JP6676314B2 - Developer container, developing device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to a technology for detecting a developer amount using capacitance.

  Many electrophotographic image forming apparatuses are provided with a toner remaining amount detecting unit for notifying a user when a developer (hereinafter, referred to as toner) is consumed. As one method of the toner remaining amount detecting means, there is a method of detecting a change in capacitance between a plurality of electrodes arranged in a developer container and detecting a toner amount. The general configuration of these electrodes is to detect a capacitance by arranging a pair of electrode plates as the other electrode at a predetermined interval from the developer carrying member as an electrode.

  Further, a method of comparing with a comparison circuit has been proposed to improve the accuracy of detecting the remaining amount of toner. There is also proposed a method in which a comparison circuit is provided and a stirring period is further taken into account (Patent Document 1).

  However, these devices for detecting the remaining amount of toner are expensive, and further cost reduction is required. Therefore, the cost is reduced by using a metal electrode plate as a resin sheet (Patent Document 2).

JP 2007-264612 A JP 2015-087743 A

  However, when the resin sheet is formed into a container and used, there is a possibility that the resin sheet may be peeled off from the container by rubbing with a stirring member or the like.

Therefore, the present invention
A developing frame housing the developer;
A stirring member rotatably supported by the developing frame and stirring the developer,
Together is attached to the developing frame, the first surface and contactable disposed and the stirring member and the agitating member when the rotating facing said agitating member, and the first surface in the front and back relationship And a conductive resin sheet for detecting the amount of the developer using the capacitance.
The first surface has a first side extending in the first direction along the axial direction of the rotary shaft of the agitating member, extending in a second direction crossing the first direction, and, upstream of the rotational direction of the agitating member A second side intersecting with the first side on the side, and a curved portion is formed at a portion where the first side intersects with the second side,
When viewed from the axial direction of the rotation axis of the stirring member, the conductive resin sheet has an end surface located on the upstream side in the rotation direction of the stirring member and connecting the first surface and the second surface,
The end surface and the second surface form an acute angle, and provide a developer container embedded in the inner wall of the developing frame.

  Further, the present invention provides a developing device, a process cartridge, and an image forming apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, it can reduce that a resin sheet peels from a container by rubbing with a stirring member etc.

FIG. 3 is an enlarged cross-sectional view around the antenna member 14 according to the first embodiment. FIG. 1 is a schematic configuration diagram of an image forming apparatus having a developing device according to a first embodiment. FIG. 2 is a schematic sectional view of a configuration of a remaining toner amount detecting unit 17 according to the first embodiment. FIG. 11 is an enlarged view of the vicinity of an antenna member 14 according to the second embodiment. (A, b) is Ri FIG der showing an outline of a shape of the end portion of the resin sheet of Example 3, (c) is a diagram showing the outline of the shape of the end portion of the resin sheet of Reference Example Oh Ru.

  Embodiments for carrying out the present invention will be illustratively described in detail below based on embodiments with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. That is, the scope of the present invention is not intended to be limited to the following embodiments.

  Further, in the present specification, a developer container refers to a container containing a developer. The developing device refers to a device having a developer carrying member that carries at least the developer. The process cartridge is a cartridge having at least an image carrier. An image forming apparatus is an apparatus that forms an image on a recording material.

<Description of Image Forming Apparatus and Image Forming Process>
FIG. 2 shows a schematic configuration of an electrophotographic laser beam printer which is an embodiment of the image forming apparatus of the present invention.

  The image forming apparatus 12 using the electrophotographic technology of the present embodiment includes a drum-shaped electrophotographic photosensitive member (hereinafter, referred to as “photosensitive drum”) 1 as an image carrier. Around the photosensitive drum 1, a charging roller 2, an exposure device 6, a developing device 3, a transfer roller 4, and a cleaning device 5 are arranged in this order along the rotation direction of the photosensitive drum 1. Further, a fixing device 7 is disposed downstream of the transfer nip N formed between the photosensitive drum 1 and the transfer roller 4 as a transfer unit in the recording material conveyance direction.

<Detailed description of image forming apparatus>
In this embodiment, the photosensitive drum 1 has an OPC photosensitive layer on a drum substrate made of aluminum, and is driven in a direction indicated by an arrow at a predetermined peripheral speed by a driving means (not shown) provided on the main body of the image forming apparatus. (Clockwise).

  A charging roller 2 as a charging unit uniformly charges the photosensitive drum 1 to a predetermined polarity and potential by a charging bias applied from a charging bias power supply (not shown). As the charging bias, an AC voltage Vpp at which the charging roller 2 sufficiently discharges is applied at 1.6 kV, and a DC voltage Vdc corresponding to the dark portion potential Vd on the photosensitive drum is superposed and applied at -560 V. The frequency at this time was 1600 Hz. The AC component of the charging bias performs constant current control such that a constant current always flows between the photosensitive drum 1 and the charging roller 2.

  The exposure device 6 converts image information input from a personal computer (not shown) or the like into a time-series electric digital image signal by a video controller (not shown). A laser beam (exposure beam L) modulated according to the converted time-series electric digital image signal is output from a laser output unit (not shown). The exposure beam L scans and exposes the charged surface of the photosensitive drum 1 to form an electrostatic latent image corresponding to image information on the surface of the photosensitive drum. In the present embodiment, the exposure beam L was applied such that the bright portion potential Vl on the photosensitive drum became -130V.

  The developing device 3, the developing voltage applying unit 15, and the developer remaining amount detecting unit (toner remaining amount detecting unit) 17 will be described later in detail.

  The transfer roller 4 as a transfer unit contacts the surface of the photosensitive drum 1 with a predetermined pressing force to form a transfer nip N, and a transfer bias is applied from a transfer bias power supply (not shown). With this transfer bias, a developer image (toner image) on the surface of the photosensitive drum 1 is transferred onto a recording material P such as paper at a transfer nip portion N between the photosensitive drum 1 and the transfer roller 4.

  The fixing device 7 has a heating roller and a pressure roller having a halogen heater (not shown) therein. The toner image transferred to the surface of the recording material P is heated, melted, pressed and thermally fixed while the recording material P is nipped and conveyed by a fixing nip between the fixing roller and the pressure roller. Fix it. The recording material P on which the fixed image is fixed is discharged out of the image forming apparatus 12.

  The cleaning blade 5a as a cleaning unit cleans the developer remaining without being transferred onto the photosensitive drum 1, and the photosensitive drum 1 is again used for image formation.

  In the present embodiment, the photosensitive drum 1, the charging roller 2, the developing device 3, and the cleaning blade 5a are integrally unitized to form a process cartridge 13 that is detachable from the image forming apparatus main body.

<Details of developing device>
The details of the developing device 3 will be described with reference to FIG. The developing device 3 includes a developing container 3a that stores a developer (hereinafter, referred to as toner T) and a stirring member 10 having a sheet member 10b that stirs the toner T. The image forming apparatus further includes a developing sleeve 8 as a developer carrier, a magnet roller 8a, a developing blade 11 for regulating a layer thickness of the toner T, and an antenna member 14 for detecting a remaining amount of the developer (hereinafter, referred to as a remaining toner amount). .

  In the present embodiment, the toner T uses a magnetic one-component toner having an average particle diameter of 7 μm, but can be applied to a non-magnetic toner and a two-component toner.

  The stirring member 10 includes a support rod 10a and a sheet member 10b (hereinafter, referred to as a stirring sheet). The support rod 10a is a rotating member, and both ends are supported by the developing container 3a. The center of the support rod 10a is the rotation axis 10c. As shown in FIG. 3, the stirring member rotates clockwise. In this embodiment, one rotation is performed in about one second. As the stirring sheet, a PPS sheet (polyphenylene sulfide sheet) having a thickness of 100 μm was used, and one of the ends in the short direction was pressure-bonded to the support rod. The other end of the stirring sheet in the short direction becomes a free end, and comes into contact with the wall surface of the developing container 3a as the stirring member rotates. The longitudinal width of the stirring sheet was 210 mm.

  Further, the stirring member has a sheet-shaped sealing member 10d that is sealed in the container so that the toner T does not leak from the container. In FIG. 3, one end of a sealing member 10d, which is a sheet, is fixed to the support rod 10a, and the other end of the sealing member 10d seals the opening in the developing container, thereby closing the toner T in the container. With the rotation of the stirring member when the developing device is used, the sealing member 10d is wound around the support rod 10a, and the opening is opened. When the opening is opened, the toner T is supplied to the developing sleeve 8, and image formation is started.

  As the developing sleeve 8 as a developer carrier, a non-magnetic aluminum sleeve whose surface is coated with a medium-resistance resin layer is used. The arrangement is at a position facing the surface of the photosensitive drum 1, and both ends of the developing sleeve are rotatably supported by a developing frame having an opening of the developing device 3. The developing frame is formed by a first frame and a second frame. The developing sleeve is connected to a developing voltage applying unit 15 arranged in the image forming apparatus main body, and applies a developing bias at a predetermined timing during printing. In the present embodiment, the DC voltage is set to Vdc = −400 V during printing, the Vpp of the AC voltage is Vpp = 1400 V, and a rectangular wave having a frequency of 2000 Hz is applied.

  A magnet roller 8a as a magnetic field generating means is provided in the developing sleeve 8, and a plurality of magnetic poles N and S are alternately formed. Further, since the magnetic pole is always kept at a fixed position without performing the rotation operation, the magnetic pole is always kept in the same direction.

  The developing blade 11 has a urethane rubber blade adhered and fixed to a supporting metal plate. The supporting metal plate is fixed to the developing container 3a so as to contact the developing sleeve 8 with an appropriate contact pressure in order to appropriately regulate the layer thickness of the toner T and to perform triboelectric charging.

  In order to prevent leakage of the toner during transportation or the like, a seal member is adhered to the inside of the developing container 3a so that the toner T does not leak from the area in the drawing.

  A resin sheet 14c is used for the antenna member 14 as an electrode disposed on the bottom surface of the inner wall of the developing container 3a. This makes it possible to reduce the cost as compared with the conventional SUS plate. In the present embodiment, a conductive resin sheet 14c in which conductivity is ensured by dispersing a conductive carbon material in a polystyrene resin (hereinafter, referred to as a PS resin) was used. When a magnetic toner is used, the conductive toner sheet 14c is preferably a nonmagnetic conductive resin sheet having flexibility. As the carbon material, carbon black, carbon fiber, graphite and the like can be used. In addition, the resin may be an acetyl vinyl acetate (EVA) resin, instead of the PS resin. The EVA resin is not compatible with the HIPS resin used for the frame (developing container), but can be bonded and fixed because it has adhesiveness. Naturally, a material having compatibility may be used, and generally a combination of the same material. However, there is a combination of compatible materials even if the materials are not the same. For example, for PS (including HIPS) which is a non-crystalline resin of the frame material, ABS and PPO which are also non-crystalline resins are exemplified.

  The shape of the resin sheet was a 216 mm × 15 mm rectangular sheet having a thickness of 400 μm. The longitudinal direction of the 216 mm resin sheet is parallel to the longitudinal direction of the developing sleeve. As a method for fixing the antenna member 14, a so-called insert molding method is used in which the conductive resin sheet 14c is fixedly contacted with the mold when the frame of the developing container is molded, and then the resin is injected and molded integrally. Both the antenna member 14 and the frame 3a are made of PS resin. For this reason, by being compatible at the time of insert molding, it is possible to bond and fix all the contact surfaces between the frame (developing container 3a) and the antenna member, including the side surfaces of the antenna member 14.

  In the present invention, the cost can be reduced by replacing the electrode with a resin sheet from a SUS plate. In addition, by using a non-magnetic resin sheet for the electrode plate, even when magnetic toner is used, the amount of toner attached to the electrode plate is reduced, and the accuracy of remaining toner detection can be reduced. The resin sheet is preferably attached to the inner wall in the developing container so as not to hinder the conveyance and circulation of the toner.

  Further, the developing container is provided with a stirring member for transporting the toner. The stirring member has a rotation axis parallel to the developer carrying member, and conveys toner by rotating a flexible stirring sheet. Furthermore, by rotating the stirring sheet while contacting the inner wall of the developing container, the toner in the developing container can be conveyed without leaving the toner as much as possible. Therefore, the tip of the stirring sheet contacts the resin sheet when stirring. In this embodiment, since the resin sheet is buried in the frame, the surface of the resin sheet on the side of the stirring member comes into contact with the stirring member. In this embodiment, the resin sheet surface on the stirring member side is formally referred to as a first surface 14a, and the resin sheet surface on the opposite side is referred to as a second surface 14b.

  With the configuration described above, the toner T near the developing sleeve 8 is supplied to the surface of the developing sleeve 8 by the magnetic field of the magnet roller 8a. Thereafter, the layer thickness of the toner T on the surface of the developing sleeve 8 is optimized by the developing blade 11, and the toner T is charged by frictional charging. The charged toner T develops the electrostatic latent image on the photosensitive drum 1 into a toner image in the developing area 31.

  Until now, detection of the remaining amount of toner in the developing device has been described, but the present invention can also be applied to a developer container containing a developer if only the detection of the amount of developer is used. . In this case, the container has no developing sleeve, which is a developer carrying member. For this reason, an electrode paired with the antenna member which is an electrode in this embodiment is separately required. Further, the present invention can be applied not only to the detection of the remaining amount of toner but also to an apparatus for detecting the amount of toner such as a detection of a full state of waste toner.

<Description of a developer remaining amount (toner remaining amount) detecting unit>
Next, referring to FIG. 3, a description will be given of the toner remaining amount detecting means 17 using a change in the capacitance value used in the present embodiment.

  In this embodiment, the toner remaining amount detecting means 17 includes a developing voltage applying means 15 for applying a bias to the electrodes, the developing sleeve 8 as an electrode, the antenna member 14 as a pair of opposed electrodes, and a developing remaining amount detecting means. It comprises a device 18. The remaining developing amount detecting device is hereinafter referred to as a remaining toner detecting device.

  The conductive resin sheet 14c as the antenna member 14 is disposed so as to be in contact with a contact (not shown) disposed in front of the bottom surface of the developing container 3a on the paper surface, and passes through a toner remaining amount detecting device 18 disposed in the image forming apparatus. Connected to earth.

  In the above configuration, when a bias is applied to the developing sleeve 8 by the developing voltage applying unit 15, the capacitance between the developing sleeve 8 and the antenna member 14 can be detected by the remaining toner amount detecting device 18. At this time, since the relative dielectric constant of the toner is higher than the relative dielectric constant of air, the detected capacitance increases as the amount of toner existing between the electrodes increases.

  This can be expressed by an area S of the antenna member 14, an interval d between the antennas, and a relational expression C = εS / d of the dielectric constant ε. Here, since the area S of the antenna member 14 and the distance d between the antennas are usually constant, a change in the amount of toner between the antennas changes the dielectric constant between the antennas, and as a result, the capacitance changes.

  Since the value of the capacitance changes as the toner moves as the stirring member 10 rotates, the remaining amount is detected by averaging the output values for one rotation of the stirring member.

<Shape of conductive resin sheet>
In this embodiment, the tip of the stirring sheet 10b of the stirring member 10 is configured to contact the conductive resin sheet 14c as the antenna member 14. Thus, even when the remaining amount of toner is low, the toner on the antenna member 14 can be conveyed to the vicinity of the developing sleeve (developing sleeve side). Further, since the conductive resin sheet 14c extends along the axial direction of the stirring member, the axial direction is the longitudinal direction. On the other hand, the rotation direction and the direction intersecting with the axis are short sides of the conductive resin sheet, and are defined as short sides. Further, since the toner does not remain unevenly on the antenna member 14, the configuration is advantageous also in the accuracy of the remaining toner detection. As described above, in this embodiment, the stirring sheet is brought into contact with the entire surface 14 a of the antenna member 14 facing the stirring shaft from the upstream end to the downstream end in the short direction.

  Here, when the conductive resin sheet 14c as the electrode plate is fixed to the inner wall in the developing container, and the flexible stirring sheet as the stirring member contacts the conductive resin sheet 14c at a part of rotation, a new Issues may arise.

  When the image forming apparatus is used for a long time, the number of times that the stirring sheet comes into contact with the conductive resin sheet 14c as the antenna member 14 increases, so that the conductive resin sheet 14c may be peeled off from the frame or the container, or the sheet itself may be damaged. There is a risk of getting it. This is because the conductive resin sheet 14c has a side surface located on the upstream side in the rotation direction of the stirring member, and one end of the stirring sheet rotates and repeats contact with the side surface of the conductive resin sheet 14c. For this reason, stress is applied to the upstream side surface of the conductive resin sheet 14c.

  If the conductive resin sheet 14c as the antenna member 14 comes off, the distance d between the antennas changes. Therefore, the capacitance changes due to a factor other than the change in the amount of toner between the antennas, and it becomes impossible to accurately detect the amount of toner.

  In addition, if the conductive resin sheet 14c is bent or broken, the area S as an antenna is reduced, so that the capacitance C is reduced even with the same remaining amount of toner.

  Therefore, in the present embodiment, the conductive resin sheet 14c located at least on the upstream side in the rotation direction of the stirring member 10 has an acute angle portion 14d having an acute angle. Then, peeling and breakage are reduced by insert molding so that the tip 14e side of the acute angle portion 14d is embedded in the frame.

  The shape of the conductive resin sheet 14c which is a feature of the present invention will be described with reference to FIG.

  FIG. 1A is an enlarged sectional view of the conductive resin sheet 14c. The stirring sheet 10b rotates so as to contact the conductive resin sheet 14c. FIG. 1B is an enlarged view of an end portion of the conductive resin sheet 14c. Here, an acute-angled acute portion 14d is provided at the end of the conductive resin sheet 14c, and the tip 14e on the acute angle side is integrally molded so as to be embedded in the container. The conductive resin sheet of the present embodiment has a trapezoidal cross section as shown in FIG. 1A, and has an acute angle portion at the end of the trapezoidal shape. In this embodiment, a resin sheet having an angle θ of 70 ° is used for the tip 14e of the acute angle portion 14d. For this reason, the lower side of the trapezoid on the acute angle side is longer than the upper side of the trapezoid on the obtuse angle side of the conductive resin sheet, and in this embodiment, the lower side is set to 145 μm. The acute angle portion protrudes upstream in the rotation direction of the stirring member 10. The upper side of the trapezoidal shape is the side in contact with the stirring sheet, and the lower side of the trapezoidal shape is buried in the frame constituting the container. Depending on the configuration, the lower side may be exposed to the outside of the container.

  By adopting such a shape, it is possible to protect the acute angle portion tip 14e, which is the most protruding portion, which is easy to peel off, by covering it with the container frame. Furthermore, since the resin constituting the frame is molded so as to cover the conductive resin sheet 14c in the peeling direction of the conductive resin sheet 14c, that is, the inner surface direction of the container, the peeling can be reduced.

  As described above, by performing insert molding so that the acute angle side of the conductive resin sheet 14c is embedded in the container, peeling and breakage of the antenna member 14 can be reduced. Therefore, it is possible to reduce a decrease in the accuracy of detecting the remaining amount of toner due to peeling or breakage of the antenna member 14.

  In the second embodiment, the shape of the longitudinal end of the conductive resin sheet is different from that of the first embodiment. That is, the end of the conductive resin sheet 14c corresponding to the end of the stirring member in the rotation axis direction of the stirring member has the curved surface shape 19.

  This embodiment will be described with reference to an enlarged sectional view of FIG. FIG. 4A is an upper view as viewed from the top of the container, and FIG. 4B is a cross-sectional view as viewed from a cross section of the container perpendicular to the rotation axis of the stirring shaft.

  The material of the conductive resin sheet 14c is PS resin as in Example 1, and the thickness is 400 μm. As in the first embodiment, an acute angled portion 14d is provided at the short end of the conductive resin sheet 14c, and the acute angle side is integrally molded so as to be embedded in the container. Here, the acute angle portion 14d of the conductive resin sheet 14c has a tip 14e having an angle θ of 70 °. The length of the acute angle side is 145 μm as compared with the length of the obtuse angle side, and the upstream side in the rotation direction of the stirring member 10 is used. Protrude.

  The method of fixing the conductive resin sheet 14c to the developing container 3a is the same as in the first embodiment, using insert molding when molding with a mold. A PS resin is used for the developing container 3a, and has compatibility with the PS resin of the antenna member 14, which is an electrode for capacitance.

  In this embodiment, the conductive resin sheet 14c has a curved surface shape 19 having a radius of curvature of 1 mm at the end of the conductive resin sheet 14c located on the upstream side in the rotation direction of the stirring member and at the end of the stirring member 10 in the rotation axis direction. doing. The conductive resin sheet 14c also has a curved surface shape 19 with a radius of curvature of 1 mm at the downstream side in the rotation direction of the stirring member and at the end in the rotation axis direction of the stirring member. By providing the curved surface shape 19, the corners that are the starting points of peeling are not rubbed against the stirring member, so that peeling and breakage of the conductive resin sheet 14c can be reduced. Furthermore, since stress concentration due to sliding friction with the stirring member is reduced, distortion at the corners is less likely to be accumulated, and peeling can be reduced. Therefore, peeling and breakage at the corners of the conductive resin sheet 14c can be reduced as compared with the configuration of the first embodiment.

  As described above, if the end portion of the conductive resin sheet 14c14 has the curved surface shape 19 as in the present embodiment, stress concentration due to rubbing of the stirring member can be reduced, and peeling of the antenna member 14 and Breakage can be reduced. Therefore, it is possible to reduce a decrease in the accuracy of detecting the remaining amount of toner due to the peeling of the antenna member 14.

  The present invention is not limited to the description of the embodiments, and various modifications are possible. These will be described.

(Resin sheet)
In the embodiments described above, the conductive resin sheet 14c has been described, but a resin sheet may be used as long as it can be used for detecting capacitance. In addition, although the resin sheet contains a conductive material and is used as the conductive resin sheet 14c, the resin itself may have conductivity.

  The electric signal from the conductive resin sheet may be transmitted to the outside through the same conductive resin wiring, or a conventional metal wiring may be used. Further, a part of the resin wiring may be extended from the conductive resin sheet, and the wiring may be changed to metal in the middle.

(Arrangement of resin sheet)
In the embodiments described so far, the sharp corners 14d at the ends of the resin sheet are embedded in the frame, but a configuration in which the resin sheet is attached to the frame may be employed. In this case, since the end of the resin sheet has an acute angle, the portion corresponding to the side surface is smaller than the conventional configuration. For this reason, the force (stress) caused by the contact with the stirring sheet is not easily transmitted to the sheet, and the possibility of peeling or breakage is reduced. Further, since the agitating sheet comes into contact with the slope of the acute angle portion 14d immediately after the agitating sheet comes into contact with the resin sheet, it is possible to reduce toner slip-through.

Further, unlike the metal sheet metal, the resin sheet is flexible and can be bent or folded. Therefore, it is also possible to arrange the frame body not only on a flat surface but also on a curved surface. In this case, the resin sheet has a curved surface that follows the curved surface of the container. As a reference example, as shown in FIG. 5C, a container having a curved surface by embedding a resin sheet may be used. The entire resin sheet does not have to have a curved surface, and at least a part of the resin sheet may have a curved surface. For example, when there is a flat surface continuing from a curved surface, a resin sheet may be disposed thereon.

(End shape of resin sheet)
It is preferable that the tip 14e of the resin sheet acute angle portion 14d is located on the second surface 14b side of the resin sheet. It is preferable that the front end 14e is located below (the second surface side) below the center of the resin sheet with respect to the thickness direction of the resin sheet. For example, an acute angle portion 14d as shown in FIGS. 5A and 5B may be used.

  Also, when viewed in a cross section that is a plane perpendicular to the rotation axis of the stirring member, the cross section of the resin sheet is trapezoidal. However, the end of the resin sheet on the downstream side in the rotation direction of the stirring member may be a vertical side surface instead of the trapezoidal shape as shown in FIG. Naturally, as shown in FIG. 1, a trapezoidal shape having acute angles 14d at both ends may be used. In the trapezoidal shape, the short side and the long side are in the height direction of the trapezoid, but the short side is disposed on the side closer to the rotation axis of the stirring member (the stirring member side). On the other hand, the long side of the trapezoid is located farther from the rotation axis of the stirring member than the short side. For this reason, the short side of the trapezoid is disposed at a position in contact with the stirring member in the configurations of the first and second embodiments.

(Other modifications)
The stirring member stirs the inside of the container with a stirring sheet, but may be a screw having a spiral blade or the like on a rotating shaft. The tip of the blade may hit the resin sheet.

  The conventional rubbing is performed by the stirring member. However, since there is a possibility that the sealing member may be peeled off when the sealing member hits the resin sheet, even if the stirring member does not hit the resin sheet, the resin sheet may be exposed to the acute angle portion 14d. Having this has the effect of reducing peeling.

  Further, in the embodiments described above, the configuration in which the resin sheet is used for the developing portion of the process cartridge has been described, but the present invention is not limited to this. A developing device having a configuration in which the photosensitive drum is fixed to the main body of the image forming apparatus and the developing device alone can be attached to and detached from the image forming apparatus can also be provided with a resin sheet. Naturally, the developer container for storing the developer may be configured to be detachable from the image forming apparatus or the developing section, and may have a configuration including a resin sheet and a stirring member.

  Further, in the above-described embodiments, the example in which the resin sheet is used for the electrode used for detecting the remaining amount of the toner used for image formation has been described. However, the toner (waste toner) remaining on the photosensitive drum after the image formation is collected. To waste toner containers. By detecting the amount of waste toner, it is possible to determine whether the waste toner container is full.

3 Developing device (developing means)
3a developing container 8 developing sleeve (developer carrier)
8a Magnet roller 10 Stirring member T Toner

Claims (11)

A developing frame housing the developer;
A stirring member rotatably supported by the developing frame and stirring the developer,
Together is attached to the developing frame, the first surface and contactable disposed and the stirring member and the agitating member when the rotating facing said agitating member, and the first surface in the front and back relationship And a conductive resin sheet for detecting the amount of the developer using the capacitance.
The first surface has a first side extending in the first direction along the axial direction of the rotary shaft of the agitating member, extending in a second direction crossing the first direction, and, upstream of the rotational direction of the agitating member A second side intersecting with the first side on the side, and a curved portion is formed at a portion where the first side intersects with the second side,
When viewed from the axial direction of the rotation axis of the stirring member, the conductive resin sheet has an end surface located on the upstream side in the rotation direction of the stirring member and connecting the first surface and the second surface,
The developer container, wherein the end surface and the second surface form an acute angle and are embedded in an inner wall of the developing frame.   The developer container according to claim 1, wherein the conductive resin sheet has a trapezoidal shape when viewed from an axial direction of a rotation shaft of the stirring member.   The developer container according to claim 1, wherein the conductive resin sheet is embedded in an inner wall of the developing frame by insert molding.   4. The developer container according to claim 1, wherein a resin forming the conductive resin sheet has compatibility or adhesiveness with a resin forming the developing frame. 5. The conductive resin sheet is pre-SL as a first side of the long side, said second side is substantially rectangular with the shorter side, the developer according to claim 1, any one of 4, characterized in that container.   The developer container according to any one of claims 1 to 5, further comprising: a pair of electrodes with the conductive resin sheet as electrodes for detecting a developer amount using the capacitance. .   The developer container according to any one of claims 1 to 6, wherein the stirring member includes a sealing member for sealing an opening of the developing frame. A developer container according to any one of claims 1 to 7,
A developer carrying member provided in the developer container and carrying a developer.   The developing device according to claim 8, wherein the developer carrier is an electrode that forms a pair with the conductive resin sheet as an electrode for detecting a developer amount using the capacitance. An image carrier for carrying a developer image,
A process cartridge comprising: the developer container according to claim 1; and at least one of the developing devices according to claim 8.   An image forming apparatus according to claim 1, further comprising at least one of the developer container according to claim 1, the developing device according to claim 8, and the process cartridge according to claim 10. Forming an image.

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