JP2009008852A - Waste toner conveying mechanism and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste toner conveying mechanism for effectively preventing waste toner from clogging the inside of a waste toner conveyance passage densely, thereby improving conveying performance for waste toner and surely collecting waste toner into a waste toner collection container 30, and to provide an image forming apparatus that has the waste toner conveying mechanism 20. <P>SOLUTION: In the image forming apparatus A, the waste toner conveying mechanism 20 by which the waste toner which is generated on toner carriers 3 and 7 is conveyed toward the waste toner collection container 30, includes the waste toner conveyance passage 21 and a waste toner conveying member 22 disposed in the waste toner conveyance passage 21 so as to be rotatable around an axial line. The waste toner conveying member 22 has: a rotating shaft 221 connected by a drive source 40; a conveying screw 222 pivotally supported by the rotating shaft 221; and an elastic member 223 held by the rotating shaft 221 or conveying screw 222. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a waste toner transport mechanism for transporting waste toner generated on a toner carrier such as an electrostatic latent image carrier toward a waste toner collection container in an image forming apparatus such as a copying machine or a printer, and the same. The present invention relates to an image forming apparatus.

  In a conventional image forming apparatus, when an image is formed by an electrophotographic image forming process, generally, an electrostatic latent image carrier (for example, a photoreceptor) acting as a toner carrier is electrostatically charged. A latent image is formed, the electrostatic latent image is visualized with toner in a developing device, and the visualized toner image is electrostatically transferred to a recording medium such as recording paper and transferred to the recording medium. By further fixing the toner image, an image is formed on the recording medium.

  In some cases, a toner image is once formed on an intermediate transfer member that acts as a toner carrier, and is transferred from the intermediate transfer member to a recording medium and fixed.

  Further, in a color image forming apparatus, a toner image for each color such as cyan, magenta, yellow, and black may be formed on a recording medium, and a color image may be formed on the recording medium by fixing the toner image.

  The toner used in such a conventional image forming apparatus is mixed with a carrier (magnetic powder) alone in the case of a one-component developer or in the case of a two-component developer in the developing tank of the developing device. It is accommodated and takes a form that contributes to image formation in a state having a predetermined charge amount.

  Not all of the toner adhering to the toner carrier is transferred onto the recording medium, but a part of the toner remains on the toner carrier, and “waste toner” is left in the cleaning device in the cleaning process of the surface of the toner carrier. Will be collected. The waste toner collected in the cleaning device is transported from the cleaning device toward the waste toner collection container by the waste toner transport mechanism, and is stored in the waste toner collection container.

  In many cases, the waste toner is transported by a waste toner transport mechanism including a waste toner transport path and a waste toner transport member that is rotatably disposed around the axis in the waste toner transport path. As the waste toner conveying member constituting the waste toner conveying mechanism, a member in which a blade (conveying screw) spirally formed along the axial direction with respect to the rotation shaft is generally used.

  For example, waste toner generated on the toner carrier is combined with unnecessary materials such as paper dust and dust mixed in the waste toner based on the pressure contact force of a cleaning member (for example, a cleaning blade) pressed against the outer peripheral surface of the toner carrier. It is collected and sent to a waste toner transport mechanism by a collecting screw in a cleaning device provided with the cleaning member.

  Waste toner sent from the cleaning device is conveyed by rotation of a conveyance screw disposed in the waste toner conveyance path, and is collected in a waste toner collection container through an opening provided in the waste toner conveyance path.

  In such a waste toner transport mechanism, it is well known that a problem such as a “blocking phenomenon” in which waste toner accumulates and stays in the waste toner transport path occurs.

  That is, the waste toner transported by the waste toner transport mechanism is not all toner. For example, dust inside the image forming apparatus, paper powder when the paper is charged in the transfer process (mainly cellulose of short fibers, etc.) Unnecessary items such as are included. The fluidity of waste toner containing such unnecessary materials is very low compared to the fluidity of toner not containing unnecessary materials. Therefore, waste toner mixed with unnecessary substances such as paper powder and dust loses its original fluidity. The waste toner whose fluidity has decreased in this way is likely to be agglomerated by stirring with a screw when transported from the cleaning device to the waste toner collection container, leading to clogging and blocking in the waste toner transport path. It was.

  Further, when the clogging phenomenon increases, the cleaning device is also filled with waste toner, a waste toner blocking phenomenon occurs in the recovery screw part, and the recovered toner does not transfer to the recovery screw part in the cleaning member part, and the cleaning member In other words, the cleaning member may be poorly cleaned, and even a phenomenon such as “filming” in which waste toner adheres to the surface of the toner carrier may be generated.

In order to solve this problem, Patent Documents 1 and 2 below propose a method for preventing the occurrence of a phenomenon such as clogging or blocking of waste toner by controlling the ON-OFF timing of a drive source that rotates the conveying screw. ing.
JP-A-1-287686 JP 2007-17544 A

  However, in the drive control methods described in Patent Documents 1 and 2 above, when the waste toner is densely packed in the waste toner conveyance path, the ON / OFF timing of the drive source that rotates the conveyance screw is controlled. However, the waste toner with poor fluidity cannot be reliably collected in the waste toner collection container.

  Accordingly, the present invention can effectively prevent waste toner from being clogged in the waste toner conveyance path, thereby improving the waste toner conveyance performance and reliably collecting the waste toner in a waste toner collection container. It is an object of the present invention to provide a waste toner transport mechanism that can be used and an image forming apparatus including the same.

  In order to solve the above problems, the present invention provides a waste toner transport mechanism for transporting waste toner generated on a toner carrier toward a waste toner collection container in an image forming apparatus, the waste toner transport path, and the waste toner transport path. A waste toner transport member disposed in the toner transport path so as to be rotatable about an axis, the waste toner transport member being connected to a rotation shaft operatively connected to a drive source, and a transport screw supported by the rotation shaft And an elastic member held by the rotating shaft or the conveying screw.

  The present invention is also an image forming apparatus comprising: the waste toner transport mechanism according to the present invention; and a drive source for rotationally driving the rotating shaft in the waste toner transport mechanism, There is also provided an image forming apparatus that is driven to rotate during warm-up of the image forming apparatus, before the image forming process, during the image forming process, and after the image forming process.

  According to the waste toner transport mechanism and the image forming apparatus according to the present invention, in the member constituting the waste toner transport member, the elastic member is held with respect to the rotary shaft or the transport screw. The elastic member rotates with the rotation of the conveying screw, and the elastic force of the elastic member causes a “unraveling phenomenon” to waste toner that is about to be clogged in the waste toner conveyance path. Can be generated. Therefore, it is possible to effectively prevent the waste toner from being clogged in the waste toner conveyance path, and it is possible to reliably collect the waste toner in the waste toner collection container.

  Examples of the toner carrier include an electrostatic latent image carrier such as a photosensitive drum and an intermediate transfer member such as an intermediate transfer belt.

  As a specific aspect of the waste toner transport mechanism according to the present invention, the transport screw is pivotally supported so as to leave a partial region along the axial direction of the rotation shaft in the waste toner transport path, The elastic member can illustrate the aspect comprised by the coil spring penetrated by the said partial area | region of the said rotating shaft.

In this specific embodiment, the following embodiments (a) to (f) can be further exemplified. That is,
(A) The coil spring is a mode in which one end is held on the coil spring side end of the conveying screw or the rotating shaft and the other end is free. In this way, the coil spring itself can be easily vibrated during the rotation of the waste toner conveying member, thereby increasing the effect of releasing the waste toner, thereby improving the waste toner conveyance performance. be able to. In this aspect, for example, the coil spring is disposed between the holding end that is held with respect to the conveying screw or the rotation shaft and a free end when the rotation shaft is rotated by the drive rotation of the drive source. Can vibrate.
(B) The partial region of the rotation shaft is located at a waste toner conveyance terminal position of the waste toner conveyance member. As a result, in the direction of waste toner conveyance, it is possible to generate a phenomenon of the waste toner downstream of the waste toner conveyance path, and efficiently prevent clogging and blocking. It becomes.
(C) The coil spring rotates with the rotation of the rotating shaft by the drive rotation of the drive source and is swingable so as to allow frictional contact with the inner peripheral surface of the waste toner conveyance path. It is the aspect which is. In this way, the waste toner adhering to the waste toner conveyance path can be effectively removed, and the amount of waste toner remaining in the waste toner conveyance path can be suppressed, whereby the waste toner is collected in the waste toner collection container. Toner recovery efficiency can be improved.
(D) The coil spring has a wire diameter determined according to the amount of collected waste toner to be conveyed. In this case, the wire diameter of the coil spring can be determined so that the waste toner is smoothly conveyed.
(E) The waste toner transport path has an opening provided in a region corresponding to the coil spring, and waste toner transported by the waste toner transport member passes from the opening to the waste toner collection container. It is the aspect comprised so that it might collect | recover. By doing so, it becomes possible to directly collect the waste toner unwound by the coil spring from the opening into the waste toner collection container.
(F) A mode in which at least two of the modes (a) to (e) are combined.

  As described above, according to the present invention, waste toner can be effectively prevented from being clogged in the waste toner transport path, thereby improving waste toner transport performance and removing waste toner to a waste toner collection container. It is possible to provide a waste toner conveyance mechanism that can be reliably collected and an image forming apparatus including the same.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the following embodiment is an example which actualized this invention, Comprising: The thing of the character which limits the technical scope of this invention is not.

FIG. 1 is a front view illustrating a schematic configuration of an image forming apparatus including a waste toner conveyance mechanism according to an embodiment of the present invention.
(Description of overall configuration of image forming apparatus)
First, the overall configuration of the image forming apparatus A shown in FIG. 1 will be described. An image forming apparatus A shown in FIG. 1 includes an image forming unit 100 that forms a toner image on a sheet-like recording medium (hereinafter referred to as a sheet) P such as a recording sheet using toner.

  The image forming unit 100 includes an electrostatic latent image carrier (here, a photosensitive drum) 3 (3a, 3b, 3c, 3d) that acts as a toner carrier, and the surface of the photosensitive member 3 (3a, 3b, 3c, 3d). A charging device (charger here) 5 (5a, 5b, 5c, 5d) for charging the light source and an exposure device for forming an electrostatic latent image on the photoreceptor 3 (3a, 3b, 3c, 3d) (Exposure unit here) 1 and a developing device 2 (2a, 2b, 2c) for visualizing the electrostatic latent image with toner and forming a toner image on the photoreceptor 3 (3a, 3b, 3c, 3d) , 2d), an intermediate transfer member (in this case, an intermediate transfer member belt) 7 acting as a toner carrying member, and a toner image on the photosensitive drum 3 (3a, 3b, 3c, 3d) are temporarily put on the intermediate transfer belt 7. Primary transfer device for transferring (here, intermediate transfer roller) 6 6a, 6b, 6c, 6d) and residual toner remaining on the surface of the photoreceptor 3 (3a, 3b, 3c, 3d) without being transferred by the intermediate transfer roller 6 (6a, 6b, 6c, 6d) 1 A secondary cleaning device (here, a cleaner unit) 4 (4a, 4b, 4c, 4d), and a secondary transfer device (here, secondary transfer unit) 11 for transferring the toner image on the intermediate transfer belt 7 onto the paper P; A secondary cleaning device (here, an intermediate transfer belt cleaning unit) 9 that removes residual toner that is not transferred by the secondary transfer unit 11 and remains on the surface of the intermediate transfer belt 7, and a toner image formed on the paper P And a fixing device 12 having a pair of fixing rollers 31 and 32 that are fixed on the sheet P by being heated and melted and fixed.

  Further, the image forming apparatus A includes a document reading device (here, a scanner device) B, a paper feeding device 10, and a discharge unit 15, and image data corresponding to a document read by the document reading device B or externally. Multi-color and single-color images are formed on the paper P in accordance with the transmitted image data.

  More specifically, the image data handled in the image forming apparatus A corresponds to a color image using each color of black (K), cyan (C), magenta (M), and yellow (Y), or a single color ( For example, it corresponds to a monochrome image using black). Accordingly, the developing device 2 (2a, 2b, 2c, 2d), the photosensitive drum 3 (3a, 3b, 3c, 3d), the charger 5 (5a, 5b, 5c, 5d), the cleaner unit 4 (4a, 4b, 4c, 4d) and four intermediate transfer rollers 6 (6a, 6b, 6c, 6d) are provided in order to form four types of images corresponding to the respective colors. The end codes a, b, c, and d correspond to black (K), cyan (C), magenta (M), and yellow (Y), respectively.

  That is, the image forming unit 100 includes a developing device 2a, a photosensitive drum 3a, a charger 5a, a cleaner unit 4a, and an intermediate transfer roller 6a, a black (K) image station, a developing device 2b, and a photosensitive drum 3b. A cyan (C) image station having a charger 5b, a cleaner unit 4b and an intermediate transfer roller 6b, and a magenta having a developing device 2c, a photosensitive drum 3c, a charger 5c, a cleaner unit 4c and an intermediate transfer roller 6c. An (M) image station and a yellow (Y) image station including a developing device 2d, a photosensitive drum 3d, a charger 5d, a cleaner unit 4d, and an intermediate transfer roller 6d are provided. Hereinafter, the last reference numerals of these members will be omitted.

  The image forming unit 100 is provided below the discharge unit 15 provided in the upper part of the image forming apparatus A.

  The charger 5 is a charging unit for uniformly charging the surface of the photosensitive drum 3 to a predetermined potential. As the charger 5, a contact type charger (for example, a roller type or a brush type) or a charger type charger as shown in FIG. 1 can be used.

  The exposure unit 1 has a function of forming an electrostatic latent image corresponding to image data on the surface by exposing the surface of the charged photosensitive drum 3 according to input image data. .

  As the exposure unit 1, a laser scanning unit (LSU) provided with a laser irradiation unit and a reflection mirror, or a writing device (for example, a writing head) in which light emitting elements such as EL and LED are arranged in an array can be used.

  The developing device 2 visualizes the electrostatic latent images formed on the respective photosensitive drums 3 with toners of each color (K, C, M, Y).

  The cleaner unit 4 includes a cleaning blade (not shown) as a cleaning member that removes and collects toner remaining on the surface of the photosensitive drum 3 after development and image transfer as waste toner. Here, the waste toner collected by the cleaner unit 4 is transported to a waste toner collection container 30 (not shown in FIG. 1; see FIGS. 2 to 6 described later) by a waste toner transport mechanism 20 described later. The transport of waste toner to the waste toner collection container 30 by the waste toner transport mechanism 20 will be described later.

  An intermediate transfer belt unit 8 is disposed above the photosensitive drum 3. The intermediate transfer belt unit 8 includes an intermediate transfer belt driving roller 81, intermediate transfer belt tension rollers 83 and 83, and an intermediate transfer belt driven in addition to the intermediate transfer belt 7, the intermediate transfer roller 6, and the intermediate transfer belt cleaning unit 9. A roller 82 is provided.

  The intermediate transfer belt drive roller 81, intermediate transfer belt tension rollers 83 and 83, intermediate transfer roller 6, intermediate transfer belt driven roller 82, and other rollers stretch and support the intermediate transfer belt 7. Can be moved in a predetermined direction (arrow D direction in the figure).

  The intermediate transfer roller 6 is rotatably supported on the side opposite to the photosensitive drum 3 with the intermediate transfer belt 7 interposed therebetween. The intermediate transfer roller 6 gives a transfer bias to the intermediate transfer belt 7 for the toner image on the photosensitive drum 3.

  The intermediate transfer belt 7 is provided so as to come into contact with the respective photosensitive drums 3, and the toner images of the respective colors formed on the photosensitive drums 3 are sequentially transferred onto the intermediate transfer belt 7. Thus, a color toner image (multicolor toner image) is formed on the intermediate transfer belt 7. Here, the intermediate transfer belt 7 is formed in an endless shape using a film having a thickness of about 100 μm to 150 μm.

  The toner image is transferred from the photosensitive drum 3 to the intermediate transfer belt 7 by the intermediate transfer roller 6 that is in contact with the back side of the intermediate transfer belt 7 (that is, the side opposite to the photosensitive drum 3 of the intermediate transfer belt 7). Done. The intermediate transfer roller 6 has a high-voltage transfer bias for transferring the toner image to the intermediate transfer belt 7, that is, a high-voltage transfer having a polarity (for example, a positive electrode) opposite to the toner charging polarity (for example, a negative electrode). A bias is applied. Here, the intermediate transfer roller 6 is based on a rotating shaft made of a metal having a diameter of 8 mm to 10 mm (for example, stainless steel), and the surface thereof is made of a conductive elastic material (for example, a material such as EPDM or urethane foam). ). The intermediate transfer roller 6 can apply a high voltage uniformly to the intermediate transfer belt 7 by the conductive elastic material. In this embodiment, a roller-shaped transfer electrode is used. However, the present invention is not limited to this, and a brush-shaped electrode can also be used.

  As described above, the toner image visualized with the toner of each color on the photosensitive drum 3 by the image data corresponding to the document read by the document reading device B or the image data received from the outside is an intermediate image. Laminated with the transfer belt 7. The toner images of the respective colors stacked in this manner are transferred to the sheet by the secondary transfer unit 11 disposed at the transfer portion where the sheet P and the intermediate transfer belt 7 face each other by the surface movement of the intermediate transfer belt 7 in the direction of arrow D. Transferred onto P.

  The intermediate transfer belt 7 and the transfer belt 11a of the secondary transfer unit 11 are pressed against each other to form a nip region. Also, the transfer belt 11a of the secondary transfer unit 11 has a voltage (that is, a negative polarity) opposite to the voltage for transferring the toner image of each color on the intermediate transfer belt 7 onto the paper P, that is, the toner charging polarity (for example, a negative electrode). For example, a positive electrode) voltage is applied. Further, in order to constantly obtain the nip region, either the roller of the secondary transfer unit 11 or the intermediate transfer belt drive roller 81 is made of a hard material such as a metal roller, and the other is a soft material such as an elastic roller. (For example, soft materials such as elastic rubber and foamable resin).

  By the way, the toner image of each color on the intermediate transfer belt 7 may not be completely transferred onto the paper P by the secondary transfer unit 11, and the toner may remain on the intermediate transfer belt 7. This residual toner causes toner color mixing in the next step.

  Therefore, the intermediate transfer belt cleaning unit 9 is configured to remove and collect the residual toner as waste toner. For example, the intermediate transfer belt cleaning unit 9 includes a cleaning blade (not shown) that contacts the intermediate transfer belt 7 as a cleaning member. The cleaning blade is supported on the back side of the intermediate transfer belt 7 at a position facing the intermediate transfer belt driven roller 82 (that is, the side opposite to the driven roller 82 of the intermediate transfer belt 7). The waste toner collected by the intermediate transfer belt cleaning unit 9 is transported to the waste toner collection container 30 by the waste toner transport mechanism 20 as in the case of the cleaning unit 4.

  The paper feed tray 10 is a tray for storing the paper P, and is provided below the image forming unit 100 of the image forming apparatus A. The discharge unit 15 is provided on the lower side of the document reading device B. In the present embodiment, the discharge unit 15 includes a discharge tray 15a. The paper discharge tray 15a is a tray for placing printed paper P face down.

  Further, the main image forming apparatus A is provided with a substantially S-shaped main transport path S1 for feeding the paper P in the paper feed tray 10 to the paper discharge tray 15a via the secondary transfer unit 11 and the fixing device 12. It has been.

  Further, a pickup roller 16, a registration roller 14, and a fixing device 12 are disposed along the main conveyance path S1 from the paper feed tray 10 to the paper discharge tray 15a.

  The pickup roller 16 is a pull-in roller that is provided at the end of the paper feed tray 10 and supplies the paper P from the paper feed tray 10 to the main transport path S1 one by one.

  The registration roller 14 temporarily stops the paper P conveyed from the paper feed tray 10 and aligns the leading ends of the paper P. The registration roller 14 has a function of conveying the paper P in a timely manner in synchronization with the toner image on the intermediate transfer belt 7.

  For example, the registration roller 14 conveys the paper P so that the image position of the toner image on the photosensitive drum 3 matches the image position on the paper P based on a detection signal from a pre-registration detection switch (not shown). It has become.

  The fixing device 12 fixes the toner image formed on the paper P by heating and melting and fixing the toner image on the paper P, and includes a pair of fixing rollers 31 and 32. The pair of fixing rollers 31 and 32 can rotate with the paper P interposed therebetween, and at least one of them is a heating roller having a heat source 33. In the present embodiment, both of the pair of fixing rollers 31 and 32 are heating rollers.

The pair of fixing rollers 31 and 32 are controlled so as to reach a predetermined fixing temperature based on a signal from the temperature detector 34. The pair of fixing rollers 31 and 32 has a function of thermally fixing the paper P to the paper P by fusing, mixing, and pressing the multicolor toner image transferred to the paper P by thermocompression bonding of the paper P. .
(Description of waste toner transport by waste toner transport mechanism)
Next, the waste toner conveyance by the waste toner conveyance mechanism 20 will be described. FIG. 2 schematically shows a configuration in which the waste toner recovered by the cleaner unit 4 (4a, 4b, 4c, 4d) and the intermediate transfer belt cleaning unit 9 is transported to the waste toner recovery container 30 by the waste toner transport mechanism 20. FIG. FIG. 3 is a side view including a partial longitudinal sectional view of the waste toner transport mechanism 20 shown in FIG.

  As shown in FIG. 2, the cleaner unit 4 (4a, 4b, 4c, 4d) of each image forming station has a cleaning member (not shown) that removes toner remaining on the surface of the photosensitive drum 3 as waste toner. A recovery screw 41 (41a, 41b, 41c, 41d) for recovering the waste toner removed by the cleaning member, and a width direction of each image forming station (axial direction of the photoreceptor 3) from one side to the other side. And a conveyance path 42 (42a, 42b, 42c, 42d) extending in the direction.

  The intermediate transfer belt cleaning unit 9 includes a cleaning member (not shown) that removes toner remaining on the surface of the intermediate transfer belt 7 as waste toner, and a collection screw 91 that collects waste toner removed by the cleaning member. And a conveyance path 92 extending from one side to the other side in the width direction of the intermediate transfer belt 7 (the axial direction of the intermediate transfer roller 6).

  The recovery screws 41 and 91 are pivotally supported on the rotation shafts 41 ′ and 91 ′, respectively, and are disposed in the transport paths 41 and 92 so as to be rotatable around the axis. The collection screws 41 and 91 are rotationally driven to convey the waste toner from the one end side to the other end side along the first conveyance direction (X direction in FIG. 2).

  The transport paths 42 and 92 are connected to a later-described waste toner transport path 21 of the waste toner transport mechanism 20 at the downstream end portion in the first transport direction X of the waste toner. Discharge ports 42x and 92x are formed at the downstream ends of the transport paths 42 and 92, respectively. The waste toner transport path 21 is provided with an opening 21 x at a position corresponding to each of the discharge ports 42 x and 92 x of the transport paths 42 and 92. The discharge ports 42x and 92x of the transport paths 42 and 92 communicate with the opening 21x of the waste toner transport path 21 at the downstream end. In FIG. 3, the opening 21x of the waste toner conveyance path 21 is not shown.

  In the cleaner unit 4 and the intermediate transfer belt cleaning unit 9, waste toners generated on the photosensitive drum 3 and the intermediate transfer belt 7 are mixed with unnecessary materials such as paper powder and dust, respectively. As described above, the waste toner is in a state in which the fluidity of the toner is deteriorated due to the loss of the original fluidity of the toner by mixing unnecessary materials such as paper powder and dust. The waste toner is collected by a cleaning member (not shown) that is in contact with the photosensitive drum 3 and the intermediate transfer belt 7 and is collected on one side in the width direction by the collection screws 41 and 91 in the cleaning unit 4 and the intermediate transfer belt cleaning unit 9. To the waste toner transport mechanism 20 along the other side (first transport direction X). The waste toner transport mechanism 20 is provided with a waste toner transport path (here, a pipe-shaped transport path) 21 and a waste toner transport member 22 disposed in the waste toner transport path 21 so as to be rotatable about an axis. Yes.

  The waste toner conveyed from the cleaner unit 4 and the intermediate transfer belt cleaning unit 9 is conveyed by the rotation around the axis of the waste toner conveyance member 22 disposed in the waste toner conveyance path 21, and is disposed in a waste toner collection container 30 (here In the waste toner collection box).

  At this time, as described above, the waste toner is in a state in which the fluidity is lowered, and is easily agglomerated in the waste toner conveyance path 21, and is in a state where clogging phenomenon and blocking phenomenon are likely to occur. In the waste toner transport mechanism 20 according to the embodiment of the invention, as shown in FIG. 3, the waste toner transport member 22 includes a rotating shaft 221, a transport screw 222, and an elastic member 223. The rotating shaft 221 is operatively connected to the drive source 40 (see FIG. 2). Here, the rotary shaft 221 is connected to the drive source 40 via a drive transmission mechanism 41 such as a gear 41a, and is driven to rotate around the axis line via the drive transmission mechanism 41 by the drive rotation of the drive source 40. It is like that. Specifically, a gear 41 a constituting the drive transmission mechanism 41 is attached to one end portion of the rotating shaft 221.

  In the present embodiment, the recovery screws 41 and 91 in the cleaner unit 4 and the intermediate transfer belt cleaning unit 9 are used from the viewpoint of making the image forming apparatus A compact, unifying the drive source 40 and saving power. The waste toner conveyance member 22 in the waste toner conveyance path 21 is configured to rotate integrally, and is configured to be driven by the same drive source 40.

  The conveying screw 222 is formed in a spiral shape along the axial direction, and is supported by the rotating shaft 221. Specifically, the conveying screw 222 has a spiral inner end fixedly supported on the outer peripheral surface of the rotating shaft 221. As a result, the transport screw 222 rotates around the axis along with the rotation of the rotating shaft 221, thereby causing the waste toner transported from the cleaner unit 4 and the intermediate transfer belt cleaning unit 9 to be on one end side (in this case, driven). It conveys along the 2nd conveyance direction (Y direction in a figure) from the side to the other end part side (specifically elastic member 223 side).

  The elastic member 223 is held so as not to rotate relative to the rotation shaft 221 or the conveying screw 222 around the axis. Note that the elastic member 223 is held by the conveying screw 222 here. Hereinafter, although the structure when the elastic member 223 is hold | maintained at the conveyance screw 222 is demonstrated, the case where the elastic member 223 is hold | maintained at the rotating shaft 221 can be comprised similarly.

   According to the waste toner conveying mechanism 20 having such a configuration, the elastic member 223 is held by the conveying screw 222, and the elastic member 223 is rotated by the rotational force of the drive source 40 via the rotating shaft 221 and the conveying screw 222, thereby being elastic. By causing the elastic member 223 to vibrate during rotation with the elastic force of the member 223, the fluidity of the conveying screw 222 decreases due to paper dust, etc. “The apparent fluidity can be restored and the waste toner collecting container 30 can be conveyed in this state. Therefore, it is possible to avoid the clogging phenomenon in the waste toner transport path 21, thereby improving the transport performance of the waste toner to the waste toner collection container 30.

  In the present embodiment, as described above, the recovery screws 41 and 91 in the cleaning devices 4 and 9 and the waste toner transport member 22 in the waste toner transport path 21 are configured to rotate integrally. At the same time, they are configured to be driven by the same drive source 40. In such a configuration, the waste toner transport mechanism 20 according to the embodiment of the present invention is particularly effective.

  More specifically, the waste toner conveyance mechanism 20 according to the embodiment of the present invention will be described. The conveyance screw 222 leaves a partial region α along the axial direction of the rotation shaft 221 in the waste toner conveyance path 22. The rotary shaft 221 is pivotally supported. That is, the rotating shaft 221 has a region (region for inserting the elastic member 223) α in which the conveying screw 222 does not exist in the axial direction in the waste toner conveying path 22.

  Here, the elastic member 223 is formed of a coil spring, and is inserted into a partial region α of the rotating shaft 221 with a gap between the outer peripheral surface of the rotating shaft 221 and the inner peripheral surface of the coil. The coil spring 223 is held so as not to rotate relative to the conveying screw 222 around the axis. As a result, the waste toner can be conveyed by the conveying action of the conveying screw 222 fixedly supported by the rotating shaft 221 and the coil spring 223 is rotated during the rotation of the rotating shaft 221 by the elastic force of the coil spring 223. By vibrating, it is possible to increase the effect of removing the waste toner and to improve the waste toner conveyance performance. In addition, the coil spring 223 can reduce the driving load compared to the driving load of the conveying screw 222. Thereby, power saving of the drive source 40 can be achieved.

  Furthermore, in the present embodiment, the coil spring 223 has one end 223 a at the coil spring side end of the conveying screw 222 in order to cause the coil spring 223 to vibrate more efficiently by the rotation of the rotating shaft 221 by the drive source 40. While being held by 222a, the other end 223b is free. In this way, the coil spring 223 includes a holding portion (one end portion) 223a that is held with respect to the conveying screw 222 and a free end portion (the other end portion) when the rotating shaft 221 is rotated by the driving rotation of the driving source 40. ) 223b can be vibrated by an elastic force between the coil spring 223b and the coil spring 223 has a [compressed and stretched] action as a spring characteristic during driving rotation. The toner conveyance performance can be improved.

  In the present embodiment, the partial region α of the rotating shaft 221 is located at the waste toner conveyance terminal position (second waste toner conveyance direction Y downstream end position) β of the waste toner conveyance member 22, A coil spring 223 is inserted into a partial region α located at the conveyance end position β. Here, a coil spring 223 is attached to the other end side opposite to the drive side away from the drive side (one end side) of the rotating shaft 221. As a result, in the second toner transport direction Y of the waste toner by the waste toner transport member 22, it is possible to cause a phenomenon to be solved with respect to the waste toner on the downstream side of the waste toner transport path 21, and a clogging phenomenon or a blocking phenomenon occurs. Can be effectively prevented.

  In the present embodiment, the coil spring 223 rotates with the rotation of the rotating shaft 221 due to the driving rotation of the driving source 40 and swings so as to allow frictional contact with the inner peripheral surface of the waste toner conveyance path 21. It is supposed to be free.

  4 is a side view including a partial vertical sectional view showing the coil spring 223 in an enlarged manner in the waste toner transport mechanism 20 shown in FIG. FIG. 5 is a side view including a partial longitudinal sectional view showing a state in which the coil outer peripheral surface 223 ′ of the coil spring 223 is in frictional contact with the inner peripheral surface 21 ′ of the waste toner conveying path 21.

  As shown in FIG. 4, the coil spring 223 rotates with the rotation of the rotation shaft 221 and allows frictional contact with the inner peripheral surface 21 ′ of the waste toner conveyance path 21 with the rotation of the rotation shaft 221. As described above, it is held so as to be swingable about a swing axis along a direction crossing the axial direction with respect to the conveying screw 222 (here, a direction substantially orthogonal to the axial direction).

  Specifically, the coil spring 223 has a rocking shaft 223c along the direction in which one end 223a crosses the coil spring side end 222a of the conveying screw 222 in the axial direction (here, a direction substantially orthogonal to the axial direction). And is swingably supported around the swing shaft 223c.

  A support portion (here, a through-hole through which the swing shaft 223 c is inserted) 222 b that rotatably supports the swing shaft 223 c of the coil spring 223 is provided at the coil spring side end portion 222 a of the conveying screw 222. . The coil outer diameter (d1 in FIG. 4) of the coil spring 223 is smaller than the inner diameter d2 of the waste toner conveyance path 21 by a predetermined amount (d ′ = d3 + d3). Note that a stopper 223 d for preventing detachment from the support portion 222 b of the conveying screw 222 is provided on the swing shaft 223 c of the coil spring 223.

  In the waste toner conveyance mechanism 20 having such a configuration, when the rotation shaft 221 rotates around the axis along with the conveyance screw 222 by the drive rotation of the drive source 40, the coil spring 223 rotates with the rotation as shown in FIG. At the same time, the swinging shaft 223c supported by the coil spring side end portion 222a of the conveying screw 222 swings around the swinging fulcrum. As a result, the coil spring 223 rotates around the axis of the rotary shaft 221, and a part of the coil outer peripheral surface 223 ′ in the circumferential direction has no gap with the inner peripheral surface 21 ′ of the waste toner conveyance path 21, so The surface 21 'is rubbed into frictional contact. At this time, a gap d ′ is provided between the side opposite to the frictional contact portion of the coil spring 223 with respect to the rotation shaft 221 and the inner peripheral surface 21 ′ of the waste toner conveyance path 21.

  According to the waste toner transport mechanism 20 configured as described above, the coil spring 223 includes the inner periphery of the waste toner transport path 21 in accordance with the rotation of a part of the coil outer peripheral surface 223 ′ around the axis of the rotation shaft 221. Since it rotates in a form of frictional contact with the surface 21 ′, the inner peripheral surface 21 ′ of the waste toner transport path 21 is caused by the cleaning effect (removal effect) of the waste toner adhering to the inner peripheral surface 21 ′ of the waste toner transport path 21. It is possible to scrape off the waste toner that easily accumulates in the toner, and it is possible to eliminate the cause of the increase in the driving load caused by the growth of the waste toner on the inner wall surface 21 ′.

  Here, the free end portion 223b, which is the other end portion of the coil spring 223, is brought into frictional contact with the inner side surface (the inner surface on the downstream side in the second waste toner transport direction) 21 "of the waste toner transport path 21 here. In addition, the spiral direction of the coil spring 223 is set to be opposite to the spiral direction of the conveying screw 222 here.

  In the present embodiment, the waste toner conveyance path 21 is provided with an opening 21 a at least partly along the axial direction and partly in the circumferential direction in the region γ corresponding to the coil spring 223. The waste toner transport mechanism 20 is configured such that the waste toner transported by the waste toner transport member 22 is collected in the waste toner collection container 30 from the opening 21a. Here, the waste toner conveyance path 21 is provided with a guide member 21 b that guides the waste toner conveyed by the waste toner conveyance member 22 from the opening 21 a to the waste toner collection container 30.

  Incidentally, the wire diameter of the coil spring 223 (the diameter of the wire constituting the coil spring 223) greatly affects the waste toner conveyance performance. In other words, if the wire diameter of the coil spring 223 is too small compared to the amount of waste toner, the entire area of the wire is covered by the waste toner, thereby substantially eliminating the waste toner conveyance performance. On the other hand, if the wire diameter of the coil spring 223 is too large compared to the amount of waste toner, the waste toner will be rubbed between the wire and the inner peripheral surface 21 ′ of the waste toner conveyance path 21, thereby causing the waste toner to generate heat. There is a risk of adhering and fusing to the coil spring 223. For this reason, it is preferable that the wire diameter of the coil spring 223 is determined in accordance with the collection amount of waste toner to be conveyed (for example, the collection amount of waste toner per unit time). Thus, by determining the amount of waste toner collected according to the wire diameter (thickness) of the coil spring 223, it becomes possible to facilitate the design of the waste toner collection mechanism 20.

  FIG. 6 shows the wire diameter when the black waste toner is conveyed in the coil spring 223 of the waste toner collecting mechanism 20 according to the embodiment of the present invention, compared with the diameter when the yellow, magenta, and cyan waste toners are conveyed. It is a figure which shows the example made thick.

  In a color image forming apparatus, the amount of black toner used is usually larger than that of color toners such as yellow, magenta, and cyan, and the amount of waste toner transported is also large in black. Therefore, in order to increase the toner conveyance amount, the conventional method has been to increase the size of the waste toner collection mechanism. However, in the waste toner collection mechanism 20 according to the embodiment of the present invention, the waste toner is intended to increase the toner conveyance amount. This can be dealt with by simply increasing the diameter φ of the coil spring 223 (see FIG. 6B) in the conveying member 22 (for example, the black waste toner conveying member 22).

  Accordingly, in the waste toner collecting mechanism 20 according to the embodiment of the present invention, the waste toner having the same shape in which only the diameter of the coil spring 223 is different by appropriately determining the wire diameter of the coil spring 223 according to the amount of waste toner collected. The collection mechanism 20 can efficiently collect the waste toner of each color.

  In the example shown in FIG. 6, the diameter φ (see FIG. 6A) of the coil spring 223 of the yellow, magenta, and cyan waste toner conveying member 22 is set to the diameter φ of the coil spring 223 of the black waste toner conveying member 22 (see FIG. 6). 6 (b)), the waste toner collecting mechanism having the same shape in which only the diameter of the coil spring 223 is different between the waste toner conveying member 22 for yellow, magenta, and cyan and the waste toner conveying member 22 for black. 20, waste toners of all colors of yellow, magenta, cyan and black can be efficiently collected.

  Further, as a large determining factor for determining the wire diameter φ of the coil spring 223, the image forming processing speed and transfer efficiency of the image forming apparatus A can be exemplified.

  For example, the wire diameter of the coil spring 223 is not limited thereto, but is generally about 5 mm to 8 mm for a low speed machine having a peripheral speed of the photosensitive member 3 of 300 mm / sec or less (about 50 sheets / min. For a medium-speed machine and a high-speed machine that are faster than that, about 8 mm to 12 mm can be exemplified. As described above, by using the coil spring 223 whose wire diameter is determined according to the image forming processing speed which is one of the factors for determining the amount of waste toner, the waste toner can be efficiently conveyed to the waste toner collection container 30. It becomes possible.

  Further, the image processing apparatus A includes a control unit (not shown). The control unit includes a CPU and a memory such as a ROM and a RAM. The CPU reads various control programs from the memory, and executes the read control programs to perform image formation processing and various control. Is configured to do.

  Then, according to the control program, the control unit rotates and rotates the rotation shaft 221 during the warm-up of the image forming apparatus A, during the pre-rotation of the image forming process, during the image forming process, and during the rotation after the image forming process. Thus, the drive source 40 is controlled. Thereby, the waste toner can be transported satisfactorily by the waste toner transport mechanism 20.

  In the image forming apparatus A of the present embodiment, the toner image on the electrostatic latent image carrier 3 is temporarily transferred onto the intermediate transfer member 7 once, and then the toner image on the intermediate transfer member 7 is further transferred to the sheet P. The toner image on the electrostatic latent image carrier 3 may be directly transferred onto the paper P.

1 is a front view illustrating a schematic configuration of an image forming apparatus including a waste toner conveyance mechanism according to an embodiment of the present invention. FIG. 6 is a diagram schematically illustrating a configuration in which waste toner collected by a cleaner unit and an intermediate transfer belt cleaning unit is conveyed to a waste toner collection container by a waste toner conveyance mechanism. FIG. 3 is a side view including a partial vertical cross-sectional view of the waste toner conveying mechanism shown in FIG. 2. FIG. 4 is a side view including a partial longitudinal sectional view showing an enlarged coil spring portion in the waste toner conveying mechanism shown in FIG. 3. FIG. 5A is a side view including a partial longitudinal sectional view showing a state in which the outer peripheral surface of the coil spring is in frictional contact with the inner peripheral surface of the waste toner conveyance path. FIG. It is a figure which shows the one state which moves, and figure (b) is a figure which shows the other state in which a coil spring rocks | fluctuates with respect to a conveyance screw. The figure which shows the example which made the wire diameter in the case of conveying black waste toner thicker than the wire diameter in the case of conveying the waste toner of yellow, magenta, and cyan in the coil spring in the waste toner collection | recovery mechanism based on implementation of this invention. FIG. 1A is a diagram illustrating an example of a waste toner recovery mechanism that transports yellow, magenta, and cyan waste toner, and FIG. 2B illustrates a waste toner recovery mechanism that transports black waste toner. It is a figure which shows an example.

Explanation of symbols

3,7 Toner carrier (photosensitive drum, intermediate transfer belt)
20 Waste toner transport mechanism 21 Waste toner transport path 21a Opening 21 'Internal surface 22 of waste toner transport path Waste toner transport member 30 Waste toner collection container (waste toner collection box)
40 Drive source 221 Rotating shaft 222 Conveying screw 223 Elastic member (coil spring)
223a Coil spring holding portion 223b Coil spring free end 223c Oscillating shaft A Image forming apparatus α Partial region of the rotation shaft β Waste toner conveyance end position γ Region corresponding to the coil spring φ Coil spring wire diameter

Claims (9)

In the image forming apparatus, a waste toner transport mechanism that transports waste toner generated on the toner carrier toward a waste toner collection container,
A waste toner transport path, and a waste toner transport member disposed in the waste toner transport path so as to be rotatable about an axis,
The waste toner conveying member includes a rotating shaft operatively connected to a driving source, a conveying screw supported by the rotating shaft, and an elastic member held by the rotating shaft or the conveying screw. A waste toner transport mechanism. The conveying screw is pivotally supported so as to leave a partial region along the axial direction of the rotating shaft in the waste toner conveying path,
The waste toner conveying mechanism according to claim 1, wherein the elastic member includes a coil spring that is inserted into the partial region of the rotating shaft.   3. The waste toner transport mechanism according to claim 2, wherein one end of the coil spring is held by a coil spring side end of the transport screw or the rotating shaft, and the other end is free. .   The coil spring vibrates between a holding portion held with respect to the conveying screw or the rotating shaft and a free end when the rotating shaft rotates by driving rotation of the driving source. The waste toner conveying mechanism according to claim 3.   5. The waste toner transport mechanism according to claim 2, wherein the partial region of the rotation shaft is located at a waste toner transport terminal position of the waste toner transport member.   The coil spring rotates in accordance with the rotation of the rotation shaft by the drive rotation of the drive source, and is swingable so as to allow frictional contact with the inner peripheral surface of the waste toner conveyance path. The waste toner conveying mechanism according to claim 2, wherein:   7. The waste toner transport mechanism according to claim 2, wherein a wire diameter of the coil spring is determined according to a collection amount of waste toner to be transported.   The waste toner transport path has an opening provided in a region corresponding to the coil spring, and waste toner transported by the waste toner transport member is collected from the opening into the waste toner collection container. The waste toner transport mechanism according to claim 2, wherein the waste toner transport mechanism is configured as described above. An image forming apparatus comprising: the waste toner transport mechanism according to claim 1; and a drive source for rotationally driving the rotation shaft of the waste toner transport mechanism.
The image forming apparatus is characterized in that the drive source is driven and rotated during warm-up of the image forming apparatus, before the image forming process, during the image forming process, and after the image forming process.

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