JP2010032668A - Recovery toner container and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing the occurrence of toner blockage in a recovery toner container 16Y without applying vibration to the container. <P>SOLUTION: A conductive layer 17Y is formed on the internal sidewall of the recovery toner container 16Y. Also, an electrical contact 18Y is provided in the recovery toner container 16Y. The electrical contact 18Y receives a voltage outputted from a blockage prevention power source 25Y for use as an external power source and having the same polarity as recovered toner, and guides this voltage to the conductive layer 17Y. A voltage having the same polarity as recovered toner is applied to the conductive layer 17Y, thereby causing the recovered toner and conductive layer 17Y electrostatically repelling each other, and hence restraining toner from adhering to the internal sidewall of the recovery toner container 16Y. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a collected toner container that stores collected toner collected from the surface of an image carrier such as a photoconductor, and an image forming apparatus such as a copying machine, a facsimile, and a printer using the same.

  In an image forming apparatus that forms an image using toner, the toner before the image forming process exhibits good fluidity, but the toner after the image forming process has lost good fluidity. Many. This is because the external additive is buried in the toner particles by stirring in the developing device, or the lubricant applied to the photosensitive member or the intermediate transfer member adheres to the toner particles to increase the cohesiveness of the toner. Recovered toner collected from the surface of the image carrier, such as transfer residual toner adhering to the surface of the image carrier and toner in a reference toner image formed on the surface of the image carrier for measurement of image forming performance Is a toner that has already undergone an image forming process. For this reason, the fluidity is low and it is easy to adhere to the inner wall of the collected toner container.

  On the other hand, with the recent miniaturization of image forming apparatuses, the collected toner container tends to be miniaturized, and it is difficult to ensure a large distance between the side walls. If the distance between the side walls is reduced for miniaturization, toner clogging is likely to occur in the container. Specifically, all of the collected toner put into the collected toner container may be smoothly dropped to the bottom of the container, but a part of the collected toner adheres to the side wall in the container. Then, the newly collected toner sequentially adheres on the adhered toner, so that the lump of adhered toner gradually grows on the side wall. In a large collected toner container in which the distance between the side walls is relatively large, the adhered toner lumps collapse before growing to a size that bridges the side walls. However, in a small collected toner container in which the distance between the side walls is relatively small, the side walls are easily cross-linked before the lump of adhering toner collapses, and toner clogging is likely to occur. When toner clogging occurs, the toner overflows from the container or a full error is detected even though there is still sufficient space on the bottom side of the container.

As an image forming apparatus capable of suppressing occurrence of toner clogging in a collected toner container, those described in Patent Document 1 and Patent Document 2 are known. In these image forming apparatuses, the collected toner container is vibrated during a print job, thereby preventing the adhesion toner mass from growing on the side wall.
JP 2005-308814 A JP 2007-199359 A

  However, the vibration applied to the collected toner container during the print job is propagated to the photoconductor and the like, which may adversely affect the image and cause image quality degradation. Note that if the print job is temporarily interrupted to apply vibration to the collected toner container, it is possible to avoid the above-mentioned image quality degradation, but the print productivity is reduced by interrupting the print job. Will end up.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a recovered toner container capable of suppressing the occurrence of toner clogging in the container without applying vibration to the recovered toner container. Etc. is to provide.

In order to achieve the above object, a first aspect of the present invention provides a recovered toner container for storing recovered toner recovered from the surface of an image carrier, wherein a conductive layer is formed on a side wall surface inside the container and the conductive toner is stored. An internal power supply for applying a voltage having the same polarity as the charge polarity of the collected toner to the layer is provided, or a voltage receiving means for receiving the voltage output from the external power supply and guiding it to the conductive layer is provided. To do.
According to a second aspect of the present invention, there is provided an image carrier for carrying a toner image, a transfer means for transferring the toner image carried on the surface of the image carrier to a transfer member, and transferring the toner image to the transfer member. In the image forming apparatus comprising a removing unit that removes the transfer residual toner adhering to the surface after the toner is removed, and a collected toner container that contains the toner removed by the removing unit. The recovered toner container according to Item 1 is used.
According to a third aspect of the present invention, in the image forming apparatus of the second aspect, the internal power source or the external power source is configured to output the voltage when the toner removing operation by the removing unit is performed. It is characterized by.
According to a fourth aspect of the present invention, in the image forming apparatus of the second or third aspect, the internal power source or the external power source is configured to switch the polarity of the output voltage at a predetermined timing. .
According to a fifth aspect of the present invention, in the image forming apparatus of the fourth aspect, the time for outputting a voltage having a polarity opposite to the charged polarity of the collected toner is set to be relatively shorter than the time for outputting the voltage having the same polarity. The internal power supply or the external power supply is configured to switch the polarity of the output voltage.
According to a sixth aspect of the present invention, in the image forming apparatus of any of the second to fifth aspects, the voltage output time is lengthened as the image area of the toner image formed on the surface of the image carrier increases. The internal power supply or the external power supply is configured.
According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the second to sixth aspects, the voltage is changed every time the total image area of the toner image formed on the surface of the image carrier reaches a predetermined value. The internal power supply or the external power supply is configured so that the output is performed for a predetermined time.
According to an eighth aspect of the present invention, there is provided the image forming apparatus according to any one of the second to seventh aspects, wherein the transfer means for transferring the toner image from the surface of the image carrier to the recording sheet, and the conveyance path for conveying the recording sheet. A clogging detecting means for detecting sheet clogging in the sheet, the removing means is configured to remove the transfer residual toner adhering to the surface after passing through the transfer means, and the clogging detecting means When the sheet jam is detected, the internal power source or the external power source is configured so that a voltage is output for a predetermined time during the return operation after the sheet jam is eliminated.

  The inventors of the present invention have focused on the fact that the charging polarity of the toner collected as the collected toner from the surface of the image carrier has a predetermined polarity depending on the apparatus configuration and the collection position. For example, in the configuration in which the transfer residual toner adhering to the surface of the photoconductor after passing through the transfer position for transferring the toner image on the surface of the photoconductor as an image carrier to the transfer body is collected by the cleaning blade Most of the toner particles contained in the toner are charged with the same polarity. So-called reversely charged toner particles that are charged in the opposite polarity to the polarity (hereinafter referred to as “charged polarity of recovered toner”) are also included in the recovered toner, but the ratio is very small. The reversely charged toner particles are charged to the opposite polarity because the particle size is far from the normal toner particles, the shape is distorted, or the external additive is insufficient. This is because the proportion of such particles in the toner is small. Whether the "collected toner charging polarity" is the same as the polarity when frictionally charged in the developing device or the opposite polarity depends on the device configuration (especially the transfer vice value), but the same device configuration If so, the polarity will not change. With the same device configuration, the polarity is determined regardless of environmental fluctuations. The same applies to the configuration in which the transfer residual toner on the intermediate transfer member serving as the image carrier is recovered by the cleaning blade. As long as the apparatus configuration is the same, most of the toner particles contained in the recovered toner recovered from the intermediate transfer member are mutually connected. The same polarity is charged, and the polarity is determined by the device configuration. As described above, most of the toner particles contained in the collected toner are charged with the same polarity, and the polarity can be specified in advance based on the apparatus configuration.

  In the present invention, a voltage having the same polarity as the “charging polarity of the collected toner” is applied to the conductive layer formed on the inner side wall surface of the collected toner container. As a result, most of the toner particles contained in the collected toner are electrically repelled from the conductive layer, thereby making it difficult for the toner particles to adhere to the side wall surface or separating the toner particle from the side wall surface. In this way, by preventing the adhesion of most of the toner particles contained in the collected toner to the side wall surface, it becomes possible to suppress the growth of the adhered toner on the side wall surface. The occurrence of toner clogging in the container can be suppressed without giving.

Hereinafter, an embodiment in which the present invention is applied to an electrophotographic printer as an image forming apparatus will be described.
FIG. 1 is a schematic configuration diagram illustrating a printer according to an embodiment. The printer includes a paper feed cassette 2 that can be pulled out from the housing 1. Process units 10Y, 10C, 10M for forming toner images (visible images) of respective colors of yellow (Y), cyan (C), magenta (M), and black (K) are formed in the central portion of the casing 1. It has 10K. Hereinafter, the subscripts Y, C, M, and K of the respective symbols indicate members for yellow, cyan, magenta, and black, respectively.

  FIG. 2 is an enlarged configuration diagram showing the Y process unit 10Y together with its peripheral configuration. The other color process units have the same configuration. In the figure, a process unit 10Y includes a drum-shaped photoconductor 11Y which is a latent image carrier that rotates clockwise in the drawing. The photoreceptor 11Y includes a metal cylindrical base and an OPC (organic photo semiconductor) photosensitive layer covering the surface. Around the photoconductor 11Y, there are a charging roller 12Y that uniformly charges the photoconductor 11Y, a developing device 13Y that is a developing unit that develops a latent image formed on the photoconductor 11Y, and a drum cleaning that cleans transfer residual toner on the photoconductor 11Y. A device 15Y and the like are provided. Since the process units of other colors have the same configuration, the description is omitted.

  In FIG. 1 described above, an optical writing unit 6 as a latent image writing means for writing a latent image on the photosensitive body of each color is disposed below the process units 10Y, 10C, 10M, and 10K for each color. Has been. A transfer unit 30 serving as a transfer unit is disposed above the process units 10Y, 10C, 10M, and 10K for the respective colors. This transfer unit 30 superimposes the toner images formed on the photoconductors 11Y, 11C, 11M, and 11K as image carriers on the intermediate transfer belt 31 that is an image carrier, and performs primary transfer. The toner image is transferred to the recording paper P by secondary transfer.

  The optical writing unit 6 irradiates the photoconductors 11Y, 11C, 11M, and 11K while deflecting writing light (laser light) L emitted from a laser diode as a light source in the main scanning direction by a polygon mirror or the like. As a result, the photoreceptors 11Y, 11C, 11M, and 11K are irradiated with light, and electrostatic latent images for Y, C, M, and K are carried at the exposed portions. These electrostatic latent images for Y, C, M, and K are respectively developed by a developing device to become Y, C, M, and K toner images.

  As the developing device (for example, 13Y in FIG. 2), a two-component developing system that performs development using a two-component developer containing toner and a magnetic carrier may be used, or a one-component developer composed of toner. A one-component developing method may be used.

  The transfer unit 30 includes an endless intermediate transfer belt 31 that is an image carrier, a driving roller 32 that stretches the belt, a backup roller 33, a tension roller 34, a secondary transfer nip inlet roller 35, and the like. Also, Y, C, M, and K primary transfer rollers 36Y, 36C, 36M, and 36K disposed inside the loop of the intermediate transfer belt 31 are provided. Further, it also has a secondary transfer roller 37 and a belt cleaning device 38 disposed outside the loop.

  The intermediate transfer belt 31 is wound around a drive roller 32, a backup roller 33, a tension roller 34, and a secondary transfer nip entrance roller 35. The lower stretched surface is brought into contact with the photoconductors 11Y, 11C, 11M, and 11K to form a primary transfer nip for Y, C, M, and K, and is driven to rotate by a driving unit (not shown). As the roller 32 rotates, it is moved endlessly in the counterclockwise direction in the figure.

  Primary transfer rollers 36Y, 36C, 36M, and 36K that rotate while being in contact with the back surface of the intermediate transfer belt 31 on the back side of the primary transfer nip for Y, C, M, and K are primary-powered by a primary transfer power source 50. A transfer bias is applied. By this application, a primary transfer electric field is formed between the photoreceptors 11Y, 11C, 11M, and 11K and the primary transfer rollers 36Y, 36C, 36M, and 36K. The Y, C, M, and K toner images formed on the photoconductors 11Y, 11C, 11M, and 11K are sequentially superimposed and superimposed on the intermediate transfer belt 31 at each primary transfer nip. As a result, a four-color superimposed toner image is formed on the intermediate transfer belt 31. The four-color superimposed toner image is secondarily transferred onto the recording paper P at a secondary transfer nip described later, and then sent to the fixing unit 55 to be fixed on the recording paper P as a recording member.

  In the drawing, the photosensitive drums 11Y, 10C, 10M, and 10K are primarily transferred onto the intermediate transfer belt 31 after passing through the primary transfer nips for Y, C, M, and K along with the clockwise rotation. A small amount of untransferred toner adhered. This is removed from the surface of the photoreceptor by a drum cleaning device (for example, 15Y in FIG. 2).

  A secondary transfer roller 37 is disposed on the right side of the intermediate transfer belt 31 in the drawing, and forms a secondary transfer nip in contact with a place where the belt is driven around the drive roller 32. A secondary transfer bias is applied to the secondary transfer roller 25 by a secondary transfer power source 51. Thereby, a secondary transfer electric field is formed between the driving roller 32 and the secondary transfer roller 25.

  The recording paper P in the paper feed cassette 2 is fed into the paper feed path 3 by a paper feed roller 2 a provided in the paper feed cassette 2 and then transported toward the secondary transfer nip by a pair of transport rollers 4. The A registration roller pair 5 is disposed near the end of the paper feed path 3. The registration roller pair 5 stops the rotation drive as soon as the recording paper P conveyed by the rotation drive of the conveyance roller pair 4 is sandwiched between the rollers. Then, rotation driving is resumed at a predetermined timing, and the recording paper P is sent out to the secondary transfer nip. Then, the recording paper P is superimposed on the four-color toner image on the intermediate transfer belt 31 in the secondary transfer nip. Within the secondary transfer nip, a four-color toner image is collectively secondary transferred onto the surface of the recording paper P due to the influence of the nip pressure and the secondary transfer electric field. As a result, the four-color toner image is combined with the white color of the recording paper P to form a full-color image.

  The recording paper P on which a full-color image is formed exits the secondary transfer nip and is sent to the fixing unit 55. Then, after passing through the fixing unit 55, an image fixing process is performed, and then the sheet is discharged to the outside through the discharge roller 59.

  The transfer residual toner adhering to the intermediate transfer belt 31 that has passed through the secondary transfer nip is cleaned by the belt cleaning device 38.

  In FIG. 2 described above, the drum cleaning device 15Y has a recovered toner container 16Y. The collected toner container 16Y has an opening at a position facing the photoconductor 11Y as an image carrier, and the photoconductor 11Y has a part of its peripheral surface in the collected toner container 16Y through the opening. To enter. In the collected toner container 16Y, the drum cleaning blade 20Y is cantilevered and the free end side is brought into contact with the photoreceptor 11Y. The transfer residual toner on the photoreceptor 11Y is scraped off from the surface of the photoreceptor 11Y by the drum cleaning blade 20Y. Then, it drops toward the bottom of the collected toner container 16Y and becomes collected toner.

  At the bottom of the collected toner container 16Y, the collected screw 21Y is arranged in such a posture that the axial direction is along the direction perpendicular to the drawing sheet. The collected toner that has fallen from the cleaning blade 20Y toward the bottom of the collected toner container 16Y is received by the collected screw 21Y, and is conveyed in a direction perpendicular to the drawing surface as the screw rotates. Then, the toner is discharged outside the collected toner container 16Y and stored in a waste toner bottle (not shown).

Next, a characteristic configuration of the printer according to the embodiment will be described.
The collected toner container 16Y has a flat shape with a relatively small size in the left-right direction in the figure, and toner clogging is likely to occur between two side walls facing each other in the left-right direction in the figure. Yes. If a toner lump bridge occurs between two side walls facing each other in the left-right direction in the drawing, the transfer residual toner scraped off from the surface of the photoreceptor 11Y by the drum cleaning blade 20Y cannot fall to the bottom of the container. Then, it is caught on the bridge of the toner lump. Eventually, the transfer residual toner overflows from the container opening.

  Therefore, in the present embodiment, in the collected toner container 16Y, the conductive layer 17Y made of a conductive material such as metal is formed on each of two side walls facing each other in the left-right direction in the drawing. Further, an electrical contact 18Y as a voltage receiving means is provided on the outer wall of the collected toner container 16Y, and the electrical contact 18Y is electrically connected to each conductive layer 17Y.

  The drum cleaning device 15Y is integrally attached to and detached from the printer body as a process unit 10Y together with the photoreceptor 11Y and the like. When the process unit 10Y is set in the printer body, the electrical contact 18Y described above is connected to a block blocking power supply 25Y as an external power source fixed in the printer body via an electrical contact (not shown) on the printer body side. It has become so.

  The block prevention power source 25Y outputs at least a voltage having a polarity opposite to the charging polarity of the transfer residual toner (collected toner) on the surface of the photoreceptor 11Y. With this output, when a voltage having a reverse polarity to the collected toner is applied to the conductive layer 17Y to electrically repel the conductive layer 17Y and the collected toner, the collected toner is applied to the side wall surface of the collected toner container 16Y. It is possible to prevent the adhesion toner from growing on the side wall surface by making it difficult to adhere or by separating the toner adhering to the side wall surface from the side wall surface. Therefore, the occurrence of toner clogging in the container can be suppressed without giving vibration to the collected toner container 16Y.

  FIG. 3 is an enlarged configuration diagram showing the belt cleaning device 38 together with its peripheral configuration. In the figure, the belt cleaning device 38 has a collected toner container 39. The recovered toner container 39 has an opening at a position facing the intermediate transfer belt 31 that is an image carrier, and the intermediate transfer belt 31 stores the recovered toner through the opening at a position where the intermediate transfer belt 31 is wound around the backup roller 33. The container 39 is entered. In the collected toner container 39, a belt cleaning blade 43 is cantilevered and the free end side is brought into contact with the intermediate transfer belt 31. Transfer residual toner on the intermediate transfer belt 31 is scraped off from the surface of the intermediate transfer belt 31 by the belt cleaning blade 43. Then, it drops toward the bottom of the collected toner container 39 to become collected toner.

  A full error detection sensor 41 is fixed at a relatively high level position on the side wall in the collected toner container 39. When the collected toner storage level in the collected toner container 39 reaches a position where the full error detection sensor 41 can detect, the full error detection sensor 41 outputs a full error signal. This full error signal is sent to the main control unit of the printer main body via a contact (not shown). When detecting the full error signal, the main control unit including a CPU, a RAM, and the like displays a message for urging replacement of the belt cleaning device 38 on a display unit (not shown) such as a display. As a result, the belt cleaning device 38 is replaced with a new one when the amount of stored toner is full.

  The collected toner container 39 of the belt cleaning device 38 also has a flat shape with a relatively small size in the left-right direction in the figure, and toner clogging due to a bridging toner block between two side walls facing each other in the left-right direction in the figure. Is likely to occur. When a toner lump bridges between two side walls facing each other in the left-right direction in the figure, the transfer residual toner scraped off from the surface of the intermediate transfer belt 31 by the belt cleaning blade 43 can fall to the bottom of the container. Without being caught by the bridge of the toner mass. Eventually, a full error is detected and the belt cleaning device 38 is urged to be replaced even though a sufficient storage space is still left at the bottom of the container.

  Therefore, in the present embodiment, the collected toner container 39 of the belt cleaning device 38 is also formed with a conductive layer 40 made of a conductive material such as metal on each of two side walls facing each other in the left-right direction in the drawing. . Further, an electrical contact 42 as a voltage receiving means is provided on the outer wall of the collected toner container 39, and the electrical contact 42 and each conductive layer 40 are electrically connected.

  When the belt cleaning device 38 is set in the printer body, the electrical contact 42 described above is connected to a block blocking power supply 45 as an external power source fixed in the printer body via an electrical contact (not shown) on the printer body side. It has come to be.

  The block prevention power source 45 outputs at least a voltage having a polarity opposite to the charging polarity of the transfer residual toner (collected toner) on the surface of the intermediate transfer belt 31. With this output, when a voltage having a polarity opposite to that of the collected toner is applied to the conductive layer 40 to electrically repel the conductive layer 40 and the collected toner, the collected toner is applied to the side wall surface of the collected toner container 39. It is possible to prevent the adhesion toner from growing on the side wall surface by making it difficult to adhere or by separating the toner adhering to the side wall surface from the side wall surface. Therefore, the occurrence of toner clogging in the container can be suppressed without giving vibration to the collected toner container 39.

  A lubricant application device is disposed on the side of the belt cleaning device 38. This lubricant applying device has a solid lubricant block 110 and a coating brush roller 111 that rotates while contacting the solid lubricant block 110 and the intermediate transfer belt 31. Then, the lubricant powder scraped from the solid lubricant black 110 is applied to the surface of the intermediate transfer belt 31. By applying the lubricant powder to the intermediate transfer belt 31 in this way, it becomes possible to improve the secondary transfer property of the toner image and the toner cleaning property from the belt. The cohesiveness is increased and the transfer residual toner (collected toner) is easily attached to the side wall of the container.

  In FIG. 1, the printer is configured to drive only the K process unit 10Y among the four process units when printing in the monochrome mode. More specifically, a belt (not shown) supporting the transfer roller 34, the primary transfer roller 36Y for Y, the primary transfer roller 36C for C, and the primary transfer roller 36M for M is moved so that the belt tension is increased. The belt is separated from the Y, C, and M photoconductors 11Y, 11C, and 11M by changing the mounting posture. Then, with the three process units 10Y, 10C, and 10M for Y, C, and M stopped, a K toner image is formed by the K process unit 10K. The drum cleaning device (for example, 15Y in FIG. 2) always keeps the cleaning blade in contact with the photosensitive member when set in the printer body. In such a drum cleaning device, the transfer residual toner is removed as the photosensitive member is driven to rotate. That is, the removal operation by the drum cleaning device is synchronized with the rotation operation of the photoconductor. In the monochrome mode, the Y, C, and M photoconductors 11Y, 11C, and 11M are not rotationally driven, and therefore the Y, C, and M drum cleaning devices are not removed. Become.

  In this printer, a block blocking power source (for example, 25Y in FIG. 2) as an external power source is configured so that the voltage application to the conductive layer of the collected toner container of the drum cleaning device is synchronized with the removal operation of the drum cleaning device. ing. Therefore, among the four block blocking power supplies corresponding to the four drum cleaning devices, the Y, C, and M block blocking power supplies do not output a voltage in the monochrome mode.

Next, printers according to the respective examples in which a more characteristic configuration is added to the printer according to the embodiment will be described.
Note that the configuration of the printer according to each example is the same as that of the embodiment unless otherwise specified.

  First, a configuration common to the embodiments will be described. In each embodiment to be described later, the primary transfer power supply 50 applies a primary transfer bias of +1800 [V] to the primary transfer vice rollers 36Y, C, M, and K, respectively. Further, the secondary transfer power source performs constant current control for adjusting the voltage so that the secondary transfer current flowing between itself and the driving roller 32 becomes +30 [μA]. Under such primary transfer conditions and secondary transfer conditions, most of the toner particles are charged with positive polarity in the residual transfer toner adhering to the surface of the intermediate transfer belt 31 after passing through the secondary transfer nip. In the present invention, the charged polarity of the collected toner does not mean the charged polarity of individual toner particles in the collected toner, but rather the positive polarity of the collected toner as a whole. To do. Therefore, in each embodiment described later, the charge polarity of the transfer residual toner adhering to the surface of the intermediate transfer belt 31 after passing through the secondary transfer nip is positive.

[First embodiment]
FIG. 4 is a timing chart showing on / off timing of device operation. In the figure, the period during which the drive of the main motor is on indicates that the print job is being performed. The charts of pattern A, pattern B, and pattern C all show output voltages from the block blocking power supply 45 that supplies a voltage to the conductive layer 40 of the collected toner container 39 of the belt cleaning device 38.

  The block blocking power supply 45 of the printer according to the first embodiment outputs a voltage as shown by a pattern A in FIG. Specifically, when a print job is started, output of a voltage of +1000 [V], which is the same polarity as the charging polarity of the residual toner on the belt, is started. The output is continued until the print job is completed. Then, during the print job, the potential of the conductive layer 40 is set to about +1000 [V] having the same polarity as the residual transfer toner, and most of the positively charged toner particles contained in the residual transfer toner and the side wall surface of the container are repelled. Can be made.

[Second Embodiment]
The block blocking power supply 45 of the printer according to the second embodiment outputs a voltage as shown by a pattern B in FIG. Specifically, when a print job is started, output of a voltage of +1000 [V], which is the same polarity as the charging polarity of the residual toner on the belt, is started. The output is continued until the print job is completed. Up to this point, the process is the same as in the first embodiment. The difference from the first embodiment is the output mode after the print job is completed. In the second embodiment, when the print job is completed, a voltage of −1000 [V] having a polarity opposite to the charged polarity of the residual toner on the belt is output for a predetermined period.

  As described above, most of the toner particles in the transfer residual toner are positively charged, but there are some toner particles that are negatively charged (hereinafter referred to as reversely charged toner particles). During the print job, the reversely charged toner particles are strongly attracted and attached to the conductive layer 40 having a potential opposite to that of the reversely charged toner particles. Therefore, in the second embodiment, after the print job is completed, a voltage of −1000 [V] having a polarity opposite to the charge polarity of the transfer residual toner is applied to the conductive layer 40 for a predetermined time. . Since this voltage has the same polarity with respect to the reversely charged toner particles, the reversely charged toner particles are repelled from the conductive layer 40. As a result, the reversely charged toner particles adhered to the conductive layer 40 during the print job can be separated from the conductive layer 40.

  It should be noted that the output time of the voltage of −1000 [V] after the end of the print job is sufficient for several seconds.

[Third embodiment]
The block blocking power supply 45 of the printer according to the third embodiment outputs a voltage as shown by a pattern C in FIG. Specifically, when a print job is started, a voltage output of +1000 [V] having the same polarity as the charging polarity of the residual toner on the belt and a voltage output of −1000 [V] having the opposite polarity are output. Are switched at a predetermined cycle. The accumulated output time of +1000 [V] is longer than the accumulated output time of -1000 [V]. This is because the content of the reversely charged toner particles is small. Both the positively charged toner particles and the reversely charged toner particles can be efficiently separated from the side wall surface of the container.

  In addition, it is possible to suppress the occurrence of sticking of the reversely charged toner particles to the conductive layer 40 by strongly attracting the reversely charged toner particles to the conductive layer 40 having the reverse polarity for a long time.

[Fourth embodiment]
FIG. 5 is a graph showing the relationship between the voltage application time to the conductive layer 40 after the print job and the image area ratio of the formed image in the printer according to the fourth embodiment. Here, the image area ratio of the formed image means the area ratio of the formed image with respect to the A3 size whole surface solid image when the A3 size whole surface solid image formed on the intermediate transfer belt 31 is 100%. In the case of the single print mode for one sheet of recording paper, this is the image area ratio of the image formed on that sheet. In the case of the continuous print mode for a plurality of recording papers, the image area ratio of the image having the largest area among the images formed on the plurality of recording papers during the continuous printing is shown. As shown in the figure, the voltage application time after the end of the print job is lengthened as the image area ratio increases.

  FIG. 6 is a timing chart showing device operation on / off timings in the printer according to the fourth embodiment. As shown in the figure, when the image area ratio of the image of the maximum area among the images formed in the print job is 40 [%], the additional image is added by 0.4 [seconds] after the print job is finished. A voltage is applied. When the image area ratio is 20 [%], an additional voltage is applied for 0.4 [second] after the print job is completed. Thus, the toner particles adhering to the conductive layer 40 immediately before the end of the print job can be reliably separated from the conductive layer 40 by applying a voltage for a time corresponding to the amount of adhesion.

[Fifth embodiment]
The block blocking power supply 45 of the printer according to the fifth embodiment applies a voltage for a predetermined time to the conductive layer 40 every time the total image area of the image formed on the intermediate transfer belt 31 reaches a predetermined value. It has become. Specifically, during the print job, the output of +1000 [V] and the output of −1000 [V] are alternately switched as in the fourth embodiment. Further, after the print job is completed, an additional voltage output is performed only for a time corresponding to the image area ratio, as in the fourth embodiment. Further, when a print job is generated in which the cumulative total reaches a predetermined value, after the job is completed, an additional voltage output similar to that of the fourth embodiment is performed, and then the voltage application time is further extended by a predetermined time. To do.

[Sixth embodiment]
When a paper jam occurs in a paper conveyance path such as the paper feed path 3 or the like, the printer according to the fifth embodiment issues a message that promptly stops the print job and prompts the user to remove the jammed paper. ing. Further, when the user who responds to this message removes the jammed paper, the returning operation is performed. This return operation is an operation that idles each device in the machine for a predetermined time. When a paper jam occurs, it is necessary to clean a toner image formed on the photosensitive member or the intermediate transfer belt that has remained on the photosensitive member or the belt at the time of the paper jam. For this cleaning, each device is idled for a predetermined time.

  The block blocking power supply 45 of the belt cleaning device 38 and the block blocking power supply corresponding to each drum cleaning device output a voltage during the return operation. Thereby, it is possible to prevent the transfer residual toner from adhering to the container side wall due to the cleaning during the returning operation.

  So far, an example has been described in which an external power source configured separately from the collected toner container is used as the power source. However, a power supply fixed to the collected toner container may be used.

  As described above, in the printer according to the embodiment, the drum cleaning blade is provided as a removing unit that removes the toner adhering to the surface of the photoconductor as the image carrier from the surface and collects the toner in the collected toner container. . The drum cleaning device is configured as a block prevention power source as an external power source so as to output a voltage when a cleaning operation as a toner removing operation by the drum cleaning blade is performed. With such a configuration, in the drum cleaning device, it is possible to prevent the transfer residual toner that falls into the collected toner container in accordance with the cleaning operation of the drum cleaning blade from adhering to the container side wall surface by applying a voltage to the conductive layer. .

  Further, in the printer according to the first embodiment, a block output power supply 45 that is an external power supply that outputs a voltage (+1000 V) having the same polarity as the charging polarity of the collected toner is used. In such a configuration, by applying a voltage having the same polarity to the conductive layer 40, most of the positively charged toner particles contained in the collected toner can be prevented from adhering to the container side wall surface.

  In the printers according to the second, third, fourth, and fifth embodiments, the block blocking power supply 45 is configured to switch the polarity of the output voltage at a predetermined timing. In such a configuration, by switching the polarity of the output voltage, even if the reversely charged toner particles slightly contained in the collected toner adhere to the conductive layer, it can be separated from the conductive layer.

  Further, in the printers according to the second, third, fourth, and fifth embodiments, the time for outputting the voltage having the opposite polarity to the charging polarity of the collected toner is relative to the time for outputting the voltage having the same polarity. The block blocking power supply 45 is configured so as to switch the polarity of the output voltage to be shortened. In such a configuration, the positively charged toner particles and the reversely charged toner particles contained in the collected toner can be efficiently prevented from adhering to the container side wall surface by outputting a voltage for a time corresponding to the respective amounts.

  In the printer according to the fourth embodiment, the block blocking power supply 45 is configured such that the voltage output time is increased as the image area of the toner image formed on the surface of the intermediate transfer belt 31 is increased. In such a configuration, by applying a voltage to the conductive layer 40 for a time corresponding to the amount of the collected toner, toner blocking is formed on the conductive layer 40 (side wall surface) without applying unnecessary voltage. Can be blocked.

  Further, in the printer according to the fifth embodiment, the block prevention is performed so that the voltage is output for a predetermined time every time the total image area of the toner image formed on the surface of the intermediate transfer belt 31 reaches a predetermined value. A power supply 45 is configured. In such a configuration, every time the cumulative amount of toner attached to the belt reaches a predetermined value, it is possible to urge toner removal from the container side wall surface.

  In the printer according to the sixth embodiment, a paper jam is detected in the transfer unit 30 serving as a transfer unit that transfers the toner image from the surface of the intermediate transfer belt 31 to the recording paper P, and in the conveyance path for conveying the recording paper P. The belt cleaning device 38 is configured to remove the transfer residual toner adhering to the belt surface after passing through the transfer unit 30, and the clogging detection unit detects the upper clogging. In this case, the block prevention power supply 45 is configured so that the voltage is output for a predetermined time during the return operation after the paper jam is cleared. With such a configuration, it is possible to prevent the transfer residual toner removed from the belt surface during the returning operation from adhering to the container side wall surface.

1 is a schematic configuration diagram illustrating a printer according to an embodiment. FIG. 3 is an enlarged configuration diagram showing a Y process unit of the printer together with its peripheral configuration. FIG. 2 is an enlarged configuration diagram showing a belt cleaning device of the printer together with its peripheral configuration. 6 is a timing chart showing on / off timings of device operation of the printer according to each embodiment. 14 is a graph showing a relationship between a voltage application time to a conductive layer after a print job and an image area ratio of a formed image in a printer according to a fourth example. 9 is a timing chart showing device operation on / off timing in a printer according to a fourth embodiment.

Explanation of symbols

11Y, M, C, K: photoconductor (image carrier)
16Y: Collected toner container 17Y: Conductive layer 18Y: Electrical contact (voltage receiving means)
20Y: Drum cleaning blade (removing means)
25Y: Block blocking power supply (external power supply)
30: Transfer unit (transfer means)
31: Intermediate transfer belt (image carrier)
39: Collected toner container 40: Conductive layer 43: Belt cleaning blade (removing means)

Claims (8)

In a collected toner container that contains collected toner collected from the surface of the image carrier,
A conductive layer is formed on the side wall surface inside the container, and an internal power source for applying a voltage having the same polarity as the charging polarity of the collected toner is provided on the conductive layer, or the voltage output from an external power source is received and the A collected toner container characterized in that voltage receiving means for guiding the conductive layer is provided. An image carrier that carries a toner image, a transfer unit that transfers the toner image carried on the surface of the image carrier to a transfer member, and a toner image that adheres to the surface after the toner image is transferred to the transfer member. In an image forming apparatus comprising: a removing unit that removes transfer residual toner that is present; and a collected toner container that contains toner removed by the removing unit
An image forming apparatus using the collected toner container according to claim 1 as the collected toner container. The image forming apparatus according to claim 2.
An image forming apparatus comprising: the internal power supply or the external power supply configured to output the voltage when the toner removing operation by the removing unit is performed. The image forming apparatus according to claim 2 or 3,
An image forming apparatus, wherein the internal power supply or the external power supply is configured to switch the polarity of the output voltage at a predetermined timing. The image forming apparatus according to claim 4.
The internal power supply or the external power supply is switched so that the polarity of the output voltage is switched so that the time for outputting the voltage having the opposite polarity to the charging polarity of the collected toner is relatively shorter than the time for outputting the same polarity voltage. An image forming apparatus comprising: The image forming apparatus according to any one of claims 2 to 5,
An image forming apparatus, wherein the internal power supply or the external power supply is configured such that the voltage output time is increased as the image area of the toner image formed on the surface of the image carrier increases. The image forming apparatus according to any one of claims 2 to 6,
The internal power supply or the external power supply is configured to output a voltage for a predetermined time each time the total image area of the toner image formed on the surface of the image carrier reaches a predetermined value. Image forming apparatus. The image forming apparatus according to any one of claims 2 to 7,
A transfer means for transferring a toner image from the surface of the image carrier to a recording sheet; and a clogging detection means for detecting a sheet clogging in a conveyance path for conveying the recording sheet
The removal means is configured to remove the transfer residual toner adhering to the surface after passing through the transfer means,
In addition, the internal power supply or the external power supply is configured so that, when a sheet jam is detected by the jam detection unit, a voltage is output for a predetermined time during the return operation after the sheet jam is cleared. An image forming apparatus.

Images