JP2007147716A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which doesn't abandon toner recovered by cleaning but prevents flocculation of the toner by a simple structure to reuse the toner, with respect to the image forming apparatus wherein a toner image is formed on an image carrier and is finally transferred and fixed onto a prescribed recording medium to form an image by the fixed toner image. <P>SOLUTION: Toner which is scraped by a cleaning blade 1151 and is temporarily stored in an internal space 1152b of an enclosure 1152 is supplied to an upper side 1151a of the cleaning blade 1151 by a paddle member 1154 taking an auger 1153 as a power source. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus for forming a toner image on an image carrier, and finally transferring and fixing the toner image on a predetermined recording medium to form an image composed of the fixed toner image on the recording medium. About.

  In an image forming apparatus used for an electrophotographic copying machine, printer, facsimile, or the like, an image carrier represented by a photosensitive drum or the like is uniformly charged, and exposure light carrying image information is supplied to the image carrier. The electrostatic latent image is formed on the image carrier by irradiating the toner, and the electrostatic latent image is developed using a developing device that attaches the toner to the electrostatic latent image. An image formed of a fixed toner image on the recording medium is formed by forming an image and transferring and fixing the formed toner image directly or on, for example, an intermediate transfer member onto the recording medium. Is formed.

  In addition, in such an image forming apparatus, the image forming apparatus includes a cleaning device that cleans the toner remaining on the image carrier after the toner image formed on the image carrier is transferred onto the recording medium. There is an image forming apparatus provided with a cleaning device for cleaning the toner remaining on the intermediate transfer body after the toner image formed on the apparatus or the image carrier is transferred onto the recording medium with the intermediate transfer body interposed therebetween. . Furthermore, there is an image forming apparatus provided with a means for supplying the toner collected by such a cleaning device to the developing device and reusing it.

  Here, with respect to such toner reuse, a change in the properties of the toner collected in the process of reuse has been a problem.

  For example, in an image forming apparatus provided with a cleaning device that has a cleaning blade that comes into contact with the surface of an object to be cleaned such as an image carrier or an intermediate transfer member and scrapes off toner remaining on the surface after the toner image is transferred. When images are output continuously, only a small amount of toner reaches a portion of the surface of the object to be cleaned that comes into contact with the cleaning blade (hereinafter, this portion is referred to as a blade nip portion). As described above, when the state where only a small amount of toner reaches the blade nip portion continues, the scraped toner stays on the cleaning blade near the blade nip portion, and the staying toner is affected by heat, pressure, and the like. And agglomeration of toner may occur. When such toner agglomerates are supplied to the developing device and reused for development, for example, white spots (image defects) due to the toner agglomerates occur in the solid portion of the image transferred onto the recording medium. There is a risk of image quality degradation. In particular, in an image forming apparatus provided with a means for supplying and reusing toner collected by a cleaning blade disposed so that the blade nip portion faces upward, the toner scraped off by the cleaning blade is removed. Such a problem becomes even more prominent because it is impossible to drop by gravity.

  As an image forming apparatus that addresses the above-described problems, a toner that includes a plurality of cleaning members and a toner conveyance path that corresponds to the toner recovered by each of the cleaning members, and that is recovered by a blade-shaped cleaning member (cleaning blade) Is an image configured to lead to a toner conveyance path connected to a toner disposal system for discarding toner, and to guide only toner collected by a brush-like cleaning member (cleaning brush) to a recycled toner supply path connected to the developing device. A forming apparatus has been proposed (see, for example, Patent Document 1 and Patent Document 2).

Further, as an image forming apparatus for preventing toner fusion at the blade nip portion, a cleaning blade and a toner supply unit disposed upstream of the cleaning blade in the moving direction of the photosensitive member are provided. There has been proposed an image forming apparatus configured to supply toner to a blade nip portion of a cleaning blade by adhering toner to the surface of the photosensitive member using a toner (see, for example, Patent Document 3).
JP 2002-287590 A JP 2003-150013 A JP 2000-231320 A

  According to the techniques proposed in Patent Document 1 and Patent Document 2 described above, toner aggregates out of the toner recovered by cleaning are unlikely to be generated and are recovered by a cleaning brush suitable for reuse. Since only the toner is reused, a good image can be obtained. However, since the toner collected by the cleaning blade is not limited to the toner agglomerates, all the toner is discarded, which causes a problem that the collected toner is wasted. There is also a problem that the cost is high due to the complicated structure.

  Further, according to the technique proposed in Patent Document 3 described above, toner is supplied to the blade nip portion, and since the supplied toner functions as a lubricant, fusion at the blade nip portion is prevented, and cleaning performance is improved. However, there is a problem that the structure is large and the control is complicated.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image forming apparatus that does not discard toner collected by cleaning and prevents the toner from aggregating with a simple structure and reuses the toner. is there.

The image forming apparatus of the present invention that achieves the above object provides:
A developing device for developing the toner by attaching toner to the electrostatic latent image formed on the image carrier that is disposed opposite to the image carrier on which an electrostatic latent image is formed. The electrostatic latent image formed thereon is developed using the developing device to form a toner image on the image carrier, and the toner image is finally transferred and fixed on a predetermined recording medium. In the image forming apparatus for forming an image composed of a fixed toner image on the recording medium,
A cleaning blade having a plate shape, and one side of the plate shape abuts on the surface of the object to be cleaned moving in a predetermined direction, and scrapes off the toner adhering to the surface;
A housing having a supply port connected to the developing device and forming an internal space for temporarily storing toner scraped off by the cleaning blade;
Toner conveying means for conveying the toner temporarily stored in the internal space of the casing toward the supply port;
And a toner supply means for supplying the toner temporarily stored in the internal space of the housing to the one side of the cleaning blade using the toner conveying means as a power source.

  In the image forming apparatus of the present invention, the toner that is scraped off by the cleaning blade and temporarily stored in the internal space of the casing is cleaned by the toner supply unit using the toner conveying unit as a power source. Is supplied to the one side. Therefore, according to the image forming apparatus of the present invention, since the toner is continuously supplied to one side, the toner is replaced without staying on the one side, and the toner scraped off by the cleaning blade is aggregated. Thus, toner agglomerates are prevented from being generated. Further, according to the image forming apparatus of the present invention, since the power source of the toner supply means is the toner transport means, no new power source is required for supplying toner to the one side, and the simple structure Thus, toner aggregation can be prevented and reused. Furthermore, according to the image forming apparatus of the present invention, the toner collected by the cleaning blade that is highly likely to generate a toner agglomerate is prevented, so that the toner collected by the cleaning is not discarded. Thus, all the collected toner can be reused efficiently, resulting in a reduction in toner consumption and cost reduction.

  Here, in the image forming apparatus of the present invention, it is preferable that the one side of the cleaning blade is an upper side of the plate shape.

  As described above, the cleaning blade disposed such that the upper side of the plate shape is the one side cannot drop the toner scraped off by the cleaning blade by gravity. By constantly supplying toner to one side, the toner is replaced without staying in one side, and the toner scraped off by the cleaning blade is aggregated to prevent the toner aggregate from being generated.

In the image forming apparatus of the present invention,
“The toner conveying means is an auger having a rotating shaft pivotally supported by the casing and a spiral blade,
The toner supply means is a paddle member having a strip shape and one side fixed to the rotating shaft of the auger.
This form is also preferable.

  According to such a preferred embodiment, the toner supply means rotates using the auger as a power source, and the toner temporarily stored in the internal space of the housing is supplied to the one side of the cleaning blade. be able to.

  Furthermore, in the image forming apparatus according to the present invention, it is also preferable that the paddle member is made of an elastic member.

  According to such a preferred embodiment, in addition to the rotational movement of the paddle member, the toner can be supplied to the one side of the cleaning blade by the elastic force of an elastic member such as a polyester film or a rubber sheet. Therefore, efficiency is good.

  According to the present invention, there is provided an image forming apparatus in which toner collected by cleaning is reused while preventing the toner from aggregating with a simple structure without being discarded.

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

  FIG. 1 is a schematic configuration diagram of a printer to which an embodiment of an image forming apparatus of the present invention is applied. Here, first, the positioning of the present invention will be described with reference to FIG.

  A printer 1 shown in FIG. 1 includes a control unit 10 that controls the entire printer 1, for example, a paper cassette 20 and a paper cassette 20 that store standard size paper represented by B5 size paper and A4 size paper. The toner image is transferred by the paper drawing unit 14 that draws the stored paper into the paper transport path 15, the image forming unit 11 that forms an image on the paper transported along the paper transport path 15, and the image forming unit 11. The image forming apparatus includes a fixing device 13 that fixes the toner image on the sheet and a conveyance roller 30 that conveys the sheet along the sheet conveyance path 15.

  1 includes a cylindrical photosensitive drum 111 that rotates counterclockwise, a charger 112 that applies a predetermined charge to the surface of the photosensitive drum 111, and a predetermined charge that has been applied. An exposure unit 113 that exposes the surface of the photosensitive drum 111 to form an electrostatic latent image, a developing device 114 that develops the electrostatic latent image with toner to form a toner image on the surface of the photosensitive drum 111, and A transfer unit 117 is provided for transferring the toner image onto the sheet.

  Further, the image forming unit 11 shown in FIG. 1 is disposed between the transfer unit 117 and the charging unit 112, contacts the surface of the photosensitive drum 111, and scrapes off the toner remaining on the surface after the toner image is transferred. A cleaning device 115 having a blade 1151 and a toner supply path 116 for supplying toner collected by the cleaning device 115 to the developing device 114 are provided. The cleaning blade 1151 corresponds to an example of the cleaning blade referred to in the present invention.

  Here, the feature of the printer 1 shown in FIG. 1 as an embodiment of the present invention is related to the cleaning device 115 provided in the printer 1, and the cleaning device 115 will be described in detail below.

  2 is an enlarged cross-sectional view of the image forming unit shown in FIG. 1, and FIG. 3 is an enlarged side view of the auger and paddle member shown in FIG.

  2 shows the photosensitive drum 111, the charger 112, the exposure device 113, the developing device 114, the cleaning device 115, the toner supply path 116, and the transfer device 117, which are also shown in FIG.

  As shown in an enlarged view in FIG. 2, the developing device 114 includes a developing roll 1141, a housing 1142, and a first auger 1143 and a second auger 1144 that stir the developer in the housing 1142.

  Further, the cleaning device 115 has a plate shape as shown in an enlarged view in FIG. 2, and an upper side 1151 a of the plate shape abuts on the surface of the photosensitive drum 111, and the toner adhered to this surface. A cleaning blade 1151 is provided to scrape off. The cleaning device 115 has a supply port 1152a connected to the developing device 114 via the toner supply path 116, and forms an internal space 1152b for temporarily storing the toner scraped off by the cleaning blade 1151. A housing 1152 is provided. This housing 1152 corresponds to an example of the housing according to the present invention.

  Furthermore, as shown in FIGS. 2 and 3 in an enlarged manner, the cleaning device 115 has a rotating shaft 1153 a and a spiral blade 1153 b that are pivotally supported by the housing 1152 and rotate counterclockwise. In addition, an auger 1153 is provided that conveys the toner temporarily stored in the internal space 1152b of the housing 1152 toward the supply port 1152a. The auger 1153 corresponds to an example of the toner conveying means referred to in the present invention. Further, the cleaning device 115 is provided with a paddle member 1154 made of an elastic member having a strip shape and having one side fixed to the rotating shaft 1153 a of the auger 1153. The paddle member 1154 corresponds to an example of the toner supply unit referred to in the present invention. Such a paddle member 1154 rotates using the auger 1153 as a power source, and supplies the toner temporarily stored in the internal space 1152b of the housing 1152 to the plate-shaped upper side 1151a of the cleaning blade 1151.

  Here, conventionally, in an image forming apparatus provided with a means for supplying the toner collected by a cleaning device having a cleaning blade to the developing device and reusing it, the toner staying on the cleaning blade is affected by heat or pressure. It is known that the toner aggregates by receiving the toner and a toner aggregate is generated. Further, when a toner aggregate having a particle diameter (average diameter) of 100 μm or more in such toner aggregate is supplied to the developing device and reused for development, for example, in the image transferred onto the recording medium It is known that in the solid portion, there is a risk of image quality deterioration, such as white spots (image defects) due to toner agglomerates being recognized.

  Therefore, the inventors of the present invention conducted a 50 kpv running test under the condition of an image density of 1%, which causes stress in the generation of toner aggregates, and aggregated toner having a particle diameter of 100 μm or more contained in 1 g of the collected toner. The number of lumps was compared using a conventional printer (not shown) and the printer 1 described with reference to FIGS. 1 to 3 to which an embodiment of the image forming apparatus of the present invention was applied. The running test result will be described with reference to FIG.

  FIG. 4 shows the number of toner aggregates having a particle diameter of 100 μm or more contained in 1 g of toner collected by a conventional printer, and 1 g of toner collected by a printer to which an embodiment of the image forming apparatus of the present invention is applied. 3 is a bar graph showing the number of toner aggregates having a particle diameter of 100 μm or more contained therein. The vertical axis represents the number (number) of toner aggregates having a particle diameter of 100 μm or more contained in 1 g of toner collected in each printer.

  As shown in FIG. 4, 43 toner aggregates having a particle diameter of 100 μm or more were confirmed in 1 g of toner collected by a conventional printer, whereas one embodiment of the image forming apparatus of the invention was In the applied toner 1g collected by the printer 1 described with reference to FIGS. 1 to 3, no toner agglomerates having a particle diameter of 100 μm or more were confirmed.

  As described above, the printer 1 according to this embodiment has the paddle member 1154 that uses the auger 1153 as a power source for the toner scraped off by the cleaning blade 1151 and temporarily stored in the internal space 1152b of the housing 1152. Therefore, a mechanism is provided for supplying to the upper side 1151a of the cleaning blade 1151. Therefore, according to the printer 1 of the present embodiment, the toner is continuously supplied to the upper side 1151a of the cleaning blade 1151 so that the toner does not stay in the side 1151a and is scraped off by the cleaning blade 1151. The generated toner is prevented from aggregating to generate toner agglomerates. Therefore, the toner collected by the cleaning device 115 including the cleaning blade 1151, the casing 1152, the auger 1153, and the paddle member 1154 is supplied to the developing device 114 for reuse, and in the image transferred onto the recording medium, the toner Image quality deterioration due to agglomerates is prevented.

  In general, the image forming apparatus includes means for supplying the toner collected by the cleaning blade disposed so that the portion of the surface of the object to be cleaned that the cleaning blade contacts faces upward to the developing device for reuse. In the apparatus, since it is impossible to drop the toner scraped off by the cleaning blade by gravity, it is known that the problem that toner agglomerates are generated becomes more remarkable. However, according to the printer 1 of the present embodiment, the toner is constantly supplied to the upper side 1151 a of the cleaning blade 1151, so that the toner is replaced on one side without stagnation, and is scraped off by the cleaning blade 1151. It is prevented that the toner that has been agglomerated and toner agglomerates are generated.

  Further, according to the printer 1 of the present embodiment, since the power source of the paddle member 1154 is the auger 1153, a new power source is not necessary when supplying toner to the side 1151a above the cleaning blade 1151, and simple. With a simple structure, toner aggregation can be prevented and reused. Furthermore, according to the printer 1 of the present embodiment, the toner collected by the cleaning blade 1151 that has a high possibility of generating toner clumps is prevented. Therefore, the toner collected by cleaning is discarded. Therefore, all the collected toner can be reused efficiently, resulting in a reduction in toner consumption and cost reduction.

  Furthermore, according to the printer 1 of the present embodiment, the paddle member 1154 is made of an elastic member such as a polyester film or a rubber sheet. Therefore, in addition to the rotational movement of the paddle member 1154, the elastic force of the elastic member However, since the toner can be supplied to the upper side 1151a of the cleaning blade 1151, the efficiency is high.

  In the above-described embodiment, the image forming apparatus of the present invention includes a cleaning device that cleans the toner remaining on the image carrier after the toner image formed on the image carrier is transferred onto the recording medium. However, the image forming apparatus of the present invention is not limited to this example. For example, the toner image formed on the image carrier is interposed between the intermediate transfer members. The present invention can also be applied to an image forming apparatus including a cleaning device that cleans toner remaining on an intermediate transfer body after being transferred onto a recording medium.

  In the above-described embodiment, the upper side of the plate shape is given as an example of one side of the plate shape of the cleaning blade according to the present invention. However, the one side according to the present invention is not limited to this. Instead, it may be one side that contacts the surface of the object to be cleaned among the plate-shaped sides of the cleaning blade.

  In the above-described embodiment, the toner conveying means according to the present invention is an auger and the toner supplying means according to the present invention is a paddle member. However, the toner conveying means and the toner supplying means according to the present invention are However, the present invention is not limited to this, and the toner conveying means in the present invention may be any means as long as it can convey the toner temporarily stored in the internal space of the housing toward the supply port, and is referred to in the present invention. The toner supply means can supply the toner temporarily stored in the internal space of the housing to one side of the cleaning blade that is in contact with the surface of the object to be cleaned using the toner conveying means as a power source. Good.

1 is a schematic configuration diagram of a printer to which an embodiment of an image forming apparatus of the present invention is applied. FIG. 2 is an enlarged cross-sectional view of the image forming unit illustrated in FIG. 1. FIG. 3 is an enlarged side view of an auger and a paddle member shown in FIG. 2. The number of toner agglomerates having a particle size of 100 μm or more contained in 1 g of toner collected in a conventional printer, and contained in 1 g of toner collected in a printer to which an embodiment of the image forming apparatus of the present invention is applied. 4 is a bar graph showing the number of toner aggregates each having a particle diameter of 100 μm or more.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 11 Image forming part 111 Photoconductor drum 112 Charger 113 Exposure device 114 Developing device 115 Cleaning device 1151 Cleaning blade 1151a Side 1152 Case 1152a Supply port 1152b Internal space 1153 Auger 1153a Rotating shaft 1153b Blade 1154 Paddle member 116 Toner supply path 117 Transfer Device 13 Fixing Device 14 Paper Pull-in Unit 15 Paper Transport Path 30 Transport Roller 20 Paper Cassette

Claims (4)

A developing device for developing the toner by attaching toner to the electrostatic latent image formed on the image carrier that is disposed opposite to the image carrier on which an electrostatic latent image is formed. The electrostatic latent image formed thereon is developed using the developing device to form a toner image on the image carrier, and the toner image is finally transferred and fixed on a predetermined recording medium. In an image forming apparatus for forming an image composed of a fixed toner image on the recording medium by
A cleaning blade having a plate shape, and one side of the plate shape is in contact with the surface of the object to be cleaned moving in a predetermined direction, and scrapes off the toner adhering to the surface;
A housing having a supply port connected to the developing device and forming an internal space for temporarily storing toner scraped off by the cleaning blade;
Toner transport means for transporting toner temporarily stored in the internal space of the housing toward the supply port;
An image forming apparatus comprising: a toner supply unit configured to supply toner temporarily stored in an internal space of the housing to the one side of the cleaning blade using the toner conveying unit as a power source. .   The image forming apparatus according to claim 1, wherein the one side of the cleaning blade is an upper side of the plate shape. The toner conveying means is an auger having a rotation shaft and a spiral blade supported on the casing.
The image forming apparatus according to claim 1, wherein the toner supply unit is a paddle member having a strip shape and one side fixed to a rotation shaft of the auger.   The image forming apparatus according to claim 3, wherein the paddle member is made of an elastic member.

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