JPS6095566A - Developing device - Google Patents

Abstract

PURPOSE:To supply an always refreshed developer to a developing part and to obtain stable image quality by agitating and conveying the developer and supplying the same by magnetic force. CONSTITUTION:An agitator 5 as a conveyance means for conveying and agitating a developer 4 is provided. A magnet roller 6 as a supply means consists of a cylindrical developing sleeve 24 and a magnet 25 provided in the sleeve 24. The magnet 25 has seven poles; three conveying poles S3, N3, S4 for forming a magnetic brush and conveying the developer onto a developing sleeve 24, one main pole N1 for holding the magnetic brush and performing development and three recovering poles S1, N2, S2 for recovering the magnetic brush after development. The developer from the surface of the sleeve 24 is pulled off by the decrease, etc. in the restraining force by the magnetic force of the 3rd S2 and succeeding recovering pole and is further fed to the agitator 5 by the flow of the developer 4 generated by the spiral rotation of the agitator 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a developing device used in, for example, an electronic copying machine or a C11-printer.

[Technical background of the invention and its problems] For example, in electronic copying machines, Ray printers, etc.
Is it formed by an electric charge? @As a developing device for making the latent age visible, those shown in Fig. 1 I13 and Fig. 2 J are used. However, in this developing device, there is a developer conveying agitator 11' (which rotates in conjunction with the developing roller C, which magnetically attracts the developer a to its surface and conveys it to the developing area, so that the direction of rotation is reversed). 1 is provided, and the current IK+ illa, which is not subjected to development and is collected into the container e by the developer roller C, is moved in the same direction as the traveling direction of the developing roller C. ; While being mixed with the developer a in the container e, the developer is sent again to the conveying magnetic pole installed at the bottom of the layer pressure regulating member r.

However, with this device, [
) The darkness of the developer sent to the layer pressure regulating part can be ensured, and the lack of developer supply to the developing magnetic brush may result in feed cost and b.
Since the developer a after development is not separated from the developing roller C and is easily used for development again, the developer a is supplied in a state suitable for replenishing toner and being charged and producing an image. There was a problem that it was too small.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its object is to provide a developing device that can constantly supply a refluxed developer to the developing area to obtain stable image quality. There is one thing to offer.

[Summary of the invention]

In order to achieve the above object, the present invention provides a conveying means for conveying a developer, and a conveyor that conveys the developer conveyed by the conveyor by magnetic force to the area to be developed. It is equipped with a supply element 1'9 for supplying and developing the same, and this supply means has 1K to 14K of the same polarity 111 arranged across a line connecting the center and the center of the conveyance means, and the supply element 1'9 has 1K to 14K of the same polarity 111 arranged on both sides of the line connecting the center and the center of the conveyance means. By forming a portion where the developer is removed from the force, the developer that has been used for development is removed from the supply means, and a fresh developer is applied to the area to be developed by the supply means. It is characterized by the fact that it is supplied with

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 to 8. 3 to 6, reference numeral 1 denotes a container with an opening 3 facing a photosensitive drum 2, which rotates in a predetermined direction and serves as a developing section, and the container 1 contains toner and carrier. a developer 4 , a stirrer 5 as a conveying means for conveying and stirring the developer 4 , and a stirrer 5 that conveys and stirs the developer 4 to the photoreceptor drum 2 .
a magnet roller 6 as a supply means for supplying the toner in the developer 4 through the opening 3; a layer thickness regulating member 7 regulating the layer thickness of the developer 40 conveyed to the magnet roller 6; A collection plate 8 for returning surplus developer 4 regulated by the layer thickness regulating member 7 to the agitator 5;
, a density detector 9 for detecting the density of the developer 4, and the like.

A bottom lid 1 is formed at the bottom of the container 1 to form a first duct 10 for sucking the developer 4 scattered from inside the container 1 to the outside.
1 is arranged, and this first duct 10 has its suction port 12
faces the photosensitive drum 2 below the developing area. In addition, the upper part of the container 1 is provided with a current 1 from the magnetic roller 6.
A top lid 13 is arranged 8Q to prevent the scattering of the drug 4,
This can be attached to the side plate 14.15 of the container 1.
JIno et al. 11. I'm here. Also, a second duct 1 is provided at the upper part of the upper lid 13 to suck up the present 1 & ξ agent 4 that has been scattered.
6 h (formed between the cover 17 and this second duct 16 t, -L, its suction port 18 faces between the magnet [1-ra 6 and the cover 17. A screen wall 19 is provided in the first and second ducts 10.16 to sequentially narrow the gap from the front side to the rear side in order to equalize the suction efficiency in the axial direction.

Also, blocks 20 are installed inside the side plates 14 and 15 of the container 1.
．． 21 are arranged to face each other, and a third duct 22 communicating with the first duct 10 of the bottom 111 is formed inside the block 20 on the rear side.

And this third dak 1-22 and one f! +! J21
The second duct 16 of 113 is located on the rear side of the container 1.
They are joined at a fourth duct 23, and connected to a suction device (not shown) through this fourth duct 23.

The magnet 1-roller 6 is a cylindrical developing sleeve 2.
4 and a magnet 25 provided inside the developing sleeve 24, which are rotatably held by the side plates 14 and 15 of the container 1.

The agitator 5 is connected to the photosensitive drum 2 of the magnet roller 6.
It is held on the side plate 14, 15 on the opposite side, and has two double spirals arranged coaxially with different winding directions, and partitioned by a cylindrical sleeve 26 to form an integral structure.

Further, a first gear 28 is attached to the shaft 27 of the developing sleeve 2/I, a second gear 30 is attached to the shaft 29 of the agitator 5, and these are connected to a third gear 31. They are connected and interlocked through. The second gear 30 is a coupling gear, and is provided with an engaging protrusion 32.

The layer thickness regulating member 7 is approximately 30 mm thicker than the magnetic roller 6.
It is placed at the top. And block 2 on both sides
0.21, and by moving it horizontally, the layer thickness of the magnetic brush formed on the developing sleeve 26-4 can be regulated and controlled.

The collection plate 8 is arranged below the layer thickness regulating member 7, and similarly to the layer thickness regulating member 7, it is supported by the blocks 20, 21 on both sides.

The concentration detector 9 is disposed on the - side of the collection plate 8, and detects the retoner 1INIff when it comes into contact with the developer 4. For example, by a magnetic bridge method, the density detector 9 detects the magnetic permeability of the current 1m developer 4, and detects the toner concentration. What is the configuration of the file?

Further, the upper lid 13 is provided with a convex portion 33 having a curvature with a slight gap between the developing sleeve 24 and the developing sleeve 24 above the non-image portions at both ends of the developing sleeve 24, so that the developer 4 can be transferred to the developing sleeve 2/I. J: It is curved to prevent it from getting in between the side plates 14 and 15 of the container 1. Furthermore, flange portions 34, 35 are provided at the portions of the blocks 20° 21 on both sides facing the developing sleeve 24, thereby allowing 1lli! +1) The gap between the sleeve 24 and the side plates 14 and 15 is approximately 0.2 to 0.4 mm to prevent the developer 4 from entering. In addition, the above cover 1
A brush 36 that contacts the photosensitive drum 2 is provided at the tip of the brush 7 to prevent the developer 4 from scattering from between the photosensitive drum 2 and the cover 17 to the upper side of the container 1 .

Next, to explain the above-mentioned stirrer 5, 37 in Fig. 7 is the first spiral, which has an inner diameter of 8 mm and an outer diameter of 25 mm.
It is made by winding around a shaft 29 two cloth-wound spirals with a front and rear lead of 20 to 40 mm.

Further, a second spiral 38 is coaxially provided on the outer periphery of the cylindrical sleeve 26 and has an outer diameter 32 to
It is wound with a left-handed double spiral with a length of 34 mm and a lead of 250 to 350 mm, and is fixed to the first spiral 37 so that it can rotate integrally therewith. Furthermore, the cylindrical sleeve 26 is provided with several first developer discharge holes 39 at the center of the opening of the first spiral 38 at a position 12 to 13 mm rotationally rearward of the second spiral 38, and a plurality of first developer discharge holes 39 are formed on the rear side. A second developer discharge hole 40 is opened from the root of the second spiral 38 to 90 degrees backward in rotation.

In addition, first and second disks 41 and 42 are provided at both ends of the first spiral 37 to regulate the flow in the axial direction on the riverside image side 4. The bearings are designed to prevent the developer 4 from entering the portions 43 and 44.Furthermore, the lead of the first spiral 37 from the second disc 42 on the I side to the rear side is The cylindrical sleeve 26 and the second spiral 38 are not provided in the length of the minute, and the first spiral 37 is exposed.The part where the first spiral 37 is exposed -C A toner replenishing port 45 is provided above, and a toner receiving portion/16 having a curvature with a slight gap along the outer diameter of the first spiral 39 is provided below.

When the agitator 5 rotates in the direction shown and 1 to toner are supplied from the toner supply port 45, 1 to the toner supply port 4
The developer 4 located at the lower part of the developer 4 is mixed with the developer 1 to the developer 4 and is conveyed to the rear side by the first spiral 37 and enters the cylindrical sleeve 26 . The developer 4 that has entered the cylindrical sleeve 26 continues to be stirred as it is and is moved to the rear side. On the way, the developer 4 that has been stirred to some extent is discharged little by little from the first developer discharge hole 39 to the outside of the cylindrical sleeve 26, and then
By the time the developer reaches the developer discharge hole 40 of the agitator 5, the developer 4 replenished with toner is present over the entire axial direction of the outer circumference of the cylindrical sleeve 26 of the agitator 5. Further, the developer 4 coming out of the cylindrical sleeve 26 is scooped up into the developing sleeve 24 by the second spiral 38 and moves from the rear side to the front side. Then, the toner finally reaches the toner supply port 45 again and repeats the above cycle. That is, the flow of the developer 4 is clear, such that the developer 4 whose density has become higher due to toner replenishment is sufficiently stirred before being used for development, and the developer 4 whose density has become lower is replenished with toner. This allows stable image density to be obtained at all times.

Next, to explain the magnet roller 6, as shown in FIG. 5 and FIG. 'All53. N
3. S4, one main J(iNl) arranged in a row on the photosensitive drum 2 to hold the magnetic brush and perform development, and three collecting parts 8 for collecting the magnetic brush after development.
1. It is configured with 7 poles with N2.82.

The magnetic poles are arranged in a J: direction with different polarities from the first transport pole S3 to the third collection section S2, and
Only the third transport pole S2 and the third transport pole S2 are connected to the same pole, and the position of the weak magnetic force created between them is the magnetic roller 6.
The center of the stirrer 5 is located near the line connecting the center of the stirrer 5. As a result, the developer 4 that is attracted to the surface of the developing sleeve 24 and is reliably transported from the first transport pole S3 to the third collection section S2 is reduced in the binding force due to the magnetic force after the third collection section S2. , due to the centrifugal force due to the rotation of the developing sleeve and the action of gravity, the developing sleeve 24
is pulled away from the surface and blown towards the stirrer 5. This developer 4 is further sent to the agitator 5 by the flow of the developer 4 generated by the rotation of the second spiral 38 of the agitator 5, and the developer 4 mixed with toner is again sent to the agitator 5.
It will be mixed with. In other words, once the toner has been consumed, the developer 4 is refreshed before being used for development. Further, since the lower frame 47 between the developing sleeve 24 and the agitator 5 is inclined with respect to the angle of repose of the developer 4, the developer 4 is less likely to sink to the bottom.

Further, in the first transport pole S3, a wide magnetic material is arranged near the inside of the developing sleeve 24.
The area near the peak value of the magnetic flux density on the surface covers the height from the top of the stirrer 5 to the tip of the collection plate 8. Therefore, the developer 4 is transferred from the top of the stirrer 5 to the collection plate 8.
It is attracted over the entire upper area of the developing sleeve 24 up to the tip,
A sufficient amount of developer is maintained according to the structure of the magnetic brush, and there is no shortage of developer supply. Further, the height of the region near the magnetic flux density peak value of the first transport pole S3 is
Since the magnetic flux density rapidly decreases above the height of the tip of the layer pressure regulating member 7, the surplus developer 4 is weakly restrained by the magnetic force, and the collection plate 8
It becomes easier to flow over the top.

Further, the collection plate 8 starts at a position where the distance from the express sleeve 24 and the distance N1 from the lower surface of the layer thickness regulating member 7 that constitutes the passage for the developer 4 are approximately the same. Corner J: Installed at a somewhat gentle slope. Therefore,
The excess developer 4 passes through a path with constant gaps, and is unlikely to stagnate or be compressed at the bottom of the layer thickness regulating member 7, and flows smoothly. , angle of repose J: The flow is controlled to a certain extent by a somewhat gentle slope.
! + It will flow evenly while being controlled. Further, the layer thickness regulating member 7 is installed so that its wedge-shaped tip has a rake angle of about 45 degrees and a relief angle of about 15 degrees with respect to the developing sleeve 24, and the developer 4 adsorbed on the developing sleeve 24 The thickness of the layer is regulated by taking two steps. Therefore, the stress applied to the developer 4 is reduced, which has the effect of reducing rotational torque and extending the life of the developer 4.

In addition, a collecting part 13-48 with a gentler slope is installed on the collecting plate 8, and the collecting part 13-48 is tilted at an angle of about 30 degrees with respect to the collecting part 48, and the gap at the closest part is maintained at 3 to 4 mm. The concentration detector 9 of the magnetic bridge type having a flat probe surface 49 is installed. The developer 4 is configured to flow between the collection section 48 and the probe surface 49. Furthermore, a first
A rectifying magnet 50 is installed with the magnetic pole SO of the same polarity as the first transport pole S3 facing downward, and the lines of magnetic force generated by the first transport pole S3 and the rectifying magnetic pole SO are approximately parallel to each other along the upper surface of the collecting section 48. It is intended to be. As a result, the collection section 4
The developer 4 between the developer 8 and the probe surface 49 has a stable steady flow with little stagnation or surface collapse, and the output for concentration detection is stabilized. Note that if the distance between the collecting section 48 and the probe surface 49 is too narrow, the flow will begin to stagnate.
Even if the toner is replenished, it will not respond sensitively, and if it is spread too much, the detection output will fluctuate greatly due to fluctuations in the laminar pressure of the flow, making it impossible to obtain a stable output.

14- Also, the first transport pole S3 is excellent! ii. The maximum width of the sheet for copying the image is the same as the maximum width of the sheet, and the other magnetic poles are longer than this. Therefore, the magnetic force is directed so that the bulge of the developer 4 due to the increase in magnetic flux near both ends of the magnetic pole passes through the layer thickness regulating member 7 and extends to both sides, and the layer thickness of the developer 4 near both ends increases. It becomes uniform, and the phenomenon can be achieved without cracking or darkening of uniformity due to excessive contact with the photoreceptor drum 2 at both end portions. In addition, all the image widths except for the first transport pole S3 are improved, and therefore, the area where the layer thickness of the developer 4 is reduced due to the decrease in magnetic force at both ends of the magnetic pole is on the outside of the iiiim width J:. , developing defects are less likely to occur at both ends. Further, since the developer 4 is effectively used at both ends of the magnetic pole and no surplus t[developer 4 is generated, the blocks 20.
Almost no developer 4 passes over the flange portions 34 and 35 of the developing sleeve 21 and enters the gap between both ends of the developing sleeve 24 and the side plates 14 and 15 of the container 1. Roughly, developing sleeve 24
There is a distance of 1 to 5 mm P from both ends of the magnetic pole on the inside of both sides.
Magnetic disks 51 and 52 having a diameter slightly smaller than the outer diameter of the developing sleeve 24 are arranged outside the developing sleeve 24 to reduce the magnetic flux density leaking outward from both ends of the developing sleeve 24. Therefore, the developer 4 is no longer drawn into the gap between both ends of the developing sleeve 24 and the side plates 14 and 15 of the container 1, and even if there is developer 4 that enters, it is not allowed to adhere to both sides of the developing sleeve 24. However, the developing sleeve 24 rarely rotates, and the developer 4 does not scatter from both ends of the developing sleeve 24.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a conveyance means for conveying the developer, and a supply means for conveying the developer conveyed by the conveyance means by magnetically attracting it, and supplying it to the area to be developed for development. and the supply means has magnetic poles of the same polarity arranged across a line connecting the center of the supply means and the center of the conveyance means, and a portion that releases the developer from the magnetic force is formed near the line. The developer used for development can be removed from the supply means, and new developer can always be supplied to the developing area by the supply means, thereby achieving excellent effects such as stable image quality.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing different conventional examples, and FIGS. 3 to 8 show an embodiment of the present invention,
Figure 3 is a perspective view, Figure 4 is a cross-sectional plan view, Figure 5 is a longitudinal side view, Figure 6 (perspective view showing the block on the J rear side, Figure 7)
The figure is a front view of the stirrer and IY device, and FIG. 8 is a partially sectional side view showing the magnet roller portion. 2...Developed area (photosensitive drum), 4...Developer,
6... Feeding means (magnetic roller), 5... Conveying means (stirrer), 26... Cylindrical sleeve, 37...
1st spiral, 38...2nd spiral. Applicant's representative Patent attorney Takehiko Suzue 17- Figure 1 Figure 2 Figure 3 Figure 4 Figure 2 Figure 5 Figure 6

Claims (2)

[Claims] (1) A conveyance means for conveying the developer, and a supply means for conveying the developer conveyed by the conveyance means by adsorbing it with a till force, and supplying it to the area to be developed for development. 1, a magnetic pole of the same [i 11 is placed between the lines connecting the center of the supply means (1) and the center of the conveyance means, and a portion for releasing the developer from the magnetic force is provided near the line. A developing device characterized by the following features: (2) The conveyance means arranges first and second spirals having different winding directions on the same axis, and partitions and rubs between the first and second spirals with a cylindrical sleeve. developing device.