JP6624507B2 - Powder amount detection device, powder supply device and image forming device - Google Patents

Description

  The present invention relates to a powder amount detection device, a powder supply device, and an image forming device.

  2. Description of the Related Art Conventionally, there has been known a powder amount detection device that detects the amount of powder in a powder storage unit that stores powder.

  Patent Document 1 discloses such a powder amount detection device, in which a flexible sheet is deformed by a pressing force of a stirring sheet for stirring toner in a toner container, and a member to be detected accompanying deformation of the flexible sheet is detected. A toner amount detection device that detects the amount of toner in a toner storage unit based on displacement is disclosed.

  The flexible sheet is stretched over a depression formed in the inner wall of the toner storage section and fixed to the edge of the depression. When the flexible sheet is pressed by the stirring sheet, the flexible sheet faces the bottom of the depression. The flexible sheet is deformed to bend. At this time, in a state where the flexible sheet is bent to the extent that the load is applied to the stirring sheet by the elastic force of the flexible sheet, the stirring sheet and the flexible sheet are locally contacted and the load is concentrated. This may cause a problem that the stirring sheet and the flexible sheet are easily damaged.

In order to solve the above-described problems, the present invention provides a powder storage unit that stores powder, a flexible member provided in the powder storage unit, and a flexible member that presses the flexible member. A pressing member for bending the flexible member, and a powder contained in the powder containing portion based on predetermined information obtained by performing an operation of bending the flexible member by the pressing member. A powder amount detection device comprising: a powder amount detection unit configured to detect an amount of the body; wherein the pressing member is provided rotatably about a rotation axis, and the flexible member is parallel to the rotation axis. The other end is fixed to the powder container and the other end is oscillated by being pressed by the pressing member and flexed, and the pressing member presses the flexible member to press the flexible member. As the deflection of the contact member increases, the contact portion provided on the pressing member contacts the contact portion. The contact area between the flexible member contacted portion provided to constitute so as to increase, and restore the elastic deformation to the flexible member by the pressing member is playing the flexible member The flexible member is caused to vibrate repeatedly, and has vibration detecting means for detecting a vibration state of the flexible member. The powder amount detecting means includes the vibration detecting means as the predetermined information. Detecting the amount of the powder stored in the powder storage unit based on the vibration state of the flexible member detected by the control unit .
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  As described above, according to the present invention, there is an excellent effect that the pressing member and the flexible member can be prevented from being damaged.

(A) The figure which shows the state before the torsion spring contacts the weight attached to the diaphragm in the example 1 of a structure, (b) In the example 1 of a structure, a torsion spring contacts a weight and the diaphragm faces a wall surface. The figure which shows the state which pushed in. FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment. FIG. 2 is a perspective view illustrating a developer supply configuration according to the embodiment. The perspective view which shows the internal structure which opened the upper part of the sub-hopper. FIG. 2 is a diagram illustrating an internal configuration of a magnetic flux sensor according to the embodiment. FIG. 5 is a diagram illustrating a mode of a count value of an output signal of the magnetic flux sensor according to the embodiment. FIG. 1 is a perspective view showing an overview of a magnetic flux sensor according to an embodiment. The figure which shows the structure of the controller which acquires the output value of a magnetic flux sensor, and a magnetic flux sensor. The figure which shows the arrangement | positioning relationship between a magnetic flux sensor and a diaphragm. The figure which shows the effect | action when magnetic flux passes through a diaphragm. The figure which shows the oscillation frequency of the magnetic flux sensor according to the space | interval of a plane pattern coil and a diaphragm. FIG. 4 is a perspective view showing an arrangement relationship around a diaphragm. The side view which shows the state before the torsion spring contacts the weight attached to the diaphragm as a rotation state of a rotating shaft. FIG. 14 is a side view showing a state where the torsion spring has further rotated from the state shown in FIG. 13. FIG. 15 is a side view showing a state where the torsion spring is further rotated from the state shown in FIG. 14. FIG. 4 is a top view illustrating a state of the diaphragm. FIG. 4 is a diagram schematically showing dots of a state of a developer held inside a sub hopper. The figure which shows the change of the count value of the oscillation signal of the magnetic flux sensor for every predetermined period until the vibration of a diaphragm attenuates and stops a vibration after a weight is flipped by a torsion spring. 9 is a flowchart illustrating an operation of detecting a remaining amount of a developer in a sub hopper. The figure which shows the analysis aspect of a count value. The figure which shows the count value sampled about the vibration for one period of a diaphragm. FIG. 3A is a perspective view showing a configuration for vibrating a diaphragm, and FIG. 3B is a perspective view of a torsion spring. FIG. 4 is a schematic diagram showing a state before a rotation shaft of a first stirring and conveying member and a torsion spring attached to the rotation shaft by a holder come into contact with a weight attached to a diaphragm. FIG. 24 is a schematic view showing a state in which the torsion spring is further rotated clockwise in the figure together with the rotation shaft from the state shown in FIG. 23. (A) The figure which shows the state before the torsion spring contacts the weight attached to the diaphragm in the reference configuration example, (b) In the reference configuration example, the torsion spring contacts the weight and the diaphragm faces the wall surface. The figure which shows the state which pushed in. (A) The figure which shows the state before the torsion spring contacts the weight attached to the diaphragm in the example 2 of a structure, (b) In the example 2 of a structure, the state where the torsion spring contacted the weight and pushed the diaphragm. FIG. (A) The figure which shows the state before the double torsion spring contacts the weight attached to the diaphragm, (b) The figure which shows the state in which the double torsion spring contacted the weight and pushed the diaphragm toward the wall surface. (A) The figure which shows the state before the double torsion spring contacts the weight attached to the diaphragm, (b) The figure which shows the state in which the double torsion spring contacted the weight and pushed the diaphragm toward the wall surface.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, in an electrophotographic image forming apparatus, a developer for developing an electrostatic latent image on a photoreceptor and a supply source of a developer comprising a mixture of toner and carrier as powders are provided. An example of detecting the remaining amount of the developer in a sub hopper that holds the developer between the container and the container will be described. In the present embodiment, a mixture of a toner and a carrier is used as the developer. However, a developer containing no carrier and containing only a toner may be used, or any other powder that can be used for image formation may be used. I don't care. Further, the present invention can be applied to other than the image forming apparatus, and the powder is not limited to the developer, but can be applied to flour, metal powder, and resin particles.

  FIG. 2 is a schematic configuration diagram of the image forming apparatus 100 according to the present embodiment. As shown in FIG. 2, in the image forming apparatus 100 according to the present embodiment, image forming units 106Y, 106M, 106C, and 106K (hereinafter, generally referred to as image forming units 106) of respective colors are arranged along the intermediate transfer belt 105. It is a so-called tandem type. The paper 104 fed from the paper feed tray 101 by the paper feed roller 102 is stopped once by the registration roller 103, and the image transfer position of the image from the intermediate transfer belt 105 according to the timing of image formation in the image forming unit 106. Will be sent to The plurality of image forming units 106Y, 106M, 106C, and 106K have the same internal configuration except for the color of the toner image to be formed. The image forming unit 106K forms a black image, the image forming unit 106M forms a magenta image, the image forming unit 106C forms a cyan image, and the image forming unit 106Y forms a yellow image.

  In the following description, the image forming unit 106Y will be specifically described. However, since the other image forming units 106M, 106C, and 106K are the same as the image forming unit 106Y, description thereof will be omitted. The intermediate transfer belt 105 is an endless belt, that is, an endless belt stretched over a driving roller 107 and a driven roller 108 that are driven to rotate. The driving roller 107 is driven to rotate by a driving motor, and the driving motor, the driving roller 107 and the driven roller 108 function as driving means for moving the intermediate transfer belt 105 which is an endless moving means.

  When forming an image, the first image forming unit 106 </ b> Y transfers a black toner image to the intermediate transfer belt 105 that is driven to rotate. The image forming unit 106Y includes a photoconductor drum 109Y as a photoconductor, a charger 110Y disposed around the photoconductor drum 109Y, an optical writing device 111, a developing device 112Y, a photoconductor cleaner 113Y, a static eliminator, and the like. ing. The optical writing device 111 is configured to irradiate light to each of the photoconductor drums 109Y, 109M, 109C, and 109K (hereinafter, referred to as “photoconductor drum 109”).

  In forming an image, the outer peripheral surface of the photoreceptor drum 109Y is uniformly charged by the charger 110Y in the dark, and then is written by light from the light source corresponding to the yellow image from the optical writing device 111, and the static image is formed. An electrostatic latent image is formed. The developing device 112Y visualizes the electrostatic latent image with yellow toner, thereby forming a yellow toner image on the photosensitive drum 109Y. This toner image is transferred onto the intermediate transfer belt 105 by the operation of the transfer unit 115Y at a position (transfer position) where the photosensitive drum 109Y and the intermediate transfer belt 105 come into contact with or come closest to each other. By this transfer, an image is formed on the intermediate transfer belt 105 using yellow toner. After the transfer of the toner image, the photosensitive drum 109Y is wiped of unnecessary toner remaining on the outer peripheral surface by the photosensitive member cleaner 113Y, then is discharged by the charge remover, and waits for the next image formation.

  As described above, the yellow toner image transferred onto the intermediate transfer belt 105 by the image forming unit 106Y is conveyed to the next image forming unit 106M by driving the intermediate transfer belt 105 with a roller. In the image forming unit 106M, a magenta toner image is formed on the photosensitive drum 109M by a process similar to the image forming process in the image forming unit 106Y, and the toner image is transferred by being superimposed on the already formed yellow image. Is done. The yellow and magenta toner images transferred onto the intermediate transfer belt 105 are further conveyed to the next image forming units 106C and 106K. Then, by the same operation, the cyan toner image formed on the photoconductor drum 109C and the black toner image formed on the photoconductor drum 109K are superimposed and transferred on the already-transferred image. Is done. Thus, a full-color intermediate transfer image is formed on the intermediate transfer belt 105.

  The papers 104 stored in the paper feed tray 101 are sent out in order from the top, and the intermediate transfer belt formed on the intermediate transfer belt 105 at a position where the conveyance path contacts or is closest to the intermediate transfer belt 105. The image is transferred onto the paper. Thus, an image is formed on the paper surface of the paper 104. The paper 104 on which an image is formed on the paper surface is further transported, and after the image is fixed by the fixing device 116, the paper 104 is discharged outside the image forming apparatus. Further, a belt cleaner 118 is provided for the intermediate transfer belt 105. The belt cleaner 118 is a cleaning blade pressed against the intermediate transfer belt 105 on the downstream side of the transfer position of the image from the intermediate transfer belt 105 to the sheet 104 and on the upstream side of the photosensitive drum 109, and is a conveyance belt. The toner attached to the surface is scraped off.

  Next, a configuration for supplying a developer to the developing device 112 will be described with reference to FIG. The supply configuration of the developer is generally common to each of the CMYK colors, and FIG. 3 shows the supply configuration for one developing unit 112. The developer is stored in a developer bottle 117 which is a developer storage container. As shown in FIG. 3, the developer is supplied from the developer bottle 117 to the sub hopper 90 via the developer bottle supply path 120. . The sub hopper 90 temporarily holds the developer supplied from the developer bottle 117, and supplies the developer to the developing device 112 according to the remaining amount of the developer inside the developing device 112. The developer is supplied from the sub hopper 90 to the developing device 112 via the sub hopper supply path 119.

  FIG. 4 is a perspective view showing an internal structure in which the upper portion of the sub hopper 90 is opened. As shown in FIG. 4, the sub hopper 90 houses a first stirring and conveying member 96, a second stirring and conveying member 97, a first conveying member 98, and a second conveying member 99. The sub hopper 90 has a developer storage section 90a for temporarily storing the developer supplied from the developer bottle 117, and a transport section 90b for transporting the developer stored in the developer storage section 90a to the developing device 112. are doing. The developer storage section 90a and the transport section 90b are formed by partitioning the inside of the case with a partition wall 92. A first opening 92a and a second opening 92b are formed on the rear side of the partition wall 92 on the side of the developer supply drive unit and on the front side opposite thereto.

  A first stirring and conveying member 96 and a second stirring and conveying member 97 are arranged side by side in the developer storage section 90a. A magnetic flux sensor 204 is provided on the right side wall of the case 93b in the drawing. The diaphragm 201 is arranged inside the right side wall of the case 93b in the drawing, at a position facing the magnetic flux sensor 204 via the case 93b. The first stirring and conveying member 96 arranged on the right side of the developer storage section 90a in the figure has a rotating shaft 96c and a spiral screw 96b having a large pitch. Further, the first stirring and conveying member 96 is provided with a torsion spring 203 for flipping the diaphragm. The second stirring / conveying member 97 arranged on the partition wall 92 side of the developer storage section 90a is provided with a spiral screw 97b having a large pitch and a paddle 97a on a rotating shaft 97c. A paddle 96a is provided at a portion of the rotating shaft 97c facing the first opening 92a and at a portion facing the second opening 92b.

  The transport section 90b is partitioned by a transport partition wall 901 into a first transport path 902A and a second transport path 902B. On the front side of the transfer partition wall 901, a transfer opening 901a is formed, and connects the first transfer path 902A and the second transfer path 902B. A first transport member 98 is disposed on the first transport path 902A, and a second transport member 99 is disposed on the second transport path 902B. Each of the transport members 98, 99 is composed of rotating shafts 98b, 99b and spiral screws 98a, 99a. In the screw 98a of the first transport member 98, the pitch at a location facing the transport opening 901a is smaller than at other locations.

  The screws 99a of the second transport member 99 have a constant pitch in the direction of the rotation axis. The first transport member 98 transports the developer in the first transport path 902A toward the transport opening 901a (from the rear side to the front side), and the second transport member 99 transports the developer in the second transport path 902B. From the front side to the rear side. A developer supply outlet that communicates with a supply port of the developing device 112 is provided at a location on the bottom surface of the case 93b that is located at the downstream end of the developer transport of the second transport path 902B. The developer transported along the second transport path 902B by the second transport member 99 is supplied to the developing device 112 from a developer supply outlet.

  Further, the sub hopper 90 includes a developer supply driving unit 130 used when supplying the developer to the developing device 112. The developer supply drive unit 130 is provided in front of the sub hopper 90, and includes a supply drive motor 131 and a gear train including a plurality of gears. The driving force of the supply drive motor 131 is transmitted to the first stirring / transporting member 96 via a supply-side one-way clutch 132 provided at the other end (the lower end in the drawing) of the rotating shaft 96c of the first stirring / transporting member 96. Then, the first stirring and conveying member 96 is driven to rotate. Further, the driving force of the supply drive motor 131 is transmitted from the first stirring and conveying member 96 to the second stirring and conveying member 97 via a plurality of gears, and the second stirring and conveying member 97 is driven to rotate. Further, a driving force is transmitted from the supply drive motor 131 to the first transport member 98 and the second transport member 99 via a plurality of gears, and the first transport member 98 and the second transport member 99 are driven to rotate.

  In the present embodiment, a developer storage section 90a is provided, and the developer is stored in the developer storage section 90a. Thus, even if the developer bottle 117 is empty, the developer stored in the developer storage unit 90a can supply the developer to the developing device 112 for a while. Thereby, a good image can be formed while the user prepares a new developer bottle 117.

  Next, an internal configuration of the magnetic flux sensor 204 according to the present embodiment will be described with reference to FIG. The magnetic flux sensor 204 is an oscillation circuit based on a Colpitts type LC oscillation circuit, and includes a planar pattern coil 11, a pattern resistor 12, a first capacitor 13, a second capacitor 14, a feedback resistor 15, unbuffer ICs 16 and 17, and an output. Terminal 18 is included.

  The plane pattern coil 11 is a plane coil formed by signal lines patterned in a plane on a substrate constituting the magnetic flux sensor 204. 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 magnetic flux passing through a space facing the plane on which the coil is formed. As a result, the magnetic flux sensor 204 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 surface of the planar pattern coil 11 faces.

  The pattern resistor 12 is a resistor configured by a signal line patterned in a plane on the substrate, like the planar pattern coil 11. The pattern resistor 12 according to the present embodiment is a pattern formed in a zigzag pattern, thereby creating a state in which current does not easily flow as compared with a linear pattern. The provision of the pattern resistor 12 is one of the points according to the present embodiment. In addition, the meandering shape is, in other words, a shape bent so as to reciprocate a plurality of times in a predetermined direction. As shown in FIG. 5, the pattern resistor 12 has a resistance value RP. 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 capacitances that constitute a Colpitts-type LC oscillation circuit together with the planar pattern coil 11. 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 loop constituted by the planar pattern coil 11, the pattern resistor 12, the first capacitor 13 and the second capacitor 14 forms a resonance current loop.

  The feedback resistor 15 is inserted to stabilize the bias voltage. Due to the functions of the unbuffer IC 16 and the unbuffer IC 17, a change in the potential of a part of the resonance current loop is output from the output terminal 18 as a rectangular wave corresponding to the resonance frequency.

  With such a configuration, the magnetic flux sensor 204 according to the present embodiment oscillates at a frequency f according to the inductance L, the resistance value RP, and the capacitance C of the first capacitor 13 and the second capacitor 14. The frequency f can be represented by the following equation (1).

  The inductance L also changes depending on the presence or concentration of the magnetic material near the planar pattern coil 11. Therefore, it is possible to determine the magnetic permeability in the space near the planar pattern coil 11 based on the oscillation frequency of the magnetic flux sensor 204. Further, as described above, the magnetic flux sensor 204 in the sub hopper 90 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 204.

  FIG. 6 is a diagram illustrating a form of the count value of the output signal of the magnetic flux sensor 204 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 204, the magnetic flux sensor 204 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 time. Then, as shown in FIG. 6, at the respective timings of t1, t2, t3, t4, and t5, count values such as aaaah, bbbbbh, cccch, ddddh, and AAAAh are obtained.

  The frequency in each period is calculated by calculating the count value at each timing based on each period of T1, T2, T3, and T4 shown in FIG. For example, when calculating a frequency by outputting an interrupt signal when the reference clock corresponding to 2 [msec] is counted, the count value in each period is divided by 2 [msec]. Thus, the oscillation frequency f [Hz] of the magnetic flux sensor 204 in each of the periods T1, T2, T3, and T4 shown in FIG. 6 is calculated. Also, 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 sum of the value obtained by subtracting ddddh from FFFFh and the value of 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, it is possible to acquire the frequency of the signal oscillated by the magnetic flux sensor 204 and determine an event corresponding to the oscillation frequency of the magnetic flux sensor 204 based on the acquired result. it can. Then, in the magnetic flux sensor 204 according to the present embodiment, the inductance L changes according to the state of the diaphragm 201 arranged to face the plane pattern coil 11, and as a result, the signal output from the output terminal 18 changes. 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 arranged to face the planar pattern coil 11. The state of the developer inside the sub hopper 90 is 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. If the period for acquiring the count value is fixed, the acquired count value is used as a parameter for indicating the frequency. It can be used as it is.

  FIG. 7 is a perspective view illustrating an overview of the magnetic flux sensor 204 according to the present embodiment. 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, a pattern resistor 12 connected in series with the flat pattern coil 11 is patterned on the detection surface on which the flat pattern coil 11 is formed. As described in FIG. 5, the plane pattern coil 11 is a signal line pattern spirally formed on a plane. The pattern resistor 12 is a signal pattern formed in a zigzag pattern on a plane, and the function of the magnetic flux sensor 204 as described above is realized by these patterns. The portion formed by the planar pattern coil 11 and the pattern resistor 12 is a magnetic permeability detecting unit in the magnetic flux sensor 204 according to the present embodiment. When attaching the magnetic flux sensor 204 to the sub hopper 90, the magnetic flux sensor 204 is attached so that the detection unit faces the diaphragm 201.

  Next, a configuration for acquiring the output value of the magnetic flux sensor 204 in the image forming apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 8 is a diagram showing the configuration of the controller 20 for obtaining the output value of the magnetic flux sensor 204 and the configuration of the magnetic flux sensor 204. The controller 20 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 an arithmetic unit, and controls the entire operation of the controller 20 by performing an arithmetic operation according to a program stored in a storage medium such as a ROM (Read Only Memory). The ASIC 22 functions as a connection interface between a system bus to which the CPU 21 and a RAM (Random Access Memory) 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. The CPU 21 outputs a read signal for acquiring the output value of the magnetic flux sensor 204 according to the interrupt signal input from the timer 23. The crystal oscillation circuit 24 oscillates a reference clock for operating each device in the controller 20. The input / output control ASIC 30 acquires a detection signal output from the magnetic flux sensor 204 and converts the signal into information that can be processed inside the controller 20. As shown in FIG. 8, the input / output control ASIC 30 includes a magnetic permeability counter 31, a read signal acquisition unit 32, and a count value output unit 33. As described above, the magnetic flux sensor 204 according to the present embodiment is an oscillation circuit that outputs a rectangular wave having a frequency according to the magnetic permeability in the detection target space.

  The magnetic permeability counter 31 is a counter that increments the value according to the rectangular wave output from the magnetic flux sensor 204. That is, the magnetic permeability counter 31 functions as a target signal counter that counts the number of signals whose frequency is to be calculated. The magnetic flux sensor 204 according to the present embodiment is provided for each of the sub-hoppers 90 connected to the developing units 112 of the respective colors CMYK, and a plurality of magnetic permeability counters 31 are provided accordingly. The read signal acquisition unit 32 acquires, via the ASIC 22, a read signal, which is an instruction from the CPU 21 to acquire the count value of the magnetic permeability counter 31. Upon acquiring the read signal from the CPU 21, the read signal acquiring 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 according to the signal from the read signal acquisition unit 32.

  The CPU 21 accesses the input / output control ASIC 30 via a register, for example. Therefore, the above-described read signal is performed by the CPU 21 writing a value to a predetermined register included in the input / output control ASIC 30. The output of the count value by the count value output unit 33 is performed by storing the count value in a predetermined register included in the input / output control ASIC 30 and obtaining the value by the CPU 21. The controller 20 shown in FIG. 8 may be provided separately from the magnetic flux sensor 204, or may be mounted on a substrate of the magnetic flux sensor 204 as a circuit including the CPU 21.

  In such a configuration, the CPU 21 detects the vibration state of the diaphragm 201 based on the count value acquired from the count value output unit 33, and detects the remaining amount of the developer inside the sub hopper based on the detection result. That is, the detection processing unit is configured by the CPU 21 performing an operation according to a predetermined program. The count value obtained from the count value output unit 33 is used as frequency-related information indicating the frequency of the magnetic flux sensor 204 that changes according to the vibration of the diaphragm 201.

  Next, the influence of the diaphragm 201 on the oscillation frequency of the magnetic flux sensor 204 according to the present embodiment will be described. As shown in FIG. 9, the surface of the magnetic flux sensor 204 on which the planar pattern coil 11 is formed and the diaphragm 201 are arranged to face each other via the housing of the sub hopper 90. 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.

  The diaphragm 201 is made of, for example, a stainless steel plate. As shown in FIG. 10, an eddy current is generated in the diaphragm 201 when the magnetic flux G1 penetrates the diaphragm 201. The eddy current generates a magnetic flux G2 and acts to cancel the magnetic flux G1 generated by the planar pattern coil 11. By canceling out the magnetic flux G1, the inductance L of the magnetic flux sensor 204 decreases. As shown in the above equation 1, when the inductance L decreases, the oscillation frequency f increases.

  The intensity of the eddy current generated inside the diaphragm 201 by receiving the magnetic flux from the planar pattern coil 11 changes depending on the distance between the planar pattern coil 11 and the diaphragm 201 in addition to the intensity of the magnetic flux. FIG. 11 is a diagram showing the oscillation frequency of the magnetic flux sensor 204 according to the distance between the planar pattern coil 11 and the diaphragm 201. The intensity of the eddy current generated inside the diaphragm 201 is inversely proportional to the distance between the planar pattern coil 11 and the diaphragm 201. Therefore, as shown in FIG. 11, as the distance between the planar pattern coil 11 and the diaphragm 201 becomes smaller, the oscillation frequency of the magnetic flux sensor 204 becomes higher. No longer.

  In the sub hopper 90 according to the present embodiment, the vibration of the diaphragm 201 is detected based on the oscillation frequency of the magnetic flux sensor 204 by utilizing the characteristics shown in FIG. Based on the vibration of the diaphragm 201 detected in this way, the remaining amount of the developer inside the sub hopper 90 is detected. That is, the diaphragm 201, the magnetic flux sensor 204, and the configuration for processing the output signal of the magnetic flux sensor 204 shown in FIG. 9 are used as the developer remaining amount detecting device which is the powder amount detecting device according to the present embodiment. Note that the magnetic flux sensor 204 functions as a vibration detecting unit.

  The vibration of the vibration plate 201 repelled by the torsion spring 203 is represented by a natural frequency determined by the rigidity of the vibration plate 201 and the weight of the weight 202, and a damping rate determined by an external factor absorbing the vibration energy. As external factors for absorbing vibration energy, in addition to fixing factors such as fixing strength of a fixing portion for fixing the diaphragm 201 in a cantilever state, air resistance, and the like, development in contact with the diaphragm 201 inside the sub hopper 90 is performed. There is an agent present. The developer that contacts the vibration plate 201 inside the sub hopper 90 varies depending on the remaining amount of the developer inside the sub hopper 90. Therefore, by detecting the vibration of the diaphragm 201, the remaining amount of the developer inside the sub hopper 90 can be detected. Therefore, in the sub hopper 90 according to the present embodiment, the torsion spring 203 for stirring the developer inside the sub hopper 90 flips the vibration plate 201 and vibrates the vibration plate 201 periodically according to the rotation.

  Next, the arrangement of components around the diaphragm 201 inside the sub hopper 90 and the configuration for the torsion spring 203 to flip the diaphragm 201 will be described. FIG. 12 is a perspective view showing a positional relationship around the diaphragm 201. As shown in FIG. As shown in FIG. 12, the diaphragm 201 is fixed to the housing of the sub hopper 90 via the fixing portion 201a. FIG. 13 is a side view showing a state before the contact portion 203a of the torsion spring 203 comes into contact with the weight 202 attached to the diaphragm 201 as the rotating state of the rotating shaft 96c. In FIG. 13, the rotation shaft 96c rotates so that the torsion spring 203 rotates clockwise in the figure. The torsion spring 203 is an elastic member provided on the rotating shaft 96c via a holder 205 (see FIG. 22), and the contact portion 203a is rotated clockwise in the drawing, which is one side in the rotating direction of the rotating shaft 96c. It is always energized.

  As shown in FIG. 13, the weight 202 is a projection 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 slope approaches the rotation shaft 96c along the rotation direction of the torsion spring 203. The inclined surface of the weight 202 is a portion that is pressed by the contact portion 203a of the torsion spring 203 when the torsion spring 203 flips and vibrates the diaphragm 201.

  FIG. 14 is a side view showing a state where the torsion spring 203 has further rotated from the state shown in FIG. When the contact portion 203a of the torsion spring 203 further rotates while being in contact with the weight 202, the diaphragm 201 is pushed in with the inclination provided on the weight 202 and is elastically deformed. 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 a “steady state”) are indicated by broken lines. As shown in FIG. 14, the diaphragm 201 and the weight 202 are pushed by the contact portion 203a of the torsion spring 203.

  Since the diaphragm 201 is fixed to the inner wall of the housing of the sub hopper 90 via the fixing portion 201a, the position on the fixing portion 201a side does not change. On the other hand, the end opposite to the free end provided with the weight 202 is pushed by the contact portion 203a of the torsion spring 203 to move to the opposite side to the side provided with the rotary shaft 96c. I do. As a result, the diaphragm 201 bends with the fixed portion 201a as a base point. In such a bent state, energy for vibrating the diaphragm 201 is stored.

  FIG. 15 is a side view showing a state where the torsion spring 203 is further rotated from the state shown in FIG. In FIG. 15, the position of the diaphragm 201 in the 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 which is depressed by the contact portion 203a of the torsion spring 203 and deflected to the opposite side when the stored vibration energy is released is indicated by a solid line. FIG. 16 is a top view illustrating the state of the diaphragm 201. As shown in FIG. 15, when the pressing of the weight 202 by the torsion spring 203 is released, the end of the side on which the weight 202 which is the free end is provided is on the opposite side by the energy of the bending stored in the diaphragm 201. Move to bend. In the state shown in FIGS. 15 and 16, the diaphragm 201 is in a state of being separated from the magnetic flux sensor 204 facing the sub hopper 90 via the housing of the sub hopper 90. Thereafter, by vibrating, the diaphragm 201 returns to the steady state due to the attenuation of the vibration while repeating a state in which the diaphragm 201 is closer to the magnetic flux sensor 204 than in the steady state and a state in which it is farther than the steady state.

  FIG. 17 is a diagram schematically showing the state of the developer held inside the sub hopper 90 by dots. As shown in FIG. 17, when the developer exists inside the sub hopper 90, the vibration plate 201 and the weight 202 come into contact with the developer while vibrating. Therefore, the vibration of the diaphragm 201 is attenuated faster than in the case where the developer does not exist inside the sub hopper 90. The remaining amount of the developer inside the sub hopper 90 can be detected based on the change in the attenuation of the vibration.

  FIG. 18 is a diagram showing a change in the count value of the oscillation signal of the magnetic flux sensor 204 every predetermined period from when the weight 202 is flipped by the torsion spring 203 until the vibration of the diaphragm 201 is attenuated and stopped. is there. The count value of the oscillation signal of the magnetic flux sensor 204 increases as the oscillation frequency increases. Therefore, the vertical axis in FIG. 18 can be replaced by the oscillation frequency instead of the count value. As shown in FIG. 18, at timing t <b> 1, the contact portion 203 a of the torsion spring 203 contacts the weight 202 and pushes the weight 202, so that the diaphragm 201 approaches the magnetic flux sensor 204. Thereby, the oscillation frequency of the magnetic flux sensor 204 increases, and the count value for each predetermined period increases. Then, at the timing t2, the pressing of the weight 202 by the torsion spring 203 is released, and thereafter, the diaphragm 201 vibrates by the stored vibration energy. As the diaphragm 201 vibrates, the state between the diaphragm 201 and the magnetic flux sensor 204 repeats a wider state and a narrower state centering on the steady state. As a result, the frequency of the oscillation signal of the magnetic flux sensor 204 oscillates with the oscillation of the diaphragm 201, and the count value for each predetermined period also oscillates.

  The amplitude of the vibration of the vibration plate 201 becomes smaller as the vibration energy is consumed. That is, the vibration of the diaphragm 201 attenuates with time. Therefore, the change in the interval between the diaphragm 201 and the magnetic flux sensor 204 also decreases with time, and the time change in the count value similarly changes as shown in FIG. Here, as described above, the vibration of the vibration plate 201 is attenuated faster as the remaining amount of the developer inside the sub hopper 90 increases. Therefore, it is recognized how the vibration of the vibration plate 201 is attenuated by analyzing the mode of the attenuation of the oscillation signal oscillation signal of the magnetic flux sensor 204 as shown in FIG. You can know the remaining amount. Therefore, as shown in FIG. 18, when the peaks of the oscillation of the count value are P1, P2, P3, P4,..., For example, the damping rate 振動 of the oscillation of the diaphragm 201 is obtained by the following equation (2). Can be.

  As shown in Equation 2, by referring to the ratio of peak values at different timings, it is possible to cancel an error due to environmental fluctuation and obtain an accurate attenuation rate. In other words, the CPU 21 according to the present embodiment obtains the attenuation rate て based on the ratio of the count values acquired at different timings.

  In Equation 2, P1, P2 and P5, P6 among the peaks shown in FIG. 18 are used, but this is an example, and other peaks may be used. However, the peak value at timing t2 when the diaphragm 201 is pushed by the torsion spring 203 and is closest to the magnetic flux sensor 204 includes an error or the like in which sliding noise due to friction between the torsion spring 203 and the weight 202 is superimposed. . For this reason, it is preferable not to be included in the calculation. Even if the attenuation of the vibration is accelerated by the presence of the developer inside the sub hopper 90 as shown in FIG. 17, the frequency of the vibration plate 201 does not change much. Therefore, by calculating the ratio of the amplitude of a specific peak as shown in Expression 2, the attenuation of the amplitude in a predetermined period can be calculated.

  Next, an operation of detecting the remaining amount of the developer in the sub hopper 90 according to the present embodiment will be described with reference to a flowchart of FIG. The operation of the flowchart shown in FIG. 19 is an operation of the CPU 21 shown in FIG. As shown in FIG. 19, the CPU 21 first detects that the weight 202 is pushed by the torsion spring 203 as shown in FIG. 14 and vibration is generated (S1). As described above, the CPU 21 obtains the count value of the output signal of the magnetic flux sensor 204 from the count value output unit 33 every predetermined period. This count value is C0 in the steady state as shown in FIG. On the other hand, when the weight 202 is pushed in as shown in FIG. 14, the count value increases as the diaphragm 201 approaches the magnetic flux sensor 204. Therefore, when the count value obtained from the count value output unit 33 exceeds a predetermined threshold, the CPU 21 detects that vibration has occurred in S1.

  Regardless of before or after S1, the CPU 21 continuously performs the count value acquisition process for each predetermined period as a normal process. Then, after S1, the CPU 21 acquires the peak value of the vibration of the count value corresponding to the vibration of the diaphragm 201 as shown in FIG. 18 (S2). In S2, the CPU 21 specifies the peak value by continuously analyzing the count value acquired every predetermined period.

  FIG. 20 is a diagram showing an analysis mode of the count value. For the count value acquired at every predetermined period, in addition to the “number n” and “count value Sn” of each count value, The signs “Sn−1−Sn” of the differences are shown in the order of acquisition. In the result as shown in FIG. 20, the value immediately before the sign of “Sn−1−Sn” is inverted is the peak value. In the case of FIG. 20, Nos. 5 and 10 are adopted as peak values. That is, the CPU 21 calculates “Sn−1−Sn” illustrated in FIG. 20 for the count values acquired in order after S1. Then, the “count value Sn” at the timing when the sign obtained as the calculation result is inverted is adopted as a peak value such as P1, P2, P3... Shown in FIG.

  Note that, as described above, it is preferable to avoid the value at the timing t2. The value of the timing t2 is the first peak after S2201. Therefore, the CPU 21 discards the first value among the peak values extracted by performing the analysis as shown in FIG. Further, the count value actually obtained may include high frequency component noise, and the timing at which the sign of “Sn−1−Sn” is inverted at a position other than the peak due to the vibration of the diaphragm 201 occurs. There is. In order to avoid erroneous detection in such a case, it is preferable that the CPU 21 performs the analysis shown in FIG. 20 after smoothing the value obtained from the count value output unit 33. In the smoothing process, a general process such as a moving average method can be adopted.

  When the peak value is obtained in this manner, the CPU 21 calculates the attenuation rate に よ り by the calculation of the above equation (S3). Therefore, in S2, the analysis of the count value is performed in the manner shown in FIG. 20 until the peak value used for calculating the attenuation rate is obtained. When using the above equation 2, the CPU 21 analyzes the count value until a peak value corresponding to P6 is obtained.

  After calculating the attenuation rate に し て in this manner, the CPU 21 determines whether or not the calculated attenuation rate 以下 is equal to or less than a predetermined threshold (S4). That is, the CPU 21 determines that the amount of the developer inside the sub hopper 90 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. 17, when sufficient developer remains in the sub hopper 90, the vibration of the diaphragm 201 attenuates quickly. Therefore, the attenuation rate ζ becomes small.

  On the other hand, when the amount of the developer inside the sub hopper 90 decreases, the attenuation of the vibration of the diaphragm 201 becomes slow, and the attenuation rate ζ increases accordingly. Therefore, by setting the attenuation rate {S according to the remaining amount of the developer to be detected as the threshold value, the remaining amount of the developer inside the sub hopper 90 should be detected based on the calculated attenuation rate （ It is possible to determine that the amount has decreased to “specified amount”.

  The remaining amount of the developer inside the sub hopper 90 does not directly affect the vibration damping mode of the diaphragm 201, but changes the contact state of the developer with the diaphragm 201 according to the remaining amount of the developer. Thus, the manner of damping the vibration of the diaphragm 201 is determined. Therefore, even if the remaining amount of the developer inside the sub hopper 90 is the same, if the manner of contact of the developer with the diaphragm 201 is different, the manner of attenuation of the diaphragm 201 will be different. On the other hand, when detecting the remaining amount of the developer inside the sub hopper 90 according to the present embodiment, the developer inside the sub hopper 90 is always agitated by the torsion spring 203. Therefore, the state of contact of the developer with the vibration plate 201 can be determined to some extent according to the remaining amount of the developer. As a result, even when the remaining amount of the developer is the same, the adverse effect that the detection result differs due to the different contact state of the developer with the diaphragm 201 can be avoided.

  As a result of the determination in S4, if the calculated attenuation rate 未 満 is less than the threshold value (NO in S4), the CPU 21 determines that a sufficient amount of the developer is held inside the sub hopper 90, and performs the processing as it is. finish. On the other hand, if the calculated attenuation rate 以上 is equal to or greater than the threshold value (YES in S4), CPU 21 determines that the amount of the developer inside sub hopper 90 is less than the specified amount, and performs the processing by detecting the lack of the developer. The process ends (S5). The CPU 21 that has detected the running out of the developer in the process of S2205 outputs a signal indicating that the remaining amount of the developer is lower than the specified amount to a higher controller that controls the image forming apparatus 100. Thus, the controller of the image forming apparatus 100 can recognize that the developer for the specific color has run out and supply the developer from the developer bottle 117.

  Next, the relationship between the frequency of the oscillation signal of the magnetic flux sensor 204 according to the present embodiment, the cycle of acquiring the count value by the CPU 21 (hereinafter referred to as “sampling cycle”), and the natural frequency of the diaphragm 201 will be described. FIG. 21 is a diagram illustrating a sampled count value for the vibration of the vibration plate 201 for one cycle. In FIG. 21, the vibration cycle of the diaphragm 201 is Tplate, and the sampling cycle is Tsample.

  In order to calculate the attenuation rate の of the diaphragm 201 with high accuracy by the modes described with reference to FIGS. 18 to 20, it is necessary to obtain the peak value of the vibration of the diaphragm 201 with high accuracy. For that purpose, a sufficient number of samples with a count value for Tplate is necessary, and therefore, Tsample needs to be sufficiently small for Tplate.

  In the example of FIG. 21, 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 aspect of FIG. 21, sampling is always performed within the period of Tpeak in the figure, and a 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 be 10 [ms] or more. In other words, for a sampling frequency of 1000 [Hz] of the CPU 21, the natural frequency of the diaphragm 201 is preferably about 100 [Hz], and more preferably lower than that. Such a natural frequency of the diaphragm 201 is realized by adjusting the material of the diaphragm 201, 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 with high accuracy. Here, the value of the sampled count value is a value according to the oscillation frequency of the magnetic flux sensor 204. Generally, the oscillation frequency of the magnetic flux sensor 204 is on the order of several [MHz], and when sampling is performed at a sampling frequency of 1000 [Hz], a count value of 1000 or more can be obtained 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 204 is not sufficient for the change in the distance between the magnetic flux sensor 204 and the diaphragm 201 due to the vibration of the diaphragm 201, the count value with respect to time as shown in FIG. The amplitude of the vibration is reduced. As a result, the change in the attenuation factor ζ becomes small, and the accuracy of detecting the remaining amount of the developer due to the vibration of the diaphragm 201 also decreases. In order to increase the amount of change in the oscillation frequency of the magnetic flux sensor 204 with respect to the change in the distance between the magnetic flux sensor 204 and the diaphragm 201, it is necessary to arrange the magnetic flux sensor 204 and the diaphragm 201 based on the characteristics shown in FIG. The interval needs to be determined. For example, as shown in a section indicated by an arrow in FIG. It is preferable to determine the interval.

  FIG. 22A is a perspective view illustrating a configuration in which the diaphragm 201 is vibrated. FIG. 22B is a perspective view of the torsion spring 203. In the present embodiment, a torsion spring 203, which is a single torsion spring using a torsion coil spring on only one side with respect to the contact portion 203a, is used as a diaphragm repelling member that is a vibration imparting unit that vibrates the diaphragm 201. . The vibration plate 201 is fixed to the case 93b of the sub hopper 90 via a fixing portion 201a provided on one end side in a direction parallel to the axial direction of the rotation shaft 96c of the first stirring and conveying member 96 (FIG. 4). reference). A weight 202, which is a protrusion having a triangular cross section, is attached to the other end of the diaphragm 201. The weight 202 protrudes from the plate surface facing the rotation axis 96c of the diaphragm 201, and the first slope portion 202a, the apex 202b, and the second slope portion 202c are sequentially formed in the rotation direction of the rotation shaft 96c in the drawing. Have been. The first slope portion 202a is formed such that the slope approaches the rotation shaft 96c along the rotation axis rotation direction in the drawing, and the second slope portion 202c has a slope that rotates along the rotation axis rotation direction in the drawing. It is formed so as to be distant from 96c, and both slope portions are connected at a vertex 202b.

  The torsion spring 203 is fixed to the rotation shaft 96c of the first stirring and conveying member 96 via the holder 205, and the rotation of the rotation shaft 96c causes the torsion spring 203 to rotate together with the rotation shaft 96c. When the torsion spring 203 rotates, the contact portion 203a comes into contact with the weight 202, and the weight 202 is pushed into the case 93b by the torsion spring 203, whereby the diaphragm 201 is elastically deformed so as to bend. Further, the torsion spring 203 is further rotated from the position where the weight 202 is pressed, and the contact portion 203a of the torsion spring 203 is separated from the weight 202, whereby the diaphragm 201 is repelled, and the diaphragm 201 is returned by the force returning to the original position. Vibrate.

  The material of the torsion spring 203 is a linear member such as a hard steel wire (SW-C), a piano wire (SWP-A, SWP-B), a stainless steel wire for a spring (SUS304-WPB), and an elastic wire. Is preferred, but can be changed as appropriate. Further, the force by which the torsion spring 203 pushes the diaphragm 201 can be changed by changing the material of the torsion spring 203, the number of turns of the torsion coil portion, and the like. Therefore, when using a developer consisting of only the toner or a developer consisting of the above-mentioned mixture having a larger weight per unit volume than this developer, the diaphragm 201 may be provided with a torsion spring as necessary. The pushing force of 203 can be changed.

  FIG. 23 shows a state before the rotating shaft 96 c of the first stirring and conveying member 96 and the contact portion 203 a of the torsion spring 203 attached to the rotating shaft 96 c by the holder 205 come into contact with the weight 202 attached to the diaphragm 201. It is the schematic diagram which showed the state. In FIG. 23, the torsion spring 203 rotates in the clockwise direction in the figure together with the rotation shaft 96c of the first stirring and conveying member 96. The diaphragm 201 has a first inclined portion (upstream inclined surface) 202a, a vertex (top portion) 202b, and a second inclined portion (downstream inclined surface) 202c from the upstream side to the downstream side in the rotation direction of the torsion spring 203. Are provided as weights 202 which are protrusions arranged in this order. The first slope portion (upstream slope surface) 202a has a shape that is inclined from the upstream side in the rotation direction toward the downstream side and is inclined with respect to the surface of the diaphragm 201 on the rotation axis 96c side. The second inclined portion (downstream inclined surface) 202c has a shape which is inclined from the upstream side in the rotation direction toward the downstream side and inclined with respect to the surface of the diaphragm 201 on the rotation axis 96c side. The apex (top) 202b is a height from the surface of the vibration plate 201 on the rotation axis 96c side of the weight 202, which connects the first inclined portion (upstream inclined surface) 202a and the second inclined portion (downstream inclined surface) 202c. Is the highest part. Note that the shape of the apex (apex) 202b may be sharp, rounded, or flat.

  FIG. 24 is a schematic diagram showing a state in which the torsion spring 203 is further rotated clockwise in the figure together with the rotation shaft 96c from the state shown in FIG. As shown in FIG. 24, as the torsion spring 203 rotates, the contact portion 203a comes into contact with the first slope portion (upstream slope) 202a of the weight 202, and a vertex (top portion) 202b on the first slope portion 202a. Move towards. Thereby, the diaphragm 201 is pushed toward the case 93b by the torsion spring 203. The torsion spring 203, which pushes the weight 202 by the rotation of the rotation shaft 96c, twists the torsion coil spring, and when the rotation shaft 96c further rotates, the contact portion 203a separates from the weight 202 through the apex 202b of the weight 202. Then, due to the force of the torsion coil spring, the contact portion 203a passes through the second slope portion (downstream slope surface) 202c of the weight 202, and the torsion spring 203 is restored to the original shape indicated by the broken line in the drawing. Then, after the diaphragm 201 pushed by the torsion spring 203 is flipped by the contact portion 203a of the torsion spring 203 passing through the vertex 202b of the weight 202, the diaphragm 201 attempts to return to the original position indicated by the broken line in the drawing. Vibrate. Then, the amount of the developer is detected by using the magnetic flux sensor 204 from the vibration of the diaphragm 201 thus generated.

  Here, when a plate-like elastic member such as mylar is used as the vibration applying means for vibrating the vibration plate 201 by vibrating, the sheet-like elastic member has low durability, but the strength is obtained by using the torsion spring 203 as the vibration applying means. And have excellent durability. When a plate-like elastic member such as mylar is used as the vibration applying means, the force for pushing the diaphragm 201 is weaker than when the torsion spring 203 is used. Therefore, if the weight per unit volume is larger than that of the developer containing only the toner, such as the developer composed of the mixture of the toner and the carrier, the diaphragm 201 may not be sufficiently pushed in to vibrate. On the other hand, by using the torsion spring 203 as the vibration imparting means, the diaphragm 201 can be sufficiently pushed in even when the weight per unit volume of the developer is large as described above. Therefore, the vibration required for the developer amount detection using the magnetic flux sensor 204 can be caused to the diaphragm 201, and the developer amount detection can be performed with high accuracy.

  Further, when a plate-like elastic member such as mylar is used as the vibration applying means, the following problem may occur if the rotation speed of the rotating shaft to which the plate-like elastic member is attached is low and slow. That is, after the plate-like elastic member is separated from the weight 202 of the diaphragm 201, the plate-like elastic member cannot quickly escape from the vibration region of the diaphragm 201 (the region facing the diaphragm 201), and the vibration of the diaphragm 201 The member gets in the way. For this reason, the vibration of the diaphragm 201 cannot be accurately detected by the magnetic flux sensor 204, and the detection accuracy of the developer amount may be reduced.

  On the other hand, even when the rotation speed of the rotation shaft 96c is low and the rotation is slow, the torsion spring 203 is in a state where the original force is not applied by the force of the torsion coil spring after the contact portion 203a is separated from the weight 202. Restore quickly. Therefore, the contact portion 203a of the torsion spring 203 can quickly escape from the vibration region of the diaphragm 201 (the region facing the diaphragm 201). Accordingly, the vibration of the diaphragm 201 by the magnetic flux sensor 204 can be accurately detected without the torsion spring 203 interfering with the vibration of the diaphragm 201, and a decrease in the detection accuracy of the developer amount is suppressed. Can be. In addition, as shown in FIG. 24 and the like, it is desirable to provide the apex 202 b of the weight 202 on the downstream side in the rotation direction of the torsion spring 203. Thus, after the contact portion 203a of the torsion spring 203 flips the weight 202, the contact portion 203a can escape from the region of the weight 202 relatively quickly.

  Further, by providing the second slope portion 202c to the weight 202, when the rotation shaft 96c rotates in the reverse direction (counterclockwise in FIG. 24), the torsion spring 203 that rotates in the reverse direction together with the rotation shaft 96c is provided on the second slope portion 202c. To move. Thus, the contact portion 203a of the torsion spring 203 smoothly rotates in the reverse direction without being caught by the weight 202, so that it is possible to prevent the torsion spring 203 and the rotating shaft 96c from being damaged by an excessive load. it can.

[Reference configuration example]
FIG. 25A illustrates a state before the torsion spring 203 contacts the weight 202 attached to the diaphragm 201 in the reference configuration example. FIG. 25B shows a state in which the torsion spring 203 contacts the weight 202 and pushes the diaphragm 201 toward the wall surface 93c (a state in which the diaphragm 201 is pressed against the wall surface 93c) in the reference configuration example. .

  As described above, the vibration plate 201 is fixed to the case 93b of the sub hopper 90 via the fixing portion 201a provided on one end side in a direction parallel to the axial direction of the rotation shaft 96c of the first stirring and conveying member 96. It is held cantilevered. Therefore, as shown in FIG. 25B, in a state where the torsion spring 203 comes into contact with the weight 202 and pushes the diaphragm 201 toward the wall surface 93c, the diaphragm 201 bends starting from the fixed portion 201a. Elastically deform. Due to such elastic deformation, the diaphragm 201 inclines so as to be more distant from the torsion spring 203 in the longitudinal direction of the diaphragm 201 toward a free end side opposite to the fixed portion 201a. Therefore, when the diaphragm 201 is most pressed by the torsion spring 203 so as to contact the wall surface 98c, the contact portion 203a of the torsion spring 203 and the weight 202 provided on the free end side of the diaphragm 201 are in point contact. It becomes a state close to. In the state where the diaphragm 201 is pushed most, the load on the contact portion 203a from the weight 202 is maximized in a state where the diaphragm 201 is pushed toward the wall surface 93c by the elastic force of the diaphragm 201. As a result, the maximum load is concentrated on the same portion of the contact portion 203a of the torsion spring 203 which is in contact with the weight 202 in a state close to the point contact, so that the load may be repeatedly damaged with time.

[Configuration Example 1]
FIG. 1A illustrates a state before the torsion spring 203 contacts the weight 202 attached to the diaphragm 201 in the configuration example 1. FIG. 1B illustrates a state in which the torsion spring 203 contacts the weight 202 and pushes the diaphragm 201 toward the wall surface 93c (a state in which the diaphragm 201 is pressed against the wall surface 93c) in the configuration example 1. .

  In this configuration example, the contact portion 203a is moved in the axial direction of the torsion spring so that the contact area between the contact portion 203a and the weight 202 increases as the deflection of the diaphragm 201 is increased by being pressed by the torsion spring 203. It is configured to be inclined. That is, as shown in FIG. 1A, before the contact portion 203a contacts the weight 202, the contact portion 203a of the torsion spring 203 is free to move in the longitudinal direction of the diaphragm with respect to the weight 202 of the diaphragm 201. It is inclined so as to approach the weight 202 toward the end. Then, as shown in FIG. 1B, when the torsion spring 203 is in contact with the weight 202 and the diaphragm 201 is pushed toward the wall surface 93c, the contact portion 203a of the torsion spring 203 and the weight 202 of the diaphragm 201 are moved. And become parallel. As described above, in the present configuration example, when the vibration plate 201 is most pressed by the torsion spring 203 so as to contact the wall surface 98c, the contact portion 203a is tilted in advance so that the contact portion 203a and the weight 202 are parallel. Let me. Thus, in the pushed state where the maximum load is applied to the torsion spring 203, the contact area between the torsion spring 203 and the weight 202 can be increased as compared with FIG. Therefore, the load applied to the torsion spring 203 from the weight 202 can be dispersed, and the damage of the torsion spring 203 due to the repeated load over time can be suppressed, and the durability of the torsion spring 203 can be improved.

[Configuration Example 2]
FIG. 26A illustrates a state before the torsion spring 203 contacts the weight 202 attached to the diaphragm 201 in the configuration example 2. FIG. 26B shows a state in which the torsion spring 203 is in contact with the weight 202 and presses the diaphragm 201 (a state in which the diaphragm 201 is pressed against the wall surface 93c of the case 93b) in the configuration example 2.

  In the present configuration example, the weight 202 is inclined with respect to the longitudinal direction of the diaphragm so that the contact area between the contact portion 203a and the weight 202 increases as the deflection of the diaphragm 201 is increased by being pressed by the torsion spring 203. It is composed. That is, as shown in FIG. 26A, before the contact portion 203a contacts the weight 202, the weight 202 of the diaphragm 201 is free to move in the longitudinal direction of the diaphragm with respect to the contact portion 203a of the torsion spring 203. It is inclined so as to approach the contact portion 203a toward the end. Then, as shown in FIG. 26B, when the contact portion 203a contacts the weight 202 and the diaphragm 201 is pushed toward the wall surface 93c, the contact portion 203a of the torsion spring 203 and the weight 202 of the diaphragm 201 are moved. And become parallel. As described above, in the present configuration example, the weight 202 is tilted in advance so that the contact portion 203a and the weight 202 are parallel to each other when the vibration plate 201 is most pressed into contact with the wall surface 98c by the torsion spring 203. Let me. Thus, in the pushed state where the maximum load is applied to the torsion spring 203, the contact area between the torsion spring 203 and the weight 202 can be increased as compared with FIG. Therefore, the load applied to the torsion spring 203 from the weight 202 can be dispersed, and the torsion spring 203 can be prevented from being damaged due to repeated load over time, and the durability of the torsion spring 203 can be improved.

  In this embodiment, a torsion spring 203, which is an elastic body, is used as the vibration applying member. Since the vibration of the diaphragm 201 is detected by the magnetic flux sensor 204, it is desirable that the diaphragm 201 approaches the magnetic flux sensor 204 for accurate detection. That is, the diaphragm 201 preferably contacts the wall surface 93c. To ensure that the vibration plate 201 and the wall surface 93c are in contact with each other, the length of the portion of the vibration applying member that projects from the axial direction to the magnetic flux sensor 204 may be increased. When the vibration applying member is a rigid body, when the vibration plate 201 comes into contact with the wall surface 93c, it cannot pass through the contact state with the weight 202 and the rotation of the rotating shaft 96c stops, or the vibration applying member Breakage failure occurs. When the vibration applying member is an elastic body, even if the vibration plate 201 comes into contact with the wall surface 93c, the vibration applying member can pass through the contact state with the weight 202 by being elastically deformed. Thus, the diaphragm 201 and the wall surface 93c can be reliably brought into contact with each other. As a result, a powder amount detection device having good detection accuracy can be realized.

  As shown in FIGS. 27 and 28, the shape of the torsion spring 203 can be changed as appropriate, such as using a double torsion spring in which a torsion coil spring is applied to both sides of the contact portion 203a as the torsion spring 203. Further, in this embodiment, a torsion spring is used as the elastic body used as the vibration applying member, but a thin sheet-shaped material such as a PET sheet may be used.

What has been described above is merely an example, and a specific effect is obtained for each of the following aspects.
(Aspect A)
A powder container such as a developer reservoir 90a for storing powder, a flexible member such as a flexible diaphragm 201 provided in the powder container, and a pressing member for pressing the flexible member. A pressing member such as a torsion spring 203 that deflects the flexible member, and a predetermined information obtained by performing an operation of bending the flexible member by the pressing member. In a powder amount detecting device provided with a powder amount detecting means such as a controller 20 for detecting an amount of stored powder, the pressing member presses the flexible member, and the bending of the flexible member is reduced. As the size increases, a contact portion such as a contact portion 203a formed on the pressing member and a contacted portion such as a weight 202 formed on the flexible member contacting the contact portion are formed. So that the contact area of It was.
In (Aspect A), as the pressing member presses the flexible member and the bending of the flexible member increases, the contact area between the contact portion and the contacted portion can be increased. Accordingly, when the pressing member presses the flexible member, the load can be dispersed by increasing the contact area between the contact portion and the contacted portion, and when the load is locally concentrated. Rather, damage to the pressing member and the flexible member can be suppressed.
(Aspect B)
In (Aspect A), the contacted portion is configured to be inclined with respect to the contact portion in a state where the pressing member does not press the flexible member. According to this, as described in the above embodiment, the contact portion and the contacted portion can be brought into surface contact with the pressing member pressing the flexible member.
(Aspect C)
In (Aspect A), the contact portion is inclined with respect to the contacted portion in a state where the pressing member does not press the flexible member. According to this, as described in the above embodiment, the contact portion and the contacted portion can be brought into surface contact with the pressing member pressing the flexible member.
(Aspect D)
In any one of (Aspect A) to (Aspect C), the contact portion and the contacted portion are configured to be parallel in a state where the pressing member presses the flexible member. According to this, as described in the above embodiment, the contact portion and the contacted portion can be brought into surface contact.
(Aspect E)
In any one of (Aspect A) to (Aspect D), the flexible member is provided in the powder container so as to be vibrable, and the pressing member is provided so as to be rotatable about a rotation axis. A vibration detecting unit that vibrates the flexible member by repeatedly elastically deforming and restoring the flexible member by flipping the flexible member, and detects a vibration state of the flexible member. Means for detecting the amount of powder stored in the powder storage unit based on the vibration state of the flexible member detected by the vibration detection means as the predetermined information. Detect the amount of According to this, as described in the above embodiment, the amount of powder can be detected with high accuracy.
(Aspect F)
In (Embodiment E), the pressing member is an elastic member provided so as to be constantly urged to one side in the rotation direction of the rotating shaft. According to this, as described in the above embodiment, it is possible to prevent the rotation of the rotation shaft from stopping or the vibration imparting member or the like from being damaged by an overload.
(Aspect G)
In (Embodiment E) or (Embodiment F), a torsion spring is used as the pressing member. According to this, as described in the above embodiment, the torsion spring can quickly escape from the vibration range of the flexible member due to the restoring force of the torsion coil spring, so that it does not obstruct the vibration of the flexible member. Can be suppressed. Further, the durability of the pressing member can be improved.
(Aspect H)
In any one of (Embodiment E) to (Embodiment G), the vibration detecting means may include an oscillating unit that outputs a signal having a frequency according to a state of a magnetic flux passing through the opposing space, and the flexible member Is formed of a material which is opposed to the oscillating portion via a housing constituting the powder accommodating portion, oscillates in a direction opposite to the oscillating portion and affects magnetic flux, The means obtains frequency-related information on the frequency of the oscillation signal of the oscillating unit at a predetermined cycle, and detects the flexibility detected based on a change in the frequency-related information that changes according to the vibration of the flexible member. The amount of powder in the powder container is detected based on the detection result of the vibration state of the conductive member. According to this, as described in the above embodiment, the detection accuracy can be improved as compared with the case where the powder amount is detected by a pressure sensor or the like.
(Aspect I)
A powder storage container that temporarily stores the powder supplied from the powder storage container and discharges the temporarily stored powder toward a replenishment target; and a powder amount in the powder storage container. In a powder replenishing apparatus provided with a powder amount detecting means for detecting, the powder amount detecting device according to any one of (A) to (H) is used as the powder amount detecting means. According to this, as described in the above-described embodiment, the durability of the pressing member and the flexible member can be improved, and the amount of the powder can be detected over time.
(Aspect J)
An image carrier, developing means for developing a latent image on the image carrier using a developer, a developer accommodating container for accommodating a developer used in the developing means, and developing in the developer accommodating container. In the image forming apparatus provided with a developer replenishing unit for replenishing the developer to the developing unit, the powder replenishing device described in (Aspect I) was used as the developer replenishing unit. According to this, as described in the above embodiment, the durability of the pressing member and the flexible member is improved, the amount of the powder is detected over time, and the developer is stably supplied to the developing unit. Thus, a decrease in image density can be suppressed, and good image formation can be performed.

DESCRIPTION OF SYMBOLS 11 Planar pattern coil 12 Pattern resistor 13 First capacitor 14 Second capacitor 15 Feedback resistor 18 Output terminal 20 Controller 23 Timer 24 Crystal oscillation circuit 31 Permeability counter 32 Read signal acquisition unit 33 Count value output unit 90 Sub hopper 90a Developer storage Unit 90b Conveying unit 92 Partition wall 92a First opening 92b Second opening 93b Case 93c Wall surface 96 First stirring and conveying member 96a Paddle 96b Screw 96c Rotating shaft 97 Second stirring and conveying member 97a Paddle 97b Screw 97c Rotating shaft 98 First conveying member 98a Screw 98b Rotary shaft 99 Second transport member 99a Screw 99b Rotary shaft 100 Image forming apparatus 101 Paper feed tray 102 Paper feed roller 103 Registration roller 104 Paper 105 Intermediate transfer belt Alt 106 Image forming unit 107 Drive roller 108 Follower roller 109 Photoconductor drum 110 Charger 111 Optical writing device 112 Developing device 113 Photoconductor cleaner 115 Transfer device 116 Fixing device 117 Developer bottle 118 Belt cleaner 119 Sub hopper supply path 120 Developer Bottle supply path 130 Developer supply drive unit 131 Supply drive motor 132 Supply side one-way clutch 201 Vibrating plate 201a Fixed unit 202 Weight 202a First slope 202b Apex 202c Second slope 203 Torsion spring 203a Contact 204 Magnetic flux sensor 205 Holder 901 transport partition wall 901a transport opening 902A first transport path 902B second transport path

JP 2013-037280 A

Claims (9)

A powder storage unit for storing the powder,
A flexible member having flexibility provided in the powder container,
A pressing member that presses the flexible member to bend the flexible member;
Powder amount detection means for detecting an amount of powder stored in the powder storage unit based on predetermined information obtained by performing an operation of bending the flexible member by the pressing member. In the powder amount detection device
The pressing member is provided rotatably about a rotation axis,
The flexible member is provided so that one end in a direction parallel to the rotation axis is fixed to the powder container and the other end is vibrated by being pressed by the pressing member and bent.
As the pressing member presses the flexible member and the flexure of the flexible member increases, a contact portion provided on the pressing member and the flexible member provided in contact with the contact portion are provided. The contact area with the contacted part is large ,
The pressing member causes the flexible member to repeat elastic deformation and restoration by flipping the flexible member to vibrate the flexible member,
Having vibration detection means for detecting a vibration state of the flexible member,
The powder amount detection unit detects the amount of powder stored in the powder storage unit based on the vibration state of the flexible member detected by the vibration detection unit as the predetermined information. Characteristic powder amount detection device. The powder amount detection device according to claim 1,
The powder amount detection device, wherein the contacted portion is inclined with respect to the contact portion in a state where the pressing member does not press the flexible member. The powder amount detection device according to claim 1,
The powder amount detecting device, wherein the contact portion is inclined with respect to the contacted portion in a state where the pressing member does not press the flexible member. The powder amount detection device according to any one of claims 1 to 3,
The powder amount detecting device, wherein the contact portion and the contacted portion are configured to be parallel in a state where the pressing member presses the flexible member . The powder amount detection device according to claim 4 ,
The powder amount detection device according to claim 1, wherein the pressing member is an elastic member provided in a state where the pressing member is constantly biased to one side in the rotation direction of the rotation shaft. The powder amount detection device according to any one of claims 1 to 5 ,
A powder amount detecting device, wherein a torsion spring is used as the pressing member. The powder amount detection device according to any one of claims 1 to 6 ,
The vibration detecting means has an oscillating unit that outputs a signal of a frequency according to a state of a magnetic flux passing through the facing space,
The flexible member is formed of a material that opposes the oscillating unit through a casing that forms the powder storage unit, vibrates in a direction opposing the oscillating unit, and affects magnetic flux,
The powder amount detecting means acquires frequency-related information on the frequency of the oscillation signal of the oscillating unit at a predetermined cycle, and detects the frequency-based information based on a change in the frequency-related information that changes according to the vibration of the flexible member. A powder amount detection device for detecting the amount of powder in the powder storage unit based on the detection result of the vibration state of the flexible member. A powder storage container that temporarily stores the powder supplied from the powder storage container and discharges the temporarily stored powder toward a replenishment target,
In a powder replenishing apparatus including a powder amount detection unit that detects a powder amount in the powder storage container,
Examples powder quantity detecting means, a powder supply device characterized by using the powder amount detecting apparatus according to any one of claims 1 to 7. An image carrier;
Developing means for developing a latent image on the image carrier using a developer,
A developer storage container that stores a developer used in the developing unit;
An image forming apparatus comprising: a developer replenishing unit configured to replenish the developer in the developer container to the developing unit.
An image forming apparatus comprising: the powder supply device according to claim 8 as the developer supply unit.

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