JP4880948B2 - Developer transport device, process cartridge, and image forming apparatus - Google Patents

Description

The present invention relates to a developer conveying device that conveys a developer, a process cartridge that can be attached to and detached from the image forming apparatus, and an image forming apparatus that includes the developer conveying device .

  2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image process, an image carrier and process means acting on the image carrier are integrally formed into a cartridge, and the cartridge can be attached to and detached from the image forming apparatus main body. A cartridge system is adopted. The process cartridge described above has a photosensitive drum as an image carrier, a cleaning member for cleaning the surface of the photosensitive drum, and a charging member for applying a charge to the photosensitive drum. The process cartridge includes parts such as a developing roller for supplying a developer to the photosensitive drum, a developing blade for regulating the developer on the developing roller, and a developer container for storing the developer.

  In the process cartridge, when the developer image formed on the photosensitive drum is transferred to a recording material such as paper, not all the developer on the photosensitive drum is transferred. If the untransferred toner as a developer remaining on the photosensitive drum without being transferred is left as it is, it becomes a harmful effect when a new toner image is formed.

  Therefore, the transfer residual toner on the photosensitive drum is cleaned by the cleaning member described above. As this cleaning member, there is a blade member using an elastic body such as rubber, and the transfer residue on the photosensitive drum is obtained by bringing the edge of the blade into contact with the surface of the photosensitive drum over the entire longitudinal direction. Scrap off the toner. The transfer residual toner (hereinafter referred to as waste toner) scraped off is accommodated in a waste toner collection space provided in the process cartridge. When the waste toner collection space is above the portion where the waste toner on the photosensitive drum is scraped off by the cleaning member, the waste toner is transported upward by the transport member.

  As a conveying member for conveying the waste toner upward, a configuration using a coil spring (see Patent Document 1), a configuration using a screw arranged in a vertical direction (see Patent Document 2), or a configuration using an endless belt. (See Patent Document 3) is generally known. Furthermore, as an example of a configuration using an endless belt, there is a configuration using a belt-shaped conveying member 27 having internal teeth and external teeth on both sides as shown in FIG. In the developer conveying device 26 shown in FIG. 12, a belt-shaped conveying member 27 surrounded by a guide member 36 is rotationally driven by pulley members 28a and 28b that are engaged with inner teeth. Then, the waste toner is carried on the outer teeth of the belt-like conveyance member 27 and conveyed upward, and the waste toner is dropped onto the delivery unit 37.

  Furthermore, in the conventional configuration, as shown in FIG. 12, the belt-like conveying member 27 supported by the two rotating pulley members 28a and 28b is moved from the vertical to the waste toner delivery portion 37 by a predetermined angle L (about 10 °). More) With such a configuration, it is possible to effectively drop the waste toner on the outer teeth of the belt-shaped conveying member 27 toward the delivery unit 37.

JP2004-139031 (page 21, FIG. 15) Japanese Patent Laid-Open No. 8-240979 (6th page, FIG. 5) JP 2003-43814 (Page 10, FIG. 5)

  Recent image forming apparatuses are required to be small and space-saving. For this purpose, it is necessary to reduce the size and space of the process cartridge that is attached to and detached from the image forming apparatus. However, the developer conveying device 26 having the above-described arrangement configuration causes the belt-shaped conveying member 27 to move vertically as shown in FIG. 12 in order to effectively drop the waste toner on the outer teeth of the belt-shaped conveying member 27. It is inclined toward the delivery part 37 from. For this reason, as the inclination angle L and the arrangement height M of the belt-like conveying member 27 increase, the arrangement space N of the belt-like conveying member 27 increases, which is a problem in saving the process cartridge. End up.

  Further, as described above, even if the belt-like conveying member 27 is inclined, if a large amount of waste toner is sent below the belt-like conveying member 27, a part of the waste toner on the outer teeth is transferred to the delivery unit. There is a possibility that the belt-shaped conveying member 27 will return to the lower side without dropping at 37. If the belt-like conveying member 27 continues to rotate in such a state, waste toner that cannot be conveyed below the belt-like conveying member 27 is accumulated. As a result, tooth skipping of the inner teeth of the belt-shaped conveying member 27 occurs, or waste toner collected below the belt-shaped conveying member 27 causes packing, and the driving of the belt-shaped conveying member 27 stops.

  On the other hand, a configuration in which a drop assisting member for knocking down the waste toner on the belt-like conveyance member 27 is provided so that the waste toner on the outer teeth of the belt-like conveyance member 27 can be reliably dropped by the delivery unit 37. However, in this configuration, the number of parts to be assembled increases, which causes other problems such as complicated assembly and increased costs.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to efficiently drop waste toner on a belt-shaped conveying member without increasing the number of parts while saving the space of the developer conveying device.

Typical configurations of the present invention for achieving the above object, an endless belt rotatable, have a plurality of projections projecting from its outer circumferential surface at predetermined intervals along the rotational direction and a conveyor belt for carrying and conveying the developer between said projections, said conveyor belt by being disposed to face the outer peripheral surface to guide the to carrying and conveying the developer, A guide member having a contact portion that contacts a part of the transport belt, wherein the transport belt transports the developer from below to above, and the contact portion The conveyance belt is bent so as to change the inclination of the conveyance belt before and after the abutting portion by abutting with a part of the conveyance belt, and the conveyance belt and the abutting portion are arranged in the rotation direction in the conveyance belt. Upstream of the upper end of the The contact at the downstream side of the position where developer is supplied to the conveyor belt in the direction, the distance between the tip of the projection in the abutment portion upstream of the said rotational direction P1, in the contact portion When the interval between the tips of the projections is P2, and the interval between the tips of the projections downstream of the contact portion in the rotational direction is P3, P2 <P1 <P3 is satisfied. The developer carried between the protrusions is dropped at a portion where the distance between the tips of the portions becomes P2 to P3.

According to the present invention, it is possible to efficiently drop the waste toner on the conveyance belt without increasing the number of parts while saving the space of the developer conveyance device.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. Therefore, unless specifically stated otherwise, the scope of the present invention is not intended to be limited thereto.

  In the following description, a multicolor electrophotographic image forming apparatus in which a plurality of process cartridges can be attached and detached will be described as an example.

  In the following description, the longitudinal direction is the direction in which the process cartridge is mounted, and is the direction that intersects (substantially orthogonal) the conveyance direction of the recording material S and is the axial direction of the image carrier (hereinafter referred to as the photosensitive drum 1). Say the same direction. Further, left and right are left and right when the conveyance direction of the recording material S is viewed from above. Further, “upper and lower” means “upper and lower” when the process cartridge and the toner cartridge are mounted.

  Here, the electrophotographic image forming apparatus forms an image on a recording material using an electrophotographic image forming system. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer, etc.), a facsimile machine, a word processor, and the like.

  The process cartridge is a cartridge in which a charging unit, a developing unit, or a cleaning unit and an image carrier are integrally formed, and the cartridge can be attached to and detached from the image forming apparatus main body. Further, it means that at least the cleaning means and the image carrier are integrated into a cartridge so that it can be attached to and detached from the apparatus main body.

[Overall configuration of multicolor image forming apparatus]
First, the overall configuration of the replenishment-type multicolor image forming apparatus will be outlined with reference to FIG. FIG. 1 is a longitudinal sectional view showing the overall configuration of a full-color laser beam printer 100 which is an embodiment of a replenishment-type multicolor image forming apparatus.

  The multicolor image forming apparatus 100 shown in the figure includes four photosensitive drums 1a, 1b, 1c, and 1d arranged in parallel in the horizontal direction. A photosensitive drum 1 (1a, 1b, 1c, 1d) as an image carrier is rotationally driven by a driving means (not shown). Around the photosensitive drum 1, a charging roller 2 (2a, 2b, 2c, 2d), a developing unit 4 (4a, 4b, 4c, 4d), a cleaning blade 7 (7a, 7b, 7c, 7d) and the like are arranged. It is installed. Here, the charging roller 2 is for uniformly charging the surface of the photosensitive drum 1. The developing unit 4 is for developing a toner image by attaching a developer (hereinafter referred to as toner) to the electrostatic latent image. The cleaning blade 7 is a cleaning member that removes transfer residual toner remaining on the surface of the photosensitive drum 1 after transfer. In FIG. 1, reference numeral 3 (3 a, 3 b, 3 c, 3 d) denotes a scanner unit that irradiates a laser beam based on image information and forms an electrostatic latent image on the photosensitive drum 1. Reference numeral 5 denotes an intermediate transfer belt for transferring the toner image on the photosensitive drum 1, and reference numeral 6 denotes a secondary transfer roller for transferring the toner image on the intermediate transfer belt 5 to the recording material S.

  Here, the photosensitive drum 1, the charging roller 2, the developing unit 4, and the cleaning blade 7 as process means acting on the photosensitive drum 1 are integrated as a process cartridge 8 (8a, 8b, 8c, 8d). ing. The process cartridge 8 is detachable from the image forming apparatus main body 100. A toner cartridge 9 (9a, 9b, 9c, 9d) for supplying toner to the process cartridge 8 is disposed on the process cartridge 8. The frame structure of the process cartridge 8 will be described later in detail.

  As an image forming operation, the process cartridges 8a, 8b, 8c, and 8d are sequentially driven in accordance with the recording timing, and the photosensitive drums 1a, 1b, 1c, and 1d are rotationally driven in accordance with the drive. Then, the scanner units 3 corresponding to the respective process cartridges 8 are sequentially driven. Further, when the photosensitive drum 1 rotates, the charging roller 2 that rotates while being in contact with the photosensitive drum 1 imparts a uniform charge to the peripheral surface of the photosensitive drum 1. The scanner unit 3 selectively exposes the circumferential surface of the photosensitive drum in accordance with an image signal to form an electrostatic latent image on the circumferential surface of the photosensitive drum. A developing roller in the developing unit 4 transfers toner to the electrostatic latent image to form (develop) a toner image on the circumferential surface of the photosensitive drum 1. The toner image on the circumferential surface of each photosensitive drum 1 is transferred (primary transfer) on the intermediate transfer belt 5 and conveyed to the position of the secondary transfer roller 6.

  On the other hand, the registration roller pair 10 starts to rotate and conveys the recording material S so that the leading edge of the toner image on the circumferential surface of the intermediate transfer belt 6 coincides with the recording start position of the recording material S. While being conveyed in this manner, the toner image on the circumferential surface of the intermediate transfer belt 5 is collectively transferred (secondary transfer) to the recording material S by the secondary transfer roller 6.

  The recording material S to which the toner image has been transferred is carried into the fixing unit 11. After the toner image is thermally fixed by the fixing unit 11, the recording material S is discharged out of the main body by the discharge roller pair 12 with the image surface facing down from the discharge unit 13.

[Description of frame structure of process cartridge]
Next, the frame structure of the process cartridge 8 will be described with reference to FIG.

  As shown in FIG. 2, the process cartridge 8 has a frame structure in which the photosensitive drum unit 14 and the developing unit 4 are integrated.

  The photosensitive drum unit 14 is configured such that the charging roller 2 and the cleaning blade 7 are disposed in a cleaning container 15 that is a frame body that rotatably supports the photosensitive drum 1.

  On the other hand, the developing unit 4 has a frame structure in which a toner container 16 for storing toner replenished from the toner cartridge 9 and a developing container 18 that is a frame body that rotatably supports the developing roller 17 are ultrasonically welded. Etc. are combined. Here, the developing roller 17 is for developing the toner in the toner container 16 onto the surface of the photosensitive drum 1.

  In addition to the developing roller 17, the developing container 18 includes a developing blade 19 for regulating the toner layer thickness on the developing roller 17 and a toner supply roller that is a sponge roller for supplying toner onto the developing roller 17. 20 etc. are provided.

  The developing unit 4 is supported so as to be swingable with respect to the photosensitive drum unit 14 around the coupling portion 21 of FIG. Further, the developing unit 4 is urged by an elastic member 22 such as a spring, whereby the developing roller 17 is configured to abut against the photosensitive drum 1.

[Process cartridge developer collection configuration]
Next, a configuration for collecting the developer generated in the process cartridge will be described with reference to FIGS.

  The toner image formed on the surface of the photosensitive drum 1 is transferred to the intermediate transfer belt 5. At this time, not all of the toner image on the photosensitive drum 1 is transferred to the intermediate transfer body 5, and a small amount of developer (hereinafter referred to as transfer residual toner) remains on the photosensitive drum 1 without being transferred. Exists. If this untransferred toner is left as it is, it will be harmful when a new toner image is formed on the photosensitive drum 1.

  Therefore, the transfer residual toner on the photosensitive drum 1 is cleaned by the cleaning blade 7 described above. As shown in FIG. 3, the cleaning blade 7 is a blade member using an elastic body such as rubber, and the edge portion 7 a of the blade is abutted against the surface of the photosensitive drum 1 over the entire longitudinal direction to thereby form a photosensitive member. The transfer residual toner H on the drum 1 is scraped off.

Transfer residual toner (hereinafter referred to as waste toner) H scraped off by the cleaning blade 7 is stored in a waste toner collection space (developer storage portion) 23 provided in the entire longitudinal area of the process cartridge 8 as shown in FIG. Collected. As shown in FIG. 5, the waste toner collection space 23 is formed by joining a cleaning container 15 and a separate lid member 24 by ultrasonic welding or the like.

[Disposition of waste toner collection space]
Further, in the replenishment-type multicolor image forming apparatus 100, the waste toner collection space 23 is sandwiched between the toner cartridges 9 and 9 disposed above the process cartridge 8, as shown in FIG. 6 (FIG. 6). It is desirable to be provided in the middle position A). This is because the position A in FIG. 6 is an enlargement of the process cartridge 8 and the image even if the waste toner collection space 23 is provided at this position in the replenishment-type multicolor image forming apparatus 100 illustrated here. This is because it is an effective empty space that does not increase the size of the forming apparatus.

  This will be described in detail. As shown in FIG. 6, a toner cartridge 9 corresponding to each process cartridge 8 is arranged above the plurality of process cartridges 8 arranged in parallel in the horizontal direction. Further, a scanner unit 3 (see FIG. 1) is disposed above the toner cartridge 9. For this reason, an empty space is created in the portion A in the figure. Therefore, if the waste toner collection space 23 is arranged in the empty space A, the space of the apparatus can be saved while effectively using the limited space.

[Waste toner transport configuration]
Next, the waste toner conveyance configuration of the process cartridge will be described.

  As shown in FIGS. 5 and 7, the waste toner scraped off by the cleaning blade 7 is conveyed by the first screw member 25 to the longitudinal end of the process cartridge 8 (in the direction of arrow F in FIG. 7). Here, the first screw member 25 is waste toner conveying means disposed over the entire length on the opposite side of the contact surface of the photosensitive drum 1 of the cleaning blade 7.

As shown in FIG. 7, a waste toner vertical upper conveyance unit 26 as a developer conveyance device is provided at one longitudinal end of the process cartridge 8. One longitudinal end of the first screw member 25 is connected to the lower side of the waste toner vertical upper conveyance unit 26. The waste toner transported by the first screw member 25 is transported to the waste toner collection space 23 by a waste toner vertical transport unit 26 as a developer transport device provided at one longitudinal end. Waste toner vertically above the transport unit 26 includes a belt-like conveying member (conveying belt) 27 which is constituted by an endless-shaped belt having internal teeth and external teeth on both sides, by the guide members 36 surrounding the outer periphery of the belt-like conveying member 27 It is configured. The belt-like conveying member 27 is a resin member using a polyester elastomer having elasticity.

  The inner teeth 27a of the belt-like conveying member 27 mesh with the rotatable upper pulley member 28a and the lower pulley member 28b. The belt-like conveying member 27 is in a state in which both ends are rotatably supported by the two pulley members 28a and 28b. When one of the two pulley members 28a and 28b rotates, the belt-shaped conveying member 27 also rotates. Further, the circumferential length of the belt-like transport member 27 is slightly shorter than the distance between the axes of the upper pulley member 28a and the lower pulley member 28b. Thus, when the belt-like conveyance member 27 is attached to the upper pulley member 28a and the lower pulley member 28b, a predetermined tension is applied to the belt-like conveyance member 27.

  Here, if the tension applied to the belt-like conveying member 27 is too high, the rotational torque of the conveying member 27 becomes high. On the other hand, if the tension is too low, tooth skipping between the pulley members 28a and 28b and the conveying member 27 occurs. Therefore, when the polyester-based elastomer conveying member 27 is used, the elongation ratio of the conveying member 27 when attached to the pulley members 28a and 28b is about 1.5 to about the conveying member 27 in a normal state (free state). It is desirable to set 2.0% and tension to 5.0-7.0N.

As shown in FIG. 8, the waste toner H transported to the longitudinal end (below the waste toner vertical upper transport unit 26) by the first screw member 25 protrudes from the outer peripheral surface of the transport member 27 at a predetermined interval. The developer enters into the external teeth 27b as the developer conveying section (plural protrusions) . The waste toner H that has entered the external teeth 27b is conveyed upward as the conveying member 27 rotates in the arrow G direction.

[Arrangement configuration of belt-shaped conveying member]
As shown in FIG. 9, the waste toner H transported by the transport member 27 is transported to a second screw member 29 as waste toner transport means connected to the upper side of the waste toner vertical transport unit 26. The second screw member 29 is provided over the entire length of the waste toner collection space 23.

As shown in FIG. 10, a bent portion (contact portion) 36a for bending a part of the transport member 27 is provided on a part of the inner wall of the guide member 36 surrounding the outer periphery of the transport member 27. . In the vicinity of the bent portion 36 a of the guide member 36, a delivery portion 37 is provided as a developer delivery portion that delivers the waste toner H that has been transported by the external teeth 27 b of the transport member 27.

  The longitudinal end of the second screw member 29 is connected to a delivery portion 37 near the bent portion 36a of the guide member 36.

  As described above, by providing the bent portion 36 a on a part of the inner wall of the guide member 36, the conveying member 27 has an angle θ from the vertical toward the second screw member 29 above the second screw member 29. Arranged in the state of holding. The reason for disposing the conveying member 27 in this manner is as follows. That is, as shown in FIG. 11, if the conveying member 27 is arranged vertically above the second screw member 29, there is a possibility that the waste toner H that has entered the external teeth 27 b does not fall onto the second screw member 29. Because there is.

  For this reason, it is desirable that the belt-shaped conveying member 27 is arranged in a state where it is inclined at a certain angle. However, as shown in FIG. 12, simply tilting the belt-like conveying member 27 supported by the pulley members 28a and 28b on the upper side and the lower side, the inclination angle L and the arrangement height M of the belt-like conveying member 27. Increases the arrangement space N of the belt-shaped conveying member 27. As a result, the installation space for the waste toner conveyance unit 36 increases, which leads to an increase in the size of the process cartridge and the image forming apparatus.

  Therefore, the above-described configuration is adopted in order to efficiently reduce the waste toner H on the belt-shaped conveying member 27 toward the second screw member 29 while achieving space saving. That is, a bent portion 36 a is provided in a part of the guide member 36, and the belt-shaped transport member 27 is disposed above the second screw member 29 with the inclination angle θ. Then, the waste toner H on the belt-like conveying member 27 is dropped onto the second screw member 29 using this inclination (angle θ). Here, the inclination angle θ is an angle at which the belt-like conveying member 27 is inclined toward the second screw member 29 with respect to the vertical line, and is preferably set to 10 ° or more.

[Movement of waste toner at the bent part]
In addition to the above-described configuration, a configuration in which the waste toner on the belt-shaped conveying member 27 is more efficiently sent to the second screw member 29 includes an amount of the external teeth 27b entering the guide member 36. The tip of the outer teeth 27b of the belt-like conveying member 27 is arranged with a certain gap (about 0.35 mm here) with respect to the inner wall of the guide member 36. However, the bent portion 36 a is disposed so that the tip of the outer teeth 27 b of the belt-like conveying member 27 contacts the inner wall of the guide member 36.

When the belt-shaped conveying member 27 is rotated in such a configuration, as shown in FIG. 13, the outer teeth 27b of the belt-shaped conveying member 27 bend upstream in the Q portion of the bent portion 36a. Here, the predetermined tip pitch of the outer teeth 27b is P1, the tip pitch of the outer teeth 27b in the bent portion 36a is P2, and the tip pitch of the outer teeth 27b downstream of the bent portion 36a in the waste toner conveying direction is P3. . At this time, the tip pitch between adjacent external teeth is narrower at the R2 portion (pitch P2) and larger at the R3 portion (pitch P3) than the normal pitch (R1 portion) of the conveying member 27. That is, the relationship between the tip pitches of the external teeth 27b is P2 <P1 <P3 . As a result, the waste toner H on the outer teeth 27 is attracted by the outer teeth 27 that are bent upstream immediately before passing through the bent portion 36a. Then, on the downstream side of the bent portion 36a, the tip pitch of the outer teeth 27b is widened by the bent outer teeth 27b. Therefore, the waste toner H gathered at the bent portion 36 a falls from the spread external teeth 27 b immediately after passing through the bent portion 36 a and is sent to the second screw member 29. With such a configuration, it is possible to drop the waste toner on the external teeth 27b to the second screw member 29 more effectively without increasing the number of separate parts while saving space. Become.

[Tooth shape of belt-shaped conveying member]
In the present embodiment, the shapes of the inner teeth 27a and the pulley members 28a and 28b of the belt-like conveying member 27 are in accordance with the standards of general-purpose toothed belts and toothed pulleys applied in JIS.

  The outer teeth 27b of the belt-shaped conveying member 27 are shaped so that if the tooth width in the conveying direction is too large, the outer teeth 27b will not bend at the bent portion 36a, and the toner will be gathered at the bent portion 36a or passed through the bent portion 36a. Immediately after the toner cannot be released. Further, torque increases at the bent portion 36a due to the outer teeth 27b not being bent. Therefore, the tooth width in the conveying direction of the external teeth 27b is set such that the width of the root portion is about 1.0 mm and the width of the tip portion is about 0.5 mm.

  Further, it is desirable to make the height of the external teeth 27b as high as possible. However, if the height is extremely high, the apparatus becomes large. In this embodiment, the height of the external teeth 27b is about 1.7 mm. Furthermore, if the tip pitch P1 of the outer teeth 27b is too small, the space formed by the adjacent outer teeth and the inner wall of the guide member 36 becomes smaller, and the amount of waste toner transported decreases. On the other hand, if the tip pitch P1 is too wide, when the waste toner is transported from below to above, the waste toner cannot be held between the adjacent external teeth, and from the gap between the inner wall of the guide member 36 and the tip of the external tooth 27b. Waste toner spills out. Therefore, in this embodiment, the tip pitch P1 of the external teeth 27b is set to about 3.0 mm.

[Storage configuration of waste toner]
Thereafter, as shown in FIG. 14, the waste toner is stored in the waste toner collection space 23 from the upstream side in the waste toner conveyance direction (the direction of arrow J in the figure) by the second screw member 29. The interior of the waste toner collection space 23 is partitioned into a plurality of spaces 31a to 31d by partition walls 30a to 30c.

  As shown in FIG. 15, the second screw member 29 has a screw in the opposite direction to the waste toner conveyance direction (in the direction of arrow J in the figure) at the center of each of the plurality of spaces 31 a to 31 c (hereinafter, reverse). 1 to 2 windings of screw portions 32a to 32c) are provided. With such a configuration, as shown in FIG. 16, the waste toner conveyed in the arrow J direction by the second screw member 29 is pushed back in the arrow J ′ direction by the reverse screw portions 32 a to 32 c. For this reason, the waste toner spreads in a direction (arrow K direction in FIG. 13) orthogonal to the waste toner conveyance direction. As a result, the bulk density of the waste toner stored in the waste toner collection space 23 is increased, and as a result, a large amount of waste toner can be stored in a limited space.

[Drive configuration of waste toner vertical upper conveyance unit]
Next, the drive configuration of the waste toner vertical upper conveyance unit 26 and the plurality of screw members 29 and 25 will be described.

  As shown in FIG. 17, the second screw member 29 is provided over the entire length of the waste toner collection space 23. One end of the second screw member 29 is connected to the waste toner vertical upper conveyance unit 26. Further, the other end of the second screw member 29 is provided with an end surface coupling member 33 for receiving a driving input from the image forming apparatus main body 100.

  A first idler gear 34 is provided on the side of the second screw member 29 connected to the waste toner vertical upper conveyance unit 26. Further, as shown in FIG. 18, the first idler gear 34 is coaxially coupled to the upper pulley member 28a (see FIG. 14) meshing with the timing belt 27 of the waste toner vertical upper conveyance unit 26. It meshes with the second idler gear 35. On the other hand, the lower pulley member 28 b is coaxially coupled to the first screw member 25.

  With the above configuration, the driving of the second screw member 29 that receives the driving input from the image forming apparatus main body 100 is transmitted to the upper pulley member 28 a via the first idler gear 34 and the second idler gear 35. . As the upper pulley member 28a rotates, the belt-like conveying member 27 also rotates, and the lower pulley member 28b also rotates. And the 1st screw member 25 rotates because the lower pulley member 28b rotates. Thus, even in a process cartridge provided with a waste toner vertical upper transport unit 26 and a plurality of screw members (waste toner transport means) 29 and 25 having different transport directions, the waste toner can be transported efficiently with one drive input. Can be performed.

  In the above-described embodiment, an image forming apparatus using four process cartridges for multicolor image formation has been illustrated. However, the number of process cartridges used is not limited to this, and may be changed as necessary. What is necessary is just to set suitably.

  In the above-described embodiment, as a process cartridge that is detachable from the image forming apparatus, a process that integrally includes a photosensitive drum and a charging unit, a developing unit, and a cleaning unit as process units that act on the photosensitive drum. A cartridge was illustrated. However, the present invention is not limited to this, and is a process cartridge having at least a photosensitive drum and a cleaning unit integrally, or a process cartridge further including any one of a charging unit and a developing unit. Also good.

  In the above-described embodiment, the configuration in which the process cartridge including the photosensitive drum is detachable from the image forming apparatus is illustrated. However, the present invention is not limited to this, and may be, for example, an image forming apparatus in which each constituent member is individually incorporated, or an image forming apparatus in which each constituent member is individually removable.

  In the above-described embodiments, the printer is exemplified as the image forming apparatus. However, the present invention is not limited to this, and other image forming apparatuses such as a copying machine and a facsimile machine, or a combination of these functions. Other image forming apparatuses such as multifunction peripherals may also be used. Further, an image forming apparatus that uses a recording material carrier and sequentially superimposes and transfers the toner images of the respective colors on the recording material carried on the recording material carrier. Further, the image forming apparatus is not limited to an image forming apparatus capable of forming a color image, and may be an image forming apparatus capable of forming a monochrome image. The same effect can be obtained by applying the present invention to the developer conveying device used in these image forming apparatuses.

1 is a longitudinal sectional view showing a multicolor image forming apparatus according to an embodiment of the present invention. 1 is a longitudinal sectional view around a process cartridge according to an embodiment of the present invention. Sectional view showing the configuration of the cleaning blade The perspective view which shows the structure of the waste toner collection | recovery space which concerns on embodiment of this invention. Sectional drawing which shows the structure of the waste toner collection space which concerns on embodiment of this invention Side view showing arrangement of waste toner collection space The perspective view which shows the structure of the 1st screw member and waste toner vertical upward conveyance unit which concern on embodiment of this invention. Explanatory drawing which shows the conveyance property of the belt-shaped conveyance member which concerns on embodiment of this invention. The perspective view which shows the structure of the 2nd screw member which concerns on embodiment of this invention. Explanatory drawing which shows the structure of the belt-shaped conveyance member which concerns on embodiment of this invention. Explanatory drawing which shows the comparative example of a structure of a belt-shaped conveyance member Sectional drawing which shows the comparative example of a structure of a belt-shaped conveyance member Explanatory drawing which shows the structure of the belt-shaped conveyance member which concerns on embodiment of this invention, and its operation | movement. The perspective view which shows the structure of the waste toner collection | recovery space which concerns on embodiment of this invention. 1 is a front view illustrating a configuration of a waste toner collection space according to an embodiment of the present invention. The perspective view which shows the structure of the waste toner collection | recovery space which concerns on embodiment of this invention. The front view which shows the drive structure of the 2nd screw member which concerns on embodiment of this invention. FIG. 3 is a perspective view illustrating a driving configuration of a waste toner vertical upper conveyance unit according to the embodiment of the invention.

Explanation of symbols

A ... Waste toner collection space area H ... Waste toner P1, P2, P3 ... Tip pitch Q of external teeth ... Position S where external teeth bend ... Recording material θ ... Inclination angle 1 of belt-like conveying member ... Photosensitive drum ( Image carrier)
7: Cleaning blade (cleaning member)
8 ... Process cartridge 23 ... Waste toner collection space 25 ... First screw member (waste toner conveying means)
26 ... Waste toner vertical upper conveyance unit (developer conveyance device)
27 ... Belt-shaped conveying member (conveying member)
27a ... internal teeth 27b ... external teeth (developer transport section)
28a, 28b ... pulley member 29 ... second screw member (waste toner conveying means)
36 ... guide member 36a ... bent part 37 ... delivery part (developer delivery part)
100: Image forming apparatus

Claims (6)

A belt of a rotatable endless, that along the rotating direction has a plurality of projections projecting from its outer circumferential surface at predetermined intervals, carrying and conveying the developer between said projection A conveyor belt;
A guide member on which the conveyor belt guides for carrying and conveying the developer has a part abutment portion abutting the conveyor belt by being disposed to face the outer circumferential surface,
A developer carrying device comprising:
The conveyor belt conveys the developer from below to above,
The contact portion bends the transport belt so as to change the inclination of the transport belt before and after the contact portion by contacting a part of the transport belt,
The conveyance belt and the abutting portion are in contact with the upstream side of the upper end of the conveyance belt in the rotational direction and the downstream side of the position where the developer is supplied to the conveyance belt in the rotational direction,
Wherein in the rotation direction of the spacing of the tip of the projecting portion on the upstream side of the contact portion P1, the spacing of the tip of the projection in the abutment portion P2, than the contact portion in the rotational direction When the interval between the tips of the protrusions on the downstream side is P3,
P2 <P1 <P3 is satisfied,
A developer conveying device, wherein the developer carried between the protrusions is dropped at a portion where the distance between the tips of the protrusions is from P2 to P3.   A developer delivery portion for delivering the developer to a developer accommodation portion for accommodating the developer, and the developer delivery portion is located below a portion where the distance between the tips of the protrusions is P2 to P3; The developer conveying device according to claim 1, wherein the developer conveying device is arranged.   The developer conveying device according to claim 1, wherein the abutting portion bends a part of the conveying belt by abutting the protrusion.   4. The developer conveying device according to claim 3, wherein portions of the guide member other than the contact portion are separated from the conveying belt. 5. A process cartridge that is detachable from the image forming apparatus,
An image carrier;
A cleaning member for removing the developer remaining on the image carrier;
The developer conveying device according to any one of claims 1 to 4 ,
Have
The process cartridge, wherein the developer conveying device conveys the developer removed by the cleaning member. An image forming apparatus comprising: a developer conveying device according to any one of claims 1 to 4.

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