JP5286311B2 - Toner discharging mechanism, toner cartridge, and image forming apparatus using toner cartridge - Google Patents

Description

  The present invention relates to a toner discharge mechanism, a toner cartridge, and an image forming apparatus using the toner cartridge.

  In a developing device using a two-component developer, if the toner in the developing device is consumed and reduced due to image formation, the toner is replenished from the toner cartridge into the developing device so that the toner concentration in the developer does not become a predetermined value or less. It has come to be.

  For example, a toner storage unit that stores replenishment toner, a toner discharge port that discharges toner toward the developing device, and a toner transfer screw (toner transfer member) that transfers the toner from the toner storage unit to the toner discharge port A known toner cartridge is known (for example, see Patent Document 1).

  Further, in a toner discharge device comprising a toner transfer path formed in a cylindrical shape and a toner transfer member rotatably provided therein, a toner discharge port is provided on the most downstream side in the toner transfer direction, and the toner transfer member A toner discharge device is also known in which the spiral direction of the spiral blade on the most downstream side is reversed (reverse spiral) (see, for example, Patent Document 2).

JP 2006-235255 A JP 2008-32769 A

  However, in a toner cartridge that discharges toner from a toner discharge port using a toner conveying member, the toner has a certain amount of toner due to a decrease in toner fluidity due to long-distance transportation or long-time leaving. When the toner is conveyed to the vicinity of the toner discharge port as a large lump (in a loosely aggregated state), the toner is not smoothly discharged from the toner discharge port. Then, the toner that has lost its place between the wall surface (bearing surface) of the most downstream portion of the toner conveying member and the toner extruded to the downstream side in the toner conveying direction by the toner conveying member becomes a compact state, and the toner conveying There was a problem of stopping the member (lock phenomenon).

  Further, when a toner conveying member in which the spiral direction of the spiral blade on the most downstream side is reversed is used, it is possible to eliminate toner remaining on the wall surface (bearing surface) of the most downstream portion of the toner conveying member. However, if the toner near the toner discharge port is not smoothly discharged from the toner discharge port, the toner extruded by the toner conveying member downstream in the toner conveying direction and the toner pushed back by the reverse spiral collide at one point. The problem of the toner transport member locking phenomenon that occurs when the toner is brought into a compacted state due to a sudden rise in pressure has not been solved.

  The present invention has been made in consideration of such circumstances, and provides a toner discharge mechanism, a toner cartridge, and an image forming apparatus using the same, in which the toner is compressed and the toner conveying member is not locked. .

  The present invention relates to a toner discharge mechanism attached to a toner cartridge for discharging and storing stored toner by an auger screw, wherein a predetermined length portion at a downstream end portion in the conveyance direction of the auger screw is set to an outer diameter of the auger screw. Covering with a cover member having a corresponding cylindrical inner wall, a stirrer plate that protrudes in the radial direction from the rotating shaft of the auger screw at the predetermined length portion and whose protruding height gradually increases downstream in the toner conveying direction is formed. In addition, the present invention provides a toner discharge mechanism in which an auger screw is formed by a ring-shaped spiral blade in contact with the outer edge of the stirring plate and a toner discharge port is formed in a cover member.

  According to this invention, the predetermined length portion of the downstream end portion in the conveying direction of the auger screw is covered with the cover member having the cylindrical inner wall corresponding to the outer diameter of the auger screw, and the rotation shaft of the auger screw is provided at the predetermined length portion. The agitator plate is protruded in the radial direction and the protrusion height gradually increases toward the downstream side of the toner conveyance direction, and the auger screw is formed by a ring-shaped spiral blade in contact with the outer edge of the agitator plate at the predetermined length portion. doing.

  Therefore, the toner conveyed as a lump of a certain size is crushed by the rotation of the stirring plate, and at the same time the toner is stirred by the rotation of the stirring plate. Even toner located at a position away from the toner discharge port (for example, the upper part of the cylindrical inner wall) quickly moves to the toner discharge port, so that the toner transport member lock phenomenon that occurs when the toner that has lost its place of contact is in a compacted state Can be prevented.

1 is a configuration explanatory diagram of an image forming apparatus according to the present invention. FIG. 1 is a perspective view of a toner cartridge according to the present invention. FIG. 3 is a configuration explanatory diagram of a toner cartridge and a toner discharge mechanism according to the present invention. 2 is a cross-sectional view of a toner cartridge and a toner discharge mechanism according to the present invention. FIG. It is sectional drawing of the toner discharge mechanism which concerns on this invention. FIG. 3 is a perspective view of a main part of a toner discharge mechanism according to the present invention.

  A feature of the toner discharge mechanism of the present invention is a toner discharge mechanism attached to a toner cartridge for transferring and discharging stored toner by an auger screw, wherein a predetermined length portion of the downstream end portion in the transfer direction of the auger screw is provided. Cover with a cover member having a cylindrical inner wall corresponding to the outer diameter of the auger screw, projecting in the radial direction from the rotating shaft of the auger screw at the predetermined length portion, and the projecting height gradually increases toward the downstream in the toner conveying direction And the auger screw is formed by a ring-shaped spiral blade in contact with the outer edge of the stirring plate, and the toner discharge port is formed in the cover member.

  A feature of the toner cartridge of the present invention is a toner cartridge that conveys and discharges stored toner by an auger screw, and a predetermined length portion of the auger screw at the downstream end in the conveyance direction is set to the outer diameter of the auger screw. Covering with a cover member having a corresponding cylindrical inner wall, a stirrer plate that protrudes in the radial direction from the rotating shaft of the auger screw at the predetermined length portion and whose protruding height gradually increases downstream in the toner conveying direction is formed. At the same time, the auger screw is formed by a ring-shaped spiral blade in contact with the outer edge of the stirring plate, and the toner discharge port is formed in the cover member.

  Here, the auger screw is a device in which a spiral blade is wound around an elongated shaft (shaft), and the shaft is rotated to convey the toner by the contact pressure of the spiral blade against the toner, and is also called a toner conveyance screw.

In the toner discharging mechanism and the toner cartridge of the present invention, it is preferable that the number of stirring plates is 2 or more and 4 or less.
When the number of stirrer plates is large, the gap formed between adjacent circumferential stirrer plates becomes narrower, and the toner tends to clog the gap. However, when the number is 2 to 4, the toner is hardly clogged, and a sufficient crushing force (agitating force in the circumferential direction of the rotating shaft) can be obtained.

Further, it is preferable that the outer diameter of the ring-shaped spiral blade is constant and the inner diameter is gradually decreased toward the downstream side of toner conveyance.
As the toner conveyance capacity goes downstream in the toner conveyance direction, the toner conveyance capacity in the toner conveyance direction by the ring-shaped spiral blades gradually decreases, and the agitation force of the agitating plate in the circumferential direction of the rotation axis increases. The toner can be smoothly discharged from the toner discharge port without causing a rapid pressure increase. As a result, it is possible to prevent the toner from losing its place due to a rapid pressure rise and becoming a compacted state.

Moreover, it is preferable that the maximum distance from the rotation axis of the stirring plate to the outer edge protruding in the radial direction is not less than 0.8 times and not more than 0.9 times the distance from the rotation axis to the cylindrical inner wall.
If the maximum distance to the outer edge protruding in the radial direction of the stirring plate is long, the shearing force generated between the cylindrical inner wall and the circumferential stirring plate becomes large, and the toner tends to generate heat and be easily fused. Conversely, if the maximum distance to the outer edge protruding in the radial direction of the circumferential stirring plate is short, sufficient stirring force in the circumferential direction of the rotating shaft cannot be obtained. However, in the present invention, the maximum distance is moderate. Therefore, the toner can be prevented from being fused and a sufficient stirring force of the toner can be obtained.

In another aspect, the present invention provides a photosensitive drum, a charging device that charges the surface of the photosensitive drum, an exposure device that forms an electrostatic latent image on the surface of the photosensitive drum, and an electrostatic on the surface of the photosensitive drum. A developing device for supplying toner to the latent image to form a toner image, a toner cartridge for supplying toner to the developing device, a transfer device for transferring the toner image on the surface of the photosensitive drum to a recording medium, and recording the toner image An image forming apparatus including a fixing device for fixing to a medium, wherein the toner cartridge is a toner cartridge having the above characteristics.
According to the present invention, the toner discharge member can be prevented from being locked, and a stable image density can be obtained.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
(Image forming device)
FIG. 1 is an explanatory diagram showing the overall configuration of an image forming apparatus according to an embodiment of the present invention.
As shown in FIG. 1, an image forming apparatus 100 according to this embodiment supplies a toner to a photosensitive drum 101 on which an electrostatic latent image is formed, and an electrostatic latent image on the surface of the photosensitive drum 101. A developing device 102 that forms a toner image, a toner cartridge 200 that supplies toner to the developing device 102 via a toner supply pipe 105, and a toner image on the surface of the photosensitive drum 101 are transferred to a sheet via an intermediate transfer belt 11. A secondary transfer roller (transfer device) 14 and a fixing device 15 for fixing the toner image onto the paper are provided, and an image is formed using toner by an electrophotographic method.

  The image forming apparatus 100 converts a multicolor or monochromatic image as a visible image 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. To form.

  As shown in FIG. 1, the image forming apparatus 100 includes an exposure unit E, photosensitive drums 101a to 101d corresponding to an image carrier on which a latent image is formed by the exposure unit E, developing devices 102a to 102d, and a charging roller 103a. 103d, cleaning units 104a-104d, intermediate transfer belt 11, primary transfer rollers 13a-13d, secondary transfer roller 14, fixing device 15, paper transport paths P1, P2, P3, paper feed cassette 16, manual paper feed tray 17 A paper discharge tray 18, a toner cartridge unit 20, and the like.

  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). A visible image is formed by the forming portions 55a to 55d.

  This corresponds to a color image using each color. Accordingly, the developing devices 102a to 102d, the photosensitive drums 101a to 101d, the charging rollers 103a to 103d, and the cleaning units 104a to 104d are provided in four each so as to form four types of latent images corresponding to the respective colors. Yes.

  Each of the image forming units 55a to 55d has the same configuration. For example, the black image forming unit 55a includes a photosensitive drum 101a, a developing device 102a, a charging roller 103a, a transfer roller 13a, a cleaning unit 104a, and the like. The

  The image forming units 55a to 55d are arranged in a line in the moving direction (sub-scanning direction) of the intermediate transfer belt 11. Note that the symbols a to d correspond to the four image forming units 55a by the above-mentioned means distinguished by a corresponding to black, b corresponding to cyan, c corresponding to magenta, and d corresponding to yellow. -55d are configured.

  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. The photosensitive drums 101a to 101d are irradiated with the laser beams modulated by the above. On the photosensitive drums 101a to 101d, electrostatic latent images based on image data of black, cyan, magenta, and yellow are formed.

  The exposure unit E is a method using a laser scanning unit (LSU) provided with a laser irradiation unit and a reflection mirror, but uses an EL or LED writing head, for example, in which light emitting elements are arranged in an array. May be.

  The photosensitive drums 101a to 101d are disposed above the exposure unit E and are substantially cylindrical image carriers, and are controlled to rotate in a predetermined direction by a driving unit and a control unit (not shown). The photoconductive drums 101a to 101d are configured by forming a photoconductive layer on a base material.

  For example, a metal drum made of aluminum or the like is used as a base material, and a photoconductive layer such as amorphous silicon (a-Si), selenium (Se), or an organic photo semiconductor (OPC) is formed in a thin film on the outer peripheral surface thereof. ing. Note that the configuration of the photosensitive drums 101a to 101d is not limited to this configuration.

  The charging rollers 103a to 103d are contact type chargers that uniformly charge the surfaces of the photosensitive drums 101a to 101d to a predetermined potential. In this embodiment, as shown in FIG. 1, contact roller charging rollers 103a to 103d are used as the charger, but a charger or brush charger may be used.

  The developing devices 102a to 102d supply toner to the surfaces of the photosensitive drums 101a to 101d on which the electrostatic latent images are formed, and develop the electrostatic latent images into toner images. Each of the developing devices 102a to 102d contains toner of each hue of black, cyan, magenta, and yellow, and an electrostatic latent image of each hue formed on each of the photosensitive drums 101a to 101d is black, The toner images are visualized as cyan, magenta, and yellow toner images.

The cleaning units 104a to 104d remove and collect the toner remaining on the surfaces of the photosensitive drums 101a to 101d after development and image transfer with a lubricant or the like.
The intermediate transfer belt 11 disposed above the photosensitive drums 101a to 101d is stretched between the driving roller 11a and the driven roller 11b to form a loop-shaped moving path. The outer peripheral surface of the intermediate transfer belt 11 faces the photosensitive drum 101d, the photosensitive drum 101c, the photosensitive drum 101b, and the photosensitive drum 101a in this order.

  Primary transfer rollers 13a to 13d are arranged at positions facing the respective photosensitive drums 101a to 101d with the intermediate transfer belt 11 interposed therebetween. Each of the positions where the intermediate transfer belt 11 faces the photosensitive drums 101a to 101d is a primary transfer position. The intermediate transfer belt 11 is formed endlessly with a film having a thickness of about 100 to 150 μm.

  The primary transfer rollers 13a to 13d have constant voltage control of a primary transfer bias opposite to the charging polarity of the toner in order to transfer the toner images carried on the surfaces of the photosensitive drums 101a to 101d onto the intermediate transfer belt 11. 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. The electrostatic latent image and the toner image are formed only on the photosensitive drum. 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 is configured by covering the surface of a shaft made of a metal (for example, stainless steel) having a diameter of 8 to 10 mm with a conductive elastic material (for example, EPDM). A high voltage is uniformly applied to the intermediate transfer belt 11 by an elastic material. In this embodiment, the primary transfer rollers 13a to 13d are used as the transfer electrodes, but a brush or 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 whose inner peripheral surface is in contact with the peripheral surface of 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 intermediate transfer belt 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 Foamed resin roller, etc.).

  When the paper fed from the paper feed cassette 16 or the manual paper feed tray 17 passes between the secondary transfer roller 14 and the intermediate transfer belt 11, the toner transfer polarity (−) Is applied with a high voltage of reverse polarity (+). As described above, the electrostatic latent images on the photosensitive drums 101 a to 101 d 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 moved to a contact position between the conveyed paper and the intermediate transfer belt 11 by the rotation of the intermediate transfer belt 11, and are transferred by the secondary transfer roller 14 disposed at this position. A toner image is transferred from the outer peripheral surface of the intermediate transfer belt 11 onto the sheet.

  The toner adhering to the intermediate transfer belt 11 due to the contact between the intermediate transfer belt 11 and the photosensitive drums 101a to 101d and the toner image from the intermediate transfer belt 11 to the sheet are not transferred and transferred onto the intermediate transfer belt 11. Since the toner remaining in the toner causes a color mixture of toner in the next process, the toner is removed and collected by the intermediate transfer belt cleaning unit 12.

  The intermediate transfer belt cleaning unit 12 includes a cleaning blade as a cleaning member that contacts the intermediate transfer belt 11. The portion of the intermediate transfer belt 11 in contact with the cleaning blade is supported from the back side by an intermediate transfer belt driven roller 11b.

  The sheet on which the toner image is transferred as a visible image is guided to a fixing device 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. The paper on which the toner image is fixed is discharged onto the paper discharge tray 18 by the paper 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 device 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 formed 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 rotatable in both forward and reverse directions. When the single-sided image is formed to form an image on one side of the paper and the second-side image is formed during double-sided image formation to form an image on both sides of the paper, Driven in the rolling 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 the fixing device 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 is connected to the secondary transfer roller 14 and the intermediate transfer belt at a timing when the sheet conveyed from the sheet cassette 16 or the manual sheet feed tray 17 or via the sheet conveyance path P3 is synchronized with the rotation of the intermediate transfer belt 11. 11 to lead. For this reason, the registration roller 19 stops rotating when the photosensitive drums 101a to 101d and the intermediate transfer belt 11 start to operate, and the sheet fed or conveyed prior to the rotation of the intermediate transfer belt 11 is the front end. Is stopped in contact with the registration roller 19, and the movement in the paper conveyance path P1 is stopped.

  Thereafter, the registration roller 19 rotates at a timing at which 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 at a position where the secondary transfer roller 14 and the intermediate transfer belt 11 are in pressure contact with each other. To start.

  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.

(Toner cartridge and toner discharge mechanism)
Next, the configuration of the toner cartridge and the toner discharge mechanism according to this embodiment will be described in detail with reference to the drawings.
2 is a perspective view showing a configuration of the toner cartridge unit 20 equipped with the toner cartridge 200 mounted on the image forming apparatus 100 shown in FIG. 1, FIG. 3A is a sectional view of the toner cartridge 200, and FIG. 3B is a cross-sectional view taken along the line AA ′ of the toner cartridge 200 in FIG. 3A, FIG. 3C is a cross-sectional view taken along the line BB ′ of the toner cartridge 200 in FIG. 3A, and FIG. 3A is a cross-sectional view of the toner cartridge 200 taken along the line CC ′, and FIG. 3E is a cross-sectional view taken along the line DD ′ of the toner cartridge 200 shown in FIG. 4 is a side view of the toner conveying member (auger screw) 202, FIG. 5 is an explanatory diagram of the configuration of the toner discharging mechanism of the toner cartridge 200, and FIG. 6 is an agitation provided on the rotating shaft 202a of the toner conveying member in FIG. It is a perspective view of a board.

  As shown in FIG. 2, four toner cartridges 200 according to this embodiment are mounted side by side on the toner cartridge unit 20. As shown in FIG. 2, the toner cartridge 200 is moved in the direction of arrow F by being lifted by the lock lever 20a, and is held in a state of being pressed against the stopper plate 20b.

  As shown in FIGS. 3A and 3B, the toner cartridge 200 includes a toner container 201 that stores toner, a toner conveying member (auger screw) 202, and a stirring paddle 207. The toner container 201 includes a substantially cylindrical toner discharge mechanism 204 at a predetermined length at the end in the toner transport direction. The toner container 201 is a substantially prismatic container, and a toner conveying member (auger screw) 202 and a stirring paddle 207 are rotatably supported therein.

  The toner discharge mechanism 204 includes a cover member 204b having a cylindrical inner wall. In the cylindrical inner wall portion of the cover member 204b, four stirring plates 202da to 202dd (FIG. 6) protrude in the radial direction from the rotating shaft 202a of the auger screw 202, and the protruding height gradually increases toward the downstream in the toner conveying direction. Form.

  In the cylindrical inner wall portion, the auger screw 202 is formed by a ring-shaped spiral blade 202bb (FIG. 5) in contact with the outer edges of the stirring plates 202da to 202dd. A toner discharge port 204a is formed at the bottom of the curved surface forming the cylindrical inner wall.

  As shown in FIGS. 3 and 4, the toner conveying member (auger screw) 202 includes a rotating shaft 202a, a spiral blade 202b, four stirring plates 204da to 204da (FIG. 6), and a drive gear 202c, and includes a cover member. The toner in the toner container 206 is rotated toward the toner discharge port 204a (in the toner transport direction), that is, in the right direction in FIG. Transport in the direction of the arrow).

  The spiral blade 202b is a ring-shaped spiral provided in contact with the outer edges of the stirring plates 202da to 202dd (FIG. 6) at a position facing the standing wave spiral blade 202ba (FIG. 5) having a constant outer diameter and the toner discharge port 204a. Consisting of blades 202bb (FIG. 5), the toner is conveyed in the direction of arrow F by rotation of the toner conveying member (auger screw) 202. In this embodiment, the standing wave spiral blade 202ba and the ring spiral blade 202bb are continuously formed.

The stirring plates 204da to 204da are four triangular plates as shown in FIG. 6, and are arranged so as to protrude in the radial direction from the rotating shaft 202a so as to form 90 degrees with each other at a position facing the toner discharge port 204a. The height protruding in the radial direction gradually increases toward the downstream side in the toner conveyance direction.
The stirring plates 204da to 204dd rotate around the rotation shaft 202a by the rotation of the toner conveying member 202, and stir the toner in the circumferential direction of the rotation shaft 202a. Two or three stirring plates may be used.

  In this embodiment, the maximum distance from the rotation axis of the stirring plates 204da to 204da to the outer edge extending in the radial direction is 0.8 to 0. 0 of the distance from the rotation axis of the rotation shaft 202a to the cylindrical inner wall. 9 times.

  The outer diameter of the ring-shaped spiral blade 202bb is constant and is 0.9 times the distance from the rotation axis to the cylindrical inner wall. Therefore, the width of the ring-shaped spiral blade is gradually reduced toward the toner conveyance direction. The width of the spiral blade here means the difference between the outer diameter and the inner diameter of the ring-shaped outer spiral blade.

  As shown in FIG. 3B, the agitation paddle 207 is an agitation member having four agitation blades around the rotation axis. The agitation paddle 207 is rotated to release the toner in the toner storage unit 206.

  The toner discharge port 204a is a rectangular opening provided at the bottom of the toner discharge mechanism 204 of the toner container 201, and discharges the toner carried by the toner transport member 202 to the developing devices 102a to 102d (FIG. 1). .

20 toner cartridge unit 20a lock lever 100 image forming devices 102a to 102d developing devices 105a to 105d toner supply pipe 200 toner cartridge 201 toner container 202 auger screw 202a rotating shaft 202b spiral blade 202c drive gear 202ba standing wave spiral blade 202bb ring spiral Blades 204da, 204db, 204dc, 204dd Stirring plate 204 Toner discharging part mechanism 204a Toner discharging port 206 Toner accommodating part 207 Stirring paddle

Claims (9)

  A toner discharging mechanism attached to a toner cartridge for discharging and storing stored toner by an auger screw, wherein a predetermined length portion of a downstream end portion in the conveying direction of the auger screw corresponds to the outer diameter of the auger screw The auger screw is covered with a cover member having an inner wall and protrudes in the radial direction from the rotation axis of the auger screw at the predetermined length portion, and the protruding height gradually increases toward the downstream in the toner conveying direction. A toner discharge mechanism in which a toner discharge port is formed in a cover member.   The toner discharging mechanism according to claim 1, wherein the number of the stirring plates is 2 or more and 4 or less.   3. The toner discharge mechanism according to claim 1, wherein the ring-shaped spiral blade has a constant outer diameter and an inner diameter that gradually increases toward a downstream side in the toner conveyance direction.   The maximum distance from the rotation axis of the stirring plate to the outer edge protruding in the radial direction is not less than 0.8 times and not more than 0.9 times the distance from the rotation axis to the cylindrical inner wall. 4. A toner discharging mechanism according to item 3.   A toner cartridge that transports and discharges stored toner by an auger screw, and covers a predetermined length portion of the auger screw downstream end in the transport direction with a cover member having a cylindrical inner wall corresponding to the outer diameter of the auger screw. In the predetermined length portion, a stirring plate that protrudes in the radial direction from the rotating shaft of the auger screw and whose protruding height gradually increases toward the downstream in the toner conveying direction is formed, and the auger screw is formed on the outer edge of the stirring plate. A toner cartridge formed by ring-shaped spiral blades in contact with each other and having a toner discharge port formed in a cover member.   6. The toner cartridge according to claim 5, wherein the number of the stirring plates is 2 or more and 4 or less.   7. The toner cartridge according to claim 5, wherein the outer ring spiral blade has a constant outer diameter and an inner diameter that gradually increases toward the downstream side in the toner conveyance direction.   The maximum distance from the rotation axis of the stirring plate to the outer edge protruding in the radial direction is not less than 0.8 times and not more than 0.9 times the distance from the rotation axis to the cylindrical inner wall. 8. The toner cartridge according to 7.   A photosensitive drum, a charging device for charging the surface of the photosensitive drum, an exposure device for forming an electrostatic latent image on the surface of the photosensitive drum, and supplying toner to the electrostatic latent image on the surface of the photosensitive drum to form a toner image. A developing device for forming, a toner cartridge for supplying toner to the developing device, a transfer device for transferring a toner image on the surface of the photosensitive drum to a recording medium, and a fixing device for fixing the toner image on the recording medium, An image forming apparatus, wherein the toner cartridge is the toner cartridge according to claim 5.

Images