JP2009003185A - Developing device and image forming apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of uniformly conveying toner stored in a toner storage part in the axial direction of a stirring member, and to provide an image forming apparatus equipped with the developing device. <P>SOLUTION: The stirring member 56 includes a flexible sheet body 82 supported in cantilever fashion by a shaft part 81. The sheet body 82 includes: an open end 82a extending in the axial direction of the shaft part 81; and a flat part 82b that holds the toner. The toner storage part 59 includes: a first partitioning member 61 with which the open end 82a can come in contact; and an upper wall 51b on which a pair of sine wave-shaped recessed and projecting parts 71 and 72 is formed. The pair of recessed and projecting parts 71 and 72 is formed to a shape having top parts 71a and 72a and bottom parts 71b and 72b repeatedly provided in parallel to one another in the axial direction, and the phases of respective recessed and projecting parts 71 and 72 are different from each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a developing device that stirs and conveys toner, and an image forming apparatus such as a copying machine, a facsimile, and a printer having the developing device.

  In an image forming apparatus that forms an electrophotographic image, such as a printer or a copying machine, a developing device is disposed opposite to a photosensitive member that forms an electrostatic latent image on the surface by irradiation of image light. By supplying toner from the roller to the surface of the photoreceptor, the electrostatic latent image is visualized as a toner image. Therefore, the developing device always needs to store a predetermined amount or more of toner, and is provided with a toner storage portion that supplies toner to the developing roller. A toner stirring member is rotatably provided in the toner storage portion. The toner stirring member stirs and mixes the toner in the toner container by rotation to prevent the toner from aggregating and solidifying, and supplies the toner to the developing roller.

  For this reason, the toner agitating member is usually composed of a rotating shaft, a support body that is a rotating blade extending in the radial direction from the circumferential surface of the rotating shaft, and a toner transport sheet that is cantilevered at the tip of the support body. When the toner agitating member is rotated, the support agitates the toner in the toner accommodating portion, and the toner conveying sheet scoops up the toner along the inner wall of the toner accommodating portion and supplies the toner to the developing roller.

  However, in the above-described developing device, since the support having a function of stirring the toner in the toner accommodating portion is formed of a hard material such as metal or resin, the elastic shaft hardly causes deformation. Only the toner located in a circle whose radius is the extended length of the support from the toner can be conveyed during stirring. When the amount of toner in the toner storage portion decreases, there is a problem that the toner cannot be sufficiently stirred and conveyed by the support.

  Therefore, in Patent Document 1, the toner agitating member is formed by integrally forming a ladder-type support body at two locations on the peripheral surface of the rotating shaft in the radial direction, and the tip of the support body is made flexible. The rotation direction conveyance member and the axial direction conveyance member of the sheet body are configured to be cantilevered so as to extend in a direction perpendicular to the radial direction of the rotation axis. The rotation direction conveying member is formed in a flat plate shape having a single rectangular shape over the entire length in the axial direction of the rotation shaft, and its open end is in contact with the inner wall of the toner accommodating portion and is bent. The axial conveying member is formed by dividing one flat plate over the entire length in the axial direction of the rotating shaft, and its open end has a V-shaped shape consisting of a peak portion and a valley portion, The inner wall of the toner container is abutted and bent.

  When the toner agitating member is rotated, the rotation direction conveying member is elastically deformed by contacting the inner wall of the toner accommodating portion at the open end, and the toner accommodating member is in a state where the open end scrapes up the inner wall of the toner accommodating portion. The toner in the unit is conveyed between the inner wall and the rotation direction. Further, the axial conveying member is elastically deformed into a twisted shape by selectively abutting the inner wall of the toner containing portion in the vicinity of the crest portion at the open end, and the toner in the toner containing portion is removed from the crest portion at the open end. It is conveyed in the direction toward the part, that is, in the axial direction.

  In this manner, the toner agitating member has a function of agitating the toner in the toner accommodating portion by the support, a function of conveying the toner in the toner accommodating portion in the rotation direction by the rotation direction conveying member, and a toner accommodating by the axial direction conveying member. The function of conveying the toner in the section in the axial direction is realized.

However, in the above-described prior art, the toner agitation is performed in a state where the toner moves in the direction from the V-shaped peak to the valley in order for the axial transport member to transport the toner in the toner storage portion in the axial direction. The member is rotated to convey toner. As a result, the toner is stacked on the portion transported from the trough in the toner storage portion. If this conveyance in the axial direction is repeated, the toner is highly accumulated in the portion conveyed from the trough portion, but the toner is not accumulated in the portion corresponding to the peak portion in the toner accommodating portion, and the toner accumulation surface is high. Is not uniform in the axial direction. In this state, when the remaining amount of toner in the toner container is detected, the height of the toner accumulation surface varies depending on the position where the remaining toner detection sensor is arranged, and the remaining amount of toner can be detected accurately. There was a problem that could not.
JP 2002-156819 A (paragraphs [0037]-[0044], FIG. 2)

  The present invention has been made to solve the above-described problems, and provides a developing device capable of uniformly transporting toner in a toner container in the axial direction of a stirring member, and an image forming apparatus including the developing device. The purpose is to provide.

  In order to achieve the above object, the present invention provides a toner storage portion, a toner supply portion that supplies toner to an image carrier, a passage portion through which toner moves from the toner storage portion to the toner supply portion, and the toner storage And a stirring member that stirs the toner and that is supported by a rotating shaft that is rotatable in the unit. The stirring member includes a flexible sheet body that is cantilevered by the rotating shaft, and the sheet body includes: An open end extending in the direction of the rotation axis; and a flat portion for holding the toner; and the toner storage portion includes a side wall on which the open end can abut and an upper surface wall on which a pair of concave and convex portions are formed. The pair of concavo-convex portions has a shape in which a concave portion and a convex portion are repeated in parallel with each other in the rotation axis direction, the phases of the concavo-convex portions are different from each other, the sheet body rotates, and the open end is When contacting the side wall, When the open end is separated from the side wall, the sheet body jumps the toner toward the upper surface wall and collides the toner with the pair of concave and convex portions. It is characterized by.

  According to this configuration, the toner colliding with the pair of uneven portions having different phases is diffused in the axial direction and falls in the toner storage portion.

  According to the present invention, in the developing device configured as described above, the pair of concave and convex portions have the same sine wave shape. According to this configuration, the toner that has collided with the sine wave-shaped slope portion diffuses in the axial direction.

  Further, according to the present invention, in the developing device configured as described above, the pair of concavo-convex portions are configured such that a plurality of triangular prism bodies are arranged in the axial direction, and one inclined surface portion of the triangular prism bodies are directed in opposite directions in the axial direction. It is characterized by being formed. According to this configuration, the toner that has collided with the inclined surface of the triangular prism body diffuses in the axial direction.

  According to the present invention, in the developing device configured as described above, the flat portion is formed with a slit from the open end toward the rotating shaft. According to this configuration, even if the open ends are inclined and come into contact with the side wall due to manufacturing errors of the members and assembly displacement, the open ends between the slits are in contact with the side walls and The toner carried on the flat surface of the toner is splashed almost directly toward the upper wall.

  According to the present invention, in the developing device configured as described above, an opening is formed in the planar portion. According to this configuration, the amount of toner carried on the flat portion is limited.

  In the developing device having the above-described configuration, the side wall is formed by a partition portion that separates the toner supply portion and the toner storage portion, and the open end is in contact with the partition portion. It is said. According to this configuration, when the open end contacts the partition portion, the sheet body holds the toner at the flat portion and bends.

  The present invention also provides an image forming apparatus equipped with the developing device having the above-described configuration.

  According to the first aspect of the present invention, when the toner colliding with the pair of concave and convex portions having different phases is diffused in the axial direction and falls in the toner accommodating portion, the height of the toner accumulation surface becomes uniform. Since the remaining amount of toner in the toner container is detected based on the uniform height of the toner accumulation surface, it is possible to accurately detect the remaining amount of toner.

  According to the second aspect of the present invention, when the toner colliding with the sine wave-shaped slope portion diffuses in the axial direction and falls in the toner accommodating portion, the height of the toner accumulation surface becomes uniform. Since the remaining amount of toner in the toner container is detected based on the uniform height of the toner accumulation surface, it is possible to accurately detect the remaining amount of toner.

  According to the third aspect of the present invention, when the toner colliding with the inclined surface of the triangular prism body diffuses in the axial direction and falls in the toner accommodating portion, the height of the toner accumulation surface becomes uniform. Since the remaining amount of toner in the toner container is detected based on the uniform height of the toner accumulation surface, it is possible to accurately detect the remaining amount of toner.

  According to the fourth aspect of the present invention, even if the release ends are inclined and come into contact with the side walls due to manufacturing errors of the members, deviations in assembly, etc., the release ends between the slits are mutually connected to the side walls. Since the toner carried on the flat portion between the slits jumps up almost directly toward the upper wall, the toner colliding with the pair of uneven portions is diffused in the axial direction without unevenness.

  Further, according to the invention described in claim 5, since the amount of toner carried on the flat portion is limited, the limited toner is bounced up toward the upper surface wall, and the toner collides with the pair of uneven portions. The amount of toner to be conveyed can be adjusted according to the size of the opening.

  According to the sixth aspect of the present invention, when the open end comes into contact with the partition portion, the sheet body holds the toner in the flat portion and bends, so the sheet body holds the held toner toward the upper surface wall. The toner is collided with the pair of bumps. When the collided toner diffuses in the axial direction and falls in the toner container, the height of the toner accumulation surface becomes uniform.

  According to the seventh aspect of the present invention, if the above-described developing device is provided, an image forming apparatus that uniformly transports the toner in the toner storage portion in the axial direction of the stirring member can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. The embodiment of the present invention shows the most preferable form of the invention, and the use of the invention and the terms shown here are not limited thereto.

  FIG. 1 is a schematic cross-sectional view for explaining a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus 1 includes an image forming unit 10, a toner replenishing device 20, an intermediate transfer unit 24, a paper feeding unit 30, a paper transport unit 35, a secondary transfer unit 45, a fixing device 47, and the like.

  The image forming unit 10 includes a rotary developing unit 2, a photosensitive drum 11, a charging roller 12, a drum cleaning device 13, a laser unit 14, and the like.

  The photosensitive drum 11 is an image bearing member on which an electrostatic latent image is formed, and is driven to rotate about the center of the image forming apparatus 1 (the direction of rotation is indicated by an arrow). The rotation shaft (not shown) is provided so as to extend perpendicular to the paper surface of FIG. The photosensitive drum 11 is formed so as to have a photosensitive layer such as amorphous silicon or an OPC photosensitive member.

  The charging roller 12 is provided on the photosensitive drum 11. The charging roller 12 is in contact with the photosensitive drum 11 and is rotatably supported in order to uniformly charge the surface of the photosensitive drum 11. A cleaner 12 a that cleans deposits adhering to the charging roller 12 is provided above the charging roller 12.

  The drum cleaning device 13 is provided on the right side of the photosensitive drum 11 in FIG. 1, and is for cleaning toner (developer) and deposits remaining on the surface of the photosensitive drum 11.

  The rotary developing unit 2 is for developing the electrostatic latent image formed on the photosensitive drum 11 with toner of each color, and is provided adjacent to the left side of the photosensitive drum 11 in FIG. The rotary developing unit 2 includes a rotary rack 15 and four developing devices 16B (black), 16Y (yellow), 16C (cyan), and 16M (magenta) supported by the rotary rack 15, and rotates. It is a cylindrical shape that can rotate around the shaft 15a. The rotating shaft 15 a passes through the center of the rotary rack 15, and the axial direction thereof is parallel to the axial direction of the rotating shaft of the photosensitive drum 11.

  The rotary rack 15 has four sections that are divided into four equal parts in the circumferential direction by a partition frame 15b extending radially from the center of the rotating shaft 15a. In each section, developing devices 16B, 16Y, 16C, and 16M corresponding to four toner colors of black, yellow, cyan, and magenta are arranged, and the developing devices 16B, 16Y, 16C, and 16M have the same configuration. is there. When the rotary developing unit 2 rotates, the developing rollers 53 of the developing devices 16B, 16Y, 16C, and 16M face the photosensitive drum 11 with a predetermined gap. The detailed configuration of the rotary rack 15 and the developing devices 16B, 16Y, 16C, and 16M will be described later.

  The laser unit 14 is for scanning and exposing the photosensitive drum 11 based on image information from an external computer or the like, and is provided above the rotary developing unit 2. Data for causing the laser unit 14 to output the laser light 14L is created by the data processing unit 17 that receives image information. Then, the laser light 14L is emitted from the laser unit 14. A reflection mirror 18 is provided on the optical path of the laser beam 14L, and the laser beam 14L is irradiated onto the surface of the photosensitive drum 11 by the reflection mirror 18 (the laser beam 14L is shown by a two-dot chain line). The laser unit 14 includes a laser light source, a polygon mirror, a polygon mirror driving motor, and the like (not shown).

  The toner supply device 20 includes a toner storage container 21 and a toner supply member 22. The toner storage containers 21 are provided above the photosensitive drum 11 and the intermediate transfer belt 25, and four toner storage containers 21 are arranged side by side in the direction perpendicular to the paper surface of FIG. Each toner storage container 21 is a portion for storing toner to be supplied to each developing device 16B, 16Y, 16C, 16M of the rotary developing unit 2. That is, each toner storage container 21 stores toner of any one color of black, yellow, cyan, and magenta. In FIG. 1, the toner container 21 is invisible except for one toner container 21.

  The toner replenishing member 22 is disposed above the photosensitive drum 11 in a space between the laser unit 14 and the toner container 21 and is configured to be movable up and down, and is provided in four corresponding to each color. Each toner supply member 22 is connected to the corresponding toner storage container 21 by a pipe, a hose, or the like, and supplies the toner of each color stored in the toner storage container 21 to the corresponding developing devices 16B, 16Y, 16C, and 16M.

  The intermediate transfer unit 24 includes an intermediate transfer belt 25 to which toner images of respective colors formed on the photosensitive drum 11 are sequentially transferred, a driving roller 26 for stretching and driving the intermediate transfer belt 25, and a tension roller 27. A primary transfer roller 28 that faces the photosensitive drum 11 with the intermediate transfer belt 25 therebetween, and a driven member provided near the primary transfer roller 28 and between the drive roller 26 and the primary transfer roller 28. The roller 28 a and a belt cleaning device 29 for cleaning the intermediate transfer belt 25 are configured. The intermediate transfer belt 25 stretched around each roller rotates and passes through the nip between the photosensitive drum 11 and the primary transfer roller 28, and the toner images of the respective colors are superimposed and primarily transferred, and the superimposed toner images. Is later transferred to the paper P by the secondary transfer unit 45.

  The paper feed unit 30 includes a paper feed cassette 31, a manual feed tray 32, and the like. A paper feed cassette 31 having a placement plate 31 a on which the paper P is placed is provided at the bottom of the image forming apparatus 1. In addition, the paper feed unit 30 prevents the double feed to the right side of the pickup roller 33 and the pickup roller 33 to the right of the pickup cassette 31 in order to send out the paper P on the loading plate 31 a one by one to the paper conveyance path. A roller pair 34 is provided. Further, a manual feed tray 32 is provided on the right side surface of the apparatus so that paper can be separately fed. The manual feed tray 32 is also provided with a pickup roller 33 for sending the paper P one by one to the paper transport path.

  The paper transport unit 35 is for transporting the paper P in the image forming apparatus 1. The sheet conveying section 35 is a sheet for discharging the image-formed sheet P from the sheet feeding section 30 to a secondary transfer roller 46 described later, and from the secondary transfer roller 46 through the fixing device 47. From the second conveyance path 37 that reaches the discharge port 42, the reverse conveyance path 38 that is provided so as to connect the middle of the first conveyance path 36 to the middle of the second conveyance path 37 on the downstream side of the fixing device 47 in the sheet conveyance direction. Composed. A discharge tray 43 for receiving the discharged paper P is provided at the end of the second transport path 37. Note that the paper transport direction is indicated by arrows.

  A curved portion 39 is provided in the first transport path 36 in order to reverse the transport direction of the paper P sent out from the paper feed cassette 31. In addition, at the upper part of the curved portion 39, the conveyance path from the manual feed tray 32 joins. In front of the secondary transfer roller 46, a registration roller pair 40 for controlling the conveyance timing of the paper P is disposed. A plurality of pairs of conveyance rollers 41 are provided in the conveyance path in which these elements are provided, and a guide plate (not shown) for guiding the paper P is also provided as appropriate.

  The secondary transfer unit 45 includes a secondary transfer roller 46 and a driving roller 26. The secondary transfer roller 46 is for transferring the toner image transferred to the intermediate transfer belt 25 onto the sheet P conveyed so as to be sandwiched between the secondary transfer roller 46 and the intermediate transfer belt 25. Therefore, the secondary transfer roller 46 is supported so as to be rotatable and in contact with and away from the intermediate transfer belt 25 so as to form a nip via the drive roller 26 and the intermediate transfer belt 25. Further, a voltage is applied to the secondary transfer roller 46 so that the toner is transferred onto the paper P at a predetermined timing by a voltage applying means (not shown).

  The fixing device 47 is for melting and fixing the toner transferred onto the paper P, and is provided in the middle of the second transport path 37 and below the rotary developing unit 2. The fixing device 47 includes a heating roller 48 that incorporates a heater and a pressure roller 49 that presses the heating roller 48. The toner is heated and pressurized and fixed on the paper P.

  Next, an image forming operation will be described. The image forming apparatus 1 executes an image forming operation based on the input image data as follows.

  First, the photosensitive drum 11 is charged by the charging roller 12. The laser unit 14 scans and exposes the surface of the photosensitive drum 11 in accordance with data from the data processing unit 17 to which image data is input, and the electrostatic latent image is formed on the photosensitive drum 11. Is formed. Next, the rotary developing unit 2 is rotated counterclockwise in FIG. 1, and any one of the corresponding color developing devices 16 faces the photosensitive drum 11. In this state, the electrostatic latent image on the photosensitive drum 11 is developed by supplying the corresponding color toner. The developed toner image is transferred to the intermediate transfer belt 25. The toner remaining on the photosensitive drum 11 after the transfer is cleaned by the drum cleaning device 13. The above operation is sequentially repeated for each color, and a full-color toner image is formed on the intermediate transfer belt 25.

  On the other hand, in the paper feed unit 30, one sheet P is taken out from the paper feed cassette 31 or the manual feed tray 32 by the pickup roller 33 and conveyed to the registration roller pair 40. Thereafter, the sheet P is conveyed from the registration roller pair 40 to the toner image on the intermediate transfer belt 25 in time, and is guided to the secondary transfer unit 45. A predetermined voltage is applied to the secondary transfer roller 46 while being in contact with the intermediate transfer belt 25, and the toner image on the intermediate transfer belt 25 is transferred to the paper P. The sheet P is guided to the fixing device 47 through the second conveyance path 37, and the toner image is fixed on the sheet P by the fixing device 47. The fixed sheet P is discharged from the sheet discharge port 42 to the discharge tray 43 through the branching claw 44.

(First embodiment)
Next, the developing devices 16B, 16Y, 16C, and 16M supported by the rotary developing unit 2 will be described with reference to FIG. Here, since the constructions of the developing devices 16B, 16Y, 16C, and 16M are the same, the following explanation and the reference numerals of the drawings are omitted unless otherwise indicated. The description will be made in a unified manner with the device 16. Therefore, the following description applies in common to the developing devices 16B, 16Y, 16C, and 16M unless otherwise specified.

  FIG. 2 is a cross-sectional view showing a schematic configuration of the developing device 16 according to the first embodiment of the present invention. Note that the developing device 16 in FIG. 2 shows a state in which the developing roller 53 is in a developing position facing the photosensitive drum 11.

  The developing device 16 includes a frame 51, a partition member 52, a developing roller 53, a supply roller 54, a regulating member 55, a stirring member 56, and the like.

  The frame 51 forms the outer shell of the developing device 16 with the lower lower wall 51a, the upper upper wall 51b, the left side wall 51c, and the like shown in FIG. Inside, a developing roller 53, a supply roller 54, a regulating member 55 and a stirring member 56 are provided, and a toner supply unit 58 and a toner storage unit 59 store toner. A pair of concave and convex portions 71 and 72 described later is formed on the upper wall 51b of the toner containing portion 59.

  The partition member 52 is formed of, for example, a metal or resin plate member, separates the toner supply unit 58 and the toner storage unit 59, and includes a first partition member 61 and a second partition member 62.

  The first partition member 61 is provided from the lower wall 51 a adjacent to the developing roller 53 and the supply roller 54 toward the opposing upper wall 51 b (from the lower side to the upper side in FIG. 2), and forms the side wall of the toner containing portion 59.

  The second partition member 62 is directed from the upper wall 51b toward the first partition member 61 so as to face the first partition member 61 closer to the toner supply portion 58 than the first partition member 61 (in FIG. 2, from above to below). ). Opposing portions of the first partition member 61 and the second partition member 62 are passage portions 64 for the toner to move from the toner storage portion 59 to the toner supply portion 58.

  The toner accommodating portion 59 is a portion surrounded by the first partition member 61, the lower wall 51a, the upper wall 51b, and the side wall 51c, and the stirring member 56 is disposed. The toner supply unit 58 is a portion surrounded by the second partition member 62, the lower wall 51a, and the upper wall 51b regulating member 55, and is provided with a developing roller 53, a supply roller 54, and the like, and supplies toner to the photosensitive drum 11. .

  A part of the developing roller 53 is exposed from the frame 51, and is disposed opposite to the photosensitive drum 11 (partially indicated by a broken line in FIG. 2) with a certain gap, and rotates around the axis 53b. Then, toner is supplied to the photosensitive drum 11. A seal member 53a is provided between the developing roller 53 and the frame 51 to prevent toner leakage.

  The supply roller 54 is provided between the developing roller 53 and the partition member 52 so as to contact the developing roller 53 in order to supply toner to the developing roller 53. The supply roller 54 is rotatable and is supported so that the axis 54b of the supply roller 54 and the axis 53b of the developing roller 53 are parallel to each other. The supply roller 54 is rotated in the same direction as the developing roller 53 (clockwise in FIG. 2) by a drive mechanism (not shown) including a gear, a motor, and the like. The supply roller 54 supplies toner to the developing roller 53 at the upper contact portion (in the vicinity of the regulating member 55) in FIG. 2 at the contact portion with the developing roller 53, and the lower contact portion (lower portion in FIG. 2). In the vicinity of the wall 51a), it functions to scrape off toner that has not been used for development.

  The regulating member 55 is for contacting the developing roller 53 and rotating the developing roller 53 to form a thin layer of toner on the developing roller 53, and further has a function of charging the toner by friction. The regulating member 55 is formed in a film shape or a blade shape extending in the direction of the axis 53 b, one end abuts against the developing roller 53, and the other end is fixedly held by the support member 66.

  The agitating member 56 is provided in parallel and in parallel with the supply roller 54 and the developing roller 53, and agitates the toner in the toner accommodating portion 59 and conveys it in the axial direction. It is comprised by the axial part 81, the sheet | seat body 82 grade | etc.,.

  The shaft portion 81 is provided so as to span the inside of the toner storage portion 59 and is rotatably supported. As shown in FIG. 2, the shaft portion 81 has a T-shaped cross section, and its axial end is connected to a gear and a motor (not shown) and is rotated.

  The sheet body 82 is made of a flexible resin such as PET, and is formed in a flat plate shape having a rectangular shape over the entire length of the shaft portion 81 in the axial direction. One end thereof is cantilevered by the shaft portion 81, and the open end 82 a is an open end parallel to the axial direction of the shaft portion 81. The sheet body 82 has such a length that the open end 82 a is located in a range exceeding the maximum distance between the shaft support position of the shaft portion 81 in the toner storage portion 59 and the first partition member 61 of the toner storage portion 59. . For this reason, when the stirring member 56 rotates counterclockwise in FIG. 2, the open end 82a abuts on the first partition member 61, but the sheet body 82 is constituted by a flexible flat plate having elasticity. As a result, while the flat portion 82b is bent like a bow, the open end 82a comes into contact with the first partition member 61, and the toner is carried on the flat portion 82b. When the stirring member 56 further rotates and the open end 82a is separated from the first partition member 61, the sheet body 82 is deformed from a bowed shape to a flat shape by its elasticity, and is supported on the flat portion 82b. The toner is splashed toward the upper wall 51b.

  The pair of concavo-convex portions 71 and 72 are formed on the upper wall 51b of the toner containing portion 59 so as to be parallel to the axial direction. FIG. 3 shows a configuration of the pair of uneven portions 71 and 72. FIG. 3 shows a configuration in which the pair of concave and convex portions 71 and 72 are shown from below in FIG. 2, the stirring member 56 is disposed on the upper side in FIG. 3, and the left-right direction on FIG. . The surface shapes of the pair of uneven portions 71 and 72 are wavy hatched.

  As shown in FIG. 3, the 1st uneven | corrugated | grooved part 71 repeats the sine wave shape which has the peak part 71a and the trough part 71b. The second concavo-convex part 72 repeats the same sine wave shape as the first concavo-convex part 71. However, the first concavo-convex part 71 is different from the first concavo-convex part 71 in that the phase P of the peak part 71a and the peak part 72a is 1 / It is shifted by 4 cycles. Therefore, when the toners T1 and T2 bounced up from the substantially same position in the axial direction collide with the slope portion 71c of the first uneven portion 71, the toners T1 and T2 fly to the right side in FIG. If it collides with the slope 72c of the part 72, it will fly to the left on FIG.

  Further, the developing device 16 includes a toner remaining amount detection unit. FIG. 4 is a perspective view showing the remaining toner amount detection unit. FIG. 4 is a view showing the toner containing portion 59 from which the upper wall 51b of the developing device 16 is omitted.

  As shown in FIG. 4, the toner remaining amount detection unit includes a light emitting unit 5a, a sensor unit including a light receiving unit 5b, incident side and emission side optical path members 7a and 7b, a cleaning member 8, a base 6, and the like. In order to perform control when toner is replenished into the developing device 16 from the replenishing device 20 (see FIG. 1), the remaining amount of toner in the toner accommodating portion 59 is detected.

  The incident side and emission side optical path members 7a and 7b penetrate through the side wall 51d of the frame 51 and are fixed. The entrance-side and exit-side optical path members 7a and 7b are light guides such as rectangular parallelepiped acrylic resin, and one end thereof is formed on the prism surface, and the light from the light projecting unit 5a is transmitted as shown by the broken line in FIG. The light is bent at a right angle and guided to the light receiving portion 5b.

  The light emitting unit 5a and the light receiving unit 5b are attached to an image forming apparatus housing (not shown), and the light emitting unit 5a has, for example, a light emitting diode and irradiates light toward the incident side optical path member 7a. The light receiving portion 5b has a phototransistor and receives irradiation light from the emission side optical path member 7b. When the rotary developing unit 2 is rotated and the developing device 16 is positioned at a predetermined position (for example, development position), the light-emitting unit 5a and the light-receiving unit 5b are opposed to the light-emitting unit 5a. The emission side optical path member 7b faces the light receiving portion 5b.

  The base 6 is rotatably provided so as to penetrate the side wall 51d of the frame 51, and is configured in a disc shape. A pair of arm portions 9a and 9b are fixedly supported on the base 6, and a pair of cleaning members 8 are attached to the pair of arm portions 9a and 9b with an angular interval of 180 degrees. When the base 6 rotates, the pair of cleaning members 8 cleans the surfaces of the incident side and exit side optical path members 7a and 7b and blocks the optical path between the incident side and exit side optical path members 7a and 7b, and then enters the incident side. The light of the light projecting unit 5a is guided to the light receiving unit 5b via the incident side and output side optical path members 7a and 7b.

  Therefore, when the developing device 16 comes to a predetermined position (for example, a developing position), the incident side optical path member 7a faces the light emitting portion 5a, and the emission side optical path member 7b faces the light receiving portion 5b. When the cleaning member 8 is rotationally driven, the surfaces of the incident side and emission side optical path members 7a and 7b are cleaned and the light from the light emitting portion 5a is blocked. When the cleaning member 8 is further rotationally driven, the cleaning member 8 is Retracting from the emission side optical path members 7a and 7b, the light from the light emitting part 5a enters the light receiving part 5b through the incident side and the emission side optical path members 7a and 7b. Here, in the rotation period in which the light from the light emitting unit 5a is incident on the light receiving unit 5b, the amount of light received by the light receiving unit 5b varies depending on the amount of toner (toner accumulation height) in the toner containing unit 59. That is, when it is detected that the amount of light received by the light receiving portion 5b is attenuated every rotation cycle of the cleaning member 8, the amount of toner in the toner containing portion 59 is decreased. On the other hand, when it is detected that the amount of light received by the light receiving portion 5 b increases every rotation cycle of the cleaning member 8, toner is supplied to the toner containing portion 59.

  Next, operations of toner conveyance and toner amount detection in the toner container 59 of the developing device 16 will be described. FIG. 5 is a side cross-sectional view showing the process of conveying the toner in the toner container 59. With reference to FIGS. 1 and 4, the process will be described according to the process of FIGS. 5A, 5 </ b> B, and 5 </ b> C.

  The toner supply member 22 (see FIG. 1) supplies the toner in the toner storage container 21 to the toner storage unit 59 from a supply port (not shown) of the developing device 16. The supplied toner accumulates on the toner remaining in the toner container 59, but accumulates in the vicinity of the replenishing port and accumulates higher than other positions in the toner container 59. Therefore, the agitating member 56 rotates and agitates and conveys the toner as described below.

  As shown in FIG. 5A, when the stirring member 56 rotates, the sheet body 82 rises upward. At this time, the open end 82a abuts on the first partition member 61 and the toner 67a is carried on the flat portion 82b while the flat portion 82b of the sheet body 82 is bent like a bow.

  When the stirring member 56 further rotates, the open end 82a is separated from the first partition member 61, and the sheet body 82 is deformed from a bent shape to a flat shape by the elastic force of the sheet body 82. When deformed into a flat shape, as shown in FIG. 5B, the toner 67a carried on the flat portion 82b is splashed up toward the upper wall 51b. When the splashed toner collides with the first concavo-convex portion 71 and the second concavo-convex portion 72, as shown in FIG. 3, the toners T1 and T2 scatter and fly in the axial direction at the plurality of inclined portions 71c and 72c. .

  As shown in FIG. 5C, the flying toner falls in the toner container 59 and accumulates uniformly in the axial direction. When this series of agitation members 56 is repeated, the replenished toner is agitated with the remaining toner, and the toner accumulation height in the toner accommodating portion 59 becomes uniform in the axial direction.

  In the state where the toner in the toner container 59 is uniformly accumulated in this way, as shown in FIG. 4, in the toner remaining amount detection unit, the light receiving unit 5b is separated from the light emitting unit 5a every rotation cycle of the cleaning member 8. Light is received and the remaining amount of toner is detected.

  According to the first embodiment, the developing device 16 includes a toner storage unit 59, a toner supply unit 58 that supplies toner to the photosensitive drum 11, and a passage unit through which toner moves from the toner storage unit 59 to the toner supply unit 58. 64 and an agitating member 56 that is rotatably supported in the toner accommodating portion 59 and agitates the toner. The agitating member 56 includes a flexible sheet body 82 that is cantilevered by a shaft portion 81, and the sheet body 82 has an open end 82 a extending in the axial direction of the shaft portion 81 and a planar portion 82 b that holds toner. With. The toner accommodating portion 59 includes a first partition member 61 with which the open end 82a can abut and an upper surface wall 51b on which a pair of sinusoidal uneven portions 71 and 72 are formed. , 72 has a shape in which crest portions 71a, 72a and trough portions 71b, 72b are repeated in parallel with each other in the axial direction, and the phases of the concave and convex portions 71, 72 are different from each other. When the sheet member 82 rotates and the open end 82a contacts the first partition member 61, the sheet member 82 holds the toner at the flat portion 82b and bends. Next, when the open end 82a is separated from the first partition member 61, the sheet body 82 jumps up the toner toward the upper surface wall 51b and collides the toner with the pair of uneven portions 71 and 72 having different phases. When the toner diffuses in the axial direction and falls in the toner container 59, the height of the toner accumulation surface becomes uniform. Since the remaining amount of toner in the toner container 59 is detected based on the uniform height of the toner accumulation surface, it is possible to accurately detect the remaining amount of toner.

  According to the first embodiment, if the image forming apparatus 1 is provided with the developing device 16 described above, the height of the toner accumulation surface is uniform when detecting the remaining amount of toner in the toner storage unit 59. Therefore, it is possible to provide the image forming apparatus 1 that can accurately detect the remaining amount of toner.

(Second Embodiment)
FIG. 6 is a perspective view illustrating a configuration of a pair of uneven portions in the developing device according to the second embodiment of the present invention. 6 shows a configuration in which the pair of concavo-convex portions 73 and 74 are shown from below in FIG. 2, the stirring member 56 is arranged on the upper side in FIG. 6, and the horizontal direction in FIG. It is. FIG. 7 is a plan view showing the configuration of the sheet member in the developing device according to the second embodiment of the present invention. A pair of uneven | corrugated | grooved parts and a sheet body different from 1st Embodiment are demonstrated, and description of the same part as 1st Embodiment is abbreviate | omitted hereafter.

  As shown in FIG. 6, the pair of concave and convex portions 73 and 74 are formed side by side in parallel to the axial direction. The first concavo-convex portion 73 is disposed such that the inclined surface portion 73a of the right triangular prism body is directed to the left in the axial direction in FIG. 6 and the short surface portion 73b is perpendicular to the axial direction. A plurality of bodies are formed side by side in the axial direction. The second concavo-convex portion 74 is formed by arranging a plurality of right triangular prisms having the same shape as the first concavo-convex portion 73 in the axial direction, and the inclined surface portion 74a faces rightward in the axial direction on FIG. 74 b is perpendicular to the axial direction and arranged so as to be aligned with the short surface portion 73 b of the first uneven portion 73.

  Accordingly, when the toners T1 and T2 bounced up by the sheet member 82 from substantially the same position in the axial direction collide with the inclined surface portion 73a of the first uneven portion 73, they fly to the right side in FIG. When it collides with the slope portion 74a of the portion 74, it flies to the left in FIG. 6, and the toner diffuses in the axial direction.

  Next, the sheet body 82 will be described with reference to FIG. The sheet body 82 is made of a flexible resin such as PET, and is formed in a flat plate shape having a rectangular shape over the entire length of the shaft portion 81 in the axial direction. One end thereof is cantilevered by the shaft portion 81, and the open end 82 a is an open end parallel to the axial direction of the shaft portion 81. A plurality of slits 82 c are formed on the flat surface portion 82 b from the release end 82 a toward the shaft portion 81.

  As shown in FIG. 2, the sheet body 82 has an open end 82 a in a range exceeding the maximum distance between the shaft support position of the shaft portion 81 in the toner storage portion 59 and the first partition member 61 of the toner storage portion 59. The length is to be. Here, even if the release end 82a is inclined and abutted against the first partition member 61 due to a manufacturing error of the member, an assembly deviation, or the like, the inclination ratio is small at the release end 82a between the slits 82c. The open end 82a is in contact with the first partition member 61 without being greatly inclined, and the flat portion 82b carries the toner. When the stirring member 56 is further rotated and the open end 82a is separated from the first partition member 61, the sheet body 82 is deformed into a flat shape by the elasticity without the flat portion 82b between the slits 82c being greatly inclined. Then, the toner is jumped almost directly above.

  According to the second embodiment, the pair of concavo-convex portions 73 and 74 are formed such that a plurality of triangular prisms are aligned in the axial direction, and the inclined surfaces 73a and 74a of the triangular prisms are directed in opposite directions in the axial direction. The Thus, when the sheet body 82 rotates and the open end 82a contacts the first partition member 61, the sheet body 82 holds the toner at the flat portion 82b and bends. Next, when the open end 82a is separated from the first partition member 61, the sheet body 82 jumps up the toner toward the upper surface wall 51b and causes the toner to collide with the inclined surface portions 73a and 74a facing in the opposite axial direction. When the toner diffuses in the axial direction and falls into the toner containing portion 59, the height of the toner accumulation surface becomes uniform. Since the remaining amount of toner in the toner container 59 is detected based on the uniform height of the toner accumulation surface, it is possible to accurately detect the remaining amount of toner.

  In addition, the flat portion 82b of the sheet body 82 is formed with a plurality of slits 82c from the open end 82a toward the shaft portion 81, so that the open end 82a is not caused by a manufacturing error of a member or a deviation in assembly. Even if the first partition member 61 is inclined and abutted, the open ends 82a between the slits 82c abut against the first partition member 61, and the toner carried on the flat portion 82b between the slits 82c is transferred to the upper wall. Since it jumps up almost directly toward 51b, the toner colliding with the slopes 73a and 74a is diffused in the axial direction without unevenness.

(Third embodiment)
FIG. 8 is a plan view showing the configuration of the sheet member in the developing device according to the third embodiment of the present invention. The sheet body 82 is made of a flexible resin such as PET, and is formed in a flat plate shape having a rectangular shape over the entire length of the shaft portion 81 in the axial direction. One end thereof is cantilevered by the shaft portion 81, and the open end 82 a is an open end parallel to the axial direction of the shaft portion 81. A plurality of openings 82d are formed in the plane portion 82b. The amount of toner carried on the flat surface portion 82b is limited by the opening 82d, and the sheet body 82 jumps up the limited amount of toner toward the upper surface wall 51b, and forms a pair of concave and convex portions 71 and 72. Since the toner collides, the amount of toner to be conveyed can be adjusted according to the size of the opening.

  In the first to third embodiments, an example in which the present invention is applied to the rotary developing unit 2 has been described. However, the present invention is not limited to this and may be applied to a tandem developing unit.

  In the first and second embodiments, the pair of concave and convex portions is formed in a sinusoidal shape or a plurality of right-angled triangular prisms. However, the present invention is not limited thereto, and is configured by a pair of a plurality of isosceles triangular prisms. However, the phases of the slope portions may be different from each other. In this case as well, the toner can be diffused in the axial direction on the inclined surface as described above.

  Further, in the first and second embodiments, the configuration in which the pair of uneven portions is arranged in the axial direction is shown. However, the present invention is not limited to this, and another pair of uneven portions is arranged in the axial direction. Good.

  The present invention can be used for a developing device in an image forming apparatus such as a copying machine, a printer, and a facsimile, and an image forming apparatus using the developing device.

FIG. 1 is a schematic diagram illustrating an overall configuration of an image forming apparatus that is an embodiment of the present invention. FIG. 2 is a side sectional view showing the developing device in the image forming apparatus according to the first embodiment of the present invention. These are side surface sectional drawings which show the structure of a pair of uneven | corrugated | grooved part in the developing device which is 1st Embodiment of this invention. FIG. 3 is a perspective view showing a toner remaining amount detection unit in the developing device according to the first embodiment of the present invention. These are side cross-sectional views showing the process of toner conveyance in the developing device according to the first embodiment of the present invention. These are perspective views which show the structure of a pair of uneven | corrugated | grooved part in the developing device which is 2nd Embodiment of this invention. These are the top views which show the structure of the sheet | seat body in the image development apparatus which is 2nd Embodiment of this invention. These are top views which show the structure of the sheet | seat body in the image development apparatus which is 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Rotary developing unit 5a Light emission part 5b Light receiving part 6 Base 7a Incident side optical path member 7b Emission side optical path member 8 Cleaning member 9a, 9b Arm part 15 Rotary rack 15a Rotating shafts 16, 16B, 16Y, 16C, 16M developing device 51 frame 53 developing roller 54 supply roller 55 regulating member 56 stirring member 58 toner supply unit 59 toner storage unit 61 first partition member (partition member 52)
62 Second partition member (partition member 52)
71, 73 First uneven portion 71a, 72a Mountain portion 71b, 72b Valley portion 71c, 72c Slope portion 72, 74 Second uneven portion 73a, 74a Slope portion 73b, 74b Short surface portion 81 Shaft portion 82 Sheet body 82a Open end 82b Plane Part 82c slit 82d opening

Claims (7)

Toner supported by a toner container, a toner supply part for supplying toner to the image carrier, a passage part through which toner moves from the toner container to the toner supply part, and a rotating shaft rotatable in the toner container. In a developing device comprising a stirring member that stirs
The stirring member includes a flexible sheet body that is cantilevered on the rotating shaft, and the sheet body includes an open end that extends in the rotating shaft direction and a flat surface that holds the toner.
The toner storage portion includes a side wall on which the open end can be contacted and an upper surface wall on which a pair of concavo-convex portions are formed. Have a shape of repeated parts, and the phase of each uneven part is different from each other,
When the sheet body rotates and the open end comes into contact with the side wall, the sheet body holds and bends toner at the flat portion, and when the open end is separated from the side wall, the sheet body is A developing device, wherein the toner is splashed toward the upper surface wall so that the toner collides with the pair of concave and convex portions.   The developing device according to claim 1, wherein the pair of concave and convex portions have the same sine wave shape.   The pair of concavo-convex portions are formed such that a plurality of triangular prisms are arranged in an axial direction, and one inclined surface portion of the triangular prisms is oriented in opposite directions in the axial direction. Development device.   The developing device according to claim 1, wherein the flat portion is formed with a slit from the open end toward the rotating shaft.   The developing device according to claim 1, wherein the flat portion has an opening.   6. The side wall according to claim 1, wherein the side wall is formed by a partition part that separates the toner supply part and the toner storage part, and the open end abuts on the partition part. Development device.   An image forming apparatus on which the developing device according to claim 1 is mounted.

Images