KR101245853B1 - image forming apparatus - Google Patents

Abstract

Provided is an image forming apparatus which can prevent scattering and resplashing of toner. The image forming apparatus includes: a toner container in which toner is stored; A photosensitive drum disposed around the toner container and having an electrostatic latent image formed thereon; A developing roller disposed corresponding to the photosensitive drum and providing a toner on the electrostatic latent image of the photosensitive drum to form a toner image; Toner collection having a fan to form air flow to induce toner particles floating near the developing roller and the photosensitive drum, and a toner deposition portion disposed on the downstream side of the fan to form a flow space of the air flow, and having different heights at the top. It includes a unit.

Image Forming Machine, Toner Collection Unit, Toner Deposit, Toner Adhesive

Description

Image forming apparatus

1 is a block diagram illustrating an image forming apparatus to which a jumping developing method or a magnetic brush developing method according to the present invention are applied.

2 is a cross-sectional view showing a developing unit and a toner collecting unit of the image forming apparatus according to the present invention.

3 is a perspective view showing the shape of a toner collection unit in the image forming apparatus according to the present invention.

4 is a developed view illustrating a ratio of height and length of the scattering prevention unit in the image forming apparatus according to the present invention.

5 is a cross-sectional view showing a state where the release paper is attached to the toner adhesive portion in the image forming apparatus according to the present invention.

6 is a cross-sectional view showing a state of removing the release paper from the toner adhesive portion in the image forming apparatus according to the present invention.

Explanation of symbols on the main parts of the drawings

50: developing unit 51: toner container

52: Photosensitive drum 53: Daejeon roller

54: developing roller 55: toner supply roller

60: transfer unit 70: fixing unit

80: optical scanning unit 100: fan

200: toner collection unit 210: base plate

220: toner deposition portion 230: toner adhesion portion

231: adhesive member 233: release paper

240: release paper removing member

The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus which prevents toner from scattering.

In general, an image forming apparatus charges the surface of a photosensitive drum by a charging roller. A predetermined electrostatic latent image is formed on the charged surface of the photosensitive drum by the light scanned by the optical scanning unit. Toner is attached to the electrostatic latent image of the photosensitive drum by a developing roller to form a predetermined toner image. The toner image of the photosensitive drum is transferred to a print medium passing between the photosensitive drum and the transfer roller. The image transferred to the print medium is fixed while passing through the fixing roller. The print media thus printed is discharged to the outside.

However, the conventional image forming apparatus has the following problems.

In the vicinity of the photosensitive drum, the photosensitive drum airflow is generated by the rotation of the photosensitive drum. Further, the transfer roller airflow is formed by rotating the transfer roller near the transfer roller. The photosensitive drum stream and the transfer roller airflow meet near the photosensitive drum and the transfer roller to form a vortex.

At this time, in the process of attaching the toner particles of the developing roller to the photosensitive drum, a part of the toner particles to be attached is mixed with the photosensitive drum stream and the transfer roller stream to float. The suspended toner particles are deposited where the air flow becomes weak while flowing along the air flow. Since toner particles are deposited in various places of the image forming apparatus, there is a problem that the inside of the image forming apparatus is contaminated.

In addition, when the floating toner particles are deposited on the transport path of the print medium, the print medium may be contaminated or images may not be clearly formed.

In addition, when the light scanning unit is contaminated by toner particles, the light scanning unit prevents the light from being properly scanned from the photosensitive drum. If the latent electrostatic image is not properly formed on the surface of the photosensitive drum, the toner image may not be properly formed on the print medium.

In addition, when the teeth of the gear device are contaminated by toner particles, the gear device is driven unevenly and the driving load also increases.

In addition, the toner particles deposited on the internal device have a problem of being re-spread by the air flow formed therein, the vibration of the internal device, or the impact applied from the outside.

In addition, the floating toner particles may be discharged to the outside of the image forming apparatus. In this case, the user may feel uncomfortable, and in particular, there is a problem that is harmful to the user's body.

Meanwhile, an image forming apparatus using a jumping development method or a magnetic brush development method in which toner is attached to an electrostatic latent image of the photosensitive drum in a state where the photosensitive drum and the developing roller are spaced at a predetermined interval. There is. In this type of image forming apparatus, since a gap is formed between the photosensitive drum and the developing roller, the above-described various problems are more prominent by this gap.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an image forming apparatus capable of preventing contamination of internal devices of an image forming apparatus and minimizing toner scattering.

According to an aspect of the present invention for achieving the above object, a toner container for storing toner; A photosensitive drum disposed around the toner container and having an electrostatic latent image formed thereon; A developing roller disposed corresponding to the photosensitive drum and providing a toner on the electrostatic latent image of the photosensitive drum to form a toner image; Toner collection having a fan to form air flow to induce toner particles floating near the developing roller and the photosensitive drum, and a toner deposit portion disposed on the downstream side of the fan to form a flow space of the air flow, and having different heights at the top. An image forming apparatus including a unit is provided.

The upper end of the toner deposition unit may have a shape in which the height thereof is lowered toward both sides from the center.

The toner depositing unit has a long axis from one end of the fan to the center of the fan, and shortens the distance from the lower center of the toner depositing unit to the upper center of the toner depositing unit, and the shortening is 9/10 times the long axis. It may be an oval shape having a length of.

The toner collection unit may further include a toner adhesive to which toner particles induced by air flow are adhered.

Release paper may be attached to the toner adhesive part. A release paper removing member may be disposed to be connected to the release paper and to release the release paper from the outside.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. The embodiments described herein may be applied to both an image forming apparatus in which a photosensitive drum and a developing roller are disposed to be in contact with each other, or a jumping developing method or a magnetic brush developing method disposed to be spaced apart by a predetermined interval.

A specific embodiment of the image forming apparatus according to the present invention, which can achieve the above object, will be described.

1 is a block diagram illustrating an image forming apparatus to which a jumping developing method or a magnetic brush developing method is applied.

Referring to FIG. 1, a paper feed cassette 10 is provided in the main body 1 of the image forming apparatus. The paper feed cassette 10 may be disposed inside the main body 1 or detachably disposed on the main body 1. A print medium is stored in the paper feed cassette 10.

The conveyance path 20 through which the print medium fed from the paper feed cassette 10 is conveyed is disposed inside the main body 1. In addition, the discharge unit 30 is disposed above the main body 1.

Pick-up rollers 41, feed rollers 42 and 43, and discharge rollers 44 are disposed in the transfer path 20. In addition, a developing unit 50, a transfer unit 60, and a fixing unit 70 are disposed in the transfer path 20. In addition, a light scanning unit 80 (Laser Scanning Unit: LSU) is disposed inside the main body 1 to scan light to the developing unit 50. In addition, a fan 100 and a toner collection unit 200 are disposed at the bottom of the developing unit 50.

First, the developing unit 50 will be described.

The developing unit 50 includes a toner container 51 in which toner is stored, and a photosensitive drum 52 which is rotated in a predetermined direction inside the toner container 51. The charging roller 53 is disposed to rotate while contacting the photosensitive drum 52. The charging roller 53 charges the surface of the photosensitive drum 52 to a constant potential. An electrostatic latent image is formed on the charged surface of the photosensitive drum 52 by the light scanned by the optical scanning unit 80.

The developing roller 54 is disposed to be spaced apart from the photosensitive drum 52 by a predetermined interval. The developing roller 54 is rotated together with the photosensitive drum 52 to attach toner to the electrostatic latent image of the photosensitive drum 52 to form a toner image. In addition, a toner supply roller 55 for supplying toner to the developing roller 54 while being rotated together with the developing roller 54 is disposed.

The photosensitive drum 52 of the developing unit 50 corresponds to the transfer unit 60. The transfer unit 60 includes a transfer roller 61. The transfer roller 61 is installed to rotate while being in contact with the photosensitive drum 52. The transfer roller 61 is rotated together with the photosensitive drum 52 on which the toner image is formed to transfer the toner image to one surface of the print medium.

The print medium on which the toner image is transferred is transferred to the fixing unit 70. The fixing unit 70 includes a heater roller 71 for applying heat to the print medium, and a pressure roller 72 for pressing the print medium while rotating in engagement with the heater roller 71. The fixing unit 70 applies heat and pressure to the print medium to fix the toner image on the print medium. The print medium on which the toner image is fixed is discharged to the discharge unit 30 by the discharge roller 44.

2 is a cross-sectional view showing a developing unit and a toner collecting unit of the image forming apparatus according to the present invention, FIG. 3 is a perspective view showing the shape of the toner collecting unit in the image forming apparatus according to the present invention, and FIG. Is a developed view showing the ratio of the height and length of the scattering prevention portion in the image forming apparatus according to the present invention.

2 to 4, the fan 100 is disposed near the photosensitive drum 52 and the developing roller 54. The fan 100 is disposed at one end of the photosensitive drum 52 side of the toner collection unit 200. The fan 100 applies a cross flow fan 100 that sucks air in a radial direction and discharges it in a radial direction. The fan 100 is rotated to form an airflow, thereby inducing floating toner particles to the toner collection unit 200.

The toner collection unit 200 includes a base plate 210 disposed under the toner container 51. The base plate 210 forms a flow space of airflow together with the bottom surface of the toner container 51. In addition, one end of the photosensitive drum 52 is opened and the other ends of the base plate 210 are closed.

The base plate 210 has a rounded shape to gently guide the airflow to the upper side of the toner container 51. In addition, an outlet 211 is formed at an upper side of the base plate 210 so that air is discharged to the outside of the toner collection unit 200.

Inside the base plate 210, as shown in FIG. 3, a toner deposition unit 220 having a different height at the top is disposed. At this time, the upper end of the toner deposition unit 220 has a plate shape in which the height is lowered toward both sides from the center.

From a hydrodynamic point of view, the flow velocity V1 of the fluid at both ends of the fan 100 is almost zero (V1 = 0), and the flow velocity of the fluid at the center of the fan 100 is maximum.

Therefore, the upper end of the toner deposition unit 220 is preferably formed in an ellipse shape. For example, as shown in FIG. 4, the distance from one end of the fan 100 to the center of the fan 100 is a long axis L, and the toner deposition part ( The distance to the center of the upper end of the 220 is to have an elliptic form with a short axis (S).

Then, the short axis (S) is to have a length of 9/10 times the length of the major axis (L) (S = 9L / 10). The reason is that the re-spread toner is deposited again on the toner deposit 220 because the upper end of the toner deposit 220 is sufficiently high even if the deposited toner is scattered again by an external impact.

In addition, since the flow rate of the airflow is changed according to the rotational speed of the fan 100, the ratio of the long axis L and the short axis S may be appropriately changed according to the rotational speed of the fan 100. It is understandable. Alternatively, the ratio of the long axis L and the short axis S may be appropriately changed depending on the length or the width of the flow space.

The toner collection unit 200 may further include a toner adhesive portion 230 to which toner particles induced by air flow are adhered. In this case, the toner adhesive portion 230 is disposed between the fan 100 and the toner deposition portion 220. An adhesive member 231 in the form of a double-sided tape is disposed on the bottom surface of the toner adhesive portion 230. In addition, ribs 232 are formed on the rear surface of the flow direction of the airflow of the adhesive member 231 in the toner adhesive portion 230. The ribs 232 help toner particles included in the airflow to be attached to the adhesive member 231.

5 is a cross-sectional view showing a state where the release paper is attached to the toner adhesive portion in the image forming apparatus according to the present invention, Figure 6 is a cross-sectional view showing a state of removing the release paper from the toner adhesive portion in the image forming apparatus according to the present invention.

5 and 6, a release paper 233 may be attached to an upper surface of the adhesive member 231. This is to prevent the adhesive member 231 from drying or adhering toner particles before using the developing unit 50.

The release paper must be removed before operating the image forming apparatus. Accordingly, the release paper removing member 240 is disposed to peel off the release paper 233 from the outside. At this time, the release paper 233 is attached to the adhesive member 231 and is disposed in a state passing through the space between the fan 100 and the toner container 51. And, the outer end of the release paper 233 is coupled to the release paper removing member 240. In addition, one end of the release paper 233 attached to the adhesive member 231 is disposed on the fan 100 side. The other end of the release paper removing member 240 passes through the photosensitive drum 52 and the fan 100.

In this case, the release paper removing member 240 is interposed at both ends of the photosensitive drum 52 to prevent the surface of the photosensitive drum 52 from being damaged by the release paper removing member 240.

The developing unit 50 is sold and distributed as individual consumables. The release paper removing member 240 serves to maintain the photosensitive drum 52 and the fan 100 at a predetermined interval while the developing unit 50 is in circulation. In addition, the release paper removing member 240 is disposed to be exposed to the outside to pull from the outside.

The operation of the embodiment according to the present invention configured as described above will be described.

When the release paper removing member 240 is pulled as shown in FIG. 6, the release paper 233 is discharged to the outside through a gap between the photosensitive drum 52 and the developing roller 54. When the release paper 233 is removed in this way, toner particles may be adhered to the upper surface of the adhesive member 231.

When printing of the print medium is started, the print medium is transferred between the photosensitive drum 52 and the transfer roller 61 through the transfer path 20. Then, the developing roller 54 and the photosensitive drum 52 are rotated together to form a toner image on the surface of the photosensitive drum 52. The toner image of the photosensitive drum 52 is printed on the print medium as the photosensitive drum 52 and the transfer roller 61 are rotated.

At this time, the photosensitive drum 52 is formed by rotating the photosensitive drum 52 near the photosensitive drum 52. At the same time, the transfer roller air flow 92 is formed by rotating the transfer roller 61 near the transfer roller 61. Since the photosensitive drum 52 is rotated in the clockwise direction, and the transfer roller 61 is rotated in the counterclockwise direction, the photosensitive drum stream 91 and the transfer roller stream 92 meet each other. At this time, the photosensitive drum air stream 91 includes a part of toner particles attached to the surface of the photosensitive drum 52 in the developing roller 50.

In addition, as the fan 100 is rotated, air flow is formed from the photosensitive drum 52 to the toner collection unit 200. The photosensitive drum stream 91 and the transfer roller stream 92 are introduced into the toner collection unit 200 while being mixed with each other. Toner particles contained in the transfer roller stream 92 are also introduced into the toner collection unit 200. The airflow introduced into the toner collection unit 200 is turbulence. In addition, since the space on the downstream side of the fan 100 suddenly becomes wider, the flow velocity of the airflow drops rapidly on the downstream side of the fan 100. Therefore, a part of the toner particles included in the air stream adheres to the adhesive member 231 due to the turbulence and the flow rate drop.

In addition, the toner particles that are not adhered to the adhesive member 231 flow to the toner deposition unit 220 by air flow. At this time, the flow rate of the airflow flowing into the toner collection unit 200 is the center of the flow space is the maximum and both sides are almost zero (zero). The airflow is guided by the toner deposit 220 and flows upward. At this time, since the flow velocity of the air stream is considerably slowed, the toner particles included in the rising air stream are deposited on the toner deposition unit 220. Subsequently, the airflow passing through the toner deposition unit 220 is discharged to the outside through the outlet 211 of the base plate 210. At this time, since the flow space is greatly widened near the outlet 211 of the base plate 210, almost all of the toner included in the airflow near the outlet 211 is deposited downward. Accordingly, the toner particles are hardly present in the air stream discharged to the outside of the toner collection unit 200.

As described above, according to the embodiment of the present invention, the toner particles contained in the air stream are adhered and deposited so that floating toner particles can be prevented from contaminating internal devices of the image forming apparatus.

In addition, since the toner particles are adhered to the adhesive member, the toner particles may be minimized from being scattered again.

In addition, since the internal devices are prevented from being contaminated, an image may be properly formed on a print medium.

In addition, the user may not feel uncomfortable and may not be harmful to the human body of the user.

Claims (5)

A toner container in which toner is stored; A photosensitive drum disposed around the toner container and having an electrostatic latent image formed thereon; A developing roller disposed corresponding to the photosensitive drum and providing a toner on the electrostatic latent image of the photosensitive drum to form a toner image; A fan for forming an air stream to induce toner particles floating near the developing roller and the photosensitive drum; And A toner collection unit disposed on a downstream side of the fan to form a flow space of the airflow, and having a toner deposit formed at a different height at an upper end thereof; And the toner collecting unit further comprises a toner adhesive portion to which toner particles induced by air flow adhere. The method of claim 1, And an upper end portion of the toner deposition portion has a shape in which the height of the toner deposition portion is lowered toward both sides from the center portion. The method of claim 1, The toner depositing unit has a long axis from one end of the fan to the center of the fan, and shortens the distance from the lower center of the toner depositing unit to the upper center of the toner depositing unit, and the shortening is 9/10 times the long axis. Image forming apparatus characterized in that the elliptical form having a length of. delete The method of claim 1, Release paper is attached to the toner adhesive portion, And a release paper removal member connected to the release paper so that the release paper can be peeled off from the outside.

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