JP2001175082A - Recovered toner recycling system image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recovered toner recycling system image forming device capable of effectively preventing the deterioration of image quality caused by the intrusion of paper powder into a developing device. SOLUTION: As for the recovered toner recycling system image forming device for recovering the toner remaining on the surface of a photoreceptor drum after the toner image is transferred by using a cleaning device, and then, recycling the recovered toner in the developing device, and in a developing housing which is packed with magnetic developer, the developing device is provided with a developer carrying sleeve arranged facing the photoreceptor drum, a developer stirring/mixing area with a developer stirring paddle which is installed adjacent to the sleeve and a recovered toner storing area which is adjacent to the developer stirring/mixing area and where a paper powder scavenging paddle is installed, and the paper powder scavenging paddle is provided with a mesh surface formed of a mesh member, and the recovered toner recovered by the cleaning device is supplied to the recovered toner storing area, and then, carried into the developer stirring/mixing area through the paper powder scavenging paddle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
Related to an image forming apparatus such as a facsimile,
In particular, the present invention relates to a recovered toner recycling type image forming apparatus that uses recycled toner in a developing device.

[0002]

2. Description of the Related Art In an image forming apparatus represented by a copying machine, the surface of a photosensitive drum is uniformly charged, and an electrostatic latent image corresponding to a document image is formed on the surface of the photosensitive drum by image exposure. By developing the electrostatic latent image to form a toner image on the surface of the photoconductor drum, transferring the toner image from the surface of the photoconductor drum onto transfer paper, and fixing the transferred toner image by heat, pressure, or the like. , An image is formed.

In such an image forming apparatus, a magnetic brush developing method is widely used as a method for developing an electrostatic latent image formed on the surface of a photosensitive drum.
The magnetic brush developing method uses a one-component magnetic developer composed of a magnetic toner or a two-component magnetic developer composed of a toner and a magnetic carrier as a developer. Developing device usually comprises a developing housing filled with a magnetic developer,
In the developing housing, a developer conveying sleeve is accommodated so as to face the surface of the photosensitive drum. That is, the developer transfer sleeve has a structure having a magnet having a plurality of magnetic poles in a non-magnetic sleeve such as aluminum, and the toner charged to a predetermined polarity by the rotation of the sleeve is in the form of a magnetic brush. The toner is conveyed to a development area (an area between the sleeve and the surface of the photosensitive drum) to perform development.

Recently, from the viewpoint of resource saving and environmental friendliness, after transferring a toner image onto a predetermined transfer material,
2. Description of the Related Art A collected toner recycling type image forming apparatus that recycles toner removed from the surface of a photoreceptor by a cleaning device such as a cleaning blade into the above-described developing device and reuses the toner is widely used.

[0005]

By the way, when the above-described image formation is performed, paper dust is generated from the transfer paper, and this paper dust may adhere to the surface of the photosensitive drum during transfer.
Since the paper dust adhering to the surface of the photoreceptor drum is collected by the cleaning device, there is almost no adverse effect on the formed image. However, in a recovered toner recycling type image forming apparatus,
The toner collected by the cleaning device is recycled into the developing device and reused for development.Therefore, paper dust generated from the transfer paper and adhered to the surface of the photosensitive drum is collected by the cleaning device together with the collected toner. It is supplied into the developing device. Therefore, as the image formation is repeated, the amount of paper dust in the developing device increases,
Since the electrostatic image is developed by a developer containing paper dust, there is a problem that the image quality is deteriorated by the paper dust.

For example, if paper dust is mixed in the toner, the toner is aggregated in the paper dust, and when the development with the aggregated toner is performed, the aggregated toner is dusted on an image to be formed. (Image portion toner dust), which causes a problem that image quality is deteriorated. Further, transfer paper contains a large amount of filler such as talc in addition to the fiber component, and due to the effect of such a filler, paper powder generated from the transfer paper has the property of being negatively charged. are doing. Therefore, especially when the positively charged toner is used as the developer, the paper powder exhibits the same behavior as the oppositely charged toner. As a result, toner scattering, fogging, and the like occur, and the deterioration of image quality becomes even more remarkable.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a recovered toner recycling type image forming apparatus in which deterioration of image quality due to mixing of paper dust into a developing device is effectively prevented.

[0008]

According to the present invention, a toner image is formed by developing an electrostatic image formed on the surface of a photosensitive drum with a magnetic developer filled in a developing device. A recovered toner recycling type image forming apparatus which transfers an image onto a predetermined transfer paper, collects toner remaining on the surface of the photosensitive drum after transfer of the toner image by a cleaning device, and recycles the collected toner into the developing device. In the developer, a developer transport sleeve disposed in a developing housing filled with a magnetic developer and facing the photosensitive drum, and a developer stirring paddle adjacent to the sleeve. It has a stirring and mixing area and a collected toner storage area provided with a paper dust collecting paddle adjacent to the developer stirring and mixing area, and the paper dust collecting paddle is formed by a mesh member. The collected toner collected by the cleaning device is supplied to the collected toner storage area, and is conveyed to the developer stirring and mixing area through a paper dust collecting paddle. An image forming apparatus is provided.

In the present invention, a paddle for collecting paper dust is provided in a collected toner storage area in the developing device. That is,
The collected toner supplied into the developing device is introduced into a developer stirring and mixing area through a paper dust collecting paddle, and is passed through a developer stirring paddle provided in the developer stirring and mixing area.
The developer is supplied to a developer conveying sleeve (developing sleeve), and is conveyed to a developing area (an area between the developing sleeve and the photosensitive drum) to perform development. Therefore, the paper dust contained in the recovered toner or the aggregated toner containing the paper dust is captured by the paper dust collecting paddle, and as a result, only the toner not containing the paper powder is supplied onto the developing sleeve and used for development. Therefore, the deterioration of the image quality caused by the paper dust can be effectively avoided.

In the present invention, the paddle for collecting paper dust has a mesh surface formed by a mesh member. For example, a mesh surface is formed on a stirring blade of the paddle, or the paddle is Has a structure in which a cylindrical mesh surface is formed along the tip of the stirring blade. That is, paper dust or agglomerated toner containing paper dust is captured on the mesh surface of such a paper dust collecting paddle, thereby effectively preventing the paper dust and the like from being transported to the development area. It is.

The use of the above-described paddle for collecting paper dust makes it possible to effectively feed the developer even when a large amount of paper dust or the like is caught on the mesh surface of the paddle and clogging occurs. It is of great technical significance in that it is performed in That is, when a normal mesh plate is arranged in the flow of the developer, if the clogging occurs, the supply of the developer is interrupted, and a sufficient amount of the developer is supplied onto the developing sleeve. Can not be done. However, when the paper dust collecting paddle having the mesh surface as described above is used, since the mesh surface itself rotates together with the stirring blade, even if clogging occurs on the mesh surface, the developer does not The feeding is not interrupted, and the development can be performed subsequently.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to specific examples shown in the accompanying drawings. FIG. 1 is a view showing a structure of a recovered toner recycling type image forming apparatus of the present invention. FIGS. 2 and 3 are views showing a structure of a paper dust collecting paddle provided in a developing device of the image forming apparatus of FIG. FIG.

In FIG. 1, in this image forming apparatus, a main charging device 2, an exposure mechanism 3, a developing device 4, a transfer device are provided around a photosensitive drum 1 rotatably provided in the direction of the arrow in FIG. 5, cleaning device 6, static elimination device 7,
The transfer paper 10 is arranged in this order along the rotation direction of the photoconductor drum 1, the transfer paper 10 is passed between the photoconductor drum 1 and the transfer device 5, and a fixing device is provided on a discharge path of the transfer paper 10. (Not shown) is provided.

As the photosensitive drum 1, an inorganic photosensitive drum in which a photosensitive layer such as selenium or amorphous silicon is provided on a conductive base roller such as aluminum, or a charge generating agent or a charge transporting agent in a binder resin. An organic photosensitive drum provided with an organic photosensitive layer in which is dispersed is used. As the main charging device 2, there is a roller-type contact charging device, but generally, a corona charger is used, and the main charging device 2 causes the surface (photosensitive layer) of the photosensitive drum 1 to change the type of the photosensitive layer. , And is uniformly charged to a predetermined polarity. At this time, the main charging potential of the photoreceptor surface is usually 200 to 1000 V (absolute value). Next, the image exposure mechanism 3 irradiates the surface of the photoreceptor drum with dot light such as a laser beam corresponding to the original by reflected light of the original or an electric signal from a computer or the like. A latent image is formed.

The electrostatic latent image is developed by magnetic brush development using a developing device 4 described later, and a toner image 15 is formed on the surface of the photosensitive drum 1. As the developer, a two-component developer composed of a magnetic carrier and an insulating toner or a one-component developer composed of a magnetic toner is used.
The developing device 4 conveys the toner triboelectrically charged to a predetermined polarity in the form of a magnetic brush, and develops an electrostatic latent image formed on the surface of the photosensitive drum 1 with the toner.
The toner image 15 is formed on the surface of the photosensitive drum 1. The charge polarity of the toner, that is, the toner image 15 is opposite to the charge polarity of the surface of the photosensitive drum 1 when image formation is performed by so-called regular development, and when the image formation is performed by reverse development, It has the same polarity as the charging polarity on the surface of the photosensitive drum 1. Further, at the time of development, a bias voltage is generally applied between the photosensitive drum 1 and the developing sleeve 31 (generally, about 100 to 300 V in absolute value in normal development, and 30 in absolute value in reversal development).
0-700V).

The transfer device 5 generally includes a transfer charger 5a.
And a separating chargeer 5b, and the transfer paper 1 introduced between the transfer device 5 and the photosensitive drum 1.
0 is transferred to the toner image 15 by the transfer charger 5a.
The toner image 15 is transferred onto the transfer paper 10 by the electrostatic attraction between the charge and the toner image 15, and a transfer toner image 16 is formed. Also, the toner image 1
Simultaneously with the formation of the photosensitive drum 6, the transfer paper 10 is separated from the surface of the photosensitive drum 1 by AC charging by the separation charger 5b. In addition, as the transfer device 5,
It is also possible to use a transfer roller, in which case,
There is no need for a transfer paper separating device such as the separating charger 5a.

The transfer paper 10 having the transfer toner image 16 is
The transfer toner image 16 is conveyed to a fixing device (not shown), and is fixed on the surface of the transfer paper 10 by heat, pressure, or the like. On the other hand, after the toner image 15 is transferred onto the transfer paper 10, the toner remaining on the surface of the photosensitive drum 1 is scraped and collected by the cleaning device 6 including a cleaning blade and the like, By irradiation
After the surface charge of the photosensitive drum 1 is removed, the next image forming process is performed. The toner collected by the cleaning device 6 is recycled to the developing device 4 along a path indicated by reference numeral 20 using a transport device such as a spiral, and is reused.

In the above-described image forming apparatus, the developing device 4 includes a developing housing 30 filled with a developer 25, and the developing housing 30 is provided in the developing housing 30 so as to face the photosensitive drum 1. A transport sleeve (developing sleeve) 31 is provided, and a developer agitating / mixing area 32 is formed adjacent to the developing sleeve 31. As is apparent from FIG. 1, developer stirring paddles 32a and 32b extending coaxially with the developing sleeve 31 are arranged in parallel in the developer stirring and mixing area 32, and these paddles 32a and 32b are arranged in parallel. A feed guide 33 is provided between them. Further, a new toner supply port 35 is provided on the upper wall of the developing housing 30 above the developer stirring and mixing area 32, and from this supply port 35, the new toner is supplied onto the developer stirring paddle 32b. It has become.

The developing sleeve 31 has a magnet having a plurality of magnetic poles fixed inside. The developing sleeve 31 conveys the developer 25 in the form of a magnetic brush by rotation of the sleeve. The interval is generally set to about 0.3 to 1.0 mm. Of course, the developing sleeve 31 may be one that fixes the sleeve and conveys the developer by rotating an internal magnet. Further, the developing sleeve 31 and the developing sleeve 31 are spaced apart from each other at a fixed interval (usually 0.
(Approximately 5 to 0.9 mm), and the ear cutting blade 37 is attached. That is, the developer 25 pumped up by the developing sleeve 31 is blocked by the spike blades 37 and is in the form of a magnetic brush adjusted to a fixed spike length. And developing sleeve 3
1), where the electrostatic latent image is developed.

The developer agitating paddles 32a and 32b provided in the developer agitating / mixing area 32 sufficiently mix and agitate the developer 25 to sufficiently frictionally charge the toner in the developer 25. The blades of the paddles 32a and 32b are set in a spiral shape so as to agitate and feed the developer 25 in the axial direction, for example, and a feed guide 33 disposed between these paddles is shown in FIG. Although not shown, a communicating portion is formed at the center or both ends. That is, these developer stirring paddles 32a, 32
b, the developer 25 is stirred and mixed with the new toner appropriately supplied from the new toner replenishing port 35, and is agitated and sent in the axial direction.
The developer 25 is put in and taken out between the central portion or both end portions of 3, so that triboelectric charging is efficiently performed. The developer (toner) 2 thus frictionally charged to a predetermined polarity.
The developer 5 is pumped up by the developing sleeve 31, and the developer is transported to the developing area in the form of a magnetic brush whose spike length has been adjusted by the cutting blade 37, and the electrostatic latent image is developed.

In the present invention, a collected toner storage area 40 defined by a relatively short partition wall 39 is formed adjacent to the developer stirring and mixing area 32, as shown in FIG. The toner collected by the cleaning device 6 is supplied to a collected toner storage area 40. A paper dust collecting paddle 41 is provided in the collected toner storage area 40. As shown in FIG. 1, the paper dust collecting paddle 41 is located on a side away from the developing sleeve 31. Is adjacent to the developer stirring paddle 32b in parallel with the paddle 32b via a partition wall 49. That is, the collected toner supplied to the collected toner storage area 40 is pumped up by the paper dust collecting paddle 41 and sent to the adjacent developer stirring paddle 32b via the partition wall 39. It is like.

In the present invention, the paddle 41 for collecting paper dust is used.
Has a mesh surface formed by a mesh member, and has a structure such that when the collected toner is pumped up by the paper dust collecting paddle 41, the paper dust is captured on the mesh surface. ing. Therefore, the toner collected by the cleaning device 6 is supplied to the developer stirring and mixing area 32 after the paper dust is captured by the paper dust collecting paddle 41, so that the paper powder is supplied to the development area by the developing sleeve 31. There is no danger that the image quality will be degraded due to paper dust.

The above-mentioned paper dust collecting paddle 41 is provided with a blade for pumping up the collected toner supplied to the collected toner storage area 40, and a mesh capable of effectively catching the paper powder from the collected collected toner. The structure is not particularly limited as long as it has a surface, but generally, the structure shown in FIGS. 2 and 3 is used.

In FIG. 2, (A) shows a plane shape of the paper dust collecting paddle 41, and (B) shows a sectional view taken along the line II of the paper dust collecting paddle 41 shown in (A). It is. The paper dust collecting paddle 41 is formed of a rotating shaft 50 and a plate-like blade 51, and the plate-like blade 51 is provided with a frame 51a.
And a plate-shaped mesh 51b attached to the frame 51a. That is, this plate-shaped mesh 51
b, a mesh surface is formed, and by rotating the blades 51, at the same time as pumping the collected toner,
Paper dust contained in the collected toner and toner aggregates containing the paper dust are captured. The paper dust collecting paddle 41 shown in FIG.
Although only one plate-shaped blade 51 is provided, it is needless to say that a plurality of such plate-shaped blades 51 may be provided.

FIG. 3 is a view showing another example of the paddle 41 for collecting paper dust. In the paddle 41 for collecting paper dust,
A plurality of plate-shaped blades 51 are provided on the rotating shaft 50, and a cylindrical mesh 52 is provided at the tip of the plate-shaped blades 51. That is, at both ends of the plate-shaped blade 51, a ring-shaped frame 53 connecting the tips of the plate-shaped blades 51 is formed, and a cylindrical mesh 5 is formed on the outer surface of the ring-shaped frame 53.
2 are fixed at both ends. According to such a paper dust collecting paddle 41, the mesh surface is formed by the tubular mesh 52, and the collected toner that has passed through the tubular mesh 52 is pumped up by the plate-like blades 51, and the collected pumped-up toner is collected. The toner again passes through the cylindrical mesh 52,
The developer is supplied to the developer stirring and mixing area 32 described above, and during this time,
Paper dust contained in the collected toner and toner aggregates containing the paper dust are captured by the tubular mesh 53.

According to the present invention described above, since the paper dust collecting paddle 41 is provided in a region separate from the developer stirring and mixing region 32, for example, clogging occurs on the mesh surface of the paddle 41. Even if it occurs, the flow of the developer 25 in the developer stirring and mixing area 32 is not impaired. Further, in the paper dust collecting paddle 41, since the mesh surface itself rotates, even if the mesh surface is completely clogged, the flow of the collected toner to the developer stirring and mixing area is completely stopped. There is no end. The mesh openings of the plate-like mesh 51b and the tubular mesh 53 shown in FIG. 2 or 3 are about 30 to 150 μm in order to effectively capture paper dust and toner aggregates including paper dust. It is preferable that the size is

In the above-described present invention, a collected toner storage area 40 is provided in the developing device 4 separately from the developer stirring and mixing area 32, and a toner collecting paddle 41 is provided in the collected toner storage area 40. However, it is also possible to provide a collected toner storage area for accommodating the paper dust collecting paddle having the structure shown in FIGS. 2 and 3 in the middle of the collected toner recycling path 20 shown in FIG. In such a case, the collected toner supplied into the developing device 4 has already captured the paper dust and the aggregated toner containing the paper dust. For example, the collected toner is supplied into the developing device 4 together with the new toner. You can also. However, in general, in order to make the image forming apparatus compact, it is preferable to form a collected toner storage area 40 in which the paper dust collecting paddle 41 is accommodated in the developing device 4.

[0028]

According to the present invention, the toner collected by the cleaning device can be recycled into the developing device without supplying the paper dust or the aggregated toner containing the paper powder to the developing area. Can be effectively prevented from deteriorating the image quality.

[Brief description of the drawings]

FIG. 1 is a diagram showing the structure of a recovered toner recycling type image forming apparatus of the present invention.

FIG. 2 is a diagram showing an example of a structure of a paper dust collecting paddle provided in a developing device of the image forming apparatus of FIG.

FIG. 3 is a diagram showing another example of the structure of the paper dust collecting paddle provided in the developing device of the image forming apparatus of FIG. 1;

[Explanation of symbols]

1: Photoreceptor drum 4: Developing device 6: Cleaning device 20: Recycle path of collected toner 25: Developer 31: Developing sleeve 32: Developer stirring mixing area 32a, 32b: Developer stirring paddle 40: Collected toner storage area 41 : Paddle for collecting paper dust 50: Rotating shaft 51: Plate blade 51 a: Plate mesh 52: Cylindrical mesh

Continuing from the front page (72) Inventor Shinji Kikuta 1-2-2, Tamazo, Chuo-ku, Osaka-shi Inside Mita Kogyo Co., Ltd. (72) Inventor Jou Nanjo 1-2-28, Tamazo, Chuo-ku, Osaka Mita Kogyo shares In-company (72) Inventor Noriyuki Sakata 1-2-28 Tamazo, Chuo-ku, Osaka-shi F-term (reference) 2H077 AA37 AB03 AB06 AC03 AC16 AD06 AD13 AD35 BA08 EA03 EA13 EA16 GA17

Claims (5)

[Claims] An electrostatic image formed on the surface of a photosensitive drum is developed by a magnetic developer filled in a developing device to form a toner image, and the toner image is transferred onto a predetermined transfer paper. A collecting device that collects toner remaining on the surface of the photosensitive drum after transfer of the toner image by a cleaning device and recycles the collected toner into the developing device; A developer carrying sleeve disposed in the developing housing facing the photosensitive drum, a developer stirring / mixing area provided with a developer stirring paddle adjacent to the sleeve, and a developer stirring / mixing area And a collected toner storage area provided with a paper dust collecting paddle adjacent to the paper dust collecting paddle. The paper dust collecting paddle has a mesh surface formed by a mesh member. Recovery toner recovered by the cleaning device, the is supplied to the recovery toner storage area, the image forming apparatus characterized by being conveyed on the developer stirring and mixing zone through the paper dust collecting paddle. 2. A mesh surface of the paper dust collecting paddle,
The image forming apparatus according to claim 1, wherein the image forming apparatus is formed on the stirring blade. 3. A mesh surface of the paper dust collecting paddle,
The image forming apparatus according to claim 1, wherein the image forming apparatus is formed in a cylindrical shape along a tip portion of the stirring blade. 4. A paper dust collecting paddle, wherein a mesh surface formed by a mesh member is formed on the stirring blade. 5. A paper dust collecting paddle, wherein a cylindrical mesh member is attached along the tip of the stirring blade.