JP2018159940A - Developing device and image forming apparatus - Google Patents

Abstract

A developing device that can sufficiently stir the longitudinal direction of a member that stirs a developer in a developing container and can accurately detect the amount of the developer in the developing container. A developer detecting unit for detecting a developer contained in a developer containing portion, and a sheet member arranged to be rotatable with respect to a rotating shaft in the developer containing portion. The member 14 includes a first developer transporting unit 15 that transports the developer in a direction toward the one axial end of the rotating shaft 12 and a second developer transport that transports in the direction toward the other axial end. The developer detection unit 22 is disposed on the inner wall of the developer accommodating portion corresponding to one end portion, and is the opening located on the most end portion side among the respective openings of the developer conveying means. L1 is the distance between the opening and the inner wall on one end side, and the distance between the opening located on the other end side among the openings of the developer conveying means and the inner wall of the developer accommodating section on the other end side is Assuming L2, there is a relationship of L1> L2. [Selection] Figure 2

Description

  The present invention relates to an agitating and conveying member of a developing device of an image forming apparatus such as a copying machine, a printer, or a facsimile that employs an electrophotographic system, and the like. The present invention relates to a developing device and an image forming apparatus provided with possible stirring and conveying members.

  Conventionally, in an electrophotographic image forming apparatus, when a developer is used and consumed, a developer replenishment method is newly employed in which a new developer is replenished. As the developer replenishing method, a method of replenishing the developer by replacing a developer replenishing container such as a toner bottle that is detachable from the electrophotographic image forming apparatus is used.

  For example, in Patent Document 1, two agitating and conveying members, each having a helical member attached around a rotation shaft, are arranged side by side so as to prevent the replenished toner from being deposited in the developing device. A developing device for forming a circulation path is described.

  Further, in Patent Document 2, the toner is brought to the center by always maintaining the tongue-like bending direction formed on the rotating stirring blade of the stirring member that conveys the toner in the toner storage portion to the toner supply portion. A toner supply device is described.

JP-A-8-30084 JP 2010-32754 A

  However, since the developing device described in Patent Document 1 is provided with two spiral rotating members, a structure for rotating and driving each of them is required, which makes the device more complicated, larger, and higher in cost. There was a problem of inviting.

  In addition, the toner supply device described in Patent Document 2 stirs the toner by bringing the toner remaining at the inner end of the container toward the center of the container. Therefore, there is a problem that an image having no density unevenness cannot be obtained due to poor charging of the toner.

  In order to solve such a problem, the present inventors have developed a developing device of an image forming apparatus capable of supplying the developer uniformly by a developer carrier by sufficiently stirring the developer in the developer accommodating portion. Are considering.

  FIG. 12 is a schematic cross-sectional view of such a developing device, which is not yet publicly known, and is under development.

  The developing device 1 is an apparatus used for an image forming apparatus such as a copying machine, a printer, or a facsimile employing an electrophotographic system. A developer container 2 as a developer container includes a developing roll 3 as a developer carrier that contains a magnet for visualizing an electrostatic latent image formed on the surface of a photosensitive drum, which is an image carrier (not shown). Have. The developing device 1 also includes a developing blade 4 that charges the toner 8 as a developer and regulates the toner layer formed on the surface of the developing roll 3. Further, as a member for stirring and transporting the developer in the developer accommodating portion, the developing container 2 is provided with a stirring and transporting member 6 that supplies and transports the toner 8 to the developing roll 3 side while stirring.

  The toner bottle 7 is a developer replenishing portion that can be attached to and detached from the developing container 2. The developer replenishing portion contains a magnetic one-component toner 8, and an opening through which the toner 8 is replenished to the developing container 2. A toner replenishing port 9. Further, the toner bottle 7 has a stirring member 10 that can rotate inside thereof. The stirring member 10 supplies the toner 8 in the toner bottle 7 to the developing container 2 through the toner supply port 9. The supplied toner 8 is guided to a facing area 11 facing the toner supply port 9 in the stirring and conveying member 6.

  FIG. 13 is a schematic diagram for explaining a plurality of developer conveying means included in the agitating / conveying member 6. The toner bottle 7 can be opposed to the developing container 2 with the toner supply port 9 and the opposed region 11 of the agitating / conveying member 6. It is the schematic diagram which looked at the inside of the structure attached so that it might become from the upper part.

  The agitating / conveying member 6 includes a rotation shaft 12 extending along the same direction as the rotation axis direction of the developing roller 3, a side perpendicular to the rotation shaft 12, and a side in the axial direction of the rotation shaft 12. And a sheet member 14 having a conveying surface 13. The sheet member 14 is attached to the rotary shaft 12 and is provided so as to be rotatable around the rotary shaft 12 inside the developing container 2 which is a developer accommodating portion. Further, the sheet member 14 includes a plurality of developer conveying means for conveying the toner 8 as the developer in the axial direction of the rotary shaft 12 between the rotation center and the rotation end in the rotation radius direction.

  In the developing container 2, toner 8 supplied from the toner replenishing port 9 is stored below the rotating shaft 12 of the stirring and conveying member 6. Further, on the conveying surface 13 of the sheet member 14, the sheet rotates around the rotation shaft 12 from the toner replenishing port 9 toward the developing roll 3 through the inside of the developing container 2, thereby moving in the axial direction of the rotation shaft 12. A plurality of developer conveying means for conveying and moving the toner is provided. Here, the developer conveying means includes a first developer conveying means 15 and a second developer conveying means 16 that extend on the conveying surface 13 along the axial direction of the rotary shaft 12. The first developer conveying means 15 is arranged adjacent to the rotating end in the rotational radius direction of the rotating shaft 12 relative to the second developer conveying means 16.

  Here, the conveying direction of the toner 8 by the first developer conveying means 15 and the conveying direction of the toner 8 by the second developer conveying means 16 are configured to be opposite to each other with respect to the axial direction of the rotary shaft 12. ing. The developer conveying means 15 and 16 whose conveying directions are opposite to each other form respective toner conveying paths on the surface of the conveying surface 13 as the stirring and conveying member 6 rotates. The toner 8 conveyed to the one end side in the axial direction of the rotary shaft 12 by the first developer conveying means 15 along the surface of the conveying surface 13 there is an end on the opposite side by the second developer conveying means 16 there. It is conveyed so as to circulate toward the part side. Thereby, the toner 8 can be prevented from staying at the end of the developing container 2 and the toner 8 can be stirred so as to be more uniform.

  The first developer conveying means 15 and the second developer conveying means 16 each have a plurality of predetermined openings 17 arranged in a row on the developer conveying surface 13 of the sheet member 14 as described below. ing.

  The opening 17 has such a shape that the size of the opening (opening width) in the direction perpendicular to the toner conveyance direction along the axial direction increases toward the toner conveyance direction. When the transport surface 13 rotates about the axis of the rotation shaft 12, the toner 8 pushed and moved by the transport surface 13 passes through the opening 17 from the front side to the back side (front to back in the rotation direction) of the transport surface 13. Then, the opening 17 moves from the smaller opening width to the larger one (for example, in the direction of the arrow in FIG. 14). This movement of the toner 8 causes toner conveyance in a predetermined direction. This is because the toner 8 is pushed and moved by the conveyance surface 13 in the direction in which the pressure from the toner 8 on the rotating conveyance surface 13 decreases, that is, in the direction in which the opening width increases (for example, the arrow direction in FIG. 14). This is because the toner is conveyed in the predetermined direction as described above.

  FIG. 14 is a schematic diagram illustrating an example of the opening 17 formed on the conveyance surface 13 of the sheet member 14 as the developer conveyance unit.

  The opening 17 has a shape in which the apex of the triangle faces in the direction opposite to the direction in which the toner 8 is conveyed so that the opening width increases so that the pressure of the toner 8 received by the conveying surface 13 decreases. Accordingly, the direction of the apexes of the triangles of the plurality of openings 17 of the first developer conveying means 15 and the direction of the apexes of the triangles of the plurality of openings 17 of the second developer conveying means 16 are opposite to each other. It has become a relationship.

  By rotating the stirring and conveying member 6 having the above-described configuration, the toner 8 can be circulated on the surface of the conveying surface 13 along the direction of the rotation shaft 12.

  However, the toner 8 in the developing container 2 is transported to both ends of the developing container 2 by the two developer transporting means 15 and 16 formed on the transporting surface 13 as the stirring and transporting member 6 rotates. The Here, the toner 8 conveyed to one end of the developing container 2 by the first developer conveying means 15 and the toner 8 conveyed to the other end of the developing container 2 by the second developer conveying means 16. Therefore, at the end of the developing container 2, the toner surface height (agent surface height) of the toner 8 greatly fluctuates up and down each time the toner 8 is agitated. For this reason, the present inventors have found a new problem that when the remaining amount of the toner 8 inside the developing container 2 is detected, the remaining amount detection accuracy becomes unstable due to the vertical fluctuation of the toner surface.

The present invention includes a developer accommodating portion that accommodates a developer, a developer detection unit that detects the developer accommodated in the developer accommodating portion, and a rotation axis that is rotatable with respect to the developer accommodating portion. A sheet member disposed, the sheet member including a first developer conveying unit that conveys the developer in a direction toward one axial end of the rotation shaft, and the first developer conveying unit. Comprises a second developer conveying means that is formed at a position where the distance from the rotating shaft is different, and that conveys the developer in a direction toward the other axial end of the rotating shaft. And each of the second developer conveying means is configured by arranging a plurality of openings in the sheet member in the axial direction, and the developer detecting unit is provided in the developer container corresponding to the one end. Disposed on the inner wall of the first and second developer conveying means. In the serial each of the openings, the distance between the inner wall of most the one end and an opening located on the side the one end side is L _1, among the each of the openings of the first and second developer conveying means the distance between the inner wall of said developer accommodating portion of the opening and the other end side positioned closest to the other end side when the L ₂ in, characterized in that it has a relationship of L _1> L _2.

  According to the present invention, there is provided a developing device and an image forming apparatus that can sufficiently stir the longitudinal direction of a member that stirs the developer in the developing container and can accurately detect the amount of the developer in the developing container. Can be provided.

1 is a schematic view of a developing device according to the present invention. It is the schematic diagram which looked at the inside of the developing device concerning the present invention from the upper part. 3 is a schematic cross-sectional view of the configuration around the magnetic permeability sensor 22 as viewed from the side surface of the developing container 2. FIG. FIG. 6 is a diagram illustrating a detection output of a magnetic permeability sensor with respect to a toner remaining amount in a developing container. It is the schematic diagram which looked at the inside of the development container of a comparative example from the upper part. It is the cross-sectional schematic diagram which looked at the structure of the magnetic permeability sensor periphery of the comparative example from the side surface of the developing container. It is a figure showing the detection output of the magnetic permeability sensor with respect to the toner remaining amount in the developing container of the comparative example. It is the schematic diagram which looked at the inside of the developing device of a 2nd embodiment concerning the present invention from the upper part. It is the schematic diagram which looked at the inside of the developing device of a 3rd embodiment concerning the present invention from the upper part. It is the schematic diagram which looked at the inside of the developing device of a 4th embodiment concerning the present invention from the upper part. It is the schematic diagram which looked at the inside of the developing device of a 5th embodiment concerning the present invention from the upper part. FIG. 2 is a schematic cross-sectional view of a developing device under examination related to the present invention. FIG. 6 is a schematic diagram illustrating a plurality of developer conveying units included in the agitating / conveying member. It is a schematic diagram of the opening part formed in the conveyance surface of a sheet member.

[First Embodiment]
(Configuration of developing device)
FIG. 1 is a schematic view of a developing device 1 according to the present invention, and FIG. 2 shows that a toner bottle 7 is attached to a developing container 2 so that a toner replenishing port 9 and a facing region 11 of a stirring and conveying member 6 can face each other. It is the schematic diagram which looked at the inside of the structure from the upper part.

  The developing device 1 according to the present embodiment is different from the developing device 1 having the configuration shown in FIGS. 12 to 14 that is under examination of a prototype before publicly known, in the first developer conveying means 15 and the second developer conveying means described later. The configuration of the developer detectable region A and the developer detecting member 22 is added to the second developer conveying means 16. The two developer conveying means are arranged on the sheet member 14 between the center of rotation in the rotational radius direction and the free end outside in the radial direction, and convey the developer 8 along the axial direction of the rotary shaft 12. One developer conveying means 15 and a second developer conveying means 16 for conveying the developer 8 along the axial direction in the opposite direction to the first developer conveying means are provided. Yes.

  In the developing device 1 according to the present embodiment, an electrostatic latent image formed on the surface of an image carrier such as a photosensitive drum, a developer 8 accommodated in a developer container 2 is passed through a developing roll 3 and the image carrier. It is used in an image forming apparatus that supplies an image to the surface and develops it to form an image.

  In this embodiment, the toner conveying path 5 is formed on the conveying surface 13 of the sheet member 14 by the rotation of the agitating and conveying member 6 by the developer conveying means 15 and 16 whose two conveying directions are opposite to each other. To do. In the toner transport path 5, the toner 8 replenished from the toner replenishing port 9 of the toner bottle 7 is transported along the transport surface 13 to the one end side of the rotating shaft 12 by the first developer transport means 15. It is formed by being conveyed by the second developer conveying means 16 so as to circulate along the conveying surface 13 toward the opposite end of the rotating shaft 12.

  As a result, the toner 8 replenished in the developing container 2 is more uniformly stirred with respect to the direction of the rotation shaft 12 while suppressing the staying at both ends of the rotation shaft 12 of the stirring and conveying member 6. It is conveyed to the developing roll 3.

  In this embodiment, the sheet | seat member 14 which can rotate centering on the rotating shaft 12 is formed using PPS resin. The opening 17 formed in the conveying surface 13 of the sheet member 14 has an isosceles triangle shape with a base length of 11 mm and a height of 16 mm. The opening 17 has a shape such that the size of the opening (opening width) in the direction perpendicular to the toner conveyance direction along the axial direction increases toward the toner conveyance direction. In other words, a toner flow is formed from the smaller opening width toward the larger opening width due to the shape of the opening.

  Note that the material of the sheet member 14 and the shape and size of the opening 17 are not limited to this example.

(Configuration of developer conveying means and developer detectable area)
In the first developer conveying means 15 and the second developer conveying means 16, the openings 17 are formed in a row in the direction along the rotation axis 12 on the conveying surface 13.

Of the openings 17 arranged in a row, the developer detectable region between the opening 17 at the end of the developer detecting member 22 and the inner wall of the developing container 2 in which the developer detecting member 22 is disposed. the interval a enters the L _1, the opening 17 on the opposite side of the column end, when the inner wall of the developing container 2 on that side, the distance between the L _2, has a L _1> L ₂ relationship ing. In this relationship, both the arrangement of the openings 17 of the first developer conveying means 15 and the arrangement of the openings 17 of the second developer conveying means 16 have this relationship. The distance difference between L ₁ and L ₂ is such that one opening 17 is inserted in the axial direction of the rotary shaft 12.

  Here, the developer detectable region A is a region where the developer detecting member 22 can determine the presence or absence of the toner 8.

  In the present embodiment, the detection area of the developer detection member 22 is within 5 mm from the toner detection surface of the developer detection member 22. When the toner detection area of the developer detection member 22 is increased, the developer detectable area A is correspondingly increased.

(Configuration of developer detection member)
As shown in FIG. 1, the developer detecting member 22 is located at a position where the sides along the rotational radius direction of the sheet member 14 face each other when the sheet member 14 of the stirring and conveying member 6 rotates around the rotation shaft 12. Arranged on the inner surface of the developing container 2.

  Furthermore, in this embodiment, as shown in FIG. 2 as viewed from the top of the developing container 2, the two developer conveying means 15 formed from the openings 17 arranged in a line on the conveying surface 13 of the sheet member 14. 16, the opening 17 is not provided in the portion of the sheet member 14 corresponding to the developer detectable region A. In this way, the two developer conveying means 15 and 16 are not provided in the developer detectable region A. A developer detection member 22 is disposed on the inner surface of the developer container 2 facing the developer detectable region A.

  The developer detection member 22 is a remaining amount detection system using a magnetic permeability sensor. The magnetic permeability sensor 22 outputs a sensor output voltage corresponding to the magnetic permeability of the magnetic material contained in the toner 8 in the developer detectable area A, and detects whether or not the sensor output voltage value exceeds the reference voltage value. I do.

  The magnetic permeability sensor 22 performs one rotation of the agitating and conveying member 6 as one cycle, and performs sampling at a constant cycle during the one cycle. The number of times the detected sensor output voltage value exceeds the reference voltage value is counted based on the sampling result of one cycle, and the number of times the permeability sensor 22 exceeds the reference voltage value per sampling cycle is a predetermined threshold value. When the value is less than the threshold value, no toner is used.

  FIG. 3 is a schematic cross-sectional view of the configuration around the magnetic permeability sensor 22 as viewed from the side surface of the developing container 2. The sheet member 14 rotates around the rotation shaft 12 inside the developing container 2. 3 schematically shows how the surface of the toner 8 to be stirred (toner surface) changes.

  In this embodiment, the opening 17 is not provided in the conveyance surface 13 of the sheet member 14 that passes through the developer detectable area A, so that the first developer conveying means 15 and the second development are provided in the developer detectable area. The structure which does not provide the agent conveyance means 16 is implement | achieved.

  With the configuration in which the developer conveying function toward the magnetic permeability sensor 22 is suppressed in the developer detectable area A, the toner 8 in the direction along the rotation axis 12 by the agitating and conveying member 6 in the developer detectable area A. The movement is suppressed. Thereby, the toner conveyance function toward the magnetic permeability sensor 22 in the developer detectable region A can be suppressed.

  In this way, by suppressing the movement of the toner 8 in the axial direction of the rotating shaft 12, even if the sheet member 14 is outside the toner reservoir (FIG. 3A), the sheet member 14 is not stored in the toner reservoir. Even when the inside is rotating (FIG. 3B), the vertical fluctuation of the toner surface height of the toner 8 in the developer detectable region A is reduced. Therefore, the accuracy of the presence / absence detection of the toner of the magnetic permeability sensor 22 can be further stabilized.

  Next, while the toner 8 in the developing container 2 was consumed, the output of the remaining amount detection by the magnetic permeability sensor 22 was monitored, and the measurement was performed twice.

  FIG. 4 shows the measurement results. The detected output of the magnetic permeability sensor 22 with respect to the remaining amount of toner in the developing container 2 is represented by the output value of the remaining amount detection on the vertical axis and the remaining toner amount in the developing container 2 on the horizontal axis. It is a figure to do.

  The detection output of the magnetic permeability sensor 22 indicates that the first measurement (N = 1) and the second measurement (N = 2) because the toner surface height in the developer detectable region A is stable. In both cases, the ripple of the remaining amount detection output value is reduced, and the remaining amount of toner in the developing container 2 can be detected with high accuracy.

(Comparative example)
As a comparative example, FIG. 5 is a schematic view of the inside of the developing container 2 in which the magnetic permeability sensor 22 is provided at the same position as that of the present embodiment in the developing device 1 under the trial examination before publicly known, as viewed from above.

  As shown in FIG. 5, an opening 17 is provided at each end of the two developer conveying means 15 and 16 on the conveying surface 13 of the sheet member 14 included in the developer detectable area A. It can be seen that there are also two developer conveying means 15 and 16 in the agent detectable region A.

  FIG. 6 is a schematic cross-sectional view of the configuration around the magnetic permeability sensor 22 of the comparative example as seen from the side surface of the developing container 2. This schematically shows how the surface of the toner 8 to be agitated changes as the sheet member 14 rotates around the rotation shaft 12 inside the developing container 2.

  In this comparative example, the toner 8 in the developing container 2 is fed to the end portion of the developing container 2 by the first developer conveying means 15 provided on the conveying surface 13 of the sheet member 14 by the rotation of the agitating and conveying member 6. There is toner 8 conveyed to the axial end of the rotating shaft 12 and toner 8 conveyed to the end opposite to the end of the developer container 2 by the second developer conveying means 16. To do.

  As described above, at the end of the developing container 2, the toner 8 presses against the end in the axial direction of the agitating / conveying member 6 of the developing container 2 every time it is agitated by the agitating / conveying member 6. A certain toner 8 is conveyed toward the inside of the developing container 2. Therefore, when the sheet member 14 is outside the toner reservoir (FIG. 6A) and when the sheet member 14 is rotating in the toner reservoir (FIG. 6B), the toner surface height is increased. Greatly fluctuates up and down, and the toner surface height is not stable.

  Next, the output of the remaining amount detection by the magnetic permeability sensor 22 was monitored while consuming the toner 8 in the developing container 2 of the comparative example, and the measurement was performed twice.

  FIG. 7 shows the measurement result. The detection output of the magnetic permeability sensor 22 with respect to the remaining amount of toner in the developing container 2 is represented by the vertical axis representing the remaining amount detection output value, and the horizontal axis representing the remaining toner amount in the developing container 2. It is a figure to do.

  Since the toner surface height at the end of the developing container 2 fluctuates up and down and becomes unstable, the output of the remaining amount detection by the magnetic permeability sensor 22 becomes unstable and the first measurement (N = 1) and In both the second measurement (N = 2), the ripple of the remaining amount detection output value of the magnetic permeability sensor 22 is large, and the actual toner remaining amount in the developing container 2 when determining that there is no toner is greatly different. Therefore, the configuration of the comparative example cannot be detected with high accuracy.

(Second Embodiment)
FIG. 8 is a schematic view of the inside of the developing device 1 according to the second embodiment of the present invention as viewed from above.

  In the second embodiment, the two developer conveying means 15 and 16 are not provided in the developer detectable region A, and the shape does not have a toner conveying function in the direction along the axial direction of the rotary shaft 12. The sheet member 14 is provided with an opening 18 for conveying the toner 8 from one surface to the opposite surface. Other configurations are the same as those of the developing device 1 of the first embodiment.

  The shape of the opening 18 has a shape in which the width of the opening perpendicular to the direction is constant with respect to the direction in which the toner is conveyed.

  As the agitating / conveying member 6 rotates, the first developer conveying means 15 and the second developer conveying means 16 perform toner movement in the axial direction of the rotary shaft 12 and toner movement to the developing roll 3. Is called. The toner 8 in the developer detectable region A has a large toner flow toward and away from the magnetic permeability sensor 22 due to the opening 18 that does not have a conveying function in the axial direction of the rotation shaft 12. Can be suppressed. Further, the toner conveyance amount to the developing roll 3 side at the end of the agitation conveyance member 6 on the magnetic permeability sensor 22 side can also be suppressed.

  Thereby, the toner conveyance function toward the magnetic permeability sensor 22 in the developer detectable region A can be suppressed.

  With the configuration in which the developer conveying function toward the magnetic permeability sensor 22 is suppressed in the developer detectable area A, the vertical fluctuation of the toner surface height of the toner 8 in the developer detectable area A is reduced. The accuracy of toner presence / absence detection of the magnetic susceptibility sensor 22 can be further stabilized.

  Even according to the configuration of the present embodiment, the output result of the magnetic permeability sensor 22 shows that the ripple of the remaining amount detection output value is reduced due to the stable toner surface height in the developer detectable region A, and the developer container 2 It is possible to accurately detect the remaining toner amount.

  The configuration of the present embodiment is effective when the toner conveyance amount in the direction of the developing roll 3 at the end portion on the magnetic permeability sensor 22 side increases.

(Third embodiment)
FIG. 9 is a schematic view of the inside of the developing device 1 according to the third embodiment of the present invention as viewed from above.

  In the third embodiment, in the developer detectable region A, the opening 17 of the second developer transporting unit 16 that transports the toner to the central side in the axial direction of the rotating shaft 12 is provided. The opening 17 of the first developer conveying means 15 that conveys the toner to the end side of the sensor 22 is not provided. At this position, an opening 19 for conveying toner to the central side in the axial direction of the rotating shaft 12 is provided, which is arranged in the same manner as the opening 17 of the second developer conveying means 16. Other configurations are the same as those of the developing device 1 of the first embodiment.

  The opening 17 and the opening 19 have such a shape that the size of the opening (opening width) in the direction perpendicular to the toner conveyance direction along the axial direction increases toward the toner conveyance direction. That is, the shape of the opening forms a toner flow from the smaller opening width to the larger opening width. Therefore, the triangular shape having the bottom on the axial center side in the developer detectable region A described above. Both the opening 17 and the opening 19 having a function of conveying toner toward the center in the axial direction.

  As a result, when the stirring and conveying member 6 rotates, the toner at the end of the sheet member 14 on the side of the magnetic permeability sensor 22 is transferred to the axis of the rotary shaft 12 by the opening 17 and the opening 19 in the developer detectable region A. It is conveyed so as to move toward the center in the direction. The toner is also conveyed to the developing roll 3 side by the rotating sheet member 14.

  Since the developer conveying function toward the magnetic permeability sensor 22 in the developer detectable area A is suppressed, the toner conveying function toward the magnetic permeability sensor 22 in the developer detectable area A can be suppressed. Variation in the toner surface height in the agent detectable region A is reduced, and the toner surface height is stabilized. For this reason, the output result of the magnetic permeability sensor 22 has a small ripple in the remaining amount detection output value, and the remaining amount of toner in the developing container 2 can be accurately detected.

  The configuration of the present embodiment is effective when the toner surface height is increased at the end on the magnetic permeability sensor 22 side. Further, in the configuration in which the toner replenishing port 9 is likely to increase in the amount of toner at the end on the magnetic permeability sensor 22 side, such as the configuration in which the toner supply port 9 is provided closer to the magnetic permeability sensor 22 than the central portion of the rotating shaft 12. Is also effective.

(Fourth embodiment)
FIG. 10 is a schematic view of the inside of the developing device 1 according to the fourth embodiment of the present invention as viewed from above.

  In the fourth embodiment, in the developer detectable region A, the end of each of the two developer transporting means 15 and 16 on the magnetic permeability sensor 22 side is on the free end side (sheet member 14 in the rotation direction of the sheet member 14). The opening 20 is disposed so as to convey the toner 8 to the outer side of the rotation radius. Other configurations are the same as those of the developing device 1 of the first embodiment.

  The two openings 20 have a shape such that the size (opening width) of the opening in the direction orthogonal to the rotation direction free end direction of the sheet member 14 increases toward the free end of the sheet member 14. Therefore, toner conveyance to the magnetic permeability sensor 22 side by the agitation conveyance member 6 can be suppressed. Thereby, the toner conveyance function toward the magnetic permeability sensor 22 in the developer detectable region A can be suppressed.

  Further, with this configuration, toner conveyance to the developing roll 3 side due to the rotational movement of the sheet member 14 is not suppressed.

  With the configuration in which the developer conveying function toward the magnetic permeability sensor 22 is suppressed in the developer detectable area A, the toner conveyance to the magnetic permeability sensor 22 by the sheet member 14 is suppressed, and therefore the developer detectable area A The fluctuation in the toner surface height is reduced, and the toner surface height is stabilized. For this reason, the output result of the magnetic permeability sensor 22 has a small ripple in the remaining amount detection output value, and the remaining amount of toner in the developing container 2 can be accurately detected.

  In this embodiment, since the toner 8 in the vicinity of the magnetic permeability sensor 22 is positively conveyed to the outside in the radial direction of the sheet member 14, the magnetic permeability sensor 22 is 1/3 or less with respect to the height direction of the side wall of the developing container 2. It is effective when it is attached at the height position.

(Fifth embodiment)
FIG. 11 is a schematic view of the inside of the developing device 1 according to the fifth embodiment of the present invention as viewed from above.

  In the fifth embodiment, in the developer detectable region A, the end of each of the two developer conveying units 15 and 16 on the magnetic permeability sensor 22 side is on the rotation axis side of the sheet member 14 (the rotation of the sheet member 14). An opening 21 is disposed so as to convey the toner 8 toward the inside of the radius. Other configurations are the same as those of the developing device 1 of the first embodiment.

  The two openings 21 have such a shape that the size of the opening (opening width) in the direction perpendicular to the free end direction of the sheet member 14 increases toward the fixed end of the sheet member 14. In addition, toner conveyance to the magnetic permeability sensor 22 side by the agitating and conveying member 6 can be suppressed. Thereby, the toner conveyance function toward the magnetic permeability sensor 22 in the developer detectable region A can be suppressed.

  Further, with this configuration, toner conveyance to the developing roll 3 side due to the rotational movement of the sheet member 14 is not suppressed.

  With the configuration in which the developer conveying function toward the magnetic permeability sensor 22 is suppressed in the developer detectable area A, the toner conveyance to the magnetic permeability sensor 22 by the sheet member 14 is suppressed, and therefore the developer detectable area A The fluctuation in the toner surface height is reduced, and the toner surface height is stabilized. For this reason, the output result of the magnetic permeability sensor 22 has a small ripple in the remaining amount detection output value, and the remaining amount of toner in the developing container 2 can be accurately detected.

  In the present embodiment, since the toner 8 in the vicinity of the magnetic permeability sensor 22 is positively conveyed radially inward of the sheet member 14, the magnetic permeability sensor 22 is at least one third in the height direction of the side wall of the developing container 2. It is effective when it is attached at the height position.

  The first to fifth embodiments described above have been described using the developing device adopting the replenishment method having the replaceable toner bottle 7, but the present invention is not limited to this. The same effect can be obtained with a cartridge that uses a single-use system.

DESCRIPTION OF SYMBOLS 1 ... Developing apparatus 2 ... Developing container 3 ... Developing roll 4 ... Developing blade 5 ... Toner conveyance path 6 ... Agitating conveyance member 7 ... Toner bottle 8 ... Toner 9 ... Toner supply port 10 ... Stirring member 11 ... Supply port communication area 12 ... Rotating shaft 13 ... Conveying surface 14 ... Sheet member 15 ... First developer conveying means 16 ... second developer conveying means 17 ... opening 18 ... opening 19 ... opening 20 ... opening 21 ... opening 22 ... permeability sensor A ...・ Developer detectable area

Claims (6)

A developer accommodating portion for accommodating the developer;
A developer detection unit for detecting the developer stored in the developer storage unit;
A sheet member arranged rotatably with respect to the rotation axis in the developer accommodating portion,
The sheet member includes a first developer conveying unit that conveys the developer in a direction toward one axial end of the rotating shaft, and the first developer conveying unit has a distance from the rotating shaft. A second developer conveying means that is formed at a different position and conveys the developer in a direction toward the other axial end of the rotating shaft,
Each of the first and second developer conveying means is configured by arranging a plurality of openings in the sheet member in the axial direction,
The developer detection unit is disposed on an inner wall of the developer accommodating portion corresponding to the one end portion,
Among the each of the openings of the first and second developer conveying unit, the distance between the most the an opening located at one end the one end side of the inner wall and L _1, said first and second L ₁ > L ₂ , where L ₂ is the distance between the opening located on the other end side of each of the openings of the developer conveying means and the inner wall of the developer containing portion on the other end side. A developing device characterized by having a relationship.   The sheet member is a third developer that conveys the developer toward the center in the axial direction, closer to the one end than the opening located closest to the one end among the openings of the first developer conveying means. The developing device according to claim 1, further comprising an opening as an agent transport unit.   The sheet member is located closer to the one end side than the opening located closest to the one end side among the respective openings of the first developer conveying means and the second developer conveying means. The developing device according to claim 1, further comprising an opening as a fourth developer conveying unit that conveys the developer in the rotation direction.   3. The opening of the first developer conveying means and the opening of the second developer conveying means have regions that overlap in the axial direction of the rotation shaft. The developing device according to 1.   5. The developing device according to claim 1, wherein the shape of the opening is a hole whose opening width expands toward a developer transport direction. In an image forming apparatus that forms an image by developing an electrostatic latent image formed on an image carrier with a developing device,
An image forming apparatus comprising the developing device according to claim 1 as the developing device.

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