JP2011022349A - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the performance of an inlet portion allowing a developer to be introduced. <P>SOLUTION: A developing device (Gy) includes: a second inlet portion (E2) allowing a developer to flow from a first storing chamber (6) to a second storing chamber (7); a first carrying member (21), which is a first carrying member (21) for carrying the developer in the first storing chamber (6) in a first carrying direction (Yb) toward a second inlet portion (E2), and includes a rotating shaft (22), a main carrying blade (23d) provided on the outer periphery of the rotating shaft (22) to carry the developer in the first carrying direction (Yb) and a circulating carrying blade (23c) disposed on the outer periphery of the rotating shaft (22) to carry the developer in the opposite direction to the first carrying direction (Yb); and a gap (SP3) formed in the axial direction of the rotating shaft (22) between the downstream end in the first carrying direction (Yb) of the main carrying blade (23d) and the upstream end in the first carrying direction (Yb) of the circulating carrying blade (23c). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  In a conventional image forming apparatus such as a copying machine or a printer, a technique described in Patent Document 1 below is conventionally known as a developing device that develops a latent image into a visible image.

  In Japanese Patent Application Laid-Open No. 2004-151354 as Patent Document 1, a first screw (40) that sends developer to the developing roller (20) and a developer conveyed in the opposite direction to the first screw (40) are circulated. In the developing device (10) having the second screw (50) to be driven, the first screw (40) includes the shaft (40s), the spiral blade portion (45), and the downstream end of the blade portion (45). Describes a technique in which a reverse-wound spiral reverse screw (45r) is provided, and a flat plate-like delivery member (48) is disposed between the blade portion (45) and the reverse screw (45r).

JP 2004-151354 A ("0043" to "0049", FIGS. 2 to 4)

  An object of the present invention is to improve the performance of allowing the developer to flow at the inflow portion.

In order to solve the technical problem, the developing device according to claim 1 is provided by:
A developer holder that rotates while holding the developer on the surface;
A first storage chamber for storing a developer supplied to the developer holder;
A second storage chamber for storing a developer that is circulated and conveyed between the first storage chamber;
A first inflow portion for allowing developer to flow into the first accommodation chamber from the second accommodation chamber;
A second inflow portion for allowing the developer to flow from the first accommodation chamber into the second accommodation chamber;
A first transport member disposed in the first storage chamber and configured to transport the developer in the first storage chamber in a first transport direction toward the second inflow portion, the rotation shaft and an outer periphery of the rotation shaft; A main conveyance blade provided corresponding to the second inflow portion from the first inflow portion and conveying the developer in the first conveyance direction, and a position corresponding to the second inflow portion on the outer periphery of the rotation shaft The first transport member, which is disposed and has a transporting blade that circulates the developer in the first storage chamber and the second storage chamber by transporting the developer in a direction opposite to the first transport direction;
A second transport member that is disposed in the second storage chamber and transports the developer in the second storage chamber in a second transport direction toward the first inflow portion;
A gap formed along the axial direction of the rotating shaft between the downstream end in the first transport direction of the main transport blade and the upstream end in the first transport direction of the circulating transport blade;
With
The downstream end in the first transport direction of the main transport blade and the upstream end in the first transport direction of the circulation transport blade are arranged at the same phase position with respect to the circumferential direction of the rotating shaft. To do.

The invention according to claim 2 is the developing device according to claim 1,
A discharge port that is formed on the downstream side in the first transport direction from the second inflow portion, and discharges the developer in the first storage chamber;
The developer in the first storage chamber disposed on the downstream side in the first transport direction with respect to the outer periphery of the rotating shaft and in the first transport direction on the downstream side with respect to the circulating transport blade is directed toward the discharge port. Waste transporting blades to be transported and discarded,
A gap formed along the axial direction of the rotating shaft between the downstream end in the first transport direction of the circulating transport blade and the upstream end in the first transport direction of the waste transport blade;
It is provided with.

The invention described in claim 3 is the developing device according to claim 1 or 2,
A discharge port that is formed on the downstream side in the first transport direction from the second inflow portion, and discharges the developer in the first storage chamber;
The developer in the first storage chamber disposed on the downstream side in the first transport direction with respect to the outer periphery of the rotating shaft and in the first transport direction on the downstream side with respect to the circulating transport blade is directed toward the discharge port. Waste transporting blades to be transported and discarded,
With
The downstream end in the first transport direction of the circulation transport blade and the upstream end in the first transport direction of the waste transport blade are arranged at the same phase position with respect to the circumferential direction of the rotating shaft. To do.

In order to solve the technical problem, an image forming apparatus according to a fourth aspect of the present invention provides:
A rotating image carrier;
A latent image forming apparatus for forming a latent image on the surface of the image carrier;
The developing device according to any one of claims 1 to 3, which develops a latent image on the surface of the image carrier 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 a visible image on the surface of the medium;
It is provided with.

According to the first aspect of the present invention, it is possible to improve the performance of allowing the developer to flow in at the inflow portion as compared with the case where there is no gap between the blades. Further, the performance of allowing the developer to flow at the inflow portion can be improved as compared with the case where the end portions of the blades are not in phase.
According to the second aspect of the present invention, the developer can be delivered smoothly as compared with the case where no gap is formed.
According to the third aspect of the present invention, the developer can be delivered smoothly compared to the case where the phase is not formed in the same phase.
According to the fourth aspect of the present invention, compared with the case where the configuration of the present invention is not provided, the performance of allowing the developer to flow in at the inflow portion can be improved.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is an enlarged explanatory view of a main part of the image forming apparatus according to the first embodiment. 3A and 3B are explanatory views of the developing device according to the first embodiment of the present invention. FIG. 3A is an explanatory cross-sectional perspective view of a main part in a state where the developing container cover is removed. FIG. 3B is an explanatory view of a supply auger. It is explanatory drawing of an auger. 4 is a cross-sectional view taken along line IV-IV in FIG. 3A. 5 is a cross-sectional view taken along line VV in FIG. 3A. 6A and 6B are explanatory views of the upstream end portion of the supply auger of the first embodiment, FIG. 6A is an enlarged view of a main part, FIG. 6B is an explanatory view of developer conveyance by blades, and FIG. It is explanatory drawing of quantity. FIG. 7 is an enlarged view of a main part of the downstream end portion of the supply auger according to the first embodiment. FIG. 8 is an explanatory view of a conventional developer conveying member, FIG. 8A is an explanatory view of a configuration in which no gap is formed, FIG. 8B is an explanatory view of a state rotated by 90 ° from the state shown in FIG. 8A, and FIG. FIG. 8D is an explanatory diagram of a state in which the phases are not aligned, and FIG. 8D is an explanatory diagram of a state rotated by 90 ° from the state shown in FIG. 8C.

Next, examples as specific examples of embodiments of the present invention will be described with reference to the drawings. However, 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 directions indicated by Z and -Z or the indicated side are defined as front, rear, right, left, upper, lower, or front, rear, right, left, upper, and lower, respectively.
In the figure, “•” in “○” means an arrow pointing 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 copier U as an example of an image forming apparatus includes an automatic document feeder U1 and an apparatus body U2 that supports the automatic document feeder U1 and has a transparent document reading surface PG at the upper end.
The automatic document feeder U1 includes a document feeding unit TG1 that stores a plurality of documents Gi to be copied, and a document feeding unit TG1 that is fed from the document feeding unit TG1 and passes a document reading position on the document reading surface PG. And a document discharge section TG2 from which the processed document Gi is discharged.
The apparatus main body U2 includes an operation unit UI for a user to input an operation command signal for starting an image forming operation, an exposure optical system A, and the like.

Reflected light from a document conveyed on the document reading surface PG by the automatic document feeder U1 or a document manually placed on the document reading surface PG is passed through the exposure optical system A by the solid-state image sensor CCD. It is converted into electrical signals of red: R, green: G, blue: B.
The information conversion unit IPS converts the RGB electrical signals input from the solid-state imaging device CCD into image information of black: K, yellow: Y, magenta: M, cyan: C, and temporarily stores the image information. The information is output to the latent image forming circuit DL as image information for forming a latent image at a preset time.
When the original image is a single color image, so-called monochrome, image information of only black: K is input to the latent image forming circuit DL.
The latent image forming circuit DL has drive circuits for the respective colors Y, M, C, and K (not shown), and signals corresponding to the input image information are set for the latent images arranged for the respective colors at a preset time. Output to the image forming apparatuses LHy, LHm, LHc, and LHk.

FIG. 2 is an enlarged explanatory view of a main part of the image forming apparatus according to the first embodiment.
Visible image forming devices Uy, Um, Uc, Uk arranged in the center of the copying machine U in the gravity direction are devices for forming visible images of Y, M, C, and K, respectively.
The Y, M, C, and K latent image writing lights Ly, Lm, Lc, and Lk emitted from the light sources of the latent image forming apparatuses LHy to LHk are respectively photoreceptors PRy, PRm, Incident on PRc and PRk. In the first embodiment, the latent image forming apparatuses LHy to LHk are configured by a so-called LED array, in which LEDs (Light Emission Diodes) as write elements are arranged in a straight line.
The Y visible image forming device Uy includes a rotating photoconductor PRy, a charger CRy, a latent image forming device LHy, a developing device Gy, a primary transfer device T1y, and a photoconductor cleaner CLy as an example of an image carrier cleaner. have. In the first embodiment, the photoconductor PRy, the charger CRy, and the photoconductor cleaner CLy are configured as an image holding unit that can be integrally attached to and detached from the apparatus main body U2.
The visible image forming apparatuses Um, Uc, Uk are all configured in the same manner as the Y visible image forming apparatus Uy.

1 and 2, the photoconductors PRy, PRm, PRc, and PRk are charged by their respective chargers CRy, CRm, CRc, and CRk, and then at the image writing positions Q1y, Q1m, Q1c, and Q1k. An electrostatic latent image is formed on the surface of the latent image writing light Ly, Lm, Lc, Lk. The electrostatic latent images on the surfaces of the photoconductors PRy, PRm, PRc, and PRk are developed in the developing regions Q2y, Q2m, Q2c, and Q2k as developing roller R0y as an example of a developer holding member of the developing devices Gy, Gm, Gc, and Gk. , R0m, R0c, and R0k are developed into a toner image as an example of a visible image.
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 units T1y, T1m, T1c, and T1k disposed on the back side of the intermediate transfer belt B in the primary transfer regions Q3y, Q3m, Q3c, and Q3k are preliminarily supplied from the power supply circuit E controlled by the control unit C. At the set time, a primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied.

  The toner images on the photoreceptors PRy to PRk are primarily transferred to an intermediate transfer belt B as an example of an intermediate transfer member by the primary transfer units T1y, T1m, T1c, and T1k. Residues and deposits on the surface of the photoreceptors PRy, PRm, PRc, and PRk after the primary transfer are cleaned by the photoreceptor cleaners CLy, CLm, CLc, and CLk. The cleaned surfaces of the photoreceptors PRy, PRm, PRc, and PRk are recharged by the chargers CRy, CRm, CRc, and CRk.

  Above the photoconductors PRy to PRk, a belt module BM as an example of an intermediate transfer device is disposed. The belt module BM includes the intermediate transfer belt B, a belt drive roll Rd as an example of an intermediate transfer member drive member, a tension roll Rt as an example of a tension applying member, a walking roll Rw as an example of a meandering prevention member, and a driven It includes an idler roll Rf as an example of a member, a backup roll T2a as an example of a secondary transfer counter member, and the primary transfer units T1y, T1m, T1c, and T1k. The intermediate transfer belt B is rotatably supported by the rolls Rd, Rt, Rw, Rf, T2a.

A secondary transfer roll T2b as an example of a secondary transfer member is disposed so as to face the surface of the intermediate transfer belt B in contact with the backup roll T2a. The backup roll T2a and the secondary transfer roll T2b constitute a secondary transfer device T2. A secondary transfer region Q4 is formed by the regions where the secondary transfer roll T2b and the intermediate transfer belt B face each other.
The single-color or multi-color toner images transferred in sequence on the intermediate transfer belt B by the primary transfer units T1y, T1m, T1c, and T1k in the primary transfer areas Q3y, Q3m, Q3c, and Q3k are the secondary transfer areas. Transported to Q4.
The primary transfer units T1y to T1k, the intermediate transfer belt B, the secondary transfer unit T2, and the like constitute a transfer device T1 + T2 + B of Example 1 that transfers an image formed on the photoconductors PRy to PRk to a medium.

  Below the visible image forming devices Uy to Uk, a pair of left and right guide rails GR as an example of a guide member is provided, and the guide rail GR has a sheet feed as an example of a sheet feeding unit. The trays TR1 to TR3 are supported so as to be able to enter and exit in the front-rear direction. The recording sheets S as an example of media stored in the paper feed trays TR1 to TR3 are taken out by a pick-up roll Rp as an example of a medium take-out member, and are separated one by one by a separating roll Rs as an example of a medium spreading member. The The recording sheet S is transported along a sheet transport path SH, which is an example of a medium transport path, by a plurality of transport rolls Ra, which is an example of a medium transport member, and is disposed upstream of the secondary transfer region Q4 in the sheet transport direction. Sent to a registration roll Rr as an example of the adjusted timing member. A sheet conveying device SH + Ra + Rr is configured by the sheet conveying path SH, the sheet conveying 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 time for the toner image formed on the intermediate transfer belt B to be conveyed to the secondary transfer area Q4. When the recording sheet S passes through the secondary transfer region Q4, the backup roll T2a is grounded, and the secondary transfer unit T2b has a polarity opposite to the toner charging polarity from the power supply circuit E controlled by the control unit C. A secondary transfer voltage is applied. At this time, the 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.

The recording sheet S on which the toner image is secondarily transferred has a fixing area Q5 which is a contact area of a heating roll Fh as an example of a heating fixing member of the fixing device F and a pressure roll Fp as an example of a pressing fixing member. And heated and fixed when passing through the fixing region. The heat-fixed recording sheet S is discharged from a discharge roller Rh as an example of a medium discharge member to a discharge tray TRh as an example of a medium discharge portion.
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 containers that store yellow Y, magenta M, cyan C, and black K developers, are disposed. Developers stored in the developer cartridges Ky, Km, Kc, Kk are replenished to the developing devices Gy, Gm, Gc, Gk according to the consumption of the developer in the developing devices Gy, Gm, Gc, Gk. Is done. In the first embodiment, the developer contained in the developing devices Gy to Gk is constituted by a two-component developer including a magnetic carrier and a toner to which an external additive is applied, and the developer cartridge Ky. From .about.Kk, so-called high-concentration toner is replenished in which the ratio of the toner to the carrier is larger than the developer in the developing devices Gy to Gk.

(Description of developing device)
3A and 3B are explanatory views of the developing device according to the first embodiment of the present invention. FIG. 3A is an explanatory cross-sectional perspective view of a main part in a state in which the developing container cover is removed. FIG. It is explanatory drawing of an auger.
4 is a cross-sectional view taken along line IV-IV in FIG. 3A.
5 is a cross-sectional view taken along line VV in FIG. 3A.
Next, the developing devices Gy, Gm, Gc, and Gk of the first embodiment of the present invention will be described. Since the developing devices Gy, Gm, Gc, and Gk of the respective colors are configured in the same manner, the development of the Y color is performed. Only the apparatus Gy will be described in detail, and detailed descriptions of the other color developing apparatuses Gm, Gc, Gk will be omitted.
2 to 5, the developing device Gy arranged to face the photoconductor PRy has a developing container V that contains a two-component developer containing toner and a carrier. The developer container V includes a developer container body 1, a developer container cover 2 as an example of a lid member that closes the upper end of the developer container body 1 as shown in FIG. 4, and a front end of the developer container body 1 as shown in FIG. And a feed / disposal cylinder 3 as an example of a feed / discard unit connected to the. In FIG. 4, the developing container V of Example 1 has an opening V1 corresponding to the developing region Q2y facing the photoconductor PRy and is open.

2 to 4, the developing container main body 1 includes a developing roll chamber 4 as an example of a holding body containing portion and a first stirring chamber as an example of a first containing chamber adjacent to the developing roll chamber 4. 6 and a second stirring chamber as an example of a second storage chamber disposed adjacent to the lower right of the first stirring chamber 6 in order to reduce the size of the developing container V in the horizontal direction and the vertical direction. 7. The developing roll chamber 4 accommodates a developing roll R0y as an example of a developer holder, and the developing roll R0y has a part of the outer surface exposed to the photoconductor PRy side through the opening V1, The photoconductor PRy is disposed so as to face the photoconductor PRy. A layer thickness regulating member 8 for regulating the layer thickness of the developer on the surface of the developing roll R0y is provided on the upstream side in the rotation direction of the developing roll R0y.
In FIG. 4, at both front and rear ends of the developing container V, on the side facing the photoconductor PRy, an abutting member Va for making the interval between the developing roll R0y and the photoconductor PRy a predetermined interval, so-called A tracking member is supported.

  In FIG. 3, a supply / disposal chamber 6 a inside the supply / discharge cylinder 3 is connected to the front side of the first stirring chamber 6, and a replenishment chamber 7 a inside the supply / discharge cylinder 3 is connected to the front side of the second stirring chamber 7. Is connected. In FIG. 3, a developer replenishing port 3a as an example of a new developer inflow portion for replenishing the developer from the developer cartridges Ky, Km, Kc, Kk is provided on the upper surface of the front end portion of the supply / disposal chamber 6a. Is formed. 3 and 5, a developer discharge port 3b as an example of a developer discharge portion is formed on the lower surface of the rear portion of the supply / disposal chamber 6a, and the deteriorated development inside the developer discharge port 3b. As the agent is discharged, the internal carrier is changed little by little.

As shown in FIG. 3, in the developing container main body 1, a partition wall 9 is formed between the first stirring chamber 6 and the second stirring chamber 7 at a portion other than both end portions. 3 and 4, the first stirring chamber 6 and the second stirring chamber 7 include a rising inflow portion E1 as an example of a first inflow portion disposed at the rear end portion and a second inflow portion disposed at the front side. This is communicated with a descending inflow portion E2 as an example of the portion, and is configured such that the developer can be circulated. An opening forming member 11 having an opening for adjusting the amount of inflow is attached to the descending inflow portion E2.
In FIG. 3A, in Example 1, the rising inflow portion E1 is disposed at a position overlapping the width L1 of the developing region Q2y where development is performed by the developing roll R0y, and the falling inflow portion E2 is partially overlapped. Are arranged.

Further, in the developer supply / discharge cylinder 3, a partition wall 12 is formed between the supply / discharge chamber 6a and the replenishment chamber 7a. Therefore, as shown in FIG. 3, the supply / disposal chamber 6a and the replenishment chamber 7a are connected by a replenishment inflow portion E3 as an example of the third inflow portion, and the developer flows into the replenishment chamber 7a from the supply / disposal chamber 6a. It is configured to be possible.
The first stirring chamber 6 and the second stirring chamber 7 constitute a circulation stirring chamber 6 + 7.

3 and 4, a supply auger 21 as an example of a supply member that supplies the developer roll R <b> 0 y as an example of a first transfer member that conveys the developer while stirring the developer is provided in the first stirring chamber 6. Has been placed.
3A and 3B, the supply auger 21 includes a first rotating shaft 22 extending parallel to the axial direction of the developing roll R0y, and a spiral first conveying blade supported on the outer periphery of the first rotating shaft 22. 23. The 1st conveyance blade 23 is arranged corresponding to the 1st replenishment conveyance blade 23a as an example of the conveyance blade arranged corresponding to the front end part of supply / discarding room 6a, and the rear part from the central part of supply / discarding room 6a Circulation as an example of the reverse conveyance unit for circulation disposed corresponding to the waste conveyance blade 23b as an example of the fourth conveyance unit and the rear end portion of the supply / disposal chamber 3a to the front side of the descending inflow portion E2 It has the conveyance blade 23c and the 1st main conveyance blade 23d as an example of the 1st conveyance part arrange | positioned corresponding to the rear end of the 1st stirring chamber 6 from the descent | fall inflow part E2.

Each of the transport blades 23a to 23d of the first embodiment is formed in a spiral shape, and includes a first supply transport blade 23a and a waste transport blade 23b, a waste transport blade 23b and a circulation transport blade 23c, and a circulation transport blade 23c. The first main transport blades 23d are each composed of a spiral wound in the reverse direction.
Further, the distance that the developer moves in one rotation of the first main transport blade 23d, that is, the interval between the blades adjacent in the axial direction, the so-called pitch, is set to be larger than each of the transport blades 23a to 23c. Further, in FIGS. 4 and 5, in Example 1, the cross-sectional area of the supply / disposal chamber 6a is smaller than that of the first stirring chamber 6, and as a result, as shown in FIG. The outer diameters of the replenishment conveyance blades 23a and the waste conveyance blades 23b arranged in the supply / disposal chamber 6a are larger than the outer diameters of the circulation conveyance blades 23c and the first main conveyance blades 23d arranged in the one stirring chamber 6. It is getting smaller.
Further, as shown in FIG. 4, the supply auger 21 of the first embodiment moves in the upward inflow portion E1 in the order of the upper direction in the gravity direction, the second developer storage chamber side, and the lower direction in the gravity direction, and will be described later with reference to FIG. The same movement occurs in the replenishment inflow portion E3.

6A and 6B are explanatory views of the upstream end portion of the supply auger of the first embodiment, FIG. 6A is an enlarged view of a main part, FIG. 6B is an explanatory view of developer conveyance by blades, and FIG. It is explanatory drawing of quantity.
In FIG. 3B and FIG. 6, 1 of the spiral first main transport blade 23 d at the rear end that is the upstream end with respect to the first transport direction Yb that is the developer transport direction by the first main transport blade 23 d. The rear end blade 23d1 of the winding has a larger pitch than the other parts. Therefore, the rear end blade 23d1 of the first main transport blade 23d is inclined toward the first rotation shaft 22 side, that is, in a so-called sleeping state, compared to the other portions. Therefore, the rear end blade 23d1 has a lower ability to convey the developer in the axial direction and a higher ability to send the developer to the developing roll R0y side as compared with the other portions.

3B and 6, an upstream end paddle 23 e is provided at the rear end portion of the supply auger 21 as an example of an end feed blade. The upstream end paddle 23 e of the first embodiment is formed in a plate shape extending along the axial direction of the first rotation shaft 22. Further, the upstream end paddle 23e is connected to the rear end blade 23d1 at the upstream end, and the downstream end surface 23e1 is formed with a gap SP1 between the upstream end paddle 23e and the first main transport blade 23d on the downstream side. Furthermore, in the first embodiment, the downstream end surface 23e1 of the upstream end paddle 23e is formed so as to be inclined in a direction in which the outer end in the radial direction is away from the first rotation shaft 22 as it goes to the rear side which is the upstream side. Yes.
In the upstream end paddle 23e of the first embodiment, the outer diameter of the upstream end paddle 23e except for the inclined downstream end surface 23e1 is set to the same outer diameter as that of the first main conveying blade 23d. The upstream end paddle 23e is disposed corresponding to the rising inflow portion E1, and the upstream end paddle 23e and the rising inflow portion E1 are disposed so as to partially overlap.

3B and 6, a small blade 23 f is provided in front of the upstream end paddle 23 e as an example of an auxiliary blade. The small blades 23 f of the first embodiment are formed in a plate shape extending along the axial direction of the first rotation shaft 22. Further, the small blade 23f is connected to the first main transport blade 23d at the downstream end, and the upstream end surface 23f1 is formed with a gap SP2 between the first main transport blade 23d on the upstream side. Yes. Further, in the first embodiment, the upstream end surface 23f1 of the small blade 23f is formed so as to be inclined in a direction in which the outer end in the radial direction is away from the first rotation shaft 22 as it goes to the front side which is the downstream side.
In addition, the small blade 23f of Example 1 is formed so that the outer diameter of the small blade 23f of the portion excluding the inclined upstream end surface 23f1 is smaller than that of the first main transport blade 23d and the upstream end paddle 23e. Yes.

Further, the small blade 23f is disposed on the downstream side of the rising inflow portion E1, and the tip of the upstream end surface 23f1 of the small blade 23f is disposed in the vicinity of the downstream end of the rising inflow portion E1. A part of the upstream end surface 23f1 of the small blade 23f may be disposed so as to overlap the rising inflow portion E1, or may be disposed so that the rising inflow portion E1 and the small blade 23f do not overlap.
Furthermore, in the supply auger 21 of the first embodiment, the two small blades 23f are arranged at positions that are 180 ° out of phase with respect to the rotation direction of the first rotation shaft 22.

FIG. 7 is an enlarged view of a main part of the downstream end portion of the supply auger according to the first embodiment.
3B and 7, in the supply auger 21 of the first embodiment, the front end 23d2 that is the downstream end of the first main transport blade 23d and the rear end 23c1 that is the upstream end of the circulation transport blade 23c are in the first rotation. The shaft 22 is disposed at a position separated in the axial direction, and a gap SP3 is formed between the front end 23d2 and the rear end 23c1. The front end 23 d 2 of the first main transport blade 23 d and the rear end 23 c 1 of the circulation transport blade 23 c are formed in the same phase with respect to the rotation direction of the first rotation shaft 22.
In the first embodiment, the circulation conveyance member 23c is formed for two turns that make two turns around the first rotation shaft 22. That is, the number of turns is set to 2.

Similarly, the front end 23c2 of the circulation conveyance blade 23b and the rear end 23b1, which is the upstream end of the waste conveyance blade 23b, are arranged at positions away from each other in the axial direction to form a gap SP4. The front end 23 c 2 of the circulation conveyance blade 23 b and the rear end 23 b 1 of the waste conveyance blade 23 b are formed in the same phase with respect to the rotation direction of the first rotation shaft 22.
In the first embodiment, in the supply auger 21, the first rotating shaft 22 and the first conveying blade 23 are integrally formed of resin. However, the shaft and the conveying blade can be separately assembled and assembled. is there. Furthermore, in the first embodiment, each of the conveying blades 23a to 23d is provided on one first rotating shaft 22, but is not limited to this configuration. For example, the first replenishing conveying blade 23a and its rotating shaft The waste conveying blade 23b and its rotating shaft, the circulating conveying blade 23c and its rotating shaft, and the first main stirring and conveying blade 23d and its rotating shaft can be configured separately.

  3A and 3C, a stirring auger 26, which is an example of a second transporting member that transports the developer while stirring and is an example of a stirring member that stirs the developer, is disposed in the second stirring chamber 7. Has been. The stirring auger 26 includes a second rotating shaft 27 extending along the axial direction of the developing roll R0y, and a spiral second conveying blade 28 supported on the outer periphery of the second rotating shaft 27. The second conveying blades 28 are arranged in correspondence with the replenishing chamber 7a, the second replenishing conveying blades 28a, and the second main conveying disposed correspondingly from the descending inflow portion E2 to the front side of the ascending inflow portion E1. It has the blade | wing 28b and the reverse conveyance blade | wing 28c arrange | positioned at the rear-end part of the 2nd stirring chamber 7. FIG.

In the first embodiment, the blades 28a to 28c are formed in a spiral shape, and the pitch of the second main transport blades 28b is set larger than the pitch of the transport blades 23a to 23c. Similarly to the rear end portion of the first main transport blade 23d, the reverse transport blade 28c has a larger pitch on the front side than the other portions. It is in a state of sleeping in the axial direction. Therefore, in the front end portion of the reverse conveying blade 28c, the ability to convey the developer in the axial direction is reduced and the ability to pump the developer to the supply auger 21 side is higher than the other portions.
Further, as shown in FIG. 3, a plurality of flat stirring members 28d are supported by the second rotating shaft 28 at predetermined intervals in an area where the second main conveying blade 28b is provided. Has been. The stirring member 28d has a greater conveying force in the circumferential direction than the conveying force along the axial direction of the second rotating shaft 28. In particular, in the first embodiment, the agitating member 28d has moved along the second rotating shaft 28. It is composed of a plate-like member, and there is almost no axial conveying force by the stirring member 28d.

  In addition, the stirring auger 26 of the first embodiment is also integrally formed in the same manner as the supply auger 21. Further, in the first embodiment, each of the blades 28a to 28c is provided on one second rotating shaft 27, but is not limited to this configuration. For example, the second replenishing conveying blade 28a and its rotating shaft, The second main conveying blade 28b and its rotating shaft, and the reverse conveying blade 28c and its rotating shaft can be configured separately.

  When each of the conveying members 21 and 26 rotates, the developer replenished from the developer replenishing port 3a flows into the replenishing inflow portion E3 by the first replenishing conveying blade 23a and the waste conveying blade 23b, and enters the replenishing chamber 7a. Be transported. The developer transported to the replenishing chamber 7a is transported to the second stirring chamber 7 in the developing container body 1 by the second replenishing transport blade 28a, and transported in the second transport direction Ya by the second main transport blade 28b. Is done. The developer transported to the rising inflow portion E1 stays and increases in developer amount due to the second main transport blade 28b and the reverse transport blade 28c transported in the direction opposite to the second transport direction. It flows into the upper first stirring chamber 6. At this time, in Example 1, since the second stirring chamber 7 is disposed adjacent to the lower right side of the first stirring chamber 6, the rotation direction of the stirring auger 26 disposed in the second stirring chamber 7 is changed. 4 is set in a clockwise direction, that is, in a direction rotating in the order of the gravity direction downward, the side facing the first stirring chamber 6, and the gravity direction upward. The blade 28c is transported so as to be lifted toward the upper left, that is, toward the first stirring chamber 6, and the flow into the first stirring chamber 6 is assisted.

The developer that has flowed into the first stirring chamber 6 is transported by the first main transport blade 23d in the first developer transport direction Yb that is opposite to the second developer transport direction Ya. The developer conveyed through the first stirring chamber 6 adheres to the surface of the developing roll R0y during conveyance and is used for development. The developer conveyed to the descending inflow portion E2 stays in the descending inflow portion E2 by the circulation conveyance blade 23c that attempts to convey the developer in the direction opposite to the first developer conveying direction Yb, and descends due to gravity. It flows into the second stirring chamber 7 through E2. As a result, the developer in the circulation stirring chamber 6 + 7 is circulated and conveyed by the stirring members 21 and 26 while being stirred.
Further, when the developer in the descending inflow portion E2 increases, a part of the developer may not be transported in the reverse direction by the circulation transport blade 23c, and may flow into the waste transport blade 23b on the supply / discharge chamber 7a side. In this case, the developer that has flowed into the waste conveyance blade 23b beyond the circulation conveyance blade 23c is conveyed to the developer discharge port 3b by the waste conveyance blade 23b and discarded. Therefore, the developer deteriorated by receiving a load during development is gradually discarded from the developer discharge port 3b.

(Operation of Example 1)
In the copying machine U according to the first embodiment having the above-described configuration, the developer circulated in the developing devices Gy to Gk is pumped up and pumped up in the direction opposite to the gravitational direction at the ascending inflow portion E1. The developed developer is conveyed downstream by the supply auger 21. Therefore, in the developing devices Gy to Gk in which the rising inflow portion E1 is within the width L1 of the developing regions Q2y to Q2k, if the pumped developer is transported too quickly by the supply auger 21, the rear end portion of the developing roll R0y. Insufficient developer may cause insufficient supply to the developing rolls R0y to R0k, resulting in poor image formation. Here, in the first embodiment, the upstream end paddle 23e having no ability to convey the developer is disposed corresponding to the ends of the developing rolls R0y to R0k, and the developer pumped up to the first stirring chamber 6 is disposed. The upstream end paddle 23e sends the developer toward the developing rolls R0y to R0k. Accordingly, insufficient supply of developer at the end portions of the developing rolls R0y to R0k is reduced, and uneven development and uneven density in the axial direction of the developing rolls R0y to R0k are reduced.

In the first embodiment, the rear end blade 23d1 of the first main stirring blade 23d has a smaller inclination angle than the other parts, approaches the upstream end paddle 23e, and has a reduced conveying capacity. Therefore, the developer is easily supplied to the end portions of the developing rolls R0y to R0k, and insufficient supply of the developer is reduced.
Furthermore, in the first embodiment, a gap SP1 is formed between the downstream end surface 23e1 of the upstream end paddle 23e and the first main conveying blade 23d on the downstream side. Accordingly, it is possible to prevent the developer transport capability from being excessively lowered as compared with the case where the gap SP1 is not formed, and the shortage of developer on the downstream side of the upstream end paddle 23e is reduced. .

  Further, in the first embodiment, the downstream end surface 23e1 of the upstream end paddle 23e is formed to be inclined so that the diameter increases as going backward. Therefore, when the downstream end surface 23e1 does not incline and extends in the radial direction perpendicular to the first rotation shaft 22, the developer conveying force changes discontinuously at the downstream end 23e1. In the supply auger 21 of the first embodiment in which the downstream end surface 23e1 is inclined, the transport force gradually changes, and the developing roll R0y is slightly uneven in density at the ends of the developing rolls R0y to R0k. The occurrence of uneven density at the end of ~ R0k is reduced.

  Furthermore, in Example 1, the small blades 23f are formed on the downstream side of the upstream end paddle 23e, and the developer conveying force is reduced. Therefore, the upstream end paddle 23e has a reduced transport capability, and less developer is transported to the downstream side where the small blades 23f are disposed than in the configuration without the upstream end paddle 23e. For example, when the total amount of the developer in the developing devices Gy to Gk is decreased by continuing the development with the developer cartridges Ky to Kc being emptied, the developer on the downstream side of the upstream end paddle 23e. There is a possibility of shortage of supply. On the other hand, in Example 1, the small blade 23f having a small developer carrying capacity is arranged on the downstream side of the upstream end paddle 23e, the carrying ability is reduced, and the developer is easily accumulated. Supply shortage has been reduced. In particular, the small blades 23f of the first embodiment are formed to have a short radial length, and have a smaller function of lowering the conveyance capacity than the upstream end paddle 23e. It is set so that supply shortages are unlikely to occur on the downstream side.

Further, the small blade 23f of the first embodiment extends upstream from the first main transport blade 23d. That is, when the spiral first main transport blade 23d transports the developer, as shown in FIG. 6B, the developer is pushed downstream on the downstream surface of the first main transport blade 23d. A relatively large amount of developer is present on the downstream side of the first main transport blade 23d, but there is little developer on the upstream side, resulting in a developer distribution as shown in FIG. 6C. Cheap. Correspondingly, in the first embodiment, a small blade 23f is provided on the upstream side of the first main transport blade 23d, where the developer tends to decrease, so that the developer is easily retained, and the developer distribution varies. Unevenness is reduced.
Further, the small blade 23f of the first embodiment has a gap SP2 formed between the small main blade 23d and the first main transport blade 23d, and similarly to the upstream end paddle 23e, it is reduced that the transport force is too low. . Further, the upstream end surface 23f1 of the small blade 23f of the first embodiment is configured to be inclined so that the radius becomes larger toward the downstream side, and the conveying ability is discontinuous like the upstream end paddle 23e. The change is prevented, and the occurrence of density unevenness is reduced.

FIG. 8 is an explanatory view of a conventional developer conveying member, FIG. 8A is an explanatory view of a configuration in which no gap is formed, FIG. 8B is an explanatory view of a state rotated by 90 ° from the state shown in FIG. 8A, and FIG. FIG. 8D is an explanatory diagram of a state in which the phases are not aligned, and FIG. 8D is an explanatory diagram of a state rotated by 90 ° from the state shown in FIG. 8C.
In FIG. 8, in the conventional developer conveying member, the end portions of the conveying blades 01 and 02 that convey the developer in opposite directions are partially overlapped along the axial direction as shown in FIGS. 8A and 8B. 8C and 8D, the phases of the end portions are not aligned, or both are formed.
8A and 8B, when the front end 01a of the first main transport blade 01 is provided to the front of the rear end 02a of the circulation transport blade 02, as in the gap SP3 of the first embodiment shown in FIG. There is no gap provided with no blades along the axial direction. Therefore, the developer transported in the first transport direction 03 by the first main transport blade 01 collides with the developer transported in the reverse direction 04 by the circulation transport blade 02 without decreasing the transport speed and stays there. To do. Therefore, the developer is subjected to a load, and there is a possibility that the deterioration is accelerated.

  On the other hand, in the supply auger 21 of the first embodiment shown in FIG. 7, the blades are arranged along the axial direction between the front end 23d2 of the first main transport blade 23d and the circulation transport blade 23c. There is no gap SP3, and the developer conveyed by the first main conveyance blade 23d collides with the developer from the downstream circulation conveyance blade 23c in a state where the conveyance speed is lowered in the gap SP3. Therefore, in Example 1, the deterioration of the developer in the descending inflow portion E2 is reduced as compared with the supply auger that does not have the gap SP3. Further, as compared with a supply auger having no gap SP3, the developer conveyed by the first main conveying blade 23d is likely to stay in the gap SP3, and the performance of flowing the developer into the descending inflow portion E2 is improved. Yes.

  8C and 8D, when the phases are not aligned, or as shown in FIGS. 8A and 8B, the front end 01a of the first main transport blade 01 is more than the rear end 02a of the circulation transport blade 02. In the case where it is provided to the front, the developer sent in the reverse direction 04 at the rear end 02a of the circulation conveyance blade 02 is pushed by the first main conveyance blade 01 and enters the upstream side of the circulation conveyance blade 02. To be returned. Accordingly, it becomes difficult for the developer to be sufficiently retained at the boundary portion between the first main transport blade 01 and the circulation transport blade 02, and the developer moves so as to reciprocate in the same place, from the descending inflow portion E2. The developer does not easily flow out, and the replacement of the developer does not proceed smoothly and is likely to deteriorate.

  On the other hand, in the supply auger 21 of Example 1 shown in FIG. 7, the front end 23d2 of the first main transport blade 23d and the rear end 23c1 of the circulation transport blade 23c are set in the same phase. Compared to the cases shown in FIGS. 8A to 8D, the developer is prevented from returning to the opposite side. Therefore, the developer tends to stay in the gap SP3, and the performance of the developer flowing into the descending inflow portion E2 is improved. Further, the developer is prevented from reciprocating in the same place, the developer is smoothly replaced, and the deterioration is reduced. In particular, even when the developer conveying speed of the supply auger 21 is increased, the ability of returning the developer conveyed by the first main conveying blade 23d to stay and flow in is sufficiently maintained, and the developer Replacement is circulated and degradation is reduced.

In FIG. 7, in the supply auger 21 according to the first embodiment, the front end 23c2 of the circulation conveyance blade 23b and the front end 23c2 of the circulation conveyance blade 23b and the waste conveyance blade 23b are similar to the front end 23d2 of the first main conveyance blade 23d and the rear end 23c1 of the circulation conveyance blade 23c. A clearance SP4 is formed between the upstream end and the rear end 23b1, and the front end 23c2 of the circulation conveyance blade 23b and the rear end 23b1 of the waste conveyance blade 23b are formed in the same phase. Therefore, even in the region corresponding to the gap SP4, the developer transport speed is reduced, the replacement is performed smoothly, and the deterioration of the developer is reduced.
In FIG. 7, in the supply auger 21 according to the first embodiment, the number of turns of the circulation conveyance member 23 c is 2, and the developer is supplied to the descending inflow portion E2 side as compared with the case of 1 turn or 1.5 turns. The ability to send to is high. Therefore, even when the image forming speed of the copying machine U, so-called productivity, increases, and the transport speed by the first main transport blade 23d increases, the developer is sent to the descending inflow portion E2, and the circulating transport member 23c is passed through. Excessive developer discharged from the discharge port 3b is reduced.

  Furthermore, in the supply auger 21 according to the first embodiment, the developer transport speed is reduced in the region corresponding to the gap SP4, and the developer tends to stay. Accordingly, the total amount of developer in the developing container V temporarily increases, and there may be an increase in the amount of developer that flows into the gap SP4 beyond the circulating conveyance blade 23c. The amount of the developer staying in the gap SP4 may be larger than the area of the transport blade 23c and the waste transport blade 23b. At this time, the circulation conveyance blade 23c of Example 1 is formed in two turns, and in the state where the circulation conveyance blade 23c makes one rotation, the developer in the gap SP4 is in an intermediate portion between the gap SP4 and the descending inflow portion E2. Be transported. If the circulation conveyance blade 23c is 1 turn, and the developer in the gap SP4 is locally increased, if the locally increased developer is conveyed to the descending inflow portion E2 in one rotation, The developer collides with the developer conveyed by the first main conveying blade 23d, so that the load on the developer is large and the developer tends to deteriorate. In contrast, in the first embodiment, when the developer in the gap SP4 is conveyed by the circulation conveyance blade 23c, the developer is relatively small in the first rotation compared to the gap SP4 and the descending inflow portion E2. It is transported to an intermediate portion between the gap SP4 and the descending inflow portion E2, leveled, and transported to the descending inflow portion E2 in the second rotation, and the load and deterioration on the developer are reduced.

(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 (H011) of the present invention are exemplified below.
(H01) Although the copying machine as an example of the image forming apparatus has been illustrated in the above embodiment, the present invention is not limited to this. For example, the copying machine is configured by a printer, a FAX, or a multifunction machine having a plurality or all of these functions. It is also possible.
(H02) In the above embodiment, the copying machine U has exemplified the configuration in which four color developers are used. However, the present invention is not limited to this. For example, a single color image forming apparatus, five or more colors, or three colors or less. The present invention can also be applied to a multicolor image forming apparatus.

(H03) In the above-described embodiment, it is desirable to provide the gaps SP1 and SP2 between the upstream end paddle 23e or the small blade 23f and the first main transport blade 23d. However, the first main transport blade is eliminated by eliminating the gap. It is also possible to connect to 23d. Conversely, one end is connected to the main transport blade 23d, but both ends may be separated from the main transport blade 23d.
(H04) In the above embodiment, it is desirable to incline the end faces 23e1, 23f1 of the upstream end paddle 23e and the small blades 23f, but it is also possible to use end faces that extend in the radial direction without being inclined.

(H05) In the above-described embodiment, it is desirable to provide the small blade 23f, but it may be omitted.
(H06) In the above-described embodiment, the upstream end paddle 23e and the small blade 23f are formed in a plate shape extending in the axial direction. However, the present invention is not limited to this configuration. It is also possible to configure with a plate.
(H07) In the above embodiment, the developing devices Gy to Gk in which the first stirring chamber 6 and the second stirring chamber 7 are arranged obliquely are illustrated, but the present invention is not limited to this configuration, and the first stirring chamber 6 and the first stirring chamber 6 The present invention can also be applied to a developing device in which the two stirring chambers 7 are arranged in the horizontal direction or the gravity direction.

(H08) In the above embodiment, it is desirable that the shape of the rear end blade 23d1 of the first main transport blade 23d is a shape lying on the first rotating shaft 22 side rather than the shape of the other portions. It is not limited to a structure, It is also possible to make it the same as the shape of another part.
(H09) In the above-described embodiment, the spiral blade is illustrated as the first main transport blade 23d, but is not limited to this configuration. For example, a semicircular plate is inclined to the first rotation shaft 22 It is also possible to adopt a configuration that supports the state.

(H010) In the above-described embodiment, the number of turns, the pitch, and the like of each of the spiral blades 23a to 23d and 28a to 28c are not limited to the configuration illustrated in the embodiment, and can be arbitrarily changed according to the design, specifications, and the like. .
(H011) In the above embodiment, it is desirable to provide the upstream end paddle 23e, but it can be omitted.

3b ... discharge port,
6 ... first containment chamber,
7 ... Second containment chamber,
21 ... 1st conveyance member,
22 ... Rotating shaft 23b ... Waste conveying blade
23c ... circulation conveyance blade,
23d ... main conveying blade,
26 ... second conveying member,
E1 ... 1st inflow part,
E2 ... second inflow part,
F: Fixing device,
Gy, Gm, Gc, Gk ... developing device,
LHy, LHm, LHc, LHk ... latent image forming device,
PRy, PRm, PRc, PRk ... Image carrier,
R0y, R0m, R0c, R0k ... developer holder,
SP3, SP4 ... clearance,
T1 + T2 + B ... transfer device,
U: Image forming apparatus,
Ya: second transport direction,
Yb ... 1st conveyance direction.

Claims (4)

A developer holder that rotates while holding the developer on the surface;
A first storage chamber for storing a developer supplied to the developer holder;
A second storage chamber for storing a developer that is circulated and conveyed between the first storage chamber;
A first inflow portion for allowing developer to flow into the first accommodation chamber from the second accommodation chamber;
A second inflow portion for allowing the developer to flow from the first accommodation chamber into the second accommodation chamber;
A first transport member disposed in the first storage chamber and configured to transport the developer in the first storage chamber in a first transport direction toward the second inflow portion, the rotation shaft and an outer periphery of the rotation shaft; A main conveyance blade provided corresponding to the second inflow portion from the first inflow portion and conveying the developer in the first conveyance direction, and a position corresponding to the second inflow portion on the outer periphery of the rotation shaft The first transport member, which is disposed and has a transporting blade that circulates the developer in the first storage chamber and the second storage chamber by transporting the developer in a direction opposite to the first transport direction;
A second transport member disposed in the second storage chamber and transporting the developer in the second storage chamber in a second transport direction toward the first inflow portion;
A gap formed along the axial direction of the rotating shaft between the downstream end in the first transport direction of the main transport blade and the upstream end in the first transport direction of the circulating transport blade;
With
The downstream end in the first transport direction of the main transport blade and the upstream end in the first transport direction of the circulation transport blade are arranged at the same phase position with respect to the circumferential direction of the rotating shaft. Developing device. A discharge port that is formed on the downstream side in the first transport direction from the second inflow portion, and discharges the developer in the first storage chamber;
The developer in the first storage chamber disposed on the downstream side in the first transport direction with respect to the outer periphery of the rotating shaft and in the first transport direction on the downstream side with respect to the circulating transport blade is directed toward the discharge port. Waste transporting blades to be transported and discarded,
A gap formed along the axial direction of the rotating shaft between the downstream end in the first transport direction of the circulating transport blade and the upstream end in the first transport direction of the waste transport blade;
The developing device according to claim 1, further comprising: A discharge port that is formed on the downstream side in the first transport direction from the second inflow portion, and discharges the developer in the first storage chamber;
The developer in the first storage chamber disposed on the downstream side in the first transport direction with respect to the outer periphery of the rotating shaft and in the first transport direction on the downstream side with respect to the circulating transport blade is directed toward the discharge port. Waste transporting blades to be transported and discarded,
With
The downstream end in the first transport direction of the circulation transport blade and the upstream end in the first transport direction of the waste transport blade are arranged at the same phase position with respect to the circumferential direction of the rotating shaft. The developing device according to claim 1 or 2. A rotating image carrier;
A latent image forming apparatus for forming a latent image on the surface of the image carrier;
The developing device according to any one of claims 1 to 3, which develops a latent image on the surface of the image carrier 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 a visible image on the surface of the medium;
An image forming apparatus comprising:

Images