KR100315635B1 - Developing unit of image forming device - Google Patents

Abstract

The present invention relates to a developing device of an image forming apparatus, which is capable of increasing image uniformity and improving image quality by quantitative supply of a developer.

A developer housing in which a developer storage chamber is formed to accommodate the developer; A process unit comprising a photosensitive unit and a developing unit is disposed, the process unit housing coupled to the developer housing so as to communicate with the interior of the developer housing;

An elastic thin plate which is fixed to an inner wall of one side of the developer passage of the coupling portion of the developer housing and the process unit housing, and has a plurality of developer passage holes;

And rocking means for rocking the elastic thin plate.

Description

DEVELOPING UNIT OF IMAGE FORMING DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a laser printer, a copying machine, a facsimile, etc. employing an electrophotographic method, and more particularly, an image forming apparatus capable of increasing image uniformity and increasing image quality by quantitative supply of developer. The developing device of the apparatus.

A developing unit detachably mounted on an image forming apparatus employing an electrophotographic method to form an image on a recording material includes a process unit including a developing unit consisting of a feeding and developing roller and a photosensitive unit consisting of a photosensitive roller, and a built-in process unit. It consists of a process unit housing, and a developer housing that is housed in the developer supplied to the developing unit and coupled to the process unit housing.

1 is a cross-sectional view showing the internal configuration of a developing device applied to an image forming apparatus such as a laser printer, a copying machine, a facsimile, etc. employing an electrophotographic method, and illustrating a process of printing characters on recording paper.

As shown, the developer 2 contained in the developer accommodating chamber 11 of the developer housing 1 is stirred by the stirrer 3 which is a toner supply member installed inside the developer housing 1. The agitated developer 2 generates static electricity by friction and thus has a constant charge.

Thereafter, the charged developer 2 is conveyed to the supply roller 4 side by the rotation of the stirrer 3.

The developer 2 is attached to the peripheral surface of the developing roller 5, which meshes with the feed roller 4, and the developer-blade 6 forms a developer layer of a triboelectrically charged state of constant thickness.

By the electrical action of the charging roller 7, the surface of the photosensitive drum 8, which is engaged with the charging roller 7 and rotates, is uniformly charged with (-) polarity.

Here, a specific portion of the photosensitive drum 8 is exposed by a laser beam according to image data generated by an exposure unit (not shown) to form an electrostatic latent image.

The electrostatic latent image formed on the surface of the photosensitive drum 8 is developed by engaging with the developing roller 5 in which the developer 2 is formed and rotating to become a visible image. That is, a developer is formed in the photosensitive drum 8.

On the other hand, the recording paper 9 mounted on the cassette (not shown) is fed to the transfer roller 10 side which is engaged with the photosensitive drum 8 and rotated by the pickup roller (not shown). Thereafter, the recording paper 9 is subjected to heat and pressure while passing between the heating roller and the compression roller, which is a fixing unit (not shown), so that an image is fixed so that desired printing is performed.

According to the developing apparatus of the conventional image forming apparatus configured as described above, the developer unit chamber 11 of the developer housing 1 includes a process unit housing in which a developing unit composed of the developing roller 5 and the supply roller 4 is disposed ( 1 '), most of the developer 2 is concentrated in the developing roller 5, the supplying roller 4, and the doctor-blade 6 constituting the developing unit. If the state in which the developer 2 is concentrated in the vicinity of the roller 5 and the feed roller 4 is left for a long time, there is a problem that the solidification or difficulty in stirring the agitator 3 is followed.

In addition, since the developer 2 is concentrated in the doctor-blade 6, the excessive pressure of the developer 2 causes the doctor-blade 6 to be fixed on the peripheral surface of the developing roller 5. The function of forming a developer layer of thickness is lost.

Therefore, the two problems described above eventually lead to deterioration of the image quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a developer of an image forming apparatus capable of increasing image uniformity and increasing image quality by quantitative supply of a developer.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view showing an internal configuration of a developing device of an image forming apparatus according to the prior art.

2 is a cross-sectional view showing an internal configuration of a developing device of the image forming apparatus according to the present invention.

Figure 3 is an exploded perspective view showing the exploded appearance of the rocking means and the elastic thin plate according to an embodiment of the present invention.

Figure 4 is a perspective view showing another embodiment of the cam member constituting the rocking means according to the present invention.

<Description of the symbols for the main parts of the drawings>

2: developer 5: developer roller

8: photosensitive roller 20: developer housing

21: developer storage chamber 22: process unit housing

23: space part 30: thin plate

31 developer passing hole 40 cam member

50: drive motor

The present invention for achieving the above object is a developer housing formed with a developer storage chamber to accommodate the developer; In the developer of a laser beam printer comprising a; a process unit consisting of a photosensitive unit and a developing unit, the process unit housing coupled to the developer housing so as to communicate with the interior of the developer housing; An elastic thin plate fixedly installed at one side of the developer passage of the coupling part of the housing and having a plurality of developer passage holes; And rocking means for rocking the elastic thin plate.

Hereinafter, a preferred embodiment of a developing device of an image forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings. For convenience of description, the same reference numerals are assigned to the same parts as in the prior art.

The developing device according to the present invention includes a process unit including a developing unit composed of a supply 4 and a developing roller 5 and a photosensitive unit composed of a photosensitive roller 8, a process unit housing 22 incorporating the process unit; And a developer housing 20 which is integrally formed in the process unit housing 22 via a common hole 23 to form a developer accommodating chamber 21 for accommodating the developer 2. Is done.

Here, the common hole 23 allows the developer 2 contained in the developer accommodating chamber 21 of the developer housing 20 to fall and move toward the developing unit installed in the process unit housing 22. It serves as a passage, and its shape is approximately square.

The upper inner wall 23a of the common hole 23 is fixed to one end of the thin plate body 30 made of a material that can be bent by exerting an elastic force. The thin plate body 30 is formed in a quadrangular shape similar to the shape of the common hole 23, and the size of the thin plate body 30 is larger than that of the common hole 23 so as to sufficiently cover the common hole 23.

A plurality of developer through holes 31 are formed in the thin plate body 30 so that the developer 2 of the developer accommodating chamber 21 can pass therethrough.

Here, it is preferable that a film is used as an example of the thin plate body 30.

As described above, the thin plate body 30 is fixedly installed in the common hole 23, so that the developer storage chamber 31 and the developing unit are partitioned so that a predetermined space portion 24 is provided inside the process unit housing 22. ) Is formed.

The space part 24 serves as a chamber in which the developer 2 passed through the developer passage hole 31 formed in the thin plate body 30 is filled.

The thin plate 30 is swinged up and down by a rocking means provided separately, thereby allowing the developer 2 to pass more smoothly through the developer through-hole 31.

Hereinafter, the configuration of the rocking means will be described with reference to FIG. 3, the thin plate 30 so that the thin plate 30 can be rocked up and down by receiving the rotational force of the drive motor 50 and the drive motor 50. The cam member 40 is rotatable through the hinge portion 41 on the lower side of the common hole 23 formed between the developer housing 20 and the process unit housing 22 so as to contact the lower surface of the free end. .

The drive gear 43 is provided on the rotation shaft 51 of the drive motor 50, and the drive gear 43 has a gear section 43a formed on the outer circumferential surface for a predetermined period.

Although not shown in another embodiment of the drive gear 43, a gear having a fan shape may be used.

The hinge portion 41 of the cam member 40 is provided with a driven gear 42 that is gear-coupled with the drive gear 43.

As described above, the cam member 40 is rotated in a predetermined direction by providing the power transmission means composed of the drive gear 43 and the driven gear 42.

Here, the reason why the gear portion 43a is formed only in a partial section on the fan gear or the outer circumferential surface of the driving gear 43 is that the gear portion 43a is driven even when the driving gear is continuously rotated by receiving the driving force of the driving motor 50. Since the cam member 40 is rotated when the gear 42 is engaged with the gear 42, the thin plate body 30, which has received the rotational force of the cam member 40, can intermittently swing up and down.

On the other hand, since the main body for oscillating the thin plate body 30 up and down is the cam member 40, it is a matter of course that a driving gear having a gear part formed on the entire outer circumferential surface thereof so as to be geared to the driven gear 42 can be used.

As shown in FIG. 4, the cam member 40 may use a shape having a different outer curved surface.

More preferably, as shown in FIG. 3, the plate-shaped body of the predetermined length in which the hinge part 41 was formed in the center is used.

Here, the reason why the cam member 40 is a plate-like member is that a part of the developer 2 laminated on the lower inner wall of the common hole 23 can be returned to the developer accommodating chamber 21.

In other words, as shown in FIG. 2, both ends of the plate-shaped body, which is the cam member 40, are rotatable about the hinge portion 41 at intervals such that they do not strike the lower inner wall of the common hole 23. It is provided so that a part of the developer 2 laminated on the lower inner wall of the common hole 23 can be returned to the developer accommodating chamber 21 by both ends thereof when the plate body 40 is rotated.

Here, the excessively supplied to the space portion 24 through the developer through hole 31 of the thin plate body 30, or collected and consumed by the developing unit, the developer needs to be used again.

In the drawings, reference numeral 4 denotes a supply roller, 5 denotes a developing roller, 6 denotes a doctor-blade, 7 denotes a charging roller, 8 denotes a photosensitive roller, 9 denotes a recorder, and 10 denotes a transfer roller.

The operation of the developing device of the image forming apparatus according to the present invention configured as described above is as follows.

First, the developer 2 of the developer accommodating chamber 21 of the developer housing 20 is collected on the upper surface of the thin plate body 30 by the stirring action of the stirrer 3.

The thin plate 30 is oscillated in the vertical direction by receiving the rotational force of the cam member 40 is rotated by receiving the driving force of the drive motor 50.

As described above, as the cam member 40 rotates, the thin plate body 30 swings up and down, so that the developer 2 collected on the upper surface of the thin plate body 30 passes through the developer passing hole 31. Is moved to the space 24.

Then, the developer 2 moved to the space 24 is used for the developing unit.

On the other hand, as the cam member 40 rotates, a part of the developer 2 laminated on the lower inner wall of the common hole 23 is returned to the developer storage chamber 21.

In this way, a constant amount of developer is always supplied to the space portion through the developer passage hole of the thin plate.

As described above, according to the present invention, the developer roller and the supply roller constituting the developing unit by dividing the developer accommodating chamber and the developing unit so that a predetermined amount of the developer is supplied to a predetermined space portion inside the process unit housing. And it is possible to prevent the concentration on the doctor-blade intensively.

In addition, since the developer is prevented from being concentrated in the doctor-blade, excessive pressure is not applied to the doctor-blade, thereby smoothly performing the function of the doctor-blade, which forms a developer layer having a constant thickness on the peripheral surface of the developing roller. You can do it.

Further, the developer is secured by rotation of a cam member which is fixedly installed on the inner wall of the upper side of the connecting portion which communicates the developer housing and the process unit housing with each other, and constitutes rocking means for rocking the elastic thin plate which allows the developer to pass therethrough. By returning a part to the inside of the developer housing again, the recyclability of the developer can be increased, and it is possible to prevent the developer collected in the space portion formed inside the process unit housing from solidifying.

Therefore, it is possible to increase the image uniformity and to increase the image quality by quantitative supply of the developer.

Claims (5)

A developer housing in which a developer storage chamber is formed to accommodate the developer; A process unit comprising a photosensitive unit and a developing unit is disposed, the process unit housing coupled to the developer housing so as to communicate with the interior of the developer housing; An elastic thin plate which is fixed to an inner wall of one side of the developer passage in the coupling portion of the developer housing and the process unit housing, and has a plurality of developer passage holes; And a rocking means for rocking the elastic thin plate. 2. The motor according to claim 1, wherein the swing means comprises: a drive motor; It is contacted with the lower end of the free end of the elastic thin plate to receive the rotational force of the drive motor to swing the elastic thin plate up and down, the hinge portion in the lower side of the connecting portion for communicating the developer housing and the process unit housing mutually And a cam member rotatably installed as a developing device of the image forming apparatus. 3. The developing device of an image forming apparatus according to claim 2, wherein the elastic thin plate is made of a film material. 3. The developing device according to claim 2, wherein a driven gear is installed in the hinge portion, and a fan-shaped drive gear is gearably coupled to the driven gear on a rotation shaft of the drive motor. 3. The cam member of claim 2, wherein the cam member is formed of a plate-shaped body having a predetermined length at the center of the hinge portion, and a part of the developer stacked below the connection part is rotated into the developer storage chamber when the plate-shaped body rotates. A developing device of an image forming apparatus, characterized in that being fed back.