JP6458765B2 - Developing device and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device and an image forming apparatus including the developing device.

  In an electrophotographic image forming apparatus such as a copying machine or a printer, an apparatus that forms a toner image on paper by developing an electrostatic latent image formed on the surface of a photosensitive drum as an image carrier with a developing device is widely used. Has been. The developing device includes an agitating member that conveys the developer inside the developing container while agitating. A stirring member is known in which a spiral screw is provided on the outer periphery of a shaft portion that extends relatively long along the developer conveyance direction.

  There has been a concern that the stirring member may be deteriorated in performance due to the developer adhering to the periphery of the shaft portion. Therefore, a stirring member has been proposed that does not include a shaft portion that extends relatively long in the developer transport direction and has a helical screw having a hollow portion in the central portion in the radial direction. However, this agitating member easily deteriorates in conveying performance, and the developer sometimes stays around the end in the axial direction. An example of a conventional developing device proposed to solve this problem is disclosed in Patent Document 1.

  The conventional developing device described in Patent Document 1 includes a protruding portion in which a conveying member (stirring member) protrudes toward an inner wall of a housing (developing container) at an end portion in the axial direction. Thereby, the developer staying in the vicinity of the inner wall of the housing can be effectively agitated with the rotation of the protrusion.

JP 2013-246270 A

  When the developer detection sensor detects and controls the amount of the developer inside the developing container, the developer detecting sensor is preferably fixed outside the developing container corresponding to one end side in the axial direction of the stirring member. In order to obtain a suitable sensor output, a cleaning member for removing the developer attached to the inner wall of the developing container is provided at one end in the axial direction of the stirring member on the side where the developer detection sensor is disposed. It is preferable.

  However, when the protrusion is provided as in the conventional developing device described in Patent Document 1, there is a problem that the protrusion and the cleaning member are close to each other and the developer stays between the protrusion and the cleaning member. It was. As a result, there is a concern that the developer transport performance may be deteriorated, which may affect the control of the developer amount by the sensor.

  The present invention has been made in view of the above points, and can improve the developer conveying performance, and can further appropriately control the amount of the developer by a sensor and an image forming apparatus The purpose is to provide.

  In order to solve the above problems, the developing device of the present invention includes a developing container, a stirring member, a developer detection sensor, and a cleaning member. The developing container contains a developer to be supplied to the image carrier. The stirring member is rotatably supported inside the developing container and conveys the developer while stirring the developer along the rotation axis direction. The developer detection sensor is fixed to the wall surface of the developing container facing the one end side in the axial direction of the stirring member, and detects the amount of the developer inside the developing container. The cleaning member is provided at one end in the axial direction of the stirring member on the side where the developer detection sensor is disposed, and rotates with the stirring member to remove the developer attached to the inner wall of the developing container. The stirring member includes a support shaft portion, a screw, a pair of rib portions, a pair of connecting portions, and a protruding portion. The support shafts are provided at both ends in the axial direction and are rotatably supported on the wall surface of the developing container. The screw has a spiral portion extending spirally along the axial direction between the support shaft portions, and a hollow portion formed at the radial center of the spiral portion. The pair of rib portions extend while connecting the opposing surfaces of the spiral portion of the screw over the entire region in the axial direction of the stirring member, and are opposed to each other in the radial direction with an axis center therebetween. The pair of connecting portions extends in the radial direction and connects the support shaft portion and the pair of rib portions. The protruding portion protrudes from the connecting portion toward the inner wall of the developing container along the direction in which the rib portion extends. Further, the stirring member forms a protruding portion on one end side of the connecting portion extending in the radial direction at one end portion in the axial direction on the side where the developer detection sensor is disposed, and the other end side is a non-projecting portion that does not form a protruding portion. To do. The cleaning member has a cleaning portion extending from the support shaft portion toward the outer side in the substantially radial direction of the stirring member, and an angle formed between a straight line extending from the support shaft portion to the non-projecting portion along the radial direction of the stirring member and the cleaning portion. It is an acute angle.

  According to the configuration of the present invention, the cleaning member is close to the non-projecting part and separated from the projecting part. Thereby, it is possible to prevent the occurrence of the problem that the developer stays between the protruding portion and the cleaning member. Therefore, the developer conveying performance can be improved, and the amount of the developer can be suitably controlled by the sensor.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a configuration of an image forming unit of the image forming apparatus according to the embodiment of the present invention. It is a top view of the stirring member of the developing device according to the embodiment of the present invention. It is a perspective view of the stirring member of the developing device according to the embodiment of the present invention. FIG. 5 is a schematic partial perspective view showing the vicinity of one end portion in the axial direction of the stirring member of the developing device according to the embodiment of the present invention. It is sectional drawing which shows the location of the cleaning member of the stirring member of the developing device which concerns on embodiment of this invention. It is sectional drawing which shows the location of the cleaning member of the modification of the stirring member of the developing device which concerns on embodiment of this invention. 6 is a graph showing a relationship between a toner amount of a developing device and an output of a toner sensor. It is sectional drawing which shows the location of the cleaning member of the 2nd comparative example of the stirring member of a developing device. It is sectional drawing which shows the location of the cleaning member of the 3rd comparative example of the stirring member of a developing device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following contents.

  First, a schematic configuration of an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an example of a cross-sectional view illustrating a schematic configuration of an image forming apparatus. FIG. 2 is a cross-sectional view illustrating a configuration of an image forming unit of the image forming apparatus. The image forming apparatus 1 is a so-called printer that receives a command related to a print job from an external computer and executes printing. The image forming apparatus 1 receives signals relating to image data and job commands from a computer.

  As shown in FIG. 1, the image forming apparatus 1 includes a paper feeding unit 2, a paper transport unit 3, an exposure unit 4, an image forming unit 10, a transfer unit 5, and a fixing unit 6.

  The paper feed unit 2 stores a plurality of sheets P, and separates and feeds the sheets P one by one during printing. The paper transport unit 3 transports the paper P sent out from the paper feed unit 2 to the transfer unit 5 and the fixing unit 6, and further discharges the fixed paper P to the paper discharge unit 7 of the apparatus. The exposure unit 4 irradiates the image forming unit 10 with laser light L controlled based on the image data.

  As shown in FIG. 2, the image forming unit 10 has a charging unit around the photosensitive drum 11 that is an image carrier that is rotatably supported in a predetermined direction (clockwise in FIG. 2). 12, a developing device 20 and a cleaning unit 13 are provided. Note that the transfer unit 5 is disposed between the developing device 20 and the cleaning unit 13.

  The charging unit 12 charges the surface of the photosensitive drum 11 to a predetermined potential by corona discharge, for example. Then, an electrostatic latent image of a document image is formed on the surface of the photosensitive drum 11 by the laser light L emitted from the exposure unit 4. The developing device 20 develops the electrostatic latent image by attaching toner to form a toner image.

  The transfer unit 5 transfers the toner image on the surface of the photosensitive drum 11 onto the paper P. After the transfer, the cleaning unit 13 removes deposits such as toner remaining on the surface of the photosensitive drum 11. The fixing unit 6 heats and presses the paper P on which the toner image is transferred to fix the toner image on the paper P.

  Next, the overall configuration of the developing device 20 of the image forming unit 10 will be described with reference to FIG.

  The developing device 20 includes a developing container 21, a first stirring member 22, a second stirring member 23, a developing roller 24, and a regulating blade 25 as shown in FIG.

  The developing container 21 is a developing container that stores a one-component developer or a two-component developer as a developer to be supplied to the photosensitive drum 11 that is an image carrier. In this description, the developer may be referred to as “toner”. The developing container 21 has an elongated shape in the axial direction of the photosensitive drum 11 and is disposed with its longitudinal direction horizontal. The developing container 21 includes a first stirring chamber 27 and a second stirring chamber 28 that are partitioned by a partition wall 26. The second stirring chamber 28 is disposed adjacent to the region where the developing roller 24 is disposed. The first stirring chamber 27 is disposed in a region separated from the developing roller 24 with the second stirring chamber 28 therebetween. The first stirring chamber 27 has a developer supply port (not shown), and the developer is supplied from the outside.

  The first stirring member 22 is disposed in the first stirring chamber 27. The first agitating member 22 has a configuration in which a screw 22b extending along the axial direction is provided between support shaft portions 22a provided at both ends in the axial direction, and can be rotated around an axis extending in the horizontal direction. Supported by the container 21. The first stirring member 22 rotates clockwise in FIG. 2, and conveys the developer while stirring the developer along the rotation axis direction. Due to the rotation of the first stirring member 22, the developer replenished to the first stirring chamber 27 from the outside is guided to the second stirring chamber 28.

  The second stirring member 23 is disposed in the second stirring chamber 28. The second agitating member 23 has a configuration in which a screw 23b extending along the axial direction is provided between support shaft portions 23a provided at both ends in the axial direction, and can be rotated around an axis extending in the horizontal direction. Supported by the container 21. The second stirring member 23 rotates clockwise in FIG. 2, and conveys the developer while stirring the developer along the rotation axis direction. The developer guided from the first stirring chamber 27 to the second stirring chamber 28 by the rotation of the second stirring member 23 is supplied to the developing roller 24.

  The developing roller 24 is a developing member disposed in a region on the photosensitive drum 11 side of the second stirring chamber 28. The developing container 21 includes an opening 29 at a location adjacent to the photosensitive drum 11. The developing roller 24 faces the opening 29 and is supported by the developing container 21 so as to be rotatable about an axis extending in the horizontal direction. The developing roller 24 rotates counterclockwise in FIG. A part of the circumferential surface of the developing roller 24 is located inside the developing container 21, and another part of the circumferential surface is exposed to the outside through the opening 29 and faces the photosensitive drum 11.

  The developing roller 24 is constituted by a magnet roller in which a magnetic field generating member (not shown) made of a permanent magnet is fixed, for example. A toner thin layer is formed by adhering toner to the surface of the developing roller 24 by the magnetic force of the magnetic field generating member.

  The developing roller 24, the first stirring member 22, and the second stirring member 23 are parallel to each other and are rotatably supported by the developing container 21. The developing roller 24, the first stirring member 22, and the second stirring member 23 are rotationally driven by a motor (not shown).

  The regulating blade 25 is provided in the opening 29 so as to be close to the developing roller 24 and to have its tip opposed to the surface of the developing roller 24. The regulating blade 25 is disposed on the upstream side in the rotation direction of the developing roller 24 with respect to the region where the developing roller 24 faces the photosensitive drum 11. The regulating blade 25 is arranged with a predetermined gap between the tip thereof and the surface of the developing roller 24 and regulates the amount of toner supplied to the photosensitive drum 11.

  The regulating blade 25 is made of a magnetic stainless steel such as SUS430. Then, a magnetic field is generated between the developing roller 24 and the regulating blade 25 by a magnetic field generating member of the developing roller 24 provided to face the tip of the regulating blade 25. As a result, not only the distance between the regulating blade 25 and the developing roller 24 but also the amount of toner adhered to the developing roller 24 is strictly regulated by the strength of the magnetic field. Therefore, it is possible to form a toner thin layer of several tens of microns.

  Next, the first stirring member 22 and the second stirring member 23 and the configuration around them will be described in detail with reference to FIGS. 3 to 6 in addition to FIG. Here, since the configurations of the first stirring member 22 and the second stirring member 23 are substantially the same, the first stirring member 22 will be described as a representative. 3 and 4 are a plan view and a perspective view of the first stirring member 22. FIG. 5 is a schematic partial perspective view showing the vicinity of one end of the first stirring member 22 in the axial direction. FIG. 6 is a cross-sectional view showing the location of the cleaning member of the first stirring member 22. 6 is a cross-sectional view taken along line VI-VI shown in FIG.

  As shown in FIGS. 3 and 4, the first stirring member 22 includes a support shaft portion 22a, a screw 22b, a rib portion 22c, a connecting portion 22d, and a protruding portion 22e. The first agitating member 22 is made of a synthetic resin, such as an ABS resin, to which toner does not easily adhere, and these constituent elements are integrally formed as the same member.

  The support shaft portion 22 a is provided at each of both end portions of the first stirring member 22 in the axial direction. The support shaft portion 22a is rotatably supported on the wall surface of the developing container 21. One spindle 22a is provided with a disk-shaped flange 22f that faces the wall surface of the developing container 21.

  The screw 22b includes a spiral portion 22g and a hollow portion 22h. The spiral portion 22g extends in a spiral shape along the axial direction between the two support shaft portions 22a, and the outer shape viewed from the axial direction forms a circular shape. The hollow portion 22h is formed at the central portion in the radial direction of the spiral portion 22g. The spiral portion 22g is formed in a blade shape having a relatively small axial thickness, and is configured such that the axial thickness increases from the radially outer side toward the radial center.

  The rib portion 22c extends between the opposing surfaces of the spiral portion 22g formed in a blade shape over almost the entire area of the first stirring member 22 in the axial direction. The rib portion 22c is provided with a pair that is opposed to each other in the radial direction with the axis center therebetween. Each of the pair of rib portions 22c is disposed at the same radial distance from the axis center. The rib portion 22c has a substantially rectangular shape whose cross-sectional shape intersecting the axial direction extends relatively long in the direction intersecting the radial direction.

  The connecting portion 22d is provided with a pair that extends in the radial direction and connects the support shaft portion 22a and the pair of rib portions 22c. Each of the pair of connecting portions 22d is arranged in such a manner that the connecting portions 22d extend toward opposite sides in the radial direction with the support shaft portion 22a interposed therebetween. The pair of connecting portions 22d is provided for each of the two support shaft portions 22a. The connecting portion 22d has a substantially rectangular shape whose cross-sectional shape intersecting the radial direction extends relatively long in the circumferential direction.

  The protrusion 22e is disposed at the tip of a connecting portion 22d extending in the radial direction from the support shaft 22a. The protruding portion 22e protrudes from the connecting portion 22d toward the inner wall of the developing container 21 in parallel with the rib portion 22c along the direction in which the rib portion 22c extends, that is, the axial direction.

  Here, as illustrated in FIG. 5, the developing device 20 includes a toner sensor 30 that is a developer detection sensor around the first stirring member 22. The toner sensor 30 is fixed to the wall surface of the developing container 21 facing the one end side of the first stirring member 22 in the axial direction. The toner sensor 30 is provided such that its detection surface faces the inside of the developing container 21. The toner sensor 30 detects the amount of toner that is a developer inside the developing container 21.

  As the toner sensor 30, for example, a piezoelectric sensor is used. The piezoelectric sensor detects a change in pressure on the detection surface and outputs a signal corresponding to the pressure. That is, if the amount of toner inside the developing container 21 changes, the pressure on the detection surface of the toner sensor 30 also changes, and the output signal of the toner sensor 30 changes accordingly. A control unit (not shown) of the image forming apparatus 1 controls the start and stop of supply of the developer to the developing device 20 based on the sensor output signal received from the toner sensor 30.

  The toner sensor 30 is not limited to a piezoelectric sensor, and for example, an optical sensor or a magnetic sensor may be used.

  As shown in FIGS. 3 to 5, the first stirring member 22 forms a protruding portion 22 e at one end of the connecting portion 22 d extending in the radial direction at one end in the axial direction on the side where the toner sensor 30 is disposed. In addition, the other end is a non-projecting portion 22k that does not form the projecting portion 22e. None of the non-protruding portions 22k protrude from the connecting portion 22d toward the inner wall of the developing container 21 in which the toner sensor 30 is disposed.

  Further, the developing device 20 includes a cleaning member 31 around the first stirring member 22 as shown in FIGS. 5 and 6. The cleaning member 31 is provided at one end in the axial direction of the first stirring member 22 on the side where the toner sensor 30 is disposed. The cleaning member 31 rotates together with the first stirring member 22 to remove the toner attached to the region including the detection surface of the toner sensor 30 on the inner wall of the developing container 21.

  The cleaning member 31 extends from the support shaft portion 22 a of the first stirring member 22 toward the outer side in the substantially radial direction of the first stirring member 22. The cleaning member 31 has a linear shape made of, for example, a flexible metal, and includes a winding spring portion 31a, a cleaning portion 31b, and a bent portion 31c.

  The winding spring portion 31a has a coil shape wound around the outer periphery of the support shaft portion 22a, and the support shaft portion 22a passes through the center of the axis. One end of the winding spring portion 31a is locked to the first stirring member 22, and the entire winding spring portion 31a cannot be freely rotated in the circumferential direction of the support shaft portion 22a.

  The cleaning portion 31 b extends from the other end side of the coiled spring portion 31 a that is not locked to the first stirring member 22, that is, from the support shaft portion 22 a toward the outer side in the substantially radial direction of the first stirring member 22. The cleaning unit 31 b is adjacent to the inner wall of the developing container 21. A bent portion 31c is provided on the distal end side of the cleaning portion 31b extending substantially outward in the radial direction of the first stirring member 22. The cleaning portion 31b bends in the bent portion 31c toward the inside of the developing container 21 and away from the inner wall of the developing container 21. The length of the cleaning portion 31b from the winding spring portion 31a to the bent portion 31c has a length that includes the entire detection surface of the toner sensor 30 on the inner wall of the developing container 21.

  When the cleaning member 31 rotates together with the first stirring member 22, the cleaning unit 31 b rotates while contacting the inner wall of the developing container 21 including the entire detection surface of the toner sensor 30. As a result, the cleaning member 31 removes the toner adhering to the region including the detection surface of the toner sensor 30 on the inner wall of the developing container 21. Further, the cleaning member 31 has the cleaning portion 31b bent in the inward direction of the developing container 21 at the bent portion 31c. Can do.

  As shown in FIG. 6, the cleaning member 31 has an acute angle α formed with the straight line Z extending along the radial direction of the first stirring member 22 from the cleaning portion 31 b and the support shaft portion 22 a to the non-projecting portion 22 k. It is provided as follows. The angle α is preferably 30 ° to 60 °.

  The first stirring member 22 and the cleaning member 31 rotate in the direction indicated by the arrow in FIG. 5, and rotate counterclockwise in FIG. And the cleaning part 31b is extended toward the substantially radial direction outer side in the rotation direction upstream of the 1st stirring member 22 rather than the position of the protrusion part 22e formed in the one end side of the connection part 22d.

  Here, FIG. 7 shows a cross-sectional view showing the location of the cleaning member 31 of a modification of the first stirring member 22. 7 is a cross-sectional view taken along line VI-VI shown in FIG.

  As in the modification described in FIG. 7, the cleaning portion 31 b extends substantially outward in the radial direction on the downstream side in the rotation direction of the first stirring member 22 from the position of the protruding portion 22 e formed on one end side of the connecting portion 22 d. Anyway. Also in this case, similarly to the cleaning member 31 described in FIG. 6, the angle α formed between the cleaning portion 31 b and the straight line Z extending along the radial direction of the first stirring member 22 from the support shaft portion 22 a to the non-projecting portion 22 k is Provided to have an acute angle.

  Subsequently, regarding the present embodiment, the toner amount of the developing device and the output of the toner sensor when the first stirring member 22 and the cleaning member 31 of the example are used and when the stirring member and the cleaning member of the comparative example are used are used. Will be described with reference to FIGS. FIG. 8 is a graph showing the relationship between the toner amount of the developing device and the output of the toner sensor. 9 and 10 are cross-sectional views showing the locations of the cleaning members of the second comparative example and the third comparative example of the stirring member of the developing device. 9 and 10 are cross-sectional views taken along the line VI-VI shown in FIG. In addition, since the basic configuration of the comparative example is the same as that of the present embodiment described above, the same components as those of the present embodiment are denoted by the same names and reference numerals as before, and the description thereof is omitted. There is.

  Here, the stirring member and the cleaning member of the first comparative example with respect to the first stirring member 22 and the cleaning member 31 of the above-described embodiment which is an example will be described. Although not shown, the stirring member of the first comparative example does not have a non-projecting portion 22k like the first stirring member 22 of the embodiment at one end in the axial direction on the side where the toner sensor 30 is disposed. A protrusion 22e that protrudes from the connecting portion toward the inner wall of the developing container 21 is also provided at a position corresponding to the protrusion 22k. In other words, the stirring member of the first comparative example has a protruding portion at the tip end portion of each of the pair of connecting portions 22d extending radially outward from the support shaft portion 22a at one axial end portion on the side where the toner sensor 30 is disposed. 22e is provided. The cleaning member of the first comparative example is substantially the radial direction of the stirring member from the support shaft portion 22a of the stirring member at one end in the axial direction on the side where the toner sensor 30 of the stirring member is disposed, like the cleaning member 31 of the embodiment. Extends outward.

  The graph of FIG. 8 shows the toner amount of the developing device 20 and the toner sensor 30 when the first stirring member 22 and the cleaning member 31 of the embodiment are used and when the stirring member and the cleaning member of the first comparative example are used. The relationship with the output of. The horizontal axis of the graph indicates the toner amount inside the developing device 20 from 100 g to 350 g, and the vertical axis of the graph indicates the output value of the toner sensor 30 from 0.2 V to 1.2 V. In both the example and the first comparative example, the amount of toner inside the developing device 20 when new toner or durable toner was used was changed, and the transition of the output value of the toner sensor 30 was evaluated. The “new toner” means toner that has just been replenished to the developing device 20. The “durable toner” means a toner in a state where the toner is not replenished and the stirring member of the developing device 20 is rotationally driven for 10 hours continuously. Further, a state where the output value of the toner sensor 30 is 0.6V indicates an empty level, that is, the toner amount is empty.

  In the embodiment, according to FIG. 8, when the toner amount is increased by a certain amount in both the new toner and the durable toner, the toner sensor output is also increased by a certain amount, and there is a linearity relationship between the toner amount and the toner sensor output. In the embodiment, the non-projecting portion 22k is provided at one end in the axial direction of the first stirring member 22 on the side where the toner sensor 30 is disposed, and the cleaning member 31 is close to the non-projecting portion 22k and separated from the projecting portion 22e. A sufficient space can be secured between the first stirring member 22 and the cleaning member 31. As a result, it is possible to prevent the occurrence of a problem that the toner stays between the protruding portion 22e and the cleaning member 31. Accordingly, it is possible to improve the toner conveyance performance, and it is possible to control the toner amount suitably by the toner sensor 30.

  On the other hand, according to FIG. 8, the first comparative example maintains the linearity of the new toner in relation to the toner amount and the toner sensor output, but cannot obtain the linearity of the durable toner. In the first comparative example, when the amount of the durable toner decreases, the output value of the toner sensor 30 does not decrease. In the first comparative example, since the protrusion 22e of the stirring member and the cleaning member are adjacent to each other, the soft block of the toner removed from the inner wall of the developing container 21 by the cleaning member is stirred when the durable toner having decreased fluidity is used. It is thought that it is caught by the protrusion part 22e of a member. As a result, even when the amount of toner inside the developing device 20 is reduced, a lump of toner is present around the detection surface of the toner sensor 30, and the output value of the toner sensor 30 is considered not to decrease.

  Next, the direction in which the cleaning part 31b of the cleaning member 31 extends was evaluated. The agitating members of the second comparative example and the third comparative example described below have the same configuration as the first agitating member 22 of the example, and are not arranged at one end in the axial direction on the side where the toner sensor 30 is disposed. It has a protrusion 22k.

  Here, the cleaning member of the 2nd comparative example and the 3rd comparative example with respect to the cleaning member 31 of the said embodiment which is an Example is demonstrated. As shown in FIGS. 9 and 10, the stirring members 131 of the second comparative example and the third comparative example are directed along the radial direction of the first stirring member 22 from the cleaning portion 131b and the support shaft portion 22a to the non-projecting portion 22k. The angle β formed with the straight line Z is provided to be an obtuse angle. The stirring member 131 of the second comparative example extends substantially outward in the radial direction on the upstream side in the rotation direction of the first stirring member 22 from the position of the protruding portion 22e formed by the cleaning portion 131b on one end side of the connecting portion 22d. The stirring member 131 of the third comparative example extends substantially radially outward on the downstream side in the rotation direction of the first stirring member 22 from the position of the protruding portion 22e formed by the cleaning portion 131b on one end side of the connecting portion 22d.

  Regarding the direction in which the cleaning portion 31b of the cleaning member 31 extends, in the embodiment (see FIG. 6), when the toner amount increases by a certain amount in both the new toner and the durable toner, the toner sensor output also increases by a certain amount. Have a linearity relationship. Then, in the comparative example (see FIG. 7) of the above-described embodiment, it was confirmed that a favorable result was obtained in the relationship between the toner amount and the toner sensor output after the embodiment.

  On the other hand, the second comparative example (see FIG. 9) and the third comparative example (see FIG. 10) are similar to the first comparative example described with reference to FIG. It was confirmed that no linearity was obtained in relation to the toner sensor output.

  As in the above-described embodiment, the developing device 20 of the image forming apparatus 1 has the first stirring member 22 on one end side of the connecting portion 22d extending in the radial direction at one end portion in the axial direction on the side where the toner sensor 30 is disposed. The protruding portion 22e is formed, and the other end side is a non-projecting portion 22k that does not form the protruding portion 22e. The cleaning member 31 has a cleaning portion 31b extending from the support shaft portion 22a of the first stirring member 22 toward the outer side in the substantially radial direction of the first stirring member 22, and the first stirring member extends from the support shaft portion 22a to the non-projecting portion 22k. The angle α formed by the straight line Z extending along the radial direction 22 and the cleaning portion 31b is an acute angle.

  According to this configuration, the cleaning member 31 is close to the non-projecting portion 22k and is separated from the protruding portion 22e. As a result, it is possible to prevent the occurrence of the problem that the toner stays between the protrusion 22e and the cleaning member 31. Therefore, it is possible to improve the toner conveyance performance, and it is possible to control the amount of toner appropriately by the toner sensor 30.

  And the cleaning part 31b is extended toward the substantially radial direction outer side in the rotation direction upstream of the 1st stirring member 22 rather than the position of the protrusion part 22e formed in the one end side of the connection part 22d.

  According to this configuration, when the cleaning portion 31b of the cleaning member 31 is curved as the first stirring member 22 rotates, the location of the bent portion 31c approaches the non-projecting portion 22k. Since there is no non-projecting part 22k corresponding to the projecting part 22e, it is possible to enhance the action of preventing the toner from staying between the projecting part 22e and the cleaning member 31.

  Further, the cleaning member 31 has a bent portion 31c that is bent inwardly toward the inner side of the developing container 21 at a tip end side thereof that extends linearly outwardly.

  According to this configuration, the toner accumulated from the inner wall of the developing container 21 to a position away from the inside can be effectively broken down and removed.

  In addition, the angle α formed by the straight line Z extending along the radial direction of the first stirring member 22 from the cleaning portion 31b and the support shaft portion 22a to the non-projecting portion 22k is 30 ° to 60 °.

  According to this configuration, the retention of toner between the protrusion 22e and the cleaning member 31 can be effectively prevented. Therefore, it is possible to more effectively realize improvement in toner conveyance performance and toner amount control.

  Further, in the embodiment, the developing device 20 having the above configuration is provided in the image forming apparatus 1.

  According to this configuration, in the image forming apparatus 1, it is possible to improve the toner conveyance performance, and it is possible to appropriately control the toner amount by the toner sensor 30.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used in a developing device and an image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Image forming part 11 Photosensitive drum (image carrier)
20 developing device 21 developing container 22 first stirring member (stirring member)
22a Support shaft part 22b Screw 22c Rib part 22d Connection part 22e Protrusion part 22g Spiral part 22h Hollow part 22k Non-protrusion part 23 2nd stirring member (stirring member)
24 Developing roller 30 Toner sensor (Developer detection sensor)
31 Cleaning member 31a Winding spring part 31b Cleaning part 31c Bending part

Claims (5)

A developer container for containing a developer to be supplied to the image carrier;
An agitation member that is rotatably supported inside the developer container and conveys the developer while agitating along the rotation axis direction;
A developer detection sensor that is fixed to the wall surface of the developer container facing one end side in the axial direction of the stirring member and detects the amount of developer inside the developer container;
A cleaning member that is provided at one end in the axial direction of the stirring member on the side where the developer detection sensor is disposed and rotates together with the stirring member to remove the developer attached to the inner wall of the developing container;
With
The stirring member is
A support shaft provided at both ends in the axial direction and rotatably supported on the wall surface of the developer container;
A screw having a spiral portion extending spirally along the axial direction between the support shaft portions and a hollow portion formed at a radial center portion of the spiral portion;
A pair of rib portions extending in an axial direction across the entire axial direction of the agitating member and connecting between the opposing surfaces of the spiral portion of the screw and facing the radial direction across the axis center;
A pair of connecting portions extending in a radial direction and connecting the support shaft portion and the pair of rib portions;
A projecting portion projecting from the connecting portion toward the inner wall of the developing container along a direction in which the rib portion extends;
With
The stirring member forms the protruding portion on one end side of the connecting portion extending in the radial direction at one end portion in the axial direction on the side where the developer detection sensor is disposed, and does not form the protruding portion on the other end side. Non-protruding,
The cleaning member has a cleaning portion that extends from the support shaft portion toward the outer side in the substantially radial direction of the stirring member, and extends from the cleaning portion and the support shaft portion to the non-projecting portion along the radial direction of the stirring member. A developing device characterized in that an angle formed by a straight line facing is an acute angle.   2. The development according to claim 1, wherein the cleaning unit extends outward in a substantially radial direction on the upstream side in the rotation direction of the stirring member with respect to a position of the protruding portion formed on one end side of the connecting portion. apparatus.   The said cleaning member has the bending part which bends in the inner side direction of the said developing container at the front end side which comprises the linear form and extends toward the substantially radial direction outer side. Development device.   The angle formed by the cleaning portion and a straight line extending from the support shaft portion to the non-projecting portion along the radial direction of the stirring member is 30 ° to 60 °. The developing device according to claim 3.   An image forming apparatus comprising the developing device according to claim 1.

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