JP2017134117A - Powder detection device, image formation device and powder detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent permanent deformation of an agitation member, and enable detection of an amount of residual powder with high accuracy.SOLUTION: A powder detection device comprises: an oscillation plate 201 that opposes a magnetic flux sensor 10 via an enclosure 200a of a sub hopper 200, oscillates in a direction opposing the magnetic flux sensor 10, and is formed of a material affecting a magnetic flux; an agitation member 205 that is rotationally driven by an agitation motor 204a, oscillates the oscillation plate 201, and agitates toner; a CPU 21 that acquires frequency relevant information about a frequency of an oscillation signal of the magnetic flux sensor 10 at a prescribed cycle, detects an oscillation state of the oscillation plate 201 on the basis of a change in frequency relevant information changing in accordance with the oscillation of the oscillation plate 201, and detects an amount of residual of the toner in the sub hopper 200 on the basis of a result of the detection; and an agitation motor control unit 25 that controls the agitation motor 204a, and causes the agitation member 205 in an opposite direction to be rotated up to a position where an amount of distortion of the agitation member 205 after an agitation operation is ended is equal to or less than a pre-set amount thereof.SELECTED DRAWING: Figure 34

Description

  The present invention relates to a powder detection apparatus, an image forming apparatus, and a powder detection method.

  In recent years, there has been a tendency to digitize information, and image processing apparatuses such as printers and facsimiles used for outputting digitized information and scanners used for digitizing documents have become indispensable devices. Among such image processing apparatuses, as an image formation output method, an electrophotographic method for performing image formation output by transferring an image formed by developing an electrostatic latent image formed on a photoreceptor onto a sheet. It has been known.

  In an electrophotographic image forming apparatus, a developer is supplied from a container that is a developer supply source to a developing device that develops an electrostatic latent image formed on a photoreceptor. As an apparatus for detecting the remaining amount of developer supplied in this way, for example, a technique described in Japanese Patent Application Laid-Open No. 2013-037280 (Patent Document 1) is known.

  In this technique, the pressure-sensitive sheet is deformed by the pressing force of the stirring sheet in the developing unit, and the toner amount is detected based on the displacement of the detected member accompanying the deformation of the pressure-sensitive sheet. More specifically, the remaining amount of toner is detected by pressing and agitating the toner in accordance with the rotating operation of the agitating sheet, and detecting the bending timing of the pressed sheet at that time. Moreover, the PET sheet is illustrated as an agitation sheet.

  The stirring sheet described in Patent Document 1 is formed to have a length that contacts the inner wall of the toner container or the toner even in the standby state. Therefore, the force is always applied in the direction in which the stirring sheet is bent or in the direction in which the stirring sheet is bent. In this case, if the amount of deformation is greater than a certain value and left for a certain period of time, the stirring sheet is plastically deformed in the bent state, and the deformation remains permanently.

  When such plastic deformation occurs, the technique described in Patent Document 1 cannot move the toner, which is powder, with a predetermined force, and the deformation amount of the pressed sheet is reduced. As a result, the timing of bending of the pressed sheet also changes, and the detection accuracy of the remaining amount of toner becomes low. The same problem occurs not only in the technique described in Patent Document 1 but also in a similar technique using a thin synthetic resin sheet such as a PET film as a stirring member.

  Therefore, the problem to be solved by the present invention is to prevent permanent deformation of the stirring member and to detect the remaining amount of powder with high accuracy.

  In order to solve the above-described problem, one aspect of the present invention is a powder detection device that detects the remaining amount of powder having fluidity in a container, and has a frequency according to the state of magnetic flux passing through an opposing space. An oscillating unit that outputs a signal and a material that is disposed inside the container, faces the oscillating unit via the casing of the container, vibrates in a direction facing the oscillating unit, and affects the magnetic flux. The vibration unit is rotationally driven by the rotation driving means, and the vibration unit is vibrated, and the stirring member that stirs the powder, and the frequency related information related to the frequency of the oscillation signal of the oscillation unit is acquired at a predetermined cycle. Detection processing for detecting a vibration state of the vibration unit based on a change in the frequency-related information that changes according to vibration of the vibration unit, and detecting a remaining amount of powder in the container based on the detection result Department and Rotation drive control means for controlling the rotation drive means and rotating the agitation member in a reverse direction to a position where the amount of deflection of the agitation member is equal to or less than a preset amount after the agitation operation by the agitation member is completed. , Provided.

  According to one aspect of the present invention, permanent deformation of the stirring member can be prevented, and highly accurate toner remaining amount detection can be performed. Note that problems, configurations, and effects other than those described above will be clarified in the following description of embodiments.

1 is a diagram illustrating 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. 3 is a perspective view illustrating a toner supply configuration according to an exemplary embodiment of the present invention. It is a perspective view which shows the external appearance of the sub hopper which concerns on embodiment of this invention. It is a figure which shows the internal structure of the sub hopper of FIG. It is a figure which shows the circuit structure of the magnetic flux sensor which concerns on embodiment of this invention. It is a figure which shows the count aspect of the output signal of the magnetic flux sensor of FIG. 1 is a perspective view showing an overview of a magnetic flux sensor according to an embodiment of the present invention. It is a block diagram which shows the structure of the controller which acquires the signal of the magnetic flux sensor of FIG. It is a figure which shows the arrangement | positioning relationship between the magnetic flux sensor of FIG. 7, and the diaphragm of FIG. It is a figure which shows the effect | action at the time of a magnetic flux passing the diaphragm of FIG. It is a figure which shows the oscillation frequency of the magnetic flux sensor according to the distance of the diaphragm shown in FIG. 9, and a magnetic flux sensor. FIG. 5 is a perspective view of the diaphragm of FIG. 4. It is a figure which shows the arrangement | positioning relationship between the diaphragm which concerns on embodiment of this invention, and a stirring member. It is a figure which shows the state which the stirring member pushed in the diaphragm from the state of FIG. 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 figure which shows the state which the stirring member detach | leaved from the diaphragm from the state of FIG. It is a top view which shows the vibration state of the diaphragm shown in FIG. It is a side view which shows the relationship between the vibration state of the diaphragm which concerns on 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 attenuation | damping of the vibration of the diaphragm which concerns on embodiment of this invention. 7 is a flowchart illustrating a toner remaining amount detection operation according to the 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 relationship between the stirring member when the weight of the diaphragm in FIG. 12 is omitted, and the rotation angle of a rotating shaft. It is a figure which shows the difference in the rotation radius of the stirring member when there is no deformation | transformation of a stirring member and when a stirring member deform | transforms. It is a figure which shows the vibration characteristic of the diaphragm before and after a deformation | transformation of a stirring member. It is a figure which shows the stop position of the stirring member in embodiment of this invention, and after the stirring member bounces the diaphragm, it shows the state which reversely rotated predetermined amount and stopped in the vicinity of the weight. FIG. 27 shows a state immediately after the stirring member repels the diaphragm from the state of FIG. The state of the stirring member at a position rotated by approximately 180 degrees from the position of FIG. 26 is shown. The state of the stirring member at a position rotated approximately 270 degrees from the state of FIG. 26 is shown. It is a block diagram which shows the structure of the controller which concerns on embodiment of this invention which controls the rotation stop position of a rotating shaft. It is operation | movement explanatory drawing which shows the operation | movement which fluctuates the diaphragm provided with the weight in embodiment of this invention, while a stirring member bends. It is explanatory drawing which shows the operation | movement principle of the reverse direction rotation control in embodiment of this invention. It is a timing chart which shows the operation | movement timing of the reverse direction rotation control of FIG. FIG. 10 is an explanatory diagram illustrating an operation of returning to reverse rotation to a position of a deformation amount that does not cause plastic deformation after the end of a print job in the embodiment of the present invention. 6 is a flowchart illustrating an operation procedure of the image forming apparatus including a process of rotating the stirring member in the reverse direction in the embodiment of the present invention. 1 is a block diagram illustrating a hardware configuration of an image forming apparatus according to an embodiment of the present invention.

  In the present invention, after the stirring operation of the toner, which is powder, is performed, the stirring member is rotated in the reverse direction, the rotation position is controlled, and the stirring member is stopped in a state where the amount of deflection does not cause plastic deformation. It is characterized by. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In this embodiment, in an electrophotographic image forming apparatus, toner is held between a developing unit that develops an electrostatic latent image formed on a photoreceptor and a container that is a supply source of toner that is a developer. An example of detecting the remaining amount of toner in the sub hopper will be described.

  FIG. 1 is a diagram showing an outline of a mechanism for image formation output included in the image forming apparatus 100 according to the present embodiment. In the figure, the image forming apparatus 100 according to the present embodiment is a so-called tandem type in which image forming units 106K, 106C, 106M, and 106Y of respective colors are arranged along the rotation direction of the conveyor belt 105. is there. In the tandem type, images of each color Y, M, C, and K formed by the image forming units 106K, 106C, 106M, and 106Y for each color are superimposed on the conveyance belt 105 in this order on the conveyance belt 105 as an intermediate transfer belt. Is transcribed. Then, the full-color image with four colors superimposed is collectively transferred from the paper feed tray 101 to the paper (an example of a recording medium) 104 that is separated and fed by the paper feed roller 102, fixed by the fixing device 116, and discharged outside the apparatus. Is done.

  In the following description, the plurality of image forming units (electrophotographic process units) 106Y, 106M, 106C, and 106K are collectively referred to as the image forming unit 106 as appropriate.

  The leading edge of the sheet 104 fed from the sheet feeding tray 101 is temporarily stopped by the registration roller 103, and the nip position (transfer position) with the conveying belt 105 is timed with the leading edge of the image superimposed on the conveying belt 105. ).

  The image forming units 106Y, 106M, 106C, and 106K have the same internal configuration except that the colors of the toner images to be formed are different. The K image forming unit 106K forms a black K image, the M image forming unit 106M forms a magenta M image, the C image forming unit 106C forms a cyan C image, and the Y image forming unit 106Y forms a yellow Y image. . In the following description, the Y image forming unit 106Y will be described in detail, but the other M, C, and K image forming units 106M, 106C, and 106K are the same as the Y image forming unit 106Y. Therefore, in the figure, each component of the image forming units 106M, 106C, and 106K of each color is given a reference that is distinguished by M, C, and K instead of Y added to each component of the Y image forming unit 106Y. The description is omitted.

  The conveyor belt 105 is an endless belt, that is, an endless belt that is stretched between a driving roller 107 and a driven roller 108 that are rotationally driven. The driving roller 107 rotates by obtaining a driving force by a driving motor (not shown).

  At the time of image formation, the first Y image forming unit 106Y transfers the yellow Y toner image to the conveyance belt 105 that is rotationally driven. The Y image forming unit 106Y includes a Y photoconductor drum 109Y, a Y charger 110Y disposed around the Y photoconductor drum 109Y, an optical writing device 111, a Y developing device 112Y, a Y photoconductor cleaner 113Y, and a static eliminator (FIG. (Not shown). The optical writing device 111 is configured to irradiate light to the photosensitive drums 109Y, 109M, 109C, and 109K (hereinafter, collectively referred to as the photosensitive drum 109 as appropriate) of each color.

  In the image formation, the outer peripheral surface of the Y photoconductor drum 109Y is uniformly charged by the Y 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 Y developing unit 112Y visualizes the electrostatic latent image with yellow toner, and forms a yellow toner image on the Y photosensitive drum 109Y.

  This toner image is transferred onto the conveyance belt 105 by the function of the Y transfer unit 115Y at a position (transfer position) where the Y photoconductor drum 109Y and the conveyance belt 105 are in contact with or closest to each other. By this transfer, an image of yellow toner is formed on the conveyance belt 105. Unnecessary toner remaining on the outer peripheral surface of the photoconductor drum 109Y after the transfer of the toner image is cleaned by the Y photoconductor cleaner 113Y, and the surface of the Y photoconductor drum 109Y is discharged by the static eliminator, and the next image formation is performed. To wait for.

  As described above, the yellow toner image transferred onto the conveyance belt 105 by the Y image forming unit 106Y is conveyed to the next M image forming unit 106M by driving the roller of the conveyance belt 105. In the M image forming unit 106M, a magenta M toner image is formed on the M photosensitive drum 109M by a process similar to the image forming process in the Y image forming unit 106Y, and the yellow Y image on which the toner image has already been formed. Is transferred in a superimposed manner.

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

  The sheets 104 stored in the sheet feed tray 101 are sent out in order from the top, and the intermediate transfer image formed on the conveyance belt 105 is transferred at a position where the conveyance path is in contact with or closest to the conveyance belt 105. 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 the image is formed on the sheet surface is further conveyed, the image is fixed by the fixing device 116, and then discharged to the outside of the image forming apparatus 100.

  A belt cleaner 118 is provided for the conveyor belt 105. As shown in FIG. 1, the belt cleaner 118 is a cleaning blade pressed against the conveyance belt 105 on the downstream side of the transfer position of the image from the conveyance belt 105 to the paper 104 and upstream of the photosensitive drum 109. It is. The belt cleaner 118 is also a developer removing unit that scrapes off toner adhering to the surface of the transport belt 105 by a cleaning blade.

  FIG. 2 is a perspective view illustrating a toner supply configuration according to the present embodiment. The toner replenishment configuration is a configuration for supplying toner to the developing device 112. The toner supply configuration is substantially the same for each color of CMYK, and FIG. 2 shows the supply configuration for one developing device 112. The toner is contained 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 via the bottle side 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 according to the remaining amount of toner in the developing device 112. Toner is supplied from the sub hopper 200 to the developing device 112 via the sub hopper side supply path 119. When the toner in the toner bottle 117 runs out, no toner is supplied to the sub hopper 200. Therefore, it is necessary to detect a state in which the amount of toner in the sub hopper 200 has decreased, and therefore, a toner detection mechanism described later is provided.

  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 the outer surface of the casing constituting the sub hopper 200. In FIG. 3, the upper part of the sub hopper 200 is opened, and the cover of the bottle side supply path 120 is attached to this opening. In addition, the attachment part of the cover is formed so as to match the shape of the opening of the sub hopper 200 so that the toner is not scattered outside. The toner held in the sub hopper 200 is sent out to the developing device 112 from the sub hopper side supply path 119 shown in FIG.

  4A and 4B are diagrams showing the internal configuration of the sub hopper 200, where FIG. 4A is a perspective view and FIG. 4B is a plan view. As shown in FIG. 4, a diaphragm 201 is provided on the inner surface of the housing of the sub hopper 200. The inner surface provided with the diaphragm 201 is the back side of the outer surface to which the magnetic flux sensor 10 is attached in FIG. Therefore, the diaphragm 201 is disposed so as to face the magnetic flux sensor 10 through the housing.

  The vibration plate 201 is a rectangular plate-shaped component, and is arranged in a cantilever state in which one end in the longitudinal direction is fixed to the housing of the sub hopper 200. A weight 202 is attached to the end of the diaphragm 201 that is not fixed in the longitudinal direction. The weight 202 has a function of adjusting the frequency when the vibration plate 201 vibrates or a function of vibrating the vibration plate 201.

  In the sub hopper 200, a rotary 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. An agitating member 205 is fixed to the rotating shaft 204, and the agitating member 205 rotates with the rotation of the rotating shaft 204, and the toner as the developer inside the sub hopper 200 is agitated. Further, the longitudinal direction of the vibration plate 201 is disposed substantially parallel to the axial direction of the rotation shaft 204.

  The stirring member 205 has a function of flipping the weight 202 provided on the vibration plate 201 by rotation in addition to the stirring of the toner. Thus, each time the stirring member 205 rotates once, the weight 202 is repelled and the diaphragm 201 vibrates. That is, the vibration plate 201 functions as a vibration unit, and the stirring member 205 functions as a vibration applying unit. In order to ensure the stirring function and the flipping function, in this embodiment, a slit 205a is formed in the vicinity of the central portion of the stirring member 205, and a vibration applying unit 205c and a stirring unit 205d are provided with the slit 205 as a boundary. Yes.

  FIG. 5 is a diagram showing a circuit configuration of the magnetic flux sensor according to the present embodiment. As shown in the figure, the magnetic flux sensor 10 according to the present embodiment is an oscillation circuit based on a Colpitts LC oscillation circuit. The oscillation circuit includes a planar pattern coil 11, a pattern resistor 12, a first capacitor 13, a second capacitor 14, a feedback resistor 15, a first unbuffer IC 16, a second unbuffer IC 17 and an output terminal 18. .

The planar pattern coil 11 is a planar coil constituted by signal lines patterned in a planar shape 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 changes due to the magnetic flux passing through the space facing the plane on 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 having a frequency corresponding to the magnetic flux passing through the space where the coil surfaces of the planar pattern coil 11 face each other. Further, the magnetic flux sensor 10 has a circuit resistance _RL whose resistance value is determined by the length of the signal line. In the magnetic flux sensor 10 of this embodiment, most signal lines are used to form the planar pattern coil 11. Therefore, the circuit resistance R _L substantially matches the resistance value of the signal line of the planar pattern coil.

The pattern resistor 12 is a resistor configured by a signal line patterned in a planar shape on a substrate, like the planar pattern coil 11. The pattern resistor 12 according to the present embodiment is a pattern formed in a zigzag shape, thereby creating a state in which current does not flow more easily than a linear pattern. Note that the zigzag folded 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 are capacitors that together with the planar pattern coil 11 constitute a Colpitts 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 resonance current loop is constituted by the 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. Due to the functions of the first unbuffered IC 16 and the second unbuffered IC 17, a change in potential of a part of the resonant current loop is output from the output terminal 18 as a rectangular wave corresponding to the resonant frequency.

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

  The inductance L also changes depending on the presence of the magnetic substance in the vicinity of the planar pattern coil 11 and its concentration. Therefore, the magnetic permeability in the space near the planar pattern coil 11 can be determined from 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.

FIG. 6 is a diagram illustrating 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 timing of each of t ₁ , t ₂ , t ₃ , t ₄ , t _5. , Count values such as aaaah, bbbbbh, cccch, ddddh, AAAAh are acquired.

By calculating the count value at each timing based on the periods T ₁ , T ₂ , T ₃ , and T ₄ shown in FIG. 6, the frequency in each period is calculated. For example, when a frequency is calculated by outputting an interrupt signal when a reference clock corresponding to 2 (msec) is counted, T ₁ and T shown in FIG. 6 are 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.

  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 T4, the total value of the value obtained by subtracting ddddh from FFFFh and AAAAh is 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 an event corresponding to the oscillation frequency of the magnetic flux sensor 10 can be determined based on the acquisition result. it can. In the magnetic flux sensor 10 according to the present embodiment, the inductance L changes according to the state of the diaphragm 201 arranged facing the planar pattern coil 11, and as a result, the signal output from the output terminal 18 is changed. The frequency changes.

  As a result, in the controller that acquires the signal, it is possible to check the state of the diaphragm 201 that is disposed to face the planar pattern coil 11. The state of the developer in the sub hopper 200 can also be determined based on the state of the diaphragm 201 thus confirmed.

  As described above, the frequency is obtained by dividing the count value of the oscillation signal by the period. However, 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 is to be detected is directed to the upper surface.

  As shown in FIG. 7, the pattern resistor 12 connected in series with the planar pattern coil 11 is patterned on the detection surface on which the planar pattern coil 11 is formed. As described with reference to FIG. 5, the planar pattern coil 11 is a signal line pattern formed in a spiral shape on a plane. Further, the pattern resistor 12 is a signal pattern formed in a zigzag pattern on the plane, and the function of the magnetic flux sensor 10 as described above is realized by these patterns.

  A portion formed by the planar pattern coil 11 and the pattern resistor 12 is a magnetic permeability detecting unit 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 detector is attached so as to face the diaphragm 201.

  FIG. 8 is a diagram illustrating the configuration of the controller 20 and the magnetic flux sensor 10 that acquire the output value of the magnetic flux sensor 10. As shown in FIG. 8, the controller 20 according to the present embodiment includes a CPU (Central Processing Unit) 21, an ASIC (Application Specific Integrated Circuit) 22, a timer 23, a crystal oscillation circuit 24, and an input / output control ASIC 30.

  The CPU 21 is a calculation means, and controls the entire operation of the controller 20 by performing calculations 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 the system bus to which the CPU 21 and RAM (Random Access Memory) are connected and other devices.

  The timer 23 generates an interrupt signal and outputs it to the CPU 21 every time the count value of the reference clock input from the crystal oscillation circuit 24 reaches a predetermined value. In response to the interrupt signal input from the timer 23, the CPU 21 outputs a read signal for acquiring the output value of the magnetic flux sensor 10. 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 in 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. The magnetic flux sensor 10 according to the present embodiment is an oscillation circuit that outputs a rectangular wave having a frequency corresponding to the magnetic permeability in a space to be detected.

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

  The read signal acquisition unit 32 acquires a read signal, which is a command for acquiring the count value of the magnetic permeability counter 31 from the CPU 21, via the ASIC 22. When the read signal acquisition unit 32 acquires the 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 the count value. The count value output unit 33 outputs the count value of the magnetic permeability counter 31 in accordance with the signal from the read signal acquisition unit 32.

  Note that the CPU 21 accesses the input / output control ASIC 30 via, for example, a register. For this reason, the above-described read signal is performed by the CPU 21 writing a value in a predetermined register included in the input / output control ASIC 30. The count value is output by the count value output unit 33 when the count value is stored 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 toner remaining amount in the sub hopper 200 based on the detection result. In other words, the detection processing unit is configured by the CPU 21 performing calculations according to a predetermined program. Further, the count value acquired from the count value output unit 33 is used as frequency-related information indicating the frequency of the magnetic flux sensor 10 that changes according to the vibration of the diaphragm 201.

  FIG. 9 is a diagram illustrating an arrangement relationship between the magnetic flux sensor and the diaphragm according to the present embodiment, and FIG. 10 is a diagram illustrating an action when the magnetic flux passes through the diaphragm. As shown in FIG. 9, the surface on which the planar pattern coil 11 is formed in the magnetic flux sensor 10 and the diaphragm 201 are disposed to face each other with the housing of the sub hopper 200 interposed therebetween. 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 magnetic flux G ₁ is canceled, the inductance L is reduced in magnetic flux sensor 10. As shown in the equation (1), when the inductance L decreases, the oscillation frequency f increases.

  The strength of the eddy current generated inside the diaphragm 201 by receiving the magnetic flux from the planar pattern coil 11 varies depending on the distance between the planar pattern coil 11 and the diaphragm 201 in addition to the strength of the magnetic flux. FIG. 11 is a diagram illustrating the oscillation frequency of the magnetic flux sensor 10 in accordance with the distance between the planar pattern coil 11 and the diaphragm 201.

The strength 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. Accordingly, as shown in FIG. 11, as the distance between the plane pattern coil 11 and the vibration plate 201 becomes narrow, the oscillation frequency of the magnetic flux sensor 10 is higher, becomes narrower than the predetermined gap g _0, the inductance L becomes too low Will not oscillate.

Therefore, the oscillation frequency in the interval of g ₀ or less is zero. On the other hand, when the distance between the planar 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 using the characteristics shown in FIG. Based on the vibration of the diaphragm 201 thus detected, the remaining amount of toner in the sub hopper 200 is detected. The distance g0 in FIG. 11, namely, by utilizing the gap 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 diaphragm 201 and the magnetic flux sensor 10 shown in FIG. 9 and the configuration for processing the output signal of the magnetic flux sensor 10 are used as the powder detection device according to this embodiment. This powder detecting device is a developer remaining amount detecting device when used for detecting the remaining amount of toner. Further, the magnetic flux sensor 10 functions as a vibration detection unit.

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

  The toner that contacts the vibration plate 201 inside the sub hopper 200 varies depending on the remaining amount of toner in the sub hopper 200. Therefore, by detecting the vibration of the vibration plate 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 stirring member 205 for stirring the toner in the inside repels the vibration plate 201 and periodically vibrates the vibration plate 201 according to the rotation.

  FIG. 12 is a perspective view showing the positional relationship around the diaphragm 201. As shown in FIG. 12, the diaphragm 201 is fixed to the housing of the sub hopper 200 via a fixing portion 201a. FIG. 13 is a side view showing a state before the stirring member 205 comes into contact with the weight 202 attached to the diaphragm 201 as the rotation state of the rotating shaft 204. In FIG. 13, the rotating shaft 204 rotates the stirring member 205 in the clockwise direction in the drawing.

  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 that is inclined with respect to the plate surface of the diaphragm 201 when viewed from the side. This inclination is configured such that the inclined surface approaches the rotating 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 repels and vibrates the vibration plate 201. FIG. 14 is a side view showing a state where 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 vibration plate 201 is pushed and deformed with the inclination provided in the weight 202. In FIG. 14, the positions of the diaphragm 201 and the weight 202 in a state where no external force is applied (hereinafter referred to as “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 as the rotating shaft 204 rotates.

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

  As shown in FIG. 15, the stirring member 205 according to this embodiment is provided with a notch 205 a between a portion (vibration applying portion 205 c) that contacts the weight 202 and another portion (stirring portion 205 d). ing. As a result, it is possible to prevent the stirring member 205 from being damaged by applying an excessive force when the stirring member 205 pushes the weight 202.

  A round hole 205b is provided at the starting point of the cut 205a. As a result, when the amount of deflection of the stirring member 205 differs from the notch 205a as a boundary, the stress applied to the starting point of the notch 205a is dispersed to suppress stress concentration and prevent the stirring member 205 from being damaged.

  FIG. 16 is a side view showing a state where the stirring member 205 is further rotated from the state shown in FIG. In FIG. 16, the position of the diaphragm 201 in a steady state is indicated by a broken line, and the position of the diaphragm 201 shown in FIG. 14 is indicated by a chain line. The position of the diaphragm 201 that has been deflected to the opposite side when the vibration energy stored by being pushed in by the stirring member 205 is released 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 weight 202 is pressed by the stirring member 205, the end portion on the side where the weight 202, which is a free end, is provided on the opposite side due to the bending energy stored in the diaphragm 201. Move to bend.

  In the state shown in FIGS. 16 and 17, the diaphragm 201 is in a state of being away from the magnetic flux sensor 10 that is opposed to the sub-hopper 200 through the housing. Thereafter, the vibration plate 201 vibrates to return to the steady state due to vibration attenuation while repeating the state closer to the magnetic flux sensor 10 than the steady state and the state away from the steady state.

FIG. 18 is a diagram schematically showing the state of toner held in the sub hopper 200 with dots. As shown in FIG. 18, when the toner 206 exists in the sub hopper 200, the vibration plate 201 and the weight 202 come into contact with the toner 206 while vibrating. For this reason, the vibration of the diaphragm 201 is attenuated faster than when the toner 206 is not present in the sub hopper 200. The remaining amount of toner in the sub hopper 200 can be detected based on the change in vibration attenuation.

  FIG. 19 is a diagram illustrating a change in the count value of the oscillation signal of the magnetic flux sensor 10 every predetermined period after the weight 202 is bounced by the stirring member 205 until the vibration of the diaphragm 201 is attenuated and the vibration stops. 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, when the stirring member 205 comes into contact with the weight 202 and pushes the weight 202 at timing t ₁ , the diaphragm 201 approaches the magnetic flux sensor 10. Thereby, the oscillation frequency of the magnetic flux sensor 10 rises and the count value for every predetermined period rises.

Then, the distance between the diaphragm 201 and the magnetic flux sensor 10 below the gap _{g 0} (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 that has been on an upward trend immediately becomes zero.

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. Thus, the distance between the diaphragm 201 and the magnetic flux sensor 10 is the distance g ₀ or more, the magnetic flux sensor 10 starts oscillating again. As a result, the count value increases rapidly from the zero state. Therefore, the start timing of vibration of the diaphragm 201 is determined based on the rapid increase in the count value.

  When the vibration plate 201 vibrates, a state where the distance between the vibration plate 201 and the magnetic flux sensor 10 is wider and narrower is repeated centering on a 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 in the same manner.

  The amplitude of vibration of the diaphragm 201 becomes narrower as the vibration energy is consumed. That is, the vibration of the diaphragm 201 is attenuated with time. For this reason, the change in the distance between the diaphragm 201 and the magnetic flux sensor 10 also decreases with time, and the time change in the count value also changes as shown in FIG.

  Here, as described above, the vibration of the vibration plate 201 attenuates earlier as the amount of remaining toner in the sub hopper 200 increases. Accordingly, by analyzing the vibration attenuation mode 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 vibration peaks of the count value are P ₁ , P ₂ , P ₃ , P ₄ ,..., The vibration of the diaphragm 201 is expressed by the following equation (2), for example. Can be obtained. By referring to the ratio of the peak values having different timings as shown in Expression (2), it is possible to cancel the error due to the environmental variation and obtain the accurate attenuation rate. In other words, the CPU 21 according to the present embodiment obtains the attenuation rate ζ based on the ratio of the count values acquired at different timings.

In the above formula (2), P ₁ , P ₂ and P ₅ , P ₆ are used among the peaks shown in FIG. 19, but this is an example, and other peaks may be used. However, since the peak value at the timing t3 when the vibration plate 201 starts to vibrate is not a value corresponding to the amplitude of vibration, it is preferable not to calculate.

  As shown in FIG. 18, even if the damping of the vibration is accelerated by the presence of the toner 206 inside the sub hopper 200, the vibration frequency of the diaphragm 201 does not change greatly. Therefore, by calculating the ratio of the amplitude of a specific peak as shown in the above formula (2), it is possible to calculate the attenuation of the amplitude in a predetermined period.

  FIG. 20 is a flowchart illustrating a processing procedure of remaining toner detection in the sub hopper 200 according to the embodiment. The processing of this flowchart is executed by 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 agitating member 205 as shown in FIG. 14 and vibration is generated (S101, the step is omitted in the figure, and only S is shown). Show.) 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. In contrast, 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.

As described above, when the distance between the diaphragm 201 and the magnetic flux sensor 10 is less than g ₀ , the oscillation of the magnetic flux sensor 10 stops and the count value becomes zero. CPU21 detects that the count value becomes zero (S101 / YES), then, it waits until the timing at which the count value increases rapidly as the timing _{t 3} of Figure 19 (S102 / NO).

  When the vibration plate 201 is bounced to start vibration, the magnetic flux sensor 10 starts to oscillate, and the count value increases rapidly. When the CPU 21 detects that the count value has rapidly increased from zero (S102 / YES), it detects that vibration has occurred in the diaphragm 201 (S103).

  Regardless of the processing in steps S101 to S103, the CPU 21 continues the count value acquisition processing for each predetermined period as normal processing. Then, after step S103, the CPU 21 acquires the peak value of the count vibration corresponding to the vibration of the diaphragm 201 as shown in FIG. 19 (S104). In step S104, the CPU 21 specifies the peak value by continuously analyzing the count value acquired every predetermined period.

FIG. 21 is a diagram illustrating a count value analysis mode. Regarding the count value acquired every predetermined period, in addition to the “number n” and “count value S _n ” of each count value, the sign “S _n−1 −S _n ” of the difference from the immediately preceding count value is Shown in order of acquisition. In the result as shown in FIG. 21, the value immediately before the sign of “S _n−1 −S _n ” is inverted is the peak value. In the case of FIG. 21, No. 5 and No. 10 are adopted as peak values.

That is, the CPU 21 calculates “S _n−1 −S _n ” shown in FIG. 21 for the count values acquired in order after S 103. Then, the “count value S _n ” at the timing when the sign obtained as the calculation result is inverted is adopted as the peak values such as P ₁ , P ₂ , P ₃ ... Shown in FIG.

The actually obtained count value may contain high-frequency component noise, and the timing at which the sign of “S _n−1 −S _n ” is reversed at a position that is not a peak due to vibration of the diaphragm 201. May occur. In order to avoid erroneous detection in such a case, the CPU 21 preferably performs 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 acquired in this way, the CPU 21 calculates the attenuation rate ζ by the calculation of the above equation (2) (S105). For this reason, in step S104, the count value is analyzed in the manner shown in FIG. 21 until the peak value used for calculating the attenuation rate is obtained. When using the above formula (2), CPU 21 analyzes the count value to a peak value corresponding to P ₆ is obtained.

  When the attenuation rate ζ is calculated in this way, the CPU 21 determines whether or not the calculated attenuation rate ζ is equal to or less than a predetermined threshold (S106). That is, the CPU 21 determines that the toner 206 in the sub hopper 200 has fallen below a predetermined amount based on the magnitude relationship between the ratio of the count values acquired at different timings and the predetermined threshold value. As described with reference to FIG. 18, when sufficient toner 206 remains in the sub hopper 200, the vibration of the vibration plate 201 is quickly attenuated. Therefore, the attenuation rate ζ becomes small.

On the other hand, when the toner 206 in the sub hopper 200 decreases, the vibration of the diaphragm 201 is attenuated accordingly, and the attenuation rate ζ increases. Therefore, by setting the attenuation rate ζ _S according to the remaining amount of toner to be detected as a threshold value, the remaining amount of toner in the sub hopper 200 to be detected (hereinafter, “ It is possible to determine that the amount has been reduced to “the prescribed amount”.

  Note that the amount of toner remaining in the sub hopper 200 does not directly affect the vibration attenuation mode of the vibration plate 201, but the contact state of the toner 206 with the vibration plate 201 changes according to the amount of remaining toner, thereby causing vibration. The vibration attenuation mode of the plate 201 is determined. Therefore, even if the remaining amount of toner in the sub hopper 200 is the same, if the toner contact mode with respect to the vibration plate 201 is different, the vibration mode of the vibration plate 201 is different.

  In contrast, when detecting the remaining amount of toner in the sub hopper 200 according to the present embodiment, the toner 206 in the sub hopper 200 is always stirred by the stirring member 205. Therefore, the contact state of the toner with respect to the vibration plate 201 can be determined to some extent according to the remaining amount of toner. As a result, even if the remaining amount of toner is the same, it is possible to avoid the adverse effect that the detection result differs due to the difference in the contact state of the toner 206 with the vibration plate 201.

  If the calculated attenuation rate ζ is less than the threshold value as a result of the determination in step S104 (S106 / NO), the CPU 21 determines that a sufficient amount of toner is held in the sub hopper 200, and performs the process as it is. finish. On the other hand, if the calculated attenuation rate ζ is equal to or greater than the threshold value (S106 / YES), the CPU 21 determines that the toner amount in the sub hopper 200 is below the specified amount, performs toner out detection, and ends the processing. (S107).

  The CPU 21 that has run out of toner in the process of step S107 outputs a signal indicating that the remaining amount of toner has fallen below a specified amount to a higher-order controller that controls the image forming apparatus 100. Accordingly, the controller of the image forming apparatus 100 can recognize that the specific color is out of toner and supply the toner 206 from the toner bottle 117.

  Next, the relationship among the frequency of the oscillation signal of the magnetic flux sensor 10 according to the present embodiment, the count value acquisition cycle 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 diagram illustrating sampled count values for vibrations in one period of the diaphragm 201. In FIG. 22, the vibration period of the diaphragm 201 is Tplate, and the sampling period is Tsample.

  In order to calculate the attenuation factor ζ of the diaphragm 201 with high accuracy according to the mode described in FIGS. 19 to 21, it is necessary to acquire the peak value of vibration of the diaphragm 201 with high accuracy. For this purpose, a sample number having a sufficient count value with respect to Tplate is required, and therefore Tsample needs to be sufficiently small with respect to Tplate.

  In the example of FIG. 22, the number of samples of the count value is 10 for one cycle of Tplate. That is, Tsample is 1/10 of Tplate. According to the mode of FIG. 22, sampling is always performed within the period of Tpeak in the figure, and the peak value can be acquired with high accuracy.

  Therefore, if the sampling period Tsample of the CPU 21 is 1 ms, it is preferable that the vibration period Tplate of the diaphragm 201 is 10 ms or more. In other words, with respect to 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 period 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 rate ζ cannot 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. When sampling is performed at a sampling frequency of 1000 Hz, a count value of 1000 or more can be obtained at each sampling timing. Therefore, the attenuation rate ζ can be calculated with high accuracy by the order of Tplate and Tsample as described above.

  However, if the amount of change in the oscillation frequency of the magnetic flux sensor 10 is not sufficient with respect to the change in the distance between the magnetic flux sensor 10 and the vibration plate 201 due to the vibration of the vibration plate 201, the count value with respect to time as shown in FIG. The amplitude of vibration becomes small. As a result, the change in the attenuation rate ζ is also reduced, and the accuracy of the toner remaining amount detection due to the vibration of the vibration plate 201 is also lowered.

  In order to increase the amount of change in the oscillation frequency of the magnetic flux sensor 10 with respect to the change in the distance between the magnetic flux sensor 10 and the diaphragm 201, the arrangement of the magnetic flux sensor 10 and the diaphragm 201 is based on the characteristics shown in FIG. The interval needs to be determined. For example, as shown in the section indicated by the arrow in the figure, the interval between the magnetic flux sensor 10 and the diaphragm 201 is set to an interval in which the change in the oscillation frequency with respect to the change in the interval between the magnetic flux sensor 10 and the diaphragm 201 is included in a steep range. It is preferable to determine the interval.

  By the way, the agitating member 205 agitates the toner 206 inside the sub hopper 200 and vibrates the vibration plate 201 while rotating according to the rotation of the rotating shaft 204. At that 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.

  The rotation of the stirring member 205 is stopped depending on the operation state of the image forming apparatus 100. For example, as shown in FIG. 14, the rotation is stopped in a state where the stirring member 205 is bent by pushing the diaphragm 201, and after a predetermined time has passed, the stirring member 205 is deformed and the deformation remains as plastic deformation. There is a possibility that. In addition, there is a possibility that defects such as deformation may occur on the vibration plate 201 side.

  FIG. 23 is a diagram showing the relationship between the stirring member 205 and the rotation angle of the rotating shaft 204 when the weight 202 of the diaphragm 201 is omitted. FIG. 23A is an initial position (0 degree), and when the rotary shaft 204 rotates 90 degrees clockwise from the initial position in the figure, the state shown in FIG. 23B is obtained. Further, when the rotating shaft 204 rotates 180 degrees, the state shown in FIG. 23C is obtained, and when the rotating shaft 204 rotates 270 degrees, the state shown in FIG. 23D is obtained. As described above, when the vibration plate 201 does not have the weight 202, even if the stirring member 205 is deformed, it is not deformed but is only deformed by the reaction force accompanying the movement of the toner when stirring the toner.

  FIG. 24 is a diagram illustrating a difference in the rotation radius of the stirring member 205 when the stirring member 205 is not deformed and when the stirring member 205 is deformed. FIG. 9A shows the state of the stirring member 205 when the stirring member 205 is not deformed, in other words, when it rotates in the state shown in FIG. Let D be the radius of rotation of the stirring member 205 in this initial state.

  On the other hand, FIG. 24B shows a case where the stirring member 205 is plastically deformed. In this case, the rotation radius of the stirring member 205 is D1. As shown in FIG. 24C, when the stirring member 205 remains in contact with the weight 202 at the tip of the vibration plate 201 for a predetermined period of time, the elasticity of the stirring member 205 does not return and the stirring member 205 does not return. Plastic deformation and deformation remains. Conditions under which plastic deformation occurs depend on the material of the stirring member 205, elasticity, elastic force at the time of deformation, duration of deformation, and the like, but when these conditions reach a threshold for causing plastic deformation, the stirring member 205 is plastic. Even if it is deformed and returns a little, it does not return to the initial shape.

In FIG. 24, even if the condition for causing plastic deformation is reached in the state of FIG. 24C and the rotating shaft 204 rotates from this state and the tip of the stirring member 205 passes over the weight 202, the stirring member 205 The plastic deformation state shown in FIG. The rotation radius of the tip of the stirring member 205 at this time is set to D1. The rotation radius D1 after plastic deformation is smaller than the rotation radius of the stirring member 205 in the initial state. That is,
D> D1
It becomes the relationship.

  Even if the rotating shaft 204 rotates in this state and the stirring member 205 contacts the weight 202 and pushes in the weight 202, the pushing force when the stirring member 205 vibrates the vibration plate 201 becomes weak, and the amplitude of the vibration plate is reduced. Decreases and the detection accuracy of the attenuation rate ζ decreases. Furthermore, depending on the stop position of the stirring member 205, the amount by which the stirring member 205 jumps up the toner 206 inside the sub hopper 200 when the rotation starts next differs. As a result, the effect of suppressing vibration of the vibration plate 201 in accordance with the amount of toner in the sub hopper 200 changes, making it difficult to accurately detect the amount of toner.

FIG. 25 is a diagram illustrating the vibration characteristics of the diaphragm 201 before and after the stirring member 205 is deformed. The solid line is the characteristic before deformation, and the broken line is the characteristic after deformation. A solid line P ₀ indicates a state in which the stirring member 205 sufficiently presses the diaphragm 201 against the inner wall of the housing 200a. On the other hand, when the stirring member 205 is deformed, the rotation radius D1 is smaller than D, and thus it is understood that the diaphragm 201 is not sufficiently pressed against the inner wall of the housing 200a. As a result, it can be seen that, in the stirring member 205 after deformation, the PtoP value between the peak and valley peaks is lower than that of the stirring member 205 before deformation. That is, the PtoP value is P ₂ −P ₁ > P−P ′.

When the PtoP value of the vibration waveform decreases in this way, the accuracy of (P ₆ −P ₅ ) / (P ₂ −P ₁ ) in the attenuation rate calculation decreases, and the false detection rate for toner presence / absence determination increases. Note that the decrease in accuracy is because the value of (P ₆ -P ₅ ) is small, and errors are likely to occur.

  26 to 29 are views showing the stop position of the stirring member 205. FIG. 26 shows a state where the agitating member 205 rotates backward by a predetermined amount after the diaphragm 201 bounces and stops near the weight 202.

  In the case of FIG. 26, when the agitating member 205 starts to rotate next, the agitating member 205 rotates almost once while stirring a large amount of toner 206 and repels the vibration plate 201. Most of the toner 206 bounced up by the stirring member 205 is dispersed on the left side in the figure, and the remaining toner is dispersed on the ceiling side and the diaphragm 201 side. The toner 206 bounced up to the ceiling hits the top plate and falls again, but a part of it falls to the diaphragm 201 side. In addition, the toner 206 that is connected to the stirring member 205 and is carried to the vibration plate 201 side falls by hitting the side plate on the vibration plate 201 or directly hitting the vibration plate 201.

  FIG. 27 shows a state immediately after the stirring member 205 flips the vibration plate 201 and passes through the weight 202 to return to deformation. When the next rotation is started from this state, about 2/3 to 3/4 of the toner 206 is picked up and rotated. FIG. 28 shows a position rotated approximately 180 degrees from the position shown in FIG. In this case, at the next rotation, only the toner 206 on the stirring member 205 is scraped up and rotated, and the diaphragm 201 is flipped. FIG. 29 shows a position rotated approximately 270 degrees from the state of FIG. 26. In this state, since the toner 206 does not exist on the stirring member 205, the stirring member 205 itself stops in an unloaded state, and vibrations occur at the next rotation. Stirring is performed such that the toner 206 present on the front side of the plate 201 is pushed in.

  As described above, when the stirring member 205 stops at a position where the stirring member 205 causes plastic deformation and a sufficient time has passed to cause the plastic deformation, the stirring member 205 undergoes plastic deformation. As described above, when such plastic deformation occurs, the accuracy of the presence / absence determination of the toner 206 decreases, and the false detection rate increases.

  In order to avoid this, the rotation stop position of the rotating shaft 204 may be controlled so that the stirring member 205 does not stop while the tip of the stirring member 205 is in contact with the weight 202. By controlling in this way, the stopped state will not be continued in a state where the stirring member 205 is elastically deformed.

  FIG. 30 is a block diagram illustrating a configuration of the controller 20 according to the present embodiment that controls the rotation stop position of the rotation shaft 204. As illustrated in FIG. 30, the controller 20 according to the present embodiment further includes a stirring motor control unit 25 that drives and controls the stirring motor 204 a in the controller 20 described in FIG. 8.

The stirring motor control unit 25 is a stirring motor 2 that is a power source for rotating the rotating shaft 204.
It is a control part which controls rotation of 4a, receives the command from CPU21 via ASIC22, and controls rotation of stirring motor 204a. 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.

  In this embodiment, as the stop position control of the stirring member 205, after the stirring member 205 stops, the rotating shaft 204 is rotated in the reverse direction so that the stop position of the stirring member 205 is removed from the contact position with the weight 202. .

  In the following description, the rotation direction when the agitating member 205 agitates the toner 206 inside the sub hopper 200 is defined as the forward direction, and the rotation direction opposite to the forward direction is defined as the reverse direction.

  FIG. 31 is an operation explanatory diagram showing an operation of flipping the diaphragm 201 provided with the weight 202 while the stirring member 205 is bent. In FIG. 5A, the rotating shaft 204 rotates in the forward direction, and the stirring member 205 is in contact with the weight 202. When the rotating shaft 204 further rotates in the forward direction from this state, as shown in FIG. 6B, the weight 202 is extended by the elasticity (strength of the waist) of the stirring member 205, and the diaphragm 201 is extended to the inner surface of the casing 200a. Press in the direction approaching.

  As the rotation in the forward direction proceeds, the stirring member 205 abuts the weight 202 and the diaphragm 201 against the inner surface of the housing 200a and presses it, as shown in FIG. Thereafter, the stirring member 205 is strongly bent and a large stress is generated in the stirring member 205. FIG. 4D shows a state immediately before the stirring member 205 is bent most and the tip of the stirring member 205 is detached from the top of the weight 202. Thereafter, when the tip of the stirring member 205 is detached from the weight 202, the vibration plate 201 is repelled, and the vibration plate 201 vibrates as described above. FIG. 4E shows a state immediately after the stirring member 205 is detached from the weight 202. In the present embodiment, for example, the stirring member 205 is rotated in the reverse direction from the state shown in FIG. This reverse rotation is performed by outputting a drive pulse for rotating the stirring motor 204a in the reverse direction from the stirring motor control unit 25. This drive pulse is a drive pulse in the reverse direction in the stirring motor drive timing chart in the present embodiment shown in FIG.

  Thus, by rotating in the reverse direction before the agitation motor 204a stops, the agitation member 205 may be stopped in a slightly elastically deformed state, but plastic deformation occurs when left for a long time. It will not stop in the state of elastic deformation. As a result, the accuracy of determination of the presence / absence of toner does not decrease due to plastic deformation of the stirring member 205, and the false detection rate does not increase.

  An example of the rotation angle when the horizontal direction of the rotating shaft 204 in FIG. 31B is set to the initial value (0 degree) is shown below each diagram in FIG. In this example, FIG. 31 (a) is −20 degrees, FIG. 31 (c) is 10 degrees, FIG. 31 (d) is 25 degrees, and FIG. The forward direction shown in the clockwise direction is positive.

  FIG. 32 is an explanatory diagram showing the operation principle of the reverse rotation control, and FIG. 33 is a timing chart showing the operation timing at that time.

  The timing chart of FIG. 33 shows the relationship between the print job, the toner supply command, and the drive timing of the stirring motor. This timing relationship is described with reference to FIG. 33 taking as an example a case where there are three print jobs and a toner replenishment command is output between the jobs. In this case, the agitation motor 204a rotates in the forward direction in accordance with the toner replenishment command, for example, as shown in FIGS. 31A to 31E, and rotates the rotating shaft 204 and the agitation member 205 in the clockwise direction in the figure.

  When the agitation member 205 repels the vibration plate 201 at the end of the three print jobs and the agitation motor 204a is stopped when the elastic deformation is eliminated (FIG. 31E), Even if it is stopped, the stirring member 205 is not plastically deformed. However, when the stirring motor 204a is stopped in the state shown in FIG. 31 (d), the stirring member must be reversely rotated by a predetermined angle (for example, 20 degrees) as shown in FIGS. 32 (a) and (b). 205 causes plastic deformation.

  FIG. 34 is an explanatory diagram showing the operation of returning to the reverse rotation to the position of the deformation amount that does not cause plastic deformation after the end of the print job. First, the angle used in FIG. 34 is defined. In FIG. 34, a line that is perpendicular to the vibration plate 201 and passes through the center of the rotation shaft 204 is taken as a reference axis (or reference line), and is shown as an x-axis in the drawing. FIG. 34A shows a state in which the tip of the stirring member 205 is in contact with the end portion 202a of the weight 202 provided on the diaphragm 201 when the stirring member 205 is rotated in the forward direction. Here, since the end portion 202a of the weight 202 is an end portion on the upstream side in contact with the stirring member 205, it is hereinafter referred to as an upstream end portion 202a. In FIG. 34A, the angle formed by the stirring member 205 (or a straight line extending from the D-cut surface of the rotating shaft 204) with the x-axis is θ1. In the example in the figure, the forward direction is positive, so θ1 is a negative value.

  When the rotation shaft 204 rotates in the forward direction (clockwise direction) from the position of the angle θ1 in FIG. 34A, the stirring member 205 rides on the weight 202 as described with reference to FIG. Push into the body 200a side. FIG. 34 (b) shows a state where it is pushed in as much as FIG. 31 (d). At this time, the angle formed by the extension line of the undeformed portion of the stirring member 205 (or the extension line of the D-cut surface of the rotating shaft 204) and the x axis is defined as θ2. This state is a state immediately before the stirring member 205 repels the vibration plate 201. In the example in the figure, the forward direction is positive, so θ2 is a positive value.

  When the rotating shaft 204 rotates in the forward direction even a little from the state of FIG. 34B, the agitating member 205 is released from the contact state with the weight 202, so that the diaphragm 201 is flipped. Thereafter, as shown in FIG. 34 (c), the bending of the stirring member 205 is restored, and the vibration plate 201 gradually attenuates while vibrating. The angle formed by the stirring member 205 (or the extension line of the D-cut surface of the rotating shaft 204) after the vibration plate 201 is bounced with the x-axis is defined as θ3. The angle θ3 is an angle slightly advanced in the forward direction from the angle θ2 in FIG. This can be seen from FIGS. 31 (d) and 31 (e). That is, since the contact state between the stirring member 205 and the weight 202 is eliminated, the angle θ3 is slightly larger than the angle θ2. In the example shown in the figure, the forward direction is positive, and thus θ3 is a positive value, similar to θ2.

  FIG. 34 (d) shows that when the rotating shaft 204 is rotated in the reverse direction from the state shown in FIG. 34 (c) and the stirring member 205 is rotated in the reverse direction, the stirring member 205 with respect to the end 202 b of the weight 202. The state which the front-end | tip contacted is shown. Here, since the end portion 202b of the weight 202 becomes an end portion on the contact downstream side when the stirring member 205 rotates in the forward direction, it will be referred to as a downstream end portion 202b hereinafter. The angle formed by the stirring member 205 (or the extension line of the D-cut surface of the rotating shaft 204) at this time with the x-axis is θ4. In the example shown in the figure, the forward direction is positive, so θ4 is a positive value.

  Here, reverse rotation control for stopping the agitating member 205 at a rotational position where the plastic deformation that lowers the accuracy of the toner presence / absence determination even if left for a long time cannot occur in the agitating member 205 will be described. .

  When the rotary shaft 204a is stopped when the print job is finished, in order to prevent the stirring member 205 from being bent so as to be convex in the forward direction, the rotary shaft 204a is stopped immediately before being stopped. Is rotated by a predetermined angle so that the stirring member 205 is not stopped in a deformed state between the state of FIG. 31A and the state of FIG.

Therefore, for example, when stopping in the state of FIG. 31 (d), if the rotating shaft 204 is reversely rotated to the position shown in FIG. 31 (a), the stirring member 205 is not plastically deformed even if left for a long time. Note that the rotational direction position of the stirring member 205 shown in FIG. 31A is the same θ1 as the rotational direction position shown in FIG. 34A, and the rotational direction position of the stirring member 205 shown in FIG. The same θ2 as the rotational direction position shown in FIG. Further, the rotation direction position of the stirring member 205 shown in FIG. 31 (e) is the same θ3 as the rotation direction position shown in FIG. 34 (c), and the rotation direction position of the stirring member 205 shown in FIG. The same θ4 as the rotational direction position shown in FIG. If the reverse rotation angle for rotating the rotation shaft 204 at this time in the reverse direction (counterclockwise direction in the figure) is θr,
θ2−θ1 ≦ θr (3)
Reverse the angle. As a result, the stirring member 205 returns to the state shown in FIG. 31A or to a position away from the end 202a that is upstream in the rotational direction. Note that the sign of θ1 is negative, and θr in equation (3) is the minimum value of the reverse rotation angle.

  Moreover, as long as it rotates in the forward direction, the stirring member 205 will not stop between FIG.31 (e) and FIG.31 (f). Therefore, it is assumed that the reverse rotation angle θr is reversely rotated from the state of FIG. If the angle (θ3-θ4) is equal to or larger than the angle (θ2-θ1), the stirring member 205 stops at a position in contact with the downstream end 202b shown in FIG. Therefore, in this case, there is no possibility that the stirring member 205 is plastically deformed.

  On the other hand, if the angle (θ3-θ4) is smaller than the angle (θ2-θ1), the stirring member 205 rides on the weight 202 from the reverse rotation direction side and stops, or has a tip more than in the state of FIG. It stops at a position away from the end 202a on the upstream side in the rotation direction. In the latter case, there is no possibility of causing plastic deformation as described above. On the other hand, in the former case, the stirring member 205 pushes the weight 202 and is bent in the direction opposite to the direction shown in FIG. More specifically, it is convex in the opposite direction, in other words, it is bent so as to be concave in the forward direction. In this case, the stirring member 205 may be plastically deformed when a long period of time elapses in this state.

  However, when such plastic deformation occurs in the stirring member 205, the forward (clockwise) rotation-side surface for stirring the toner 206 becomes concave, but such concave wrinkles (plastic deformation) Even when the toner 206 is agitated, a force acts in the direction of correcting wrinkles when the weight 202 is pushed while stirring the toner 206, and the push-in is not insufficient. That is, when the value of the expression (3) is used as the minimum value of the reverse rotation angle θr, it does not adversely affect the vibration imparted to the diaphragm 201 (giving the maximum amplitude) by the stirring member 205.

  On the other hand, when the maximum value of the reverse rotation angle θr is considered, the maximum value is 360 °, but when rotating in the reverse direction by 360 ° from the state of FIG. 31 (d), the state almost becomes as shown in FIG. 31 (e). In the case of FIGS. 31E and 31F, the state returns to the state shown in the figure. Therefore, there is no problem in these cases. However, in the case of FIG. 31 (a), the rotating shaft 204 is in the position of FIG. 31 (a), and the tip of the stirring member 205 hits the downstream end 202b, and the bending direction shown in FIG. 31 (d). Bends in the opposite direction and stops. When a long period of time elapses in this state, the stirring member 205 may be plastically deformed, and the forward (clockwise) rotation side surface for stirring the toner 206 may become concave. However, as described above, there is no problem even in this state.

  That is, if the reverse rotation angle θr is set so as to satisfy the minimum value (3), the problem described with reference to FIG. 24 due to plastic deformation of the stirring member 205 does not occur.

  Thus, although it is not necessary to set the upper limit value of the reverse rotation angle θr, it is set to 90 ° in the present embodiment. This is because as the reverse rotation amount increases, the time required for the stirring member 205 to rotate forward and play the weight 202 becomes longer. If this time becomes longer, the time from the return of the image forming apparatus 100 to the detection of the remaining amount of toner becomes longer and the efficiency decreases. Therefore, the angle is set as the appropriate reverse rotation amount.

  Thus, the range of the reverse rotation angle θr is set to (θ2−θ1) or more. As shown in FIG. 33, the reverse rotation is performed by inputting a driving pulse for rotating the stirring motor 204a in the reverse direction.

That is, the agitation motor 204a is driven for a drive time sufficient to drive the reverse rotation angle θr in the above-described equation (3), and the rotary shaft 204 is rotated in the reverse direction. When a stepping motor is used as the stirring motor 204a, if the reverse rotation pulse number is Pr, the step angle of the stepping motor to be used can be understood.
(Θ2−θ1) / step angle ≦ Pr
Can be obtained from The step angle is a rotation angle when one pulse is input to the stepping motor. Generally, a step angle of 1.8 ° or 0.9 ° is often used.

  In the present embodiment, a stepping motor is used as the agitation motor 204a and the motor control is performed with the step pulse. However, a DC motor may be used. In this case, a control corresponding to the angle may be executed using a DC motor and an encoder.

  34 (a) is shown in FIG. 31 (a), FIG. 34 (b) is shown in FIG. 31 (d), FIG. 34 (c) is shown in FIG. 31 (e), and FIG. Each corresponds to f).

  Further, the angles θ1, θ2, θ3, and θ4 are individually different depending on the material conditions such as the length, thickness, and material of the stirring member 205, but the relationship between them is (3 ) Can be defined by the inequality.

  When the stirring member 205 is reversely rotated as described above after the stirring of the toner by the stirring member 205 is stopped, the stirring member 205 stops at a position where plastic deformation does not occur. Or, even if plastic deformation occurs, it stops at a position where the toner amount can be detected.

  FIG. 35 is a flowchart showing an operation procedure of the image forming apparatus 100 including a process of rotating the stirring member 205 in the reverse direction. Control of the image forming apparatus 100 is executed by the CPU 100h shown in FIG.

  As shown in FIG. 35, when the power of the image forming apparatus 100 is turned on (S201), the CPU 100h enters a standby state (S202) and waits for the print signal to be turned on (S203). When the print signal is turned on (S203: YES), the printing operation is started (S204).

  When the printing operation is started, the developing device 112 rotates (S205), and the toner density is detected by the magnetic flux sensor (permeability sensor) 10 described above (S206). From this detection result, it is determined whether or not the toner density is low. If the toner density is not low, the rotation of the developing device 112 is stopped (S208), and it is determined whether or not the printing operation to be executed is continuous printing (S209). .

  If it is determined in this determination that the print is continuous, the process returns to step S205 and the subsequent processing is repeated. If it is determined that the printing is not continuous printing, the printing operation is terminated (S210), the sub hopper replenishment motor, that is, the stirring motor 204a is rotated in the reverse direction, the process returns to step S202, and the subsequent processing is repeated.

  On the other hand, if it is determined in step S207 that the toner concentration is low, the sub-hopper replenishment motor (agitating motor 204a) is rotated in the forward (forward) direction (S212), and the toner end detection in the hopper is performed (S213). If the toner end is not detected (S214: NO), the counter 1 is reset (S215), the process returns to step S206, the toner density is detected, and the processes in and after step S207 are repeated.

  If it is determined in step S214 that the toner has ended, the bottle motor that rotates the toner bottle holding the toner 206 is rotated (S216), and the counter 1 is incremented by 1 (S217). Next, it is determined whether or not the counter 1 has reached the specified value 1 (S218). If the specified value 1 has not been reached, the process returns to step S212 and the subsequent processing is repeated.

  If the counter 1 has reached the specified value 1 (S218: YES), a near-end display is performed (S219), and it is further determined whether or not the counter 1 has reached the specified value 2 (S220). If the predetermined value 2 is not reached in this determination, the process returns to step S212 and the subsequent processing is repeated. If the specified value 2 has been reached, the bottle end display is performed (S221), the rotation of the developing device 112 is stopped (S222), the printing operation is terminated (S223), and then the drive of the image forming apparatus 100 is stopped. (S224).

  The counter 1 is a counter that counts the number of toner ends. The specified value 1 defines the number of toner near ends, and the defined value 2 defines the number of toner ends that become a bottle end.

  FIG. 36 is a block diagram illustrating a hardware configuration of the image forming apparatus 100. In FIG. 1, an image forming apparatus (printer) 100 includes a printer controller 100 a that controls the main body of the image forming apparatus 100, a printer engine 100 b that prints an image on a sheet, and a user input to the image forming apparatus main body. It is basically composed of an operation panel 100c that displays the status and the like, and is connected to the network NT.

  The network NT is for communicating with a server, for example. The printer engine 100b controls the printing unit (image forming unit) by a signal from the printer controller 100a, and forms an image by feeding transfer paper from the paper feeding unit. The operation panel 100c is a user I / F provided with a display device that is input by the user and displays the state of the image forming apparatus 100 main body.

  The printer controller 100a is a general term for control mechanisms that convert print data from the host into video data and output it to the printer engine 100b in accordance with the control mode set at that time and the control code received from the host. The printer controller 100a includes modules of a network I / F 100d, a program ROM 100e, a font ROM 100f, an operation unit I / F 100g, a CPU 100h, a RAM 100i, an NV-RAM 100j, an engine I / F 100k, and an HDD (hard disk device) 100m.

  The function of each module is as follows. The network I / F 100d is an interface for communicating with a server, and a program ROM (Programmable Read Only Memory) 100e stores a program for managing data and controlling peripheral modules in the printer controller 100a. ing. A font ROM (FONT ROM) 100f stores various types of fonts used for printing. The operation unit I / F 100g is an interface of the operation panel 100c.

  A CPU (Central Processing Unit, the same applies hereinafter) 100h processes data (print data, control data) from the host according to the procedure of the program stored in the program ROM 100e. A RAM (Random Access Memory) 100i is a work memory when the CPU 100h processes, and is used as a buffer for temporarily storing data from the host, a memory for processing data stored in the buffer, and the like.

  The NV-RAM 100j is a nonvolatile RAM for storing data that is to be retained even when the power is turned off. The engine I / F 100k is an interface for controlling the printer engine 100b from the controller 100a. The HDD 100m is a large-capacity storage medium that holds a large volume of data in a readable / writable manner.

  As described above, according to the present embodiment, the following effects can be obtained. In the following description, each component in the claims corresponds to each part of the present embodiment, and when the terms are different, the latter is shown in parentheses to clarify the correspondence between the two.

  (1) The powder detection device (the vibration plate 201, the magnetic flux sensor 10, and the controller 20) according to this embodiment for detecting the remaining amount of powder (toner 206) having fluidity in the container (sub hopper 200) An oscillating unit (magnetic flux sensor 10) that outputs a signal having a frequency corresponding to the state of magnetic flux passing through the opposing space, and a container 200a of the container (sub hopper 200) are disposed in the container (sub hopper 200). A vibration part (diaphragm 201) formed of a material that vibrates in a direction opposite to the oscillation part (flux sensor 10) and vibrates in a direction opposite to the oscillation part (flux sensor 10), and rotates. An agitating member 205 that is rotationally driven by a driving means (agitating motor 204a) to vibrate the vibrating portion (vibrating plate 201) and agitate the powder (toner). The frequency-related information regarding the frequency of the oscillation signal of the oscillating unit (magnetic flux sensor 10) is acquired at a predetermined period, and based on the change in the frequency-related information that changes according to the vibration of the vibrating unit (diaphragm 201). A detection processing unit (CPU 21) that detects a vibration state of the vibration unit (diaphragm 201) and detects the remaining amount of powder (toner 206) in the container (sub hopper 200) based on the detection result; After the rotation driving means (stirring motor 204a) is controlled and the stirring operation by the stirring member 205 is finished, the stirring member 205 is moved in the reverse direction to a position where the amount of deflection of the stirring member 205 is equal to or less than a preset amount. And a rotation drive control means (agitating motor control unit 25) for rotating the agitating member to prevent permanent deformation of the agitating member 205 and to detect the remaining amount of the powder (toner 206) with high accuracy. I can.

  That is, when the agitation member 205 finishes the printing job immediately before the top of the weight 202 (for example, FIG. 31D and FIG. 34B), the agitation member 205 stops in the state where the strongest stress is applied. However, if the stirring member 205 is rotated in a reverse direction at a constant angle or a fixed number of steps, it is rotated in the reverse direction from the apex position to reduce the stress applied to the stirring member 205, and the position where plastic deformation does not occur (FIG. 31 (a), FIG. 34 (a)).

  The fixed angle or the fixed number of steps is an angle to a position where the amount of deflection of the stirring member 205 becomes equal to or less than a preset amount when the stirring member 205 is rotated in the reverse direction, and is the number of steps.

  (2) In the powder detection device according to (1), the preset amount is a deflection amount that does not undergo plastic deformation even if the stirring member 205 is left in a bent state. Even when the apparatus is not used for a long time, the stirring member 205 is not plastically deformed, and the remaining amount of powder can be detected with high accuracy.

  (3) In the powder detection device according to (1) or (2), the vibrating portion (vibrating plate 201) is attached to the casing 200a of the container (sub hopper 200) in a cantilevered manner. A predetermined vibration can be obtained with respect to a predetermined push-in amount, and a high-accuracy powder remaining amount can be detected.

  (4) In the powder detection device according to any one of (1) to (3), the amount of rotation in the reverse direction by the rotation drive control unit (stirring motor control unit 25) is such that the stirring member 205 is the vibrating unit. The angle from the position (FIG. 34 (a)) in contact with (the diaphragm 201 or the weight 202) to the position (FIG. 34 (b)) immediately before the vibration part (the diaphragm 201 or the weight 202) is vibrated and vibrated ( Since θ2−θ1) or more, the stirring member 205 is not plastically deformed in a state where the front surface on the forward rotation side is convex, and the accuracy in detecting the remaining amount of the high-precision powder (toner 206) is not impaired.

  (5) In the powder detection device according to any one of (1) to (4), the detection processing unit (CPU 21) detects the remaining amount of the developer that develops the latent image. Is also applicable to a developer (color toner).

  (6) Image forming means (image formation) that visualizes a latent image by the powder detection device (the vibration plate 201, the magnetic flux sensor 10, and the controller 20) of any one of (1) to (5) and the developing device 112. According to the image forming apparatus 100 according to this embodiment in which the developing device 112 includes the powder detection device, the image forming apparatus that exhibits the effects described in (1) to (5) above is provided. Can be configured.

  (7) In the image forming apparatus of (6), the end of the stirring operation by the stirring member 205 is the end of the image forming job by the image forming unit (image forming unit 106). The stirring member 205 can be moved to a position where it does not undergo plastic deformation. Thereby, even when the image forming apparatus 100 is not used for a long period of time, it is possible to prevent the image quality from being deteriorated.

  (8) According to the powder detection method according to the present embodiment for detecting the remaining amount of powder (toner) having fluidity in the container (sub hopper 200), it is in accordance with the state of magnetic flux passing through the facing space. A signal having a frequency is output from the oscillating unit (magnetic flux sensor 10), arranged in the container (sub hopper 200), and the oscillating unit (magnetic flux sensor 10) via the casing 200a of the container (sub hopper 200). The vibrating portion (vibrating plate 201) formed of a material that affects the magnetic flux in a direction opposite to the oscillating portion (magnetic flux sensor 10) is vibrated and is rotationally driven by a rotation driving means (agitating motor 204a). The agitating member 205 vibrates the vibrating portion (vibrating plate 201) and agitates the powder (toner), and the oscillation signal of the oscillating portion (magnetic flux sensor 10) is rotated. Frequency-related information regarding the number is acquired at a predetermined cycle, and the vibration state of the vibration part (diaphragm 201) is detected based on the change in the frequency-related information that changes according to the vibration of the vibration part (diaphragm 201). Then, based on the detection result, the remaining amount of the powder (toner) in the container (sub hopper 200) is detected by the detection processing unit (CPU 21), and the rotation driving means (stirring motor 204a) is controlled, After the agitation operation by the agitation member 205 is completed, the agitation member 205 is rotated in the reverse direction by the rotation drive control means (agitation motor control unit 25) until the deflection amount of the agitation member 205 becomes equal to or less than a preset amount. Therefore, the same effects as those of the powder detection apparatus described in (1) can be obtained.

  (9) In the powder detection method of (8), the rotation drive control unit (stirring motor control unit 25) is configured so that the stirring member 205 is in contact with the vibrating unit (the vibrating plate 201 or the weight 202) (see FIG. Since the stirring member 205 is rotated in the reverse direction at an angle equal to or greater than the angle (θ2−θ1) from the position 34 (a)) to the position immediately before the vibration part (diaphragm 201) is flipped (FIG. 34B), The same effects as those of the powder detection apparatus described in (4) are obtained.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention, and all technical matters included in the technical idea described in the claims are included. The subject of the present invention. The above embodiment shows a preferable example, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification, These are included in the technical scope described in the appended claims.

10 Magnetic flux sensor (powder detection device, oscillation unit)
11 Planar pattern coil 20 Controller (powder detection device)
21 CPU
25 Stirring motor control unit 100 Image forming apparatus 106 Image forming unit (image forming unit)
200 Sub hopper (container)
200a Case 201 Vibration plate (powder detection device, vibration unit)
202 Weight 204 Rotating shaft 204a Stirring motor 205 Stirring member 206 Toner (powder)
θ1, θ2, θ3, θ4 angle

JP2013-037280A

Claims (9)

A powder detection device for detecting the remaining amount of powder having fluidity in a container,
An oscillating unit that outputs a signal having a frequency according to the state of magnetic flux passing through the opposing space;
A vibrating portion that is disposed in the container and faces the oscillating portion via the housing of the container, vibrates in a direction facing the oscillating portion, and is formed by a material that affects magnetic flux;
An agitation member that is rotationally driven by a rotational drive means to vibrate the vibration part and stir the powder;
Obtaining frequency-related information related to the frequency of the oscillation signal of the oscillating unit at a predetermined cycle, detecting a vibration state of the oscillating unit based on a change in the frequency-related information that changes according to the vibration of the oscillating unit; A detection processing unit for detecting the remaining amount of powder in the container based on a detection result;
Rotation drive control means for controlling the rotation drive means and rotating the agitation member in a reverse direction to a position where the amount of deflection of the agitation member is equal to or less than a preset amount after the agitation operation by the agitation member is completed. ,
A powder detection device. The powder detection device according to claim 1,
The powder detection device, wherein the preset amount is a bending amount that is not plastically deformed even when the stirring member is left in a bent state. The powder detection device according to claim 1 or 2,
The vibrating part is a powder detection device attached to the casing of the container in a cantilever manner. The powder detection device according to any one of claims 1 to 3,
The powder detection device, wherein an amount of rotation in the reverse direction by the rotation drive control unit is equal to or greater than an angle from a position at which the stirring member contacts the vibration part to a position immediately before the vibration part is repelled and vibrated. The powder detection device according to any one of claims 1 to 4,
The powder detection apparatus in which the detection processing unit detects the remaining amount of the developer for developing the latent image. The powder detection device according to any one of claims 1 to 5,
Image forming means for visualizing the latent image by the developing device;
With
An image forming apparatus in which the developing device includes the powder detection device. The image forming apparatus according to claim 6, wherein
An image forming apparatus in which the end of the stirring operation by the stirring member is the end of an image forming job by the image forming unit. A powder detection method for detecting the remaining amount of powder having fluidity in a container,
A signal with a frequency corresponding to the state of magnetic flux passing through the opposing space is output from the oscillator,
The vibrator disposed in the container and opposed to the oscillating section through the casing of the container, and vibrates a vibrating section formed by a material that affects magnetic flux in a direction facing the oscillating section,
The agitating member that is rotationally driven by the rotational driving means vibrates the vibration part and agitates the powder.
Obtaining frequency-related information related to the frequency of the oscillation signal of the oscillating unit at a predetermined cycle, detecting a vibration state of the oscillating unit based on a change in the frequency-related information that changes according to the vibration of the oscillating unit; Based on the detection result, the remaining amount of the powder in the container is detected by the detection processing unit,
After the rotation driving means is controlled and the stirring operation by the stirring member is completed, the stirring member is rotated in the reverse direction by the rotation driving control means until the deflection amount of the stirring member becomes equal to or less than a preset amount. Powder detection method. The powder detection method according to claim 8,
The rotational drive control means is a powder detection method in which the stirring member is rotated in the reverse direction at an angle equal to or greater than an angle from a position where the stirring member contacts the vibrating portion to a position immediately before the vibrating portion is flipped.