KR101973316B1 - Method of manufacturing developer container, method of manufacturing developing apparatus, method of manufacturing process cartridge, and method of manufacturing image forming apparatus - Google Patents

Abstract

A first electrode and a second electrode disposed on a surface of the frame and having a surface facing the first electrode, wherein the first electrode and the second electrode And the amount of the developer in the developer accommodating portion is detected based on the electrostatic capacity between the electrodes, characterized in that a conductive resin member constituting the second electrode is formed on a mold configured to mold the frame A step of injecting a resin to be formed in the frame into the mold in which the conductive resin member is held; and a step of curing the resin to form the second And forming the frame on which the electrodes are fixed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer container manufacturing method, a developing apparatus manufacturing method, a process cartridge manufacturing method, and an image forming apparatus manufacturing method, and more particularly to a method, apparatus,

The present invention relates to a developer container manufacturing method, a developer container, a developing apparatus, a process cartridge, and an image forming apparatus used in an image forming apparatus such as a copying machine, a printer, and a facsimile apparatus using an electrophotographic printing method or an electrostatic recording method.

Conventionally, for example, an image forming apparatus using an electrophotographic method is provided with a developing apparatus configured to supply a developer to an electrostatic latent image formed on an electrophotographic photosensitive member (photosensitive member) as an image bearing member to form a developer image. In recent years, development cartridges or process cartridges that include a developing apparatus alone or included with other process means, and which are detachable from the main body of the image forming apparatus are widely used.

According to the cartridge system in which the developing cartridge or the process cartridge (hereinafter also referred to simply as the developing cartridge or the process cartridge) is detachably attached to the apparatus main assembly of the image forming apparatus, the supply of the developer and other maintenance work .

With regard to the cartridge system, in general, when the developer in the developer container of the developing apparatus is removed, an operator such as a user or a service man replaces the cartridge or replenishes the developer, so that the image forming apparatus can form an image again . Therefore, the image forming apparatus of the cartridge type generally has detecting means for detecting the consumption of the developer and detecting the amount (remaining amount) of the developer for notifying the user of the replacement time of the cartridge.

As a type of detecting means, a pair of input side electrodes and output side electrodes are provided as disclosed in Japanese Patent Application Laid-Open No. 2001-117346, and the electrostatic capacity between both electrodes is measured, A capacitance detection method for detecting a capacitance is used. The electrode is an antenna member which is generally a plate-like member (SUS sheet metal or the like) formed of a metal.

Japanese Patent Application Laid-Open No. 2003-248371 discloses a developing device in which an alternating voltage is applied to a developer bearing member, a developer carrying member is used as an input side electrode, and a capacitance detecting member, Another example is provided in a portion opposed to the developer carrying member in the developer accommodating portion. This capacitance detecting member is also generally an antenna member such as a plate-like member (SUS sheet metal or the like) formed of a metal.

The electrostatic capacitance between the electrodes (between the antenna members or between the developer bearing member and the antenna member) in the electrostatic capacitance detection method changes depending on the amount of developer composed of insulating toner or the like. Specifically, when the space between the electrodes is filled with the developer, the electrostatic capacitance between the electrodes becomes large, and as the developer is reduced, the ratio of air occupying the space between the electrodes increases, and the electrostatic capacitance becomes small. Therefore, the relationship between the electrostatic capacity between the electrodes and the amount of the developer can be obtained in advance, and the amount of the developer can be detected by measuring the electrostatic capacity.

However, if an electrode plate such as SUS sheet metal as described above is used as the antenna member, the cost of the component tends to be relatively high. Therefore, if the antenna member is increased or increased in number, for example, in order to improve the detection accuracy of the amount of the developer, or to continuously detect the remaining amount of the developer from the early stage of use, Is likely to increase in price.

Japanese Patent Application Laid-Open No. 2002-40906 discloses a method of fixing an antenna member by attaching an antenna member to a frame forming the developer container of the developing apparatus using a double-sided adhesive tape. Japanese Patent Application Laid-Open No. 2002-40906 discloses a method in which a conductive coating layer or a vapor deposition layer is directly formed on a frame by performing a process such as vapor deposition or printing directly on the frame, But it does not disclose a detailed description of such an alternative.

Japanese Patent Application Laid-Open No. 08-15975 discloses a method of applying a coating solution in which an appropriate amount of carbon black fine particles are dispersed in a mixed solution of a urethane resin and a vinyl chloride resin to a sheet base and thermally curing the applied coating to form an electrode layer Lt; / RTI >

However, as described above, the method of attaching the antenna member to the frame with the double-sided adhesive tape, or forming the antenna member on the frame by vapor deposition or printing is required because of the necessity of the step of machining the frame after forming the frame The manufacturing process is likely to become complicated.

Japanese Patent Application Laid-Open No. 2001-117346 Japanese Patent Application Laid-Open No. 2003-248371 Japanese Patent Application Laid-Open No. 2002-40906 Japanese Patent Application Laid-Open No. 08-15975 Japanese Patent Application Laid-Open No. 2007-264612

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and therefore, the present invention provides a method of easily manufacturing a developer container in which the amount of the developer is detected by the electrostatic capacity detection method.

The present invention provides a developer container, a developing device, and a process cartridge that improve the detection accuracy of the developer amount by the electrostatic capacitance detection method when the conductive resin member is used for an electrode.

According to an embodiment of the present invention, in consideration of the above points, there is provided a developing apparatus comprising a frame configured to define a containing portion of a developer, a first electrode, and a surface disposed on the surface of the frame and facing the first electrode A method for manufacturing a developer container including a second electrode and detecting the amount of the developer in the developer containing portion based on the electrostatic capacity between the first electrode and the second electrode, A step of holding a conductive resin member constituting the second electrode in a mold constituted so as to form a surface of the conductive resin member on the surface of the mold, A step of injecting a resin to be formed in the frame into the mold in which the conductive resin member is held; and a step of curing the resin, And forming the frame to which the second electrode to be fixed is fixed.

According to another aspect of the present invention, there is provided a developer container configured to receive a developer, the developer container including an antenna member configured to detect an amount of developer using electrostatic capacitance, And a conductive resin member having a resistance of 10 ³ Ω or more and 10 ⁵ Ω or less.

According to still another aspect of the present invention, there is provided a developing apparatus comprising a frame configured to define a developer accommodating portion, a first electrode, and a second electrode disposed on a surface of the frame and having a surface facing the first electrode Wherein an amount of the developer in the developer accommodating portion is detected based on a capacitance between the first electrode and the second electrode, the second electrode is constituted by a conductive resin member, The closest point between the first electrode and the second electrode on the second electrode is arranged at a position other than the end of the second electrode when viewed along the axial direction of the first electrode, The two electrodes have at least one convex portion protruding toward the first electrode, and the closest contact point is located at least one convex portion.

According to still another aspect of the present invention, there is provided a developing apparatus, a process cartridge, and an image forming apparatus including the developer container.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

1 is a schematic sectional view of an image forming apparatus according to a first embodiment;
2 is a schematic cross-sectional view of the process cartridge of the first embodiment;
3 is a schematic sectional view of the developing apparatus of the first embodiment.
4 is a graph showing the relationship between the amount of toner and the electrostatic capacity of the first embodiment.
5A, 5B, 5C and 5D are schematic views for explaining the manufacturing process of the developing frame of the first embodiment.
6A and 6B are cross-sectional views of a part of a developing frame in the vicinity of the antenna member of the first embodiment;
7A, 7B and 7C are cross-sectional views of a part of the developing frame in the vicinity of the antenna member of Comparative Examples 1 and 2;
8 is a schematic cross-sectional view of the developing apparatus according to the second embodiment according to the first embodiment.
9 is a schematic sectional view of a developing apparatus showing a schematic configuration of a detecting apparatus according to a second embodiment.
10 is a graph showing the relationship between the remaining toner amount and electrostatic capacity of the second embodiment.
11A and 11B are graphs respectively showing the relationship between the amount of remaining toner and the electrostatic capacity in Example 3 and Comparative Example 3 according to the second embodiment.
12A, 12B and 12C are schematic diagrams illustrating an example of a conductive resin sheet.
13 is a schematic view of a toner remaining amount detecting circuit.
14A and 14B are explanatory diagrams of a plan view of an example of the antenna member and a method of measuring resistance, respectively.
Figs. 15A and 15B are perspective views for explaining the arrangement of the antenna member in the developing frame. Fig.
16 is a schematic sectional view of the developing apparatus of the third embodiment.
17 is a flowchart of a process of detecting and notifying the remaining amount of toner.
18 is a schematic sectional view of a mold for explaining the manufacturing process of the developer container of the third embodiment.
19 is a graph showing an example of the relationship between the remaining amount of toner and electrostatic capacity in the third embodiment.
20A and 20B are schematic diagrams for explaining the toner deposition method in the developer container.
21A is a schematic sectional view of a main part of the developing apparatus of the third embodiment.
21B is a graph for explaining the relationship between the transition of the detection result of capacitance and the position of the antenna member.
22A is a schematic sectional view of a main part of a developing apparatus of Comparative Example 5. Fig.
22B is a graph for explaining the relationship between the transition of the detection result of capacitance and the position of the antenna member.
23A is a schematic sectional view of a main part of the developing apparatus of the fourth embodiment.
23B is a graph for explaining the relationship between the transition of the detection result of capacitance and the position of the antenna member in the fourth embodiment.
24A is a schematic sectional view of a main part of the developing apparatus of the fifth embodiment.
24B is a graph showing an example of the relationship between the remaining toner amount and electrostatic capacity;
24C is a graph for explaining the relationship between the transition of the detection result of capacitance and the position of the antenna member.
25A is a schematic sectional view of the main part of the developing apparatus of Comparative Example 6. Fig.
25B is a graph for explaining the relationship between the transition of the detection result of electrostatic capacitance and the position of the antenna member.

Hereinafter, a method of manufacturing a developer container, a developer container, a developing apparatus, a process cartridge, and an image forming apparatus according to the present invention will be described in detail with reference to the drawings.

First Embodiment

Ⅰ. The overall configuration and operation of the image forming apparatus

1 is a schematic sectional view of an image forming apparatus according to a first embodiment of the present invention. The image forming apparatus of this embodiment, indicated by reference numeral 100, is a laser beam printer configured to form an image using an electrophotographic printing method. The image forming apparatus 100 employs a cartridge type and includes a process cartridge 120 detachable from the apparatus main body 110.

The image forming apparatus 100 is connected to an external host apparatus such as a personal computer or an image reading apparatus. The image forming apparatus 100 receives image information from such a host apparatus, forms an image according to the image information on a recording material (recording medium or transfer material), and outputs (prints) the image. As the recording material, a sheet material such as paper can be preferably used.

The image forming apparatus 100 has a photosensitive drum 1 as a drum-shaped (cylindrical) electrophotographic photosensitive member (photosensitive member) as an image bearing member. On the periphery of the photosensitive drum 1, the following means are arranged in order along the rotational direction of the photosensitive drum 1. [ First, a charging roller 2, which is a roller-shaped charging member as a charging means, is disposed. Next, an exposure apparatus (laser scanner unit) 3 as exposure means is disposed. Next, a developing device 4 as developing means is disposed. Next, a transfer roller 5 which is a roller-shaped transfer member as transfer means is disposed. Next, a cleaning device 6 as cleaning means is disposed.

When a print start signal is input to the image forming apparatus 100 and image formation is started, a rotational driving force is transmitted from the driving motor (not shown) as the driving means provided in the apparatus main body 110 to the photosensitive drum 1. Thereby, the photosensitive drum 1 is rotationally driven in the direction of the arrow X1 in Fig. 1 at a predetermined, for example, 147.6 mm / s main speed (process speed). In this embodiment, the photosensitive drum 1 includes a drum body made of aluminum and an OPC photosensitive layer provided on the drum body. The charging roller 2 is disposed in contact with the photosensitive drum 1 and rotates following the rotation of the photosensitive drum 1. The surface (peripheral surface) of the rotating photosensitive drum 1 is charged substantially uniformly at a predetermined potential of a predetermined polarity (negative in this embodiment) by the charging roller 2. [ A predetermined charging bias (charging voltage) is applied to the charging roller 2 from a charging power supply (high voltage power supply) (not shown) provided in the apparatus main body 110 during charging. In this embodiment, as the charging bias, an AC voltage Vpp of 1.6 kV (frequency: 1600 Hz) sufficient for discharging the charging roller 2 and a DC voltage Vdc of -560 V corresponding to the dark portion potential Vd on the photosensitive drum 1 And the generated oscillating voltage is applied. The AC component of the charging bias is controlled by the constant current control so that a substantially constant current flows between the photosensitive drum 1 and the charging roller 2. [

The surface of the charged photosensitive drum 1 is exposed to laser light L emitted from the exposure apparatus 3 according to image information. The exposure apparatus 3 outputs laser light (exposure light) L modulated corresponding to a time-series electrical digital image signal of image information input from the personal computer 20 or the like to the video controller 19 from the laser output unit 3a Output. The laser light L output from the exposure apparatus 3 enters the process cartridge 120 and is irradiated onto the surface of the photosensitive drum 1. [ The surface of the photosensitive drum 1 charged almost uniformly is scanned and exposed by the laser beam L, whereby an electrostatic latent image (electrostatic image) corresponding to image information is formed on the surface of the photosensitive drum 1. [ In this embodiment, the bright portion potential Vl on the photosensitive drum 1 irradiated with the laser light L is -130V. In the present embodiment, the image portion of the electrostatic latent image is exposed (image exposure method).

The electrostatic latent image formed on the surface of the photosensitive drum 1 is developed by the developing device 4 using the toner T as a developer. Details of the developing apparatus 4 will be described later.

On the other hand, the pick-up roller 8 as the conveying means is driven at a predetermined control timing to feed the recording material P such as recording paper stored in the recording material tray 7 as the recording material receiving portion one by one. Thereby, the recording material P is conveyed to the transfer portion N by the conveying means (not shown) at a predetermined control timing. The transfer roller 5 contacts the surface of the photosensitive drum 1 with a predetermined pressing force to form a transfer portion (transfer nip) N. [ The recording material P is conveyed to the transfer portion N via a transfer guide 9 as a guide member. The toner image on the surface of the photosensitive drum 1 is electrostatically transferred to the surface of the recording material P while the recording material P is sandwiched between the photosensitive drum 1 and the transfer roller 5 and conveyed through the transfer portion N. [ At this time, a direct-current voltage (negative polarity) opposite in polarity to the charging polarity (negative polarity in this embodiment) of the toner at the time of development is applied to the transfer roller 5 from a transfer power source (high voltage power source) A transfer bias (transfer voltage) is applied.

The recording material P onto which the toner image has been transferred is separated from the photosensitive drum 1 and is conveyed to a fixing device 10 as a fixing means provided on the downstream side in the conveying direction of the recording material P in the transferring portion N. [ The recording material P is heated and pressed by the fixing device 10 to undergo a fixing process of the toner image. In the present embodiment, the fixing device 10 includes a heating roller having a halogen heater therein, and a pressure roller that is pressure-contacted to the heating roller. The fixing device 10 heats and presses the toner image transferred to the surface of the recording material P while holding and conveying the recording material P in the fixing nip between the heating roller and the pressure roller. Thereby, the toner image is melted and fixed on the surface of the recording material P. Thereafter, the recording material P is discharged to a discharge tray 11 provided in the upper portion of the apparatus main body 110 in Fig.

The surface of the photosensitive drum 1 after the recording material P is separated is cleaned by the cleaning device 6 and the image forming process starting from the above-described charging is repeatedly performed. The cleaning device 6 uses the cleaning blade 61 as a cleaning member disposed in contact with the photosensitive drum 1 to remove deposits such as transfer residual toner from the surface of the rotating photosensitive drum 1, Is recovered in the recovered toner container (62).

Ⅱ. Process cartridge

2 is a schematic sectional view of the process cartridge 120. Fig. In the present embodiment, the photosensitive drum 1 and the process means acting on the photosensitive drum 1, that is, the charging roller 2, the developing device 4 and the cleaning device 6 are integrally formed into a cartridge, A process cartridge 120 detachable from the apparatus main body 110 is constructed.

The process cartridge 120 is constructed by connecting a cleaning unit 12 and a developing unit (developing device) 4 which is a unit separate from the cleaning unit 12. [

The cleaning unit 12 includes a photosensitive drum 1, a charging roller 2 and a cleaning device 6. [ The cleaning unit 12 has a cleaning frame 60 which forms the recovery toner container 62 and supports the photoconductor drum 1, the charging roller 2 and the cleaning blade 61. Details of the developing unit 4 will be described later.

The process cartridge is generally made of a cartridge including an image bearing member such as a photosensitive member and a process means acting on the image bearing member, and is detachable from the apparatus body of the image forming apparatus. The process means includes, for example, a charging means, a developing means, a cleaning means, and a toner charging means for charging the transfer residual toner. Here, the process cartridge includes at least a developer container or a developing device and an image bearing member integrally formed into a cartridge, and is attachable to and detachable from the apparatus main assembly of the image forming apparatus.

Ⅲ. The developing device

3 is a schematic cross-sectional view of the developing apparatus 4 in the present embodiment. 3 also schematically shows the functional blocks constituting the detecting device 130 described later.

The developing apparatus 4 of the present embodiment includes a developer container 46 configured to receive a magnetic one-component developer (toner) T as a developer, (40). The developer container 46 includes a developing chamber 46a and a toner chamber 46b. In the present embodiment, the developing chamber 46a and the toner chamber 46b, which are formed from the developing frame 40 and can accommodate the toner T, constitute the developer accommodating portion 40a.

The developing sleeve 41 is disposed in the developing chamber 46a such that a part of the developing sleeve 46a from the opening 46c formed in the developing chamber 46a on the side of the photosensitive drum 1 is exposed to the outside of the developing chamber 46a. The developing sleeve 41 is a cylindrical member formed of a non-magnetic material as a developer carrying member. The developing sleeve 41 is rotatably supported by the developing sleeve 41 by the developing frame 40. The developing sleeve 41 is arranged opposite to the photosensitive drum 1 with a predetermined gap therebetween. A rotational driving force from a driving motor (not shown) provided in the apparatus main body 110 is transmitted to the developing sleeve 41 so that the developing sleeve 41 is rotationally driven in the direction of arrow X2 in Fig. In the hollow portion of the developing sleeve 41, a magnet roller 44 having a plurality of magnetic poles is disposed in the peripheral direction as a magnetic field generating means. The magnet roller 44 is fixedly (non-rotatably) supported by the developing frame 40. The developing chamber 46a is provided with a developing blade 42 which is a regulating member formed of an elastic material as a developer layer regulating means so as to come into contact with the outer peripheral surface of the developing sleeve 41. [ The developing blade 42 is supported by the developing frame 40.

In the toner chamber 46b, a stirring member 45 as developer stirring means is disposed. The stirring member 45 includes a support rod 45a and a stirring sheet 45b fixed to the support rod 45a. The support rod 45a is rotatably supported by the support frame 45a by the development frame 40. [ A rotational driving force from a driving motor (not shown) provided in the apparatus main body 110 is transmitted to the stirring member 45 so that the stirring member 45 is rotationally driven in the direction of arrow X3 in Fig. The toner T accommodated in the toner chamber 46b is rotated and driven by the agitating member 45 to rotate the toner chamber 46b through the toner supply port 46d, which is an opening for communicating between the developing chamber 46a and the toner chamber 46b, (46b) to the developing chamber (46a).

The toner supply port 46d is sealed (sealed) by the seal member 48 (see Fig. 16) in order to prevent toner leakage during transportation of the process cartridge 120. Fig. A seal member is present until the start of use of the process cartridge 120 to prevent toner leakage. The sealing member may be manually removed, or the opening member may be provided in the toner chamber or the developing chamber, and the sealing member may be driven to automatically remove the sealing member by rotating or the like. The opening member may be combined with the agitating member. For example, when the stirring member has the stirring shaft and the stirring sheet member, the stirring sheet member may also serve as the toner sealing member, and the stirring shaft may have the function of the opening member. Alternatively, the toner sealing member may be attached to the stirring shaft separately from the stirring sheet member (Fig. 16). In the relationship with the electrodes configured to detect the developer amount, when the seal member is rotated and stirred while holding the developer, a constant level of electrostatic capacity is detected between the electrodes do. This may be prevented by providing a hole in a portion other than the toner sealing portion of the toner sealing member so that the developer in the toner sealing member falls to the bottom surface of the container. The toner T is stored only in the developing chamber 46a, the toner chamber 46b, and the middle toner chamber 46b (Fig. 3) until the sealing member is removed.

A part of the bottom surface of the toner chamber 46b is provided with an antenna member 43 constituting a detecting device 130 described later.

The toner T conveyed to the developing chamber 46a can be pulled close to the developing sleeve 41 by the magnetic force of the magnet roller 44 contained in the developing sleeve 41. By the rotation of the developing sleeve 41 The developing blade 42 and the developing sleeve 41 are conveyed to a contact portion where they contact each other (Fig. 3). The toner T passes through contact portions where the developing blades 42 and the developing sleeve 41 come into contact with each other, thereby giving charge (charge electricity) due to friction and being subjected to the regulation of the thickness of the toner layer. Thereafter, the toner T is conveyed to the developing area 31 where the photosensitive drum 1 and the developing sleeve 41 face each other.

A predetermined developing bias (developing voltage) is applied to the developing sleeve 41 from a developing power supply (high voltage power supply) serving as voltage applying means provided in the apparatus main body 110. In the present embodiment, a generated oscillation voltage is applied as a developing bias by superimposing a DC voltage (for example, Vdc = -400 V) and an AC voltage (for example, a voltage between peaks = 1500 Vpp and a frequency f = 2400 Hz) . The photosensitive drum 1 is electrically grounded. As a result, an electric field is generated in the developing area 31 where the photosensitive drum 1 and the developing sleeve 41 face each other. The charged toner T conveyed to the developing zone 31 is transferred to the surface of the photosensitive drum 1 in accordance with the electrostatic latent image on the surface of the photosensitive drum 1 by the action of this electric field. Thereby, the electrostatic latent image on the photosensitive drum 1 is developed by the toner T. [ In the present embodiment, the photosensitive drum 1 is charged with the same polarity (negative polarity) as the charging polarity of the photosensitive drum 1, on the exposed portion (image portion) on the photosensitive drum 1 where the absolute value of the potential is attenuated after being uniformly charged By adhering the toner T, the electrostatic latent image is developed (inversion developing system).

The description of this embodiment uses an example in which the electrostatic latent image is developed with a negatively charged magnetic one-component developer (toner), but a non-magnetic developer or a two-component developer may be used instead. In addition, a developer charged with a positive polarity may be used instead of a negative polarity at the time of development.

IV. Detection device

(Developer amount detecting apparatus) 130 that uses the electrostatic capacity detecting method as the detecting means (developer amount detecting means) for detecting the amount of the developer in the present embodiment will be described.

The detection device 130 of this embodiment includes a developing sleeve 41 as a first electrode, an antenna member 43 as a second electrode, a developing power source 131, a capacitance detection circuit 132, And the like. The antenna member 43 is disposed on the surface of the developing frame 40 and has a surface opposed to the developing sleeve 41. In this embodiment, the antenna member is formed on the flat surface portion from the viewpoint of ease of manufacture. The amount of the toner T in the containing portion is determined based on the electrostatic capacity between the developing sleeve 41 and the antenna member 43. [ The electrostatic capacity detection circuit 132 and the controller unit 133 together constitute a developer remaining amount detecting device (toner remaining amount detecting device) Hereinafter, this will be described in more detail.

In the present embodiment, the developing sleeve 41 also functions as a first electrode (input side electrode) configured to detect electrostatic capacitance. An antenna member 43 serving as a capacitance detecting member is provided as a second electrode (an output side electrode or an opposite electrode) configured to detect capacitance. In this embodiment, the antenna member 43 is made of a conductive resin sheet which is a conductive resin member. The antenna member 43 has a width in the longitudinal direction substantially parallel to the longitudinal direction (rotation axis direction) of the developing sleeve 41 and a width in the direction perpendicular to the longitudinal direction of the antenna member 43 (substantially orthogonal in this embodiment) Direction, and has a rectangular portion in the plan view. In the present embodiment, this rectangular portion is a measurement portion forming a surface opposed to the developing sleeve 41. The antenna member 43 may have a portion configured to form a conductive path in addition to the measurement portion configured to form the surface facing the developing sleeve 41. [ For example, a portion configured to form a conductive path at an end portion in the longitudinal direction of the rectangular measuring portion may be formed as one sheet continuously. This conductive resin sheet is a sheet-like member having a conductive single layer structure or multilayer structure formed on the basis of a resin, as will be described later in detail. The antenna member 43 is disposed on a part of the bottom surface of the toner chamber 46b formed by the developing frame 40. The surface of the antenna member 43 opposed to the developing sleeve 41 and the surface of the developing sleeve 41, It is possible to detect a change in the amount of the toner T existing between the toner particles. In this embodiment, the antenna member 43 is flat.

When an AC voltage (AC bias) is applied to the developing sleeve 41, a current corresponding to the electrostatic capacitance between the developing sleeve 41 and the antenna member 43 is generated. This electrostatic capacity changes in accordance with the amount of the toner T between the developing sleeve 41 and the antenna member 43. That is, since the relative dielectric constant of the toner T is larger than the relative dielectric constant of air, the amount of the toner T existing between the electrodes becomes large, and the detected capacitance becomes large. The current value flowing through the antenna member 43 is supplied to the process cartridge 120 via a contact (not shown) provided in the process cartridge 120 and a contact (not shown) provided in the device main body 110, And is measured by the capacitance detection circuit 132. In the present embodiment, the electrostatic capacitance detection circuit 132 generates a voltage signal relating to the current value (i.e., electrostatic capacitance value) and inputs the voltage signal to the controller unit 133 provided in the apparatus main body 110 . The controller unit 133 can obtain the amount of the toner T based on information (data table or the like) indicating the relationship between the preset capacitance and the amount of the toner T from the input voltage signal.

The controller unit 133 displays information on the display unit of the apparatus main body 110 serving as the notification means and the monitor of the personal computer connected to the apparatus main body 110 based on the amount of the obtained toner T, T and the like. Thus, preparation of a new process cartridge 120 for a user or the like can be urged.

4 is a graph showing the relationship between the amount of the toner T in the accommodating portion 40a and the electrostatic capacity in the present embodiment. In this embodiment, the antenna member 43 is provided on the bottom surface of the toner chamber 46b, and a change in the amount of the toner T between the developing sleeve 41 and the antenna member 43 is detected. In the present embodiment, a change in the amount of the toner T from the time when the amount of the toner T consumed to some extent and the amount of the toner T in the accommodating portion 40a becomes about 150 g to when the toner disappears is detected. Thereby, the image forming apparatus 100 of the present embodiment can sequentially inform the user, etc., of the amount (remaining amount) of the toner T during this period. Since the range of the remaining amount of the toner T that can be detected by the arrangement of the antenna member 43 changes, the antenna member 43 can be disposed at an arbitrary desired position. The antenna member 43 may be disposed in the toner chamber 46b or in the developing chamber 46a.

In the present embodiment, the length in the longitudinal direction of the antenna member 43 is set to a length substantially in the same range as the image area (direction substantially orthogonal to the conveying direction of the image). This is because, even when the amount of the toner T is uneven in the longitudinal direction, detection accuracy can be improved by detecting a wide range of capacitance including the uneven portion. Therefore, the length in the longitudinal direction of the antenna member 43 may be longer than the range of the image area. However, depending on the desire, for example, the antenna member 43 whose length in the longitudinal direction is shorter than the range of the image area may be disposed at the center or near the end of the image area. If the amount of unevenness of the toner T in the longitudinal direction is not caused by the stirring member 45, for example, from the viewpoint of detection accuracy, the amount of unevenness (or unevenness) of the amount of toner T in the longitudinal direction Defects of the image) itself by the electrostatic capacity detection method. Further, by providing a plurality of conductive resin members having different lengths in the longitudinal direction of the developing sleeve, it is possible to detect the difference in the plurality of electrostatic capacitances between the developing sleeve and the electroconductive resin member and the difference to detect a nonuniform toner distribution or a toner amount . The difference in capacitance may be detected using a configuration in which the length (width) in the width direction is gradually shortened from one end to the other end in the longitudinal direction instead of a plurality of conductive resin members having different lengths.

The length of the antenna member 43 in the width direction may be shorter or longer than that of the present embodiment. For example, in the case of detecting the remaining amount of the toner T in a wider range, the length of the antenna member 43 in the width direction can be made longer than in the present embodiment. In this case, the antenna member 43 is not limited to the bottom surface of the toner chamber 46b, and may be in any range of the surface of the developing frame 40. [ The length of the antenna member 43 in the width direction is made shorter than that of the present embodiment and the length of the developing sleeve 41 is set to be shorter than that of the present embodiment, Can be closer to.

In this embodiment, since the AC voltage is applied to the developing sleeve 41 at the time of image formation, the developing sleeve 41 is set as an input portion (input side electrode) of the AC voltage configured to detect the amount of the toner T, And an antenna member 43 is provided as an output unit (output side electrode) for detection. Therefore, in the present embodiment, the developing frame 40 has a holding portion configured to hold the developing sleeve 41 therein. The input portion of the AC voltage is not limited to the developing sleeve 41 but may be a conductive member. In that case, the developing frame 40 may have a holding portion configured to hold the conductive member. Further, the electrode constituted by the conductive resin sheet may be an AC voltage input portion (input side electrode). In this case, an AC voltage from the AC voltage source may be applied to the electrode made of the conductive resin sheet through the contact provided in the process cartridge 120 and the contact provided in the apparatus main body 110.

In this embodiment, a detection device for detecting the electrostatic capacitance between the developing sleeve and the electrode is described. However, the present invention is not limited to this, and both of the electrodes may be a conductive resin member. That is, it is also possible to detect the amount of the developer using the difference in capacitance between the conductive resin members (Fig. 13). In this case, the present invention can also be used for detecting the toner remaining amount of the non-magnetic toner usable in a full-color image forming apparatus in which a plurality of cartridges are detachable.

Ⅴ. Manufacturing method

Next, a method of manufacturing the developer container 46 in the present embodiment will be described.

As described above, the method used for producing the developer container in which the amount of the developer is detected by the electrostatic capacitance detection method is a method in which the antenna member is adhered to the frame by double-sided adhesive tape, And printing on the frame. However, such a method requires a process for post-processing the frame after the frame is formed, and thus the manufacturing process is likely to be complicated. In addition, for example, in the method of bonding the antenna member to the frame by using the double-sided adhesive tape, there is a risk that the detection accuracy is lowered due to the variation of the dimension and position of each component.

Another possible method is to use a metal plate member (SUS sheet metal or the like) to be inserted into the frame when the resin frame is formed as an antenna member. However, with this method, since the degree of shrinkage when the molded resin is cooled is large, and the shrinkage of the metal plate member is small, distortion is likely to occur in the produced container, which makes the design difficult. In this method, it is necessary to provide a portion (fixed portion or fixed portion) for fixing the antenna member and the frame to each other. For example, this method needs to prevent the antenna member from moving by molding the frame so that the end face and both sides of the antenna member cover the fixing portion of the frame at the longitudinal end of the antenna member. This means that the frame itself needs to be made thick and the frame tends to become complicated with the uneven surface of the frame where the mold and the frame are fixed. In addition, this method changes the area of the concave-convex fixing part configured to fix the antenna member, the area where the change of the capacitance is originally caused by the change of the amount of the developer, to the area where the change of the capacitance does not occur, The performance of the shape member is not sufficiently utilized.

On the other hand, the use of a resin electrode (conductive portion) as an electrode configured to detect capacitance is advantageous in that the electrode can be easily and accurately formed by a relatively simple method using a mold, It is advantageous in terms of improvement of precision. As described later, the use of a resin electrode is advantageous in that it is possible to reduce the price of the electrode itself and to suppress deterioration of detection accuracy due to adhesion of the magnetic developer to the electrode.

For example, it is conceivable to form a conductive part on a frame from a conductive resin by two-color molding. However, since this method requires two forming steps, there is still a need for improvement in order to simplify manufacturing. As described above, the method of providing the electrode layer on the sheet member for preventing scattering of the developer tends to complicate the manufacturing process due to the step of attaching the sheet member to the frame of the developing apparatus.

Thus, a method of simply manufacturing a developer container in which the amount of the developer is detected by the electrostatic capacity detection method is required. A manufacturing method for realizing the detection of the amount of the developer of high precision is also pursued.

The conductive resin sheet constituting the antenna member 43 is first held on the metal mold and then the resin (synthetic resin) to be formed in the developing frame 40 is pressed into the mold To address the problem. In this manner, the developing frame 40 in which the antenna member 43 is integrally fixed is molded. Hereinafter, this will be described in more detail.

In the present embodiment, as the conductive resin sheet 24, a polystyrene (PS) resin sheet in which a conductive material, specifically carbon, is coated on one side to make it conductive is used. The carbon-coated side of the conductive resin sheet 24 is referred to as A side (Figs. 6A and 6B). The surface of the conductive resin sheet 24 opposite to the A side and the side on which the PS resin is exposed is referred to as B side. In the present embodiment, the A side of the conductive resin sheet 24 is a side that comes into contact with the mold when the developing frame 40 is molded. In this way, at least a part of the surface of the conductive resin sheet 24 which contacts the metal mold (nearly all in this embodiment) becomes the surface of the antenna member 43 opposed to the developing sleeve 41. In the present embodiment, at least the B side of the conductive resin sheet 24 is a side in contact with the resin injected into the mold when the developing frame 40 is molded. In this embodiment, the PS resin is also exposed on the side end face between the A side and the B side, and the side end face is also the side which comes into contact with the resin injected into the mold when the developing frame 40 is molded.

5A, 5B, 5C and 5D schematically show the manufacturing process of the developing frame 40 in this embodiment. The developing frame 40 may be formed by combining a plurality of molded frame parts. 3, the developing frame 40 includes a lower frame 40A that forms the bottom surface of the accommodating portion 40a, and a lower frame 40A that covers the upper frame 40A, (40B) are combined. The lower frame 40A and the upper frame 40B are formed separately from each other. 5A to 5D schematically show the manufacturing process of the lower frame (hereinafter, the lower frame 40A will be simply referred to as a " developing frame " 40) ").

5A, the mold 201 of the injection molding machine 200 has a first mold 202 (or a male mold (core)) and a second mold 203 (or a female mold (cavity)). The first mold 202 has a surface 221 forming a surface on the side of the accommodating portion of the developing frame 40. The second mold 203 has a surface 231 forming a surface of the development frame 40 opposite to the accommodating portion 40a (outside the development frame 40). Fine air holes (air suction portions) 222 are provided in a predetermined holding region Y used for holding the conductive resin sheet 24 of the first mold 202. [ The suction device 204 is connected to the fine air holes 222 to suck air in the direction of arrow S1 in Fig. 5A. The second mold 203 is provided with a gate 232.

The surface A of the conductive resin sheet 24 is first brought into contact with the surface 221 of the first mold 202 so as to form the developing frame 40 using the injection molding machine 200, The conductive resin sheet 24 is placed in the holding region Y so that the air suction by the suction device 204 is activated. In this way, the A side of the conductive resin sheet 24 is adsorbed and held on the surface 221 of the first metal mold 202.

Thereafter, as shown in Fig. 5C, the first mold 202 and the second mold 203 are brought into close contact with each other at a desired pressing force to form a cavity for forming the developing frame 40. [ The thermoplastic resin forming the development frame 40 is injected from the gate 232 in the direction of the arrow S2 in Fig. 5C. The injected thermoplastic resin is cooled and hardened (fixed) to form a developing frame 40 in which the antenna member 43 composed of the conductive resin sheet is integrally fixed. In this embodiment, an impact resistant polystyrene (HIPS) resin having compatibility with at least the B side (and the side end surface in the present embodiment) of the conductive resin sheet 24 is used as the thermoplastic resin to be injected into the mold 201. The resin is injected into the mold 201 and hardened, whereby the antenna member 43 composed of the conductive resin sheet is molded integrally with the developing frame 40. [

5D, the developing frame 40, in which the antenna member 43 is integrally fixed, is detached from the mold 201 while the air suction by the suction device 204 is stopped, Can be.

The lower frame 40A molded as described above and the separately formed upper frame 40B are joined together by any suitable fixing method such as thermal welding. Thereby, the developer container 46 formed from the developing frame 40 can be manufactured. The above described other elements of the developing sleeve 41 and the developing device 4 are attached to the developer container 46 before and / or after the upper frame 40A and the lower frame 40B are engaged , The developing device (developing unit) 4 can be manufactured. The process cartridge 120 can be manufactured by connecting (holding) the above-described cleaning unit 12 to the developing apparatus (developing unit) 4.

In this embodiment, the metal contact is pressed against the conductive portion (not shown) of the end portion of the developing frame 40 integrally molded with the antenna member 43. The conductive member connected at one end to this contact or continuing therefrom is geared to the outside of the process cartridge 120 and the other end side of the conductive member is used as a contact with the apparatus main body 110. As a result, the current flowing through the antenna member 43 when the AC voltage is applied to the developing sleeve 41 during image formation is detected by the electrostatic capacitance detection circuit 132 provided in the apparatus main body 110 do.

VI. effect

According to the present embodiment, by the simple method of holding the conductive resin sheet 24 by adsorbing and holding the metal mold 201 (the first metal mold 202) in advance at the time of molding the development frame 40, It is possible to manufacture the developing frame 40 in which the member 43 is integrally molded.

6A is a cross-sectional view (cross section along the width direction of the antenna member 43) of a portion of the development frame 40 in the vicinity of the antenna member 43 at the center in the longitudinal direction of the antenna member 43. Fig. As described above, in the present embodiment, at least the B side (and the side end surface in the present embodiment) of the conductive resin sheet 24 has compatibility with the thermoplastic resin injected into the mold 201. Therefore, at least the B side (and the side end surface in this embodiment) of the conductive resin sheet 24 is integrated with the thermoplastic resin injected into the mold when the developing frame 40 is molded. Therefore, the formed developing frame 40 is already integrated with the antenna member 43, and it is not necessary to further process the developing frame 40 in a special shape configured to fix the antenna member 43. [

It is known that the capacitance changes in proportion to the reciprocal of the distance between two electrodes. This is because the conductive resin sheet 24 is held during molding so that the A side of the conductive resin sheet 24 which faces the developing sleeve 41 contacts the side of the mold 201 (first mold 202) This is not a problem in the present embodiment. This substantially prevents the fluctuation of the position of the A-plane by, for example, the variation of the thickness of the conductive resin sheet 24 and the fixing method of the conductive resin sheet 24 or the like. As described above, the variation of the distance between the two electrodes is suppressed, so that the variation of the capacitance is suppressed, and the detection of the amount of the toner T with high accuracy is realized.

According to the present embodiment, the entirety of the B side of the conductive resin sheet 24 is fixed to the developing frame 40 substantially uniformly and integrally. Therefore, for example, the antenna member 43 is partly peeled off by the deformation of the developer container 46 when an external force is temporarily applied, and the detection accuracy of the amount of the toner T is lowered .

In this embodiment, as a method of holding the conductive resin sheet 24 on the mold 201, a method of adsorbing the conductive resin sheet 24 by air suction is used. However, the present invention is not limited thereto. For example, electrostatic force, magnetic force, gravity, or any other binding force can be used as long as the conductive resin sheet 24 can be held at a desired position of the mold 201. [ For example, the conductive resin sheet 24 may be held using grease. However, the holding by the air suction is preferable because it can be carried out simply without requiring a special material. In the present embodiment, the substantially entire surface of the conductive resin sheet 24 is sucked by air suction, but an air hole 222 is disposed in a part of the metal mold which contacts the conductive resin sheet 24 at least near the gate 232 The displacement of the conductive resin sheet 24 during injection of the resin into the mold 201 can be suppressed easily.

In the present embodiment, the conductive resin sheet 24 is provided on at least the side of the development frame 40 (frame side) with a material compatible with the thermoplastic resin injected into the mold 201 when the development frame 40 is molded (In this embodiment, the B surface and the side end surface). Compatibility generally refers to the property that two or more kinds of substances have affinity with each other and are mixed with each other substantially homogeneously without causing a chemical reaction to form a solution or a mixture. Here, under the reasonable conditions (temperature, time, etc.) as the molding method of the above-described development frame, at least a part of the interface between the resin and the material injected into the mold is melted or mixed, . The same material as the resin to be injected into the mold, or another material, is a material having compatibility as long as it has the above-described properties. However, the present invention is not limited thereto, and the conductive resin sheet 24 may be provided at least on the side of the developing frame 40 so as to have adhesiveness to the resin injected into the mold 201 when the developing frame 40 is molded Or may have a surface composed of a material. Adhesion generally refers to the property that two faces are bonded to each other by a chemical force or a physical force or both. Here, as a method of forming the above-described developing frame, a method of forming a developing frame is proposed in which, at an interface between a resin and a material to be injected into a mold under a reasonable condition (temperature, time, Means the property that the material can be fixed. Here, since the conductive resin sheet only has to have a compatibility with the resin to be injected or a material having adhesiveness, it is necessary to determine whether or not the conductive resin sheet is fixed to the developing frame by the compatibility and the adhesiveness Need not be strictly distinguished.

For example, when the resin to be injected into the mold is a HIPS resin, examples of the material compatible with the resin include PS resin, HIPS resin, and PS resin and HIPS resin, respectively, A carbon-dispersed PS resin obtained by dispersing black, and a carbon-dispersed HIPS resin. Although the resin injected into the mold does not have compatibility with the HIPS resin, examples of the material having adhesiveness include a carbon dispersed EVA in which carbon black is dispersed as an ethylene vinyl acetate (EVA) resin and a conductive material .

The surface having compatibility or adhesion with the resin to be injected into the mold of the conductive resin sheet 24 is always set so that the surface of the conductive resin sheet 24 on the developing frame 40 side And substantially the entire surface of the side end face). A part of the surface of the conductive resin sheet 24 on the side of the developing frame 40 may not have compatibility and adhesiveness if the antenna member 43 is sufficiently fixed to the developing frame 40. [ However, from the viewpoint of suppressing the peeling of the antenna member 43 from the development frame 40 and the like, it is preferable that the surface of the conductive resin sheet 24 on the side opposite to the A side (the surface facing the other electrode) It is preferable that the B side of the conductive resin sheet 24 has compatibility or adhesiveness with the resin injected into the mold. In this case, a portion of the B side may have compatibility or adhesiveness, but it is more preferable that the substantially entire surface of the B side has compatibility or adhesiveness.

The conductive resin sheet 24 may have conductivity on side A, side B, or both sides thereof. The conductive resin sheet 24 has electrical connection between the electrostatic capacitance detecting circuit 132 and the conductive portion of the antenna member when the developing frame 40 is provided as an antenna member (in the case of the output side electrode) And may have any structure capable of establishing such an electrical connection (in the case of the input side electrode). The conductive resin sheet 24 only needs to have a sufficient level of conductivity as an electrode configured to detect the amount of the developer by the electrostatic capacitance detection method when the conductive resin sheet 24 is provided as an antenna member in the development frame 40. For this reason, in the present embodiment, the conductive resin sheet 24 has a two-layer structure including a conductive layer, but may have a three-layer structure including at least one conductive layer. The conductive resin sheet 24 is not limited to a sheet-like member having a multilayer structure formed on the basis of a synthetic resin, but may be a single sheet-shaped member having conductivity formed on the basis of a synthetic resin. For example, as the conductive resin sheet member 24, a conductive sheet member formed of a resin in which carbon black as a conductive material is dispersed can be used. The resin (base), which is the base of the conductive resin sheet 24, has compatibility or adhesiveness with the resin injected into the mold when the developing frame 40 is molded. Thus, at least the side (usually the entirety) of the conductive resin sheet 24 on the developing frame 40 side has compatibility or adhesion with the resin injected into the mold when the developing frame 40 is molded.

In the present embodiment, a sheet-like member made of a carbon-coated PS resin is used as the conductive resin sheet 24 having a multilayer structure, but the present invention is not limited thereto. For example, the conductive resin sheet 24 may be formed by covering a sheet-like member made of resin with another conductive material other than carbon, or a conductive material deposited or printed on a resin sheet-like member. The conductive resin sheet 24 may have a two-layer structure in which a protective layer is formed on the surface of the sheet-like member having conductivity to prevent shaving, or may be made of PS resin, Layer structure in which a conductive material is interposed between conductive layers obtained by dispersing ashes. In this case, similarly to the present embodiment, the sheet member (base) made of resin is formed from a material having compatibility or adhesion with the resin to be injected into the mold when the developing frame 40 is molded (Figs. 12A and 12B And 12c).

The conductive resin sheet 24 is preferably made of non-magnetic or non-magnetic sheet-like members so that the magnetic toner T does not adhere to the conductive resin sheet 24 when a magnetic toner is used.

The conductive material is not limited to carbon black, and any material capable of imparting conductivity to the conductive resin sheet 24 such as graphite, carbon fiber, or carbon nanotube can be used.

VII. Shrinkage of conductive resin sheet

When the developing frame 40 is formed or after demoulding, the developing frame 40 shrinks. When the Young's modulus of the conductive resin sheet 24 is larger than the Young's modulus 3.5 GPa of the HIPS resin forming the development frame 40 at the time of shrinkage, the development frame 40 may be turned upside down. If the distance between the antenna member 43 composed of the conductive resin sheet and the developing sleeve 41 changes by more than the allowable range due to this phenomenon, the detection accuracy of the amount of the toner T is considered to be lowered.

This reversal of the developing frame 40 can be reversed when the developing frame 40 is molded or when the developing frame 40 is demolded by using a conductive resin sheet having a higher Young's modulus than the material forming the developing frame 40, Is a phenomenon caused by contraction of the developing frame 40 that occurs later. That is, the conductive resin sheet 24 is also contracted in accordance with the contraction of the developing frame 40 when the developing frame 40 is molded or after the removing. However, when the Young's modulus of the conductive resin sheet 24 is larger than the Young's modulus of the material of the developing frame 40 and the developing frame 40 and the conductive resin sheet 24 have different shrinkage amounts, the conductive resin sheet 24 The shrinkage of the developing frame 40 can not be absorbed by deformation or the like. For example, in the vicinity of the conductive resin sheet 24, in the direction of the arrow A in Fig. 6B (the direction along the width direction of the conductive resin sheet 24) of the developing frame 40, (The direction along the width direction of the conductive resin sheet 24). The amount of shrinkage in the direction of arrow B in Fig. 6B is smaller than that in the direction of arrow A in Fig. 6B, so that the development frame 40 is inverted in the direction of arrow C in Fig. 6B . When the Young's modulus of the conductive resin sheet 24 in which the carbon black was dispersed in the EVA sheet was changed from 2.5 GPa to 3.5 GPa by changing the dispersed state of the carbon black, the developing frame 40 did not turn upside down. In addition, when the PS resin (Young's modulus = 2.5 GPa) coated with carbon, which is the conductive resin sheet 24 in this embodiment, was used, the developing frame 40 did not turn upside down. Likewise, even when a conductive resin sheet having a Young's modulus of 3.5 GPa in which carbon is dispersed in a PS resin sheet is used and a conductive resin sheet having a Young's modulus of 0.2 GPa in which carbon is dispersed in the EVA sheet is used, 40) did not occur.

From this fact, it is appropriate to use the conductive resin sheet 24 having the Young's modulus or less of the Young's modulus of the resin forming the development frame 40 in the present embodiment. That is, the Young's modulus of the conductive resin sheet 24 is preferably equal to or less than the Young's modulus of the resin forming the development frame 40. It is more preferable that the Young's modulus of the conductive resin sheet 24 is smaller than the Young's modulus of the resin forming the development frame 40 (for example, 1/10 or less) The contraction of the developing frame 24 follows the contraction of the developing frame 40 more closely. When the resin forming the development frame 40 is HIPS resin (Young's modulus = 3.5 GPa), for example, a conductive resin sheet (Young's modulus = 0.2 GPa) in which carbon black is dispersed in EVA sheet or a similar sheet can be suitably used .

VIII. Comparison of Examples and Comparative Examples

Next, the superiority of the present embodiment will be described using a comparative example. In the comparative example, elements having functions and configurations equivalent to those of the present embodiment are denoted by the same reference numerals.

(Configuration of Embodiment 1)

The first embodiment is the same as that described in the first embodiment.

(Configuration of Comparative Example 1)

7A is a cross-sectional view (cross section along the width direction of the antenna member 47) of a portion of the development frame 40 in the vicinity of the antenna member 47 at the center in the longitudinal direction of the antenna member 47 of Comparative Example 1 . In Comparative Example 1, an antenna member 47, which is a plate member (SUS sheet metal) formed of SUS (stainless steel), is attached to the formed developing frame 40 with a double-sided adhesive tape 48. That is, in Comparative Example 1, the manufacturing method of the developer container 46 has a step of attaching the previously prepared antenna member 47 to the developing frame 40 after molding with the double-sided adhesive tape 48.

(Advantage for Comparative Example 1 of Example 1)

In Comparative Example 1, a step of fixing the antenna member 47 to the molded developing frame 40 with the double-sided adhesive tape 48 is required. On the other hand, in the first embodiment, only when the conductive resin sheet 24 is adsorbed and held on the metal mold 201 when the developing frame 40 is molded, the antenna member 43 is integrally formed with the developing frame (40) can be obtained. Therefore, in the first embodiment, the developing frame 40 having the antenna member 43 can be manufactured with a smaller number of steps than the first comparative example.

In the comparative example 1, the position of the antenna member 47 may vary due to the variation of the thickness of the double-sided adhesive tape 48 and the thickness of the antenna member 47. [ On the other hand, in the first embodiment, since the A-plane of the antenna member (conductive resin sheet) 43 is held in contact with the metal mold 201, So that the position of the movable member 43 does not vary. As a result, in Example 1, the distance between the antenna member 43 and the developing sleeve 41 is higher than in Comparative Example 1, and the amount of the toner T can be detected with high accuracy.

(Composition of Comparative Example 2)

7B is a cross-sectional view (cross section along the width direction of the antenna member 47) of the development frame 40 in the vicinity of the antenna member 47 at the center in the longitudinal direction of the antenna member 47 of the second comparative example. Fig. 7C is a view similar to the antenna member 47 of the second comparative example in the longitudinal direction. In Comparative Example 2, the antenna member 47, which is an SUS sheet metal, is inserted when the developing frame 40 is molded.

Since the double-sided adhesive tape 48 is not used for fixing the antenna member 47 as in Comparative Example 1, the antenna member 47 of Comparative Example 2 is bonded to the resin of the developing frame 40 in Comparative Example 2 It does not. In the comparative example 2, as shown in Fig. 7C, the stationary part (or fixed shape) 49 is provided on a part of the developing frame 40 corresponding to the longitudinal end of the antenna member 47, (47) to the developing frame (40). In the comparative example 2, the fixing part 49 was formed so as to cover the end face and the both faces (A face and B face) of the antenna member 47 at the longitudinal end of the antenna member 47.

(Advantage for Comparative Example 2 of Example 1)

In the comparative example 2, the thickness " t " of the developing frame 40 at the longitudinal end of the antenna member 47 is larger than that of the first embodiment. Further, in Comparative Example 2, the fixing portion 49 formed of resin is provided between the developing sleeve 41 and the antenna member 47. The detection of the amount of the toner T using the change in capacitance is realized by detecting the change in the capacitance between the electrodes in accordance with the use of the toner T. Therefore, in the comparative example 2, the capacitance changes according to the use of the toner T The detection accuracy of the amount of the toner T can be lowered. On the other hand, in the first embodiment, there is no need to provide a member corresponding to the fixing portion 49, and there is no possibility that the detection accuracy of the toner T caused by the above-described reasons is lowered.

In the comparative example 2, the antenna member 47 can be separated from the developing frame 40 (partially peeled off) as the temperature changes in the atmosphere or when the external force is applied. On the other hand, in the first embodiment, the antenna member (conductive resin sheet) 43 is fixed substantially uniformly and integrally with the developing frame 40 on the B face, It does not. This is presumed to be because the fixing force between the resins is strong. Thereby, the distance between the developing sleeve 41 and the antenna member 47 is stabilized, and the detection accuracy of the amount of the toner T is stabilized. Therefore, deterioration of the detection accuracy of the amount of the toner T hardly occurs.

(Configuration of Embodiment 2)

The second embodiment is configured in accordance with the first embodiment, but the shape of the antenna member 43 is different from that of the first embodiment.

8 is a schematic cross-sectional view of the developing device 4 according to the second embodiment, which is a modification of the first embodiment. Fig. 8 schematically shows a functional block diagram constituting the detection device 130. As shown in Fig.

In Embodiment 2, as shown in Fig. 8, the surface of the developing frame 40 on which the antenna member 43 is provided is not a straight shape (flat shape). However, the conductive resin sheet constituting the antenna member 43 in the second embodiment has flexibility. Therefore, when the developing frame 40 is formed, the developing resin frame 40 having a curved surface as shown in Fig. 8 ) Can be held on the surface of the mold 201 by air suction or the like as in the first embodiment. As described above, it is also possible to make the conductive resin follow the mold surface by a method other than air suction. The resin sheet constituting the antenna member 43 in the first embodiment also has flexibility.

In this way, since the conductive resin sheet constituting the antenna member 43 has caution, the antenna member 43 can be easily disposed on the curved surface of the development frame 40. [ Thus, by positioning the antenna member 43 in a wider range on the bottom surface of the toner chamber 46b having a curved surface, for example, the image forming apparatus 100 can detect the remaining amount of the toner T in a wider range Lt; / RTI >

(Advantage of Example 2)

For example, suppose that an antenna member formed of SUS sheet metal is inserted when the developing frame 40 is molded. The method of fixing the antenna member is the same as that of Comparative Example 2 described above. In this case, since the antenna member is formed of the SUS sheet metal having no flexibility, the SUS sheet metal is processed in advance into the shape corresponding to the curved shape of the portion where the antenna member is disposed in the development frame 40, Is set in a mold and insert-molded. That is, in this case, it is necessary to previously process the SUS sheet metal into a shape conforming to the shape of the corresponding portion of the development frame 40. Further, since the curved surfaces of both the mold and the SUS sheet metal have tolerances, the SUS sheet metal does not adhere to the surface of the curved surface of the metal mold, and a gap may be formed between the metal mold and the SUS sheet metal. In this case, the accuracy of the distance between the antenna member and the developing sleeve 41 may be reduced.

On the other hand, in Embodiment 2, it is possible to maintain the conductive resin sheet on the surface of the mold having a curved surface shape in the same manner as in Embodiment 1 without reducing the accuracy of the distance between the antenna member 43 and the developing sleeve 41 The developing frame 40 including the antenna member 43 can be formed.

[Second Embodiment]

Next, a second embodiment of the present invention will be described. In the second embodiment, elements having the same functions or configurations as those of the first embodiment or corresponding to those of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

In this embodiment, the electrical characteristics of the antenna member, which is preferable for improving the detection accuracy when the amount of the developer is detected by the electrostatic capacitance detection system using the resin-made antenna member, will be described.

Ⅰ. The developing device

9 is a schematic cross-sectional view of the developing apparatus 4 in the present embodiment. The developing apparatus 4 has a developer frame 46 configured to accommodate the toner T as a developer and a developing frame 40 for supporting each element described later. In the present embodiment, the toner T is a developer having an average particle diameter of 7 mu m. In the present embodiment, the development frame 40 is formed of HIPS (impact-resistant polystyrene).

In the present embodiment, the developing sleeve 41 is formed by covering a resin layer of intermediate and low resistance with a thickness of 10 mu m on the surface of a sleeve made of aluminum which is a non-magnetic material. The volume resistivity of the resin layer is about 1 to 10 OMEGA.

In the hollow portion of the developing sleeve 41, a magnet roller 44 as a magnetic field generating means is disposed. The magnet roller 44 is fixedly (non-rotatably) supported by the developing frame 40. In this embodiment, the magnet roller 44 has a plurality of magnetic poles (four magnetic poles of S1, N1, S2, and N2 in the present embodiment) in which N poles and S poles are alternately arranged in the peripheral direction And 20b). The magnetic pole S1 is disposed at a position opposite to the photosensitive drum 1, and is a developing pole for controlling the development of the electrostatic latent image by the toner T. The magnetic pole N1 is a regulating pole arranged at a position opposite to the developing blade 42 to be described later and controlling the amount of the toner T on the developing sleeve 41. [ The magnetic pole S2 is a supply pole (intake pole) for supplying the toner T in the developer container 46 onto the developing sleeve 41. The magnetic pole N2 is a toner leakage preventing pole (seal pole) arranged at a position provided with an ejection preventing sheet 32 configured to prevent leakage of the toner T from the developer container 46. [ Since the magnet roller 44 is always kept at a constant position without performing a rotating operation, the magnetic poles are always held in the same direction.

The developing chamber 46a is provided with a developing blade 42 serving as a regulating member serving as the developer layer thickness regulating means so as to come into contact with the outer circumferential surface of the developing sleeve 41. [ In this embodiment, the developing blade 42 is formed by adhering and fixing a urethane rubber blade, which is a plate-like member formed of an elastic member, to a supporting sheet metal, and the supporting sheet metal is fixed to the developing frame 40. Thereby, the urethane rubber blade is brought into contact with the developing sleeve 41 at an appropriate contact pressure so that the layer thickness of the toner T on the developing sleeve 41 is properly regulated, and the toner layer is triboelectrified. The regulating member may be formed from a material, a resin, or the like that can shield the magnetism. Further, the development chamber 46a is provided with an ejection preventing sheet 32 which is a sheet-like member configured to prevent the toner from being ejected. The ejection preventing sheet 32 contacts the developing sleeve 41 along the edge on the opposite side of the opening 46c on which the developing blade 42 is provided.

In the present embodiment, an antenna member 43 constituting a detection device 130 to be described later is disposed in a part of the bottom surface of the developing chamber 46a.

On the other hand, a stirring member 45 as developer stirring means is disposed in the toner chamber 46b. The stirring member 45 includes a support rod 45a and a stirring sheet 45b fixed to the support rod 45a. The supporting rod 45a is rotatably supported by the developing frame 40 at both ends in the longitudinal direction (rotation axis direction) of the supporting rod 45a. A rotational driving force from a driving motor (not shown) provided in the apparatus main body 110 is transmitted to the stirring member 45 so that the stirring member 45 is rotationally driven in the direction of arrow X3 in Fig. In the present embodiment, the support bar 45a rotates once per second. In this embodiment, the stirring sheet 45b is a PPS sheet (sheet-like member formed of polyphenylene sulfide resin) having a thickness of 100 占 퐉, and the support rod 45a is formed at one end in the width direction of the stirring sheet 45b. As shown in Fig. In the present embodiment, the length in the longitudinal direction of the stirring sheet 45b is 216 mm. The toner T accommodated in the toner chamber 46b is rotated by the stirring member 45 to rotate the toner chamber 46a through the toner supply port 46d, which is an opening for communicating between the developing chamber 46a and the toner chamber 46b 46b to the developing chamber 46a.

The toner T that has been conveyed to the developing chamber 46a and reaches the vicinity of the developing sleeve 41 is pulled close to the developing sleeve 41 by the magnetic pole S2 of the magnet roller 44 and is attracted to the surface of the developing sleeve 41 . The toner T supplied to the developing sleeve 41 by the magnetic force of the magnetic pole S2 is conveyed by the developing sleeve 41 and regulated by the developing blade 42. [ At this time, the toner T passed through the regulating portion is charged by friction. The electrostatic latent image formed on the photosensitive drum 1 is developed by the toner T which has passed through the regulating portion. On the other hand, the toner T regulated by the developing blade 42 is divided into a state in which it is held by the magnetic pole N1 and stays in the vicinity of the developing blade 42 and a state in which the magnetic force of the magnetic pole N1 is insufficient. When the amount of the toner T remaining in the developer container 46 is large, the blown toner T is stirred by the stirring member 45 and then supplied to the developing sleeve 41 again. When the amount of the toner remaining in the developer container 46 is small, the dropped toner T falls vertically and falls in the vicinity of the antenna member 43. The dropped toner T is not attached to the antenna member 43 but is pushed by the toner T sent by the stirring member 45. [ Alternatively, the dropped toner T is pulled close to the developing sleeve 41 by the magnetic force of the magnetic pole S2, and is supplied again to the developing sleeve 41.

A predetermined developing bias (developing voltage) is applied to the developing sleeve 41 from a developing power supply (high voltage power supply) serving as voltage applying means provided in the apparatus main body 110. In the present embodiment, as the developing bias, a generated oscillating voltage is applied by superimposing a DC voltage Vdc of -400 V and an AC voltage Vpp (frequency = 2000 Hz, rectangular wave) of 1400 V. The photosensitive drum 1 is electrically grounded. As a result, an electric field is generated in the developing area 31 where the photosensitive drum 1 and the developing sleeve 41 face each other.

The toner supply port 46d is provided so as to prevent the leakage of the toner from the seal member 48 until the seal member 48 is removed at the start of use of the process cartridge 120 in order to prevent toner leakage in transporting the process cartridge 120, (Fig. 16). In the present embodiment, the seal member 48 is a PS resin sheet, and is bonded in the developer container 46 so that the toner T does not leak in the region shown in Fig. 9 in order to prevent toner leakage during transportation or the like.

Ⅱ. Detection device

Next, the detection device 130 of the present embodiment will be described. 9 is a schematic cross-sectional view of the developing apparatus 4 also showing a functional block of the detecting apparatus 130 of the present embodiment. The basic configuration and operation of the detection device 130 in this embodiment are substantially the same as those in the first embodiment.

In this embodiment, the antenna member 43 as the second electrode (output side electrode, counter electrode) is disposed on a part of the bottom surface of the developing chamber 46a formed by the developing frame 40. [ The antenna member 43 detects a change in the amount of the toner T existing between the surface of the antenna member 43 opposed to the developing sleeve 41 and the developing sleeve 41. In this embodiment, the developing sleeve 41 is used as one electrode of the pair of electrodes, as in the first embodiment, but the developing sleeve 41 may not be used as the electrode of the toner remaining amount detecting means, As shown in Fig. In this case, the degree of freedom in designing the arrangement of the electrodes is increased. That is, the developer container or the developing apparatus needs at least an antenna member configured to detect the developer amount (toner amount) by using the electrostatic capacity.

Ⅲ. About antenna member

The antenna member 43 of this embodiment is formed of a nonmagnetic or a nonmagnetic conductive resin sheet so as not to adhere to the antenna member 43 and arranged so as to be opposed to the vertically lower side of the developing sleeve 41. Specifically, the antenna member 43 was bonded and fixed to the vicinity of the developing sleeve 41 through insert molding, at the bottom surface of the inner wall of the developer container 46. The conductive sheet member constituting the antenna member 43 is provided so that a part of the conductive sheet member when mounted on the developer container 46 overlaps with a part of the developing sleeve 41 in the gravitational direction in order to more accurately detect the electrostatic capacity (Region A in Fig. 9). In the configuration in which the antenna member 43 is located in the vicinity of the lower portion of the developing sleeve 41 and the toner is liable to accumulate on the surface of the electrode due to gravity, by using the conductive resin sheet containing resin, And the effect of being said to be particularly remarkable. This is because the toner having magnetism is not attached to the conductive resin sheet containing resin by magnetic force. In this embodiment also, a conductive resin sheet is provided below the developing sleeve 41 in the gravitational direction. However, the antenna member 43 can also be used when the electrodes are juxtaposed in the horizontal direction with respect to the developer carrying member, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-264612. Specifically, as will be described later, the conductive resin sheet is disposed so as to be in contact with a contact (not shown) disposed in front of the paper surface of Fig. 9 on the bottom surface of the developer container 46, And is connected to the ground through the remaining amount detecting device 134.

The electrostatic capacity between the developing sleeve 41 and the antenna member 43 can be detected by the residual toner amount detecting device 134 by applying a bias to the developing sleeve 41 from the developing power source 131 . In the configuration of the present embodiment, sequential remaining amount detection for sequentially detecting electrostatic capacitance during printing is performed.

12A, 12B and 12C show cross-sectional views of the conductive resin sheet 24. Here, a configuration in which a carbon material is dispersed in a resin, a configuration in which a resin layer containing a dispersed carbon material is interposed between different resin layers, and a configuration in which a carbon material is applied to the surface of the resin layer on the developer bearing member side do.

12A shows a three-layer structure conductive resin sheet (Fig. 12A) in which a resin layer of the PS resin 24d is sandwiched between conductive layers 24c (thickness of 20 mu m to 40 mu m each) 24). In this case, the conductive layer is an electrode, and the entire conductive resin sheet becomes an electrode. Electrical connection to the outside can be done as follows. Specifically, when the conductive resin sheet is cut, the conductive layers on both sides are deformed and connected, and the external electrical contact is connected to the portion to which the conductive layer is connected. As another option, it is also possible to use a conductive resin sheet 24 of a single-layer structure (single-layer structure) in which carbon black 24e is mixed with EVA resin 24d as shown in Fig. 12B. In this case, the entire conductive resin sheet is an electrode. It is also possible to use a conductive resin sheet 24 of a two-layer structure obtained by printing carbon black 24e on the PS resin 24d of Fig. 12C.

In this embodiment, a flexible single-layer conductive resin sheet in which carbon black is dispersed in EVA gas shown in Fig. 12B is used. The content of the carbon black dispersed in the EVA is 35 (30 to 40) wt. %to be. The carbon black content to be dispersed is such that the resistance measured by a measuring method described later is 10 ³ to 10 ⁵ Ω as a countermeasure against a spike current to be described later. The total thickness " t " of the conductive resin sheet 24 depends on the shape of the surface to which the conductive resin sheet 24 of the developer container 46 is attached, It is preferable to use a material having a thickness of 0.05 to 0.3 mm. In the present embodiment, the total thickness "t" is 0.1 mm. An example using carbon black as a carbon material for imparting conductivity has been described. However, it is also possible to impart conductivity by carbon materials other than carbon black, such as graphite, carbon fibers, or carbon nanotubes.

14A is a plan view showing the antenna member 43 of this embodiment in more detail. In this embodiment, the antenna member 43 is formed so as to intersect with the longitudinal direction substantially parallel to the longitudinal direction (rotation axis direction) of the developing sleeve 41 and the longitudinal direction of the antenna member 43 ), Each of which has a predetermined length in the width direction and has a rectangular plan view. In order to obtain an electrical connection from the end in the width direction farther from the developing sleeve 41 to the contact (not shown) of the apparatus main body 110 at the front end of the sheet of Fig. 9 of this rectangular portion, The conductive resin sheet is extended to the outside of the conductive resin sheet 46. That is, in this embodiment, as shown in Fig. 14A of the antenna member 43, the rectangular region is the measuring unit 43A. The extended region surrounded by the dotted line in Fig. 14A of the antenna member 43 is the contact portion 43B serving as an electrical contact point between the antenna member 43 and the apparatus main body 110. [ The contact portion 43B is connected to the ground through a contact point (not shown) with the apparatus main body 110 and a remaining toner amount detecting device 134 disposed in the apparatus main body 110. [ Figs. 15A and 15B are perspective views showing the development frame (in particular, the lower frame 40A) of the present embodiment. 15 (a) shows the inside of the developer container 46, and Fig. 15 (b) shows the outside of the developer container 46. Fig. The measuring portion 43A of the antenna member 43 is disposed on the developing frame 40 so as to face the developing sleeve 41 as shown in Figs. 15A and 15B, but the contact portion 43B Is disposed on the outside of the developing frame 40. The conductive resin member passes through the inside of the developing frame and extends to the outside to form the contact portion 43B on the outside. In the present embodiment, two frames are welded together by ultrasonic welding. A part of the conductive resin member from the point inside the welded portion toward the outside is passed through the thickness of the developing frame and arranged outside the developing frame. A part of the conductive resin member exposed to the outside of the developing frame extends from the inside of the welded portion and reaches the outside of the welded portion around the welded portion. In this way, the contact portion 43B can be formed without being affected by the bonded portion.

In this embodiment, the width in the longitudinal direction (L1 in Fig. 14A) of the rectangular measuring portion 43A of the antenna member 43 is 216 mm, which is the length dimension of the print guarantee area (image area) The width of the measuring portion 43A in the width direction, which is the direction, is 15 mm. In this embodiment, the thickness of the antenna member 43 is 100 占 퐉.

Although the present embodiment uses insert molding, it is more accurate to fix the antenna member 43 using the double-sided adhesive tape in the positioning accuracy of the arrangement of the conductive resin sheet 24 by performing the insert molding, Can be commercially or adhesively fixed to the inner wall of the developer container 46. [ As a result, the distance between the developing sleeve 41, which is an electrode, and the antenna member 43 is improved, and the detection accuracy of the amount of the developer is improved. Particularly, the fixing method according to the first embodiment is preferable.

On the other hand, when the conductive resin sheet 24 of EVA is molded into the developer container 46 by insert molding, due to the difference in the amount of heat shrinkage between the conductive resin sheet 24 and the developer container 46, A phenomenon may occur. The first phenomenon occurs when the shrinkage amount of the developer container 46 is larger than the shrinkage amount of the conductive resin sheet, and the conductive resin sheet 24 may have undulations after cooling. As a result, the distance accuracy to the developing sleeve 41 is consequently deteriorated, so that the detection accuracy of the amount of the developer is lowered. The second phenomenon occurs when the shrinkage amount of the conductive resin sheet 24 is larger than the shrinkage amount of the developer container 46 and the rigidity of the developer container 46 is smaller than the shrinkage force of the conductive resin sheet. (46). As a result, the distance accuracy with respect to the developing sleeve 41 is reduced, so that the detection accuracy of the amount of the developer is lowered. The release preventing sheet 32 is undulated and the toner leaks.

In order to suppress the above phenomenon, for example, the shrinkage amount of the conductive resin sheet should be larger than the shrinkage amount of the developer container 46, and the rigidity of the developer container 46 should be larger than the shrinkage force of the conductive resin sheet . In this way, the conductive resin sheet is brought into close contact with the developer container 46 and is pulled, and the molding is completed. As a result of the examination, by setting the Young's modulus of the conductive resin sheet 24 to 0.2 to 0.3 GPa and the sheet thickness to 0.1 mm for the HIPS developer container 46 having the Young's modulus of 2.5 to 3.5 GPa and the thickness of 1.5 mm, I knew I could satisfy. With this setting, the molding can be completed while maintaining the distance accuracy with respect to the developing sleeve 41 without undulation of the conductive resin sheet 24 and deformation of the developer container 46, and detection of the amount of the developer It is possible to improve the accuracy. In view of the above, in the present embodiment, the thickness of the conductive resin sheet 24 is 0.1 mm and the Young's modulus is 0.25 GPa.

The resin of the conductive resin sheet 24 is bonded to the developer container 46 and the magnetic toner should not adhere thereto. When the HIPS developer container 46 is used, the conductive resin sheet 24 may be formed of PS in addition to EVA. The conductive resin sheet 24 may have any structure as long as the conductive resin sheet 24 includes a conductive layer in which carbon black is dispersed in a surface layer of a conductive layer which is in contact with the toner to be measured. The same effect can be obtained with a sheet of constitution.

It is preferable that the conductive resin sheet 24 is disposed in the vicinity of the developing sleeve 41 in the width direction. This is because the toner that is regulated by the developing blade 42 and dropped is also accurately detected as the remaining toner.

IV. Comparison of Examples and Comparative Examples

(Configuration of Embodiment 3)

The third embodiment is configured in accordance with the second embodiment. The resistance of the conductive resin sheet of Example 3 measured by a measuring method (1) described below is 10 ⁵ Ω or less (10 ⁵ Ω, 10 ⁴ Ω, 10 ³ Ω, 0 Ω).

(Composition of Comparative Example 3)

The third comparative example is different from the antenna member 43 of the third embodiment. The antenna member 43 used in Comparative Example 3 is SUS 304 obtained by rolling the steel sheet to a thickness of 500 μm and machining the SUS metal by cutting the SUS into 216 mm in the longitudinal direction and 15 mm in the width direction. SUS 304 is originally non-magnetic, but when stress is applied, the austenite phase causes martensite transformation and becomes magnetized. The antenna member 43 of Comparative Example 3 is also subjected to rolling and cutting to give stress and magnetic force.

(Example 4)

The fourth embodiment is configured in accordance with the second embodiment, but the antenna member 43 is different from the third embodiment. The shape, material, and fixing method of the antenna member 43 in the fourth embodiment are the same as those in the third embodiment, but in the fourth embodiment, the conductive resin sheet 24 in which the amount of the carbon black dispersed in the EVA resin is reduced is used did. This conductive resin sheet 24 has a resistance of 10 ⁶ Ω when measured by a measuring method (1) to be described later.

(Assessment Methods)

The remaining toner amount is obtained by the following method of calculating the toner remaining amount.

10 is an example of the relationship between the remaining toner amount and electrostatic capacity according to the second embodiment. The vertical axis indicates the electrostatic capacity detected by the toner remaining amount detecting means 134, and the abscissa indicates the remaining toner amount (%). In the configuration of the second embodiment, there is no change in capacitance during the period between the initial point (100%) and 20% (dotted line A). This is because the amount of toner (developer amount) between the developing sleeve 41 and the antenna member 43 does not change because the toner remains sufficiently. When the toner remaining amount becomes 20% or less, the capacitance also decreases linearly as the toner remaining amount decreases. This indicates that the toner amount (developer amount) between the developing sleeve 41 and the antenna member 43 varies with the change in the remaining toner amount.

The difference between capacitance C ₀ and capacitance C _s is called ΔE ₀ . The electrostatic capacity C ₀ represents the electrostatic capacity in a state where the cartridge is brand new and there is no toner between the developing sleeve 41 and the antenna member 43. The electrostatic capacity Cs represents the capacitance at the time of the remaining toner amount of 100% (when it is full) and the time of the remaining toner amount of 20%. When the average value of the electrostatic capacitances measured during the printing of one sheet of image is outputted as the electrostatic capacity C, the electrostatic capacity in the image factor and the electrostatic capacity in the state in which there is no toner between the developing sleeve 41 and the antenna member 43 The difference in capacitance C ₀ is called ΔE. Then, the current remaining toner amount is calculated by the following equation (1).

[Equation 1]

Current toner remaining amount = 20% x? E /? E ₀

The detection result is notified to the user by displaying the result on the display unit of the image forming apparatus, the monitor 21 of the personal computer, and the like.

(Evaluation results)

≪ Comparison of the detection accuracy of toner remaining amount in Example 3 and Comparative Example 3 >

11A shows the relationship between the remaining toner amount and electrostatic capacity measured or outputted by actually performing the endurance test in the third embodiment. Fig. 11B shows the relationship between the remaining amount of toner and the electrostatic capacity after the endurance test was actually performed for Comparative Example 3. Fig. The abscissa is actually the remaining amount of toner in the developer container 46, and the ordinate is the electrostatic capacity.

In Fig. 11A, which is a graph of Example 3, there is no change in the capacitance between 100% and 20% of the remaining toner amount. In the region where the remaining toner amount is 20% or less, the capacitance also linearly decreases as the toner remaining amount decreases. (Hereinafter referred to as " an image having a blank area ") in which the toner is not developed in the longitudinal band pattern at the timing of "1" in FIG. 11A. At this time, Therefore, even if the developing device 4 is shaken at the time of "1", the blank area is not solved.

In Comparative Example 3, as shown in Fig. 11B, similarly to Example 3, when the remaining amount of toner is 100% to 20%, there is no change in the electrostatic capacity. In the region where the remaining toner amount is 20% or less, the capacitance also linearly decreases as the remaining toner amount decreases. However, an image having a blank area was generated when the remaining toner amount was larger than that in Example 3 (" 2 " in Fig. 11B). At this time, it was confirmed that the toner was attached to the antenna member 43. Even if the same amount of toner (developer amount) remains between the electrodes, the toner attached to the antenna member 43 can not be used for development. Therefore, a blank region is generated when the detected toner amount (developer amount) is " 2 "

Toner is attached to the antenna member 43 because the antenna member 43 is magnetized. When the toner remaining amount was measured again after the toner attached to the antenna member 43 was suctioned, the remaining toner amount detected was " 3 " The generated image has a blank area similarly to the image generated at the time of " 2 ". Thus, in the comparative example 3, the generation timing of the image having the blank area differs depending on the amount of toner adhered to the antenna member 43. [ Further, since the amount of toner adhered to the antenna member 43 is different for each developing apparatus, the detection accuracy of the residual toner amount is lowered.

In the third embodiment, it can be seen from the test that all of the toner between the electrodes can be used effectively because the toner is not adhered to the antenna member 43 at the timing " 1 ". That is, it is possible to suppress deterioration in the detection accuracy of the remaining amount of toner due to adhesion of the toner to the antenna member 43, and to improve the detection accuracy of the remaining amount of toner.

≪ Comparison of Detection Accuracy of Toner Remaining Amounts in Examples 3 and 4 >

Table 1 shows the relationship between the resistance of the conductive resin sheet and the detection accuracy of the toner remaining amount measured by the measuring method (1) described later. The symbol " o " in the " remaining amount detection " indicates that the remaining toner amount can be accurately detected. The symbol " Is preferable. The symbol " x " in " remaining amount detection " indicates that the remaining toner amount could not be detected successfully.

In Table 1, in Example 3 in which the resistance of the conductive resin sheet was 10 ⁵ Ω or less, the detection accuracy of the toner remaining amount was good. On the other hand, when the resistance of the conductive resin sheet is 10 ⁶ ? As in the fourth embodiment, the detection signal becomes small, and any sort of signal processing is required to accurately grasp the electrostatic capacitance. This is because the resistance of the conductive resin sheet is high, the current flowing in the toner remaining amount detecting device 134 becomes small, and the toner remaining amount detecting device 134 becomes difficult to detect the electrostatic capacity. Therefore, the resistance of the conductive resin sheet is preferably 10 ⁵ Ω or less. The resistance value per unit length at this time was 420 OMEGA / mm.

The relationship between the conductive sheet resistance measured by the measuring method (1) and the toner remaining amount detection accuracy

Resistance [Ω] Remaining amount detection Example 4 10 ⁶ △ Example 3 10 ⁵ o 10 ⁴ o 10 ³ o 0 o

(Configuration of Embodiment 5) Embodiment 5 is configured in accordance with the second embodiment. The resistance of the conductive resin sheet 24 measured by the measurement method (2) to be described later is 10 ³ Ω or more.

Fig. 13 shows a toner remaining amount detecting circuit as disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-264612. In the case of this toner remaining amount detecting circuit, there is no mechanism (protection resistor) for reducing the amount of current flowing through the remaining toner amount detecting circuit when a spike current such as swinging due to AC voltage application flows. For this reason, there is a risk that the detector of the toner remaining amount detecting device 134 malfunctions. Therefore, it is noted that the fifth embodiment solves the malfunction of the detector due to the spike current.

In Example 4, the antenna member 43 adjusted the amount and dispersion of carbon black so that the resistance measured by the measuring method 2 described later was 10 ³ Ω or more (10 ³ Ω, 10 ⁴ Ω).

(Configuration of Comparative Example 4)

The antenna member 43 of Comparative Example 4 was SUS 304 generally used. The resistance of SUS 304 measured by a measuring method (2) described later was 0 OMEGA.

(Evaluation results)

<Comparison of spike current reduction between Example 5 and Comparative Example 4>

Table 2 shows the relationship between the resistance and the spike current reduction effect measured by the measurement method (2) described later. The relationship between symbols "o", "Δ" and "x" in Table 2 is shown in Table 1.

In Table 2, when the resistance of the conductive resin sheet is 10 ³ ? Or more, both the detection accuracy of the remaining toner amount and the spike current reduction effect are good. The resistance value per unit length at this time was 30? / Mm. In the case of Comparative Example 4 in which the resistance is 0 OMEGA, the effect of reducing the spike current was low, and there was a fear that the detection accuracy of the toner remaining amount by the toner remaining amount detecting device 134 would be lowered.

Relationship between the conductive sheet resistance and the spike current reduction effect measured by the measurement method (2)

Resistance [Ω] Spike current reduction Example 5 10 ⁴ o Comparative Example 4 10 ³ o 0 x

From the above, the results of Examples 3 to 5, the resistance of the conductive resin sheet, a resistance value measuring a resistance value measured by the measuring method (1) to 10 ⁵ Ω or less, and measuring method (2) 10 ³ Ω , It is possible to reduce the spike current while maintaining the detection accuracy of the toner remaining amount. That is, the resistance of the conductive resin sheet is preferably 10 ³ Ω or more and 10 ⁵ Ω or less. Method of measuring resistance of conductive resin sheet

A method of measuring the resistance of the conductive resin sheet in the second embodiment will be described.

The resistance of the conductive resin sheet changes depending on the distance from the contact point. Therefore, the resistance of the conductive resin sheet is defined by the following two measuring methods.

&Lt; Measurement method (1) >

The resistance between the measurement point A and the measurement point B shown in Fig. 14B is measured. The measurement point A is the tip of the contact portion 43B (a surface on the same side as the surface of the measurement portion 43A in contact with the developer). The measurement point B is the point at which the measurement point A is the farthest from the measurement point A on the surface of the measurement section 43A (the surface in contact with the developer) (measurement point B is the point on the development sleeve 41 side in the width direction). Conductive grease is applied to each of the measurement points in a circular pattern having a diameter of 5 mm and the resistance between the measurement point A and the measurement point B is measured using a Fluke 87V (Fluke 87V) manufactured by Fluke.

&Lt; Measurement method (2) >

The resistance between the measurement point A and the measurement point C shown in Fig. 14B is measured. Similarly to the above, the measurement point A is the tip of the contact portion 43B (a surface on the same side as the surface in contact with the developer of the measurement portion 43A). The measurement point C is the closest distance from the measurement point A on the measuring section 43A (the surface in contact with the developer) (the measurement point C is the point on the developing sleeve 41 side in the width direction). Conductive grease is applied to each of the measurement points in a circular pattern having a diameter of 5 mm and the resistance between the measurement point A and the measurement point C is measured using a flick 87V manufactured by Fluke.

In the second embodiment, the magnetic toner adheres to the electrodes. In the second embodiment, the constitution itself is new, and even in the non-magnetic toner which does not cause adhesion problems, the toner remaining amount detecting member A conductive sheet can be used.

[Third embodiment]

Next, a third embodiment of the present invention will be described. In the third embodiment, elements having the same or equivalent functions and configurations as those in the first and second embodiments are denoted by the same reference numerals, and a detailed description thereof will be omitted.

In this embodiment, the arrangement of the antenna members is described in order to improve the detection accuracy of the developer amount by the electrostatic capacitance detection system using the resin-made antenna member.

Ⅰ. The developing device

16 is a schematic sectional view of the developing apparatus 4 in the present embodiment.

In the third embodiment, the seal member 48 is adhered to a seal welding rib 47 provided on a part of the bottom surface of the accommodating portion 40a in the vicinity of the toner supply port 46d. Therefore, when the bottom surface of the accommodating portion 40a is flat, the seal welding ribs 47 can prevent the circulation of the toner T from the toner chamber 46b to the developing chamber 46a. In order to avoid this, in the third embodiment, between the developing sleeve 41 and the agitating member 45, there is a gap of a height equal to or higher than that of the sealing welding rib 47 in the use state of the developing apparatus 4 A convex portion 46e is provided. In the third embodiment, the convex portion 46e is provided on a part of the bottom surface of the toner chamber 46b adjacent to the toner supply port 46d. The convex portion 46e protrudes toward the inside of the developer container and protrudes toward the developing sleeve 41. [ The convex portion 46e allows the agitating member 45 to send the toner T to the vicinity of the developing sleeve 41 without delay even when the sealing welding rib 47 is present. A part of the bottom surface of the toner chamber 46b opposite to the developing sleeve 41 with respect to the convex portion 46e becomes the concave portion 46f. The stirring sheet 45b appropriately penetrates the concave portion 46f when the stirring member 45 is rotationally driven. The toner T sent toward the convex portion 46e by the stirring sheet 45b is raised by the stirring sheet 45b released in the vicinity of the vertex of the convex portion 46e to correspond to the magnetic pole S2 of the magnet roller 44 To the vicinity of a part of the surface of the developing sleeve 41. [ In this manner, the toner T deposited on the bottom surface of the toner chamber 46b can be more reliably conveyed to the vicinity of the developing sleeve 41. [ In the third embodiment, the seal member 48 is attached to the stirring shaft of the stirring member.

Ⅱ. Detection device

Next, the detection device 130 of the present embodiment will be described. The basic configuration and operation of the detection device 130 in this embodiment are substantially the same as those in the first and second embodiments.

17 schematically shows the flow of processing for detecting the amount (remaining amount) of the toner T and notifying the detected amount of the toner T to the user or the like. First, the controller unit 133 starts the image printing operation (S101). Next, the controller unit 133 obtains the result of measuring the electrostatic capacitance by the electrostatic capacitance detecting circuit 132 during image printing (S102). Next, the controller unit 133 refers to the electrostatic capacity detection result and the data table to obtain the remaining amount of the toner T (S103). Next, the controller unit 133 displays information on the obtained remaining amount of the toner T on a display unit (not shown) provided on the apparatus main body 110 or on a monitor (not shown) of the personal computer, .

A change in the electrostatic capacitance due to the consumption of the toner T, such as a transition shown by a solid line in FIG. 19, which will be described later, is a data table for obtaining the remaining amount of the present toner T from the electrostatic capacitance detected by the electrostatic capacitance detection circuit 132 . In the third embodiment, this information is stored in the cartridge-side memory 13 (Fig. 2) provided in the process cartridge 120. Fig. The relationship between the amount of the toner T and the electrostatic capacity can be obtained, for example, as follows. The process cartridge 120 including the developer container 46 is installed in the image forming apparatus 100 every time a predetermined amount of the toner T is sequentially placed in the empty developer container 46 for the first time, (pre-multi-rotation operation), and thereafter, the electrostatic capacitance is measured by the electrostatic capacitance detection circuit 132. The pre-rotation operation is a preparatory operation performed until the image forming apparatus becomes capable of image formation after the image forming apparatus 100 is turned on.

Ⅲ. Configuration and Manufacturing Method of Antenna Member

As a result of the examination by the present inventors, there has been a case where the detection accuracy of the amount of the developer is sometimes lowered even when the conductive resin sheet as the resin electrode is molded integrally with the developing frame by insert molding. For example, even when it is notified that the developer has been used up, a relatively large amount of developer remains in some cases. This is for the following reasons. That is, the conductive resin sheet provided in the mold at a high positional precision for forming a developing frame is heated by the heat of the injected resin and shrunk in the cooling (curing) step. As a result, the positional accuracy of the end portion of the conductive resin sheet changes, and the distance between the end portion of the conductive resin sheet and the developing sleeve as the other electrode changes. As a result, the detection result of the electrostatic capacity becomes different even for the same amount of the developer, and the detection accuracy of the amount of the developer thereby deteriorates.

In the third embodiment, even when the distance between the antenna member 43 and the developing sleeve 41 changes as described above, it is possible to prevent the deterioration of the detection accuracy of the amount of the toner T, Set the batch to solve this problem. The details of the configuration will be described later.

Fig. 18 is a cross-sectional view of a part of a mold 201 configured to mold a developing frame 40 in the vicinity of the place where the conductive resin sheet constituting the antenna member 43 is disposed. The air suction portion 222 is disposed on the side of the end of the conductive resin sheet 24 on the side of the gate 232 and the conductive resin sheet 24 is attached to the first mold 202 Adsorbed. This makes it possible to suppress the occurrence of wrinkles caused by the extension of the conductive resin sheet 24 due to heat from the resin injected into the metal mold 201 and to suppress the positional deviation caused by the heat shrinkage of the conductive resin sheet 24 during cooling can do. Regarding the positioning by the air suction, the position of the conductive resin sheet 24 is not changed by the pressure of the injected resin, and the substantially entire surface of the conductive resin sheet 24 may be sucked by air suction.

In the third embodiment, the conductive resin sheet 24 is a conductive resin sheet having a single-layer structure in which carbon black is dispersed as a conductive material in a base body of EVA to make it conductive. The conductive resin sheet 24 having a multilayer structure generally has a thin conductive layer. Therefore, in order to obtain an electrical connection with the ground electrode, it is desirable to pay attention to the friction generated when, for example, a metal contact or the like is brought into contact with the conductive resin sheet 24.

In the third embodiment, the measuring portion of the conductive resin sheet 24 has a substantially rectangular shape. The length in the longitudinal direction of the measurement section is 216 mm which is equal to the dimension of the image area (the factor guaranteeing area) in the direction substantially orthogonal to the conveying direction of the image. And the length in the width direction of the measurement portion is 40 mm. The thickness of the conductive resin sheet 24 is 100 占 퐉. The developing frame 40 (particularly the bottom surface of a part of the accommodating portion 40a near the antenna member 43) has a thickness of 1.5 mm.

IV. Arrangement of antenna member

Next, the arrangement of the antenna member 43 will be described. There is a possibility that the position of the antenna member 43 is displaced even when the above-described manufacturing method is used. Particularly, there is a possibility that the position of the end portion in the width direction of the antenna member 43, which is a direction intersecting with the longitudinal direction (axial direction) of the developing sleeve 41 as the other electrode (almost orthogonal in the third embodiment) high. This is because the tolerance of the mounting position of the conductive resin sheet 24 provided on the mold 201 (the first mold 202) and the tolerance of the mounting position of the conductive resin sheet 24 (Heat shrinkage or the like) of the heat-shrinkable film. The detection accuracy of the amount of the toner T is likely to deteriorate when the position of the end portion B deviates. The end portion B is an end portion of the antenna member 43 closer to the developing sleeve 41 as viewed in the longitudinal direction (axial direction) of the developing sleeve 41 and exists on the developing sleeve 41 side in the width direction 18).

In the third embodiment, the end portion B in the width direction of the antenna member 43 is located at the position (by the air suction) compared with the other end portion (the end on the gate 232 side at the time of molding) The amount of change in the distance between the developing sleeve 41 and the developing sleeve 41 is liable to increase (Fig. 18).

In the third embodiment, this is solved by setting the arrangement of the latest contact A as shown in Fig. 21A. The nearest point A is a recent point of contact between the antenna member 43 on the antenna member 43 and the developing sleeve 41 when viewed along the longitudinal direction (axial direction) of the developing sleeve 41. [ That is, the nearest point A is disposed at a position other than the end (more precisely, the end B closer to the developing sleeve 41) of the antenna member 43.

In this way, even if the distance between the antenna member 43 and the developing sleeve 41 changes due to shrinkage of the conductive resin sheet 24 or the like, deterioration in the detection accuracy of the amount of the toner T can be suppressed.

Ⅴ. effect

(Relationship between Toner Deposition Method and Detected Capacitance)

19 shows the relationship between the residual amount of toner and the electrostatic capacity. The abscissa is the remaining amount of toner, and the ordinate is the electrostatic capacity to be detected. C ₀ is a capacitance detected when the remaining toner amount is 0%. In the third embodiment, when the electrostatic capacity reaches C ₀ , an image having a blank area is generated at that time, so that the user is notified of toner depletion (drop of toner).

The solid line in Fig. 19 shows the relationship between the remaining amount of toner and the electrostatic capacity obtained in advance as in the above-described configuration in the third embodiment. The broken line in Fig. 19 indicates that when the distance between the antenna member 43 and the developing sleeve 41 is increased due to a shift of the position of the antenna member 43, The relationship between the remaining amount and the capacitance to be detected is shown. The difference between the solid line and the broken line is denoted by? C. When the broken line comes below the solid line, the distance between the antenna member 43 and the developing sleeve 41 is widened, so that the value of the detected capacitance is lowered even though the remaining toner amount is the same. When the electrostatic capacitance C ₀ is detected, the remaining toner amount indicated by the solid line becomes 0%. However, the toner remaining amount indicated by the broken line is not 0%, and a large amount of toner remains by? M. Thus, when the distance between the antenna member 43 and the developing sleeve 41 changes, the detection value of the capacitance with respect to the remaining amount of toner changes by? C. The change in the electrostatic capacity causes the difference? M of the toner remaining amount when the capacitance C ₀ is detected.

In Fig. 19, in the interval 1 from the toner remaining amount m1 to m2, the electrostatic capacity is constant regardless of the remaining toner amount. 20A is a schematic sectional view of a part of the developer container 46 near the antenna member 43 and schematically shows a method of depositing the toner in the developer container 46 in this section. 20A is viewed in the longitudinal direction (rotation axis direction) of the developing sleeve 41 (the same is true of Figs. 20B, 21A, 22A, 23A, 24A and 25A). 20A, the broken lines R1 and R2 show tangential lines of the developing sleeve 41 passing through the widthwise end of the antenna member 43, respectively. The area enclosed by the broken line R1, the broken line R2, the surface of the developing sleeve 41 and the surface of the antenna member 43 is the measurement area of the remaining toner amount (the same applies to Figs. 20b, 21a, 22a and 23a). The surface level of the toner is at the position of H1 when the process cartridge 120 is new, and the position of H2 is determined as the toner is consumed by performing image formation, Until the surface level of the toner reaches the position of H2, the electrostatic capacity is constant irrespective of the remaining toner amount since the measurement region of the toner remaining amount is filled with the toner. The toner conveyed to the vicinity of the developing sleeve 41 by the agitating member 45 is conveyed to the magnetic poles S2 of the magnet roller 44 (Not shown) of the developing sleeve 41 The toner supplied to the surface of the developing sleeve 41 is conveyed to the contact portion between the developing blade 42 and the developing sleeve 41 by the rotation of the developing sleeve 41 The toner peeled off from the surface of the developing sleeve 41 by the developing blade 42 is returned to the toner chamber 46b by the agitating member 45 (arrow T3).

Next, in Fig. 19, in the interval 2 from the toner remaining amount m2 to 0%, the capacitance decreases as the toner remaining amount decreases. 20B is a schematic sectional view of a part of the developer container 46 in the vicinity of the antenna member 43, which schematically shows the method of depositing the toner in the developer container 46 in this section. In Fig. 20B, H3 and H4 indicate the surface level of the toner, respectively. In Fig. 19, near the time when the remaining toner amount is less than m2, the surface level of the toner is at the positions of H3 and H4. The surface level of the toner just before the generation of the image having the blank area is H4. Since the surface level H3 of the toner enters the measurement region of the toner remaining amount, the capacitance decreases as the toner is consumed. Finally, as indicated by the surface level H4 of the toner, the toner is deposited in the vicinity of the contact area between the developing sleeve 41 and the developing blade 42 by the action of the magnetic poles of the magnet roller 44. [ The circulation of toner in the interval 2 is not limited to the circulation in the interval 1, and there is also toner falling in the vicinity of the antenna member 43 as indicated by the arrow t4. Finally, when the surface level of the toner reaches H4, the toner moves from the arrow t1 to the arrow t2, and then to the arrow t3 (from t1 to t2 to t3), the toner is conveyed to the developing sleeve 41 along with the rotation of the developing sleeve 41, And in the toner deposition in the vicinity of the contact area of the developing blade 42.

(Positional relationship between the antenna member and the developing sleeve)

The dispersion of the position of the antenna member 43 results in dispersion of the detection result of the capacitance. The closer the distance between the developing sleeve 41 and the antenna member 43 is, the higher the detection sensitivity of the electrostatic capacity becomes. Therefore, particularly high accuracy is required for the positional accuracy of a part of the antenna member 43 near the developing sleeve 41. [

21A is a schematic sectional view in the vicinity of the antenna member 43 showing the arrangement relationship between the developing sleeve 41 and the antenna member 43 in the third embodiment. In the third embodiment, the most recent contact point A in the antenna member 43 is located at a position other than the end B. [ More specifically, in the antenna member 43, the nearest point A is located between the end B and the opposite end. In the third embodiment, the nearest distance between the nearest point A and the developing sleeve 41 is 5 mm, and the distance between the nearest point A and the end B is 3 mm. The closest distance between the end portion B and the developing sleeve 41 is 5.2 mm.

The specific arrangement of the antenna member 43 is not limited to that of the third embodiment. The proximal contact point A between the developing sleeve 41 and the antenna member 43 on the antenna member 43 (second electrode) is at a position other than the end B on the developing sleeve 41 (first electrode) side It is only necessary to arrange the antenna member 43 so that the antenna member 43 is disposed at a predetermined position. If the distance between the closest position A and the end portion B is further away, the influence of the vibration of the position of the end portion B on the detection accuracy of the residual toner amount is preferable.

(Composition of Comparative Example 5)

22A is a schematic sectional view in the vicinity of the antenna member 43 showing the arrangement relationship of the developing sleeve 41 and the antenna member 43 in Comparative Example 5. Fig. The configuration of the comparative example 5 is substantially the same as that of the third embodiment except for the following points.

In the comparative example 5, the antenna member 43, which is a plate member (SUS sheet metal) formed of stainless steel (SUS), adheres the antenna member 43 to the development frame 40 with double- Respectively. In Comparative Example 5, the nearest point A to the developing sleeve 41 in the antenna member 43 coincides with the end B on one side of the developing sleeve 41.

(Evaluation of Third Embodiment and Comparative Example 5)

In the third embodiment shown in Fig. 21A and the comparative example 5 shown in Fig. 22A, the portion where the end portion B of the antenna member 43 is located in Fig. 22A is shifted in the direction indicated by the arrow Z Toward the other end of the member 43) was reduced in size to change the position of the end portion B by 2 mm. Then, the influence of the positional accuracy on the detection accuracy of the toner remaining amount was evaluated.

21B shows the relationship between the remaining amount of toner remaining in the developer container 46 and the detected electrostatic capacity in the configuration of the third embodiment. 22B shows the relationship between the remaining amount of toner remaining in the developer container 46 and the detected electrostatic capacity in the constitution of Comparative Example 5. Fig. The solid line in Fig. 21B shows the relationship between the toner remaining amount and the electrostatic capacity in the third embodiment in which the antenna member 43 is disposed as shown in Fig. 21A. The solid line in Fig. 22B shows the relationship between the toner remaining amount and the electrostatic capacity in Comparative Example 5 in which the antenna member 43 is disposed as shown in Fig. 22A. 21B and 22B, the broken line indicates the relationship between the remaining amount of toner and the electrostatic capacity when the position of the antenna member 43 is shifted by 2 mm as described above.

The solid lines in Figs. 21B and 22B indicate that the electrostatic capacity detected in the section 1 where the remaining toner amount is from m1 to m2 is not changed. This is because, as described above with reference to Fig. 20A, the surface level of the toner is between H1 and H2 in the interval 1. As described above, since the amount of toner in the measurement area is not changed even if the toner remaining amount is reduced in this section, the detected capacitance is constant. In the third embodiment, the amount of m2 is about 20% of the remaining amount of the toner.

The solid lines in Figs. 21B and 22B indicate that the electrostatic capacity detected in the section 2 where the remaining toner amount is from m &lt; 2 &gt; to 0% linearly deviates from the remaining amount of the toner. This is because, as described with reference to Fig. 20B, when the surface level of the toner shifts from the position of H3 to the position of H4, the amount of toner in the measurement area is reduced.

The broken lines in Figs. 21B and 22B indicate that the trend of the electrostatic capacity shown by the solid line has the same tendency. However, as a whole, the value of the capacitance to be detected becomes smaller in the case of the broken line than in the case of the solid line. This is because, as can be seen from Figs. 21A and 22A, the position of the end portion B of the antenna member 43 is shifted, so that the antenna member 43 is moved away from the developing sleeve 41, And the value of the detected capacitance is lowered. When the detected electrostatic capacity decreases, the remaining toner amount obtained by referring to the data table becomes small.

Comparing the difference (difference)? C between the solid line and the broken line in the third embodiment shown in Fig. 21B and the difference? C between the solid line and the broken line in Comparative Example 5 shown in Fig. 22B, the difference? Big. The reason why? C in Comparative Example 5 is larger than that in the third embodiment is as follows.

Reason 1: Since the nearest point A with the highest detection sensitivity of the capacitance in the antenna member 43 coincides with the end B, when the position of the end B is shifted by 2 mm, The distance changes. As a result, the detection value of the electrostatic capacitance largely changes (goes down), so that? C becomes large.

Reason 2: The antenna member 43 becomes 2 mm smaller in the direction of the arrow Z in FIG. 22A, so that the measurement range of the capacitance is narrowed, and the detection value of the capacitance becomes small.

On the other hand, the third embodiment is different from the fifth comparative example in the above-mentioned reason 1. In the third embodiment, the end contact point A and the end contact point B, which have the highest electrostatic capacitance detection sensitivity, do not coincide with each other. Therefore, even if the position of the end portion B is shifted by 2 mm, the closest distance that most affects the detection sensitivity of the capacitance does not change, so that the detection value of the capacitance is relatively less influenced. As a result, in the third embodiment,? C is smaller than Comparative Example 5 for the reason 1 described above. The difference ΔM of the residual toner amount when the electrostatic capacity C ₀ at which the image with the blank area is generated is detected because ΔC is smaller in the third embodiment than in ΔM 2 in the comparative example 5, The smaller the value of? M1 is.

In the third embodiment, the positions of the nearest point A and the end B in the antenna member 43 are shifted as described above. As a result, even when the position of the end portion B of the antenna member 43 is accidentally deviated due to the influence of the positional deviation at the time of installation, the tolerance of each component, the deformation due to heat shrinkage, or the like, , The remaining amount of toner can be notified precisely until the toner is used up. Therefore, it is possible to suppress deterioration in the detection accuracy of the amount of the developer when the conductive resin sheet is used as the electrode configured to detect the electrostatic capacitance. Accordingly, it becomes possible to provide a developer container, a developing apparatus, a process cartridge, and an image forming apparatus of a more inexpensive construction while maintaining or improving the detection accuracy of the amount of the developer.

[Fourth Embodiment]

Next, a fourth embodiment of the present invention will be described. Elements having the same functions and configurations as those of the first to third embodiments in the fourth embodiment, and corresponding to those in the first to third embodiments are denoted by the same reference numerals, and a detailed description thereof will be omitted. The fourth embodiment is, in particular, a modification of the third embodiment.

23A is a schematic sectional view of a part of the vicinity of the antenna member 43 of the developing apparatus 4 in the fourth embodiment. In the fourth embodiment, the antenna member 43 is disposed in the convex portion 46e formed on the bottom surface of the accommodating portion 40a. The nearest point A is disposed in a part near the apex of the convex portion 46e of the antenna member 43. [ As a result, the end portion B (the end on the side of the developing sleeve 41) of the antenna member 43 is in contact with the developing sleeve 41, as compared with the third embodiment in which the antenna member 43 is flat, And the distance between the developing sleeve 41 and the developing sleeve 41 becomes wider. Therefore, the influence of the vibration at the position of the end portion B of the antenna member 43 becomes smaller as compared with the third embodiment.

In the fourth embodiment, the closest distance between the nearest point A and the developing sleeve 41 is 5 mm, and the distance between the nearest point A and the end B is 3 mm. The closest distance between the end portion B and the developing sleeve 41 is 6.8 mm, which is longer than that of the third embodiment.

Evaluation of the fourth embodiment was conducted in a manner similar to that used in the third embodiment. 23B shows the relationship between the remaining amount of toner remaining in the developer container 46 and the detected electrostatic capacity in the configuration of the fourth embodiment. The solid line in Fig. 23B is the relationship between the toner remaining amount and the electrostatic capacity in the arrangement of the antenna member 43 of the fourth embodiment shown in Fig. 23A. The broken line in Fig. 23B shows a reduction in the size of a part of the antenna member 43 of the fourth embodiment in which the end portion B is located in the direction indicated by the arrow Z in Fig. 23A (toward the other end of the antenna member 43) The relationship between the amount of residual toner and the electrostatic capacity when the position of the end portion B deviates by 2 mm is shown.

From Fig. 23 (b), it is known that the electrostatic capacitance detected with respect to the actual remaining toner amount becomes small due to the influence of shifting the position of the end portion B of the antenna member 43. [ In the fourth embodiment shown in Fig. 23B, the difference? C in the solid line and the broken line is compared with the difference? C in the solid line and the broken line in the comparative example 5 shown in Fig. 22B. The reason why the difference? C in Comparative Example 5 is larger than that in the fourth embodiment is that, for reasons 1 and 2 above, there are one of the following reasons.

Reason 3: By disposing the most recent contact point A on the convex portion 46e, the distance between the end portion B and the developing sleeve 41 is smaller than the distance between the end portion B and the developing sleeve 41 as compared with the case where the antenna member 43 is flat, Is far away. Thus, the influence of the displacement of the end portion B on the detected value of the capacitance is further reduced.

Thus, in the fourth embodiment, the difference? C is smaller than that in Comparative Example 5. As a result, the difference ΔM of the residual toner amount when the capacitance C _{0, which} is the timing at which the image with the blank area is generated, is smaller in ΔM 3 in the fourth embodiment than in Comparative Example 5 in which the difference ΔM is ΔM 2 Loses.

The difference? C in the fourth embodiment is smaller than? C in the third embodiment, and the difference? M3 in the fourth embodiment is smaller than? M1 in the third embodiment. This is also believed to be due to reason 3 above.

According to the fourth embodiment, the same effects as those of the third embodiment can be obtained. Further, by disposing the most recent contact A on the convex portion 46e, it is possible to suppress the deterioration of the detection accuracy of the toner remaining amount to a better level .

[Fifth Embodiment]

Next, another embodiment of the present invention will be described. Elements having the same functions and configurations as those of the first to fourth embodiments in the fifth embodiment and corresponding to those in the first to fourth embodiments are denoted by the same reference numerals and detailed description thereof will be omitted. The fifth embodiment is particularly another modification of the third embodiment.

In the third and fourth embodiments, the remaining amount of toner that can be detected is from 20% to 0%. This is because the third and fourth embodiments are configured such that the amount of toner in the measurement region does not change until the remaining toner amount is reduced to 20%. By bringing the antenna member 43 close to the developing sleeve 41, it is possible to accurately detect the vicinity of the residual toner amount of 0%. However, in this case, the measurement area of the toner remaining amount can be reduced. It is preferable to increase the measurement area by the antenna member 43 in order to start the detection of the remaining amount of toner from the initial stage where the residual toner amount is larger while maintaining the detection accuracy near the toner residual amount 0%.

As a method for increasing the measurement area of the toner remaining amount, a method of increasing the measurement area of the toner is disclosed in which a plurality of pieces (for example, two sheets) of the antenna member formed of SUS sheet metal or the like, Etc.) were carried out. In this case, each antenna member is connected to a capacitance detection circuit. However, in the case of such a configuration, since the tolerance of the distance as described in the third embodiment by each antenna member attached to the developer container is applied to the equation, the detection result of the remaining toner amount changes. In addition, since the antenna member 43 is stuck with a plurality of pieces (for example, two pieces), the number of steps for manufacturing the developer container is higher than in the case of the comparative example 5, for example.

24A is a schematic sectional view of a part of the vicinity of the antenna member 43 of the developing apparatus 4 in the fifth embodiment. In the fifth embodiment, the antenna member 43 is continuously arranged from the convex portion 46e formed on the bottom surface of the accommodating portion 40a to the concave portion 46f. Thereby, the antenna member 43 faces the developing sleeve 41 and has two surfaces, that is, a measuring region 1 and a measuring region 2, which are capable of measuring electrostatic capacitance. The antenna member 43 is disposed behind the convex portion 46e with respect to the developing sleeve 41 between the convex portion 46e and the concave portion 46f and has a non- . In this manner, in the fifth embodiment, the antenna member 43 has at least one convex portion protruding toward the developing sleeve 41 side (first electrode side), and the latest contact point A is located at the convex portion. In the fifth embodiment, the antenna member 43 has at least one concave portion facing the developing sleeve 41 with respect to the convex portion. As described above, a single antenna member 43 forms a plurality of surfaces facing the developing sleeve 41. [

Specifically, in FIG. 24A, the broken line R 1 indicates that the boundary line R 4 of the region behind the convex portion 46 e with respect to the developing sleeve 41 is located at the point of contact with the antenna member 43 at the developing sleeve 41 side The vicinity of the vertex of the developing sleeve 46e). The broken line R2 is a tangent line of the developing sleeve 41 passing through the end portion B of the antenna member 43 on the developing sleeve 41 side. The area enclosed by the broken line R1, the broken line R2, the surface of the developing sleeve 41, and the surface of the antenna member 43 is the measurement area 1 of the residual toner amount. 24A, the broken line R3 is a tangent of the developing sleeve 41 passing through the end of the antenna member 43 on the side facing the developing sleeve 41 side. The broken line R4 is a boundary line of the region behind the convex portion 46e with respect to the developing sleeve 41. [ The area enclosed by the broken line R3, the broken line R4, the surface of the developing sleeve 41, and one of the surfaces of the antenna member 43 is the measurement area 2 of the residual toner amount. In Fig. 24A, the surface of the antenna member 43 and the region surrounded by the broken line R4 are non-measurement regions where the residual toner amount is not measured.

FIG. 24B shows the relationship between the remaining amount of toner and the electrostatic capacity, as previously described in the configuration of the fifth embodiment. The abscissa is the residual amount of toner, and the abscissa is the electrostatic capacity at which the abscissa is detected. C ₀ is a capacitance detected when the residual toner amount is 0% at which an image having a blank area is generated.

In Fig. 24B, in the interval 1 from the toner remaining amount m1 to m2, the electrostatic capacity becomes constant regardless of the remaining toner amount. The surface level of the toner in this section is the position of H5 in Fig. 24A. When the process cartridge 120 is new, the surface level of the toner is higher than the position of H5, and shifts toward the position of H5 as toner is consumed by performing image formation. Until the surface level of the toner reaches the position of H5, since the respective measurement regions are filled with the toner, the electrostatic capacity is constant regardless of the remaining toner amount. In the fifth embodiment, the remaining toner amount ranges from 100% to 50%.

Next, in Fig. 24B, in the section 2 where the remaining toner amount is from m2 to m3, the electrostatic capacity is reduced as the remaining toner amount is reduced. The surface level of the toner in this section is a position between H5 and H6 in Fig. 24A. Since the toner amount changes in the measurement region 2 when the toner surface level is between H5 and H6, the change in the capacitance in the region 2 is dominant in the detection result in the measurement region 2. [ In the fifth embodiment, the remaining toner amount ranges from 50% to 30%.

Next, in Fig. 24B, in the interval 3 from the m3 to m4 toner remaining amount, the electrostatic capacity becomes constant again irrespective of the remaining toner amount. The surface level of the toner in this section is, for example, the position of H7 in Fig. 24A. While the toner is present in the non-measurement area, since the amount of toner in the area can not be measured, the electrostatic capacity becomes constant irrespective of the remaining toner amount. In the fifth embodiment, the remaining toner amount ranges from 30% to 20%.

The vicinity of the developing sleeve 41 is substantially filled with the toner sent from the agitating member 45 while the surface level of the toner is between H5 and H7 and the detection result in the measuring region 1 does not change so much.

Next, in Fig. 24B, in the section 4 where the remaining toner amount is from m4 to 0%, the residual toner amount and the electrostatic capacity become linear again. The surface level of the toner in this section is changed as described in the third embodiment with reference to Fig. 20B. Specifically, the surface level of the toner changes from the position H7 to the position H8 in Fig. 24A. Since the toner amount changes in the measurement region 1 while the surface level of the toner changes from H7 to H8, the change in the capacitance in the region 4 is dominant in the detection result in the measurement region 1. [ In the fifth embodiment, the remaining toner amount ranges from 20% to 0%.

(Configuration of Comparative Example 6)

25A is a schematic sectional view of a part of the vicinity of the antenna member 43 of the developing apparatus 4 in the comparative example 6. Fig. The configuration of Comparative Example 6 is substantially the same as that of the fifth embodiment except for the following points. In the comparative example 6, two antenna members, i.e., a first antenna member 43a and a second antenna member 43b, which are SUS sheet metal, are provided. The first and second antenna members 43a and 43b are disposed so as to face the developing sleeve 41, respectively. The first antenna member 43a is disposed in the vicinity of the developing sleeve 41 and the second antenna member 43b is disposed in the vicinity of the developing sleeve 41 so that the remaining toner amount can be detected in a wider area than the above- (41). The first and second antenna members 43a and 43b correspond to the nearest point A to the developing sleeve 41 and the end B to the developing sleeve 41 side, respectively. The first and second antenna members 43a and 43b are each connected on a coin and connected to the ground through the capacitance measurement circuit 132. [

(Evaluation of the fifth embodiment and Comparative example 6)

The evaluation of the fifth embodiment and the comparative example 6 was carried out in the same manner as in the case of the third embodiment. In the fifth embodiment shown in Fig. 24A and the comparative example 6 shown in Fig. 25A, the end portion B of the antenna member 43 on the side of the developing sleeve 41 is bent in the direction of arrow Z ), The position of the end portion B was changed by 2 mm. Then, the influence of the positional accuracy on the detection accuracy of the toner remaining amount was evaluated. In Comparative Example 6, the position of the end portion B on the developing sleeve 41 side in each of the first antenna member 43a and the second antenna member 43b was changed by 2 mm as described above.

Fig. 24C shows the relationship between the remaining amount of toner remaining in the developer container 46 and the detected electrostatic capacity in the configuration of the fifth embodiment. 25B shows the relationship between the amount of remaining toner remaining in the developer container 46 and the detected electrostatic capacity in the configuration of Comparative Example 6. Fig. The solid line in Fig. 24C shows the relationship between the toner remaining amount and the electrostatic capacity in the fifth embodiment in which the antenna member 43 is arranged as shown in Fig. 24A. The solid line in Fig. 25B shows the relationship of the remaining toner amount-capacitance in Comparative Example 6 in which the antenna member 43 is disposed as shown in Fig. 25A. In each of Figs. 24C and 25B, the broken line indicates the relationship between the remaining amount of toner and the electrostatic capacity when the position of the end portion B side of the antenna member 43 is shifted by 2 mm as described above.

It is seen from Figs. 24C and 25B that the electrostatic capacity detected with respect to the remaining amount of toner is small due to the influence of shifting the position of the end portion B of the antenna member 43. [ Comparing the difference (difference)? C between the solid line and the broken line in the fifth embodiment shown in Fig. 24C and the difference? C between the solid line and the broken line in the comparative example 6 shown in Fig. 25B, This is big. The reason why the difference? C in Comparative Example 6 is larger than that in the fifth embodiment is considered to be the reasons 1, 2, and 3 described above.

Thus, in the fifth embodiment, the difference? C is smaller than that in Comparative Example 6. [ As a result, the difference ΔM of toner remaining amount when the electrostatic capacity C ₀ at which the image with the blank area is generated is smaller than that of Comparative Example 6 in which ΔM is ΔM5, ΔM4 in the fifth embodiment is smaller.

According to the fifth embodiment, the same effects as those of the third and fourth embodiments can be obtained. In addition, it is possible to notify the remaining amount of toner sequentially from the initial stage in which the remaining amount of toner is large without promoting deterioration in the detection accuracy of the remaining amount of toner, for example, by increasing the number of antenna members.

According to the embodiments disclosed in this specification, a developer container in which the amount of developer is detected by the electrostatic capacity detection method can be simply manufactured. The developer container, the developing device, and the process cartridge of the embodiments disclosed herein can improve the detection accuracy when the amount of developer is detected by the electrostatic capacity detection method using the conductive resin member as the electrode.

While the invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (23)

A method of manufacturing a developer container for a developing apparatus,
Wherein the developer container includes a frame configured to define a developer accommodating portion,
Wherein the developing device is provided with an electrode which is used for outputting an output reflecting a capacitance according to an amount of the developer stored in the developer accommodating portion and which is disposed on the inner surface of the frame of the developer accommodating portion,
The method of manufacturing the developer container,
Holding the conductive resin sheet having the thickness of 0.05 mm to 0.3 mm, which functions as the electrode, for positioning the conductive resin sheet on a mold configured to mold the frame,
Contacting the surface of the conductive resin sheet with the surface of the mold, the surface of the mold being on a side for forming the inner surface of the frame of the developer receiving portion; And
Holding the first region of the conductive resin sheet in the holding region of the mold by the holding means;
The resin to form the frame is inserted into the mold in which the conductive resin sheet is held from the position where the gate is provided without overlapping with the conductive resin sheet when viewed in the direction crossing the longitudinal direction of the frame, Injecting in the crossing direction; And
And curing the resin to form the frame in which the electrode constituted by the conductive resin sheet is fixed,
Wherein the conductive resin sheet has one end portion and the other end portion with respect to the width direction of the conductive resin sheet and the width direction intersects the longitudinal direction of the conductive resin sheet,
Wherein the other end is located farther from the first region than the one end and the other end is located farther from the gate than the first region. The conductive resin sheet according to claim 1, wherein the electrode includes a second electrode having a surface facing the first electrode, wherein the conductive resin sheet has, on the frame side, Wherein the surface of the developer container is made of a material having a specific surface area. The method for manufacturing a semiconductor device according to claim 1, wherein the electrode includes a second electrode having a surface facing the first electrode, and at least a part of a surface of the conductive resin sheet which contacts the metal mold Of the developer container. The method for manufacturing a developer container according to claim 2, wherein the opposite side of the surface of the conductive resin sheet opposite to the first electrode has compatibility or adhesiveness with respect to the resin forming the frame. The method for manufacturing a developer container according to claim 2, wherein all the surfaces of the conductive resin sheet on the side of the frame have compatibility or adhesiveness with respect to the resin forming the frame. The method according to claim 1, wherein holding the conductive resin sheet on the mold further comprises holding the conductive resin sheet on the mold by air suction through a hole provided in the mold, Gt; The method of manufacturing a developer container according to claim 1, wherein the surface of the mold on which the conductive resin sheet is held comprises a curved surface. The method of manufacturing a developer container according to claim 1, wherein the conductive resin sheet has a single-layer structure or a multi-layer structure. The method according to claim 1, wherein the conductive resin sheet has a resistance of 10 ³ Ω or more and 10 ⁵ Ω or less. The method of claim 1, wherein the holding step includes holding the conductive resin sheet so that the surface of the conductive resin sheet is in direct contact with the surface of the mold. The method for manufacturing a developer container according to claim 1, wherein the conductive resin sheet has a Young's modulus equal to or lower than the Young's modulus of the resin forming the frame. 2. The method of claim 1, wherein the electrode comprises a second electrode having a surface facing the first electrode,
A closest point on the second electrode closest to the first electrode is disposed at a position other than the end of the second electrode when viewed along the axial direction of the first electrode,
The second electrode has one or more convex portions protruding toward the first electrode,
And the nearest point is located in the at least one convex portion. 13. The organic electroluminescence device according to claim 12, wherein the second electrode has at least one concave portion on the opposite side to the first electrode with respect to the at least one convex portion, Wherein the plurality of developer containers are formed. The method of manufacturing a developer container according to claim 1, wherein the conductive resin sheet has a curved surface. The method according to claim 1, wherein the shape of the frame in a plane perpendicular to the longitudinal direction of the frame is asymmetric with respect to a line as a symmetry axis extending in the injection direction of the resin through the position. A method of manufacturing a developing apparatus,
Producing a developer container by the method for manufacturing a developer container according to claim 1; And
And attaching a developer carrying member configured to carry and carry the developer to the developer container. 17. The method of claim 16, wherein the electrode comprises a second electrode having a surface facing the first electrode,
Wherein the developer carrying member functions as the first electrode. A method of manufacturing a process cartridge detachably mountable to a main body of an image forming apparatus,
Producing a developer container by the method for manufacturing a developer container according to claim 1; And
And attaching an image bearing member on which an electrostatic image is formed to the developer container. A manufacturing method of an image forming apparatus in which an electrostatic image is developed into a developer image by using a developer, the developer image is transferred to a recording material, and the recording material is output,
Producing a developer container by the method for manufacturing a developer container according to claim 1; And
And attaching an image bearing member on which an electrostatic image is formed to the developer container. The method of manufacturing a developer container according to claim 1, wherein the developing apparatus includes a plurality of conductive resin sheets, and the developer amount is detected using the electrostatic capacitance between the plurality of conductive resin sheets. 2. The image forming apparatus according to claim 1, wherein the electrode includes a second electrode having a surface facing the first electrode, and an amount of the developer in the developer accommodating portion is detected based on electrostatic capacity between the first electrode and the second electrode Wherein the developer container is made of a synthetic resin. The method of manufacturing a developer container according to claim 1, wherein the conductive resin sheet is non-magnetic or non-magnetic. delete

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