KR0174682B1 - The toner supply device - Google Patents

Abstract

1. Technical field to which the invention described in the claims belongs

The present invention relates to a toner supply device in a developing device in a developing device of an image forming apparatus that performs printing using an electrophotographic method, in which a smooth and clean image can be obtained by smoothly flowing the toner in the developing device.

2. Technical Challenges to be Solved by the Invention

An object of the present invention is to provide a toner supply device in a developing device of an image forming apparatus which smoothly charges toner by allowing the flow of toner above the supply roller provided inside the developing cartridge to smoothly charge.

3. The point of the solution of the invention

The developing device of the image forming apparatus according to the present invention comprises a toner housing for storing toner on an upper portion thereof, an agitator for transferring the toner to the toner housing by agitating the toner on one side of the supply roller, A developing roller for developing the toner on the electrostatic latent image formed on the surface of the photosensitive drum is provided on one side of the supplying roller and a developing roller for supplying the agitated toner to the developing roller side is provided, And a blade for uniformly regulating the amount of the toner at a constant height is provided at an upper end of the developing roller.

4. Important Uses of the Invention

The present invention relates to a toner supplying device in a developing device of an image forming apparatus using an electrophotographic developing method.

Description

The toner supply device

FIG. 1 is a schematic view of a general developing device. FIG.

FIG. 2 is a block diagram of a toner supply device in a conventional developing device. FIG.

FIG. 3 is a structural view of the toner supply apparatus in which a flow assist device is provided in the developing device of the present invention. FIG.

FIG. 4 is a schematic view showing a film attached to the flow assist device of the present invention. FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

21: developing device 22: toner housing

23: Lower frame 24: Toner

25: agitator 26: flow assist device

26a: Film 27: Toner supply port

28: Feed roller 29: Develop roller

30: photosensitive drum 31: blade

The present invention relates to a developing device of an image forming apparatus, and more particularly, to a developing device of an image forming apparatus that performs printing using an electrophotographic method, in which a toner supply in a developing device ≪ / RTI >

BACKGROUND ART [0002] An electrophotographic developing method is most widely used for an image forming apparatus, and an image forming apparatus using a conventional electrophotographic developing method includes a recording apparatus such as a copying machine, a laser beam printer, and a plain paper facsimile. As is well known, an electrophotographic image forming apparatus forms an invisible electrostatic latent image on the surface of a photosensitive drum. Then, an image is formed on the surface of the photosensitive drum, on which the electrostatic latent image is formed, with toner, and is visualized.

1 and 2, in the electrophotographic processor using the one-component developing method, a photosensitive drum 30 is rotated at a constant peripheral speed, and a photosensitive drum 30 The upper portion is provided with a charging roller 32 for uniformly charging the surface of the charge layer electrically and a photoreceptor 33 for forming an electrostatic latent image on the surface of the photoreceptor drum 30 electrically charged. A transfer roller 34 for transferring an image of the toner 24 on the surface of the photosensitive drum 30 onto the paper 35 is provided at the lower end of the photosensitive drum 30. A developing device 21 for forming an image is provided at one side of the photosensitive drum 30 and a toner housing 22 for storing the toner 24 is formed at an upper end of the developing device 21, Is provided with an agitator 25 for uniformly stirring the toner 24 electrically. A supply roller 28 for supplying the agitated toner 24 to the developing roller 29 is provided in the lower frame 23 inside the developing device 21 and one side of the supplying roller 28 is connected to the photosensitive drum 29. [ A developing roller 29 for developing the toner 24 is provided on the electrostatic latent image formed on the surface of the developing roller 29 and a toner 24 formed on the surface of the developing roller 29 is fixed to the upper end of the developing roller 29 And a blade 31 uniformly regulating the height thereof.

When the toner 24 is supplied to the toner housing 22 of the developing device 21, the toner 24 is agitated by the agitator 25, Static electricity is generated, and a certain electric charge is obtained. The agitated toner 24 is conveyed to the supply roller 28 through the toner supply port 27 and supplied to the supply roller 28 of the lower frame 23 by rotation to the developing roller 29 side. The toner 24 formed on the surface of the developing roller 29 is uniformly regulated to a constant height by the blade 31.

At this time, the surface of the photosensitive drum 30 is electrically and uniformly charged by the electric action of the charging roller 32, and the portion charged by the rotation of the photosensitive drum 30 is exposed to the image through the exposure section 33 When the surface of the photosensitive drum 30 is exposed to an electric signal for forming the electrostatic latent image, a portion that receives light in an initially charged state forms an electrostatic latent image. At this time, the electrostatic latent image of the photosensitive drum 30 is developed by the toner 24 passing through the rotating developing roller 29 and changed into a visible image. The recording paper 35 mounted on the paper feed cassette is fed by the paper feed roller so that the image of the toner 24 on the surface of the photosensitive drum 30 is transferred to the recording paper 35 by the high pressure action of the transfer roller 34 .

Thereafter, when the recording paper 35 is conveyed and passes between the heating roller and the pressing roller of the fixing unit, an image is fixed on the recording paper 35 surface by heat and pressure, and the printed paper is conveyed to the output tray side Printing is performed.

However, in such a conventional image forming apparatus, when the toner is stirred by the agitator provided in the toner housing of the developing device and conveyed to the lower side of the supply roller, the supply roller supplies the toner to the developing roller side. At this time, The toner can not move to another place, and the motion becomes stagnant for a long period of time. This toner is not only poor in chargeability due to its insufficient amount of friction, but also tends to cling to each other, adversely affecting the image. In an image forming apparatus in which one of them uses an inversion developing method, a large amount of reverse charging, that is, + charged toner causes contamination of the substrate surface, a large amount of waste toner, contamination of the charging roller, and the like. As described above, since the toner is supplied in a stagnant state above the supply roller, charging of the toner becomes uneven and the density of the image is lowered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus and a developing device in an image forming apparatus which can smoothly charge the toner by naturally holding the flow of toner above the supply roller, And a toner supply device.

Another object of the present invention is to provide a toner supply device in a developing device of an image forming apparatus which causes a supply path of toner to be generated between a supply roller and a developing roller.

It is still another object of the present invention to provide a toner supply device in a developing device of an image forming apparatus which prevents toner transferred from a supply roller to a developing roller to stay in a specific area for a long time.

According to an aspect of the present invention, there is provided an image forming apparatus including: a developing unit of an image forming apparatus; a toner housing for storing toner; a agitator for agitating and conveying the toner to the toner housing by a supply roller; A developing roller for developing the toner on the electrostatic latent image formed on the surface of the photosensitive drum is installed on one side of the supplying roller, A flow assist device which is spaced apart from the upper surface of the developing roller so as to form a passage for the movement of the toner, and a blade for uniformly regulating the amount of the toner at a constant height is provided at the upper end of the developing roller.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a configuration diagram of a toner supply device in which a flow assist device is installed in a developing device in the image forming apparatus of the present invention, and FIG. 4 is a configuration diagram in which a film is attached to the flow assist device of the present invention. The configuration of the toner supply device in the developing device of the image forming apparatus according to the present invention will be described with reference to FIGS. 1, 3 and 4.

It should be noted that the same reference numerals are used for the same functions as those of the conventional codes.

The developing device 21 of the image forming apparatus has a toner housing 22 for storing toners and one lower end of the toner housing 22 forms a toner supply opening 27. The toner housing 22 is provided with a toner 24 Is agitated and an agitator (25) for transferring the toner to the supply roller (28) through the toner supply port (27) is rotatably installed. A supply roller 28 for supplying the agitated toner 24 to the developing roller 29 is provided in the lower frame 23 inside the developing device 21 and one side of the supplying roller 28 is connected to the photosensitive drum The developing roller 29 for developing the toner 24 is provided on the electrostatic latent image formed on the surface of the photosensitive drum 30. A regulating blade 31 for uniformly regulating the toner 24 at a predetermined height is provided at the upper end of the developing roller 29 and is spaced apart from the upper portion of the developing roller 29 and the upper side of the supplying roller 28, 24 is provided with a flow assist device 26 which constitutes a passage for movement.

The flow assisting mechanism 26 attaches the film 26a to the toner outlet of the gap formed with the developing roller 29 so that one end of the film 26a passes through the toner regulated by the regulating blade 31 And is extended toward the developing roller 29 so as not to enter again.

The flow assist device 26 eliminates the space in which the toner stays and provides a space through which the toner can flow, that is, a passage, and at the same time, provides a flow force that allows the toner to flow.

The action and effect of the present invention thus constituted are as follows.

In the image forming apparatus using the electrophotographic developing method, in a state in which the toner 24 is supplied to the toner housing 22 formed at the upper end of the developing device 21, the toner 24 is agitated by the agitator 25, The agitated toner 24 is supplied downward through the toner supply port 27 of the toner housing 22 and is supplied to the supply roller 28 of the lower frame 23, Toner is supplied to the developing roller 29 side by rotation.

At this time, the agitator 25 of the toner housing 22 is rotated in the clockwise direction as shown in FIG. 3, so that the toner 24 of the toner housing 22 is agitated and fed to the feed roller 28 side by the agitator 25 Loses. At this time, the supply roller 28 rotates counterclockwise and supplies the toner 24 to the developing roller 29 rotated in the counterclockwise direction.

The supply roller 28 is provided with a flow assist device 26 and a supply roller 28 provided between the supply roller 28 and the upper portion of the development roller 29 to supply the supplied toner to the development roller 29 And the developing roller 29 is arranged so as to form a passage for the flow of the toner with a gap of D so that the toner 24 is supplied to the supplying roller 28 by the agitator 25, And a certain amount of the toner is moved to the developing roller 29 by the gap d. This amount is FS as shown in the drawing.

At this time, the toner is subjected to triboelectrification by the supply roller 28 rotating with the fixed wall of the flow assist device 26 in the gap d. This toner is brought into contact with the developing roller 29, and a part thereof enters into the gap of the developing roller 29 and moves downward. This amount is relatively small and is shown as FDs in the figure. At this time, the remainder is moved toward the regulating blade 31 by the developing roller 29. This amount is FD as shown in the drawing. The toner is further subjected to triboelectrification in the gap D between the rotating developing roller 29 and the fixed flow assist device 26 and only a certain amount of toner is transferred to the photosensitive drum by the regulating blade 31. [ At this time, unlike the previous case, the remaining toner flows to the supply roller 28 again by the upper surface of the flow assist device 26. Even if the toner amount is large, The supply of the toner to the developing roller 29 as in the conventional case is prevented.

At this time, the surface of the photosensitive drum 30 is electrically uniformly charged by the electric action of the charging roller 32, and the portion charged by the rotation of the photosensitive drum 30 passes through the exposed portion 33, And is uniformly developed and visually changed by the toner 24 while passing through the developing roller 29 where the electrostatic latent image of the photosensitive drum 30 is rotated. The recording paper 35 mounted on the paper feed cassette is fed by the paper feed roller so that the image of the toner 24 on the surface of the photosensitive drum 30 is transferred to the recording paper 35 by the high pressure action of the transfer roller 34 .

Thereafter, when the recording paper 35 is conveyed and passes between the heating roller and the pressing roller of the fixing unit, an image is fixed on the recording paper 35 surface by heat and pressure, and the printed paper is conveyed to the output tray side, And a clear image is obtained.

FIG. 4 is a view showing a configuration in which a film is attached to the flow assist device of the present invention, in which a film is put on the toner outlet of the flow assist device 26 at the side of the regulating blade 31 to regulate the toner regulated by the regulating blade 31 So that it is further prevented from returning to the roller (29). It is preferable that the film 26a is adhered to the flow assist device 26 by an adhesive and is thin with a thickness of 0.3 mm or less.

The side surface of the flow assist device 26 may have an inclined straight line or a slight curved surface so long as each corner is rounded to some extent or does not form a passage with the roller. What is important is that the flow assist device 26 is positioned between the developing roller 29 and the supplying roller 28 and is configured to form a passage through which the developing roller 29 and the supplying roller 28 and the toner 24 move .

According to the present invention as described above, a flow assist device is provided between the developing roller and the upper portion of the supplying roller in the developing device to eliminate the space in which the toner stays and to allow the toner to flow therethrough, And friction charging is performed in the gap between the flow assistant mechanism and the supply roller when the toner is supplied so that the charging of the toner becomes uniform and the image density of the developing roller becomes uniform so that a clear and clear image can be obtained.

Claims (4)

A developing device of an image forming apparatus, comprising: a developing roller for transferring toner to a photosensitive drum; a supplying roller for supplying the toner to the developing roller; an agitator for transferring the toner to the supplying roller and stirring the toner; A regulating blade contacting the developing roller to regulate the amount of toner transferred from the developing roller to the photosensitive drum and a flow assist device located between the developing roller and the supplying roller, And the auxiliary mechanism is spaced apart from the developing roller and the supplying roller so as to form a passage for toner movement. The method of claim 1, Wherein the flow assisting mechanism attaches a film to an outlet of toner in a gap formed with the developing roller and one end of the film extends toward the developing roller so that the toner regulated by the regulating blade does not enter the outlet again. Wherein the toner supplying device is a toner supplying device. The toner supply device as set forth in claim 1, wherein the film is adhered to the flow assist device with an adhesive, and the thickness is thinner than 0.3 mm. The toner supply device as set forth in claim 1, wherein the flow assist device is formed in a straight line so that the side is inclined so long as the passage and the roller are not formed.