JP6248958B2 - Developer supply device and image forming apparatus provided with the same - Google Patents

Description

  The present invention relates to a developer replenishing device that replenishes a developer, and an image forming apparatus to which the developer replenishing device is applied.

  In an electrophotographic image forming apparatus, in order to develop an electrostatic latent image on a photosensitive drum, toner (developer) is supplied from the developing device to the circumferential surface of the photosensitive drum. As the toner is consumed, the toner is supplied from the toner container (developer storage container) to the developing device. It is desirable to use up as much as possible the toner contained in the toner container. However, the toner may remain inside the container due to toner adhering to the inner wall surface of the container.

  In view of the above problems, a toner container in which a moving wall is disposed inside the container is known (for example, Patent Documents 1 and 2). The moving wall moves so as to approach the toner discharge port according to the remaining amount of toner. The movement of the moving wall is controlled based on a detection result of a toner sensor disposed in the vicinity of the toner discharge port. According to such a toner container, since the toner inside the container is conveyed by the moving wall, it is possible to guide all the toner to the toner discharge port without leaving the toner on the inner wall surface or the like.

JP 2001-92230 A JP 2007-264073 A

  In a toner container having a moving wall as described above, it is actually difficult to reliably detect that the toner in the container is empty. That is, the moving wall is moved so as to approach the toner discharge port when the toner sensor detects that the toner near the toner discharge port has decreased. As a result, the toner in the container is pushed toward the toner discharge port, and the vicinity of the toner discharge port becomes a toner rich state.

  As described above, the movement control of the moving wall can be performed based on the detection result of the toner sensor. However, the final determination of whether the toner is still in the container and the moving wall should be moved or whether the toner in the container is empty is used as the detection result of the toner sensor. It is difficult to rely on.

  An object of the present invention is to make it possible to reliably determine whether or not a developer remains in a developer container in a developer supply device having a moving wall.

A developer replenishing device according to one aspect of the present invention includes a developer container that contains a developer, a sensor that detects a predetermined detection target and generates an electrical output, and an output of the sensor, A determination unit that determines the presence or absence of the developer in the developer storage container, the developer storage container extending in the first direction in the internal space, and a container main body including a wall that partitions the internal space. A shaft portion arranged in this manner, a moving wall that moves from the upstream side to the downstream side in the first direction along the shaft portion in the internal space, and transports the developer, and the first of the container body A developer discharge port that is disposed near the downstream end in the direction and passes through the wall to communicate the internal space and the outside; and a detection piece that is mounted on the moving wall and that is the detection target of the sensor. wherein, the sensor is, before A detectable sensor common physical quantity in said developer detection piece, the moving wall is disposed in detectable position the detection piece when approaching the developer discharge opening, wherein the determination unit When the sensor generates a predetermined output indicating that the detection piece has been detected, it is determined that there is no developer in the developer container.

  According to this developer supply device, the detection piece is mounted on the moving wall, the sensor can detect the detection piece, and the detection piece is detected when the moving wall approaches the developer discharge port. Is arranged. Therefore, the sensor detects that the moving wall has reached the vicinity of the developer discharge port, and the presence of the moving wall at this position means that there is developer in the developer container. It means that it is in a state that cannot be obtained. Therefore, the determination unit can reliably determine that there is no developer in the developer container based on the output of the sensor.

Further, the sensor is Ru detectable sensor der common physical quantity the developer to said detection piece.

For this reason , the sensor installed for the detection of the developer can be used for the detection of the detection piece, and the number of parts can be reduced and the cost can be reduced.

  In this case, the developer is a magnetic toner containing a magnetic component, the sensor is a sensor for detecting magnetism, the detection piece is made of a magnetic material, and the sensor detects a predetermined value when the magnetic toner is detected. It is desirable to output a first value and output a second value higher than the first value when the detection piece is detected.

  According to this developer replenishing device, the output of the sensor differs between when the magnetic toner is detected and when the detection piece is detected. Therefore, even when a sensor that can be used for the detection of the developer and the detection piece is used as the sensor, it is possible to easily distinguish which of the two is detected.

  The developer replenishing device further includes a control unit that controls the movement of the moving wall, and the sensor outputs a third value lower than the first value when the magnetic toner is not detected. The control unit temporarily stops the moving wall when the sensor outputs the first value, and stops the moving wall when the sensor outputs the third value. It is desirable that the moving wall be permanently stopped after the sensor has moved a predetermined amount downstream in the direction and the sensor has output the second value.

  According to this developer replenishing device, the movement and temporary stop of the moving wall, as well as the permanent stop of the moving wall after the developer in the developer container becomes empty, are controlled by three outputs of the sensor. It can be executed simply and reliably based on the value.

  In the developer supply device, the moving wall includes a transport surface perpendicular to the shaft portion on a surface facing the downstream side in the first direction, and the detection piece projects from the transport surface to the downstream side. In this state, it is desirable to be attached to the moving wall.

  According to this developer supply device, the detection piece can be detected by the sensor just before the moving wall is closest to the developer discharge port. Accordingly, a so-called near-end state in which almost no developer exists in the developer container can be detected based on the output of the sensor.

  In the developer supply device, the detection piece may have a shape having different areas per unit length in the first direction.

  According to this developer supply device, since the shape of the detection piece is different in the first direction, the sensor output can also be changed according to the shape. Therefore, the position of the moving wall can be grasped with higher resolution.

  In this case, the detection piece includes a first detection area on the downstream side and a second detection area on the upstream side in the first direction, and is between the first detection area and the second detection area. The non-detection region that is not the detection target of the sensor may be arranged.

  According to this developer replenishing device, since the non-detection area is arranged between the first detection area and the second detection area, a clear difference occurs in the output of the sensor as the moving wall moves. Therefore, the near-end state can be clearly identified.

  An image forming apparatus according to another aspect of the present invention includes the developer replenishing device, an image carrier that carries an electrostatic latent image and a developer image, and the developer is replenished from the developer replenishing device. A developing device that supplies the developer to the image carrier and a transfer unit that transfers the developer image from the image carrier to a sheet.

  According to the present invention, in a developer replenishing device having a moving wall and an image forming apparatus to which the developer replenishing device is applied, it is reliably determined whether or not the developer remains in the developer container. Can be made.

1 is a perspective view showing an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a perspective view of a state where a part of the housing of the image forming apparatus is opened. FIG. 2 is a schematic cross-sectional view showing an internal structure of the image forming apparatus. FIG. 2 is a plan view showing an internal structure of a developing device provided in the image forming apparatus. FIG. 4 is a schematic cross-sectional view showing a state where developer is supplied to the developing device. It is a side view showing a developer storage container according to an embodiment of the present invention. FIG. 6 is a cross-sectional view of the developer storage container of FIG. 5 in the left-right direction. (A)-(C) are sectional drawings which show a mode that a movement wall moves in a container main body. 1 is a block diagram schematically showing a configuration of a developer supply device according to an embodiment of the present invention. (A)-(C) are sectional drawings which show a mode that a movement wall provided with the detection piece which concerns on 1st Embodiment moves. (A) And (B) is a graph which shows the sensor output in 1st Embodiment. (A)-(C) are sectional drawings which show a mode that a movement wall provided with the detection piece which concerns on 2nd Embodiment moves. It is a graph which shows the sensor output in 2nd Embodiment. (A)-(D) are sectional drawings which show a mode that a movement wall provided with the detection piece which concerns on 3rd Embodiment moves. It is a graph which shows the sensor output in 3rd Embodiment. 6 is a flowchart showing the operation of the developer supply device. (A)-(D) are sectional drawings which show the movement state of a movement wall. (A)-(C) are sectional drawings which show the movement state of a movement wall. It is a graph which shows the sensor output in each in the movement state of the movement wall shown in FIG.16 and FIG.17.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a printer 100 (image forming apparatus) according to an embodiment of the invention, FIG. 2 is a perspective view in which a part of a casing 101 of the printer 100 is opened, and FIG. It is sectional drawing which shows an internal structure schematically. The printer 100 is a so-called monochrome printer, but in another embodiment, the image forming apparatus may be a color printer, a facsimile machine, a multifunction machine having these functions, or the like.

  The printer 100 includes a housing 101 that houses various apparatuses for forming an image on the sheet S. The housing 101 includes an upper wall 102 that defines the upper surface of the housing 101, a bottom wall 103 (FIG. 3) that defines the bottom surface of the housing 101, and a rear wall 105 (between the upper wall 102 and the bottom wall 103). 3) and a front wall 104 located in front of the rear wall 105. The housing 101 includes an internal space 107 in which various devices are arranged. The internal space 107 of the housing 101 is provided with a sheet conveyance path PP through which the sheet S is conveyed in a predetermined conveyance direction. A part of the casing 101 can be opened by an opening / closing cover 100C as shown in FIG. When the opening / closing cover 100C is rotated about the axis of the hinge shaft 108 and opened upward, the upper portion of the internal space 107 is opened to the outside. A portion exposed by the opening is a container housing portion 109 for housing a toner container 30 described later.

  A paper discharge unit 102 </ b> A is disposed at the center of the upper wall 102. The sheet S on which an image has been formed in the image forming unit 120 described later is discharged to the paper discharge unit 102A. A manual feed tray 104 </ b> A is disposed at the center of the front wall 104 in the vertical direction. The manual feed tray 104A can be turned up and down with its lower end as a fulcrum (arrow DT in FIG. 3).

  Referring to FIG. 3, the printer 100 includes a cassette 110, a pickup roller 112, a first paper feed roller 113, a second paper feed roller 114, a transport roller 115, a registration roller pair 116, an image forming unit 120, and a fixing device 130. I have.

  The cassette 110 accommodates the sheet S inside. The cassette 110 includes a lift plate 111 that is inclined so as to push up the leading edge of the sheet S. The pickup roller 112 is disposed on the leading edge of the sheet S pushed up by the lift plate 111. When the pickup roller 112 rotates, the sheet S is pulled out from the cassette 110. The first paper feed roller 113 is disposed downstream of the pickup roller 112 and sends the sheet S further downstream. The second paper feed roller 114 is disposed on the inner side (rear side) of the fulcrum of the manual feed tray 104 </ b> A, and draws the sheet S on the manual feed tray 104 </ b> A into the housing 101.

  The transport roller 115 is disposed on the downstream side of the first paper feed roller 113 and the second paper feed roller 114 in the sheet transport direction. The transport roller 115 transports the sheet S sent out by the first paper feed roller 113 and the second paper feed roller 114 further downstream. The registration roller pair 116 has a function of correcting the oblique conveyance of the sheet S. Further, the registration roller pair 116 supplies the sheet S to the image forming unit 120 in accordance with the timing of image formation by the image forming unit 120.

  The image forming unit 120 includes a photosensitive drum 121 (image carrier), a charger 122, an exposure device 123, a developing device 20, a toner container 30 (developer container; a part of a developer supply device), and a transfer roller 126 ( A transfer unit) and a cleaning device 127.

  The photosensitive drum 121 is a cylindrical member, and carries an electrostatic latent image and a toner image (developer image) on its peripheral surface. The charger 122 charges the peripheral surface of the photosensitive drum 121 substantially uniformly. The exposure device 123 forms an electrostatic latent image on the peripheral surface of the photosensitive drum 11. The exposure device 123 includes a light source such as a laser diode, a deflecting body, a scanning lens, an optical element, and the like. The peripheral surface of the photosensitive drum 121 that is substantially uniformly charged by the charger 122 corresponds to image data. Irradiate with laser light.

  The developing device 20 supplies toner (developer) to the peripheral surface of the photosensitive drum 121 on which the electrostatic latent image is formed. The toner container 30 is a container for storing toner, and replenishes the developing device 20 with the toner. When the developing device 20 supplies toner to the photosensitive drum 121, the electrostatic latent image formed on the peripheral surface of the photosensitive drum 121 is developed (visualized). As a result, a toner image is formed on the peripheral surface of the photosensitive drum 121. Detailed structures of the developing device 20 and the toner container 30 will be described in detail later.

  The transfer roller 126 is disposed to face the photosensitive drum 121 from below, and forms a transfer nip portion therebetween. A transfer bias is applied to the transfer roller 126, and the toner image formed on the photosensitive drum 121 is transferred to a sheet. The cleaning device 127 removes the toner remaining on the peripheral surface of the photosensitive drum 121 after the toner image is transferred to the sheet S.

  The fixing device 130 includes a fixing roller 131 having a built-in heater, and a pressure roller 132 disposed to face the fixing roller 131. The fixing device 130 fixes the toner image on the sheet by heating and pressing the sheet on which the toner image is transferred. A transport roller pair 133 and a discharge roller pair 134 disposed downstream of the transport roller pair 133 are disposed downstream of the fixing device 130. The sheet S after the fixing process is conveyed upward by the conveying roller pair 133 and is finally discharged from the housing 101 by the discharging roller pair 134. The sheets S discharged from the housing 101 are stacked on the paper discharge unit 102A.

  Next, the developing device 20 will be described in detail. FIG. 4A is a plan view showing the internal structure of the developing device 20. The developing device 20 includes a developing housing 210 having a box shape that is long in one direction (left-right direction). The development housing 210 includes a storage space 220 and a toner supply port 25. In the storage space 220, the developing roller 21, the first stirring screw 23, and the second stirring screw 24 are disposed. In this embodiment, a one-component development system is applied, and the storage space 220 is filled with magnetic toner containing a magnetic component as a developer. In another embodiment to which the two-component development method is applied, the storage space 220 is filled with a developer in which toner and a carrier made of a magnetic material are mixed. The toner is agitated and conveyed in the storage space 220 and is sequentially supplied from the developing roller 21 to the photosensitive drum 121 in order to develop the electrostatic latent image. The developing roller 21 has a cylindrical shape that extends in the longitudinal direction of the developing housing 210 and has a sleeve portion that is rotationally driven on the outer periphery.

  The storage space 220 of the developing housing 210 is covered with a top plate (not shown), and is partitioned into a first transport path 221 and a second transport path 222 that are long in the left-right direction by a partition plate 22 extending in the left-right direction. Yes. The partition plate 22 is shorter than the width of the developing housing 210 in the left-right direction, and a first communication path 223 and a first communication path 223 that connect the first transport path 221 and the second transport path 222 to the right end and the left end of the partition plate 22, respectively. A double communication path 224 is provided. Thereby, a circulation path that reaches the first conveyance path 221, the second communication path 224, the second conveyance path 222, and the first communication path 223 is formed in the storage space 220. The toner is conveyed clockwise in the circulation path as indicated by arrows D1 and D2 in FIG. 4A.

  The toner supply port 25 is an opening drilled in the top plate, and is disposed above the right end of the first transport path 221. The toner replenishing port 25 is an opening for receiving the replenishing toner replenished from the toner container 30 into the storage space 220, which is disposed to face the circulation path.

  The first stirring screw 23 is disposed in the first conveyance path 221. The first stirring screw 23 includes a first rotating shaft 23a and a first spiral blade 23b projecting in a spiral shape on the circumference of the first rotating shaft 23a. The first agitating screw 23 is driven to rotate about the first rotation shaft 23a, thereby conveying the toner in the direction of arrow D1 in FIG. 4A. The first agitation screw 23 conveys the developer so that the toner replenishing port 25 passes through a position facing the first conveyance path 221. As a result, the first agitating screw 23 conveys the new toner flowing in from the toner supply port 25 and the toner carried into the first conveying path 221 from the second conveying path 222 side while mixing. The toner transported to the downstream end in the D1 direction by the first stirring screw 23 is delivered to the second transport path 222 via the second communication path 224.

  A small blade portion 26 in which the outer diameter of the first spiral blade 23 b is partially reduced by a certain interval in the left-right direction on the downstream side of the first agitating screw 23 in the toner transport direction from the toner supply port 25. Is formed. In the small blade portion 26, the toner conveyance capability is lowered by the amount of the blade diameter smaller than the other portions of the first spiral blade 23b. That is, the region where the small blade portion 26 is formed serves as a conveyance capability suppressing unit 27 that partially suppresses the toner conveyance capability. The conveyance capacity suppression unit 27 is provided to retain toner near the toner supply port 25.

  The second stirring screw 24 is disposed in the second conveyance path 222. The second agitating screw 24 includes a second rotating shaft 24a and a second spiral blade 24b protruding in a spiral shape on the circumference of the second rotating shaft 24a. The second agitating screw 24 is driven to rotate about the second rotation shaft 24a, thereby supplying the toner to the developing roller 21 while conveying the toner in the direction of the arrow D2. The toner transported to the downstream end in the direction D2 by the second stirring screw 24 is delivered to the first transport path 221 through the first communication path 223.

  The toner container 30 (FIG. 3) is disposed above the toner supply port 25 of the development housing 210. The toner container 30 includes a toner discharge port 319 (developer discharge port). The toner replenishing port 25 of the developing device 20 is opened to the developing housing 210 at a position corresponding to the lower side of the toner discharge port 319. The toner stored in the toner container 30 is supplied into the developing housing 210 from the toner discharge port 319 through the toner supply port 25.

  In the present embodiment, as a method of supplying toner to the developing device 20, a volume replenishing method is employed in which toner is automatically supplied from the toner container 30 when the amount of toner in the developing device 20 decreases without depending on the toner sensor. Yes. The flow of toner newly supplied from the toner supply port 25 in this volume supply method will be described. FIG. 4B is a cross-sectional view schematically showing the vicinity of the coupling portion between the toner supply port 25 of the developing device 20 and the toner discharge port 319 of the toner container 30.

  The replenishing toner T2 supplied from the toner discharge port 319 falls to the first conveying path 221 and is mixed with the existing toner T1, and is conveyed in the direction of the arrow D1 by the first agitating screw 23. At this time, the toners T1 and T2 are stirred and charged. As described above, the first agitating screw 23 includes the conveyance capability suppressing unit 27 having a relatively low toner conveyance performance on the downstream side of the toner supply port 25 in the toner conveyance direction. When the first agitating screw 23 is rotationally driven in a state where the toner is sufficiently present in the storage space 220, the toner T1 starts to stay in the conveyance capacity suppressing unit 27. The toner T <b> 1 stays immediately upstream of the conveyance capability suppressing unit 27 and reaches a position where the toner supply port 25 faces the first conveyance path 221. As a result, the inlet of the toner replenishing port 25 is blocked by the staying toner T1.

  Therefore, the replenishment toner T <b> 2 cannot fall from the toner discharge port 319 when there is sufficient toner in the storage space 220. Therefore, the supply of the supply toner T2 is restricted. On the other hand, when the toner in the storage space 220 is consumed and the toner staying in the conveyance capacity suppressing unit 27 is reduced, the toner that is blocking the toner supply port 25 is also reduced. As a result, the replenishment toner T2 can flow from the toner replenishment port 25 into the first transport path 221 (storage space 220), and toner replenishment is realized. In the case where a toner sensor is attached to the developing device 20 and toner is replenished completely depending on the toner sensor (when the volume replenishment method is not adopted), the conveyance capability suppressing unit 27 may not be provided. .

  Next, the detailed structure of the toner container 30 according to the first embodiment will be described. FIG. 5 is a side view of the toner container 30, and FIG. 6 is a cross-sectional view of the toner container 30 in the left-right direction. The toner container 30 includes a container main body 31 (container main body), a stirring disk 32, a shaft 33 (shaft portion), a moving wall 34, a sponge seal 36, a lid portion 37, a rotation gear 38, a cover 39, and a detection piece 40.

  The container main body 31 is a main body portion of the toner container 30 having a cylindrical shape. The container main body 31 includes an inner peripheral portion 311 and an internal space 312. The inner peripheral portion 311 is an inner peripheral surface of the container main body 31 and extends in a cylindrical shape along the left-right direction that is the longitudinal direction of the toner container 30. The internal space 312 is a space that can accommodate toner. The internal space 312 includes a cylindrical body portion 314 (a wall defining the internal space), a left wall 315 that seals the left end side of the body portion 314, a flange portion 316 that seals the right end side of the body portion 314, and It is partitioned by a lid portion 37. Of the internal space 312, a region defined by the left wall 315, the moving wall 34 described later, and the inner peripheral portion 311 is an accommodation space 313. The storage space 313 is a space in which the toner is actually stored inside the toner container 30.

  The container body 31 includes a shutter member 317, a first guide portion 318, and a toner discharge port 319 (developer discharge port). The shutter member 317 has a U-shape and is mounted on the outer periphery near the left end of the container body 31 so as to be movable in the left-right direction with respect to the container body 31. The first guide portion 318 is a protruding portion that extends in the vertical direction outside the left wall 315. The first guide portion 318 guides the mounting of the toner container 30 to the housing 101 together with the second guide portion 392 described later.

  The toner discharge port 319 is an opening that penetrates the body portion 314 at a lower position near the left end (downstream end in the first direction) of the container main body 31, and is an opening that allows the internal space 312 to communicate with the outside. The shutter member 317 is a member that changes the posture between a closing posture in which the toner discharge port 319 is sealed from the outer peripheral side of the container body 31 and an open posture in which the toner discharge port 319 is opened. When the toner discharge port 319 is opened, the toner stored in the storage space 313 is discharged from the toner discharge port 319 toward the developing device 20 (toner supply port 25).

  The stirring disk 32 is a plate member having a disk shape. The stirring disk 32 is fixed to a second shaft end 332 of the shaft 33 described later and rotates integrally with the shaft 33. The stirring disk 32 is disposed near the left wall 315 in the container main body 31 and stirs the toner existing above the toner discharge port 319. If the fluidity of the toner stored in the storage space 313 is low, a protrusion that protrudes rightward toward the storage space 313 may be provided on the stirring disk 32.

  The shaft 33 extends in the left-right direction in the internal space 312 (in this embodiment, the direction from right to left is the “first direction”, the right side is “upstream side”, and the left side is “downstream side”). It arrange | positions and is rotatably supported by the container main body 31 and the cover part 37 mentioned later. The shaft 33 is rotationally driven by a motor M around its axis. The shaft 33 includes a first shaft end portion 331, a second shaft end portion 332, a male spiral portion 333, and a moving wall stop portion 334.

  The first shaft end 331 is the right end of the shaft 33 and is pivotally supported by the lid shaft hole 37 </ b> J of the lid 37. The second shaft end portion 332 is the left end of the shaft 33 and is pivotally supported by a bearing portion 31J provided on the left wall 315 of the container body 31. The male spiral portion 333 is a spiral thread portion formed on the outer peripheral surface of the shaft 33 at a predetermined pitch. The male spiral portion 333 of the present embodiment is formed in a region of the shaft 33 from a position facing the flange portion 316 to a position close to the toner discharge port 319. The moving wall stop 334 is an area of only the shaft portion that is arranged adjacent to the left end of the male spiral portion 333 and does not have a convex portion like the male spiral portion 333. The moving wall stop 334 is located above the toner discharge port 319 and in a region adjacent to the right thereof.

  The moving wall 34 is disposed in the internal space 312 and moves from the right side (upstream side in the first direction) to the left side (downstream side) along the shaft 33 in the internal space 312. The moving wall 34 is a wall that defines the right end surface of the storage space 313 in which the toner is actually stored. The moving wall 34 moves from the preset initial position to the final position facing the toner discharge port 319 from the preset initial position from the start of use of the toner container 30 to the end of use. At this time, the moving wall 34 conveys the toner in the accommodation space 313 toward the toner discharge port 319. The moving wall 34 is engaged with the male spiral portion 333 of the shaft 33, and moves in the direction of the arrow DA when the shaft 33 is rotated by driving the motor M.

  The moving wall 34 includes a wall main body 340, a moving wall shaft hole 34 </ b> J, an outer peripheral wall 341, an inner wall seal 342, a shaft seal 343, and an outer peripheral portion 344. The wall main body 340 is a part of the wall that defines the accommodation space 313, and includes a conveyance surface 340 </ b> S perpendicular to the shaft 33. The conveyance surface 340 </ b> S is provided on the left side surface (surface toward the downstream side) of the moving wall 34, and conveys the toner in the accommodation space 313 while pressing the toner in the accommodation space 313. A cylindrical hole that holds the shaft seal 343 and penetrates the shaft 33 is formed at the center of the wall main body 340. The moving wall shaft hole 34J is a cylindrical portion protruding rightward from the center of the right surface of the wall main body 340. A female spiral portion 345 that engages with the male spiral portion 333 of the shaft 33 is provided on the inner peripheral surface of the moving wall shaft hole portion 34J.

  The outer peripheral wall part 341 is a side peripheral wall of the wall main body part 340 and faces the inner peripheral part 311 of the container main body 31 with a predetermined gap. The inner wall seal 342 is a seal member disposed so as to cover the periphery of the outer peripheral wall portion 341, and is compressed and deformed between the inner peripheral portion 311 and the outer peripheral wall portion 341. When the moving wall 34 moves in the arrow DA direction, the inner wall seal 342 prevents the toner in the accommodation space 313 from flowing out from between the inner peripheral portion 311 and the moving wall 34 to the upstream side of the moving wall 34 in the moving direction. Is done.

  The shaft seal 343 is disposed so as to come into contact with the male spiral portion 333 of the shaft 33, and cleans the toner attached to the male spiral portion 333 as the moving wall 34 moves. The shaft seal 343 is disposed downstream of the moving wall shaft hole 34J in the moving direction of the moving wall 34. Therefore, the shaft seal 343 comes into contact with the male spiral portion 333 before the female spiral portion 345, and the toner spiral portion 345 is placed on the male spiral portion 333 in a state where the toner is almost removed from the male spiral portion 333. Can proceed. Further, the seal function of the shaft seal 343 prevents the toner in the accommodation space 313 from flowing out to the upstream side in the movement direction through the gap between the shaft 33 and the movement wall 34.

  The lid portion 37 is fixed to the flange portion 316 of the container main body 31 and seals the opening on the right surface of the container main body 31. The lid portion 37 includes a lid shaft hole portion 37J. The lid shaft hole portion 37J rotatably supports the first shaft end portion 331 side of the shaft 33 in a rotatable manner. The sponge seal 36 is disposed between the moving wall shaft hole portion 34J and the lid portion 37. The sponge seal 36 prevents the toner from leaking from the lid shaft hole portion 37J of the lid portion 37 in a state where the lid portion 37 is fixed to the container main body 31.

  The rotation gear 38 is fixed to the first shaft end 331 of the shaft 33 and rotates integrally with the shaft 33. The rotation gear 38 is connected to a motor M disposed in the housing 101 via a transmission gear mechanism (not shown). When a rotational driving force is input from the motor M, the rotational gear 38 transmits the rotational driving force to the shaft 33 and moves the moving wall 34.

  The cover 39 is a cover member that is attached to the right end surface of the container main body 31. The cover 39 covers the right end surface of the container main body 31 with a part of the rotating gear 38 exposed. The cover 39 includes a shaft cover part 391 and a second guide part 392. The shaft cover portion 391 covers the end portion of the first shaft end portion 331 protruding from the rotary gear 38. The 2nd guide part 392 is a projection part extended in the up-and-down direction. The toner container 30 is guided by the second guide portion 392 and the first guide portion 318 on the left end surface side of the container main body 31 when the toner container 30 is attached to the printer 100.

  The detection piece 40 is a member that is mounted on the moving wall 34 and is a detection target of a toner sensor 31T described later. The detection piece 40 is attached to the conveyance surface 340S in a state of protruding leftward from the conveyance surface 340S. The detection piece 40 according to the first embodiment is a columnar or prismatic member, and a base end portion 401 thereof is fixed to the transport surface 340S by a method such as screwing, fitting, or bonding, and a distal end portion 402 is transported. It is in a position protruding leftward from 340S. This detection piece 40 is arranged so as to reliably identify that the moving wall 34 has reached the most downstream position of the moving range in the left-right direction, that is, that the toner in the toner container 30 is empty. It is a member made.

  In the present embodiment, the detection piece 40 is made of a member formed of a magnetic material so that the toner sensor 31T that detects magnetic toner can be sensed. The material for forming the detection piece 40 is not limited as long as it is a magnetic material, but is preferably a material having a higher magnetic permeability than the toner contained in the toner container 30. Accordingly, when both are magnetically sensed, different sensor outputs can be obtained, and the magnetic toner and the detection piece 40 can be identified.

  A toner sensor 31T is attached to the toner container 30. The toner sensor 31T is attached to an outer wall surface in the vicinity of the toner discharge port 319 of the container body 31. The toner sensor 31T is a sensor that detects the magnetism of a detection target, specifically, a sensor that detects the magnetic permeability (an example of a physical quantity) of the detection target and generates an electrical output. That is, the toner sensor 31T is a sensor capable of detecting a physical quantity common to the magnetic toner and the detection piece 40 made of a magnetic material. As a result, the sensor originally installed for detecting the toner can be used for detecting the detection piece 40, and the number of parts can be reduced and the cost can be reduced. As one of the preferable toner sensors 31T, a magnetic bridge type magnetic permeability sensor using a differential transformer can be exemplified. The toner sensor 31T does not necessarily have to be attached to the wall surface of the container main body 31, and may be disposed at an appropriate position of the container accommodating portion 109 of the housing 101, for example.

  7A to 7C are cross-sectional views showing how the moving wall 34 moves in the container main body 31, and FIG. 7A shows a state in which the moving wall 34 is at the initial position (the most upstream position). FIG. 7B shows a state in which the moving wall 34 has been moved about half to the left from the initial position, and FIG. 7C shows a final position (the most downstream position) where the moving wall 34 is close to the toner discharge port 319. ) Shows each state. In these drawings, the shutter member 317 is not shown.

  The state of FIG. 7A is the state where the accommodation space 313 for accommodating the toner is the widest, and the accommodation space 313 occupies most of the internal space 312 of the container main body 31. Such a state is a state in which the toner is fully accommodated, and is a state before the toner container 30 is used. At this time, the moving wall 34 is in a position adjacent to the lid portion 37. The detection piece 40 is at a position farthest from the toner sensor 31T.

  FIG. 7B shows a state where about half of the toner is consumed. The moving wall 34 moves to the left (first direction) in accordance with toner consumption from the initial position in FIG. The volume of the storage space 313 is reduced to about half of the internal space 312. At this time, the conveyance surface 340 </ b> S of the wall main body 340 conveys the toner toward the toner discharge port 319 by pushing the toner in the accommodation space 313. In addition, there is no limitation in particular in the movement aspect of the movement wall 34. FIG. For example, the moving wall 34 can be moved sequentially with a fine pitch according to the decrease in toner. Alternatively, the shaft 33 may be roughly divided into about 3 to 6 sections in the longitudinal direction, and the moving wall 34 may be moved in units of the sections in accordance with a decrease in toner.

  FIG. 7C shows a state (empty) in which the toner in the container is substantially used up. The moving wall 34 moves to the vicinity of the left end of the shaft 33 (near the toner discharge port 319), and the accommodation space 313 is very narrow. As a result, the amount of toner remaining in the storage space 313 of the container body 31 at the end of use is reduced compared to a toner container in which the volume of the storage space does not change. In the state of FIG. 7C, the moving wall shaft hole 34 </ b> J of the moving wall 34 reaches the moving wall stop 334. For this reason, the driving force is no longer applied to the moving wall 34 to the left. In this final position, the left and right positions of the detection piece 40 and the toner sensor 31T overlap. The front end portion 402 of the detection piece 40 is adjacent to the right surface of the stirring disk 32. That is, the toner sensor 31T is disposed at a position where the detection piece 40 can be detected when the moving wall 34 is closest to the toner discharge port 319.

  FIG. 8 is a block diagram schematically showing the configuration of the toner supply device 300 (developer supply device) according to the first embodiment. The toner replenishing device 300 is a device for replenishing toner to the developing device 20 and includes the above-described toner container 30, toner sensor 31T, motor M, and control unit 50.

  The motor M is a drive source that moves the moving wall 34 via the shaft 33. The output shaft of the motor M is connected to a rotary gear 38 (FIG. 6) fixed to the shaft 33 via a transmission gear mechanism (not shown).

  The control unit 50 is composed of a microcomputer, and controls the operation of the toner replenishing device 300 by executing a predetermined program. The control unit 50 functionally includes a moving wall control unit 51 (control unit) and a determination unit 52. The moving wall control unit 51 controls the movement of the moving wall 34. Specifically, the moving wall control unit 51 operates the motor M under predetermined conditions to rotate the shaft 33 and controls the moving position of the moving wall 34 on the shaft 33. The determination unit 52 determines the presence / absence of toner in the toner container 30 based on the output of the toner sensor 31T.

  The toner sensor 31T generates different sensor outputs when there is magnetic toner (replenishment toner TZ) in the detection area, when there is no toner, and when the detection piece 40 is present. The toner sensor 31T of this embodiment has a predetermined voltage V1 (first value) when toner is detected, and a voltage V2 (third value) lower than V1 when no toner is detected, and a detection piece. When 40 is detected, sensor outputs of V3 (second value) higher than V1 are generated. As illustrated in FIG. 18 to be described later, for example, V1 = 0.75V, V2 = 0.35V, and V3 = 1.2V can be set. In this case, for example, by setting a detection threshold value in the vicinity of 1.0 V, both can be distinguished even when the toner sensor 31T is shared for the detection of the replenishment toner TZ and the detection piece 40.

  In the present embodiment, the determination unit 52 receives the sensor output of the toner sensor 31T as described above, and identifies the toner storage state in the toner container 30. When the toner sensor 31T outputs V1, the determination unit 52 determines that the supply toner TZ is sufficiently present in the vicinity of the toner discharge port 319 (FIG. 8 shows this state). To do. In this case, the toner T2 can be discharged from the toner discharge port 319 to the developing device 20 through the toner supply port 25. Therefore, the moving wall control part 51 makes the moving wall 34 a temporary stop state, when the determination part 52 is performing said determination.

  On the other hand, when the toner sensor 31T outputs V2, the determination unit 52 determines that the replenishment toner TZ is not sufficiently present in the vicinity of the toner discharge port 319. In this case, sufficient toner T2 cannot be discharged from the toner discharge port 319. This state is a state in which the toner T2 has been dispensed from the state of FIG. 8 and the replenishment toner TZ existing around the toner discharge port 319 has been consumed. If it determines with this state, the moving wall control part 51 will drive the motor M, and will move the moving wall 34 to the left (downstream side) only the predetermined distance. As a result, the replenishing toner TZ in the container main body 31 (accommodating space 313) is pressed by the conveying surface 340S of the moving wall 34 and conveyed leftward. Then, the periphery of the toner discharge port 319 is again filled with the replenishing toner.

  When the toner sensor 31T outputs V3 (a predetermined output indicating that the detection piece has been detected) is generated, the determination unit 52 determines that the toner in the toner container 30 is not present. Thus, the position of the moving wall 34 at which the detection piece 40 is detected by the toner sensor 31T is the final position at the left end. At this time, the storage space 313 is minimized, and the replenishment toner TZ hardly exists in the container main body 31. That is, the determination unit 52 identifies whether or not the moving wall 34 has reached the final position based on whether or not the detection piece 40 has been detected by the toner sensor 31T. It is determined that the toner container 30 is in a toner empty state.

  The moving wall control unit 51 permanently stops the moving wall 34 after V3 is output. This is because the state in which the toner sensor 31T outputs V3 indicates that only the vicinity of the toner discharge port 319 is not in a state of running out of toner, and a state in which the replenishment toner TZ does not substantially exist in the container main body 31 is reached. . Moreover, since the moving wall 34 interferes with the container main body 31, it has reached the state which cannot move to the left any more. In the toner replenishing device according to the comparative example in which the detection piece 40 does not exist, the toner is still left in the container main body 31 and the moving wall 34 may be moved. Cannot be determined deterministically based on the output of the toner sensor 31T.

  9A to 9C are cross-sectional views showing how the moving wall 34 including the detection piece 40 according to the first embodiment moves toward the arrangement position of the toner sensor 31T. FIG. 9A shows a state where the moving wall 34 exists at a position P1 where the detection piece 40 has not yet entered the detection area of the toner sensor 31T. FIG. 9B shows a state where the moving wall 34 exists at a position P2 where a part of the front end side of the detection piece 40 has entered the detection area. FIG. 9C shows a state where the moving wall 34 exists at the position P3 where the entire detection piece 40 has entered the detection area. This state of the position P3 is a state in which the replenishing toner TZ in the toner container 30 is substantially empty.

  FIG. 10 is a graph showing an example of the output of the toner sensor 31T in the state of the positions P1 to P3. Here, the amount of toner detected is not considered. FIG. 10A shows a sensor output when a digital output type sensor is used as the toner sensor 31T. The toner sensor 31T has a predetermined threshold, and outputs a Low signal below the threshold and a Hi signal above the threshold. In this case, when the moving wall 34 exists at the positions P1 and P2, the sensor output becomes Low, and when it exists at the position P3, it becomes a Hi signal. The threshold is set so that such an output can be obtained. According to this output example, when the Hi signal is obtained, it can be determined that the moving wall 34 has reached the final position.

  FIG. 10B shows a sensor output when an analog output type sensor is used as the toner sensor 31T. The sensor output is Low when the moving wall 34 is present at the position P1, and a Hi signal is obtained when the moving wall 34 is present at the position P3, which is the same as the output example of FIG. On the other hand, the sensor output gradually increases during an intermediate position including the position P2 and after the part of the detection piece 40 starts to enter the detection area until the moving wall 34 reaches the final position. According to this output example, when the Hi signal is obtained, it can be determined that the moving wall 34 has reached the final position, and the moving wall 34 is in accordance with the height of the output value between the intermediate positions. Can be monitored. The monitor makes it possible to know a so-called near-end state in which almost no toner remains in the toner container 30.

  FIGS. 11A to 11C illustrate a toner container 30A including a moving wall 34A on which the detection piece 41 according to the second embodiment is mounted. The moving wall 34A moves toward the arrangement position of the toner sensor 31T. It is sectional drawing which shows a mode to do. The detection piece 41 has a shape with different areas per unit length in a side view in the left-right direction. Specifically, the detection piece 41 includes a sharp tip portion 411 and a wide base end portion 412, and has a right triangle shape (a cross-sectional shape in the depth direction is constant) when viewed from the side. The base end portion 412 is attached to the transport surface 340S of the moving wall 34A, and the distal end portion 411 side protrudes leftward from the transport surface 340S.

  FIG. 11A shows a state in which the moving wall 34A exists at a position P11 immediately before the leading end 411 of the detection piece 41 enters the detection area of the toner sensor 31T. FIG. 11B shows a state in which a moving wall 34A exists at a position P12 where a part including the tip 411 of the detection piece 41 has entered the detection area. FIG. 11C shows a state in which a moving wall 34A exists at a position P13 where almost the entire detection piece 41 has entered the detection area. This state of the position P13 is a state in which the moving wall 34A has advanced to the final position, and the replenished toner TZ in the toner container 30A is substantially empty.

  FIG. 12 is a graph showing an example of the output of the toner sensor 31T in the state of the positions P11 to P13. Here, the amount of toner detected is not considered. The graph of FIG. 12 shows the sensor output when an analog output type sensor is used as the toner sensor 31T. In the case of the digital output type, the output is substantially the same as the graph of FIG.

  As shown in FIG. 12, when the moving wall 34A exists at the position P11, the sensor output is Low, and thereafter the output gradually increases. At the position P12, the sensor output is about halfway between Hi and Low. When the moving wall 34A exists at the position P13, a Hi signal is generated. According to the detection piece 41 of 2nd Embodiment, since the shape differs in the left-right direction, a sensor output can also change according to the said shape. Therefore, the position of the moving wall 34A on the shaft 33 can be grasped with higher resolution.

  FIGS. 13A to 13D show a toner container 30B having a moving wall 34B on which the detection piece 42 according to the third embodiment is mounted, and the moving wall 34B moves toward the arrangement position of the toner sensor 31T. It is sectional drawing which shows a mode to do. The detection piece 42 also has a shape with different areas per unit length in a side view in the left-right direction. However, unlike the second embodiment, the detection piece 42 has a shape divided in the left-right direction, thereby constructing shapes having different areas.

  The detection piece 42 includes a first detection area 421 on the downstream side, a second detection area 422 on the upstream side, and a non-detection area disposed between the first detection area 421 and the second detection area 422 in the left-right direction. 423. The first detection region 421 and the second detection region 422 are portions formed of a magnetic material, and the non-detection region 423 is a portion formed of a non-magnetic material, that is, a portion that is not a detection target of the toner sensor 31T. The right end surface of the second detection region 422 is attached to the transport surface 340S of the moving wall 34B, and the first detection region 421 side protrudes leftward from the transport surface 340S.

  FIG. 13A shows a state in which the moving wall 34B exists at a position P21 where the detection piece 42 has not yet entered the detection area of the toner sensor 31T. FIG. 13B shows a state where the moving wall 34B exists at the position P22 where the first detection area 421 of the detection piece 42 has entered the detection area. 13C shows the position P23 where the non-detection area 423 has entered the detection area, and FIG. 13D shows the position P24 where the second detection area 422 has entered the detection area. It shows the existing state. The state of the position P24 is a state in which the moving wall 34B has advanced to the final position, and the replenishment toner TZ in the toner container 30B is substantially empty.

  FIG. 14 is a graph showing an example of the output of the toner sensor 31T in the state of the positions P21 to P24. When the moving wall 34B is at the position P21, the sensor output is Low. On the other hand, at the position P22 or the position P24 where the first detection area 421 or the second detection area 422 faces the toner sensor 31T, the sensor output becomes Hi. On the other hand, at the position P23 where the non-detection region 423 faces the toner sensor 31T, the sensor output is about halfway between Hi and Low, depending on the length of the non-detection region 423 in the horizontal direction. If the length in the left-right direction of the non-detection area 423 is set longer than the left-right width of the detection area of the toner sensor 31T, it may be difficult to distinguish the sensor output from the position P21 and the position P23. For this reason, it is desirable to set the length in the left-right direction of the non-detection region 423 to a length that does not cover the entire width of the detection area of the toner sensor 31T.

  According to the detection piece 43 of the third embodiment, since the non-detection region 423 is disposed between the first detection region 421 and the second detection region 422, the toner sensor 31T is moved along with the movement of the moving wall 34B. There is a clear difference in output. That is, a trough portion of the output characteristic occurs at a position P23 slightly before the moving wall 34B reaches the final position (position P24). Therefore, the near-end state can be clearly identified by detecting this valley.

  Next, the operation of the toner replenishing device 300 when the toner container 30 of the first embodiment is used will be described. FIG. 15 is a flowchart showing the processing of the control unit 50. FIGS. 16A to 16D and FIGS. 17A to 17C are schematic cross-sectional views showing the moving state of the moving wall 34 and the state of the replenishing toner TZ, respectively. Here, as exemplified above, the toner sensor 31T has a voltage V1 = 0.75V (first value) when toner is detected, and a voltage V2 = 0.35V when toner is not detected. (Third value) When the detection piece 40 is detected, a sensor output of voltage V3 = 1.2 V (second value) is generated. It is assumed that the first threshold value for determining the presence / absence of toner detection is set to 0.5V, and the second threshold value for determining the presence / absence of detection of the detection piece 40 is set to 1.0V.

  Beginning with the setting of the toner container 30 in which the replenishment toner TZ is fully stored in the internal space 107 (FIG. 2) of the casing 101, the control unit 50 (FIG. 8) starts processing. FIG. 16A shows the toner container 30 in “State 1” immediately after being set in the internal space 107. The moving wall 34 is located at the right end of the shaft 33. Of course, the periphery of the toner discharge port 319 is filled with the replenishing toner TZ.

  The determination unit 52 of the control unit 50 acquires the sensor output from the toner sensor 31T at every predetermined sampling period. The determination unit 52 determines whether the sensor output exceeds the first threshold value of 0.5 V for each sampling period (step S1). If there is a sufficient amount of toner in the detection area of the toner sensor 31T, the sensor output is 0.75 V, so a YES determination is made in step S1. In the above “state 1”, a YES determination is made. On the other hand, if no toner is present, the sensor output = 0.35V, so a NO determination is made in step S1.

  When the sensor output exceeds 0.5V (YES in step S1), the determination unit 52 subsequently determines whether or not the sensor output exceeds 1.0V that is the second threshold (step S2). ). Since the sensor output = 1.2V when the toner sensor 31T is detecting the detection piece 40, a YES determination is made in step S2. In other states, a NO determination is made in step S2, and a “NO” determination is also made in “state 1” described above.

  FIG. 16B shows “state 2” in which the supply toner TZ from the “state 1” has been supplied to the developing device 20 and the supply toner TZ around the toner discharge port 319 has decreased. In this case, a NO determination is made in step S1. In response to this, the moving wall control unit 51 drives the motor M to rotate the shaft 33 by a predetermined amount of rotation, and moves the moving wall 34 to the left by a predetermined distance (step S3). FIG. 16C shows “state 3” after the moving wall 34 has moved by a predetermined distance. By the movement of the moving wall 34, the replenishment toner TZ is pushed to the left, and the periphery of the toner discharge port 319 returns to a toner rich state. Accordingly, when “state 3” is reached, step S1 is YES.

  FIG. 16D shows “state 4” in which the supply toner TZ from the “state 3” has been supplied to the developing device 20 and the supply toner TZ around the toner discharge port 319 has decreased again. When “state 4” is reached, step S1 returns to NO determination again. Therefore, the moving wall controller 51 moves the moving wall 34 further to the left by a predetermined distance (step S3). FIG. 17A shows “state 5” after the moving wall 34 has further moved by a predetermined distance. In “State 5”, the periphery of the toner discharge port 319 returns to a toner-rich state, and Step S1 is YES.

  FIG. 17B shows “state 6” in which the supply toner TZ from the “state 5” has been supplied to the developing device 20 and the supply toner TZ around the toner discharge port 319 has decreased again. When “state 6” is reached, step S1 is again NO, and the moving wall control unit 51 moves the moving wall 34 further to the left by a predetermined distance. As a result, as shown in FIG. 17C, a “state 7” in which the moving wall 34 moves to the final position is reached. In “state 7”, the replenishment toner TZ hardly remains in the container main body 31. Here, an example is shown in which the moving wall 34 is moved to the left in units of approximately 1/3 length of the shaft 33. However, the moving wall 34 may be moved in finer units.

  In “State 7”, the detection piece 40 enters the detection area of the toner sensor 31T. Accordingly, a YES determination is made at step S2. In this case, the determination unit 52 determines that the toner container 30 is in the “no toner” state (step S4). Then, the control unit 50 uses a display panel or a display lamp (not shown) provided in the printer 100 to display to the user that the toner is empty (step S5). Thereafter, the control unit 50 stops the operation of the printer 100.

  FIG. 18 is a graph showing the sensor output in each of “State 1” to “State 7” described above. During “state 1” to “state 6”, the sensor output repeatedly exceeds and does not reach 0.5 V, which is the first threshold, while it does not exceed 1.0 V, which is the second threshold. During this time, in “State 1”, “State 3”, and “State 5” in which the sensor output exceeds 0.5V, the moving wall 34 is temporarily stopped, and “State 2” and “State” in which the sensor output is less than 0.5V. In “4” and “state 6”, the moving wall 34 is moved to the downstream side by a predetermined distance (approximately 1/3 length of the shaft 33). Therefore, a state in which the periphery of the toner discharge port 319 is filled with toner can be formed in a timely manner.

  On the other hand, when shifting from “state 6” to “state 7”, the sensor output exceeds the second threshold value of 1.0V. This means that the toner sensor 31T has detected that the moving wall 34 has reached the final position near the toner discharge port 319. The presence of the moving wall 34 at the final position means that the toner in the toner container 30 is in an empty state. Therefore, according to the toner replenishing device 300 of the present embodiment, it can be reliably determined that the toner is empty based on the output of the toner sensor 31T. Incidentally, if the detection piece 40 is not provided on the moving wall 34, the sensor output in “state 7” is 0.75V, or 0.35V when no toner remains, and “state 1” to “state” 6 ”is indistinguishable. On the other hand, in the present embodiment, since the detection piece 40 exists, the sensor output = 1.2V can be obtained in “state 7”, so that it can be clearly distinguished from “state 1” to “state 6”. it can.

  The toner container 30 and the printer 100 including the toner container 30 according to the embodiment of the present invention have been described above, but the present invention is not limited to this. The present invention can employ the following modified embodiments, for example.

  (1) In the above-described embodiment, the example in which the detection piece 40 is attached to the moving wall 34 in a state of protruding from the conveyance surface 340 </ b> S of the moving wall 34 to the downstream side is shown. Instead of this, the detection piece 40 may be mounted so as to be embedded in the moving wall 34. In this case, the moving wall 34 can be moved to the vicinity of the left end wall of the container main body 31 by the amount that the detection piece 40 does not protrude, and the remaining toner can be reduced. Further, there is an advantage that the toner discharge port 319 can be closed by the moving wall 34.

  (2) In the above embodiment, the detection piece 40 is a magnetic material, and the toner sensor 31T is a magnetic permeability sensor. This combination is an example, and the present invention is not limited to this. For example, a combination sensing system that measures an electric quantity such as capacitance or inductance, an optical sensing system, or a combination sensing system that performs wireless measurement such as an IC tag can be applied. Or you may apply a mechanical sensing system, such as arrange | positioning the member which interferes with the moving wall 34 inside the container main body 31 inside.

1 Printer (image forming device)
121 Photosensitive drum (image carrier)
126 Transfer roller (transfer section)
20 Developing Device 25 Toner Supply Port 30 Toner Container (Developer Container)
300 Toner supply device (Developer supply device)
31 Container body (container body)
31T Toner sensor (sensor)
319 Toner outlet (developer outlet)
33 Shaft (Shaft)
34 Moving wall 340S Conveying surface 40, 41, 42 Detection piece 50 Control unit 51 Moving wall control unit (control arm)
52 Judgment part

Claims (7)

A developer container for containing the developer;
A sensor that detects a predetermined detection target and generates an electrical output;
A determination unit for determining the presence or absence of the developer in the developer container based on the output of the sensor,
The developer container is
A container body having a wall defining an internal space;
A shaft portion arranged to extend in the first direction in the internal space;
A moving wall that moves from the upstream side to the downstream side in the first direction along the shaft portion in the internal space and conveys the developer;
A developer discharge port disposed near the downstream end of the container body in the first direction and passing through the wall to communicate the internal space with the outside;
A detection piece mounted on the moving wall and serving as the detection target of the sensor,
The sensor is a sensor capable of detecting a physical quantity common to the developer and the detection piece, and is disposed at a position where the detection piece can be detected when the moving wall approaches the developer discharge port. ,
The developer replenishing device, wherein the determination unit determines that there is no developer in the developer container when the sensor generates a predetermined output indicating that the detection piece has been detected. . The developer supply device according to claim 1 ,
The developer is a magnetic toner containing a magnetic component, the sensor is a sensor for detecting magnetism, the detection piece is made of a magnetic material,
The developer supply device, wherein the sensor outputs a predetermined first value when the magnetic toner is detected, and outputs a second value higher than the first value when the detection piece is detected. The developer replenishing device according to claim 2 ,
A control unit for controlling the movement of the moving wall;
The sensor outputs a third value lower than the first value when the magnetic toner is not detected;
The controller is
When the sensor is outputting the first value, the moving wall is temporarily stopped,
When the sensor outputs the third value, the moving wall is moved by a predetermined amount downstream in the first direction,
After the sensor outputs the second value, the developer replenishing device that permanently stops the moving wall. The developer replenishing device according to any one of claims 1 to 3 ,
The moving wall includes a conveyance surface perpendicular to the shaft portion on a surface facing the downstream side in the first direction,
The developer replenishing device, wherein the detection piece is attached to the moving wall in a state of protruding from the transport surface to the downstream side. The developer supply device according to any one of claims 1 to 4 ,
The developer replenishing device, wherein the detection piece has a shape having different areas per unit length in the first direction. The developer supply device according to claim 5 , wherein
The detection piece includes a first detection area on the downstream side and a second detection area on the upstream side in the first direction,
A developer replenishing device, wherein a non-detection region that is not a detection target of the sensor is disposed between the first detection region and the second detection region. A developer replenishing device according to any one of claims 1 to 6 ,
An image carrier carrying an electrostatic latent image and a developer image;
A developing device that replenishes the developer from the developer replenishing device and supplies the developer to the image carrier;
A transfer unit for transferring the developer image from the image carrier to a sheet;
An image forming apparatus comprising: