JPH066380Y2 - Developing device for electrophotographic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a developing device for an electrophotographic apparatus.

[Conventional technology]

The two-component developing device of the electrophotographic apparatus performs good development by carrying out good stirring of the two-component developer consisting of toner and carrier to charge the toner, then carrying the developer by the developing roll and transporting it to the photoreceptor. ing. Then, the toner supplied along with the consumption of the toner is mixed and stirred with the carrier in the mixing section, and the screw auger that conveys the developer in the axial direction is developed so that the toner concentration becomes uniform over the axial direction of the developing roll. There is a developing device provided parallel to the roll. Further, there is a developing device in which two screw augers are arranged on the same horizontal plane in parallel with the developing roll,
Each screw auger conveys the developer in different directions, and agitates while circulating the developer in a mixing section in the developing device.

[Problems to be solved by the invention]

However, the toner concentration of the developer conveyed to the screw auger becomes thinner toward the downstream in the conveying direction, so that the toner is not uniformly supplied in the axial direction of the developing roll, and a recorded matter having a uniform concentration cannot be obtained. There is. In particular, when the developing device is downsized and the amount of the developer accommodated is small, or when a large amount of high-density images are recorded, the density difference in the developing roll axial direction becomes remarkable.

Also, the developer conveyed to one screw auger is not conveyed over the entire length of the screw auger, but is conveyed to the other screw auger from the middle, and the developer circulates in a part of the area, which is effective in the developing device. There is a problem of not circulating. Then, not only the toner and the carrier are not uniformly mixed, but also the toner is not properly charged.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems, and to provide a developing device for an electrophotographic apparatus, which has a uniform toner concentration in the axial direction of the developing roll and which can charge the toner well. Especially.

[Means and Actions for Solving Problems]

According to the present invention, the above-mentioned object is a developing device for an electrophotographic apparatus, which is disposed between a pair of screw augers that are arranged in parallel with the developing means and convey the developer in different directions. A partition wall, and the partition wall has a plurality of notch windows for passing the developer in the axial direction of the auger, and the partition wall is inclined with respect to the developer transport direction and guides the developer into the notch window. It is achieved by a developing device having a guide member for

In other words, the developer conveyed by the screw auger in different directions with the partition wall as a boundary passes through the notched window of the partition wall and is mixed with the developer flowing in the opposite direction. The agents are mixed and stirred well, the toner concentration becomes uniform in the axial direction of the developing roll, and the charging failure of the toner is prevented.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a sectional view of the developing device.

In the developing device 1, there are provided a developing roll 3 facing the photoconductor 2 and screw augers 5a, 5b for stirring the developer 4 in the developing device 1. Further, the developing device 1
A toner box 7 for containing the replenishing toner 6 and a toner supply roll 8 for supplying the toner 6 into the developing device 1 are provided on the upper part of. A toner stirring member 9 is provided in the toner box 7, the toner 6 accommodated in the toner box 7 is appropriately stirred, and the toner 6 is supplied into the developing device 1 by rotating the toner supply roll 8. The supplied toner is screw augers 5a and 5b.
Is mixed and stirred with the carrier, and is conveyed to the developing roll 3 as the developer 4. The developing roll 3 is composed of a sleeve 10 and a magnet 11 disposed inside the sleeve 10.
The developer 4 is carried on top of the trimmer 1 by rotating it.
After the thickness is regulated by 2, the developer 4 is developed so as to face the photoconductor 2.

A partition wall 13 is provided between the pair of screw augers 5a and 5b to limit the axial transport path of the developer 4 by the screw augers 5a and 5b, and FIG. 2 shows only the cross section of the partition wall 13. 2 is a partial sectional view taken along line AA of the developing device 1 shown in FIG. The partition wall 13 is arranged in parallel with the screw augers 5a and 5b, and has a plurality of cutout windows 14 formed in the axial direction. The toner 6 supplied from the toner box 7 is screw augers 5a and 5b.
Thus, while being conveyed in the B, D, C and E directions, the developer 4 having a predetermined concentration is mixed and stirred with the carrier. Then, the developer 4 not carried by the developing roll 3 is returned to the screw auger 5a, circulated, stirred, and reused.

The developer 4 has a high concentration of the toner 6 in the region of the flow B of the screw auger 5b, and is conveyed to the screw auger 5a by the flow D at the end while keeping the high concentration. Next, while the developer 4 flows like C, the toner 6 gradually moves to the photoconductor 2 via the developing roll 3 and is consumed, and the toner concentration decreases from the upstream side of the flow C to the downstream side.

On the other hand, the developer 4 in the flows B and C passes through the notch window 14 of the partition wall 13 and shifts to the opposite flow, so that the developer 4 having a high toner concentration in the flow B is mixed with the developer 4 in the flow C, The developer 4 having a low toner concentration in the stream C mixes with the developer 4 in the stream B. Therefore, the axial concentration of the flow C of the developer 4 by the screw auger 5a for supplying the developer 4 to the developing roll 3 can be made uniform.

Further, since the developer 4 conveyed by the screw augers 5a, 5b flows in the directions B and C in general by the partition wall 13, the toner 6 is favorably slidably contacted with the carrier during the conveyance of the developer 4 to be charged.

Further, the partition wall 13 has a guide member 15 for guiding the developer 4 in the cutout window 14, and the guide member 15 is inclined with respect to the flows B and C and guides a part of the developer 4 into the cutout window 14. The flow can be reversed.

[Effect of device]

According to the present invention, since a partition wall is provided between a pair of screw augers for transporting the developer in different directions, and the partition wall has a notch window for passing the developer, the screw auger transports the developer. Mixing can be carried out at several points in the direction, and the concentration of the developer conveyed to the developing means can be made uniform in the axial direction. Furthermore, since the developer transporting direction is different at the partition wall, the developer is transported in the axial direction by the screw auger, and the toner is favorably triboelectrically charged. Therefore, according to the present invention, it is possible to perform development with a uniform density, and it is possible to obtain a high-quality recorded material without development failure.

[Brief description of drawings]

FIG. 1 is a side sectional view of the developing device, and FIG. 2 is AA of FIG.
FIG. Reference numerals in the figure: 1 ... Developing device, 2 ... Photoconductor, 3 ... Developing roll, 4
... Developer, 5a, 5b ... Screw auger, 6 ...
... toner, 7 ... toner box, 8 ... toner supply roll, 9 ... toner stirring member, 10 ... sleeve, 11
...... Magnet, 12 ...... Trimmer, 13 ...... Partition wall, 14 ......
Notch, 15 ... Guiding member.

Claims (1)

[Scope of utility model registration request] 1. A developing device for an electrophotographic apparatus, comprising a pair of screw augers arranged in parallel with a developing means for conveying a developer in mutually different directions, and partition walls arranged between the augers. , The partition wall has a plurality of notch windows for passing the developer in the axial direction of the auger, and the partition wall has a guide member which is inclined with respect to the developer transport direction and guides the developer into the notch window. A developing device characterized by the above.