JP4816783B2 - Development unit - Google Patents

Description

  The present invention relates to a developing unit that supplies developer to an electrostatic latent image formed on a photoreceptor.

  2. Description of the Related Art Conventionally, there is known a developing unit including a developing unit having a developing roller for carrying a developer, and a developer accommodating unit that accommodates the developer and is disposed adjacent to and below the developing unit ( Patent Document 1). Specifically, the developing unit in this technique includes a supply roller that is disposed obliquely below the developing roller and supplies developer to the developing roller, and a developer that is slidably contacted below the developing roller and carried on the developing roller. And a regulating member that regulates the thickness.

  A supply port for supplying the developer from the developer accommodating portion to the developing portion is formed in the partition wall that partitions the developing portion and the developer accommodating portion. Specifically, the supply port is formed at a position opposite to the regulating member with the supply roller interposed therebetween, so that the developer sent from the developer container to the developing unit through the supply port Is supplied to the supply roller.

JP 2009-47770 A

  However, in the prior art, only the supply port is formed in the partition wall, and the supply port is formed at a position opposite to the regulating member across the supply roller. There is a possibility that the deteriorated developer that is dropped will remain in the developing portion. If the deteriorated developer remains in one place, the deteriorated developer lump may be supplied to the photoconductor via the supply roller and the development roller, thereby deteriorating the image quality. was there.

  Therefore, the present invention provides a developing unit that can improve the image quality by reducing the influence of the deteriorated developer by improving the circulation of the developer between the developing unit and the developer containing unit. The purpose is to do.

  The present invention that solves the above-described problems includes a developing section having a developing roller for carrying a developer, and a developer accommodating section that accommodates the developer and is disposed adjacently below the developing section. A partition wall is provided between the developing section and the developer accommodating section, and a supply for supplying the developer from the developer accommodating section to the developing section is provided on the partition wall An opening and a return port for returning the developer from the developing section to the developer accommodating section; the developer accommodating section is rotated so as to be in sliding contact with the partition wall; A stirring member for conveying the developer in the section to the supply port is provided, and the developing section is disposed below the developing roller, and a supply roller that supplies the developer to the developing roller, and slides on the developing roller. The thickness of the developer that is in contact with the developing roller A regulating member that regulates, and a feeding member that is arranged below the regulating member and feeds the developer in the developing section in the axial direction of the supply roller, and the supply port sandwiches the feeding member and It is arrange | positioned on the opposite side of a supply roller, The said return port is arrange | positioned under the said control member so that it may overlap with the said control member seeing from upper direction, It is characterized by the above-mentioned.

  According to the present invention, since the delivery member and the return port are arranged below the regulating member, the deteriorated developer scraped off by the regulating member is sent out in the axial direction by the delivery member and stirred in the developing unit. The deteriorated developer is discharged from the return port to the developer accommodating portion. Thereby, the deteriorated developer can be diffused as a whole in the developing unit, and the influence can be weakened. Further, since the supply port is disposed on the opposite side of the supply roller across the delivery member, the new developer supplied from the supply port into the developing unit is dispersed in the axial direction by the delivery member, and the deteriorated developer and The developer can be mixed, and a good developer can be supplied to the supply roller.

  According to the present invention, the delivery member and the return port are disposed below the regulating member, and the supply port is disposed on the opposite side of the supply roller with the delivery member interposed therebetween, so that the gap between the developing unit and the developer storage unit is achieved. Therefore, it is possible to improve the image quality by reducing the influence of the deteriorated developer.

It is sectional drawing which shows the laser printer provided with the image development unit which concerns on one Embodiment of this invention. FIG. 4 is a cross-sectional view illustrating a state where a front cover is opened and a toner cartridge is taken out. It is sectional drawing which shows a developing unit. FIG. 6 is an explanatory diagram illustrating an arrangement of a supply port and a return port of a toner cartridge. FIG. 4 is a cross-sectional view of the developing unit taken along line XX in FIG. 3. FIG. 4 is a cross-sectional view (a) and a side view (b) showing the toner cartridge. It is explanatory drawing which shows the modification of arrangement | positioning of a supply port and a return port. It is sectional drawing which shows the positions of the partition wall etc. corresponding to the form of FIG.

Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
In the following description, the direction will be described with reference to the user when using the laser printer. That is, in FIG. 1, the right side toward the paper surface is “front side (front side)”, the left side toward the paper surface is “rear side (back side)”, the back side toward the paper surface is “right side”, and it faces the paper surface. The front side is the “left side”. In addition, the vertical direction toward the page is defined as the “vertical direction”.

<Overall configuration of laser printer>
As shown in FIG. 1, the laser printer 1 includes an apparatus main body 2, a feeder unit 3, an image forming unit 4, and the like.

  The apparatus main body 2 is formed in a hollow case shape, and an opening 2A is formed on the front wall thereof, and a front cover 21 that opens and closes the opening 2A is provided so as to be swingable back and forth ( (See FIG. 2). The front cover 21 is formed with a manual feed opening 21A so as to face a first conveyance path 32B described later. The upper surface of the apparatus main body 2 is a paper discharge tray 22 on which printed paper P is placed.

  The feeder unit 3 includes a paper feed tray 31 and a paper supply mechanism 32.

  The paper feed tray 31 is a tray for stacking and placing the sheets P, and is disposed below the image forming unit 4 (lower part of the apparatus main body 2). In the paper feed tray 31, a pressing plate 31A that presses the front end of the paper P toward a paper feed roller 32A described later is provided.

  The paper supply mechanism 32 is disposed on the upper front side of the paper feed tray 31 and mainly includes a paper feed roller 32A, a first transport path 32B, a transport roller 32C, and a registration roller 32D.

  The paper feed roller 32A is a roller that folds the paper P placed in the paper feed tray 31 into a U-shape and conveys it toward the image forming unit 4, and has a relatively large diameter in order to fold back the paper P well. It is formed with.

  The first conveyance path 32B is configured by a plurality of guides G and the like, and is formed so as to be inclined obliquely downward and rearward from the upper part of the paper feed roller 32A. Further, the second transport path 23 is formed continuously at the rear end portion of the first transport path 32B.

  The second transport path 23 is configured by a guide G, a process cartridge 42, which will be described later, and the like, and is formed so as to be inclined rearward and upward from a continuous portion 23A with the first transport path 32B toward a fixing device 43, which will be described later. Has been.

  The transport rollers 32C are a pair of rollers that sandwich and transport the paper P, and are provided in the first transport path 32B. More specifically, the transport roller 32C is disposed away from the V-shaped continuous portion 23A on the upstream side in the transport direction by a distance shorter than the entire length of the paper P (length in the transport direction). As a result, when the leading edge of the paper P reaches the continuous portion 23A, a transport force can be applied to the paper P by the transport roller 32C, so that the leading edge of the paper P is prevented from being caught by the continuous portion 23A.

  Further, the conveyance roller 32 </ b> C is disposed away from the manual feed opening 21 </ b> A formed in the front cover 21 by a distance shorter than the total length of the paper P. This ensures that the user can insert the paper P into the apparatus main body 2 from the manual feed port 21 </ b> A, that is, in a state in which a part of the paper P protrudes out of the apparatus main body 2. Therefore, the conveyance roller 32C can be used as a manual feed roller.

  The registration rollers 32 </ b> D are a pair of rollers for aligning the leading end position of the paper P, and are provided in the second conveyance path 23. Specifically, the registration roller 32D is disposed at a position slightly away from the continuous portion 23A on the downstream side in the transport direction.

  In the feeder unit 3 configured as described above, the paper P in the paper feed tray 31 is folded by the paper feed roller 32A and then conveyed to the registration roller 32D by the conveyance roller 32C. Thereafter, the paper P is transported to the image forming unit 4 with its leading end position aligned by the registration rollers 32D.

  The image forming unit 4 includes a scanner unit 41, a process cartridge 42, a fixing device 43, and the like.

  The scanner unit 41 has a known structure including a laser light emitting unit, a polygon mirror, and the like, and scans the laser beam on the surface of the photosensitive drum 51 of the process cartridge 42 at a high speed.

  The process cartridge 42 includes a drum cartridge 5, a developing device 6 as an example of a developing unit, and a toner cartridge 7 as an example of a developer storage unit.

  The drum cartridge 5 includes a photosensitive drum 51, a transfer roller 52, a scorotron charger 53, and the like.

  The developing device 6 includes a developing roller 61, a layer thickness regulating blade 62 as an example of a regulating member, a supply roller 63, and the like, and is attachable to and detachable from the drum cartridge 5.

  The toner cartridge 7 is a container that contains toner as an example of a developer therein, and is detachable from the developing device 6. Details of the structures of the developing device 6 and the toner cartridge 7 will be described later.

  The toner cartridge 7 is disposed along the first conveyance path 32B. Thereby, there is no useless space between the toner cartridge 7 and the first transport path 32B, and the apparatus main body 2 is downsized. Further, the toner cartridge 7 is disposed so as to be adjacent to the continuous portion 23A, that is, disposed so as to approach the second transport path 23 rising from the first transport path 32B. Therefore, there is no useless space between the toner cartridge 7 and the second transport path 23, and the apparatus main body 2 is further downsized.

  Further, the developing device 6 is disposed above the toner cartridge 7 and at a position adjacent to the second transport path 23. As a result, as shown in FIG. 2, the connecting portion 7A of the toner cartridge 7 with the developing device 6 (the surface on which the supply port and the like are formed) can be directed upward, so that toner leakage from the connecting portion 7A is suppressed. It is possible. Further, by making the developing device 6 adjacent to the second transport path 23, there is no useless space between the developing device 6 and the second transport path 23, and the apparatus main body 2 is further reduced in size.

  The drum cartridge 5, the developing device 6 and the toner cartridge 7 described above can be attached to and detached from the apparatus main body 2 through an opening 2A which is opened by opening the front cover 21, as shown in FIG. ing.

  In the process cartridge 42 configured as described above, as shown in FIG. 1, the toner fed into the developing device 6 from the toner cartridge 7 is supplied to the developing roller 61 by the supply roller 63. At this time, the supply roller The frictional charge is positive between 63 and the developing roller 61. The toner supplied (carrying) on the developing roller 61 enters between the layer thickness regulating blade 62 and the developing roller 61 as the developing roller 61 rotates, and the thickness is regulated by the layer thickness regulating blade 62. As a result, it is carried on the developing roller 61 as a thin layer having a constant thickness.

  On the other hand, in the drum cartridge 5, the surface of the photosensitive drum 51 is uniformly positively charged by the scorotron charger 53 and then exposed by high-speed scanning of the laser beam from the scanner unit 41. Thereby, the potential of the exposed part is lowered, and an electrostatic latent image based on the image data is formed. Next, when the developing roller 61 rotates, the toner carried on the developing roller 61 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 51 when it contacts the photosensitive drum 51. The

  Thus, the toner is selectively carried on the surface of the photosensitive drum 51 to be visualized, and a toner image is formed by reversal development. Thereafter, when the paper P is conveyed between the photosensitive drum 51 and the transfer roller 52, the toner image carried on the surface of the photosensitive drum 51 is transferred onto the paper P.

  The fixing device 43 includes a heating roller 43A and a pressure roller 43B. In the fixing device 43, the toner image transferred onto the paper P is thermally fixed while the paper P passes between the heating roller 43A and the pressure roller 43B. The paper P thermally fixed by the fixing device 43 is discharged onto the paper discharge tray 22 by a paper discharge roller 44 disposed on the downstream side of the fixing device 43 in the transport direction.

  A third conveyance path 24 for double-sided printing is provided on the rear side of the fixing device 43 and the process cartridge 42. The third transport path 24 extends rearward and downward from the downstream side in the transport direction of the fixing device 43 (specifically, between the fixing device 43 and the paper discharge roller 44), and the second transport path 24 is upstream of the registration roller 32D in the transport direction. It is formed so as to join the path 23. Accordingly, it is possible to form a conveyance path for double-sided printing without increasing the size of the apparatus main body 2 up and down, compared to a mode in which the third conveyance path is merged with the first conveyance path 32B.

  The third transport path 24 is provided with a plurality of pairs of return rollers 24A that transport the paper P while pinching it. Specifically, among the plurality of pairs of return rollers 24A, the upstream three pairs of return rollers 24A are more than the full length of the sheet P from the obtuse angle bending portion 24B that bends at an obtuse angle of 90 ° or more in the third transport path 24. A short distance is arranged away from the upstream side in the transport direction. Thereby, when the leading edge of the paper P reaches the obtuse angle bent portion 24B, a conveying force can be applied to the paper P by the return roller 24A, so that the leading edge of the paper P is prevented from being caught by the obtuse angle bent portion 24B. Yes.

  Further, the pair of return rollers 24A located on the most downstream side is disposed in the vicinity of the apex of the acute angle bent portion 24C that bends at an acute angle of less than 90 ° in the third transport path 24. As a result, even if the leading edge of the paper P is likely to be jammed by abutting against the acute angle bent portion 24C, the leading edge of the paper P is forcibly conveyed by being sandwiched between the pair of return rollers 24A at the apex of the acute angle bent portion 24C. Further, it is possible to suppress the jamming of the paper P.

<Details of Development Device and Toner Cartridge Structure>
Next, details of the structures of the developing device 6 and the toner cartridge 7 will be described with reference to FIG. As shown in FIG. 3, the developing device 6 and the toner cartridge 7 are combined to form a single developing unit DU.

  The developing device 6 includes the developing roller 61, the layer thickness regulating blade 62, and the supply roller 63 described above, and also includes an auger 64 as an example of a feeding member and a developing case 65 that accommodates these components.

  An opening 65A facing the photosensitive drum 51 (see FIG. 1) is formed in the upper part on the rear side of the developing case 65, and a supply port 71B and two return ports 71C of the toner cartridge 7 described later are formed in the lower part on the front side. A supply port 65B and two return ports 65C corresponding to (see FIG. 4) are formed. In the present embodiment, the partition wall that partitions between the developing device 6 and the toner cartridge 7 includes two partitions: a partition wall 65D on the developing device 6 side and a partition wall 71A on the toner cartridge 7 side.

  The developing roller 61 is disposed so as to be exposed from the opening 65 </ b> A of the developing case 65, and a supply roller 63 is disposed below the developing roller 61. In addition, the layer thickness regulating blade 62 is disposed adjacent to the front of the supply roller 63 and is in sliding contact with the obliquely lower front portion of the developing roller 61.

  The auger 64 is disposed below the layer thickness regulating blade 62 and, as shown in FIG. 5, extends in the axial direction of the developing roller 61 (supply roller 63), specifically from the center in the left-right direction toward both sides in the left-right direction. It is configured to convey toner. As a result, the deteriorated toner scraped off by the layer thickness regulating blade 62 is favorably dispersed in the left-right direction by the auger 64.

  Specifically, the auger 64 includes a rotating shaft 64A, and a first spiral blade 64B and a second spiral blade 64C that are provided so as to be spirally wound around the rotating shaft 64A.

  The first spiral feather 64B and the second spiral feather 64C are arranged on the right side and the left side, respectively, with the axial center portion (near the supply port 65B) of the rotation shaft 64A as a boundary, and the spiral directions are different. . Thus, the toner is conveyed to the right by the first spiral wing 64B, and the toner is conveyed to the left by the second spiral wing 64C.

  As shown in FIG. 3, the toner cartridge 7 includes a first storage portion 71 that stores toner, a second storage portion 72, and a third storage portion 73.

  The first accommodating portion 71 is below the front side of the developing device 6 when the toner cartridge 7 is attached to the developing device 6 (specifically, when the developing unit DU is attached to the device main body 2). It is arranged adjacent to. The first accommodating portion 71 is formed in a substantially hollow cylindrical shape, and the partition wall 71 </ b> A adjacent to the developing device 6 among the walls forming the first accommodating portion 71 is recessed toward the inside of the first accommodating portion 71. It is formed as follows.

  Specifically, the partition wall 71A is formed in a circular arc shape in cross section having a portion extending in a substantially horizontal direction and a portion extending in a substantially vertical direction. The partition wall 71A has a supply port 71B for supplying toner from the toner cartridge 7 to the developing device 6 and two return ports 71C for returning toner from the developing device 6 to the toner cartridge 7 (see FIG. 4). And are formed.

  As shown in FIG. 4, only one supply port 71B is formed at the center in the left-right direction of the upper half of the partition wall 71A. Further, the return ports 71C are formed one by one on the left and right sides of the lower half of the partition wall 71A, specifically outside the print area PA. That is, the return port 71C is formed at a position shifted from the supply port 71B in the left-right direction (the axial direction of the supply roller 63) and downward.

  By thus shifting the return port 71C in the axial direction of the supply roller 63, the toner supplied from the supply port 71B into the developing device 6 immediately returns from the return port 71C into the toner cartridge 7. Can be prevented. If the return port and the supply port are arranged at the same position in the axial direction, it is difficult to create a toner flow in the developing device 6. However, as in the present embodiment, the supply port 71B and the return port 71C are provided. By shifting in the axial direction, it is possible to create a flow from the supply port 71B toward the return port 71C as shown in FIG.

  Moreover, as shown in FIG. 3, the supply port 71B is formed in the part extended in the substantially perpendicular direction of the partition wall 71A, and is opened sideways. Here, “laterally” means not only the horizontal direction but also a direction slightly inclined from the horizontal direction.

  Thus, the supply port 71B is turned sideways so that the toner can be efficiently conveyed from the supply port 71B into the developing device 6 by a first agitator A1 as an example of a stirring member (first stirring member) described later. ing. That is, if the supply port 71B is upward, the toner may return from the supply port 71B into the toner cartridge 7 immediately after the first agitator A1 pushes the toner from the supply port 71B into the developing device 6. Such a reversal is suppressed by setting the sideways.

  Further, since the supply port 71B is turned sideways, the upper surface (water level) of the toner in the developing device 6 is not extremely above or below the lower edge of the supply port 71B. It is kept constant so as to be near the lower edge of 71B. As a result, the pressure applied from the toner to the sliding contact portion between the developing roller 61 and the layer thickness regulating blade 62 and between the various sealing members (not shown) that slide on the developing roller 61 is reduced. Therefore, it is possible to prevent more than necessary toner from leaking from the sliding contact portion or the like.

  Further, the return port 71C is formed in a portion extending in the substantially horizontal direction of the partition wall 71A, thereby opening downward. Here, “downward” means not only the vertical direction but also a direction slightly inclined from the vertical direction.

  Thus, since the return port 71C faces downward, the toner can be efficiently returned from the developing device 6 to the toner cartridge 7, and the circulation property can be improved. Further, since the efficiency of returning the toner can be increased by setting the return port 71C downward, the opening area of the return port 71C can be reduced. Therefore, even if the return port 71C is provided outside the print area PA (see FIG. 4), the developing unit DU is not increased in size.

  Here, the printing area PA means an area inside the maximum width of the toner image transferred onto the paper P (the length in the direction orthogonal to the transport direction). Since the return ports 71C are arranged outside the print area PA in this way, toner is suppressed from collecting at both left and right ends (outside the print area PA) in the developing device 6. In addition, toner may tend to be insufficient in the developing device 6 facing the return port 71C, but since it is outside the print area PA, there is no problem in printing.

  As shown in FIG. 3, in a state where the toner cartridge 7 is assembled to the developing device 6 (specifically, a state where the developing unit DU is attached to the apparatus main body 2), the supply port 71 </ b> B sandwiches the auger 64. It is arranged on the opposite side of the supply roller 63. Therefore, new toner supplied into the developing device 6 from the supply port 71B can be dispersed in the axial direction by the auger 64 and mixed with the deteriorated toner.

  Further, in a state where the toner cartridge 7 is assembled to the developing device 6, the return port 71C is disposed below the layer thickness regulating blade 62 so as to overlap the layer thickness regulating blade 62 when viewed from above. Therefore, the deteriorated toner scraped off by the layer thickness regulating blade 62 is easily discharged to the toner cartridge 7 from the return port 71C.

  As shown in FIG. 6A, a first shutter S1 that opens and closes the supply port 71B and the return port 71C by moving along the circumferential direction of the partition wall 71A is provided outside the partition wall 71A. ing. The first shutter S1 is configured by a thin metal plate or the like formed in an arc shape along the partition wall 71A.

As shown in FIG. 3, the partition wall 65D on the developing device 6 side is also provided with an arcuate second shutter S2 along the partition wall 65D. The first shutter S1 and the second shutter S2 are configured to engage with each other and rotate integrally.
Here, there is a problem that the toner leaks between the first shutter S1 and the partition wall 71A and between the second shutter S2 and the partition wall 65D. In this embodiment, the return is made by setting the return port 71C downward. Since the opening area of the opening 71C can be reduced, toner leakage can be reduced. In addition, there is a case where a sponge having a shape surrounding the return port 71C is provided between the first shutter S1 and the partition wall 71A and between the second shutter S2 and the partition wall 65D to prevent toner leakage. Also in this case, the sponge corresponding to the return port 71C can be reduced by reducing the return port 71C, and the sliding resistance when the shutter is opened and closed can be reduced.

  Further, a first agitator A1 that rotates (rotates counterclockwise in the drawing) so as to be in sliding contact with the partition wall 71A from the top to the bottom is provided in the first housing portion 71. The first agitator A1 includes a rotation shaft portion A11 that is rotatably supported on the left and right walls of the toner cartridge 7 (first housing portion 71), a support portion A12 that extends radially outward from the rotation shaft portion A11, and a support portion. And a stirring blade A13 supported by A12.

  As shown in FIG. 5, the stirring blade A13 is composed of a first film A14 disposed at the center in the left-right direction, and a second film A15 disposed on both sides of the first film A14 in the left-right direction. Yes. In other words, the stirring blade A13 is formed with a width that can accommodate both the supply port 71B and each return port 71C (a width that allows sliding contact with both) as a whole.

  The first film A14 is a rectangular film that can be elastically deformed, and has a width that is substantially the same as the width of the supply port 71B (the width in the left-right direction). And this 1st film A14 is slid in the state bent to the opposing wall 71D (refer Fig.6 (a)) of circular arc view in cross section formed between the 1st accommodating part 71 and the 2nd accommodating part 72. As shown in FIG. It comes to touch.

  Here, the opposing wall 71D is erected so as to block the central portion of the wide opening that allows the first storage portion 71 and the second storage portion 72 to communicate with each other, and specifically, faces the supply port 71B ( And a width equal to or greater than the width of the first film A14. As a result, the toner conveyed by the first film A14 is conveyed upward between the first film A14 and the opposing wall 71D, and then is favorably conveyed toward the supply port 71B.

  Each second film A15 is an elastically deformable film, and the rotation direction (the direction of the arrow indicated by the broken line in the drawing) is such that the sliding contact portion A16 that is in sliding contact with the inner surface of the first accommodating portion 71 approaches the first film A14 side. It is comprised so that it may incline back. Specifically, each second film A15 has its shape and the direction of being supported by the support portion A12 appropriately set, so that the inner portion in the left-right direction is the first accommodation than the outer portion in the left-right direction of the sliding contact portion A16. It comes into sliding contact with the inner surface of the portion 71 with a delay.

  In this way, the inner side portion in the left-right direction with respect to the outer side portion in the left-right direction of the sliding contact portion A16 of each second film A15 comes in sliding contact with the inner surface of the first accommodating portion 71 so that the toner returns to the return port on the outer side in the left-right direction. It is conveyed from 71C toward the central supply port 71B. In addition, a hole A17 is formed in the center of each second film A15, so that the toner returning from the return port 71C into the first container 71 is more than necessary from the first container 71 to the second. It is prevented from being pushed back to the accommodating portion 72.

  In other words, by appropriately setting the size of the hole A17, it is possible to push the toner in the first storage unit 71 back to the second storage unit 72 by a favorable amount. As a result, a part of the deteriorated toner returned from the developing device 6 into the toner cartridge 7 is sent into the second storage portion 72 and deteriorated between the first storage portion 71 and the second storage portion 72. It is possible to favorably disperse the toner.

  As shown in FIG. 3, the second storage portion 72 is placed in the first storage portion 71 when the toner cartridge 7 is attached to the developing device 6 (specifically, when the developing unit DU is attached to the device main body 2). On the other hand, it is arranged adjacent to the upper front diagonally. Thereby, the toner can be favorably transported from the second storage unit 72 to the first storage unit 71 using gravity.

  The second accommodating portion 72 is formed in a substantially hollow cylindrical shape, and its rear portion communicates with the first accommodating portion 71 at a portion other than the above-described opposing wall 71D, and substantially the entire front portion thereof is the third accommodating portion 73. Communicating with The toner stored in the bottom of the second storage portion 72 is rotated in the second storage portion 72 in the direction opposite to the rotation direction of the first agitator A1 (clockwise in the drawing). A second agitator A <b> 2 is provided as an example of a second stirring member that is transported to 71. In other words, the first agitator A1 and the second agitator A2 rotate with respect to each other such that the first agitator A1 and the second agitator A2 rotate from bottom to top with respect to the communication port formed between the first housing portion 71 and the second housing portion 72. Is different. The second agitator A2 includes a rotation shaft portion A21 and a support portion A22 that have substantially the same structure as the first agitator A1, and a stirring blade A23 that has a structure different from the first agitator A1.

  As shown in FIG. 5, the stirring blade A23 has a pair of elastically deformable third films A24 disposed at the center in the left-right direction, and two elastically deformable plates disposed on both sides of the third film A24 in the left-right direction. And a rectangular fourth film A25.

  The third film A24 is provided side by side within the width of the opposing wall 71D described above, and the sliding contact portion A26 that is in sliding contact with the inner surface of the second housing portion 72 approaches the adjacent third film A24 side. It is comprised so that it may incline in the rotation direction (the direction of the arrow shown with the broken line of a figure) ahead. Specifically, each third film A24 has a shape in which the shape and the direction supported by the support portion A22 are appropriately set, so that the left and right outer portions of the third contact portions A26 are accommodated in the second direction. The inner surface of the portion 72 comes into sliding contact with a delay.

  In this way, the outer side portion in the left-right direction with respect to the inner side portion in the left-right direction of the sliding contact portion A26 of each third film A24 slidably comes into contact with the inner surface of the second storage portion 72, so that the toner is directed outward in the left-right direction. It is designed to be transported. That is, each third film A24 functions as a wing that conveys the toner from the center in the left-right direction to the outside in the left-right direction. Therefore, the toner conveyed by each third film A24 is moved toward the fourth film A25 side so as to avoid the opposing wall 71D disposed behind each third film A24, and then is transferred to the fourth film A25 by the fourth film A25. 1 is sent to the accommodating portion 71.

  As shown in FIG. 3, the third storage portion 73 is provided in the second storage portion 72 when the toner cartridge 7 is attached to the developing device 6 (specifically, when the developing unit DU is attached to the device main body 2). On the other hand, it is arranged adjacent to the upper front diagonally. Thereby, the toner can be favorably transported from the third storage unit 73 to the second storage unit 72 using gravity.

  The third housing portion 73 is formed in a substantially hollow cylindrical shape, and substantially the entire rear portion thereof communicates with the second housing portion 72. The toner stored in the bottom of the third storage unit 73 is rotated in the direction opposite to the rotation direction of the first agitator A1 (clockwise in the drawing) in the third storage unit 73. A third agitator A <b> 3 for conveying to 72 is provided. The third agitator A3 includes a rotation shaft portion A31 and a support portion A32 that have substantially the same structure as the second agitator A2, and a stirring blade A33 that has a slightly different structure from the second agitator A2.

  As shown in FIG. 5, the stirring blade A33 has one rectangular fifth film A34 that can be elastically deformed at the center in the left-right direction, and the same as the second agitator A2 on the left and right sides of the fifth film A34. There are two fourth films A25 each. As a result, all the toner in the third storage unit 73 can be transported to the second storage unit 72 all at once.

  As shown in FIG. 6B, the first agitator gear AG1, the second agitator gear AG2, and the third agitator gear AG3 are provided at one end portions of the first agitator A1, the second agitator A2, and the third agitator A3. Each is provided coaxially (concentrically) integrally. Two gears GE and GE are provided between the first agitator gear AG1 and the second agitator gear AG2, and one gear GE is provided between the second agitator gear AG2 and the third agitator gear AG3. Is provided.

  As a result, when a driving force is transmitted from a driving source (not shown) to the coupling portion CP formed in the central shaft portion of the third agitator gear AG3, the third agitator gear AG3 and the second agitator gear AG2 are in the same direction. The first agitator gear AG1 rotates in the reverse direction. These gears AG1,... Are covered with a gear case (not shown) that is attached to and detached from the side wall of the toner cartridge 7.

According to the above, the following effects can be obtained in the present embodiment.
Since the auger 64 and the return port 71C are disposed below the layer thickness regulating blade 62, the deteriorated toner scraped off by the layer thickness regulating blade 62 is sent out in the axial direction by the auger 64 and stirred in the developing device 6. At the same time, the deteriorated toner is discharged to the toner cartridge 7 from the return port 71C. Thereby, the deteriorated toner can be diffused as a whole in the developing unit DU, and the influence thereof can be weakened, and the image quality can be improved. Further, since the supply port 71B is disposed on the opposite side of the supply roller 63 with the auger 64 interposed therebetween, new toner supplied from the supply port 71B into the developing device 6 is dispersed in the axial direction by the auger 64 and deteriorated. The toner can be mixed with the toner, and a good toner can be supplied to the supply roller 63 to improve the image quality.

  Since the supply port 71B is formed so as to open sideways in the partition wall 71A formed so as to be recessed toward the inside of the toner cartridge 7, the first agitator A1 efficiently enters the developing device 6 from the supply port 71B. Toner can be conveyed. Further, since the supply port 71B is opened sideways, the toner supplied into the developing device 6 can be kept at a constant water level in the developing device 6, so that the sliding between the developing roller 61 and the layer thickness regulating blade 62 can be maintained. It is possible to suppress leakage of toner more than necessary from the contact portion.

  Since the return port 71C opens downward, the toner can be efficiently returned from the developing device 6 to the toner cartridge 7, and the circulation property can be improved. Further, since the efficiency of returning the toner can be increased by setting the return port 71C downward, the opening area of the return port 71C can be reduced, and the return port 71C can be printed without increasing the size of the developing unit DU. It can be provided outside the area PA.

  Since the supply port 71B and the return port 71C are displaced in the axial direction, it is possible to prevent the toner from the supply port 71B from returning immediately to the return port 71C.

  Since the first shutter S1 and the second shutter S2 are movably provided along the circumferential direction of the partition walls 71A and 65D formed in an arc shape, for example, the shutter can be moved in the left-right direction (the axial direction of the arc). Compared to the structure, the movement of the shutter can be made smooth. In the structure in which the first shutter S1 and the second shutter S2 are movable in the circumferential direction, the shutter is inclined as compared with the case where the partition wall or the shutter is formed in a flat plate shape and the shutter is moved along the partition wall. Can be prevented from moving.

  Since the second storage portion 72 and the third storage portion 73 are disposed adjacent to the first storage portion 71, the toner storage amount of the toner cartridge 7 can be increased. In addition, since the agitators A1 to A3 can be provided for each of the accommodating portions 71 to 73, the toner can be transported favorably in the toner cartridge 7.

  Between the 1st accommodating part 71 and the 2nd accommodating part 72, since the opposing wall 71D which is arrange | positioned facing the supply port 71B and the 1st agitator A1 slidably contacts is provided, with 1st agitator A1 The toner can be held between the opposing wall 71D and the toner can be satisfactorily conveyed to the supply port 71B disposed above.

  Since the first agitator A1 and the second agitator A2 rotate from the bottom to the top with respect to the communication port formed between the first housing portion 71 and the second housing portion 72, the first agitator A1 and the second agitator A2 are accumulated in the first housing portion 71. The toner is returned to the second container 72 by the first agitator A1, and the toner accumulated in the second container 72 is pushed out to the first container 71 by the second agitator A2. Therefore, the toner can be circulated between the second storage portion 72 and the first storage portion 71, and the retention of the toner in the toner cartridge 7 can be prevented.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above-described embodiment, each of the developing unit and the developer storage unit is configured with two parts (the developing device 6 and the toner cartridge 7). You may comprise integrally. That is, the developing unit may be composed of one component instead of two components. When the developing unit is composed of one component, only one partition wall is required to partition the developing unit and the developer storage unit, and a shutter or the like is not necessary.

  In the above embodiment, the supply ports 65B and 71B and the return ports 65C and 71C are provided in the partition walls 65D and 71A of the developing device 6 and the toner cartridge 7, respectively, but the present invention is not limited to this, and one partition is provided. One large opening formed so as to communicate with both the supply port and the return port of the wall may be provided in the other partition wall. In other words, for example, the partition wall 71A of the toner cartridge 7 in the above-described embodiment may be entirely open, and the opening of the toner cartridge 7 may be closed by the partition wall 65D of the developing device 6. In other words, a part (partition wall) of the toner cartridge may be configured by the partition wall of the developing device.

  Further, the positions and the number of the supply ports and the return ports are not limited to the above embodiment, and can be set as appropriate. For example, as shown in FIG. 7, one wide supply port 81B is formed on one end side in the left-right direction of the partition wall 81A of the toner cartridge 8, and the other end side is positioned below the supply port 81B. One return port 81C may be formed.

  In this case, as shown in FIG. 8, an auger for feeding toner from one end to the other in the left-right direction, that is, an auger 641 having only one type of wings (second spiral wings 64C) is employed as the sending member. That's fine. In this case, the positions of the opposing wall 81D, the first film A14, and the second film A15 are changed to correspond to the position of the supply port 81B, or the third film A27 disposed on the front side of the opposing wall 81D. The shape may be changed to a shape that conveys toner only to one side.

  In the above-described embodiment, the first agitator A1 having the rotation shaft portion A11, the support portion A12, and the stirring blade A13 is used as the stirring member. However, the present invention is not limited to this, and for example, an agitator without the support portion A12 is used. May be. Further, as the restricting member, for example, a blade composed only of a metal plate without rubber is employed, instead of the layer thickness restricting blade 62 with rubber attached to the tip of the metal plate as in the above embodiment. Also good.

  In the above embodiment, the present invention is applied to the laser printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.

6 Developing Device 7 Toner Cartridge 61 Developing Roller 62 Layer Thickness Restricting Blade 63 Supply Roller 64 Auger 65B Supply Port 65C Return Port 65D Partition Wall 71 First Storage Portion 71A Partition Wall 71B Supply Port 71C Return Port 71D Opposing Wall 72 Second Storage Portion A1 First agitator DU Development unit

Claims (9)

A developing section having a developing roller carrying a developer;
A developer containing unit, and a developer containing unit disposed adjacent to and below the developing unit,
A partition wall is provided between the developing unit and the developer containing unit,
The partition wall is formed with a supply port for supplying the developer from the developer containing portion to the developing portion, and a return port for returning the developer from the developing portion to the developer containing portion,
In the developer container,
A stirring member that rotates to slidably contact the partition wall and conveys the developer in the developer container to the supply port is provided,
In the developing section,
A supply roller that is disposed below the developing roller and supplies developer to the developing roller;
A regulating member that regulates the thickness of the developer carried on the developing roller in sliding contact with the developing roller;
A feeding member disposed below the regulating member and sending the developer in the developing section in the axial direction of the supply roller; and
The supply port is disposed on the opposite side of the supply roller across the delivery member;
The developing unit, wherein the return port is disposed below the restriction member so as to overlap the restriction member when viewed from above. The partition wall is formed so as to be recessed toward the developer accommodating portion when viewed from the rotation axis direction of the stirring member,
The developing unit according to claim 1, wherein the supply port is opened sideways.   The developing unit according to claim 2, wherein the return port is opened downward.   The developing unit according to claim 1, wherein the supply port and the return port are displaced in the axial direction.   The developing unit according to claim 1, wherein the developer accommodating portion is detachable from the developing portion. The partition wall is formed in an arc shape,
The developing unit according to claim 5, wherein a shutter that opens and closes the supply port and the return port is provided to be movable along a circumferential direction of the partition wall. The developer container is
A first accommodating portion disposed adjacent to the developing portion;
7. The developing unit according to claim 1, further comprising: a second housing portion disposed adjacent to the first housing portion. Between the first storage part and the second storage part,
The developing unit according to claim 7, further comprising a facing wall that is disposed to face the supply port and is in sliding contact with the stirring member. The stirring member includes a first stirring member provided in the first housing part and a second stirring member provided in the second housing part,
A communication port is formed between the first housing portion and the second housing portion,
The first stirring member and the second stirring member rotate from bottom to top with respect to the communication port, and the first stirring member and the second stirring member have different rotation directions. The developing unit according to claim 7 or 8.

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