JP2017040776A - Development device and image formation apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a development device which is reduced in size in comparison to a conventional development device and an image formation apparatus.SOLUTION: A development device 21 includes: a housing body 30 which has a storage part 35 storing toner; a development roller 32 which is provided on the upper side than the storage part 35 in the housing body 30, supported so as to be rotatable in the predetermined rotation direction X2, carries the toner in the storage part 35 on the surface thereof by receiving the toner at a predetermined position P1, and conveys the toner to a predetermined position P2 on the downstream side in the rotation direction X2 with rotation; a planar regulation blade 34 which is provided on the downstream side in the rotation direction L2 with respect to the position P1 and on the upstream side in the rotation direction X2 with respect to the position P2, and regulates the layer thickness of the toner carried on the surface of the development roller 32; and a support part 70 which is integrally formed in the housing body 30 and supports a regulation blade 34 between the development roller 32 and the surface.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a developing device that develops an electrostatic latent image by an electrophotographic method, and an image forming apparatus including the developing device.

  Generally, a developing device is mounted on an image forming apparatus such as a multifunction peripheral. As an example of this type of developing device, an apparatus including a developing roller and a layer thickness regulating member is known. The bottom of the developing device has a reservoir for storing the developer. When the developer roller receives the developer from the reservoir, the developer roller carries the developer on the surface thereof. The layer thickness regulating member adjusts the layer thickness of the developer formed on the surface of the developing roller to a constant thickness.

  As a technique for installing the layer thickness regulating member, a predetermined portion of a housing for housing the developing roller has a double structure, and a storage chamber capable of accommodating the layer thickness regulating member by the double structure is provided. Is known (see, for example, Patent Document 1). The layer thickness regulating member has a cylindrical shape. In the storage chamber, the layer thickness regulating member can be stored in parallel with the rotation axis of the developing roller.

  As another technique for installing the layer thickness regulating member, a technique is known in which a layer thickness regulating member formed in a blade shape is supported by a housing of a developing device. A support member as a separate part is attached to the housing, and the layer thickness regulating member is supported by the housing via the support member. The layer thickness regulating member is attached to the support member in a posture extending toward a predetermined layer thickness regulating position of the developing roller.

JP 2010-210993A

  In the configuration in which the blade-shaped layer thickness regulating member is attached to the support member, the layer thickness regulating member is disposed at a position relatively away from the storage portion. In other words, the layer thickness regulating member is disposed at a position separated from the housing by a space for attaching the support member to the housing. For this reason, the distance between the layer thickness regulating member and the reservoir is reduced, and the distance between the layer thickness regulating position and the receiving position for receiving the developer from the reservoir is increased. For this reason, there is a problem that the developing device cannot be made compact.

  An object of the present invention is to provide a developing device and an image forming apparatus that are made more compact than a conventional developing device.

  A developing device according to one aspect of the present invention includes a housing body, a first rotating body, a layer thickness regulating member, and a first support portion. The housing body has a reservoir for storing the developer. The first rotating body is provided above the reservoir in the housing body, and is supported so as to be rotatable in a predetermined rotation direction. The developer in the reservoir is received in advance. It is received at the position, carried on the outer peripheral surface, and conveyed to a predetermined supply position downstream in the rotation direction by being rotated. The layer thickness regulating member is provided downstream of the receiving position in the rotational direction and upstream of the supply position in the rotational direction. The layer thickness regulating member is plate-shaped and regulates the layer thickness of the developer carried on the outer peripheral surface of the first rotating body. The first support portion is formed integrally with the housing body, and supports the layer thickness regulating member between the outer peripheral surface of the first rotating body.

  An image forming apparatus according to another aspect of the present invention includes a photoreceptor and the developing device. An electrostatic latent image is formed on the surface of the photoreceptor. The developing device visualizes the electrostatic latent image into a toner image by supplying toner contained in the developer to the photoconductor.

  According to the present invention, it is possible to provide a developing device and an image forming apparatus that are made more compact than a conventional developing device.

FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the configuration of the developing device. FIG. 3 is a cross-sectional view showing the developing roller and its supporting structure. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an explanatory diagram of a method for mounting the regulating blade. FIG. 6 is a diagram showing a modified embodiment relating to a configuration for applying a pressing force to the regulating blade. FIG. 7 is a view showing a modified embodiment relating to the configuration for supporting the proximal end portion of the regulating blade. FIG. 8 is a view showing a modified form of the support structure for supporting the support portion.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention. In the following description, the up-down direction 501, the left-right direction 502, and the front-rear direction 503 shown in FIG.

[First Embodiment]
The configuration of the image forming apparatus 1A according to the first embodiment of the present invention will be described with reference to FIGS. The image forming apparatus 1A is an electrophotographic image forming apparatus. The image forming apparatus 1A includes a sheet supply unit 2, a sheet conveying unit 3, an image forming unit 4, an optical scanning unit 5, a fixing unit 6, a toner supply unit 8, and the like in a housing 7.

  The image forming apparatus 1A is a tandem image forming apparatus and a color printer. Therefore, the image forming unit 4 further includes an intermediate transfer belt 9, a cleaning device 10, and a secondary transfer device 11.

  The image forming unit 4 includes a plurality of single-color image forming units 4A corresponding to cyan, magenta, yellow, and black colors. Further, the image forming apparatus 1A includes a plurality of toner replenishing units 8 that supply toner of each color of cyan, magenta, yellow, and black to each storage unit 35 (see FIG. 2) of each developing device 21 described later. The toner replenishing unit 8 is detachably attached to the housing 7 of the image forming apparatus 1A. In the present embodiment, the toner replenishing unit 8 is mounted above the image forming unit 4.

  Note that the image forming apparatus 1A may be a copier, a facsimile, or a multifunction machine having both a printer function, a facsimile function, a scan function, and the like.

  The sheet supply unit 2 includes a sheet receiving unit 12 and a sheet sending unit 13. The sheet receiving unit 12 can stack a plurality of recording sheets 14. The recording sheet 14 is a sheet-like image forming medium such as paper, coated paper, postcard, envelope, and OHP sheet.

  The sheet delivery unit 13 rotates in contact with the recording sheet 14 to send the recording sheet 14 from the sheet receiving unit 12 toward the conveyance path 15.

  The sheet conveyance unit 3 includes a registration roller 16, a conveyance roller 17, a discharge roller 18, and the like. The registration roller 16 and the conveyance roller 17 convey the recording sheet 14 supplied from the sheet supply unit 2 toward the secondary transfer device 11 of the image forming unit 4. Further, the discharge roller 18 discharges the recording sheet 14 after the image formation from the discharge port of the conveyance path 15 onto the discharge tray 26.

  The intermediate transfer belt 9 is an endless belt-like member formed in an annular shape. The intermediate transfer belt 9 rotates while being stretched between two rollers. In the image forming unit 4, each single color image forming unit 4 </ b> A forms an image of each color on the surface of the rotating intermediate transfer belt 9. As a result, a color image in which the images of the respective colors are superimposed is formed on the intermediate transfer belt 9.

  The secondary transfer device 11 transfers the toner image formed on the intermediate transfer belt 9 to the recording sheet 14. The cleaning device 10 removes toner remaining on a portion of the intermediate transfer belt 9 after passing through the secondary transfer device 11.

  Each monochrome image forming unit 4A includes a photosensitive drum 19 that carries a toner image, a charging device 20, a developing device 21, a primary transfer device 22, a cleaning device 23, and the like. The electrostatic drum image is formed on the photosensitive drum 19 by irradiating laser light based on image data from the optical scanning unit 5, and the electrostatic latent image is visualized by the toner supplied from the developing device 21. Is done. The primary transfer device 22 and the secondary transfer device 11 transfer the toner image formed on the photosensitive drum 19 to the recording sheet 14. The cleaning device 23 removes the toner remaining on the photosensitive drum 19 from the photosensitive drum 19 after the transfer process executed by the primary transfer device 22.

  Each of the photosensitive drums 19 rotates at a peripheral speed corresponding to the peripheral speed (moving speed) of the intermediate transfer belt 9. As the photosensitive drum 19, for example, the photosensitive drum 19 may be an amorphous silicon (a-Si) photosensitive member or an organic photosensitive member.

  In each monochrome image forming unit 4A, the photosensitive drum 19 rotates, and the charging device 20 charges the surface of the photosensitive drum 19 uniformly. Further, an electrostatic latent image is formed on the surface of the charged photosensitive drum 19 by the optical scanning unit 5 scanning the laser beam.

  The developing device 21 supplies the toner to the photosensitive drum 19 and develops the electrostatic latent image using a two-component developer including toner and a carrier. The developing device 21 charges the toner by stirring the two-component developer and supplies the charged toner to the photosensitive drum 19. The two-component developer is an example of the developer of the present invention.

  The charging device 20 includes a charging roller 25 that charges a portion of the photosensitive drum 19 before the electrostatic latent image is written.

  The image forming apparatus 1A is communicably connected to another communication device. The other communication device is, for example, a personal computer. The image forming apparatus 1A executes an image forming job requested from the other communication device. The job information of the image forming job includes information such as the type of the image forming mode and the type of the recording sheet 14. The recording sheet 14 includes types such as plain paper and cardboard.

  As shown in FIG. 2, the developing device 21 includes a housing main body 30 that is an apparatus main body of the developing device 21. The housing body 30 has a long shape in the front-rear direction 503. The developing device 21 includes a developing roller 32, two stirring members 33, and a regulation blade 34. The developing roller 32, the agitating member 33, and the regulating blade 34 have a long shape in the front-rear direction 503, similar to the housing body 30. The developing roller 32 and the stirring member 33 are provided in the housing main body 30. Specifically, the developing roller 32 and the stirring member 33 are supported by the housing body 30 so as to be rotatable about rotation axes that are parallel to each other. The two stirring members 33 are juxtaposed in the left-right direction 502 with a predetermined distance therebetween. The developing roller 32 is disposed obliquely upward to the right with a predetermined distance from the stirring member 33 located on the right side. A photosensitive drum 19 is disposed diagonally to the right of the developing roller 32.

  The housing body 30 is made of resin. The lower frame 41, the upper frame 42, the first plate 43, the second plate 44 (see FIG. 3), and the third plate 45 (see FIG. 3). And have. Note that these members are connected to each other by screwing, engagement, adhesion, or the like. Alternatively, the second plate 44 and the third plate 45 may be integrally formed with the lower frame 41. The 2nd plate 44 and the 3rd plate 45 are provided in the both ends of the direction orthogonal to the paper surface of FIG. The lower frame 41 is an example of a lower housing in the present invention. In the present embodiment, the upper frame 42 and the first plate 43 are separate members, but the upper frame 42 and the first plate 43 may be integrally formed. The upper frame 42 and the first plate 43 are an example of an upper housing in the present invention.

  The lower frame 41 constitutes a lower portion of the housing body 30 and forms a storage portion 35 for storing the two-component developer therein. The storage unit 35 includes a first storage chamber 35A and a second storage chamber 35B. Specifically, the lower frame 41 includes a bending portion 41A, a bending portion 41B, a wall portion 41C, and a wall portion 41D. The curved portion 41A is curved downward in a circular arc shape to form the first storage chamber 35A. The curved portion 41B is curved downward in a circular arc shape to form the second storage chamber 35B. The curved portion 41A and the curved portion 41B are connected at the end 41E of the arc.

  The toner contained in the two-component developer stored in the storage unit 35 is supplied from the toner supply unit 8 (see FIG. 1). Specifically, the toner supplied from the toner supply unit 8 is first supplied to the first storage chamber 35A. Thereafter, the toner is supplied to the second storage chamber 35 </ b> B while being conveyed by a stirring member 33 described later. The toner is made of resin, and the carrier is made of a magnetic material. The toner has a particle size smaller than that of the carrier. The toner has a smaller weight than the carrier. The carrier is magnetic particles made of ferrite or the like. As will be described later, the toner is charged by static electricity generated by friction between the toner and the carrier by being stirred in a mixed state with the toner. Due to the presence of the carrier, the two-component developer can easily charge the toner as compared with a one-component developer composed of only toner, and the image quality can be improved. However, the developer accommodated in the developer accommodating portion 35 may be a one-component developer. A one-component developer is an example of the developer of the present invention. Further, an external additive is added to the two-component developer, and the external additive adheres to the surface of the toner. Examples of the external additive include metal oxides such as silica, alumina, titanium oxide, zinc oxide, and magnesium oxide.

  The wall portion 41C is a portion that extends upward from the right end portion 41F in the left-right direction 502 among the both end portions 41E and 41F of the arc that is the cross-sectional shape of the curved portion 41B. The wall portion 41C defines the right side of the second storage chamber 35B. The wall portion 41C has a tapered cross section. Specifically, the wall portion 41 </ b> C has an outer surface 411 and an outer surface 412 on the side opposite to the surface facing the stirring member 33. The outer side surface 411 extends upward from the end portion 41F. The outer side surface 412 extends obliquely upward from the upper end of the outer side surface 411 toward the storage portion 35 side. The wall portion 41C is an example of a first wall portion in the present invention.

  The wall portion 41D is a portion extending upward from the connecting portion between the bending portion 41A and the bending portion 41B, and partitions the upper space of the first storage chamber 35A and the upper space of the second storage chamber 35B. The wall portion 41D has a communication hole (not shown) that allows the first storage chamber 35A and the second storage chamber 35B to communicate with each other, and the two-component developer stored in the first storage chamber 35A is second through the communication hole. It is supplied to the storage chamber 35B.

  The upper frame 42 is provided on the upper side of the lower frame 41. The upper frame 42 includes a cover part 421 and a cover part 422. The cover part 421 extends along the outer periphery of the stirring member 33 provided in the first storage chamber 35A so as to cover the first storage chamber 35A from above. The cover part 422 covers the second storage chamber 35B from above and obliquely upwards from the right end of the cover part 421 to the right side in the left-right direction 502 so as to define a space S1 for installing the developing roller 32. It extends and reaches above the upper end portion 42A of the wall portion 41C. Due to the shape of the upper frame 42, a space in the vertical direction of FIG. 2 is provided in the space S1 above the wall portion 41C.

  The first plate 43 is provided on the right side in the left-right direction 502 with respect to the wall 41C, that is, at a position opposite to the second storage chamber 35B with respect to the wall 41C. The left-right direction 502 is a direction that intersects the extending direction in which the wall portion 41C extends. Further, the right side in the left-right direction 502 corresponds to the direction opposite to the second storage chamber 35B with respect to the wall portion 41C. The first plate 43 is a member for receiving the toner falling from the developing roller 32 and returning the toner to the second storage chamber 35B.

  The first plate 43 has a dish-shaped cross-sectional shape, and is provided in a posture that is inclined from the upper right to the lower left so as to oppose the lower right portion of the peripheral surface of the developing roller 32. Yes. The first plate 43 is provided such that the upper end portion 43A is spaced obliquely downward to the right from the upper end portion 42A of the upper frame 42, and the lower end portion 43B is opposed to the substantially central portion of the side surface 34D of the regulating blade 34 in the vertical direction. Yes. That is, the upper end portion 43A of the first plate 43 is separated from the wall portion 41C to the opposite side of the second storage chamber 35B with respect to the wall portion 41C than the lower end portion 43B. As a result, a space in the left-right direction 502 (lateral direction in FIG. 2) of the space S1 is provided above the wall portion 41C. The 1st plate 43 is an example of the 2nd wall part of the present invention. A space S1 is provided above the wall 41C by the upper frame 42 and the first plate 43, and the developing roller 32 is provided in the space S1.

  The upper end portion 42A of the upper frame 42 and the upper end portion 43A of the first plate 43 are separated from each other, and an opening 30A is formed in an upper right portion of the housing body 30. The upper end 42A of the upper frame 42 defines the upper edge of the opening 30A, and the upper end 43A of the first plate 43 defines the lower edge of the opening 30A. A part of the peripheral surface of the developing roller 32 is exposed from the housing body 30 through the opening 30 </ b> A, and the exposed portion and the photosensitive drum 19 face each other.

  An insertion port 30 </ b> B is formed in the right side portion of the housing body 30 by the upper end portion 415 of the wall portion 41 </ b> C and the lower end portion 43 </ b> B of the first plate 43. The upper end portion 415 of the wall portion 41 </ b> C and the lower end portion 43 </ b> B of the first plate 43 define an edge portion of the insertion port 30 </ b> B of the restriction blade 34. The restriction blade 34 penetrates the insertion opening 30B. In order to prevent the toner from leaking out of the housing body 30 through the gap between the insertion port 30B and the regulating blade 34, the gap is closed by a seal member (not shown).

  The stirring member 33 is rotatably provided inside the first storage chamber 35A and the second storage chamber 35B. The stirring member 33 stirs the two-component developer in the first storage chamber 35A and the second storage chamber 35B. The stirring member 33 is a screw member in this embodiment. The stirring member 33 is a long member extending along a direction orthogonal to the paper surface of FIG. The agitating member 33 is made of resin. The stirring member 33 is rotatably supported by the second plate 44 and the third plate 45. A rotation axis Q3 shown in FIG. 2 indicates the rotation axis of the agitating member 33 that agitates the two-component developer in the second storage chamber 35B. As the stirring member 33 rotates, the two-component developer in the reservoir 35 is stirred while moving. The toner is charged to a predetermined polarity by static electricity generated by the stirring.

  The developing roller 32 is disposed in the space S <b> 1 in the housing body 30 and is rotatably provided. That is, the developing roller 32 is located above the second storage chamber 35B and the upper end portion of the wall portion 41C, and the surface (outer peripheral surface) of the developing roller 32 faces the upper end portion 415 of the wall portion 41C. The developing roller 32 receives the two-component developer stirred by the stirring member 33 from the second storage chamber 35B by a magnetic force and receives the developer on the surface thereof.

  As shown in FIGS. 2 and 3, the developing roller 32 includes a developing sleeve 48 and a magnetic pole portion 54.

  The developing sleeve 48 includes a sleeve main body 48A and a shaft member 48B. The sleeve body 48 </ b> A is a part having a cylindrical shape and constitutes the surface of the developing roller 32. The shaft member 48B is provided at both ends in the axial direction of the sleeve main body 48A. The shaft member 48B includes a fitting portion 481 that is fitted into and fixed to the openings at both ends of the sleeve main body 48A, and a columnar rotary shaft portion 482 provided on the outer surface of the fitting portion 481. The rotation shaft portion 482 is a portion that extends in the direction orthogonal to the outer surface from the center of the outer surface of the fitting portion 481. The center of the cross section perpendicular to the protruding direction of the rotation shaft portion 482 becomes the rotation axis Q1 (see FIG. 2) of the developing sleeve 48. The rotating shaft portion 482 is an example of the rotating shaft of the first rotating body.

  The developing sleeve 48 is rotatably supported by the second plate 44 and the third plate 45. Specifically, the inner side surface 441 of the second plate 44 and the inner side surface 451 of the third plate 45 face each other. A boss portion 442 that protrudes in the axial direction of the rotation shaft portion 482 of the developing roller 32 is formed on the inner side surface 441 of the second plate 44. A boss portion 452 that protrudes in the axial direction of the rotation shaft portion 482 of the developing roller 32 is formed on the inner surface 451 of the third plate 45. The boss portions 442 and 452 are formed with concave portions 443 and 453 that are recessed in the axial direction from the protruding end portions. In other words, the boss portions 442 and 452 have a cylindrical shape. The boss portion 442 and the boss portion 452 face each other.

  A ball bearing 80 is fitted into the concave portion 443 of the boss portion 442, and a ball bearing 81 is fitted into the concave portion 453 inside the boss portion 452. That is, the diameters of the recesses 443 and 453 formed in the boss portions 442 and 452 are substantially the same as the outer diameters of the ball bearings 80 and 81. The boss portion 442 is fitted on the ball bearing 80, and the boss portion 452 is fitted on the ball bearing 81. As described above, the ball bearings 80 and 81 are fixed to the second plate 44 and the third plate 45. The ball bearings 80 and 81 are an example of a bearing portion in the present invention.

  The rotation shaft portion 482 of the shaft member 48B of the developing sleeve 48 is fitted into the ball bearings 80 and 81. Accordingly, the rotation shaft portion 482 of the developing sleeve 48 is rotatably supported by the second plate 44 and the third plate 45 through the ball bearings 80 and 81. The developing sleeve 48 is rotationally driven in the rotation direction X1 in FIG. 2 (counterclockwise direction in FIG. 2) during the development period in which the developing roller 32 develops the electrostatic latent image. The developing sleeve 48 is an example of a first rotating body of the present invention. The rotation direction X1 is an example of a predetermined rotation direction of the present invention.

  As shown in FIG. 3, the magnetic pole portion 54 has a plurality of magnetic poles provided inside the developing sleeve 48. The plurality of magnetic poles are a draw-up pole 49, a regulation pole 50, a transport pole 51, a main pole 52, and a separation pole 53, which are arranged in parallel at a predetermined interval in the circumferential direction. The positions of these magnetic poles 49 to 53 are fixed inside the developing sleeve 48. That is, the magnetic pole part 54 does not rotate. Each magnetic pole 49-53 is comprised with the permanent magnet which generate | occur | produces magnetic force, for example.

  The upper drawing pole 49 is a magnetic pole that generates a peak magnetic force at a position facing the stirring member 33 provided in the second storage chamber 35B. Specifically, the pumping pole 49 generates the peak magnetic force in the direction of the line segment connecting the rotation axis Q3 of the stirring member 33 provided in the second storage chamber 35B and the rotation axis Q1 of the developing roller 32. The two-component developer is attracted and attracted to the surface of the developing sleeve 48 by the magnetic force by the drawing upper pole 49. As a result, the two-component developer is carried on the surface of the developing sleeve 48. Then, when the developing sleeve 48 is rotated in this state, the two-component developer is carried downstream. A position P1 in FIG. 2 indicates a transfer position where the two-component developer accommodated in the second storage chamber 35B is transferred to the developing sleeve 48, and is an example of a receiving position in the present invention.

  The regulation pole 50 is provided at a position facing a later-described tip portion 34A of the regulation blade 34, and magnetizes the regulation blade 34. Thereby, a magnetic field is formed in the gap between the tip end portion 34 </ b> A of the regulating blade 34 and the regulating pole 50. When the two-component developer attached to the surface of the developing sleeve 48 by the scooping upper pole 49 passes through the gap, the two-component developer is magnetically restrained by the magnetic field in the gap, and the two-component developer layer The thickness is regulated by the tip end portion 34 </ b> A of the regulation blade 34. As a result, a developer layer having a uniform layer thickness is formed on the surface of the developing sleeve 48.

  The conveyance pole 51 is provided at a position adjacent to the regulation electrode 50 on the downstream side in the rotation direction X1 from the regulation electrode 50. The transport pole 51 carries the two-component developer on the developing sleeve 48 and transports it in the circumferential direction.

  The main pole 52 is a magnetic pole that is provided at a position facing the photosensitive drum 19 and generates a peak magnetic force at a position facing the photosensitive drum 19. The main electrode 52 attracts the toner remaining on the developing roller 32 to the developing sleeve 48 after the toner has transferred to the photosensitive drum 19 at the position P2. The position P2 is an example of the supply position in the present invention.

  A voltage is applied to each developing roller 32. As a result, a potential difference is generated between the developing roller 32 and the electrostatic latent image formed on the photosensitive drum 19. Due to this potential difference, the toner of the two-component developer carried on the developing roller 32 is transferred to the photosensitive drum 19. A position P <b> 2 in FIG. 2 indicates a transfer position where the toner carried on the developing roller 32 is transferred to the photosensitive drum 19. This position P2 can be said to be a position where the photosensitive drum 19 receives the toner from the developing roller 32.

  Thus, the developing sleeve 48 of the developing roller 32 is rotatably supported at a position above the storage portion 35 in the housing main body 30. The developing sleeve 48 rotates in the rotation direction X1 to convey the toner to a position P2 where the toner is carried to the developing roller 32 while carrying the toner on the surface at the position P1.

  The peeling pole 53 is a magnetic pole that forms a peeling region R1 having substantially zero magnetic flux density in the developing sleeve 48. When the two-component developer is transported to the peeling region R1, the developing sleeve 48 loses the force for magnetically adsorbing the toner, and the two-component developer is peeled from the peeling region R1. The peeled two-component developer falls into the second storage chamber 35B located below, and is conveyed while being stirred again by the stirring member 33. Then, after being stirred and transported by the stirring member 33, the toner is uniformly charged again with an appropriate toner concentration, and is again pumped onto the developing sleeve 48 by the pumping pole 49.

  When developing the electrostatic latent image formed on the photosensitive drum 19, the developing roller 32 receives the two-component developer from the second storage chamber 35 </ b> B at the position P <b> 1 by the magnetic force of the scooping pole 49 and develops in the rotation direction X <b> 1. The two-component developer is conveyed by the rotation of the sleeve 48. When the two-component developer is conveyed to the position P <b> 2, the toner contained in the two-component developer is transferred to the photosensitive drum 19 due to a potential difference between the developing roller 32 and the photosensitive drum 19.

  The developing roller 32 conveys the two-component developer including residual toner remaining on the surface of the developing sleeve 48 to the downstream side by further rotation of the developing sleeve 48 in the rotation direction X1. Then, when the developing roller 32 transports the two-component developer to the peeling region R <b> 1, the developing roller 32 peels the two-component developer from the developing roller 32. Thereby, the peeled two-component developer falls into the second storage chamber 35B below.

  The regulating blade 34 is a plate-like member that regulates the layer thickness of the two-component developer carried on the surface of the developing roller 32. The regulating blade 34 is an example of a layer thickness regulating member of the present invention. The regulating blade 34 regulates the layer thickness of the two-component developer at the position P4 in FIG. The position P4 is a position on the upstream side in the rotation direction X1 from the position P2 on the outer periphery of the developing roller 32. The position P4 is a position on the downstream side in the rotation direction X1 with respect to the position P1. The position P4 is an example of a restriction position according to the present invention.

  The regulation blade 34 is a long plate-like member along the axial direction of the developing roller 32. The regulating blade 34 is arranged in a posture along a normal line at a position facing the position P4 in a circle formed by the outer periphery of the developing roller 32. That is, the distal end portion 34A of the regulating blade 34 is opposed to the surface of the developing sleeve 48 of the developing roller 32 with a gap at the position P4, and the base end portion 34B opposite to the distal end portion 34A is the distal end portion 34A. It is located outside in the radial direction of the circle.

  When developing the electrostatic latent image formed on the photosensitive drum 19, the developing roller 32 rotates in a rotation direction X 1 opposite to the rotation direction X 2 of the photosensitive drum 19. As a result, the mutually opposing portions on the surfaces of the photosensitive drum 19 and the developing roller 32 move in the same direction.

  Thus, the toner is consumed when developing the electrostatic latent image. Therefore, the toner is replenished from the toner replenishing unit 8 to the storage unit 35 to supplement the consumption.

  By the way, conventionally, a plate-shaped regulating blade is attached to the support member. In such a configuration, the restriction blade is disposed at a position relatively away from the storage portion. That is, the restriction blade is disposed at a position separated from the housing by an amount corresponding to a space for mounting the support member to the housing. For this reason, the distance between the regulation blade and the storage unit is reduced, and the distance between the regulation blade and the receiving position for receiving toner from the storage unit is increased. For this reason, there is a problem that the developing device cannot be made compact. On the other hand, in the present embodiment, it is made more compact than the conventional developing device as follows.

  In the present embodiment, as illustrated in FIGS. 3 and 4, the developing device 21 includes a support portion 70 and support portions 90 and 91, and the regulation blade 34 includes the support portion 70 and the support portions 90 and 91. Supported.

  The support portion 70 is formed integrally with the wall portion 41 </ b> C of the housing body 30. Specifically, the support portion 70 is integrally formed with the wall portion 41C on the outer side surface 411 of the wall portion 41C. The support portion 70 is a short portion extending from the outer surface 411 in the opposite direction to the second storage chamber 35B by a length corresponding to the thickness of the regulating blade 34. In other words, the support part 70 protrudes from the outer surface 411 in a direction intersecting with the outer surface 411. The support unit 70 faces the surface of the developing roller 32 with a predetermined distance. The support part 70 is an example of a first support part of the present invention.

  The support part 70 includes an extension part 71 and an extension part 72. The extending portion 71 extends from the outer surface 411 of the wall portion 41 </ b> C in a direction intersecting the outer surface 411, specifically in a direction orthogonal to the outer surface 411. The extending portion 72 extends upward from the tip portion of the extending portion 71. And the groove part 73 is formed of the extended part 71, the extended part 72, and the outer surface 411 of 41 C of wall parts. The base end portion 34 </ b> B of the regulating blade 34 is inserted into the groove portion 73. In addition, although the groove part 73 shown by FIG. 2 is rectangular shape, it is not limited to a rectangular shape. When the base end portion 34 </ b> B is inserted into the groove portion 73, the regulating blade 34 takes a posture of extending toward the surface of the developing sleeve 48. The extension part 71 is an example of a first extension part of the present invention. The extension part 72 is an example of a second extension part of the present invention. The groove part 73 is an example of the second groove part of the present invention. The support part 70 supports the base end part 34 </ b> B of the regulation blade 34 by inserting the base end part 34 </ b> B of the regulation blade 34 into the groove part 73. As described above, the support portion 70 supports the regulating blade 34 between the surface of the developing sleeve 48. The support unit 70 supports the regulating blade 34 in a posture that extends toward the surface of the developing sleeve 48.

  The support portion 70 can be elastically deformed in the extending direction in which the regulating blade 34 extends toward the surface of the developing roller 32. In other words, the support portion 70 has elasticity such that the extending portion 72 can be displaced in the vertical direction, that is, in the direction of approaching and separating from the developing roller 32. Further, the support portion 70 has a tapered surface 75. The tapered surface 75 is an inclined surface that is inclined so as to move away from the developing roller 32 as the portion is separated from the second storage chamber 35B.

  The support portion 90 is provided in the housing body 30. Specifically, the support part 90 is a flat plate-like member, and has a base part 95 and an extension part 96 as shown in FIG. 3 or FIG. The base 95 has an annular shape. The extending portion 96 is a portion having a bifurcated shape and extending from the base portion 95 toward the wall portion 41C. A through hole 92 (see FIG. 3) is formed at the center of the base portion 95, and the support portion 90 is fitted around the boss portion 442 through the through hole 92. Although not shown, the rotation of the base portion 95 in the boss portion 442 is restricted by an engagement structure (not shown) provided between the bottom surface of the boss portion 442 of the second plate 44 and the base portion 95. . The support portion 90 supports the end portion of the tip end portion 34 </ b> A of the regulation blade 34. This end is a part different from the part facing the surface of the developing roller 32.

  A recessed portion 93 is formed on the distal end surface of the extending portion 96. The leading end 34 </ b> A of the regulation blade 34 is fitted in the recess 93. As a result, the support portion 90 supports one end in the longitudinal direction of the distal end portion 34 </ b> A of the regulation blade 34.

  Specifically, the recess 93 has a bottom surface 93A, a side surface 93B, and a side surface 93C. The bottom surface 93 </ b> A makes surface contact with the tip end portion 34 </ b> A of the regulating blade 34 fitted in the recess 93. The side surface 93B is orthogonal to the bottom surface 93A and comes into surface contact with the side surface 34C located on the wall 41C side of the side surfaces 34C and 34D of the regulating blade 34. The side surface 93C is a tapered surface inclined with respect to the bottom surface 93A. In other words, the opening of the concave portion 93 has a shape that expands in a portion closer to the first plate 43 than the tip end portion 34 </ b> A of the regulating blade 34.

  When the operator attaches the restriction blade 34 to the support portion 70 and the support portions 90 and 91, first, the operator causes the tip end portion 34 </ b> A of the restriction blade 34 to enter the recess 93. Here, since the opening of the recessed portion 93 has a shape that expands in a portion closer to the first plate 43 than the distal end portion 34A of the regulating blade 34, the operator can easily enter the distal end portion 34A into the recessed portion 93. Is possible. As shown in FIG. 5A, when the operator causes the distal end portion 34A to enter the recess 93, the side surface 93C guides the distal end portion 34A of the regulating blade 34 fitted into the recess 93 to the bottom surface 93A. When the distal end portion 34A hits the bottom surface 93A of the recess 93, the operator presses the regulating blade 34 toward the wall portion 41C. At this time, the base end portion 34 </ b> B comes into contact with the tapered surface 75 of the support portion 70. Here, as described above, the support portion 70 is elastically deformable. Therefore, as shown in FIG. 5B, the base end portion 34B of the regulating blade 34 rides on the tapered surface 75 while deforming the support portion 70 so as to displace the extended portion 72 downward by the pressing force. To go. Then, when the base end portion 34 </ b> B of the regulating blade 34 gets over the extending portion 72, the base end portion 34 </ b> B fits into the groove portion 73. As a result, the regulation blade 34 is attached to the support portion 70 and the support portions 90 and 91. Thus, the operator can easily attach the regulating blade 34.

  Even if the base end portion 34B of the regulating blade 34 is fitted into the groove portion 73, the support portion 70 does not return to the natural state, and the extended portion 72 is in a deformed state that is displaced downward by a predetermined length. . Accordingly, as shown in FIG. 5C, the base end portion 34 </ b> B of the regulating blade 34 extends in the extending direction from the support portion 70 toward the surface of the developing roller 32 due to the restoring force of the support portion 70. The pressing force F1 is received. Accordingly, the regulation blade 34 is elastically supported in the extending direction between the support portion 70 and the support portions 90 and 91. That is, the regulation blade 34 is elastically held between the support portion 70 and the support portions 90 and 91.

  As described above, the support portion 90 is held by the ball bearing 80 and the second plate 44. The support portion 90 supports one end in the longitudinal direction of the distal end portion 34 </ b> A of the regulation blade 34. Specifically, the support portion 90 rotatably supports the shaft member 48B at a position of an end portion of the tip end portion 34A of the regulating blade 34 that avoids a portion facing the surface of the sleeve main body 48A of the developing sleeve 48.

  The support portion 91 is provided in the housing body 30 and is held by the ball bearing 81 and the third plate 45. The support portion 91 supports the other end in the longitudinal direction of the distal end portion 34 </ b> A of the regulating blade 34. In addition, since the support part 91 is the structure similar to the support part 90, the description beyond this is abbreviate | omitted. The support portions 90 and 91 are an example of the second support portion of the present invention.

  The regulating blade 34 has a bent shape. Specifically, the regulation blade 34 is bent according to the fact that the outer surface 411 and the outer surface 412 intersecting each other are provided on the wall portion 41C. That is, the regulating blade 34 is bent along the outer surface 411 and the outer surface 412. Accordingly, when the wall portion 41C exists on a straight line connecting the groove portion 73 formed by the extending portion 71, the extending portion 72, and the outer surface 411 of the wall portion 41C, and the concave portion 93 of the support portions 90 and 91. Even so, it is possible to regulate the layer thickness of the two-component developer on the surface of the developing roller 32 by avoiding the wall portion 41C. The regulating blade 34 is not limited to a bent shape, and may be a curved shape. Further, depending on the height of the wall portion 41C and the like, there may be a case where a regulation blade 34 having a flat shape (cross section is straight) which is not a bent shape or a curved shape may be employed.

  A seal member 150 is provided between the outer surfaces 411 and 412 of the wall portion 41 </ b> C and the regulation blade 34. The seal member 150 closes between the wall portion 41 </ b> C and the regulation blade 34. Thereby, it is possible to prevent the two-component developer from leaking out of the housing main body 30 from the gap between the wall portion 41 </ b> C and the regulating blade 34. The seal member 150 is a sheet-like member made of an elastic material such as rubber or urethane, and is provided in a compressed state. Due to the restoring force of the seal member 150, the regulating blade 34 is pressed toward the first plate 43 in the direction along the normal line of the side surfaces 34C and 34D of the regulating blade 34. As a result, the base end portion 34 </ b> B of the regulating blade 34 is firmly sandwiched between the extending portion 72 and the wall portion 41 </ b> C, and is firmly held in the groove portion 73. The seal member 150 is an example of a second elastic member of the present invention.

  As described above, in the present embodiment, the support portion 70 is formed integrally with the housing body 30. Thereby, the separation distance between the regulation blade 34 and the storage portion 35 can be shortened, and the distance between the regulation blade 34 and the position P2 can be reduced as compared with the conventional case. As a result, the developing device 21 can be made compact.

  And since the distance of the control blade 34 and position P1 can be made small compared with the past, the following structures are realizable. That is, a line segment connecting the rotation axis Q1 of the shaft member 48B of the developing sleeve 48 and the position of the tip end portion 34A of the regulating blade 34, and the rotation axis Q1 of the developing sleeve 48 and the rotation axis Q3 of the stirring member 33 are connected. The regulating blade 34 can be arranged so that the angle θ (see FIG. 2) formed by the connecting line segment is an angle in the range of 30 ° to 35 °. That is, the distance between the drawing pole 49 and the regulation pole 50 in the rotation direction X1 can be reduced. As a result, the magnetic force required at the position P1 and the position P4 can be reduced, and the scooping pole 49 and the regulation pole 50 can be reduced in size. Further, the space required for installing the pumping pole 49 and the regulation electrode 50 can be reduced by the amount that the pumping pole 49 and the regulation electrode 50 can be reduced in size, and the development roller 32 and the development device 21 can be downsized. Can contribute. Furthermore, the magnet that generates the magnetic force required at the position P1 and the magnet that generates the magnetic force required at the position P4 can be combined into one magnet.

  In the embodiment, the two support portions (the support portion 90 and the support portion 91) are provided to hold the tip end portion 34A of the regulating blade 34, but either one may be used. Further, when the restriction blade 34 can be reliably supported only by the support portion 70, the support portions 90 and 91 may not be provided.

  As shown in FIG. 6, a sheet-like elastic member 200 such as rubber or urethane is formed between the groove portion 73 of the support portion 70 and the base end portion 34 </ b> B of the regulating blade 34, that is, on the bottom surface 73 </ b> A of the groove portion 73. It may be provided. By providing the elastic member 200, the bottom surface 73 </ b> A of the groove 73 and the bottom surface 93 </ b> A of the recess 93 are separated from each other along the extending direction of the regulation blade 34 more than the length of the regulation blade 34. In addition, the tip end portion 34A of the regulating blade 34 can be brought into close contact with the support portions 70, 90, 91. The regulating blade 34 can be elastically held by the support portion 70 and the support portions 90 and 91. The elastic member 200 is an example of a first elastic member of the present invention.

  Instead of the groove portion 73, as shown in FIG. 7, a groove portion 78 may be provided at a position separated from the outer surface 411 of the wall portion 41 </ b> C on the surface of the support portion 70 facing the developing roller 32. In this case, in the support part 70, the base end part 34 </ b> B of the regulation blade 34 is inserted into the groove part 78. The regulating blade 34 is supported by the support portion 70 in the groove portion 78. The groove part 78 is an example of the first groove part of the present invention. In addition, although the groove part 78 shown by FIG. 7 is rectangular shape, it is not limited to a rectangular shape.

  The developing device mounted on the image forming apparatus 1A is not limited to this. That is, the developing device mounted on the image forming apparatus 1A includes a magnetic roller, and the magnetic roller receives the two-component developer stored in the storage unit 35 and supplies the toner to the developing roller 32. It may be a developing device. In this case, the magnetic roller 32 corresponds to the first rotating body.

  Further, the configuration shown in FIG. 8 may be used instead of the configuration in which the support portions 90 and 91 are supported by the boss portions 442 and 452. That is, as shown in FIG. 8, recesses 447 and 457 are formed on the inner surfaces of the second plate 44 and the third plate 45, and the ball bearing 80 and the ball bearing 81 are fitted in the recess 447 and 457, respectively. It is. The support portion 90 is fitted on the ball bearing 80 through the through hole 92. The support portion 91 is fitted on the ball bearing 81 through the through hole 92. The support portion 90 supports the end portion of the tip end portion 34 </ b> A of the regulation blade 34.

1A: Image forming apparatus 19: Photosensitive drum (photosensitive member)
21: Developing device 30: Housing body 33: Stirring member 34: Restricting blade (layer thickness restricting member)
34A: distal end portion 34B: proximal end portion 35: storage portion 41C: wall portion (first wall portion)
41: Lower frame (lower housing)
42: Upper frame (upper housing)
43: First plate (upper housing)
44: Second plate 45: Third plate 44: Housing (second wall)
48: Developing sleeve (first rotating body)
482: Rotating shaft (rotating shaft)
70: support portions 71, 72: extending portions 73, 78: groove portions (first groove portion, second groove portion)
80, 81: Ball bearing (bearing part)
90, 91: support part (second support part)
150, 200: elastic member (first elastic member, second elastic member)
S1: Space (Installation space)
P1, P2: Position (receiving position, supplying position)

Claims (14)

A housing body having a reservoir for storing the developer;
Provided above the reservoir in the housing main body and supported to be rotatable in a predetermined rotation direction, and receives the developer in the reservoir at a predetermined receiving position on the outer peripheral surface. A first rotating body that is carried and rotated to convey to a predetermined supply position downstream of the rotation direction;
A layer thickness of the developer that is provided downstream of the receiving position in the rotational direction and upstream of the supply position in the rotational direction and carried on the outer peripheral surface of the first rotating body is regulated. A plate-like layer thickness regulating member to be
A developing device, comprising: a first support portion that is formed integrally with the housing body and supports the layer thickness regulating member between the outer peripheral surface of the first rotating body. The housing body extends from below to above and has a lower housing having a first wall portion that partitions the storage portion, and an upper portion that is provided above the lower housing and partitions the installation space for the first rotating body. A housing, and
The first support part is formed integrally with the first wall part on the outer surface of the first wall part,
The layer thickness regulating member is supported by the first support portion in a posture extending toward the outer peripheral surface of the first rotating body, and a distal end portion in the extending direction of the layer thickness regulating member is the first The developing device according to claim 1, wherein the developing device is disposed at a position facing the outer peripheral surface of the one rotating body. The upper housing includes a second wall portion that is in a direction intersecting with an extending direction in which the first wall portion extends and is separated in a direction opposite to the storage portion,
The developing device according to claim 2, wherein the installation space is a space above the first wall portion. A stirring member that is rotatably provided in the storage portion of the housing body and stirs the developer stored in the storage portion;
The first support portion includes a line segment connecting a rotation axis of the first rotating body and a restriction position by the layer thickness regulating member, the rotation axis of the first rotating body, and a rotation axis of the stirring member. 4. The developing device according to claim 1, wherein the layer thickness regulating member is supported such that an angle formed by a line segment connecting the two and the line segment is an angle in a range of 30 ° to 35 °.   5. The developing device according to claim 1, wherein the first support portion supports a base end portion opposite to an end portion positioned at a restriction position by the layer thickness restriction member.   The developing device according to claim 5, wherein the first support portion includes a first groove portion that supports the layer thickness regulating member when the base end portion of the layer thickness regulating member is inserted.   The developing device according to claim 6, wherein a first elastic member is provided between the first groove portion of the first support portion and the base end portion of the layer thickness regulating member. The first support portion includes a first extending portion extending in a direction intersecting the outer surface from the outer surface of the first wall portion, and a second extending portion extending upward from a distal end portion of the first extending portion. And
The layer thickness regulating member is formed by inserting the base end portion of the layer thickness regulating member formed by the outer surface of the first extending portion, the second extending portion, and the first wall portion. The developing device according to claim 5, further comprising a second groove portion to be supported.   The developing device according to claim 8, wherein a second elastic member is provided in a compressed state between the outer surface of the first wall portion and the layer thickness regulating member. The layer thickness regulating member is a long plate-like member along the axial direction of the first rotating body,
The developing device according to claim 1, further comprising a second support portion provided in the housing main body and supporting one end or both ends in the longitudinal direction of the tip end portion of the layer thickness regulating member. The first support portion protrudes from the outer surface of the first wall portion, and is elastically deformable in an extending direction in which the layer thickness regulating member extends toward the outer peripheral surface of the first rotating body,
The developing device according to claim 10, wherein the layer thickness regulating member is held by the first support portion and the second support portion. A boss portion formed in the housing body so as to protrude in the axial direction of the rotation shaft of the first rotating body, and having a recess recessed in the axial direction;
A bearing portion that is provided in the concave portion of the boss portion and rotatably supports the rotation shaft of the first rotating body at an end portion of the rotation shaft, and the second support portion has a through hole, And it fits in the said boss | hub part through the said through-hole, and supports the site | part different from the site | part which opposes the surrounding surface of the said 1st rotary body among the said front-end | tip parts of the said layer thickness control member. The developing device described.   The first support portion is elastic to the extension direction in which the layer thickness regulating member extends toward the outer peripheral surface of the first rotating body between the first support portion and the second support portion. The developing device according to claim 10, wherein the developing device supports the regulating member. A photoreceptor having an electrostatic latent image formed on the surface;
The developing device according to claim 1, wherein the electrostatic latent image is visualized as a toner image by supplying toner contained in the developer to the photoreceptor.
An image forming apparatus comprising:

Images