JPH02248974A - Developing device for electrophotographic recorder - Google Patents

Abstract

PURPOSE:To prevent toner from leaking to the both sides of a roller in its shaft direction by disposing a low friction seal body with a high wear resistance on the right inside of a roller shaft bearing, allowing the roller axis to penetrate the low friction seal body and attaching the low friction seal body to the roller shaft. CONSTITUTION:A side plate 42 supports the bearing 28 which supports the roller shaft 27 of a developing roller 26. That is, a bearing housing recessed part 42a is formed on the outer surface of the side plate 42, where the bearing 28 and an electrode 43 are housed and the low friction seal body 44 with a high wear resistance is arranged with interposed the electrode 43 on the right inside of the bearing 28. The low friction seal body 44 is penetrated and attached with tight fit to the roller shaft 27, rotated together with the roller shaft 27, but dose not raise the rotational torque of the roller shaft 27 because of the low friction coefficient of the seal body 44. Thereby, the seal body 44 can prevent toner from leaking along the roller shaft 27.

Description

[Detailed description of the invention] Production! This invention can be applied to electrophotographic recording devices that perform electrophotographic recording, such as laser printers, laser copying machines, and laser facsimiles. Specifically, in such electrophotographic recording devices.

The present invention relates to a developing device that attaches toner to a photoreceptor and develops an electrostatic latent image on the surface of the photoreceptor into a visible image.

Conventionally, in this type of developing device, as shown in FIGS. 6 and 7, toner 2 is placed on the photoreceptor 1 in the image chamber
a developing roller 3 that adheres to the electrostatic latent image on the surface of the photoreceptor 1 to make it visible; a thinning roller 4 that thins the toner 2 on the surface of the developing roller 3; and a thinning roller that thins the toner 2 on the surface of the developing roller 3. A rectangular and flat scraper 5 is provided to scrape off the toner 2 adhering to the toner 4.

By the way, in this type of developing device, if the toner 2 leaks from both sides of the developing roller 3 and the layer thinning roller 4 in the axial direction,
Not only does the inside of the recording apparatus get dirty, but also the toner 2 gets into the bearing 6 that supports the developing roller 3 and the bearing 7 that supports the thinning roller 4, causing so-called bearing lock, and also causes problems between the electrode and the roller shaft. There was a risk that conduction would be interrupted and bias application failure would occur.

For this reason, conventionally, a sponge type or flocked type seal member 8 is attached to the casing 9, and the tip of the seal member 8 is pushed against both ends of the developing roller 3 and the thinning roller 4 in the axial direction and both ends of the scraper 5 in the width direction. A sealing area 8 was formed there.

In addition, as shown in FIG. 8, a packing g is attached to the side plate p and pressed against the outer periphery of the roller shaft r of the developing roller 3, the thinning roller 4, etc. to prevent toner leakage along the roller shaft r. The symbol t in the figure that was blocking the rotation is an electrode that is electrically connected to the roller shaft r through the bearing b and applies a bias to the roller shaft r.

However, in the conventional developing device of the type shown in FIG.
There was a problem that the toner would gradually accumulate there and eventually cause toner to leak from there.

In particular, since the conventional packing G was made of nitrile rubber that has a high affinity with Toner 2, toner tends to adhere to the packing G, and when using highly fluid toner or toner with small particle size, it is sometimes difficult to There is a problem in that the toner 2 gets into the packing g over time, resulting in toner leakage.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve such conventional problems in a developing device of an electrophotographic recording device, and to prevent toner leakage to both sides in the axial direction of rollers such as a developing roller and a thinning roller. be.

to solve Therefore, claim 1. This invention is described in .

For example, as shown in the illustrated embodiment below, in a developing device 16 of an electrophotographic recording apparatus that attaches toner 34 to a photoreceptor 13 and visualizes an electrostatic latent image on the surface of the photoreceptor 13, a roller shaft 27 is used. A highly wear-resistant low-friction seal body 44 is arranged immediately inside the bearing 28 of the bearing 28, and the low-friction seal body 44
It is characterized in that it is attached to the roller shaft 27 by passing through it.

Also, claim 2. The present invention described in , for example, as shown in the illustrated embodiments below, is a developing method for an electrophotographic recording device in which toner 34 is attached to a photoreceptor 13 and an electrostatic latent image on the surface of the photoreceptor 13 is visualized. In the device 16, a gasket 46 for preventing toner leakage along the roller shaft 27 is provided.
It is characterized by being made of fluororubber.

Life-11 And then! 1 request 1. In the present invention described in , toner leakage along the roller shaft 27 is prevented by the low-friction seal body 44 .

Also, claim 2. In the present invention described in , toner leakage along the roller shaft 27 is prevented by a packing 46 made of fluororubber that has no affinity with the toner 34 .

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

FIG. 5 shows a schematic configuration of a laser printer equipped with a developing device according to the present invention. In FIG.
Reference numeral 1 denotes a paper feed cassette provided in the printer main body 10. Paper 5 fed from the paper cassette 11 in the direction of arrow A
0 is conveyed to a drum-shaped photoreceptor 13 at the correct timing by a pair of registration rollers 12 . The photoreceptor 13 is
The photoreceptor 13 is rotated in a clockwise direction, the surface of which is uniformly charged by the charger 14, and a laser beam from the laser optical system 15 is irradiated to form an electrostatic latent image on the photoreceptor 13. This latent image is made visible by toner when passing through the developing device 16 according to the present invention, and this visible image is transferred by the transfer charger 17 to the paper 50 conveyed to the photoreceptor 13, and the visible image on the transferred paper 50 is is fixed by the fixing bag w18. And the fixing device! The paper 50 that has come out of the paper 18 is discharged, for example, to paper discharge sections 19 in the direction of the arrow. on the other hand,
A cleaning device 20 removes residual toner from the photoreceptor 13 after the visible image has been transferred.

The developer bag mentioned above! 16 is a casing constructed as shown in FIGS. 3 and 4, and 21 in FIG. 1 is a casing. A developing chamber 23 having an opening 22 on the side of the photoreceptor 13 and a toner supply chamber 25 having an opening 24 above are formed therein. A developing roller 26 that applies toner to the latent image on the photoreceptor 13 is housed in the developing chamber 23 . Both ends of the roller shaft 27 of the developing roller 26 are supported via bearings 28 . Further, a developing roller 26 is provided in the developing chamber 23.
The toner layer on the surface of the developing roller 26 is
A thinning roller 29 for thinning the layer to 20μ is housed and arranged.

Both ends of the roller shaft 30 of the layer thinning roller 29 are supported via bearings 31. Furthermore, a scraper 32 is housed in the developing chamber 23 for cleaning by pressing the tip of the scraper 32 against the surface of the layer-thinning roller 29 to scrape off toner adhering to the layer-thinning roller 29 . The scraper 32
The proximal end of is fixed to the casing 21 with a screw 33.

The toner supply chamber 25 houses toner 34, and also houses an agitator 35 for stirring the toner 34 and a replenishment roller 36 for feeding the toner 34 to the developing roller 26. Further, in the opening 24 of the toner supply chamber 25,
A toner cartridge 37 for replenishing toner 34 is attached replaceably.

By the way, in the developing device 16 according to the present invention.

A sealing member 38 is pressed against both ends of the developing roller 26 and the layer thinning roller 29 in the axial direction and both ends of the scraper 32 in the width direction, in contact with each other on the side opposite to the photoreceptor 13,
A sealing area S is formed. The sealing member 38 consists of a sponge seal 39 and a flocked seal 40, each of which is attached to the casing 21 using double-sided tape or the like.

and.

The sponge seal 39 is made of foamed polyurethane, felt, etc., and
Contact with 2. On the other hand, the flocked seal 40 is made of Teflon fiber, for example, and contacts the thinning roller 29 and the developing roller 26 . Thus, both ends of the thinning roller 29 in the axial direction and both ends of the scraper 32 in the width direction are reliably sealed with the highly airtight sponge seals 39. In addition, both axial ends of the thinning roller 29 and the developing roller 26 are
A flexible flocked seal 40 securely seals both rollers without increasing their rotational torque.

Now, in such a developing device 16, as shown in FIGS.
As shown in the figure, a bearing 28 that receives a roller shaft 27 of a developing roller 26 is supported by a side plate 42 .

That is, a bearing storage recess 42a is formed on the outer surface of the side plate 42, and the bearing 28 is stored therein together with the electrode 43. The bearing housing recess 42a also contains the bearing 2 with the electrode 43 sandwiched therebetween.
A low-friction seal body 44 with high wear resistance is arranged just inside the 8. The low-friction seal body 44 is made of, for example, a polyester film with a thickness of about 0.11 mm and has a donut shape, and its inner diameter is made slightly smaller than the roller shaft diameter. Then, the low-friction seal body 44 is penetrated by tight fit and attached to the roller shaft 27. Therefore, the low-friction seal body 44 rotates together with the roller shaft 27, but since the coefficient of friction is low, the rotational torque of the roller shaft 27 is not increased.

As is well known, it is extended to the outer surface of the side plate 42.

Thus, the roller shaft 27 is electrically connected to the roller shaft 27 through the bearing 28, and a bias is applied to the roller shaft 27.

The low-friction seal body 44 prevents toner from leaking along the roller shaft 27.

On the other hand, a packing accommodating recess 42b is formed on the inner surface of the side plate 42 corresponding to the bearing accommodating recess 42a, into which a packing holder 45 is press-fitted and a packing 46 is accommodated. The packing 46 is made of fluororubber that has no affinity with the toner 34, and has a lip portion 46a pressed against the outer periphery of the roller shaft 27.

A packing 46 made of fluororubber that has no affinity with the toner 34 prevents toner from leaking along the roller shaft 27. In other words, toner 3 has no affinity for fluororubber.
4 does not adhere, the sealing performance is improved and toner 34 can be prevented from entering into the packing 46 over time.

In the above-described embodiment, the bearing portion of the roller shaft 27 of the developing roller 26 has been described, but the present invention can be similarly applied to the bearing portion of the roller shaft 30 of the thinning roller 29, etc.

Therefore, claim 1. According to the invention described in , it is possible to prevent toner leakage along the roller shaft with the low-friction seal body.

Also, claim 2. According to the invention described in , it is possible to prevent toner from leaking along the roller axis using a packing made of fluororubber that has no affinity with toner.

This prevents the inside of the recording apparatus from being contaminated, further prevents bearing lock from occurring, and prevents failure of bias application due to interruption of conduction.

[Brief explanation of drawings]

FIG. 1 is an enlarged view of the bearing portion of a developing roller in a developing device according to an embodiment of the present invention, FIG. 2 is a perspective view of the shaft end of the developing roller, FIG. 3 is a sectional view of the developing device, and FIG. 4 is a view taken along the line IV-rV in FIG. 3, and FIG. 5 is a schematic diagram of a laser printer equipped with the developing device. FIG. 6 is a sectional view of a conventional developing device, FIG. 7 is a view taken along the line ■-■ in FIG. 6, FIG. 8 is a detailed view of a portion thereof, and FIG. 9 is a partially enlarged view of FIG. . 13...Photoreceptor 16...Developing device 26...Developing roller 27...Roller shaft 28. ......Bearing 29...Thinning roller 30...Roller shaft 31...Bearing 34... ..... Toner 44 ..... Low friction seal body 46 .....
...Patsukin

Claims (1)

[Scope of Claims] 1. In a developing device of an electrophotographic recording device that attaches toner to a photoreceptor and visualizes an electrostatic latent image on the surface of the photoreceptor, a resistive material is installed just inside the bearing of the roller shaft. A developing device for an electrophotographic recording device, comprising a low-friction seal with high abrasion properties, and the low-friction seal is attached to the roller shaft by passing through the low-friction seal. 2. In the developing device of an electrophotographic recording device that attaches toner to a photoreceptor and visualizes the electrostatic latent image on the surface of the photoreceptor, the packing that prevents toner leakage along the roller axis is made of fluorine. A developing device for an electrophotographic recording device made of rubber.