JP6950225B2 - Develop equipment, assembly and image forming equipment - Google Patents

Description

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

The developing apparatus described in Patent Document 1 is a developing apparatus including a stirring member for transporting and stirring the developing agent and a developing agent carrier, and is a developing agent replenishing tank for supplying the developing agent to the developing tank and a trickle. It is equipped with a discharge mechanism of the type, and the transport path is the first connecting path connecting the upper transport path, the lower transport path, the downstream side of the upper transport path and the upstream side of the lower transport path, and the lower transport path. It includes a second connecting path connecting the downstream side and the upstream side of the upper transport path, and includes a circulation path in which the developer circulates through the upper transport path, the first connecting path, the lower transport path, and the second connecting path. , The discharge mechanism is arranged at the downstream end of the upper transport path, the bottom surface on the downstream side of the upper transport path is located above the bottom surface on the upstream side of the lower transport path, and the first connecting path is on the horizontal plane. On the other hand, it is arranged diagonally downward.

Japanese Unexamined Patent Publication No. 2009-198760

An object of the present invention is to suppress variations in the amount of the developer in the transport direction of the developing device, as compared with the case where the partition plate partitions the supply path and the stirring path from the lower end to the upper end in the supply path of the developing apparatus. ..

The developing apparatus according to the first aspect is provided in a housing having a stirring path formed on one side and a supply path formed alongside the stirring path on the other side, and the stirring path. The stirring member, the supply member provided in the supply path, the upstream side connecting path and the downstream side provided in the housing, partitioning the stirring path and the supply path, and connecting the stirring path and the supply path. It has a partition plate that is sandwiched between the connecting paths and a flow path that is provided above the partition plate and connects the supply path and the stirring path.

The developing apparatus according to the second aspect is the developing apparatus according to the first aspect , wherein a plurality of the flow paths are arranged at intervals from each other.

The developing apparatus according to the third aspect is the developing apparatus according to the second aspect. It is getting smaller.

The developing apparatus according to the fourth aspect is the developing apparatus according to the second or third aspect , wherein the stirring member includes a spiral blade and a plate-shaped member extending in the axial direction of the stirring member. The plurality of flow paths are arranged so that a part or all of them face each other with respect to the plate-shaped member.

The developing device according to a fifth aspect, in the developing device according to any one aspect of the fourth embodiment from the first embodiment, the lower side surface of the flow path of the partition plate, projecting above the agitation path It also has an eaves to do.

The developing apparatus according to the sixth aspect is the developing apparatus according to the fifth aspect , wherein the eave has a base portion connected to the partition plate and a tip portion protruding above the stirring path, and the eaves. The upstream side of the stirring path is inclined from the base portion to the tip portion and from the upstream side to the downstream side in the transport direction of the developer.

The assembly according to the seventh aspect is any one of the first to sixth aspects , wherein the image holder on which the latent image is formed and the latent image formed on the outer peripheral surface of the image holder are developed as a toner image. It is assembled so as to be integrally replaceable with the image forming apparatus main body, including the developing apparatus according to one aspect.

The image forming apparatus according to the eighth aspect forms a latent image on an image holder, a charging device that charges the outer peripheral surface of the image holder, and an outer peripheral surface of the image holder charged by the charging device. comprising a latent image forming device, a developing device according to the first aspect in any one of the sixth aspect of developing the latent image as a toner image, and a transfer device for transferring the toner image to a transfer member It is a thing.

According to the configuration of the first aspect , it is possible to suppress variations in the transport amount of the developer in the transport direction, as compared with the case where the partition plate partitions the supply path and the stirring path from the lower end to the upper end.

According to the configuration of the second aspect , it is possible to suppress the variation in the transport amount in the transport direction of the developer as compared with the one having one flow path.

According to the configuration of the third aspect , it is possible to suppress the variation in the transport amount in the transport direction of the developer as compared with the case where the opening areas of the plurality of flow paths are constant.

According to the configuration of the fourth aspect , the variation in the transport amount in the transport direction of the developer is suppressed as compared with the flow path facing the portion of the stirring member where the plate-shaped member is not arranged. Can be done.

According to the configuration of the fifth aspect , it is possible to suppress variations in the transport amount of the developer in the transport direction as compared with the case where the developer directly flows from the flow path into the stirring path.

According to the configuration of the sixth aspect , it is possible to suppress variations in the amount of the developer transported in the transport direction, as compared with the case where the upstream side of the eaves extends in the width direction of the stirring path.

According to the configuration of the seventh aspect , unevenness of the toner image on the image holder can be suppressed as compared with the case where the partition plate of the developing device partitions the supply path and the stirring path from the lower end to the upper end.

According to the configuration of the eighth aspect, it is possible from the first embodiment in comparison with those not using the developing apparatus according to any one of the sixth aspect, to suppress image unevenness in the output image.

It is a top view which shows the whole structure of the inside of the developing apparatus which concerns on 1st Embodiment. 2-2 is a cross-sectional view taken along the line 2-2 of the developing apparatus and the photoconductor according to the first embodiment. (A) It is a cross-sectional view of 3A-3A in the developing apparatus which concerns on 1st Embodiment. (B) It is a cross-sectional view of 3B-3B in the developing apparatus which concerns on 1st Embodiment. It is a front view which shows the schematic layout of the image forming apparatus using the developing apparatus which concerns on 1st Embodiment. It is a perspective view which shows the main part of the developing apparatus which concerns on 1st Embodiment. It is a side view which shows the structure of the flow path of the partition plate which concerns on 1st Embodiment. It is a perspective view which shows the main part of the developing apparatus which concerns on 2nd Embodiment. It is a perspective view which shows the main part of the developing apparatus of a comparative example.

<First Embodiment>
An example of the developing apparatus and the image forming apparatus according to the first embodiment will be described with reference to FIGS. 1 to 8. The arrow H shown in the figure indicates the vertical direction (vertical direction) of the device, the arrow W indicates the width direction (horizontal direction) of the device, and the arrow D indicates the depth direction (horizontal direction) of the device. ..

(Overall configuration of image forming apparatus)
As shown in FIG. 4, the image forming apparatus 10 according to the first embodiment conveys the accommodating portion 14 accommodating the sheet material P as a recording medium and the accommodating portion 14 accommodating the sheet material P. A unit 16 is provided.

Further, the image forming apparatus 10 is provided with an image forming unit 20 that forms an image on the sheet material P conveyed from the accommodating unit 14 by the conveying unit 16, and a control unit 12 that controls each unit.

[Accommodation]
The accommodating portion 14 is provided with an accommodating member 26 that can be pulled out from the apparatus main body 10A of the image forming apparatus 10 toward the front side in the depth direction of the apparatus, and the sheet material P is loaded on the accommodating member 26.

Further, the accommodating member 26 is provided with a delivery roll 30 that sends the sheet material P loaded on the accommodating member 26 to the conveying path 28 constituting the conveying unit 16.

[Transport section]
The transport unit 16 is provided with a plurality of transport rolls (reference numerals omitted) for transporting the sheet material P along the transport path 28 to which the sheet material P is transported.

[Image forming part]
The image forming unit 20 is provided with four image forming units 18Y, 18M, 18C, and 18K of yellow (Y), magenta (M), cyan (C), and black (K). In the following description, if it is not necessary to distinguish Y, M, C, and K, Y, M, C, and K may be omitted.

The image forming unit 18 of each color is attached to and detached from the apparatus main body 10A, respectively. Here, the image forming unit 18 is an example of an assembly.

The image forming unit 18 of each color is provided with a photoconductor drum 36 that rotates in the direction of arrow B in the drawing, and a charging member 38 that charges the surface of the photoconductor drum 36.

Further, the image forming unit 18 has an exposure device 42 that irradiates the charged photoconductor drum 36 with exposure light, and an electrostatic latent image formed by irradiating the exposure light to be developed and visualized as a toner image (development). ) Is provided with a developing device 40.

Further, the image forming unit 20 includes an endless belt 22 that circulates in the direction of arrow A in the drawing, an auxiliary roll 52 around which the endless belt 22 is wound, a tension applying roll 54, and a drive roll 56. Has been done.

Further, the image forming unit 20 is provided with a primary transfer roll 44 that transfers the toner image formed by the image forming unit 18 of each color to the endless belt 22.

Further, the image forming unit 20 is provided with a secondary transfer roll 46 that transfers the toner image transferred to the endless belt 22 to the sheet material P.

The transfer device 32 includes an endless belt 22, an auxiliary roll 52, a tension applying roll 54, a drive roll 56, and a primary transfer roll 44.

Further, the image forming unit 20 is provided with a fixing device 50 for fixing the toner image to the sheet material P by heating and pressurizing the sheet material P to which the toner image is transferred.

(Action of image forming device)
In the image forming apparatus 10, an image is formed as follows.

First, the charging member 38 of each color to which the voltage is applied uniformly negatively charges the surface of the photoconductor drum 36 of each color at a predetermined potential.

Subsequently, the exposure apparatus 42 irradiates the surface of the charged photoconductor drum 36 of each color with exposure light based on the image data input from the outside to form an electrostatic latent image.

As a result, an electrostatic latent image corresponding to the data is formed on the surface of the photoconductor drum 36 of each color. Further, the developing device 40 for each color develops this electrostatic latent image and visualizes it as a toner image.
Further, the toner images formed on the surface of the photoconductor drum 36 of each color are sequentially transferred to the endless belt 22 by the primary transfer roll 44. In this way, the endless belt 22 holds the toner image on the outer peripheral surface.

Therefore, the sheet material P sent from the accommodating member 26 to the transfer path 28 by the delivery roll 30 is sent to the transfer position T where the endless belt 22 and the secondary transfer roll 46 come into contact with each other.

At the transfer position T, the sheet material P is conveyed between the endless belt 22 and the secondary transfer roll 46, so that the toner image on the outer peripheral surface of the endless belt 22 is transferred to the sheet material P.

Further, the toner image transferred to the surface of the sheet material P is fixed to the sheet material P by the fixing device 50. Then, the sheet material P on which the toner image is fixed is discharged to the outside of the apparatus main body 10A.

(Main part composition)
Next, the developing device 40 will be described.

Here, regarding terms that define each direction in the developing device, the front side (left side in the figure) of the device in the depth direction is the upstream side of the stirring path or the downstream side of the supply path, and the depth side of the device in the depth direction. (Right side in the figure) may be appropriately paraphrased as the downstream side of the stirring path or the upstream side of the supply path.

As shown in FIG. 2, the developing apparatus 40 includes a housing 72, a developing roll 60 arranged to face the photoconductor drum 36, a supply auger 66 for supplying the developing agent G to the developing roll 60, and developing. It is provided with a stirring auger 68 for stirring the agent G.

Here, the supply auger 66 is an example of a supply member, and the stirring auger 68 is an example of a stirring member.

The developer G in this embodiment is a two-component developer composed of toner T and magnetic carrier particles (hereinafter, “carrier C”) as main components.

[Case]
As shown in FIG. 2, the housing 72 is arranged next to the photoconductor drum 36, and in the housing 72, an opening 72A that opens the inside of the housing 72 at a portion facing the photoconductor drum 36. Is formed so as to extend in the depth direction of the device.

Further, in the housing 72, a delivery path 72B in which the developing roll 60 is arranged extends in the depth direction of the device on the opposite side of the photoconductor drum 36 with the opening 72A interposed therebetween.

Further, in the housing 72, a supply path 72C in which the supply auger 66 is arranged extends diagonally below the delivery path 72B in the depth direction of the device.

Further, in the housing 72, on the opposite side of the delivery path 72B with the supply path 72C interposed therebetween, a stirring path 72D in which the stirring auger 68 is arranged extends in the depth direction of the device.

Further, in the housing 72, a partition plate 72E that separates the supply path 72C and the stirring path 72D is formed between the supply path 72C and the stirring path 72D.

Then, in the housing 72, an upstream connecting path 72K is formed adjacent to the end of the partition plate 72E on the depth side in the device depth direction, and adjacent to the end of the partition plate 72E on the front side in the device depth direction. As a result, a downstream connecting path 72L is formed.

Further, as shown in FIGS. 1 and 3, in the housing 72, the stirring auger 68 extends from the upstream side (front side in the device depth direction) to the downstream side (back side in the device depth direction) of the stirring path 72D. Have been placed.

Further, the housing 72 is formed with a supply path 72F which is continuous on the upstream side of the stirring path 72D and for supplying the toner T and the carrier C to the stirring path 72D.

In this configuration, the toner T and the carrier C supplied to the developing device 40 flow from the toner cartridge 48 into the supply path 72F through the supply port 72H.

The supply path 72F extends from the upstream side of the stirring path 72D to the front side in the depth direction of the device, and extends to the downstream side of the supply path 72C (the front side in the depth direction of the device) (not shown). It is formed by bending (see FIG. 1).

The supply path 72F that is bent and changed in an L-shape in a plan view has a supply port 72H above the supply path 72F on the side of the extension line extending from the supply path 72C.

Further, the supply port 72H is connected to any of the toner cartridges 48Y, 48M, 48C, and 48K corresponding to each color shown in FIG.

Further, in the housing 72, the supply auger 66 is arranged with respect to the supply path 72C from the upstream side (depth side in the device depth direction) to the downstream side (front side in the device depth direction) of the supply path 72C. There is.

Further, a discharge path 72G for discharging the developer G from the developing device 40 is formed continuously from the downstream side of the supply path 72C to the front side in the depth direction of the device.

In this configuration, the developer G discharged from the developing device 40 is discharged to the outside of the developing device 40 through the discharge port 72J.

The discharge path 72G extends to the front of the supply path 72F and has a discharge port 72J below the discharge path 72G (see FIG. 3B).

-Supply path / stirring path / partition plate-
As shown in FIG. 2, the wall surface forming the supply path 72C and the stirring path 72D has a U-shaped cross section.

Further, the partition plate 72E extends diagonally upward when viewed from the depth direction of the device, and connects the supply path 72C and the stirring path 72D except for the portion on the back side in the depth direction of the device and the portion on the front side in the depth direction of the device. It rises from the inner surface of the bottom wall 72M of the housing 72 so as to partition.

[Development roll]
As described above, the developing roll 60 is arranged in the delivery path 72B. Further, as shown in FIG. 2, a gap (development gap) for passing the developer G from the developing roll 60 to the photoconductor drum 36 is formed between the developing roll 60 and the photoconductor drum 36. ..

The developing roll 60 includes a magnet roll 60A having a circular cross section and a rotary sleeve 60B that is placed on the magnet roll 60A and rotates around the magnet roll 60A.

The rotary sleeve 60B is adapted to rotate in the direction of arrow C (clockwise) in the drawing by transmitting a rotational force from a drive source (not shown).

[Supply auger]
As described above, the supply auger 66 is arranged in the supply path 72C and the discharge path 72G (see FIG. 1).

As shown in FIG. 1, the supply auger 66 includes a supply shaft 66A extending in the depth direction of the device, a spiral supply blade 66B formed on the outer peripheral surface of the supply shaft 66A, and a spiral circulation blade. It is configured to include 66C and a spiral discharge blade 66D.

Both ends of the supply shaft 66A are rotatably supported by the wall of the housing 72, and a gear (not shown) to which rotational force is transmitted from the drive source is fixed to one end of the supply shaft 66A. Has been done. In the present embodiment, as an example, the outer diameter of the supply shaft 66A is set to 8 mm.

The supply blade 66B is formed in a portion of the supply shaft 66A arranged in the supply path 72C.

Further, the circulation blade 66C is formed in a portion of the supply shaft 66A between the supply path 72C and the discharge path 72G.

The winding direction of the spiral of the circulation blade 66C is opposite to the winding direction of the spiral of the supply blade 66B, and the developer G conveyed through the supply path 72C acts in a dampening direction on the downstream side of the supply path 72C. Then, it is made to flow into the downstream side connecting path 72L side.

In the present embodiment, as an example, the outer diameter of the supply blade 66B is 16 mm, and the outer diameter of the circulation blade 66C is slightly larger than the outer diameter of the supply blade 66B.

Further, in the present embodiment, the pitch of the supply blades 66B is 28 mm, and the pitch of the circulation blades 66C is smaller than that of the supply blades 66B.

As shown in FIGS. 1 and 3B, the discharge blade 66D is formed in a portion of the supply shaft 66A arranged in the discharge path 72G.

Specifically, the discharge blade 66D has a spiral winding direction similar to that of the supply blade 66B. In the present embodiment, as an example, the outer diameter of the spiral blade constituting the discharge blade 66D is 16 mm.

In this configuration, the rotating supply auger 66 conveys the developer G of the supply path 72C from the upstream side to the downstream side of the supply path 72C with stirring, and supplies the developer G to the developing roll 60. There is.

Further, the developer G conveyed in the supply path 72C through the downstream connecting path 72L arranged on the downstream side of the supply path 72C by the supply vane 66B and the circulation vane 66C of the rotating supply auger 66 is passed through the stirring path 72D. It is designed to be handed over to the stirring auger 68.

At this time, at the inlet of the discharge path 72G continuous to the downstream side of the supply path 72C, the developer G surplus in the supply path 72C without being delivered to the stirring path 72D resists the damming action of the circulation blade 66C. Then, it flows into the discharge path 72G over the circulation blade 66C.

The developer G that has flowed into the discharge path 72G is conveyed through the discharge path 72G by the discharge blade 66D and discharged to the outside of the developing apparatus 40 through the discharge port 72J.

[Stirring auger]
As described above, the stirring auger 68 is arranged in the stirring path 72D and the supply path 72F (see FIG. 1).

The stirring auger 68 includes a stirring shaft 68A extending in the depth direction of the device, a spiral stirring blade 68B, a spiral circulation blade 68C, and a spiral replenishment formed on the outer peripheral surface of the stirring shaft 68A. It is configured to include a blade 68D.

Here, the stirring blade 68B is an example of a spiral blade.

Both ends of the stirring shaft 68A are rotatably supported by the wall of the housing 72, and a gear (not shown) to which rotational force is transmitted from the drive source is fixed to one end of the stirring shaft 68A. Has been done. In the present embodiment, as an example, the outer diameter of the stirring shaft 68A is 11 mm.

The stirring blade 68B is formed in a portion of the stirring shaft 68A arranged in the stirring path 72D.

The circulation blade 68C is formed in a portion of the stirring shaft 68A arranged on the downstream side of the stirring path 72D so that a part thereof faces the upstream connecting path 72K communicating with the supply path 72C, and the stirring blade 68B and the supply are supplied. The winding direction of the spiral of the blade 68D is opposite to that of the winding direction.

The replenishment blade 68D is formed in a portion of the agitation shaft 68A arranged in the replenishment path 72F continuous on the upstream side of the agitation passage 72D in the same winding direction as the spiral winding direction of the stirring blade 68B.

The outer diameters of the stirring blade 68B and the supply blade 68D are the same.

Further, the spiral pitch of the supply blade 68D is smaller than the spiral pitch of the stirring blade 68B.

Further, the outer diameter of the circulation blade 68C is larger than the outer diameter of the stirring blade 68B.

A plurality of stirring auxiliary plates 68E are provided along the axial direction of the stirring shaft 68A of the stirring auger 68 in a part of the portion where the stirring blade 68B is formed. Here, the stirring auxiliary plate 68E is an example of a plate-shaped member.

Each of the plurality of stirring auxiliary plates 68E is arranged in a part of the stirring blades 68B, for example, between 1 pitch or 2 pitches.

The height of the stirring auxiliary plate 68E from the surface of the stirring shaft 68A is set smaller than the height of the stirring blade 68B from the surface of the stirring shaft 68A, and the height of the stirring shaft 68A is set to be smaller than the height of the stirring shaft 68A when viewed from the axial direction of the stirring shaft 68A. A plurality of stirring auxiliary plates 68E are arranged in the circumferential direction.

As shown in FIG. 1, in this configuration, the stirring blade 68B of the rotating stirring auger 68 is delivered from the supply auger 66 through the developer G flowing from the supply path 72F into the stirring path 72D and the downstream connecting path 72L. The developer G is conveyed while being stirred.

Specifically, the stirring blade 68B of the rotating stirring auger 68 conveys the developer G from the upstream side to the downstream side while stirring.

Further, the circulation blade 68C of the rotating stirring auger 68 acts to dam the developer G conveyed by the stirring blade 68B, and delivers it to the supply auger 66 through the upstream connecting path 72K. There is.

In this way, the developer G circulates between the supply path 72C and the stirring path 72D (see the arrow in the figure).

[Partition plate and flow path]
As described above, the partition plate 72E is formed so as to rise from the inner surface of the bottom wall 72M of the housing 72 so as to partition the supply path 72C and the stirring path 72D. Here, the flow path, which is a main part, will be described in detail together with the partition plate 72E.

As shown in FIGS. 1 and 5, the flow path 80 is formed at the upper end portion 72E1 of the partition plate 72E at a portion sandwiched between the upstream side connecting path 72K adjacent to the partition plate 72E and the downstream side connecting path 72L. It is formed in the shape of a notch with an open upper end.

The flow path 80 connects the stirring path 72D and the supply path 72C below the upper end portion 72E1 of the partition plate 72E.

In the present embodiment, as shown in FIG. 6, the flow paths 80 are arranged at three locations separated from each other from the upstream side to the downstream side (arrow E in the figure) of the supply path 72C.

FIG. 6 is a side view of the partition plate 72E in which the flow paths 80 are arranged at three locations as viewed from the stirring path 72D side.

The three flow paths 80 are the first flow path 80A and the second flow path 80A and the second flow path 80 in order from the upstream side connecting path 72K in which the developer G agitated and conveyed in the stirring path 72D is sent to the supply path 72C in the direction E. The road 80B and the third flow path 80C are used.

Each of the flow paths 80A, 80B, and 80C has a rectangular shape, and each has a different opening area.

The first flow path 80A is an opening having dimensions of width w1 and depth d1, the second flow path 80B is an opening having dimensions of width w2 and depth d2, and the third flow path 80C is a width. An opening having dimensions of w2 and a depth of d2.

Then, these dimensions are set to w1 <w2 <w3 and d1 <d2 <d3.

That is, the width and depth of the opening of the first flow path 80A are set to be the smallest, and the width and depth of each opening are gradually increased toward the third flow path 80C.

Further, as shown in FIG. 2, the bottom surface 80b of each flow path 80 is at least above the upper end 66At on the vertical axis VL line passing through the axis of the supply shaft 66A in the supply shaft 66A of the supply auger 66, and , It is located in a range below the upper end portion 72E1 of the partition plate 72E.

In the present embodiment, as shown in FIG. 1, the first flow path 80A does not face the stirring auxiliary plate 68E provided on the stirring blade 68B of the stirring auger 68.

Further, the second flow path 80B and the third flow path 80C are arranged so as to face the stirring auxiliary plate 68E provided on the stirring blade 68B of the stirring auger 68.

Further, in one flow path 80 facing the stirring auxiliary plate 68E, a part or all of the width at which the flow path 80 opens is arranged so as to face the stirring auxiliary plate 68E.

Specifically, as shown in FIG. 1, as in the second flow path 80B and the third flow path 80C, the upstream end of the stirring path 72D of the flow path 80 is the stirring path of the stirring auxiliary plate 68E. It is preferably located on the upstream side of the 72D on the upstream side.

Further, the downstream end of each flow path 80 in the stirring path 72D is at the same position, or the position facing the downstream end of the stirring auxiliary plate 68E in the stirring path 72D is slightly shifted to the same position, upstream or downstream. May be.

(Action of main part composition)
Next, the operation of the developing device 40 will be described.

Inside the housing 72 of the developing apparatus 40, a rotating supply auger 66 and a rotating stirring auger 68 stir the developer G between the supply path 72C and the stirring path 72D, as shown in FIG. Circulate (see arrow in the figure).

When the developer G is agitated, the toner T in the developer G and the carrier C rub against each other, and the toner T is triboelectrically charged to a predetermined polarity.

Then, as shown in FIG. 2, the rotating supply auger 66 supplies the developer G to the developing roll 60.

The developer G supplied to the developing roll 60 is held in a state where a magnetic brush (not shown) is formed on the surface of the developing roll 60 by the magnetic force of the magnet roll 60A.

Then, the rotating rotary sleeve 60B conveys the developer G.

The rotating rotary sleeve 60B conveys the developer G to a position facing the photoconductor drum 36.

Then, the toner T contained in the developer G conveyed to the position facing the photoconductor drum 36 adheres to the electrostatic latent image formed on the photoconductor drum 36, and the electrostatic latent image is developed as a toner image. ..

In the developing apparatus 40, the control unit 12 (see FIG. 4) receives information from a detection means (not shown) that the toner T in the developing agent G circulating between the supply path 72C and the stirring path 72D has decreased.

The control unit 12 flows the toner T contained in the toner cartridge 48 together with the carrier C into the supply path 72F through the supply port 72H.

The developer G in the developing apparatus 40 is maintained in an amount required for development (a standard amount required in advance) while the toner T is appropriately replenished.

However, the amount of the developer G to be replenished is not uniform every time, and the developer G containing a surplus may be replenished.

Then, the liquid level of the developer G that has been conveyed while being agitated in the stirring path 72D and has flowed into the supply path 72C from the upstream connecting path 72K rises.

Further, in the stirring path 72D, the developer G to which the toner T is replenished may be insufficiently stirred and a part of the developer G may flow into the supply path 72C as a lump (hereinafter, referred to as “soft block”). ..

Then, the liquid level of the developer G on the supply path 72C is wavy in a part thereof.
The undulation of the liquid level is larger on the upstream side connecting path 72K side (upstream side of the supply path 72C) than on the downstream side connecting path 72L side (downstream side of the supply path 72C).

In the present embodiment, the opening areas of the first flow path 80A, the second flow path 80B, and the third flow path 80C gradually decrease from the upstream side to the downstream side of the stirring path 72D.

Looking at this from the side of the supply path 72C, the opening areas of the first flow path 80A, the second flow path 80B, and the third flow path 80C gradually increase from the upstream side to the downstream side of the supply path 72C. There is.

That is, the first flow path 80A (width w1, depth d1) having a small opening area is located in the portion of the partition plate 72E on the upstream side connecting path 72K side (upstream side of the supply path 72C) where the developer G has a large waviness. Have been placed.

Since the liquid level is high in the portion where the liquid level of the developer G has a large waviness, even if the opening area of the first flow path 80A is smaller than the opening areas of the other second flow paths 80B and the third flow path 80C, the supply path The developer G on the 72C side can be returned to the stirring path 72D side.

On the other hand, in the partition plate 72E, the third flow path 80C (width w3, depth) having a large opening area is located in the portion where the waviness of the developer G on the downstream side connecting path 72L side (downstream side of the supply path 72C) is small. d3) is arranged.

Since the liquid level is low in the portion where the waviness of the liquid level of the developer G is small, the opening area of the third flow path 80C is made larger than the opening areas of the other first flow paths 80A and the second flow path 80B. , The developer G on the supply path 72C side is returned to the stirring path 72D side.

By making the heights of the bottom surfaces 80b of each flow path 80 different from each other in this way, the liquid level of the developer G conveyed in the supply path 72C changes from the upstream to the downstream of the supply path 72C. It can correspond to the height.

Further, the bottom surface 80b of each flow path 80 is at least above the upper end 66At on the vertical axis VL line passing through the axis of the supply shaft 66A in the supply shaft 66A of the supply auger 66, and the upper end portion of the partition plate 72E. It is located in the range below 72E1.

As a result, not only the developer G conveyed through the supply path 72C but also the developer G including the developed developer G returned from the surface of the photoconductor drum 36 to the supply path 72C is passed through the flow path in the partition plate 72E. It can be secured in the supply path 72C at a position below the bottom surface 80b of the 80.
In other words, as long as the amount of the developer G conveyed through the supply path 72C is within the range of the appropriate amount (predetermined standard amount) required for development, the developer G on the supply path 72C side. The height of the bottom surface 80b of the flow path 80 is set at a position where is not returned to the stirring path 72D side.

Here, as shown in FIG. 8, in the developing apparatus 400 according to the comparative example, the partition plate 720E does not have a flow path.

Therefore, the developer G sent to the supply path 720C via the upstream connecting path 720K on the downstream side (right side of the drawing) of the stirring path 720D is the downstream connecting path 720L on the downstream side (left side of the drawing) of the supply path 720C. On the way to, it is transported without being reduced, including the surplus.

As a result, the amount of the developer G in the entire depth direction of the developing roll (not shown) remains non-uniform, the amount of the developer G transferred to the photoconductor drum (not shown) becomes unstable, and the sheet material P becomes unstable. This may cause problems such as unevenness in the formed image.

As described above, in the comparative example without the flow path 80, the developer G in the supply path 720C has a non-uniform property and amount from the upstream side to the downstream side of the supply path 720C and is retained on the developing roll. The amount and the amount of transfer to the photoconductor drum vary.

As a result, uneven development may occur in the image on the sheet material P.

On the other hand, in the present embodiment, the flow path 80 is a developer whose bulk is higher than the upper end 66At on the vertical axis VL line passing through the axis of the supply shaft 66A in the supply shaft 66A of the supply auger 66. A part of G is returned to the stirring path 72D in the middle of transportation toward the downstream connecting path 72L.

A part of the surplus amount of the developer G on the supply path 72C is returned to the stirring path 72D through the first flow path 80A, so that the amount of the developer G transported at the position of the supply path 72C is reduced. , The liquid level of the developer G is lowered, and the waviness of the liquid level is reduced.

As a result, it is possible to suppress variations in the amount of the developer G transported in the transport direction, as compared with the partition plate 72E partitioning the supply path 72C and the stirring path 72D from the lower end to the upper end.

A part or all of the surplus amount of the developer G in the supply path 72C is returned to the stirring path 72D by the first flow path 80A, and the developer G conveyed through the supply path 72C continues to be the downstream connecting path 72L. Is transported toward.

Rippling of the liquid surface of the developer G may still remain, and the developer G returns to the stirring path 72D through the second flow path 80B arranged closer to the connecting path 72L on the downstream side of the first flow path 80A. The amount of the developer G transported at this position is reduced.

Also in the third flow path 80C, if the amount of the developer G conveyed is larger than the predetermined amount, the surplus amount of the developer G is generated in the stirring path 72D as in the first flow path 80A and the second flow path 80B. Be returned.

As a result, the transport amount of the developer G in the transport direction is settled within a certain range as compared with the case where the flow path 80 is one, and the variation in the transport amount of the developer G in the transport direction can be suppressed.

Further, in the partition plate 72E, the opening areas of the first flow path 80A, the second flow path 80B, and the third flow path 80C gradually decrease from the upstream side to the downstream side of the stirring path 72D.

Since the liquid level is high in the portion where the liquid level of the developer G has a large waviness, even if the opening area of the first flow path 80A is smaller than the opening areas of the other second flow paths 80B and the third flow path 80C, the liquid level is supplied. The developer G on the path 72C side can be returned to the stirring path 72D side.

On the other hand, since the liquid level is low in the portion where the waviness of the liquid level of the developer G is small, the opening area of the third flow path 80C is larger than the opening areas of the other first flow paths 80A and the second flow path 80B. The size is increased so that the developer G on the supply path 72C side is returned to the stirring path 72D side.

As a result, it is possible to suppress variations in the amount of the developer G transported in the transport direction, as compared with the case where the opening areas of the plurality of flow paths 80 are constant.

Further, as shown in FIG. 1, a plurality of stirring auxiliary plates 68E are provided along the axial direction of the stirring shaft 68A of the stirring auger 68 in a part of the portion where the stirring blade 68B is formed.

The second flow path 80B and the third flow path 80C provided on the partition plate 72E are arranged so as to face the stirring auxiliary plate 68E provided on the stirring blade 68B of the stirring auger 68.

Specifically, like the second flow path 80B and the third flow path 80C, the upstream end of each of the flow paths 80B and 80C in the stirring path 72D is the upstream side of the stirring auxiliary plate 68E in the stirring path 72D. It is located upstream of the end of.

The stirring auxiliary plate 68E has an action of strongly stirring the developer G conveyed while being stirred in the stirring path 72D in the rotation direction of the stirring shaft 68A, and the generation of soft blocks of the developer G is suppressed.

As a result, it is possible to suppress variations in the amount of the developer G transported in the transport direction, as compared with the flow path 80 facing the portion of the stirring member 68 where the stirring auxiliary plate 68E is not arranged. ..

By returning a part of the developer G on the supply path 72C side to the stirring path 72D in this way, the variation in the amount of the developer G transported in the region from the upstream side to the downstream side of the supply path 72C is suppressed. NS.

As a result, the amount of the developer G held on the developing roll 60 is stabilized over the entire area of the developing roll 60 in the device depth direction.

Further, since the developing apparatus 40 and the photoconductor drum 36 integrally form the image forming unit 18, the developing apparatus 40 and the photoconductor drum 36 can be integrally replaced with the apparatus main body 10A of the image forming apparatus.

The image forming unit 18 can suppress unevenness of the toner image on the image holder as compared with the case where the partition plate of the developing device partitions the supply path and the stirring path from the lower end to the upper end.

In the image forming apparatus 10, the amount of the developer G transferred from the developing roll 60 to the photoconductor drum 36 is stable over the entire depth direction of the apparatus of the photoconductor drum 36, so that the above direction is developed on the sheet material P. The print density of the image is stable, and the occurrence of uneven development can be suppressed.

As a result, image unevenness such as color streaks in the output image can be suppressed as compared with the case where the developing apparatus 40 according to the present embodiment is not used.

Further, the developer G returned from the supply path 72C to the stirring path 72D promotes the stirring property of the developing agent G conveyed while being stirred in the stirring path 72D, and suppresses the generation of soft blocks of the developing agent G. , The variation in the properties of the developer G flowing into the supply path 72C is suppressed.

Further, by suppressing the waviness of the liquid surface of the developer G, cloud contamination in the apparatus is reduced.

On the other hand, the developing apparatus 40 according to the present embodiment is configured to have the flow path 80 in the partition plate 72E, so that the variation in the amount of the developing agent G conveyed in the supply path 72C is suppressed.

<Second Embodiment>
An example of the developing apparatus according to the second embodiment of the present invention will be described mainly with reference to FIG. Regarding the second embodiment, the same reference numerals are used for the parts common to the first embodiment, and different parts will be mainly described.

The developing device 40 according to the second embodiment is provided with eaves 90 corresponding to the flow path 80.

The eaves 90 are provided so as to project onto the stirring path 72D from the stirring path 72D side below the flow path 80 in the partition plate 72E.

The eaves 90 includes a base 90A, a tip 90B, an upper surface 90D, and a lower surface, and the base 90A has a plate-like shape having a larger dimension than the tip 90B.

Further, of the sides connecting the base 90A and the tip 90B, the side 90C on the upstream side of the stirring path 72D in the transport direction of the developer G is directed from the base 90A to the tip 90B in the width direction of the stirring path 72D. , The developer G is inclined to the downstream side in the transport direction.

In the present embodiment, the dimension of the base 90A of each eaves 90 corresponds to the widths of the opening of the flow path w1 to w3, and the dimension of the tip 90B is w = 0.

Further, the eaves 90 has a length equivalent to the width of the stirring path 72D.

The upper surface 90D of the eaves 90 is connected to the side surface of the partition plate 72E on the stirring path 72D side in accordance with the height of the bottom surface 80b of the flow path 80.

Further, the lower surface of the eaves 90 is not in contact with the stirring auger 68 arranged in the stirring path 72D.

[Action in the second embodiment]
Next, the operation of the developing device 40 in the second embodiment will be described.
In the developing apparatus 40 according to the second embodiment, the agitation, supply, and each action of the developer G in the flow path are the same as those in the first embodiment.

As shown in FIG. 7, the eaves 90 are provided so as to project from the stirring path 72D side of the flow path 80 in the partition plate 72E onto the stirring path 72D.

When the liquid level of the developer G conveyed through the supply path 72C is wavy or the amount of replenishment is large, the surplus is returned from the flow path 80 to the stirring path 72D through the upper surface 90D of the eaves 90.

At this time, the developer G falls from the upper surface 90D of the eaves 90 to the stirring path 72D.

As a result, the stirring property of the developer G that is agitated and conveyed in the stirring path 72D is improved, and the developer G at the time of being sent to the supply path 72C suppresses the generation of soft blocks and alleviates the waviness of the liquid surface. Will be done.

As a result, it is possible to suppress variations in the amount of the developer G transported in the transport direction, as compared with the case where the developer directly flows from the flow path 80 into the stirring path 72D.

Further, in the eaves 90, of the sides connecting the base 90A and the tip 90B, the side 90C on the upstream side in the transport direction of the developer G in the stirring path 72D is directed from the base 90A to the tip 90B. It is inclined from the upstream side to the downstream side in the transport direction of.

Since this side 90C is inclined from the upstream side to the downstream side in the transport direction of the developer G, the developer G is located on the upper surface 90D of the eaves 90 from the base 90A to the tip corresponding to the shape of the side 90C. It falls into the stirring path 72D in order toward the part 90B.

That is, the falling developer G is dispersed and returned on the developer G that is agitated and conveyed over the entire width direction of the stirring path 72D.

As a result, the agitation property of the developer G that is agitated and conveyed in the agitation path 72D in the entire width direction is improved, and the developer G at the time of being sent to the supply path 72C suppresses the generation of soft blocks and the liquid level. Rippling is alleviated.

As a result, a part of the developer G in the supply path 72C can be returned over the entire width direction of the stirring path 72D while being conveyed toward the downstream connecting path 72L, so that the supply path 72C can be returned. The variation in the amount of the developer G in the above can be suppressed.

As a result, it is possible to suppress variations in the amount of the developer transported in the transport direction, as compared with the case where the upstream side of the eaves extends in the width direction of the stirring path.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is obvious to the trader.

For example, in the above embodiment, the flow path 80 is an opening notched at the upper end 72E1 of the partition plate 72E, but may be an opening penetrating the upper part of the partition plate 72E without notching the upper end 72E1. ..

Further, the bottom surface 80b of the flow path 80 is above the upper end 66At on the vertical axis VL line passing through the axis of the supply shaft 66A in the supply shaft 66A of the supply auger 66 and below the upper end 72E1 of the partition plate 72E. It is said that it is located in the range of, but it is not limited to this.
For example, in consideration of the type and printing performance (printing resolution, printing speed, etc.) of the image forming apparatus, the properties of the developer G, the performance of the developing apparatus depending on the pitch and rotation speed of the auger used, and the like, the flow path 80 is appropriately used. The position of the bottom surface 80b of the above may be used.

Further, although the flow path 80 is set to three places, it may be set to one place or two places, or four or more places.

Further, although the opening areas of the first flow path 80A, the second flow path 80B, and the third flow path 80C are made different, the opening areas may be the same, and the opening width w is the same. The depth d may be different, or the width w may be different with the same depth d.

Further, although a plurality of stirring auxiliary plates 68E are provided in a part of the portion of the stirring member 68 where the stirring blades 68B are formed, they may be provided in a portion corresponding to the entire stirring path 72D.

Further, although the stirring auxiliary plate 68E is provided along the axial direction of the stirring shaft 68A of the stirring auger 68, the stirring auxiliary plate 68E may be provided so as to be bent, curved or inclined with respect to the axial direction of the stirring shaft 68A. The plate thickness can be set arbitrarily.

Further, although the stirring auxiliary plate 68E is described as a linear and rectangular plate-shaped member in FIGS. 1 and 5 to 7, it is bent or curved with respect to the radial direction of the stirring shaft 68A of the stirring auger 68. Alternatively, it may be inclined, and the plate thickness can be arbitrarily set.

Further, although each of the plurality of stirring auxiliary plates 68E is arranged between 1 pitch or 2 pitches of the stirring blades 68B, it may be provided over 3 pitches or more of the stirring blades 68B. It may be provided so as not to come into contact with the surface of the stirring blade 68B in one pitch.

Further, the height of the stirring auxiliary plate 68E from the surface of the stirring shaft 68A is set to be smaller than the height of the stirring blade 68B from the surface of the stirring shaft 68A, but the surface of the stirring shaft 68A of the stirring blade 68B is set to be smaller. It may be set to the same level as the height from.

Further, although a plurality of stirring auxiliary plates 68E are arranged in the circumferential direction of the stirring shaft 68A when viewed from the axial direction of the stirring shaft 68A, one may be used.

Further, the connection position of the eaves 90 to the side surface of the partition plate 72E was adjusted so that the heights of the upper surface 90D of the eaves 90 and the bottom surface 80b of the flow path 80 were matched, but the upper surface 90D was lower than the bottom surface 80b. It may be connected and arranged with a step between the bottom surface 80b and the top surface 90D.

Further, the dimension of the base 90A of the eaves 90 is made to correspond to the width w of the flow path 80, but the dimensions do not necessarily have to be the same, and the base 90A of the eaves 90 is larger than the width w of the flow path 80. The dimensions of the can be large or small.

Further, the positions of the eaves 90 and the flow path 80 in the transport direction of the developer G may also be arranged so as to be displaced in the transport direction.

Further, although the protruding form of the eaves 90 to the stirring path 72D is not particularly mentioned, the protruding form may be horizontal with respect to the stirring path 72D from the base 90A toward the tip, or may be inclined in the vertical direction. , Or may be bent or curved.

Further, the image forming unit 18 as an assembly is configured to include a photoconductor drum 36, a developing device 40, a charging member 38, and an exposure device 42, but the present invention is not limited to this. It suffices that the image forming unit 18 includes at least a photoconductor drum 36 and a developing device 40, and may have a configuration different from that of the above embodiment.

Further, the photoconductor drum 36 and the developing device 40 are not limited to those that are an assembly such as the image forming unit 18, and may be independent elements (single items).

Further, the image forming apparatus 10 is not limited to the one having the image forming unit 18, and the photoconductor drum 36 and the developing apparatus 40 may be independent.

10 Image forming device 18 Image forming unit (an example of an assembly)
36 Photoreceptor drum (example of image holder)
40 Developing device 48 Toner cartridge 54 Secondary transfer roll 60 Developing roll (an example of rotating member)
66 Supply auger (example of supply member)
66A Supply shaft 66At Upper end 66B Supply blade 66C Circulation blade 66D Discharge blade 68 Stirring auger (example of stirring member)
68A Stirring shaft 68B Stirring blade 68C Circulation blade 68D Replenishment blade 68E Stirring auxiliary plate (example of plate-shaped member)
70 Housing 72C Supply path 72D Stirring path 72E Partition plate 72E1 Upper end 72F Supply path 72G Discharge path 72H Supply port 72J Discharge port 72K Upstream side connecting path 72L Downstream side connecting path 72M Bottom wall 80 Flow path 80A First flow path 80B 2 Flow path 80C Third flow path 80b Bottom surface 90 Eaves 90A Base 90B Tip 90C Side 90D Top surface w (Flower path) Opening width d (Flower path) Opening depth G Developer T Toner VL Vertical axis

Claims (7)

A housing having a stirring path formed on one side and a supply path formed alongside the stirring path on the other side.
The stirring member provided in the stirring path and
The supply member provided in the supply path and
A partition plate provided in the housing, which separates the stirring path and the supply path, and is arranged so as to be sandwiched between an upstream connecting path and a downstream connecting path connecting the stirring path and the supply path.
A plurality of flow paths provided above the partition plate and connecting the supply path and the stirring path, which are arranged at intervals from each other, and are located upstream of the developer in the transport direction in the stirring path. The plurality of flow paths whose width and depth are gradually reduced from the to the downstream side, and
A developing device having. The stirring member includes a spiral blade and a plate-shaped member extending in the axial direction of the stirring member.
The developing apparatus according to claim 1, wherein the plurality of flow paths are partially or wholly arranged to face the plate-shaped member. The developing apparatus according to claim 1 or 2, further comprising an eaves protruding above the stirring path from the lower side surface of the flow path of the partition plate. A housing having a stirring path formed on one side and a supply path formed alongside the stirring path on the other side.
The stirring member provided in the stirring path and
The supply member provided in the supply path and
A partition plate provided in the housing, which separates the stirring path and the supply path, and is arranged so as to be sandwiched between an upstream connecting path and a downstream connecting path connecting the stirring path and the supply path.
A flow path provided on the upper part of the partition plate and connecting the supply path and the stirring path,
The eaves protruding above the stirring path from the lower side surface of the flow path of the partition plate,
A developing device having. The eave has a base portion connected to the partition plate and a tip portion protruding above the stirring path, and the upstream side of the stirring path of the eaves is downstream from the base portion toward the tip portion. The developing apparatus according to claim 3 or 4, which is inclined to the side. An image holder on which a latent image is formed, and
The developing apparatus according to any one of claims 1 to 5 , wherein a latent image formed on the outer peripheral surface of the image holder is developed as a toner image.
Including
An assembly assembled so that it can be exchanged as a unit with the image forming apparatus main body. Image holder and
A charging device that charges the outer peripheral surface of the image holder, and
A latent image forming device that forms a latent image on the outer peripheral surface of the image holder charged by the charging device,
A developing device according to any one of claims 1 to 5 for developing the latent image as a toner image,
A transfer device that transfers the toner image to the transfer target, and
An image forming apparatus equipped with.

Images