JPH03127087A - Image forming device - Google Patents

Abstract

PURPOSE:To perform sharp printing by providing a means satisfactorily attracting toner splashing from a gap between a developing unit and an image forming body. CONSTITUTION:Toner in the gap between the developing unit 4 and the image forming body 1 mainly splashes in the downstream side of the developing unit 4 due to the rotation thereof. Since an air flow is created in the full length of a nozzle 22 by the air suction of a sucking means 23 and the air blow of a blower means 24, the action of dynamic pressure in the gap between the nozzle 22 and the image forming body 1 increases in the full length of the nozzle 22. Consequently, the nozzle 22 satisfactorily sucks nearby air at any location in the longitudinal direction thereof. Further, the nozzle 22 is arranged near the downstream side of the developing unit 4. Accordingly, toner splashing from the gap between a toner attracting mechanism 20 and the developing unit 4 is satisfactorily attracted. Thus, sharp printing is attainable.

Description

[Detailed Description of the Invention] [Summary] This invention relates to an image forming device that develops an electrostatic image formed on an image forming body with toner using a developing device facing the cough image forming body, and provides clear printing over a long period of time. The object of the present invention is to provide a toner absorption mechanism that can satisfactorily absorb toner scattered from the gap between the developing device and the image forming body. a cylindrical nozzle having an opening facing the image forming body near the downstream side of the developing device in the direction of rotation of the image forming body; a suction means for sucking air in the nozzle from one end of the nozzle; and an air supply means for blowing air into the nozzle from the other end.

[Industrial application field]

The present invention relates to an image forming apparatus that develops an electrostatic image formed on a rotating image forming body with toner using a developing device facing the image forming body, and transfers the toner image onto a medium for printing. The present invention relates to a toner absorption mechanism for absorbing toner scattered from a gap between the developing device and the image forming body.

The image forming apparatus is generally called an electrophotographic printing apparatus, and is widely used as a recording apparatus such as a copying machine or a facsimile machine.

Some of them are equipped with the toner absorption mechanism to enable clear printing for a long time, but it is desirable that the toner absorption mechanism sufficiently absorb the scattered toner. It will be done.

[Conventional technology]

FIG. 3 is a side view illustrating the image forming apparatus.

In the figure, a charger 2, an optical unit 3, a developer 4, a transfer section 5, a static eliminator 6, and a cleaner 7 are arranged around a rotating cylindrical image forming body (photosensitive drum) 1 according to the direction of rotation. The image forming body 1 has a surface charged by a charger 2 and is irradiated with optical data configured through a predetermined conversion process from an optical unit 3 to form an electrostatic image. The electric image is developed with toner by a developing device 4 to become a toner image, and the toner image is transferred to a medium (printing paper) P by a transfer section 5. After the transfer is completed, the charge is removed by a charge remover 6, cleaned by a cleaner 7, and charged again by a charger 2.

The medium P is fed from a cassette (not shown) to a conveyance path 8, where the transfer is performed, the transferred toner image is fixed by a fixing device 9, printing is completed, and the medium P is discharged.

Some image forming apparatuses having this configuration are equipped with a toner absorption mechanism (indicated by 10 here) beside the developing device 4. This toner absorption mechanism absorbs the toner that scatters from the gap between the developing device 4 and the image forming body 1 and reduces the scattering of toner within the device, so that clear printing can be performed for a long time. established in

FIG. 4 is a perspective view showing a conventional toner absorption mechanism section.

In the figure, the toner absorption mechanism 30 corresponds to IO in FIG. The nozzle 32 has a suction means 33 for sucking air in the nozzle 32 from one end of the nozzle 32, and the other end of the nozzle 32 is closed. The suction means 33 has a configuration similar to that of a vacuum cleaner, and the tip of an suction pipe is connected to the one end of the nozzle 32, and has a bag-shaped filter at the end of the suction pipe.

Then, by suctioning the air inside the nozzle 32 with the suction means 33, the toner scattered from the gap between the developing device 4 and the image forming member 1 and floating near the nozzle 32 is removed from the nozzle 32 and the image forming member 1. It is absorbed along with air through the gap and collected in the filter.

[Problem to be solved by the invention]

However, since the toner absorption mechanism 30 has a structure in which the air inside the nozzle 32 is sucked from one end of the nozzle 32 and the other end of the nozzle 32 is closed, the toner absorption mechanism 30 has a structure in which the air in the nozzle 32 is sucked from one end of the nozzle 32 and the other end of the nozzle 32 is closed. The static pressure caused by air suction and the dynamic pressure caused by the air flow inside the nozzle 32 act to effectively absorb the toner, but at the other end, the static pressure decreases and at the same time, the action of the dynamic pressure also decreases, causing the toner to absorb. The absorption is poor, and the toner cannot be absorbed well as a whole. For this reason, an image forming apparatus equipped with this toner absorption mechanism 30 has a problem in that even if the period during which clear printing is performed is longer than that of an apparatus not equipped with a toner absorption mechanism, the period cannot be sufficiently long. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image forming apparatus that can perform clear printing for a long period of time.

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention.

The above object is an image forming apparatus for developing an electrostatic image formed on an image forming body with toner by a developing device facing the image forming body, and as shown in FIG. The toner absorption mechanism 20 includes a toner absorption mechanism 20 for absorbing toner scattered from the gap with the image forming body 1, and the toner absorption mechanism 20 includes:
One side is open and the opening 21 is the image forming body 1 of the developing device 4.
A cylindrical nozzle 22 facing the image forming body l on the downstream side in the rotation direction, an air suction means 23 for sucking air inside the nozzle 22 from one end of the nozzle 22, and a suction means 23 for sucking air inside the nozzle 22 from the other end of the nozzle 22. This is closely related to the image forming apparatus of the present invention, which has an air supply means 24 for blowing air into the image forming apparatus.

[For production]

Toner scattering from the gap between the developing device 4 and the image forming body 1 is caused by
Due to the rotation of the image forming body 1, this occurs mainly on the lower side of the developing device 4. Further, since an air flow is generated inside the nozzle 22 over its entire length by suction of air by the suction means 23 and blowing of air by the air supply means 24, the effect of dynamic pressure in the gap between the nozzle 22 and the image forming body l is reduced. It becomes large over the entire length of the nozzle 22, and absorbs air in the vicinity well at any point in the longitudinal direction of the nozzle 22. and,
The nozzle 22 is located beside the developing device 4 on the lower side.

For this reason, the toner absorption mechanism 20 satisfactorily absorbs toner scattered from the gap between the developing device 4 and the image forming body 1.

In this way, the image forming apparatus can print clearly over a long period of time.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG.

FIGS. 2(a) and 2(b) are a side view and a perspective view showing the toner absorption mechanism of the embodiment, and the overall structure of the image forming apparatus is the same as that shown in FIG. 3 described above.

The same reference numerals indicate the same objects throughout the figures.

In FIG. 2, the toner absorption mechanism 20 corresponds to 10 in FIG. A nozzle 22 having a cylindrical shape and having a U-shaped cross section faces the image forming body 1 with an appropriate gap therebetween; It has air supply means 24 for blowing air into the nozzle 22 from the other end.

The suction means 23, like the suction means 33 of the conventional example, has a tI command similar to that of a vacuum cleaner, and the tip of the suction pipe is connected to the one end of the nozzle 22, and a bag is placed at the hand of the suction pipe. It has a filter shaped like this.

The air blowing means 24 is configured to blow air by a fan rotated by a motor, and its blowing side is connected to the other end of the nozzle 22 via a pipe. Note that the air suction means 23 may be used and its air discharge side may be used instead of the air supply means 24.

Then, the air in the nozzle 22 is sucked by the suction means 23, and the air is blown into the nozzle 22 by the air supply means 24, thereby forming an air flow inside the nozzle 22 over the entire length thereof. Then, the toner absorption mechanism 20 satisfactorily absorbs the toner scattered from the gap between the developing device 4 and the image forming body 1 based on the principle described above, and collects the toner in the filter.

The specifications in the example are as follows.

Cross section of nozzle 22: 10-square Length of nozzle 22: 300 mIIl (matched to the length of developing device 4) Gap between opening 21 and image forming body l: 1+nm Static pressure of suction means 23: 511IIllAq Air supply means 2
Static pressure of 3: 5 + mmAq Air volume inside the nozzle 22 = 4 vo/min And when doing this, even if the number of sheets printed reached 10,000, no dirt was observed inside the device due to toner scattering, and the printing condition was is extremely clear.

By the way, in the case of the conventional example explained earlier, the number of prints is 3.
When the number of sheets reaches about 1,000, the inside of the device becomes conspicuous due to toner scattering.

In the embodiment, the static pressure of the air intake means 23 was made equal to the static pressure of the air supply means 24, but as can be understood from the above explanation, if the static pressure of the air supply means 24 is ensured, the air intake means 2
3 may be greater than the static pressure of the air supply means 23.

Further, the cross-sectional shape of the nozzle 22 is not limited to the U-shape of the embodiment.

〔Effect of the invention〕

As explained above, according to the configuration of the present invention, there is provided an image forming apparatus that develops an electrostatic image formed on a rotating image forming body with toner using a developing device facing the image forming body. It is possible to provide a toner absorption mechanism that can satisfactorily absorb the toner scattered from the gap with the image forming body, which has the effect of making it possible to perform clear printing for a long period of time.

[Brief explanation of the drawing]

1 is a diagram explaining the principle of the present invention, FIGS. 2(a) and 2(c) are a side view and a perspective view showing the toner absorption mechanism section of the embodiment, and FIG. 3 is a side view and perspective view illustrating the image forming apparatus. FIG. 4 is a perspective view showing the lateral part of the toner absorber a of the conventional example. In the figure, l is an image forming body, 4 is a developing device, 10 and 20.30 are toner suction mechanisms, 21.31 are openings, 22.32 are nozzles, 23.33 are air suction means, and 24 are air supply means. be. 1: Figurine A) Body 20: Toner suction mechanism 22; Nozzle 24: Air supply means 4: Developing device 21: Opening 23: Air intake means Figure 1: Explanation of the principle of the invention Figure 1: East formation body 20? Toner suction mechanism 22: Nozzle 24: Air supply means 4: Developing unit 21 2 16"l Port 23: Air suction means Side view and perspective image of the toner absorber/p1 part of the embodiment 2 FIG. 5; Transfer section :Yanagi explaining the image forming device) Top view 3 FIG. 1: Image forming body 30: Toner suction spear 32/nozzle 4: Detector 31; Opening 33: Air suction means

Claims (1)

[Claims] An electrostatic image formed on the image forming body (1) is transferred to the image forming body (1).
1) An image forming device that develops with toner using developing devices (4) facing each other, and a toner absorption mechanism for absorbing toner scattered from a gap between the developing device (4) and the image forming body (1). (20)
The toner absorption mechanism (20) has one side open, and the opening (21) is located near the downstream side of the image forming body (1) of the developing device (4) in the rotational direction of the image forming body (1). (1), a cylindrical nozzle (22) facing the nozzle (22), a suction means (23) for sucking air in the nozzle (22) from one end of the nozzle (22), and a suction means (23) that sucks air from the other end of the nozzle (22). An image forming apparatus comprising an air supply means (24) for blowing air into the nozzle (22).