JPS62186285A - Developing device - Google Patents

Abstract

PURPOSE:To prevent toner from being scattered from a developing device as less as possible by forming a tuft regulating part for regulating the tuft of developer due to a magnetic pole formed immediatedly after a developing part. CONSTITUTION:The developer D is made to be tufted on the surface of a non- magnetic sleeve 33b by the line of magnetic force generated from respective magnetic pole parts N1, N2 N3, S1, S2 and attracted like a brush to form a developer magnetic brush D', the magnetic brush D' is successively carried to a developing part 34, and toner (a) in the magnetic brush D' adheres to an electrostatic latent image on a photosensitive body 6 to develop the latent image. In this case, the tuft of the developer D due to the carrying magnetic pole S2 generated immediatedly after the developer 34 is regulated, i.e. smashed, by the tuft regulating member 55 to make the magnetic brush D' dense. Consequently, the passage of an air flow is interrupted and the floating toner (a) in the developing device body 40 is not discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement of the current magnetic brush type III device applied to a brass forming device such as an electronic copying machine.

(Prior Art) This type of magnetic brush type developing device is equipped with a developing roller having a magnetic roll having a plurality of magnetic poles and a non-magnetic sleeve surrounding the magnetic roll. The developer which has been absorbed by the developer is conveyed to the developing section by the rotation of the sleeve, and development is performed.

In addition, a two-component developer consisting of a non-magnetic toner and a magnetic carrier, which are frictionally charged and attracted to each other, is usually used as a developer, and this is magnetically collected by a plurality of magnetic poles arranged on a magnetic roll. A vertical magnetic brush is formed, and the toner in the magnetic brush is electrostatically attached to one image for development.

In addition, among the magnetic poles arranged on the magnetic roll, the transport anode immediately after the developing section is located near the opening edge of the developing device main body, but conventionally, the transport anode immediately after the developing section is located near the opening edge of the developing device. The structure is such that no means is taken to prevent the spikes of developer from accumulating (Φ-wise).

(Problem to be Solved by the Invention) For this reason, the magnetic brush becomes rough near the front edge of the main body of the developing device, and the air flow generated by the rotation of the developer agitator disposed in the developer storage section, etc. accompanied by present ll
I! Some of the floating toner inside the apparatus body may scatter to the outside of the developing apparatus. In addition, the magnetic brush immediately after passing through the developing section is in a state where it is very likely to be scattered due to uneven charging or reverse band N of toner due to the potential of the photoreceptor, since it has just contributed to the development, and the magnetic brush is rough. If it is in this state, it will be more likely to scatter, and a portion of it will scatter every time a developing operation is performed. Then, there is a problem that this scattered toner accumulates and causes various adverse effects on the image forming operation.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a phenomenon device that has a simple configuration and is capable of preventing toner scattering from a developing device as much as possible. It is.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention has a magnetic roll having a plurality of magnetic poles and a non-magnetic sleeve surrounding the magnetic roll. In a magnetic brush type developing device that is equipped with a developing roller and conveys the developer adsorbed to the surface of the sleeve to the developing section by rotation of the sleeve, the magnetic pole immediately after the developing section prevents the developer from standing up. It is equipped with a panicle stand regulation section.

(Function) That is, the present invention regulates the spikes of developer caused by the magnetic pole immediately after the developing section, which is located near the opening edge of the main body of the developing device, by the establishment regulating section. is kept in a dense state, blocking the passage of airflow from the developing device main body to the outside caused by the rotation of the developer agitating body, and removing toner floating inside the developing device main body and self-imposed defects that have passed through the developing section. This prevents the toner from scattering in the developer magnetic brush which is in a stable state.

(Example) The following is an example of the present invention! An example will be explained with reference to FIGS. 1 and 2. FIG. 1 is a schematic sectional front view showing one embodiment of the present invention, and FIG. 2 is a schematic sectional front view 11 of a copying apparatus as an image forming apparatus to which the embodiment is applied.

In FIG. 2, reference numeral 1 indicates a copying machine main body as an image forming apparatus main body, and a document table 2 is provided on the top surface of the copying device main body 1 so as to be movable back and forth. is equipped with an operation panel.

Further, a paper feed cassette 3 is attached to the right side of the copying apparatus main body 1, and a cassette cover 4 of the paper feed cassette 3 serves as a manual paper feed table 5 for manually feeding paper P as appropriate.

A drum-shaped photoreceptor 6 serving as an image carrier is provided approximately at the center of the copying apparatus main body 1, and a charging device 7. Exposure device [8, developing device 98 transfer device 10
．． Peeling device 11. and a cleaning device W112 are arranged in this order.

Also, at the bottom of the copying machine main body 1 is an automatic paper feeder with a paper feed cassette 3 installed! ! Paper P1 supplied from 15
Then, the paper P fed from the manual paper feed tray 5 is transferred to the photoreceptor 6 and the transfer device l! 10, and a paper output tray 17 provided on the left side of the copying apparatus main body 1.
A paper transport path 18 is formed that leads to.

Further, a pair of aligning rollers 20 is arranged on the upstream side of the image-transfer section 16 of the paper transport path 18, and a fixing device 21 and a pair of paper ejection rollers 22 are arranged on the downstream side.

During the copying operation, the photoreceptor 6 is driven by a drive mechanism (not shown) in the direction of the arrow (clockwise in the state shown in FIG. The exposure lamp 23 lights up. First, the charging device 7 uniformly charges the document image, and the exposure device 8 sets the document image on the document table 2 onto the photoreceptor 6.
An electrostatic latent image thereof is formed. Next, the electrostatic latent image on the photoreceptor 6 is transferred as a developer image by a developing device 9 that uses a two-component developer consisting of non-magnetic toner a and magnetic carrier b, which are frictionally charged and attracted to each other. It is sent to the device 10 side.

On the other hand, a sheet of paper P that is automatically or manually fed is fed through a pair of aligning rollers 20, and the developer image previously formed on the photoreceptor 6 is transferred to the sheet of paper P by the movement of the transfer device 10.
transcribed into. Then, the paper P is peeled off from the photoreceptor 6 by a peeling device 11 using AC corona electricity, passes through a conveyance path 18, and is fed into a constant @v device. After the developer image is melted and fixed on the paper P, the paper ejection roller pair 2
2, the paper is discharged onto the paper discharge tray 17.

Note that after the developer image is transferred onto the paper P, the residual toner remaining on the photoreceptor 6 is cleaned by the cleaning device @12, and the next copying operation is ready.

Further, the above-mentioned image device 19 has a structure as shown in detail in FIG.

That is, this phenomenon device 9 consists of a lower unit 30a and an upper unit 30b, and the lower unit 30a is
*It consists of a structural part 31 and a developer stirring part 32.

The developing mechanism section 31 includes a developing roller 33 disposed opposite to an opening 41 in a lower casing 40a of a developing device main body 40, and a developer magnetic brush D' formed on the surface of the developing roller 33 exposed to light. A doctor 35 is provided at the sliding contact portion with the body 6, that is, on the upstream side of the developing section 34, and regulates the thickness of the developer magnetic brush D', and the developer magnetic brush D' whose thickness is regulated by the doctor 35 is leveled. It has a thin plate member 36. Further, the developer stirring section 32 includes a developer storage section 3 formed in the direction of the arrangement section of the developing roller 33.
It has first and second developer stirring bodies 38 and 39 housed in the developer stirring body 7 .

Further, the developing roller 33 has five f11 pole portions N1.
Magnetic roll 33a with N2, N3.8t, 32
and a non-magnetic sleeve 33b that is fitted onto the magnetic roll 33a and rotates counterclockwise in the figure.

The non-magnetic sleeve 33b is in a so-called with mode, in which development is performed by rotating in a direction that follows the rotation of the photoreceptor 6 (counterclockwise in the figure), and in a direction that follows the flow of the image on the photoreceptor 6. The developer brush D' held on its surface is
By this arrangement, sufficient developing time is ensured, and the static latent image formed on the photoreceptor 6 is developed in a high-quality image state.

Further, N1, which is the main pole (developing pole) disposed opposite the developing section 34, is i ooo Gauss, N2, which is the other transport pole, is 470 Gauss, N3 is 320 Gauss, and S+ is 90 Gauss.
0 Gauss, 82 has a magnetic force of 950 Gauss. In addition, Nr, which is the main pole (development pole), and Sl located upstream of this pole are at a position angle of 90 degrees (es = 90°), and Sl located downstream of the main pole (development pole) and Nt J-co are at a position angle of 60 degrees. It is in a state where it is arranged at a position angle (e2-60'').

Also, Sl and N3 are at a position angle of 65 degrees (e3-65°
), and N3 and N2 have a position angle of 65 degrees (es
-65°). Also, N2
and S1 are arranged at a position angle of 80 degrees (es = 80 degrees).

Further, the upper unit 30b includes an upper casing 40b of the developing device main body 40, a toner hopper 50 that is detachable from the upper casing 40b, and the developer storage section 3.
a developer concentration detector 51 that detects the developer 1rX in the toner hopper 7; and a replenishment device driving means that drives the replenishment roller 52 incorporated in the toner hopper 51 as necessary. (not shown), etc. are incorporated.

The first developer agitating body 38 has a plurality of blades attached so as to be externally fitted obliquely to the rotating shaft, and the first developer stirring body 38 is configured to move the developer in the developer storage section 37 in the axial direction of the developing roller 33. The image forming apparatus is fed to the developing roller 33 side while reciprocating along the same direction.

Further, the second developer stirring body 39 has a plurality of blades arranged in two rows with a phase of 180° along the axial direction of the rotating shaft, and is located directly below the toner supply port 54. The supplied toner a is uniformly mixed into the developer in the developer storage section 37.

As a result, developer particles stand on the surface of the non-magnetic sleeve 33b due to the lines of magnetic force generated from the respective F11 pole parts Nt, N2, N3, St, and 32, and are adsorbed in a brush-like manner to form a developing agent magnetic brush D'. The developer magnetic brush D' is sequentially conveyed to the developing section 34 by the rotation of the sleeve 33b, and the toner a in the magnetic brush D' adheres to the electrostatic latent image on the photoreceptor 6 and develops it. .

At this time, a bias voltage of the same polarity as the photoreceptor 6 is applied to the sleeve 33b via the shaft of the magnetic roll 33a to prevent fogging on the image, and a The replenishment roller 52 is driven by the replenishment signal, and the insufficient toner a is appropriately replenished.

On the other hand, the developer stirring body 3 disposed inside the developer storage section 37
The developer d is agitated by the rotation of 8.39, and the toner a and the carrier b are mixed together at 11! It is designed to perform frictional electrification well.

At this time, the rotation of the developer stirring body 38 scrapes out the developer in the developer container 37 to the lower part of the developing roller 533, and the developer passes directly under the developing roller 33 and enters the opening 41 of the developing device main body 40. However, in the present invention, there is a condition in which an air flow is generated such that the airflow is exhausted to the outside through Since the magnetic brush D' is regulated, that is, crushed and brought into a dense state, the air flow is blocked and the floating toner a inside the developing device main body 40 is not discharged.

Further, the magnetic brush D' immediately after passing through the developing section 34 is
Since the toner has just contributed to development, it is in a state where it is very likely to scatter due to uneven charging or reverse charging of the toner a due to the potential of the photoreceptor 6, but as described above, the magnetic brush D' is tightly controlled by the bristling control section 55. Since the state is set as follows, there is no scattering of the toner a in the developer magnetic brush D' which is in an unstable state.

It has been confirmed through experiments that a gap G between the sleeve 33 and the ear holder regulating part 55 of 1.1 m to 1.6 m is effective in preventing scattering of toner a, and it has been confirmed that the smaller the gap G, the greater the effect. Ta.

The developing conditions at this time were: a gap of 1.2 m between the photoreceptor 6 and the sleeve 33b, a gap of 1.1 m+ between the doctor 35 and the sleeve 33b, and a rotational speed of the sleeve 33b of 230 m.
s/s.

Although we have explained the development method using the with mode method, there is no difference in theory from the against method in which the sleeve 33b is rotated in the opposite direction to the rotation direction of the photoreceptor 6, and the developer immediately after development is The same effect can be obtained by pressing the holder of the magnetic brush D'.

Further, in the above-mentioned embodiment, a case has been described in which the spike-stand regulating section 55 is provided facing the magnetic pole S2 disposed immediately after the developing section 34, but the present invention is not limited to this, and for example, as shown in FIG. The magnetic pole S2 immediately after the developing section 34 may be provided in this way so as to face the TA bridge N3 disposed next, or as shown in FIG. It is also possible to provide a counter only in the part where the curve starts to stand.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the gist of the invention.

〔Effect of the invention〕

As explained above, the present invention uses a developing roller having a magnetic roll having a plurality of magnetic poles and a non-magnetic sleeve surrounding the magnetic roll, and removes the developing agent adsorbed onto the surface of the sleeve. This is a magnetic brush type developing device that performs development by being conveyed to a developing section by rotation, and is provided with a spike M611 section for regulating spikes of developer caused by magnetic poles immediately after the developing section. Therefore, it is possible to provide a developing device which prevents toner from scattering from the developing device as much as possible, although it has a simple structure.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a schematic longitudinal sectional front view, FIG. 2 is a schematic longitudinal sectional front view of an image forming apparatus incorporating the present invention, and FIGS.
The figures are configuration explanatory diagrams showing other different embodiments of the present invention. 6... Image carrier (photoreceptor), 9... Developing device, 33
...Phenomenon roller, 33a...Magnetic roll, 33b.
...Nonmagnetic sleeve, 34...Developing section, Sl, 82
, Nt. N2, N3...l1fi pole, D...developer, D'
...magnetic brush. Applicant's agent Patent attorney Takehiko Suzue 1 "1"

Claims (4)

[Claims] (1) A developing roller has a magnetic roll having a plurality of magnetic poles and a non-magnetic sleeve surrounding the magnetic roll, and the developer adsorbed on the surface of the sleeve is conveyed to the developing section by rotation of the sleeve. A developing device of a magnetic brush type that performs development, characterized in that a developing device is provided with a spike regulating section that regulates spikes of developer caused by magnetic poles immediately after the developing section. (2) The developing device according to claim 1, wherein the spike regulating section is provided facing a magnetic pole disposed immediately after the developing section. (3) The developing device according to claim 1, wherein the spike regulating section is provided to face a magnetic pole immediately after the developing section and a magnetic pole disposed next thereto. (4) The developing device according to claim 1, wherein the spike regulating section is provided so as to face only a portion of the magnetic pole immediately after the developing section where the spikes begin to rise.