JP5617206B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to a configuration using recycled toner.

  In an image forming apparatus using an electrophotographic system, an electrostatic latent image is formed on a photoreceptor that can be used as a latent image carrier in accordance with image information, and the electrostatic latent image is supplied from a developing device. A transfer process is used after a visible image is processed with toner.

  Some image forming apparatuses are configured to form not only a single color but also a plurality of colors. In the latter case, in the transfer process, images of each color are sequentially transferred to the intermediate transfer member, and from a paper feeder or the like. The case of superimposing and transferring an image for each color on the fed transfer paper is selected.

  As a configuration for forming a multi-color image, for example, a tandem method in which a belt is used as an intermediate transfer member or a transfer paper conveying member, and a plurality of image forming units are juxtaposed along the belt's extended surface. The configuration to be done is known.

  Each image forming unit is provided with a photoconductor and a charging device, a writing device, a developing device, and a cleaning device for executing image forming processing on the photoconductor. It is supposed to be removed.

  By the way, in recent years, by reusing the transfer residual toner removed from the photoconductor by cleaning, there is an increasing demand for preventing an increase in running cost due to disposal of the transfer residual toner and shortening maintenance time by replacement. It is coming.

  Therefore, conventionally, a configuration in which the transfer residual toner removed from the photosensitive member by cleaning in each image forming unit is returned to the developing device provided in each color image forming unit and reused can be considered.

  However, when the toner collected by cleaning in the image forming unit for each color is returned to the developing device of the image forming unit and reused, there is a problem of color mixing.

  That is, when images of different colors are sequentially transferred to the transfer body, the color image on the upstream side in the movement direction of the transfer body also faces the color image forming portion on the downstream side in the movement direction. The photosensitive member positioned in the downstream image forming unit is to be cleaned in a state where the upstream color toner is mixed in the cleaning process when the upstream color toner is reversely transferred.

  In order to solve such problems, conventionally, the transfer residual toner collected for each image forming unit is collected in one place, and the collected color toner is used to form an image different from full color image formation. There has been proposed a configuration that performs the above (for example, Patent Documents 1 and 2).

  Japanese Patent Laid-Open No. 2004-260688 collects the transfer residual toner that has been cleaned and collected from the photosensitive member of each image forming unit and collects the collected color toner separately from the developing device provided in each image forming unit. A configuration for supplying the toner to a developing device using the regenerated developer is disclosed.

  In Patent Document 2, a reproduction-only image forming unit that uses a new reproduction developer in addition to the yellow, cyan, magenta, and black image forming units used for full-color images is added to the other image forming units, and a transfer body. A configuration is disclosed in which the toner collected in the above-described high color image forming unit cleaning device is supplied to the developing device of the reproduction-only image forming unit.

  When the reproduction developer disclosed in Patent Documents 1 and 2 is used, the color tone is different from that of the developer used for regular full-color image formation. The reproduction toner is used for a pattern image or the like that is used when detecting a timing unrelated to the normal image so as to be close to the color tone of the normal color toner.

  However, in the configuration disclosed in each of the above patent documents in which a regenerated developer is used, it is assumed that transfer residual toner collected by cleaning in each image forming unit is collected in one place. Further, a transport structure from the collection position toward the developing device dedicated to the regenerated developer is required, which may increase the cost of the device.

  In addition, in the configuration disclosed in the above-mentioned patent document, a configuration in which a new image forming unit is juxtaposed in addition to the existing image forming unit juxtaposed with respect to the stretched surface of the transfer body. Therefore, when an image is formed using a reproduction developer, the transfer member needs to be moved even though the existing image forming unit is not used. Further, when a developing device dedicated to the reproduction developer is used in each image forming unit, it is necessary to operate the photosensitive member, the exposure device, and the charging device as in the case of using a regular developing device. For these reasons, energy saving efficiency may be deteriorated.

  An object of the present invention is to reduce the cost of the apparatus and to improve the energy saving efficiency in view of the problems in the conventional image forming apparatus, in particular, the problem in the case of using a regenerative developer. An object of the present invention is to provide an image forming apparatus having the configuration.

In order to achieve this object, the present invention has the following configuration.
(1) An image forming unit including a latent image carrier and a charging device, a developing device, and a cleaning device that perform image forming processing on the latent image carrier, and a stretched surface onto which an image of a color formed in the image forming unit is transferred And an image forming apparatus in which at least one of the image forming units is disposed on a stretched surface of the transfer body.
The transfer body is provided with a cleaning device that performs cleaning after the image is transferred from the image forming unit, and a secondary transfer device that collectively transfers the image transferred and superimposed on the transfer body,
In the vicinity of the cleaning device, when the image forming unit is the first image forming unit, apart from this, the writing unit and the transfer unit used in the first image forming unit are the same. And a second image forming unit including a developing device to which the transfer residual toner collected from the cleaning device is supplied, and the second image forming unit is disposed at a position where the secondary transfer device is disposed. Separately from the above, the first image forming unit formed on a latent image carrier provided in the second image forming unit on a recording sheet conveyed through the conveyance path toward the second image forming unit An image forming apparatus comprising a transfer unit that transfers an image different from the image forming apparatus.
( 2 ) The image forming apparatus according to (1), wherein the developing device provided in the second image forming unit is integrated with a cleaning device provided in the transfer body.
( 3 ) The developing device in the second image forming unit forms a black image when a plurality of the first image forming units are juxtaposed on the extending surface of the transfer body and image formation of a plurality of colors is possible. The image forming apparatus according to (1) or (2) , further comprising a configuration in which toner is supplied by being connected to a toner replenishing device to a developing device provided in the image forming unit.
( 4 ) When the toner used in the developing device provided in the first image forming unit is deteriorated, the first image forming unit is operated to transfer the toner of the developing device to a transfer member, and The image forming apparatus according to any one of (1) to ( 4) , wherein the toner transferred by the transfer body cleaning device is collected.

  According to the present invention, in addition to the first image forming unit, the toner collected by the transfer body cleaning device is located near the cleaning device at a position different from the position where the image transfer from the existing image forming unit is received. Since the second image forming unit provided with the developing device to be supplied is provided, the target is between the position where the transfer residual toner of all colors is collected for the transfer body and the second image forming unit. A supply path is sufficient. Accordingly, it is not necessary to provide a special transfer residual toner supply / conveyance path from the first image forming unit to the second image forming unit, so that the cost of the apparatus can be suppressed.

  In addition, the second image forming unit can form an image different from the first image forming unit, and the first image forming unit can be stopped when the second image forming unit is in operation. It is possible to reduce energy consumption in the first image forming unit including stopping the operation of the first image forming unit.

1 is a schematic diagram for explaining an overall configuration of an image forming apparatus according to the present invention. FIG. 2 is a schematic diagram for explaining an arrangement configuration of a first image forming unit and a transfer body in the image forming apparatus illustrated in FIG. 1. FIG. 3 is a schematic view corresponding to FIG. 2 for explaining the first embodiment of the present invention targeting the configuration of the image forming apparatus shown in FIGS. FIG. 4 is a schematic view corresponding to FIG. 3 for explaining the characteristics of the second embodiment of the present invention. It is an enlarged view for demonstrating the detail of the characteristic part shown in FIG. It is a schematic diagram for demonstrating the characteristic of 3rd Example of this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 1 according to the present invention, and FIG. 2 is a diagram illustrating an arrangement configuration of each image forming unit and an intermediate transfer belt 2.
An image forming apparatus 1 shown in FIG. 1 has a tandem configuration in which a plurality of photoconductors as image carriers capable of forming a color image corresponding to color separation are juxtaposed, and a toner image formed on each photoconductor. Is a color printer that can form a multicolor image by superimposing and transferring the image onto an intermediate transfer member and then transferring the superimposed image onto a sheet such as recording paper. In the present invention, the image forming apparatus is not limited to a color printer, but of course includes a color copying machine, a facsimile machine, and a printing machine.

In FIG. 1, in the color printer 1, an image forming unit 1A is disposed at a central portion in the vertical direction, a sheet feeding unit 1B is provided below the image forming unit 1A, and an original document scanning table 1C1 is provided above the image forming unit 1A. Each of the parts 1C is arranged.
In the image forming unit 1A, a transfer unit composed of an intermediate transfer belt 2 is disposed as an intermediate transfer member having a horizontally extending surface, and the intermediate transfer belt 2 has a complementary color relationship with a color separation color. A configuration for forming an image of a certain color is provided.

In the image forming unit 1A, at least one image forming unit capable of forming an image with toners of complementary colors (yellow, magenta, cyan, black) is arranged. In the image forming apparatus shown in FIG. A four-color image forming unit using the above-described color toner is provided.
Photosensitive members 3B, 3C, 3M, and 3Y that can carry images are juxtaposed along the extended surface of the intermediate transfer member 2 in each image forming unit. In the following description, in the case of contents common to all the photoconductors, the photoconductor is denoted by reference numeral 3.

  Each of the photoreceptors 3B, 3C, 3M, 3Y, and 3T is configured by a drum that can rotate in the same direction (counterclockwise in FIG. 1), and an image forming process is executed in the periphery of the drum. A charging device 4, a writing device 5, a developing device 6, a primary transfer device 7 which is one of transfer bias applying means as a transfer body, and a cleaning device 8 are disposed (for the sake of convenience, each of the photosensitive members 3B is a target). (B is attached to the symbol of the device).

  The intermediate transfer belt 2 corresponds to a primary transfer unit to which toner images from an image forming unit including each photoconductor are sequentially transferred, and includes a plurality of rollers 2A to 2C (some rollers are provided with reference numerals). A roller 2C different from the rollers 2A and 2B located at both ends in the moving direction of the transfer surface facing the photoconductor. The intermediate transfer belt 2 is opposed to a secondary transfer position where a secondary transfer device 9 composed of rollers is disposed.

  Due to the installation space of the intermediate transfer belt 2, a part of the transfer surface wound around the roller indicated by reference numeral 2A and the roller indicated by reference numeral 2B is extended in the horizontal direction. The portion provided is provided with a tension roller 2D for applying tension.

  The intermediate transfer belt 2 is provided with a cleaning device 10 at a corresponding position after passing through the secondary transfer position so as to remove residual toner from the intermediate transfer belt 2.

  In the vicinity of the secondary transfer position, a conveying device 11 including a belt 11C wound around a driving roller 11A and a driven roller 11B is disposed. The conveyance device 11 is a device that conveys a recording sheet fed out from a sheet feeding unit 1B described later using air adsorption or electrostatic adsorption. When air suction is used, the conveyance belt has suction holes, and the recording sheet is sucked by a suction fan. When electrostatic attraction is used, a bias power source having a polarity opposite to that of the toner is connected to one roller 11A.

A recording sheet is fed from the paper feeding unit 1B to the secondary transfer position.
The paper feed unit 1B includes a plurality of paper feed cassettes 1B1, a plurality of transport rollers 1B2 arranged in a transport path for recording sheets fed from the paper feed cassette 1B1, and a registration roller 1B3 positioned in front of the secondary transfer position. I have. In this embodiment, in addition to the conveyance path of the recording sheet fed out from the sheet feeding tray 1B1, a recording sheet of a type not stored in the sheet feeding cassette 1B1 is fed to the sheet feeding unit 1B toward the secondary transfer position. A possible configuration is provided. As a configuration for this purpose, a manual feed tray 1A1 and a feeding roller 1A2 provided so that a part of the wall surface of the image forming unit 1A can be tilted are used.

  In the middle of the conveyance path of the recording sheet from the sheet feeding cassette 1B1 to the registration roller 1B3, the conveyance path of the recording sheet fed out from the manual feed tray 1A1 joins, and the recording sheet fed from any conveyance path is also a registration roller. Registration timing is set by 1B3.

  The writing device 5 (in FIG. 1, the writing light for forming a black image is indicated by reference numeral 5B for the sake of convenience) is an image obtained by scanning the document on the document table 1C1 in the document scanning unit 1C. The writing light is controlled by the information or image information output from a computer (not shown) to form an electrostatic latent image corresponding to the image information on the photoreceptors 3B, 3C, 3M, and 3Y.

  The document scanning unit 1C is provided with a scanner 1C2 that exposes and scans the document on the document table 1C1, and an automatic document feeder 1C3 is disposed on the upper surface of the document table 1C1. The automatic document feeder 1C3 has a configuration capable of reversing the document fed on the document table 1C1, and can perform scanning on both sides of the document.

  An electrostatic latent image on the photosensitive member 3 (members indicated by reference numerals 3B, 3C, 3M, and 3Y in FIG. 1) formed by the writing device 5 is indicated by reference numeral 6B in FIG. 1 for convenience. ), And the primary transfer is performed on the intermediate transfer belt 2. When the color toner images are superimposed and transferred onto the intermediate transfer belt 2, the secondary transfer device 9 performs secondary transfer on the recording sheet at once.

  The unfixed image carried on the surface of the recording sheet that has been secondarily transferred is fixed by the fixing device 12. Although not described in detail, the fixing device 12 includes a belt fixing structure that includes a fixing belt heated by a heating roller and a pressure belt that contacts and contacts the fixing belt. By providing a contact area, that is, a nip area, the heating area for the recording sheet can be expanded as compared with the structure of the heat roller fixing system.

  The recording sheet that has passed through the fixing device 12 is conveyed through a conveying device 13 disposed behind the fixing device 12, and the conveying direction is switched by a switching claw 13 </ b> A located at the end of the conveying device 13. The transport direction is selected for the transport path toward the paper discharge tray 14 and the reverse transport path RP.

  In the color printer 1 having the above-described configuration, the uniformly charged photoconductor 3 is exposed and scanned by the document placed on the document placing table 1C1 or by image information from the computer. After the electrostatic latent image is formed and the electrostatic latent image is subjected to a visible image processing by the developing device 6, the toner image is primarily transferred to the intermediate transfer belt 2.

  The toner image transferred to the intermediate transfer belt 2 is transferred as it is to the recording sheet fed from the paper feed unit 1B in the case of a single color image, and the primary transfer is repeated in the case of a multicolor image. After being superimposed, it is secondarily transferred to the recording sheet at once. The recording sheet after the secondary transfer is fixed on the unfixed image by the fixing device 12 and then conveyed to the paper discharge tray 14 or reversed in the reverse conveyance path RP and fed again toward the registration roller 1B3. Is selected.

The intermediate transfer belt 2 is wound around at least a pair of support rollers 2A and 2B, a roller 2D having a tension roller function, and a transfer backup roller 2C provided at the secondary transfer position. By setting the rotation in the direction, it is possible to move in the direction of the arrow shown inside the intermediate transfer belt 2 in FIG.
The stretched surface of the belt that moves between the support rollers 2A and 2B corresponds to the transfer surface, and faces the photoreceptors 3B, 3Y, 3C, 3M, and 3T of each image forming unit. A transfer roller 7 corresponding to a transfer member for electrostatically transferring a visible image on the photoconductor (in FIG. 1, reference is made to black toner) at a position facing each photoconductor across the intermediate transfer belt 2. 7B) are arranged.

The features of the present invention will be described below for the image forming apparatus having the above configuration.
A feature of the present embodiment is that when the image forming unit juxtaposed on the extended surface of the intermediate transfer belt 2 is the first image forming unit, the cleaning device 10 is located near the cleaning device 10 for the intermediate transfer belt 1. A second image forming unit including a developing device that receives supply of the transfer residual toner collected in step S1.

  FIG. 3 is a diagram for explaining the above-described characteristics. In FIG. 3, in the vicinity of the cleaning device 10 of the intermediate transfer belt 2, the structure for writing and the transfer with respect to the first image forming unit described above. A second image forming unit 100R having a similar configuration except for the structure is provided.

  The second image forming unit 100R is provided with a photoconductor 101R as a latent image carrier. Around the photoconductor 101R, the moving direction of the photoconductor (the counterclockwise rotation direction in FIG. 3). A charging device 102R, a writing device 103R, a developing device 104R, a transfer device 105R, and a cleaning device 106R for performing image forming processing are arranged along the lines.

  In the configuration shown in FIG. 3, an LED array is used as the writing device 103R, unlike the polygon mirror used in the first image forming unit, and the installation space is reduced.

  Further, a transfer roller to which a transfer bias is applied is used for the transfer device 105R.

  Further, a recovery path (not shown) is provided between the developing device 104 </ b> R and the cleaning device 10 of the intermediate transfer belt 2, and the transfer residual toner recovered by the cleaning device 10 is supplied.

Since the transfer residual toner supplied to the developing device 104R includes toner of a color that has not been transferred among the images transferred from the first image forming unit, each development in the first image forming unit is performed. This is different from the original color of toner supplied from the apparatus.
Therefore, in this embodiment, the second image forming unit 100 R, rather than the reproduced image using the toner color of the normal, for example, and interim documents circulation, etc. that does not require accurate color reproduction Image reproduction is performed when the content printed as an object is confirmed, that is, when the printed drawing layout or typographical error is confirmed. In such operations, a recording sheet having a relatively poor color reproducibility, such as a backing paper or recycled paper that is not completely bleached, may be used, so there is no problem even if the color tone is inferior to normal color reproduction. Therefore, the toner collected from the cleaning device 10 for such work is used as a regenerated developer.

The second image forming unit 100 R is the time of image formation by the first image forming portion is used is maintained to stop used when need a different color reproduction from the original as described above. If the second image forming unit 100 R is running, an apparatus for performing the image formation using the first image forming unit is stopped. That is, each device and the intermediate transfer belt 2 included in the first image forming unit are stopped. Although the secondary transfer device 9 is also stopped, there is a possibility that the progress of the recording paper sheet that is in contact with the intermediate transfer belt 2 may be obstructed. In this case, as shown by an arrow in FIG. In addition, it is desirable that the intermediate transfer belt 2 be separated.

Since this embodiment is constructed as described above, at the time of image formation using the first imaging unit and the second image forming portion 100 R is stopped.

On the other hand, in the case of using the second image forming unit 100 R is apparatus for image formation using a first image forming unit is stopped.

In the second image forming unit 100 R, the recording sheet S fed from the sheet feeding unit 1B is conveyed toward the transfer unit 11, the second image forming unit 100 R is attracted transported to the transport belt 11C of the conveying device 11 The image formed on the photosensitive member 101R is transferred to the opposite position between the photosensitive member 101R and the transfer device 105R.

In this embodiment, the developing device 104R of the second image forming unit 100 R is arranged in the vicinity cleaning device 10 of the intermediate transfer belt 2, it is possible to simplify the carrier structure of the collected toner. Thereby, it is possible to reduce the size of the apparatus, thereby preventing an increase in cost.

Moreover, the first image forming unit, since so as to stop during operation of the second image forming unit 100 R, to operate the respective devices in a state where the second image forming unit 100 is operating Energy consumption can be reduced.
As the image formed by the second image forming unit 100 R, not only the image described above, for example, a serial number Ya for the first recording sheet which has been transferred the formed image imaging unit It can also be used when auxiliary image reproduction such as output date and time is formed in a range other than the image area formed by the first image forming unit.

Next, a second embodiment of the present invention will be described.
As shown in FIG. 4, the second embodiment is characterized in that the developing device 104R ′ and the cleaning device 10 for the intermediate transfer belt 2 in the second image forming unit 100R ′ are integrated.

  As shown in FIGS. 4 and 5, in the developing device 104R ′, in addition to the developing sleeve 104R1 ′ and the stirring supply roller 104R2 ′ facing the photosensitive member 101R ′, a cleaning member provided in the cleaning device 10 is provided. 10A and 10B are arranged.

  In the configuration as described above, the transport path for the recovered toner is not required between the cleaning device 10 and the developing device 104R ′, and the apparatus required for transporting the recovered toner is not required, thereby reducing the size of the apparatus. In addition, the cost can be reduced by saving energy.

Next, a third embodiment of the present invention will be described.
A feature of the third embodiment is that a toner replenishing structure for the developing device 104R is provided for the second image forming unit 100 shown in FIG.

  FIG. 6 is a schematic diagram for explaining the above feature. In FIG. 6, toner supply bottles 200 and 201 are connected to the developing device 104R provided in the second image forming unit 100R.

  Among the supply bottles, the reference numeral 100 is also used as a toner supply bottle for the developing device provided in the image forming section of the black image in the first image forming section. The residual toner collected from the cleaning device 10 for the intermediate transfer belt 2 is accommodated.

  The toner bottles 200 and 201 and the developer storage portion of the developing device 104R are connected by a transport tube, and open / close valves 200A and 201A are provided in the tubes.

  The reason why the toner bottles 200 and 201 are provided is to compensate for a shortage of toner in the second image forming unit in consideration of a case where the amount of toner collected from the intermediate transfer belt 2 is small. That is, when there is a possibility that the collected toner stored in the developing device 104R in the second image forming unit 100R is insufficient, black toner is supplied from the toner bottle 200. As a result, image formation in the second image forming unit 100R is not impossible and density is not insufficient. The toner bottle 200 can store not only black toner but also waste toner and the like, and further, a toner bottle equipped in a waste toner collecting unit can be used.

  Alternatively, the toner bottle 201 may be directly connected to the cleaning device 10 for the intermediate transfer belt 2 instead.

  In the above-described embodiments, the first image forming unit and the second image forming unit 100R are selectively used. However, the present invention is not limited to this. For example, toner used in the developing device in the first image forming unit is used. When the toner deteriorates, the toner may be supplied to the second image forming unit 100R. In this case, image transfer is performed on the intermediate transfer belt 1 in the first image forming unit, and then the recording sheet. All the toner remaining on the intermediate transfer belt 2 is collected by the cleaning device 10 without being transferred to the developing device 104R, 104R ′ of the second image forming unit 100R. As a result, the toner to be discarded can be reused.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Intermediate transfer belt 3 Photoconductor 4 Charging device 5 Writing device 6 Developing device 7 Primary transfer device 10 Cleaning device 11 Conveying device 100R, 100R ′ Second image forming unit 101R, 101R ′ Photoconductor 102R, 102R 'Charging device 103R, 103R' Writing device 104R, 104R 'Developing device 105R Transfer device 200, 201 Toner bottle

Japanese Patent No. 3616238 JP 2006-30519 A

Claims (4)

A latent image carrier, an image forming unit including a charging device, a developing device, and a cleaning device for performing image forming processing on the latent image carrier, and a transfer member having a stretched surface on which an image of a color formed in the image forming unit is transferred In an image forming apparatus in which at least one of the image forming units is disposed on the extended surface of the transfer body,
The transfer body is provided with a cleaning device that performs cleaning after the image is transferred from the image forming unit, and a secondary transfer device that collectively transfers the image transferred and superimposed on the transfer body,
In the vicinity of the cleaning device, when the image forming unit is the first image forming unit, apart from this, the writing unit and the transfer unit used in the first image forming unit are the same. And a second image forming unit including a developing device to which the transfer residual toner collected from the cleaning device is supplied, and the second image forming unit is disposed at a position where the secondary transfer device is disposed. Separately from the above, the first image forming unit formed on a latent image carrier provided in the second image forming unit on a recording sheet conveyed through the conveyance path toward the second image forming unit An image forming apparatus comprising a transfer unit that transfers an image different from the image forming apparatus. The second developing device provided in the image forming unit, an image forming apparatus according to claim 1, wherein the a configuration integrated with a cleaning device provided on the transfer member. The developing device in the second image forming unit is an image forming unit that forms a black image when a plurality of the first image forming units are juxtaposed on the extended surface of the transfer body and image formation of a plurality of colors is possible. the image forming apparatus according to claim 1 or 2 is connected to the toner replenishing device to the developing device provided with toner is characterized in that it comprises a structure to be supplied to. When the toner used in the developing device provided in the first image forming unit is deteriorated, the toner of the developing device is transferred to the transfer member by operating the first image forming unit, and then the transfer member the image forming apparatus according to any one of claims 1 to 3, wherein recovering the toner transferred by the cleaning device.

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