JP2010230760A - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device in which agitating and mixing performance for a developer is improved. <P>SOLUTION: The developing device (Gy, Gm, Gc, Gk) includes: an inflow section (4) into which a developer from circulating parts (2+3) where the developer is circulated flows; an outflow section (6) disposed near the inflow section (4) and connected to the circulating parts (2+3); a conveyance regulating vane (R1d) disposed upstream of the inflow section in a first conveyance direction and used for regulating the amount of developer conveyed downstream in the first conveyance direction; and an inlet (7c) which causes a developer to flow into the outflow section (6) from the inflow section (4) and is formed in the gravity direction above the upper end of a second rotation shaft (R2a). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Conventionally, in an image forming apparatus such as a copying machine or a printer, a developer contained in a developing device that develops a latent image into a visible image is circulated while stirring to loosen a lump of developer, As techniques for frictionally charging a carrier, the techniques described in the following Patent Documents 1 and 2 are conventionally known.

  Japanese Patent Application Laid-Open No. 2005-352042 as Patent Document 1 circulates and conveys developer in a developing device (4) by two conveying screws (22, 23) extending in parallel to a developing roller (21). At the same time, a sub-channel (30) is provided on the further outer side of the conveying screw (23) farthest from the developing roller (21), and a new developer is supplied to the sub-channel (30), so that the sub-channel (30) is provided. A technique for reducing a lack of stirring of a new developer by stirring with an inner stirring screw (31) is described.

  Japanese Patent Application Laid-Open No. 2007-121331 as Patent Document 2 discloses a developing device that circulates a developer in the developer transport region (13, 14), and has an opening (12b) in the developer transport region (13, 14). A developer transported in the first developer transport region (13) by narrowing the cross-sectional area of the developer transport region (13, 14) and disposing a developer retaining plate (18) for retaining the developer. The developer that is struck against the damming plate (18) and divided into the opening (12b) side and the first extension conveyance region (21) side, and the developer conveyed through the second extension conveyance region (22) By hitting against the damming plate (18) and being divided into two parts, the opening (12b) side and the second developer transport area (14) side, the bisected developers are mixed together, so that the developer A technique for enhancing the mixing and stirring effect is described.

Japanese Patent Laying-Open No. 2005-352042 ("0030" to "0034", FIGS. 3 and 4) JP 2007-121331 A (“0036” to “0048”, FIG. 3 and FIG. 4)

  An object of the present invention is to improve the stirring and mixing performance of a developer.

In order to solve the technical problem, the developing device according to claim 1 is provided by:
A developer holding body disposed opposite to an image holding body on which a latent image is formed and holding a developer on the surface;
A holding member receiving portion for storing the developer holding member; a circulating portion disposed adjacent to the holding member receiving portion for circulating the developer therein; and connected to the circulating portion and from the circulating portion. An inflow portion into which the developer flows in, and an outflow portion that is disposed adjacent to the inflow portion and is connected to the circulation portion and from which the developer flows out into the circulation portion, and contains the developer therein. A developing container,
A first rotation shaft and a first transport blade provided on the first rotation shaft, the first rotation shaft being housed in the inflow portion and transporting the developer in the inflow portion in a first transport direction; The first transport member includes a transport regulating blade that is disposed upstream of the inflow portion in the first transport direction and regulates the amount of developer transported downstream in the first transport direction. The first transport member having the transport blades;
A second rotating shaft; and a second conveying blade provided on the second rotating shaft, the developer contained in the outflow portion being in a direction opposite to the first conveying direction. A second conveying member that conveys in the second conveying direction;
An inflow port through which developer flows into the outflow portion from the inflow portion, the inflow port formed above the upper end of the second rotation shaft in the direction of gravity;
It is provided with.

The invention according to claim 2 is the developing device according to claim 1,
A replenishment part formed in the outflow part and into which a new developer flows;
It is provided with.

According to a third aspect of the present invention, in the developing device according to the first or second aspect,
The circulation part having a first stirring part adjacent to the holding body accommodating part and a second stirring part adjacent to the first stirring part;
The first transport member housed in the first stirring section and transporting the developer in the first stirring section in a first transport direction toward the inflow section;
The second conveying member that is accommodated in the second agitating section and conveys the developer in the outflow section in a second conveying direction that causes the developer to flow out into the second agitating section;
A first connecting portion that connects a downstream portion in the first transport direction of the first stirring portion and an upstream portion in the second transport direction of the second stirring portion; and a first connection portion of the first stirring portion. Provided between the first connecting portion and the second connecting portion connecting the upstream portion in the second conveying direction and the downstream portion in the second conveying direction of the second stirring portion. A circulation partition member for partitioning between the stirring unit and
It is provided with.

According to a fourth aspect of the present invention, in the developing device according to the third aspect,
A stirrer blade provided in a region corresponding to the first stirrer and a transport provided at a position corresponding to the upstream end of the inflow portion in the first transport direction and having a transport speed lower than that of the stirrer blade A first conveying blade having a regulating blade,
It is provided with.

According to a fifth aspect of the present invention, in the developing device according to the fourth aspect,
The conveyance regulating blade partially disposed in a region corresponding to the first connecting portion;
It is provided with.

The invention according to claim 6 is the developing device according to claim 4 or 5,
The conveyance regulating blade constituted by a stirring member extending along the axial direction of the first rotation shaft;
It is provided with.

According to a seventh aspect of the present invention, in the developing device according to any one of the third to sixth aspects,
The second conveying blade in which the outer diameter of the region corresponding to the outflow portion is smaller than the outer diameter of the region corresponding to the second stirring portion;
It is provided with.

The invention according to claim 8 is the developing device according to any one of claims 3 to 7,
The second conveying member in which the shaft diameter of the region corresponding to the front outflow portion is smaller than the shaft diameter of the region corresponding to the second stirring portion;
It is provided with.

The invention according to claim 9 is the developing device according to any one of claims 1 to 8,
A partition member that partitions between the inflow portion and the outflow portion;
The inflow port formed in the partition member;
It is provided with.

In order to solve the technical problem, an image forming apparatus according to claim 10 is provided.
An image carrier on which a latent image is formed on the surface;
The developing device according to any one of claims 1 to 9, wherein the latent image on the surface of the image carrier is developed into a visible image;
A transfer device for transferring a visible image on the surface of the image carrier to a medium;
A fixing device for fixing the visible image transferred to the medium;
It is provided with.

According to the first and tenth aspects of the present invention, the stirring and mixing performance of the developer can be improved as compared with the case where the present configuration is not provided.
According to the second aspect of the present invention, the newly replenished developer and the developer flowing in from the inflow port can be stirred and mixed.
According to the third aspect of the present invention, the developer in the first agitating portion and the inflow portion can be agitated and conveyed by the first agitating member, and the developer in the second agitating portion and the outflow portion is second agitated. Can be stirred and transported by members.
According to the fourth aspect of the present invention, the developer can be circulated in the circulation portion while the amount of the developer flowing into the inflow portion is restricted by the difference in the conveyance speed between the stirring blade and the conveyance restriction blade. .

According to the fifth aspect of the present invention, the developer is more efficiently supplied to the first connection portion side than in the case where the amount conveyed by the conveyance restriction blades is regulated outside the region corresponding to the first connection portion. Can be allowed to flow into.
According to the sixth aspect of the present invention, the amount of the developer flowing into the outflow portion can be regulated by the speed reduction caused by the stirring blade having no conveyance capability.
According to invention of Claim 7, compared with the case where an outer diameter is not a small diameter, it can reduce conveying before fully agitating in an outflow part, and can reduce a stirring failure.

According to invention of Claim 8, compared with the case where a shaft diameter is not a small diameter, it can reduce that it is conveyed before fully stirring at an outflow part, and can reduce a stirring failure.
According to the ninth aspect of the present invention, it is possible to allow the developer to flow from above into the outflow portion from the inflow port formed in the partition member.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is an overall explanatory view of the developing device used in the image forming apparatus of Embodiment 1 of the present invention. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an explanatory diagram of the partition member of Example 1, FIG. 5A is an explanatory diagram of the positional relationship between the partition member and the first stirring member, and FIG. 5B is the positional relationship between the partition member and the second stirring member. It is explanatory drawing. FIG. 6 is an explanatory diagram of the developing device of the second embodiment, and corresponds to FIG. 2 of the first embodiment. FIG. 7 is an explanatory diagram of the developing device of the third embodiment, FIG. 7A is an explanatory diagram corresponding to FIG. 2 of the first embodiment, and FIG. 7B is an explanatory diagram of a modified example of the third embodiment. FIG. 8 is an explanatory diagram of the developing device of Example 4, FIG. 8A is an explanatory diagram of the positional relationship between the partition member and the admixing auger corresponding to FIG. 5B of Example 1, and FIG. It is sectional drawing of the inflow port part corresponding to.

Next, specific examples of embodiments of the present invention (hereinafter referred to as examples) will be described with reference to the drawings, but the present invention is not limited to the following examples.
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, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention.
In FIG. 1, a copying machine U as an image forming apparatus according to a first embodiment of the present invention includes an automatic document feeder U1 and an image forming apparatus that supports the automatic document feeder U1 and a platen glass PG as an example of a transparent document table at the upper end. And a main body U2.
The automatic document feeder U1 includes a document feed tray TG1 as an example of a document storage unit in which a plurality of documents Gi to be copied are stored, and a document reading on the platen glass PG from the document feed tray TG1. It has a document discharge tray TG2 as an example of a document discharge portion from which the document Gi conveyed through the position is discharged.
The image forming apparatus main body U2 includes an operation unit UI through which a user inputs an operation command signal for starting copying, an exposure optical system A, and the like.

Reflected light from a document conveyed on the platen glass PG by the automatic document feeder U1 or a document manually placed on the platen glass PG is red by the solid-state imaging device CCD via the exposure optical system A: It is converted into electrical signals of R, green: G, blue: B.
The image processing unit GS converts the RGB electrical signals input from the solid-state imaging device CCD into black: K, yellow: Y, magenta: M, cyan: C image information and temporarily stores the image information. The information is output to the write drive circuit DL as image information for forming a latent image.
When the original image is a black monochrome image, only black: K image information is input to the writing drive circuit DL.
The write drive circuit DL has write drive circuits for the respective colors Y, M, C, and K, and a latent image forming apparatus at a time when a write drive signal corresponding to input image information is set in advance. Output to a laser diode (not shown) as an example of a latent image writing member for each color of ROS.

The visible image forming devices Uy, Um, Uc, Uk arranged above the latent image forming device ROS respectively display visible images of respective colors of yellow: Y, magenta: M, cyan: C, and black: K. It is an apparatus to form.
Laser beams Ly, Lm, Lc, and Lk as examples of Y, M, C, and K latent image writing light emitted from the laser diodes (not shown) of the latent image forming apparatus ROS are respectively rotated image carriers. As an example, the light enters the photoconductors PRy, PRm, PRc, and PRk.
The Y visible image forming device Uy includes a rotating photosensitive member PRy, a charging roll CRy as an example of a charger, a developing device Gy, a transfer roll T1y as an example of a transfer device, and an example of an image carrier cleaner. The visible image forming devices Um, Uc, Uk are all configured in the same manner as the Y visible image forming device Uy.

The photoconductors PRy, PRm, PRc, and PRk are uniformly charged by the respective charging rolls CRy, CRm, CRc, and CRk, and then at the latent image forming positions Q1y, Q1m, Q1c, and Q1k, the laser beams Ly, An electrostatic latent image is formed on the surface by Lm, Lc, and Lk. The electrostatic latent images on the surfaces of the photoreceptors PRy, PRm, PRc, and PRk are developed into toner images as an example of a visible image by the developing devices Gy, Gm, Gc, and Gk in the development areas Q2y, Q2m, Q2c, and Q2k. The
The developed toner image is conveyed to primary transfer regions Q3y, Q3m, Q3c, and Q3k that are in contact with an intermediate transfer belt B as an example of an intermediate transfer member. The primary transfer rolls T1y, T1m, T1c, and T1k as an example of the primary transfer unit disposed on the back side of the intermediate transfer belt B in the primary transfer regions Q3y, Q3m, Q3c, and Q3k are controlled by the control unit C. A primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied at a preset time from the power supply circuit E to be controlled.
The toner images on the photoconductors PRy to PRk are primarily transferred onto the intermediate transfer belt B by the primary transfer rolls T1y, T1m, T1c, and T1k. Residues on the surface of the photoconductors PRy, PRm, PRc, and PRk after the primary transfer are cleaned by the photoconductor cleaners CLy, CLm, CLc, and CLk.

  Above the photoconductors PRy to PRk, a belt module BM as an example of an intermediate transfer unit that is movable up and down and can be pulled out forward is disposed. The belt module BM includes the intermediate transfer belt B, a tension roll Rt as an example of a tension applying member, a walking roll Rw as an example of a meandering correction member, and an idler roll Rf as an example of a driven support member. A backup roll T2a, which is an example of a member and an example of a secondary transfer counter member, and the primary transfer rolls T1y, T1m, T1c, T1k are included. The tension roll Rt, the walking roll Rw, the idler roll Rf, and the backup roll Rf constitute a belt support roll Rt + Rw + Rf + T2a as an example of the intermediate transfer support member of Example 1 that rotatably supports the intermediate transfer belt B. .

A secondary transfer roll T2b as an example of a secondary transfer member is disposed facing the surface of the intermediate transfer belt B in contact with the backup roll T2a. A secondary transfer device T2 is constituted by the backup roll T2a and the secondary transfer roll T2b. Further, a secondary transfer region Q4 as an example of a final transfer region is formed by the regions where the secondary transfer roll T2b and the intermediate transfer belt B face each other.
The color toner images sequentially transferred onto the intermediate transfer belt B by the transfer devices T1y, T1m, T1c, and T1k in the primary transfer areas Q3y, Q3m, Q3c, and Q3k are conveyed to the secondary transfer area Q4. .

  Below the latent image forming device ROS, paper feed trays TR1 to TR3 as an example of a medium accommodating portion for accommodating a recording sheet S as an example of a medium are disposed. It is supported by a pair of left and right guide rails GR, GR as an example of a guide member that is supported so as to be able to enter and exit in the front-rear direction. The recording sheets S in the paper feed trays TR1 to TR3 are taken out by a pickup roll Rp as an example of a medium takeout member and separated one by one by a separating roll Rs as an example of a medium separating member, and then an example of a medium transport member. Are sent to a registration roll Rr as an example of a timing adjusting member. A plurality of the sheet conveyance rolls Ra are provided along a conveyance path SH formed by a sheet guide as an example of a medium guide member, and a registration roll Rr is disposed upstream of the secondary transfer region Q4 in the medium conveyance direction. Yes. A medium transport device SH + Ra + Rr is configured by the transport path SH, the sheet transport roll Ra, the registration roll Rr, and the like.

The registration roll Rr conveys the recording sheet S to the secondary transfer area Q4 in accordance with the timing when the color toner image formed on the intermediate transfer belt B is conveyed to the secondary transfer area Q4. When the recording sheet S passes through the secondary transfer area Q4, the backup roll T2a is grounded, and a secondary transfer voltage having a polarity opposite to the toner charging polarity is applied from the power supply circuit E to the secondary transfer roll T2b. . At this time, the color toner image on the intermediate transfer belt B is transferred to the recording sheet S by the secondary transfer device T2.
The intermediate transfer belt B after the secondary transfer is cleaned by a belt cleaner CLb as an example of an intermediate transfer body cleaner.

  Accordingly, the toner images formed on the photoreceptors PRy to PRk of the toner image forming apparatuses Uy to Uk are transferred to the intermediate transfer belt B by the primary transfer rolls T1y to T1k of the belt module BM in the primary transfer regions Q3y to Q3k. After the primary transfer, the secondary transfer region Q4 is secondarily transferred onto the recording sheet S by the secondary transfer roll T2b of the secondary transfer unit T2. Accordingly, the belt module BM, the secondary transfer layer T2b, and the like constitute a transfer device BM + T2b that transfers the toner images on the surfaces of the photoreceptors PRy to PRk that pass through the transfer regions Q3y to Q3k to the recording sheet S.

The recording sheet S on which the toner image is secondarily transferred is conveyed to the fixing device F. The fixing device includes a heating roll Fh as an example of a heat fixing member and a pressure roll Fp as an example of a pressure fixing member, and a fixing area that is a contact area between the heating roll Fh and the pressure roll Fp. The recording sheet S is conveyed to Q5. The recording sheet S conveyed to the fixing area Q5 is heated and fixed when passing through the fixing area Q5, and is discharged to a discharge tray TRh as an example of a medium discharge portion by a discharge roller Rh as an example of a medium discharge member. .
Note that a release agent for improving the releasability of the recording sheet S from the heating roll is applied to the surface of the heating roll Fh by a release agent application device Fa.

  Above the belt module BM, developer cartridges Ky, Km, Kc, and Kk, which are examples of developer storage containers that store developers of Y, M, C, and K colors, are disposed. The developers contained in the developer cartridges Ky, Km, Kc, and Kk are supplied from the developer replenishment path (not shown) to the developer units Gy according to the consumption of the developer in the developing devices Gy, Gm, Gc, and Gk. , Gm, Gc, Gk. In the image forming apparatus U according to the first exemplary embodiment, a two-component developer including a toner and a carrier is used as the developer, and the toner in the developing apparatuses Gy to Gk is consumed with the image formation. The developer cartridges Ky to Kk are configured to be supplied with high-concentration toner having a higher toner ratio than the ratio between the toner and the carrier in the developing devices Gy to Gk, that is, the so-called toner density. .

In FIG. 1, the image forming apparatus U includes an upper frame UF and a lower frame LF, and the upper frame UF includes photoconductors PRy, PRm, PRc, arranged above the ROS and ROS. PRk, developing devices Gy, Gm, Gc, Gk, a belt module BM, and the like are supported.
The lower frame LF supports a guide rail GR that supports the paper feed trays TR1 to TR3, a pickup roll Rp that feeds paper from the trays TR1 to TR3, a separating roll Rs, a sheet conveying roll Ra, and the like. ing.

(Developer)
FIG. 2 is an overall explanatory view of the developing device used in the image forming apparatus of Embodiment 1 of the present invention.
3 is a cross-sectional view taken along line III-III in FIG.
The developing units Gy, Gm, Gc, and Gk for the colors Y, M, C, and K have the same configuration. Therefore, the developing unit Gy will be described below, and the other developing units Gm, Gc, and Gk are described. Description is omitted.

  2 and 3, the developing device Gy disposed opposite the photoconductor PR in the developing region Q2y contains a two-component developer composed of a negatively charged toner and a positively charged magnetic carrier. A developing container V is provided. The developing container V includes a developing container main body V1 and a developing container cover V2 as an example of a lid member that closes the upper end thereof. A layer thickness regulating member Sk extending in the longitudinal direction of the developing device Gy is fixedly supported on the developing container body V1. Further, on the outer wall of the developing container main body V1 on the photosensitive member PRy side, as an example of a leakage prevention member, a flexible upstream seal Js extending in the longitudinal direction of the developing device Gy is provided.

4 is a cross-sectional view taken along line IV-IV in FIG.
In FIG. 2, the developing container main body V <b> 1 has a developing roll chamber 1 as an example of a holding body accommodating portion for accommodating a developing roll R <b> 0 as an example of a developer holding body, and a first adjacent to the developing roll chamber 1. A supply chamber 2 as an example of one stirring unit and a stirring chamber 3 as an example of a second stirring unit adjacent to the supply chamber 2 are provided. The supply chamber 2 and the agitation chamber 3 constitute a circulation chamber 2 + 3 as an example of a circulation section of the first embodiment.
A discharge chamber 4 as an example of an inflow portion is continuously formed at the front end of the supply chamber 2, and a supply chamber as an example of an outflow portion is adjacent to the discharge chamber 4 at the front end of the stirring chamber 3. 6 are continuously formed. A developer discharge port 4a for discharging the developer is formed in the lower surface of the front end of the discharge chamber 4, and a replenishment portion for supplying a new developer to the developer container cover V2 is formed at the front end of the supply chamber 6. As an example, a supply port 6a is formed. In FIG. 4, the replenishing port 6 is formed at the right end of the developing container cover V <b> 2 and is set so that a new developer flows into the right side of the replenishing chamber 6.

FIG. 5 is an explanatory diagram of the partition member of Example 1, FIG. 5A is an explanatory diagram of the positional relationship between the partition member and the first stirring member, and FIG. 5B is the positional relationship between the partition member and the second stirring member. It is explanatory drawing.
In FIG. 3, between the supply chamber 2 and the discharge chamber 4, the stirring chamber 3, and the replenishment chamber 6 inside the developing container main body 1, an example of a circulation partition member extending in the front-rear direction is provided. An example partition wall 7 is formed. 3 to 5, the partition wall 7 has a front connection port 7 a as an example of a first connection portion and a second connection at positions corresponding to the front and rear ends of the supply chamber 2 and the stirring chamber 3. A rear-side connection port 7b is formed as an example of the portion, and the developer can flow in and out between the supply chamber 2 and the stirring chamber 3.
3 to 5, a window-like inflow window 7c formed at the upper part in the gravitational direction is formed as an example of an inflow port on the rear side of the developer discharge port 4a at the front end portion of the partition wall 7. Thus, the developer can flow into the replenishment chamber 6 from the discharge chamber 4.

  3 and 4, the developing roll R0 is an example of a magnet roll 11 as an example of a magnet member fixedly supported by the developing container body V1, and an example of a rotating member rotatably supported on the outer periphery of the magnet roll 11. And a developing sleeve 12. A gear G0 as an example of a gear is fixedly supported at the rear end of the developing sleeve 12. The developer in the supply chamber 2 is adsorbed on the surface of the developing sleeve 12 by the magnetic force of the magnet roll 11 and conveyed to the developing region Q2y.

3 and 4, the supply chamber 2 and the discharge chamber 4 are provided with a supply auger R1 as an example of a first stirring member, and the stirring chamber 3 and the replenishing chamber 6 have a second stirring. An admixing auger R2 as an example of a member is disposed.
The supply auger R1 includes a supply shaft R1a as an example of a first rotating shaft extending in the axial direction of the developing roll R0, and a supply blade R1b as an example of a first transport blade supported on the outer periphery of the supply shaft R1a. And have. A gear G1 as an example of a gear is fixedly supported at the rear end of the supply shaft R1a, and the rotation is transmitted.
In FIG. 3, in the supply auger R <b> 1 of the first embodiment, the supply blade R <b> 1 b is accommodated in the supply chamber 2 and the developer in the supply chamber 2 is first transported from the rear connection portion 7 b toward the front connection portion 7 a. It has a spiral main transport blade R1c as an example of a stirring blade transported in the direction.

At the upstream end in the first transport direction of the discharge chamber 4 that is in front of the main transport blade R1c of the supply shaft R1a, as an example of the transport regulating blade, a pitch that is a distance that travels in the axial direction when it makes one rotation is A helical low-speed conveyance blade R1d that is shorter than the conveyance blade R1c, that is, has a low conveyance speed, is supported. In the low-speed transport blade R1d of the first embodiment, the rear portion, that is, a part on the upstream side in the first transport direction is arranged in the region of the supply chamber 2 corresponding to the front connection portion 7a.
A high-speed conveyance blade R1e having a larger pitch than the low-speed conveyance blade R1d is supported on the downstream side in the first conveyance direction, which is in front of the low-speed conveyance blade R1d. In front of the high-speed conveyance blade R1e, a spiral reverse conveyance blade R1f that is wound in a reverse direction to each of the blades R1c to R1e is supported as an example of a flow rate adjustment blade. Between the high-speed conveying blade R1e and the reverse conveying blade R1f, a stirring blade R1g that is formed in a plate shape extending in the axial direction of the supply shaft R1a and agitates the developer is supported. The supply blades R1b of Example 1 are configured by the blades R1c to R1g.

The admix auger R2 is an example of the admix shaft R2a as an example of a second rotating shaft extending in the axial direction of the developing roll R0 and the supply auger R1, and an example of the second transport blade supported on the outer periphery of the admix shaft R2a. As an admix blade R2b. A gear G2, which is an example of a gear, is fixedly supported at the rear end of the admix shaft R2a, and rotation is transmitted.
In FIG. 3, in the admix auger R2 of the first embodiment, the admix blade R2b is housed in the stirring chamber 3 as an example of the stirring blade, and the developer in the stirring chamber 3 is transferred from the front connection portion 7a to the rear connection portion 7b. It has a spiral main stirring blade R2c that is transported in the second transport direction toward the side.
In the replenishment chamber 6 in front of the main stirring blade R2c of the admix axis R2a, as an example of the stirring and mixing blade, a spiral mixing blade R2d whose pitch is shorter than that of the main stirring blade R2c, that is, the conveyance speed is low. It is supported. Each of the blades R2c and R2d constitutes an admix blade R2b of the first embodiment.

  5A and 5B, the inflow window 7c of the first embodiment is formed further above the upper end in the gravity direction of the supply axis R1a of the supply auger R1 and the admixing axis R2a of the admixing auger R2. Therefore, as shown in FIG. 4, when the amount of the developer in the portion of the inflow window 7c of the discharge chamber 4 becomes larger than that of the inflow window 7c, the developer overflows and flows into the left side of the replenishment chamber 6. At this time, the inflowing developer is supplied from above the admix axis R2a.

In FIG. 3, the gear G0 supported at the rear end of the developing sleeve 12 is engaged with the gear G1 of the supply auger R1, and the gear G1 is engaged with the gear G2 of the admixing auger R2. The gear G0 receives the rotational force of a developing device motor as an example of a drive source (not shown). When the gear G0 is rotated by the motor, the gear G1 rotates in the opposite direction to the gear G0, and the gear G1 and the gear G2 Rotate in opposite directions. That is, the supply auger R1 and the admixing auger R2 that rotate together with the gear G1 and the gear G2 rotate in opposite directions as shown in FIG. Therefore, the developer in the supply chamber 2 and the stirring chamber 3 is conveyed and circulated in opposite directions by the rotation of the supply auger R1 and the admixing auger R2.
The supply auger R1 and the admix auger R2 constitute the circulating member R1 + R2 of Example 1, and the developing container V, the developing roll R0, the supply auger R1, the admix auger R2, and the like constitute a developing device Gy.

(Operation of Example 1)
In the copying machine U according to the first embodiment having the above-described configuration, when image formation is performed, the developing devices Gy to Gk are operated to rotate the developing roll R0, the supply auger R1, and the admixing auger R2.
With the rotation of the supply auger R1, in the supply chamber 2, the developer is transported in the first transport direction by the main transport blade R1c, and at the front side connection portion 7a, the speed difference between the main transport blade R1c and the low speed transport blade R1d. The developer stays. Therefore, a part of the developer flows into the discharge chamber 4 according to the transport performance of the low-speed transport blade R1d, and most of the remaining developer flows into the stirring chamber 3 through the front connection portion 7a. That is, the amount of developer conveyed to the discharge chamber 4 is regulated by the low-speed conveying blade R1d, and the main flow of the developer is from the front connection portion 7a to the stirring chamber 3 side. In particular, the low-speed conveying blade R1d according to the first embodiment is arranged so as to partially overlap the front side connection portion 7a, and it is easy for the front side connection portion 7a to generate a stay due to a speed difference. It is easy to ensure the main flow of developer.

The developer flowing into the discharge chamber 4 is conveyed while being agitated by the high-speed conveyance member R1e, and stays at the position of the outflow window 7c due to the difference in the conveyance direction between the high-speed conveyance blade R1e and the reverse conveyance blade R1f. Developer exceeding 7c flows into the supply chamber 6 side. At this time, the developer flowing into the discharge chamber 4 by the low-speed conveying blade R1d that regulates the flow rate is stable in the discharge chamber 4 even if the amount of the developer in the supply chamber 2 increases or decreases. As shown by the one-dot chain line in FIG. 5A, the height of the upper surface of the developer in the discharge chamber 4 is also stabilized. That is, the amount of developer flowing from the discharge chamber 4 into the replenishment chamber 6 is also a stable amount.
The developer that has flowed into the discharge chamber 4 includes a developer that has deteriorated due to the load in the development regions Q2y to Q2k and the conveyance in the supply chamber 2, etc., and a part of the developer is discharged from the developer discharge port 4a. The Therefore, in the developing devices Gy to Gk of Example 1, the deteriorated developer is discharged little by little from the developer discharge port 4a while supplying the developer from the supply port 6a.

  In the replenishing chamber 6, the new developer replenished from the replenishing port 6a and the developer that has flowed in from above the admix axis R2a through the inflow window 7c are mixed. At this time, the new developer that is not sufficiently agitated and is hardly charged falls to the right side of the mixing blade R2d, passes below the replenishment chamber 6 along the rotation direction of the mixing blade R2d, and moves to the left. Moving. Then, on the left side of the replenishment chamber 6, the developer that has fallen from the inflow window 7 c and that is sufficiently agitated and charged collides from the upside down direction and is mixed. Then, the developer from the replenishing port 6a and the developer from the inflow window 7c are agitated and mixed by the mixing blade R2d and conveyed toward the agitating chamber 3 at the rear. At this time, the mixing blade R2d of the first embodiment has a small pitch, and has a lower conveying speed than the main stirring blade R2c, and is sufficiently stirred and mixed while being conveyed through the replenishing chamber 6.

  In particular, in Example 1, the amount flowing in through the inflow window 7c is stable, and it is reduced that the total amount of developer in the replenishing chamber 6 becomes excessive. Therefore, as the total amount of developer in the developer container V increases or decreases, the amount of developer in the region where new developer is replenished becomes excessive, and compared to the conventional configuration in which stirring and mixing properties tend to be reduced. Developer agitation and mixing performance is improved. In the first embodiment, the average of the upper end surface of the developer in the replenishing chamber 6 is set at a position lower than the height in the gravity direction at the center of the axis of the admix axis R2a. Compared to the case, the stirring and mixing performance is improved. Therefore, in the developing devices Gy to Gk according to the first embodiment, even when the length of the replenishing chamber 6 is shorter than the conventional one, the stirring failure is reduced.

In the stirring chamber 3, the developer flowing in from the supply chamber 2 through the front connection portion 7a and the developer flowing in from the replenishing chamber 6 are mixed and stirred toward the rear connection portion 7b while being stirred by the main stirring blade R2c. Are transported. The developer conveyed to the rear end of the stirring chamber 3 flows into the supply chamber 2 through the rear connection portion 7b and is supplied to the developing roll R0.
Therefore, in the developing devices Gy to Gk of the first embodiment, the new developer replenished from the replenishing port 6a passes through the replenishing chamber 6 and the agitating chamber 3 and is stirred and mixed, and then conveyed to the supplying chamber 2. Used for development. Therefore, compared with the case where it is conveyed to the supply chamber 2 before passing through the stirring chamber 3, the stirring failure is reduced. Further, the developer discharge port 4a is not disposed in the path from the supply chamber 6 to the supply chamber 2, and the supply of the supplied developer before it is used by the developing roll R0 is reduced. .

FIG. 6 is an explanatory diagram of the developing device of the second embodiment, and corresponds to FIG. 2 of the first embodiment.
Next, a second embodiment of the present invention will be described. 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 is omitted. To do.
This embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 6, in the developing devices Gy to Gk of the second embodiment, instead of the low speed transport blade R1d of the first embodiment, as an example of the transport regulating blade, a spiral staying blade R1d that is wound in a reverse direction to the spiral of the main transport blade R1c. 'Is supported.

(Operation of Example 2)
In the developing devices Gy to Gk of Example 2 having the above-described configuration, the developer stays in the front connection portion 7a due to the difference in the transport direction between the main transport blade R1c and the stay blade R1d ′, and the supply chamber 2 The amount of developer flowing into the discharge chamber 4 is regulated, and the total amount of developer in the discharge chamber 4 is stabilized.

FIG. 7 is an explanatory diagram of the developing device of the third embodiment, FIG. 7A is an explanatory diagram corresponding to FIG. 2 of the first embodiment, and FIG. 7B is an explanatory diagram of a modified example of the third embodiment.
Next, a third embodiment of the present invention will be described. In the description of the third 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. To do.
This embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
7A, in the developing devices Gy to Gk according to the third embodiment, instead of the low-speed conveyance blade R1d according to the first embodiment, a stirring paddle R1d ″ as an example of a conveyance regulating blade configured by a stirring member extending in the radial direction is supported. The stirring paddle R1d ″ of Example 3 extends in the radial direction and is disposed along the axial direction, has no ability to transport the developer, and has only a stirring function.

(Operation of Example 3)
In the developing devices Gy to Gk of Example 3 having the above-described configuration, the developer stays at the front side connection portion 7a due to the difference in transport capability between the main transport blade R1c and the stirring paddle R1d ″ having no transport capability. The amount of developer flowing from the supply chamber 2 into the discharge chamber 4 is restricted, and the total amount of developer in the discharge chamber 4 is stabilized.
In FIG. 7B, the stirring paddle R1d ″ according to the third embodiment is not limited to a rectangular plate shape, and may have an arbitrary shape such as a triangular shape as illustrated in FIG. 7B.

FIG. 8 is an explanatory diagram of the developing device of Example 4, FIG. 8A is an explanatory diagram of the positional relationship between the partition member and the admixing auger corresponding to FIG. 5B of Example 1, and FIG. It is sectional drawing of the inflow port part corresponding to.
Next, the fourth embodiment of the present invention will be described. 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. To do.
This embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 8, the developing devices Gy to Gk of the fourth embodiment have a mixing blade R2d ′ whose outer diameter is smaller than the outer diameter of the main stirring blade R2c instead of the mixing blade R2d of the first embodiment. . Accordingly, in the fourth embodiment, the bottom surface of the replenishment chamber 6 is also raised upward as compared with the first embodiment. Therefore, in the fourth embodiment, the transport speed that is the transport amount per unit time of the developer by the mixing blade R2d ′ is lower than that in the first embodiment.
In the fourth embodiment, the diameter of the first embodiment is changed to the same admix axis R2a along the axial direction, and the large-diameter portion R2a1 ′ accommodated in the stirring chamber 3 and the large-diameter portion accommodated in the replenishing chamber 6 are used. An admix axis R2a ′ having a small-diameter portion R2a2 ′ smaller in diameter than the portion R2a1 ′ is disposed.

(Operation of Example 4)
In the developing devices Gy to Gk of Example 4 having the above-described configuration, the developer conveyance speed by the mixing blade R2d ′ having a reduced diameter is low, and the newly supplied replenished developer is sufficiently stirred and mixed. It is reduced that it is transported to the agitating chamber 3 before being carried out.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H07) of the present invention are exemplified below.
(H01) In the above-described embodiment, the printer U is a so-called printer. However, the printer U is not limited to this. For example, the printer U may be a copying machine, a FAX, or a multifunction machine having a plurality or all of these functions. Is also possible.
(H02) In the above embodiment, the printer U is not limited to a configuration in which toner of four colors is used, and can be applied to, for example, an image forming apparatus of 5 colors or more, 3 colors or less, or a single color.

(H03) In the above embodiment, the configuration of the conveyance regulating blades R1d, R1d ′, R1d ″ is not limited to the configuration illustrated in the embodiment, and any configuration can be used as long as the flow rate can be adjusted. For example, it is possible to increase the diameter of the shaft R1a corresponding to the conveyance regulating blades R1d, R1d ′, R1d ″. Similarly, in the fourth embodiment, the mixing blade R2d ′ is reduced in diameter to reduce the conveying speed. However, the present invention is not limited to this configuration, and the shaft diameter is increased or the configuration is similar to that of the stirring paddle R1d ″. It is possible to adopt an arbitrary configuration, such as adding.
(H04) In the above embodiment, the developer discharge port 4a can be omitted according to the design and specifications of the developing device.

(H05) In the embodiment, the inflow window 7c is formed on the partition wall 7 supported by the developing container main body V1, but is not limited to this configuration. For example, the inflow window 7c is formed on the partition wall extending downward from the developing container cover V2. It is possible to adopt any configuration such as. Further, the shape of the inflow window 7c is not limited to a square shape, and may be an arbitrary shape such as a triangle or a round shape.
(H06) In the above-described embodiment, the configuration using the two-component developer composed of the toner and the carrier is exemplified. However, the configuration is not limited to this configuration, and a configuration using a one-component developer composed only of the toner may be used. Is possible. Further, the high-concentration toner is exemplified as the developer replenished from the developer cartridges Ky to Kk. However, the present invention is not limited to this configuration, and only the toner is replenished, or the toner density in the developing containers Gy to Gk is supported. It is also possible to employ a configuration in which the developer having the toner density is supplied.

(H07) In the above-described embodiment, the front connection port 7a and the rear connection port 7b have a configuration in which the partition wall 7 does not exist. However, the present invention is not limited to this configuration, and the front connection port 7a and the rear connection port 7b are not limited thereto. In addition, it is also possible to adopt a configuration in which the amount of movement of the developer is adjusted by providing a wall having a height lower than that of other portions or by providing a wall that hangs down from the developer container cover V2.

1 ... holding body accommodating part,
2 ... 1st stirring part,
2 + 3 ... circulation part,
3 ... 2nd stirring part,
4 ... Inflow part,
6 ... Outflow part,
6a ... replenishment section,
7 ... partition member, circulation partition member,
7a ... 1st connection part,
7b ... second connection part,
7c ... Inlet,
BM + T2b ... transfer device,
F: Fixing device,
Gy, Gm, Gc, Gk ... developing device,
PRy, PRm, PRc, PRk ... Image carrier,
R0: developer holder,
R1 ... first conveying member,
R1c: stirring blade,
R1a ... first rotation axis,
R1b ... first conveying blade,
R1d, R1d ′, R1d ″... Conveying restriction blade,
R1d ″: stirring member,
R2 ... second conveying member,
R2a, R2a '... the second rotation axis,
R2b ... second conveying blade,
S ... medium,
U: Image forming apparatus,
V: Developer container.

Claims (10)

A developer holding body disposed opposite to an image holding body on which a latent image is formed and holding a developer on the surface;
A holding member receiving portion for storing the developer holding member; a circulating portion disposed adjacent to the holding member receiving portion for circulating the developer therein; and connected to the circulating portion and from the circulating portion. An inflow portion into which the developer flows in, and an outflow portion that is disposed adjacent to the inflow portion and is connected to the circulation portion and from which the developer flows out into the circulation portion, and contains the developer therein. A developing container,
A first rotation shaft and a first transport blade provided on the first rotation shaft, the first rotation shaft being housed in the inflow portion and transporting the developer in the inflow portion in a first transport direction; The first transport member includes a transport regulating blade that is disposed upstream of the inflow portion in the first transport direction and regulates the amount of developer transported downstream in the first transport direction. The first transport member having the transport blades;
A second rotating shaft; and a second conveying blade provided on the second rotating shaft, the developer contained in the outflow portion being in a direction opposite to the first conveying direction. A second conveying member that conveys in the second conveying direction;
An inflow port through which developer flows into the outflow portion from the inflow portion, the inflow port formed above the upper end of the second rotation shaft in the direction of gravity;
A developing device comprising: A replenishment part formed in the outflow part and into which a new developer flows;
The developing device according to claim 1, further comprising: The circulation part having a first stirring part adjacent to the holding body accommodating part and a second stirring part adjacent to the first stirring part;
The first transport member housed in the first stirring section and transporting the developer in the first stirring section in a first transport direction toward the inflow section;
The second conveying member that is accommodated in the second agitating section and conveys the developer in the outflow section in a second conveying direction that causes the developer to flow out into the second agitating section;
A first connecting portion that connects a downstream portion in the first transport direction of the first stirring portion and an upstream portion in the second transport direction of the second stirring portion; and a first connection portion of the first stirring portion. Provided between the first connecting portion and the second connecting portion connecting the upstream portion in the second conveying direction and the downstream portion in the second conveying direction of the second stirring portion. A circulation partition member for partitioning between the stirring unit and
The developing device according to claim 1, further comprising: A stirrer blade provided in a region corresponding to the first stirrer and a transport provided at a position corresponding to the upstream end of the inflow portion in the first transport direction and having a transport speed lower than that of the stirrer blade A first conveying blade having a regulating blade,
The developing device according to claim 3, further comprising: The conveyance regulating blade partially disposed in a region corresponding to the first connecting portion;
The developing device according to claim 4, further comprising: The conveyance regulating blade constituted by a stirring member extending along the axial direction of the first rotation shaft;
The developing device according to claim 4, wherein the developing device is provided. The second conveying blade in which the outer diameter of the region corresponding to the outflow portion is smaller than the outer diameter of the region corresponding to the second stirring portion;
The developing device according to claim 3, further comprising: The second conveying member in which the shaft diameter of the region corresponding to the front outflow portion is smaller than the shaft diameter of the region corresponding to the second stirring portion;
The developing device according to claim 3, further comprising: A partition member that partitions between the inflow portion and the outflow portion;
The inflow port formed in the partition member;
The developing device according to claim 1, further comprising: An image carrier on which a latent image is formed on the surface;
The developing device according to any one of claims 1 to 9, wherein the latent image on the surface of the image carrier is developed into a visible image;
A transfer device for transferring a visible image on the surface of the image carrier to a medium;
A fixing device for fixing the visible image transferred to the medium;
An image forming apparatus comprising: