JP2012150246A - Toner distribution mechanism and developing device including the same, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner distribution mechanism that puts toner supplied from a toner storage container in a distributed state with a simple configuration, and supplies the toner into a developing device, and a developing device including the toner distribution mechanism, as well as an image forming apparatus.SOLUTION: A toner distribution mechanism 21 comprises a housing 24 on which a toner intake port 24a and a toner discharge port 24b are provided thereon, and a toner distribution member 25. A projection part 26 is formed on the inner wall surface of the housing 24 at a position in the vicinity of the downstream side of the toner discharge port 24b relative to the rotation direction of the toner distribution member 25. As the toner distribution member 25 rotates, each of projections 25b for distribution sequentially comes into contact first with a projection 26a and then with the projection part as a whole, and elastically deforms. When each of the projections 25b for distribution returns from the deformed state to the original state, toner that has been held between the projections 25b for distribution and slightly aggregated is removed off by force, and therefore the toner distribution member 25 rotates without being clogged with toner.

Description

  The present invention relates to a toner dispersion mechanism that is mounted on an image forming apparatus such as a copying machine, a printer, or a facsimile using an electrophotographic system, and that disperses toner supplied from a toner storage container such as a hopper or a container into a developing device. And a developing device and an image forming apparatus having the same.

  Conventionally, in a developing device mounted on an image forming apparatus, a certain amount of toner is filled in the developing device for easy maintenance, and the developing device is replaced when the toner runs out. However, the developing device cannot be replaced frequently from an economic point of view, and the toner capacity must be increased in order to form a certain number of images. Therefore, it is difficult to reduce the size of the developing device. Therefore, in order to reduce the size of the developing device, a developing device that supplies toner from the outside has been proposed.

  In such a toner supply type developing device, when the fluidity of the toner is lowered due to the use environment or the like, a block of toner may be replenished in the developing device. For this reason, the mixing property with the developer present in the developing device is deteriorated, the developer thin layer formed on the developing roller is disturbed, and there is a possibility that problems such as uneven image density and fogging may occur.

  In view of this, various techniques for suppressing the occurrence of image defects by dispersing toner replenished into the developing device in advance have been proposed. For example, Patent Document 1 discloses a developer carrier, a developer container, A developing device is disclosed in which a grid-like member (mesh) and a brush-like developer supply roller are disposed between the two. Patent Document 2 discloses a developing device provided with a toner replenishing port stirring member that stirs toner in a toner replenishing port of a toner hopper. Further, in Patent Document 3, a toner dispersion member composed of a core metal and a cylindrical foam member is disposed so as to close the replenishing port of the toner bottle, and the toner dispersion member is rotated so that the toner is little by little in the developing device. A method of dropping into a dome is disclosed.

  On the other hand, in Patent Document 4, the toner supplied from the toner supply container and the carrier supplied from the carrier supply container are individually received, and the toner and the carrier are sufficiently mixed using a screw-shaped stirring and conveying member. An image forming apparatus including an auxiliary stirring container for stirring and premixed in the auxiliary stirring container and supplying a developer having stable charging characteristics to the developing device is disclosed.

Japanese Utility Model Publication No. 2-111161 JP 2000-275939 A JP 2008-304650 A JP 2008-268783 A

  However, in the method of Patent Document 1, when toner is agglomerated due to the use environment or mechanical stress, it is difficult to supply a small amount of toner due to clogging of the lattice-like member or toner fusion. Further, in the method of Patent Document 2, although an effect of smoothly conveying the toner by breaking the bridge formed by aggregation of the toner in the toner supply port can be expected, it is difficult to completely disperse the bulk toner. However, it was not sufficient as a means for solving the above problems.

  In the method of Patent Document 3, since the toner dispersion member is attached to the toner bottle side, the toner dispersion mechanism is also replaced when the toner bottle is replaced, leading to an increase in cost. In addition, since the cylindrical foam member is used as the toner dispersion member, the foam member is clogged with toner, and the durability of the toner dispersion member is lowered.

  Further, although the auxiliary stirring container provided with the screw-shaped stirring and conveying member described in Patent Document 4 has a function of efficiently mixing and stirring the toner and the carrier, the effect of dispersing the aggregated toner in units of particles is not effective. It could not be expected and could not be used as a toner dispersion mechanism.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a toner dispersion mechanism that supplies toner replenished from a toner storage container into a developing device in a dispersed state with a simple configuration, and a developing device including the same. To do. Another object of the present invention is to provide an image forming apparatus capable of effectively suppressing image defects such as density unevenness and fog by mounting the toner dispersion mechanism and the developing device.

  In order to achieve the above object, the present invention is a toner dispersion mechanism that is disposed between a toner container and a developing device and disperses toner replenished from the toner container, and communicates with the toner container. A housing in which a toner inlet and a toner outlet that communicates with the developing device are formed, a rotating shaft that is rotatably supported in the housing, and a large number of elastic materials formed on the outer peripheral surface of the rotating shaft. A toner dispersion member composed of a dispersion protrusion, and a protrusion that contacts the dispersion protrusion on an inner wall surface of the housing is at least a portion where the dispersion protrusion faces in the longitudinal direction of the housing This is a toner dispersion mechanism formed continuously.

  According to the present invention, in the toner dispersion mechanism having the above-described configuration, the protrusion is formed in the vicinity of the downstream side of the opening edge of the toner discharge port with respect to the rotation direction of the dispersion member.

  According to the present invention, in the toner dispersion mechanism configured as described above, the dispersion protrusion is formed by winding a flexible film member having a large number of cuts on one side around the outer peripheral surface of the rotating shaft with the cuts facing outward. It is characterized by being formed.

  According to the present invention, in the toner dispersion mechanism having the above-described configuration, a protrusion protruding upstream in the rotation direction of the toner dispersion member is formed at an upstream end of the protrusion with respect to the rotation direction of the toner dispersion member. It is characterized by being.

  According to the present invention, in the toner dispersion mechanism having the above-described configuration, the distance from the inner wall surface of the housing to the protrusion is 50% or more of the distance from the inner wall surface of the housing to the outer peripheral surface of the rotating shaft. It is said.

  According to the present invention, in the toner dispersion mechanism having the above-described configuration, the dispersion protrusion is fixed to be inclined with respect to the axial direction of the rotation shaft, and a projection length of the dispersion protrusion on the rotation shaft is set to the rotation shaft. It is characterized by being larger than the pitch of the dispersing protrusions in the direction.

  According to the present invention, in the toner dispersion mechanism having the above-described configuration, an opening width of the toner discharge port in a longitudinal direction of the dispersion member is formed larger than an opening width of the toner input port, and the dispersion member is the toner dispersion mechanism. The toner charged into the housing from the charging port is dispersed and discharged from substantially the entire area of the toner discharging port.

  According to the present invention, in the toner dispersion mechanism configured as described above, the dispersion protrusions are spirally arranged with respect to the rotation shaft.

  According to the present invention, in the toner dispersion mechanism configured as described above, a screw portion having a conveying force from the toner inlet to the toner outlet is formed on the rotating shaft adjacent to the dispersion protrusion. The toner inlet is formed immediately above the screw portion.

  According to the present invention, in the toner dispersion mechanism configured as described above, the toner dispersion member can be rotated forward and backward.

  According to the present invention, in the toner dispersion mechanism configured as described above, the toner dispersion member can reciprocate in a thrust direction.

  According to another aspect of the present invention, there is provided a developing device including the toner dispersing mechanism having the above-described configuration and a developing container having the toner dispersing mechanism connected to an upper portion thereof.

  According to the present invention, in the developing device configured as described above, a stirring conveyance blade is formed on the outer peripheral surface of the agitating / conveying rotary shaft at a toner dropping position in the developing container where the toner discharged from the toner discharge port falls. And a developer that is circulated and conveyed in the developing container by the agitating / conveying member.

  According to the present invention, in the developing device configured as described above, the bulk of the developer present at the toner dropping position is lower than the upper surface of the rotating shaft of the stirring and conveying member.

  According to another aspect of the present invention, there is provided a developing device having the above-described configuration, and a toner storage container that is detachably disposed above the toner dispersion mechanism and stores toner to be replenished into the development device via the toner dispersion mechanism. The image forming apparatus is mounted.

  In the image forming apparatus having the above-described configuration, the image forming apparatus further includes a control unit that changes a rotation speed of the toner dispersion member based on at least one of a toner replenishment amount from the toner container and toner fluidity. It is a feature.

  According to the first configuration of the present invention, as the toner dispersion member rotates, the dispersion protrusion comes into contact with the protrusion formed on the inner wall surface of the housing and swings, so that it is held between the dispersion protrusions. Lightly agglomerated toner can be effectively removed. Accordingly, a simple and low-cost toner dispersion mechanism that does not cause a decrease in dispersion performance due to clogging of the dispersion protrusions is obtained.

  According to the second configuration of the present invention, in the toner dispersion mechanism of the first configuration, the protrusion is formed in the vicinity of the downstream side of the opening edge of the toner discharge port, so that the dispersion protrusion is swung. Since the splashed toner slides down to the toner discharge port along the upper surface of the projecting portion, the retention of the toner inside the housing can be suppressed.

  According to the third configuration of the present invention, in the toner dispersion mechanism of the first or second configuration, the film member in which a large number of cuts are formed along one side in the longitudinal direction is provided on the outer peripheral surface of the rotating shaft. The dispersion protrusions can be easily formed on the outer peripheral surface of the rotating shaft by winding the wire around the surface. In addition, hair loss and sponge tearing do not occur unlike the brush roller and sponge roller, and assemblability is improved. Therefore, the toner dispersion member is simple, low cost and excellent in durability.

  Further, according to the fourth configuration of the present invention, in the toner dispersion mechanism of the third configuration, the protrusion that protrudes upstream in the rotation direction of the toner dispersion member is formed on the protrusion, thereby rotating the toner dispersion member. As a result, the vicinity of the center first comes into contact with the protrusion rather than the tip of the dispersion protrusion. As a result, the dispersion protrusion is greatly deformed from the vicinity of the center to the base portion of the dispersion protrusion formed of the film member, so that the dispersion protrusion can be greatly swung.

  Further, according to the fifth configuration of the present invention, in the toner dispersion mechanism of the fourth configuration, the distance from the inner wall surface of the housing to the projection is 50, which is the distance from the inner wall surface of the housing to the outer peripheral surface of the rotating shaft. By setting the ratio to at least%, since the portion closer to the root than the center of the dispersion protrusion first comes into contact with the protrusion, the dispersion protrusion can be sufficiently deformed.

  According to the sixth configuration of the present invention, in the toner dispersion mechanism having any one of the third to fifth configurations, the dispersion protrusion is fixed to be inclined with respect to the axial direction of the rotation shaft. By making the projection length of the projections on the rotation axis larger than the pitch of the dispersion projections in the direction of the rotation axis, it is possible to prevent the toner from being poorly dispersed due to the blocky toner passing through the dispersion projections.

  According to the seventh configuration of the present invention, in the toner dispersion mechanism having any one of the third to sixth configurations, the opening width of the toner discharge port in the longitudinal direction of the dispersion member is greater than the opening width of the toner input port. The dispersion member disperses the toner charged into the housing from the toner inlet and discharges it from substantially the entire area of the toner outlet, thereby reducing the amount of toner replenished per unit area to the developing device. And the developer mixing property is improved.

  Further, according to the eighth configuration of the present invention, in the toner dispersion mechanism of the seventh configuration, by arranging the dispersion protrusions in a spiral manner with respect to the rotation axis, the toner in the rotation axis direction in the housing can be obtained. Since the conveying force is increased, the toner can be discharged in a wide range from the toner discharge port.

  According to the ninth configuration of the present invention, in the toner dispersion mechanism having any one of the first to eighth configurations, a screw portion having a conveying force from the toner inlet to the toner outlet is provided on the rotating shaft. By forming it adjacent to the dispersion projection, the toner introduced from the toner introduction port is conveyed toward the toner discharge port by the screw portion and reaches the dispersion projection, so that the toner discharge port is provided directly below the toner introduction port. Even when the toner cannot be formed, the toner can be effectively dispersed.

  According to the tenth configuration of the present invention, in the toner dispersion mechanism having any one of the first to ninth configurations, the toner dispersion member can be rotated in the forward and reverse directions so that it cannot be completely removed during the forward rotation. The light agglomerated toner between the dispersing protrusions can be effectively removed.

  According to the eleventh configuration of the present invention, in the toner dispersing mechanism having any one of the first to tenth configurations, the toner dispersing member can reciprocate in the thrust direction, whereby the dispersing projection is provided. It is possible to more effectively remove the light agglomerated toner held in the dispersion protrusion by swinging in a complicated manner so as to be twisted.

  According to the twelfth configuration of the present invention, the toner dispersion mechanism having any one of the first to eleventh configurations described above and the developing container having the toner dispersion mechanism coupled to the upper portion are provided. A sufficient amount of toner can be mixed in time, and the developing device has a short aging time.

  According to the thirteenth configuration of the present invention, in the developing device of the twelfth configuration, the stirring / conveying member configured by the stirring / transporting rotating shaft and the stirring / transporting blade is disposed at the toner dropping position in the developing container. And the developer circulated and conveyed in the developing container by the agitating and conveying member, the toner replenished from the toner dispersing mechanism can be rapidly agitated and mixed with the developer in the developing container.

  Further, according to the fourteenth configuration of the present invention, in the developing device of the thirteenth configuration, the volume of the developer present at the toner dropping position is made lower than the upper surface of the agitating / conveying rotation shaft. Is replenished in the vicinity of the rotating shaft for stirring and transporting, and is transported while being repeatedly raised and dropped by the stirring and transporting blades. Therefore, the toner replenished from the toner dispersion mechanism and the developer in the developing container can be efficiently stirred.

  According to the fifteenth configuration of the present invention, the developing device having any one of the twelfth to fourteenth configurations described above is detachably disposed above the toner dispersion mechanism and is placed in the development device via the toner dispersion mechanism. By mounting a toner container that stores toner for replenishment, the mixing property between the toner replenished from the toner container and the developer present in the developing device can be improved. An image forming apparatus capable of effectively suppressing image defects such as fogging.

  According to the sixteenth configuration of the present invention, in the image forming apparatus having the fifteenth configuration, the rotation speed of the toner dispersing member is controlled based on at least one of the toner replenishment amount from the toner container and the toner fluidity. By providing the changing control means, when the toner replenishment amount is large or when the toner fluidity is low, the rotation speed of the toner dispersion member can be increased to increase the toner dispersion ability.

1 is a schematic configuration diagram showing an overall configuration of an image forming apparatus of the present invention. FIG. 3 is a side sectional view of the developing device including the toner dispersion mechanism according to the first embodiment of the present invention (cross sectional view taken along the line XX ′ in FIG. 3). The top view which looked at the developing device provided with the toner dispersion mechanism of a 1st embodiment from the upper part The perspective view which looked at the toner distribution mechanism of a 1st embodiment from the upper part FIG. 3 is a plan view of a toner dispersion mechanism according to the first embodiment. FIG. 3 is a development view illustrating an example of a film member that forms a dispersion protrusion of a toner dispersion member used in the toner dispersion mechanism of the first embodiment. The perspective view of the toner dispersion member used for the toner dispersion mechanism of 1st Embodiment. Partial enlarged view of the film member showing a state in which the double-sided tape 56 is attached so as to overlap the base end portion 53 a of the cut 53. FIG. 5 is a front sectional view of the toner dispersion mechanism of the first embodiment (a sectional view taken along the arrow ZZ ′ in FIG. 5). Front sectional view showing a modification of the toner dispersion mechanism of the first embodiment Front sectional view showing another modification of the toner dispersion mechanism of the first embodiment. FIG. 6 is a development view showing another example of a film member for forming a dispersion protrusion of a toner dispersion member used in the toner dispersion mechanism of the first embodiment. The perspective view of the toner dispersion member used for the toner dispersion mechanism of 1st Embodiment which formed the protrusion for dispersion | distribution with the film member shown in FIG. The partial enlarged view which shows the relationship between the pitch a of the processus | protrusion for dispersion | distribution of the rotating shaft direction in the toner dispersion mechanism of 2nd Embodiment, and the projection length b of the processus | protrusion for dispersion | distribution with respect to a rotating shaft. Side surface sectional view showing the positional relationship between the toner dispersion mechanism and the developing device of the first embodiment FIG. 6 is a plan view of a toner dispersion mechanism according to a second embodiment of the present invention. Side surface sectional view of the toner dispersion mechanism of the second embodiment Side surface sectional view which shows the example which has arrange | positioned the toner dispersion | distribution mechanism in the boundary of the 1st storage chamber of a developing device, and a 2nd storage chamber Side sectional view showing an example in which the toner dispersion mechanism is disposed obliquely above the developing device. Top view of a toner dispersion mechanism having a mechanism for reciprocating the toner dispersion member in the thrust direction

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing the overall configuration of an image forming apparatus equipped with a toner dispersion mechanism of the present invention and a developing device equipped with the same, and the right side is shown as the front side of the image forming apparatus. As shown in FIG. 1, the image forming apparatus 100 includes a paper feed cassette 2 that stores sheets stacked on the lower part of the main body. Above this paper feed cassette 2 is formed a paper transport path 4 that extends substantially horizontally from the front of the main body to the rear of the main body and further extends upward to reach the paper discharge section 3 formed on the upper surface of the main body. A pickup roller 5, a feed roller 6, an intermediate transport roller 7, a registration roller pair 8, an image forming unit 9, a fixing unit 10, and a discharge roller pair 11 are arranged in this order from the upstream side along the transport path. Further, in the image forming apparatus 100, a control unit (CPU) 30 for controlling operations of the above-described rollers, the image forming unit 9, the fixing unit 10, and the like is disposed.

  The paper feed cassette 2 is provided with a paper stacking plate 12 that is rotatably supported with respect to the paper feed cassette 2 by a rotation fulcrum 12a provided at the rear end in the paper transport direction. The paper stacked on the paper 12 is pressed by the pickup roller 5. A retard roller 13 is disposed in front of the paper feed cassette 2 so as to be in pressure contact with the feed roller 6. When a plurality of sheets are simultaneously fed by the pickup roller 5, these feed rollers 6 are fed. The paper is rolled by the roller 6 and the retard roller 13 so that only the uppermost sheet is conveyed.

  Then, the paper rolled by the feed roller 6 and the retard roller 13 is conveyed to the registration roller pair 8 by changing the conveyance direction to the rear of the apparatus by the intermediate conveyance roller 7, and the timing is adjusted by the registration roller pair 8. Are supplied to the image forming unit 9.

  The image forming unit 9 forms a predetermined toner image on a sheet by an electrophotographic process. The photosensitive drum 14 is an image carrier that is pivotally supported in a clockwise direction in FIG. Above the charging drum 15, the developing device 16, the cleaning device 17, the transfer roller 18 disposed so as to face the photosensitive drum 14 across the sheet conveyance path 4, and the photosensitive drum 14. An exposure unit (LSU) 19 is arranged, and a toner container 20 for supplying toner to the developing device 16 is arranged above the developing device 16. Between the developing device 16 and the toner container 20, a toner dispersing mechanism 21 for dispersing toner supplied to the developing device 16 is disposed.

  The charging device 15 includes a conductive rubber roller 15 a to which a power source (not shown) is connected, and the conductive rubber roller 15 a is disposed so as to contact the photosensitive drum 14. When the photosensitive drum 14 rotates, the conductive rubber roller 15a comes into contact with the surface of the photosensitive drum 14 and is driven to rotate. At this time, by applying a predetermined voltage to the conductive rubber roller 15a, the photosensitive drum The surface of the drum 14 is uniformly charged.

  Next, an electrostatic latent image based on the image data input on the photosensitive drum 14 is formed by the laser beam from the exposure unit (LSU) 19, and toner is attached to the electrostatic latent image by the developing device 16, and the photosensitive member. A toner image is formed on the surface of the drum 14, and the transfer roller 18 transfers the toner image on the surface of the photosensitive drum 14 to the sheet supplied to the transfer position formed in the nip portion between the photosensitive drum 14 and the transfer roller 18. It is transcribed.

  The sheet on which the toner image has been transferred is separated from the photosensitive drum 14 and conveyed toward the fixing unit 10. The fixing unit 10 is disposed on the downstream side of the image forming unit 9 in the paper conveyance direction, and the sheet on which the toner image is transferred in the image forming unit 9 includes a heating roller 22 provided in the fixing unit 10 and the heating roller 22. The toner image heated and pressed by the pressure roller 23 pressed against the heating roller 22 is fixed to the toner image transferred to the paper.

  The paper on which the image is formed in the image forming unit 9 and the fixing unit 10 is discharged to the paper discharge unit 3 by the discharge roller pair 11. On the other hand, the toner remaining on the surface of the photosensitive drum 14 after the transfer is removed by the cleaning device 17. The photosensitive drum 14 is charged again by the charging device 15 and image formation is performed in the same manner.

  Next, the developing device 16 provided with the toner dispersion mechanism of the present invention will be described in detail with reference to FIGS. FIG. 2 is a side sectional view of the developing device of the present invention, and FIG. 3 is a plan view of the developing device as viewed from above. 2 corresponds to a cross-sectional view taken along the line XX ′ in FIG. 3, and FIG. 3 shows a state where the cover 31b is removed for convenience of explanation.

  As shown in FIGS. 2 and 3, the developing device 16 includes a container main body 31a in which a two-component developer containing a non-magnetic toner and a magnetic carrier is stored, and the developer stored in the container main body 31a leaks to the outside. A first agitation and conveyance screw 32, a second agitation and conveyance screw 33, a developing roller 35, and a regulating blade 36 are provided in a developing container 31 that includes a cover 31b that is sealed so as not to exist.

  The inside of the container main body 31a is partitioned into a first storage chamber 38 and a second storage chamber 39 by a partition plate 37 extending in the longitudinal direction. In the first storage chamber 38, the first stirring and conveying screw 32 is provided. In the second storage chamber 39, the second stirring and conveying screw 33 is provided. Further, as shown in FIG. 3, the partition plate 37 is not provided at the left and right ends of the container body 31a, and the developer moves between the first storage chamber 38 and the second storage chamber 39 in this portion. A passage (developer delivery part) 40 is formed.

  The first agitating and conveying screw 32 and the second agitating and conveying screw 33 are respectively composed of rotating shafts 32a and 33a and spiral blades 32b and 33b integrally formed on the outer peripheral surface thereof, and the container main body 31a so as to be substantially parallel to each other. The first agitating and conveying screw 32 and the second agitating and conveying screw 33 are rotated in a predetermined direction so that the developer in the first storage chamber 38 is conveyed in the direction of arrow A. 2 The developer in the storage chamber 39 is configured to be conveyed in the direction of arrow B. Further, the cover 31b is provided with a toner supply port 34 through which toner is supplied from the toner container 20 (see FIG. 1) so that the toner can be supplied into the container body 31a according to the detection result of the toner concentration sensor 44 described later. It has been.

  The drive input gears 41 a and 41 b are connected to the rotation shafts 32 a and 33 a of the first stirring and conveying screw 32 and the second stirring and conveying screw 33, and the driving input gears 41 a and 41 b are connected via the driving output gear 42. A motor 43 is connected. By driving the first and second agitating and conveying screws 32 and 33 in a predetermined direction by the drive input gears 41 a and 41 b, the drive output gear 42 and the motor 43, the developer is supplied to the first storage chamber 38 and the second storage chamber. 39, and passes through the passages 40 provided at the left and right ends of the container body 31a as described above, and circulates between the first storage chamber 38 and the second storage chamber 39. .

  The developing roller 35 is rotatably supported in the first storage chamber 38 so as to be substantially parallel to the first agitating and conveying screw 32 and the second agitating and conveying screw 33, and is driven by a motor via a gear train (not shown). 43 is connected. As the developing roller 35, a magnet roller having a magnetic field generating member (not shown) made of a permanent magnet fixed to the inner surface is used. When the developing roller 35 rotates in accordance with the rotation of the photosensitive drum 14, A developer is adhered (carried) to the surface of the developing roller 35 by the magnetic force of the magnetic field generating member, and a developer layer is formed.

  Then, the toner in the developer attached to the developing roller 35 in a predetermined developing area flies to the photosensitive drum 14 due to the potential difference between the surface potential of the photosensitive drum 14 and the developing bias applied to the developing roller 35. A toner image is formed on the surface of the photosensitive drum 14 by adhering to the photosensitive layer. Note that a driving unit separate from the motor 43 may be connected to the developing roller 35 so that the developing roller 35 is driven independently.

  The regulating blade 36 regulates the amount of toner supplied to the photosensitive drum 14, that is, the amount of developer attached to the developing roller 35. For example, a nonmagnetic SUS (stainless steel) such as SUS303 is used. The regulating blade 36 is disposed so that a predetermined gap is formed between the tip of the regulating blade 36 and the developing roller 35, and the developing onto the developing roller 35 is performed by the gap between the regulating blade 36 and the developing roller 35. The amount of the applied agent is regulated, and a thin developer layer of several hundred microns is formed on the surface of the developing roller 35.

  A toner concentration sensor 44 is disposed on the inner wall surface of the second storage chamber 39. As the toner concentration sensor 44, a magnetic permeability sensor for detecting the magnetic permeability of a two-component developer composed of toner and magnetic carrier in the container main body 31a is used. Here, the toner concentration is the ratio of toner to the magnetic carrier in the developer. In this embodiment, the toner concentration sensor 44 detects the magnetic permeability of the developer, and the voltage value corresponding to the detection result. Is output to the control unit 30 (see FIG. 1), and the control unit 30 determines the toner density from the output value of the toner density sensor 44.

  The sensor output value changes according to the toner concentration. The higher the toner concentration, the higher the ratio of toner to the magnetic carrier, and the higher the ratio of toner that does not pass magnetism, the lower the output value. On the other hand, the lower the toner concentration, the lower the ratio of toner to carrier, and the higher the ratio of carrier that passes magnetism, the higher the output value.

  The toner dispersion mechanism 21 includes a housing 24 that is integrally formed with the cover 31 b of the developing device 16 and a toner dispersion member 25 that is rotatably supported in the housing 24. A toner input port 24 a is formed on the upper surface of the housing 24, and a toner discharge port 24 b communicating with the toner supply port 34 of the developing device 16 is formed on the lower surface of the housing 24 a. When a predetermined amount of toner is introduced into the toner dispersion mechanism 21 from the toner introduction port 24a in accordance with the output of the toner density sensor 44, the toner particles are dispersed by the rotation of the toner dispersion member 25, and then the toner discharge port 24b. And is supplied into the developing device 16 through the toner supply port 34.

  The “dispersion” used in the present specification means a state in which the toner is finely divided into units of one particle, and is clearly distinguished from “mixing” using a screw or a spiral.

  4 and 5 are a perspective view and a plan view of the toner dispersion mechanism according to the first embodiment of the present invention. With reference to FIGS. 2 and 3, the configuration of the toner dispersion mechanism will be described with reference to FIGS. 4 and 5. The toner dispersion mechanism 21 includes a housing 24 and a toner dispersion member 25 that is rotatably supported in the housing 24. For convenience of explanation, in FIGS. 4 and 5, the upper surface of the housing 24 is opened and the inside can be seen.

  A toner input port 24 a is formed on the upper surface of the housing 24, and a toner discharge port 24 b communicating with the toner supply port of the developing device 16 is formed on the lower surface of the housing 24. When a predetermined amount of toner is introduced into the toner dispersion mechanism 21 from the toner introduction port 24a in accordance with the output of the toner density sensor 44, the toner particles are dispersed by the rotation of the toner dispersion member 25, and then the toner discharge port 24b. And is supplied to the developing device 16. In addition, a shutter member (not shown) that is opened when the toner container 20 is attached and is closed when the toner container 20 is detached is attached to the toner inlet 24a.

  The toner dispersion member 25 has a large number of dispersion protrusions 25b formed of an elastic material on the outer peripheral surface of the rotation shaft 25a. One end of the rotating shaft 25a extends to the outside of the housing 24, and the drive input gear 50 is fixed. The drive input gear 50 is connected to a drive mechanism (not shown) through a gear train. Further, the tip of the dispersion projection 25b is arranged so as to contact the opening edge of the toner discharge port 24b.

  FIG. 6 is a development view showing an example of a dispersion protrusion of a toner dispersion member used in the toner dispersion mechanism of the first embodiment, and FIG. 7 is a view in which the dispersion protrusion of FIG. 6 is spirally wound around a rotation shaft. FIG. 6 is a perspective view of a toner dispersion member. In the toner dispersion member 25 according to the present embodiment, a large number of cuts 53 are formed on one side of the ribbon-shaped film member 51 in the longitudinal direction (upper side in FIG. 6), and a portion where the cuts 53 are not formed is used as a fixing portion 54. The film member 51 is spirally wound around the outer peripheral surface of the rotary shaft 25a with the notch 53 facing outward to form the dispersion protrusion 25b.

  As shown in FIG. 6, the cut 53 is formed not diagonally to the longitudinal direction of the film member 51 but obliquely. Thereby, when the film member 51 is wound around the outer peripheral surface of the rotating shaft 25a, the portion where the cut 53 is inserted rises at a certain angle with respect to the rotating shaft 25a, so that the dispersion protrusion 25b is not spread by hand. It can be formed uniformly and easily. The rising angle of the dispersion protrusion 25 b with respect to the rotation shaft 25 a can be arbitrarily adjusted by the angle of the cut 53.

  Engaging projections 55 are formed at both ends of the film member 51, and engaging portions 57 that engage with the engaging projections 55 are provided at two locations on the outer peripheral surface of the rotating shaft 25a. A double-sided tape 56 is attached to the fixed portion 54 of the film member 51 over the entire longitudinal direction. When assembling the toner dispersion member 25, the engagement protrusion 55 at one end of the film member 51 is inserted into the slit 57a of one engagement portion 57, and the film member 51 is attached with a double-sided tape 56 while being wound around the rotary shaft 25a. By inserting the engaging protrusion 55 at the other end into the slit 57a of the other engaging portion 57, the film member 51 can be easily fixed to the rotating shaft 25a.

  According to the configuration of the present embodiment, by rotating the toner dispersion member 25 in accordance with the timing of toner supply from the toner container 20 (see FIG. 1) to the toner supply port 24 a, the tip of the dispersion protrusion 25 b is located on the housing 24. It is possible to efficiently disperse the lump of toner that has rocked in contact with the inner surface and the edge of the toner discharge port 24b and entered the housing 24 from the toner input port 24a up to one particle unit.

  Further, by forming the dispersion protrusions 25b with the film member 51, hair loss and spun off of the sponge do not occur unlike the flocked brush roller and sponge roller, so that the toner dispersion member has excellent durability. Further, since there is no possibility that foreign matter caused by the toner dispersion member 25 enters the developing container 30, image defects such as white spots caused by foreign matter being caught in the gap between the regulating blade 36 and the developing roller 35 are effectively prevented. Can be prevented. As a material of the film member 51, a PET film or a urethane sheet excellent in flexibility and resilience (elasticity) is preferable.

  Further, when the film member 51 is wound around the rotation shaft 25a to form the toner dispersion member 25, a load is applied to the dispersion protrusion 25b, and the notch 53 may be further broken to break the dispersion protrusion 25b. Therefore, when the double-sided tape 56 is affixed to the fixing portion 54, it is preferable that the double-sided tape 56 is affixed so as to overlap the base end portion 53a of the cut 53 as shown in FIG. By sticking in this way, the base end portion 53a of the cut 53 is reinforced by the double-sided tape 56, so that the dispersal projection 25b can be prevented from being broken.

  FIG. 9 is a front cross-sectional view (a cross-sectional view taken along the arrow ZZ ′ in FIG. 5) of the toner dispersion mechanism of the first embodiment. On the inner wall surface of the housing 24, a protruding portion 26 (hatched portion in FIG. 9) is formed in the vicinity of the downstream side of the toner discharge port 24b with respect to the rotation direction of the toner dispersion member 25 (the arrow direction in FIG. 9). The protruding portion 26 is formed continuously at least at the portion facing the dispersion protrusion 25b in the longitudinal direction of the housing 24 (the front and back direction in FIG. 9), and a toner dispersion member is provided at the upstream end of the protruding portion 26. A protrusion 26a is formed to protrude to the upstream side in the rotational direction of 25.

  When the toner dispersion member 25 rotates in the direction of the arrow in FIG. 9, the dispersion protrusions 25b sequentially come into contact with the protrusions 26 from the protrusions 26a to be elastically deformed and bent in the radial direction. When the toner dispersion member 25 further rotates, the dispersion protrusions 25b bent in the radial direction are sequentially separated from the protrusions 26 and returned to the original state by the restoring force.

  When the dispersion protrusion 25b is restored from the bent state, the toner that is held between the dispersion protrusions 25b and lightly agglomerated is bounced off, so that the toner dispersion member 25 rotates without being clogged by the toner. To do. Accordingly, it is possible to effectively suppress a decrease in the amount of toner conveyed (dropped) from the toner discharge port 24b, a reduction in dispersion effect, and an increase in rotational torque.

  In addition, since the protrusion 26 a is formed at the upstream end of the protrusion 26, the vicinity of the center first comes into contact with the protrusion 26 a than the tip of the dispersion protrusion 25 b by the rotation of the toner dispersion member 25. As a result, the dispersion protrusion 25b is greatly deformed from the central portion to the root portion, and swinging when the separation protrusion 25b is separated from the protruding portion 26 and restored to the original state also increases.

  The height at which the protrusion 26a is formed is not particularly limited, but in order to sufficiently bend the dispersion protrusion 25b from the root portion, the distance from the inner wall surface of the housing 24 to the protrusion 26a is such that the distance from the inner wall surface of the housing 24 Preferably, the protrusion 25b is formed so as to be 50% or more of the distance to the attachment surface (the outer peripheral surface of the rotating shaft 25a).

  The arrangement position of the protruding portion 26 is not limited to the vicinity of the downstream side of the toner discharge port 24 b, and can be provided at an arbitrary position on the inner wall surface of the housing 24. For example, as shown in FIG. 10, the protruding portion 26 may be provided on the upstream side of the toner discharge port 24b. However, when the protruding portion 26 is provided in the vicinity of the downstream side of the toner discharge port 24b as shown in FIG. 9, the toner splashed by the swinging of the dispersion projection 25b along the upper surface of the protruding portion 26. Therefore, the toner can be prevented from staying in the housing 24. Further, as shown in FIG. 11, the protruding portions 26 can be provided at a plurality of locations on the inner wall surface of the housing 24.

  FIG. 12 is a development view showing another example of the dispersion protrusion used for the toner dispersion member of the toner dispersion mechanism of the first embodiment, and FIG. 13 shows the toner by winding the dispersion protrusion of FIG. 12 around the rotation shaft. It is the perspective view used as the dispersion member. In the present embodiment, a large number of cuts 53 are formed inward from the outer peripheral edge of the fan-shaped film member 51 as shown in FIG. 12, and the inner peripheral edge portion where the cuts 53 of the film member 51 are not formed is fixed. As the portion 54, a double-sided tape 56 is attached to the fixed portion 54. A plurality of (in this case, nine) the film members 51 are wound around the rotating shaft 25a in a conical shape at a predetermined pitch to form the dispersion protrusions 25b.

  Also in the toner dispersion member 25 shown in FIG. 13, as with the toner dispersion member 25 shown in FIG. 7, there is no possibility that foreign matters caused by the toner dispersion member 25 enter the developing container 30, and problems such as white-out images are caused. It can be effectively prevented.

  Further, in the toner dispersion member 25 shown in FIG. 13, since the dispersion protrusions 25 b are formed by a plurality of film members 51, the thickness and hardness of the film member 51 that forms the dispersion protrusions 25 b in one toner dispersion member 25. You can change the stiffness. Accordingly, the dispersibility in the longitudinal direction of the toner dispersion member 25 can be arbitrarily adjusted. Further, when the dispersion protrusion 25b is partially deteriorated due to a change over time or the like, only the film member 51 in the deteriorated portion needs to be replaced, so that the maintainability of the toner dispersion member 25 is improved. In order to prevent the dispersal projection 25b from being broken, it is preferable to attach the double-sided tape 56 so as to overlap the base end portion 53a of the cut 53, as in FIG.

  FIG. 14 is an enlarged cross-sectional view of the toner dispersion member 25 used in the toner dispersion mechanism of the first embodiment. As shown in FIG. 14A, the relationship between the distance (pitch) a of the dispersion protrusions 25b in the thrust direction of the rotation shaft 25a and the projection length b of the dispersion protrusions 25b viewed from the direction perpendicular to the rotation shaft 25a. Is a ≧ b, the massive toner charged from the toner inlet 24a passes through the gaps of the dispersion projections 25b and is replenished into the developing device 16 from the toner outlet 24b without being sufficiently dispersed. There is a fear.

  On the other hand, as shown in FIG. 14B, when a <b, the lump-like toner charged from the toner charging port 24a always comes into contact with the dispersion projection 25b and is finely conveyed while being conveyed in the longitudinal direction. Distributed. Therefore, it is preferable to fix the dispersion protrusion 25b by inclining a predetermined amount with respect to the rotation shaft 25a so that a <b.

  FIG. 15 is a side sectional view showing the positional relationship between the toner dispersion mechanism and the developing device of the first embodiment. In the present embodiment, the opening width of the toner discharge port 24b in the longitudinal direction (left and right direction in FIG. 15) of the toner dispersion member 25 is formed larger than the opening width of the toner input port 24a. Then, the dispersion protrusion 25b arranged in a spiral shape rotates, so that the toner introduced into the housing 24 from the toner introduction port 24a is dispersed and conveyed in the longitudinal direction, and from substantially the entire area of the toner discharge port 24b. The toner is supplied to the second storage chamber 39 of the developing device 16 through the toner supply port 34.

  According to this configuration, since the toner is replenished over a wide range of the second storage chamber 39, it can be quickly mixed with the developer D present in the second storage chamber 39 by the second stirring and conveying screw 33. it can. The opening width of the toner discharge port 24b can be appropriately set according to the characteristics of the toner used, the specifications of the developing device 16, and the like.

  Further, as shown in FIG. 15, the volume of the developer D located immediately below the toner discharge port 24 b (toner dropping position) is lower than that of the other portions, and the rotation shaft of the second agitating and conveying screw 33. The upper surface of 33a is exposed. Thus, the toner discharged from the toner discharge port 24b is supplied to the vicinity of the rotating shaft 33a of the stirring and conveying screw 33 through the toner supply port 34, and is conveyed in the direction of arrow B while being repeatedly raised and dropped by the spiral blade 33b. The Therefore, the newly supplied toner can be efficiently stirred with the developer D.

  As a method of reducing the volume of the developer D located immediately below the toner discharge port 24b, the pitch of the spiral wing 33b is changed, or a rib is provided on the rotating shaft 33a, so that the inside of the second storage chamber 39 is increased. A method of partially changing the developer conveyance speed is mentioned.

  In the toner dispersing member 25 shown in FIG. 13, the toner conveying force in the longitudinal direction of the toner dispersing member 25 is slightly reduced as compared with the toner dispersing member 25 in FIG. 7 in which the dispersing protrusions 25b are spirally arranged. . Therefore, when the toner discharge port 24b is widened and toner is supplied from the entire opening width, it is more preferable to dispose the dispersion protrusions 25b in a spiral shape as shown in FIG.

  FIG. 16 is a plan view of the toner dispersion mechanism according to the second embodiment of the present invention, and FIG. 17 is a side sectional view of the toner dispersion mechanism of the second embodiment (cross-sectional view taken along the arrow ZZ ′ in FIG. 16). is there. In the present embodiment, a part of the rotating shaft 25a is provided by providing a spiral conveying blade on a portion of the outer peripheral surface of the rotating shaft 25a constituting the toner dispersing member 25 where the dispersing protrusion 25b is not provided. The screw portion 29 is used. The toner inlet 24a is formed above the screw portion 29, and the toner outlet 24b is formed below the dispersion projection 25b. Since the configuration of other parts is the same as that of the first embodiment, description thereof is omitted.

  According to this configuration, the toner charged into the housing 24 from the toner charging port 24a is conveyed to the dispersion projection 25b by the rotation of the screw portion 29, and is dispersed into particles by the dispersion projection 25b. The toner is supplied from 24b to the toner supply port 34 (see FIG. 15). Therefore, even when the toner discharge port 24b cannot be formed immediately below the toner input port 24a due to the layout of the apparatus, the blocky toner can be effectively dispersed.

  In the toner dispersion mechanism 21 of each of the above-described embodiments, the toner discharge port 24b is provided on the lower surface of the housing 24, and the toner dispersion mechanism 21 is disposed immediately above the second storage chamber 39 of the developing device 16. It is not limited to this configuration. For example, as shown in FIG. 18, the toner dispersion mechanism 21 is disposed at the boundary between the first storage chamber 38 and the second storage chamber 39, and the toner discharge port 24 b communicating with the second storage chamber 39 is formed on the side surface of the housing 24. You may do it. According to this configuration, the arrangement space of the toner dispersion mechanism 21 can be further reduced.

  Further, there may be a case where the toner dispersion mechanism 21 cannot be disposed immediately above the developing device 16 due to the layout of the image forming apparatus. In such a case, for example, as shown in FIG. 19, a toner discharge port 24b is formed on the side surface of the housing 24 of the toner dispersion mechanism 21, and a toner supply port 34 that communicates the toner discharge port 24b and the second storage chamber 39 is formed. By adopting the bent shape, the toner dropping position can be controlled.

  In the toner dispersion mechanism 21 described in the above embodiments, it is preferable that the toner dispersion member 25 be rotatable forward and backward. For example, the arrow direction (clockwise) in FIG. 9 is forward rotation, the opposite direction (counterclockwise direction) is reverse rotation, and during normal image formation, the toner dispersion member 25 is rotated forward, and the image forming apparatus 100 is turned on. When the toner dispersion member 25 is rotated in the reverse direction at a timing such as when returning from the sleep (power saving) mode or when the driving time of the toner dispersion mechanism 21 reaches a predetermined time, The dispersion protrusion 25b that has fallen down can be raised again.

  Further, at the time of reverse rotation, the dispersion protrusion 25b contacts and protrudes from the protruding portion 26 from the opposite direction to that at the time of normal rotation, so that the swinging state of the dispersion protrusion 25b is different from that at the time of normal rotation. This makes it possible to effectively remove the light agglomerated toner between the dispersion protrusions 25b that could not be removed during the forward rotation.

  Further, by rotating the toner dispersion member 25 and reciprocating in the thrust direction (rotation axis direction), the dispersion protrusion 25b swings not only in the rotation direction but also in the thrust direction. As a result, the dispersion protrusion It swings in a complicated manner so that 25b is twisted. Thereby, the light agglomerated toner held in the dispersion projection 25b can be more effectively removed.

  An example of a mechanism for reciprocating the toner dispersion member 25 in the thrust direction while rotating the toner dispersion member 25 is a cam mechanism as shown in FIG. In FIG. 20, one end of the rotating shaft 25a is supported by a coil spring 60, and an eccentric cam 61 is brought into contact with the other end of the rotating shaft 25a. A worm gear 65 that rotates integrally with the drive output gear 63 is attached to the rotation shaft of the drive output gear 63 that transmits the drive force to the drive input gear 50, and the worm wheel 67 that rotates integrally with the eccentric cam 61 is attached to the worm gear 65. It is connected to.

  Further, the rotational speed of the toner dispersion member 25 may be changed based on the amount of toner replenished from the toner container 20 to the developing device 16. Specifically, since the toner replenishment amount to the developing device 16 is determined according to the detection result of the toner density sensor 44, it is based on the detection signal of the toner density sensor 44 received by the control unit 30 (see FIG. 1). Then, the toner replenishment amount is calculated, and the rotational speed of a drive mechanism (not shown) connected to the drive input gear 50 is adjusted according to the calculated toner replenishment amount.

  With this configuration, when the amount of toner replenishment is large, the rotational speed of the toner dispersion member 25 can be increased to increase the toner dispersion capability. Further, instead of the toner replenishment amount, the rotational speed of the toner dispersion member 25 may be changed according to the fluidity of the toner. Since the toner fluidity changes depending on the temperature and humidity inside the apparatus, it can be estimated from the output value of an in-machine temperature and humidity sensor (not shown) transmitted to the control unit 30.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention, and the structure which combined each said embodiment arbitrarily is also included by this invention. Further, the developing device provided with the toner dispersion mechanism of the present invention is not limited to the developing device 16 as shown in FIGS. 2 and 3, for example, and the stirring is performed between the first stirring and conveying member 32 and the developing roller 35. A developing device provided with a paddle may be used, or a touch-down developing device provided with a supply roller (magnetic roller) between the first stirring and conveying member 32 and the developing roller 35 may be used. Further, the present invention is not limited to the configuration including the two agitating / conveying members 32 and 33, and can be applied to, for example, a developing device including one agitating / conveying member.

  In each of the above-described embodiments, the developing device using the two-component developer including the magnetic carrier and the toner has been described as an example. However, the present invention can be similarly applied to a developing device using the one-component developer including only the toner. It is. Further, the image forming apparatus of the present invention is not limited to the monochrome printer as shown in FIG. 1, and may be other image forming apparatuses such as monochrome and color copiers, color printers, facsimiles and the like. Hereinafter, the effects of the present invention will be described more specifically with reference to examples.

  The development performance when using the developing device of the present invention was investigated. As test conditions, a film member 51 as shown in FIG. 6 was formed by forming a large number of cuts 53 having a width of 75 μm and an angle of 75 ° on one side of a ribbon-like film having a width of 8 mm. The film member 51 was spirally wound around the outer peripheral surface of the rotary shaft 25a having a diameter of 6 mm to form the dispersion protrusions 25b, and the toner dispersion member 25 having a brush diameter of 14 mm as shown in FIG. 7 was produced. The toner dispersion member is attached to the housing 24 having a longitudinal dimension of 40 mm and a width dimension of 15 mm (inner dimension 13 mm) as shown in FIG. 4, and a dispersion projection 25 b on the inner wall surface of the housing 24. A toner dispersion mechanism 21 according to the first embodiment in which the amount of biting in was 0.5 mm was produced.

  Then, as shown in FIG. 9, a protrusion 26 is formed in the vicinity of the downstream side of the toner outlet 24b of the housing 24, and the amount of biting of the dispersion protrusion 25b into the formed protrusion 26 is 0.5 mm (total The present invention 1 is defined as the biting amount 1.0 mm), and the present invention 2 is defined as the biting amount to the protrusion 26 of 1.0 mm (total biting amount 1.5 mm). Further, Comparative Example 1 was provided without the protrusion 26.

  Using the image forming apparatus shown in FIG. 1 in which the produced toner dispersion mechanism 21 of the present invention 1 and 2 and comparative example 1 is mounted between the developing device 16 and the toner container 20, solid images having different densities are continuously printed. The image density (ID; image density) after printing 100k sheets (100,000 sheets) was measured with a reflection densitometer (Macbeth RD912). Further, the occurrence of fog was visually observed, and the case where no fog was observed was rated as “◯” and the case where fog was generated was marked as “X”. The driving conditions of the image forming apparatus were a drum linear speed (process speed) of 260 mm / sec and a rotation speed of the toner dispersion member 25 of 126 mm / sec. The results are shown in Table 1.

  As can be seen from Table 1, when an image with a printing rate of 5% to 20% was printed, there was no problem in both the image density and fogging in both Inventions 1 and 2 and Comparative Example 1. On the other hand, when an image with a printing rate of 30% was printed, fogging was observed in Comparative Example 1. This is because, in Comparative Example 1 in which no protrusion 26 is provided on the housing, the toner replenishment amount does not decrease, so even if an image with a high printing rate is output, the image density does not decrease, but the amount of biting of the dispersion protrusion 25b is 0.5 mm. Therefore, the toner clogging in the gaps of the dispersion protrusions 25b occurs, and the effect of loosening the blocky toner is reduced. Therefore, the developer in the developing device and the replenishment toner cannot be sufficiently mixed, and the toner This is thought to be due to the unstable charging.

  Further, in the present invention 1 in which the total biting amount of the dispersion protrusions 25b is 1.0 mm, fogging was observed when an image with a printing rate of 50% was printed, but the total biting amount was 1.5 mm. In the second invention, fog was not observed. This is considered to be because as the amount of biting of the dispersion protrusion 25b increases, the dispersion protrusion 25b can be sufficiently curved from the root portion, and toner clogging into the gap of the dispersion protrusion 25b can be effectively suppressed. It is done.

  From the above results, the developer in the developing device and the replenishment toner are sufficiently mixed by using the toner dispersion mechanism of the present invention in which the inner wall surface of the housing is provided with a protrusion that contacts the dispersion protrusion. It was confirmed that it was advantageous for stabilizing the charging of the toner.

  The present invention can be used in an image forming apparatus that replenishes toner into a developing device from a toner container such as a hopper or a container, and includes a toner inlet that communicates with the toner container, and a toner outlet that communicates with the developer. And a dispersion member comprising a rotation shaft rotatably supported in the housing and a plurality of dispersion protrusions formed of an elastic material on an outer peripheral surface of the rotation shaft. In the housing inner wall surface of the mechanism, a protruding portion that contacts the dispersion protrusion is formed continuously at least at a portion where the dispersion protrusion faces in the longitudinal direction of the housing.

  By disposing the toner dispersion mechanism of the present invention between the toner container and the developing device, the toner supplied from the toner container can be replenished into the developing device in a sufficiently dispersed state. An image forming apparatus capable of effectively suppressing image defects such as fogging can be provided.

14 Photosensitive drum 16 Developing device 20 Toner container (toner container)
DESCRIPTION OF SYMBOLS 21 Toner dispersion | distribution mechanism 24 Housing 24a Toner insertion port 24b Toner discharge port 25 Dispersion member 25a Rotating shaft 25b Dispersion protrusion 26 Projection part 26a Projection 29 Screw part 30 Control part (control means)
31 Developing container 31a Container body 31b Cover 32 First stirring and conveying screw (stirring and conveying member)
33 Second stirring and conveying screw (stirring and conveying member)
32a, 33a Rotating shaft (Agitating and conveying rotating shaft)
32b, 33b Spiral feathers (stirring conveyance feathers)
35 Developing roller 36 Regulating blade 37 Partition plate 51 Film member 53 Notch 100 Image forming apparatus

Claims (16)

A toner dispersion mechanism that is disposed between the toner container and the developing device and disperses the toner replenished from the toner container;
A housing in which a toner inlet port communicating with the toner container and a toner outlet port communicating with the developing device are formed;
A toner dispersing member comprising a rotating shaft rotatably supported in the housing and a number of dispersing protrusions formed of an elastic material on an outer peripheral surface of the rotating shaft;
Have
2. A toner dispersing mechanism according to claim 1, wherein a protrusion that contacts the dispersion protrusion is formed on an inner wall surface of the housing continuously with at least a portion where the dispersion protrusion faces in the longitudinal direction of the housing.   The toner dispersion mechanism according to claim 1, wherein the protrusion is formed in the vicinity of the downstream side of the opening edge of the toner discharge port with respect to the rotation direction of the dispersion member.   2. The dispersion projection is formed by winding a flexible film member having a large number of cuts on one side and winding the film around the outer peripheral surface of the rotary shaft with the cuts facing outward. The toner dispersion mechanism according to claim 2.   4. The toner according to claim 3, wherein a protrusion protruding upstream in the rotation direction of the toner dispersion member is formed at an upstream end of the protrusion with respect to the rotation direction of the toner dispersion member. Distributed mechanism.   5. The toner dispersion mechanism according to claim 4, wherein the distance from the inner wall surface of the housing to the protrusion is 50% or more of the distance from the inner wall surface of the housing to the outer peripheral surface of the rotation shaft.   The opening width of the toner discharge port in the longitudinal direction of the toner dispersion member is formed to be larger than the opening width of the toner insertion port, and the dispersion member receives the toner charged into the housing from the toner insertion port. 6. The toner dispersion mechanism according to claim 3, wherein the toner dispersion mechanism is dispersed and discharged from substantially the entire area of the toner discharge port.   The dispersion protrusion is fixed to be inclined with respect to the axial direction of the rotation shaft, and the projection length of the dispersion protrusion onto the rotation shaft is larger than the pitch of the dispersion protrusion in the rotation axis direction. The toner dispersion mechanism according to claim 3, wherein the toner dispersion mechanism is a toner dispersion mechanism.   The toner dispersion mechanism according to claim 7, wherein the dispersion protrusions are spirally arranged with respect to the rotation shaft.   A screw portion having a conveying force from the toner inlet to the toner outlet is formed on the rotating shaft adjacent to the dispersion protrusion, and the toner inlet is formed immediately above the screw portion. The toner dispersion mechanism according to claim 1, wherein the toner dispersion mechanism is a toner dispersion mechanism.   The toner dispersion mechanism according to claim 1, wherein the toner dispersion member is rotatable in forward and reverse directions.   The toner dispersion mechanism according to claim 1, wherein the toner dispersion member is capable of reciprocating in a thrust direction.   12. A developing device comprising: the toner dispersion mechanism according to claim 1; and a developing container having the toner dispersion mechanism connected to an upper portion thereof.   In the developer container, at a toner dropping position where the toner discharged from the toner discharge port falls, an agitating / conveying member having an agitating / conveying blade formed on the outer peripheral surface of the agitating / conveying rotary shaft, and the agitating / conveying member The developing device according to claim 12, wherein there is a developer circulated and conveyed in the developing container.   The developing device according to claim 13, wherein a bulk of the developer present at the toner dropping position is lower than an upper surface of the stirring and conveying rotary shaft.   15. The developing device according to claim 12, and a toner that is detachably disposed above the toner dispersion mechanism and stores toner to be replenished into the development device via the toner dispersion mechanism. An image forming apparatus including a storage container.   The image forming apparatus according to claim 15, further comprising a control unit configured to change a rotation speed of the toner dispersion member based on at least one of a toner replenishment amount from the toner container and toner fluidity.