Image forming apparatus

Abstract

The present application relates to an image forming apparatus. The image forming apparatus includes a storage portion, an image forming portion, a first electrode, a second electrode, a detected portion, a moving portion, a measuring portion, and a processor. The storage portion stores a recording material. The image forming portion forms an image using the recording material supplied from the storage portion. The detected portion is located inside the storage portion and is movable in a manner that at least one of a distance from the first electrode and a distance from the second electrode varies. The moving portion moves the detected portion located inside the storage portion. The measuring portion measures electrostatic capacitances of the first electrode and the second electrode. The processor controls the image forming portion based on an anomaly detected based on the electrostatic capacitances.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to an image forming apparatus. BACKGROUND

[0002] In the related art, a piezoelectric sensor or the like is used in order to detect whether toner is present in a storage portion that stores toner in an auxiliary hopper or the like. However, the method using the piezoelectric sensor or the like requires a hole to be formed in a wall surface of the storage portion, which can be a main cause of toner leakage. In the method using the piezoelectric sensor or the like, the sensor is expensive in many cases. In the method using the piezoelectric sensor or the like, the power consumption of the sensor is large in many cases.

[0003] In the related art, a method of detecting the presence of toner using an electrostatic capacity sensor has also been proposed. However, in the case of using the electrostatic capacity sensor, there is a problem in that the presence or absence of toner in an initial state is not known. SUMMARY

[0004] The image forming apparatus of the embodiment includes a storage portion, an image forming portion, a first electrode, a second electrode, a detected portion, a moving portion, a measuring portion, and a processor. The storage portion stores a recording material. The image forming portion forms an image using the recording material supplied from the storage portion. The detected portion is located inside the storage portion and is movable in a manner in which at least one of a distance from the first electrode and a distance from the second electrode changes. The moving portion moves the detected portion located inside the storage portion. The measuring portion measures an electrostatic capacity of the first electrode and the second electrode. The processor controls the image forming portion based on an abnormality detected based on the electrostatic capacity. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 FIG. 1 is a diagram of an example of a main structure of an image forming apparatus to which the embodiment is applied.

[0006] Figure 2 FIG. 2 is a cross-sectional view showing an example of a main structure of an auxiliary hopper in FIG. 1. Figure 1

[0007] Figure 3 FIG. 3 is a diagram of an example of a main structure of an image forming portion in FIG. 1. Figure 1

[0008] Figure 4 FIG. 4 is a block diagram showing an example of a main circuit structure of an image forming apparatus to which the embodiment is applied.

[0009] Figure 5 FIG. 5 is a diagram showing a model of an electrostatic capacity C between a first electrode and a second electrode in FIG. 1. Figure 2

[0010] FIG. 5 is a diagram showing a model of an electrostatic capacity C between a first electrode and a second electrode in FIG. 1.​​Figure 6 is a graph showing a model of the electrostatic capacitance Cd.

[0011] Figure 7 is a graph showing a model of the electrostatic capacitance Cd. Figure 2 Figure 2 is a graph showing a model of the electrostatic capacitance Cdb when the detected portion in the

[0012] Figure 8 is a graph showing a model of the electrostatic capacitance Cdb when the detected portion in the Figure 2 Figure 2 is a graph showing a model of the electrostatic capacitance Cdb when the detected portion in the

[0013] Figure 9 is a graph showing a model of the electrostatic capacitance Cdb when the detected portion in the Figure 2 Figure 2

[0014] Figure 10 is a flowchart showing an example of processing by the processor 151 in the Figure 4

[0015] Figure 11 is a graph showing a time change of the electrostatic capacitance C.

[0016] Figure 12 is a graph showing a model of the electrostatic capacitance Cdb when the detected portion in the Figure 2

[0017] BRIEF DESCRIPTION OF DRAWINGS

[0018] 100 … … image forming apparatus, 101 … … printer, 103 … … operation panel, 114 … … toner cartridge, 115 … … auxiliary reservoir, 116 … … image forming portion, 151 … … processor, 152 … … ROM, 153 … … RAM, 154 … … auxiliary storage device, 155 … … communication interface, 156 … … bus, 1031 … … touch panel, 1033 … … speaker, 1151 … … storage portion, 1152 … … wall surface, 1153 … … detected portion, 1154 … … rotating body, 1155 … … substrate, 1156 … … first electrode, 1157 … … second electrode, 1158 … … control circuit, 1159 … … supply portion, 1163 … … developing assembly, 11631 … … developer container, 11632 … … stirring mechanism, 11633 … … developing roller, 11635 … … toner sensor. DETAILED DESCRIPTION ​​​​​​

[0019] Next, an image forming apparatus according to an embodiment will be described using the drawings. Each of the drawings used to describe the following embodiments has a case where the scale of each part is appropriately changed. Each of the drawings used to describe the following embodiments has a case where a structure is omitted for convenience of description. In each of the drawings and this specification, the same reference signs indicate the same elements.

[0020] Figure 1 is a view showing an example of a main structure of an image forming apparatus 100 according to an embodiment.

[0021] The image forming apparatus 100 is, for example, an MFP (multifunction peripheral), a copier, a printer, a facsimile, or the like. Hereinafter, the image forming apparatus 100 will be described as an MFP. The image forming apparatus 100 has, for example, a print function, a scan function, a copy function, a facsimile function, or the like. The print function is a function of forming an image using toner as a recording material with respect to an image forming medium P or the like. The image forming medium P is, for example, a sheet-like paper or the like. The scan function is a function of reading an image from a document or the like on which an image is formed. The copy function is a function of printing an image read from a document or the like using the scan function to the image forming medium P using the print function. The image forming apparatus 100 includes, for example, a printer 101, a scanner 102, and an operation panel 103.

[0022] The printer 101 prints an image on an image forming medium P by forming an image using toner or the like. The printer 101 has, for example, an electrophotographic printer 101 by which printing is performed. The printer 101 includes, for example, a paper feed tray 111, a manual paper feed tray 112, a paper feed roller 113, a toner cartridge 114, an auxiliary reservoir 115, an image forming section 116, an optical scanning device 117, a transfer belt 118, a secondary transfer roller 119, a fixing section 120, a double-sided assembly 121, a conveyance roller 122, and a paper discharge tray 123.

[0023] The paper feed tray 111 is a tray that stores an image forming medium P used for printing.

[0024] The manual paper feed tray 112 is a tray for manually feeding an image forming medium P.

[0025] The paper feed roller 113 rotates by working of a motor, and moves an image forming medium P stored in the paper feed tray 111 or the manual paper feed tray 112 from the paper feed tray 111 or the manual paper feed tray 112.

[0026] The image forming apparatus 100 groups one toner cartridge 114, one auxiliary reservoir 115, and one image forming section 116 as one set, and has one or more of the sets. The image forming apparatus 100, as an example, has four of the sets as shown. Figure 1 The image forming apparatus 100 shown in FIG. 1 has four of the sets. Each of the sets corresponds to toner of each color of CMYK (cyan, magenta, yellow, and black). Figure 1 The image forming apparatus 100 shown in FIG. 1 has four of the sets. Each of the sets corresponds to toner of each color of CMYK (cyan, magenta, yellow, and black). Figure 1 The image forming apparatus 100 shown in FIG. 1 has four of the sets. Each of the sets corresponds to toner of each color of CMYK (cyan, magenta, yellow, and black).

[0027] The toner cartridge 114, which is a storage section, stores (holds) toner to be supplied to the auxiliary reservoir 115. The toner stored in each toner cartridge 114 is toner of a color corresponding to the toner cartridge 114.

[0028] The auxiliary reservoir 115 stores toner supplied from the toner cartridge 114. The auxiliary reservoir 115 supplies the stored toner to the image forming section 116.

[0029] Figure 2 is a cross-sectional view showing an example of the main structure of the auxiliary reservoir 115. The auxiliary reservoir 115, as an example, includes a storage section 1151, a wall surface 1152, a detected section 1153, a rotating body 1154, a substrate 1155, a first electrode 1156, a second electrode 1157, and a control circuit 1158.

[0030] The storage section 1151 stores toner supplied from the toner cartridge 114.

[0031] The wall surface 1152 is a wall that surrounds the storage section 1151. The inside of the wall surface 1152 is the storage section 1151.

[0032] The detected portion 1153 is, for example, a dielectric. The dielectric refers to a substance with a high relative dielectric constant, for example. The shape of the detected portion 1153 is not limited, and is, for example, a sphere, a disc, or a cylinder, or the like. The detected portion 1153 is movable in a manner in which the distance from the first electrode 1156 and the second electrode 1157 changes. The detected portion 1153 is moved by rotation of the rotating body 1154. The detected portion 1153 can not be applied with a voltage. The detected portion 1153 can not be applied with a current.

[0033] The rotating body 1154 and the supply portion 1159 are connected to the motor M via a gear or the like. The rotating body 1154 and the supply portion 1159 are rotated by the operation of the motor M. The rotating body 1154 and the supply portion 1159 can also be rotated by different motors, respectively.

[0034] The rotating body 1154 is a circular member that is rotated by the operation of the motor M. The rotating body 1154 has the detected portion 1153 mounted on the outer side than the rotation axis. The detected portion 1153 performs a circular motion when the rotating body 1154 is rotated. The rotating body 1154 can have two or more detected portions 1153. The rotating body 1154 can have a plurality of detected portions 1153 at equal intervals on the same circumference with the rotation axis as the center. The rotating body 1154 has a portion with a dielectric constant different from other portions on the same circumference with the rotation axis as the center as the detected portion.

[0035] In a case where a plurality of detected portions 1153 are provided at equal intervals on the same circumference with the rotation axis as the center, the balance of the weight can be obtained, and thus the rotation of the rotating body 1154 is less likely to be shaken. The rotating body 1154 can be mounted with a counterweight or the like in order to obtain the balance of the weight. Alternatively, the weight of the rotating body 1154 can be heavier on the side opposite to the mounting position of the detected portion 1153 in order to obtain the balance of the weight.

[0036] The substrate 1155 is mounted on the outer side of the wall surface 1152. The substrate 1155 has a circuit for measuring the electrostatic capacitance between the first electrode 1156 and the second electrode 1157. The substrate 1155 outputs an electrostatic capacitance signal that represents the electrostatic capacitance. The substrate 1155 has an electrostatic capacitance sensor that measures the electrostatic capacitance.

[0037] The substrate 1155 is an example of a measurement portion that measures the electrostatic capacitance between the first electrode 1156 and the second electrode 1157. Alternatively, a portion of the substrate 1155 including a circuit or a wiring or the like that connects the substrate 1155 and other portions is an example of a measurement portion.

[0038] The first electrode 1156 and the second electrode 1157 are, for example, patterns on the substrate 1155. Alternatively, the first electrode 1156 and the second electrode 1157 are conductor strips attached to the outer side of the wall surface 1152. The conductor strips are electrically connected to the wiring on the substrate 1155. The first electrode 1156 and the second electrode 1157 are not in contact but are separated by a distance.

[0039] The control circuit 1158 is a circuit that controls the motor M. The control circuit 1158 is connected to the power supply PS.

[0040] The power supply PS supplies electric power to the motor M via the control circuit 1158.

[0041] The supply portion 1159 is a circular member that rotates by the operation of the motor M. The supply portion 1159 transports toner from the storage portion 1151 to the image forming portion 116 by rotation in an amount corresponding to the amount of rotation of the supply portion 1159.

[0042] The image forming portion 116 forms an image by toner and transfers (primary transfer) the image to the transfer belt 118.

[0043] Figure 3 is a view showing an example of the main structure of the image forming portion 116. The image forming portion 116 includes, for example, a photosensitive drum 1161, a charging member 1162, a developing member 1163, a primary transfer roller 1164, and a cleaner 1165.

[0044] The optical scanning device 117 irradiates a light beam in order to form an electrostatic latent image on the surface of the photosensitive drum 1161.

[0045] The charging member 1162 positively charges the surface of the photosensitive drum 1161.

[0046] The developing member 1163 develops the electrostatic latent image on the surface of the photosensitive drum 1161 using toner supplied from the auxiliary reservoir 115 to form an image using toner. The developing member 1163 includes, for example, a developer container 11631, an agitation mechanism 11632, a developing roller 11633, a blade 11634, and a toner sensor 11635.

[0047] The developer container 11631 is a container that stores a developer. The developer is, for example, a developer composed of two components of toner and a carrier. The developer container 11631 receives toner that is sent out by the operation of the rotating body 1154 from the auxiliary reservoir 115. The carrier is housed in the developer container 11631 at the time of manufacturing or assembling the image forming apparatus 100.

[0048] The agitation mechanism 11632 agitates the toner and the carrier in the developer container 11631 by motor drive.

[0049] The developing roller 11633 rotates within the developer container 11631. By this, the developer adheres to the surface of the developing roller 11633.

[0050] The blade 11634 is a member disposed apart from the surface of the developing roller 11633 by a gap. In order to form a layer of the developer of a thickness corresponding to the gap between the blade 11634 and the surface of the developing roller 11633 on the surface of the developing roller 11633, the blade 11634 removes a portion of the developer adhering to the surface of the rotating developing roller 11633.

[0051] The toner sensor 11635 is, for example, a magnetic flux sensor having a coil and detecting a voltage value generated in the coil. The detected voltage of the toner sensor 11635 varies according to the density of the magnetic flux generated by the toner within the developer container 11631. The toner sensor 11635 outputs a voltage corresponding to the concentration of the toner (hereinafter, simply referred to as "toner concentration") in the developer within the developer container 11631. The voltage outputted by the toner sensor 11635 is used for measurement of the toner concentration within the developer container 11631.

[0052] In order to transfer (primary transfer) the image formed on the surface of the photosensitive drum 1161 onto the transfer belt, the primary transfer roller 1164 generates a transfer voltage between the photosensitive drum 1161.

[0053] The cleaner 1165 removes the toner remaining on the surface of the photosensitive drum 1161.

[0054] The optical scanning device 117 is also referred to as an LSU (laser scanning unit) or the like. The optical scanning device 117 controls laser light in accordance with inputted image data to form an electrostatic latent image on the surface of the photosensitive drum of each image forming portion 116.

[0055] The transfer belt 118 is, for example, a belt in a ring shape, and is rotatable by the operation of a roller. The transfer belt 118 conveys the image transferred from each image forming portion 116 to the position of the secondary transfer roller 119 by rotation.

[0056] The secondary transfer roller 119 has two rollers facing each other. The secondary transfer roller 119 transfers (secondary transfer) the image formed on the transfer belt 118 to the image forming medium P passing between the secondary transfer rollers 119.

[0057] In order to fix the image transferred on the image forming medium P, the fixing portion 120 performs heating and pressure application to the image forming medium P on which the image is transferred. The fixing portion 120 has a heating portion 1201 and a pressure roller 1202 facing each other. The fixing portion 120 includes, as an example, the heating portion 1201 and the pressure roller 1202.

[0058] The heating section 1201 is, for example, a roller provided with a heat source for heating the heating section 1201. The heat source is, for example, a heater. The roller heated by the heat source heats the image forming medium P.

[0059] The heating section 1201 can also be provided with a loop-shaped belt stretched over a plurality of rollers. For example, the heating section 1201 is provided with a plate-shaped heat source, a loop-shaped belt, a belt conveying roller, a tension roller, and a pressure roller. The loop-shaped belt is, for example, a film-shaped member. The belt conveying roller drives the loop-shaped belt. The tension roller applies tension to the loop-shaped belt. The pressure roller has an elastic layer formed on the surface. The heat generating section side of the plate-shaped heat source is in contact with the inner side of the loop-shaped belt and is pressed toward the direction of the pressure roller, thereby forming a nip between the heat generating section and the pressure roller.

[0060] The pressure roller 1202 applies pressure to the image forming medium P passing between the pressure roller 1202 and the heating section 1201.

[0061] The double-sided assembly 121 sets the image forming medium P in a state in which the back surface can be printed. For example, the double-sided assembly 121 turns the image forming medium P in a zigzag shape by using a roller or the like, thereby inverting the surface and the back surface of the image forming medium P.

[0062] The conveying roller 122 rotates by the operation of a motor, thereby conveying the image forming medium P.

[0063] The paper discharge tray 123 is a table that discharges the image forming medium P on which printing is completed.

[0064] The scanner 102 reads an image from an original or the like. The scanner 102 is an optical reduction method provided with a photographing element such as a CCD (charge-coupled device) image sensor or the like. Alternatively, the scanner 102 is a close contact sensor (CIS (contact image sensor)) method provided with a photographing element such as a CMOS (complementary metal-oxide-semiconductor) image sensor or the like. Alternatively, the scanner 102 can be another publicly known method.

[0065] The operation panel 103 is provided with a human-machine interface or the like that performs input and output between the image forming apparatus 100 and an operator of the image forming apparatus 100. The operation panel 103 is provided with, for example, a touch panel 1031, an input device 1032, a speaker, and the like.

[0066] The touch panel 1031 is, for example, a display in which a display such as a liquid crystal display or an organic EL (electro-luminescence) display is layered with a pointing device based on a touch input. The display included in the touch panel 1031 functions as a display device of a display screen that is a screen for notifying an operator of the image forming apparatus 100 of various kinds of information. The touch panel 1031 functions as an input device that receives a touch operation based on the operator.

[0067] The input device 1032 receives an operation based on an operator of the image forming apparatus 100. The input device 1032 is, for example, a digital keypad or a touch panel.

[0068] Figure 4 is a block diagram showing an example of a main circuit structure of the image forming apparatus 100.

[0069] The image forming apparatus 100 includes, for example, a processor 151, a ROM (read-only memory) 152, a RAM (random-access memory) 153, an auxiliary storage device 154, a communication interface 155, the printer 101, the scanner 102, and the operation panel 103. These components are connected by a bus 156 or the like.

[0070] The processor 151 corresponds to a central part of a computer that performs processing of operations and control and the like required for the image forming apparatus 100 to function. The processor 151 controls each section for realizing various functions of the image forming apparatus 100 based on a program of firmware, system software, and application software and the like stored in the ROM 152 or the auxiliary storage device 154 and the like. The processor 151 performs the processing described later based on the program. Part or all of the program can also be incorporated in the circuit of the processor 151. The processor 151 is, for example, a CPU (central processing unit), an MPU (micro processing unit), a SoC (system on a chip), a DSP (digital signal processor), a GPU (graphics processing unit), an ASIC (application specific integrated circuit), a PLD (programmable logic device), or an FPGA (field-programmable gate array), or the like. Alternatively, the processor 151 can be formed by combining a plurality of these.

[0071] The ROM 152 corresponds to a main storage device of a computer that has the processor 151 as a central part. The ROM 152 is a nonvolatile memory that is used exclusively for reading out data. The ROM 152 stores, for example, firmware and the like among the above-described programs. The ROM 152 also stores data and the like used when the processor 151 performs various processing.

[0072] The RAM 153 corresponds to a main storage device of a computer that has the processor 151 as a central part. The RAM 153 is a memory for reading and writing data. The RAM 153 is used as a work area or the like that stores data temporarily used when the processor 151 performs various processing. The RAM 153 is a typical volatile memory.

[0073] The auxiliary storage device 154 corresponds to an auxiliary storage device of a computer having the processor 151 as a hub. The auxiliary storage device 154 is, for example, an EEPROM (electric erasable programmable read-only memory), an HDD (hard disk drive), a flash memory, or the like. The auxiliary storage device 154 stores, for example, system software and application software among the above-described programs. The auxiliary storage device 154 stores data used when the processor 151 performs various processes, data generated by the processes of the processor 151, various setting values, and the like. The image forming apparatus 100 can also have, as the auxiliary storage device 154, an interface capable of inserting a detachable storage medium such as a memory card or a USB (universal serial bus) memory. The interface performs reading and writing of information to and from the storage medium.

[0074] The auxiliary storage device 154 stores the threshold value THa to the threshold value THc.

[0075] The communication interface 155 is an interface for the image forming apparatus 100 to perform communication via a network such as the Internet or a LAN (local area network).

[0076] The bus 156 includes a control bus, an address bus, a data bus, and the like, and transmits signals exchanged between the respective units of the image forming apparatus 100.

[0077] Hereinafter, the operation of the image forming apparatus 100 according to the embodiment will be described.

[0078] Figure 5 is a view illustrating a model of the electrostatic capacitance C between the first electrode 1156 and the second electrode 1157.

[0079] The electrostatic capacitance C between the first electrode 1156 and the second electrode 1157 can be considered as an electrostatic capacitance in which a capacitor of the electrostatic capacitance Ca, a capacitor of the electrostatic capacitance Cb, a capacitor of the electrostatic capacitance Cc, and a capacitor of the electrostatic capacitance Cd are connected in parallel, as illustrated in Figure 5

[0080] C≈Ca+Cb+Cc+Cd (1)

[0081] The electrostatic capacitance Ca is an electrostatic capacitance of a portion represented by a power line passing outside the auxiliary reservoir 115. The power line mainly passes through the air.

[0082] The electrostatic capacitance Cb is an electrostatic capacitance of a portion represented by a power line inside the substrate 1155. ​

[0083] The electrostatic capacitance Cc is the electrostatic capacitance of the portion represented by the electric field lines within the wall 1152.

[0084] The electrostatic capacitance Cd is the portion of the electrostatic capacitance represented by the electric field lines from the first electrode 1156 through the material SU inside the wall 1152, inside the wall 1152 (in the storage section 1151), and inside the wall 1152 to the second electrode 1157.

[0085] The electrostatic capacitances Ca to Cd are unaffected by the presence or absence of toner in storage section 1151 or their quantity, and therefore can be disregarded here.

[0086] Figure 6 This is a diagram showing the model of the electrostatic capacitance Cd.

[0087] Static capacitance Cd, for example Figure 6 As shown, the electrostatic capacitor Cd can be considered as a capacitor consisting of capacitors Cda, Cdb, and Cdc connected in series. That is, the electrostatic capacitor Cd can be represented by the following formula.

[0088] Cd≈1 / (1 / Cda+1 / Cdb+1 / Cdc) (2)

[0089] The electrostatic capacitance Cda is the portion of the electric field line that passes from the first electrode 1156 through the material SU in the wall 1152, the storage section 1151, and the wall 1152 to the second electrode 1157, representing the portion of the wall 1152 that passes from the first electrode 1156 to the inner wall of the wall 1152.

[0090] The electrostatic capacitance Cdb is the portion of the electric field line that passes through the material SU in the storage section 1151 from the first electrode 1156 through the material SU in the wall 1152, the storage section 1151, and the wall 1152 to the second electrode 1157.

[0091] The electrostatic capacitance Cdc is the portion of the electric field line that passes from the first electrode 1156 through the material SU in the wall 1152, the storage section 1151, and the wall 1152 to the second electrode 1157, and is represented by the portion of the wall 1152 that passes from the second electrode 1157 to the inner wall of the wall 1152.

[0092] Regarding the electrostatic capacitors Cda and Cdc, they do not change regardless of the presence or amount of toner in the storage section 1151, and therefore can be ignored here.

[0093] Figure 7is a diagram illustrating a model in which the electrostatic capacitance Cdb when the detected portion 1153 is sufficiently separated from the first electrode 1156 and the second electrode 1157 is replaced with a parallel-plate capacitor.

[0094] In a case where the detected portion 1153 is sufficiently separated from the first electrode 1156 and the second electrode 1157, the presence of the detected portion 1153 has almost no influence on the electrostatic capacitance Cdb, and thus the electrostatic capacitance Cdb can be found by disregarding the presence of the detected portion 1153.

[0095] In this model, the capacitor of the electrostatic capacitance Cdb is regarded as a parallel-plate capacitor in order to simplify the calculation.

[0096] Thus, in a case where the distance between the parallel plates is d, the area of the parallel plates is S, the dielectric constant of vacuum is ε0, and the relative dielectric constant of the substance SU is ε, the electrostatic capacitance Cdb when the detected portion 1153 is sufficiently separated from the first electrode 1156 and the second electrode 1157 can be represented by the following equation.

[0097] Cdb≈ε0εS / d (3)

[0098] Figure 8 is a diagram illustrating a model of the electrostatic capacitance Cdb in a state where the detected portion 1153 is closest to the first electrode 1156 and the second electrode 1157.

[0099] In a case where the detected portion 1153 is present, the electrostatic capacitance Cdb can be considered as an electrostatic capacitance in which a capacitor of an electrostatic capacitance Cdba in which the electric lines do not pass through the detected portion 1153 but pass through only a portion inside the substance SU and a capacitor of an electrostatic capacitance in which the electric lines pass through the detected portion 1153 are connected in parallel.

[0100] The electrostatic capacitance of the capacitor of the portion in which the electric lines pass through the detected portion 1153 can be considered as an electrostatic capacitance in which a capacitor of an electrostatic capacitance Cdbb, a capacitor of an electrostatic capacitance Cdbc, and a capacitor of an electrostatic capacitance Cdbd are connected in series. That is, the electrostatic capacitance Cdb can be represented by the following equation.

[0101] Cdb≈Cdba+1 / (1 / Cdbb+1 / Cdbc+1 / Cdbd) (4)

[0102] The electrostatic capacitance Cdbb is an electrostatic capacitance Cdbc of a portion represented by the electric lines passing through only the substance SU inside the detected portion 1153 from the inner wall of the wall surface 1152.

[0103] The electrostatic capacitance Cdbc is an electrostatic capacitance of a portion represented by the electric lines inside the detected portion 1153.

[0104] The electrostatic capacitance Cdbd is the electrostatic capacitance of only the portion indicated by the electric lines of force within the substance SU from the detected portion 1153 to the inner wall of the wall surface 1152.

[0105] Figure 9 is a view showing the electrostatic capacitance Cdb in a state in which the detected portion 1153 is closest to the first electrode 1156 and the second electrode 1157, as a model of a parallel-plate capacitor in which the electrostatic capacitance Cdb is replaced. Figure 9 In the model shown in FIG. 15, the area of the parallel plates of each of the parallel-plate capacitors of the electrostatic capacitances Cdba to Cdbd is set to S / 2 for the sake of simplifying the calculation. Figure 9 In the model shown in FIG. 15, the distance between the parallel plates of the capacitor of the electrostatic capacitance Cdba is set to d. Figure 9 In the model shown in FIG. 15, the distance between the parallel plates of the capacitor of the electrostatic capacitance Cdbb is set to d / 4, the distance between the parallel plates of the capacitor of the electrostatic capacitance Cdbc is set to d / 2, and the distance between the parallel plates of the capacitor of the electrostatic capacitance Cdbd is set to d / 4. In this case, the dielectric constant of the detected portion 1153 is set to ε R The electrostatic capacitance Cdb can be expressed by the following equation when ε

[0106] Cdb≈εε0S / 2d+1 / (1 / (2εε0S / d)+1 / (ε R 0S / d)+1 / (2εε0S / d)) (5)

[0107] The equation (5) is arranged to become the following equation.

[0108] Cdb≈(1 / 2+ε R / (ε+ε R ))εε0(S / d) (6)

[0109] Accordingly, the difference Cdif between the electrostatic capacitance Cdb when the detected portion 1153 is sufficiently separated from the first electrode 1156 and the second electrode 1157 and the electrostatic capacitance Cdb in a state in which the detected portion 1153 is closest to the first electrode 1156 and the second electrode 1157 can be expressed by the following equation according to the equation (3) and the equation (6).

[0110] Cdif≈(1 / 2+ε R / (ε+ε R ))εε0(S / d)-ε0εS / d (7)

[0111] The equation (7) is arranged to become the following equation.

[0112] Cdif≈(ε R / (ε+ε R )-1 / 2)εε0(S / d) (8)

[0113] According to formula (8), it is known that the higher the relative dielectric constant of the substance SU, the greater the amount of change in the electrostatic capacitance C generated by the movement of the detected portion 1153. Since the relative dielectric constant of the toner is higher than the relative dielectric constant of the air, the amount of change in the electrostatic capacitance C generated by the movement of the detected portion 1153 is greater in the case where the storage portion 1151 is filled with the toner than in the case where the storage portion 1151 is empty.

[0114] According to formula (8), it is known that the higher the relative dielectric constant of the detected portion 1153, the greater the amount of change in the electrostatic capacitance C generated by the movement of the detected portion 1153.

[0115] Figure 10 This flowchart shows an example of the processing of the processor 151 of the image forming apparatus 100. The processor 151 performs the processing of formula (1) on the basis of, for example, a program stored in the ROM 152 or the auxiliary storage device 154, and the like. Figure 10

[0116] The processor 151 starts the processing shown in FIG. 10 in response to, for example, the end of the execution of the print function. This is because the toner concentration decreases by the execution of the print function. The processor 151 performs the processing shown in FIG. 10 for each color of CMYK. Figure 10 Figure 10

[0117] In ACT 11, the processor 151 measures the toner concentration in the developer container 11631 using the toner sensor 11635.

[0118] In ACT 12, the processor 151 determines whether to replenish the toner to the developer container 11631. The processor 151 determines to replenish the toner in the case where, for example, the toner concentration is equal to or lower than a predetermined concentration. The processor 151 determines NO in ACT 12 and ends the processing shown in FIG. 10 if it is not determined to replenish the toner to the developer container 11631. The processor 151 determines YES in ACT 12 and proceeds to ACT 13 if it is determined to replenish the toner to the developer container 11631. Figure 10

[0119] In ACT 13, the processor 151 rotates the rotating body 1154 and the supply portion 1159 by causing the motor M to operate, thereby replenishing the toner to the developer container 11631. The processor 151 measures the electrostatic capacitance C using the substrate 1155 simultaneously with or in parallel with the replenishment of the toner. The processor 151 measures the amount of rotation of the rotating body 1154 in ACT 13. The processor 151 measures this amount of rotation using, for example, the operation time of the motor M, and the like.

[0120] ​​​​In ACT 14, the processor 151 determines whether the amount of rotation of the rotating body 1154 is equal to or greater than a predetermined amount of rotation. For example, the processor 151 determines that the amount of rotation of the rotating body 1154 is equal to or greater than the predetermined amount of rotation when the operation time of the motor M is equal to or greater than a predetermined time. If the processor 151 determines that the amount of rotation of the rotating body 1154 is less than the predetermined amount of rotation, the processor 151 determines NO in ACT 14 and ends the process Figure 10 If the processor 151 determines that the amount of rotation of the rotating body 1154 is equal to or greater than the predetermined amount of rotation, the processor 151 determines YES in ACT 14 and proceeds to ACT 15.

[0121] In ACT 15, the processor 151 determines whether the measurement result of the electrostatic capacity C is within a normal range.

[0122] Figure 11 FIG. 9 is a graph showing a time change of the electrostatic capacity C. Figure 11 Three graphs, a graph Ga, a graph Gb, and a graph Gc, are shown. The graph Ga is an example of a graph when the electrostatic capacity C can be normally measured.

[0123] In the graph Ga, the detected portion 1153 approaches the first electrode 1156 and the second electrode 1157 around the time ta to the time tc, and thus the electrostatic capacity C increases. At the time tb, the detected portion 1153 is closest to the first electrode 1156 and the second electrode 1157, and thus the electrostatic capacity C is largest. At the time tb, after the detected portion 1153 is closest to the first electrode 1156 and the second electrode 1157, the detected portion 1153 is also closest to the first electrode 1156 and the second electrode 1157 at the time td. The electrostatic capacity C periodically increases at a period of (td-tb).

[0124] Figure 11 The change amount Cpp of the electrostatic capacity C is also shown in FIG. 9. The change amount Cpp is, for example, a peak-to-peak value as shown in FIG. 9. Figure 11

[0125] The graph Gb is an example of a graph showing that the measurement result of the electrostatic capacity C is an abnormal value outside the normal range. When the measurement result of the electrostatic capacity C is in a range of equal to or greater than a threshold value THa and equal to or less than a threshold value THb, the measurement result is within the normal range. When the measurement result of the electrostatic capacity C is less than the threshold value THa or exceeds the threshold value THb, the measurement result is an abnormal value. The threshold values THa and THb are, for example, determined in advance by a manufacturer, a designer, or a manager of the image forming apparatus 100, or the like.

[0126] ​The processor 151 determines that the measurement result of the electrostatic capacity C is outside the normal range even if the measurement result is less than the threshold THa or exceeds the threshold THb for only an instant. For example, the processor 151 determines that the measurement result of the electrostatic capacity C is outside the normal range if the measurement result is less than the threshold THa or exceeds the threshold THb for a predetermined time or more. For example, the processor 151 determines that the measurement result of the electrostatic capacity C is outside the normal range if the measurement result is less than the threshold THa or exceeds the threshold THb for a certain time or more for a predetermined time or more.

[0127] The threshold THb can not be set. The normal range can be from the threshold THa or more and have no upper limit. The threshold THa can not be set. The normal range can be from 0 or more and the threshold THb or less. The threshold THb is an example of a first threshold. The threshold THa is an example of a second threshold.

[0128] If the processor 151 determines that the measurement result of the electrostatic capacity C is outside the normal range, the processor 151 determines YES in ACT 15 and proceeds to ACT 16.

[0129] If the measurement result of the electrostatic capacity C is outside the normal range, it is considered that there is an abnormality in the measurement of the electrostatic capacity C. The abnormality is, for example, an abnormality of the electrostatic capacity sensor that measures the electrostatic capacity C. The abnormality is, for example, an abnormality of a circuit or wiring that connects the electrostatic capacity sensor and other parts. The circuit or wiring is, for example, a circuit within the substrate 1155, and a wiring and a circuit that connect the substrate 1155 and the processor 151. In a case where, for example, the electrostatic capacity sensor, the circuit, or the wiring is broken or short-circuited, it is considered that the measured value of the electrostatic capacity C becomes abnormally low or abnormally high.

[0130] In ACT 16, the processor 151 stores a value indicating that there is an abnormality in the electrostatic capacity sensor or a circuit that connects the electrostatic capacity sensor and other parts to the auxiliary storage device 154 or the like. The processor 151 can refer to the value later to know that there is an abnormality in the electrostatic capacity sensor or the circuit that connects the electrostatic capacity sensor and other parts.

[0131] In ACT 17, the processor 151 reports to an operator or a manager of the image forming apparatus 100 or the like that there is an abnormality in the electrostatic capacity sensor. The processor 151, for example, controls the touch panel 1031 to display an image indicating that there is an abnormality in the electrostatic capacity sensor on the touch panel 1031 to make the report. The processor 151 can also output a sound indicating that there is an abnormality in the electrostatic capacity sensor from the speaker to make the report. The processor 151 can also transmit information indicating that there is an abnormality in the electrostatic capacity sensor to another computer or the like via the communication interface 155 or the like to make the report. The computer that receives the information, for example, displays an image indicating that there is an abnormality in the electrostatic capacity sensor. The processor 151 ends the process after making the report in ACT 17.Figure 10 The processing shown.

[0132] The processor 151 functions as an example of a reporting section that reports the presence of an abnormality in the measurement of the electrostatic capacity (the electrostatic capacity sensor) in cooperation with the operation panel 103 or the communication interface 155 by performing the processing of ACT 17.

[0133] As described above, the processor 151 performs the control based on the abnormality that is detected based on the electrostatic capacity C by performing the processing of ACT 15 to ACT 17.

[0134] The processor 151 determines that the measurement result of the electrostatic capacity C is within the normal range, and determines NO in ACT 15 to proceed to ACT 18.

[0135] The processor 151 determines whether the measurement value of the electrostatic capacity C is periodically changed in ACT 18.

[0136] Figure 11 The graph Gc shown is an example of a graph in which the measurement value of the electrostatic capacity C does not change. The measurement value shown in the graph Gc is within the normal range.

[0137] The processor 151 determines that the measurement value of the electrostatic capacity C does not change periodically, for example, in a case where the amount of change of the electrostatic capacity C is equal to or less than a predetermined amount of change. The processor 151 determines that the amount of change of the electrostatic capacity C is equal to or less than the predetermined amount of change, for example, in a case where the amount of change Cpp is equal to or less than a threshold THc. The threshold THc is a predetermined value for determining that the amount of change of the electrostatic capacity C is equal to or less than the predetermined amount of change. The threshold THc is determined in advance, for example, by a manufacturer, a designer, or a manager of the image forming apparatus 100, or the like.

[0138] The processor 151 determines that the measurement value of the electrostatic capacity C does not change periodically, even if the measurement value of the electrostatic capacity C changes, if the period is not fixed.

[0139] The processor 151 determines that the measurement value of the electrostatic capacity C does not change periodically, and determines NO in ACT 18 to proceed to ACT 19.

[0140] In a case where the measured value of the electrostatic capacitor C does not change, it is considered that there is an abnormality in a mechanism (hereinafter referred to as "rotation mechanism") that rotates the detected portion 1153, for example. The rotation mechanism includes a rotating body 1154, a control circuit 1158, a motor M, and a power supply PS. The rotation mechanism is an example of a moving portion that moves the detected portion 1153. In a case where the rotation mechanism has an abnormality and the circular motion of the detected portion 1153 is stopped or hardly moves, for example, the electrostatic capacitor C does not change or changes little. In a case where the rotation mechanism has an abnormality and the circular motion of the detected portion 1153 is not periodic, the change in the electrostatic capacitor C is no longer periodic.

[0141] In ACT 19, the processor 151 stores a value indicating that the rotation mechanism has an abnormality to the auxiliary storage device 154 or the like. The processor 151 thereafter refers to the value and can know that the rotation mechanism has an abnormality.

[0142] In ACT 20, the processor 151 reports that the rotation mechanism has an abnormality to an operator or a manager of the image forming apparatus 100 or the like. The processor 151 controls the touch panel 1031, for example, and causes an image indicating that the rotation mechanism has an abnormality to be displayed on the touch panel 1031 and thereby performs the reporting. The processor 151 can also perform the reporting by outputting a sound indicating that the rotation mechanism has an abnormality from a speaker. The processor 151 can further perform the reporting by transmitting information indicating that the rotation mechanism has an abnormality to another computer or the like via the communication interface 155 or the like. The computer that receives the information displays an image indicating that the rotation mechanism has an abnormality, for example. The processor 151 ends the processing illustrated above after performing the processing of ACT 20. Figure 10

[0143] The processor 151 functions as an example of a reporting portion that reports that an abnormality is present in the measurement of the electrostatic capacitor (rotation mechanism) in cooperation with the operation panel 103 or the communication interface 155 by performing the processing of ACT 20.

[0144] As described above, the processor 151 performs the control based on the abnormality that is detected based on the electrostatic capacitor C by performing the processing of ACT 18 to ACT 20.

[0145] The processor 151 enters ACT 21 in a case where the measured value of the electrostatic capacitor C changes in ACT 18.

[0146] ​In ACT 21, the processor 151 performs processing to find the presence or absence of toner or the toner remaining amount in the auxiliary reservoir 115. The presence of toner means that a case where the toner in the storage portion 1151 is equal to or more than a predetermined amount is regarded as the presence of toner, and a case where the toner is less than the predetermined amount is regarded as the absence of toner. The processor 151 determines that there is toner in a case where, for example, the change amount Cpp is equal to or more than a predetermined threshold value. Also, the processor 151 determines that there is no toner in a case where the change amount Cpp is less than the threshold value.

[0147] The processor 151 finds the toner remaining amount using the change amount Cpp or the like. It is considered that the greater the change amount of the electrostatic capacity C, the more toner there is. The processor 151 finds the toner remaining amount by using a function of, for example, the change amount Cpp. The processor 151 can also find the toner remaining amount using the value of the electrostatic capacity C without using the change amount of the electrostatic capacity.

[0148] In ACT 22, the processor 151 determines whether to replenish toner to the auxiliary reservoir 115. For example, the processor 151 determines to replenish toner in a case where the result of ACT 21 is the absence of toner. For example, the processor 151 determines to replenish toner in a case where the toner remaining amount found in ACT 21 is equal to or less than a predetermined amount. For example, the processor 151 determines to replenish toner in a case where the change amount Cpp is equal to or less than a threshold value THd. If the processor 151 determines to replenish toner to the auxiliary reservoir 115, the processor 151 determines YES in ACT 22 and proceeds to ACT 23. Also, the size relationship of the threshold value THc and the threshold value THd is THd > THc.

[0149] In ACT 23, the processor 151 controls each of the toner cartridge 114 and the like in such a manner as to replenish toner to the auxiliary reservoir 115. Based on this control, the toner cartridge 114 supplies toner to the auxiliary reservoir 115.

[0150] In ACT 24, the processor 151 stores a value indicating the presence of toner in the storage portion 1151 or a value indicating that the toner remaining amount in the storage portion 1151 is full to the auxiliary storage device 154 or the like. The processor 151 can know the presence or absence of toner or the toner remaining amount by referring to this value later. After the processor 151 performs the processing of ACT 24, the processor 151 ends the processing shown in FIG. 8. Figure 10

[0151] In contrast, if the processor 151 does not replenish toner to the auxiliary reservoir 115, the processor 151 determines NO in ACT 22 and proceeds to ACT 25.

[0152] ​The processor 151 of the ACT 25 stores a value indicating the presence or absence of toner or the toner remaining amount to the auxiliary storage device 154 or the like based on the result of the ACT 21. The processor 151 can know the presence or absence of toner or the toner remaining amount by referring to the value later. The processor 151 ends the processing illustrated in FIG. 8 after the processing of the ACT 25 is performed. Figure 10 The processor 151 of the ACT 25 stores a value indicating the presence or absence of toner or the toner remaining amount to the auxiliary storage device 154 or the like based on the result of the ACT 21. The processor 151 can know the presence or absence of toner or the toner remaining amount by referring to the value later. The processor 151 ends the processing illustrated in FIG. 8 after the processing of the ACT 25 is performed.

[0153] The image forming apparatus 100 of the embodiment has a rotation mechanism that moves the detected portion 1153 inside the storage portion 1151 that stores toner. The substrate 1155 measures the electrostatic capacitance C of the first electrode 1156 and the second electrode 1157. The processor 151 determines that there is an abnormality in the substrate 1155, a wiring or a circuit that connects the substrate 1155, or the rotation mechanism in a case where the measured value of the electrostatic capacitance C is an abnormal value or a case where the variation amount of the electrostatic capacitance C is less than a predetermined value. The image forming apparatus 100 of the embodiment can detect in a case where there is an abnormality in a portion related to the measurement of the electrostatic capacitance C.

[0154] The image forming apparatus 100 of the embodiment can reduce the cost because it does not use a high-priced piezoelectric sensor. The image forming apparatus 100 of the embodiment can reduce the power consumption because it does not use a piezoelectric sensor that consumes a large amount of power. The image forming apparatus 100 of the embodiment can perform the detection of the presence or absence of toner or the toner remaining amount even without knowing the presence or absence of toner in the initial state because it uses the variation amount Cpp.

[0155] The image forming apparatus 100 of the embodiment determines that there is an abnormality in the rotation mechanism in a case where the variation amount of the electrostatic capacitance C is less than a predetermined value. The image forming apparatus 100 of the embodiment can detect an abnormality of the rotation mechanism.

[0156] The image forming apparatus 100 of the embodiment determines that there is an abnormality in the substrate 1155 or a wiring or a circuit that connects the substrate 1155 in a case where the measured value of the electrostatic capacitance C is an abnormal value. The image forming apparatus 100 of the embodiment can detect an abnormality of the measurement of the electrostatic capacitance C.

[0157] The image forming apparatus 100 of the embodiment reports that there is an abnormality in the rotation mechanism or the substrate 1155 in a case where the measured value of the electrostatic capacitance C is an abnormal value or a case where the variation amount of the electrostatic capacitance C is less than a predetermined value. The operator or the administrator of the image forming apparatus 100 or the like can know that there is an abnormality in the rotation mechanism or the substrate 1155.

[0158] The image forming apparatus 100 of the embodiment assumes that the measured value of the electrostatic capacitance C is an abnormal value in a case where the measured value is less than the threshold value THb. The image forming apparatus 100 of the embodiment can detect that the measured value of the electrostatic capacitance C becomes abnormally low.

[0159] The image forming apparatus 100 of the embodiment assumes that the measured value of the electrostatic capacitance C is an abnormal value in a case where the measured value exceeds the threshold value THa. The image forming apparatus 100 of the embodiment can detect that the measured value of the electrostatic capacitance C becomes abnormally high.

[0160] The image forming apparatus 100 of the embodiment mounts the detected portion 1153 to the rotating body 1154. The image forming apparatus 100 of the embodiment can perform the measurement of the electrostatic capacitance C while or in parallel with the replenishment of the toner to the toner container 11631.

[0161] The image forming apparatus 100 of the embodiment performs the detection of the abnormality of the substrate 1155, the wiring or circuit connecting the substrate 1155, or the rotating mechanism in a case where the amount of rotation of the rotating body 1154 is equal to or more than a predetermined amount of rotation. The image forming apparatus 100 of the embodiment does not perform the detection of the abnormality in a case where the amount of replenishment of the toner is small, thereby reducing the number of times of the detection of the abnormality and thus being able to reduce the cost.

[0162] The above-described embodiment can also be modified as follows.

[0163] In the above-described embodiment, the processor 151 performs the determination of whether the measured value of the electrostatic capacitance C is periodically changed after determining whether the measurement result of the electrostatic capacitance C is within the normal range. The order of the determination of the processor 151 is reversed. For example, the processor 151 enters ACT18 if YES is determined in the processing of ACT14. If YES is determined in the processing of ACT18, the processor 151 enters ACT15. The processor 151 enters ACT21 if YES is determined in the processing of ACT15.

[0164] In the above-described embodiment, the processor 151 performs the determination of whether the measured value of the electrostatic capacitance C is periodically changed in a case where the measurement result of the electrostatic capacitance C is outside the normal range. The processor 151 can also perform both the determination of whether the measurement result of the electrostatic capacitance C is within the normal range and the determination of whether the measured value of the electrostatic capacitance C is periodically changed regardless of the determination result. For example, the processor 151 enters ACT18 after the processing of ACT17. If YES is determined in ACT18 in a case where the processor 151 enters ACT18 from ACT17, the processor 151 skips the processing of ACT21 and ACT25.

[0165] In the above embodiment, the processor 151 determines that there is an abnormality in the wiring or circuit connecting the substrate 1155 or the rotation mechanism when the measurement result of the electrostatic capacitance C is outside the normal range. The processor 151 can also not determine whether the abnormality is in the substrate 1155 or the wiring or circuit connecting the substrate 1155 or the rotation mechanism when the measurement result of the electrostatic capacitance C is outside the normal range. The processor 151 can also determine that there is an abnormality in the wiring or circuit connecting the substrate 1155 or the rotation mechanism when the measurement result of the electrostatic capacitance C is outside the normal range.

[0166] In the above embodiment, the processor 151 determines that there is an abnormality in the rotation mechanism when the measurement value of the electrostatic capacitance C does not periodically change. The processor 151 can also not determine whether the abnormality is in the substrate 1155 or the wiring or circuit connecting the substrate 1155 or the rotation mechanism when the measurement value of the electrostatic capacitance C does not periodically change. The processor 151 can also determine that there is an abnormality in the wiring or circuit connecting the substrate 1155 or the rotation mechanism when the measurement value of the electrostatic capacitance C does not periodically change.

[0167] The detected portion 1153 can also be of a conductor.

[0168] Figure 12 is a diagram showing a model in which the electrostatic capacitance Cdb in a state in which the detected portion 1153 of a conductor is closest to the first electrode 1156 and the second electrode 1157 is replaced with a parallel-plate capacitor.

[0169] In Figure 12 the model shown in Figure 9 , the electrostatic capacitance of the portion through which the power line passes the detected portion 1153 is an electrostatic capacitance in which the capacitor of the electrostatic capacitance Cdbb and the capacitor of the electrostatic capacitance Cdbd are connected in series. This is because the detected portion 1153 functions as an electrode. Therefore, the electrostatic capacitance Cdb can be represented by the following equation.

[0170] Cdb≈Cdba+1 / (1 / Cdbb+1 / Cdbd) (9)

[0171] Further, the equation (9) can be represented by the following equation.

[0172] Cdb≈εε0S / 2d+1 / (1 / (2εε0S / d)+1 / (2εε0S / d)) (10)

[0173] The equation (10) is arranged to be the following equation.

[0174] Cdb≈(3 / 2)εε0(S / d) (11)

[0175] In this case, the difference Cdif between the electrostatic capacitance Cdb in the case where the detected portion 1153 is sufficiently separated from the first electrode 1156 and the second electrode 1157 and the electrostatic capacitance Cdb in the case where the detected portion 1153 is closest to the first electrode 1156 and the second electrode 1157 becomes the following expression according to (3) and (11).

[0176] Cdif≈(1 / 2)εε0(S / d) (12).

[0177] Therefore, it is understood that even if the detected portion 1153 is a conductor, the higher the relative dielectric constant of the substance SU, the larger the change in the electrostatic capacitance C generated by the movement of the detected portion 1153, as in the case where the detected portion 1153 is a dielectric. The relative dielectric constant of the toner is larger than that of air, so it is understood that in the case where the storage portion 1151 is filled with toner, the change in the electrostatic capacitance C generated by the movement of the detected portion 1153 is larger than in the case where the storage portion 1151 is empty.

[0178] It is considered that the detected portion 1153 is more difficult to charge if it is a dielectric. Therefore, from the viewpoint of suppressing the effects of the change in the electrostatic capacitance C generated by the charging of the detected portion 1153, it is considered that the detected portion 1153 is more preferably a dielectric.

[0179] The detected portion 1153 can also be installed in a different rotating body from the rotating body 1154. In this case, the rotating body on which the detected portion 1153 is installed and the motor that rotates the rotating body are examples of the rotating portion.

[0180] The developer in the above-described embodiment is a two-component developer composed of toner and a carrier. The developer can also be a single-component developer composed of only toner. The developer can also be a developer of another component, and can also be a developer composed of three or more components.

[0181] The image forming apparatus of the embodiment can also use the configuration in the above-described embodiment to detect the presence or absence or the remaining amount of the developer in the developing assembly. The image forming apparatus of the embodiment can also use the configuration in the above-described embodiment to detect an abnormality in the portion for detecting the presence or absence or the remaining amount of the developer. The developing assembly has, for example, a first electrode, a second electrode, and a substrate provided on the outer wall of the wall surface, and has a rotating body and a detected portion provided on the inside of the developing assembly. The developing assembly can use a stirring mechanism as the rotating body. The developing assembly in the above-described embodiment is generally not free of the developer. In the developing assembly and the like using a single-component developer of only toner, the developer in the developing assembly is reduced, so it is useful.

[0182] The image forming apparatus of the embodiment can also use the configuration in the above-described embodiment to detect the presence or absence or the remaining amount of toner in the toner cartridge. The image forming apparatus of the embodiment can also use the configuration in the above-described embodiment to detect an abnormality in the portion that detects the presence or absence or the remaining amount of toner in the toner cartridge. The toner cartridge has, for example, the first electrode, the second electrode, and the substrate on the outer wall of the wall surface, and has the rotating body and the detected portion on the inner side of the developing assembly. The toner cartridge can also use the stirring mechanism as the rotating body.

[0183] The image forming apparatus 100 of the above-described embodiment causes the detected portion 1153 to move on the same circumference centered on the rotation axis. The movement path of the detected portion 1153 is not limited to the same circumference centered on the rotation axis. The image forming apparatus of the embodiment can also cause the detected portion 1153 to move reciprocally, for example.

[0184] The electrostatic capacitance C increases when the distance between the detected portion 1153 and both the first electrode 1156 and the second electrode 1157 decreases. The electrostatic capacitance C decreases when the distance between the detected portion 1153 and both the first electrode 1156 and the second electrode 1157 increases. The electrostatic capacitance decreases when the distance between the detected portion 1153 and one electrode is fixed and only the distance to the other electrode increases. The electrostatic capacitance also increases when the distance between the detected portion 1153 and one electrode is fixed and only the distance to the other electrode decreases. The movement path of the detected portion 1153 can be considered to be a path in which the distance to at least one of the first electrode 1156 and the second electrode 1157 changes. The change amount of the electrostatic capacitance is larger when the movement path of the detected portion 1153 is considered to be a path in which the distance to both the first electrode 1156 and the second electrode 1157 changes.

[0185] The method of moving the detected portion 1153 can also use the gravity or the buoyancy force applied to the detected portion or the like to move.

[0186] The image forming apparatus of the embodiment can also be configured to directly supply toner from the toner cartridge to the developing assembly.

[0187] The image forming apparatus in the above-described embodiment detects the presence or remaining amount of toner. The image forming apparatus of the embodiment can also detect the presence or remaining amount of something other than toner. The image forming apparatus of the embodiment can also detect an abnormality in the portion that detects the presence or remaining amount of something other than toner using the configuration in the above-described embodiment. For example, the image forming apparatus of the embodiment can also detect the presence or remaining amount of ink. The printer provided in the image forming apparatus is, for example, an inkjet printer that uses ink as a recording material. The image forming apparatus detects the presence or remaining amount of ink in, for example, an ink cartridge, an ink tank, or an inkjet head that stores ink. The inkjet printer can also eject a liquid including conductive particles for forming a wiring pattern of a printed wiring board, a liquid including cells for artificially forming a human tissue or an organ, or the like, an adhesive such as an adhesive, a hair wax, or a liquid resin. The inkjet printer is not limited to forming a two-dimensional image, and can be a 3D (three-dimensional) printer or a manufacturing machine for industry.

[0188] In the above-described embodiment, the case where the presence or remaining amount of toner is detected is described. The presence or remaining amount of another substance can also be detected using the above-described configuration. An abnormality in the portion that detects the presence or remaining amount of the another substance can also be detected using the configuration in the above-described embodiment. The device that detects the presence of the another substance can also detect the presence or remaining amount of a powder other than toner, a liquid other than ink, a gas, a solid, or a dispersion system in a storage portion. The closer the relative permittivity is to 1, the more difficult it is to detect. The substance to be detected needs to be a substance whose relative permittivity is sufficiently larger than 1.

[0189] The processor 151 can also realize a part or all of the processing realized by the program through the hardware configuration of the circuit in the above-described embodiment.

[0190] Each device in the above-described embodiment is, for example, delivered to a manager or the like of each device in a state where a program for executing each processing described above is stored. Alternatively, each device is delivered to the manager or the like in a state where the program is not stored. Also, the program is separately delivered to the manager or the like, and is stored in each device based on an operation performed by the manager or a service person or the like. The delivery of the program at this time can be realized using, for example, a detachable storage medium such as a magnetic disk medium or a semiconductor memory, or by downloading via the Internet or a LAN or the like.

[0191] Although several embodiments have been described, these embodiments are presented by way of example only, and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included within the scope and spirit of the invention, and are included within the scope of the invention and equivalents thereof recited in the claims.

Claims

1. An image forming apparatus characterized by comprising: Possessing: a storage section that stores recording material; an image forming section that forms an image using the recording material supplied from the storage section; a first electrode; a second electrode; a detected section that is located inside the storage section and is movable in a manner that the distance from the first electrode and the distance from the second electrode change; a moving section that moves the detected section located inside the storage section; a measuring section that measures the electrostatic capacitance of the first electrode and the second electrode; and a processor that controls based on an anomaly that is detected based on the electrostatic capacitance.

2. The image forming apparatus according to claim 1, wherein the processor detects an anomaly based on the amount of change in the electrostatic capacitance.

3. The image forming apparatus according to claim 1, wherein the processor detects the anomaly when the electrostatic capacitance is less than a first threshold value.

4. The image forming apparatus according to claim 1, wherein the processor detects the anomaly when the electrostatic capacitance exceeds a second threshold value.

5. The image forming apparatus according to claim 1, wherein the moving section rotates the detected section in a manner that the distance changes.

6. The image forming apparatus according to claim 1, wherein the moving section rotates to supply the recording material to the image forming section and to move the detected section in a manner that the distance changes.

7. The image forming apparatus according to claim 1, wherein the processor detects the anomaly when the amount of rotation of the moving section is a predetermined amount or more.

8. The image forming apparatus according to claim 1, wherein the detected section is made of a dielectric.

9. The image forming apparatus according to claim 1, further comprising a holding section that holds the recording material supplied to the storage section, wherein the processor controls the supply of the recording material from the holding section to the storage section according to the change in the electrostatic capacitance measured by the measuring section.

10. The image forming apparatus according to claim 1, further comprising a reporting section that reports that the processor has detected the anomaly, wherein the processor controls the reporting section based on the anomaly. ​ ​ ​

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