JP5359248B2 - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a function of reliably preventing leak of a developer from a discharge port with a simple constitution without requiring large design change. <P>SOLUTION: The developing apparatus includes: a developer storing vessel 12 having a supply section 22 for storing a developer containing toner and carrier and supplying the developer, and a discharging section 26 for discharging the stored developer; and a developer conveying means 13 for circulating and moving the developer stored in the developer storing vessel 12 while it is stirred. The developer conveying means 13 forms spiral blades 30 around a rotation shaft, is supported by the developer storing vessel 12 so that both ends of the rotation shaft are rotatable and can reciprocate in the axial direction, and includes an opening/closing section 32 opening/closing the discharging section 26. When the developer storing vessel 12 tilts, the discharging section 26 is located at a lower side. The developer conveying means 13 moves axially by own weight and the discharge section is closed or substantially closed by the opening/closing section 32. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a developing device and an image forming apparatus.

  Conventionally, as a developing device, a so-called trickle type device is known in which a deteriorated developer is discarded from a discharge port and a new developer is replenished from a replenishing port (see, for example, Patent Documents 1 and 2). .

Japanese Patent Laying-Open No. 2005-221852 JP 2006-308689 A

  In the conventional developing device, the discharge port may be located on the lower side during the conveyance or replacement. In this case, there is a possibility that the developer stored in the developer storage container gathers on the discharge port side and applies pressure, and the developer leaks from the discharge port.

  However, none of the developing devices has a configuration capable of preventing leakage of the developer from the discharge port.

  Accordingly, the present invention provides a developing device and an image forming apparatus having a function capable of reliably preventing the leakage of the developer from the discharge port with a simple configuration without requiring a significant design change. The task is to do.

As a means for solving the above problems, the present invention provides:
Developing device
A supply unit for supplying a developer including toner and carrier, replenished developer is a circulation path that can be circulated and moved, the developer accommodating container and a discharge portion for discharging the developer circulating movement When,
A developer conveying means for forming a spiral blade around the rotating shaft, and circulating the developer in the circulation path while stirring;
The discharge unit communicates with the circulation path, and has an opening where the rotation axis of the developer conveying unit intersects,
The developer conveying means is formed with an opening / closing portion that can open and close the opening , around the rotation shaft, having a larger projected area in the axial direction than the opening .
When the developer container is inclined and the discharge portion is on the lower side, the developer conveying means is moved in the axial direction by its own weight, and at least a part of the opening / closing portion is brought into contact with the closing surface around the opening. Thus, the opening is closed or substantially closed.

  With this configuration, even if the developer container is inclined and the discharge portion is positioned on the lower side, the pressure of the developer acting on the discharge portion is suppressed by the opening / closing portion, and leakage thereof can be prevented.

Closing portion of the developer transport means, preferably composed of a part of the vane.

  With this configuration, it is possible to prevent leakage of the developer from the discharge unit without adding a new configuration to the developer conveying means as an opening / closing unit.

  However, it is good also as a structure which provided the sealing member comprised with urethane, silicone rubber, etc. in the rotating shaft separately from a blade | wing as an opening / closing part.

  The opening / closing part of the developer conveying means is preferably constituted by a surface substantially parallel to the closing surface.

It said closure surface of the developer container, or, in at least one of opening and closing portion of the developer transport means, preferably integrated with the elastic member closable discharge portion abut each other.

  With this configuration, it is possible to appropriately prevent the leakage of the developer by further ensuring the closed state of the discharge portion.

The discharge portion of the developer container is composed of a flow path restriction portion having a flow path cross-sectional area smaller than a flow path through which the developer circulates.
The blades of the developer conveying means are formed in a reverse winding with the first blade portion for circulating and moving the developer in the circulation path, and prevents the developer from being discharged to the discharge portion. A second blade portion, and a third blade portion that has the same winding direction as the first blade portion, is disposed in the flow path restriction portion, and conveys the developer that has moved beyond the second blade portion,
The opening / closing part of the developer conveying means may be constituted by a part of the second blade part that closes or substantially closes the inlet of the flow path restriction part that is the opening of the discharge part .

The discharge portion of the developer container is composed of a flow path restriction portion having a flow path cross-sectional area smaller than a flow path through which the developer circulates.
The blades of the developer conveying means are formed in a reverse winding with the first blade portion for circulating and moving the developer in the circulation path, and prevents the developer from being discharged to the discharge portion. A second blade portion, and a first blade portion that has the same winding direction as the first blade portion, and a third blade portion that conveys the developer that has moved beyond the second blade portion, and
The third blade portion and the second blade portion is disposed in the flow path limiting portion,
The opening / closing part of the developer conveying means may be constituted by a part of the first blade part that closes or substantially closes the inlet of the flow path restriction part that is the opening of the discharge part .

The circulation path of the developer container is divided into a first container part and a second container part formed with a discharge part on one end side,
A first conveying member accommodated in the first accommodating portion, and the developer conveying means, and a second conveying member accommodated in the second accommodating portion,
The rotating shafts of the respective conveying members protrude from the end face of the developer container and are provided with helical gears that mesh with each other.
Second conveying member, when the emissions part is downward, by gravity, from the normal position reaches the closed position by moving axially within the meshing range of helical gears, closing the discharge portion in the closing part or It is preferable that the first transfer member is substantially closed and the first conveying member is rotationally driven to receive a thrust force via a helical gear and move from the closed position to the normal position.

Further, the present invention provides a means for solving the above-described problems,
Developing device
A developer storage container comprising a replenishment section for replenishing developer including toner and carrier, a circulation path through which the replenished developer can be circulated, and a discharge section for discharging the circulated and moved developer When,
A first conveying member that is provided in the developer container and conveys the developer in a first direction by rotating;
A second conveying member provided in the developer container parallel to the first conveying member, and conveying the developer in a second direction opposite to the first direction;
A circulation channel in the developer container is provided between the first transport member and the second transport member, and the first fluid flows from the downstream region of the first transport member to the upstream region of the second transport member. And a partition wall having a second communication portion that causes the developer to flow from the downstream region of the second conveying member to the upstream region of the first conveying member,
A developer discharge mechanism provided on the downstream side of the first conveying member in the developer container;
With
The first transport member has a blade for transporting the developer, and is supported so as to be reciprocally movable in a predetermined range in the axial direction in the developer container.
The developer discharging mechanism, and communicates with the circulation passage has an opening that intersects with the axial direction, when the first conveying member is moved to the developer discharging mechanism side, around a portion of the vane the opening It is made to contact | abut to the closing surface of this, and it is made to close substantially .

Further, the present invention provides a means for solving the above-described problems,
Developing device
A developer container containing a developer containing toner and carrier;
A replenishment section for replenishing the developer in the developer container;
A first conveying member that is provided in the developer container and conveys the developer in a first direction by rotating;
A second conveying member provided in the developer container parallel to the first conveying member, and conveying the developer in a second direction opposite to the first direction;
A first communicating portion that is provided between the first conveying member and the second conveying member in the developer containing container and causes the developer to flow from the downstream area of the first conveying member to the upstream area of the second conveying member; A partition wall having a second communicating portion for allowing the developer to flow from the downstream area of the second conveying member to the upstream area of the first conveying member;
A developer discharge mechanism provided on the downstream side of the first conveying member in the developer container;
With
The first transport member has a blade for transporting the developer, and is supported so as to be reciprocally movable in a predetermined range in the axial direction in the developer container.
The developer discharge mechanism has an opening that is closed by the blade when the first transport member moves toward the developer discharge mechanism.

  What is necessary is just to form the blade | wing of a said 1st conveying member in the screw shape continued in the axial direction.

  The first conveying member is provided at one end with a helical gear for transmitting a driving force to the first conveying member, and the direction of the teeth of the helical gear is rotated and driven, What is necessary is just to make it the direction which the blade | wing of a conveyance member moves to the direction away from an opening part.

  Further, according to the present invention, as means for solving the above-described problems, an image forming apparatus includes the developing device described above.

  The developing device can also be configured as follows.

That is, the developing device
The interior is divided into a first accommodating portion and a second accommodating portion having a discharge portion formed on one end side, a developer containing toner and a carrier is accommodated, and a replenishing portion for replenishing the developer is accommodated. A developer storage container having a discharge portion for discharging the released developer;
A developer conveying means for circulating and moving the developer accommodated in the developer accommodating container,
The developer conveying means includes a first conveying member and a second conveying member in which spiral blades are formed around the rotation shaft,
The first conveying member is accommodated in the first accommodating portion in a state where both ends of the rotation shaft are rotatably supported,
The second conveying member is provided with an opening / closing part capable of opening and closing the discharge part, and is accommodated in the second accommodating part in a state where both ends of the rotating shaft are supported so as to be rotatable and reciprocally movable in the axial direction.
The rotating shafts of the respective conveying members protrude from the end face of the developer container and are provided with helical gears that mesh with each other.
The second conveying member receives the thrust force within the meshing range of the helical gear by rotating the first conveying member forward and backward, moves in the axial direction, and closes or substantially closes the discharge portion at the opening / closing portion. It can also comprise so that it may move to a closed position and the regular position which opens a discharge part with an opening-and-closing part.

  With this configuration, the second transport member can be moved in the axial direction by rotating the first transport member, and can be positioned at the closed position or the normal position. Therefore, when it is positioned at the closed position, it is possible to reliably prevent the developer from being discharged from the discharge section, and when it is positioned at the normal position, the rotation of the first transport member and the second transport member. And the developer can be circulated while stirring. In addition, when positioning a 2nd conveying member in a closed position, it is preferable to provide the mechanism which prevents rotation after rotating a 1st conveying member.

  According to the present invention, when the developer container is tilted and the discharge part is on the lower side, the developer conveying means moves in the axial direction by its own weight, and the discharge part is closed or substantially closed by the opening / closing part. it can. Therefore, it is possible to reliably prevent the developer from leaking through the discharge portion without requiring a significant design change.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In the following description, terms indicating specific directions and positions (for example, terms including “up”, “down”, “side”, “end”) are used as necessary. Is for facilitating understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms.

(Constitution)
FIG. 1 shows a so-called trickle-type image forming apparatus in which a developer containing not only toner but also a small amount of carrier is replenished among electrophotographic systems using a two-component developer. The image forming apparatus generally includes an image forming unit 1, a transfer unit 2, an exposure unit 3, a fixing unit 4, a paper feeding unit 5, a cleaning unit 6, a control unit 7 (see FIG. 9), and the like. However, the present invention is not only applied to this type of image forming apparatus 1, but can also be applied to, for example, a so-called four-cycle color image forming apparatus or a monochrome output image forming apparatus. Further, the present invention can also be applied to a copying machine, a printer, a facsimile machine, or a multi-function machine having a combination of these functions.

  The image forming unit 1 is disposed at four locations along the intermediate transfer belt 44 of the transfer unit 2 and performs image formation of yellow (Y), magenta (M), cyan (C), and black (Bk) from the left side, respectively. As a result, a color image is formed on the surface of the intermediate transfer belt 44. As shown in FIG. 2, each image forming unit 1 includes a charging device 9, a developing device 10, a cleaning device 11, and the like around the photosensitive drum 8.

  The charging device 9 forms a predetermined surface potential on the surface of the photosensitive drum 8. This surface potential becomes an electrostatic latent image when exposed by the exposure unit 3. Here, a non-contact type scorotron charger is used as the charging device 9, but a contact type device such as a blade shape or a brush shape can also be used. It is also possible to use a charging roller.

  As shown in FIGS. 2 and 3, the developing device 10 is one in which a stirring screw 13, a supply screw 14, and a developing roller 15 are accommodated in a developer container 12.

  As shown in FIG. 3, the developer container 12 has a long box shape extending from one end side to the other end side. One end side covers helical gears 38 and 39 to be described later, and each screw 13. , 14 are rotatably supported, and a guide piece 16 having a substantially L-shaped cross section is formed. Further, the inside of the developer container 12 is divided into a first container 18 and a second container 19 along the longitudinal direction by a partition wall 17. However, both end sides of the first accommodating portion 18 and the second accommodating portion 19 are communicated with each other by communicating portions 20a and 20b. The communication portions 20 a and 20 b move the developer between the first storage portion 18 and the second storage portion 19 so that the developer can circulate within the developer storage container 12.

  The first storage unit 18 is provided with a toner density sensor 21 as means for detecting the toner amount per unit volume. The toner concentration sensor 21 is a conventionally known sensor that outputs a difference in magnetic permeability of a developer (iron contained in a carrier) as a frequency and calculates a toner concentration (weight ratio of toner to developer).

  Further, a developer supply port 22 is formed on one end side of the first accommodating portion 18, and a supply duct 23 is connected to the developer supply port 22 as shown in FIG. The supply duct 23 includes a shutter 25 urged in the closing direction by an opening / closing spring 24 to completely block leakage of the developer from the developer supply port 22. The shutter 25 is opened against the biasing force of the opening / closing spring 24 by mounting the developer container 12 on the apparatus main body. As a result, as will be described later, the developer can be replenished from the corresponding developer replenishment container 42 to the developer storage container 12 via the replenishment duct 23. Here, a two-component developer containing toner and carrier is used as the developer. However, an external additive or the like may be further included in the developer.

  Further, as shown in FIG. 3, FIG. 4B, and FIG. 10, a developer discharge port 26 is formed on the other end side of the first accommodating portion 18 and is deteriorated by appropriately discharging the developer. The carrier is prevented from remaining in the developer container 12 for a long period of time. In the new developing device 10, the developer discharge port 26 is closed by a seal member such as a cap (not shown). However, the developer leakage may be insufficient only with this seal member. Therefore, as will be described later, the pressure of the developer acting on the developer discharge port 26 is controlled by a part of the stirring blade 30 of the stirring screw 13. I'm trying to reduce it. A predetermined range from the inside of the developer container 12 to the developer discharge port 26 is a flow path restriction portion 27 having a reduced flow path cross-sectional area. As a result, the contact surface 28 is formed around the opening of the flow path restriction portion 27 inside the developer container 12.

  The stirring screw 13 has a configuration in which a spiral stirring blade 30 is provided around the stirring side rotating shaft 29. Both end portions of the stirring side rotating shaft 29 are supported by both end walls constituting a part of the first housing portion 18 so as to be rotatable and reciprocally movable in the axial direction. In addition, the stirring blade 30 includes a first blade portion 31, a second blade portion 32, and a third blade portion 33. The 1st blade | wing part 31 conveys the developer in the 2nd accommodating part 19 from the communication part 20a side to the communication part 20b side, stirring. The second blade portion 32 is formed in a reverse winding with respect to the first blade portion 31, and is provided in the vicinity of the flow path restricting portion 27 and applies a certain resistance to the developer toward the developer discharge port 26. . As a result, only the excess developer is discharged from the developer discharge port 26. The second blade portion 32 is formed so that the inclination with respect to the plane orthogonal to the rotation axis is smaller than that of the first blade portion 31 and the angle with the contact surface 28 of the flow path restriction portion 27 is small. The third blade portion 33 has the same winding direction as the first blade portion 31 and has a small diameter arranged in the flow path restriction portion 27. A stirring paddle 34 is appropriately formed on the outer peripheral surface of the stirring side rotating shaft 29.

  As shown in FIG. 3, the supply screw 14 includes a spiral supply blade 36 and a supply paddle 37 around the supply-side rotation shaft 35, similarly to the stirring screw 13. 19 is arranged. The supply screw 14 is rotatably supported at both end walls of the second accommodating portion 19 at both ends of the supply-side rotation shaft 35. When the supply screw 14 rotates, the developer is conveyed by the supply blade 36 while stirring from the communicating portion 20b side to the communicating portion 20a side, and the developer is supplied to the developing roller 15 in the conveying process.

  As shown in FIG. 4A, the agitation screw 13 and the supply screw 14 are engaged with each other at the ends of the agitation side rotating shaft 29 and the supply side rotation shaft 35 protruding from the developer container 12. A helical gear 38 and a second helical gear 39 are respectively integrated. As described above, the agitating screw 13 is provided so as to be reciprocally movable in the axial direction, and is configured such that the first helical gear 38 and the second helical gear 39 are maintained in an engaged state in the moving range. ing. The first helical gear 38 and the second helical gear 39 have tooth inclination directions in which the second helical gear 39 is rotationally driven so that the stirring screw 13 and the supply screw 14 are in the direction of the arrow in FIG. (The direction in which the developer is conveyed in the direction of the arrow in FIG. 3), the first helical gear 38 is oriented so as to receive a thrust force on the right side in FIG. The moving range of the stirring screw 13 is a range in which the first helical gear 38 is regulated by the end face of the developer container 12 and the guide piece 16. The supply screw 14 rotates when the second helical gear 39 is engaged with a drive gear provided on a rotating shaft of a motor (not shown) and power is transmitted. The stirring screw 13 also rotates in synchronization with the supply screw 14 via the first helical gear 38.

  As shown in FIG. 2, the developing roller 15 has a plurality of permanent magnets 41 accommodated in a cylindrical sleeve 40 (here, five permanent magnets S2, N2, S1, N1, and S3 are connected to the developing roller 15). In order and clockwise.) The sleeve 40 is configured to rotate in the direction of the arrow in the drawing by a sleeve driving means (not shown).

  Above the developing device 10, as shown in FIG. 1, a developer replenishment container 42 for replenishing a replenishment two-component developer (hereinafter simply referred to as a developer) composed of toner and carrier is detachable. ing. The toner concentration of the developer stored in the developer storage container 12 in advance is 7%, and the toner concentration of the developer supplied from the developer supply container 42 is 80% (carrier concentration is 20%, usually 10-20%). is there.

  The cleaning device 11 collects and cleans the toner remaining on the surface after the transfer to the surface of the photosensitive drum 8. Here, a plate-like blade is used as the cleaning device 11, and one end thereof is in contact with the outer peripheral surface of the photosensitive member. The cleaning device 11 is not limited to a blade, and other cleaning members (for example, a fixed brush, a rotating brush, and a roller) can be used. In addition, a plurality of cleaning devices 11 may be used together, or a cleanerless system in which untransferred toner is collected by the developing device 10 instead of the cleaning device 11 may be employed.

  The transfer unit 2 spans an intermediate transfer belt 44 between a pair of support rollers 43, drives the support roller 43 by a driving means (not shown), and circulates the intermediate transfer belt 44 in the direction of the arrow. A transfer unit 45 and a secondary transfer unit 46 are provided.

  The exposure unit 3 irradiates the photosensitive drum 8 with laser light to form an electrostatic latent image corresponding to image data read by a scanner (not shown). As the exposure unit 3, for example, a laser or a light emitting diode can be used.

  Although not shown, the fixing unit 4 is configured to rotatably support a fixing roller and a pressure roller. The fixing roller is made of a conductive material, is rotationally driven by a motor (not shown), and is induction-heated by an exciting coil 38 (not shown). The pressure roller is pressed against the fixing roller and sandwiches the recording medium 48. Thereby, the toner transferred by the transfer unit 2 can be fixed on the recording medium 48.

  The sheet feeding unit 5 sequentially conveys the recording medium 48 accommodated in the cassette 47 to the secondary transfer unit 46 via the conveyance roller 49. The toner image is transferred to the recording medium 48 conveyed to the secondary transfer unit 46, and the toner image transferred by the fixing unit 4 is fixed, and then is carried out to the discharge tray 50.

  The cleaning unit 6 can come into contact with and separate from the intermediate transfer belt 44 and collects and cleans the toner remaining on the intermediate transfer belt 44 when approached.

  The control unit 7 executes a developer replenishment process based on the detection voltage input from the toner density sensor 21.

(Operation)
Next, the operation of the image forming apparatus having the above configuration will be described.

  At the time of image formation, color print data obtained by reading an image or image data output from a personal computer or the like is subjected to predetermined signal processing, and then yellow (Y), magenta (M), cyan (C ) And black (Bk) image signals of each color are transmitted to each image forming unit 1.

  In each image forming unit 1, a laser beam modulated by an image signal is projected onto each photosensitive drum 8 to form an image latent image. Then, toner is supplied from the developing device 10 to the photosensitive drum 8.

  In the developing device 10, the developer stored in the developer container 12 is circulated while being stirred by rotationally driving the stirring screw 13 and the supply screw 14. Then, the toner is supplied from the supply screw 14 to the developing roller 15, scraped off by the regulating member 12 a to a constant amount, and then conveyed to the photosensitive drum 8.

  As a result, yellow, magenta, cyan, and black toner images are formed on the respective photosensitive drums 8. The formed yellow, magenta, cyan, and black toner images are primary-transferred by the primary transfer unit 45 while sequentially superposed on the moving intermediate transfer belt 44. The superimposed toner image formed on the intermediate transfer belt 44 in this way moves to the secondary transfer unit 46 as the intermediate transfer belt 44 moves.

  A recording medium 48 is supplied from the paper supply unit 5. The supplied recording medium 48 is conveyed between the secondary transfer unit 46 and the intermediate transfer belt 44 by the conveyance roller 49, and the toner image formed on the intermediate transfer belt 44 is transferred. The recording medium 48 to which the toner image has been transferred is further conveyed to the fixing unit 4 where the transferred toner image is fixed and then discharged to the discharge tray 50.

  By the way, in the image forming apparatus, when the image forming apparatus is moved (when a new image forming apparatus is conveyed) or the developing apparatus 10 is replaced with a new one, the developing apparatus 10 itself may be inclined. Although the developer discharge port 26 is sealed by a seal member (not shown), when the developing device 10 is inclined and the developer discharge port 26 side is positioned below, the pressure of the acting developer increases and the developer is increased. May leak. In this case, the stirring screw 13 moves in the axial direction due to its own weight, and as shown in FIGS. 6B and 7, a part (opening / closing part) of the second blade part 32 is brought into contact with the flow restricting part 27. 28. The second blade portion 32 has a spiral shape, and a slight gap is generated between the second blade portion 32 and the contact surface 28, but the developer pressure acting on the developer discharge port 26 side is greatly reduced. Therefore, the developer does not leak from the sealed developer discharge port 26.

  As shown in FIGS. 4B and 5, when image formation is performed as described above with the stirring screw 13 moved to the closed position, the developing device 10 operates as follows. That is, the supply screw 14 rotates by driving a motor (not shown) via the drive gear. At this time, the stirring screw 13 is located at the closed position. As shown in FIG. 4A, the second helical gear 39 provided on the supply-side rotating shaft 35 of the supply screw 14 is connected to the stirring side of the stirring screw 13. The first helical gear 38 provided on the rotating shaft 29 is engaged with the first helical gear 38. Therefore, when the supply screw 14 rotates and the second helical gear 39 rotates the first helical gear 38, a thrust force (axial force) acts on the stirring screw 13. As a result, the stirring screw 13 moves in the axial direction and moves until the end face of the first helical gear 38 comes into contact with the guide piece 16. As a result, the agitating screw 13 is positioned at the normal position, and rotates in a state in which the second blade portion 32 is separated from the contact surface 28 of the flow path restriction portion 27. In the same manner as described above, the developer stored in the developer storage container 12 circulates while being stirred, and the toner is supplied from the supply screw 14 to the developing roller 15 and is scraped off by the regulating member 12a to be a constant amount. After that, it is conveyed to the photosensitive drum 8.

(Other embodiments)
In addition, this invention is not limited to the structure described in the said embodiment, A various change is possible.

  For example, in the above-described embodiment, only the third blade portion 33 formed on the stirring screw 13 is disposed in the flow passage restriction portion 27. However, as shown in FIG. It is also possible to configure so as to be arranged in the restriction unit 27. In this case, the outer diameter dimension of the second blade part 32 is made smaller than the inner diameter dimension of the flow path restriction part 27, and the developer gets over between the second blade part 32 and the flow path restriction part 27. It is necessary to form a gap that can be used. An opening / closing part is constituted by a part of the first blade part 31 so as to be able to contact and separate from the contact surface 28 of the flow path restriction part 27. It is preferable that at least a portion constituting the opening / closing portion of the first blade portion 31 has a small inclination with respect to a plane orthogonal to the rotation axis and is substantially parallel to the contact surface 28.

  In the above-described embodiment, the contact surface 28 is a flat surface, but may be curved according to the shape of the supply blade 36 of the supply screw 14. In this case, the contact portion between the contact surface 28 and the supply blade 36 is made of a material with little friction so that the surface of the supply blade 36 can move smoothly along the contact surface 28 by suppressing the surface roughness. Is preferable.

  Moreover, in the said embodiment, although a part of stirring blade 30 of the stirring screw 13 was made to contact directly to the contact surface 28 of the flow-path restriction | limiting part 27, as shown in FIG. In addition, the elastic member 51 may be integrated with 28 separately. Further, the elastic member 51 can be provided not on the abutting surface 28 but on the supply blade 36 of the stirring screw 13 or on both. As the elastic member 51, it is possible to use a member in which urethane, silicon rubber or the like is formed in a ring shape and adhered to a part of the contact surface 28 or the supply blade 36. According to this, when the supply screw 14 moves to the closed position, the elastic member 51 is elastically deformed and pressed against the surface of the stirring blade 30 of the stirring screw 13 so that there is no gap. Accordingly, the developer pressure acting on the developer discharge port 26 can be sufficiently suppressed to reliably prevent leakage.

  In addition, the elastic member 51 is preferably not limited to an annular shape, but preferably has a width dimension as small as possible as long as sealing performance can be secured. According to this, when the stirring screw 13 is moved from the closed position to the normal position, it is possible to prevent a problem that the supply blade 36 or a part of the contact surface 28 of the flow path restriction portion 27 is in close contact and is not easily separated. Can do. However, when the width dimension is reduced, the pressure contact portion is not limited to a single annular shape, and it is configured by a plurality of double or more annular shapes so as to maintain the separation and improve the sealing performance. Good.

DESCRIPTION OF SYMBOLS 1 ... Image formation unit 2 ... Transfer unit 3 ... Exposure unit 4 ... Fixing unit 5 ... Paper feed unit 6 ... Cleaning unit 7 ... Control unit 8 ... Photoconductor drum 9 ... Charging device 10 ... Developing device 11 ... Cleaning device 12 ... Development Agent storage container 13 ... Stir screw (developer conveying means)
DESCRIPTION OF SYMBOLS 14 ... Supply screw 15 ... Developing roller 16 ... Guide piece 17 ... Partition wall 18 ... 1st accommodating part 19 ... 2nd accommodating part 20a, 20b ... Communication part 21 ... Toner density sensor 22 ... Developer supply port (replenishment part)
23 ... Supply duct 24 ... Opening / closing spring 25 ... Shutter 26 ... Developer discharge port (discharge section)
27 ... Flow path restriction part (discharge part)
DESCRIPTION OF SYMBOLS 28 ... Contact surface 29 ... Agitation side rotating shaft 30 ... Agitation blade 31 ... 1st blade part 32 ... 2nd blade part 33 ... 3rd blade part 34 ... Agitation paddle 35 ... Supply side rotation shaft 36 ... Supply blade 37 ... Supply Paddle 38 ... First helical gear 39 ... Second helical gear 40 ... Sleeve 41 ... Permanent magnet 42 ... Developer supply container 43 ... Support roller 44 ... Intermediate transfer belt 45 ... Primary transfer portion 46 ... Secondary transfer Section 47 ... Cassette 48 ... Recording medium 49 ... Conveying roller 50 ... Ejection tray 51 ... Elastic member

  In the above embodiment, the driving force from the motor is sequentially transmitted to the driving gear, the second helical gear 39, and the first helical gear 38. It can also be configured to transmit to the helical gear 39.

1 is a schematic view of an image forming apparatus according to an embodiment. FIG. 2 is a transverse sectional view showing the developing device of FIG. 1. FIG. 2 is a longitudinal sectional view showing the developing device of FIG. 1. (A) is a partial cross-sectional view showing the helical gear side when the stirring screw of the developing device of FIG. 1 is located at the normal position, and (b) is a partial cross-sectional view showing the developer discharge port side. . It is sectional drawing which shows the flow-path restriction | limiting part of FIG.4 (b). (A) is a partial cross-sectional view showing the helical gear side when the stirring screw of the developing device of FIG. 1 is located at the closed position, and (b) is a partial cross-sectional view showing the developer discharge port side. . It is sectional drawing which shows the flow-path restriction | limiting part of FIG.6 (b). FIG. 4 is a perspective view showing a supply duct connected to the developer recovery container of FIG. 3. 1 is a block diagram of an image forming apparatus according to an embodiment. (A) is the schematic which shows the state which inclined the developer container which concerns on this embodiment, (b) is the schematic which shows the state which moved the stirring screw to the regular position. It is the schematic which shows the developer storage container which concerns on other embodiment. It is the schematic which shows the developer storage container which concerns on other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image formation unit 2 ... Transfer unit 3 ... Exposure unit 4 ... Fixing unit 5 ... Paper feed unit 6 ... Cleaning unit 7 ... Control unit 8 ... Photoconductor drum 9 ... Charging device 10 ... Developing device 11 ... Cleaning device 12 ... Development Agent storage container 13 ... Stir screw (developer conveying means)
DESCRIPTION OF SYMBOLS 14 ... Supply screw 15 ... Developing roller 16 ... Guide piece 17 ... Partition wall 18 ... 1st accommodating part 19 ... 2nd accommodating part 20a, 20b ... Communication part 21 ... Toner density sensor 22 ... Developer supply port (replenishment part)
23 ... Supply duct 24 ... Opening / closing spring 25 ... Shutter 26 ... Developer discharge port (discharge section)
27 ... Flow path restricting portion 28 ... Abutting surface 29 ... Agitating side rotating shaft 30 ... Agitating blade 31 ... First blade portion 32 ... Second blade portion 33 ... 3rd blade portion 34 ... Agitating paddle 35 ... Supply side rotating shaft 36 ... Supply blade 37 ... Supply paddle 38 ... First helical gear 39 ... Second helical gear 40 ... Sleeve 41 ... Permanent magnet 42 ... Developer supply container 43 ... Support roller 44 ... Intermediate transfer belt 45 ... Primary transfer Section 46 ... Secondary transfer section 47 ... Cassette 48 ... Recording medium 49 ... Conveying roller 50 ... Ejection tray 51 ... Elastic member

Claims (11)

A supply unit for supplying a developer including toner and carrier, replenished developer is a circulation path that can be circulated and moved, the developer accommodating container and a discharge portion for discharging the developer circulating movement When,
A developer conveying means for forming a spiral blade around the rotating shaft, and circulating the developer in the circulation path while stirring;
The discharge unit communicates with the circulation path, and has an opening where the rotation axis of the developer conveying unit intersects,
The developer conveying means is formed with an opening / closing portion that can open and close the opening , around the rotation shaft, having a larger projected area in the axial direction than the opening .
When the developer container is inclined and the discharge portion is on the lower side, the developer conveying means is moved in the axial direction by its own weight, and at least a part of the opening / closing portion is brought into contact with the closing surface around the opening. Accordingly , the developing device is configured to close or substantially close the opening . The developing device according to claim 1, wherein the opening and closing part of the developer conveying means is constituted by a part of the blade.   The developing device according to claim 1, wherein the opening / closing part of the developer conveying unit is configured by a surface substantially parallel to the closing surface. Closing surface of the developer container, or, according to claim 1 wherein that at least one of opening and closing portion of the developer conveying unit, characterized in that it is integrated with the elastic member closable discharge portion in contact with each other The developing device according to 1. The discharge portion of the developer container is composed of a flow path restriction portion having a flow path cross-sectional area smaller than a flow path through which the developer circulates.
The blades of the developer conveying means are formed in a reverse winding with the first blade portion for circulating and moving the developer in the circulation path, and prevents the developer from being discharged to the discharge portion. A second blade portion, and a third blade portion that has the same winding direction as the first blade portion, is disposed in the flow path restriction portion, and conveys the developer that has moved beyond the second blade portion,
5. The opening / closing part of the developer conveying means is constituted by a part of a second blade part that closes or substantially closes an inlet of a flow path restriction part that is an opening of the discharge part . The developing device according to claim 1. The discharge portion of the developer container is composed of a flow path restriction portion having a flow path cross-sectional area smaller than a flow path through which the developer circulates.
The blades of the developer conveying means are formed in a reverse winding with the first blade portion for circulating and moving the developer in the circulation path, and prevents the developer from being discharged to the discharge portion. A second blade portion, and a first blade portion that has the same winding direction as the first blade portion, and a third blade portion that conveys the developer that has moved beyond the second blade portion, and
The third blade portion and the second blade portion is disposed in the flow path limiting portion,
The opening / closing part of the developer conveying means is constituted by a part of a first blade part that closes or substantially closes an inlet of a flow path restriction part that is an opening of the discharge part . The developing device according to claim 1. The circulation path of the developer container is divided into a first container part and a second container part formed with a discharge part on one end side,
A first conveying member accommodated in the first accommodating portion, and the developer conveying means, and a second conveying member accommodated in the second accommodating portion,
The rotating shafts of the respective conveying members protrude from the end face of the developer container and are provided with helical gears that mesh with each other.
Second conveying member, when the emissions part is downward, by gravity, from the normal position reaches the closed position by moving axially within the meshing range of helical gears, closing the discharge portion in the closing part or 7. The apparatus according to claim 1, wherein the first transfer member is substantially closed and rotationally driven to receive a thrust force via a helical gear and move from a closed position to a normal position. The developing device according to any one of the above. A developer storage container comprising a replenishment section for replenishing developer including toner and carrier, a circulation path through which the replenished developer can be circulated, and a discharge section for discharging the circulated and moved developer When,
A first conveying member that is provided in the developer container and conveys the developer in a first direction by rotating;
A second conveying member provided in the developer container parallel to the first conveying member, and conveying the developer in a second direction opposite to the first direction;
A circulation channel in the developer container is provided between the first transport member and the second transport member, and the first fluid flows from the downstream region of the first transport member to the upstream region of the second transport member. And a partition wall having a second communication portion that causes the developer to flow from the downstream region of the second conveying member to the upstream region of the first conveying member,
A developer discharge mechanism provided on the downstream side of the first conveying member in the developer container;
With
The first transport member has a blade for transporting the developer, and is supported so as to be reciprocally movable in a predetermined range in the axial direction in the developer container.
The developer discharging mechanism, and communicates with the circulation passage has an opening that intersects with the axial direction, when the first conveying member is moved to the developer discharging mechanism side, around a portion of the vane the opening A developing device characterized in that it is substantially closed by abutting against a closing surface of the developing device.   The developing device according to claim 8, wherein the blades of the first conveying member are formed in a screw shape continuous in the axial direction. The first conveying member is provided at one end with a helical gear for transmitting a driving force to the first conveying member, and the direction of the teeth of the helical gear is rotated and driven, the developing device according to claim 8 or 9, wherein the blades of the conveying member is a direction to move to the open port or et away direction.   An image forming apparatus comprising the developing device according to claim 1.

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