JP6544042B2 - Powder detection device, developer residual amount detection device and powder detection method - Google Patents

Description

  The present invention relates to a powder detection device, a developer residual amount detection device, and a powder detection method.

  In recent years, there is a tendency to promote the computerization of information, and image processing apparatuses such as printers and facsimiles used for outputting computerized information and scanners used for computerizing documents have become indispensable devices. Among such image processing apparatuses, as a method of image formation output, an electrophotographic method of performing image formation output by transferring an image formed by developing an electrostatic latent image formed on a photosensitive member onto a sheet of paper It has been known.

  In an electrophotographic image forming apparatus, a developer is supplied from a container serving as a developer supply source to a developing device that develops an electrostatic latent image formed on a photosensitive member. As a method for detecting the remaining amount of the developer thus supplied, for example, the pressure receiving sheet is deformed by a member for agitating the developer, and the detection target member accompanying the deformation of the pressure receiving sheet A method has been proposed that refers to the change of (see, for example, Patent Document 1).

  In the case of the method disclosed in Patent Document 1, the amount of toner in the container is not necessarily reflected uniformly on the deformation of the pressure receiving sheet. In addition, there is a problem in detection accuracy, such as temporal change of the pressure receiving sheet and adhesion of the developer to the pressure receiving sheet.

  To solve such a problem, the vibration mode of the vibrating unit that bounces and vibrates is changed according to the toner remaining amount, and the toner remaining amount is detected by detecting the vibration mode of the vibrating unit. Is considered. According to such an aspect, since the delicate event of the vibration of the vibrating portion is to be detected, it is possible to clearly detect the change of the state due to the toner remaining amount. As a result, it is possible to detect the remaining amount of developer in the container with high accuracy.

  The above-described vibration unit is periodically vibrated in accordance with the operation of the container in which the toner is stored. Then, when detecting the remaining amount of toner, the vibration mode of the vibrating portion vibrated as such is analyzed. Here, in order to increase the accuracy of the detection result of the toner remaining amount by the analysis of the vibration mode of the vibrating portion, it is necessary to accurately detect the timing at which the vibrating portion starts vibrating.

  As described above, in order to vibrate the vibrating portion, for example, a force is applied to the vibrating portion which is an elastic body to form a bent state of the vibrating portion, and then the applied force is released. At this time, sliding vibration occurs due to sliding between the portion for pushing in the vibrating portion and the vibrating portion, and this sliding vibration may result in erroneous detection of the timing at which the vibrating portion starts vibrating. . Such an adverse effect is not limited to the above-described toner remaining amount detection mechanism, and may similarly be a problem when detecting the remaining amount of powder in the container.

  The present invention has been made in consideration of the above situation, and in a mechanism for detecting a state in which powder is low by detecting a vibration mode of a vibration part vibrating in opposition to a sensor, the vibration of the vibration part The purpose is to detect the start timing with high accuracy.

In order to solve the above-mentioned subject, one mode of the present invention is a powder detection device which detects the residual amount in a container of powder which has fluidity, and the frequency according to the state of the magnetic flux which passes through the space which counters And an oscillating unit for outputting a signal of the above-mentioned components, and is formed of a material which is disposed in the container, is opposed to the oscillating unit through the case of the container, and vibrates in a direction opposite to the oscillating unit. The frequency-related information related to the frequency of the oscillation signal of the oscillating unit, the oscillation applying unit that vibrates the oscillating unit, and the oscillation signal of the oscillating unit at a predetermined cycle, A detection processing unit that detects a vibration state of the vibration unit based on a change in information, and detects a remaining amount of powder in the container based on a detection result; and the oscillation unit includes the vibration unit Interval is less than a predetermined threshold In this case, the oscillation is stopped, and the vibration applying unit applies a force to the vibrating unit in a direction approaching the oscillating unit so that an interval between the vibrating unit and the oscillating unit becomes equal to or less than the threshold. The vibrating portion is vibrated by moving the vibrating portion and releasing the applied force.

  According to the present invention, it is possible to detect the vibration start timing of the vibrating unit with high accuracy in the mechanism that detects the state where the powder is low by detecting the vibration mode of the vibrating unit that vibrates facing the sensor. It becomes possible.

FIG. 1 is a view showing a mechanical configuration of an image forming apparatus including a developing device on which a magnetic flux sensor according to an embodiment of the present invention is mounted. FIG. 2 is a perspective view showing a toner supply configuration according to an embodiment of the present invention. It is a perspective view showing the outline of the sub hopper concerning the embodiment of the present invention. It is a perspective view showing the outline of the sub hopper concerning the embodiment of the present invention. It is a figure showing the circuit composition of the magnetic flux sensor concerning the embodiment of the present invention. It is a figure which shows the count aspect of the output signal of the magnetic flux sensor which concerns on embodiment of this invention. It is a perspective view showing an outline of a magnetic flux sensor concerning an embodiment of the present invention. It is a block diagram showing composition of a controller which acquires a signal of a magnetic flux sensor concerning an embodiment of the present invention. It is a figure which shows the arrangement | positioning relationship of the magnetic flux sensor which concerns on embodiment of this invention, and a diaphragm. It is a figure which shows the effect | action when magnetic flux passes through the diaphragm which concerns on embodiment of this invention. It is a figure which shows the oscillation frequency of the magnetic flux sensor according to the distance of the diaphragm and magnetic flux sensor which concern on embodiment of this invention. It is a perspective view showing a diaphragm concerning an embodiment of the present invention. It is a side view which shows the arrangement | positioning relationship between the diaphragm which concerns on embodiment of this invention, and a stirring member. It is a side view which shows the arrangement | positioning relationship between the diaphragm which concerns on embodiment of this invention, and a stirring member. It is a top view which shows the arrangement | positioning relationship between the diaphragm which concerns on embodiment of this invention, and a stirring member. It is a side view which shows the arrangement | positioning relationship between the diaphragm which concerns on embodiment of this invention, and a stirring member. It is a top view which shows the vibration state of the diaphragm which concerns on embodiment of this invention. It is a side view which shows the relationship between the vibration state of the diaphragm concerning embodiment of this invention, and a color developer. It is a figure which shows a time-dependent change of the count value according to the oscillation frequency of the magnetic flux sensor which changes according to damping of the vibration of the diaphragm which concerns on embodiment of this invention. It is a flowchart which shows the detection operation of the amount of remaining toner concerning an embodiment of the present invention. It is a figure which shows the analysis aspect of the count value which concerns on embodiment of this invention. It is a figure which shows the relationship between the sampling period of the count value which concerns on embodiment of this invention, and the vibration period of a diaphragm. It is a figure which shows the space | interval of the magnetic flux sensor which concerns on embodiment of this invention, and a diaphragm. It is a figure which shows the space | interval of the magnetic flux sensor which concerns on embodiment of this invention, and a diaphragm. It is a figure which shows the example of the arrangement | positioning height of the magnetic flux sensor which concerns on embodiment of this invention, and a diaphragm. It is a figure which shows the example of the arrangement | positioning height of the magnetic flux sensor which concerns on embodiment of this invention, and a diaphragm. It is a figure which shows the example in the case of employ | adopting the magnetic flux sensor which concerns on embodiment of this invention, and a diaphragm to a developing device. It is a side view showing other examples of a coil concerning an embodiment of the present invention. It is a front view which shows the other example of the coil which concerns on embodiment of this invention. It is a figure which shows a time-dependent change of the count value according to the oscillation frequency of the magnetic flux sensor which changes according to damping of the vibration of the diaphragm which concerns on a prior art. It is a figure which shows the rotation state of the stirring member which concerns on embodiment of this invention. It is a figure which shows the rotation state of the stirring member which concerns on embodiment of this invention. It is a figure which shows the rotation state of the stirring member which concerns on embodiment of this invention. It is a figure which shows the rotation state of the stirring member which concerns on embodiment of this invention. It is a figure which shows the rotation state of the stirring member which concerns on embodiment of this invention. It is a block diagram showing composition of a controller which acquires a signal of a magnetic flux sensor concerning an embodiment of the present invention. It is a flow chart which shows stop operation of a stirring member concerning an embodiment of the present invention.

Embodiment 1
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, in an electrophotographic image forming apparatus, toner is transferred between a developing unit that develops an electrostatic latent image formed on a photosensitive member and a container that is a supply source of toner that is a developer. The detection of the remaining amount of toner in the sub hopper to be held will be described as an example.

  FIG. 1 is a side view showing an image forming output mechanism included in the image forming apparatus 100 according to the present embodiment. As shown in FIG. 1, the image forming apparatus 100 according to the present embodiment has a configuration in which the image forming units 106K to 106Y of respective colors are arranged along the conveyance belt 105 which is an endless moving unit. It is called a tandem type. That is, along the transport belt 105 which is an intermediate transfer belt on which an intermediate transfer image for transfer from the paper feed tray 101 to a sheet (an example of a recording medium) 104 separated and fed by the paper feed roller 102 is formed. A plurality of image forming units (electrophotographic process units) 106Y, 106M, 106C, and 106K (hereinafter collectively referred to as an image forming unit 106) are arranged in order from the upstream side of the conveyance direction of the conveyance belt 105.

  Further, the sheet 104 fed from the sheet feed tray 101 is once stopped by the registration roller 103, and is sent out to the transfer position of the image from the conveyance belt 105 according to the timing of image formation in the image forming unit 106.

  The plurality of image forming units 106Y, 106M, 106C, and 106K have the same internal configuration except that the color of the toner image to be formed is different. The image forming unit 106K forms a black image, the image forming unit 106M forms a magenta image, the image forming unit 106C forms a cyan image, and the image forming unit 106Y forms a yellow image. In the following description, the image forming unit 106Y will be specifically described, but since the other image forming units 106M, 106C, and 106K are the same as the image forming unit 106Y, the image forming units 106M, 106C, and 106K are described. As for each component of the above, instead of Y attached to each component of the image forming unit 106Y, the symbols distinguished by M, C, and K are displayed in the figure, and the description will be omitted.

  The conveying belt 105 is an endless belt, that is, an endless belt, which is bridged between a driving roller 107 and a driven roller 108 which are rotationally driven. The drive roller 107 is driven to rotate by a drive motor (not shown), and the drive motor, the drive roller 107, and the driven roller 108 function as drive means for moving the transport belt 105 which is an endless moving means. .

  At the time of image formation, the first image forming unit 106Y transfers a yellow toner image to the rotationally driven conveyance belt 105. The image forming unit 106Y includes a photosensitive drum 109Y as a photosensitive member, a charger 110Y disposed around the photosensitive drum 109Y, an optical writing device 111, a developing device 112Y, a photosensitive cleaner 113Y, and a charge eliminator (not shown). And so on. The optical writing device 111 is configured to emit light to the respective photosensitive drums 109Y, 109M, 109C, and 109K (hereinafter collectively referred to as "photosensitive drum 109").

  At the time of image formation, the outer peripheral surface of the photosensitive drum 109Y is uniformly charged by the charger 110Y in the dark, and then writing is performed by the light from the light source corresponding to the yellow image from the optical writing device 111. An electrostatic latent image is formed. The developing device 112Y visualizes this electrostatic latent image with yellow toner, whereby a yellow toner image is formed on the photosensitive drum 109Y.

  The toner image is transferred onto the conveyance belt 105 by the function of the transfer device 115Y at a position (transfer position) where the photosensitive drum 109Y and the conveyance belt 105 abut or approach each other. By this transfer, an image of yellow toner is formed on the conveyance belt 105. After the transfer of the toner image is completed, the unnecessary toner remaining on the outer peripheral surface is wiped off by the photosensitive body cleaner 113Y, and the charge is removed by the charge removing device, and the process waits for the next image formation.

  As described above, the yellow toner image transferred onto the conveying belt 105 by the image forming unit 106Y is conveyed to the next image forming unit 106M by the roller driving of the conveying belt 105. In the image forming unit 106M, a toner image of magenta is formed on the photosensitive drum 109M by the same process as the image forming process in the image forming unit 106Y, and the toner image is superimposed on the yellow image already formed and transferred. Be done.

  The yellow and magenta toner images transferred onto the conveyance belt 105 are further conveyed to the next image forming units 106C and 106K, and the cyan toner image formed on the photosensitive drum 109C by the same operation, The black toner image formed on the body drum 109K is superimposed and transferred onto the image that has already been transferred. Thus, a full color intermediate transfer image is formed on the transport belt 105.

  The sheets 104 stored in the sheet feeding tray 101 are fed out in order from the top, and the intermediate transfer image formed on the conveying belt 105 is at a position where the conveying path contacts the conveying belt 105 or a position closest to it. It is transferred onto the paper. As a result, an image is formed on the surface of the sheet 104. The sheet 104 on which an image is formed on the sheet is further conveyed, and after the image is fixed by the fixing unit 116, the sheet is discharged to the outside of the image forming apparatus.

  Further, a belt cleaner 118 is provided for the transport belt 105. As shown in FIG. 1, the belt cleaner 118 is a cleaning blade pressed against the conveyance belt 105 at the downstream side of the transfer position of the image from the conveyance belt 105 to the sheet 104 and at the upstream side of the photosensitive drum 109. This is a developer removing unit that scrapes the toner attached to the surface of the conveyance belt 105.

  Next, the configuration for supplying the toner to the developing unit 112 will be described with reference to FIG. The toner supply configuration is generally common to each of the CMYK colors, and FIG. 2 shows the supply configuration for one developing unit 112. The toner is accommodated in the toner bottle 117, and as shown in FIG. 2, the toner is supplied from the toner bottle 117 to the sub hopper 200 through the toner bottle supply path 120.

  The sub hopper 200 temporarily holds the toner supplied from the toner bottle 117, and supplies the toner to the developing device 112 in accordance with the toner remaining amount in the developing device 112. Toner is supplied from the sub hopper 200 to the developing device 112 through the sub hopper supply path 119. The gist of the present embodiment is to detect a state in which the toner in the toner bottle 117 is exhausted and the toner is not supplied to the sub hopper 200 and the amount of toner in the sub hopper 200 is decreased.

  FIG. 3 is a perspective view showing an overview of the sub-hopper 200 according to the present embodiment. As shown in FIG. 3, a magnetic flux sensor 10 (permeability sensor) is attached to an outer wall of a casing constituting the sub hopper 200. In FIG. 3, the upper portion of the sub hopper 200 is an opening, and a cover on which the toner bottle supply path 120 is formed is attached to the opening. Further, the toner held in the sub hopper 200 is sent out from the sub hopper supply path 119 shown in FIG.

  FIG. 4 is a perspective view showing the inside of the sub hopper 200. As shown in FIG. As shown in FIG. 4, a diaphragm 201 is provided on the inner wall inside the sub hopper 200. The inner wall provided with the diaphragm 201 is the back side of the outer wall to which the magnetic flux sensor 10 is attached in FIG. Therefore, the diaphragm 201 is disposed to face the magnetic flux sensor 10.

  The diaphragm 201 is a rectangular plate-like component, and one end in the longitudinal direction is disposed in a cantilevered state fixed to the housing of the sub hopper 200. Further, a weight 202 is disposed at the end of the vibrating plate 201 which is not fixed in the longitudinal direction. The weight 202 has a function of adjusting the frequency when the diaphragm 201 vibrates and a function of vibrating the diaphragm 201.

  In the sub hopper 200, a rotating shaft 204 and a stirring member 205 are provided as a configuration for stirring the toner inside. The rotating shaft 204 is a shaft that rotates inside the sub hopper 200. The stirring member 205 is fixed to the rotation shaft 204, and the rotation of the rotation shaft 204 rotates the stirring member 205 to stir the toner as a color developing agent in the sub hopper 200. Further, the longitudinal direction of the diaphragm 201 is disposed substantially in parallel with the axial direction of the rotary shaft 204.

  Further, the stirring member 205 has a function of repelling the weight 202 provided on the diaphragm 201 by rotation in addition to stirring of the toner. Thus, the weight 202 is repelled every time the stirring member 205 rotates one turn, and the diaphragm 201 vibrates. That is, the vibrating plate 201 functions as a vibrating unit, and the stirring member 205 functions as a vibration applying unit. The gist of the present embodiment is that the remaining amount of toner in the sub hopper 200 is detected by detecting the vibration of the diaphragm 201.

  Next, the internal configuration of the magnetic flux sensor 10 according to the present embodiment will be described with reference to FIG. As shown in FIG. 5, the magnetic flux sensor 10 according to the present embodiment is an oscillation circuit based on a Colpitts-type LC oscillation circuit, and the flat pattern coil 11, the pattern resistor 12, the first capacitor 13, and the second capacitor 14. , Feedback resistors 15, unbuffered ICs 16, 17 and an output terminal 18.

  The planar pattern coil 11 is a planar coil constituted by signal lines patterned in a planar manner on a substrate constituting the magnetic flux sensor 10. As shown in FIG. 5, the planar pattern coil 11 has an inductance L obtained by the coil. In the planar pattern coil 11, the value of the inductance L is changed by the magnetic flux passing through the space opposed to the plane in which the coil is formed. As a result, the magnetic flux sensor 10 according to the present embodiment is used as an oscillating unit that oscillates a signal of a frequency according to the magnetic flux passing through the space where the coil surface of the planar pattern coil 11 faces.

The pattern resistor 12 is a resistor composed of signal lines patterned on the substrate in the same manner as the planar pattern coil 11. The pattern resistor 12 according to the present embodiment is a pattern formed in a serpentine shape, thereby creating a state in which current does not flow more easily than a linear pattern. Providing the pattern resistor 12 is one of the gist of the present embodiment. In addition, in other words, the zigzag shape is a shape bent so as to reciprocate a plurality of times in a predetermined direction. As shown in FIG. 5, the pattern resistors 12, having a resistance value _{R P.} As shown in FIG. 5, the planar pattern coil 11 and the pattern resistor 12 are connected in series.

  The first capacitor 13 and the second capacitor 14 together with the planar pattern coil 11 constitute a Colpitts-type LC oscillation circuit. Therefore, the first capacitor 13 and the second capacitor 14 are connected in series with the planar pattern coil 11 and the pattern resistor 12. A resonant current loop is constituted by a loop constituted by the planar pattern coil 11, the pattern resistor 12, the first capacitor 13 and the second capacitor 14.

  The feedback resistor 15 is inserted to stabilize the bias voltage. By the functions of the unbuffer IC 16 and the unbuffer IC 17, the fluctuation of the potential of a part of the resonant current loop is output from the output terminal 18 as a rectangular wave according to the resonant frequency.

With such a configuration, the magnetic flux sensor 10 according to the present embodiment oscillates at a frequency f according to the inductance L, the resistance value R _P , and the electrostatic capacitance C of the first capacitor 13 and the second capacitor 14. The frequency f can be expressed by the following equation (1).

  The inductance L also changes depending on the presence of the magnetic substance in the vicinity of the planar pattern coil 11 and the concentration thereof. Therefore, the permeability in the space near the flat pattern coil 11 can be determined by the oscillation frequency of the magnetic flux sensor 10.

  Further, as described above, the magnetic flux sensor 10 in the sub hopper 200 according to the present embodiment is disposed to face the diaphragm 201 via the housing. Therefore, the magnetic flux generated by the planar pattern coil 11 passes through the diaphragm 201. That is, the diaphragm 201 affects the magnetic flux generated by the planar pattern coil 11 and affects the inductance L. As a result, the presence of the diaphragm 201 affects the frequency of the oscillation signal of the magnetic flux sensor 10. This is one of the gist of the present embodiment. Details will be described later.

FIG. 6 is a diagram showing an aspect of the count value of the output signal of the magnetic flux sensor 10 according to the present embodiment. If there is no change in the magnetic flux generated by the planar pattern coil 11 included in the magnetic flux sensor 10, the magnetic flux sensor 10 continues to oscillate at the same frequency in principle. As a result, as shown in FIG. 6, the count value of the counter uniformly increases with the passage of time, and as shown in FIG. 6, the timings of t ₁ , t ₂ , t ₃ , t ₄ and t _{5 respectively} The count values such as aaaah, bbbbh, cccch, ddddh, AAAAh are acquired.

By calculating the count value at each timing based on each of T ₁ , T ₂ , T ₃ , and T ₄ shown in FIG. 6, the frequency in each period is calculated. For example, when counting the reference clock corresponding to 2 (msec) and calculating the frequency by outputting an interrupt signal, T ₁ and T shown in FIG. 6 can be obtained by dividing the count value in each period by 2 (msec). The oscillation frequency f (Hz) of the magnetic flux sensor 10 in each of the periods T ₂ , T ₃ and T ₄ is calculated.

Further, as shown in FIG. 6, when the upper limit of the count value of the counter is FFFFh, when calculating the frequency in the period _{T 4,} a value obtained by subtracting ddddh from FFFFh, the sum of the values of the AAAAh 2 (msec The oscillation frequency f (Hz) can be calculated by dividing by.

  As described above, in the image forming apparatus 100 according to the present embodiment, the frequency of the signal oscillated by the magnetic flux sensor 10 is acquired, and the event corresponding to the oscillation frequency of the magnetic flux sensor 10 is determined based on the acquisition result. it can. Then, in the magnetic flux sensor 10 according to the present embodiment, the inductance L changes in accordance with the state of the diaphragm 201 disposed facing the planar pattern coil 11, and as a result, of the signal output from the output terminal 18 The frequency changes.

  As a result, in a controller that acquires a signal, it is possible to confirm the state of the diaphragm 201 disposed to face the planar pattern coil 11. It is one of the gist of the present embodiment to judge the state of the developer inside the sub hopper 200 based on the state of the diaphragm 201 thus confirmed.

  As described above, the frequency can be obtained by dividing the count value of the oscillation signal by the period, but if the period for acquiring the count value is fixed, the acquired count value is used as a parameter for indicating the frequency. It is also possible to use it as it is.

  FIG. 7 is a perspective view showing an overview of the magnetic flux sensor 10 according to the present embodiment. In FIG. 7, the surface on which the planar pattern coil 11 and the pattern resistor 12 described in FIG. 5 are formed, that is, the detection surface facing the space where the magnetic permeability should be detected is directed to the upper surface.

  As shown in FIG. 7, on the detection surface on which the planar pattern coil 11 is formed, the pattern resistor 12 connected in series to the planar pattern coil 11 is patterned. As described in FIG. 5, the planar pattern coil 11 is a pattern of signal lines spirally formed on a plane. The pattern resistor 12 is a pattern of signals formed in a zigzag manner on a plane, and the function of the magnetic flux sensor 10 as described above is realized by these patterns.

  A portion formed by the flat pattern coil 11 and the pattern resistor 12 is a detection unit of the magnetic permeability in the magnetic flux sensor 10 according to the present embodiment. When the magnetic flux sensor 10 is attached to the sub hopper 200, the detection unit is attached to face the diaphragm 201.

  Next, a configuration for acquiring the output value of the magnetic flux sensor 10 in the image forming apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 8 is a diagram showing the configuration of the controller 20 and the magnetic flux sensor 10 for acquiring the output value of the magnetic flux sensor 10. As shown in FIG. As shown in FIG. 8, the controller 20 according to the present embodiment includes a central processing unit (CPU) 21, an application specific integrated circuit (ASIC) 22, a timer 23, a crystal oscillation circuit 24, and an input / output control ASIC 30.

  The CPU 21 is an arithmetic unit, and controls the entire operation of the controller 20 by performing an operation according to a program stored in a storage medium such as a ROM (Read Only Memory). The ASIC 22 functions as a connection interface between a system bus to which the CPU 21 and a RAM (Random Access Memory) or the like are connected and other devices.

  The timer 23 generates an interrupt signal each time the count value of the reference clock input from the crystal oscillation circuit 24 reaches a predetermined value, and outputs the interrupt signal to the CPU 21. The CPU 21 outputs a read signal for acquiring the output value of the magnetic flux sensor 10 in response to the interrupt signal input from the timer 23. The crystal oscillation circuit 24 oscillates a reference clock for operating each device in the controller 20.

  The input / output control ASIC 30 acquires a detection signal output from the magnetic flux sensor 10 and converts it into information that can be processed inside the controller 20. As shown in FIG. 8, the input / output control ASIC 30 includes a permeability counter 31, a read signal acquisition unit 32, and a count value output unit 33. As described above, the magnetic flux sensor 10 according to the present embodiment is an oscillation circuit that outputs a rectangular wave of a frequency according to the permeability in the space to be detected.

  The permeability counter 31 is a counter that increments a value according to the rectangular wave output from such a magnetic flux sensor 10. That is, the permeability counter 31 functions as a target signal counter that counts the number of signals of a target whose frequency is to be calculated. The magnetic flux sensor 10 according to the present embodiment is provided for each sub hopper 200 connected to the developing device 112 for each color of CMYK, and a plurality of magnetic permeability counters 31 are also provided accordingly.

  The read signal acquisition unit 32 acquires a read signal, which is an instruction to acquire the count value of the permeability counter 31 from the CPU 21, through the ASIC 22. When the read signal acquisition unit 32 acquires a read signal from the CPU 21, the read signal acquisition unit 32 inputs a signal for causing the count value output unit 33 to output a count value. The count value output unit 33 outputs the count value of the permeability counter 31 in accordance with the signal from the read signal acquisition unit 32.

  The access from the CPU 21 to the input / output control ASIC 30 is performed, for example, via a register. Therefore, the read signal described above is performed by the CPU 21 writing a value in a predetermined register included in the input / output control ASIC 30. The count value output unit 33 outputs the count value by storing the count value in a predetermined register included in the input / output control ASIC 30, and the CPU 21 acquires the value. The controller 20 shown in FIG. 8 may be provided separately from the magnetic flux sensor 10, or may be mounted on the substrate of the magnetic flux sensor 10 as a circuit including the CPU 21.

  In such a configuration, the CPU 21 detects the vibration state of the diaphragm 201 based on the count value acquired from the count value output unit 33, and detects the remaining amount of toner in the sub hopper 200 based on the detection result. That is, the detection processing unit is configured by the CPU 21 performing an operation according to a predetermined program. Further, the count value obtained from the count value output unit 33 is used as frequency related information indicating the frequency of the magnetic flux sensor 10 which changes in accordance with the vibration of the diaphragm 201.

  Next, the influence of the diaphragm 201 on the oscillation frequency of the magnetic flux sensor 10 according to the present embodiment will be described. As shown in FIG. 9, the surface of the magnetic flux sensor 10 on which the flat pattern coil 11 is formed and the diaphragm 201 are disposed to face each other via the housing of the sub hopper 200. Then, as shown in FIG. 9, a magnetic flux is generated around the center of the planar pattern coil 11, and the magnetic flux penetrates the diaphragm 201.

Diaphragm 201, for example SUS is constituted by plates, the magnetic flux G ₁ as shown in FIG. 10 eddy current is generated in the vibrating plate 201 by penetrating the vibrating plate 201. This eddy current generates a magnetic flux G _2, acts so as to cancel out the magnetic fluxes G ₁ by a plane pattern coil 11. By thus canceling out the magnetic flux G1, the inductance L in the magnetic flux sensor 10 is reduced. As shown in the above equation (1), the oscillation frequency f increases as the inductance L decreases.

  The strength of the eddy current generated in the diaphragm 201 in response to the magnetic flux from the planar pattern coil 11 varies not only with the strength of the magnetic flux but also with the distance between the planar pattern coil 11 and the diaphragm 201. FIG. 11 is a diagram showing the oscillation frequency of the magnetic flux sensor 10 according to the distance between the flat pattern coil 11 and the diaphragm 201. As shown in FIG.

The intensity of the eddy current generated inside the diaphragm 201 is inversely proportional to the distance between the planar pattern coil 11 and the diaphragm 201. Therefore, as shown in FIG. 11, the smaller the distance between the planar pattern coil 11 and the diaphragm 201, the higher the oscillation frequency of the magnetic flux sensor 10. When the distance between the flat pattern coil 11 and the diaphragm 201 becomes narrower than the predetermined distance g ₀ , the inductance L becomes too low. It does not oscillate.

Therefore, the oscillation frequency in the interval of not more than g ₀ is zero. On the other hand, when the distance between the flat pattern coil 11 and the diaphragm 201 becomes wide, the oscillation frequency of the magnetic flux sensor 10 converges to a frequency that is not affected by the eddy current generated inside the diaphragm 201.

In the sub hopper 200 according to the present embodiment, the vibration of the diaphragm 201 is detected based on the oscillation frequency of the magnetic flux sensor 10 by utilizing the characteristics as shown in FIG. It is one of the gist according to the present embodiment to detect the remaining amount of toner in the sub hopper 200 based on the vibration of the diaphragm 201 detected as described above. The distance g0 in FIG. 11, i.e., it is one aspect of this embodiment by using the interval g ₀ oscillation stops the flux sensor 10 to determine the vibration start timing of the diaphragm 201. The g ₀ is a distance between the magnetic flux sensor 10 and the vibration plate 201, the magnetic flux sensor 10 is used as the predetermined threshold value for stopping the oscillation.

  That is, the structure which processes the output signal of the diaphragm 201 shown in FIG. 9, the magnetic flux sensor 10, and the magnetic flux sensor 10 is used as a powder detection apparatus which concerns on this embodiment. This powder detection device is a developer remaining amount detection device if it is used to detect the toner remaining amount. Further, the magnetic flux sensor 10 functions as a vibration detection unit.

  The vibration of the diaphragm 201 that is bounced by the stirring member 205 is represented by the natural frequency determined by the rigidity of the diaphragm 201 and the weight of the weight 202, and a damping factor determined by an external factor that absorbs the vibration energy. As external factors for absorbing vibration energy, in addition to the fixing strength of the fixing portion for fixing the diaphragm 201 in a cantilever state, fixing factors such as air resistance, etc., the toner contacting the diaphragm 201 inside the sub hopper 200 There is a presence of

  The toner in contact with the diaphragm 201 in the sub hopper 200 fluctuates depending on the amount of toner remaining in the sub hopper 200. Therefore, by detecting the vibration of the diaphragm 201, it is possible to detect the remaining amount of toner in the sub hopper 200. Therefore, in the sub hopper 200 according to the present embodiment, the agitating member 205 for agitating the toner in the inside repels the diaphragm 201 and periodically vibrates the diaphragm 201 according to the rotation.

  Next, the arrangement of parts around the diaphragm 201 in the sub hopper 200 and the configuration for the stirring member 205 to repel the diaphragm 201 will be described. FIG. 12 is a perspective view showing the arrangement of the periphery of the diaphragm 201. As shown in FIG. 12, the diaphragm 201 is fixed to the housing of the sub hopper 200 via the fixing portion 201 a.

  FIG. 13 is a side view showing a state before the stirring member 205 comes in contact with the weight 202 attached to the diaphragm 201 as the rotation state of the rotating shaft 204. As shown in FIG. In FIG. 13, the rotating shaft 204 rotates so that the stirring member 205 rotates clockwise.

  As shown in FIG. 13, the weight 202 is a protruding portion that protrudes from the plate surface of the diaphragm 201, and has a shape having an inclination with respect to the plate surface of the diaphragm 201 when viewed from the side. This inclination is configured such that the slope approaches the rotation shaft 204 along the rotation direction of the stirring member 205. The inclined surface of the weight 202 is a portion that is pushed by the stirring member 205 when the stirring member 205 bounces the diaphragm 201 and vibrates. FIG. 14 is a side view showing a state in which the stirring member 205 is further rotated from the state shown in FIG.

  By further rotating the stirring member 205 in contact with the weight 202, the diaphragm 201 is pushed in and deformed with the inclination provided to the weight 202. In FIG. 14, the positions of the diaphragm 201 and the weight 202 in a state in which no external force is applied (hereinafter referred to as a “steady state”) are indicated by broken lines. As shown in FIG. 14, the diaphragm 201 and the weight 202 are pushed by the stirring member 205.

  FIG. 15 is a top view showing the state shown in FIG. Since the diaphragm 201 is fixed to the inner wall of the sub hopper 200 via the fixing portion 201a, the position on the fixing portion 201a does not change. On the other hand, when the weight 202 is provided and the free end of the opposite end is pushed by the agitating member 205, it moves to the opposite side to the side where the rotation shaft 204 is provided. As a result, the diaphragm 201 is bent as shown in FIG. 15 with the fixing portion 201a as a base point. In such a bent state, energy for vibrating the diaphragm 201 is stored.

  As shown in FIG. 15, in the stirring member 205 according to the present embodiment, a notch 205a is provided between a portion in contact with the weight 202 and the other portion. As a result, when the stirring member 205 pushes the weight 202, it is possible to prevent the stirring member 205 from being damaged by applying an excessive force.

  In addition, a round portion 205b is provided at the start point of the incision 205a. Thereby, when the deflection amount of the stirring member 205 is different at the boundary of the cut 205a, the stress applied to the start point of the cut 205a can be dispersed, and the breakage of the stirring member 205 can be prevented.

  FIG. 16 is a side view showing a state in which the stirring member 205 is further rotated from the state shown in FIG. In FIG. 16, the position of the diaphragm 201 in the steady state is shown by a broken line, and the position of the diaphragm 201 shown in FIG. 14 is shown by a dashed line. The position of the diaphragm 201 which is bent to the opposite side by releasing the vibration energy which is pushed in and stored by the stirring member 205 is indicated by a solid line.

  FIG. 17 is a top view showing the state shown in FIG. As shown in FIG. 16, when the pressing of the weight 202 by the stirring member 205 is released, the energy of the deflection stored in the diaphragm 201 causes the end on the side provided with the weight 202 as the free end to be opposite. Move to bend.

  In the state shown in FIG. 16 and FIG. 17, the diaphragm 201 is in a state of being separated from the magnetic flux sensor 10 which is opposed via the housing of the sub hopper 200. Thereafter, the diaphragm 201 vibrates, and thereby the magnetic flux sensor 10 returns to the steady state by damping of the vibration while repeating the state closer to the solid state than in the steady state and the state away from the steady state.

  FIG. 18 schematically shows the state of the toner held in the sub hopper 200 by dots. When toner is present inside the sub hopper 200 as shown in FIG. 18, the diaphragm 201 and the weight 202 vibrate and contact the toner while vibrating. Therefore, the vibration of the diaphragm 201 is attenuated earlier than when no toner is present in the sub hopper 200. The remaining amount of toner in the sub hopper 200 can be detected based on the change in damping of the vibration.

  FIG. 19 is a diagram showing a change in the count value of the oscillation signal of the magnetic flux sensor 10 every predetermined period until the vibration of the diaphragm 201 is damped and stopped after the weight 202 is repelled by the stirring member 205. is there. The count value of the oscillation signal of the magnetic flux sensor 10 increases as the oscillation frequency increases. Therefore, the vertical axis in FIG. 19 can be replaced with the oscillation frequency instead of the count value.

As shown in FIG. 19, at timing t ₁ , the stirring member 205 contacts the weight 202 and pushes the weight 202, whereby the diaphragm 201 approaches the magnetic flux sensor 10. Thereby, the oscillation frequency of the magnetic flux sensor 10 is increased, and the count value for each predetermined period is increased.

Then, the distance between the diaphragm 201 and the magnetic flux sensor 10 is below the gap g ₀ described in Fig. 11 at time t _2, the oscillation of the magnetic flux sensor 10 is stopped. In other words, the stirring member 205, a force in a direction approaching to the magnetic flux sensor 10 to the vibration plate 201, the distance between the magnetic flux sensor 10 to move the diaphragm 201 such that g ₀ or less. As a result, the count value which has been on the rise becomes zero immediately.

Then, the pressing of the weight 202 is released by the stirring member 205 at the timing t _3, the vibration plate 201 is released from the pushed state to vibrate by the vibration energy stored. As a result, the distance between the diaphragm 201 and the magnetic flux sensor 10 becomes equal to or larger than the interval g ₀ , and the magnetic flux sensor 10 starts oscillation again. As a result, the count value rises rapidly from the zero state. It is a gist according to the present embodiment to determine the start timing of the vibration of the diaphragm 201 based on the rapid increase of the count value.

Figure 30 is when the distance between the diaphragm 201 and the magnetic flux sensor 10 is pushed by the stirring member 205 does not fall below the spacing g ₀ as described above, is a diagram illustrating a change of the count value of the oscillation signal of the flux sensor 10. In FIG. 30, the case where the diaphragm 201 pushed in by the stirring member 205 is pressed against the inner wall of the sub hopper 200 is taken as an example.

As shown in FIG. 30, the timing t ₁ and later, by the diaphragm 201 is pressed by the stirring member 205, it will approach the distance between the diaphragm 201 and the magnetic flux sensor 10, the count value increases. Then, at timing t ′ ₂ , the diaphragm 201 is pressed against the inner wall of the sub hopper, and the count value does not further increase.

Thereafter, at timing t ′ ₃ , the pressing of the weight 202 by the stirring member 205 is released, the diaphragm 201 is released from the pushed-in state, and vibrates by the stored vibration energy. Comparing timing _t'3 at the timing t ₃ and Figure 30 in FIG. 19, when the timing t _3, the contrast distinct changes of the count value rises rapidly from zero occurs, timing _t'3 In the case of, there is no such clear change. Therefore, according to the present embodiment, it is possible to determine the start timing of the vibration of the diaphragm 201 with high accuracy based on the rapid rise of the count value.

  The vibration of the diaphragm 201 causes the distance between the diaphragm 201 and the magnetic flux sensor 10 to be larger and smaller than that in the steady state. As a result, the frequency of the oscillation signal of the magnetic flux sensor 10 vibrates with the vibration of the diaphragm 201, and the count value for each predetermined period also vibrates.

  The amplitude of the vibration of the diaphragm 201 becomes narrower as the vibration energy is consumed. That is, the vibration of the diaphragm 201 attenuates with time. Therefore, the change of the interval between the diaphragm 201 and the magnetic flux sensor 10 also becomes smaller with the lapse of time, and as shown in FIG. 19, the change of the count value with time also changes.

  Here, as described above, the vibration of the diaphragm 201 is attenuated faster as the amount of remaining toner in the sub hopper 200 is larger. Therefore, it is recognized how the vibration of the diaphragm 201 has been damped by analyzing the damping of the oscillation signal of the magnetic flux sensor 10 as shown in FIG. You can know the amount.

Therefore, as shown in FIG. 19, assuming that the peaks of the oscillation of the count value are P1, P2, P3, P4, ..., for example, the damping rate 振動 of the oscillation of the diaphragm 201 by the following equation (2) You can ask for By referring to the ratio of peak values having different timings as shown in the equation (2), it is possible to cancel the error due to environmental fluctuation and obtain an accurate attenuation rate. In other words, the CPU 21 according to the present embodiment obtains the attenuation rate 基 づ い based on the ratio of the count values acquired at different timings.

In the above equation (2), P ₁ , P _2, P ₅ , and P ₆ among the peaks shown in FIG. 19 are used, but this is an example, and other peaks may be used. However, the peak value at the timing t ₃ when the vibration plate 201 starts to vibration is not a value corresponding to the amplitude of the vibration, it is preferable not to the calculation.

  Even if the damping of the vibration is accelerated by the presence of the toner in the sub hopper 200 as shown in FIG. 18, the frequency of the diaphragm 201 does not largely change. Therefore, the attenuation of the amplitude in a predetermined period can be calculated by calculating the ratio of the amplitude of a specific peak as shown in the above-mentioned equation (2).

  Next, the operation of detecting the amount of remaining toner in the sub hopper 200 according to the present embodiment will be described with reference to the flowchart of FIG. The operation of the flowchart shown in FIG. 20 is the operation of the CPU 21 shown in FIG. As shown in FIG. 20, the CPU 21 first detects that the weight 202 is pushed in by the stirring member 205 as shown in FIG. 14 to generate vibration (S2001).

As described above, the CPU 21 acquires the count value of the output signal of the magnetic flux sensor 10 from the count value output unit 33 every predetermined period. This count value is C ₀ as shown in FIG. 19 in the steady state. On the other hand, when the weight 202 is pushed in as shown in FIG. 14, the count value increases as the diaphragm 201 approaches the magnetic flux sensor 10.

Then, as described above, when the distance between the diaphragm 201 and the magnetic flux sensor 10 falls below g ₀ , the oscillation of the magnetic flux sensor 10 is stopped, and the count value becomes zero. CPU21 detects that the count value becomes zero (S2001 / YES), then, waits until the timing at which the count value increases rapidly as the timing _{t 3} of Figure 19 (S2002 / NO).

  When the diaphragm 201 is flipped to start vibration, the magnetic flux sensor 10 starts oscillation and the count value rapidly increases. When detecting that the count value has rapidly increased from zero (S2002 / YES), the CPU 21 detects that vibration has occurred in the diaphragm 201 (S2003).

  Regardless of the processing of S2001 to S2003, the CPU 21 continuously performs the acquisition processing of the count value for each predetermined period as the normal processing. Then, after S2003, the CPU 21 obtains the peak value of the vibration of the count value corresponding to the vibration of the diaphragm 201 as shown in FIG. 19 (S2004). In S2004, the CPU 21 specifies a peak value by analyzing the count value continuously acquired every predetermined period.

FIG. 21 is a diagram showing an aspect of analyzing the count value, and for the count value acquired every predetermined period, in addition to the “number n” and “count value S _n ” of each count value, the immediately preceding count value And the difference code “S _n−1 −S _n ” with the above are shown in the order of acquisition. In the result as shown in FIG. 21, the immediately preceding value obtained by inverting the sign of "S _n-1 -S _n " is the peak value. In the case of FIG. 21, the fifth and tenth numbers are adopted as peak values.

That is, the CPU 21 calculates "S _n-1 -S _n " shown in FIG. 21 for the count values sequentially acquired from S2003. The “count value S _n ” at the timing when the sign obtained as the calculation result is inverted is adopted as a peak value such as P ₁ , P ₂ , P ₃ ... Shown in FIG.

Also, the actually obtained count value may include noise of high frequency components, and the timing at which the sign of “S _n−1 −S _n ” is inverted at a position not a peak due to the vibration of the diaphragm 201 is It may occur. In order to avoid erroneous detection in such a case, it is preferable that the CPU 21 perform the analysis shown in FIG. 21 after smoothing the value acquired from the count value output unit 33. In the smoothing process, a general process such as a moving average method can be employed.

When the peak value is obtained in this way, the CPU 21 calculates the attenuation factor に よ り by the calculation of the above equation (2) (S2005). Therefore, in S2004, the count value is analyzed in the manner shown in FIG. 21 until the peak value used to calculate the attenuation factor is obtained. When using the above formula (2), CPU 21 analyzes the count value to a peak value corresponding to P ₆ is obtained.

  After calculating the attenuation factor よ う in this way, the CPU 21 determines whether the calculated attenuation factor ζ is less than or equal to a predetermined threshold (S2006). That is, the CPU 21 determines that the toner in the sub hopper 200 has fallen below a predetermined amount, based on the magnitude relationship between the ratio of the count value obtained at different timings and the predetermined threshold. As described in FIG. 18, when sufficient toner remains in the sub-hopper 200, the vibration of the diaphragm 201 is quickly damped. Therefore, the attenuation factor 小 さ く な る decreases.

On the other hand, when the toner in the sub hopper 200 is reduced, the damping of the vibration of the diaphragm 201 is delayed accordingly, and the damping rate 大 き く is increased. Therefore, by setting the attenuation rate ζ _S according to the toner remaining amount to be detected as a threshold, the remaining amount of toner in the sub hopper 200 should be detected based on the calculated attenuation rate ((hereinafter referred to as “ It can be determined that the amount has decreased to the specified amount.

  Note that the remaining amount of toner in the sub hopper 200 does not directly affect the damping aspect of the vibration of the diaphragm 201, but the contact state of the toner with respect to the diaphragm 201 changes according to the remaining amount of toner. The damping mode of the vibration of 201 is determined. Therefore, even if the amount of remaining toner in the sub hopper 200 is the same, if the contact aspect of the toner with respect to the diaphragm 201 is different, the attenuation aspect of the diaphragm 201 will be different.

  On the other hand, when detecting the remaining amount of toner in the sub hopper 200 according to the present embodiment, the toner in the sub hopper 200 is always stirred by the stirring member 205. Therefore, the contact state of the toner with respect to the diaphragm 201 can be determined to a certain extent according to the remaining amount of toner. As a result, even if the amount of remaining toner is the same, the contact state of the toner with respect to the diaphragm 201 is different, and the adverse effect that the detection result is different can be avoided.

  As a result of the determination in S2004, if the calculated attenuation factor 未 満 is less than the threshold (S2006 / NO), the CPU 21 determines that a sufficient amount of toner is held in the sub hopper 200, and the process ends. Do. On the other hand, if the calculated attenuation rate 以上 is equal to or higher than the threshold (S2006 / YES), the CPU 21 determines that the toner amount inside the sub hopper 200 is less than the specified amount, performs toner out detection, and ends the processing. (S2007).

  The CPU 21 that has detected the toner out in the process of S2007 outputs a signal indicating that the remaining amount of toner is lower than the specified amount to the higher-order controller that controls the image forming apparatus 100. As a result, the controller of the image forming apparatus 100 can recognize the toner shortage for a specific color, and can supply the toner from the toner bottle 117.

Next, the relationship between the frequency of the oscillation signal of the magnetic flux sensor 10 according to the present embodiment, the acquisition cycle of the count value by the CPU 21 (hereinafter referred to as “sampling cycle”), and the natural frequency of the diaphragm 201 will be described. FIG. 22 is a view showing the sampled count value of the vibration of the diaphragm 201 in one cycle. In FIG. 22, the period of vibration of the diaphragm 201 is T _plate , and the sampling period is T _sample .

In order to calculate the attenuation factor ζ of the diaphragm 201 with high accuracy by the aspect described in FIGS. 19 to 21, it is necessary to acquire the peak value of the vibration of the diaphragm 201 with high accuracy. In order to do so, a sufficient number of samples for the T _plate is required, and for this reason, T _sample needs to be sufficiently smaller than the T _plate .

In the example of FIG. 22, the number of samples of the count value is 10 for one cycle of T _plate . That is, T _sample is 1/10 of T _plate . According to the aspect of FIG. 22, sampling is always performed within the period of T _{peak in} the figure, and it is possible to obtain a peak value with high accuracy.

Therefore, assuming that the sampling period T _{sample of the} CPU 21 is 1 ms, it is preferable that the vibration period T _plate of the diaphragm 201 be 10 ms or more. In other words, for the sampling frequency of 1000 Hz of the CPU 21, the natural frequency of the diaphragm 201 is preferably about 100 Hz, and more preferably less than that. Such a natural frequency of the diaphragm 201 is realized by adjusting the material of the diaphragm 201, the dimensions including the thickness of the diaphragm 201, and the weight of the weight 202.

  On the other hand, if the value of the count value sampled at each sampling cycle is too small, the change in the count value for each sample according to the vibration of the diaphragm 201 becomes small, and the attenuation factor ζ can not be calculated accurately. Here, the value of the count value to be sampled is a value according to the oscillation frequency of the magnetic flux sensor 10.

Generally, the oscillation frequency of the magnetic flux sensor 10 is on the order of several MHz, and when sampling is performed at a sampling frequency of 1000 Hz, a count value of 1000 or more can be obtained for each sampling timing. Therefore, it is possible to calculate the attenuation factor 高 with high accuracy by the order of T _plate and T _sample as described above.

  However, if the variation of the oscillation frequency of the magnetic flux sensor 10 is not sufficient for the change of the distance between the magnetic flux sensor 10 and the diaphragm 201 due to the vibration of the diaphragm 201, the count value for the time as shown in FIG. The amplitude of the vibration is reduced. As a result, the change in the attenuation factor 小 さ く also becomes small, and the accuracy of the toner remaining amount detection due to the vibration of the diaphragm 201 also decreases.

  In order to increase the change amount of the oscillation frequency of the magnetic flux sensor 10 with respect to the change of the distance between the magnetic flux sensor 10 and the diaphragm 201, the arrangement of the magnetic flux sensor 10 and the diaphragm 201 based on the characteristics as shown in FIG. It is necessary to determine the interval. For example, as shown by the section of the arrow in the figure, the spacing between the magnetic flux sensor 10 and the diaphragm 201 is within the range where the change of the oscillation frequency is steep with respect to the change of the spacing between the magnetic flux sensor 10 and the diaphragm 201. It is preferable to determine as an interval.

  FIG. 23 is a diagram showing an adjustment mode of the arrangement interval between the magnetic flux sensor 10 and the diaphragm 201. As shown in FIG. As shown in FIG. 23, adjustment of the arrangement distance g between the magnetic flux sensor 10 and the diaphragm 201 is achieved by fixing the thickness of the housing 200 a of the sub hopper 200 to which the magnetic flux sensor 10 and the diaphragm 201 are attached, and the diaphragm 201. It can be adjusted by the thickness of the fixed portion 201a.

Further, as shown in FIG. 23, in the case 200a according to the present embodiment, the magnetic flux sensor 10 is attached, and the wall of the portion facing the diaphragm 201 is formed thinner than the other portion of the case 200a. It is a thin portion 200b. The thickness g _L of the thin portion 200 b is thinner than the distance g ₀ shown in FIG. Thereby, as shown in FIG. 24, the interval g _min between the diaphragm 201 and the magnetic flux sensor 10 in the state where the diaphragm 201 is pushed in by the agitating member 205 and is most deflected is made narrower than the interval g _0. It can.

As described in FIGS. 19 and 20, in order for the CPU 21 to determine the vibration start timing of the diaphragm 201, the interval between the diaphragm 201 and the magnetic flux sensor 10 needs to be smaller than g ₀ and the count value needs to be zero once. is there. Such control can be performed by providing the thin portion 200 b as shown in FIG. 23 and adjusting the pressing amount of the diaphragm 201 by the stirring member 205 in accordance with the wall surface of the thin portion 200 b.

Note that, in FIG. 24, the case where the diaphragm 201 and the thin portion 200b are not in contact with each other is taken as an example, even if the diaphragm 201 is most pushed in by the stirring member 205. However, this is only an example, and the mode may be such that the diaphragm 201 is pushed until it contacts the thin portion 200 b. Thereby, if the thickness of the thin portion 200b is less than the interval g ₀ , g _min shown in FIG. 24 can be reliably made less than g ₀ .

  As described above, according to the method for detecting the remaining amount of toner according to the present embodiment, the influence of the toner on the delicate event of the vibration of the diaphragm 201 is detected. Also, unlike the mode in which the pressure or the like of the toner is directly detected, since the pressure is detected through the vibration of the diaphragm, a pressure sensor or the like whose accuracy is difficult to improve is not used, and the remaining amount of toner in the container is high. It becomes possible to detect to accuracy.

Then, when the diaphragm 201 is pushed in a direction approaching the magnetic flux sensor 10 in order to vibrate, the spacing between the diaphragm 201 and the magnetic flux sensor 10 is arranged to be less than the spacing g _{0 at} which the oscillation of the magnetic flux sensor 10 stops. There is. As a result, when the diaphragm 201 is pushed in and then repelled to start vibration, the oscillation of the magnetic flux sensor 10 is always stopped. Therefore, the start of the vibration of the diaphragm 201 can be accurately detected based on the stop and restart of the oscillation of the magnetic flux sensor 10.

Further, according to the judging method of the vibration start timing of the diaphragm 201 where the magnetic flux sensor 10 utilizes the fact that no longer temporarily oscillated by g _min shown in Figure 24 is configured to be below the g _0, the housing interior There is no need to secure continuity from the housing to the outside. Therefore, it is not necessary to provide a through hole or the like on the wall surface of the housing, and it is possible to prevent the toner inside from leaking through the through hole and scattering to the outside of the sub hopper.

  In addition, since the seal member and the like required when providing the through hole in the wall surface of the housing are not necessary, and the number of parts can be reduced, the cost can be reduced and the assembling operation can be facilitated.

  Further, it is premised that the diaphragm 201 to be sensed by the magnetic flux sensor 10 used as a sensor in the present embodiment is vibrating. Therefore, even if the toner adheres to the diaphragm 201, the toner adhering to the diaphragm 201 is shaken off due to the vibration, and it is possible to avoid a decrease in detection accuracy due to the adhesion of the toner.

  Further, no physical contact is required between the magnetic flux sensor 10 used as a sensor in the present embodiment and the diaphragm 201 which is an object of sensing. Therefore, even if the magnetic flux sensor 10 is provided on the outside of the toner container, it is not necessary to make a hole in the container housing to ensure physical access. Therefore, it is possible to attach easily and to improve productivity.

  Further, according to the aspect of the present embodiment, detection of the remaining amount of toner is triggered by the fact that the diaphragm 201 is pushed by the stirring member 205 and displaced as shown in S2001, and the peak value after that is acquired. To be executed. Therefore, when the diaphragm 201 is pushed in by the agitating member 205 as shown in FIG. 14, the detection result of the toner remaining amount can not be obtained.

  On the other hand, in the case of a mode in which the pressure corresponding to the toner remaining amount is detected by a pressure sensor or the like, the pressure pressed by the stirring member for stirring the toner in the container and the pressure generated according to the toner remaining amount Distinction is difficult, and improvement of detection accuracy is difficult. According to the aspect which concerns on this embodiment, such a subject is solvable.

In the above embodiment, as shown in FIG. 23, the case where the thin portion 200b is provided to the housing 200a has been described as an example. This is to make the thickness of the wall of the housing thinner than the gap g ₀ as described above. Therefore, in the case without providing the thin portion 200b is a wall thickness of the housing 200a thinner than the spacing g _0, it is not necessary to provide the thin portion.

  Moreover, in the said embodiment, as a target of the sensing by the magnetic flux sensor 10, the case where the diaphragm 201 which is a plate-shaped member of a metal raw material was used was demonstrated as an example. However, this is an example. The conditions required for the diaphragm 201 affect the magnetic flux in accordance with the change of the distance from the magnetic flux sensor 10 to generate the vibration with the predetermined frequency as described in FIG. To affect the frequency.

  In the above embodiment, a metal material is used which cancels the magnetic flux and decreases the inductance L as it gets closer to the magnetic flux sensor 10. Conversely, a ferromagnetic material which increases the magnetic flux and increases the inductance L as it gets closer to the magnetic flux sensor 10. The material of

  In the above embodiment, the diaphragm 201, which is a plate-like member, is used as the sensing target of the magnetic flux sensor 10 from the viewpoint of affecting the magnetic flux generated by the planar pattern coil 11 of the magnetic flux sensor 10 and the natural frequency. However, this is only an example, and as long as it satisfies the condition of vibrating and affecting the magnetic flux, it may be not only a plate but a rod-like part.

  Further, in the above embodiment, the diaphragm 201 is formed using a material that affects the magnetic flux, and the embodiment in which the damping of the vibration of the diaphragm 201 is detected by the magnetic flux sensor 10 has been described as an example. However, this is only an example, and any mode may be used as long as the residual amount of toner in the container is detected by the influence of the toner on the delicate event of damping of the vibration of the plate-like member.

  Further, the prescribed amount described above can be adjusted by the arrangement of the diaphragm 201 and the magnetic flux sensor 10 in the sub hopper 200. FIG. 25 and FIG. 26 are diagrams showing the relationship between the arrangement of the diaphragm 201 and the magnetic flux sensor 10 in the sub hopper 200 and the prescribed amount. In the case of FIG. 25, when the height of the toner held in the sub hopper 200 is lower than the height of the broken line A shown in the drawing, the toner does not contact the diaphragm 201. Therefore, in the vicinity of the height of the broken line A in the figure, it is detected that the toner remaining amount has fallen below the specified amount.

  On the other hand, in the case of FIG. 26, the arrangement height of the diaphragm 201 and the magnetic flux sensor 10 is lower than that of FIG. When the height of the toner held in the sub hopper 200 is lower than the height of the broken line B shown in the figure, the toner does not contact the diaphragm 201. Therefore, in the vicinity of the height of the broken line B in the figure, it is detected that the toner remaining amount has fallen below the specified amount.

  The aspect of adjusting the prescribed amount by the arrangement of the diaphragm 201 and the magnetic flux sensor 10 in this manner can be used, for example, to adjust the supply state of the toner of each color of CMYK. For example, for a color that is frequently used among CMYK, as shown in FIG. 25, the diaphragm 201 and the magnetic flux sensor 10 are disposed relatively high.

  On the other hand, for a color that is used less frequently, as shown in FIG. 26, the diaphragm 201 and the magnetic flux sensor 10 are disposed relatively low. Such adjustment makes it possible to efficiently supply the toner according to the frequency of use. And, in the range in which the arrangement of the diaphragm 201 and the magnetic flux sensor 10 is adjusted as described above, it is preferable that the thin portion 200b is formed as described in FIG.

  Further, in the above embodiment, as a mechanism for detecting the remaining amount of toner in the sub hopper 200 shown in FIG. 2, the configuration including the magnetic flux sensor 10 and the diaphragm 201 has been described as an example. However, the above configuration can be widely used as a configuration for detecting the amount of toner that is powder, and can also be used, for example, as a configuration for detecting the remaining amount of toner in the developing device 112.

  FIG. 27 is a cross-sectional view of a case where the developing device 112 is adopted. In the developing device 112, a supply chamber conveyance member 112b and a collection chamber conveyance member 112c, which are screws for conveying the toner in the main scanning direction, are rotated to convey the toner.

  When the configuration including the magnetic flux sensor 10 and the diaphragm 201 is adopted for the developing device 112, as shown in FIG. 27, the magnetic flux sensor 10 places the surface on which the flat pattern coil 11 is formed at the sensor mounting position 112a in the developing device 112. It is attached facing. Thereby, as shown in FIG. 27, the flat pattern coil 11 is disposed so as to face the developer movement space in which the transport path by the recovery chamber transport member 112c and the transport path by the supply chamber transport member 112b are connected. .

  In the developing device 112, a diaphragm 201 is disposed in the developer moving space. The vibrating plate 201 disposed inside the developing device 112 is vibrated by being bounced by the rotating collection chamber conveyance member 112 c as in the case of being provided in the sub hopper 200. Thereby, it becomes possible to detect the vibration of the diaphragm 201 by the magnetic flux sensor 10 in the same manner as described above.

  In the developer movement space, the toner moves between the conveyance path by the collection chamber conveyance member 112c and the conveyance path by the supply chamber conveyance member 112b, so the residence time of the toner is relatively longer than each conveyance path, The density of the toner is increased. Therefore, by disposing the diaphragm 201 in the developer movement space as shown in FIG. 27, the influence of the toner on the vibration of the diaphragm 201 is increased, and the residual amount of toner in the developing device 112 is detected with high accuracy. Is possible.

Also in the embodiment shown in FIG. 27, the same effect as described above can be obtained by configuring the distance between the magnetic flux sensor 10 and the diaphragm 201 in the state where the diaphragm 201 is most depressed less than g _0. It is. Further, by providing the thin portion in the casing of the developing device 112, the condition of the distance between the magnetic flux sensor 10 and the diaphragm 201 in the state where the diaphragm 201 is most pushed in is also satisfied.

  Further, in the above embodiment, as the powder for which the remaining amount is to be detected, the toner which is a color developer used in the image forming apparatus of the electrophotographic type has been described as an example. However, this is only an example, and any powder that affects the vibration of the diaphragm 201 according to the remaining amount by having fluidity can be similarly applied. For example, a premix in which toner and carrier are mixed in advance It is applicable to an agent etc. Further, not only powder, but any substance that affects the vibration of the diaphragm 201 according to the remaining amount by having fluidity can similarly be the detection target of the remaining amount, and it is a liquid as an object It is also possible to adopt

Moreover, in the said embodiment, the case where attenuation factor (zeta) was calculated by said Formula (2) was demonstrated as an example. However, this is only an example, and for example, an average value of attenuation rates among a plurality of peaks may be used as shown in the following equation (3).

Further, as shown in the following equation (4), it may be simply a ratio of peak values of the same sign.

  Moreover, in the said embodiment, the case where the planar pattern coil patterned and formed on the board | substrate was used was demonstrated as an example. By forming the coil on a plane, it is possible to reduce the thickness in the direction opposite to the diaphragm 201 which is the target of sensing, and it is possible to preferably achieve the miniaturization of the device.

  However, even if the coil is not formed in a planar pattern, it is possible to obtain the same effect by forming the coil so that the magnetic flux is generated in parallel with the direction facing the diaphragm 201. Another example of the formation of the coil is shown in FIG. 28 and FIG. FIG. 28 is a view seen from the direction parallel to the plate surface of the substrate constituting the magnetic flux sensor 10, and FIG. 29 is a view seen from the direction perpendicular to the plate surface of the substrate constituting the magnetic flux sensor 10.

  In the example of FIG. 28, FIG. 29, coil 11 'is formed by winding and arrange | positioning the wiring by which the surface was insulated on the board | substrate which comprises the magnetic flux sensor 10. In FIG. Also in the examples of FIGS. 28 and 29, the thickness of the coil 11 'can be made sufficiently thin by appropriately selecting the type of wiring, and the device can be miniaturized.

Second Embodiment
In the present embodiment, an aspect of controlling the stop position of the stirring member 205 will be described. In addition, about the structure which attaches | subjects the code | symbol same as Embodiment 1, an identical or corresponding part shall be shown and detailed description is abbreviate | omitted.

  As described in the first embodiment, while stirring member 205 rotates according to the rotation of rotary shaft 204, it stirs the toner inside sub hopper 200 and vibrates diaphragm 201. At this time, the diaphragm 201 is vibrated by repelling the diaphragm 201 as shown in FIG. 16 from the state where the diaphragm 201 is pushed in as shown in FIG.

  Such rotation of the stirring member 205 is stopped depending on the operating state of the image forming apparatus 100. For example, as shown in FIG. 14, when rotation is stopped in a state where the stirring member 205 is bent by pushing the vibrating plate 201, the stirring member 205 may be deformed. In addition, defects such as deformation may occur on the diaphragm 201 side.

  That is, depending on the stop position of the agitating member 205 when the rotation of the rotary shaft 204 is stopped, there is a possibility that a failure may occur in the components that constitute the apparatus. When the stirring member 205 or the diaphragm 201 is deformed, the pressing force when the stirring member 205 vibrates the diaphragm 201 is weakened, the amplitude of the diaphragm is reduced, and the detection accuracy of the attenuation factor 低下 is reduced.

  Furthermore, depending on the stop position of the agitating member 205, the amount by which the agitating member 205 bounces the toner inside the sub hopper 200 when the rotation is started next time differs. As a result, the effect of suppressing the vibration of the diaphragm 201 according to the amount of toner in the sub hopper changes, which makes it difficult to accurately detect the amount of toner.

  FIG. 31 is a view showing a state in which the stirring member 205 is stopped immediately after repelling the diaphragm 201 as one aspect of the stopping position of the stirring member 205. As shown in FIG. In the following description, the case where about 50% of the toner remains in the sub hopper 200 will be described as an example.

  In the case of FIG. 31, when the agitating member 205 starts to rotate next, the agitating member 205 rotates about one round while agitating a large amount of toner and repels the diaphragm 201. Most of the toner picked up by the stirring member 205 is dispersed on the left side in the drawing, and the remaining toner is dispersed on the ceiling side and the diaphragm 201 side. The toner splashed to the ceiling side hits the top plate and falls again, but a part thereof falls to the diaphragm 201 side.

  Further, the toner carried to the vibrating plate 201 side in series with the stirring member 205 falls on a side plate on the vibrating plate 201 or falls directly on the vibrating plate. At this time, the diaphragm 201 is in the process of being damped and vibrated by the agitating member 205, and the falling toner and the damped vibration are appreciated and become an unstable operation. That is, it is not preferable to stop the stirring member 205 in the state shown in FIG.

  FIG. 32 is a view showing a state where the stirring member 205 is rotated about 90 ° after repelling the diaphragm 201 as one aspect of the stop position of the stirring member 205. As shown in FIG. In the case of FIG. 32, although the amount of toner to be jumped up is smaller than that of FIG. 31, the toner falls on the vibrating plate 201 during vibration as described above, causing a problem that the vibration becomes unstable.

  FIG. 33 is a view showing a state where the 90 ° stirring member 205 is further rotated from the state of FIG. 32, and the stirring member 205 is exposed from the toner contained in the sub hopper 200. In the case of FIG. 33, the amount of toner to be bounced up is significantly smaller than in FIGS. 31 and 32, but depending on the remaining amount of toner in the sub hopper 200, the toner bounces up and the diaphragm 201 is vibrating. There is a possibility of falling into

  FIG. 34 is a view showing a state where the 90 ° stirring member 205 is further rotated from the state of FIG. Also in FIG. 34, the stirring member 205 is exposed from the toner contained in the sub hopper 200 as in FIG. In this case, the toner does not jump up during the period from when the stirring member 205 starts to rotate until the diaphragm 201 is vibrated, but other problems may occur.

  As indicated by the arrows in FIG. 34, toner is supplied from a supply port provided on the top plate of the sub hopper 200 and drops. Essentially, the toner supplied from the supply port is deposited on the front surface of the diaphragm 201 and dispersed by rotation of the stirring member 205.

  However, when the stop position of the stirring member 205 is in the state shown in FIG. 34, the vibrating plate 201 is covered by the stirring member 205 with respect to the toner supplied from the supply port, and the supplied toner is stirred. It will be led to the rotating shaft 204 side by the member 205. As a result, the supplied toner is not deposited on the front surface of the diaphragm 201, but is deposited on the side of the rotary shaft 204 away from the diaphragm 201 or further to the left in the drawing.

  As a result, it waits for the internal toner to be stirred to a certain extent before the supplied toner exerts the effect of damping the vibration of the diaphragm 201, and the vibration relative to the toner supplied into the sub hopper 200 The attenuation factor 板 of the plate 201 is different from the design. In other words, the timing from when the "no toner" is detected to when the "toner" is detected is delayed, and the toner is excessively supplied.

  FIG. 35 is a view showing an ideal stopping position of the stirring member 205 for avoiding the problems described in FIGS. 31 to 34. In the state of FIG. 35, the stirring member 205 is stopped in the state of standing vertically upward from the rotating shaft 204. Thus, the sub hopper 200 is exposed from the toner having a remaining amount of about 50%, and the diaphragm 201 is not covered with the toner supplied from the supply port.

  If the stirring member 205 is in the stopped state shown in FIG. 35, the instability of the vibration of the diaphragm 201 due to the toner splashing as described in FIGS. 31 to 33 or the supply as described in FIG. There is no problem with the deposition position of the toner. Therefore, in the image forming apparatus 100 according to the present embodiment, when stopping the rotation of the stirring member 205, control is performed so as to stop in the state shown in FIG.

  FIG. 36 is a diagram showing a configuration of the controller 20 according to the present embodiment. As shown in FIG. 36, the controller 20 according to this embodiment is substantially the same as the aspect described in FIG. Here, the controller 20 according to the present embodiment is different from that of the first embodiment in that the stirring motor control unit 25 is included.

  Stirring motor control unit 25 is a control unit that controls the rotation of stirring motor 24a, which is a power source for rotating rotary shaft 204, receives an instruction from CPU 21 via ASIC 22, and controls the rotation of stirring motor 204a. Do. That is, the CPU 21 and the stirring motor control unit 25 work together to function as a rotation control unit that controls the rotation of the stirring member 205. The operation at the time of stopping the rotation of the stirring motor 204a according to the present embodiment will be described with reference to the flowchart of FIG.

  As shown in FIG. 37, the CPU 21 starts stop control of the stirring motor 204a according to the operation state of the image forming apparatus 100 (S3701). When the stop control of the stirring motor 204a is started, the CPU 21 stands by until it is detected that vibration is generated in the diaphragm 201 by the processing of S2001 to S2003 in FIG. 20 (S3702 / NO).

  When it is detected that vibration has occurred in the diaphragm 201 (S3702 / YES), the CPU 21 instructs the stirring motor control unit 25 to stop via the ASIC 22 (S3703). The stirring motor control unit 25 that has received the stop instruction starts counting until the rotation of the stirring motor 204a is stopped (S3704). This count is a count for measuring a period (hereinafter, referred to as “stop period”) in which the stirring member 205 rotates to the state shown in FIG. 35 after repelling the vibrating plate 201.

  Stirring motor control unit 25 continues counting until the counting of the predetermined stop period is completed (S3705 / NO), and stops the rotation of stirring motor 204a when the stop period is counted (S3705 / YES). As a result, the stirring member 205 stops rotating in the state shown in FIG.

  As described above, in the image forming apparatus 100 according to the present embodiment, the stirring member 205 for vibrating the diaphragm 201 is stopped in a state where the diaphragm 201 is pushed in, and the stirring member 205 and the diaphragm 201 are deformed. Can be avoided.

  Further, as described in FIG. 19 of the first embodiment, in the image forming apparatus 1 according to the present embodiment, the timing at which the stirring member 205 flips the diaphragm 201 based on the count value of the oscillation signal of the magnetic flux sensor 10. Can be accurately detected. Therefore, it is possible to accurately make the determination in S3702 of FIG. 37 and to more accurately realize the stop state of the stirring member 205 shown in FIG.

  In the above embodiment, as the determination of S3702, the case where the same processing as S2001 to S2003 in FIG. 20 is applied is described as an example. However, this is an example. In the determination of S3702, it is not necessary to detect that the vibration plate 201 has started to vibrate, and it may be detected that the stirring member 205 has been separated from the vibration plate 201. Therefore, the determination in S3702 may be made based on the fact that the count value of the oscillation signal of the magnetic flux sensor 10 is not zero.

  The purpose of the present embodiment is to stop the rotation of the stirring member 205 in a state where the stirring member 205 is separated from the diaphragm 201. Although the case where the count value of the oscillation signal of the magnetic flux sensor 10 described in the first embodiment is used as a mechanism for detecting the state in which the stirring member 205 is separated from the diaphragm 201 has been described as an example, it is not limited thereto. Other aspects may be used.

  Further, in the above embodiment, after the stirring member 205 is separated from the diaphragm 201, after the predetermined period has elapsed, that is, after the stirring member 205 is rotated by a predetermined angle and then stopped, the stop position shown in FIG. The case of the case has been described as an example. However, this is only an example, and it is shown in FIGS. 31 to 34 if the purpose is only to prevent the deformation of the stirring member 205 and the diaphragm 201 by stopping the stirring member 205 in the state as shown in FIG. In the state, the stirring member 205 may be stopped.

  However, as described above, the aspect shown in FIG. 35 improves the stability of the vibration of the diaphragm 201 and the real-time property of the detection timing of the toner remaining amount in the sub hopper 200.

  On the other hand, if the purpose is only to prevent the deformation of the stirring member 205 and the diaphragm 201 and the purpose is to at least stop the stirring member 205 in the state as shown in FIG. 14, steps S3704 and S3705 in FIG. The processing may be omitted. Thereby, the stirring motor control unit 25 stops the stirring motor 204a immediately after the stirring member 205 is separated from the diaphragm 201. Even in this case, it can be avoided that the stirring member 205 stops in a state where the vibrating plate 201 is pushed in.

DESCRIPTION OF SYMBOLS 10 magnetic flux sensor 11 planar pattern coil 12 pattern resistance 13 1st capacitor 14 2nd capacitor 15 feedback resistance 16 17 unbuffered IC
18 output terminal 20 controller 21 CPU
22 ASIC
23 timer 24 crystal oscillation circuit 25 stirring motor control unit 30 input / output control ASIC
31 magnetic permeability k counter 32 read signal acquisition unit 33 count value output unit 101 paper feed tray 102 paper feed roller 103 registration roller 104 paper 105 conveyance belt 106K, 106C, 106M, 106Y image forming unit 107 drive roller 108 driven roller 109K, 109C , 109M, 109Y photosensitive drum 110K, 110C, 110M, 110Y charger 111 light writing device 112, 112K, 112C, 112M, 112Y developing device 112a sensor mounting position 112b supply chamber conveyance member 112c collection chamber conveyance member 113K, 113C, 113M , 113Y photoconductor cleaner 115K, 115C, 115M, 115Y transfer unit 116 fixing unit 117 toner bottle 118 belt cleaner 119 sub hopper supply path 120 toner Torr supply path 200 sub hopper 200a housing 200b thin portion 201 the diaphragm 201a fixed part 202 weight 204 rotating shaft 204a stirring motor 205 stirring member 205a cuts 205b round section

JP, 2013-37280, A

Claims (11)

A powder detection device for detecting the remaining amount of flowable powder in a container, comprising:
An oscillating unit that outputs a signal of a frequency according to the state of the magnetic flux passing through the opposing space;
Said disposed within the container, the opposed to the oscillating unit via the housing of the container, and vibrating in a direction opposite to the oscillating portion, the vibration portion formed by the material that affects the magnetic flux,
A vibration applying unit that vibrates the vibrating unit;
The frequency related information on the frequency of the oscillation signal of the oscillation unit is acquired at a predetermined cycle, and the vibration state of the vibration unit is detected based on the change of the frequency related information that changes according to the vibration of the vibration unit. A detection processing unit that detects the remaining amount of powder in the container based on the detection result;
The oscillation unit stops oscillation when the distance from the vibration unit becomes equal to or less than a predetermined threshold value,
The vibration applying unit moves the vibrating unit such that an interval between the vibrating unit and the oscillating unit is equal to or less than the threshold value by applying a force to the vibrating unit in a direction approaching the oscillating unit. A powder detection device characterized in that the vibration unit is vibrated by releasing the force applied in the above.   The detection processing unit determines, based on the acquired frequency-related information, the timing at which the vibration unit starts to vibrate based on the timing at which the oscillation unit starts oscillation from a state where the oscillation is stopped, and the vibration unit The powder detection device according to claim 1, wherein the remaining amount of the powder in the container is detected based on a damping aspect of the vibration after the start of the vibration. The powder according to claim 1 or 2, wherein the oscillating portion is disposed to face the vibrating portion via a thin wall portion in which a wall surface is thinner than other portions in the container. Body detection device.   The thickness of the wall surface of the said thin part is thinner than the said threshold value, The powder detection apparatus of Claim 3 characterized by the above-mentioned.   The powder detection device according to claim 1, wherein the vibration applying unit is a stirring unit for stirring the powder in the container.   And a rotation control unit configured to stop the vibration applying unit in a state of being separated from the vibration unit when controlling the rotation of the vibration applying unit for stirring the powder and stopping the rotation of the vibration applying unit. The powder detection device according to claim 5, characterized in that   The rotation control unit may stop rotation of the vibration applying unit by determining that the vibration applying unit is in a state of being separated from the vibrating unit based on the frequency related information. The powder detection device according to.   The rotation control unit may stop the rotation of the vibration applying unit after a predetermined period of time after determining that the vibration applying unit is in a state of being separated from the vibrating unit based on the frequency related information. The powder detection device according to claim 7, wherein Developer remaining amount detection apparatus characterized by detecting the remaining amount of the developer used in the image forming apparatus by a powder sensing device according to any one of claims 1 to 8. A powder detection method for detecting the remaining amount of flowable powder in a container, comprising:
The oscillator outputs a signal having a frequency according to the state of the magnetic flux passing through the opposing space,
Disposed in the container, the opposed to the oscillating unit via the housing of the container, and vibrating in a direction opposite to the oscillating portion, the vibration portion formed by the material that affects the magnetic flux, the oscillating unit Move by applying force in the direction approaching
By moving the vibrating portion, the force applied to the oscillating portion is released after the interval between the vibrating portion and the oscillating portion becomes narrower than the interval at which the oscillating portion stops oscillating. Vibrate the vibrating part,
Acquiring frequency related information on a frequency of an oscillation signal of the oscillation unit at a predetermined cycle;
Detecting a vibration state of the vibration unit based on a change of the frequency related information which changes according to the vibration of the vibration unit;
A powder detection method comprising: detecting a remaining amount of powder in the container based on a detection result of a vibration state of the vibration unit. Based on the acquired frequency related information, the timing at which the vibration unit starts to vibrate is determined based on the timing at which the oscillation unit starts to oscillate from the state where the oscillation is stopped.
The powder detection method according to claim 10, wherein the remaining amount of powder in the container is detected based on a damping aspect of vibration after the vibration unit starts vibration.