing toner from the outside, and the above-mentioned arrangement arranged on the downstream side of the toner conveyance path 201y for discharging the toner from the toner conveyance path 201y to the outside. And a toner discharge port 204a.

Therefore, the toner cartridge 200 is provided on the outer surface side of the cartridge main body 201 and the cartridge main body 201 having the toner containing device 201x disposed adjacent to the toner transport device G1 and the toner transport device G1. A shutter 203 for opening and closing the outlet 204a, and a paddle member 206 that is rotatably provided in the cartridge main body 201 and feeds the toner in the toner container 201x from the toner introduction port into the toner conveyance path 201y. Yes.
Here, the toner inlet corresponds to a communication portion at the boundary between the toner storage portion 201x and the toner conveyance path 201y.

FIG. 5 is a side view showing a part of the screw shaft of the toner conveying device according to the first embodiment, and FIG. 6A is a side sectional view showing a part of the screw shaft of the toner conveying device according to the first embodiment. FIG. 6B is a partially enlarged cross-sectional view of FIG.
As shown in FIGS. 3 to 6, the screw shaft 202, the inclined with the rotation shaft 202a, from the inner end of the rotating shaft 202a side to the first surface 202b ₁ and the upstream sloping downstream towards the outer end a auger screw having a spiral blade 202b attached to the rotary shaft having two surfaces 202b _2.

The spiral blade 202b has a trapezoidal cross-sectional shape that gradually becomes thinner from the inner end toward the outer end on the rotating shaft 202a side, and toward the downstream side of the toner conveyance path 201y at a position facing the toner discharge port 204a. In the thick portion 202A, the first surface 202b ₁ gradually becomes parallel to the axial center of the rotation shaft 202a toward the downstream side of the toner conveyance path 201y. And the second surface 202b ₂ is inclined so as to gradually approach parallel to the downstream side of the toner conveyance path 201y with respect to the axis of the rotation shaft 202a.

More specifically, as shown in FIG. 5, in the thick portion 202A, the inclination angle of the first surface 202b ₁ with respect to the axis (or a parallel line thereof) of the rotation shaft 202a is an inclination angle from the upstream side toward the downstream side. P1, P2, P3, P4 with which is gradually reduced in the order of the inclination angle with respect to the second face 202b ₂ of the rotary shaft 202a of the shaft center (or parallel lines), the angle of inclination as the upstream side toward the downstream side It gradually decreases in the order of Q1 and Q2.

As shown in FIGS. 5 and 6, for example, in the case of a spiral blade 202b having a spiral pitch L1 of 15 to 30 mm and a height h of 5 to 12 mm, the first surface 202b ₁ other than the thick portion 202A The inclination angle P0 and the inclination angle Q0 of the second surface 202b ₂ are both 80 to 90 degrees, the inclination angle of the first surface 202b ₁ of the thick part 202A is reduced to about 20 to 45 degrees, and the thick part 202A The inclination angle of the second surface 202b ₂ decreases to about 20 to 45 degrees.
Further, in this spiral blade 202b, the thicknesses D and D1 at the height 1 / 2h of the part other than the thick part 202A are 2 to 5 mm, and the thickness of the thick part 202A is increased from the upstream side toward the downstream side. The thickness gradually increases in the order of D2 and D3, the thickness D2 is 6 to 8 mm, and the thickness D3 is 10 to 12 mm.

Furthermore, the spiral blade 202b is on the end of the most downstream side of the thick portion 202A, the vertical end surface 202b ₃ perpendicular to the first surface 202b ₁ and adjacent and the axis of the rotary shaft 202a is arranged.
That is, the downstream end of the spiral blade 202b has a shape that is expanded in diameter toward the wall surface 204b on the most downstream side of the toner discharge portion 204.

[Effects of toner cartridge]
By attaching the toner cartridge 200 to the image forming apparatus, the shutter 203 is opened and the toner discharge port 204a and the toner supply pipe 105 communicate with each other.
Then, when the image forming apparatus is driven, the paddle member 206 is rotated so as to scrape the toner in the toner accommodating portion 201x while being sent to the toner conveying path 201y, and the screw shaft 202 is rotated to rotate the toner conveying path 201y. The toner inside is sent to the toner discharge unit 204, and the toner is supplied from the toner discharge port 204a to the developing device 102 through the toner supply path 105 (see FIG. 1).

At this time, the toner cartridge 200 may have toner agglomerates or lumps on the toner discharge portion 204 side before use.
However, when the thick portion 202A of the spiral blade 202b of the screw shaft 202 rotates, the aggregated toner around the rotation shaft 202a causes the conveyance force in the conveyance direction by the thick portion 202A, the radial force, and the rotation shaft. The shape and volume of the space between the thick wall portion 202A and the inner peripheral wall of the toner discharge portion 204 (for example, the upper portion of the thick wall portion 202A and the upper surface of the inner peripheral wall of the toner discharge portion 204) in response to the rotational force in the circumferential direction. Is solved by fluctuations and restores liquidity.

As a result, the toner whose fluidity around the rotating shaft 202a has been recovered is smoothly pushed out from the toner discharge port 204a and replenished to the developing unit without being compressed as in the conventional case, and the toner discharge unit 204 is also supplied. Thus, the locking phenomenon of the screw shaft 202 due to the toner being in a consolidated state is prevented.
Further, the vertical end surface 202b ₃ at the downstream end of the spiral blade 202b covers the wall surface 204b on the most downstream side of the toner conveyance path 201y, and the toner conveyance is terminated by the first surface 202b ₁ that is not the extrusion surface. Is not transmitted to the toner, it is possible to prevent the toner from being pressed against the wall surface 204b on the most downstream side and to prevent toner accumulation on the wall surface 204b on the most downstream side.

(Embodiment 2)
7 is a side sectional view of the toner cartridge in the image forming apparatus according to the second embodiment, FIG. 8 is a side view showing a part of the screw shaft of the toner conveying apparatus according to the second embodiment, and FIG. FIG. 4 is a side cross-sectional view illustrating a part of a screw shaft of a toner conveying device.
A toner cartridge 300 according to the second exemplary embodiment includes a paddle member (not shown) and a toner conveying device G2 in the cartridge main body 301. The toner shaft 300 of the toner conveying device G2 is the same as that of the first exemplary embodiment except that the screw shaft 302 is different from the first exemplary embodiment. It has the composition of. Hereinafter, points of the second embodiment different from the first embodiment will be mainly described.
In FIG. 7, reference numeral 301y denotes a toner conveyance path, 303 denotes a shutter, 304 denotes a toner discharge portion, and 304a denotes a toner discharge port.

As shown in FIG. 7, the screw shaft 302 of the second embodiment is attached to one end of a rotating shaft 302a, a spiral blade 302b attached to the rotating shaft 302a, and the rotating shaft 302a protruding from the toner discharge portion 304 to the outside. Drive gear 302c.
The spiral blade 302b has a first surface 302b ₁ inclined to the downstream side from the inner end to the outer end on the rotating shaft 302a side and a second surface 302b ₂ inclined to the upstream side.

The spiral blade 302b has a trapezoidal cross-sectional shape that gradually becomes thinner from the inner end toward the outer end on the rotating shaft 302a side, and at the position facing the toner discharge port 304a, on the downstream side of the toner conveyance path 301y. It has a thick portion 302A that gradually increases in thickness.
As shown in FIGS. 8 and 9, in the thick portion 302A, the first surface 302b ₁ is inclined with respect to the axis of the rotation shaft 302a so as to gradually approach parallel to the downstream side of the toner conveyance path 301y. The second surface 302b ₂ is inclined at a constant angle with respect to the axis of the rotation shaft 302a.

More specifically, in the thick portion 302A, the inclination angle of the first surface 302b ₁ with respect to the axis (or parallel line thereof) of the rotation shaft 302a is inclined as P11, P12, P13, P14 from the upstream side toward the downstream side. In addition, the inclination angles Q11, Q12, Q13, Q14 from the upstream side to the downstream side with respect to the axis (or parallel line thereof) of the rotation shaft 302a of the second surface 302b ₂ are thick portions. It is the same as the portion other than 302A.

For example, in the case of the spiral blade 302b having a spiral pitch L2 of 15 to 30 mm and a height h (see FIG. 6B) of 5 to 12 mm, the inclination angle of the first surface 302b ₁ other than the thick portion 302A In addition, the inclination angle of the second surface 302b ₂ is 80 to 90 degrees, the inclination angle of the first surface 302b ₁ of the thick portion 302A is reduced to about 20 to 40 degrees, and the second surface 302b of the thick portion 302A. The inclination angle of ₂ is about 80 to 90 degrees.
Further, in this spiral blade 302b, the thickness of the portion other than the thick portion 302A at the height 1 / 2h is 2 to 5 mm, and the thickness of the thick portion 302A gradually increases from the upstream side toward the downstream side. ing.

Furthermore, the spiral blade 302b is on the end of the most downstream side of the thick portion 302A, the vertical end surface 302b ₃ orthogonal to the axis of the first face 302b ₁ and adjacent and the rotary shaft 302a is arranged.
In other words, the downstream end of the spiral blade 302b has a shape whose diameter is increased toward the wall surface 304b on the most downstream side of the toner discharge portion 304.

In the toner cartridge 300 of the second embodiment, the fluidity is recovered by releasing the aggregated toner in the toner discharge portion 304 as in the first embodiment by rotating the thick portion 302A of the spiral blade 302b of the screw shaft 302. Therefore, the toner can be smoothly supplied to the developing unit, and the locking phenomenon of the screw shaft 302 in the toner discharge unit 304 and the toner accumulation on the wall surface 304b on the most downstream side of the toner conveyance path 301 can be performed. Can be prevented.
Further, in the case of the second embodiment, since the inclination angle of the second surface 302b ₂ that is the extrusion surface of the thick portion 302A with respect to the rotation axis is constant, the toner can be solved while reducing the radial force, As a result, the stress caused by the toner being pressed against the peripheral wall of the toner discharge portion 304 can be reduced.

(Embodiment 3)
FIG. 10 is a side sectional view showing a part of the screw shaft of the toner conveying device in the image forming apparatus according to the third embodiment.
In the third embodiment, the screw shaft 402 is different from the first embodiment, and the other points are the same as in the first embodiment.
In FIG. 10, reference numeral 401y denotes a toner conveyance path, 404 denotes a toner discharge portion, and 404a denotes a toner discharge port.

Similar to the first embodiment, the screw shaft 402 according to the third embodiment includes a rotating shaft 402a and a spiral blade 402b having a thick portion 402A attached to the rotating shaft 402a. The first surface 402b ₁ and the second surface 402b ₂ have a plurality of protrusion-shaped stepped portions 402c arranged in a spiral direction on both the first surface 402b ₁ and the second surface 402b ₂ .
The ridge-shaped stepped portion 402c has a longitudinal direction that is long in the radial direction, and the plurality of ridge-shaped stepped portions 402c are arranged at predetermined intervals in the spiral direction, and when viewed from the axial direction of the rotating shaft 402a, the rotating shaft They are arranged radially around 402a.

In the case of the third embodiment, in addition to the effects of the first embodiment, when the thick wall portion 402A rotates, it becomes easy to transmit the rotational force to the toner around the rotation shaft 402a by the plurality of stepped portions 402c, and thus effectively agglomerates. While releasing the toner, the toner can be discharged more smoothly from the toner discharge port 404a, and the effect of further reducing the stress caused by the toner being pressed against the peripheral wall of the toner discharge portion 404 can be obtained.
Note that the stepped portion 402c is not limited to a ridge shape, and for example, a dot-shaped or small-shaped convex portion may be provided in a region where the ridge-shaped stepped portion 402c is provided, or a dot-shaped or groove-shaped portion may be provided. A recess may be provided. Further, the stepped portion 402c may be only _{one of} the first surface 402b ₁ and the second surface 402b ₂ .

(Embodiment 4)
FIG. 11 is a side sectional view showing a part of the screw shaft of the toner conveying device in the image forming apparatus according to the fourth embodiment.
In the fourth embodiment, the screw shaft 502 is different from the second embodiment, and the other points are the same as in the second embodiment.
In FIG. 11, reference numeral 501y denotes a toner conveyance path, 504 denotes a toner discharge portion, and 504a denotes a toner discharge port.

Similar to the second embodiment, the screw shaft 502 according to the fourth embodiment includes a rotating shaft 502a and a spiral blade 502b having a thick portion 502A attached to the rotating shaft 502a. Similar to the third embodiment, the first surface 502b ₁ and the second surface 502b ₂ are provided with a plurality of protrusion-shaped step portions 502c arranged in the spiral direction.
In the case of the fourth embodiment, the effect of the third embodiment is obtained in addition to the effect of the second embodiment.

(Embodiment 5)
FIG. 12 is a schematic cross-sectional view of the toner conveying device in the image forming apparatus according to the fifth exemplary embodiment as viewed from the upstream side. FIG. 13 is a cross-sectional view illustrating the toner conveying device according to the fifth exemplary embodiment.
In the first to fourth embodiments, the case where the toner conveying device is provided in the toner cartridge of the image forming apparatus is illustrated.
On the other hand, in the fifth embodiment, a case where the toner conveying device G3 is provided in the cleaning unit 104 (see FIG. 1) of the image forming apparatus is illustrated.
As shown in FIG. 13, the image forming apparatus according to the fifth embodiment further includes a waste toner collection unit 610 and a relay conveyance device 630 that connects the cleaning unit 104 and the waste toner collection unit 620.

As described above, the cleaning unit 104 removes residual toner on the surface of the photosensitive drum 101 remaining after transfer.
The toner conveying device G3 provided in the cleaning unit 104 includes an internal toner conveying path 601y, a toner discharging portion 604 having a toner discharging port 604a disposed on the downstream side of the toner conveying path 601y, and a photosensitive drum 101 side. The toner conveying cylinder 601 having a substantially rectangular parallelepiped shape having an open toner introduction port 601a is provided, and a screw shaft 602 having the same configuration as that of the first embodiment is rotatably provided in the toner conveying cylinder 601.
In FIG. 13, reference numeral 602a denotes a rotating shaft, 602b denotes a spiral blade, 602c denotes a drive gear, and 602A denotes a thick portion.

The cleaning unit 104 includes an upper blade member (cleaning blade) 611 and a lower blade member (waste toner) attached to the upper and lower opening edges of the toner introduction port 601a in the toner conveyance device G3 and the toner conveyance cylinder 601 of the toner conveyance device G3. Fall prevention mylar) 612.
The upper blade member 611 is made of a rubber-like member having a predetermined hardness, and is in contact with the surface of the photosensitive drum 101 to drop the residual toner, and is inclined downward toward the front end side with a screw to form a toner conveying cylinder. 601 is attached.
The lower blade member 612 is made of a plastic material, and is inclined upward toward the front end side so as to receive residual toner dropped from the surface of the photosensitive drum 101 by the upper blade member 611 and introduce it into the toner conveyance path 601y. In this state, it is attached to the toner transport cylinder 601.
In FIG. 12, an arrow A indicates the rotation direction of the photosensitive drum 101.

The relay conveyance device 630 is rotatably provided in the relay conveyance path 631 and a relay conveyance path 631 composed of a flexible tube that connects the toner discharge port 604a of the toner conveyance device G3 and the waste toner collecting unit 620. A coil spring 632 and a drive unit 633 that rotationally drives the coil spring 632 are provided.
More specifically, an L-shaped connecting tube portion 601b communicating with the toner discharge port 604a is provided at the downstream end portion of the toner conveying tube 601. The lower end of the connecting cylinder 601b is opened in a direction orthogonal to the toner discharge port 604a and connected to the relay conveyance path 631. And the conveyance upstream end part of the coil spring 632 is arrange | positioned in the connection cylinder part 601b.

As the drive unit 633 of the relay conveyance device 630, for example, an interlocking shaft that is pivotally attached through the side wall of the connection tube portion 601b and an end portion on the inner side of the connection tube portion 601b of the connection shaft are fixed. And a transmission gear (not shown) that transmits the rotational force of the rotary shaft 602a of the screw shaft 602 to the interlocking shaft. The upstream side of the coil spring 632 is conveyed on the rotary plate. The ends of are connected.
The waste toner collection unit 620 includes an outer box having an upper connection port that is connected to the downstream conveyance side of the relay conveyance path 631 and an upper-open waste toner collection box that is detachably mounted in the outer box.

  The cleaning unit 104 configured as described above is a phenomenon in which the tip of the upper blade member 611 that contacts the outer peripheral surface of the photosensitive drum 101 with a predetermined pressure is repelled from the surface of the rotating photosensitive drum 101 (so-called “stick slip”). Using the phenomenon “), residual toner, paper dust and the like adhering to the surface of the photosensitive drum 101 are blown off from the photosensitive drum 101, and the residual toner and the like which are blown off by the lower blade member 612 are removed from the toner conveying cylinder 601. Introduced in.

According to the cleaning unit G3 configured in this manner, when the screw shaft 602 rotates, waste toner, paper dust, and the like introduced into the toner conveying cylinder 601 are sent to the toner discharge port 604a as in the first embodiment. It is conveyed and sent into the relay conveyance device 630.
Also in this case, similarly to the first embodiment, the lock phenomenon in which the waste toner becomes a lump in the toner discharge portion 604 in the cleaning unit G3 is prevented.

On the other hand, when the screw shaft 602 is rotated, the drive unit 633 of the relay conveyance device 630 is interlocked with the coil spring 632 and the waste toner in the relay conveyance path 631 is relayed by the rotating coil spring 632 to the relay conveyance path. 631 is conveyed into the waste toner collecting unit 620.
The waste toner (including residual toner and paper dust) collected in the waste toner collection unit 620 is collected when a certain amount is accumulated, after the cleaning unit G3 is driven for a predetermined time, or periodically. During maintenance, the waste toner storage box is removed from the outer box and discarded.

(Other embodiments)
Instead of the screw shaft 602 in the toner conveying device G3 of the fifth embodiment, any one of the screw shafts of the first to fourth embodiments may be used.

DESCRIPTION OF SYMBOLS 15 Fixing part 101 Photosensitive drum 102 Developing part 104 Cleaning unit 200 Toner cartridge 201, 301, 401, 501 Cartridge main body 201x Toner accommodating part 201y, 301y, 401y, 501y, 601y Toner conveyance path 202, 302, 402, 502, 602 screw shafts 202A, 302A, 402A, 502A, 602A thick portion 202a, 302a, 402a, 502a, 602a rotating shaft 202b, 302b, 402b, 502b, 602b spiral blade _{202b 1, 302b 1, 402b 1} , 502b 1 first surface _{202b 2, 302b 2, 402b 2} , 502b 2 second surface 202b _3, 302b ₃ vertical end faces 203, 303 shutter 204a, 394a, 404a, 504a, 604a toner Outlet 206 paddle member 402c, 502c stepped portion 601 toner transporting cylinder body 601a toner introduction port 611, 612 blade member 620 waste toner recovery unit G1, G2, G3 toner conveying device

Claims (9)

A toner conveyance path disposed inside, a toner introduction port disposed on the upstream side of the toner conveyance path for introducing toner from the outside into the toner conveyance path, and discharging the toner from the toner conveyance path to the outside A toner transport cylinder having a toner discharge port disposed on the downstream side of the toner transport path,
A screw shaft that is rotatably provided in the toner conveying cylinder and conveys the toner in the toner conveying path from the upstream side to the downstream side;
The screw shaft has a rotating shaft, a spiral blade attached to the rotating shaft having a first surface inclined to the downstream side from the inner end to the outer end on the rotating shaft side and a second surface inclined to the upstream side. And
The spiral blade has a cross-sectional shape that gradually decreases from the inner end toward the outer end on the rotating shaft side, and has a thickness toward the downstream side of the toner conveyance path at a position facing the toner discharge port. A toner conveying device characterized by having a thick portion that gradually becomes thicker.   In the thick part of the spiral blade, the first surface is inclined with respect to the axis of the rotation shaft so as to gradually approach parallel to the downstream side of the toner conveyance path, and the axis of the rotation shaft The toner conveying device according to claim 1, wherein the second surface is inclined so as to gradually approach parallel as it goes downstream of the toner conveying path.   In the thick part of the spiral blade, the first surface is inclined with respect to the axis of the rotation shaft so as to gradually approach parallel to the downstream side of the toner conveyance path, and the axis of the rotation shaft The toner conveying device according to claim 1, wherein the second surface is inclined at a constant angle.   In the spiral blade, a vertical end surface adjacent to the first surface and orthogonal to the axis of the rotation shaft is disposed at the most downstream end of the thick portion. The toner conveying device according to one.   5. The toner conveying device according to claim 1, wherein the thick portion includes a plurality of stepped portions arranged in a spiral direction on at least one of the first surface and the second surface.   6. The toner conveying device according to claim 1, and a cartridge main body having a toner accommodating portion disposed adjacent to the toner conveying device, and an outer surface of the cartridge main body, the cartridge main body being provided on the outer surface side of the cartridge main body. A toner comprising: a shutter for opening and closing a toner discharge port; and a paddle member that is rotatably provided in the cartridge body and feeds the toner in the toner storage portion from the toner introduction port into the toner conveyance path. cartridge.   A cleaning unit comprising: the toner conveying device according to claim 1; and a blade member attached to an opening edge of the toner introduction port in the toner conveying cylinder of the toner conveying device.   A photosensitive drum on which an electrostatic latent image is formed, a developing unit for supplying toner to the electrostatic latent image on the surface of the photosensitive drum to form a toner image, and supplying toner to the developing unit 7. An image forming apparatus comprising: the toner cartridge according to claim 6; a transfer unit that transfers the toner image on the surface of the photosensitive drum to a recording medium; and a fixing unit that fixes the toner image to the recording medium.   A photosensitive drum on which an electrostatic latent image is formed; a developing unit that supplies toner to the electrostatic latent image on the surface of the photosensitive drum to form a toner image; and a toner image on the surface of the photosensitive drum 8. A transfer portion for transferring the toner image to the recording medium, a fixing portion for fixing the toner image to the recording medium, a waste toner recovery portion, and the blade member are provided so as to contact the surface of the photosensitive drum. An image forming apparatus that removes residual toner on the surface of the photosensitive drum remaining after transfer by the cleaning unit and conveys the toner to the waste toner collecting unit.

Images