JPH03194572A - Developing device - Google Patents

Abstract

PURPOSE:To make a developer which is carried to a developing area constant by providing first to third carrying paths behind a developing part, regulating the developer carried in the second carrying path with the aid of a regulation means and keeping the developer in the first carrying path constant. CONSTITUTION:The developer in the third carrying path 15 is carried in a direction shown by an arrow X8 and sent to the second carrying path 14 through a passage 12. Then, the developer in the path 14 is carried in a direction shown by an arrow X4. The developer carried in the path 14 is regulated on the way by a regulation plate 21 and the regulated developer is sent to the path 15 through an adjustment passage 20. The developer passing under the plate 21 is adjusted to be a fixed quantity and distributed to a passage 9 and a passage 10 at an end part on an inner side of the path 14. Then, it is sent to the respective first carrying path 13 and the path 15. The developer in the path 13 is carried in a direction shown by an arrow X1 and carried to the path 14 through a passage 11. When the developer is carried in the path 13, a part thereof is supplied to a developing sleeve 5. Thus, the developer in the path 13 is maintained to be almost constant. Thus, the stable developer is supplied to the developing part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device for a copying machine, a printer, etc. that uses a powder developer.

(Prior Art) Conventionally, the developing device shown in FIG. 13 has been provided.

This developing device (lOl) includes a developing section (104) provided at the front of a casing (102), and a developing sleeve (105) containing a magnetic roller (not shown) facing a photoreceptor drum (100). It is located. The rear of the developing section (104) is partitioned by a partition wall (107) and connected to the first transport path (104).
13) and a second conveyance path (114) are formed, and these conveyance paths (l l 3) and (I I 4)
) first passages (109) formed on the back side and the front side, respectively;
They are connected via the second passage (Ill) and are connected via the conveyance path (Ill).
3), (114), first screw (116), second
Screws (117) are each rotatably arranged.

The developing device (101) having the above configuration accommodates a two-component developer consisting of toner and carrier, and the developer in the second conveyance path (114) is distributed according to the arrows indicated by the arrows based on the rotation of the second screw (117). It is conveyed in the (I4) direction, and at the back end, it is conveyed through the passageway (109) along the arrow (Y, ) direction to the first conveyance path (113). The developer in the first conveyance path (113) is conveyed in the direction of the arrow (Yl) based on the rotation of the first screw (116), and passes through the path (111) at the front end of the developer in the direction of the arrow (Yl). ) along the M2 conveyance path (114). Further, when the developer is conveyed through the conveyance path (113), a part of the developer is conveyed through the developing sleeve (113).
105). The developer supplied to the developing sleeve (105) is conveyed in the direction of the arrow (I2) based on the rotation of the developing sleeve (105), and is transferred to the photosensitive drum (10
The photoreceptor drum (
A toner image is formed by supplying toner to the electrostatic latent image formed on the surface of the image forming apparatus 100).

Further, in the developing device 11 (101), the developing section (10
4) In order to always stably supply a certain amount of developer or more,
The developer conveyance capacity of the second screw (117) is made larger than the conveyance capacity of the first screw (116), and the notch width of the first passage (109) is made larger than that of the first passage (116).
By making the notch width larger than the notch width of l l 1), the developer level in the first transport path (113) is maintained at a high level.

(Problems to be Solved by the Invention) However, the developing device (lO1) does not include any means for adjusting the amount of developer conveyed to the first conveyance path (113) via the first path (109). Therefore, the effect of the decrease in the amount of developer immediately appears on the conveyance amount of the first conveyance path (113).

Therefore, by repeating the development operation,
When not only the toner but also the carrier is gradually consumed and the total amount of developer decreases, or when the amount of developer temporarily fluctuates due to the toner replenished to the second conveyance path (114),
This effect immediately appears in the amount of developer conveyed to the developing area (P), resulting in the problem that the image quality is unstable.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and will be described with reference to FIG. 1 showing one embodiment. a. a developing section (4); b, the first transport path (13) located at the rear of the developing section (4);
); C1: a second conveyance path (14) located at the rear of the first conveyance path (13); d: a third conveyance path (15) located at the rear of the second conveyance path (14); e, a front wall (7) located between the first transport path (I3) and the second transport path (14); f, the second transport path (14) and the third transport path (15); the rear wall (8) located between the front wall (8), and the front wall (7). The second front passageway (9), the second front passageway (Il), and the second conveyance path (14) and the third conveyance path (15 ), a rear first passageway (10) and a rear second passageway (I2) respectively communicating with the first conveyance path (13), the second conveyance path (14), and the third conveyance path (13).
The developer accommodated in the transport path (15) and the developer in the first transport path (13) are transported from the back side to the front side (in the direction of arrow ); k, a second conveyance means (I7) for conveying the developer in the second conveyance path (14) from the front side to the back side (arrow X direction); 1. A third conveyance means (18) for conveying the developer in the third conveyance path (I5) from the back side to the front side (arrow X direction); m. The developer in the second conveyance path (14) a regulating means (21) for regulating the conveyance amount;
It consists of an adjustment path (20) for sending the feed to the third conveyance path (15) from five directions.

Note that the rear first passage (10) is connected to the adjustment passage (20).
).

(Function) According to the above configuration, the developer is transported through the transport paths (13) and (14).
, (+5).

The developer in the second transport path (14) is regulated by a regulating means (21) during transport, and the amount of developer that passes through this is regulated to be constant. Note that the regulated developer is transported to the third transport path (15) via the adjustment path (20).

Therefore, the amount of developer transported to the back side through the second transport path (14) becomes constant. Further, the amount of developer sent to and transported to the first transport path (13) is also constant, and the developing section (
4) The amount of developer supplied is stabilized.

(Example) Hereinafter, the present invention will be described with reference to the accompanying drawings showing one example thereof.

FIG. 1 shows a developing device (1) according to the present invention;
FIG. 3 is a sectional view taken along line nn and line III-III of the developing device (1) on the back side and the front side.

The housing of the developing device (1) consists of a bottom casing (2)
and an upper casing (3), and a developing section (
4) is a provision.

A developing sleeve (5) is arranged in the developing section (4) so as to be rotatably driven in the direction of the arrow (a), and a magnetic pole (N
l-N1,51. A magnetic roller (6) having a plurality of axially extending magnets S2) is housed in a fixed state.

Behind the developing section (4), a first partition wall (7) and a second partition wall (8) are formed by extending the bottom casing (2) upward. ) partitions the rear part of the housing, and a first conveyance path (13), a second conveyance path (14),
A third conveyance path (15) is formed sequentially at the rear. Note that the bottoms of the first conveyance path (13) and the third conveyance path (15) are parallel to the developing sleeve (5), and the bottoms of the first conveyance path (13) and the third conveyance path (15) are parallel to the developing sleeve (5).
) is inclined so that it is lower than the conveyance paths (13), (15) on the front side and higher than the conveyance paths (13), (15) on the back side.

@l The rear and front ends of the partition wall (7) are cut off, respectively, to form a first passage (9) and a second passage (l l), and the rear side of the second partition wall (8), The ends on the near side are similarly cut off to form a third passage (10) and a fourth passage (12), respectively.

A portion of the second partition wall (8) moved from the back side to the front side by a predetermined distance is cut to a predetermined depth to form an adjustment passageway (20). Further, a regulating plate (21) attached to the upper casing (3) is suspended from the second conveyance path (14) facing the adjustment path (20).

(See Figure 4). This regulating plate (21) is, for example, a film unit.

The first to third conveyance paths (13) to (15) each have a
3 screws (16), (17), (18) are arrows (b
).

It is installed so as to be rotatably driven in the directions (c) and (d), and the developer contained in the transport paths (13), (14), and (15) is moved by the arrows (X,), (X, ), (X
8) It is designed to be conveyed in the direction. Further, the regulation plate (21) is in contact with the second screw (17) of the second conveyance path (I4).

Toner is supplied to the developing device (1) through the second conveyance path (14).
This is done through a supply route (not shown) formed in front of the
The second screw (17) transports the paper to the second conveyance path (14).

The developer toner concentration detection sensor (23) is connected to the developing device (
As shown in Figure 5, which shows the flow of the developer in 1),
It is provided in the bottom casing (2) on the near side of the second conveyance path (14).

The developing device (1) having the above configuration accommodates a two-component developer consisting of toner and carrier, and this developer is circulated and conveyed through the following route.

The developer in the third conveyance path (15) is transferred to the third screw (18).
) from the back side to the front side in the direction of the arrow (I8), and is transported through the fourth passageway (12) to the second conveyance path (14
) is sent to the front side.

The developer in the second conveyance path (14) is transferred to the second screw (14).
7), it is transported from the front side to the back side in the direction of arrow (I4).

Further, the developer transported to the back side through the second transport path (14) is regulated by a regulation plate (21) on the way, and the regulated developer passes through the adjustment path (20) in the direction of the arrow (I5). towards the third conveyance path (15).

The amount of developer passing under the regulation plate (2I) is adjusted to a constant amount, and the developer passes through the first passage (9) at the back end of the second conveyance passage (14).
are distributed to the third passage (10), and are respectively distributed to the first conveyance passage (1
3), and sent to the third conveyance path (15).

The developer in the first conveyance path (13) is transferred to the first screw (I6).
) from the back side toward the front side in the direction of the arrow (Xl), and the second
A portion of the developer is supplied to the developing sleeve (5) while being conveyed to the passageway (14) and conveyed through the first conveyance path (13).

The developer supplied to the developing sleeve (5) is regulated by the height regulating member (19) attached to the front part of the upper caning (3), and is directed by the arrow (I2) based on the rotation of the developing sleeve (5). It is conveyed in a magnetic brush state in the direction of the arrow (
The electrostatic latent image formed on the surface of the photoreceptor drum (Ioo) is developed in the development area (P) facing the photoreceptor drum (100) rotating in the e) direction.

The developer that has passed through the development area (5) and is mixed into the developer being conveyed through the first conveyance path (I3).

The toner concentration of the developer is detected by a toner concentration detection sensor (23), and if the toner concentration is below a predetermined reference value, a second
Toner is replenished from the front side of the conveyance path (I4).

Next, the amount of developer transported through the transport paths (13), (14), and (15) will be explained.

The amount of developer (Vυ) carried into the first conveyance path (13) is equal to the amount of developer (■6) passing through the first path (9). Amount of developer (V3) carried into the second conveyance path (I4) via the second path (II)
and the amount of toner consumed by development (XV2 including the amount of carrier disappearance).

The developer transport amount (V,) transported by the second screw (17) from the front side of the second transport path (14) to the front side of the regulation plate (21) is the same as that of the first transport path (13), the third transport Road (
15) The amount of developer carried in from (■, ), (Vl), respectively
and the amount of toner newly replenished to the second conveyance path (14) (
ΔV).

Further, the developer conveyed through the second conveyance path (14) is regulated by a regulation plate (21), and the developer that has passed through this regulation plate (21) is transferred to the first passage (9) and the third passage (10). Since the developer is distributed to the adjusting path (2) from the developer conveyance amount (V4),
The amount of developer minus the amount of developer passing through 0) (V, ) is
It is equal to the sum of the amount of developer passing through the first passage (9) (V6) and the amount of developer passing through the third passage (10) (7).

The amount of developer conveyed by the third screw (]8) is from the rear end to the position of the adjustment path (20).
) is equal to the amount of developer (V7) conveyed from V7.

In addition, there is a fourth passage (12) on the near side from the adjustment passage (20).
The amount of developer (V,) transported up to the third transport path (10
) and the adjustment path (2).
0), and this is the sum of the amount of developer (V, ) conveyed from
It is equal to the amount of developer (V,) sent to

From the above, the following relationship can be obtained.

V + max > V + = V a = V2 + V.

V 4 max> V a = V 3 + V @+△
V=V, +V, -V.

V, max) VB=v, +v.

-V.

Vlmax: Conveyance capacity V, m of the first screw (16)
ax: Conveying capacity of the second screw (17) ■81Tla
x=transport capacity of the third screw (18) Here, since the amount of developer passing under the regulating plate (2I) of the second transport path (14) is constant, 3 aisles (1
The amount of developer (V6) and (V7) passing through 0) becomes constant, respectively, and the amount of developer jt(
v, X= v a) becomes constant.

Therefore, in the developing device (1), even if the total amount of developer contained in the developing device (1) fluctuates, the amount of variation is compensated for by the adjustment passage (20).
) from the second conveyance path (14) to the third conveyance path (15)
It is expressed in the amount of developer (V, ) sent to the first transport path (1
3) The amount of developer transported is always maintained constant. That is, the third conveyance path (15) is a cooling device for an automobile.
Similar to the sub-tank that keeps the coolant of the radiator constant at all times, it functions to keep the amount of developer in the first transport path (13) almost constant.

Therefore, it is possible to stably supply developer to the developing section (4).

In particular, even when using a high-speed copying machine that consumes a large amount of toner per unit time, or when continuously copying originals with a large area occupied by images, it is possible to stably supply developer to the developing section (4), thereby preventing density drop. High-quality images without uneven density can be obtained.

Therefore, a stable toner is always supplied to the electrostatic latent image on the photoreceptor drum (1), thereby stabilizing the quality of the developed image.

(Other Embodiments) In the embodiments described above, the third passageway (
lO) is provided, and the third passage (lO) and the adjustment passage (20) are provided.
The developer is supplied to the third conveyance path (15) from the above, but as shown in FIG. Tenomi No. 3
The developer may be supplied to the transport path (15).

In this case, all the developer passing under the regulation plate (21) is conveyed to the first conveyance path (13) via the first passage (9), and the developer in the second conveyance path (14) is conveyed to the first conveyance path (13). The regulating means is not limited to the regulating plate (21), but may be as shown in FIGS. 7-12.

In the one shown in FIG. 7.8, the developer is removed by making the conveying blade (17b) of the second screw (17) which the adjustment passage (20) faces smaller than the conveying blade (17a) in other areas. This reduces the transport capacity of

In this case, the developer sent by the transport blade (17a) stays at the transport blade (17b) and swells.
Excess developer passes through the adjustment path (20) and is transferred to the third conveyance path (
15) and the amount of developer that passes through the opposing portion of the adjustment path (20) becomes constant.

In addition, in the case shown in Fig. 9.10, a regulating part (14a), (1
4b) to narrow the width, and the transport blades (17c) and (17d) in that area are connected to the transport blades (17d) in other areas.
This is smaller than 7a) and has lower conveyance capacity. The regulating portion (14a) shown in FIGS. 9 and 10 has a tapered shape so that the width gradually becomes narrower along the developer transport direction, and the regulating portion (14b) shown in FIGS. 11 and 12 has a - They come in various sizes.

In these devices, the developer conveyed to the opposing portion of the adjustment path (20) is regulated by the restriction portions (14a) and (14b) and rises, and the excess developer is transferred to the adjustment path (20).
is conveyed to the third conveyance path (15) beyond the restriction part (14).
The amount of developer passing through a) and (14b) is constant.

(Effects of the Invention) As is clear from the above description, in the developing device according to the present invention, a first conveyance path, a second conveyance path, and a third conveyance path are provided behind the developing section, and the second conveyance path is used for conveyance. The developer is regulated by the regulating means, and the fluctuation amount of the developer is absorbed by the amount of developer regulated by the regulating means and conveyed to the third conveyance path.

Therefore, even if the amount of developer decreases due to carrier consumption, or even if the amount of developer temporarily fluctuates due to toner replenishment, the amount of variation is adjusted by the adjustment path, and the amount of developer in the first conveyance path is adjusted. The amount of drug is maintained constant.

Therefore, the amount of developer transported to the development area is constant, and stable image quality can be obtained.

Also, since it is longer toward the rear, it can accommodate more developer and carrier than conventional developing devices with the same bulk. By accommodating developers of different colors in the carrier, it is possible to make a copying machine, etc. multicolored, and the replenishment cycle of the carrier can be lengthened, so that the useful life of the developer can be extended.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a developing device according to the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIG. 3 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is a sectional view of the developing device FIG. 5 is a partial sectional view showing the flow of developer in the developing device. FIG. 6 is a diagram showing the flow of developer in the developing device of another embodiment, FIGS. 7 to 12 show other embodiments of the regulating means, and FIGS. A partial cross-sectional view of
Figure 8 is a cross-sectional view taken along line III-I [1] in Figure 7, Figure 10 is a cross-sectional view taken along line ■ to ■ in Figure 9, and Figure 12 is a cross-sectional view taken along line ■-v in Figure 11.
FIG. FIG. 13 is a perspective view of a conventional developing device. l...Developing device, 2...Casing, 4
...Developing section, 5...Developing sleeve, 6
...Magnetic roller, 7.First partition wall, 8.
...Second partition wall, IO...Third passage, I2...Fourth passage, 14...Second transport path, 15...No.'' screw, 18...Third screw, 21. ...Regulation board. 9...First passage, 11...Second passage, I3...First conveyance path, 15...Third conveyance path, 17...Second screw, 20...Adjustment passage,

Claims (2)

[Claims] (1) A developing section, a first conveying path located at the rear of the developing section, a second conveying path located at the rear of the first conveying path, and a third conveying path located at the rear of the second conveying path. a front wall located between the first transport path and the second transport path, a rear wall located between the second transport path and the third transport path, and a back side of the front wall. On the front side, a front first passage and a front second passage connect the first conveyance path and the second conveyance path, respectively, and on the back side and front side of the rear wall, the second conveyance path and the second A rear first passage, a rear second passage that communicate with the three conveyance paths, and the first
A first conveyance path that conveys the developer accommodated in the conveyance path, the second conveyance path, and the third conveyance path, and the developer in the first conveyance path from the back side to the front side, and supplies it to the developing section during the conveyance process. a conveyance means, a second conveyance means for conveying the developer in the second conveyance path from the front side to the rear side, and a third conveyance means for conveying the developer in the third conveyance path from the rear side to the front side; A developing device comprising: a regulating means for regulating the amount of developer conveyed in the second conveying path; and an adjusting passage for sending the developer regulated by the regulating means to a third conveying path. (2) The developing device according to claim 1, wherein the rear first passage coincides with the adjustment passage.