JP2000112238A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of developer discharged from the inside of a developing container by the force of a circumferential direction or a radial direction acting on the developer when a stirring and carrying member is rotated. SOLUTION: This developing device is provided with developer circulation areas 45 and 46 which are formed by being adjacent to a developing roll housing part housing a developing roll and in which the two-component developer is stirred and carried while being circulated the developing container V having a developer discharge port 51 discharging the developer in the areas 45 and 46 and the developing roll carrying the two-component developer attached to the rotating surface to a developing area so as to use it for developing. Then the two-component developer in the areas 45 and 46 is circulated while being stirred and carried and supplied to the developing roll housing part. Besides the force of the circumferential direction or the outward radial direction acting on the developer by the rotation of the stirring and carrying member R1 in an area Sa opposed to the port 51 is set to be smaller than that in the other area Sb.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing an electrostatic latent image formed on an image carrier into a toner image in an image forming apparatus such as an electrophotographic copying machine or a laser printer. And a developing device using a two-component developer composed of a carrier.

[0002]

2. Description of the Related Art As a developing device using a two-component developer, for example, the following technology (J01) is conventionally known.

(J01) Technology described in Japanese Patent Publication No. Hei 2-21591 (Japanese Unexamined Patent Application Publication No. Sho 59-100471). This publication describes replenishment of toner consumed by a developer replenishing device and replenishment of a new carrier into a developing container. A technique is described in which excess developer in the developer container is overflowed and discharged from a developer discharge port provided on a wall surface of the developer container, and collected in a developer collection container. I have.

[0004]

[Problem to be Solved by the Invention] (Problem of the above (J01)) In the above-mentioned prior art (J01), the amount of surplus developer to be discharged is arranged in a developing container and the developer in the container is stirred and conveyed. It is determined by the position, size, and shape of the developer discharge port provided on the side wall facing the auger (stirring / conveying member). However, at this time, irrespective of the position, size, and shape of the developer outlet for regulating the amount of the surplus developer, the surplus of the auger in the developing container facing the developer outlet is not excessive. There has been a problem that even the necessary developer is discharged.

[0005] In view of the above-mentioned examination results, the present invention has the following description (O01) as a technical problem. (O01) To reduce the amount of the developer discharged from the inside of the developing container by a circumferential or outward radial force acting on the developer when the stirring and conveying member rotates.

[0006]

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.

(1st invention) In order to solve the aforementioned problem,
The developing device of the first invention of the present application has the following requirements (A01) to
(A01) A two-component developer (A01) containing a developing roll (R0) and a toner and a carrier adjacent to the developing roll housing (44). A developer circulation area (45 + 46) in which the developer is circulated while being circulated, a developer supply port (49) for supplying a two-component developer to the developer circulation area (45 + 46), and a developer circulation area (45). 45 + 46) A developer discharge port (51) for discharging the developer stirred and conveyed in (45 + 46).
And a developing container (V) containing a developer, and (A02)
The two-component developer rotatably accommodated in the developing roll accommodating portion (44) and attached to the rotating surface is transferred to a developing area where an electrostatic latent image is written and opposed to the rotating image carrier (16) surface. (Q2) a developing roll (R0) for developing the electrostatic latent image and (A03) a rotating shaft (R1a, rotatable) rotatably housed in the developer circulation area (45 + 46).
R2a) and a stirring / conveying blade (R1b, R2b), and circulates the two-component developer while stirring and conveying during rotation, and supplies the two-component developer to the developing roll housing part (44). Members (R1 + R2), (A04)
Due to the rotation of the stirring and conveying member (R1), a circumferential or outward radial force acting on the developer in the region (Sa) facing the developer discharge port (51) is applied to the other region (S1).
The stirring and conveying member (R1) configured to be smaller than b).

(Operation of the First Invention) In the developing device of the first invention of the present application having the above-mentioned features, the rotary shaft (45 + 46) rotatably housed in the developer circulation area (45 + 46) of the developing container (V). A stirring and conveying member (R1 + R2) having the stirring and conveying blades (R1a, R2a) and the stirring and conveying blades (R1b, R2b) circulates the two-component developer composed of the toner and the carrier while stirring and conveying while rotating, and at the same time to the developing roll accommodating section (44). Supply. The developing roll (R0) rotatably accommodated in the developing roll accommodating section (44) is attached to the rotating surface of the developing roll (R0).
The component developer is transported to a developing area (Q2) opposite to the surface of the image carrier (16) on which the electrostatic latent image is written and which is rotated to develop the electrostatic latent image. The two-component developer (toner) is consumed by the developing operation, and the two-component developer is supplied into the developer circulation area (45 + 46) in accordance with the consumption of the toner in the developer circulation area (45 + 46). From the developer discharge port (51), the developer circulation area (4)
5 + 46) is discharged.

The agitating / conveying member (R1) applies a circumferential or outward radial force acting on the developer in a region (Sa) facing the developer outlet (51) by rotation to another region. It is configured to be smaller than (Sb). Therefore, the amount of the developer discharged from the inside of the developing container (V) by the circumferential or outward radial force acting on the developer when the stirring and conveying member (R1) rotates can be reduced.

(Second invention) In order to solve the above problems,
The developing device of the second invention of the present application has the following requirements (B01) to
(B01) a two-component developing roller accommodating section (44) for accommodating a developing roll (R0) and a toner and a carrier adjacent to the developing roll accommodating section (44). A developer circulation area (45 + 46) in which the developer is circulated while being circulated, a developer supply port (49) for supplying a two-component developer to the developer circulation area (45 + 46), and a developer circulation area (45). 45 + 46) A developer discharge port (51) for discharging the developer stirred and conveyed in (45 + 46).
And a developing container (V) containing a developer, and (B02)
The two-component developer rotatably accommodated in the developing roll accommodating portion (44) and attached to the rotating surface is transferred to a developing area where an electrostatic latent image is written and opposed to the rotating image carrier (16) surface. (Q2) a developing roll (R0) for developing the electrostatic latent image, and (B03) a rotating shaft (R1a, rotatable) rotatably housed in the developer circulation area (45 + 46).
R2a) and a stirring / conveying blade (R1b, R2b), and circulates the two-component developer while stirring and conveying during rotation, and supplies the two-component developer to the developing roll housing part (44). Members (R1 + R2), (B04)
The developer discharge port (51) is generated by a circumferential or outward radial force acting on the developer in a region (Sa) facing the developer discharge port (51) by the rotation of the stirring and conveying member (R1). A developer scatter prevention member (81) for preventing the developer scattered outward from being discharged from the developer discharge port (51);

(Operation of the Second Invention) In the developing device of the second invention of the present application having the above-described features, the rotating shaft (45 + 46) rotatably accommodated in the developer circulation area (45 + 46) of the developing container (V). A stirring and conveying member (R1 + R2) having the stirring and conveying blades (R1a, R2a) and the stirring and conveying blades (R1b, R2b) circulates the two-component developer composed of the toner and the carrier while stirring and conveying while rotating, and at the same time to the developing roll accommodating section (44). Supply. The developing roll (R0) rotatably accommodated in the developing roll accommodating section (44) is attached to the rotating surface of the developing roll (R0).
The component developer is transported to a developing area (Q2) opposite to the surface of the image carrier (16) on which the electrostatic latent image is written and which is rotated to develop the electrostatic latent image. The two-component developer (toner) is consumed by the developing operation, and the two-component developer is supplied into the developer circulation area (45 + 46) in accordance with consumption of the toner in the developer circulation area (45 + 46). . The developer agitated and conveyed in the developer circulation area (45 + 46) is discharged from the developer discharge port (51).

The developer scatter and discharge prevention member (81) is arranged so as to act on the developer in the region (Sa) facing the developer discharge port (51) by rotation of the stirring and conveying member (R1). The developer scattered in the outward direction of the developer outlet (51) due to the radial force in the direction is prevented from being discharged from the developer outlet (51). Therefore, the amount of the developer discharged from the inside of the developing container (V) by the circumferential or outward radial force acting on the developer when the stirring and conveying member (R1) rotates can be reduced.

[0013]

(First Embodiment of the First Invention) First
Embodiment 1 of the developing device of the invention is characterized in that the first invention has the following requirement (A05).
05) Area (Sa) facing the developer discharge port (51)
The stirring and conveying member (R1) in which the stirring and conveying blade (R1b) is omitted.

(Operation of the First Embodiment of the First Invention) In the developing device of the first embodiment of the present invention having the above-described configuration, the stirring and conveying member (R1) is connected to the developer discharge port (R1). 5
In the region (Sa) facing 1), the stirring and conveying blade (R1b) is omitted. For this reason, when the stirring / transporting member (R1) rotates, the circumferential or outward radial force acting on the developer in the region (Sa) facing the developer discharge port (51) is applied to the other region. (Sb). Therefore, the developing device according to the first embodiment of the present invention of the present application has the same operation as the developing device according to the first invention.

(Embodiment 2 of the first invention) Embodiment 2 of the developing device of the first invention is characterized in that the first invention has the following requirement (A06). The stirring and conveying member (R1) in which the outer diameter of the stirring and conveying blade (R1b) is formed to be small in a region (Sa) facing the developer discharge port (51).

(Operation of the Second Embodiment of the First Invention) In the developing device of the second embodiment of the present invention having the above-described configuration, the agitating and conveying member (R1) is connected to the developer discharge port (R1). 5
In the region (Sa) facing 1), the outer diameter of the stirring and conveying blade (R1b) is formed small. For this reason, when the stirring / transporting member (R1) rotates, the circumferential or outward radial force acting on the developer in the region (Sa) facing the developer discharge port (51) is applied to the other region. (Sb)
Therefore, the developing device according to the second embodiment of the present invention has the same function as the developing device according to the first invention.

(Third Embodiment of the First Invention) A third embodiment of the developing device of the first invention is characterized in that the first invention has the following requirement (A07). The stirring and conveying member (R1) in which the pitch of the stirring and conveying blades (R1b) is formed small in a region (Sa) opposed to the developer discharge port (51).

(Effect of Embodiment 3 of First Invention) In the developing device of Embodiment 3 of the present invention having the above-described configuration, the agitating / conveying member (R1) is connected to the developer discharge port (R1). 5
In the region (Sa) facing 1), the pitch of the stirring and conveying blades (R1b) is formed small. For this reason, when the stirring / transporting member (R1) rotates, the circumferential or outward radial force acting on the developer in the region (Sa) facing the developer discharge port (51) is applied to the other region. (S
Since it is smaller than b), the developing device of the third embodiment of the first invention also has the same operation as the developing device of the first invention.

(Embodiment 1 of the Second Invention) Embodiment 1 of the developing apparatus of the second invention is characterized in that the second invention has the following requirement (B05). The developer scattering discharge prevention member (81) disposed to protrude downward from an upper end edge of the container wall having the developer discharging port (51) formed outside the developer discharging port (51).

(Operation of the First Embodiment of the Second Invention) In the developing device of the first embodiment of the present invention having the above-mentioned configuration, the member for preventing the developer from being scattered and discharged (81) is provided with the developing device. The developer outlet (51) is disposed so as to protrude downward from an upper edge of the container wall formed with the developer outlet (51) outside the developer outlet (51). For this reason, the developer scattering discharge prevention member (81)
Is caused by a circumferential or outward radial force acting on the developer in a region (Sa) facing the developer discharge port (51) when the stirring and conveying member (R1) rotates. (51) The developer scattered outward is prevented from being discharged from the developer discharge port (51). Therefore, the first embodiment of the second invention has the same operation as the second invention.

(Embodiment 2 of the Second Invention) Embodiment 2 of the developing apparatus of the second invention is characterized in that the second invention has the following requirement (B06). The developer scatter discharge prevention member (81), which is disposed to protrude upward below a lower end edge inside the developer discharge port (51) of the container wall in which the developer discharge port (51) is formed.

(Operation of the Second Embodiment of the Second Invention) In the developing device according to the second embodiment of the present invention having the above-described configuration, the developer scatter and discharge prevention member (81) is provided with the developing device. The developer outlet (51) is disposed so as to protrude downward from an upper edge of the container wall formed with the developer outlet (51) outside the developer outlet (51). For this reason, the developer in the region (Sa) opposed to the developer discharge port (51) tends to scatter outside the developer discharge port (51) due to a circumferential or outward radial force acting on the developer. The developer is discharged from the developer outlet (51);
Prevent from being discharged from. Therefore, the second embodiment of the second invention has the same effect as the second invention.

[0023]

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 left-right direction is the Y-axis direction, and the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The directions indicated by Z and -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 image forming apparatus provided with a developing device according to Embodiment 1 of the present invention. FIG.
FIG. 2 is an enlarged explanatory view of a main part of FIG. FIG. 3 is a perspective view of the developing container of the developing device according to the first embodiment of the present invention. FIG. 4 is an enlarged explanatory view of a developer discharge port portion of the developing container.
FIG. 5 is a view seen from the direction of arrow IV. FIG. 5 is an explanatory view of the developing container, FIG. 5A is a sectional view taken along line VA-VA of FIG.
FIG. 5B is a sectional view taken along line VB-VB of FIG. 4, and FIG. FIG. 6 shows VI- of FIG. 5B.
FIG. 6 is a sectional view taken along line VI. FIG. 7 is an enlarged explanatory view of a portion of the agitating / conveying member in the developing container that faces the developer discharge port. In FIG. 1, an image forming apparatus U includes a digital copying machine U1 as an image forming apparatus main body having a platen glass (transparent document table) A1 on an upper surface, and an automatic removably mounted on the platen glass A1. A document feeder U2 is provided. The automatic document feeder U2 supplies various sizes of originals Gi (i = 1, 2, 2) to be copied.
..) Are placed on top of each other. The document Gi placed on the document feed tray TRk is transported to a copy position on the platen glass A1, and the copied document Gi is discharged to the document discharge tray TRh.

The copying machine U1 has a UI (user interface), an IIT (image input terminal) as an image reading unit and an IOT as an image recording operating unit sequentially arranged below the platen glass A1.
(Image output terminal) and an IPS (image processing system) provided between the IIT and the IOT.

The UI is a portion for the user to input an operation command signal such as copy start and the like, and has a display portion, a copy start button, a key for inputting a set number of copies, and the like. The display section displays information relating to the current setting state of the image forming apparatus U. The IIT disposed below the transparent platen glass A1 on the upper surface of the copying machine body U1 has an exposure system registration sensor (platen registration sensor) Sp and an exposure optical system 1 arranged at a platen registration position (OPT position). I have. 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).

The IPS converts the three-color electric signals input from the CCD into four-color image data of Y (yellow), M (magenta), C (cyan), and K (black). I as image data for writing (laser drive data)
It outputs to the laser drive signal output device 14 of OT.

The IOT laser drive signal output device 14
Converts the laser drive signal corresponding to the input image data to R
Output to OS (optical writing scanning device, that is, latent image forming device). The ROS is rotated by a laser beam modulated by the input laser drive signal.
The electrostatic latent image writing position Q1 on the six surfaces is scanned. A charging charger 17 is arranged around the image carrier 16 along the rotation direction on the upstream side of the latent image writing position Q1, and sequentially on the downstream side of the latent image writing position Q1. The developing device D is disposed at the developing position Q2, and the transfer device 19 is disposed at the transferring position Q3.
Is disposed, and further downstream of the cleaner unit 20.
Is arranged. A toner image density sensor SNd for detecting the density of a small area density detection toner image (that is, a patch) formed on the image carrier 16 is disposed between the development position Q2 and the transfer position Q3. ing.

Further, the copying machine main body U1 is provided with a first paper feed tray T for storing recording sheets sequentially in a downward direction.
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 a tray used when circulating the recording sheet S on which the first copy has been performed and re-sending the same to the transfer position Q3 during double-sided copying or the like.

At the upper right side of the first paper feed tray T1, a manual feed tray 21 is provided. The recording sheets conveyed from the manual feed tray 21 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 22 to the transfer position Q3. It is designed to be transported. The recording sheet conveyed through the first sheet conveyance path 22 is detected by the sheet registration sensor SNy. The first sheet conveying path 22
At the end of the registration gate 23 for temporarily stopping the recording sheet S conveyed to the upstream side of the transfer position Q3 in the sheet conveyance direction and then carrying the recording sheet S to the transfer position Q3.
And a registration roll 24. Transfer position Q3
The transfer device 19 arranged at the position transfers the toner image on the surface of the image carrier 16 to the recording sheet S passing through the transfer position Q3. The toner remaining on the surface of the image carrier 16 having passed the transfer position Q3 is
After being collected by the charging device 17, the charging device 17 uniformly charges again.

The recording sheet S to which the toner image has been transferred at the transfer position Q3 is connected to a sheet discharge tray TR by a second
The fixing position Q passes through the conveying belt 26 of the sheet conveying path 25.
Conveyed to 4. At the fixing position Q4, a pair of fixing rolls 27 composed of a heating roll 27 and a pressure roll 28,
A fixing device F having a fixing position Q
The unfixed toner image on the recording sheet S passing through the sheet 4 is fixed by heating and pressing. A fixing heater 27h is built in the fixing roll 27.
The surface temperature of the heating roll 27 is determined by the fixing temperature sensor SNt.
, And a fixing device discharge sensor SNf is disposed immediately after the fixing device F. The second
The sheet transport path 25 is provided with a discharge roller 29 for discharging a recording sheet to the sheet discharge tray TR downstream of the fixing position Q4.

In the second sheet conveying path 25, a switching gate 31 is disposed upstream of the discharge roller 29.
The switching gate 31 is used when switching the transport direction of the recording sheet S on the second sheet transport path 25 to the sheet circulation path 32 or the sheet discharge tray TR.
The sheet circulation path 32 is connected to a sheet reversal path 33 and the intermediate tray T0 via a switching gate.
The switching gate 34 directs the recording sheet S of the sheet circulation path 32 to the sheet reversing path 33 when performing double-sided copying. The sheet-shaped and comb-shaped mylar gate 36 provided in the sheet reversing path 33 includes:
When the passing recording sheet S is conveyed downward, it is elastically deformed to allow the recording sheet S to move downward, and when the recording sheet S passing through the mylar gate 36 is switched back and conveyed upward. Are configured to be guided in the direction of the intermediate tray T0. The recording sheet S once stored in the intermediate tray T0 is re-transported from the intermediate tray T0 to the transfer position Q3 by the first sheet transport path 22.

In FIG. 3, FIG. 5, and FIG.
A developing device D disposed opposite to the image carrier 16
Has a developing container V containing a two-component developer composed of a negatively charged toner and a positively charged magnetic carrier. 3, 5, and 6, the developing container V includes a developing container main body 41 and a front connection member 42 connected to a front end (X side end) and a rear end (−X side end) of the developing container main body 41. And a rear connection member 43. In FIG. 3, a pair of supported portions 41a, 41a are provided at upper portions of the front end and the rear end of the developing container main body 41, respectively, and the developing container V is mounted inside the image forming apparatus U. At this time, the supported portions 41a are supported by a frame (not shown) of the image forming apparatus U.

5B and 6, inside the developing container V, a developing roll accommodating section 44 (see FIG. 5B) for accommodating a developing roll R0, a first developer reservoir 45, and the first A second developer reservoir 46 below the developer reservoir 45 is provided. The first developer reservoir 45
And the second developer reservoir 46, the developer circulation area (45).
+46) is formed. In FIG. 6, the first developer reservoir 45 includes a first developer reservoir central portion 45a inside the developing container main body 41, a first developer reservoir front end 45b above the front connection member 42, A first developer reservoir rear end 45c above the rear connection member 43 is provided. In FIG. 6, the second developer pool 4
Reference numeral 6 denotes a second developer pool central portion 46a inside the developing container main body 41, a second developer pool front end 46b above the front connection member 42, and a second developer pool front end 46b above the rear connection member 43. And a developer pool rear end 46c. 4, 5B, and 6, inside the developing container main body 41 of the developing container V, the developing roll accommodating portion 44 and the first developer reservoir central portion 45 a are formed adjacent to each other. The second developer pool center 46a is formed below the first developer pool center 45a with a partition wall 48 (see FIG. 5B) therebetween.

In FIG. 6, the first developer pool 4
The first developer reservoir front end 45b of the fifth developer reservoir 46 and the second developer reservoir front end 46b of the second developer reservoir 46 are connected by a connection port E1, and the first developer reservoir rear end. 45c and the second developer reservoir rear end 46c are also connected by a connection port E2. Therefore, the first developer reservoir 45 and the second developer reservoir 46 communicate with each other at the connection ports E1 and E2. 2 and 3, a developer supply port 49 is formed at the front end of the upper portion of the front connection member 42. In FIGS. 3, 5A, and 6, a developer discharge port 51 is formed above the front connection member 42. The developer outlet 51 is connected to the developer supply port 4.
In order to reduce the rate at which the fresh developer supplied from 9 is discharged immediately after replenishment, it is formed upstream (rear end side) in the transport direction from the position of the developer supply port 49. 6 and 7, a region of the first developer reservoir 45 facing the developer outlet 51 is denoted by Sa, and the other region is denoted by Sb.

In FIG. 5B, the developing roll housing 4
The developing roll R0 accommodated in 4 comprises a conventionally known fixed magnet roll R0a and a developing sleeve R0b rotating around its outer periphery. Further, as shown in FIG. 5B, a layer thickness regulating member 52 for regulating the layer thickness of the developer on the developing roll R0 is disposed in the developing roll accommodating section 44. As described above, the developing container V (41 to 52) according to the first embodiment is obtained from the elements indicated by the reference numerals 41 to 52.
Is configured.

Referring to FIGS. 5A, 5B and 6, the first
The first transport member R1 is disposed in the developer reservoir 45 of
A second transport member R2 is disposed in the second developer reservoir 46. Further, between the second transport member R2 and the developing roll R0, a staying developer transport member R3 (see FIG. 5B)
Is arranged. The staying developer conveying member R3 is a member for stirring and conveying the developer staying between the second conveying member R2 and the developing roll R0. The first transport member R1, the second transport member R2, and the staying developer transport member R3 constitute a stirring transport member (R1 + R2 + R3).

In FIGS. 6 and 7, the first transport member R
1 is a rotating shaft R1a extending in the axial direction of the developing roll R0.
And the stirring / conveying blade R fixed to the outer periphery of the rotary shaft R1a.
1b. The second transport member R2 also has a rotating shaft R2a and a stirring transport blade R2b. In the portion (see FIG. 7) of the first transport member R1 disposed in the area Sa, the stirring transport blade R1b is omitted. Therefore, the circumferential or outward radial force that the first transport member R1 acts on the developer in the region Sa is:
It is smaller than the other area Sb (see FIGS. 6 and 7).

In FIG. 5C, a gear G0 and the gear G0 are provided at the rear end (the -X side end) of the shaft of the developing roll R0.
And a coaxial gear G0 '. The gear G0 '
The rotational force of a developing device motor (not shown) is transmitted to the motor. In FIG. 5C, a driven gear G1 is fixed to a rear end (-X side end) of the shaft of the first transport member R1. The gear G1 is meshed with a driven gear Ga, and the gear Ga is a driven gear G
The gear Gb meshes with a driven gear G2 fixed to the rear end (-X side end) of the shaft of the second transport member R1. A gear G2 'coaxial with the gear G2 of the second conveying member R2 meshes with a gear G3 mounted on the rear end (-X side end) of the shaft of the staying developer conveying member R3. The gear G3 meshes with a driven gear Gc, and the gear Gc meshes with the gear G0 mounted on the rear end (-X side end) of the shaft of the developing roll R0.

The gear G0 is rotated via a gear G0 'by the rotational force of a developing device motor (not shown). Gear G
When 0 rotates, the gears Gc and G3 rotate, and the gears G2 'and G2'
2 rotates in the direction opposite to the rotation direction of the gear G0. When the gear G2 further rotates, the gear G
The gear G1 is configured to rotate in the opposite direction to the gear G2 via b and Ga. Then, as shown in FIG. 6, the first and second transport members R1 and R2 which rotate integrally with the gears G1 and G2 allow the developer to be stored in the first and second developer reservoirs 46 and 47, respectively. It is circulating.

In FIG. 2, a developer supply cylinder support member 53 is disposed above the developer supply port 49 of the developer container V. A developer supply cylinder 54 is adhered to the developer supply cylinder support member 53, and a developer supply opening 54a of the developer supply cylinder 54 is provided inside the developer supply cylinder support member 53.
(See FIG. 2). In FIG. 2, a replenishment developer conveying member 56 having a rotating shaft 56a and a blade 56b fixed around the rotating shaft 56a is rotatably disposed in the developer replenishing cylinder 54. A gear G4 is provided at one end of the rotary shaft 56a.
(See FIG. 2), and the rotating shaft 56a is driven to rotate by a developing device motor (not shown) that meshes with the gear G4.

In FIG. 2, a developer supply case 57 is disposed above the developing container V. The developer supply case 57 is provided with a two-component developer having a high toner concentration (hereinafter, referred to as a two-component developer).
A developer storage container 58 in which a “high-concentration developer” is stored, and a developer stirring container 59 provided below the developer storage container 58. The two-component developer (high-concentration developer) supplied from the developer storage container 58 to the developer stirring container 59 is supplied to the replenishing developer conveying member 56 of the developer replenishing cylinder 54 in the developer stirring container 59. The developer is stirred while being circulated in synchronization with the rotation and supplied to the developer supply cylinder 54 from the supply cylinder connection port 59a. A developer replenishing device (53 to 59 + G4) is constituted by the components denoted by reference numerals 53 to 59 and G4.

The high-concentration developer supplied from the developer storage container 54 into the developer replenishing cylinder 54 is transported by the revolving developer transport member 56 which is driven to rotate. Second developer pool front end 46
It is to be replenished within b. The replenishment of the high-density developer is performed by the value of the toner image density sensor SNd for detecting the toner image density Ta during normal use.

In FIGS. 3 and 5A, a discharge developer transport tube connecting portion 61 is disposed outside the developer discharge port 51 (see FIGS. 5A and 3) of the developing container V. The discharge developer transport tube connecting portion 61 is connected to the discharge developer transport tube 62.
The developer collecting container 63 (see FIG. 3) is connected to the front end (the end on the X side) of the discharge developer transport cylinder 62 and to the rear end (the end on the −X side) of the discharge developer transport cylinder 62. I have. In FIG. 3, a rotating shaft 64 is provided inside the discharge developer transport cylinder 62.
and a discharge developer transport member 64 having transport blades 64b fixed to the outer periphery of the rotary shaft 64a.

In FIG. 3, a gear G5 is mounted at the rear end of the rotating shaft 64a of the discharging developer conveying member 64, and the developing device motor (not shown) rotates the gear G5 through the gear G5. The discharge developer transport member 64 is configured to rotate. Due to the rotation of the discharge developer transport member 64, the discharge developer transport tube 62 is connected to the developer discharge port 51 through the discharge developer transport tube connecting portion 61.
The surplus developer discharged into the developer collecting container 63
To be transported to

(Operation of Embodiment 1) In FIGS. 4 and 6,
Second developer pool 4 in the developing container V of the developing device D
The second transport member R2 accommodated in the second developer container 6 transfers the high-concentration developer supplied from the developer supply port 49 to the second developer reservoir front end 46b to the second developer reservoir rear end 46c. Stir and transport. The developer at the rear end portion 46c of the second developer pool is pushed upward by the pressure of the developer conveyed by the second conveyance member R2, and the connection port E is opened.
After passing through 2, the developer is conveyed to the first developer pool rear end 45c above the second developer pool rear end 46c.

5B and 4, in the first developer reservoir 45, the first transport member R1 agitates and transports the developer in a direction opposite to the transport direction of the second transport member R2. The two-component developer triboelectrically charged by the mixing action of the toner and the carrier during the stirring and transport is adsorbed on the surface of the developing roll R0 by the magnetic force of the magnet roll R0a. The developer on the surface of the developing roll R0 is formed into a uniform layer by the layer thickness regulating member 52. The uniform developer layer formed on the surface of the developing roll R0 is provided in the developing region Q2.
, The electrostatic latent image on the image carrier 16 is developed into a toner image. The toner image on the image carrier 16 is transferred onto the recording sheet S. The recording sheet S to which the toner image has been transferred is heated and fixed by the fixing device F, and is discharged to the sheet discharge tray TR. When the above-described copying operation is repeated, the toner in the developer contained in the developing container V of the developing device D is gradually consumed, and the ratio of the toner to the carrier, that is, the toner concentration decreases. The high-concentration developer (toner) is supplied into the developing container V according to the change in the toner concentration.

On the other hand, the carrier in the developer in the developing container V is not consumed by the developing operation but is deteriorated by being stirred with the toner in the developing container V. Therefore, the surplus developer (deteriorated carrier) in the developing container V increases. When the upper surface of the surplus developer increases beyond the position of the lower edge of the developer discharge port 51, the surplus developer flows into the discharge developer transport cylinder connecting portion 61 provided outside the developer discharge port 51. And is collected in the developer collection container 63.

The first stirring / conveying member R1 is rotated by a circumferential or outward radial force acting on the developer in the region Sa facing the developer discharge port 51 in the other region Sb (see FIG. 6, see FIG. 7). Accordingly, the amount of the developer discharged from the developing container V by the circumferential or outward radial force acting on the developer when the first transport member R1 rotates can be reduced.

(Embodiment 2) FIG. 8 is an enlarged explanatory view of a portion of a stirring and conveying member in a developing container of a developing apparatus according to Embodiment 2 of the present invention, which is opposed to the developer discharge port, and corresponds to FIG. 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. Example 2
Is different from the first embodiment in the following points, but is configured similarly to the first embodiment in other points. As shown in FIG. 8, the first transport member R1 of the second embodiment includes a stirring transport blade R1b in a region Sa facing the developer discharge port 51.
Has a small outer diameter. For this reason, the circumferential or outward radial force acting on the developer in the area Sa due to the rotation of the first transport member R1 is applied to the other area Sb.
Is smaller than the force acting on the developer. Therefore, the second embodiment has the same operation as the first embodiment.

(Embodiment 3) FIG. 9 is an enlarged explanatory view of a portion of a stirring and conveying member in a developing container of a developing apparatus according to Embodiment 3 of the present invention, which is opposed to the developer discharge port, and corresponds to FIG. FIG. 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. Example 3
Is different from the first embodiment in the following points, but is configured similarly to the first embodiment in other points. As shown in FIG. 9, in the first transport member R1 of the third embodiment, the pitch of the stirring transport blades R1b is formed small in the region Sa facing the developer discharge port 51. Therefore, the circumferential or outward radial force acting on the developer in the area Sa due to the rotation of the first transport member R1 becomes smaller than the force acting on the developer in the other area Sb. Therefore, the third embodiment has the same operation as the first embodiment.

(Embodiment 4) FIG. 10 is an enlarged explanatory view showing a state in which a developer scatter prevention member is provided at a developer discharge port of a developing device according to Embodiment 4 of the present invention, and FIG. FIG. 10B is a cross-sectional view of the outlet, and FIG.
FIG. 10C is a cross-sectional view taken along the line B, as viewed from the arrow XC in FIG. 10B. In the description of the fourth embodiment, the same reference numerals are given to the components corresponding to the components of the first embodiment, and the detailed description thereof will be omitted. Example 4
Is different from the first embodiment in the following points, but is configured similarly to the first embodiment in other points. In FIG. 10, the region Sa of the first stirring and conveying member R1 of the fourth embodiment is shown.
The portion arranged in the (area facing the developer discharge port 51) does not omit the stirring and transporting blade R1b as in the first embodiment. Further, a developer scattering discharge preventing member 8 protruding downward is provided at an upper end edge outside the developer discharging port 51.
1 is arranged. In FIGS. 10B and 10C, the developer scatter and discharge prevention member 81 is formed of an elastic member, and is formed in a comb shape in accordance with the pitch of the agitating and conveying blades R1b of the opposing first agitating and conveying member R1. ing.
The developer scattering / discharging preventing member 81 may be formed in a plate shape instead of a comb tooth shape.

The developer scatter and discharge prevention member 81 is connected to the first transport member R1 in the area Sa facing the developer discharge port 51.
Prevents the developer scattered in the outward direction of the developer discharge port 51 from being discharged from the developer discharge port 51 due to the circumferential or outward radial force acting on the developer due to the rotation of. Therefore, the amount of the developer discharged from the developing container V by the circumferential or outward radial force acting on the developer in the region Sa when the first transport member R1 rotates can be reduced.

(Embodiment 5) FIG. 11 is an enlarged explanatory view showing a state in which a developer scattered discharge preventing member of a developing apparatus according to Embodiment 5 of the present invention is provided at a developer discharge port, and FIG. FIG. 11B is a cross-sectional view of the discharge port, and FIG.
FIG. 11C is a cross-sectional view taken along the line XIB, and FIG. 11C is a diagram viewed from the arrow XIC in FIG. 11B. In the description of the fifth embodiment,
The same reference numerals are given to the components corresponding to the components of the fourth embodiment, and the detailed description thereof will be omitted. The fifth embodiment differs from the fourth embodiment in the following points, but has the same configuration as the fourth embodiment in other points.

In FIG. 11, a plate-like developer scattering discharge prevention member 81 projecting upward is disposed below the lower end edge inside the developer discharge port 51 of the developing device D of the fifth embodiment. . Also in the fifth embodiment, the developer scatter and discharge prevention member 81 is provided in the circumferential direction or the outward direction which acts on the developer by the rotation of the first stirring and conveying member R1 in the area Sa facing the developer discharge port 51. Is prevented from being discharged from the developer discharge port 51 by the radial force of the developer. Therefore, the fifth embodiment also has the same operation as the fourth embodiment.

(Modification) 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, instead of replenishing the developer having a high toner concentration into the developer container V, it is possible to replenish the toner and carrier stored separately from each other into the developer container V. (H02) In each of the above-described embodiments, the case where the second developer reservoir 46 is provided below the first developer reservoir 45 inside the developing container V has been described, but the first developer reservoir 45 is provided. It is also possible to provide a second developer reservoir at a position adjacent to and opposite to the developing roll housing portion 44. In this case, the circumferential or outward radial force acting on the developer in the area facing the developer discharge port by rotation is smaller than in the other areas by rotating the second transport member of the second developer reservoir. It is possible to configure so that

[0057]

The developing device of the present invention described above has the following effects. (E01) The amount of the developer discharged from the inside of the developing container can be reduced by a circumferential or outward radial force acting on the developer when the stirring and conveying member rotates. (E02) Therefore, the minimum developer amount in the developing container can be accurately maintained.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram of an image forming apparatus including a developing device according to a first embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a main part of FIG. 1;

FIG. 3 is a perspective view of a developing container of the developing device according to the first exemplary embodiment of the present invention.

FIG. 4 is an enlarged explanatory view of a developer discharge port portion of the developing container, as viewed from the direction of the arrow IV in FIG. 2;

5 is an explanatory view of the developing container, FIG. 5A is a cross-sectional view taken along line VA-VA of FIG. 4, FIG. 5B is a cross-sectional view taken along line VB-VB of FIG. 4, and FIG. It is explanatory drawing of a gear.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 5B.

FIG. 7 is an enlarged explanatory view of a portion of the stirring / conveying member in the developing container which faces the developer discharge port.

FIG. 8 is an enlarged explanatory view corresponding to FIG. 7 of a portion of the stirring and conveying member in the developing container of the developing device according to the second embodiment of the present invention, the portion facing the developer discharge port.

FIG. 9 is an enlarged explanatory view corresponding to FIG. 7 of a portion of the stirring and conveying member in the developing container of the developing device according to the third embodiment of the present invention, the portion being opposed to the developer discharge port.

FIG. 10 is an enlarged explanatory view showing a state in which a developer scattering and discharging prevention member of a developing device according to a fourth embodiment of the present invention is provided at a developer discharging port, and FIG. 10A is a cross section of the developer discharging port. FIG. 10B is a sectional view taken along line XB-XB of FIG. 10A.
FIG. 10C is a view as seen from the arrow XC in FIG. 10B.

FIG. 11 is an enlarged explanatory view showing a state in which a developer scattering and discharging prevention member of a developing device according to a fifth embodiment of the present invention is provided at a developer discharging port, and FIG. 11A is a cross section of the developer discharging port. 11B is a sectional view taken along the line XIB-XIB in FIG. 11A, and FIG. 11C is a view as seen from the arrow XIC in FIG. 11B.

[Explanation of symbols]

Q2: developer area, R0: developing roll, R1a, R2a: rotating shaft, R1b, R2b: stirring and conveying blade, R1 + R2: stirring and conveying member, Sa: area facing developer outlet, Sb: other area, V .., A developer container, 16 an image carrier, 44 a developing roll housing, 45 + 46 a developer circulating area, 49 a developer replenishing port, 51 a developer outlet, 81 a developer scatter and discharge prevention member.

Claims (2)

[Claims] 1. A developing device having the following requirements (A01) to (A04): (A01) a developing roll accommodating section accommodating a developing roll; A developer circulating region in which a two-component developer including a carrier is stirred and conveyed while being circulated; a developer supply port for replenishing the two-component developer in the developer circulating region; and a stirring and conveying in the developer circulating region. A developer container having a developer discharge port for discharging the developer,
02) The two-component developer rotatably accommodated in the developing roll accommodating portion and adhered to the rotating surface is transported to a developing area where an electrostatic latent image is written and faces the rotating image carrier surface. A developing roll for developing the electrostatic latent image, (A
03) having a rotating shaft and a stirring / conveying blade rotatably housed in the developer circulation area, and circulating the two-component developer while stirring and conveying at the time of rotation; A stirring / conveying member for supplying the developer; (A04) a circumferential or outward radial force acting on the developer in a region opposed to the developer discharge port by rotation of the stirring / conveying member is higher than in other regions; The stirring and conveying member configured to be small. 2. A developing device having the following requirements (B01) to (B04): (B01) a developing roll accommodating section accommodating a developing roll; A developer circulating region in which a two-component developer including a carrier is stirred and conveyed while being circulated; a developer supply port for replenishing the two-component developer in the developer circulating region; and a stirring and conveying in the developer circulating region. A developer container having a developer discharge port for discharging the developer,
02) The two-component developer rotatably accommodated in the developing roll accommodating portion and adhered to the rotating surface is transported to a developing area where an electrostatic latent image is written and faces the rotating image carrier surface. A developing roll for developing the electrostatic latent image, (B
03) having a rotating shaft and a stirring / conveying blade rotatably housed in the developer circulation area, and circulating the two-component developer while stirring and conveying at the time of rotation; A stirring / conveying member for supplying the developer, and (B04) an outer circumferential or outward radial force acting on the developer in a region opposed to the developer outlet by rotation of the stirring / conveying member, the outer side of the developer outlet. A developer scattering prevention member for preventing the developer scattered in the direction from being discharged from the developer discharging port;