JPH0264584A - Developing device - Google Patents

Abstract

PURPOSE:To supply the developer where toner and carrier are sufficiently mixed and agitated to a developing sleeve and to miniaturize a device by providing a toner replenishing hole on the side of a circulating passage and a partitioning plate of a transporting means. CONSTITUTION:Toner supplied to the side of a circulating passage 16 and the side of a partitioning plate 13 of a transporting means 11 from a toner replenishing hole 23a of a toner replenishing device 17 is transported to a circulating passage 15 while being mixed and agitated with the developer. A transporting means 12 is rotated and transports the developer where toner is replenished to the circulating passage 16 while mixing and agitating it, and only toner is supplied to a developing sleeve 14 during this transportation. The developer which has the toner concentration reduced and reaches the passage 16 passes the passages 16 and is transported by the transporting means 11 again while being mixed and agitated with fresh toner replenished from the device 17.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device in an image forming apparatus such as a copying machine.

(Prior Art) Some developing devices in image forming apparatuses such as copying machines use a two-component developer in which toner, which is a colored pigment, is mixed with iron powder, which is called a carrier. Such a developing device is provided with a transport means for sufficiently mixing and stirring the toner and carrier and transporting the mixed and stirred developer in a predetermined direction.

The developing device according to the above-mentioned prior art will first be explained with reference to FIG. Figure 3 shows a plan sectional view of the area around the developer stirring device for stirring and transporting the developer in the developing device.
Reference numeral 00 denotes a first transfer means that transfers the developer to the right of the arrow in the figure while stirring the toner supplied from the toner supply port 106a of the toner supply device 106 with the carrier.
One side of the transfer means 100 receives the developer from the first transfer means 100, and while stirring the toner and carrier, transfers the developer to the left of the arrow in the figure, and then transfers the developer again. A second transfer means 101 is also provided for transferring the second transfer means 100 to the first transfer means 100.

Between the first and second transfer means 100 and 101, the first and second
A partition plate 102 is provided to prevent the developers stirred and transferred by the transfer means 100 and 101 from mixing with each other, and both ends of the partition plate 102 and the side wall 110 of the main body of the developing device
, 111 are provided with developer circulation passages 103 and 104 for moving the developer between the first and second transfer means Zoo and 101. Further, a developing sleeve 105 is disposed on one side of the second transporting means 101, and the developing sleeve 105 supplies only the toner in the developer being transported by the second transporting means 101 to the photosensitive drum or the like. , development work is performed.

(Problem to be Solved by the Invention) However, in the prior art shown in FIG. 3, since the toner replenishment port 106a of the toner replenishment device 106 is provided almost at the same length in the axial direction of the first transfer means lOO,
The replenished toner directly enters the circulation path 103 that transfers the developer from the first transfer means 100 side to the second transfer means 101 side, as shown by the arrow, and is not sufficiently stirred and mixed with the carrier until it enters the developing sleeve 105. There was the inconvenience of arriving in the wrong direction. For this reason, developing sleeve 1
In No. 05, there was a problem that the toner density was partially high and uneven development occurred.

On the other hand, in order to eliminate the above-mentioned inconvenience, as shown in FIG. A toner replenishing device 203 is provided separately from the developing device main body 210, and the toner replenishing port 2 of this is provided separately from the developing device main body 210.
Some developing devices replenish toner from 03a to the first transfer means 200, but such a developing device has the disadvantage that it becomes larger and more complicated.

The present invention has been made in view of the above-mentioned problems, and its purpose is to supply a developing sleeve with a developer in which toner and carrier are sufficiently mixed and stirred, and to provide a small and compact developing device. There is something to do.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an arrangement in which a toner replenishing device and a developing sleeve are disposed parallel to each other in the axial direction, and a developer consisting of toner and carrier is disposed in opposite directions in the axial direction. first and second transfer means for agitating and transferring the toner, and a first transfer means provided between the transfer means to prevent mixing of the developer during transfer, and a first transfer means disposed at both ends of the toner replenishing device. a first circulation path for moving the developer from the transfer means to a second transfer means disposed on the developing sleeve side; and a first circulation path for moving the developer from the second transfer means side to the first transfer means side. In the developing device, the toner replenishment port of the toner replenishing device is located on a second circulation path side other than the first circulation path side of the first transfer means, or It is characterized by being provided on the partition plate side.

(Function) The developer is transferred from the first transport means to the second circulation passage through the first circulation path.
The toner is then transferred to the second transfer means, and then returned from the second transfer means to the first transfer means through the second circulation path and circulated within the developing device, or the toner supply port of the toner supply device is Because it is installed on the second circulation path side or on the partition plate side of the first transfer means, the supplied toner is not mixed or stirred and is directly transferred to the first transfer means.
The replenished toner does not move toward the developing sleeve via the second transfer means, but is mixed with a sufficient amount of developer in the first transfer means and then flows toward the first circulation path. Moving.

(Example) Next, an example of the present invention will be explained by taking a developing device of a copying machine as an example.
This will be explained according to the attached drawings.

FIG. 1 is a plan sectional view of the area around the developer agitating device of the developing device, and FIG. 2 is a view taken along the line II in FIG. 1. 11.1 in Figure 1
2, its left and right ends are parallel main body side walls 2 of the developing device l.
0.21 for screw-type developer, the first and second transport means 11.
Reference numeral 12 mixes and stirs toner, which is a colored pigment in the developer, and iron powder, which is called a carrier, and transports and circulates them within the developing device 1.

Further, a developing device 1 is provided between the first and second transport means 11 and 12.
The bottom of the body! ! ! 22 (see FIG. 2), a partition plate 13 is disposed to protrude from the first and second transfer means 11.
12 prevents mutual mixing of the developers transported respectively. Further, a first circulation passage 15 is provided between the right end of the partition plate 13 in FIG. The left end of the partition plate 13 and the left main body side wall 2
A second circulation path 16 is provided between the first and second transfer means 1 for moving the developer transferred by the second transfer means 12 to the first transfer means 11 side.

On the other hand, a toner replenishing device 1 is provided on one side of the first transfer means 11.
7 are provided along one transporting means 11. The toner replenishing device 17 includes a toner hopper 17a constituted by a main body side wall 20° 21, a main body bottom wall 221, a main body partition wall 23, and a main body rear wall 24.

A toner moving means 17b provided in the hopper 17a, and a toner supply port 23a provided in the main body partition wall 23.
The toner supply port 23a is opened toward the second circulation passage 16 side and the partition plate 13 side of the first transfer means 11. Further, on one side of the second transfer means 12, along the second transfer means 12, both ends thereof are directed to the side plate 20.21 of the main body of the apparatus, and the electrostatic latent image formed on the photosensitive tram 2 is As shown in FIG. 2, a developing sleeve 14 supplies toner to visualize the electrostatic latent image.
or has been set up.

Thus, from the toner supply port 23a of the toner supply bag 5!17 to the second circulation passage 16 side of the first transfer means 11 and the partition plate 1
The toner supplied to the third side is mixed and stirred with other developer by the first transfer means 11 rotating in the direction of the arrow in FIG. 1, and is transferred to the first circulation path 15 on the right side in the figure. On the other hand, the second transfer means 12 is rotating in the direction of the arrow in FIG.

The developer replenished with the toner is mixed and stirred and transferred to the second circulation path 16 in the left direction in the figure, and during this time only the toner is supplied to the developing sleeve 14. Then, the developer whose toner concentration has decreased and has reached the second circulation path 16 passes through the second circulation path 16 and is mixed and agitated with new toner supplied from the toner replenishment device 17 and returned to the first transport means. 11 to the right, and this operation is repeated thereafter.

As described above, according to the present invention, the toner supply 023a of the toner supply device 17 is transferred to the second circulation passage 16 of the first transfer means 11.
Since the toner is provided on the partition plate 13 side, the supplied toner is directly supplied from the second transfer means 12 to the developing sleeve 14 through the first circulation passage 15 without being mixed or stirred with other developer. There isn't. Therefore, the developer having a high toner concentration is partially supplied to the developing sleeve 14, and uneven development does not occur in the development by the developing sleeve 14, and toner replenishment of the prior art developing device shown in FIG. Mouth 1
Since the purpose can be achieved by only slightly changing the position of 06a, the device does not need to be enlarged.

Furthermore, in the present invention, since the hopper 17a of the toner replenishing device 17 is constructed using the main body wall of the developer bag fit,
In addition to making the device smaller and more compact and saving on materials, the toner replenishing port 23a of the toner replenishing device 17 is disposed within the developing area width A of the developing sleeve 14, so the fourth
The configuration of the prior art shown in the figure is no longer necessary, and the device can be further miniaturized and compact.

Although the hopper 17a of the toner replenishing device 17 is constructed using the side plates 20.21 of the main body of the developing device 1, it is of course possible to construct the hopper 17a with a separate member from the side plates 20.21 of the main body.

(Effects of the Invention) As is clear from the above description, according to the present invention, the toner replenishing port of the toner replenishing device is positioned at an appropriate position with respect to the developer circulation direction, that is, at the first position relative to the first transport means. Since it is provided on the side of the second circulation path other than the side of the first circulation path or on the partition plate side, the replenished toner is sufficiently mixed and stirred with the carrier and supplied to the developing sleeve. Therefore, the developer having a high toner concentration is not supplied to the developing sleeve partially, and uneven development does not occur in the developing sleeve.

Further, in the present invention, compared to the conventional one, only a part of the position of the toner replenishment port is changed, so that the apparatus does not become large in size and becomes compact.

[Brief explanation of the drawing]

Fig. 1 is a plan cross-sectional view of the area around the developer agitating device of the developing device, Fig. 2 is a view taken along the line I-I in Fig. 1, and Fig. 3 is a plan view of the area around the developer agitating device of the developing device showing the prior art. 4 is a plan sectional view of the area around a developer stirring device of a developing device showing another conventional technique. 1-.Developing device, 11-.First transport means, 12.
...Second transport means, 13...Partition plate, 14...Developing sleeve, 15...First circulation passage, 16...Second circulation passage, 17...Toner supply device, 17a...
・Hopper, 20.21... Device main body side wall, 22...
Device main body bottom wall, 23--Device main body partition wall, 24...
Device main body rear wall (20 to 24... device main body wall). Patent Applicant: Canon Co., Ltd.

Claims (3)

[Claims] (1) first and second transport means that are disposed axially parallel to each other between the toner replenishing device and the developing sleeve, and that stir and transport developer consisting of toner and carrier in mutually different axial directions; A first transfer means is provided between the transfer means to prevent the developer from being mixed during transfer, and a second transfer means is provided on both end sides of the transfer means, from the first transfer means disposed on the toner replenishing device side to the second transfer means disposed on the developing sleeve side. The partition plate includes a first circulation path for moving the developer to the transfer means side and a second circulation path for moving the developer from the second transfer means side to the first transfer means side. A developing device characterized in that a toner replenishing port of the toner replenishing device is provided on a second circulation path side or a partition plate side of the first transfer means other than the first circulation path side. (2) The developing device according to claim 1, wherein the toner replenishing port of the toner replenishing device is disposed within the width of the developing area of the developing sleeve. (3) a toner storage hopper section in which a toner replenishment port of the toner replenishment device is formed;
Claims 1 and 2 are characterized in that the conveying means and the wall of the main body of the apparatus that houses the developing sleeve are integrally constructed.
The developing device described.