JPH10149022A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device which can make circulative transport stably without applying a load on a developer. SOLUTION: A developer is carried out of an upper screw part 2 and dropped, and a lower screw part 3 receives the dropped developer and supplies it to a magnet roller 5 while the developer is transported in stirring in the second direction which is opposite to the first direction. Besides the lower screw part 3, a developing device includes an inclined surface part 15 furnished with a through hole 15a to admit threading of that part of the lower screw part 3 which is positioned downstream about the developer transporting direction, to guide upward the developer transported in stirring by the lower screw part 3 and to transmit it to the upper screw part 2, and a sealing member 19 to seal the gap which is formed between the through hole 15a of the inclined surface part 15 and the part of the lower screw part 3 threaded into the hole 15a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing an electrostatic latent image such as an electrophotographic image.

[0002]

2. Description of the Related Art There is a developing apparatus of this type which performs development using a two-component developer composed of a non-magnetic toner and a magnetic carrier. This developing device includes a developing sleeve which conveys a two-component developer in a circumferential direction as a magnetic brush and supplies the two-component developer to a portion to be supplied. In the developing sleeve, a mag roller having an arbitrary magnetic pole pattern is fixedly arranged.

[0003] Upper and lower developer transport paths are arranged in a developing container, and a lower screw section and an upper screw section for stirring and transporting the developer are disposed in the upper and lower developer transport paths, respectively.

The developer present in the lower transport path is pumped up by the magnetic pole of the mag roller and supplied to the developing sleeve. After the development, the toner remaining on the developing sleeve is separated between the magnetic poles such as the mag roller and collected again in the lower conveyance path.

The upper transport path and the lower transport path are separated by a partition wall, and the developer existing in the upper transport path is only stirred and transported without being supplied to the developing sleeve. That is, the toner is sufficiently charged in this section.

[0006] At both ends of the partition wall of the upper and lower transport paths, an opening for dropping the developer transported by the upper screw section to the lower transport path, and transported to the end of the lower transport path by the lower screw section. An opening is provided for pushing up the supplied developer to the upper transport path.

[0007] With such a configuration, the developer circulates through a lower transport path through which the developer can be supplied to and separated from the developing sleeve and an upper transport path through which the toner is sufficiently charged. You can do it.

[0008]

However, conventionally, there has been a problem in that the developer is pushed up from the lower transport path to the upper transport path. That is, since the developer conveyed in the longitudinal direction by the lower screw portion collides with the vertical wall of the developing container at the outermost portion, the developer conveyed by the lower screw portion causes pressure between the developers. And moves to the opening of the partition wall, which is the only escape route, and is supplied to the upper transport path.

For this reason, there is an inconvenience that a load is applied to the developers and the life is shortened. In particular, the toner in the case of a color copier needs to have good fixability,
Since the softening point is set lower, the toner is more likely to spend on the carrier due to the heat generated when the lower mixer agitates and transports the developer and the heat generated in the upper and lower transport paths.

Furthermore, if the developing device is small and high-speed, the stirring and transport of the developer becomes severe in order to satisfy the solid followability and the charging stability, which is disadvantageous for spent. Further, in the related art, since only the developer conveying force in the horizontal direction by the lower screw portion is used, it is unlikely that the developer is stably lifted upward.

Therefore, it has been difficult to achieve stable developer circulation. SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing device which can stably circulate and convey a developer without imposing a load on the developer, and can prevent leakage of the developer.

[0012]

In order to solve the above-mentioned problems, the present invention is directed to a developer supply means for supplying a developer comprising a toner and a carrier to a portion to be developed,
A first stirring / transporting means provided near the developer supply means for stirring / transporting the developer in a first direction; and a first stirring / transporting means provided below the first stirring / transporting means. A second stirring and conveying means for supplying the developer to the developer supply means while stirring and conveying the developer in a second direction opposite to the first direction upon receiving the developer dropped out of the apparatus; And an inclined surface portion having a through-hole for inserting a portion of the second stirring and conveying means on the downstream side in the developer conveying direction,
Guide means for guiding the developer agitated and conveyed by the second stirring and conveying means upward along the inclined surface portion and sending the developer to the first stirring and conveying means; a through hole in the inclined surface portion; And a sealing means for sealing a gap formed between the second stirring and conveying means and a portion of the second stirring and conveying means inserted therein.

According to a second aspect of the present invention, there is provided a developer supply means for supplying a developer comprising a toner and a carrier to a portion to be developed, and a developer supply means provided in the vicinity of the developer supply means for supplying the developer in a first direction. A first stirring / transporting means for stirring / transporting, and a developer provided below the first stirring / transporting means and receiving the developer dropped out of the first stirring / transporting means and dropping the developer into the first stirring / transporting means; A second stirring / conveying means for supplying to the developer supplying means while stirring / conveying in a second direction which is a direction opposite to the direction, and a downstream portion of the second stirring / conveying means in the developer conveying direction. A guide having an inclined surface formed with a through-hole through which the developer is stirred and conveyed by the second stirring and conveying means, and guiding the developer upward along the inclined surface to be sent to the first stirring and conveying means; Means, provided on the inclined surface portion, wherein the second It has a flexible tubular portion through which the end of the stirring and conveying means is inserted in close contact, and a flange formed in the tubular portion and attached to the inclined surface portion, and is inserted through the through hole of the inclined surface portion and the through hole. And sealing means for sealing a gap formed between the second stirring and conveying means and the second stirring and conveying means.

According to a third aspect of the present invention, there is provided a developer supply means for supplying a developer comprising a toner and a carrier to a portion to be developed, and a developer supply means provided near the developer supply means so that the developer is supplied in a first direction. A first stirring / transporting means for stirring / transporting, and a developer provided below the first stirring / transporting means and receiving the developer dropped out of the first stirring / transporting means and dropping the developer into the first stirring / transporting means; A second stirring / conveying means for supplying to the developer supplying means while stirring / conveying in a second direction which is a direction opposite to the direction, and a downstream portion of the second stirring / conveying means in the developer conveying direction. A guide having an inclined surface formed with a through-hole through which the developer is stirred and conveyed by the second stirring and conveying means, and guiding the developer upward along the inclined surface to be sent to the first stirring and conveying means; Means, a through hole in the inclined surface portion, and a through hole inserted into the through hole. And sealing means for sealing the gap formed between the portion of the second stirring and conveying means which,
And a supporting means for supporting an end of the second stirring and conveying means which passes through the through hole of the inclined surface.

According to a fourth aspect of the present invention, there is provided a developer supply means for supplying a developer comprising a non-magnetic toner and a magnetic carrier to a portion to be developed, and a rotary shaft and a rotary shaft provided near the developer supply means. A first stirring / conveying means having a blade portion rotated by a shaft, for stirring and conveying the developer in a first direction by the rotation of the blade portion, and provided below the first stirring / conveying means; A shaft and a blade portion rotated by the rotating shaft; receiving the developer dropped out of the first stirring / conveying means and dropping the developer into the first direction by rotating the blade portion; Is a second stirring / conveying means for supplying to the developer supplying means while stirring / conveying in a second direction which is the opposite direction, and a downstream portion of the rotating shaft of the second stirring / conveying means in the developer conveying direction. Through Guide means for guiding the developer agitated and conveyed by the second stirring and conveying means upward along the inclined surface part and sending the developer to the first stirring and conveying means; Sealing means for sealing a gap formed between a through hole in the inclined surface portion and a portion of the rotary shaft of the second stirring and conveying means inserted into the through hole.

According to a fifth aspect of the present invention, there is provided a developer supply means for supplying a developer comprising a non-magnetic toner and a magnetic carrier to a portion to be developed, and provided near the developer supply means; A first stirring / conveying means having a blade portion rotated by a shaft, for stirring and conveying the developer in a first direction by the rotation of the blade portion, and provided below the first stirring / conveying means; A shaft and a blade portion rotated by the rotating shaft; receiving the developer dropped out of the first stirring / conveying means and dropping the developer into the first blade by rotation of the second blade portion; A second stirring / conveying means for supplying the developer supplying means while stirring / conveying the developer in a second direction which is opposite to the first direction, and a partition between the first and second stirring / conveying means; The first stirring and transporting A partition member having a first opening for dropping the developer discharged from the means, a second opening for feeding the developer conveyed by the second stirring and conveying means upward at the other end, and The second stirring / conveying means has an inclined surface portion formed with a through hole for inserting a portion of the rotating shaft on the downstream side in the developer conveying direction of the rotating shaft, and the developer stirred and conveyed by the second stirring / conveying means is inclined. Guiding means for guiding upward along the surface portion and sending it to the first stirring / conveying means through the second opening; and a through hole in the inclined surface portion and the second means inserted into the through hole. A sealing means for sealing a gap formed between the stirring and conveying means and a portion of the rotating shaft.

According to the present invention, the developer stirred and conveyed by the second stirring and conveying means is guided upward along the inclined surface of the guide means and sent to the first stirring and conveying means.
The developer can be transported upward without imposing a load on the developer.

The sealing means seals a gap formed between the through-hole of the inclined surface of the guide means and the portion of the second stirring and conveying means inserted into the through-hole. To prevent leakage of developer.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIGS. 1 to 3 show the developing device 1. FIG. 1 is an external perspective view showing the developing device 1.

The developing device 1 has a developing container 1A, and a photosensitive drum 2 (see FIG.
Is provided with a magnet roller 5 as a developer supply means for supplying a developer, and a carrier to which toner has adhered adheres on the magnet roller 5 by magnetic force. The magnet roller 5 has a plurality of N-poles and S-poles disposed adjacent to each other inside, and a developing bias of 200 to 300V.
Applied.

An upper screw portion 2 as a first stirring and conveying means is rotatably provided on an upper side in the developing container 1A, and a lower portion of the upper screw portion 2 as a second stirring and conveying means is provided. The lower screw part 3 is provided rotatably. The developer is circulated and conveyed while being stirred by the rotation of the upper screw portion 2 and the lower screw portion 3, and is supplied from the lower screw portion 3 to the magnet roller 5.

FIG. 2 is a sectional view taken along the line II-II in FIG. In the developing container 1A, a two-component developer T composed of a non-magnetic toner and a magnetic carrier is stored. Styrene acrylic is used as the toner particles, and has an average particle size of about 10 μm and is negatively charged. 30-1 carrier particles
00 μm iron powder, a magnetic substance. In the developing container 1A, there is provided a doctor blade 6 for making the developer adhered on the magnet roller 5 a uniform developer layer.

In a practical developer obtained by mixing a toner and a carrier, the toner adheres as a substantially one-particle layer on the carrier particles.
5 to 20 carrier particles are connected by magnetic force to the developing gap therebetween to form brush ears. The developer at the tip of the brush tip carries toner particles to the electrostatic latent image surface on the photosensitive drum 2 to perform development.

The magnet roller 5 has a cylindrical sleeve 9 of φ20, in which the magnet 7 is provided. The magnet 7 has N1 pole, S1 pole, N2 pole, S2 pole,
It is fixed with the S3 pole, and the sleeve 9 is rotatably provided.

The developer in the lower screw 3 is attracted to the magnet roller 5 for image printing by the magnetic force of the N2 pole,
With the rotation of the sleeve 9, the doctor blade 6
Transport to The developer on the sleeve 9 is thinned by the doctor blade 6, and the photosensitive drum 2 is
The above development is performed. The developer on the sleeve 9 after the development has the weakest magnetic force between the N2 pole and the N3 pole (0G).
And transported into the lower screw 3.

By the circulation of the developer, the developer sufficiently supplied with the toner is rotated on the image printing magnet roller 5 to develop the photosensitive drum 2. FIG. 3 is FIG.
FIG. 3 is a cross-sectional view taken along line III-III.

The upper and lower screw parts 2 and 3 are
a, 16b and blades 17a, 17b rotated by the rotating shafts 16a, 16b.

Between the upper screw portion 2 and the lower screw portion 3, there is provided a partition plate 11 as a partition member for partitioning the two. One end of the partition plate 11 is opposed to one end of the lower screw portion 3 and has a first opening 12 for dropping the developer T, and the other end of the partition plate 11 is at the other end of the lower screw portion 3. An opposing second opening 13 is provided.

As the upper screw portion 2 rotates, the toner and the carrier are agitated and conveyed from one end to the other end as shown by the arrow, and fall from the first opening 12 downward. The toner and the carrier fall to one end of the lower screw portion 3 and are supplied to the developing magnet roller 5 while being agitated and conveyed toward the other end by the rotation of the lower screw portion 3 as shown by the arrow. Is done. The developer T that has not been supplied is sent to the upper screw unit 2 through the second opening 13 and is conveyed.

Thereafter, the developer is similarly stirred and conveyed cyclically and supplied to the developing magnet roller 2. FIG.
Denotes an inclined surface portion 1 as a guide means for guiding the developer upward.
It is sectional drawing which shows 5.

The inclined surface portion 15 is formed integrally with the inner bottom portion of the developing container 1, is opposed to the second opening 13 of the partition plate 11, and the end of the rotary shaft 16b is an insertion hole formed in the inclined surface portion 15. 15a. Rotating shaft 16
The end of b is rotatably supported by the developing container 1A via a ball bearing 18 with a rubber seal. A seal member 19 as a sealing means for sealing a gap between the insertion port 15a and the rotary shaft 16b inserted through the insertion port 15a is attached to the inclined surface portion 15.

FIG. 5 is a perspective view showing the seal member 19. The sealing member 19 is a rotary shaft 1 of the lower screw portion 3.
6b, and a flange 22 formed integrally with the base end of the cylindrical portion 21.

The seal member 19 is mounted by engaging its flange 22 with a mounting recess 23 formed in the inclined surface 15. A circular groove 21a is formed in the distal end surface of the cylindrical portion 21 so as to have flexibility so that the cylindrical portion 21 can be sufficiently adhered to the outer peripheral surface of the rotary shaft 16b.

The tip surface of the cylindrical portion 21 is perpendicular to the rotating shaft 16b of the lower screw portion 3, and the flange 22 is parallel to the inclined surface portion 15. Therefore, the angle θ in FIG. 5 is equal to the angle θ in FIG.

A notch 21b is formed in the outer peripheral surface of the cylindrical portion 21 so that the distal end surface portion and the flange portion 22 of the cylindrical portion 21 follow the lower screw portion 3 and the inclined surface portion 15, so that the cylindrical portion 21 can move flexibly. ing.

The rotating shaft 16 of the lower screw portion 3
After the ball bearing 18 with a rubber seal is fitted in the mounting groove 25 on the wall surface of the developing container 1A, the b is inserted into the ball bearing 18 and closed by the E-ring 26 to be supported.

With the above configuration, the developer conveyed by the lower screw portion 3 moves along the inclined surface portion 15 due to the conveying force. Unlike the conventional case where the developer is at right angles to the vertical wall of the developing container, the amount of compression even when pressed by the subsequent developer is reduced, and the developer is moved upward along the inclined surface portion 15. To go.

Here, an evaluation result showing that the inclined surface portion 15 is advantageous with respect to the vertical circulation of the developer will be reported. A developer in which a color toner and a coat carrier, which are expected to have a low softening point and are likely to be spent, are mixed with one another in a conventional vertical developing device, and the same developer is supplied to the inclined surface portion 15 of this embodiment. Replenish the developing unit 1 provided and perform forced stirring for 8 hours to analyze the spent amount of the carrier (carbon analysis)
The result of performing is shown.

According to this, a conventional developing device (with a vertical wall) shows a numerical value of about 1.9, and a developing device of the embodiment type having the inclined surface portion 15 shows a numerical value of 1.75. Was. From this, the inclined surface portion 15 is provided on the developing container 1a.
It has been found that the provision of reduces the load on the developer and enables stable conveyance.

[0040]

As described above, according to the present invention, since the guide means for guiding the developer upward is provided, the developer of the developing device which is small and has the developer agitating and conveying means arranged vertically is stably provided. In addition to being able to be circulated and transported, the load on the developer can be reduced and the life can be satisfied.

Further, since a gap between the insertion hole of the inclined surface and the portion of the second stirring and conveying means inserted through the insertion hole is sealed by the sealing means, leakage of the developer from the gap is prevented. Dirt can be prevented.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing a developing device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a cross-sectional view showing an inclined surface of a guide unit for guiding a developer upward.

FIG. 5 is a perspective view showing a seal member.

[Explanation of symbols]

 5 magnet roller (developer supply means) 9 developing sleeve 7 magnet 3 lower screw part (second stirring and conveying means) 4 upper screw part (first stirring and conveying means) 11 partition wall (partition member) 12) first opening 13 ... second opening 15 ... inclined surface (guide means) 19 ... sealing member 21b ... cutout 22 ... flange 15a ... insertion opening 18 ... ball bearing with rubber seal 23 ... mounting recess θ ... angle.

Claims (5)

[Claims] 1. A developer supply means for supplying a developer comprising a toner and a carrier to a developing portion, and a first means provided near the developer supply means for stirring and transporting the developer in a first direction. A stirring / transporting means, provided below the first stirring / transporting means, for receiving the developer dropped out of the first stirring / transporting means and dropping the developer in a direction opposite to the first direction; And supplying the developer to the developer supply unit while stirring and transporting the developer in the second direction.
And a slanted surface portion having a through hole through which a portion of the second stirring and conveying device on the downstream side in the developer conveying direction is inserted.
Guide means for guiding the developer agitated and transported by the agitating and transporting means upward along the inclined surface portion and sending the developer to the first agitating and transporting means; and inserting the developer into the through hole and the through hole of the inclined surface portion A sealing means for sealing a gap formed between the second stirring and conveying means and the second stirring and conveying means. 2. A developer supply means for supplying a developer comprising a toner and a carrier to a portion to be developed, and a first means provided near the developer supply means for stirring and transporting the developer in a first direction. A stirring / transporting means, provided below the first stirring / transporting means, for receiving the developer dropped out of the first stirring / transporting means and dropping the developer in a direction opposite to the first direction; And supplying the developer to the developer supply unit while stirring and transporting the developer in the second direction.
And a slanted surface portion having a through hole through which a portion of the second stirring and conveying device on the downstream side in the developer conveying direction is inserted.
Guide means for guiding the developer agitated and transported by the agitating and transporting means upward along the inclined surface and sending the developer to the first agitating and transporting means; and A flexible tubular portion through which the ends of the means are inserted in close contact with each other, and a flange formed in the tubular portion and attached to the inclined surface portion; and a through hole of the inclined surface portion and the through hole inserted into the through hole. A sealing means for sealing a gap formed between the second stirring and conveying means and the second stirring and conveying means. 3. A developer supply means for supplying a developer comprising a toner and a carrier to a portion to be developed, and a first means provided near the developer supply means for stirring and transporting the developer in a first direction. A stirring / transporting means, provided below the first stirring / transporting means, for receiving the developer dropped out of the first stirring / transporting means and dropping the developer in a direction opposite to the first direction; And supplying the developer to the developer supply unit while stirring and transporting the developer in the second direction.
And a slanted surface portion having a through hole through which a portion of the second stirring and conveying device on the downstream side in the developer conveying direction is inserted.
Guide means for guiding the developer agitated and transported by the agitating and transporting means upward along the inclined surface portion and sending the developer to the first agitating and transporting means; and inserting the developer into the through hole and the through hole of the inclined surface portion Sealing means for sealing a gap formed between the second stirring and conveying means and a supporting means for supporting an end of the second stirring and conveying means which passes through the through hole of the inclined surface. And a developing device comprising: 4. A developer supply means for supplying a developer comprising a non-magnetic toner and a magnetic carrier to a portion to be developed, a rotary shaft provided near the developer supply means and rotated by the rotary shaft. A first stirring and conveying means for stirring and conveying the developer in a first direction by the rotation of the blades; a first stirring and conveying means provided below the first stirring and conveying means; A rotating blade, receiving the developer dropped out of the first stirring and conveying means and dropping the developer, and rotating the blade to rotate the developer in a direction opposite to the first direction; A second stirring / conveying means for supplying to the developer supplying means while stirring / conveying in the direction of 2, and a through-hole for inserting a portion of the rotating shaft of the second stirring / conveying means on the downstream side in the developer conveying direction; Inclined surface Guiding means for guiding the developer stirred and conveyed by the second stirring and conveying means upward along the inclined surface portion and sending the developer to the first stirring and conveying device; A sealing means for sealing a gap formed between the second stirring and conveying means and a portion of the rotary shaft of the second stirring and conveying means inserted into the through hole. 5. A developer supply means for supplying a developer comprising a non-magnetic toner and a magnetic carrier to a portion to be developed, a rotary shaft provided near the developer supply means and rotated by the rotary shaft. A first stirring and conveying means for stirring and conveying the developer in a first direction by the rotation of the blades; a first stirring and conveying means provided below the first stirring and conveying means; A rotating blade, receiving the developer dropped out of the first stirring and conveying means and dropping the developer, and rotating the second blade to rotate the developer in a direction opposite to the first direction; A second stirring / conveying means for supplying the developer supplying means while stirring / conveying in a second direction, and a partition between the first and second stirring / conveying means; Unloaded from the stirring and conveying means A partition member having a first opening for dropping an image agent, and a second opening at the other end for feeding the developer conveyed by the second stirring and conveying means upward; and the second stirring and conveying. A rotating hole having a through-hole for inserting a portion of the rotating shaft on the downstream side in the developer transport direction, the developer agitated and transported by the second agitating and transporting means being moved upward along the inclined surface portion Guiding means for guiding to the first stirring and conveying means through the second opening, and a through hole of the inclined surface portion and rotation of the second stirring and conveying means inserted into the through hole. A sealing means for sealing a gap formed between the shaft and a portion of the shaft.