JP2004020661A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color image forming apparatus which is provided with an intermediate transfer member cleaning means for recovering the residual developer on an intermediate transfer member and which eliminates the developer to be processed as waste and has the extremely outstanding environmental protection properties not possible heretofore. <P>SOLUTION: The image forming apparatus is for forming an electrostatic image on an image carrier, developing the image on the image carrier by a developing means, primarily transferring the resulted developed image to the intermediate transfer member, and secondarily transferring the developed image primarily transferred onto the intermediate transfer member. The device is provided with an image carrier cleaning means for recovering the residual developer on the image carrier, a recycling mechanism for recycling the developer recovered by the image carrier cleaning means, and intermediate transfer member cleaning means for recovering the residual developer on the intermediate transfer member. The image forming device has the recycling mechanism for returning the developer recovered by the intermediate transfer member cleaning means to the developing means and recycling the developer. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly, to an image forming apparatus that collects residual developer from an intermediate transfer member of an image forming device having an intermediate transfer member.
[0002]
[Prior art]
2. Description of the Related Art Today, electrophotographic apparatuses, such as color copying machines and color printers, which form a color image have been increasing in accordance with market requirements. 2. Description of the Related Art A color electrophotographic apparatus includes a plurality of color developing devices around a single photoreceptor, and forms toner images on the photoreceptor by attaching toner with the developing devices, and transfers the toner image. A so-called one-drum type in which a color image is recorded on a transfer material, and a plurality of photoconductors arranged side by side, each having a developing device individually, forming a single-color toner image on each photoconductor, and forming the single-color toner image Are sequentially transferred and a composite color image is recorded on a transfer material, which is a so-called tandem type. Recently, tandem type has been attracting attention because demand for full-color is required to be as fast as monochrome.
By the way, in recent years, it is very important to make industrial products recyclable for environmental protection. In the field of color image forming equipment as well, the material, design and assembly of the main body of the equipment has already reached the technical area where high-level recycling can be achieved.In recent years, recycling of supplies such as developer has been further promoted. Attempts have been made. The recycling of the developer is to collect unnecessary residual developer in the apparatus and use it again as a developer. A monochrome image forming apparatus using a single-color developer has already been put to practical use. However, in an image forming apparatus using developers of a plurality of colors, there is a problem that developers of different colors are mixed at the time of recovery, and color reproducibility is reduced when the recovery agent is reused. At present, recycling is difficult.
From such a background, Japanese Patent Application Laid-Open No. 11-282225 discloses that the developer is recovered only from the image carrier of the most upstream first color and is recycled so as to prevent color mixture, or only black which is inconspicuous even when color mixture is performed. We are trying to recycle. Japanese Patent Application Laid-Open No. 2000-35737 discloses a developer recovery method in which a color developer of each color recovered from an image carrier is supplied to a developing device as a reproduction developer of a different color from the developer used in the color image forming process. It is proposed to provide a supply means.
[0003]
[Problems to be solved by the invention]
However, the image forming apparatus using the intermediate transfer member has a problem that the recycling effect is reduced by half even with the above invention. The problem is that the residual developer on the intermediate transfer body cannot be recycled. From the viewpoint of transfer efficiency, it is said that the relative relationship between the friction coefficients is such that the lower the material, the higher the friction coefficient. In an image forming apparatus using an intermediate transfer member, the friction coefficient is
In general, the relationship of image carrier <intermediate transfer member <transfer material is satisfied. At this time, when the amount of the residual developer on the image carrier after the primary transfer is compared with the amount of the residual developer on the intermediate transfer member after the secondary transfer, the amount of the remaining developer is represented by the absolute value of the friction coefficient. Because it is greatly affected,
In many cases, the amount of the residual developer after the primary transfer is smaller than the amount of the residual developer after the secondary transfer.
In the primary transfer step from the image carrier to the intermediate transfer member, the image carrier and the intermediate transfer member are combinations unique to the machine, and are not changed by the user.
Therefore, the transfer rate of the developer can be generally designed at a high level, so that the state of the residual developer can be kept low. However, in the secondary transfer process from the intermediate transfer member to a transfer material such as paper, various transfer materials are used according to the use of the user, so that the transfer rate of the developer is significantly reduced depending on the type of the transfer material. As a result, the amount of the residual developer increases. In particular, in the case of recycled paper, which is often used in recent years for the purpose of environmental protection, the surface irregularities are increased compared to non-recycled paper due to the influence of foreign substances contained in the used paper as a raw material, and secondary transfer is performed. Properties tend to be further reduced. That is, as the recycled paper is used for environmental protection, contradiction arises in that the amount of the residual developer that is processed as a waste agent increases. Therefore, in the image forming apparatus using the intermediate transfer member, if the recovery and reuse of the residual developer on the intermediate transfer member is not considered, a waste agent is eventually generated and the recycling effect is reduced by half. . Further, when the waste agent is generated as described above, it is necessary to provide a mechanism for discarding the waste agent, and for that purpose, a waste agent storage member must be provided. In general, since the size is increased in consideration of long-term use, there arises a problem that a layout margin is lost to secure an installation place, and a cost is increased. Further, as a problem in terms of maintainability, it becomes necessary to periodically replace the waste agent storage member.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a color image forming apparatus which eliminates a developer to be treated as a waste agent and has extremely excellent environmental protection. It is in.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, according to the first aspect of the present invention, an electrostatic image is formed on an image carrier, and the electrostatic image on the image carrier is developed by a developing unit. An image forming apparatus for primary-transferring a developed image on a body to an intermediate transfer member, and further secondary-transferring the developed image primary-transferred on the intermediate transfer member to a transfer material, further comprising: An image carrier cleaning unit for collecting the residual developer, a recycling mechanism for reusing the developer collected by the image carrier cleaning unit, and an intermediate unit for collecting the residual developer on the intermediate transfer body The most main feature of the image forming apparatus provided with the transfer member cleaning means is an image forming apparatus having a recycling mechanism for recycling the developer collected by the intermediate transfer member cleaning means back to the developing means.
According to a second aspect of the present invention, there is provided an image forming apparatus according to the first aspect, wherein the developer recovered by the image carrier cleaning means and the intermediate transfer body cleaning means is sent to a developing means for black development to be reused. Characteristics.
According to a third aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein the developer collected by the image carrier cleaning unit and the intermediate transfer body cleaning unit is sent to a developing unit dedicated to the recovered developer and reused. Main features.
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the main feature is that the image carrier is composed of a plurality of carriers.
According to a fifth aspect of the present invention, among the plurality of image carriers of the fourth aspect, the developer recovered from the image carrier located at the most upstream position in the rotation direction of the intermediate transfer member is located at the most upstream position. The main feature of the present invention is an image forming apparatus that re-uses the recovered developer to the developing means of the image carrier to be reused.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention, which is an electrophotographic apparatus of a tandem type indirect transfer system. The copying apparatus main body 100 shown in the figure is placed on a paper feed table 200, a scanner 300 is mounted on the copying apparatus main body 100, and an automatic document feeder (ADF) 400 is further mounted thereon.
An endless belt-shaped intermediate transfer body 10 is provided at the center of the copying apparatus main body 100. As shown in FIG. 2, the intermediate transfer body 10 is formed by forming a base layer 11 made of a non-stretchable material such as canvas on a low elongation fluororesin or a high elongation rubber material. 12 are provided. The elastic layer 12 is made of, for example, fluorine-based rubber or acrylonitrile-butadiene copolymer rubber. The surface of the elastic layer 12 is coated with, for example, a fluorine-based resin and covered with a coat layer 13 having good smoothness.
Then, as shown in FIG. 1, in the illustrated example, the intermediate transfer body 10 is wrapped around three support rollers 14, 15, 16 so as to be rotatable clockwise in the figure. In the illustrated example, an intermediate transfer body cleaning device 17 for removing residual toner remaining on the intermediate transfer body 10 after image transfer is provided to the left of the second support roller 15 among the three support rollers. In addition, the black, cyan, magenta, and yellow colors are provided on the intermediate transfer member 10 extending between the first support roller 14 and the second support roller 15 among the three support rollers along the transport direction. The tandem image forming apparatus 20 is configured by arranging the four image forming units 18 side by side. An exposure device 21 is further provided on the tandem image forming device 20, as shown in FIG.
On the other hand, a secondary transfer device 22 is provided on the side opposite to the tandem image forming device 20 with the intermediate transfer member 10 therebetween. In the illustrated example, the secondary transfer device 22 is configured by wrapping a secondary transfer belt 24, which is an endless belt, between two rollers 23, and pressing the secondary transfer belt 24 against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet.
A fixing device 25 for fixing a transferred image on a sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 which is an endless belt. The above-described secondary transfer device 22 also has a sheet conveying function of conveying the sheet after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be disposed as the secondary transfer device 22, and in such a case, it is difficult to additionally provide the sheet conveying function.
In the illustrated example, a sheet reversing device 28 that reverses the sheet so as to record an image on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. Is provided.
[0006]
Now, when making a copy using this color electrophotographic apparatus, an original is set on the original table 30 of the automatic original transport apparatus 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed. When a start switch (not shown) is pressed, when the original is set on the automatic document feeder 400, the original is conveyed and moved onto the contact glass 32, and then the original is set on the other contact glass 32. At this time, the scanner 300 is immediately driven to travel on the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface to the second traveling body 34, is reflected by the mirror of the second traveling body 34, and passes through the imaging lens 35. The original is read by a reading sensor 36 and read.
When a start switch (not shown) is pressed, one of the support rollers 14, 15, and 16 is driven to rotate by a drive motor (not shown), and the other two support rollers are driven to rotate. I do. At the same time, the photoreceptors 40 are rotated by the individual image forming means 18 to form black, yellow, magenta, and cyan monochromatic images on the respective photoreceptors 40, respectively. Then, as the intermediate transfer body 10 is transported, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer body 10.
On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and a sheet is fed out from one of the paper feed cassettes 44 provided in the paper bank 43 in multiple stages. The sheet is separated one by one into a sheet feeding path 46, conveyed by a conveying roller 47, guided to a sheet feeding path 48 in the copying machine main body 100, and stopped against a registration roller 49. Alternatively, the sheet feeding roller 50 is rotated to feed out the sheet on the manual feed tray 51, separated one by one by the separation roller 52, and then put into the manual sheet feeding path 53, and similarly hit against the registration roller 49 and stopped. Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer body 10, the sheet is fed between the intermediate transfer body 10 and the secondary transfer device 22, and the sheet is transferred by the secondary transfer device 22. Record a color image on the sheet.
The sheet after the image transfer is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the transfer image is fixed by applying heat and pressure by the fixing device 25, and then switched by the switching claw 55 to discharge the sheet. The sheet is discharged at 56 and stacked on a sheet discharge tray 57. Alternatively, the sheet is switched into the sheet reversing device 28 by the switching claw 55, reversed and guided again to the transfer position, the image is recorded on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer member 10 after the image transfer is removed by an intermediate transfer member cleaning device 17 to remove the residual toner remaining on the intermediate transfer member 10 after the image transfer, and the tandem image forming device 20 prepares for another image formation. Here, the registration roller 49 is generally often used while grounded, but it is also possible to apply a bias for removing paper dust from the sheet.
Now, in the tandem image forming apparatus 20 described above, the individual image forming means 18 includes, for example, a charging device 60, a developing device 61, and a primary device around a drum-shaped photoconductor 40 as shown in FIG. It includes a transfer device 62, a photoconductor cleaning device 63, a charge removing device 64, and the like.
[0007]
Next, the details of the developer recycling which is the gist of the present invention will be described. FIG. 4 is a schematic configuration diagram of a tandem-type image forming apparatus showing a basic portion of the drawings used in the description below. In the center of the drawing, there is an intermediate transfer member 10. In the intermediate transfer member 10, a drum-shaped photosensitive member 40 includes a black photosensitive member 40 -Bk and a cyan photosensitive member from the upstream side in the rotation direction of the intermediate transfer member 10. The photoconductor 40-C, the magenta photoconductor 40-M, and the yellow photoconductor 40-Y are arranged in this order. Similarly, a developing device 61 and a photoconductor cleaning device 63 are arranged around the photoconductor 40 for each color. Further, the intermediate transfer body 10 is provided with an intermediate transfer body cleaning device 17.
Several forms can be proposed for the image forming apparatus of the present invention. First, FIG. 5 shows an example. In this example, the developer is collected from the photoconductor 40 for each color by the photoconductor cleaning device 63 included in the photoconductor 40, and the collected developer is temporarily stored by the collection developer moving unit A (recycling mechanism). It is transported to the collection tank T. Similarly, the developer collected from the intermediate transfer body cleaning device 17 is transported to the collection tank T by the collected developer moving means B (recycling mechanism). The developer collected in the collection tank T is stirred in such a manner that there is no color unevenness, and then mixed little by little into the developer replenishment section of the Bk developing means, in which mixed colors are not conspicuous, and are reused.
[0008]
FIG. 6 shows another example. In this example, the developer recovered by the photoconductor cleaning device 63 of each color and the developer recovered from the intermediate transfer body cleaning device 17 are recovered by the recovered developer moving unit A and the recovered developer moving unit B, respectively. Carry to tank T. The developer collected in the collection tank T is transported to the developing device 61-X dedicated to the collected developer and reused. Since the developing device 61-X forms an image with a turbid color developer in which a plurality of developers are mixed, the developing device 61-X is suitable for printing a character document that does not need to worry about colors and for trial printing. It is consumed for use.
FIG. 7 shows a further example. In this example, the basic recovery operation is the same as the example shown in FIG. 6, but the development recovered from the photoconductor 40 (40-Bk in the illustrated example) located at the most upstream position in the rotation direction of the intermediate transfer body 10 is performed. It is characterized in that the developer is returned to the developing device 61 for the same color (61-Bk in the illustrated example). That is, the black toner collected from the black photosensitive member cleaning unit 63-Bk is returned to the developing device 61Bk by the transport unit A-1. Since the developer of another color is not mixed into the photosensitive member cleaning means located upstream in the rotation direction of the intermediate transfer member 10, the collected developer is collected by the same developing device as it is, The same can be reused.
In the above example, the tandem type image forming apparatus has been described. However, the present invention is of course applicable to a one-drum type image forming apparatus. FIG. 8 is a schematic configuration diagram of an image forming apparatus when the tandem type example of FIG. 5 is developed into a one-drum type. FIG. 9 is a schematic configuration diagram of an image forming apparatus when the tandem type example of FIG. 6 is developed into a one-drum type. In both cases, the tandem-type embodiment is simply replaced with a one-drum type, and a detailed description thereof will be omitted.
As described above, by applying the present invention, it is possible to provide an image forming apparatus which does not generate any waste agent, has a very high recyclability, and is thus excellent in environmental protection.
Note that the present invention is not limited to the above embodiment, but is applicable to all devices utilizing the technical idea of the present invention. The photoreceptor, the intermediate transfer member, and the secondary transfer means may have any of a belt shape, a drum shape, and a roller shape.
[0009]
【The invention's effect】
As described above, according to the first aspect of the present invention, an electrostatic image is formed on an image carrier, and the electrostatic image on the image carrier is developed by a developing unit. An image forming apparatus for primary-transferring the developed image to an intermediate transfer member, and further secondary-transferring the developed image primary-transferred onto the intermediate transfer member to a transfer material, wherein the residual developer on the image carrier is removed. Image carrier cleaning means for recovering, a recycling mechanism for reusing the developer recovered by the image carrier cleaning means, and intermediate transfer body cleaning means for recovering residual developer on the intermediate transfer body Wherein the developer collected by the intermediate transfer member cleaning means is provided with a recycling mechanism for returning the developer to the developing means and reused. Agent Can be eliminated Ssai, it is possible to provide an excellent image forming apparatus environmental protection.
According to the second aspect of the present invention, the developer recovered by the image carrier cleaning unit and the intermediate transfer body cleaning unit is sent to a black developing unit and reused. By the image forming apparatus, the toner is mixed little by little with respect to the developer replenishing section of the Bk developing means, which is less noticeable in color mixture after being stirred so that there is no color unevenness, and is reused without significantly affecting the image quality. It is possible to provide an image forming apparatus which does not discharge waste agent and has excellent environmental protection.
According to the third aspect of the present invention, the developer recovered by the image carrier cleaning unit and the intermediate transfer body cleaning unit is sent to a developing unit dedicated to the recovered developer and reused. With the image forming apparatus described above, the toner is poured into the dedicated developing means, and an image is formed with a turbid color developer in which a plurality of developers are mixed, but printing of a character original without worrying about the color, The image forming apparatus is suitable for test printing and the like, is consumed for these uses, does not discharge waste materials, and can provide an image forming apparatus with excellent environmental protection.
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the image carrier includes a plurality of carriers. It is possible to provide an image forming apparatus which is excellent in environmental protection because it can eliminate any developer treated as waste in a tandem type apparatus used for recent color image formation. effective.
According to the fifth aspect of the present invention, among the plurality of image carriers according to the fourth aspect, the developer collected from the image carrier located at the most upstream position in the rotation direction of the intermediate transfer member is the most upstream. The image forming apparatus is characterized in that the collected developer is fed again to the developing means of the image carrier located there, and is reused. Since the developer is not mixed, the collected developer can be collected by the same developing device as it is, and can be reused in the same manner as a new agent.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a color image forming apparatus of the present invention.
FIG. 2 is a sectional configuration diagram of an intermediate transfer belt used in the color image forming apparatus of the present invention.
FIG. 3 is a schematic configuration diagram around a photoreceptor of the color image forming apparatus of the present invention.
FIG. 4 is a schematic diagram of a basic main part of the color image forming apparatus of the present invention.
FIG. 5 is a schematic view illustrating an example of toner collection of the tandem-type color image forming apparatus of the present invention.
FIG. 6 is a schematic diagram of an example of using a developing unit dedicated to collected toner in the same type image forming apparatus of the present invention.
FIG. 7 is a schematic view showing an example of collecting and utilizing the most upstream photosensitive member toner of the image forming apparatus of the present invention.
FIG. 8 is a schematic diagram illustrating an example of toner collection of the one-drum type color image forming apparatus of the present invention.
FIG. 9 is a schematic view showing an example of using a developing means dedicated to collected toner in the one-drum type color image forming apparatus of the present invention.
[Explanation of symbols]
Reference Signs List 10 intermediate transfer member, 11 intermediate transfer member base layer, 12 intermediate transfer member elastic layer, 13 intermediate transfer member coat layer, 14 support roller, 15 support roller, 16 support roller, 17 intermediate transfer member cleaning device, 18 image forming means, Reference Signs List 20 tandem image forming device, 21 exposure device, 22 secondary transfer device, 23 roller, 24 secondary transfer belt, 25 fixing device, 26 fixing belt, 27 pressure roller, 28 sheet reversing device, 30 platen, 32 contact glass , 33 1st running body, 4th running body, 35 imaging lens, 36 reading sensor, 40 photoconductor, 42 paper feed roller, 43 paper bank, 44 paper feed cassette, 45 separation roller, 46 paper feed path, 47 Transport roller, 48 paper feed path, 49 registration roller, 50 paper feed roller, 51 manual feed tray, 52 separation roller, 53 manual feed Paper path, 55 switching claw, 56 discharge roller, 57 discharge tray, 60 charging device, 61 developing device, 62 primary transfer device, 63 photoconductor cleaning device, 64 static elimination device, 100 copying device main body, 200 paper feed table, 300 scanner, 400 automatic document feeder.

Claims (5)

An electrostatic image is formed on the image carrier, the electrostatic image on the image carrier is developed by a developing unit, and the obtained developed image on the image carrier is primarily transferred to an intermediate transfer member. An image forming apparatus for secondary-transferring a developed image primary-transferred onto a transfer body to a transfer material, further comprising: an image carrier cleaning unit for collecting residual developer on the image carrier; An image forming apparatus comprising: a recycling mechanism for reusing the developer collected by a carrier cleaning unit; and an intermediate transfer body cleaning unit for collecting a residual developer on the intermediate transfer body. An image forming apparatus having a recycling mechanism for returning the developer recovered by the means to the developing means for reuse. 2. The image forming apparatus according to claim 1, wherein the developer collected by the image carrier cleaning unit and the intermediate transfer body cleaning unit is sent to a developing unit for black color development and reused. 2. The image forming apparatus according to claim 1, wherein the developer recovered by the image carrier cleaning unit and the intermediate transfer body cleaning unit is sent to a developing unit dedicated to the recovered developer and reused. The image forming apparatus according to claim 1, wherein the image carrier includes a plurality of carriers. The developer recovered from the most upstream image carrier with respect to the rotation direction of the intermediate transfer member among the plurality of image carriers according to claim 4, wherein the developing means of the most upstream image carrier is used as a developer. An image forming apparatus wherein the collected developer is sent again and reused.

Images