JP2011017920A - Toner cartridge and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner cartridge stably supplying toner by preventing toner avalanche, and to provide an image forming apparatus using the toner cartridge.SOLUTION: The toner cartridge 200 includes: a toner storage part 206 for storing the toner; a toner discharge part 204 having a toner discharge port 204a; and a screw auger 202 including a rotary shaft 202a and a helical blade 202b, for conveying the toner stored in the toner storing part 206 to the toner discharge part 204. The screw auger 202 includes: an airtight plate 205 for closing a space formed between the inner wall part in the toner discharge part 204, and adjacent helical blades 202b in the axial direction of the rotary shaft 202a.

Description

  The present invention relates to a toner cartridge used in an image forming apparatus such as a laser beam printer or a multi-function machine, and an image forming apparatus using the same, and more particularly, a toner cartridge for storing toner such as a toner hopper and a toner bottle which are attached in a replaceable manner. And an image forming apparatus using the same.

  Conventionally, an image forming apparatus using an electrostatic electrophotographic method generally includes processing steps such as a charging step, an exposure step, a development step, a transfer step, a peeling step, a cleaning step, a charge removal step, and a fixing step.

  In the image forming apparatus configured as described above, the process of forming an image is performed, for example, by uniformly charging the surface of the photosensitive member that is rotationally driven by the charging device (charging step) and then charging the photosensitive member surface charged by the exposure device. Laser light is irradiated to form an electrostatic latent image (exposure process). Subsequently, the electrostatic latent image on the photoconductor is developed by the developing device, and a toner image is formed on the surface of the photoconductor (development process). The toner image on the photosensitive member is transferred onto the transfer material by the transfer device (transfer process), and then heated by the fixing device to fix the toner image on the transfer material (fixing and peeling step). Further, the transfer residual toner remaining on the surface of the photoconductor is removed by a cleaning device and collected in a predetermined collection unit (cleaning process), and the remaining charge is removed from the surface of the photoconductor after cleaning by the static eliminator. Prepare for image formation (static elimination process).

  As the developer for developing the electrostatic latent image on the photoreceptor, a one-component developer composed of only toner or a two-component developer composed of toner and carrier is generally used.

  Since the one-component developer does not use a carrier, it does not require a stirring mechanism for uniformly mixing the toner and the carrier, and thus has an advantage that the developing device is simplified. However, there are drawbacks such as the toner charge amount being difficult to stabilize.

  On the other hand, the two-component developer requires a stirring mechanism for uniformly mixing the toner and the carrier, and thus has a drawback that the developing device becomes complicated. However, it is often used in high-speed image forming apparatuses and color image forming apparatuses because of its excellent toner charge amount stability and compatibility with high-speed machines.

In recent years, in order to meet the user's demand for energy saving and high image quality, a small particle size toner having a low softening temperature and a volume average particle size of 5 to 9 μm is often used.
Such toner enables fixing at low temperature and is effective for high image quality such as high resolution and reduction of graininess, but the toner fluidity is low, and the toner replenishment amount from the toner cartridge to the developing device is reduced. There was a problem that it was difficult to control.

  In particular, there is a problem that the fluidity is extremely lowered by burying the external additive of the toner due to friction with a sponge-like supply roller used as a toner discharge member of the toner cartridge.

  Therefore, as a conventional technique for dealing with such problems, for example, a screw-like stirring and conveying member is used to supply toner (see Patent Document 1), or a screw-like toner discharging member is used as a sponge. Japanese Patent Application Laid-Open No. 2004-26853 discloses a technique in which friction between a supply member and toner during toner replenishment is reduced by using the toner supply roller instead of a supply roller (see Patent Document 2).

JP 2001-83802 A JP 2008-216360 A

  However, when a screw-like toner discharge member as described in Patent Document 1 is used, if some vibration is applied to the toner cartridge, even if the toner discharge member is not rotating (not during toner replenishment). There is a problem that a phenomenon in which the toner suddenly flows out (hereinafter referred to as “toner avalanche”) occurs.

The conventional problems will be specifically described below.
FIG. 6A is an explanatory view showing the state of toner in the toner container when the screw auger is stopped in the conventional toner cartridge, and FIG. 6B is a state where toner avalanche occurs when the rotation of the screw auger is stopped. It is explanatory drawing shown.

  As shown in FIG. 6A, a conventional toner cartridge 500 includes a toner storage portion 506 for storing toner, a toner discharge portion 504 having a toner discharge port 504a, and a shutter 503 for opening and closing the toner discharge port 504a. And a screw auger 502 that conveys the toner in the toner storage unit 506 to the toner discharge unit 504, and supplies toner to a developing device (not shown) via the toner supply pipe 105. It comes to supply.

  The toner transported from the toner container 506 to the vicinity of the toner discharge port 504a by the screw auger 502 remains in the toner discharge unit 504 while maintaining the repose angle of the toner. At this time, when the entire toner in the toner cartridge 500 starts to flow due to vibration or the like, the air is mixed with the toner and becomes an aerosol state (a state where the flow resistance is low), as shown in FIG. So-called “toner avalanche” occurs in which toner near the discharge port 504a falls at once. This increases the amount of toner to be replenished, causing a problem that the toner density of the developer in the developing device is not stable.

  SUMMARY An advantage of some aspects of the invention is that it provides a toner cartridge that prevents toner avalanche and enables stable toner supply and an image forming apparatus using the same. To do.

  A toner cartridge and an image forming apparatus using the toner cartridge according to the present invention for solving the above-described problems are as follows.

  The present invention includes a toner accommodating portion that accommodates toner, a toner discharging portion having a toner discharging port, a toner conveying screw that includes a rotating shaft and a spiral blade and conveys toner in the toner accommodating portion to the toner discharging portion, In the toner cartridge comprising: a space formed between the inner wall portion in the toner discharge portion and the spiral blade and the spiral blade adjacent to each other along the axial direction of the rotating shaft, that is, the toner conveying screw, It is characterized by comprising a shielding portion for closing a spiral groove formed between the peripheral wall and the spiral blade along the axial direction.

  In the present invention, it is preferable that the shielding portion is provided on a plane along an axial direction passing through the rotation axis.

  In the present invention, it is preferable that the shielding portion is formed of a flexible member.

  The present invention also provides a photosensitive drum on which an electrostatic latent image is formed, a developing device that supplies toner to the electrostatic latent image on the surface of the photosensitive drum to form a toner image, and the developing device. A toner cartridge that replenishes toner via a toner replenishing member; a transfer device that transfers the toner image on the surface of the photosensitive drum to a recording medium; and a fixing device that fixes the transferred toner image on the recording medium. An image forming apparatus that forms an image using toner by a photographic method uses the toner cartridge according to any one of claims 1 to 3 as the toner cartridge.

  According to the present invention, a toner conveying screw that includes a toner accommodating portion that accommodates toner, a toner discharging portion having a toner discharging port, a rotating shaft and a spiral blade, and conveys toner in the toner accommodating portion to the toner discharging portion. A space formed between the inner wall portion in the toner discharge portion and the spiral blades adjacent to each other along the axial direction of the rotation shaft as the configuration of the toner conveying screw. By providing the shielding portion that is closed along the direction, the air in the toner cartridge does not easily enter the toner near the toner discharge port through the space, that is, the spiral groove between the spiral blade. As a result, the toner near the toner discharge port becomes an aerosol due to vibration or the like, and the avalanche of toner flowing down from the toner discharge port can be prevented. Thereby, stable toner supply can be realized.

  Also, according to the present invention, the shielding portion is provided on a plane along the axial direction passing through the rotation shaft, so that the shielding portion is against the peripheral wall inside the toner discharge portion by the rotation of the toner conveying screw. Since it moves in the vertical direction, the effect of scraping off toner adhering to the peripheral wall is enhanced. As a result, even if the gap between the shielding portion and the peripheral wall in the toner discharge portion is not extremely narrowed, the scraped toner fills the gap, so that high confidentiality can be obtained.

  Further, according to the present invention, since the shielding portion is formed of a flexible member, the shielding portion is deformed flexibly, and therefore, shear generated between the shielding portion and the peripheral wall in the toner discharge portion. The force can prevent the toner from being compressed and agglomerated, and can smoothly supply toner.

  In addition, according to the present invention, a photosensitive drum on which an electrostatic latent image is formed on the surface, a developing device that supplies toner to the electrostatic latent image on the surface of the photosensitive drum to form a toner image, and the development A toner cartridge that replenishes toner via a toner replenishing member; a transfer device that transfers a toner image on the surface of the photosensitive drum to a recording medium; and a fixing device that fixes the transferred toner image onto the recording medium. In an image forming apparatus that forms an image using toner by electrophotography, the toner cartridge according to any one of claims 1 to 4 is used as the toner cartridge. The toner in the vicinity of the toner discharge port for discharging the toner to the outside is compressed and hardened by the pressure of the toner transfer screw for transferring the toner, and the toner transfer screw Because it can prevent the Liu locks allows reliable toner supply operation. As a result, a predetermined toner concentration can be obtained, so that high-quality image output can be performed stably.

1 is an explanatory diagram illustrating an overall configuration of an image forming apparatus using a toner cartridge according to an exemplary embodiment of the present invention. FIG. 3 is a perspective view illustrating a configuration of a toner cartridge unit including a toner cartridge mounted on the image forming apparatus. (A) is a side sectional view showing a state before the toner cartridge is mounted on the image forming apparatus, (b) is a sectional view taken along line AA in (a), and (c) is a sectional view taken along line BB in (a). FIG. (A) is a side view showing the configuration of a screw auger and an airtight plate constituting the toner cartridge, (b) is a view as seen from the arrow C in (a), and (c) is a configuration of the airtight portion of (a). It is an enlarged view of D section. (A) is an explanatory view showing a state where a shutter is closed immediately before the toner cartridge according to the present embodiment is mounted on the image forming apparatus, and (b) is a state where the toner cartridge is mounted on the image forming apparatus and the shutter is opened. It is explanatory drawing which shows the state. (A) is explanatory drawing which shows the state of the toner in a toner container when a screw auger is stopped in the conventional toner cartridge, (b) is an explanation which shows a state where toner avalanche occurs when the rotation of the screw auger is stopped. FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is an example of an embodiment for carrying out the invention, and is an explanatory diagram showing the overall configuration of an image forming apparatus using a toner cartridge according to an embodiment of the present invention.

  As shown in FIG. 1, the image forming apparatus 100 according to the present embodiment supplies a toner to the photosensitive drum 101 on which the electrostatic latent image is formed, and the 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. In the image forming apparatus 100 that includes a secondary transfer roller (transfer device) 14 and a fixing device 15 that fixes the transferred toner image onto a sheet and forms an image using toner by an electrophotographic method, the toner cartridge 200 The configuration of the toner cartridge according to the present invention is employed.

First, the overall configuration of the image forming apparatus 100 according to the present embodiment will be described.
The image forming apparatus 100 according to the present embodiment has a multicolor or single color 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. The image is formed as a visible image.

  As shown in FIG. 1, the image forming apparatus 100 includes an exposure unit E, 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 device 102 (102a). -102d), charging roller 103 (103a-103d), cleaning unit 104 (104a-104d), intermediate transfer belt 11, primary transfer roller 13 (13a-13d), secondary transfer roller 14, fixing device 15, paper transport path P1, P2, P3, a paper feed cassette 16, a 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 unit 55 (55a to 55d). This corresponds to a color image using each color.

  Accordingly, the developing device 102 (102a to 102d), the photosensitive drum 101 (101a to 101d), the charging roller 103 (103a to 103d), and the cleaning unit 104 (104a to 104d) generate four types of latent images corresponding to the respective colors. Four each are provided to form.

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 55 a to 55 d are arranged in a line in the moving direction (sub-scanning direction) of the intermediate transfer belt 11.
The symbols a to d correspond to a as black, b as cyan, c as magenta, and d as yellow, and four image stations are constituted by the above-mentioned means distinguished by these symbols. Yes.

An exposure unit E which is an exposure apparatus of the present embodiment includes a semiconductor laser, a polygon mirror 4, a first reflection mirror 7, a second reflection mirror 8, and the like (not shown), and each 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 hue image data.
On each of the photosensitive drums 101a to 101d, electrostatic latent images are formed based on image data of black, cyan, magenta, and yellow hues.

  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 is configured by forming a photoconductive layer on a substrate. 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 drum 101 is not particularly limited to the above-described 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 this embodiment, as shown in FIG. 1, a contact-type roller-type charging roller 103 is used as the charger. However, instead of the charging roller 103, a charger-type or brush-type charger is used instead. Also good.

  The developing device 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 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 unit 104 removes and collects 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 is disposed above the photosensitive drum 101 and is formed endlessly with a film having a thickness of about 100 to 150 μm. And it is stretched between the driving roller 11a and the driven roller 11b to form a loop-shaped movement 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 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 drum 101 (101a to 101d) are sequentially superimposed on 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. It is formed.

  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 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, urethane foam, or the like). 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 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 respective photoconductive drums 101 (101a to 101d) are visualized with toners corresponding to the respective hues to become toner images, and these toner images are transferred onto the intermediate transfer belt 11. Are stacked. 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 drum 101 and the toner image remaining on the intermediate transfer belt 11 are not transferred when the toner image is transferred from the intermediate transfer belt 11 to the sheet. The toner is removed and collected by the intermediate transfer belt cleaning unit 12 because it causes a color mixture of the toner in the next process.

  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 feed 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. Paper transport path P1 is provided.

  In the paper transport path P1, a pickup roller 16a that feeds the paper in the paper feed 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 A registration roller 19 that guides between the secondary transfer roller 14 and the intermediate transfer belt 11 at a predetermined 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 fed from the paper feed cassette 16 or the manual paper feed tray 17 or the paper transported via the paper transport path P <b> 3 is synchronized with the rotation of the intermediate transfer belt 11 at the secondary transfer roller 14. And the intermediate transfer belt 11. Therefore, 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 is registered at the front end. The movement in the paper transport path P1 is stopped in a state where it is in contact with the roller 19.

  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.

Next, a characteristic configuration of the toner cartridge 200 according to the present embodiment will be described in detail with reference to the drawings.
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 present embodiment. FIG. 3A is a state before the toner cartridge is mounted on the image forming apparatus. FIG. 4B is a sectional view taken along line AA of FIG. 4A, FIG. 4C is a sectional view taken along line BB of FIG. 4A, and FIG. The side view which shows the structure of a board, (b) is the C arrow directional view of (a), (c) is an enlarged view of the D section of (a) which shows the structure of the said airtight board.
In FIG. 2, one of the four toner cartridges is in a state before being completely installed.

  As shown in FIG. 1, the toner cartridge 200 according to the present embodiment is mounted on a toner cartridge unit 20 mounted on the image forming apparatus 100.

  A toner supply pipe (toner supply unit) 105 into which toner discharged from the toner cartridge 200 is introduced is provided on the main body side of the image forming apparatus 100. The toner supply pipe 105 is disposed at a position facing a toner discharge port 204a (to be described later) of the toner cartridge 200 in a state where the toner cartridge 200 is mounted on the toner cartridge unit 20.

  In this embodiment, a developing device 102 is disposed below the toner supply pipe 105, and toner is supplied to the developing device 102 through the toner supply pipe 105. An intermediate transfer belt 11 is disposed in the space of the toner supply pipe 105 so that color images can be formed by superimposing toner images.

  As shown in FIG. 2, the toner cartridge unit 20 is formed in a box shape having an open top, and has four colors of black (K), cyan (C), magenta (M), and yellow (Y) inside. Four toner cartridges 200 each containing toner are stored.

  The toner cartridge 200 is formed long along the intermediate transfer belt width direction (arrow A direction), and each of the toner cartridges 200 faces the developing device 102 (102a to 102d) along the intermediate transfer belt conveyance direction (arrow B direction). It is installed side by side.

  The toner cartridge unit 20 includes a stopper plate 20b for positioning the toner cartridge 200 on one end side in the width direction of the intermediate transfer belt, and moves and holds each toner cartridge 200 on the other end side toward the stopper plate 20b. The lock lever 20a is provided.

  The lock lever 20a is in a collapsed state when the toner cartridge 200 is simply placed. When the toner cartridge 200 is mounted on the toner cartridge unit 20 so as to be usable, the toner cartridge 200 is moved in the direction of the arrow F by being raised by the lock lever 20a and is held in a state of being pressed against the stopper plate 20b. ing.

  As shown in FIGS. 3A, 3B, and 3C, the toner cartridge 200 includes a toner container (toner container) 201 that contains toner, a screw auger (toner conveying screw) 202, and a toner discharge port 204a. , A shutter 203, an airtight plate (shielding member) 205, and a stirring paddle 207.

  As shown in FIG. 3A, the toner container 201 includes a substantially prismatic toner storage portion 206 that stores toner therein, and a toner discharge port 204a is formed at one end in the longitudinal direction. A toner discharge portion 204 is provided so as to protrude outward.

  As shown in FIG. 3C, the toner discharge unit 204 is formed in a substantially cylindrical shape in which an internal space having a circular vertical cross-sectional shape is formed. As shown in FIG. 3B, a screw auger 202 and a stirring paddle 207 are rotatably supported in the toner storage unit 206.

The screw auger 202 includes a rotating shaft 202a, a spiral blade 202b, and a drive gear 202c. The screw auger 202 is disposed below the toner container 201 from the toner container 206 to the toner discharge part 204 and is positioned above the toner discharge port 204a. Is provided.
The spiral blade 202b rotates to convey the toner inside the toner container 201 toward the toner discharge port 204a. The drive gear 202c is disposed so as to protrude outside the toner discharge unit 204, and a drive force by a motor provided in the image forming apparatus main body (not shown) is transmitted.

  Further, the screw auger 202 has a space formed between the inner wall portion in the toner discharge portion 204 and the spiral blade 202b and the spiral blade 202b adjacent to each other along the axial direction of the rotation shaft 202a, that is, one spiral groove 202d. An airtight plate 205 that closes the part is provided.

  As shown in FIGS. 4A and 4B, the airtight plate 205 is formed of a thin plate having a trapezoidal shape of 0.2 mm to 2 mm, and extends along the axial direction passing through the rotating shaft 202 a of the screw auger 202. It is provided on a plane. As a result, as shown in FIG. 3A, it is possible to prevent the air in the toner cartridge 200 from flowing through the spiral groove 202d formed by the peripheral wall of the toner discharge portion 204 and the spiral blade 202b.

  As a material that can be used for the hermetic plate 205, a general plastic material such as PET can be used. In this embodiment, as shown in FIG.4 (c), slit part 205c1-205c5 cut | disconnected from the upper part (part near a surrounding wall) 205a of the airtight board 205 toward the base part 205b by the side of the rotating shaft 202a is provided. Yes. As a result, the airtight plate 205 is divided and easily deformed, so that excessive stress on the toner can be suppressed.

  As shown in FIG. 3B, the stirring paddle 207 includes four stirring blades 207b around the rotation shaft 207a disposed substantially parallel to the screw auger 202 along the axis of the rotation shaft 207a. The stirring blade 207b rotates to release the toner in the toner storage unit 206.

  The toner discharge port 204 a is formed in a rectangular shape at the bottom of the peripheral wall of the toner discharge unit 204, and discharges the toner conveyed by the screw auger 202 to the outside of the toner cartridge 200.

  The shutter 203 is a shutter member that opens and closes the toner discharge port 204a, and is configured by a substantially rectangular plate-like member. The shutter 203 is provided outside the lower portion of the toner container 201 so as to be slidable along the longitudinal direction of the toner container 201. It has been. In a normal state, the toner discharge port 204a is biased to a position where it is closed by a spring member (not shown). When the toner cartridge 200 is mounted on the image forming apparatus 100, the toner discharge port 204a is opened in conjunction with the operation of mounting the toner cartridge 200.

  That is, when the toner cartridge 200 is attached to the toner cartridge unit 20, the toner container 201 moves in a substantially horizontal direction with respect to the toner supply pipe 105, whereby the shutter 203 moves in a substantially horizontal direction. When the toner discharge port 204 a is disposed at a position facing the toner supply pipe 105, the toner discharge port 204 a is opened and the toner can be supplied from the upper surface of the toner supply pipe 105.

  As shown in FIG. 1, the toner cartridge 200 configured as described above is disposed above the developing device 102 and is connected to the toner supply pipe 105 to supply toner to the developing device 102.

Next, the mounting operation and operation of the toner cartridge 200 in the image forming apparatus 100 according to the present embodiment will be described.
FIG. 5A is an explanatory diagram illustrating a state in which the shutter immediately before the toner cartridge according to the present embodiment is mounted on the image forming apparatus is closed, and FIG. 5B is a shutter when the toner cartridge is mounted on the image forming apparatus. It is explanatory drawing which shows the state which opened.

  When the toner cartridge 200 mounted on the image forming apparatus 100 is in a single product state (for example, stored in units of parts), as shown in FIG. Is disposed upstream of the toner discharge port 204a in the toner conveyance direction, and blocks the toner in the spiral groove 202d. At this time, as shown in FIG. 3C, the airtight plate 205 is disposed at a position that does not overlap the toner discharge port 204a, that is, a position that does not face the toner discharge port 204a.

  When the toner cartridge 200 is attached to the image forming apparatus 100, as shown in FIG. 5A, the shutter 203 comes into contact with the toner supply pipe 105 provided in the insertion path immediately before the completion of the attachment. ing.

  When the toner cartridge 200 is completely attached to the predetermined position of the image forming apparatus 100, as shown in FIG. 5B, the toner cartridge 200 reaches the predetermined position in a state where the shutter 203 collides with the toner supply pipe 105 and stops. Since the shutter 203 is inserted, the shutter 203 relatively moves in the left direction in the figure, and the toner discharge port 204a is opened. At the same time, the toner discharge port 204a and the toner replenishment port 105a of the toner replenishment pipe 105 coincide with each other in a plan view and are in a communication state.

  When the toner supply operation is started by the toner cartridge 200, the screw auger 202 is rotated to rotate the hermetic plate 205, and the spiral groove 202d on the upstream side of the hermetic plate 205 is opposed to the toner discharge port 204a. During this time, the inside of the toner container 206 and the toner supply pipe 105 communicate with each other via the toner discharge port 204a, and the toner is supplied from the toner discharge port 204a to the toner supply pipe 105.

  With the above configuration, according to the present embodiment, in the toner cartridge 200, the screw auger 202 is configured such that the spiral blade 202b adjacent to the inner wall portion in the toner discharge portion 204 along the axial direction of the rotation shaft 202a. By providing an airtight plate 205 that closes the space formed between the spiral blade 202b and the spiral blade 202b, the space (that is, the spiral groove 202d between the spiral blade 202b and the spiral blade 202b) passes through the space in the toner cartridge 200. Since air does not easily enter the toner in the vicinity of the toner discharge port 204a, the toner in the vicinity of the toner discharge port becomes an aerosol due to vibration or the like, and the avalanche of toner flowing down from the toner discharge port can be prevented.

  In addition, according to the present embodiment, the airtight plate 205 is provided on a plane along the axial direction passing through the rotation shaft 202 a, so that the airtight plate 205 is attached to the peripheral wall inside the toner discharge unit 204 by the rotation of the screw auger 202. On the other hand, since it rotates in a state of facing vertically, the effect of scraping off the toner adhering to the peripheral wall is enhanced. As a result, even if the gap between the airtight plate 205 and the peripheral wall in the toner discharge portion 204 is not extremely narrowed, the scraped toner fills the gap, so that high confidentiality can be obtained.

  Further, in the present embodiment, the slit portions 205c1 to 205c5 are provided on the upper portion 205a side facing the peripheral wall of the hermetic plate 205, so that the hermetic plate 205 is easily divided and deformed. It can suppress joining.

  In the above-described embodiment, the example in which the configuration of the image forming apparatus according to the present invention is applied to the image forming apparatus 100 as shown in FIG. 1 has been described. However, the toner is supplied to the developing device using a toner cartridge. As long as the image forming apparatus is configured as described above, the present invention is not limited to the image forming apparatus having the above-described configuration, and can be expanded to image forming apparatuses having other configurations. For example, the present invention can be applied to an electrophotographic image forming apparatus capable of forming only a monochrome image.

  As described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope not departing from the gist of the present invention are also included in the technical scope of the present invention.

15 fixing device 100 image forming apparatus 101 photoconductor drum 102 developing device 105 toner supply pipe 105a toner supply port 200 toner cartridge 201 toner container 202 screw auger (toner conveying screw)
202a Rotating shaft 202b Spiral blade 202d Spiral groove (space)
204 Toner discharge part 204a Toner discharge port 205 Airtight plate (shielding part)
205a Upper part 205b Base part 205c1 to 205c5 Slit part 206 Toner accommodating part

Claims (4)

A toner cartridge comprising: a toner accommodating portion that accommodates toner; a toner discharging portion having a toner discharging port; and a toner conveying screw that includes a rotation shaft and a spiral blade and conveys toner in the toner accommodating portion to the toner discharging portion. In
The toner conveying screw is provided with a shielding portion that blocks a space formed between an inner wall portion in the toner discharge portion and the spiral blades adjacent to each other along the axial direction of the rotation shaft. cartridge.   The toner cartridge according to claim 1, wherein the shielding portion is provided on a plane along an axial direction passing through the rotation shaft.   The toner cartridge according to claim 1, wherein the shielding portion is formed of a flexible member. A photosensitive drum on which an electrostatic latent image is formed, a developing device for supplying toner to the electrostatic latent image on the surface of the photosensitive drum to form a toner image, and a toner replenishing member to the developing device A toner cartridge for replenishing toner, 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 transferred toner image to the recording medium, and using toner by an electrophotographic method In an image forming apparatus for forming an image by
An image forming apparatus using the toner cartridge according to claim 1 as the toner cartridge.

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