JP2000081787A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the developer quantity in the developer container possible to be maintained in the appropriate range by discharging the developer in the above developer container according to the replenished quantity with a simple constitution. SOLUTION: This developing device is constituted of, a developing roll R0, the developer container provided with the first developer agitation area 63 and the second developer agitation area 64 arranged on the side opposite to the developing roll R0 adjacent to the agitation area 63, the developer discharging port 67a capable of discharging the developer when a top surface of the developer in the second agitation area 64 is raised beyond a specific height and increasing the discharge quantity in accordance with the quantity exceeding the above mentioned specific quantity, and the second transporting member R2 provided with a rotary wing R2b, being arranged on the second developer agitation area 64, capable of locally raising the developer top surface height in the area that the developer discharging outlet 67a is arranged higher than another area by retaining the developer fixed on the rotary shaft R2a and the normal transporting part R2c provided with the specified transporting force, and moreover the lower transporting part R2d whose transporting force is lower than that of the normal transporting part R2c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image bearing member (photoreceptor) of an electrophotographic image forming apparatus such as a copying machine or a printer.
Regarding a developing device that develops a latent image formed thereon into a toner image, in particular, a plurality of developing containers each having a developer of a different color are supported by a rotating developing container support member, and sequentially moved to a developing position, The present invention relates to a developing device configured to stop and perform development.

[0002]

2. Description of the Related Art Conventionally, in a dry copying machine or the like, an image carrier (photoreceptor) is formed by a two-component developer composed of a toner and a carrier.
2. Description of the Related Art A developing device that visualizes an electrostatic latent image on a surface, that is, performs development is used. In the developing container containing the two-component developer of such a developing device, the toner is consumed by the developing operation, while the carrier is not consumed and remains in the developing container. The toner is brought into frictional contact with the toner to charge the toner. When such friction and collision with the toner are repeated, a part of the toner adheres to the carrier, thereby contaminating the carrier surface and peeling off the carrier coat layer. Therefore, the charging ability of the carrier to the toner gradually decreases,
Fogging or the like due to poor charging of the toner occurs, which causes the image quality to significantly deteriorate.

Heretofore, since the developer in the developing container was periodically replaced before such image quality defects occurred, a great deal of maintenance work was required. In addition, as the size of the device progresses due to space saving, 1
Since the size of the developing container per unit is also limited, a sufficient amount of developer cannot be secured inside each developing container. for that reason,
The replacement interval of the developer or the developing container is further shortened, and the service cost for replacing the developer and the cost of consumables due to frequent replacement of the developing cartridge are increased.
There is a problem that the unit price per sheet becomes high. For the purpose of suppressing such deterioration of the developer, the developer composed of a mixture of the carrier and the toner or the carrier and the toner is separately supplied into the developing container, and the deteriorated developer having the deteriorated charging performance is developed. There has been proposed an apparatus which is discharged from a container and capable of suppressing a decrease in charging performance. This type of technology is conventionally called a "trickle development system", and the following technology (J01) is known.

(J01) Technology described in Japanese Patent Publication No. Hei 2-21591 (Japanese Unexamined Patent Publication No. 59-100471) The technology described in this publication discloses that a new carrier is placed in a developing container separately from replenishment of consumed toner. The replenished developer in the excess developer container overflows and is discharged from a developer discharge port provided on the developing container wall surface,
Collected in a developer collection container. By repeatedly supplying and discharging the developer, the developer that is contaminated and deteriorates in the developing container is replaced with newly supplied toner and carrier. Thereby, the charging performance of the developer is maintained, and the deterioration of the image quality is suppressed.

In recent years, there has been an increasing demand for color image forming apparatuses such as copying machines and printers. In order to obtain a color image in an image forming apparatus such as a copying machine or a printer, there is a method of installing a plurality of developing containers for developing a plurality of color toners and superimposing the plurality of color toners on a recording medium. General. As means for realizing this, a plurality of developing containers are arranged around the image carrier, only the developing container to be developed is brought into contact with the image carrier, and the other is separated, a so-called retract method in which the developing container is held on a rotating body. A method such as a so-called rotary method in which a developing container of a required color is opposed to an image carrier by a rotation operation, a so-called tandem method in which a combination of one image carrier and one or a plurality of developing containers arranged around the image carrier are arranged in series. Proposed and put to practical use.

When the trickle system is applied to such a color image forming method, a mechanism for discharging the deteriorated developer to the outside of the developing container in accordance with a replenishment amount of a new carrier and toner is required. The following technology (J02) is known as one of such mechanisms. (J02) Japanese Patent Application Laid-Open No. 5-289506 discloses a technique in which a shutter is provided at a developer discharge port of a developing container, the shutter is opened and closed by a solenoid, and an amount of excess developer corresponding to an opening and closing time is discharged. The technology to do this is described.

[0007]

(Problem of (J02)) The prior art (J02) has a problem that the structure is complicated and the reliability is low because the opening and closing of the shutter is electrically controlled. is there.

As described above, the following techniques (J03) and (J04) are conventionally known as methods for controlling the discharge amount without using a driving device for opening and closing the shutter. (J03) (Technology of providing a lower edge of a developer discharge port at an appropriate amount of developer upper surface position in a developer container) In this technology, a developer container of a developing device is kept horizontal in a full-color image forming method. In a developing container used in the horizontal retract method and the tandem method, a lower end edge of a developer discharge port is provided at an appropriate amount of developer upper surface position in the developing container. As a result, a new carrier is replenished, and the amount of the developer in the container increases. Until it is no higher than the lower edge of the
The developer in the container continues to be discharged.

(J04) (Technical application of Japanese Patent Application No. 10-158076, that is, technology described in Japanese Patent Application Laid-Open No. Hei 10-158076) A developer discharge port is provided on the upper wall of the container when the plurality of developing containers supported by the container stop moving to the developing position. A shutter rotatable by its own weight is provided at a position of the developer outlet inside the container upper wall. In the developing position, the shutter is rotated inside the container to open the developer discharge port, and the tip of the shutter is set close to the upper surface of the developer in the container. When the amount of the developer in the container increases, the state is such that the tip of the shutter sneaks into the developer, and the developer moves to the upper surface of the shutter by the movement of the developer due to the conveying force of the conveying member. The developer accumulated on the shutter in this way is
When the shutter closes the developer outlet when the developing container support member rotates, the developer is discharged out of the developing container.

The prior arts (J03) and (J04) both aim at maintaining the developer amount in the developing container within an appropriate range by a simple mechanism. The reason is that if the amount of developer in the developer container cannot be maintained within an appropriate range,
This is because the following problems (a) and (b) occur. (A) If the amount of the developer is too large, the driving torque of the developing roll and the conveying member increases, and the power consumption of the driving motor increases, and it becomes difficult to sufficiently agitate the replenishment toner in the developing container. Problems such as fogging occur. (B) Conversely, if the amount is too small, the supply of the developer to the developing roll becomes insufficient, and image defects such as uneven density and white spots occur. Therefore, in order to maintain the amount of the developer in the developing container within an appropriate range, when the replenishing amount in the developing container is large, the amount increased by the replenishment is promptly discharged, and the developing amount in the developing container is reduced. When the amount of the developer decreases, it is necessary to reduce the amount of the developer discharged from the container.

However, there are the following problems in maintaining the amount of the developer in the container within an appropriate range. For example, when a developer outlet is provided in the container side wall as in the prior art (J03), the position of the lower end edge of the developer outlet from the upper surface of the developer within an appropriate range of the amount of the developer in the developer container. If it is located above, it is difficult for the developer in the container to be discharged from the developer discharge port. Therefore, when the replenishment amount of the developer is large, the amount of the developer in the container increases, and the amount of the developer in the container becomes an appropriate range or more. Further, when the lower edge of the developer outlet is located below the upper surface of the developer in the appropriate range, the developer in the container is easily discharged. However, in this case, when the developer replenishment amount is small, the developer in the container is continuously discharged, and the developer amount in the container falls below an appropriate range.

In the case where a shutter is provided at the developer outlet on the upper wall of the container as in the prior art (J04), a position where the developer in the developer container is difficult to be discharged (the upper surface of the developer in the appropriate range). (Upper position), when the amount of developer supplied is large, the amount of developer in the container increases, and the amount of developer in the container becomes an appropriate range or more. When the shutter is held at a position where the developer is easily discharged (a position below the developer upper surface position in the appropriate range), the amount of the developer in the container becomes less than an appropriate range.

[0013] In view of the above-mentioned examination results, the present invention has the following description (O01) as a technical subject. (O01) The developer in the developing container is discharged with a simple configuration according to the supply amount so that the amount of the developer in the developing container can be maintained within an appropriate range.

[0014]

Next, a description will be given of the present invention which has solved the above-mentioned problems. In the description of the present invention, reference numerals in parentheses added after constituent elements of the present invention denote constituent elements of the present invention. Reference numerals of corresponding components of the embodiment described later. The reason why the present invention is described in association with the reference numerals of the components of the embodiments described later is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(Invention) In order to solve the above-mentioned problems, a developing device of the present invention has the following requirements. (A01) An image writing device (ROS) adapted to image information. An image carrier (1) on which a latent image is written and rotates.
6) a developing region (Q) which is arranged adjacent to the surface and develops a latent image on the image carrier (16) into a toner image;
2) a developing roll (R0) for transporting a two-component developer composed of a toner and a carrier; (A02) a developing roll accommodating section (62) accommodating the developing roll (R0); ) Adjacent to the developing roll (R
0) a first developer stirring area (63) extending in the axial direction;
A portion except for the connection ports (E) at both ends in the axial direction is disposed adjacent to the first developer stirring area (63) and on the opposite side to the development roll (R0), and is formed by the partition wall (66). 1
A partition wall (66) and a container sidewall extending along the partition wall (66), the partition wall being connected to the first developer stirring region (63) and having both axial ends connected to the first developer stirring region (63); The second developer stirring area (6
(A03) a rotating shaft (R1a) disposed in the first developer stirring area (63) and extending in the transport direction of the two-component developer; ) Is fixed to the outer periphery of the developing roller (R1b), and the rotating blade (R1b) rotates with the rotation of the rotating shaft (R1a) to agitate the developer to the developing roll (R0). A first conveying member (R1) for conveying, (A04) a rotating shaft (R2a) disposed in the second developer stirring area (64) and extending in a conveying direction of the two-component developer; and a rotating shaft (R2a). A rotating blade (R2b) fixed to the outer periphery of the first conveying member (R1) while stirring the developer by rotating the rotating blade (R2b) with the rotation of the rotating shaft (R2a). (R2), (A05) which transports the developer in the opposite direction to the second developer stirring area (64) Is provided on an outer wall of the container forming the second developer stirring area (64) for discharging the developer, and discharges the developer when the height of the upper surface of the developer is equal to or higher than a certain height, and discharges the developer at the certain height. Developer discharge port (67a + 69b; 67a '), the discharge amount of which increases as the amount of toner exceeds the limit, (A06) developer container (U)
Developer supply port (7) for replenishing new developer
6), (A07) a normal transport unit (R2
c) and a low conveying section (R2d; R2d ') provided downstream of the developer discharge port (67a + 69b; 67a') in the developer conveying direction and having a lower conveying force than the normal conveying section (R2c).
And the developer is retained by the low transport section (R2d; R2d '), and the developer outlets (67a + 69b; 67)
The rotor (R2) for locally increasing the developer upper surface height in the region (Sa) where the a ') is disposed than the other region (Sb).
The second transport member (R2) having b).

In the present invention, it is preferable that the developer is discharged when the height of the upper surface of the developer is equal to or higher than a predetermined height, and the discharge amount increases as the amount exceeding the predetermined height increases. Examples of the “developer outlet” include the following developer outlet. (A) A developer outlet (67a ') provided on the side wall of the developing container (U). (B) A developer outlet (67a + 69b) provided on the upper wall of the developing container (U) of the rotary developing device and provided with an opening / closing shutter (71) on the inner surface side.

(Function of the Present Invention) In the developing device of the present invention having the above-described features, the developing roll (R0) housed in the developing roll housing portion (62) of the developing container (U) is an image writing device. A latent image corresponding to the image information is written by (ROS) and is arranged adjacent to the surface of the rotating image carrier (16). A first transport member (R1) disposed in a first developer stirring area (63) extending in the axial direction of the developing roll (R0) has a rotation shaft (R1) extending in the transport direction of a two-component developer composed of toner and carrier. R1a) and a rotor (R1b) fixed to the outer periphery of the rotating shaft (R1a).
The rotating blade (R1b) together with the rotation of the rotating shaft (R1a)
The developer roll (R) is rotated while stirring the developer.
Transport to 0). A second developer stirring area (64) disposed adjacent to the first developer stirring area (63) and on the opposite side of the developing roll (R0) is axially aligned with the first developer stirring area (63). Portions other than the connection port (E) at both ends in the direction are partitioned by a partition wall (66) and formed between the partition wall (66) and a container side wall extending along the partition wall (66). The second transport member (R2) disposed in the second developer stirring area (64) rotates the rotary blade (R2b) with the rotation of the rotating shaft (R2a) to stir the first developer while stirring the developer. It is transported in the opposite direction to the transport member (R1). The latent image on the image carrier (16) is developed into a toner image by the toner of the two-component developer conveyed to the developing area (Q2), and the two-component developer consumed by the developing operation is 2 The developer is sent to the developer stirring area (64). New developer is supplied into the developing container (U) from the developer supply port (76).

The rotor (R2) of the second transport member (R2)
b) a normal transport section (R2c) having a predetermined transport force and a downstream side of the developer discharge port (67a + 69b; 67a ') in the developer transport direction and the normal transport section (R2c)
And a lower conveying portion (R2d; R2d ') having a lower conveying force than that, and the developer is retained by the low conveying portion (R2d; R2d'), and the developer outlets (67a + 69b; 67a ') are arranged. The height of the developer upper surface of the region (Sa) is locally higher than the other region (Sb). When the height of the upper surface of the developer is locally higher than a predetermined height, the developer having the locally increased upper surface height is discharged from the developer outlet (67a + 69b; 6).
7a '). The discharge amount increases as the amount of the developer whose locally upper surface height is higher than the predetermined height increases. Therefore, it is possible to prevent the developer amount in the developing container (U) from being excessively increased. When the upper surface height of the developer at the position where the upper surface height of the developer locally increases becomes equal to or less than a certain height, the developer is discharged to the developer outlet (67a + 69b; 6).
7a '). At this time, the position of the developer upper surface in the other region (Sb) is maintained at a position corresponding to the developer upper surface height (the upper surface height equal to or less than the predetermined height) at the locally raised position. The development container (U)
It is possible to prevent the height of the developer in the inside from becoming too low.

[0019]

(Embodiment 1) A developing device according to Embodiment 1 of the present invention is characterized by satisfying the following requirements in the present invention. (A08) The low transport section (R2
The rotating blade (R2b) formed so that the outer diameter of d) is smaller than the outer diameter of the normal transport section (R2c). (Operation of the First Embodiment) In the developing device of the first embodiment of the present invention having the above-described configuration, the outer diameter of the rotary blade (R2b) is formed to be smaller than the outer diameter of the normal transport section (R2c). The low-conveyance section (R2d) also allows the developer discharge port (67a
+ 69b; 67a ') is located in the region (Sa) where the developer is located. For this reason, the upper surface height of the developer in the area (Sa) where the developer discharge port (67a) is arranged is locally higher than the other area (Sb) by the low transport section (R2d). Therefore, the first embodiment has the same operation as that of the present invention.

(Embodiment 2) A developing device according to Embodiment 2 of the present invention is characterized by satisfying the following requirements in the present invention. (A09) The pitch of the low transport section (R2d ') Are the rotors (R2b) formed shorter than the pitch of the normal transport section (R2c). (Effect of Embodiment 2) In the developing device of Embodiment 2 of the present invention having the above-described configuration, the pitch of the rotating blades (R2b) is shorter than the pitch of the normal transport section (R2c). (R2d ') allows the developer to flow into the developer outlet (6
7a + 69b) stays in the arranged area (Sa). Therefore, the area (S) where the developer discharge port (67a) is located
The upper surface height of the developer a) is locally higher than the other region (Sb). Therefore, the second embodiment also has the same operation as that of the present invention.

(Embodiment 3) A developing device according to Embodiment 3 of the present invention is characterized by satisfying the following requirements in the present invention or Embodiment 1 or 2.
(A010) The developer outlet (67a ') formed on the side wall of the outer wall of the container. (Operation of the Third Embodiment) In the developing device of the third embodiment of the present invention having the above-described configuration, the developer outlet (67a ')
Is formed on the side wall of the outer wall of the container. In the region (Sa) where the developer outlet (67a ') is arranged, the upper surface of the portion where the developer locally rises is the developer outlet (67).
When the position becomes higher than the position of the lower edge of a '), the developer in the container is discharged from the developer discharge port (67a').
As the upper surface of the developer becomes higher than the position of the lower end edge of the developer discharge port (67a '), the developer is more easily discharged, so that the discharge amount of the developer increases. Therefore, when the replenishment amount of the developer is large, the developer amount in the container does not increase.
The amount of the developer in the container is in an appropriate range. In addition, when the amount of the developer supplied is small, as the amount of the developer in the developing container (U) decreases, the height of the locally higher portion of the developer becomes higher than the developer outlet (67a '). ) Approaches the position of the lower edge. Emissions decrease as approaching. When the upper surface of the developer is located at the lower end edge of the developer discharge port (67a '), the developer is not discharged, so that it is possible to maintain the required minimum amount of developer.

(Embodiment 4) A developing device according to Embodiment 4 of the present invention is the same as that of Embodiment 1 or 2 of the present invention.
(A01)
1) A latent image of a plurality of color components corresponding to image information is written by the image writing device (ROS), and the latent image is arranged adjacent to the surface of the rotating image carrier (16). , F2), a developing container supporting member (H) having a supporting member rotating shaft (Do) rotatably supported by the developing container supporting member (H), and (A012) the supporting member rotating shaft (Do) supported by the developing container supporting member (H). A plurality of developing containers (U) sequentially stopping at a first stop position (P1) where the latent image of each color component on the surface of the image carrier (16) is developed into a toner image of each color with the rotation and stop of (A013) A discharge developer transport device (J) that transports the developer discharged from the developer discharge ports (67a + 69b) to a developer collection container (Tv).

(Operation of the Fourth Embodiment) In the developing device according to the fourth embodiment of the present invention having the above-described configuration, a latent image of a plurality of color components corresponding to image information is formed by an image writing device (ROS). The information is sequentially written on the surface of the rotating image carrier (16). The fixed frames (F1, F2) are mounted on the image carrier (1).
6) rotatably supports the support member rotation axis (Do) of the developing device support member (H) disposed adjacent to (6). A plurality of developing containers (U) supported by the developing device support member (H);
Rotates sequentially with the rotation of the support member rotating shaft (Do), stops at the first stop position (P1), and develops a latent image of each color component on the surface of the image carrier (16) into a toner image. Stop sequentially at the first stop position (P1). The discharged developer conveying device (J) conveys the developer discharged from the developer discharge port (67a + 69b) to a developer collecting container (Tv).

Fifth Embodiment A developing device according to a fifth embodiment of the present invention is characterized in that the following requirements are satisfied in the fourth embodiment. (A014) The first stop position (P1) (A015) When the developer discharge port (67a + 69b) provided on the upper wall portion of the developer container at the time when the developer discharge port (67a + 69b) faces upward,
The developer discharge opening (67a + 69b) is rotated to the opening position by the action of gravity to open the developer discharge opening (67a + 69b).
+ 69b) is a shutter (71) that rotates to a closing position for closing the developer discharge port (67a + 69b) by the action of gravity when the shutter is at the open position, and is conveyed by the second conveying member (R2) at the opening position. The developer in the second developer agitating region (64) is stored on the outer surface, and the developer stored on the outer surface is rotated by the developer from the opening position to the closing position to the developer discharge port (67a + 69b). ) Discharged from the shutter (71).

(Supplementary Description of Embodiment 5) Developer outlets (67a + 69b) provided on the upper wall of the developing container (U)
Are formed only on the upper wall (W2) of the developing container (U) or formed on both the upper wall (W2) and the discharge port forming member (69) supported on the upper wall (W2). Outlet (6
7a, 69b) can be arranged in an overlapping manner.

(Effect of Fifth Embodiment) In the developing device of the fifth embodiment of the present invention having the above-described configuration, the developer discharge port (67a + 69b) is stopped at the first stop position (P1). It is provided on the upper wall of the developing container. Therefore, when stopped at the first stop position (P1), the developer discharge port (67a + 69b) faces upward, so that the shutter (71) rotates to the open position and the developer discharge port (6).
7a + 69b) are opened. The developer discharge port (67a + 69b) is arranged by the low conveyance section (R2d) of the rotating blade (R2b) of the second conveyance member (R2) of the developer container (U) stopped at the first stop position (P1). The developer in the region (Sa) is retained. Therefore, the developer outlet (67)
a + 69b), the upper surface height of the developer in the region (Sa) where the (a + 69b) is arranged is locally higher than the other region (Sb),
The developer is transported to the outer surface of the shutter (71) rotated to the opening position by the transport member (R2). When the developer container (U) stopped at the first stop position (P1) rotates and stops along with the rotation of the developer container support member (H), the shutter (71) rotates to the closed position. I do. When the shutter (71) rotates to the closed position, the developer on the outer surface of the shutter (71) is discharged from the developer discharge ports (67a + 69b). Also,
Each of the developing containers (U) is rotated to rotate the developer outlet (6).
7a + 69b) in the downward direction, the shutter (7
1) is rotated to the closing position by the action of gravity, and closes the developer discharge port (67a + 69b).

As the height of the developer locally higher in the region (Sa) where the developer outlets (67a + 69b) are arranged becomes higher than the outer surface of the shutter (71), the shutter (71) Since the amount of developer on the outer side surface increases, the amount of discharge from the developer discharge port (67a + 69b) increases. Therefore, the amount of developer in the container does not increase when the amount of developer supplied is large. When the amount of the developer supplied is small, as the amount of the developer in the developer container (U) decreases, the upper surface of the locally higher portion of the developer decreases, and the discharge amount decreases. . When the upper surface of the developer is lower than the outer surface of the shutter (71), the developer is not discharged, so that the necessary minimum amount of the developer can be maintained.

(Embodiment 6) A developing device according to Embodiment 6 of the present invention is characterized by satisfying the following requirements in the present invention or Embodiments 1 to 5 (A01).
6) The pitch of the normal transport section (R2c) of the rotary blade (R2b) is po, the axial length of the low transport section (R2d; R2d ') is L1, and the developer discharge ports (67a + 69b; 67a'). ≤L1≤1.5po, 0≤, where L2 is the length between the downstream end of the low transfer section (R2d; R2d ') and the upstream end
The rotor (R2b) formed so that L2 ≦ po.

(Operation of the Sixth Embodiment) In the developing device of the sixth embodiment of the present invention having the above-described configuration, the rotating blade (R2
b) is the pitch of the normal transport section (R2c) of the rotor,
o, the axial length of the low conveying section (R2d; R2d ') is L
1. If the length between the downstream end of the developer discharge port (67a + 69b; 67a ') and the upstream end of the low conveying section (R2d; R2d') is L2, po≤L1≤1.5po , 0 ≦ L2
≦ po. The developer discharge port (67a + 69) is formed by the rotating blade (R2b) thus formed.
b; 67a '), the developer stays in the area (Sa) where the developer outlet (67a + 69b; 67a') is located, and the height of the upper surface of the developer in the area (Sa) where the developer outlet (67a + 69b; 67a ') is located is set to another area. (Sb) It can be locally higher than (Sb). Therefore, the developer outlet (67a + 69b; 67a ') is
Since the developer is discharged when the height of the upper surface of the developer is equal to or higher than a certain height, the developer whose height of the upper surface of the developer is locally increased is discharged to the developer outlet (67a + 69b; 6).
7a '). The discharge amount increases as the amount of the developer whose locally upper surface height is higher than the predetermined height increases. Therefore, it is possible to prevent the developer amount in the developing container (U) from being excessively increased. When the upper surface height of the developer at the position where the upper surface height of the developer locally increases becomes equal to or less than a certain height, the developer is discharged to the developer outlet (67a + 69b; 6).
7a '). At this time, the position of the developer upper surface in the other region (Sb) is maintained at a position corresponding to the developer upper surface height (the upper surface height equal to or less than the predetermined height) at the locally raised position. The development container (U)
It is possible to prevent the height of the developer in the inside from becoming too low.

[0030]

Next, examples (embodiments) of the embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the right-left direction is the Y-axis direction, the vertical direction is the Z-axis direction, and arrows X, -X, Y, -Y, The directions indicated by Z, -Z or the sides indicated are forward, rearward, rightward, leftward, upward, downward,
Or, the front side, the rear side, the right side, the left side, the upper side, and the lower side.
Also, in the figure, those with “•” in “○” mean arrows pointing from the back of the paper to the front, and those with “x” in “○” indicate the arrow on the paper. From the back to the back.

(Embodiment 1) FIG. 1 is an overall explanatory view of an embodiment of the image forming apparatus of the present invention. In FIG. 1, an image forming apparatus F has a platen glass (transparent platen) A
1 is provided with a digital copying machine F1 as an image forming apparatus main body having an automatic document feeder 1 and an automatic document feeder F2 detachably mounted on the platen glass A1. The automatic document feeder F2 is provided with a document Gi stored in a document feed tray TRk.
(I = 1, 2,...) Are sequentially taken out, conveyed to a copy position on the platen glass A1, and the copied document is discharged to a document discharge tray TRh. Also,
The automatic document feeder F2 has a document presence / absence sensor S1 for detecting the presence / absence of a document on the document feed tray TRk, a document registration sensor S2 for detecting the passage of the conveyed document, and the like.

The copying machine body F1 has a UI (user interface) arranged on the upper surface thereof, and an I (document reading device) sequentially arranged below the platen glass A1.
It has an IT (Image Input Terminal), an IPS (Image Processing System), and an IOT (Image Output Terminal) as an image recording operation unit. The UI (user interface) includes an input operation member (not shown) such as a copy start button, a copy setting number input key, and the like, for a user of the image forming apparatus F to input an operation command signal such as a copy start; And a display unit (not shown) on which information on the current setting state of F is displayed.

IIT as an original reading device disposed below transparent platen glass A1 on the upper surface of copying machine main body F1
Is the OP located at the platen registration position (OPT position)
It has a T registration sensor (platen registration sensor) Sp and an exposure optical system 1 as an image reading device. The reflected light of the document Gi illuminated by the exposure optical system 1 is configured to converge on a CCD (solid-state image sensor) through the exposure optical system 1. The CCD converts the original reflected light converged on the image pickup surface into an R (Red) G (Green)
n, green) and B (Blue, blue).

An IPS (image processing system) converts the three color electric signals input from the CCD into Y (yellow), M (magenta), C (cyan), and K
The image data is converted into image data of four colors (black) and output to the IOT laser drive signal output device 14 as write data. The IOT laser drive signal output device 14 outputs a laser drive signal corresponding to the input image data to an ROS (optical writing scanning device, that is, a latent image (image) writing device).

The ROS scans an electrostatic latent image writing position Q1 on the rotating image carrier 16 with a laser beam L modulated by the input laser drive signal. A charger 17 for uniformly charging the image carrier 16 is disposed along the rotating image carrier 16 and upstream of the latent image writing position Q1 in the moving direction of the image carrier 16. After the image carrier 16 is uniformly charged by the charger 17,
At the latent image writing position Q1, an electrostatic latent image is written by the laser beam L.

A rotary developing unit (developing device) for developing the electrostatic latent image into a toner image is provided in a developing area Q2 downstream of the latent image writing position Q1 along the moving direction of the image carrier 16. (Device) D is disposed. The developing unit D
Are developing units Dk and D mounted around the support member rotation axis Do.
y, Dm, and Dc, and each developing unit Dk, Dy, Dm, and D
c is a developing unit that performs development using a two-component developer having toners and carriers of each color of K, Y, M, and C.
The developing units Dk, Dy, Dm, and Dc for the four colors are sequentially moved to a first stop position shown in FIG. 3 (the developing position, ie, the developing area Q2, Replenishment position) P1, second stop position (developer discharge position where the developer is discharged from the developing container) P2, third stop position P3,
And stop at the fourth stop position P4.

In FIG. 1, the rotating image carrier 16
A toner image density sensor SNd is disposed on the downstream side of the development area Q2 along the surface, and a transfer drum 21 and a transfer unit 22 are disposed at a transfer position Q3 set on the downstream side. Further, along the rotating image carrier 16,
A static eliminator 23 and a cleaner unit 24 are arranged downstream of the transfer position Q3. The toner image density sensor SNd is composed of a light emitting element and a light receiving element arranged close to the image carrier 16, and is a toner image (patch) formed by developing a test electrostatic latent image formed on the image carrier 16. ) Is measured to detect the toner image density.
The transfer device 22 extends along the rotation direction of the transfer drum 21.
On the downstream side, a static eliminator 26, a cleaner 27, and an adsorption corotron 28 are sequentially arranged. The adsorption corotron 28 is arranged at the adsorption position Q4.

Below the transfer drum 21, a first paper feed tray T for storing recording sheets is sequentially arranged downward.
1, a second paper supply tray T2, an intermediate tray T0 for temporary stock used for duplex copying, a third paper supply tray T3, a fourth paper supply tray T4, a fifth paper supply tray T5 for storing a large number of recording sheets. Is detachably stored. The intermediate tray T0 is an intermediate tray used when circulating the recording sheet (hereinafter referred to as a sheet) S on which the first copy has been performed at the time of double-sided copying and retransmitting the recording sheet S to the transfer position Q3. A manual feed tray 31 is provided at an upper right position of the first paper feed tray T1. The recording sheets conveyed from the manual feed tray 31 by the paper feeding rollers R6 and R7 and the recording sheets sent out from the paper feeding trays T1 to T5 pass through the first sheet conveying path 32 to the suction position Q4. It is designed to be transported. The recording sheet conveyed in the first sheet conveying path 32 is detected by the registration sensor SNy, temporarily stopped by the registration roller 33, and then conveyed to the suction position Q4 at a predetermined timing. At the suction position Q4, the sheet S
Is adsorbed to the transfer drum 21 by an adsorption roll 34.

The sheet S adsorbed on the transfer drum 21
Is transferred to the transfer position Q3 as the transfer drum 21 rotates. The transfer unit 22 transfers the toner image on the image carrier 16 to the sheet S passing through the transfer position Q3.
After the developer remaining on the surface of the image carrier 16 that has passed the transfer position Q3 is recovered by the cleaner unit 24, the image carrier 16 is uniformly charged again by the charger 17. At the suction position Q4, the transfer drum 21
The sheet S adsorbed to is rotated four times in the case of full color,
Every time it passes through the transfer unit 22, K (black), Y (yellow),
Magenta (M) and C (cyan) toner images are transferred. The sheet S on which the four full-color images are formed is separated from the transfer drum 21 by the separation corotron 36,
The sheet is conveyed to the fixing position Q5 through the second sheet conveying path 37.

At the fixing position Q5, a pair of fixing rolls 41 and 4 composed of a heating roll 41 and a pressure roll 42 are provided.
2 is disposed, and the fixing position Q
It is configured to fix the unfixed toner image on the sheet S passing through the sheet 5 by applying heat and pressure. The heating roll 4
1 has a fixing heater 41h built therein. A discharge roller 43 for discharging a sheet to a sheet discharge tray TR is provided on the second sheet conveying path 37 downstream of the fixing position Q5.

In the second sheet conveying path 37, a switching gate 44 is disposed upstream of the discharge roller 43.
The switching gate 44 is used when switching the transport direction of the sheet S on the second sheet transport path 37 to the sheet circulation path 46 or the direction of the sheet discharge tray TR. The sheet circulation path 46 is connected to a sheet reversing path 47 and the intermediate tray T0 via a switching gate 48. The switching gate 48 is configured to direct the sheet S of the sheet circulation path 46 to the sheet reversing path 47 when performing double-sided copying. The sheet-shaped and comb-shaped mylar gate 49 provided in the sheet reversing path 47 allows the sheet S to move downward by elastic deformation when the sheet S passing therethrough is conveyed downward. When the sheet S that has passed through the switch 49 is switched back and conveyed upward, the sheet S is guided in the direction of the intermediate tray T0. Sheet S once stored in intermediate tray T0
Are transported again from the intermediate tray T0 to the suction position Q4 by the first sheet transport path 32.

FIG. 2 is an enlarged sectional view of a main part of the developing device according to the first embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of a portion different from FIG. 2 of the first embodiment of the developing device of the present invention. FIG.
FIG. 4 is a diagram showing a state where the developing container of the embodiment is mounted on a rotating developing container support member. 5 is an enlarged cross-sectional view of a rotation shaft of a support member provided in the developing device according to the first embodiment of the present invention. FIG. 5A is a cross-sectional view taken along the line VA-VA of FIG. 4, and FIG. 5B is a cross-sectional view taken along the line VB-VB of FIG. It is a line sectional view. 6 is a perspective view of the developing container shown in FIG. 4, and FIG. 6A is a diagram showing a state in which a developer supply cylinder is removed from the developing container.
B is a diagram showing a state in which a developer supply cylinder is attached to the developing container. FIG. 7 is a sectional view taken along line VII-VII of FIG. 2 to 4, the developing unit D
The rotary shaft Do of the cylindrical support member to which the developing units Dk, Dy, Dm and Dc of the four colors K, Y, M and C are mounted is connected to the front wall of the fixed cylindrical member F1a fixedly supported by the front fixed frame F1. It is rotatably supported by the portion and the rear fixed frame F2 (see FIG. 4). A driven gear G1, which meshes with the drive gear G0, is fixed to the rear (-X direction) outer end of the support member rotation shaft Do. The drive gear G0 is driven to rotate by a drive motor (not shown). When the gear G0 rotates, the gear G1 and the support member rotation shaft Do are also driven to rotate integrally.

In FIG. 5, a developer discharging cylinder 51 is disposed within the cylindrical support member rotating shaft Do. The rear end (-X end) of the developer discharge cylinder 51 is fixed by a rear discharge cylinder fixing member F2a, and the rear discharge cylinder fixing member F2a is fixed to the rear surface of the rear fixing frame F2. ing. The front end of the developer discharge tube 51 is fixed to a front discharge tube fixing member F1a1, and the front discharge tube fixing member F1a1 is fixed to the center of the front surface of the fixed cylindrical member F1a. In FIG. 5A, the developer discharge cylinder 51
The connection port 51 is located on the rear end (the end in the -X direction) and on the upper side.
a is formed, and the front end (X
A collection container communication port 51b is formed in a lower portion on the (end) side. In FIG. 5B, the support member rotating shaft Do has a communication port Doa (see FIG. 3) and the communication port Do.
a, the rotation-axis-side recovery container communication port Dob in front of a (FIG. 17, FIG. 1)
9) are formed at 90 ° intervals in the circumferential direction. The communication ports Doa are formed at the same position in the axial direction as the connection ports 51a (see FIG. 3) formed in the upper portion of the developer discharge cylinder 51.

In FIG. 5, a magnet seal 52 is adhered and fixed to a portion adjacent to the connection port 51a on the outer peripheral surface of the fixedly supported developer discharge cylinder 51. A communication port 52 a is formed in the magnet seal 52 so as to communicate with a connection port 51 a of the developer discharge cylinder 51. A slight gap is provided between the outer peripheral surface of the magnet seal 52 and the inner peripheral surface of the support member rotation shaft Do so that contact friction resistance does not occur when the support member rotation shaft Do rotates. The magnet seal 52 allows the developer to pass through a gap between the outer peripheral surface of the developer discharge cylinder 51 and the inner peripheral surface of the support member rotation shaft Do to another communication port Doa of the support member rotation shaft Do. It is a member for preventing movement. The developer discharge cylinder 51
The collection container communication port 51b (FIG. 5)
A, see FIG. 17), and the collection container communication port 51b communicates with the developer collection container Tv (see FIG. 17).

In FIG. 5A, a discharge developer transport member 53 having a rotating shaft 53a and a rotating blade 53b fixed to the outer periphery of the rotating shaft 53a is provided in the developer discharging tube 51.
Is arranged. A rear end side of the rotating shaft 53a of the discharge developer conveying member 53 is a rear side conveying member support member 54.
4 and 5, and is rotatably supported. The rear transport member support member 54 is fixed to the rear end of the developer discharge cylinder 51. The front end of the rotary shaft 53a is rotatably supported via a bearing on the center side of the front discharge tube fixing member F1a1 (see FIGS. 4 and 5). A gear G2 (see FIGS. 4 and 5A) is fixed to the rear end of the rotating shaft 53a of the discharge developer transport member 53 that extends rearward (-X) through the rear transport member support member 54. The gear G2 is meshed with a rotation driving gear G3. When the gear G3 rotates, the gear G2
The rotary shaft 53a is configured to be integrally driven to rotate.

In FIG. 4, a front rotating plate 56 is fixedly supported at the front end of the support member rotating shaft Do, and a rear rotating plate 57 is fixedly supported at the rear end. The support member is supported so as to be rotatable integrally with the rotation axis Do. In FIG. 4, a pair of front and rear connection blocks 58, 58 made of plastic are provided on the outer periphery of the support member rotation shaft Do.
The connection block 58 includes the developing units Dk, Dy, Dm, and Dc.
This is a member used to connect and support. The connection blocks 58, 58 have a substantially square cross section (see FIGS. 2 and 3), and pin insertion holes 59 are formed on each side surface. The pin insertion hole 59 is provided with developing units Dk, Dy,
Dm, Dc are holes into which projecting pins are inserted.
These holes are used for positioning and fixing k, Dy, Dm, and Dc. In the connection block 58 in the adjacent portion on the front side of the rear rotation plate 57, communication holes 60 (see FIG. 3) are formed in the direction of the support member rotation axis Do from four side surfaces extending in the axial direction. ing. 3 and 5
As shown in B, the communication hole 60 rotates around the axis together with the rotation of the support member rotation axis Do and moves to a position (Z direction) above the support member rotation axis Do.
Only the magnet seal 5 in the support member rotation axis Do.
2 communication port 52a (see FIG. 5B) and developer discharge cylinder 5
The first connection port 51a communicates with the first connection port 51a. The developer container supporting member H is constituted by the reference numerals Do and 56 to 60.

In FIGS. 2 and 3, each of the developing devices Dk, Dy,
Dm and Dc rotate with the rotation of the support member rotation shaft Do due to the rotation of the drive gear G0 (see FIG. 4), and sequentially move to the first stop position (development position, developer supply position) P1,
It is configured to stop at a second stop position (a developer discharge position where the developer is discharged from the inside of the developer container) P2, a third stop position P3, and a fourth stop position P4. In the first embodiment, the first stop position P1 is a developing position,
The developing unit Dk, Dy, Dm, and Dc perform the developing operation at the first stop position. Each of the developing units Dk, Dy, Dm, and Dc has a developing container U. At the first stop position, the inside of each developing container U by the developer supply member (Th) (see FIGS. 4 and 6B). Replenishment of the developer, discharge of the surplus developer from the developing container U, and movement of the discharged surplus developer (described later).

In FIG. 6, each of the developing containers U comprises a developing container main body V and a developing container cover W for closing the upper end thereof. The developing container body V of each developing container U has a pair of front and rear locking claws V1, V1 (FIG.
) And projecting pins 61, 61 (see FIG. 6). The pair of projecting pins 61, 61 are provided in the pin insertion holes 5 of the connection blocks 58, 58 of the developing container supporting member H.
9, 59 and used to position and fix the developing container U.

Each of the developing units Dk, Dy, Dm, and Dc has the same configuration, so that the developing unit Dk will be described below. 3 and 6, the developing container U of the developing device Dk contains a two-component developer composed of a negatively charged toner and a positively charged magnetic carrier. The developing container main body V has a developing roll R inside thereof.
0, a first developer pool (first developer stirring area) 63 and a first developer pool 6 adjacent to the development roll storage section 62.
Second developer pool adjacent to 3 (second developer stirring area)
64. When the developing container cover W is mounted on the developing container main body V, in order to regulate the layer thickness of the developer on the developing roll R0 on the inner surface side of the developing container cover W in the developing roll accommodating portion 62. Is provided.

As shown in FIG. 7, between the first developer reservoir 63 and the second developer reservoir 64 inside the developing container main body V, partition walls 66 are provided at portions other than both ends thereof.
Are formed, and the first developer reservoir 63 and the second developer reservoir 64 are connected at the connection portions E at both ends in the front-rear direction (X-axis direction). In the first developer reservoir 63 and the second developer reservoir 64, a first transport member R1 and a second transport member R2 for transporting the developer while stirring the developer are arranged. The first and second developer conveying members R1 and R2 constitute a stirring and conveying member (R1 + R2). Further, the first developer reservoir 63 and the second developer reservoir 64 allow the developer stirring area (63+
64) is configured.

In FIG. 7, the first developer reservoir 63
Has a rotary shaft R1a extending in the axial direction of the developing roll R0, and a rotary blade R1b fixed to the outer periphery of the rotary shaft R1a. The second
The second transport member R disposed in the developer reservoir 64
2 also has a rotating shaft R2a and a rotating blade R2b,
The rotary blade R2b has a rotary blade normal transport portion R2c having the same transport force as the rotary blade R1b and a rotary blade low transport portion R2d having a low transport force.

The developing roll R shown in FIG. 2, FIG. 3, and FIG.
Numeral 0 is a conventionally known one provided with a sleeve outside the magnet roll. The developer in the first developer reservoir 63 is moved by the magnetic force of the magnet roll to the developing roll R0.
Adsorbed on the surface of the developing area Q2 (see FIGS. 2 and 3)
To be transported. Further, the developing roll R
The axis 0 is rotatably supported by the front rotation plate 56 (see FIG. 4) and the rear rotation plate 57.

In FIG. 4, the rear fixed frame F2
A gear G6 that is rotationally driven by a drive motor (not shown) and a gear G that rotates coaxially and integrally with the gear G7.
8 is rotatably supported. 4 and 7,
A gear G9 is provided at the rear end of the rotation shaft of the first developer conveying member R1.
(See FIG. 4) and gear G10 (see FIG. 7). A gear G11 (see FIG. 4) is mounted at the rear end of the rotation shaft of the developing roll R0, and a gear G12 (see FIG. 7) is mounted at the rear end of the rotation shaft of the second developer conveying member R2. It is installed. The gear G10 is connected to the gears G11 and G
Meshes with 12.

When the torque of the drive motor (not shown) is transmitted to the gear G9 via the gears G6 to G8, the gears G10, G11, G12 rotate, and the developing roll R0 and the stirring and conveying member (R1 + R2) are rotated. Rotate. Due to the rotation of the stirring and conveying member (R1 + R2), the developers in the first and second developer reservoirs 63 and 64 circulate while being conveyed in opposite directions.

FIG. 8 is an enlarged partial cross-sectional view of a communication passage forming member formed on the upper surface of the container upper wall of the developing container.
It is an enlarged view of the part shown by arrow VIII of A. FIG. 9 is a plan sectional view of the communication path forming member shown in FIG. FIG.
0 is a cross-sectional view of the communication path forming member shown in FIG.
10A is a sectional view taken along line XA-XA in FIG. 9, FIG. 10B is a sectional view taken along line XB-XB in FIG. 9, and FIG. 10C is a sectional view taken along line XC-XC in FIG. FIG. 11 is a longitudinal sectional view of the communication passage forming member shown in FIG. 8, and is a sectional view taken along line XI-XI of FIG. FIG. 12 is an explanatory diagram of the inner surface side of the container upper wall adjacent to a developer discharge port formed on the container upper wall,
FIG. 12A is a view seen from the arrow XIIA in FIG.
FIG. 12B is a sectional view taken along the line XIIB-XIIB of FIG. 12A. FIG. 13 is an explanatory view of a discharge port forming member mounted on the developer discharge port and a shutter rotatably supported by the discharge port forming member, showing a state before the developer discharge port is mounted. FIG. FIG. 14 is a view showing a state where the discharge port forming member and the shutter shown in FIG. 13 are mounted on the developer discharge port. FIG. 15 is a view showing a state of a discharge port forming member and a shutter mounted on the developer discharge port in the developing container, FIG. 15A is a longitudinal sectional view, and FIG.
FIG. 15B is a sectional view taken along line XVB-XVB in FIG. 15A. FIG.
6 is an explanatory view of the discharge port forming member shown in FIG.
FIG. 16A is a lower surface (−Z side surface) in the state of FIG.
16B is a plan view as seen from the perspective, and FIG.
FIG. 16C is a plan view of the state shown in FIG. 13 when viewed from the upper surface (Z-side surface) in FIG.
FIG. 16D is a view from IC, and XVID-X in FIG. 16C.
It is a VID line sectional view.

3, 6, and 10, the developing container cover W is attached to the developing roll accommodating portion 62 (FIG.
3) and an upper wall W disposed on the second developer reservoir 64 of the developing container main body V.
2 (container upper wall) and a locked wall W3 extending downward from the right side of the upper wall W2 and abutting against the side wall of the developing container main body V. The roll housing wall W1 has a top wall W1a and a side wall W1b, and a lower end of the side wall W1b contacts an upper end surface of a partition wall 66 of the developing container main body V as shown in FIG. When the developing container cover W is mounted on the developing container main body V, a locking opening W3a (see FIG. 15B) formed in a locked wall W3 of the developing container cover W is connected to the developing container main body V. Locking claws V1, V1 formed on the outer surface (FIG. 15B
Reference).

8 to 10, the upper wall W2 of the developer container U stopped at the first stop position P1 has a concave portion forming upper wall bulging upward at a rear portion thereof (-X side portion). 67
have. As shown in FIGS. 8 and 10, the recess forming upper wall 67 is inclined upward as it goes to the left (Y direction). A lower protruding portion 68 is provided on the right side of the recess forming upper wall 67. The recess forming upper wall 67
An outer developer outlet 67a (6 mm.times.12 mm in the first embodiment) is formed in the center of. Locking portions 67b, 67b (see FIG. 10B) are formed on the left and right side edges of the outer developer outlet 67a.

Referring to FIGS. 12A and 13A, concave grooves 67d, 67d are formed on the inner surface (67c) of the upper wall before and after the outer developer discharge port 67a.
The width of each of the developer discharge grooves 67d increases at a position apart from the outer developer discharge port 67a. 13 to 1
5, a substantially rectangular discharge port forming member 69 is mounted below the outer developer discharge port 67a. FIG.
6, the discharge port forming member 69 has a rectangular discharge path forming section 69a and a rectangular inner developer discharge port 69b formed at the center of the discharge path forming section 69a. In the first embodiment, the inner developer outlet 69b
Are formed larger than the outer developer outlet 67a. The outer developer outlet 67a and the inner developer outlet 69b constitute a developer outlet (67a + 69b). As shown in FIG. 15A, in a state where the discharge port forming member 69 is mounted inside the outer developer discharge port 67a, the discharge path forming section 69a and the discharge path forming section 6 are formed.
The developer discharge passages 70, 70d are formed between the developer discharge grooves 67d, 67d formed on the inner surface of the upper wall W2 opposite to 9a.
Is formed. The developer discharge paths 70, 70 are discharge paths through which excess developer in the developing container U is discharged to the outer developer discharge port 67a.

In FIG. 16C, locked portions 69c, 69c are formed on the upper surface of the discharge path forming portion 69 on both long sides (left and right sides) of the rectangular inner developer discharge port 69b. As shown in FIG. 15B, the locked portions 69c, 69c are locking portions 6 on the left and right side edges of the outer developer discharge port 67a.
7b and 67b are elastically locked.
16A, 16B, and 16D, a pair of front and rear shutter support portions 69d, 69d are formed on the left end side of the lower surface of the discharge path forming portion 69a, and an intermediate portion between the shutter support portions 69d, 69d. A shutter locking portion 69e is formed. 13 and 14, the left end (the end in the -Y direction) of the shutter 71 is rotatably supported by the shutter support portions 69d and 69d.

The shutter 71 has an opening position (see FIG. 15B and a first stop position P1 in FIG. 3) which is locked by the shutter locking portion 69e and a closing position (FIG. 15B) which closes the inner developer discharge port 69b. 3 (see third stop position P3). The shutter 71 at the opening position
The free end of the rotating blade normal transport portion R2c of the second transport member R2 when the developer amount in the developer container U is appropriate is
Is disposed above the upper surface of the developer at the position of and at a position lower than the upper surface of the developer at the position of the rotating blade low conveyance section R2d. The shutter 71 rotated to the opening position
The developer having an increased upper surface height is placed on the outer surface of the shutter 71, and the developer placed on the outer surface of the shutter 71 is moved when the shutter 71 is turned to the closing position. The developer is discharged from the outer developer outlet 67a via the inner developer outlet 69b.

As shown in FIG. 15A, the developer agitating area (63 + 64) is provided at the upstream end of the developer discharge paths 70, 70.
Are formed with the sub-discharge ports 72, 72 that are connected to the sub-discharge ports. The sub outlets 72 are located at a first stop position P1 which is a developing position.
Is provided above the inner developer discharge port 69b, and is always open. When a large number of copies are made in the single color mode, the developing operation is performed while the developing container U is stopped at the developing position, the developer is not discharged from the developing container U, and the excess developer in the developing container U increases. . The increased excess developer pushes up the shutter 71,
Even when the shutter 71 closes the inner developer outlet 69b, the increased surplus developer flows in from the sub outlets 72, 72 and onto the shutter 71 through the developer outlets 70, 70. It is being discharged.

In FIGS. 3 and 7, the second developer reservoir 6 is located downstream of an outer developer outlet 67a formed in the upper wall W2 above the second developer reservoir 64.
4 low-conveying section R2d of the rotary blade R2b of the second conveying member R2
Is arranged. Since the rotating blade low transfer section R2d having a small diameter of the rotating blade R2b has a small area for pressing the developer, the transfer of the two-component developer from the rotating blade normal transfer section R2c which is another part on the rotating shaft R2a is performed. Power is low. For this reason, the two-component developer in the second developer reservoir 64 is supplied to the area Sa where the outer developer outlet 67a is arranged (that is, the area Sa adjacent to the outer developer outlet 67a, see FIG. 23). ), The developer upper surface of the region Sa where the outer developer outlet 67a is arranged is locally higher than the other region Sb (see FIG. 23) (arrow Td in FIG. 23).
reference).

According to the study of the inventor, the conveying force of the low-rotor blade conveying section 2d can be adjusted by adjusting the following dimensions (1) to (3). (1) The diameter r of the rotating blade low transfer section R2d. (2) The length L1 in the axial direction of the low-conveying portion R2d. (3) The pitch of the rotor low-conveyance section R2d.

The height of the developer upper surface locally increasing in the region Sa where the outer developer discharge port 67a is disposed is determined by the following parameters. (4) The difference between the conveying force of the normal conveying section R2c of the rotating blade R2b of the second conveying member R2 and the conveying force of the low conveying section R2d. (5) The distance L2 between the downstream end of the outer developer outlet 67a and the upstream end of the low-rotor blade conveyance section R2d.

In the first embodiment, the rotating blade low transfer section R2d
Is fixed to the same size as the pitch of the rotary blade normal transport section R2c. In this case, as the diameter r of the low-rotor blade transport section R2d decreases and the axial length L1 of the low-rotor blade transport section R2d increases, the transport force of the low-rotor blade low transport section R2d decreases. The height of the upper surface of the developer in the region Sa in which the outer developer outlet 67a is disposed can be adjusted by adjusting the diameter r of the rotary blade low-conveying portion R2d.
The axial length L1 of the rotor low-conveyance portion R2d makes a greater contribution than the above. Therefore, the axial length L1
Is determined, and as the fine adjustment means, the rotating blade low conveyance section R2d is used.
By adjusting the diameter r of the developer, the conveying force of the rotor low conveying section R2d is adjusted to adjust the height of the upper surface of the developer in the region Sa in which the outer developer outlet 67a is arranged, and the discharge amount is adjusted to a predetermined amount. It can be set. The height of the developer upper surface of the second developer pool 64 formed by the stagnation of the two-component developer in the region Sa where the outer developer outlet 67a is arranged is inclined in the transport direction. It can also be adjusted by the position in the axial direction of the developer outlet 67a (the distance L2 between the downstream end of the outer developer outlet 67a and the upstream end of the low-rotor blade transport section R2d).

In the first embodiment, the second transport member R2 has the following dimensions (1) to (3). (1) The diameter of the rotating blade normal transfer section R2c (the portion other than the rotating blade low transfer section R2d) is 20 mm. (2) The diameter of the rotating shaft R2a is 8 mm. (3) The pitch po of the rotor R2b is 25 mm. in this case,
Experiments have shown that the developer upper surface height in the region Sa adjacent to the outer developer outlet 67a can be appropriately maintained within the following dimensions (4) to (6). (4) The diameter r of the rotating blade low transfer section R2d is 14-18 mm. (5) The axial length L1 of the rotating blade low transfer section R2d is 1 to 2.5 times the pitch po of the rotating blade R2b. (6) The distance L2 between the downstream end of the outer developer discharge port 67a and the upstream end of the low rotor conveying section R2d is 0 to 1 times the pitch po of the rotary blade R2b.

Therefore, in the first embodiment, the following (7) to
The dimensions were set to (9). (7) The diameter r of the rotating blade low transfer section R2d is 15 mm. (8) The axial length L1 of the low-rotor blade transfer section R2d is 3
7.5 mm (1.5 times the pitch po of the rotor R2b). (9) The distance L2 between the downstream end of the outer developer outlet 67a and the upstream end of the low-rotor blade transport section R2d is 18.75 mm.
(0.75 times the pitch po of the rotor R2b).

In FIGS. 3, 6, 8 to 11, a communication path forming member 74 for forming a discharged developer temporary storage space 73 is provided above the outer developer discharging port 67a. 8, a connection port 74a is provided on the right end side of the communication path forming member 74. The connection port 74a is provided when the developing container U is mounted on the developing container supporting member H (see FIG. 4). The communication hole 60 of the rear connection block 58
(See FIGS. 3 and 4) and the support member rotation axis D
O communicates with the developer discharge cylinder 51 inside.
The developer discharged from the discharged developer temporary storage space 73 is configured to be collected in a developer collection container Tv disposed on the front end side via a developer discharge cylinder 51 in the support member rotation shaft Do. ing.

In FIG. 8, the discharged developer temporary storage space 73 in the communication path forming member 74 is provided with a backflow preventing partition wall 7.
A developer discharge space 73a connected to the outer developer discharge port 67a and a backflow developer storage space 73b are defined by 4b. When the developer flows backward from the connection port 74a, the backflow developer flows into the backflow developer storage space 73b along the backflow prevention partition wall 74b.

As shown in FIGS. 2, 6 and 7, the outer developer discharge port 6 is formed at the upper wall W2 of the developing container cover W.
A developer supply port 76 is formed on the upstream side in the developer transport direction from 7a. In the first embodiment, the developer supply port 7
The developer supply port 76 and the outer developer outlet 67a are formed at positions far apart from each other so that the new developer supplied from 6 is not discharged from the outer developer outlet 67a immediately after the supply. However, the developer supply port 76 can be formed downstream of the position of the outer developer discharge port 67a in the transport direction.

In FIG. 6, a supply cylinder support 77 having a cylinder receiving arc surface is provided on the upper surface of the upper wall W2 of the developer container cover W before and after the position of the developer supply port 76. The supply cylinder support portion 77 is a member that supports the cylindrical outer surface of the developer supply cylinder 78. 2 and 6,
The developer supply cylinder 78 disposed on the upper wall W2 has a supply port connection portion 78a (FIG. 2) connected to the developer supply port 76.
Reference). In the developer supply cylinder 78, a supply developer transport member 79 is rotatably disposed as shown in FIG. 6B. The replenishment developer conveying member 79 includes a rotating shaft 79a and a rotating blade 79b fixed around the rotating shaft 79a.
have. The developer replenishing member Th (see FIG. 6B) is composed of the developer replenishing cylinder 78 and the replenishing developer conveying member 79. Further, the supply developer conveying member 79 is
The developer supply cylinder 78 extends forward from an opening (developer carry-in port) 78b at the front end (the end in the X-axis direction) of the developer supply cylinder 78, and as shown in FIG.
A bearing 81 is rotatably supported at the front end (the end in the X direction) of a.

4 and 6, the rear end of the rotating shaft 79a (-
A gear G13 is fixed to the X-axis direction end). The gear G13 meshes with a gear G12 of the stirring and conveying member (R1 + R2). The rotation of the gear G12 rotates the supply developer conveying member 79, and the developer carried into the developer supply cylinder 78 from the developer carry-in port 78b is conveyed backward (-X direction). The supply port connection part 7
8a and a developer supply port 76 (see FIGS. 2 and 7) are supplied into the second developer reservoir 64 (see FIGS. 2 and 7). The reference numerals 61 to 81, G
9 to G13, R0, R1, R2, U, V, and W constitute the developing units Dk, Dy, Dm, and Dc.

In FIGS. 4, 19 and 20, a fixed cylindrical member F1a is fixed to the front side (X side) of the front fixed frame F1 which is the front side (X direction) of the developer supply cylinder 78. ing. The fixed cylindrical member F1a is provided in the developing container U
A plurality of ring-shaped members sealed so as not to mix the toners of the respective colors to be supplied to the toner are connected in the front-rear direction. That is, the fixed cylindrical member F1a includes a frame fixing ring-shaped connecting member Lb connected to the front surface of the front fixed frame F1, a discharge ring-shaped connecting member Lh sequentially connected to the front surface thereof (see FIG. 17), K (black) ring connecting member Lk (see FIG. 18A), Y (yellow) ring connecting member Ly, and M (magenta) ring connecting member Lm for replenishing developer of each color to developing container U. ,
It comprises a C (cyan) ring-shaped connecting member Lc (see FIG. 18B) and a front wall ring-shaped connecting member Lf.

FIG. 17 is a cross-sectional view taken along the line XVII-XVII in FIG. 4, and is an explanatory view of the discharge ring-shaped connecting member Lh shown in FIG. is there. FIG. 18 shows K,
FIG. 18A is a cross-sectional view taken along line XVIIIA-XVIIIA of FIG. 4, and FIG. It is XVIIIB-XVIIIB line sectional drawing. FIG. 19 is a sectional view taken along line XIX-XIX in FIG. FIG. 20 is a sectional view taken along line XX-XX in FIG. 4, 19,
In FIG. 20, the ring-shaped connecting members Lk, Ly, Lm, and Lc for K, Y, M, and C are connected to the ring-shaped connecting member main body 8.
6.

In FIGS. 17, 18, and 19, three connection fixing portions 86a, 3a are provided on the outer periphery of the ring-shaped connection member main body 86 of each of the ring-shaped connection members Lb, Lh, Ly, Lm, Lc.
86b and 86c are formed, connected by screws N1a, N1b and N1c, and fixed to the front fixed frame F1. Further, at a position deviated from the diameter of the outer peripheral surface of the ring-shaped connecting member main body 86, a developer supply portion 86d is provided.
(See FIG. 18) is formed integrally with the outer peripheral surface of the ring-shaped connecting member main body 86, and a developer supply port 86e is formed inside the developer supply section 86d. A sponge cylindrical transport pipe receiving member 87 (see FIG. 18A) is adhered to the opening end surface (upper end surface) of the developer supply port 86e. The transport pipe receiving member 87 is connected to a developer supply case Tc (see FIGS. 21 and 22 and described later).

In FIGS. 19 and 20, elastic ring-shaped seal members 88, 88 are attached to both ends in the axial direction of the inner surface of the ring-shaped connecting member main body 86. Each of the ring connecting members Lk, Ly, L for K, Y, M, C
m and Lc are a ring-shaped connecting member main body 86, a transport pipe receiving member 87 (see FIG. 18), and the pair of seal members 88, 88 mounted on the inner peripheral surface of the ring-shaped connecting member main body 86, respectively. It is composed of Ring-shaped spacers 89 are provided on the inner surfaces of the connecting portions of the ring-shaped connecting member bodies 86, 86 adjacent to the ring-shaped connecting members Lk, Ly, Lm, Lc so as to be sandwiched by the seal members 88, 88.
(See FIGS. 19 and 20).

The discharging ring-shaped connecting member Lh shown in FIGS. 17 and 19 has a ring-shaped connecting member main body 86 'similar to the ring-shaped connecting member main body 86. In the ring-shaped connecting member main body 86 ', the developer supply portion 86d and the developer supply port 8 of the ring-shaped connecting member main body 86 are provided.
Instead of 6e, a recovery container connecting port 86g 'is formed below the rotation axis Do, and the ring-shaped connecting member main body 86' of the discharge ring-shaped connecting member Lh (see Figs. 17 and 19). Other configurations are the same as those of the K ring-shaped connecting member main body 86. A developer collecting container Tv is arranged below the collecting container connection port 86g '.

The frame fixing ring-shaped connecting member Lb
(See FIGS. 4, 19, and 20) are joined to the rear side surface (the -X side surface) of the discharge ring-shaped connecting member Lh.
It has a ring-shaped connecting member main body having the same diameter as the ring-shaped connecting member main body 86 'and a short axial length. The frame fixing ring-shaped connecting member Lb is fixed to the front fixing frame F1 in a joined state.

In FIGS. 4, 19 and 20, the front wall ring-shaped connecting member Lf is joined to the front side of the C (cyan) ring-shaped connecting member Lc, and the ring-shaped connecting member main body. A cylindrical portion Lf1 having the same diameter as 86 has a flat portion Lf2 on the front end surface of the cylindrical portion Lf1. The cylindrical portion Lf1 and the flat plate portion Lf2 are integrally formed. On the outer surface of the cylindrical portion Lf1, the three connection fixing portions 86a,
86b and 86c (see FIG. 18).

Each of the ring-shaped connecting members L shown in FIG.
b, Lh, Lk, Ly, Lm, Lc, Lf are Lk, Ly,
The three connection fixing portions 86a, 86b, 86c of Lm, Lc and the connection fixing portions of Lb, Lh, Lf similar thereto are screwed with the screws N1a, N1b, and N1c (see FIGS. 17, 18 and 19). It is fixed to the fixed frame F1. Further, the front wall ring-shaped connecting member Lf is provided with the flat plate portion Lf.
The rotation shaft Do is rotatably supported at the center of the shaft 2.
Each of the ring-shaped connecting members Lb, Lh, Lk, Ly, Lm, L
The fixed cylindrical member F1a is constituted by c and Lf.

In FIGS. 4, 18, 19, and 20,
A plurality of rotating cylindrical members B are provided inside the fixed cylindrical member F1a.
A rotating cylindrical member B composed of h, Bk, By, Bm, Bc, and Bf is arranged. The rotating cylindrical member B has a central portion supported by being fitted to the rotating shaft Do, and is configured to rotate integrally with the rotating shaft Do. The rotary cylindrical member B includes a discharge cylindrical member Bh and a K (black) cylindrical member Bk, Y () that supports a distal end portion of the developer supply cylinder 78 of the developer container U of each toner color along the rotation axis Do. Yellow) cylindrical member By, M (magenta) cylindrical member Bm, C
The (cyan) cylindrical member Bc and the front cylindrical member Bf are sequentially connected.

Each of the cylindrical members Bk, By, Bm, and Bc has a cylindrical member main body 90 (see FIGS. 18 and 20). The cylindrical member main body 90 has an outer cylinder 91, and the outer cylinder 91
Has a rear large-diameter outer cylinder portion 92 and a front small-diameter outer cylinder portion 93. The outer diameter of the front-side small-diameter outer cylinder portion 93 is formed to be the same as the inner diameter of the rear-side large-diameter outer cylinder portion 92.
As shown in FIG. 20, when the K cylindrical member Bk is connected to other cylindrical members back and forth, the front small-diameter outer cylindrical portion 9
3 is fitted into the rear large-diameter outer cylindrical portion 92. On the side surface of the front small-diameter outer cylindrical portion 93, a supply developer receiving port 93a is provided.
(See FIGS. 18 to 20) are formed at positions on both sides in the circumferential direction of the replenishment developer receiving port 93a.
As shown in FIG. 8, an inner bent portion 93b whose tip extends in the center direction and bends, and an outer bent portion 93c whose tip extends outward and bends are formed.

The cylindrical member main body 90 has an inner cylindrical portion 94 at the center thereof. A portion 97 is provided. The outer diameter of the rear-side small-diameter inner cylindrical portion 97 is formed to be the same as the inner diameter of the front-side large-diameter inner cylindrical portion 96, and as shown in FIGS. When the front and rear cylindrical members Bh and By are connected to each other, the rear-side small-diameter inner cylinder portion 97 fits into the front-side large-diameter inner cylinder portion 96,
The end surfaces of the large-diameter inner cylinder portion 96 of the inner cylinder portion 94 come into contact with each other to perform positioning in the front-rear direction. Also, the cylindrical member main body 90
The ring-shaped connecting wall 98 (see FIGS. 18 and 19) connecting the outer cylindrical portion 91 and the inner cylindrical portion 94 and the front side surface (X-side surface) of the connecting wall 98 are totaled every 90 °. It has four formed ribs 99 (see FIG. 18) for strength reinforcement.

The inner cylindrical portion 94 has a rotary shaft fitting hole 94a (see FIGS. 19 and 20) formed in the rear portion thereof, and a small-diameter inner cylindrical portion fitting hole 94b formed in the front portion. FIG.
As shown in FIG. 9, the rotary shaft fitting hole 94a is fitted to and mounted on the rotary shaft Do, and the small-diameter inner cylindrical portion fitting hole 94b is connected to the rear small-diameter inner cylindrical portion 97 (see FIG. 20). ).

The connecting wall 98 has the four ribs 9
9, a supply cylinder through-hole 98 is formed in each wall portion divided into four.
a is formed, and a bearing through-hole 98b (see FIG. 20) having a small inner diameter is formed in one wall portion. In FIG. 20, the replenishment developer receiving port 93a is formed at the front side (X side) of the bearing through hole 98b, and at the front side thereof, a bearing accommodating hole 98c having the same diameter as the inside diameter of the bearing through hole 98b (see FIG. 20). 20) is formed. This bearing housing hole 98c is provided in the manner shown in FIG.
B is a hole for accommodating the bearing 81 shown in FIG. In FIG. 20, the developer supply cylinder 78 and the bearing 81
The bearing 81 penetrates through the supply cylinder through hole 98a from the rear to the front, and the bearing 81 penetrates through the bearing through hole 98b and is accommodated in the bearing accommodation hole 98c. At this time, since the developer supply cylinder 78 cannot pass through the bearing through-hole 98b, the front end of the developer supply cylinder 78 is positioned in contact with the connection wall 98 in which the bearing through-hole 98b is formed. At this time, the developer carrying-in port 78b shown in FIG. 6B is disposed in the supply developer receiving port 93a between the bearing through-hole 98b and the bearing accommodating hole 98c shown in FIG.

18 and 20, a ring cover 100 is mounted on the outer surface of the large-diameter outer cylindrical portion 92 on the rear side of the cylindrical member main body 90. And the K, Y, M, C
The cylindrical members for use Bk, By, Bm, and Bc are each constituted by the cylindrical member main body 90 and the ring cover 100.

As can be seen from FIGS. 19 and 20, the ring-shaped connecting members Lk, Ly, Lm and Lc are arranged in order from the rear to the front along the X-axis. The developer supply ports 86e (see FIGS. 18 and 21) of the shape-like connecting members Lk, Ly, Lm, and Lc shown in FIG. 18 are arranged in order along the X-axis direction. The replenishment developer receiving port 93a of each of the cylindrical members Bk, By, Bm, and Bc disposed inside each of the ring-shaped connecting members Lk, Ly, Lm, and Lc (see FIGS. 18A and 18B). ) Are displaced by 90 ° around the rotation axis Do.

That is, for example, as shown in FIG.
When the supply developer receiving port 93a of the cylindrical member Bk is connected to the developer supply port 86e, the supply developer reception port 93e of the cylindrical member Bc is connected to the developer supply port 86e (see FIG. 18A). Counterclockwise from position 2
It is arranged at a position rotated by 70 ° (see FIG. 18B). The replenishment developer receiving port 93e of each of the other cylindrical members By and Bm is 90 ° counterclockwise from a position (see FIG. 18A) connected to the developer supply port 86e.
And 180 ° rotated (not shown). In FIG. 18, the rotation axis Do is 90 °.
As each of the cylindrical members By rotates clockwise, the cylindrical members By,
The replenishment developer receiving ports 93a for Bm and Bc are sequentially moved to a position connected to the developer supply port 86e (see FIG. 21).

The developer supplied from the developer supply port 86e of FIG. 18 is supplied to a replenishment developer receiving port 93a (FIGS. 18, 19, and 2) formed on the side surface of the front small-diameter outer cylindrical portion 93.
0), the developer is supplied to the developer carrying-in port 78b (see FIG. 20), and the developer is conveyed backward (-X direction) through the developer replenishing cylinder 78 by the replenishing developer conveying member 79. 4 and 6, the inside of the developer supply cylinder 78 is located rearward (-
The developer transported in the X direction) is supplied to the supply port connection portion 78a.
(See FIG. 2) and the developer supply port 76 supplies the developer to the inside of the developing container U.

(Explanation of Developer Discharge Portion) The discharge cylindrical member Bh shown in FIGS. 17 and 19 is a cylindrical member main body 90 'having a shape similar to the cylindrical member main body 90 of the K cylindrical member Bk.
And a ring cover 100. FIG.
7, FIG. 19 and FIG. 20, the cylindrical member main body 90 '
Of the cylindrical member main body 90.
The components corresponding to 1 to 98 are denoted by the same reference numerals,
(Dash) is attached and the description is omitted. The cylindrical member main body 90 ′ of the discharge cylindrical member Bh is omitted from the four ribs 99 and the replenishment developer receiving port 93 a of the cylindrical member main body 90 of the K cylindrical member Bk, and is replaced with the connecting wall 98. It has a thicker connecting wall 98 '. In the thicker connecting wall 98 ', four supply cylinder through holes 98a' having the same inner diameter are formed.

An inner cylindrical portion 94 'of the cylindrical member main body 90' is provided with a rotary shaft fitting hole 94a 'at the center of the inner cylindrical portion 94'.
(See FIGS. 17 and 19) Four recovery container communication holes 94 radially extending from the side toward the outer surface of the inner cylindrical portion 94 '.
c 'is formed. The four collection container communication holes 94
c ′ are formed at 90 ° intervals in the circumferential direction, and the collection container communication port Dob on the rotation shaft side of the support member rotation shaft Do
(See FIG. 17). The collection container communication port Dob on the rotation shaft side of the support member rotation shaft Do and the respective collection container communication holes 94c 'rotate around the axis together with the rotation of the support member rotation shaft Do and the cylindrical member main body 90'. When rotated below the rotation axis Do, it is configured to communicate with the collection container communication port 51b (see FIG. 5) of the developer discharge cylinder 51. The surplus developer conveyed to the front end side in the developer discharge cylinder 51 and discharged from the collection container communication port 51b is a rotation axis side collection container communication port Dob of the rotation shaft Do.
From the discharge cylinder member Bh through the collection container communication port 51b, and from the collection container communication port 93a '(see FIGS. 17 and 19) formed in the discharge cylinder member Bh. Recovery container connection port 86g 'of connecting member Lh
And is discharged to the developer collecting container Tv through the above-mentioned and collected.

The four developer supply cylinders 78 penetrate the four supply cylinder through holes 98a '(see FIGS. 17 and 19). Further, a total of four collection container communication ports 93a 'are formed in the front small-diameter outer cylindrical portion 93 at every 90 °. The developer discharge cylinder 51 and the discharge developer transport member 5
3. The discharged developer conveying device J (J = 51 + 53 +) by the discharging cylindrical member Bh and the discharging ring-shaped connecting member Lh.
Bh + Lh).

In FIGS. 4, 19, and 20, the front cylindrical member Bf is disposed on the front surface of the cylindrical member Bc for C, and the front cylindrical member Bf is fixed by four fixing screws N2 (see FIGS. 17 to 20). , Bm, By, Bk, and Bh. The tip of the fixing screw N2 is screwed to a nut (not shown) fixed to the front rotation plate 58. The rotating cylindrical members Bh, Bk, By, Bm, and Bc and the fixedly supported ring-shaped connecting members Lh, Lk, Ly, Lm,
The space between Lc is sealed by the sealing member 88 for each of the cylindrical members Bh, Bk, By, Bm, and Bc. Therefore, a two-component developer having a new carrier and toner to be replenished from the developer supply port 86e to the replenishment developer receiving port 93a, or from the collection container communication port 73b to the collection container communication port 93a 'through the collection container communication port 93a'. 86g 'of mouth
Surplus developer discharged to the cylindrical members Bh, Bk,
By, Bm, Bc and each ring-shaped connecting member Lh, Lk, L
In the space between y, Lm and Lc, it is prevented from moving toward another cylindrical member.

FIG. 21 is an explanatory diagram showing the positional relationship between the developer supply case and the developer supply device. FIG.
FIG. 11 is a diagram viewed from the direction of arrow XXII. 21 and 22, a developer supply case Tc is disposed above the fixed cylindrical member F1a. The developer supply case Tc
Are developer storage containers 111k, 111y, and 1 in which a two-component developer containing K (black), Y (yellow), M (magenta), and C (cyan) toners and carriers is stored.
11m and 111c, and developer stirring containers 112k, 112y, 112m and 112c provided therebelow. The developer storage containers 111k, 111y, 111m, 111c
In the first embodiment, a two-component developer having a high toner concentration (hereinafter referred to as a "high-density developer") is used as the two-component developer stored in the printer.

The developer storage containers 111k, 111y, 1
11m, 111c to developer stirring containers 112k, 112y,
The high-concentration developer supplied to 112m and 112c is supplied to developer stirring containers 112k, 112y, 112m and 112c, respectively.
It is stirred while circulating inside. The developer stirring container 11
The high-concentration developer stirred at 2k, 112y, 112m, and 112c is connected to pipe connection holes 113k, 113y, 113m, and 1.
13c to developer transfer pipes 114k, 114y, 114
m, 114c. Each developer transport pipe 11
4k, 114y, 114m and 114c are provided with rotatable conveying screws 116, respectively, and are rotated by motor units 117k to 117c disposed at the ends of the developer conveying pipes 114k, 114y, 114m and 114c. Driven. Each developer transport pipe 114
k, 114y, 114m, 114c conveying screw 116
Rotation of the developer storage containers 111k, 111y, 11
1m, 111c of new developer is supplied to the developer supply port 86e.
To be transported.

(Operation of Embodiment 1) In FIG. 1, the image carrier 16 on which an electrostatic latent image has been written by a ROS (optical writing scanning device, ie, a latent image writing device) at a latent image writing position Q1. Moves to the development area Q2. The developing container supporting member H rotatably supported by the front fixed frame F1 and the rear fixed frame F2 is disposed adjacent to the surface of the image carrier 16 in the developing area Q2. A plurality of developing units Dk, Dy, Dm, Dc supported by the developing container supporting member H;
A first developing unit that develops a latent image on the surface of the image carrier 16 into a toner image with the rotation and stop of the developing container supporting member H;
Stop position (development position, developer supply position) P1, second stop position (developer discharge position at which developer is discharged from inside developer container U) P2, third stop position P3, and fourth stop position P4
And stop moving sequentially.

FIG. 23 is a view for explaining the operation of the second stirring member and the shutter provided in the developing container stopped at the first stop position, and is a longitudinal sectional view of the developing container. FIG. 24 is a diagram showing a state in which the developer outlet and the inner developer outlet face downward.

(Operation at First Stop Position P1) FIG.
In FIG. 6, the developing containers U of the developing units Dk, Dy, Dm and Dc stopped at the first stop position P1 (see FIGS. 2 and 3).
The gear G9, which is coaxial with the gear G10, is engaged with the gear G8, which is supported by the fixed frame F2. The rotation of the gear G8 rotates the gears G9 and G10, so that the gears G11 and G12 meshing with the gear G10 also rotate, and the gear G13 meshing with the gear G12 also rotates. By the rotation of the gears G10, G11, G12, G13, the developing roll R
0, the first transport member R1, the second transport member R2, and the replenishment developer transport member 79 rotate. Due to the rotation of these members, at the first stop position P1, the following operations (1), (2),
(3) is performed.

(1) Developing operation In the developing container U, a stirring and conveying member (R1 + R2)
Supplies the developer to the developing roll R0. Developing roll R0
Transports a two-component developer composed of a toner and a carrier to a development region Q2 facing the surface of the image carrier 16.
At this time, the electrostatic latent image on the surface of the image carrier 16 is developed into a toner image by the toner conveyed. By this developing operation, the toner in the developing container U is consumed and reduced, and the carrier is contaminated and deteriorated. The two-component developer having the carrier and the toner is supplied, but the carrier is not consumed, so that the amount of the two-component developer in the developing container U increases.
In particular, when performing continuous copying of a single color, the amount of the developer increases rapidly. Therefore, it becomes necessary to discharge the deteriorated two-component developer including the carrier.

(2) Developer supply operation New developer (high-concentration developer) in the developer supply case Tc
Are transported to the developer supply ports 86e (see FIG. 18) of the ring-shaped connecting members Lk, Ly, Lm, and Lc. The developer supply port 86e communicates with any one of the replenishment developer receiving ports 93a of the cylindrical members Bk, By, Bm, and Bc, and the developer supply port 78b extends from the replenishment developer receiving port 93a (FIG. 6).
B, see FIG. 20). In the present embodiment, the supplied developer is conveyed to the developer supply port 76 (see FIG. 6) of the developing container U by the rotational driving of the supply developer conveying member 79 in the developer supply cylinder 78. When the supply developer conveying member 79 rotates,
The developer in the developer supply cylinder 78 (see FIG. 6) is transported to the rear (−X direction) developer supply port 76, and the transported new developer is supplied from the developer supply port 76 to the developing container. Replenished in U.

The developer discharging operation for discharging the developer (surplus developer including deteriorated carriers) increased by the replenishment of the developer during the developing operation is performed at the first and second stop positions P1 and P2. (3) Developer Discharge Operation at First Stop Position At the first stop position P1, the shutter 71 that opens and closes the inner developer discharge port 69b on the downstream side of the second developer reservoir 64 is opened by its own weight (see FIG. 3), and the inside developer outlet 69b is opened. The first
The rotation of the conveying member R1 and the second conveying member R2 causes the first,
The developer in the second developer pools 64 and 66 is transported,
The developer circulates in the first and second developer reservoirs 64 and 66. In FIG. 23, the rotor R2 of the second transport member R2
In b, the rotary blade low conveyance section R2d is provided downstream of the outer developer outlet 67a, so that the two-component developer stays in the region Sa where the outer developer outlet 67a is arranged. , The area Sa in which the outer developer outlet 67a is arranged
Is locally higher than the other region Sb (see arrow Td). When the amount of the developer in the container increases and the height of the accumulated two-component developer reaches a predetermined height, the developer is loaded on the outer surface of the shutter 71. The effect of the low-rotor blade transport section R2d will be described later.

(Developer discharging operation at second stop position P2) In FIG. 3, the developing devices Dk, Dy, and Dy at the first stop position P1 are shown.
When Dm and Dc move to and stop at the second stop position P2, the shutter 71, which has been rotated to the open position at the first stop position P1, is rotated by its own weight to the closed position, and at the same time, the developer 71 in the container is removed. The inner developer outlet 69b is closed by pressure. At this time, the developer on the outer surface of the shutter 71 at the first stop position P1 is discharged from the inner developer discharge port 69b to the discharged developer temporary storage space 73 via the outer developer discharge port 67a. You. The developer discharged into the discharged developer temporary storage space 73 is:
The support member rotating shaft Do falls below the inside of the developer container U and falls into the developer discharge tube 51, and is conveyed to the collection container communication port 51b at the tip end of the developer discharge tube 51 to recover the developer. Collected in container Tv.

(Operation at Third Stop Position P3) FIGS. 3 and 24
, The developing devices Dk, Dy, D at the second stop position P2
When m and Dc move to and stop at the third stop position P3, the inner developer outlet 69b is directed downward, but the inner developer outlet 69b reduces the gravity and the pressure of the developer in the developing container U. Since the shutter 71 is closed by the receiving shutter 71, the developer in the developing container U is discharged from the inner developer outlet 69.
Not emitted from b.

(Operation of Fourth Stop Position P4) In FIG. 3, the developing devices Dk,
The shutters 71 for Dy, Dm, and Dc are connected to the developing container U
The developer in the developing container U is not discharged because it is not opened due to the pressure of the developer therein.

(Effects of the First Embodiment, That is, Effects of the Low Conveying Section R2d of the Rotor Blade R2a of the Second Conveying Member R2) FIG. 25 shows the use of the second conveying member having no rotating blade low conveying section. When the discharge amount of the developer in the developing container is increased and decreased, the change in the developer discharge amount with respect to the developer amount in the container and the second transport member provided with the rotating blade low transport portion 6 is a graph showing a change in the amount of discharged developer with respect to the amount of developer in a developing container when used.

(Ideal Amount of Developer Discharged Amount of Developer in Developing Container) As shown in FIG. 25, the developing container shown in FIG.
And a good developed image is obtained. If the amount of the developer in the container is 400 g or less, unevenness and white streaks will occur,
When the amount of the developer in the container is 500 g or more, the developing roll R
The drive torque of the 0 and first and second stirring members R1 and R2 increases, and the power consumption of the drive motor increases, the mixing of the replenishment toner deteriorates, and fogging occurs. A graph I (○-○) of FIG. 25 shows an example of the characteristic of an ideal amount of developer discharged with respect to the amount of developer in the developing container. In the graph I, the amount of the developer in the developing container is 4
When the amount is 50 g or less, the amount of the developer in the developing container is hardly discharged, so that the amount of the developer in the developing container is maintained. Also,
If the amount exceeds 450 g, the amount of the developer in the developing container is not increased because the amount is discharged with a discharge amount capable of following the maximum supply (a maximum discharge amount target value). Thus, in the graph I, 450 g
In the case where the amount of the developer in the container is about 470 g, the amount of the developer is discharged with a discharge amount (maximum discharge target value) that can follow the maximum supply when the amount exceeds 450 g. , 450 g within a certain range. The “minimum discharge amount target value” in the graph of FIG. 25 indicates a target value of the developer discharge amount when the amount of the developer in the developing container is within an appropriate range.

(Development Discharge Amount Characteristics of Prior Art vs. Amount of Developer in Developing Container) The amount of the developing agent in the developing container from which the discharging of the developer is started depends on the center of the rotating shaft of the second stirring member under its own weight. Can be controlled by the distance Lc (see FIG. 15B) from the leading end of the shutter. By bringing the tip of the shutter closer to the rotation axis of the second stirring member (ie, moving the tip of the shutter to the lower side of the developer upper surface), the discharge is started even when the amount of the developer in the developer container is small. The discharge can be started after the amount of the developer is increased by increasing the distance. Further, the amount of the discharged developer at a predetermined amount of the developer can also be controlled by control parameters (a parameter for controlling the amount of discharged developer) such as the size of the developer outlet, the mounting position, and the mounting height of the shutter. The contribution of the leading end position of the shutter to the height of the upper surface of the developer conveyed in the developing container is significantly larger than other control parameters.

In graph II (■-■) of FIG. 25, the leading end position of the shutter is brought close to the second stirring member so that it can follow the maximum developer supply amount, and the proper upper limit of the developer amount in the developer container is 500 g. 5 is a graph showing Conventional Example 1 in which the amount of exhaust gas reaches a maximum emission target value. In the graph II, when the amount of the developer in the developing container exceeds 450 g, the amount of the developing agent in the developing container is reduced to around 450 g because the amount of the discharged developer is discharged at the maximum discharge amount target value.
Even at 00 g, the developer is discharged. For this reason, the minimum amount of the developer cannot be maintained, and the amount of the developer supplied to the developing roll is insufficient, causing unevenness and white streaks.
In graph III (▲-▲) of FIG. 25, in order to maintain the minimum amount of the developer of 400 g, the distal end position of the shutter is moved away from the second stirring member, and the amount of the developer in the developing container to start discharging is set to 4
9 is a graph showing Conventional Example 2 in which the amount is set to 00 g or more. In the graph III, when the amount of the developer in the developing container is 450 g or less, the developer is hardly discharged, so that the minimum amount is maintained. However, in the conventional example II, the discharge amount when the amount of the developer is increased is small, so that it cannot follow the increase at the time of the maximum supply. Therefore, the amount of the developer in the developing container increases, and problems such as an increase in torque occur. As described above, in the conventional developing device, the distance Lc (see FIG. 15B) from the center of the rotation shaft of the second stirring member, that is, the position of the tip of the shutter with respect to the height of the upper surface of the developer is determined by the control parameter of the developer discharge amount. As a result, it has been difficult to maintain both the minimum amount of developer and the amount of developer discharged to follow the maximum amount of developer supply.

(Example 1 for the amount of developer in the developing container)
So, in order to solve the above problem,
In the first embodiment of the present invention, the low transport section R2d is provided on the rotating blade R2b of the second stirring member R2 downstream of the outer developer discharge port 67a. Graph IV (◇-◇) in FIG.
6 is a graph showing a developer discharge amount characteristic of Example 1 with respect to a developer amount in a developing container. In the graph IV,
When the amount of the developer in the developing container becomes 450 g or more, the developer is discharged at the maximum discharge amount target value, so that the amount of the developer in the developing container U becomes 4 g.
It decreases to around 50g. Further, when the amount of the developer in the developing container becomes 450 g or less, the developer is hardly discharged from the container. The reason is as follows.

In the low transport section R2d, the transport speed of the developer becomes slow, so that the developer stays on the upstream side,
A local swell is formed (arrow Td in FIG. 23). At this point, the upper surface of the developer rises as if the amount of the developer in the container U increased, so that the outer developer discharge port 67a is located in the rising area Sa of the upper surface of the developer.
Can be discharged when the amount of the developer in the developing container U is small, and the developer can be discharged at the maximum discharge amount. Therefore, in the first embodiment, it is possible to obtain a transition of the discharge amount (graph I) close to the ideal as shown in the graph of FIG. 25, and to maintain the amount of the developer in the developing container U within an appropriate range. Can be. In the first embodiment, if the low transport unit R2d is set over a range wider than a predetermined range or if the transport force is significantly reduced, the amount of accumulated developer becomes too large, and the amount of developer during transport decreases. It will be impossible to balance the whole. Therefore, it is important to increase the height of the developer upper surface only in the portion facing the outer developer outlet 67a as much as possible.

(Embodiment 2) FIG. 26 is a plan sectional view of a developing container provided in a developing apparatus according to Embodiment 2 of the present invention.
FIG. In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG.
In the second embodiment, the second container provided in the developing container U of the second embodiment
In the low conveying section R2d 'of the rotating blade R2b of the stirring member R2, the pitch pa of the low blade conveying section R2d is shorter than the pitch po of the normal rotating blade conveying section R2c. In the second embodiment, the dimensions of the second stirring member R2 are set to the following values. (1) Rotor blade normal transfer unit R2c (rotor blade low transfer unit R2
The diameter of the part other than d ') is 20 mm. (2) The diameter of the rotating shaft R2a is 8 mm. (3) The pitch po of the rotating blade normal transport section R2c is 25 mm. (4) The pitch pa of the low-rotor blade transfer section R2d 'is 12.
5 mm. (5) The axial length L1 of the rotary blade low transfer section R2d 'is 25 mm.

Since the pitch pa of the low-rotor blade transport section R2d 'is formed to be shorter than the pitch po of the normal rotary blade transport section R2c, the blade of the low-rotor blade low transport section R2d' rotates the developer in one rotation. The distance in the axial direction for transporting is reduced. For this reason, the rotary blade R2 downstream of the outer developer discharge port 67a
Since the conveying force of the rotor low conveying section R2d'b is lower than that of the rotor normal conveying section R2c, the outer developer discharging port 6
The two-component developer stagnates in the region Sa where 7a is arranged,
The second embodiment has the same operation as the first embodiment.

(Embodiment 3) FIG. 27 is an enlarged sectional view of a main part of a developing device according to a third embodiment of the present invention, FIG. 27A is an enlarged view of a main part of the developing device of the third embodiment, and FIG. FIG. 27B is an enlarged sectional view of a main part of the device, which is different from FIG. 27A.
FIG. 28 is a perspective view of a developing container provided in the developing device, FIG. 28A is a diagram illustrating a state in which a developer supply cylinder is removed from the developing container, and FIG. It is a figure showing the state where it was attached.
FIG. 29 is a sectional view taken along the line XXIX-XXIX of FIG. 27A,
FIG. 8 is a diagram corresponding to FIG. 7. In the description of the third embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The third embodiment differs from the first embodiment in the following points, but has the same configuration as the first embodiment in other points.

27 to 29, in the third embodiment, one developing container D is disposed at a position facing the surface of the image carrier 16. Developer outlet 6 of the third embodiment
7a 'is formed on the side wall of the developing container main body V of the developing container U of the developing container D, and the developer discharging port 67
The position of the lower edge of a 'is the upper surface of the developer when an appropriate amount of the developer is held in the developer container U (an area other than the area Sa in which the developer outlet 67a' is arranged. (The upper surface position of the developer in the region Sb). Further, the developer discharge grooves 67d, 67d of the first embodiment are not formed inside the container side wall of the developer discharge port 67a ', and the discharge port forming member 69 and the shutter 71 of the first embodiment are also provided. Not provided. FIG. 27A, FIG.
In the above, the height of the local top surface is
The developer that has become higher than the position of the lower edge of a ′ is discharged from the developer discharge port 67 a ′, passes through a discharge pipe 122 provided on the container side wall of the developing container main body V, and passes through the discharge pipe 122. The developer is collected in a developer collection container Tv attached to the lower end. Further, the developer supply port 76 of the developer container U of the third embodiment is provided on the downstream side of the developer discharge port 67a ', and the developer supply port 76 has the toner stored in the developer storage container 127. The two-component developer having a high concentration is configured to be replenished from the replenishment developer transport member 79.

Also in the third embodiment, since the height of the developer upper surface in the region Sa where the developer outlet 67a 'is located is locally increased, the developer in the container is discharged from the developer outlet 67a'. And the amount of developer in the container is in an appropriate range when the amount of developer supplied is large. Further, the position of the lower edge of the developer discharge port 67a 'is formed above the position of the developer upper surface of another area Sb other than the area Sa in which the developer discharge port 67a' is arranged. Therefore, it is possible to maintain the minimum amount of developer required when the supply amount of the developer is small.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments.
Various design changes can be made without departing from the invention as set forth in the claims. Modified embodiments of the present invention will be exemplified below. (H01) In each of the above embodiments, it is possible to replenish separately stored toner and carrier into the developer container U instead of replenishing the developer having a high toner concentration into the developer container U. (H02) In the first and second embodiments, the support member rotation axis Do
Although the respective communication ports Doa are exemplified to be formed in the circumferential direction of the support member rotation axis Do, the support member rotation axis Do
It is also possible to form them at different positions in the axial direction. (H03) In the third embodiment, the case where the outer diameter of the low conveying portion R2d of the second stirring member R2 is formed smaller than the outer diameter of the normal conveying portion R2c has been described, but the pitch of the low conveying portion R2d is described. May be formed to be shorter than the pitch of the normal transport section R2c. (H04) In the first and second embodiments, the developer discharge grooves 67d and 67d formed on the inner surface of the upper wall W2 of the developing container U are omitted, and the discharge port forming member 69 is formed from the inner surface of the upper wall W2.
The upper discharge port forming portion 69a is separated from the upper surface of the auxiliary discharge port 72, 7 by separating the upper surface of the discharge path forming portion 69a from the upper wall W2.
2 and the developer discharge passages 70, 70 can also be formed. (H05) In the first and second embodiments, the shutter locking portion 69e for locking the shutter 71 rotated to the opening position may be formed separately from the discharge port forming member 69. (H06) In the first and second embodiments, the shutter 71
And the outlet forming member 69 is omitted, and the developing container U
It is also possible to provide an outer developer outlet 67a provided on the upper wall W2 on the side wall of the developing container U.

[0117]

The developing device of the present invention described above has the following effects. (E01) The developer in the developing container can be discharged with a simple configuration according to the supply amount, and the amount of the developer in the developing container can be maintained within an appropriate range.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram of one embodiment of an image forming apparatus of the present invention.

FIG. 2 is an enlarged sectional view of a main part of a developing device according to a first embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a portion different from FIG. 2 of the developing device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a state where the developing container of the embodiment is mounted on a rotating developing container supporting member.

FIG. 5 is an enlarged cross-sectional view of a support member rotating shaft provided in the developing device according to the first embodiment of the present invention, and FIG.
5B is a sectional view taken along line VA-VA, and FIG. 5B is a sectional view taken along line VB-V in FIG. 5A.
It is a B sectional view.

FIG. 6 is a perspective view of the developing container shown in FIG. 4;
FIG. 6A is a diagram illustrating a state where the developer supply cylinder is removed from the developing container, and FIG. 6B is a diagram illustrating a state where the developer supply cylinder is attached to the developer container.

FIG. 7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is an enlarged partial cross-sectional view of a communication path forming member formed on the upper surface of a container upper wall of the developing container.
It is an enlarged view of the part shown by arrow VIII.

FIG. 9 is a plan sectional view of the communication path forming member shown in FIG.

10 is a cross-sectional view of the communication path forming member shown in FIG. 8, FIG. 10A is a cross-sectional view taken along line XA-XA in FIG. 9, and FIG. 10B is a cross-sectional view taken along line XB-XB in FIG. FIG. 1
FIG. 10 is a sectional view taken along line XC-XC in FIG.

11 is a longitudinal sectional view of the communication path forming member shown in FIG. 8, and is a sectional view taken along line XI-XI of FIG.

12 is an explanatory view of an inner surface side of the container upper wall adjacent to a developer discharge port formed in the container upper wall, FIG. 12A is a view seen from an arrow XIIA in FIG. 11, and FIG.
FIG. 12B is a sectional view taken along the line XIIB-XIIB of FIG. 12A.

FIG. 13 is an explanatory view of an outlet forming member mounted on the developer outlet and a shutter rotatably supported by the outlet forming member, before the developer is mounted on the developer outlet. FIG.

FIG. 14 is a view showing a state where the discharge port forming member and the shutter shown in FIG. 13 are mounted on the developer discharge port.

FIG. 15 is a view showing a state of a discharge port forming member and a shutter mounted on the developer discharge port in the developing container, FIG. 15A is a longitudinal sectional view, and FIG.
It is XVB-XVB line sectional drawing of 5A.

FIG. 16 is an explanatory view of the discharge port forming member shown in FIG. 13; FIG. 16A is a plan view of the state shown in FIG. Figure 1
FIG. 16C is a view from arrow XVIB of FIG. 6A, and FIG.
FIG. 16D is a plan view seen from the upper surface (the surface on the Z side) in the state shown in FIG.
It is XVID-XVID sectional view taken on the line of 6C.

17 is a sectional view taken along the line XVII-XVII of FIG. 4, and is an explanatory view of the discharge ring-shaped connecting member Lh shown in FIG. 4 and the discharge rotary cylindrical member Bh rotatably disposed therein; It is.

FIG. 18 shows K, Y, M, and K having the same configuration.
FIG. 18A is an explanatory view of a ring-shaped connecting member for C and a rotatable cylindrical member rotatably supported therein.
FIG. 18B is a sectional view taken along the line VIIIA-XVIIIA, and FIG.
It is a VIIIB-XVIIIB line sectional view.

FIG. 19 is a sectional view taken along line XIX-XIX in FIG. 17;

FIG. 20 is a sectional view taken along the line XX-XX in FIG. 17;

FIG. 21 is an explanatory diagram showing a positional relationship between a developer supply case and a developer supply device.

FIG. 22 is a view as seen from the direction of arrow XXII in FIG. 21.

FIG. 23 is an explanatory view of an operation of a second stirring member and a shutter provided in the developing container stopped at the first stop position, and is a longitudinal sectional view of the developing container.

FIG. 24 is a diagram illustrating a state in which a developer outlet and an inner developer outlet face downward.

FIG. 25 is a diagram illustrating a case where the discharge amount of the developer in the developer container is increased and decreased when the second transport member that is not provided with the rotating blade low transport unit is used. 6 is a graph showing a change in the amount of the developer discharged with respect to the amount and a change in the amount of the discharged developer with respect to the amount of the developer in the developing container when the second conveying member provided with the low-rotor blade conveying section is used.

FIG. 26 is a plan sectional view of a developing container provided in the developing device according to the second embodiment of the present invention, and is a view corresponding to FIG.

27 is an enlarged sectional view of a main part of a developing device according to a third embodiment of the present invention, FIG. 27A is an enlarged view of a main part of the developing device of the third embodiment, and FIG. 27B is a main part of the developing device. 27B is an enlarged sectional view of a portion different from that of FIG. 27A.

28 is a perspective view of a developing container provided in the developing device, FIG. 28A is a diagram showing a state in which a developer supply cylinder is removed from the developing container, and FIG. It is a figure showing the state where the medicine supply cylinder was attached.

FIG. 29 is a view showing XXIX-XXIX shown in FIG. 27A.
FIG. 8 is a cross-sectional view corresponding to FIG. 7.

[Explanation of symbols]

Do: support member rotating shaft, E: connection part, F1, F2: fixed frame, H: developer container support member, J: discharged developer conveying device, P1: first stop position, Q2: development area, ROS: image book Loading device, R1 ... first stirring member, R2 ... second stirring member, R
1a, R2a: rotary shaft, R1b, R2b: rotary blade, R2c: normal transport section, R2d; R2d ': low transport section, R0: developing roll, Sa
... A region where the developer outlet is arranged, Sb... Another region, Tv
... developer collecting container, U ... developing container, W2 ... upper wall 16 ... image carrier, 62 ... developing roll accommodating section, 63 ... first
Developer stirring area, 64: second developer stirring area, 66: partition wall, 67a + 69b; 67a ': developer discharge port, 71 ...
Shutter 76: developer supply port.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Motoki Noya 2274 Hongo, Ebina-shi, Kanagawa Prefecture F-Terms within Fuji Xerox Co., Ltd. (Reference) 2H077 AB02 AB07 AB14 AB15 AC02 AD06 AD12 BA01 BA08 BA10 CA19 EA03 GA13

Claims (3)

[Claims] 1. A developing device characterized by the following requirements: (A01) a latent image corresponding to image information is written by an image writing device, and the developing device is arranged adjacent to the surface of a rotating image carrier. A developing roll for transporting a two-component developer composed of a toner and a carrier to a developing area for developing a latent image on the image carrier into a toner image; and (A02) a developing roll accommodating section accommodating the developing roll. A first roller extending in the axial direction of the developing roll adjacent to the developing roll accommodating portion;
A developer agitating region, and a portion except for a connection portion at both ends in the axial direction, which is disposed adjacent to the first developer agitating region on the opposite side to the developing roll and is separated from the first developer agitating region by a partition wall. A developing container which is partitioned and has both ends in the axial direction connected to the first developer stirring region and has a second developer stirring region formed between the partition wall and a container side wall extending along the partition wall; (A03) a rotating shaft disposed in the first developer stirring area and extending in a conveying direction of the two-component developer, and a rotating blade fixed to an outer periphery of the rotating shaft; (A04) a first transporting member for transporting the developer to the developing roll while stirring the developer by rotating the rotating blades;
A rotating shaft extending in the transport direction of the component developer, and a rotating blade fixed to an outer periphery of the rotating shaft, wherein the rotating blade rotates with the rotation of the rotating shaft to stir the developer, and A second transport member that transports in a direction opposite to the one transport member,
(A05) When the height of the upper surface of the developer is greater than or equal to a predetermined height, provided on an outer wall of a container that forms the second developer stirring area for discharging the developer in the second developer stirring area. A developer outlet for discharging the developer and increasing the discharge amount as the amount exceeding the certain height increases,
(A06) a developer replenishing port for replenishing a new developer into the developing container; (A07) a normal transport section having a predetermined transporting force; and a downstream side in the developer transport direction from the developer outlet, and A low-conveying section having a conveying force lower than the normal conveying section, wherein the developer is retained by the low-conveying section, and the developer upper surface height of the area where the developer outlet is arranged is higher than other areas. The second transport member having the rotary wing that is locally raised. 2. The developing device according to claim 1, wherein the developing unit satisfies the following requirements: (A08) The rotating unit in which the outer diameter of the low conveying unit is smaller than the outer diameter of the normal conveying unit. Wings. 3. The developing device according to claim 1, wherein the following requirement is satisfied: (A09) The rotating blade in which a pitch of the low transport section is shorter than a pitch of the normal transport section.