JP6117686B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a collection container for collecting waste toner.

  As an image forming apparatus, a copying machine, a printer, a facsimile, and the like are known. Some image forming apparatuses form (print) images (toner images) on transfer paper using toner. Some image forming apparatuses transfer a toner image from a photoconductor to a transfer sheet. Some other image forming apparatuses first transfer a toner image from a photosensitive member to an intermediate transfer belt, and then transfer the toner image from the intermediate transfer belt to a transfer sheet.

  The toner may remain on the photoreceptor without being transferred during the printing operation. Similarly, toner may remain on the intermediate transfer belt. The remaining toner is called waste toner. The toner remaining on the photoconductor is dropped onto a waste toner transport path by a cleaning device installed in the photoconductor unit. The toner remaining on the intermediate transfer belt is dropped onto a waste toner conveyance path by a cleaning device installed in the intermediate transfer unit.

  A transport member for transporting the waste toner is disposed in the transport path for the waste toner. The conveying member is generally composed of a spiral blade. Waste toner is conveyed in the conveyance path by the rotation of the spiral blade. The waste toner conveyed in the conveyance path falls into the collection container. In this way, the waste toner is collected in the collection container.

  In order to increase the amount of waste toner that can be collected in the collection container, the following waste toner collection mechanism has been proposed (see Patent Document 1). In this waste toner collecting mechanism, a staying chamber is provided in front of the waste toner inlet. Waste toner is collected in the staying chamber. The collected waste toner is compressed and solidified, and then dropped into a collection container. Specifically, the receding rod is disposed in the waste toner conveyance path so as to face the tip of the spiral blade. The receding trap usually closes the waste toner inlet. Furthermore, a compression spring is arranged behind the retracting rod. The compression spring elastically biases the receding rod toward the tip of the spiral blade. A retention chamber is formed between the tip of the spiral blade and the receding rod. Waste toner is collected in the retention chamber by the rotation of the spiral blade.

  This waste toner collecting mechanism has been proposed with the expectation of the following action. That is, when the staying chamber becomes full of waste toner, the receding trap is pushed in the direction in which the conveying force of the spiral blade acts via the waste toner in the staying chamber. On the other hand, the receding rod is elastically biased by a compression spring in a direction against the conveying force of the spiral blade. Therefore, the waste toner in the staying chamber is compressed by the clamping pressure. When the waste toner in the staying chamber is compressed and solidified, the receding rod moves backward in the direction in which the conveying force of the spiral blade acts by the conveying force of the spiral blade. As a result, the waste toner inlet is opened, and the waste toner compressed and solidified falls into the collection container.

  According to the waste toner collecting mechanism disclosed in Patent Document 1, since the waste toner is compressed, the waste toner can be collected in the collection container by increasing the density of the waste toner. Therefore, the amount of waste toner that can be collected in the collection container increases. That is, in a general waste toner recovery mechanism, the waste toner transported along the transport path falls into the recovery container as it is. On the other hand, according to the waste toner collecting mechanism disclosed in Patent Document 1, the waste toner collected and compressed in the retention chamber falls into the collection container. Therefore, since the waste toner can be collected in the collection container by increasing the density of the waste toner as compared with a general waste toner collection mechanism, the amount of waste toner that can be collected in the collection container increases.

JP-A-5-158385

  As described above, Patent Document 1 discloses a waste toner collection mechanism for increasing the amount of waste toner that can be collected in a collection container. However, in actuality, in the waste toner collecting mechanism disclosed in Patent Document 1, the receding rod cannot be retracted by the conveying force of the spiral blade, and when the staying chamber is filled with waste toner, each blade constituting the spiral blade During this time, the waste toner stays. Therefore, the waste toner cannot be collected in the collection container by increasing the density of the waste toner.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of increasing the amount of waste toner that can be collected in a collection container.

  In order to solve the above problems, the present invention has the following gist. In other words, the image forming apparatus of the present invention includes a collection container, a waste toner retention portion, and a conveying member. A waste toner inlet is formed in the recovery container. The waste toner retention portion is provided in the vicinity of the waste toner inlet. The conveyance member conveys waste toner to the waste toner retention portion. The waste toner transported by the transport member pushes the waste toner accumulated in the waste toner retention portion. As a result, the waste toner aggregated in the waste toner retention portion falls to the waste toner inlet and is collected into the collection container.

  According to the present invention, the amount of waste toner that can be collected in the collection container can be increased.

1 is a cross-sectional view showing an internal structure of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view schematically illustrating a waste toner recovery mechanism according to Embodiment 1 of the present invention. FIG. 6 is a cross-sectional view for explaining the operation of the waste toner transport mechanism according to Embodiment 1 of the present invention. It is sectional drawing which shows a general waste toner collection | recovery mechanism typically. It is sectional drawing which shows typically the waste toner collection | recovery mechanism which concerns on Embodiment 2 of this invention. FIG. 9 is a cross-sectional view for explaining the operation of a waste toner transport mechanism according to Embodiment 2 of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, in the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof is not repeated. The thickness, length, number, and the like of each illustrated component are different from actual ones for the convenience of drawing. Note that the materials, shapes, dimensions, and the like of the components shown in the following embodiments are merely examples and are not particularly limited, and various changes can be made without departing from the effects of the present invention. It is.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing an internal structure of an image forming apparatus 1 according to Embodiment 1 of the present invention. Here, the image forming apparatus 1 is exemplified by a multifunction machine having a printer function and a copying function, but the image forming apparatus may be, for example, a printer, a copying machine, or a facsimile machine.

[Configuration of Image Forming Apparatus 1]
The image forming apparatus 1 includes an apparatus main body 10 and an automatic document feeder 20. The automatic document feeder 20 is disposed on the apparatus main body 10. Inside the apparatus main body 10, a reading unit 25, an image forming unit 30, a fixing unit 60, a paper feeding unit 40, and a conveyance path 50 are accommodated. The reading unit 25 optically reads a document image to be copied. The image forming unit 30 forms a toner image on the transfer paper P. The fixing unit 60 fixes the toner image on the transfer paper P. The paper feed unit 40 stores the standard transfer paper P conveyed to the image forming unit 30. The conveyance path 50 is a path through which the transfer sheet P is conveyed from the sheet feeding unit 40 or the manual sheet feeding unit 46 to the transfer sheet discharge port 10 </ b> A via the image forming unit 30 and the fixing unit 60.

  An automatic document feeder (ADF) 20 is rotatably attached to the upper surface of the apparatus body 10. The ADF 20 automatically feeds a document sheet to be copied toward a predetermined document reading position in the apparatus main body 10. When the user manually places the document sheet on a predetermined document reading position, the ADF 20 is opened upward.

  The reading unit 25 passes through a first contact glass for reading a document sheet automatically fed from the ADF 20 on the upper surface of the apparatus main body 10 or a second contact glass for reading a manually placed document sheet. Is read optically. However, neither the first nor second contact glass is shown.

  The image forming unit 30 transfers the full-color toner image onto the transfer paper P. The image forming unit 30 includes an image forming unit 32, an intermediate transfer unit 33, and a toner supply unit 34. The image forming unit 32 includes four image forming units 32Y, 32M, 32C, and 32Bk that form toner images of respective colors of yellow Y, magenta M, cyan C, and black Bk.

  Each of the image forming units 32Y, 32M, 32C, and 32Bk includes a photosensitive drum 321, a charger 322, an exposure device 323, a developing device 324, a primary transfer roller 325, and a cleaning device 326. The charger 322, the exposure device 323, the developing device 324, the primary transfer roller 325, and the cleaning device 326 are disposed around the photosensitive drum 321.

  An electrostatic latent image and a toner image are formed on the peripheral surface of the rotating photosensitive drum 321. The charger 322 uniformly charges the peripheral surface of the photosensitive drum 321. The exposure device 323 irradiates the circumferential surface of the photosensitive drum 321 with light based on the image data of the document image. Thereby, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 321. The developing device 324 supplies toner to the circumferential surface of the photosensitive drum 321 in order to develop the electrostatic latent image.

  The primary transfer roller 325 forms a primary transfer nip portion together with the photosensitive drum 321 with the intermediate transfer belt 331 interposed therebetween. The intermediate transfer belt 331 is provided in the intermediate transfer unit 33. The primary transfer roller 325 primarily transfers the toner image formed on the peripheral surface of the photosensitive drum 321 to the intermediate transfer belt 331.

  The cleaning device 326 includes a cleaning blade and / or a fur brush. Even after the toner image is transferred, the toner may remain on the peripheral surface of the photosensitive drum 321. The remaining toner (waste toner) is removed from the peripheral surface of the photosensitive drum 321 by the cleaning device 326. The waste toner is dropped onto a waste toner conveyance path (not shown) disposed below the cleaning device 326, and then collected through a conveyance path into a collection container described later.

  The intermediate transfer unit 33 includes an intermediate transfer belt 331, a driving roller 332, a driven roller 333, and a cleaning device 334. The intermediate transfer belt 331 is an endless belt that is stretched between the driving roller 332 and the driven roller 333. Toner images are superimposed and transferred from each of the plurality of photosensitive drums 321 to the same position on the outer peripheral surface (transfer surface) of the intermediate transfer belt 331. Transfer of the toner image by the primary transfer roller 325 is called primary transfer.

  A secondary transfer roller 35 is disposed to face the peripheral surface of the drive roller 332. The secondary transfer roller 35 is an example of a transfer unit. The drive roller 332 and the secondary transfer roller 35 form a secondary transfer nip portion.

  The secondary transfer nip portion transfers the full-color toner image overcoated on the intermediate transfer belt 331 onto the transfer paper P. A secondary transfer bias potential is applied to one of the driving roller 332 and the secondary transfer roller 35, and the other roller is grounded. The secondary transfer bias potential is a potential having a polarity opposite to that of the toner image.

  The cleaning device 334 includes a cleaning blade and / or a fur brush. Even after the toner image is transferred, toner may remain on the outer peripheral surface of the intermediate transfer belt 331. The remaining toner (waste toner) is removed from the outer peripheral surface of the intermediate transfer belt 331 by the cleaning device 334. The waste toner is dropped onto a waste toner conveyance path (not shown) disposed below the cleaning device 334, and then collected through a conveyance path into a collection container described later.

  The toner supply unit 34 includes a yellow toner container 34Y, a magenta toner container 34M, a cyan toner container 34C, and a black toner container 34Bk. The toner containers 34Y, 34M, 34C, and 34Bk store toner of each color of yellow Y, magenta M, cyan C, and black Bk, respectively. The yellow Y, magenta M, cyan C, and black Bk toners are transferred from the toner containers 34Y, 34M, 34C, and 34Bk to the image forming units 32Y, 32M, 32C, and 32Bk developing devices 324 corresponding to the respective colors. , And supplied through a supply path (not shown).

  The paper feed unit 40 includes two stages of paper feed cassettes 40A and 40B. Each of the paper feed cassettes 40A and 40B accommodates a standard transfer paper P.

  A pickup roller 43, a paper feed roller 44, and a retard roller 45 are arranged on the upper right side of the paper feed cassette 40A. By driving the pickup roller 43 and the sheet feeding roller 44, the uppermost transfer sheet P in the sheet bundle 40A is fed out one by one. The transferred transfer paper P is carried into the upstream end of the transport path 50. Similarly to the paper feed cassette 40A, a pickup roller, a paper feed roller, and a retard roller are also arranged on the upper right side of the paper feed cassette 40B. In this specification, “right” and “left” indicate “right” and “left” on the paper surface of FIG.

  A manual paper feed unit 46 is disposed on the right side surface 10 </ b> R of the apparatus main body 10. The manual paper feed unit 46 includes a manual feed tray 46 </ b> A and a paper feed roller 461. When manual feeding is performed, the user opens the manual tray 46A as illustrated and places the transfer paper P on the manual tray 46A. The transfer paper P is carried into a manual sheet conveyance path extending from the manual feed tray 46 </ b> A by driving the paper feed roller 461 and the conveyance roller pair 462. Further, the transfer paper P is carried into the conveyance path 50 from the manual sheet conveyance path.

  The fixing unit 60 is an induction heating type fixing device. The fixing unit 60 includes a heating roller 61, a fixing roller 62, a pressure roller 63, a fixing belt 64, and an induction heating unit 65. A pressure roller 63 is pressed against the fixing roller 62 to form a fixing nip portion. The heating roller 61 and the fixing belt 64 are induction heated by the induction heating unit 65. Heat from the heating roller 61 and heat from the fixing belt 64 are applied to the fixing nip portion. When the transfer paper P passes through the fixing nip portion, the toner image is fixed on the transfer paper P.

[Waste toner recovery mechanism]
Further, the image forming apparatus 1 includes a waste toner collecting mechanism. However, the waste toner collecting mechanism is not shown in FIG. FIG. 2 is a cross-sectional view schematically showing the waste toner collecting mechanism 70 according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view for explaining the operation of the waste toner transport mechanism 72 according to the first embodiment of the present invention. Hereinafter, the waste toner collecting mechanism 70 will be described with reference to FIGS. 2 and 3.

  The waste toner collection mechanism 70 includes a collection container 71 and a waste toner transport mechanism 72. Waste toner 73 is collected in the collection container 71. The waste toner transport mechanism 72 transports the waste toner 73 to the collection container 71. The collection container 71 is disposed in a region below the image forming unit 30. The waste toner 73 includes toner removed from the peripheral surface of the photosensitive drum 321 by the cleaning device 326 and toner removed from the outer peripheral surface of the intermediate transfer belt 331 by the cleaning device 334.

  A waste toner inflow port 71 a is formed on the upper surface of the collection container 71. The waste toner inflow port 71 a opens in the vertical direction, and allows the internal space of the collection container 71 to communicate with the outside of the collection container 71.

  The waste toner transport mechanism 72 includes a transport path 74. The transport path 74 shown in FIGS. 2 and 3 is a path after the two transport paths for waste toner merge. A conveyance member that conveys the waste toner 73 is disposed in the conveyance path 74. In the first embodiment, the spiral blade 75 is disposed along the transport path 74 as the transport member. The spiral blade 75 is formed on the rotation shaft 76. The tip end of the rotating shaft 76 is rotatably supported by a bearing (not shown). The bearing is fixed to the housing 77 on the downstream side of the conveyance path 74. The pitch of the spiral blade 75 is, for example, 1 cm. When the rotating shaft 76 is rotated by a drive mechanism (not shown), the spiral blade 75 rotates around the rotating shaft 76. The waste toner 73 moves on the conveyance path 74 toward the waste toner inlet 71 a by the rotation of the spiral blade 75. The rotating shaft 76 may be omitted. However, since the spiral blade 75 is formed on the rotation shaft 76, the rotation of the spiral blade 75 is stabilized.

  The waste toner transport mechanism 72 includes a cylindrical body 77. The internal space of the cylinder 77 serves as a conveyance path 74. The cross-sectional shape of the inner surface of the housing 77 may be a cylindrical shape corresponding to the outer diameter of the spiral blade 75. In the drawing, the gaps between the inner surface of the casing 77 and the blades of the spiral blade 75 are shown larger than actual. For example, the gap between each blade of the spiral blade 75 and the inner surface of the housing 77 is smaller than the diameter of the waste toner 73.

  An opening 77 a is formed in the housing 77. The opening 77a connects the internal space of the housing 77, that is, the conveyance path 74 to the waste toner inflow port 71a.

  A waste toner retention portion 78 is provided in the conveyance path 74. The waste toner retention portion 78 is a portion of the housing 77 that is downstream of the conveyance path 74 and in front of the opening 77a. The length of the waste toner retaining portion 78 is, for example, 10 mm. The spiral blade 75 extends from the upstream side of the conveyance path 74 to the front of the waste toner retention portion 78. Accordingly, the spiral blade 75 is provided on the upstream side of the waste toner inflow port 71 a in the transport path 74. Therefore, the spiral blade 75 does not exist above the waste toner inflow port 71a.

  The spiral blade 75 conveys the waste toner 73 to the waste toner retention part 78 by rotating. As a result, the waste toner 73 stays in the waste toner retention part 78, and a waste toner mass 73 a is formed in the waste toner retention part 78. The waste toner lump 73a is an aggregate of waste toner 73 and is aggregated. Further, the waste toner 73 is sequentially sent to the waste toner retention part 78. Therefore, the waste toner mass 73 a is compressed by the subsequent waste toner 73. Aggregation occurs when the waste toner 73 is charged. Therefore, aggregation is charge aggregation.

  By sequentially sending the waste toner 73 to the waste toner retention part 78, the amount of the waste toner mass 73a reaches the limit of the amount of waste toner 73 that can be retained in the waste toner retention part 78, and the waste toner 73 A stage in which the mass 73a is pushed by the transported waste toner 73 occurs. At this time, as shown in FIG. 3, a part of the waste toner mass 73 a falls to the waste toner inlet 71 a and is collected inside the collection container 71. Waste toner 73 b falling into the collection container 71 is compressed and aggregated, and is larger than the waste toner 73 conveyed by the spiral blade 75. For example, the diameter of the waste toner 73b is about 1 to 2 mm. The length of the waste toner retention portion 78 is selected so that the diameter of the falling waste toner 73b is in millimeters.

  As described above, the waste toner lump 73a is formed in the waste toner retention portion 78, and the waste toner lump 73a is pushed by the subsequent waste toner 73, so that the waste toner 73b that has been compressed and aggregated becomes the waste toner. It is recovered from the inlet 71a to the inside of the recovery container 71. Therefore, even when the amount of waste toner 73 transported through the transport path 74 is very small, the waste toner 73 is recovered in the recovery container 71 by increasing the density of the waste toner 73 compared to before being compressed and aggregated. Therefore, the amount of waste toner 73 that can be collected in the collection container 71 can be increased.

  Particularly in recent years, the transfer efficiency of image forming apparatuses has been improved to 90 to 100%. For this reason, a very small amount of waste toner falls to the waste toner transport path by the cleaning device. The spiral blades are driven in accordance with the drive of the image forming apparatus, and the spiral blades are driven for many times other than during the toner image transfer operation. Therefore, in many cases, a very small amount of waste toner is conveyed along the conveyance path. On the other hand, according to the first embodiment, as described above, even when the amount of waste toner 73 conveyed through the conveyance path 74 is very small, the very small amount of waste toner 73 is recovered as it is. Instead of falling into the container 71, the compressed and agglomerated waste toner 73b falls into the collection container 71, so that the amount of waste toner 73 that can be collected in the collection container 71 can be increased.

  The collection container 71 is replaced with an empty collection container 71 as appropriate. Therefore, a shutter 79 may be provided as shown in FIG. 2 so that the waste toner 73 does not fall from the conveyance path 74 through the opening 77a when the collection container 71 is replaced. The shutter 79 is automatically closed when the collection container 71 is removed from the image forming apparatus 1. The shutter 79 is automatically opened when the collection container 71 is set in the image forming apparatus 1.

  Further, the image forming apparatus 1 may include an optical detector 80 in order to detect the amount of waste toner 73 in the collection container 71. The optical detector 80 includes a light emitting unit 80a and a light receiving unit 80b. For example, the light emitting unit 80a and the light receiving unit 80b are disposed in the vicinity of the waste toner inflow port 71a, so that it is possible to detect that the collection container 71 is full of the waste toner 73. In the first embodiment, as shown in FIG. 2, the light emitting unit 80a and the light receiving unit 80b are arranged in the vicinity of the waste toner inlet 71a.

  An LED or the like is used for the light emitting unit 80a. On the other hand, a photodiode or the like is used for the light receiving unit 80b. The light emitting unit 80a emits light L. The light receiving unit 80b is arranged to receive the light L.

  The light emitting unit 80 a emits light L toward the upper side wall of the collection container 71. A portion of the upper side wall of the collection container 71 that is irradiated with the light L from the light emitting unit 80a is provided with a transmissive member (not shown) that transmits light. The permeable member is made of the same material as the collection container 71.

  The light receiving unit 80b is disposed so as to face the light emitting unit 80a with the collection container 71 interposed therebetween. A portion of the upper side wall of the collection container 71 facing the light receiving unit 80b is provided with a transmissive member (not shown) that transmits light. The permeable member is made of the same material as the collection container 71.

  The light L is emitted from the light emitting unit 80a, passes through the transmissive members facing each other, and is received by the light receiving unit 80b. That is, the light L passes through the vicinity of the waste toner inlet 71a. Therefore, when the waste toner 73 (73b) is accumulated in the collection container 71 by the printing operation of the image forming apparatus 1 and the waste toner 73 (73b) is accumulated up to the vicinity of the waste toner inflow port 71a, the accumulated waste toner 73 (73b) emits light. L is blocked. As a result, the light receiving unit 80b does not receive the light L. Thereby, the full state of the collection container 71 is detected.

  When the light receiving unit 80b stops receiving the light L, the control unit (not shown) of the image forming apparatus 1 may display a warning display for warning the replacement of the collection container 71 on the display monitor (not shown). Alternatively, when the light receiving unit 80b does not receive the light L, the control unit (not shown) of the image forming apparatus 1 generates a warning sound for warning the replacement of the collection container 71 to the sound generation device (not shown). Also good.

  According to the first embodiment, the compressed and aggregated waste toner 73 b falls into the collection container 71. On the other hand, in a general waste toner recovery mechanism, when the amount of waste toner transported along the transport path is very small, the amount of waste toner that falls into the recovery container at a time is smaller than that in the first embodiment. Very small amount.

  When the amount of waste toner that falls into the collection container at a time is very small, the waste toner tends to adhere to the inner wall surface of the collection container in the internal space of the collection container. This is because the waste toner falling into the collection container is lightweight and charged, so that the influence of charging becomes larger than the influence of gravity. In other words, the force of the charge is superior to the force of dropping the waste toner, and the waste toner is moved by the force of charge in the internal space of the collection container. As a result, the waste toner drifts in the internal space of the collection container. Therefore, the waste toner is likely to adhere to the inner wall surface of the collection container in the internal space of the collection container.

  In particular, in recent years, the toner particle diameter has been reduced due to a demand for image quality improvement, and waste toner is more easily affected by charging. Further, when the printing rate is lowered, waste toner is likely to adhere to the inner wall surface of the collection container. This is because as the printing rate decreases, the printing amount decreases and the amount of waste toner decreases.

  In general, the collection container is made of a material that is easily charged, such as polyethylene. When the amount of waste toner that falls into the collection container at a time is very small, when the collection container is charged, the waste toner is attracted to the inner wall surface of the collection container and easily adheres to the inner wall surface of the collection container. Further, whether or not the waste toner easily adheres to the inner wall surface of the collection container depends on the environment such as temperature and humidity.

  Here, a general waste toner collecting mechanism will be described with reference to FIG. FIG. 4 is a cross-sectional view schematically showing a general waste toner recovery mechanism. As shown in FIG. 4, a spiral blade 103 is arranged in the waste toner conveyance path 101. The spiral blade 103 extends to above the waste toner inlet 104 a formed on the upper surface of the collection container 104. The waste toner 102 is transported in the transport path 101 by the rotation of the spiral blade 103. The waste toner 102 conveyed in the conveyance path 101 falls into the collection container 104 as it is through the waste toner inlet 104a. Therefore, in a general waste toner recovery mechanism, when the amount of waste toner 102 transported through the transport path 101 is very small, the amount of waste toner 102 that falls into the recovery container 104 at a time is the amount of this embodiment. Very small compared to 1. For this reason, the waste toner 102 is likely to adhere to the inner wall surface of the collection container 104. Therefore, in order to detect that the collection container 104 is filled with the waste toner 102, even if the light emitting unit 105a and the light receiving unit 105b are arranged in the vicinity of the waste toner inlet 104a so as to face each other, In the waste toner collection mechanism, the waste toner 102 adheres to the inner wall surface of the collection container 104 before the waste toner 102 is deposited up to the vicinity of the waste toner inlet 104a, and the light receiving unit 105b prevents light L from being received. There is a risk. This leads to false detection of the full state of the collection container 104.

  On the other hand, according to the first embodiment, the compressed and agglomerated waste toner 73b falls into the collection container 71. Therefore, even if the waste toner 73b is charged, the influence of gravity is greater than the influence of charging. That is, the force that drops the waste toner 73b is superior to the force of electric charge, and the waste toner 73b falls without drifting through the internal space of the collection container 71. Therefore, the waste toner 73b is unlikely to adhere to the inner wall surface of the collection container 71.

  Therefore, even when the toner particle size is small, the waste toner 73 b is difficult to adhere to the inner wall surface of the collection container 71. Even when the printing rate is low, the waste toner 73b is unlikely to adhere to the inner wall surface of the collection container 71. Even when the collection container 71 is made of a material that is easily charged, such as polyethylene, the waste toner 73 b hardly adheres to the inner wall surface of the collection container 71. Further, the waste toner 73b falls without drifting through the internal space of the collection container 71 regardless of the environment such as temperature and humidity.

  Therefore, even when the amount of waste toner 73 transported along the transport path 74 is very small, the waste toner 73b is difficult to adhere to the transmissive member. Therefore, the light L is received by the light receiving unit 80b. It is difficult to be inhibited by 73b. As a result, it is possible to prevent erroneous detection of the amount of waste toner 73 (73b) in the collection container 71. In the first embodiment, erroneous detection of the full state of the collection container 71 can be prevented.

(Embodiment 2)
FIG. 5 is a cross-sectional view schematically showing a waste toner collecting mechanism 70 according to Embodiment 2 of the present invention. FIG. 6 is a cross-sectional view for explaining the operation of the waste toner transport mechanism 72 according to the second embodiment of the present invention. Since the configuration of the image forming apparatus according to the second embodiment is the same as that of the image forming apparatus 1 according to the first embodiment, the description thereof is omitted. Hereinafter, with reference to FIGS. 5 and 6, a difference between the waste toner collection mechanism 70 according to the second exemplary embodiment and the waste toner collection mechanism 70 according to the first exemplary embodiment will be described.

  In the second embodiment, a main waste toner staying part 78a and a sub-waste toner staying part 78b are provided in the transport path 74. The main waste toner retention portion 78a is a portion of the housing 77 downstream of the conveyance path 74 and in front of the opening 77a, like the waste toner retention portion 78 of the first embodiment. The sub-waste toner staying part 78b is provided on the upstream side of the transport path 74 from the main waste toner staying part 78a. The length of the main waste toner retention part 78a is, for example, 10 mm.

  A first spiral blade 75a and a second spiral blade 75b are formed on the rotating shaft 76. The first spiral blade 75a is an example of a first transport member, and the second spiral blade 75b is an example of a second transport member. The first spiral blade 75a extends from the upstream side of the conveyance path 74 to the front of the auxiliary waste toner retaining portion 78b. The second spiral blade 75b extends from the downstream end of the auxiliary waste toner retaining portion 78b to the front of the main waste toner retaining portion 78a. That is, the first spiral blade 75a and the second spiral blade 75b are arranged with the auxiliary waste toner retaining portion 78b interposed therebetween. That is, the conveying member of the second embodiment has a configuration in which some of the plurality of blades constituting the spiral blade 75 of the first embodiment are removed. The length of the auxiliary waste toner retaining portion 78b is, for example, 20 mm. In this case, the conveying member of the second embodiment has a configuration in which one of the plurality of blades constituting the spiral blade 75 of the first embodiment is removed.

The waste toner 73 is conveyed to the auxiliary waste toner retention part 78b by the rotation of the first spiral blade 75a. As a result, the waste toner 73 stays in the sub-waste toner stay part 78b and aggregates. Further, the waste toner 73 is sequentially sent to the sub-waste toner retention part 78b. Therefore, the waste toner 73 staying in the auxiliary waste toner staying part 78 b is compressed by the subsequent waste toner 73. When the waste toner 73c compressed and aggregated in the auxiliary waste toner retention part 78b is pushed by the subsequent waste toner 73 and reaches the second spiral blade 75b, the main waste toner retention part 78a is rotated by the rotation of the second spiral blade 75b. It is conveyed to. Accordingly, since the waste toner 73c is compressed and aggregated, the amount of the waste toner 73c sent to the main waste toner retention portion 78a is larger than the amount of the waste toner 73 sent to the waste toner retention portion 78 of the first embodiment. Become more. That is, the amount of waste toner 73 that is sent to the main waste toner retaining portion 78a at a time is larger than that in the first embodiment. As a result, as shown in FIG. 6 , the amount of waste toner 73 (73b) that falls from the main waste toner retaining portion 78a at a time is larger than that in the first embodiment.

  As described above, according to the second embodiment, as in the first embodiment, the compressed and aggregated waste toner 73b is collected from the waste toner inlet 71a into the collection container 71. Therefore, even when the amount of waste toner 73 transported through the transport path 74 is very small, the waste toner 73 is recovered in the recovery container 71 by increasing the density of the waste toner 73 compared to before being compressed and aggregated. Therefore, the amount of waste toner 73 that can be collected in the collection container 71 can be increased. In addition, since the waste toner 73 is less likely to adhere to the inner wall surface of the collection container 71, it is possible to prevent erroneous detection of the full state of the collection container 71.

  In addition, there is a possibility that the amount (size) of the waste toner 73c to be conveyed increases as the length of the auxiliary waste toner retention portion 78b increases, and the rotation of the spiral blades 75a and 75b is locked by the waste toner 73c. The length of the auxiliary waste toner retaining portion 78b is determined so that the rotation of the spiral blades 75a and 75b is not locked.

  A plurality of sub-waste toner retaining portions 78b may be provided. However, as the number of sub-waste toner retaining portions 78b increases, the amount (size) of the transported waste toner 73c gradually increases, and the rotation of the spiral blades 75a and 75b may be locked by the waste toner 73c. . The number of sub-waste toner retaining portions 78b is determined so that the rotations of the spiral blades 75a and 75b are not locked.

  Further, in the second embodiment, the two spiral blades 75a and 75b are formed on the rotating shaft 76, but instead, the diameter of the spiral blade is smaller than other portions in the auxiliary waste toner retaining portion 78b. May be.

  The present invention is not limited to the above embodiments. For example, in each of the embodiments described above, the image forming apparatus including the intermediate transfer belt has been described. In this type of image forming apparatus, a toner image is formed on the surface of the photoreceptor by development. Thereafter, the toner image is transferred from the photosensitive member to the intermediate transfer belt (primary transfer), and then the toner image is transferred from the intermediate transfer belt to the transfer paper (secondary transfer). The present invention is not limited to this type of image forming apparatus. The present invention is also applicable to an image forming apparatus that transfers a toner image from a photoreceptor to a transfer sheet. In this type of image forming apparatus, after a toner image is formed on the surface of the photoconductor by development, the toner image is transferred from the photoconductor to the transfer paper without using an intermediate transfer belt.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Apparatus main body 10A Transfer paper discharge port 20 Automatic document feeder (ADF)
25 Reading unit 30 Image forming unit 32, 32Y, 32M, 32C, 32Bk Image forming unit 321 Photosensitive drum 322 Charger 323 Exposure unit 324 Developing device 325 Primary transfer roller 326 Cleaning device 33 Intermediate transfer unit 331 Intermediate transfer belt 332 Drive roller 333 Follower roller 334 Cleaning device 34 Toner replenishment part 34Y, 34M, 34C, 34Bk Toner container 35 Secondary transfer roller 40 Paper feed part 40A, 40B Paper feed cassette 43 Pickup roller 44 Paper feed roller 45 Retard roller 46 Manual paper feed part 46A Manual feed tray 461 Feed roller 462 Transport roller pair 50 Transport path 60 Fixing unit 61 Heating roller 62 Fixing roller 63 Pressure roller 64 Fixing belt 65 Induction Unit 70 Waste toner collection mechanism 71 Collection container 71a Waste toner inflow port 72 Waste toner transport mechanism 73, 73b, 73c Waste toner 73a Waste toner lump 74 Transport path 75 Spiral blade 75a First spiral blade 75b Second spiral blade 76 Rotating shaft 77 Housing 77a Opening 78 Waste toner staying part 78a Main waste toner staying part 78b Sub-waste toner staying part 79 Shutter 80 Optical detector 80a Light emitting part 80b Light receiving part 101 Transport path 102 Waste toner 103 Spiral blade 104 Recovery container 104a Waste toner Inflow port 105 Optical detector 105a Light emitting part 105b Light receiving part

Claims (5)

A collection container having a waste toner inlet formed therein;
A main waste toner retaining portion provided in the vicinity of the waste toner inlet;
A sub-waste toner staying section where the waste toner stays,
A first conveying member that conveys waste toner to the sub-waste toner staying portion;
A second conveying member to feed transportable waste toner aggregated in the secondary waste toner retention part to the main waste toner retention part,
A rotating shaft on which the first conveying member and the second conveying member are provided ,
The first transport member and the second transport member are disposed with the auxiliary waste toner staying portion interposed therebetween, and transport the waste toner in the same direction.
The sub-waste toner staying portion is provided upstream of the main waste toner staying portion in a direction in which waste toner is transported by the first transport member and the second transport member,
The waste toner transported to the sub-waste toner staying portion by the first transport member presses the waste toner stored in the sub-waste toner staying portion, so that the waste toner aggregated in the sub-waste toner staying portion is 2 reach the conveying member,
The waste toner conveyed by the second conveying member, by pushing the waste toner accumulated in the main waste toner retention portion, the waste toner aggregated in the main waste toner retention part falls into the waste toner inlet, An image forming apparatus that is collected into the collection container. The image forming apparatus according to claim 1 , wherein a conveying member is not provided at a location corresponding to the sub-waste toner staying portion of the rotating shaft . It said first and second conveying member has a threaded旋羽roots,
The image forming apparatus according to claim 1 , wherein the spiral blade is provided upstream of the waste toner inflow port in a direction in which the waste toner is conveyed. The recovery, further comprising an optical detector for detecting the amount of waste toner in the container, an image forming apparatus according to any one of claims 1-3. The image forming apparatus according to claim 4 , wherein the optical detector is disposed in the vicinity of the waste toner inlet.

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